Vocal cord paralysis associated with Ramsay Hunt syndrome

DEFF Research Database (Denmark)

Rasmussen, Eva Rye; Mey, Kristianna

2014-01-01

Ramsay Hunt syndrome is defined by herpes zoster oticus and peripheral facial nerve palsy which is often associated with otalgia. The syndrome is, in rare cases, associated with other cranial nerve paralyses including the vagal nerve causing unilateral vocal cord paralysis. Vocal cord paralysis...

Thoracolumbar spinal neurenteric cyst with tethered cord syndrome and extreme cervical lordosis in a child: A case report and literature review.

Science.gov (United States)

Lan, Zhi Gang; Richard, Seidu A; Lei, Chuanfen; Huang, Siqing

2018-04-01

Neurenteric cysts, are rare benign tumors of the central nervous system that are mostly located in the spinal cord and predominantly seen in male children although adult form of the disorder also occurs. The etiology and treatment of this disorder is still a matter of debate. Our case further throws more light on the pathogenesis and treatment of this disorder. A 4-year-old boy presented with 5-month history of cervical lordosis and bilateral lower extremity pain that progressed to his abdomen and upper body. The pain was general, recurrent, non-persistent and progressive in nature with no paralysis. The pain was aggravated by trunk stretching and relieved when he assumed opisthotonos position so he preferred sleeping in this position at night. Magnetic resonance imaging (MRI) revealed a cystic lesion at the thoracolumbar spine with tethering of spinal cord and cervical lordosis. He was operated on successfully and the cervical lordosis and pain resolved. The child recovered well with no tumor recurrence and massive improvement of his life. The gold standard treatment for this disorder is surgery although the precise surgical approach is still a matter of debate. We are of the view that surgical approach should be individualized and aim at total excision of the cyst.

Fixed cord

International Nuclear Information System (INIS)

Levy, L.M.; DiChiro, G.; DeSouza, B.; McCullough, D.C.; McVeigh, E.; Hefffez, D.

1989-01-01

Pulsatile longitudinal motion of the spinal cord was examined with MR phase imaging in healthy subjects and in cases involving cord tethering and compression. Asymptomatic patients with a low conus medullaris demonstrated normal cord motion. Clinical improvement was associated with improved cord motion after surgical untethering, provided permanent neurologic damage had not occurred. Decreased and unchanged cord motion was associated with unchanged neurologic deficits. In cases of normal cord motion and possible retethering versus syringomyelia, clinical improvement occurred after shunting only. MR imaging of pulsatile cord motion can be clinically useful in the evaluation of diseases restricting motion of the neuraxis

Acute traumatic central cord syndrome: analysis of clinical and radiological correlations.

Science.gov (United States)

Miranda, P; Gomez, P; Alday, R

2008-12-01

In patients with traumatic spinal cord injury, several studies correlate neurological impairment and radiological findings. However, little information is available about this correspondence in the particular group of acute traumatic central cord syndrome. The object of the present work was to describe the clinical and radiological features of a series of patients presenting with acute traumatic central cord syndrome and to analyze clinical and radiological correlations on admission and at last follow-up. Retrospective review of 15 patients diagnosed of acute traumatic central cord syndrome between 1995 and 2005. Global motor score and motor score in upper extremities were determined on admission and at last follow-up (6 months-4 years, mean 16 months). Plain films, cervical computed tomography and magnetic resonance (MR) were performed in every patient and retrieved for the study. In seven patients, serial MR studies were performed during follow-up. Clinical and radiological correlations were statistically analyzed with non-parametric tests. Cervical spondylosis appeared associated with older age, falls, and absence of fracture. Spinal cord edema was the most common finding in MR studies but hemorrhage was also observed. The length of spinal cord edema significantly correlated with initial motor score. The decrease in T2-weighted hyperintensity in serial MR studies correlated with the gain of motor power in upper limbs at last follow-up. Elderly patients with more degenerated cervical spines commonly develop acute traumatic central cord syndrome after incidental falls. Length of spinal cord edema correlates with neurological impairment on admission and may provide significant prognostic information.

Acute traumatic central cord syndrome: MRI-pathological correlations

International Nuclear Information System (INIS)

Quencer, R.M.; Bunge, R.P.; Egnor, M.; Green, B.A.; Puckett, W.; Naidich, T.P.; Post, M.J.D.; Norenberg, M.

1992-01-01

The acute traumatic central cord syndrome (ATCCS) is commonly stated to result from an injury which affects primarily the center of the spinal cord and is frequently hemorrhagic. To test the validity of this widely disseminated hypothesis, the magnetic resonance images [MRI] of 11 consecutive cases of ATCCS caused by closed injury to the spine were analyzed and correlated with the gross pathological and histological features of 3 cervical spinal cords obtained at post mortem from patients with ATCCS, including 2 of patients studied by MRI. In this study, the MRI and pathological observations indicate that ATCCS is predominantly a white matter injury and that intramedullary hemorrhage is not a necessary feature of the syndrome; indeed, it is probably an uncommon event in ATCCS. We suggest that the most common mechanism of injury in ATCCS may be direct compression of the cervical spinal cord by buckling of the ligamenta flava into an already narrowed cervical spinal canal; this would explain the predominance of axonal injury in the white matter of the lateral columns. (orig./GDG)

Acute traumatic central cord syndrome: MRI-pathological correlations

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Quencer, R.M. (Dept. of Radiology, Univ. of Miami MRI Center, FL (United States) Miami Project to Cure Paralysis, FL (United States)); Bunge, R.P.; Egnor, M.; Green, B.A. (Miami Project to Cure Paralysis, FL (United States) Dept. of Neurological Surgery, Univ. of Miami School of Medicine, FL (United States)); Puckett, W. (Miami Project to Cure Paralysis, FL (United States)); Naidich, T.P. (Dept. of Radiology, Univ. of Miami MRI Center, FL (United States) Miami Project to Cure Paralysis, FL (United States) Baptist Hospital of Greater Miami, FL (United States)); Post, M.J.D. (Dept. of Radiology, Univ. of Miami MRI Center, FL (United States)); Norenberg, M. (Dept. of Neuropathology, Univ. of Miami School of Medicine, FL (United States))

1992-04-01

The acute traumatic central cord syndrome (ATCCS) is commonly stated to result from an injury which affects primarily the center of the spinal cord and is frequently hemorrhagic. To test the validity of this widely disseminated hypothesis, the magnetic resonance images [MRI] of 11 consecutive cases of ATCCS caused by closed injury to the spine were analyzed and correlated with the gross pathological and histological features of 3 cervical spinal cords obtained at post mortem from patients with ATCCS, including 2 of patients studied by MRI. In this study, the MRI and pathological observations indicate that ATCCS is predominantly a white matter injury and that intramedullary hemorrhage is not a necessary feature of the syndrome; indeed, it is probably an uncommon event in ATCCS. We suggest that the most common mechanism of injury in ATCCS may be direct compression of the cervical spinal cord by buckling of the ligamenta flava into an already narrowed cervical spinal canal; this would explain the predominance of axonal injury in the white matter of the lateral columns. (orig./GDG).

Sonography compared with MR imaging in the evaluation of card tethering following myelomeningocele repair

International Nuclear Information System (INIS)

Newman, B.; Bowen, A.; Albright, L.

1989-01-01

This paper reports on MR imaging and videotaped US spine examinations to evaluate cord tethering were retrospectively compared in 12 children with prior myelomeningocele repair and correlated with clinical and surgical findings. Although US did not delineate normal or abnormal anatomy as well as MR imaging, both types of studies confirmed the presence of tethering in 10 patients. One child with a normal US examination and abnormal MR images had tethering confirmed surgically. A second child had a US study suggestive of tethering with equivocal MR images. Postoperative studies in eight patients correlated less well; US suggested persistent tethering in five patients and MR imaging indicated tethering in two

Intramedullary spinal cord metastasis from colonic carcinoma presenting as Brown-Sequard syndrome: a case report

LENUS (Irish Health Repository)

Kaballo, Mohammed A

2011-08-02

Abstract Introduction Intramedullary spinal cord metastasis is very rare. The majority are discovered incidentally during autopsy. Most symptomatic patients present with rapidly progressive neurological deficits and require immediate examination. Few patients demonstrate features of Brown-Séquard syndrome. Radiotherapy is the gold-standard of therapy for Intramedullary spinal cord metastasis. The overall prognosis is poor and the mortality rate is very high. We present what is, to the best of our knowledge, the first case of Intramedullary spinal cord metastasis of colorectal carcinoma presenting as Brown-Séquard syndrome. Case presentation We present the case of a 71-year-old Caucasian man with colonic adenocarcinoma who developed Intramedullary spinal cord metastasis and showed features of Brown-Séquard syndrome, which is an uncommon presentation of Intramedullary spinal cord metastasis. Conclusion This patient had an Intramedullary spinal cord metastasis, a rare form of metastatic disease, secondary to colonic carcinoma. The metastasis manifested clinically as Brown-Séquard syndrome, itself a very uncommon condition. This syndrome is rarely caused by intramedullary tumors. This unique case has particular interest in medicine, especially for the specialties of medical, surgical and radiation oncology. We hope that it will add more information to the literature about these entities.

MR diagnosis and clinical management of whiplash injury syndrome of spinal cord

International Nuclear Information System (INIS)

Lin Shixu; Lin Daiying; Wu Xianheng; Zeng Xianting

2003-01-01

Objective: To study the MR manifestations of whiplash injury syndrome of spinal cord. Methods: MR images of 21 cases diagnosed as whiplash injury syndrome were retrospectively studied. Those images included transverse and sagittal views and coronal scan had been performed in some cases. Results: MRI inspection safely and objectively reveals the extent of the spinal injury, and helps the anticipation of the prognosis. Conclusion: MRI is the first choice of the imaging modalities assessing the whiplash injury syndrome of the spinal cord. An early diagnosis is valuable to clinical management and rehabilitation

MRI of anterior spinal artery syndrome of the cervical spinal cord

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Takahashi, S. (Dept. of Radiology, Tohoku Univ. School of Medicine, Sendai (Japan)); Yamada, T. (Dept. of Radiology, Tohoku Univ. School of Medicine, Sendai (Japan)); Ishii, K. (Dept. of Radiology, Tohoku Univ. School of Medicine, Sendai (Japan)); Saito, H. (Dept. of Neurology, Tohoku Univ. School of Medicine, Sendai (Japan)); Tanji, H. (Dept. of Neurology, Tohoku Univ. School of Medicine, Sendai (Japan)); Kobayashi, T. (Inst. of Rehabilitation Medicine, Tohoku Univ. School of Medicine, Miyagi (Japan)); Soma, Y. (Div. of Neurology, Takeda Hospital, Aizuwakamatsu (Japan)); Sakamoto, K. (Dept. of Radiology, Tohoku Univ. School of Medicine, Sendai (Japan))

1992-12-01

Cervical spinal cord lesions in the anterior spinal artery syndrome were delineated on magnetic resonance images (MRI) in four patients. The lesion was always seen anteriorly in the cervical cord. On T2-weighted images, the lesions appeared hyperintense relative to the normal spinal cord, while on T1-weighted images, two chronic lesions appeared hypointense, with local atrophy of the cord. In one case, repeated T1-weighted images showed no signal abnormality 4 days after the ictus, but the lesion became hypointense 18 days later, when contrast enhancement was also recognized after injection of Gd-DTPA; this sequence of intensity changes was similar to that of cerebral infarction. The extent of the lesion seen MRI correlated closely with neurological findings in all cases. Although the findings may not be specific, MRI is now the modality of choice for confirming the diagnosis in patients suspected of having an anterior spinal artery syndrome. (orig.)

Paraplegia como manifestação inicial de medula presa: relato de caso Paraplegia as initial manifestation of tethered spinal cord: case report

Directory of Open Access Journals (Sweden)

ANA GUARDIOLA

1999-03-01

Full Text Available A medula presa (MP é entidade pouco frequente que ocorre quando há restrição da migração normal do cone medular por cistos, lipomas ou disrafismos espinhais. Esta patologia pode levar a paraplegia, distúrbios sensoriais e esficterianos. Relatamos o caso de uma menina de 22 meses que consultou com quadro de paraplegia. O diagnóstico de medula presa foi confirmado pela mielotomografia e a paciente foi submetida à cirurgia para liberação do filo terminal.Tethered spinal cord (TSC is a rare disorder; it occurs when the conus medularis is anchored to the base of the vertebral canal by thickened filum terminale cysts, lipoma and spinal dysraphia. This disorder may cause paraplegia, sensory and sphincter disturbance. We report a twenty-two months-old girl presenting with paraplegia. TSC diagnostic was confirmed by myelotomography. The patient was submitted to surgical relief of tethered filum terminale.

Magnetic resonance imaging of spinal cord syndromes

International Nuclear Information System (INIS)

Einsiedel, H. von; Stepan, R.

1985-01-01

Thirty-four patients with intramedullary space-occupying lesions or cord compression syndromes were examined with a resistive and two different superconductive magnetic resonance (MR) imaging units. Studies were done primarily by the spin-echo (SE) technique and in the majority of patients different pulse sequences were used. Images with short echo-time (TE) and short recovery-time (TR) were best for demonstration of spinal cord anatomy, for depicting cystic portions in intramedullary tumours and for showing syringomyelia. Solid intramedullary tumours showed normal cord signal intensity. Images with prolonged TE and TR predominantly enhanced CSF signal intensity and, to a more considerable extent, solid intramedullary tumours. Thus, the diameter of the subarachnoid space and the presence of a solid intramedullary tumour, not concomittant with a significant enlargement of the spinal cord, could only be recognized on these prolonged SE images. Major advantages of MR in comparison to CT are that the spinal cord can be imaged in the sagittal plane and that beam hardening artifacts do not occur; in comparison to myelography the cord can be imaged directly by MR. Partial volume is a major limitation of MR, not only in the preferably applied sagittal plane. The choice of slice thickness adequate to the diameter of the lesion and straight positioning of the patient for sagittal single slice midline images are fundamental for reliable MR investigations. Another limitation to MR is that cortical bone gives no signal. The actual diameter of the spinal canal therefore cannot be correctly appreciated and consequently it was difficult or impossible to assess spinal stenosis. (orig.)

"White Cord Syndrome" of Acute Hemiparesis After Posterior Cervical Decompression and Fusion for Chronic Cervical Stenosis.

Science.gov (United States)

Antwi, Prince; Grant, Ryan; Kuzmik, Gregory; Abbed, Khalid

2018-05-01

"White cord syndrome" is a very rare condition thought to be due to acute reperfusion of chronically ischemic areas of the spinal cord. Its hallmark is the presence of intramedullary hyperintense signal on T2-weighted magnetic resonance imaging sequences in a patient with unexplained neurologic deficits following spinal cord decompression surgery. The syndrome is rare and has been reported previously in 2 patients following anterior cervical decompression and fusion. We report an additional case of this complication. A 68-year-old man developed acute left-sided hemiparesis after posterior cervical decompression and fusion for cervical spondylotic myelopathy. The patient improved with high-dose steroid therapy. The rare white cord syndrome following either anterior cervical decompression and fusion or posterior cervical decompression and fusion may be due to ischemic-reperfusion injury sustained by chronically compressed parts of the spinal cord. In previous reports, patients have improved following steroid therapy and acute rehabilitation. Copyright © 2018 Elsevier Inc. All rights reserved.

A traumatic central cord syndrome occurring after adequate decompression for cervical spondylosis: biomechanics of injury: case report.

Science.gov (United States)

Dickerman, Rob D; Lefkowitz, Michael; Epstein, Joseph A

2005-10-15

Case report with review of the literature. To present the first case of a central cord syndrome occurring after adequate decompression, and review the mechanics of the cervical spinal cord injury and postoperative biomechanical and anatomic changes occurring after cervical decompressive laminectomy. Cervical spondylosis is a common pathoanatomic occurrence in the elderly population and is thought to be one of the primary causes for a central cord syndrome. Decompressive laminectomy with or without fusion has been a primary treatment for spondylotic disease and is thought to be protective against further injury. To our knowledge, there are no cases of a central cord syndrome occurring after adequate decompression reported in the literature. Case study with extensive review of the literature. The patient underwent C3-C7 cervical laminectomy without complications. After surgery, the patient's spasticity and gait difficulties improved. She was discharged to inpatient rehabilitation for further treatment of upper extremity weakness. The patient fell in the rehabilitation center, with a central cord syndrome despite adequate decompression of her spinal canal. The patient was treated conservatively for the central cord and had minimal improvement. Decompressive laminectomy provides an immediate decompressive effect on the spinal cord as seen by the dorsal migration of the cord, however, the biomechanics of the cervical spine after decompressive laminectomy remain uncertain. This case supports the ongoing research and need for more intensive research on postoperative cervical spine biomechanics, including decompressive laminectomies, decompressive laminectomy and fusion, and laminoplasty.

The significance of dorsal migration of the cord after extensive cervical laminectomy for patients with traumatic central cord syndrome.

Science.gov (United States)

Levi, L; Wolf, A; Mirvis, S; Rigamonti, D; Fianfaca, M S; Monasky, M

1995-08-01

Central cord syndrome (CCS) resulting from traumatic cervical injury is often associated with cervical stenosis and/or spondylosis. The efficacy of multilevel laminectomy in the treatment of this condition has been controversial. The objective of this study was to validate by magnetic resonance (MR) imaging the occurrence of dorsal cord migration after extensive laminectomy for patients with the clinical syndrome of central cord damage and its relationship to the short-term outcome. During a 28-month period, the authors evaluated 20 patients (mean age 54 years) who sustained CCS after cervical spine trauma. Pre- and postoperative MR imaging assessed the adequacy of cervical cord decompression by multilevel laminectomy. All patients had cervical canal stenosis with complete obliteration of the anterior subarachnoid space over multiple levels. Seventeen patients initially had CCS of different degrees of severity. One had no motor deficit and two had motor complete with sensory deficits greater in their arms. Laminectomy, generally from C2 to C7 without facetectomy, was performed after plateau of neurological recovery (mean 17 days postinjury). Neurological assessment 3 months after operation revealed improvement in 12, stable function in 7, and progression of deficit in one with no mortality. The postoperative midsagittal MR images demonstrated adequate decompression with restoration of anterior cerebrospinal fluid space and posterior cord migration in 12 patients (60% of the 20), but only 8 of them also had improved function. MR imaging demonstrated that, in the presence of multilevel spondylosis/stenosis, laminectomy may provide adequate spinal cord decompression in patients with traumatic CCS.(ABSTRACT TRUNCATED AT 250 WORDS)

Braided multi-electrode probes: mechanical compliance characteristics and recordings from spinal cords

Science.gov (United States)

Kim, Taegyo; Branner, Almut; Gulati, Tanuj; Giszter, Simon F.

2013-08-01

Objective. To test a novel braided multi-electrode probe design with compliance exceeding that of a 50 µm microwire, thus reducing micromotion- and macromotion-induced tissue stress. Approach. We use up to 24 ultra-fine wires interwoven into a tubular braid to obtain a highly flexible multi-electrode probe. The tether-portion wires are simply non-braided extensions of the braid structure, allowing the microprobe to follow gross neural tissue movements. Mechanical calculation and direct measurements evaluated bending stiffness and axial compression forces in the probe and tether system. These were compared to 50 µm nichrome microwire standards. Recording tests were performed in decerebrate animals. Main results. Mechanical bending tests on braids comprising 9.6 or 12.7 µm nichrome wires showed that implants (braided portions) had 4 to 21 times better mechanical compliance than a single 50 µm wire and non-braided tethers were 6 to 96 times better. Braided microprobes yielded robust neural recordings from animals' spinal cords throughout cord motions. Significance. Microwire electrode arrays that can record and withstand tissue micro- and macromotion of spinal cord tissues are demonstrated. This technology may provide a stable chronic neural interface into spinal cords of freely moving animals, is extensible to various applications, and may reduce mechanical tissue stress.

Caudal Duplication Syndrome: the Vital Role of a Multidisciplinary Approach and Staged Correction.

Science.gov (United States)

Samuk, Inbal; Levitt, Marc; Dlugy, Elena; Kravarusic, Dragan; Ben-Meir, David; Rajz, Gustavo; Konen, Osnat; Freud, Enrique

2016-12-01

Caudal duplication syndrome is a rare entity that describes the association between congenital anomalies involving caudal structures and may have a wide spectrum of clinical manifestations. A full-term male presented with combination of anomalies including anorectal malformation, duplication of the colon and lower urinary tract, split of the lower spine, and lipomyelomeningocele with tethering of the cord. We report this exceptional case of caudal duplication syndrome with special emphasis on surgical strategy and approach combining all disciplines involved. The purpose of this report is to present the pathology, assessment, and management strategy of this complex case.

Caudal Duplication Syndrome: the Vital Role of a Multidisciplinary Approach and Staged Correction

Science.gov (United States)

Samuk, Inbal; Levitt, Marc; Dlugy, Elena; Kravarusic, Dragan; Ben-Meir, David; Rajz, Gustavo; Konen, Osnat; Freud, Enrique

2015-01-01

Caudal duplication syndrome is a rare entity that describes the association between congenital anomalies involving caudal structures and may have a wide spectrum of clinical manifestations. A full-term male presented with combination of anomalies including anorectal malformation, duplication of the colon and lower urinary tract, split of the lower spine, and lipomyelomeningocele with tethering of the cord. We report this exceptional case of caudal duplication syndrome with special emphasis on surgical strategy and approach combining all disciplines involved. The purpose of this report is to present the pathology, assessment, and management strategy of this complex case. PMID:28018799

Transitory spinal cord swelling in a 6-year-old boy with Guillain-Barre syndrome

International Nuclear Information System (INIS)

Delhaas, T.; Kamphuis, D.J.; Witkamp, T.D.

1998-01-01

A 6-year-old boy developed progressive motor weakness and areflexia. The clinical picture, combined with electrophysiological findings, indicated a diagnosis of Guillain-Barre syndrome (GBS). MRI on admission revealed spinal cord swelling and increased signal intensity within the cord. It is concluded that, since a degree of central nervous system involvement can occasionally be part of the spectrum of GBS, swelling of the spinal cord without contrast enhancement does not exclude a diagnosis of GBS. (orig.)

Vocal cord collapse during phrenic nerve-paced respiration in congenital central hypoventilation syndrome.

Science.gov (United States)

Domanski, Mark C; Preciado, Diego A

2012-01-01

Phrenic nerve pacing can be used to treat congenital central hypoventilation syndrome (CCHS). We report how the lack of normal vocal cord tone during phrenic paced respiration can result in passive vocal cord collapse and produce obstructive symptoms. We describe a case of passive vocal cord collapse during phrenic nerve paced respiration in a patient with CCHS. As far as we know, this is the first report of this etiology of airway obstruction. The patient, a 7-year-old with CCHS and normal waking vocal cord movement, continued to require nightly continuous positive airway pressure (CPAP) despite successful utilization of phrenic nerve pacers. On direct laryngoscopy, the patient's larynx was observed while the diaphragmatic pacers were sequentially engaged. No abnormal vocal cord stimulation was witnessed during engaging of either phrenic nerve stimulator. However, the lack of normal inspiratory vocal cord abduction during phrenic nerve-paced respiration resulted in vocal cord collapse and partial obstruction due to passive adduction of the vocal cords through the Bernoulli effect. Bilateral phrenic nerve stimulation resulted in more vocal cord collapse than unilateral stimulation. The lack of vocal cord abduction on inspiration presents a limit to phrenic nerve pacers.

Transitory spinal cord swelling in a 6-year-old boy with Guillain-Barre syndrome

Energy Technology Data Exchange (ETDEWEB)

Delhaas, T. [Section of Child Neurology, Wilhelmina Children`s Hospital, University Hospital for Children and Youth, Utrecht (Netherlands)]|[Department of Pediatrics, University Hospital Maastricht, P0 Box 5800, 6202 AZ Maastricht (Netherlands); Kamphuis, D.J. [Section of Child Neurology, Wilhelmina Children`s Hospital, University Hospital for Children and Youth, Utrecht (Netherlands); Witkamp, T.D. [Department of Radiology, University Hospital Utrecht, Utrecht (Netherlands)

1998-07-01

A 6-year-old boy developed progressive motor weakness and areflexia. The clinical picture, combined with electrophysiological findings, indicated a diagnosis of Guillain-Barre syndrome (GBS). MRI on admission revealed spinal cord swelling and increased signal intensity within the cord. It is concluded that, since a degree of central nervous system involvement can occasionally be part of the spectrum of GBS, swelling of the spinal cord without contrast enhancement does not exclude a diagnosis of GBS. (orig.) With 2 figs., 8 refs.

Electroencephalographic evoked pain response is suppressed by spinal cord stimulation in complex regional pain syndrome: a case report.

Science.gov (United States)

Hylands-White, Nicholas; Duarte, Rui V; Beeson, Paul; Mayhew, Stephen D; Raphael, Jon H

2016-12-01

Pain is a subjective response that limits assessment. The purpose of this case report was to explore how the objectivity of the electroencephalographic response to thermal stimuli would be affected by concurrent spinal cord stimulation. A patient had been implanted with a spinal cord stimulator for the management of complex regional pain syndrome of both hands for 8 years. Following ethical approval and written informed consent we induced thermal stimuli using the Medoc PATHWAY Pain & Sensory Evaluation System on the right hand of the patient with the spinal cord stimulator switched off and with the spinal cord stimulator switched on. The patient reported a clinically significant reduction in thermal induced pain using the numerical rating scale (71.4 % reduction) with spinal cord stimulator switched on. Analysis of electroencephalogram recordings indicated the occurrence of contact heat evoked potentials (N2-P2) with spinal cord stimulator off, but not with spinal cord stimulator on. This case report suggests that thermal pain can be reduced in complex regional pain syndrome patients with the use of spinal cord stimulation and offers objective validation of the reported outcomes with this treatment.

Tether dynamics and control results for tethered satellite system's initial flight

Science.gov (United States)

Chapel, Jim D.; Flanders, Howard

The recent Tethered Satellite System-1 (TSS-1) mission has provided a wealth of data concerning the dynamics of tethered systems in space and has demonstrated the effectiveness of operational techniques designed to control these dynamics. In this paper, we review control techniques developed for managing tether dynamics, and discuss the results of using these techniques for the Tethered Satellite System's maiden flight on STS-46. In particular, the flight results of controlling libration dynamics, string dynamics, and slack tether are presented. These results show that tether dynamics can be safely managed. The overall stability of the system was found to be surprisingly good even at relatively short tether lengths. In fact, the system operated in passive mode at a tether length of 256 meters for over 9 hours. Only monitoring of the system was required during this time. Although flight anomalies prevented the planned deployment to 20 km, the extended operations at shorter tether lengths have proven the viability of using tethers in space. These results should prove invaluable in preparing for future missions with tethered objects in space.

Bilateral complex regional pain syndrome following spinal cord injury and bilateral calcaneus fracture

Directory of Open Access Journals (Sweden)

Ahmet Boyacı

2013-09-01

Full Text Available Complex regional pain syndrome (CRPS is a disease affectingone or more extremities, characterized by spontaneouspain, allodynia, hyperpathia and hyperalgesia.CRPS is separated into Type 1 and Type 2. CRPS whichdevelops after a nociceptive event is labeled as Type 1and when it develops following peripheral nerve damage,Type 2. Although the pathogenesis is not fully understood,peripheral and central sensitivity are held responsible.Bilateral lower extremity involvement is extremely rare.However, it should be borne in mind that it can develop intraumatic injuries which occur in more than one area anddiagnosis and commencement of a rehabilitation programshould be made in the early period. The case is presentedhere of bilateral Type 1 CRPS developing after incompletespinal cord injury and bilateral calcaneus fracture. JClin Exp Invest 2013; 4 (3: 360-363Key words: complex regional pain syndrome, calcaneusfracture, spinal cord injury

Experiments and simulation of a net closing mechanism for tether-net capture of space debris

Science.gov (United States)

Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

2017-10-01

This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

Design of COSMIC: a randomized, multi-centre controlled trial comparing conservative or early surgical management of incomplete cervical cord syndrome without spinal instability

NARCIS (Netherlands)

Bartels, R.H.M.; Hosman, A.J.F.; Meent, H.; Hofmeijer, Jeannette; Vos, P.E.; Slooff, W.B.; Öner, F.C.; Coppes, M.H.; Peul, W.C.; Verbeek, A.L.M.

2013-01-01

Background Incomplete cervical cord syndrome without spinal instability is a very devastating event for the patient and the family. It is estimated that up to 25 % of all traumatic spinal cord lesions belong to this category. The treatment for this type of spinal cord lesion is still subject of

Design of COSMIC: a randomized, multi-centre controlled trial comparing conservative or early surgical management of incomplete cervical cord syndrome without spinal instability

NARCIS (Netherlands)

Bartels, R.H.M.A.; Hosman, A.J.F.; Meent, H. van de; Hofmeijer, J.; Vos, P.E.; Slooff, W.B.; Oner, F.C.; Coppes, M.H.; Peul, W.C.; Verbeek, A.L.M.

2013-01-01

ABSTRACT: BACKGROUND: Incomplete cervical cord syndrome without spinal instability is a very devastating event for the patient and the family. It is estimated that up to 25% of all traumatic spinal cord lesions belong to this category. The treatment for this type of spinal cord lesion is still

Spinal cord toxoplasmosis in human immunodeficiency virus infection/acquired immunodeficiency syndrome.

Science.gov (United States)

García-García, Concepción; Castillo-Álvarez, Federico; Azcona-Gutiérrez, José M; Herraiz, María J; Ibarra, Valvanera; Oteo, José A

2015-05-01

Neurological complications in patients with human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) are still common, even in the era of highly active antiretroviral therapy. Opportunistic infections, immune reconstitution, the virus itself, antiretroviral drugs and neurocognitive disorders have to be considered when establishing the differential diagnosis. Toxoplasmic encephalitis remains the major cause of space-occupying lesions in the brain of patients with HIV/AIDS; however, spinal cord involvement has been reported infrequently. Here, we review spinal cord toxoplasmosis in HIV infection and illustrate the condition with a recent case from our hospital. We suggest that most patients with HIV/AIDS and myelitis with enhanced spine lesions, multiple brain lesions and positive serology for Toxoplasma gondii should receive immediate empirical treatment for toxoplasmosis, and a biopsy should be performed in those cases without clinical improvement or with deterioration.

[Central cervical cord syndrome: a case report on rehabilitation, with special references to accidental falls in the elderly].

Science.gov (United States)

Ina, G; Eto, F; Furuichi, T; Suzuki, H; Shibuya, K

1995-03-01

An 81-year-old man with Parkinson's disease was admitted to our hospital with impaired function of all extremities. Four weeks before his symptoms developed, he had tripped on the steps, fallen and bruised his jaw. Following this episode he experienced a few more falls inside his house. On examination his greatest weakness was in the hands and wrists. He was hyper-reflexic in all extremities and had bilateral Babinski's sign. He could not walk and needed physical assistance in most of his daily living activities. X-ray films of the cervical spine showed significant degenerative changes. The magnetic resonance images suggested central cervical cord damage at the level of the C6 vertebral body. After three months' rehabilitation treatment, he became able to walk with a cane and became independent in all the basic activities of daily living except for bathing. He never regained skillful function of his hands despite later levodopa treatment of Parkinson's disease. His clinical features were consistent with the central cervical cord syndrome, described by Schnneider and co-workers in 1954. This syndrome may occur as a result of hyperextension neck injury, occasionally associated with an accidental fall in the elderly with cervical spondylosis. Thirteen patients with cervical spinal cord injury above 65 of age were admitted to our department from 1983 to 1993. Six of them presented with the central cervical cord syndrome, and all patients had a history of accidental injuries related to falling.

SPINAL CORD STIMULATION IN TREATMENT OF THE NEUROPATHIC PAIN SYNDROMES: INITIAL EXPERIENCE

Directory of Open Access Journals (Sweden)

D. A. Rzaev

2010-01-01

Full Text Available In the article initial experience of spinal cord stimulation for chronic pain syndromes is described. The trial was done for 62 patients, in 52 cases trial was successful and subcutaneous pulse generator were implanated. Maximal follow-up is 26 months. The level of pain evaluates at VAS. Permanent pain-relieve results were achieved in 46 patients (74,2%. These results correspond to literature data.

Electroversion in treatment of arrhythmia in a patient with Wolff-Parkinson-White syndrome and cervical spinal cord injury

Directory of Open Access Journals (Sweden)

SHEN Peng

2013-06-01

Full Text Available 【Abstract】We report electroversion in treatment of atrial fibrillation (AF and atrioventricular nodal reentry ta-chycardia (AVNRT in a patient with Wolff-Parkinson-White syndrome and cervical spinal cord injury. At first, the pa-tient sustained respiratory failure and weak cough reflex, thereafter repeated bronchoscopy was used to aspirate the sputum as well as control the pneumonia, which resulted in arrhythmia (AF and AVNRT. Two doses of intravenous amiodarone failed to correct the arrhythmia. After restora-tion of sinus rhythm by electroversion, he was successfully weaned from mechanical ventilation and discharged from the intensive care unit without recurrent arrhythmia. Key words: Arrhythmia, cardiac; Atrial fibrillation; Electric countershock; Wolff-Parkinson-White syndrome; Spinal cord injuries

Tethers in Space

Science.gov (United States)

Johnson, Les; Bilén, Sven G.; Gilchrist, Brian E.; Krause, Linda Habash

2017-09-01

This Special Section of Acta Astronautica contains several peer-reviewed papers selected from among those presented at the Fifth International Conference on Tethers in Space (TiS2016). After a hiatus of 21 years since the last Conference on Tethers in Space, TiS2016 brought together experts, practitioners, and other interested in space tethers and related fields. TiS2016 was held May 24-26, 2016 at The University of Michigan in Ann Arbor, Michigan, U.S.A. Leveraging the hard work of a great many volunteers, the conference co-chairs Prof. Brian Gilchrist and Prof. Sven Bilén welcomed an international contingent with authors from the U.S., Canada, Japan, Spain, China, Finland, Estonia, and Italy. The community provided updates on what has transpired since their last gathering by providing lessons learned; describing new technologies and subsystems; and proposing new tether missions and applications. Papers overviewed de-orbit systems, power generation, orbital maneuvering, momentum capture, debris removal, space tugs, space elevators, collision avoidance, and tether dynamics, among others.

Spinal cord injury-induced immune deficiency syndrome enhances infection susceptibility dependent on lesion level.

Science.gov (United States)

Brommer, Benedikt; Engel, Odilo; Kopp, Marcel A; Watzlawick, Ralf; Müller, Susanne; Prüss, Harald; Chen, Yuying; DeVivo, Michael J; Finkenstaedt, Felix W; Dirnagl, Ulrich; Liebscher, Thomas; Meisel, Andreas; Schwab, Jan M

2016-03-01

Pneumonia is the leading cause of death after acute spinal cord injury and is associated with poor neurological outcome. In contrast to the current understanding, attributing enhanced infection susceptibility solely to the patient's environment and motor dysfunction, we investigate whether a secondary functional neurogenic immune deficiency (spinal cord injury-induced immune deficiency syndrome, SCI-IDS) may account for the enhanced infection susceptibility. We applied a clinically relevant model of experimental induced pneumonia to investigate whether the systemic SCI-IDS is functional sufficient to cause pneumonia dependent on spinal cord injury lesion level and investigated whether findings are mirrored in a large prospective cohort study after human spinal cord injury. In a mouse model of inducible pneumonia, high thoracic lesions that interrupt sympathetic innervation to major immune organs, but not low thoracic lesions, significantly increased bacterial load in lungs. The ability to clear the bacterial load from the lung remained preserved in sham animals. Propagated immune susceptibility depended on injury of central pre-ganglionic but not peripheral postganglionic sympathetic innervation to the spleen. Thoracic spinal cord injury level was confirmed as an independent increased risk factor of pneumonia in patients after motor complete spinal cord injury (odds ratio = 1.35, P spinal cord injury directly causes increased risk for bacterial infection in mice as well as in patients. Besides obvious motor and sensory paralysis, spinal cord injury also induces a functional SCI-IDS ('immune paralysis'), sufficient to propagate clinically relevant infection in an injury level dependent manner. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Why Not Space Tethers?

Science.gov (United States)

Stone, Noble H.

2007-01-01

The Tethered Satellite System Space Shuttle missions, TSS-1 in 1993 and TSS-1R in 1996, were the height of space tether technology development. Since NASA's investment of some $200M and two Shuttle missions in those two pioneering missions, there have been several smaller tether flight experiments, but interest in this promising technology has waned within NASA as well as the DOD agencies. This is curious in view of the unique capabilities of space tether systems and the fact that they have been flight validated and shown to perform as, or better than, expected in earth orbit. While it is true that the TSS-1, TSS-1R and SEDS-2 missions experienced technical difficulties, the causes of these early developmental problems are now known to be design or materials flaws that are (1) unrelated to the basic viability of space tether technology, and (2) they are readily corrected. The purpose of this paper is to review the dynamic and electrodynamic fundamentals of space tethers and the unique capabilities they afford (that are enabling to certain types of space missions); to elucidate the nature, cause, and solution of the early developmental problems; and to provide an update on progress made in development of the technology. Finally, it is shown that (1) all problems experienced during early development of the technology now have solutions; and (2) the technology has been matured by advances made in strength and robustness of tether materials, high voltage engineering in the space environment, tether health and status monitoring, and the elimination of the broken tether hazard. In view of this, it is inexplicable why this flight-validated technology has not been utilized in the past decade, considering the powerful and unique capabilities that space tethers can afford that are, not only required to carryout, otherwise, unobtainable missions, but can also greatly reduce the cost of certain on-going space operations.

Spinal Cord Stimulation

DEFF Research Database (Denmark)

Meier, Kaare

2014-01-01

Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain that is refractory to other treatment. Originally described by Shealy et al. in 1967(1), it is used to treat a range of conditions such as complex regional pain syndrome (CRPS I)(2), angina pectoris(3), radicular...... pain after failed back surgery syndrome (FBSS)(4), pain due to peripheral nerve injury, stump pain(5), peripheral vascular disease(6) and diabetic neuropathy(7,8); whereas phantom pain(9), postherpetic neuralgia(10), chronic visceral pain(11), and pain after partial spinal cord injury(12) remain more...

Relative shortening and functional tethering of spinal cord in adolescent scoliosis - Result of asynchronous neuro-osseous growth, summary of an electronic focus group debate of the IBSE.

Science.gov (United States)

Chu, Winnie Cw; Lam, Wynnie Mw; Ng, Bobby Kw; Tze-Ping, Lam; Lee, Kwong-Man; Guo, Xia; Cheng, Jack Cy; Burwell, R Geoffrey; Dangerfield, Peter H; Jaspan, Tim

2008-06-27

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE) introduced the electronic focus group (EFG) as a means of increasing debate on knowledge of important topics. This has been designated as an on-line Delphi discussion. The Statement for this debate was written by Dr WCW Chu and colleagues who examine the spinal cord to vertebral growth interaction during adolescence in scoliosis. Using the multi-planar reconstruction technique of magnetic resonance imaging they investigated the relative length of spinal cord to vertebral column including ratios in 28 girls with AIS (mainly thoracic or double major curves) and 14 age-matched normal girls. Also evaluated were cerebellar tonsillar position, somatosensory evoked potentials (SSEPs), and clinical neurological examination. In severe AIS compared with normal controls, the vertebral column is significantly longer without detectable spinal cord lengthening. They speculate that anterior spinal column overgrowth relative to a normal length spinal cord exerts a stretching tethering force between the two ends, cranially and caudally leading to the initiation and progression of thoracic AIS. They support and develop the Roth-Porter concept of uncoupled neuro-osseous growth in the pathogenesis of AIS which now they prefer to term 'asynchronous neuro-osseous growth'. Morphological evidence about the curve apex suggests that the spinal cord is also affected, and a 'double pathology' is suggested. AIS is viewed as a disorder with a wide spectrum and a common neuroanatomical abnormality namely, a spinal cord of normal length but short relative to an abnormally lengthened anterior vertebral column. Neuroanatomical changes and/or abnormal neural function may be expressed only in severe cases. This asynchronous neuro-osseous growth concept is regarded as

Tethering sockets and wrenches

Science.gov (United States)

Johnson, E. P.

1990-01-01

The tethering of sockets and wrenches was accomplished to improve the safety of working over motor segments. To accomplish the tethering of the sockets to the ratchets, a special design was implemented in which a groove was machined into each socket. Each socket was then fitted with a snap ring that can spin around the machined groove. The snap ring is tethered to the handle of the ratchet. All open end wrenches are also tethered to the ratchet or to the operator, depending upon the type. Tests were run to ensure that the modified tools meet torque requirements. The design was subsequently approved by Space Safety.

Tethering sockets and wrenches

Science.gov (United States)

Johnson, E. P.

1990-07-01

The tethering of sockets and wrenches was accomplished to improve the safety of working over motor segments. To accomplish the tethering of the sockets to the ratchets, a special design was implemented in which a groove was machined into each socket. Each socket was then fitted with a snap ring that can spin around the machined groove. The snap ring is tethered to the handle of the ratchet. All open end wrenches are also tethered to the ratchet or to the operator, depending upon the type. Tests were run to ensure that the modified tools meet torque requirements. The design was subsequently approved by Space Safety.

Relative shortening and functional tethering of spinal cord in adolescent scoliosis – Result of asynchronous neuro-osseous growth, summary of an electronic focus group debate of the IBSE

Directory of Open Access Journals (Sweden)

Burwell R Geoffrey

2008-06-01

Full Text Available Abstract There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS. As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE introduced the electronic focus group (EFG as a means of increasing debate on knowledge of important topics. This has been designated as an on-line Delphi discussion. The Statement for this debate was written by Dr WCW Chu and colleagues who examine the spinal cord to vertebral growth interaction during adolescence in scoliosis. Using the multi-planar reconstruction technique of magnetic resonance imaging they investigated the relative length of spinal cord to vertebral column including ratios in 28 girls with AIS (mainly thoracic or double major curves and 14 age-matched normal girls. Also evaluated were cerebellar tonsillar position, somatosensory evoked potentials (SSEPs, and clinical neurological examination. In severe AIS compared with normal controls, the vertebral column is significantly longer without detectable spinal cord lengthening. They speculate that anterior spinal column overgrowth relative to a normal length spinal cord exerts a stretching tethering force between the two ends, cranially and caudally leading to the initiation and progression of thoracic AIS. They support and develop the Roth-Porter concept of uncoupled neuro-osseous growth in the pathogenesis of AIS which now they prefer to term 'asynchronous neuro-osseous growth'. Morphological evidence about the curve apex suggests that the spinal cord is also affected, and a 'double pathology' is suggested. AIS is viewed as a disorder with a wide spectrum and a common neuroanatomical abnormality namely, a spinal cord of normal length but short relative to an abnormally lengthened anterior vertebral column. Neuroanatomical changes and/or abnormal neural function may be expressed only in severe cases. This asynchronous neuro-osseous growth

Experiments and Numerical Simulations of Electrodynamic Tether

Science.gov (United States)

Iki, Kentaro; Kawamoto, Satomi; Takahashi, Ayaka; Ishimoto, Tomori; Yanagida, Atsushi; Toda, Susumu

As an effective means of suppressing space debris growth, the Aerospace Research and Development Directorate of the Japan Aerospace Exploration Agency (JAXA) has been investigating an active space debris removal system that employs highly efficient electrodynamic tether (EDT) technology for orbital transfer. This study investigates tether deployment dynamics by means of on-ground experiments and numerical simulations of an electrodynamic tether system. Some key parameters used in the numerical simulations, such as the elastic modulus and damping ratio of the tether, the spring constant of the coiling of the tether, and deployment friction, must be estimated, and various experiments are conducted to determine these values. As a result, the following values were obtained: The elastic modulus of the tether was 40 GPa, and the damping ratio of the tether was 0.02. The spring constant and the damping ratio of the tether coiling were 10-4 N/m and 0.025 respectively. The deployment friction was 0.038ν + 0.005 N. In numerical simulations using a multiple mass tether model, tethers with lengths of several kilometers are deployed and the attitude dynamics of satellites attached to the end of the tether and tether libration are calculated. As a result, the simulations confirmed successful deployment of the tether with a length of 500 m using the electrodynamic tether system.

Tethered Satellite System Contingency Investigation Board

Science.gov (United States)

1992-11-01

The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether

Banking on cord blood stem cells.

Science.gov (United States)

Sullivan, Michael J

2008-07-01

Umbilical cord blood gifted to non-profit public cord blood banks is now routinely used as an alternative source of haematopoietic stem cells for allogeneic transplantation for children and adults with cancer, bone marrow failure syndromes, haemoglobinopathies and many genetic metabolic disorders. Because of the success and outcomes of public cord banking, many companies now provide private cord banking services. However, in the absence of any published transplant evidence to support autologous and non-directed family banking, commercial cord banks currently offer a superfluous service.

Toxoplasmosis of spinal cord in acquired immunodeficiency syndrome patient presenting as paraparesis: A rare entity

Directory of Open Access Journals (Sweden)

Sachin R Agrawal

2014-01-01

Full Text Available Although brain has been the most common site for toxoplasma infection in acquired immunodeficiency syndrome patients, involvement of spinal cord by toxoplasma has been rarely found. Spinal cord toxoplasmosis can present as acute onset weakness in both lower limbs associated with sensory and bladder dysfunction. A presumptive diagnosis can be made in patients with CD4 count <100/mm 3 based on a positive serum Toxoplasma gondii IgG antibodies, no recent prophylaxis against toxoplasmosis, intramedullary ring enhancing lesion in spinal cord supported by similar lesions in brain parenchyma. Institutions of antitoxoplasma treatment in such patients result in prompt clinical response and therefore avoiding the need of unnecessary invasive diagnostic tests. Here, we report a case of toxoplasmic myelitis in immunocompromised patient presenting as myelopathy who showed significant clinical improvement after starting antitoxoplasma treatment. Hence toxoplasmic myelitis should be considered in toxoplasma seropositive immunocompromised patients presenting as myelopathy and imaging studies showing ring enhancing intramedullary lesion.

Space Station tethered elevator system

Science.gov (United States)

Haddock, Michael H.; Anderson, Loren A.; Hosterman, K.; Decresie, E.; Miranda, P.; Hamilton, R.

1989-01-01

The optimized conceptual engineering design of a space station tethered elevator is presented. The tethered elevator is an unmanned, mobile structure which operates on a ten-kilometer tether spanning the distance between Space Station Freedom and a platform. Its capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The report discusses the potential uses, parameters, and evolution of the spacecraft design. Emphasis is placed on the elevator's structural configuration and three major subsystem designs. First, the design of elevator robotics used to aid in elevator operations and tethered experimentation is presented. Second, the design of drive mechanisms used to propel the vehicle is discussed. Third, the design of an onboard self-sufficient power generation and transmission system is addressed.

Coat/Tether Interactions—Exception or Rule?

Science.gov (United States)

Schröter, Saskia; Beckmann, Sabrina; Schmitt, Hans Dieter

2016-01-01

Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers. PMID:27243008

Coat/Tether Interactions-Exception or Rule?

Science.gov (United States)

Schroeter, Saskia; Beckmann, Sabrina; Schmitt, Hans Dieter

2016-01-01

Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.

Acute intraparenchymal spinal cord injury in a cat due to high-rise syndrome.

Science.gov (United States)

Cruz-Arámbulo, Robert; Nykamp, Stephanie

2012-03-01

A 9-year-old spayed female Bengal Red cat was evaluated for high-rise syndrome. The cat had paraplegia of the hind limbs, intact reflexes and pain perception, and hyperesthesia in the caudal thoracic area. Mentation, cranial nerve function, forelimb proprioceptive responses, and spinal reflexes were normal. There were no abnormalities on radiographs or computed tomography scan, but magnetic resonance imaging revealed a hyperintense intraparenchymal spinal cord lesion on T2-weighted and T2 fat saturation images.

Acute intraparenchymal spinal cord injury in a cat due to high-rise syndrome

OpenAIRE

Cruz–Arámbulo, Robert; Nykamp, Stephanie

2012-01-01

A 9-year-old spayed female Bengal Red cat was evaluated for high-rise syndrome. The cat had paraplegia of the hind limbs, intact reflexes and pain perception, and hyperesthesia in the caudal thoracic area. Mentation, cranial nerve function, forelimb proprioceptive responses, and spinal reflexes were normal. There were no abnormalities on radiographs or computed tomography scan, but magnetic resonance imaging revealed a hyperintense intraparenchymal spinal cord lesion on T2-weighted and T2 fat...

Bilateral vocal cord paralysis and hypothyroidism as presenting symptoms of Williams-Beuren syndrome: a case report.

Science.gov (United States)

Koren, Ilana; Kessel, Ira; Rotschild, Avi; Cohen-Kerem, Raanan

2015-09-01

Williams-Beuren syndrome is a rare neurodevelopmental disorder caused by deletion of 1.5-1.8Mb genes on chromosome 7q11.23. The syndrome was first described as a triad of supra-valvular aortic stenosis, mental retardation, and distinctive facial features. Our patient was referred due to audible inspiratory stridor when he was seven days old. Following endoscopy he was diagnosed with bilateral vocal cord paralysis and was eventually intubated due to respiratory de-compensation followed by tracheotomy. On further workup he was diagnosed with hypothyroidism. Genetic workup supported the diagnosis of Williams-Beuren syndrome. We report here a case with an unusual clinical presentation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Two Tethered Balloon Systems

Science.gov (United States)

Youngbluth, Otto; Owens, Thomas L.; Storey, Richard W.

1990-01-01

Systems take meteorological measurements for variety of research projects. Report describes work done by NASA Langley Research Center in atmospheric research using tethered balloon systems composed of commercially available equipment. Two separate tethered balloon systems described in report have payloads and configurations tailored to requirements of specific projects. Each system capable of measuring atmospheric parameter or species in situ and then telemetering this data in real time to ground station. Meteorological data and concentration of ozone typically measured. Indicates instrumented tethered balloon systems have distinct advantages over other systems for gathering data on troposphere.

Metabolic syndrome in people with a long-standing spinal cord injury : associations with physical activity and capacity

NARCIS (Netherlands)

de Groot, Sonja; Adriaansen, Jacinthe J.; Tepper, Marga; Snoek, Govert J.; van der Woude, Lucas H. V.; Post, Marcel W. M.

This study investigated (i) the prevalence of the metabolic syndrome (MetS) in people with a long-standing spinal cord injury (SCI); (ii) whether personal or lesion characteristics are determinants of the MetS; and (iii) the association with physical activity or peak aerobic capacity on the MetS. In

First Case of Autonomic Dysreflexia Following Elective Lower Thoracic Spinal Cord Transection in a Spina Bifida Adult.

Science.gov (United States)

Garces, Juanita; Mathkour, Mansour; Scullen, Tyler; Kahn, Lora; Biro, Erin; Pham, Alex; Sulaiman, Olawale A R; Smith, Roger; Bui, Cuong J

2017-12-01

Spinal cord transection is a radical but effective treatment for highly selective cases of symptomatic spinal retethering in paraplegic spina bifida patients. Autonomic dysreflexia (AD) is a potentially life-threatening syndrome involving a dysregulated sympathetic discharge reflex commonly seen following cervical and high thoracic spinal cord injury, leading to a disconnect between autonomic pathways above and below the lesion that can lead to severe complications including uncontrolled hypertension, bradycardia, stroke, and potentially death. Herein we present a case in which a paraplegic spina bifida patient presenting with symptomatic spinal retethering experienced autonomic dysreflexia following an elective spinal cord transection. A 51-year-old male with a history of complex spina bifida presented with an active cerebrospinal fluid leak. Physical examination revealed a thin covering of abnormal epidermis over the large placode. Magnetic resonance imaging revealed a large myelomeningocele defect with posterior element defects spanning from L2 to the sacrum with evidence of tethering. The patient underwent an intradural transection of the spinal cord with a "blind-pouch" closure of the dura at the level of T12/L1. Postoperatively, the patient developed intermittent episodes of hypertension, bradycardia, headaches, altered mental status, severe perspiration, and red flushing of the upper torso, face, and arms. The diagnosis of AD was made clinically and managed with a positive response to a combination of beta- and alpha-blockade along with patient education on avoidance of common AD triggers. At 5-year follow-up the patient has continued to do well on medication. This case highlights a potential major side effect from elective transection of the spinal cord. If unrecognized and untreated, AD can cause significant distress and morbidity. We hope this first case report serves to supplement existing data and aid in future surgical and medical decision

Space tether dynamics: an introduction

Science.gov (United States)

Denny, Mark

2018-05-01

The dynamics of orbiting tethers (space elevators and skyhooks) is developed from an unusual direction: Lagrangian rather than Newtonian mechanics. These basic results are derived among others: space elevator required length with and without counterweight, location and magnitude of maximum tether tension, skyhook orbital parameters and tether tension. These conceptual devices are being increasingly discussed as technologically feasible; here they make an interesting pedagogical application of Lagrangian mechanics suitable for undergraduate physics students.

The space station tethered elevator system

Science.gov (United States)

Anderson, Loren A.

1989-01-01

The optimized conceptual engineering design of a space station tethered elevator is presented. The elevator is an unmanned mobile structure which operates on a ten kilometer tether spanning the distance between the Space Station and a tethered platform. Elevator capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The potential uses, parameters, and evolution of the spacecraft design are discussed. Engineering development of the tethered elevator is the result of work conducted in the following areas: structural configurations; robotics, drive mechanisms; and power generation and transmission systems. The structural configuration of the elevator is presented. The structure supports, houses, and protects all systems on board the elevator. The implementation of robotics on board the elevator is discussed. Elevator robotics allow for the deployment, retrieval, and manipulation of tethered objects. Robotic manipulators also aid in hooking the elevator on a tether. Critical to the operation of the tethered elevator is the design of its drive mechanisms, which are discussed. Two drivers, located internal to the elevator, propel the vehicle along a tether. These modular components consist of endless toothed belts, shunt-wound motors, regenerative power braking, and computer controlled linear actuators. The designs of self-sufficient power generation and transmission systems are reviewed. Thorough research indicates all components of the elevator will operate under power provided by fuel cells. The fuel cell systems will power the vehicle at seven kilowatts continuously and twelve kilowatts maximally. A set of secondary fuel cells provides redundancy in the unlikely event of a primary system failure. Power storage exists in the form of Nickel-Hydrogen batteries capable of powering the elevator under maximum loads.

Impact of spinal cord stimulation on sensory characteristics in complex regional pain syndrome type I - A randomized trial

NARCIS (Netherlands)

Kemler, MA; Reulen, JPH; Barendse, GAM; van Kleef, M; de Vet, HCW; van den Wildenberg, FAJM

Background: A randomized trial was performed to assess the effect of spinal cord stimulation (SCS) on detection and pain thresholds for pressure, warmth, and cold and on the extent of mechanical hyperalgesia in patients with chronic complex regional pain syndrome type I. Methods: Fifty-four chronic

Surgery for acute subaxial traumatic central cord syndrome without fracture or dislocation.

Science.gov (United States)

Song, Joonsuk; Mizuno, Junichi; Nakagawa, Hiroshi; Inoue, Tatsushi

2005-05-01

Twenty-two patients with subaxial acute traumatic central cord syndrome (CCS) without fracture or dislocation who underwent surgery between 1995 and 2002 were reviewed, retrospectively. There were 13 males and nine females ranging in age from 24 to 84 years (mean 61.2). Falls were the most common injury (68%), followed by motor vehicle accidents (32%). All patients had dynamic cervical lateral radiographs and magnetic resonance imaging (MRI). Cord compression was present in all cases and cervical instability in 11. Associated pathology included disc herniation in seven patients, cervical spondylosis (CS) in 11 and ossification of the posterior longitudinal ligament (OPLL) in four. Anterior decompression and fusion was performed in 12 patients with 1- or 2-level lesions. Posterior decompression and fusion was performed for multilevel lesions in 11 patients, including one patient who required re-operation. The interval between injury and surgery ranged from 1 to 37 days (mean 8.0). Postoperatively, all patients improved clinically. We conclude that surgical management of subaxial acute traumatic CCS without fracture or dislocation improved neurological status and prevented delayed neurological deterioration in our patients.

Skin vasomotor hemiparesis followed by overactivity: characteristic thermography findings in a patient with Horner syndrome due to spinal cord infarction.

Science.gov (United States)

Kobayashi, Makoto

2016-04-01

We present a 21-year-old female with Horner syndrome due to spinal cord infarction. In this patient, infrared thermography revealed a hemibody skin temperature increase followed by excessive focal decreases, indicating skin vasomotor hemiparesis and overactivity.

Coat/tether interactions – exceptions or rule?

Directory of Open Access Journals (Sweden)

Saskia eSchroeter

2016-05-01

Full Text Available Coat complexes are important for cargo selection and vesicle formation. Recent evidence suggests that they may also be involved in vesicle targeting. Tethering factors, which form an initial bridge between vesicles and the target membrane, may bind to coat complexes. In this review, we ask whether these coat/tether interactions share some common mechanisms, or whether they are special adaptations to the needs of very specific transport steps. We compare recent findings in two multisubunit tethering complexes, the Dsl1 complex and the HOPS complex, and put them into context with the TRAPP I complex as a prominent example for coat/tether interactions. We explore where coat/tether interactions are found, compare their function and structure, and comment on a possible evolution from a common ancestor of coats and tethers.

Acute traumatic central cord syndrome--experience using surgical decompression with open-door expansile cervical laminoplasty.

Science.gov (United States)

Uribe, Juan; Green, Barth A; Vanni, Steven; Moza, Kapil; Guest, James D; Levi, Allan D

2005-06-01

Open-door expansile cervical laminoplasty (ODECL) is an effective surgical technique in the treatment of multilevel cervical spondylotic myelopathy. In the present study, we reviewed the safety and short-term neurological outcome after expansile cervical laminoplasty in the treatment of acute central cord syndrome. We retrospectively reviewed our database over a 3-year period (January 1997-January 2001) and identified 69 surgically treated cervical spinal cord injuries, including 29 cases of acute traumatic central cord syndrome (ATCCS). Fifteen of these patients underwent expansile cervical laminoplasty, whereas 14 did not because of radiographic evidence of sagittal instability. We collected data on the preoperative and the immediate postoperative and 3-month neurological examinations. Neurological function was assessed using the Asia Spinal Injury Association (ASIA) grading system. We also reviewed the occurrence of complications and short-term radiological stability after the index procedure. The median age was 56 years. All patients had hyperextension injuries with underlying cervical spondylosis and stenosis in the absence of overt fracture or instability. The average delay from injury to surgery was 3 days. The preoperative ASIA grade scale was grade C, 8 patients, and grade D, 7 patients. There were no cases of immediate postoperative deterioration or at 3 months follow-up. Neurological outcome: 71.4% (10/14) of patients improved 1 ASIA grade when examined 3 months post injury. Surgical intervention consisting of ODECL can be safely applied in the subset of patients with ATCCS without instability who have significant cervical spondylosis/stenosis. Open-door expansile cervical laminoplasty is a safe, low-morbidity, decompressive procedure, and in our patients did not produce neurological deterioration.

Three-dimensional reconstructed computed tomography-magnetic resonance fusion image-based preoperative planning for surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele repair. Technical note

International Nuclear Information System (INIS)

Bamba, Yohei; Nonaka, Masahiro; Nakajima, Shin; Yamasaki, Mami

2011-01-01

Surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele (MMC) repair are often difficult and complicated, because the anatomical structures can be deformed in complex and unpredictable ways. Imaging helps the surgeon understand the patient's spinal anatomy. Whereas two-dimensional images provide only limited information for surgical planning, three-dimensional (3D) reconstructed computed tomography (CT)-magnetic resonance (MR) fusion images produce clearer representations of the spinal regions. Here we describe simple and quick methods for obtaining 3D reconstructed CT-MR fusion images for preoperative planning of surgical procedures using the iPlan cranial (BrainLAB AG, Feldkirchen, Germany) neuronavigation software. 3D CT images of the vertebral bone were combined with heavily T 2 -weighted MR images of the spinal cord, lipoma, cerebrospinal fluid (CSF) space, and nerve root through a process of fusion, segmentation, and reconstruction of the 3D images. We also used our procedure called 'Image Overlay' to directly project the 3D reconstructed image onto the body surface using an light emitting diode (LED) projector. The final reconstructed 3D images took 10-30 minutes to obtain, and provided the surgeon with a representation of the individual pathological structures, so enabled the design of effective surgical plans, even in patients with bony deformity such as scoliosis. None of the 19 patients treated based on our 3D reconstruction method has had neurological complications, except for CSF leakage. This 3D reconstructed imaging method, combined with Image Overlay, improves the visual understanding of complicated surgical situations, and should improve surgical efficiency and outcome. (author)

Tether Elevator Crawler Systems (TECS)

Science.gov (United States)

Swenson, Frank R.

1987-01-01

One of the needs of the experimenters on the space station is access to steady and controlled-variation microgravity environments. A method of providing these environments is to place the experiment on a tether attached to the space station. This provides a high degree of isolation from structural oscillations and vibrations. Crawlers can move these experiments along the tethers to preferred locations, much like an elevator. This report describes the motion control laws developed for these crawlers and the testing of laboratory models of these tether elevator crawlers.

Anophthalmia-plus syndrome: a clinical report and review of the literature.

Science.gov (United States)

Makhoul, Imad R; Soudack, Michalle; Kochavi, Orna; Guilburd, Joseph N; Maimon, Shimon; Gershoni-Baruch, Ruth

2007-01-01

We describe a term male infant of healthy non-consanguineous parents, born with congenital malformations, including bilateral cleft palate and lip, mild microphthalmia with iris coloboma and glaucoma of the right eye, and blepharophimosis with severe microphthalmia of the left eye. Spine radiograph and MRI showed first sacral hemivertebra with spina bifida, and agenesis of the 2nd, 3rd, 4th, and 5th sacral vertebrae and coccyx. Spine MRI showed caudal tethering of spinal cord at L(3) level, filum terminalis lipoma and a syringomyelia. Brain ultrasound and MRI showed hypoplasia of corpus callosum with mild dilatation of the lateral ventricles. Orbital MRI showed bilateral microphthalmia-distorted small left eyeball with posteriorly located lens, and a split vitreous body in the right eye, suggestive of primary hyperplastic vitreous. The karyotype was normal. Summary of the findings in nine cases (our case and eight published cases) support the notion that anophthalmia-plus syndrome (APS) is a distinct syndrome. Gene locus of APS is yet to be identified. (c) 2006 Wiley-Liss, Inc.

Molecular Structure of Membrane Tethers

NARCIS (Netherlands)

Baoukina, Svetlana; Marrink, Siewert J.; Tieleman, D. Peter

2012-01-01

Membrane tethers are nanotubes formed by a lipid bilayer. They play important functional roles in cell biology and provide an experimental window on lipid properties. Tethers have been studied extensively in experiments and described by theoretical models, but their molecular structure remains

Long-term outcome of neurosurgical untethering on neurosegmental motor and ambulation levels

NARCIS (Netherlands)

Schoenmakers, M. A. G. C.; Gooskens, R. H. J. M.; Gulmans, V. A. M.; Hanlo, P. W.; Vandertop, W. P.; Uiterwaal, C. S. P. M.; Helders, P. J. M.

2003-01-01

The aim of this study was to determine the long-term outcome of neurosurgical untethering on neurosegmental motor level and ambulation level in children with tethered spinal cord syndrome. Forty-four children were operated on (17 males, 27 females; mean age at operation 6 years 2 months, SD 5

Space Environmental Effects on Coated Tether Materials

Science.gov (United States)

Gittemeier, Keith A.; Hawk, Clark W.; Finckenor, Miria M.; Watts, Ed

2005-01-01

The University of Alabama in Huntsville s Propulsion Research Center has teamed with NASA's Marshall Space Flight Center (MSFC) to research the effects of atomic oxygen (AO) bombardment on coated tether materials. Tethers Unlimited Inc. has provided several candidate tether materials with various coatings for AO exposure in MSFC s Atomic Oxygen Beam Facility. Additional samples were exposed to ultraviolet (UV) radiation at MSFC. AO erodes most organic materials, and ultraviolet radiation embrittles polymers. This test series was performed to determine the effect of AO and UV on the mechanical integrity of tether materials that were treated with AO-protective coatings, such as polyhedral oligomeric silsesquioxane (POSS) or metallization. Both TUI's Multi-Application Survivable Tether (MAST) Experiment and Marshall Space Flight Center s Momentum Exchange Electrodynamic Reboost (MXER) programs will benefit from this research by helping to determine tether materials and coatings that give the longest life with the lowest mass penalty.

Membrane tethering complexes in the endosomal system

Directory of Open Access Journals (Sweden)

Anne eSpang

2016-05-01

Full Text Available Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the CORVET complex, while fusion of late endosomes with lysosomes depends on the HOPS complex. Recycling through the TGN and to the plasma membrane is facilitated by the GARP and EARP complexes, respectively. However, there are other tethering functions in the endosomal system as there are multiple pathways through which proteins can be delivered from endosomes to either the TGN or the plasma membrane. Furthermore, complexes that may be part of novel tethering complexes have been recently identified. Thus it is likely that more tethering factors exist. In this review, I will provide an overview of different tethering complexes of the endosomal system and discuss how they may provide specificity in membrane traffic.

Development of a tree shrew metabolic syndrome model and use of umbilical cord mesenchymal stem cell transplantation for treatment.

Science.gov (United States)

Pan, Xing-Hua; Zhu, Lu; Yao, Xiang; Liu, Ju-Fen; Li, Zi-An; Yang, Jian-Yong; Pang, Rong-Qing; Ruan, Guang-Ping

2016-12-01

The aim of this study was to establish a tree shrew metabolic syndrome model and demonstrate the utility of MSCs in treating metabolic syndrome. We used tree shrew umbilical cord mesenchymal stem cell (TS-UC-MSC) transplantation for the treatment of metabolic syndrome to demonstrate the clinical application of these stem cells and to provide a theoretical basis and reference methods for this treatment. Tree shrew metabolic syndrome model showed significant insulin resistance, high blood sugar, lipid metabolism disorders, and hypertension, consistent with the diagnostic criteria. TS-UC-MSC transplantation at 16 weeks significantly reduced blood sugar and lipid levels, improved insulin resistance and the regulation of insulin secretion, and reduced the expression levels of the pro-inflammatory cytokines IL-1 and IL-6 (P metabolic syndrome model and showed that MSC migrate in diseased organs and can attenuate metabolic syndrome severity in a tree shrew model.

Attitude control analysis of tethered de-orbiting

Science.gov (United States)

Peters, T. V.; Briz Valero, José Francisco; Escorial Olmos, Diego; Lappas, V.; Jakowski, P.; Gray, I.; Tsourdos, A.; Schaub, H.; Biesbroek, R.

2018-05-01

The increase of satellites and rocket upper stages in low earth orbit (LEO) has also increased substantially the danger of collisions in space. Studies have shown that the problem will continue to grow unless a number of debris are removed every year. A typical active debris removal (ADR) mission scenario includes launching an active spacecraft (chaser) which will rendezvous with the inactive target (debris), capture the debris and eventually deorbit both satellites. Many concepts for the capture of the debris while keeping a connection via a tether, between the target and chaser have been investigated, including harpoons, nets, grapples and robotic arms. The paper provides an analysis on the attitude control behaviour for a tethered de-orbiting mission based on the ESA e.Deorbit reference mission, where Envisat is the debris target to be captured by a chaser using a net which is connected to the chaser with a tether. The paper provides novel insight on the feasibility of tethered de-orbiting for the various mission phases such as stabilization after capture, de-orbit burn (plus stabilization), stabilization during atmospheric pass, highlighting the importance of various critical mission parameters such as the tether material. It is shown that the selection of the appropriate tether material while using simple controllers can reduce the effort needed for tethered deorbiting and can safely control the attitude of the debris/chaser connected with a tether, without the danger of a collision.

Tethering factors as organizers of intracellular vesicular traffic.

Science.gov (United States)

Yu, I-Mei; Hughson, Frederick M

2010-01-01

Intracellular trafficking entails the budding, transport, tethering, and fusion of transport vesicles and other membrane carriers. Here we review recent progress toward a mechanistic understanding of vesicle tethering. The known tethering factors are large complexes important for one or more intracellular trafficking pathways and are capable of interacting directly with many of the other principal components of the cellular trafficking machinery. Our review emphasizes recent developments in the in vitro reconstitution of vesicle tethering and the structural characterization of multisubunit tethering factors. The combination of these and other approaches has led to exciting progress toward understanding how these essential nanomachines work.

Atmospheric Electricity and Tethered Aerostats, Volume 1

Science.gov (United States)

1976-05-11

CATALOG NUMBER AFETR -TR-76-07 __ 4. TITLE (and Subtitle) -. TYPE OF REPORT & PERIOD COVERED ATMOSPHERIC ELECTRICITY AND TETHERED AEROSTATS, FINAL. 1...Electricity Faraday Capes Balloons Lightning Effects , Protection, Warning Systems Conducting and Non-Conducting ’Tethers Potential Geadient Anomalies...and identifying feasible protective systems. After a brief introductory section math models of effects of tethered balloons on surrounding

Tether Deployer And Brake

Science.gov (United States)

Carroll, Joseph A.; Alexander, Charles M.

1993-01-01

Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

Review of deployment technology for tethered satellite systems

Science.gov (United States)

Yu, B. S.; Wen, H.; Jin, D. P.

2018-03-01

Tethered satellite systems (TSSs) have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a TSS. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. Hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

Dynamic multibody modeling for tethered space elevators

Science.gov (United States)

Williams, Paul

2009-08-01

This paper presents a fundamental modeling strategy for dealing with powered and propelled bodies moving along space tethers. The tether is divided into a large number of discrete masses, which are connected by viscoelastic springs. The tether is subject to the full range of forces expected in Earth orbit in a relatively simple manner. Two different models of the elevator dynamics are presented. In order to capture the effect of the elevator moving along the tether, the elevator dynamics are included as a separate body in both models. One model treats the elevator's motion dynamically, where propulsive and friction forces are applied to the elevator body. The second model treats the elevator's motion kinematically, where the distance along the tether is determined by adjusting the lengths of tether on either side of the elevator. The tether model is used to determine optimal configurations for the space elevator. A modal analysis of two different configurations is presented which show that the fundamental mode of oscillation is a pendular one around the anchor point with a period on the order of 160 h for the in-plane motion, and 24 h for the out-of-plane motion. Numerical simulation results of the effects of the elevator moving along the cable are presented for different travel velocities and different elevator masses.

Atmospheric Electricity and Tethered Aerostats, Volume 2

Science.gov (United States)

1976-05-11

EASTERN TEST RANGE PATRICK AIR FORCE BASE, FLORIDA 11 MAY 1976 028 099 AFETR -TR-76-07 ATMOSPHERIC ELECTRICITY AND ~TETHERED AEROSTATS, VOLUME 11 Range...number) Atmospheric Electricity Lightning- Effects , Protection, Warning Balloons Systems Conducting & Nonconducting Tethers Potential Gradient Anomalies...if necessary and Identify by block number) Part A, "Atmospheric Electrical Effects of and on Tethered Balloon Systems," by Latham includes airborne

GRASP: A multitasking tether

Directory of Open Access Journals (Sweden)

Catherine eRabouille

2016-01-01

Full Text Available Originally identified as Golgi stacking factors in vitro, the Golgi reassembly stacking protein (GRASP family has been shown to act as membrane tethers with multiple cellular roles. As an update to previous comprehensive reviews of the GRASP family (Vinke et al., 2011 (Giuliani et al., 2011;Jarvela and Linstedt, 2012, we outline here the latest findings concerning their diverse roles. New insights into the mechanics of GRASP-mediated tethering come from recent crystal structures. The models of how GRASP65 and GRASP55 tether membranes relate directly to their role in Golgi ribbon formation in mammalian cells and the unlinking of the ribbon at the onset of mitosis. However, it is also clear that GRASPs act outside the Golgi with roles at the ER and ER exit sites (ERES. Furthermore, the proteins of this family display other roles upon cellular stress, especially in mediating unconventional secretion of both transmembrane proteins (Golgi bypass and cytoplasmic proteins (through secretory autophagosomes.

Symptomatic epidural lipomatosis of the spinal cord in a child: MR demonstration of spinal cord injury

International Nuclear Information System (INIS)

Munoz, Alberto; Barkovich, James A.; Mateos, Fernando; Simon, Rogelio

2002-01-01

We report a case of symptomatic epidural lipomatosis in an 8-year-old girl with Cushing's syndrome secondary to longstanding high-dose steroid therapy for Crohn's disease. MR imaging of the spine revealed massive diffuse epidural fat compressing the entire spinal cord with T2 prolongation in the central gray matter of the cord suggesting ischemic myelopathy. This finding has not been previously demonstrated on imaging. A proposed mechanism underlying these findings is discussed. (orig.)

Passivity-Based Control of a Rigid Electrodynamic Tether

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2011-01-01

Electrodynamic tethers provide actuation for performing orbit correction of spacecrafts. When an electrodynamic tether system is orbiting the Earth in an inclined orbit, periodic changes in the magnetic field result in a family of unstable periodic solutions in the attitude motion. This paper shows...... how these periodic solutions can be stabilized by controlling only the current through the tether. A port-controlled Hamiltonian formulation is employed to describe the tethered satellite system and a passive input-output connection is utilized in the control design. The control law consists of two...

'Pseudofailure' of spinal cord stimulation for neuropathic pain following a new severe noxious stimulus: learning points from a case series of failed spinal cord stimulation for complex regional pain syndrome and failed back surgery syndrome.

Science.gov (United States)

Muquit, Samiul; Moussa, Ahmad Abdelhai; Basu, Surajit

2016-05-01

Failure of spinal cord stimulation (SCS) may be due to hardware problems, migration of electrodes and, in the long-term, plasticity in the spinal cord with habituation to the stimulation current. We describe a series of seven patients who experienced acute therapeutic loss of SCS effects following an acute nociceptive event unrelated to primary pathology. There were no hardware problems. We called this 'Pseudofailure', as the effective stimulation returned in all patients following a period off stimulation or reprogramming. This phenomenon has not been reported previously in the literature. Over a 4-year period, we managed seven patients with this feature: four had received SCS for complex regional pain syndrome and three for failed back surgery syndrome. In all seven cases, there was cessation of the pain relief afforded by SCS following an acute painful event: four patients had trauma, two patients had domestic electric shock and one patient suffered shingles (varicella zoster infection). We excluded hardware-related problems in all cases. In two patients, SCS effects could be regained by an initial attempt at reprogramming. In the remaining five cases reprogramming was unsuccessful, and stimulation was switched off for several months before recommencing, when we discovered a return of good therapeutic effect. We conclude that SCS may seem to fail following a separate strong nociceptive stimulus. Stimulation may be regained with reprogramming or following a period with stimulation switched off. We would, therefore, advise against removal of SCS hardware in the first instance.

Assessing tether anchor labeling and usability in pickup trucks.

Science.gov (United States)

Klinich, Kathleen D; Manary, Miriam A; Malik, Laura A; Flannagan, Carol A; Jermakian, Jessica S

2018-04-03

The objective of this study was to investigate vehicle factors associated with child restraint tether use and misuse in pickup trucks and evaluate 4 labeling interventions designed to educate consumers on proper tether use. Volunteer testing was performed with 24 subjects and 4 different pickup trucks. Each subject performed 8 child restraint installations among the 4 pickups using 2 forward-facing restraints: a Britax Marathon G4.1 and an Evenflo Triumph. Vehicles were selected to represent 4 different implementations of tether anchors among pickups: plastic loop routers (Chevrolet Silverado), webbing routers (Ram), back wall anchors (Nissan Frontier), and webbing routers plus metal anchors (Toyota Tundra). Interventions included a diagram label, Quick Response (QR) Code linked to video instruction, coordinating text label, and contrasting text tag. Subjects used the child restraint tether in 93% of trials. However, tether use was completely correct in only 9% of trials. An installation was considered functional if the subject attached the tether to a tether anchor and had a tight installation (ignoring routing and head restraint position); 28% of subjects achieved a functional installation. The most common installation error was attaching the tether hook to the anchor/router directly behind the child restraint (near the top of the seatback) rather than placing the tether through the router and attaching it to the anchor in the adjacent seating position. The Nissan Frontier, with the anchor located on the back wall of the cab, had the highest rate of correct installations but also had the highest rate of attaching the tether to components other than the tether anchor (seat adjustor, child restraint storage hook, around head restraint). None of the labeling interventions had a significant effect on correct installation; not a single subject scanned the QR Code to access the video instruction. Subjects with the most successful installations spent extensive time

Cervical Klippel-Feil syndrome predisposing an elderly African man to central cord myelopathy following minor trauma

OpenAIRE

Olufemi Adeleye, A; Olusola Akinyemi, R

2010-01-01

An otherwise-healthy, active 83-year-old Nigerian man developed reversible central cord myelopathy from a mild fall on a level surface. Cervical spine magnetic resonance imaging (MRI) revealed C5, 6, and 7 block vertebrae and marked disc extrusions only at the immediately adjoining upper and lower non-fused segments of the cervical spine. There was no spinal canal stenosis otherwise. We think that the unique presentation of this case of Klippel-Feil syndrome further supports the impression th...

Mobile tethering: Overview, perspectives and challengess

NARCIS (Netherlands)

Constantinescu, M.; Onur, E.; Durmus, Y.; Nikou, S.; Reuver, M. de; Bouwman, H.; Djurica, M.; Glatz, P.M.

2014-01-01

Purpose: The purpose of this paper is to analyze mobile tethering from technological and social perspectives. Mobile tethering allows us to share cellular data connection with others over WiFi, Bluetooth or USB. Although the technology is ready and has promising outcomes, service providers and the

Membrane Tethering Complexes in the Endosomal System

OpenAIRE

Spang, Anne

2016-01-01

Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the class C core vacuole/endosome tethering (CORVET) complex, while fusion of late endosomes with lysosomes depends on the homotypic fusion and vacuole protein sorting (HOPS) complex. Recycling through the trans-Golgi network (TGN) and to the plasma membrane is...

Enabling Tethered Exploration on Mars, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Strong science motivations exist for exploring hard to reach terrain on Mars and the leading systems proposed to do so require tethers. While tethers are used...

Symptomatic epidural lipomatosis of the spinal cord in a child: MR demonstration of spinal cord injury

Energy Technology Data Exchange (ETDEWEB)

Munoz, Alberto [Department of Radiology, Section of Neuroradiology, 505 Parnassus Av, L-371, University of California-San Francisco, CA 94143-0628 (United States); Servicio de Radiodiagnostico, Seccion de Neurorradiologia, Hospital Universitario ' ' 12 de Octubre' ' , 28040 Madrid (Spain); Barkovich, James A. [Department of Radiology, Section of Neuroradiology, 505 Parnassus Av, L-371, University of California-San Francisco, CA 94143-0628 (United States); Mateos, Fernando; Simon, Rogelio [Seccion de Neurpediatria, Servicio de Neurologia, Hospital Universitario ' ' 12 de Octubre' ' , 28041 Madrid (Spain)

2002-12-01

We report a case of symptomatic epidural lipomatosis in an 8-year-old girl with Cushing's syndrome secondary to longstanding high-dose steroid therapy for Crohn's disease. MR imaging of the spine revealed massive diffuse epidural fat compressing the entire spinal cord with T2 prolongation in the central gray matter of the cord suggesting ischemic myelopathy. This finding has not been previously demonstrated on imaging. A proposed mechanism underlying these findings is discussed. (orig.)

Tether applications for space station

Science.gov (United States)

Nobles, W.

1986-01-01

A wide variety of space station applications for tethers were reviewed. Many will affect the operation of the station itself while others are in the category of research or scientific platforms. One of the most expensive aspects of operating the space station will be the continuing shuttle traffic to transport logistic supplies and payloads to the space station. If a means can be found to use tethers to improve the efficiency of that transportation operation, it will increase the operating efficiency of the system and reduce the overall cost of the space station. The concept studied consists of using a tether to lower the shuttle from the space station. This results in a transfer of angular momentum and energy from the orbiter to the space station. The consequences of this transfer is studied and how beneficial use can be made of it.

Investigation of electrodynamic stabilization and control of long orbiting tethers

Science.gov (United States)

Colombo, G.; Arnold, D.

1984-01-01

The state-of-the-art in tether modelling among participants in the Tethered Satellite System (TSS) Program, the slack tether and its behavior, and certain advanced applications of the tether to problems in orbital mechanics are identified. The features and applications of the TSS software set are reviewed. Modelling the slack tether analytically with as many as 50 mass points and the application of this new model to a study of the behavior of a broken tether near the Shuttle are described. A reel control algorithm developed by SAO and examples of its use are described, including an example which also demonstrates the use of the tether in transferring a heavy payload from a low-orbiting Shuttle to a high circular orbit. Capture of a low-orbiting payload by a Space Station in high circular orbit is described. Energy transfer within a dumbbell-type spacecraft by cyclical reeling operations or gravitational effects on the natural elasticity of the connecting tether, it is shown, can circularize the orbit of the spacecraft.

Flowing Plasma Interaction with an Electric Sail Tether Element

Science.gov (United States)

Schneider, Todd; Vaughn, Jason; Wright, Kenneth; Anderson, Allen; Stone, Nobie

2017-01-01

Harnessing the power of the solar wind, an Electric Sail, or E-sail, is a relatively new concept that promises to deliver high speed propellant-less propulsion. The electric sail is an invention made in 2006 at the Kumpula Space Centre in Finland by Pekka Janhunen [Janhunen and Sandroos, 2007]. At its core, an electric sail utilizes multiple positively biased tethers which exchange momentum with solar wind protons via the repelling electric field established around each tether, in other words, by reflecting the solar wind protons. Recognizing the solar wind is a plasma, the effective repelling area of each tether is increased significantly by the formation a plasma sheath around each tether. Fig. 1 shows schematically a spacecraft employing an electric sail. The positive voltage bias (greater than10kV) applied to each tether naturally results in electron collection. Therefore, the electric sail concept necessarily includes an electron source (electron gun) to return collected electrons to space and maintain the positive bias of the tether system.

Modeling and Simulation of a Tethered Harpoon for Comet Sampling

Science.gov (United States)

Quadrelli, Marco B.

2014-01-01

This paper describes the development of a dynamic model and simulation results of a tethered harpoon for comet sampling. This model and simulation was done in order to carry out an initial sensitivity analysis for key design parameters of the tethered system. The harpoon would contain a canister which would collect a sample of soil from a cometary surface. Both a spring ejected canister and a tethered canister are considered. To arrive in close proximity of the spacecraft at the end of its trajectory so it could be captured, the free-flying canister would need to be ejected at the right time and with the proper impulse, while the tethered canister must be recovered by properly retrieving the tether at a rate that would avoid an excessive amplitude of oscillatory behavior during the retrieval. The paper describes the model of the tether dynamics and harpoon penetration physics. The simulations indicate that, without the tether, the canister would still reach the spacecraft for collection, that the tether retrieval of the canister would be achievable with reasonable fuel consumption, and that the canister amplitude upon retrieval would be insensitive to variations in vertical velocity dispersion.

Guillain-Barre syndrome: A possibility in a spinal cord injured patient

Directory of Open Access Journals (Sweden)

Jagatsinh Yogendrasinh

2007-01-01

Full Text Available A 28-year-old male had paraplegia as a result of fracture dislocation of T12/L1 six years ago. He was functioning independently until four weeks ago, when he started complaining of trunkal paraesthesia which later progressed to include the upper extremities. The initial diagnosis was that of posttraumatic syringomyelia (PTS. While awaiting the MRI scan he developed weakness of upper limbs. The weakness restricted his self-care activities including transfers. The MRI did not show any evidence of syringomyelia. Neurological consultation and assessment yielded provisional diagnosis of Guillain-Barre syndrome (GBS. The patient was treated with immunoglobulins and regained 90% of his previous neurological status. This case is reported to raise awareness among clinicians to include the possibility of the GBS in the differential diagnosis of progressive neurological loss on top of existing neurological deficiency in spinal cord injured patients.

Tension waves in tethered satellite cables

Science.gov (United States)

Lallman, F. J.

1984-01-01

A one-degree-of-freedom simulation of the Tethered Satellite System (TSS) was programmed using a distributed system model of the tether based on the one-dimensional wave equation. This model represents the time varying tension profile along the tether as the sum of two traveling waves of tension moving in opposite directions. A control loop was devised which combines a deployment rate command with the measured tension at the deployer to produce a smooth, stable rate of deployment of the subsatellite. Simulation results show a buildup of periodic bursts of high frequency oscillation in tension. This report covers the mathematical modelling and simulation results and explains the reason for the observed oscillations. The design of a possible vibration damping device is discussed.

The stochastic dynamics of tethered microcantilevers in a viscous fluid

Energy Technology Data Exchange (ETDEWEB)

Robbins, Brian A.; Paul, Mark R. [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Radiom, Milad; Ducker, William A. [Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Walz, John Y. [Department of Chemical Engineering, University of Kentucky, Lexington, Kentucky 40506 (United States)

2014-10-28

We explore and quantify the coupled dynamics of a pair of micron scale cantilevers immersed in a viscous fluid that are also directly tethered to one another at their tips by a spring force. The spring force, for example, could represent the molecular stiffness or elasticity of a biomolecule or material tethered between the cantilevers. We use deterministic numerical simulations with the fluctuation-dissipation theorem to compute the stochastic dynamics of the cantilever pair for the conditions of experiment when driven only by Brownian motion. We validate our approach by comparing directly with experimental measurements in the absence of the tether which shows excellent agreement. Using numerical simulations, we quantify the correlated dynamics of the cantilever pair over a range of tether stiffness. Our results quantify the sensitivity of the auto- and cross-correlations of equilibrium fluctuations in cantilever displacement to the stiffness of the tether. We show that the tether affects the magnitude of the correlations which can be used in a measurement to probe the properties of an attached tethering substance. For the configurations of current interest using micron scale cantilevers in water, we show that the magnitude of the fluid coupling between the cantilevers is sufficiently small such that the influence of the tether can be significant. Our results show that the cross-correlation is more sensitive to tether stiffness than the auto-correlation indicating that a two-cantilever measurement has improved sensitivity when compared with a measurement using a single cantilever.

Models of dynamic extraction of lipid tethers from cell membranes

International Nuclear Information System (INIS)

Nowak, Sarah A; Chou, Tom

2010-01-01

When a ligand that is bound to an integral membrane receptor is pulled, the membrane and the underlying cytoskeleton can deform before either the membrane delaminates from the cytoskeleton or the ligand detaches from the receptor. If the membrane delaminates from the cytoskeleton, it may be further extruded and form a membrane tether. We develop a phenomenological model for this process by assuming that deformations obey Hooke's law up to a critical force at which the cell membrane locally detaches from the cytoskeleton and a membrane tether forms. We compute the probability of tether formation and show that tethers can be extruded only within an intermediate range of force loading rates and pulling velocities. The mean tether length that arises at the moment of ligand detachment is computed as are the force loading rates and pulling velocities that yield the longest tethers

Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

Science.gov (United States)

Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

2013-01-01

Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

The PROPEL Electrodynamic Tether Demonstration Mission

Science.gov (United States)

Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

2012-01-01

The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

Spinal cord compression in {beta}-thalassemia: follow-up after radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Silvana Fahel da; Figueiredo, Maria Stella; Cancado, Rodolfo Delfini; Nakadakare, Fernando; Segreto, Roberto; Kerbauy, Jose [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina

1998-12-01

Spinal cord compression due to extramedullary hematopoiesis is a well-described bu rare syndrome encountered in several hematologic disorders, including {beta}-thalassemia. We report a case of a patient with intermediate {beta}-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms. (author)

Spinal cord compression in β-thalassemia: follow-up after radiotherapy

International Nuclear Information System (INIS)

Fonseca, Silvana Fahel da; Figueiredo, Maria Stella; Cancado, Rodolfo Delfini; Nakadakare, Fernando; Segreto, Roberto; Kerbauy, Jose

1998-01-01

Spinal cord compression due to extramedullary hematopoiesis is a well-described bu rare syndrome encountered in several hematologic disorders, including β-thalassemia. We report a case of a patient with intermediate β-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms. (author)

Use of top tethers with forward-facing child restraints: observations and driver interviews.

Science.gov (United States)

Eichelberger, Angela H; Decina, Lawrence E; Jermakian, Jessica S; McCartt, Anne T

2014-02-01

Despite the safety benefits, many parents do not use top tethers with forward-facing child restraints. Detailed information was collected about why parents are not using tethers. The sample included 479 drivers who had forward-facing child restraints installed in passenger vehicles equipped with tether anchors. The survey was conducted primarily at shopping centers, recreation facilities, child care facilities, car seat check events, and health care facilities in mostly suburban areas surrounding Philadelphia, Washington, DC, Fredericksburg (VA), and Seattle. Drivers were surveyed about their knowledge and use of tethers and experience with child restraints. Tether use was observed to verify whether tethers were being used correctly. Fifty-six percent of forward-facing child restraints were installed with the tether; 39% were installed with the tether used correctly. The tether was used with 71% of LATCH lower anchor installations and 33% of seat belt installations. Drivers who installed child restraints without tethers most often said they did not know about the tether or how to use it. Although the tether use rate was slightly higher in the current research than in previous studies, many parents and caregivers still use forward-facing child restraints without attaching the tether. Because the main problem is lack of awareness of the tether or how to use it, public education should focus specifically on the safety benefits of tethers and how to use them. Information about why caregivers fail to use top tethers is potentially useful to child restraint manufacturers, child passenger safety technicians, and others who work with parents to improve motor vehicle safety. Copyright © 2013 Elsevier Ltd and National Safety Council. All rights reserved.

Numerical modelling of elastic space tethers

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Palmer, P. L.; Roberts, R. M.

2012-01-01

In this paper the importance of the ill-posedness of the classical, non-dissipative massive tether model on an orbiting tether system is studied numerically. The computations document that via the regularisation of bending resistance a more reliable numerical integrator can be produced. Furthermo....... It is also shown that on the slow manifold the dynamics of the satellites are well-approximated by the finite dimensional slack-spring model....

Modeling and Control of Electrodynamic Tethers - an Energy and Topology Approach

DEFF Research Database (Denmark)

Larsen, Martin Birkelund

A space tether is a cable used to connect spacecrafts in an orbiting structure. If an electrical current is lead through the tether, it can be utilized to provide propulsion for the spacecraft. In this case the cable is referred to as an electrodynamic tether. The system utilizes the magnetic field...... of the Earth for creating a Lorentz force along the tether which occur when a current carrying wire operates in a magnetic field. The use of electrodynamic tethers are interesting since they operate solely on electrical energy, which can be provided by solar panels of the spacecrafts. In this way the amount...... when using electrodynamic tethers is that the force created along the tether is based on an external uncontrollable condition, namely the magnetic field. Even whit a known model of the magnetic field, limitations to the creation of the Lorentz force still exists, since the force can only be generated...

One kilometer (1 km) electric solar wind sail tether produced automatically.

Science.gov (United States)

Seppänen, Henri; Rauhala, Timo; Kiprich, Sergiy; Ukkonen, Jukka; Simonsson, Martin; Kurppa, Risto; Janhunen, Pekka; Hæggström, Edward

2013-09-01

We produced a 1 km continuous piece of multifilament electric solar wind sail tether of μm-diameter aluminum wires using a custom made automatic tether factory. The tether comprising 90,704 bonds between 25 and 50 μm diameter wires is reeled onto a metal reel. The total mass of 1 km tether is 10 g. We reached a production rate of 70 m/24 h and a quality level of 1‰ loose bonds and 2‰ rebonded ones. We thus demonstrated that production of long electric solar wind sail tethers is possible and practical.

Selected Tether Applications Cost Model

Science.gov (United States)

Keeley, Michael G.

1988-01-01

Diverse cost-estimating techniques and data combined into single program. Selected Tether Applications Cost Model (STACOM 1.0) is interactive accounting software tool providing means for combining several independent cost-estimating programs into fully-integrated mathematical model capable of assessing costs, analyzing benefits, providing file-handling utilities, and putting out information in text and graphical forms to screen, printer, or plotter. Program based on Lotus 1-2-3, version 2.0. Developed to provide clear, concise traceability and visibility into methodology and rationale for estimating costs and benefits of operations of Space Station tether deployer system.

Spinal cord compression in b-thalassemia: follow-up after radiotherapy

Directory of Open Access Journals (Sweden)

Silvana Fahel da Fonseca

Full Text Available CONTEXT: Spinal cord compression due to extramedullary hematopoiesis is a well-described but rare syndrome encountered in several clinical hematologic disorders, including b-thalassemia. CASE REPORT: We report the case of a patient with intermediate b-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. DISCUSSION: Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms.

TMBM: Tethered Micro-Balloons on Mars

Science.gov (United States)

Sims, M. H.; Greeley, R.; Cutts, J. A.; Yavrouian, A. H.; Murbach, M.

2000-01-01

The use of balloons/aerobots on Mars has been under consideration for many years. Concepts include deployment during entry into the atmosphere from a carrier spacecraft, deployment from a lander, use of super-pressurized systems for long duration flights, 'hot-air' systems, etc. Principal advantages include the ability to obtain high-resolution data of the surface because balloons provide a low-altitude platform which moves relatively slowly. Work conducted within the last few years has removed many of the technical difficulties encountered in deployment and operation of balloons/aerobots on Mars. The concept proposed here (a tethered balloon released from a lander) uses a relatively simple approach which would enable aspects of Martian balloons to be tested while providing useful and potentially unique science results. Tethered Micro-Balloons on Mars (TMBM) would be carried to Mars on board a future lander as a stand-alone experiment having a total mass of one to two kilograms. It would consist of a helium balloon of up to 50 cubic meters that is inflated after landing and initially tethered to the lander. Its primary instrumentation would be a camera that would be carried to an altitude of up to tens of meters above the surface. Imaging data would be transmitted to the lander for inclusion in the mission data stream. The tether would be released in stages allowing different resolutions and coverage. In addition during this staged release a lander camera system may observe the motion of the balloon at various heights above he lander. Under some scenarios upon completion of the primary phase of TMBM operations, the tether would be cut, allowing TMBM to drift away from the landing site, during which images would be taken along the ground.

Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

Science.gov (United States)

Lorenzini, Enrico C.; Gullahorn, Gordon E.; Cosmo, Mario L.; Estes, Robert D.; Grossi, Mario D.

1994-01-01

This final report covers nine years of research on future tether applications and on the actual flights of the Small Expendable Deployment System (SEDS). Topics covered include: (1) a description of numerical codes used to simulate the orbital and attitude dynamics of tethered systems during station keeping and deployment maneuvers; (2) a comparison of various tethered system simulators; (3) dynamics analysis, conceptual design, potential applications and propagation of disturbances and isolation from noise of a variable gravity/microgravity laboratory tethered to the Space Station; (4) stability of a tethered space centrifuge; (5) various proposed two-dimensional tethered structures for low Earth orbit for use as planar array antennas; (6) tethered high gain antennas; (7) numerical calculation of the electromagnetic wave field on the Earth's surface on an electrodynamically tethered satellite; (8) reentry of tethered capsules; (9) deployment dynamics of SEDS-1; (10) analysis of SEDS-1 flight data; and (11) dynamics and control of SEDS-2.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya

2012-04-17

Phase behavior of poly(ethylene glycol) (PEG) tethered silica nanoparticles dispersed in PEG hosts is investigated using small-angle X-ray scattering. Phase separation in dispersions of densely grafted nanoparticles is found to display strikingly different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer composites incorporating results from this as well as various other contemporary studies is presented. We show that in the range of moderate to high grafting densities the dispersion state of nanoparticles in composites is largely insensitive to the grafting density of the tethered chains and chemistry of the polymer host. Instead, the ratio of the particle diameter to the size of the tethered chain and the ratio of the molecular weights of the host and tethered polymer chains (P/N) are shown to play a dominant role. Additionally, we find that well-functionalized nanoparticles form stable dispersions in their polymer host beyond the P/N limit that demarcates the wetting/dewetting transition in polymer brushes on flat substrates interacting with polymer melts. A general strategy for achieving uniform nanoparticle dispersion in polymers is proposed. © 2012 American Chemical Society.

Gross and fine motor skills of children with Hurler syndrome (MPS-IH) post umbilical cord blood transplantation: a case series report.

Science.gov (United States)

Dusing, Stacey C; Rosenberg, Angela; Hiemenz, Jennifer R; Piner, Shelley; Escolar, Maria

2005-01-01

Recent advancements in medical treatment of Hurler syndrome have resulted in longer life expectancies and a greater need for therapeutic services. The purpose of this case series is to provide recommendations for assessing children with Hurler syndrome after umbilical cord blood transplant (UCBT). CLINICAL DESCRIPTIONS: Two children with Hurler syndrome were seen for longitudinal assessments following an UCBT for Hurler syndrome. The raw scores and percentage of fine and gross motor items each child completed on the Motor Scale of the Bayley Scales of Infant Development II (BSID-II) were reviewed. Both children gained new motor skills with each successive motor assessment. Both children were able to complete a higher percentage of fine motor skills than gross motor skills in the most advanced item set assessed. The children presented in these two case reports both had better fine motor skills than gross motor skills, which inflated their standard scores on the BSID-II. Clinicians assessing children with Hurler syndrome should use standardized assessments that allow for differentiation of fine and gross motor skills to prevent this situation.

The Science and Applications Tethered Platform (SATP) project

Science.gov (United States)

Merlina, P.

1986-01-01

The capabilities of tether systems in orbit are going to be demonstrated by the first planned flights of the Tethered Satellite System (TSS). These test flights will investigate the properties of tether systems as low altitude atmospheric research facilities and as electric power generators. Studies are being conducted with the purpose of testing a variety of concepts and approaches. A comparative analysis of results will allow the choosing of the most promising ideas for further development. The broad range of applications presently under study include applications in electrodynamics, transportation, microgravity in addition to basic research. The SATP project definition study is now about midway through its first phase. The analyses conducted have led to an appraisal of users interest in the project and to a deeper understanding of the problems associated with large, long-lived tether systems in space. In addition, two specialized platform designs, devoted to microgravity and precise pointing applications, are being studied because of their potential usefulness and the promise of technical feasibility.

Relaxation Dynamics of Nanoparticle-Tethered Polymer Chains

KAUST Repository

Kim, Sung A

2015-09-08

© 2015 American Chemical Society. Relaxation dynamics of nanoparticle-tethered cis-1,4-polyisoprene (PI) are investigated using dielectric spectroscopy and rheometry. A model system composed of polymer chains densely grafted to spherical SiO2 nanoparticles to form self-suspended suspensions facilitates detailed studies of slow global chain and fast segmental mode dynamics under surface and geometrical confinement-from experiments performed in bulk materials. We report that unentangled polymer molecules tethered to nanoparticles relax far more slowly than their tethered entangled counterparts. Specifically, at fixed grafting density we find, counterintuitively, that increasing the tethered polymer molecular weight up to values close to the entanglement molecular weight speeds up chain relaxation dynamics. Decreasing the polymer grafting density for a fixed molecular weight has the opposite effect: it dramatically slows down chain relaxation, increases interchain coupling, and leads to a transition in rheological response from simple fluid behavior to viscoelastic fluid behavior for tethered PI chains that are unentangled by conventional measures. Increasing the measurement temperature produces an even stronger elastic response and speeds up molecular relaxation at a rate that decreases with grafting density and molecular weight. These observations are discussed in terms of chain confinement driven by crowding between particles and by the existence of an entropic attractive force produced by the space-filling constraint on individual chains in a self-suspended material. Our results indicate that the entropic force between densely grafted polymer molecules couples motions of individual chains in an analogous manner to reversible cross-links in associating polymers.

Climber Motion Optimization for the Tethered Space Elevator

NARCIS (Netherlands)

Williams, P.; Ockels, W.J.

The tethered space elevator could provide a revolutionary means for enabling cheap transportation to geostationary altitude and beyond. Assuming that such a system can be built, one of the dynamic design problems is determining a means of moving the elevator along the tether so as to minimize the

The effects of tether placement on antibody stability on surfaces

Science.gov (United States)

Grawe, Rebecca W.; Knotts, Thomas A.

2017-06-01

Despite their potential benefits, antibody microarrays have fallen short of performing reliably and have not found widespread use outside of the research setting. Experimental techniques have been unable to determine what is occurring on the surface of an atomic level, so molecular simulation has emerged as the primary method of investigating protein/surface interactions. Simulations of small proteins have indicated that the stability of the protein is a function of the residue on the protein where a tether is placed. The purpose of this research is to see whether these findings also apply to antibodies, with their greater size and complexity. To determine this, 24 tethering locations were selected on the antibody Protein Data Bank (PDB) ID: 1IGT. Replica exchange simulations were run on two different surfaces, one hydrophobic and one hydrophilic, to determine the degree to which these tethering sites stabilize or destabilize the antibody. Results showed that antibodies tethered to hydrophobic surfaces were in general less stable than antibodies tethered to hydrophilic surfaces. Moreover, the stability of the antibody was a function of the tether location on hydrophobic surfaces but not hydrophilic surfaces.

Tethered Pyrotechnic Apparatus for Acquiring a Ground Sample

Science.gov (United States)

Jones, Jack; Zimmerman, Wayne; Wu, Jiunn Jenq; Badescu, Mircea; Sherrit, Stewart

2009-01-01

A proposed alternative design for the balloon-borne ground-sampling system described in the immediately preceding article would not rely on free fall to drive a harpoonlike sample-collecting device into the ground. Instead, the harpoon-like sample-collecting device would be a pyrotechnically driven, tethered projectile. The apparatus would include a tripod that would be tethered to the gondola. A gun for shooting the projectile into the ground would be mounted at the apex of the tripod. The gun would include an electronic trigger circuit, a chamber at the breech end containing a pyrotechnic charge, and a barrel. A sabot would be placed in the barrel just below the pyrotechnic charge, and the tethered projectile would be placed in the barrel just below the sabot. The tripod feet would be equipped with contact sensors connected to the trigger circuit. In operation, the tripod would be lowered to the ground on its tether. Once contact with the ground was detected by the sensors on all three tripod feet, the trigger circuit would fire the pyrotechnic charge to drive the projectile into the ground. (Requiring contact among all three tripod feet and the ground would ensure that the projectile would be fired into the ground, rather than up toward the gondola or the balloon.) The tethered projectile would then be reeled back up to the gondola for analysis of the sample.

Neuroimaging features of Cornelia de Lange syndrome

Energy Technology Data Exchange (ETDEWEB)

Whitehead, Matthew T. [Department of Radiology, Washington, DC (United States); Nagaraj, Usha D. [Department of Radiology, Washington, DC (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States); Pearl, Phillip L. [Department of Radiology, Washington, DC (United States); Boston Children' s Hospital, Department of Neurology, Boston, MA (United States)

2015-08-15

Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms ''Cornelia'', ''Brachmann'' and ''de Lange.'' The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present. (orig.)

Neuroimaging features of Cornelia de Lange syndrome

International Nuclear Information System (INIS)

Whitehead, Matthew T.; Nagaraj, Usha D.; Pearl, Phillip L.

2015-01-01

Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms ''Cornelia'', ''Brachmann'' and ''de Lange.'' The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present. (orig.)

Spinal cord toxoplasmosis in AIDS

International Nuclear Information System (INIS)

Carteret, M.; Petit, E.; Granat, O.; Marichez, M.; Gilquin, J.

1995-01-01

Toxoplasmosis is the most common brain parasitic infection in acquired immunodeficiency syndrome (AIDS). Spinal cord localizations are still rare (2 cases with cerebral involvement, 2 cases without). A case of both spinal cord and cerebral involvement is reported. Magnetic resonance imaging (MR imaging) was performed because of sensory level (L 1). A focal conus medullaris enlargement was seen, iso intense on T 1 weighted images. This lesion was hyperintense on T 2 weighted sequence, and was homogeneously enhanced after Gadolinium on T 1 weighted images. A medullary oedema was noted. A toxoplasmosis treatment was initiated, without cortico therapy. MR imaging performed one month later (D 30), while important clinical improvements were seen, pointed out normal thickness of conus medullaris, without enhancement after Gadolinium. Disease lesions in AIDS with focal spinal cord processes are reviewed, and diagnostic work-up is discussed. Spinal cord single lesion, associated or not with brain involvements should be treated as a toxoplasmic infection, with MR imaging follow up. This work up should avoid medullary biopsy, still required in case of treatment failure. Cerebral involvements, with multiples lesions can mask medullary localization. (authors). 8 refs., 2 figs

Fluid-membrane tethers: minimal surfaces and elastic boundary layers.

Science.gov (United States)

Powers, Thomas R; Huber, Greg; Goldstein, Raymond E

2002-04-01

Thin cylindrical tethers are common lipid bilayer membrane structures, arising in situations ranging from micromanipulation experiments on artificial vesicles to the dynamic structure of the Golgi apparatus. We study the shape and formation of a tether in terms of the classical soap-film problem, which is applied to the case of a membrane disk under tension subject to a point force. A tether forms from the elastic boundary layer near the point of application of the force, for sufficiently large displacement. Analytic results for various aspects of the membrane shape are given.

THE COMPLEX TREATMENT OF THE PATIENT WITH MULTIPLE SPINE AND SPINAL CORD MALFORMATIONS

Directory of Open Access Journals (Sweden)

S. V. Vissarionov

2011-01-01

Full Text Available Clinical case of the patient with the congenital deformation of thoracic and lumbar parts of the spine due to multiple congenital anomalies of vertebrae (disturbance of formation, fusion and segmentation, a terminale filum lipoma at the level of L5, tethered cord, rightside lower leg monoparesis. Multistage surgical treatment was performed: removing of intracanal deformity, correction and stabilization of the deformity at the thoracic and lumbar part of the spine. Patient was followed up during 2,5 years after the last step of the surgical operation. No evidence of recurrence or neurological deterioration were observed.

Autonomous Vision-Based Tethered-Assisted Rover Docking

Science.gov (United States)

Tsai, Dorian; Nesnas, Issa A.D.; Zarzhitsky, Dimitri

2013-01-01

Many intriguing science discoveries on planetary surfaces, such as the seasonal flows on crater walls and skylight entrances to lava tubes, are at sites that are currently inaccessible to state-of-the-art rovers. The in situ exploration of such sites is likely to require a tethered platform both for mechanical support and for providing power and communication. Mother/daughter architectures have been investigated where a mother deploys a tethered daughter into extreme terrains. Deploying and retracting a tethered daughter requires undocking and re-docking of the daughter to the mother, with the latter being the challenging part. In this paper, we describe a vision-based tether-assisted algorithm for the autonomous re-docking of a daughter to its mother following an extreme terrain excursion. The algorithm uses fiducials mounted on the mother to improve the reliability and accuracy of estimating the pose of the mother relative to the daughter. The tether that is anchored by the mother helps the docking process and increases the system's tolerance to pose uncertainties by mechanically aligning the mating parts in the final docking phase. A preliminary version of the algorithm was developed and field-tested on the Axel rover in the JPL Mars Yard. The algorithm achieved an 80% success rate in 40 experiments in both firm and loose soils and starting from up to 6 m away at up to 40 deg radial angle and 20 deg relative heading. The algorithm does not rely on an initial estimate of the relative pose. The preliminary results are promising and help retire the risk associated with the autonomous docking process enabling consideration in future martian and lunar missions.

Dynamics and stability of a tethered centrifuge in low earth orbit

Science.gov (United States)

Quadrelli, B. M.; Lorenzini, E. C.

1992-01-01

The three-dimensional attitude dynamics of a spaceborne tethered centrifuge for artificial gravity experiments in low earth orbit is analyzed using two different methods. First, the tethered centrifuge is modeled as a dumbbell with a straight viscoelastic tether, point tip-masses, and sophisticated environmental models such as nonspherical gravity, thermal perturbations, and a dynamic atmospheric model. The motion of the centrifuge during spin-up, de-spin, and steady-rotation is then simulated. Second, a continuum model of the tether is developed for analyzing the stability of lateral tether oscillations. Results indicate that the maximum fluctuation about the 1-g radial acceleration level is less than 0.001 g; the time required for spin-up and de-spin is less than one orbit; and lateral oscillations are stable for any practical values of the system parameters.

Successful management of aortic thrombi resulting in spinal cord infarction in a patient with antiphospholipid antibody syndrome and acute cholecystitis

Directory of Open Access Journals (Sweden)

Izumi M

2011-12-01

Full Text Available Manabu Izumi, Shoko Teraoka, Keisuke Yamashita, Kenji Matsumoto, Tomohiro Muronoi, Yoshimitsu Izawa, Chikara Yonekawa, Masaki Ano, Masayuki SuzukawaDepartment of Emergency and Critical Care Medicine, Jichi Medical University, Tochigi, JapanAbstract: A 74-year-old man with coronary artery disease was suffering from acute nonobstructive cholecystitis and was admitted to a nearby hospital. Dual antiplatelet (aspirin and ticlopidine therapy was discontinued before preparation for surgical resection of the gall bladder. During his time in hospital he was aware of lumbar pain and weakness in both legs. He was transferred to our hospital for further evaluation and therapy. Diffuse intra-aortic thrombi were revealed by computed tomography with contrast media, and magnetic resonance imaging showed spinal cord infarction. However, computed tomography scans of the descending aorta obtained 4 months before admission exhibited no signs of atherosclerotic plaques or intra-aortic thrombi. Laboratory data suggest that antiphospholipid antibody syndrome might have caused these acute multiple intra-arterial thrombi. By restarting dual antiplatelet therapy and increasing the dose of heparin (from 10,000 IU/day to 15,000 IU/day we successfully managed the patient's clinical condition and symptoms. It is important to understand that stopping antiplatelet therapy may rapidly grow thrombi in patients with a hypercoagulative state.Keywords: intra-aortic thrombus, antiphospholipid antibody syndrome, spinal cord infarction

T-Rex: A Japanese Space Tether Experiment

Science.gov (United States)

Johnson, Les

2009-01-01

Electrodynamic tether (EDT) thrusters work by virtue of the force a magnetic field exerts on a wire carrying an electrical current. The force, which acts on any charged particle moving through a magnetic field (including the electrons moving in a current-carrying wire), were concisely expressed by Lorentz in 1895 in an equation that now bears his name. The force acts in a direction perpendicular to both the direction of current flow and the magnetic field vector. Electric motors make use of this force: a wire loop in a magnetic field is made to rotate by the torque the Lorentz Force exerts on it due to an alternating current in the loop times so as to keep the torque acting in the same sense. The motion of the loop is transmitted to a shaft, thus providing work. Although the working principle of EDT thrusters is not new, its application to space transportation may be significant. In essence, an EDT thruster is just a clever way of getting an electrical current to flow in a long orbiting wire (the tether) so that the Earth s magnetic field will accelerate the wire and, consequently the payload attached to the wire. The direction of current flow in the tether, either toward or away from the Earth along the local vertical, determines whether the magnetic force will raise or lower the orbit. The bias voltage of a vertically deployed metal tether, which results just from its orbital motion (assumed eastward) through Earth s magnetic field, is positive with respect to the ambient plasma at the top and negative at the bottom. This polarization is due to the action of the Lorentz force on the electrons in the tether. Thus, the natural current flow is the result of negative electrons being attracted to the upper end and then returned to the plasma at the lower end. The magnetic force in this case has a component opposite to the direction of motion, and thus leads to a lowering of the orbit and eventually to re-entry. In this generator mode of operation the Lorentz Force

Tethered Forth system for FPGA applications

Science.gov (United States)

Goździkowski, Paweł; Zabołotny, Wojciech M.

2013-10-01

This paper presents the tethered Forth system dedicated for testing and debugging of FPGA based electronic systems. Use of the Forth language allows to interactively develop and run complex testing or debugging routines. The solution is based on a small, 16-bit soft core CPU, used to implement the Forth Virtual Machine. Thanks to the use of the tethered Forth model it is possible to minimize usage of the internal RAM memory in the FPGA. The function of the intelligent terminal, which is an essential part of the tethered Forth system, may be fulfilled by the standard PC computer or by the smartphone. System is implemented in Python (the software for intelligent terminal), and in VHDL (the IP core for FPGA), so it can be easily ported to different hardware platforms. The connection between the terminal and FPGA may be established and disconnected many times without disturbing the state of the FPGA based system. The presented system has been verified in the hardware, and may be used as a tool for debugging, testing and even implementing of control algorithms for FPGA based systems.

Infantile Hemophagocytic Lymphohistiocytosis in a Case of Chediak-Higashi Syndrome Caused by a Mutation in the LYST/CHS1 Gene Presenting With Delayed Umbilical Cord Detachment and Diarrhea

DEFF Research Database (Denmark)

Nielsen, Christian; Agergaard, Charlotte N; Jakobsen, Marianne A

2015-01-01

A 2-month-old female infant, born to consanguineous parents, presented with infections in skin and upper respiratory tract. She was notable for delayed umbilical cord detachment, partial albinism, and neurological irritability. Giant granules were present in white blood cells. The intracellular...... in this severe phenotype of Chediak-Higashi syndrome was probably induced by rotaviral infection. Interestingly, the intracellular perforin content in CD8 T cells seems to correlate to the immune activation state of the patient. Late separation of the umbilical cord in concordance with clinical symptoms should...

Mild Moxibustion Decreases the Expression of Prokineticin 2 and Prokineticin Receptor 2 in the Colon and Spinal Cord of Rats with Irritable Bowel Syndrome

Directory of Open Access Journals (Sweden)

Cili Zhou

2014-01-01

Full Text Available It has been proven that prokineticin 2 (PK2 and its receptor PKR2 play an important role in hyperalgesia, while mild moxibustion can relieve visceral hypersensitivity in a rat model of irritable bowel syndrome (IBS. The goal of the present study was to determine the effects of mild moxibustion on the expression of PK2 and PKR2 in colon and spinal cord in IBS rat model, which was induced by colorectal distension using inflatable balloons. After mild moxibustion treatment, abdominal withdrawal reflex (AWR scores were assessed by colorectal distension; protein and mRNA expression of PK2 and PKR2 in rat colon and spinal cord was determined by immunohistochemistry and fluorescence quantitative PCR. Compared with normal rats, the AWR scores of rats and the expressions of PK2/PKR2 proteins and mRNAs in colon and spinal cord tissue were significantly increased in the model group; compared with the model group, the AWR scores of rats and the expressions of PK2/PKR2 proteins and mRNAs in colon and spinal cord tissue were significantly decreased in the mild moxibustion group. These findings suggest that the analgesia effect of mild moxibustion may be associated with the reduction of the abnormally increased expression of the PK2/PKR2 proteins and mRNAs in the colon and spinal cord.

Learning characteristics of a space-time neural network as a tether skiprope observer

Science.gov (United States)

Lea, Robert N.; Villarreal, James A.; Jani, Yashvant; Copeland, Charles

1993-01-01

The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table.

Vascular anatomy of the spinal cord

International Nuclear Information System (INIS)

Thron, A.K.

1988-01-01

The book summarizes the anatomic guidelines of external blood supply to the spinal cord. The basic principles of arterial supply and venous drainage are illustrated by explicit schemes for quick orientation. In the first part of the book, systematic radiologic-anatomic investigations of the superficial and deep vessels of all segments of the spinal cord are introduced. The microvascular morphology is portrayed by numerous microradiographic sections in all three dimensions without overshadowing. The three-dimensional representation of the vascular architecture illustrates elementary outlines and details of arterial territories, anastomotic cross-linking as well as the capillary system, particularly the hitherto unknown structure of the medullary venous system with its functionally important anastomoses and varying regional structures. These often now radiologic-anatomic findings are discussed as to their functional and pathophysiologic impact and constitute the basic on which to improve one's understanding of vascular syndromes of the spinal cord

Trace gas measurements from tethered balloon platforms

Science.gov (United States)

Bandy, Alan R.; Bandy, Terese L.; Youngbluth, Otto; Owens, Thomas L.

1987-01-01

Instrumentation and chemical sampling and analysis procedures are described for making measurements of atmospheric carbon disulfide in the concentration range 1-1000 pptv from tethered balloon platforms. Results of a study on the CS2 composition of air downward of a saltwater marsh are reported. A method for obtaining the necessary data for solving the budget equations for surface fluxes, chemical formation rates and chemical destruction rates using data acquired from tethered balloon platforms is presented.

Transitions of tethered chain molecules under tension.

Science.gov (United States)

Luettmer-Strathmann, Jutta; Binder, Kurt

2014-09-21

An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

Value of MRI and DTI as Biomarkers for Classifying Acute Spinal Cord Injury

Science.gov (United States)

2014-10-29

Datasets were checked for goodness of fit as part of the quality assurance process. Whole cord FA, MD, LD (λ1) and TD (λ23) were calculated for...discussion 1658. 10. Marino RJ, Ditunno JF,Jr, Donovan WH, Maynard F ,Jr. Neurologic recovery after traumatic spinal cord injury: Data from the model spinal...Jan;75(1):67-72. 17. Foo D, Subrahmanyan TS, Rossier AB. Post-traumatic acute anterior spinal cord syndrome. Paraplegia. 1981;19(4):201-5. 18

Dynamic analysis of the tether transportation system using absolute nodal coordinate formulation

Science.gov (United States)

Sun, Xin; Xu, Ming; Zhong, Rui

2017-10-01

Long space tethers are becoming a rising concern as an alternate way for transportation in space. It benefits from fuel economizing. This paper focuses on the dynamics of the tether transportation system, which consists of two end satellites connected by a flexible tether, and a movable vehicle driven by the actuator carried by itself. The Absolute Nodal Coordinate Formulation is applied to the establishment of the equation of motion, so that the influence caused by the distributed mass and elasticity of the tether is introduced. Moreover, an approximated method for accelerating the calculation of the generalized gravitational forces on the tether is proposed by substituting the volume integral every step into summation of finite terms. Afterwards, dynamic evolutions of such a system in different configurations are illustrated using numerical simulations. The deflection of the tether and the trajectory of the crawler during the transportation is investigated. Finally, the effect on the orbit of the system due to the crawler is revealed.

Thrust Control During Towing of Space Debris using an Elastic Tether

Directory of Open Access Journals (Sweden)

A. D. Ledkov

2014-01-01

Full Text Available The paper considers a maneuver for deorbiting the large space debris using an active spacecraft connected with the debris by an elastic tether. Tether slacking during the maneuver can lead to the tether rupture, kinking, and winding on the descending object. Therefore it is important to prevent slacking. The objective of this work is to find the law of thrust force control of the active spacecraft to ensure a continuously strained tether during the maneuver.Using Lagrange formalism a mathematical model to describe the system plane motion is developed. This model considers the active spacecraft as a mass point, the space debris as a rigid body, and the tether as a weightless elastic rod. A thrust force is directed along the local horizon of the spacecraft. Linearization of nonlinear differential equation describing longitudinal oscillations of the tether length is performed. Its phase portrait is analyzed. An approximate expression describing the position of the center on the phase portrait is obtained. A time-optimal control with full feedback to ensure that the tether is in the strained state is found by solving the Bellman equation. To use the obtained optimal law it is necessary to set the measuring equipment on the spacecraft, which is capable of accurate measuring a distance to the space debris and its relative velocity. An alternative control law, which is simpler in terms of the practical implementation, is proposed. As an example, the descent from an orbit of nonfunctioning Soviet satellite Meteor-2 is considered. It is shown that both proposed laws provide continuous strain of the tether during deorbiting of the satellite. Moreover, slack does not occur even at the first period of oscillation of the tether length. It is shown that the use of the proposed control laws leads to slight increase of deorbiting time as compared to the case of using the constant thrust.The results can be used to develop the control systems of small spacecrafts

The investigation of tethered satellite system dynamics

Science.gov (United States)

Lorenzini, E. C.

1986-01-01

The analysis of the rotational dynamics of the satellite was focused on the rotational amplitude increase of the satellite, with respect to the tether, during retrieval. The dependence of the rotational amplitude upon the tether tension variation to the power 1/4 was thoroughly investigated. The damping of rotational oscillations achievable by reel control was also quantified while an alternative solution that makes use of a lever arm attached with a universal joint to the satellite was proposed. Comparison simulations between the Smithsonian Astrophysical Observatory and the Martin Marietta (MMA) computer code of reteival maneuvers were also carried out. The agreement between the two, completely independent, codes was extremely close, demonstrating the reliability of the models. The slack tether dynamics during reel jams was analytically investigated in order to identify the limits of applicability of the SLACK3 computer code to this particular case. Test runs with SLACK3 were also carried out.

Scissors stab wound to the cervical spinal cord at the craniocervical junction.

Science.gov (United States)

Zhang, Xiao-Yong; Yang, Ying-Ming

2016-06-01

Stab wounds resulting in spinal cord injury of the craniocervical junction are rare. A scissors stab wound to the cervical spinal cord has been reported only once in the literature. This paper aimed to report a case of Brown-Séquard-plus syndrome in an 8-year-old boy secondary to a scissors stab wound at the craniocervical junction. Case report and review of the literature. Case report of an 8-year-old boy accidentally stabbed in the neck by scissors, which were thrown as a dart. The case study of an 8-year-old boy who was hospitalized because of a scissors stab wound at the craniocervical junction. The patient developed Brown-Séquard-plus syndrome on the left side of the body. Magnetic resonance imaging revealed a laceration of the spinal cord at the craniocervical junction with cerebrospinal fluid leakage. Careful cleansing and interrupted sutures of the wounds were performed to prevent cerebrospinal fluid leakage. Rehabilitation therapy was performed 2 days later. A follow-up examination revealed complete recovery of the neurologic deficit 8 months post-injury. Treatment of scissors stab wounds to the cervical spinal cord, whether conservative management or thorough surgical exploration, should be individualized based on history, examination, and imaging. As shown in this case report, despite conservative management, complete recovery, which was unexpected, was attributed to the initial mild laceration of the spinal cord and ipsilateral spinal cord functional compensation. Copyright © 2016 Elsevier Inc. All rights reserved.

Vesicle fusion observed by content transfer across a tethered lipid bilayer.

Science.gov (United States)

Rawle, Robert J; van Lengerich, Bettina; Chung, Minsub; Bendix, Poul Martin; Boxer, Steven G

2011-10-19

Synaptic transmission is achieved by exocytosis of small, synaptic vesicles containing neurotransmitters across the plasma membrane. Here, we use a DNA-tethered freestanding bilayer as a target architecture that allows observation of content transfer of individual vesicles across the tethered planar bilayer. Tethering and fusion are mediated by hybridization of complementary DNA-lipid conjugates inserted into the two membranes, and content transfer is monitored by the dequenching of an aqueous content dye. By analyzing the diffusion profile of the aqueous dye after vesicle fusion, we are able to distinguish content transfer across the tethered bilayer patch from vesicle leakage above the patch. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Vocal cord palsy: An uncommon presenting feature of myasthenia gravis

Directory of Open Access Journals (Sweden)

Sethi Prahlad

2011-01-01

Full Text Available Vocal cord palsy can have myriad causes. Unilateral vocal cord palsy is common and frequently asymptomatic. Trauma, head, neck and mediastinal tumors as well as cerebrovascular accidents have been implicated in causing unilateral vocal cord palsy. Viral neuronitis accounts for most idiopathic cases. Bilateral vocal cord palsy, on the other hand, is much less common and is a potentially life-threatening condition. Myasthenia gravis, an autoimmune disorder caused by antibodies targeting the post-synaptic acetylcholine receptor, has been infrequently implicated in its causation. We report here a case of bilateral vocal cord palsy developing in a 68-year-old man with no prior history of myasthenia gravis 2 months after he was operated on for diverticulitis of the large intestine. Delay in considering the diagnosis led to endotracheal intubation and prolonged mechanical ventilation with attendant complications. Our case adds to the existing literature implicating myasthenia gravis as an infrequent cause of bilateral vocal cord palsy. Our case is unusual as, in our patient, acute-onset respiratory distress and stridor due to bilateral vocal cord palsy was the first manifestation of a myasthenic syndrome.

Hierarchical Structure in Semicrystalline Polymers Tethered to Nanospheres

KAUST Repository

Kim, Sung A

2014-01-28

We report on structural and dynamic transitions of polymers tethered to nanoparticles. In particular, we use X-ray diffraction, vibrational spectroscopy, and thermal measurements to investigate multiscale structure and dynamic transitions of poly(ethylene glycol) (PEG) chains densely grafted to SiO2 nanoparticles. The approach used for synthesizing these hybrid particles leads to homogeneous SiO2-PEG composites with polymer grafting densities as high as 1.5 chains/nm2, which allows the hybrid materials to exist as self-suspended suspensions with distinct hierarchical structure and thermal properties. On angstrom and nanometer length scales, the tethered PEG chains exhibit more dominant TTG conformations and helix unit cell structure, in comparison to the untethered polymer. The nanoparticle tethered PEG chains are also reported to form extended crystallites on tens of nanometers length scales and to exhibit more stable crystalline structure on small dimensions. On length scales comparable to the size of each hybrid SiO 2-PEG unit, the materials are amorphous presumably as a result of the difficulty fitting the nanoparticle anchors into the PEG crystal lattice. This structural change produces large effects on the thermal transitions of PEG molecules tethered to nanoparticles. © 2014 American Chemical Society.

NASA Langley Research Center tethered balloon systems

Science.gov (United States)

Owens, Thomas L.; Storey, Richard W.; Youngbluth, Otto

1987-01-01

The NASA Langley Research Center tethered balloon system operations are covered in this report for the period of 1979 through 1983. Meteorological data, ozone concentrations, and other data were obtained from in situ measurements. The large tethered balloon had a lifting capability of 30 kilograms to 2500 meters. The report includes descriptions of the various components of the balloon systems such as the balloons, the sensors, the electronics, and the hardware. Several photographs of the system are included as well as a list of projects including the types of data gathered.

Tethered catalysts for the hydration of carbon dioxide

Science.gov (United States)

Valdez, Carlos A; Satcher, Jr., Joe H; Aines, Roger D; Wong, Sergio E; Baker, Sarah E; Lightstone, Felice C; Stolaroff, Joshuah K

2014-11-04

A system is provided that substantially increases the efficiency of CO.sub.2 capture and removal by positioning a catalyst within an optimal distance from the air-liquid interface. The catalyst is positioned within the layer determined to be the highest concentration of carbon dioxide. A hydrophobic tether is attached to the catalyst and the hydrophobic tether modulates the position of the catalyst within the liquid layer containing the highest concentration of carbon dioxide.

Numerical Simulation of Tethered Underwater Kites for Power Generation

Science.gov (United States)

Ghasemi, Amirmahdi; Olinger, David; Tryggvason, Gretar

2015-11-01

An emerging renewable energy technology, tethered undersea kites (TUSK), which is used to extract hydrokinetic energy from ocean and tidal currents, is studied. TUSK systems consist of a rigid-winged ``kite,'' or glider, moving in an ocean current which is connected by tethers to a floating buoy on the ocean surface. The TUSK kite is a current speed enhancement device since the kite can move in high-speed, cross-current motion at 4-6 times the current velocity, thus producing more power than conventional marine turbines. A computational simulation is developed to simulate the dynamic motion of an underwater kite and extendable tether. A two-step projection method within a finite volume formulation, along with an Open MP acceleration method, is employed to solve the Navier-Stokes equations. An immersed boundary method is incorporated to model the fluid-structure interaction of the rigid kite (with NACA 0012 airfoil shape in 2D and NACA 0021 airfoil shape in 3D simulations) and the fluid flow. PID control methods are used to adjust the kite angle of attack during power (tether reel-out) and retraction (reel-in) phases. Two baseline simulations (for kite motions in two and three dimensions) are studied, and system power output, flow field vorticity, tether tension, and hydrodynamic coefficients (lift and drag) for the kite are determined. The simulated power output shows good agreement with established theoretical results for a kite moving in two-dimensions.

Tethered Cord Syndrome with Syrinx in A Nigerian Adult Female: A ...

African Journals Online (AJOL)

Examination revealed reduced power in both lower limbs with loss of peripheral sensation, pain and light touch beginning at the level of L3, power in upper limbs was normal and the cranial nerves were intact. Urogenital and Musculoskeletal systems examination were normal. The respiratory and gastrointestinal systems ...

Tethered Cord Syndrome with Syrinx in A Nigerian Adult Female: A ...

African Journals Online (AJOL)

Alasia Datonye

group of spinal disorders that typically occurs in children, but occurs ... METHODS: The case record of the patient in review and literature ... modern imaging tools like MRI, the diagnosis of TCS is no more as ... Musculoskeletal system did not ...

DRG Spinal Cord Stimulation as Solution for Patients With Severe Pain Due to Anterior Cutaneous Nerve Entrapment Syndrome: A Case Series.

Science.gov (United States)

Mol, Frédérique Mathilde Ulrike; Roumen, Rudi M H

2018-04-01

Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is a debilitating neuropathic pain condition. A small portion of patients do not respond to any currently available treatment modalities. These patients, often young women, might benefit from targeted spinal cord stimulation of the dorsal root ganglion (DRG). This retrospective case series describes five ACNES patients who were referred from a Dutch dedicated tertiary referral center to collaborating sites with extensive experience in DRG stimulation to be implanted with a DRG Axium System (St. Jude/Abbott, IL, USA) in the period of 2013-2016. Numeric pain rating scores at routine 6- and 12-month follow-up visits were analyzed. Three patients experienced >50% pain reduction at 12 months follow-up. Four patients experienced device-related complications, such as lead dislocation, lead breakage, pain at the battery site, and overstimulation. This case series suggests DRG spinal cord stimulation can be safe and effective for some patients with persistent pain due to ACNES. © 2017 International Neuromodulation Society.

Biomimicry enhances sequential reactions of tethered glycolytic enzymes, TPI and GAPDHS.

Directory of Open Access Journals (Sweden)

Chinatsu Mukai

Full Text Available Maintaining activity of enzymes tethered to solid interfaces remains a major challenge in developing hybrid organic-inorganic devices. In nature, mammalian spermatozoa have overcome this design challenge by having glycolytic enzymes with specialized targeting domains that enable them to function while tethered to a cytoskeletal element. As a step toward designing a hybrid organic-inorganic ATP-generating system, we implemented a biomimetic site-specific immobilization strategy to tether two glycolytic enzymes representing different functional enzyme families: triose phosphoisomerase (TPI; an isomerase and glyceraldehyde 3-phosphate dehydrogenase (GAPDHS; an oxidoreductase. We then evaluated the activities of these enzymes in comparison to when they were tethered via classical carboxyl-amine crosslinking. Both enzymes show similar surface binding regardless of immobilization method. Remarkably, specific activities for both enzymes were significantly higher when tethered using the biomimetic, site-specific immobilization approach. Using this biomimetic approach, we tethered both enzymes to a single surface and demonstrated their function in series in both forward and reverse directions. Again, the activities in series were significantly higher in both directions when the enzymes were coupled using this biomimetic approach versus carboxyl-amine binding. Our results suggest that biomimetic, site-specific immobilization can provide important functional advantages over chemically specific, but non-oriented attachment, an important strategic insight given the growing interest in recapitulating entire biological pathways on hybrid organic-inorganic devices.

Biomimicry enhances sequential reactions of tethered glycolytic enzymes, TPI and GAPDHS.

Science.gov (United States)

Mukai, Chinatsu; Gao, Lizeng; Bergkvist, Magnus; Nelson, Jacquelyn L; Hinchman, Meleana M; Travis, Alexander J

2013-01-01

Maintaining activity of enzymes tethered to solid interfaces remains a major challenge in developing hybrid organic-inorganic devices. In nature, mammalian spermatozoa have overcome this design challenge by having glycolytic enzymes with specialized targeting domains that enable them to function while tethered to a cytoskeletal element. As a step toward designing a hybrid organic-inorganic ATP-generating system, we implemented a biomimetic site-specific immobilization strategy to tether two glycolytic enzymes representing different functional enzyme families: triose phosphoisomerase (TPI; an isomerase) and glyceraldehyde 3-phosphate dehydrogenase (GAPDHS; an oxidoreductase). We then evaluated the activities of these enzymes in comparison to when they were tethered via classical carboxyl-amine crosslinking. Both enzymes show similar surface binding regardless of immobilization method. Remarkably, specific activities for both enzymes were significantly higher when tethered using the biomimetic, site-specific immobilization approach. Using this biomimetic approach, we tethered both enzymes to a single surface and demonstrated their function in series in both forward and reverse directions. Again, the activities in series were significantly higher in both directions when the enzymes were coupled using this biomimetic approach versus carboxyl-amine binding. Our results suggest that biomimetic, site-specific immobilization can provide important functional advantages over chemically specific, but non-oriented attachment, an important strategic insight given the growing interest in recapitulating entire biological pathways on hybrid organic-inorganic devices.

Tethered Ozonesonde Measurements During FRAPPE July-August 2014

Science.gov (United States)

Oltmans, S. J.; Johnson, B.; Sterling, C. W.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Wendell, J.; Schnell, R. C.; McClure-Begley, A.; Thompson, A. M.

2015-12-01

O3 and temperature profiles were measured from tethered ozonesondes from surface to 400 m above ground level on 9 days during the summer of 2014 Colorado Front Range Air Pollution and Photochemistry Experiment (FRAPPE). The portable tethered ozonesonde system was set up at one of 3 sites located next to a Colorado Department of Public Health and Environment surface monitoring station. The day and site chosen were based on the previous day O3 and weather forecast. Measurements typically began at 8:30 AM and ended at 4:30 PM, averaging 40 profiles in one day. The ozonesonde when sampling at the surface consistently read within 0-3 ppbv of the surface monitor at each of the sites with a typical daytime range of 20-90 ppbv. The hourly values were averaged at 50 meter intervals showing O3 production rates were consistently around 8 ppbv per hour from 50 to 300 meters above ground level. On sunny, light wind days the O3 mixing ratio reached a maximum of 80-90 ppbv between 14:00 and 15:00 local time. The generally constant mixing ratio with height and highest mixing ratios above the surface indicate that photochemical O3 production was taking place throughout the profile. Continuous O3 profiles from a tall tower (5 and 300 m) and daily ozonesondes tracked O3 variability through the experiment. High O3 at each site was associated with different local wind directions. At Ft. Collins winds were generally out of the southeast, at Chatfield from the northeast, and at City Park Golf Course more variable. The tether system was developed at NOAA/ESRL to provide a cost effective method to measure O3 profiles on a continuous basis. The tether system consisted of a deep sea fishing pole, electric motor driving the reel with light-weight fishing line attached to the balloon ozonesonde, a tether control box, and laptop. The in house software package monitored data and controlled the tether speed and turn-around point based on real time GPS altitude from the transmitting radiosonde.

An Effective Approach Control Scheme for the Tethered Space Robot System

Directory of Open Access Journals (Sweden)

Zhongjie Meng

2014-09-01

Full Text Available The tethered space robot system (TSR, which is composed of a platform, a gripper and a space tether, has great potential in future space missions. Given the relative motion among the platform, tether, gripper and the target, an integrated approach model is derived. Then, a novel coordinated approach control scheme is presented, in which the tether tension, thrusters and the reaction wheel are all utilized. It contains the open-loop trajectory optimization, the feedback trajectory control and attitude control. The numerical simulation results show that the rendezvous between TSR and the target can be realized by the proposed coordinated control scheme, and the propellant consumption is efficiently reduced. Moreover, the control scheme performs well in the presence of the initial state's perturbations, actuator characteristics and sensor errors.

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.

2012-09-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Modelling a tethered mammalian sperm cell undergoing hyperactivation

KAUST Repository

Curtis, M.P.; Kirkman-Brown, J.C.; Connolly, T.J.; Gaffney, E.A.

2012-01-01

The beat patterns of mammalian sperm flagella can be categorised into two different types. The first involves symmetric waves propagating down the flagellum with a net linear propulsion of the sperm cell. The second, hyperactive, waveform is classified by vigorous asymmetric waves of higher amplitude, lower wavenumber and frequency propagating down the flagellum resulting in highly curved trajectories. The latter beat pattern is part of the capacitation process whereby sperm prepare for the prospective penetration of the zona pellucida and fusion with the egg. Hyperactivation is often observed to initiate as sperm escape from epithelial and ciliary bindings formed within the isthmic regions of the female oviducts, leading to a conjecture in the literature that this waveform is mechanically important for sperm escape. Hence, we explore the mechanical effects of hyperactivation on a tethered sperm, focussing on a Newtonian fluid. Using a resistive force theory model we demonstrate that hyperactivation can indeed generate forces that pull the sperm away from a tethering point and consequently a hyperactivated sperm cell bound to an epithelial surface need not always be pushed by its flagellum. More generally, directions of the forces generated by tethered flagella are insensitive to reductions in beat frequency and the detailed flagellar responses depend on the nature of the binding at the tethering point. Furthermore, waveform asymmetry and amplitude increases enhance the tendency for a tethered flagellum to start tugging on its binding. The same is generally predicted to be true for reductions in the wavenumber of the flagellum beat, but not universally so, emphasising the dynamical complexity of flagellar force generation. Finally, qualitative observations drawn from experimental data of human sperm bound to excised female reproductive tract are also presented and are found to be consistent with the theoretical predictions. © 2012 Elsevier Ltd.

Spinal cord magnetic resonance imaging in suspected multiple sclerosis

International Nuclear Information System (INIS)

Lycklama a Nijeholt, G.J.; Bergers, E.; Castelijns, J.A.; Barkhof, F.; Uitdehaag, B.M.J.; Polman, C.H.

2000-01-01

We examined the value of spinal cord magnetic resonance imaging (MRI) in the diagnostic work-up of multiple sclerosis (MS). Forty patients suspected of having MS were examined within 24 months after the start of symptoms. Disability was assessed, and symptoms were categorized as either brain or spinal cord. Work-up further included cerebrospinal fluid analysis and standard proton-density, T2-, and T1-weighted gadolinium-enhanced brain and spinal cord MRI. Patients were categorized as either clinically definite MS (n = 13), laboratory-supported definite MS (n = 14), or clinically probable MS (n = 4); four patients had clinically probable MS, and in nine MS was suspected. Spinal cord abnormalities were found in 35 of 40 patients (87.5 %), consisting of focal lesions in 31, only diffuse abnormalities in two, and both in two. Asymptomatic spinal cord lesions occurred in six patients. All patients with diffuse spinal cord abnormality had clear spinal cord symptoms and a primary progressive disease course. In clinically definite MS, the inclusion of spinal imaging increased the sensitivity of MRI to 100 %. Seven patients without a definite diagnosis had clinically isolated syndromes involving the spinal cord. Brain MRI was inconclusive, while all had focal spinal cord lesions which explained symptoms and ruled out other causes. Two other patients had atypical brain abnormalities suggesting ischemic/vascular disease. No spinal cord abnormalities were found, and during follow-up MS was ruled out. Spinal cord abnormalities are common in suspected MS, and may occur asymptomatic. Although diagnostic classification is seldom changed, spinal cord imaging increases diagnostic sensitivity of MRI in patients with suspected MS. In addition, patients with primary progressive MS may possibly be earlier diagnosed. Finally, differentiation with atypical lesions may be improved. (orig.)

Tethered elevator and platforms as space station facilities: Systems studies and demonstrative experiments

Science.gov (United States)

1986-01-01

Several key concepts of the science and applications tethered platforms were studied. Some conclusions reached are herein listed. Tether elevator and platform could improve the space station scientific and applicative capabilities. The space elevator presents unique characteristics as microgravity facility and as a tethered platform servicing vehicle. Pointing platforms could represent a new kind of observation facility for large class of payloads. The dynamical, control and technological complexity of these concepts advised demonstrative experiments. The on-going tethered satellite system offers the opportunity to perform such experiments. And feasibility studies are in progress.

Functional and metabolic changes in the brain in neuropathic pain syndrome against the background of chronic epidural electrostimulation of the spinal cord.

Science.gov (United States)

Sufianov, A A; Shapkin, A G; Sufianova, G Z; Elishev, V G; Barashin, D A; Berdichevskii, V B; Churkin, S V

2014-08-01

Changes in functional and metabolic activities of the brain were evaluated by EEG and positron-emission/computer tomography with 18F-fluorodeoxyglucose in patients with neuropathic pain syndrome previous to and 3 months after implantation of a system for chronic epidural spinal cord stimulation. In most cases, the use of a nerve stimulator was followed by alleviation of neuropathic pain and partial normalization of functional and metabolic activities of brain structures responsible for pain perception, emotiogenic, behavioral, and autonomic responses.

Spinal Cord Stimulation With Hybrid Lead Relieves Pain in Low Back and Legs

NARCIS (Netherlands)

de Vos, Cecilia Cecilia Clementine; Levy, R.M.; Dijkstra, Cindy; Lenders, Mathieu W.P.M.; Holsheimer, J.

Objective:  The failed back surgery syndrome (FBSS) is the most common chronic pain syndrome. Whereas it is relatively easy to achieve pain relief in the lower limbs of FBSS patients with spinal cord stimulation (SCS), it is difficult to manage low back pain with SCS. The performance of a

Is early cord clamping, delayed cord clamping or cord milking best?

Science.gov (United States)

Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

2018-04-01

To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

Forces, energetics, and dynamics of conjugated-carbon ring tethers adhered to CNTs: a computational investigation.

Science.gov (United States)

Filla, Nicholas; Ramasamy, Ramaraja; Wang, Xianqiao

2018-04-25

The strength and nature of the interactions between carbon nanotubes (CNTs) and molecular tethers plays a vital role in technology such as CNT-enzyme sensors. Tethers that attach noncovalently to CNTs are ideal for retaining the electrical properties of the CNTs since they do not degrade the CNT surface and effect its electrical conductivity. However, leaching due to weak CNT-tether attachment is very common when using noncovalent tethers, and this has limited their use in commercial products including biosensors. Thus, understanding the fundamental mechanics governing the strength of CNT-tether adhesion is crucial for the design of highly sensitive, viable sensors. Here, we computationally investigate the adhesion strength of CNT-tether complexes with 8 different tethering molecules designed to adhere noncovalently to the CNT surface. We study the effects of CNT diameter, CNT chirality, and the size/geometry of the tethering molecule on the adhesion energy and force. Our results show an asymptotic relationship between adhesion strength and CNT diameter. Calculations show that noncovalent tethers tested here can reach adhesion forces and energies that are up to 21% and 54% of the strength of the carbon-carbon single bond force and bond energy respectively. We anticipate our results will help guide CNT-enzyme sensor design to produce sensors with high sensitivity and minimal leaching.

Novel roaming and stationary tethered aerial robots for continuous mobile missions in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Gu, Beom W.; Choi, Su Y.; Rim, Chun T. [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cai, Guowei; Seneviratne, Lakmal [Dept. of Aerospace Engineering, Khalifa University, Abu Dhabi (United Arab Emirates)

2016-08-15

In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

Directory of Open Access Journals (Sweden)

Beom W. Gu

2016-08-01

Full Text Available In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs for radioactive material sampling and stationary tethered aerial robots (STARs for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

Restriction of the Patau syndrome to duplication of 13q22{yields}q.32 and possible role of interphase nuclear structure

Energy Technology Data Exchange (ETDEWEB)

Helali, A.N.; Jafolla, A.K.; Oumsiych, M.B. [Duke Univ. Medical Center, Durham, NC (United States)

1994-09-01

A 10-year-old white male presented with mild microcephaly, slight growth and psychomotor retardation, soft fleshy ears, and normal facial features except for thin lips. No other significant anomalies were reported except for tethered cord discovered at age 8 years. The karyotype was found to be 46,XY,der(18)t(13;18)(q32;p11.32)pat. The mild phenotype appears to be primarily due to the duplication of 13q32{yields}qter. None of the cardinal features of trisomy 13 are found in cases of duplication of bands 13q22 to qter. This case shows that Patau syndrome phenotype does not originate by duplication of 13q32{yields}qter and may thus be restricted to 13q22 to 13q32. The variability in phenotypes points to an alternative explanation to the classical one of additive and interactive gene effects. This model involves effects of changes in chromosome position in the interphase nucleus on gene expression.

Electron Emitter for small-size Electrodynamic Space Tether using MEMS Technology

DEFF Research Database (Denmark)

Fleron, René A. W.; Blanke, Mogens

2004-01-01

Adjustment of the orbit of a spacecraft using the forces created by an electro-dynamic space-tether has been shown as a theoretic possibility in recent literature. Practical implementation is being pursued for larger scale missions where a hot filament device controls electron emission...... and the current flowing in the electrodynamic space tether. Applications to small spacecraft, or space debris in the 1–10 kg range, possess difficulties with electron emission technology, as low power emitting devices are needed. This paper addresses the system concepts of a small spacecraft electrodynamic tether...... system with focus on electron emitter design and manufacture using micro-electro-mechanical- system (MEMS) technology. The paper addresses the system concepts of a small size electrodynamic tether mission and shows a novel electron emitter for the 1-2 mA range where altitude can be effectively affected...

Results from a tethered rocket experiment (Charge-2)

Science.gov (United States)

Kawashima, N.; Sasaki, S.; Oyama, K. I.; Hirao, K.; Obayashi, T.; Raitt, W. J.; White, A. B.; Williamson, P. R.; Banks, P. M.; Sharp, W. F.

A tethered payload experiment (Charge-2) was carried out as an international program between Japan and the USA using a NASA sounding rocket at White Sands Missile Range. The objective of the experiment was to perform a new type of active experiment in space by injecting an electron beam from a mother-daughter rocket system connected with a long tether wire. The electron beam with voltage and current up to 1 kV and 80 mA (nominal) was injected from the mother payload. An insulated conductive wire of 426 m length connected the two payloads, the longest tether system flown so far. The electron gun system and diagnostic instruments (plasma, optical, particle and wave) functioned correctly throughout the flight. The potential rise of the mother payload during the electron beam emission was measured with respect to the daughter payload. The beam trajectory was detected by a camera onboard the mother rocket. Wave generation and current induction in the wire during the beam emission were also studied.

Radiation tolerance of the cervical spinal cord

International Nuclear Information System (INIS)

McCunniff, A.J.; Liang, M.J.

1989-01-01

The incidence of permanent injury to the spinal cord as a complication of radiation therapy generally correlates positively with total radiation dosage. However, several reports in the literature have indicated that fraction size is also an important factor in the development or nondevelopment of late injuries in normal tissue. To determine the effect of fraction size on the incidence of radiation-induced spinal cord injuries, we reviewed 144 cases of head and neck cancer treated at our institution between 1971 and 1980 with radiation greater than 5600 cGy to a portion of the cervical spinal cord. Most of these patients received greater than or equal to 6000 cGy, with fraction sizes ranging from 133 cGy to 200 cGy. Fifty-three of the 144 patients have been followed up for 2 years or more. Nearly half of these (26 patients) received greater than 6000 cGy with fraction sizes of 133 cGy to 180 cGy. Only 1 of the 53 (1.9%) has sustained permanent spinal cord injury; 20 months after completion of radiation treatments he developed Brown-Sequard syndrome. Our experience suggests that radiation injuries to the spinal cord correlate not only with total radiation dosage, but also with fraction size; low fraction sizes appear to decrease the incidence of such injuries

Síndrome de Klippel-Trenaunay-Parkes-Weber com angiomatose medular Klippel-Trénaunay-Parkes-Weber syndrome with spinal cord angioma: a case report

Directory of Open Access Journals (Sweden)

James Pitagoras de Mattos

1975-09-01

Full Text Available É relatado um caso de síndrome de Klippel-Trénaunay-Parkes-Weber associada a angiomatose medular. O autor salienta ter encontrado na literatura somente uma referência com tal associação.A case of Klippel-Trénaunay-Parkes-Weber syndrome associated with spinal cord angioma is reported. The author points out that it was found only one reference in literature with such association.

Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome (CRPS) Recurrence after Amputation for CRPS, and Failure of Conventional Spinal Cord Stimulation.

Science.gov (United States)

Goebel, Andreas; Lewis, Sarah; Phillip, Rhodri; Sharma, Manohar

2018-01-01

Limb amputation is sometimes being performed in long-standing complex regional pain syndrome (CRPS), although little evidence is available guiding management decisions, including how CRPS recurrence should be managed. This report details the management of a young soldier with CRPS recurrence 2 years after midtibial amputation for CRPS. Conventional spinal cord stimulation did not achieve paraesthetic coverage, or pain relief in the stump, whereas L4 dorsal root ganglion stimulation achieved both coverage and initially modest pain relief, and over time, substantial pain relief. Current evidence does not support the use of amputation to improve either pain or function in CRPS. Before a decision is made, in exceptional cases, about referral for amputation, dorsal root ganglion stimulation should be considered as a potentially effective treatment, even where conventional spinal cord stimulator treatment has failed to achieve reliable paraesthetic cover. Furthermore, this treatment may provide pain relief in those patients with CRPS recurrence in the stump after amputation. © 2017 World Institute of Pain.

A Brain–Spinal Interface Alleviating Gait Deficits after Spinal Cord Injury in Primates

Science.gov (United States)

Capogrosso, Marco; Milekovic, Tomislav; Borton, David; Wagner, Fabien; Moraud, Eduardo Martin; Mignardot, Jean-Baptiste; Buse, Nicolas; Gandar, Jerome; Barraud, Quentin; Xing, David; Rey, Elodie; Duis, Simone; Jianzhong, Yang; Ko, Wai Kin D.; Li, Qin; Detemple, Peter; Denison, Tim; Micera, Silvestro; Bezard, Erwan; Bloch, Jocelyne; Courtine, Grégoire

2016-01-01

Spinal cord injury disrupts the communication between the brain and the spinal circuits that orchestrate movement. To bypass the lesion, brain–computer interfaces1–3 have directly linked cortical activity to electrical stimulation of muscles, which have restored grasping abilities after hand paralysis1,4. Theoretically, this strategy could also restore control over leg muscle activity for walking5. However, replicating the complex sequence of individual muscle activation patterns underlying natural and adaptive locomotor movements poses formidable conceptual and technological challenges6,7. Recently, we showed in rats that epidural electrical stimulation of the lumbar spinal cord can reproduce the natural activation of synergistic muscle groups producing locomotion8–10. Here, we interfaced leg motor cortex activity with epidural electrical stimulation protocols to establish a brain–spinal interface that alleviated gait deficits after a spinal cord injury in nonhuman primates. Rhesus monkeys were implanted with an intracortical microelectrode array into the leg area of motor cortex; and a spinal cord stimulation system composed of a spatially selective epidural implant and a pulse generator with real-time triggering capabilities. We designed and implemented wireless control systems that linked online neural decoding of extension and flexion motor states with stimulation protocols promoting these movements. These systems allowed the monkeys to behave freely without any restrictions or constraining tethered electronics. After validation of the brain–spinal interface in intact monkeys, we performed a unilateral corticospinal tract lesion at the thoracic level. As early as six days post-injury and without prior training of the monkeys, the brain–spinal interface restored weight-bearing locomotion of the paralyzed leg on a treadmill and overground. The implantable components integrated in the brain–spinal interface have all been approved for investigational

Self-assembled tethered bimolecular lipid membranes.

Science.gov (United States)

Sinner, Eva-Kathrin; Ritz, Sandra; Naumann, Renate; Schiller, Stefan; Knoll, Wolfgang

2009-01-01

This chapter describes some of the strategies developed in our group for designing, constructing and structurally and functionally characterizing tethered bimolecular lipid membranes (tBLM). We introduce this platform as a novel model membrane system that complements the existing ones, for example, Langmuir monolayers, vesicular liposomal dispersions and bimolecular ("black") lipid membranes. Moreover, it offers the additional advantage of allowing for studies of the influence of membrane structure and order on the function of integral proteins, for example, on how the composition and organization of lipids in a mixed membrane influence the ion translocation activity of integral channel proteins. The first strategy that we introduce concerns the preparation of tethered monolayers by the self-assembly of telechelics. Their molecular architecture with a headgroup, a spacer unit (the "tether") and the amphiphile that mimics the lipid molecule allows them to bind specifically to the solid support thus forming the proximal layer of the final architecture. After fusion of vesicles that could contain reconstituted proteins from a liposomal dispersion in contact to this monolayer the tethered bimolecular lipid membrane is obtained. This can then be characterized by a broad range of surface analytical techniques, including surface plasmon spectroscopies, the quartz crystal microbalance, fluorescence and IR spectroscopies, and electrochemical techniques, to mention a few. It is shown that this concept allows for the construction of tethered lipid bilayers with outstanding electrical properties including resistivities in excess of 10 MOmega cm2. A modified strategy uses the assembly of peptides as spacers that couple covalently via their engineered sulfhydryl or lipoic acid groups at the N-terminus to the employed gold substrate, while their C-terminus is being activated afterward for the coupling of, for example, dimyristoylphosphatidylethanol amine (DMPE) lipid molecules

Tripolar spinal cord stimulation for the treatment of abdominal pain associated with irritable bowel syndrome.

Science.gov (United States)

Rana, Maunak V; Knezevic, Nebojsa Nick

2013-01-01

The objective of this case report is to describe the use of transverse tripolar dorsal column stimulation in a patient with a history of irritable bowel syndrome (IBS) associated with abdominal pain resistant to conservative treatments. We report a 36-year-old man who presented to the pain clinic with an eight-year history of IBS (constipation predominant with occasional diarrheal episodes), with "crampy and sharp" abdominal pain. He also had nonradicular thoracic spine pain due to thoracic scoliosis. Both pains were affecting his ability to function as an attorney. Prior conservative therapy, including psychologic treatment, antidepressants, and opioids, was without any benefits. The use of a spinal cord stimulator (SCS) was discussed with the patient. The procedure was performed after Institutional Review Board approval. A tripolar SCS was implanted at the T8 level using one-eight contact and two-four contact percutaneous leads based on paresthesia reproduction of patient's areas of discomfort. This tripolar spinal cord stimulation provided relief of abdominal and thoracic pain, and better management of gastrointestinal symptoms. The patient was followed-up for one year, and his quality of life also was improved via the IBS-Severity Scoring System quality of life tool. The use of the tripolar SCS in this patient provided relief of abdominal and thoracic spine pain, regulated bowel habits, and improved the patient's quality of life. We believe that the use of SCS should be considered as a treatment option in patients with IBS when all conservative treatments failed. © 2012 International Neuromodulation Society.

Design of COSMIC: a randomized, multi-centre controlled trial comparing conservative or early surgical management of incomplete cervical cord syndrome without spinal instability.

Science.gov (United States)

Bartels, Ronald H M A; Hosman, Allard J F; van de Meent, Henk; Hofmeijer, Jeannette; Vos, Pieter E; Slooff, Willem Bart; Öner, F Cumhur; Coppes, Maarten H; Peul, Wilco C; Verbeek, André L M

2013-01-31

Incomplete cervical cord syndrome without spinal instability is a very devastating event for the patient and the family. It is estimated that up to 25% of all traumatic spinal cord lesions belong to this category. The treatment for this type of spinal cord lesion is still subject of discussion. From a biological point of view early surgery could prevent secondary damage due to ongoing compression of the already damaged spinal cord. Historically, however, conservative treatment was propagated with good clinical results. Proponents for early surgery as well those favoring conservative treatment are still in debate. The proposed trial will contribute to the discussion and hopefully also to a decrease in the variability of clinical practice. A randomized controlled trial is designed to compare the clinical outcome of early surgical strategy versus a conservative approach. The primary outcome is clinical outcome according to mJOA. This also measured by ASIA score, DASH score and SCIM III score. Other endpoints are duration of the stay at a high care department (medium care, intensive care), duration of the stay at the hospital, complication rate, mortality rate, sort of rehabilitation, and quality of life. A sample size of 36 patients per group was calculated to reach a power of 95%. The data will be analyzed as intention-to-treat at regular intervals, but the end evaluation will take place at two years post-injury. At the end of the study, clinical outcomes between treatments attitudes can be compared. Efficacy, but also efficiency can be determined. A goal of the study is to determine which treatment will result in the best quality of life for the patients. This study will certainly contribute to more uniformity of treatment offered to patients with a special sort of spinal cord injury. Gov: NCT01367405.

Design of COSMIC: a randomized, multi-centre controlled trial comparing conservative or early surgical management of incomplete cervical cord syndrome without spinal instability

Directory of Open Access Journals (Sweden)

Bartels Ronald HMA

2013-01-01

Full Text Available Abstract Background Incomplete cervical cord syndrome without spinal instability is a very devastating event for the patient and the family. It is estimated that up to 25% of all traumatic spinal cord lesions belong to this category. The treatment for this type of spinal cord lesion is still subject of discussion. From a biological point of view early surgery could prevent secondary damage due to ongoing compression of the already damaged spinal cord. Historically, however, conservative treatment was propagated with good clinical results. Proponents for early surgery as well those favoring conservative treatment are still in debate. The proposed trial will contribute to the discussion and hopefully also to a decrease in the variability of clinical practice. Methods/Design A randomized controlled trial is designed to compare the clinical outcome of early surgical strategy versus a conservative approach. The primary outcome is clinical outcome according to mJOA. This also measured by ASIA score, DASH score and SCIM III score. Other endpoints are duration of the stay at a high care department (medium care, intensive care, duration of the stay at the hospital, complication rate, mortality rate, sort of rehabilitation, and quality of life. A sample size of 36 patients per group was calculated to reach a power of 95%. The data will be analyzed as intention-to-treat at regular intervals, but the end evaluation will take place at two years post-injury. Discussion At the end of the study, clinical outcomes between treatments attitudes can be compared. Efficacy, but also efficiency can be determined. A goal of the study is to determine which treatment will result in the best quality of life for the patients. This study will certainly contribute to more uniformity of treatment offered to patients with a special sort of spinal cord injury. Trial Registration Gov: NCT01367405

High-cervical spinal cord electrical stimulation in brain low perfusion syndromes: experimental basis and preliminary clinical report.

Science.gov (United States)

Broseta, J; García-March, G; Sánchez-Ledesma, M J; Gonçalves, J; Silva, I; Barcia, J A; Llácer, J L; Barcia-Salorio, J L

1994-01-01

Previous studies of our group showed that C1-C2 spinal cord stimulation increases carotid and brain blood flow in normal conditions in the goat and dog and it has a beneficial vasomotor effect in a model of vasospasm in the rat. For further clinical application it seemed rational to investigate the possible vascular changes mediated by this technique in experimental brain infarction. To this aim, 45 New Zealand rabbits were used. Brain infarction was produced by bilateral carotid ligation in 15, unilateral microcoagulation of the middle cerebral artery in 15 and by microcoagulation of the vertebral artery at the craniocervical junction in the other 15. One week later, following daily clinical scoring and cortical and posterior fossa blood flow readings by laser Doppler, a period of 120 min of right C1-C2 spinal cord electric stimulation was performed. A mean of 27% increase in previous blood flow recordings was obtained at the right hemisphere and a mean of 32% in the posterior fossa. This procedure was used in 10 patients presenting with various cerebral low perfusion syndromes. Though not constant, an increase in alertness, retention, speech, emotional lability and performance in skilled acts was achieved. No MR changes were observed, though SPECT readings showed an increase in blood flow in the penumbral perilesional area.

Continuous Thoracic Sympathetic Ganglion Block in Complex Regional Pain Syndrome Patients with Spinal Cord Stimulation Implantation

Directory of Open Access Journals (Sweden)

EungDon Kim

2016-01-01

Full Text Available The sympathetic block is widely used for treating neuropathic pain such as complex regional pain syndrome (CRPS. However, single sympathetic block often provides only short-term effect. Moreover, frequent procedures for sympathetic block may increase the risk of complications. The use of epidural route may be limited by concern of infection in case of previous implantation of the spinal cord stimulation (SCS. In contrast, a continuous sympathetic block can be administered without such concerns. The continuous thoracic sympathetic block (TSGB has been used to treat the ischemic disease and other neuropathic conditions such as postherpetic neuralgia. We administered continuous thoracic sympathetic block using catheter in CRPS patients who underwent SCS implantations and achieved desirable outcomes. We believe a continuous sympathetic block is a considerable option before performing neurolysis or radiofrequency rhizotomy and even after SCS implantation.

Two-Way Tether Gun

Science.gov (United States)

Sanger, George F.

1994-01-01

Safety-tether device enables crewmembers on spacecraft to retrieve crewmember drifting away from spacecraft. Alternatively, drifting crewmember who carries device uses it to grasp and return to spacecraft. Also used on Earth. For example, rescuer on vessel or pier uses it to retrieve and haul drowning or unconscious person to safety; drifting person or rescuer in water uses it to grasp and hold onto support.

Role of rehabilitation a case of diastematomyelia

Directory of Open Access Journals (Sweden)

Stanescu Ioana

2017-12-01

Full Text Available Diastematomyelia (split cord malformation is a rare dysraphic lesion in which a part of the spinal cord is split in the sagittal plane into two hemicords, a bony, cartilagenous or fibrous spur projecting through the dura mater is visible in 33% of cases. Vertebral anomalies (spina bifida are common. It occurs usually between D9 and S1. Classificatin includes two types: type 1 with a duplicated dural sac, with common midline spur, usually symptomatic, and type 2 with a single dural sac and usually less symptomatic. The majority of patients are presenting with tethered cord syndrome (neurologic deficits in the lower limbs and perineum. MRI is the modality of choice for diagnosis. In symptomatic cases, surgical release of the cord and resection of spur with repair of dura are performed, with good results. We present a case of a pauci-symptomatic type 1 dyastematomyelia, manifested by intermittent and resistant lumbar pain, in which physiotherapy during rehabilitation program have shown to improve pain intensity.

Investigation of electrodynamic stabilization and control of long orbiting tethers. [space shuttle payloads

Science.gov (United States)

Arnold, D. A.; Dobrowolny, M.

1981-01-01

An algorithm for using electric currents to control pendular oscillations induced by various perturbing forces on the Skyhook wire is considered. Transverse and vertical forces on the tether; tether instability modes and causes during retrieval by space shuttle; simple and spherical pendulum motion and vector damping; and current generation and control are discussed. A computer program for numerical integration of the in-plane and out-of-plane displacements of the tether vs time was developed for heuristic study. Some techniques for controlling instabilities during payload retrieval and methods for employing the tether for launching satellites from the space shuttle are considered. Derivations and analyses of a general nature used in all of the areas studied are included.

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

, Keigo Watanabe

2014-10-01

Full Text Available In Japan, aging of infrastructures, such as roads, bridges, and water and sewer services, etc. poses a problem, and it is required to extend the life-span of such infrastructures by maintenance. Among infrastructures, especially bridges are periodically inspected by short range visual observations, which check the damage and deterioration of the surface. However, since there are some cases where the short range visual observation is difficult, an alternative method is required so as to replace the short range visual observation with it. So, "X4-Flyer" is very attractive because of realizing a movement at high altitude easily. The objective of this study is to develop a tethered X4- Flyer, so that the conventional short range visual observation of bridges is replaced by it. In this paper, a method for the measurement and control of the position is described by using a tether for controlling the position of the X4-Flyer. In addition, it is checked whether the tethered X4-Flyer can control the position using the proposed method or not, letting it fly in a state in which a tether is being attached.

Untethering an unusual cause of kidney injury in a teenager with Down syndrome.

Science.gov (United States)

Yen, Elizabeth; Miele, Niel F; Barone, Joseph G; Tyagi, Rachana; Weiss, Lynne S

2014-11-01

Acute kidney injury (AKI) is characterized by the acute nature and the inability of kidneys to maintain fluid homeostasis as well as adequate electrolyte and acid-base balance, resulting in an accumulation of nitrogenous waste and elevation of serum blood urea nitrogen and creatinine values. Acute kidney injury may be a single isolated event, yet oftentimes, it results from an acute chronic kidney disease. It is critical to seek out the etiology of AKI and to promptly manage the underlying chronic kidney disease to prevent comorbidities and mortality that may ensue. We described a case of a 16-year-old adolescent girl with Down syndrome who presented with AKI and electrolyte aberrance.Abdominal and renal ultrasounds demonstrated a significantly dilated bladder as well as frank hydronephrosis and hydroureter bilaterally. Foley catheter was successful in relieving the obstruction and improving her renal function. However, a magnetic resonance imaging was pursued in light of her chronic constipation and back pain, and it revealed a structural defect (tethered cord) that underlies a chronic process that was highly likely contributory to her AKI. She was managed accordingly with a guarded result and required long-term and close monitoring.

Asthma mimic: Case report and literature review of vocal cord nodule associated with wheezing.

Science.gov (United States)

Kashif, Muhammad; Singh, Tushi; Aslam, Ahsan; Khaja, Misbahuddin

2017-01-01

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. Various clinical conditions can mimic asthma, such as foreign body aspiration, subglottic stenosis, congestive heart failure, diffuse panbronchiolitis, aortic arch anomalies, reactive airway dysfunction syndrome, chronic obstructive pulmonary disease, retrosternal goiter, vocal cord tumors, other airway tumors, and vocal cord dysfunction. Upper airway obstruction can be a life-threatening emergency. Here, we present the case of a 58-year-old female with recurrent hospital visits for wheezing and exacerbations of asthma, who was later found to have a vocal cord nodule confirmed to be squamous cell carcinoma, which was mimicking like asthma.

Spinal Meninges and Their Role in Spinal Cord Injury: A Neuroanatomical Review.

Science.gov (United States)

Grassner, Lukas; Grillhösl, Andreas; Griessenauer, Christoph J; Thomé, Claudius; Bühren, Volker; Strowitzki, Martin; Winkler, Peter A

2018-02-01

Current recommendations support early surgical decompression and blood pressure augmentation after traumatic spinal cord injury (SCI). Elevated intraspinal pressure (ISP), however, has probably been underestimated in the pathophysiology of SCI. Recent studies provide some evidence that ISP measurements and durotomy may be beneficial for individuals suffering from SCI. Compression of the spinal cord against the meninges in SCI patients causes a "compartment-like" syndrome. In such cases, intentional durotomy with augmentative duroplasty to reduce ISP and improve spinal cord perfusion pressure (SCPP) may be indicated. Prior to performing these procedures routinely, profound knowledge of the spinal meninges is essential. Here, we provide an in-depth review of relevant literature along with neuroanatomical illustrations and imaging correlates.

Synthesis and insertion chemistry of mixed tether uranium metallocene complexes

Energy Technology Data Exchange (ETDEWEB)

Siladke, Nathan A.; LeDuc, Jennifer; Ziller, Joseph W.; Evans, William J. [Department of Chemistry, University of California, Irvine, CA (United States)

2012-11-12

The synthesis of mixed tethered alkyl uranium metallocenes has been investigated by examining the reactivity of the bis(tethered alkyl) metallocene [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC){sub 2}U] (1) with substrates that react with only one of the U-C linkages. The effect of these mixed tether coordination environments on the reactivity of the remaining U-C bond has been studied by using CO insertion chemistry. One equivalent of azidoadamantane (AdN{sub 3}) reacts with 1 to yield the mixed tethered alkyl triazenido complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}-CH{sub 2}NNN-Ad-κ{sup 2}N{sup 1,3})]. Similarly, a single equivalent of CS{sub 2} reacts with 1 to form the mixed tethered alkyl dithiocarboxylate complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}- CH{sub 2}C(S){sub 2}-κ{sup 2}S,S{sup '})], a reaction that constitutes the first example of CS{sub 2} insertion into a U{sup 4+}-C bond. Complex 1 reacts with one equivalent of pyridine N-oxide by C-H bond activation of the pyridine ring to form a mixed tethered alkyl cyclometalated pyridine N-oxide complex [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC)(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 3})U(C{sub 6}H{sub 4}NO-κ{sup 2} C,O)]. The remaining (η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}-κC){sup 2-} ligand in each of these mixed tethered species show reactivity towards CO and tethered enolate ligands form by insertion. Subsequent rearrangement have been identified in [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 3})U(C{sub 5}H{sub 4}NO-κ{sup 2}C,O)(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}C(=CH{sub 2})O- κO)] and [(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}CH{sub 2}NNN-Ad-κ{sup 2}N{sup 1,3})U(η{sup 5}-C{sub 5}Me{sub 4}SiMe{sub 2}C(=CH{sub 2})O-κO)]. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Simulations of momentum transfer process between solar wind plasma and bias voltage tethers of electric sail thruster

Science.gov (United States)

Xia, Guangqing; Han, Yajie; Chen, Liuwei; Wei, Yanming; Yu, Yang; Chen, Maolin

2018-06-01

The interaction between the solar wind plasma and the bias voltage of long tethers is the basic mechanism of the electric sail thruster. The momentum transfer process between the solar wind plasma and electric tethers was investigated using a 2D full particle PIC method. The coupled electric field distribution and deflected ion trajectory under different bias voltages were compared, and the influence of bias voltage on momentum transfer process was analyzed. The results show that the high potential of the bias voltage of long tethers will slow down, stagnate, reflect and deflect a large number of ions, so that ion cavities are formed in the vicinity of the tether, and the ions will transmit the axial momentum to the sail tethers to produce the thrust. Compared to the singe tether, double tethers show a better thrust performance.

Low Earth Orbit Environmental Effects on Space Tether Materials

Science.gov (United States)

Finckernor, Miria M.; Gitlemeier, Keith A.; Hawk, Clark W.; Watts, Ed

2005-01-01

Atomic oxygen (AO) and ultraviolet (UV) radiation erode and embrittle most polymeric materials. This research was designed to test several different materials and coatings under consideration for their application to space tethers, for resistance to these effects. The samples were vacuum dehydrated, weighed and then exposed to various levels of AO or UV radiation at the NASA Marshall Space Flight Center. They were then re-weighed to determine mass loss due to atomic oxygen erosion, inspected for damage and tensile tested to determine strength loss. The experiments determined that the Photosil coating process, while affording some protection, damaged the tether materials worse than the AO exposure. TOR-LM also failed to fully protect the materials, especially from UV radiation. The POSS and nickel coatings did provide some protection to the tethers, which survived the entire test regime. M5 was tested, uncoated, and survived AO exposure, though its brittleness prevented any tensile testing.

Radiation nephritis causing nephrotic syndrome

Energy Technology Data Exchange (ETDEWEB)

Jennette, J.C.; Ordonez, N.G.

1983-12-01

Clinical symptoms of acute radiation nephritis with nephrotic syndrome developed in a fifty-six-year-old woman after abdominal radiation therapy for an astrocytoma of the spinal cord. The diagnosis of radiation nephritis was confirmed by renal biopsy. To our knowledge, this is the first documented case of radiation nephritis associated with nephrotic syndrome.

The motion and control of a complex three-body space tethered system

Science.gov (United States)

Shi, Gefei; Zhu, Zhanxia; Chen, Shiyu; Yuan, Jianping; Tang, Biwei

2017-11-01

This paper is mainly devoted to investigating the dynamics and stability control of a three body-tethered satellite system which contains a main satellite and two subsatellites connected by two straight, massless and inextensible tethers. Firstly, a detailed mathematical model is established in the central gravitational field. Then, the dynamic characteristics of the established system are investigated and analyzed. Based on the dynamic analysis, a novel sliding mode prediction model (SMPM) control strategy is proposed to suppress the motion of the built tethered system. The numerical results show that the proposed underactuated control law is highly effective in suppressing the attitude/libration motion of the underactuated three-body tethered system. Furthermore, cases of different target angles are also examined and analyzed. The simulation results reveal that even if the final equilibrium states differ from different selections of the target angles, the whole system can still be maintained in acceptable areas.

Evaluation of spinal cord stimulation on the symptoms of anxiety and depression and pain intensity in patients with failed back surgery syndrome.

Science.gov (United States)

Robb, L P; Cooney, J M; McCrory, C R

2017-08-01

Spinal cord stimulation (SCS) is now established as the primary treatment for failed back surgery syndrome (FBSS). Commonly, patients with chronic pain and FBSS often report symptoms of anxiety and depression resulting from this condition. These factors can modulate and amplify the pain experience, therefore, further challenging treatment success. This study examined the efficacy of SCS on alleviating the symptoms of anxiety and depression associated with chronic pain as well as pain intensity in a group of patients with FBSS. A convenience sample (n = 26) was selected for participation. Questionnaires [Hospital Anxiety and Depression Scale (HADS) and Brief Pain Inventory Short Form (BPI-SF)] were completed and examined pre and post spinal cord implant. Analysis of the data 1 year following SCS indicates that there was a statistical significant improvement in the symptoms of depression and anxiety reported as well as pain intensity in all participants (p anxiety and depression scores on the HADS were significantly lower compared to baseline (p anxiety and depression with an associated reduction in opioid consumption.

Emerging insights into the roles of membrane tethers from analysis of whole organisms: The tip of an iceberg?

Directory of Open Access Journals (Sweden)

Wei Hong eToh

2016-02-01

Full Text Available Membrane tethers have been identified throughout different compartments of the endomembrane system. It is now well established that a number of membrane tethers mediate docking of membrane carriers in anterograde and retrograde transport and in regulating the organization of membrane compartments. Much of our information on membrane tethers have been obtained from the analysis of individual membrane tethers in cultured cells. In the future it will be important to better appreciate the network of interactions mediated by tethers and the potential co-ordination of their collective functions in vivo. There are now a number of studies which have analyzed membrane tethers in tissues and organisms which are providing new insights into the role of this class of membrane protein at the physiological level. Here we review recent advances in the understanding of the function of membrane tethers from knock outs (or knock downs in whole organisms and from mutations in tethers associated with disease.

Cooperative networks : The mobile tethering game

NARCIS (Netherlands)

Constantinescu, M.; Bouwman, H.; Djurica, M.; Durmus, Y.; Onur, E.; Reuver, M. de

2012-01-01

We propose an analysis of cooperation for data sharing and the behavioral aspects involved in the process of decision making. Starting with the tethering capabilities of recent devices we apply game theoretical principles and models, inquire what makes the cooperation work, and what are the

ER-to-plasma membrane tethering proteins regulate cell signaling and ER morphology.

Science.gov (United States)

Manford, Andrew G; Stefan, Christopher J; Yuan, Helen L; Macgurn, Jason A; Emr, Scott D

2012-12-11

Endoplasmic reticulum-plasma membrane (ER-PM) junctions are conserved structures defined as regions of the ER that tightly associate with the plasma membrane. However, little is known about the mechanisms that tether these organelles together and why such connections are maintained. Using a quantitative proteomic approach, we identified three families of ER-PM tethering proteins in yeast: Ist2 (related to mammalian TMEM16 ion channels), the tricalbins (Tcb1/2/3, orthologs of the extended synaptotagmins), and Scs2 and Scs22 (vesicle-associated membrane protein-associated proteins). Loss of all six tethering proteins results in the separation of the ER from the PM and the accumulation of cytoplasmic ER. Importantly, we find that phosphoinositide signaling is misregulated at the PM, and the unfolded protein response is constitutively activated in the ER in cells lacking ER-PM tether proteins. These results reveal critical roles for ER-PM contacts in cell signaling, organelle morphology, and ER function. Copyright © 2012 Elsevier Inc. All rights reserved.

Immediate Return to Ambulation and Improved Functional Capacity for Rehabilitation in Complex Regional Pain Syndrome following Early Implantation of a Spinal Cord Stimulation System

Directory of Open Access Journals (Sweden)

Brandon Jesse Goff

2014-01-01

Full Text Available Complex regional pain syndrome (CRPS is a neuropathic pain condition that is characterized by vasomotor, sensory, sudomotor, and motor symptoms. Spinal cord stimulation (SCS has been successfully utilized for the treatment of pain refractory to conventional therapies. We present a case of a previously highly functioning 54-year-old female who developed a rarely reported case of idiopathic CRPS of the right ankle which spontaneously occurred four months after an uncomplicated anterior cervical disc fusion. This condition resulted in severe pain and functional impairment that was unresponsive to pharmacological management. The patient’s rehabilitation was severely stymied by her excruciating pain. However, with the initiation of spinal cord stimulation, her pain was adequately controlled allowing for progression to full unassisted ambulation, advancing functional capacity, and improving quality of life. This case report supports the concept that rapid progression to neuromodulation, rather than delays that occur due to attempts at serial sympathetic blocks, may better control symptoms leading allowing for a more meaningful recovery.

Tethered balloon-based measurements of meteorological variables and aerosols

Science.gov (United States)

Sentell, R. J.; Storey, R. W.; Chang, J. J. C.; Jacobsen, S. J.

1976-01-01

Tethered balloon based measurements of the vertical distributions of temperature, humidity, wind speed, and aerosol concentrations were taken over a 4-hour period beginning at sunrise on June 29, 1976, at Wallops Island, Virginia. Twelve consecutive profiles of each variable were obtained from ground to about 500 meters. These measurements were in conjuction with a noise propagation study on remotely arrayed acoustic range (ROMAAR) at Wallops Flight Center. An organized listing of these vertical soundings is presented. The tethered balloon system configuration utilized for these measurements is described.

Idiopathic transdural spinal cord herniation: a case report and review of the literature; Herniacion transdural idiopatica de la medula espainal. A proposito de un caso y revision de la bibliografia

Energy Technology Data Exchange (ETDEWEB)

Lopez, M. C.; Rodriguez, D.; Martinez Cueto, P.; Martinez, R. [Complejo Hospitalario Xeral-Cies. Vigo (Spain)

2000-07-01

Idiopathic transdural herniation of the spinal cord is an uncommon entity that is usually associated with Brown-Sequard syndrome. This syndrome consists of ipsilateral and loss of contralateral pain and temperature sensitivity. The radiological findings (Computed tomography myelography and magnetic resonance imaging) are characteristics, with angulation and anterolateral displacement of the spinal cord. It typically affects middle-aged adults and requires surgical treatment. We report the case of a woman who presented the clinical symptoms of Brown-Sequard syndrome and the radiological signs associated with transdural spinal cord herniation. The correct diagnosis of this disease is important since surgical repair of the dural defect improves the neurological symptoms. (Author) 11 refs.

MRI signal intensity as a maker of impairment in incomplete cervical spinal cord injuries

International Nuclear Information System (INIS)

Chiba, Hidefumi; Aoki, Haruhito; Hamabe, Masaki; Sasao, Yutaka; Miura, Takehiko

1998-01-01

Incomplete cervical spinal cord injuries such as central cord syndrome may result in prolonged spasticity of the limbs, especially disabilities of the upper extremities, even if the patient is able to walk. In this study, relationship between cord impairment and clinical outcome was investigated using MRI. Results showed that small foci of low signal intensity in T 1 -weighted imaging combined with foci of high signal intensity in T 2 -weighted imaging in follow-up MRI are closely related to the severity of sequelae. Small foci of low signal intensity in T 1 -weighted imaging are considered in the literature to indicate myelomalacia or cyst formation with gliosis. (author)

A tethering complex drives the terminal stage of SNARE-dependent membrane fusion

Science.gov (United States)

D'Agostino, Massimo; Risselada, Herre Jelger; Lürick, Anna; Ungermann, Christian; Mayer, Andreas

2017-11-01

Membrane fusion in eukaryotic cells mediates the biogenesis of organelles, vesicular traffic between them, and exo- and endocytosis of important signalling molecules, such as hormones and neurotransmitters. Distinct tasks in intracellular membrane fusion have been assigned to conserved protein systems. Tethering proteins mediate the initial recognition and attachment of membranes, whereas SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein complexes are considered as the core fusion engine. SNARE complexes provide mechanical energy to distort membranes and drive them through a hemifusion intermediate towards the formation of a fusion pore. This last step is highly energy-demanding. Here we combine the in vivo and in vitro fusion of yeast vacuoles with molecular simulations to show that tethering proteins are critical for overcoming the final energy barrier to fusion pore formation. SNAREs alone drive vacuoles only into the hemifused state. Tethering proteins greatly increase the volume of SNARE complexes and deform the site of hemifusion, which lowers the energy barrier for pore opening and provides the driving force. Thereby, tethering proteins assume a crucial mechanical role in the terminal stage of membrane fusion that is likely to be conserved at multiple steps of vesicular traffic. We therefore propose that SNAREs and tethering proteins should be considered as a single, non-dissociable device that drives fusion. The core fusion machinery may then be larger and more complex than previously thought.

Observing Formation of Flux Rope by Tether-cutting Reconnection in the Sun

Energy Technology Data Exchange (ETDEWEB)

Xue, Zhike; Yan, Xiaoli; Yang, Liheng; Wang, Jincheng; Zhao, Li, E-mail: zkxue@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, Kunming Yunnan 650216 (China)

2017-05-10

Tether-cutting reconnection is considered as one mechanism for the formation of a flux rope. It has been proposed for more than 30 years; however, so far, direct observations of it are very rare. In this Letter, we present observations of the formation of a flux rope via tether-cutting reconnection in NOAA AR 11967 on 2014 February 2 by combining observations with the New Vacuum Solar Telescope and the Solar Dynamic Observatory . The tether-cutting reconnection occurs between two sets of highly sheared magnetic arcades. Comprehensive observational evidence of the reconnection is as follows: changes of the connections between the arcades, brightenings at the reconnection site, hot outflows, formation of a flux rope, slow-rise motion of the flux rope, and flux cancelation. The outflows are along three directions from the reconnection site to the footpoints with the velocities from 24 ± 1 km s{sup −1} to 69 ± 5 km s{sup −1}. Additionally, it is found that the newly formed flux rope connects far footpoints and has a left-handed twisted structure with many fine threads and a concave-up-shape structure in the middle. All the observations are in agreement with the tether-cutting model and provide evidence that tether-cutting reconnection leads to the formation of the flux rope associated with flux shear flow and cancelation.

Cord Blood

Directory of Open Access Journals (Sweden)

Saeed Abroun

2014-05-01

Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

Relaxation Dynamics of Nanoparticle-Tethered Polymer Chains

KAUST Repository

Kim, Sung A; Mangal, Rahul; Archer, Lynden A.

2015-01-01

© 2015 American Chemical Society. Relaxation dynamics of nanoparticle-tethered cis-1,4-polyisoprene (PI) are investigated using dielectric spectroscopy and rheometry. A model system composed of polymer chains densely grafted to spherical SiO2

Phobos L1 Operational Tether Experiment (PHLOTE)

Data.gov (United States)

National Aeronautics and Space Administration — A sensor package that “floats” just above the surface of Phobos, suspended by a tether from a small spacecraft operating at the Mars/Phobos Lagrange 1 (L1) Point...

Unilateral pedicle screws asymmetric tethering: an innovative method to create idiopathic deformity

Directory of Open Access Journals (Sweden)

Zhang Xuesong

2007-10-01

Full Text Available Abstract Objective To evaluate the feasibility of the method that unilateral pedicle screws asymmetric tethering in concave side in combination with convex rib resection for creating idiopathic deformity. Summary of background data Various methods are performed to create idiopathic deformity. Among these methods, posterior asmmetric tethering of the spine shows satisfying result, but some drawbacks related to the current posterior asymmetric tether were still evident. Materials and methods Unilateral pedicle screws asymmetric tethering was performed to 14 female goats (age: 5–8 week-old, weight: 6–8 kg in concave side in combination with convex rib resection. Dorsoventral and lateral plain radiographs were taken of each thoracic spine in the frontal and sagittal planes right after the surgery and later every 4 weeks. Results All animals ambulated freely after surgery. For technical reasons, 2 goats were excluded (one animal died for anesthetic during the surgery, and one animal was lost for instrumental fail due to postoperative infection. Radiography showed that 11 goats exhibited scoliosis with convex toward to the right side, and as the curve increased with time, only 1 goat showed nonprogressive. The initial scoliosis generated in the progressors after the procedures measured 29.0° on average (range 23.0°–38.5° and increased to 43.0° on average (range 36.0°–58.0° over 8 to 10 weeks. The average progression of 14.0° was measured. The curvature immediately after tethering surgery (the initial Cobb angle did have a highly significant correlation with the final curvature (p Conclusion Unilateral pedicle screws asymmetric tethering is a practical method to create experimental scoliosis, especially for those who would like to study the correction of this deformity.

Titanium-tethered vancomycin prevents resistance to rifampicin in Staphylococcus aureus in vitro.

Directory of Open Access Journals (Sweden)

Martin Rottman

Full Text Available Rifampicin is currently recognized as the most potent drug against Gram positive implant related infections. The use of rifampicin is limited by the emergence of bacterial resistance, which is often managed by coadministration of a second antibiotic. The purpose of this study was to determine the effectiveness of soluble rifampicin in combination with vancomycin tethered to titanium metal as a means to control bacterial growth and resistance in vitro. Bacterial growth was inhibited when the vancomycin-tethered titanium discs were treated with Staphylococcus aureus inocula of ≤2×10⁶ CFU, however inocula greater than 2×10⁶ CFU/disc adhered and survived. The combination of surface-tethered vancomycin with soluble rifampicin enhanced the inhibitory effect of rifampicin for an inoculum of 10⁶ CFU/cm² by one dilution (combination MIC of 0.008 mg/L versus 0.015 mg/L for rifampicin alone. Moreover, surface tethered vancomycin prevented the emergence of a rifampicin resistant population in an inoculum of 2×10⁸ CFU.

Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

Directory of Open Access Journals (Sweden)

Amir-Mohammad Armanian

2017-05-01

Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

Two-Stage Winch for Kites and Tethered Balloons or Blimps

Science.gov (United States)

Miles, Ted; Bland, Geoff

2011-01-01

A winch system provides a method for launch and recovery capabilities for kites and tethered blimps or balloons. Low power consumption is a key objective, as well as low weight for portability. This is accomplished by decoupling the tether-line storage and wind ing/ unwinding functions, and providing tailored and efficient mechanisms for each. The components of this system include rotational power input devices such as electric motors or other apparatus, line winding/unwinding reel(s), line storage reel(s), and independent drive trains. Power is applied to the wind/unwind reels to transport the tether line. Power is also applied to a line storage reel, from either the wind/unwind power source, the wind/unwind reel itself, or separate power source. The speeds of the two reels are synchronized, but not dependent on each other. This is accomplished via clutch mechanisms, variable transmissions, or independent motor controls. The speed of the storage reel is modulated as the effective diameter of the reel changes with line accumulation.

FCAPD Protective Coating for Space Tethers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Alameda Applied Sciences Corporation (AASC) proposes to demonstrate extended service lifetime of space tethers in the Low Earth Orbit (LEO) environment by using...

Clinical Evidence for Spinal Cord Stimulation for Failed Back Surgery Syndrome (FBSS): Systematic Review.

Science.gov (United States)

Kapural, Leonardo; Peterson, Erika; Provenzano, David A; Staats, Peter

2017-07-15

A systematic review. A systematic literature review of the clinical data from prospective studies was undertaken to assess the efficacy of spinal cord stimulation (SCS) in the treatment of failed back surgery syndrome (FBSS) in adults. For patients with unrelenting back pain due to mechanical instability of the spine, degenerative disc disease, spinal injury, or deformity, spinal surgery is a well-accepted treatment option; however, even after surgical intervention, many patients continue to experience chronic back pain that can be notoriously difficult to treat. Clinical evidence suggests that for patients with FBSS, repeated surgery will not likely offer relief. Additionally, evidence suggests long-term use of opioid pain medications is not effective in this population, likely presents additional complications, and requires strict management. A systematic literature review was performed using several bibliographic databases, prospective studies in adults using SCS for FBSS were included. SCS has been shown to be a safe and efficacious treatment for this patient population. Recent technological developments in SCS offer even greater pain relief to patients' refractory to other treatment options, allowing patients to regain functionality and improve their quality of life with significant reductions in pain. N/A.

Case Report: Cervical Klippel-Feil syndrome predisposing an ...

African Journals Online (AJOL)

Case Report: Cervical Klippel-Feil syndrome predisposing an elderly African man to central cord myelopathy following minor trauma. ... unique presentation of this case of Klippel-Feil syndrome further supports the impression that following fusion (congenital or acquired) of one segment of the spinal column, hypermobility of ...

The ATPases of cohesin interface with regulators to modulate cohesin-mediated DNA tethering

Science.gov (United States)

Çamdere, Gamze; Guacci, Vincent; Stricklin, Jeremiah; Koshland, Douglas

2015-01-01

Cohesin tethers together regions of DNA, thereby mediating higher order chromatin organization that is critical for sister chromatid cohesion, DNA repair and transcriptional regulation. Cohesin contains a heterodimeric ATP-binding Cassette (ABC) ATPase comprised of Smc1 and Smc3 ATPase active sites. These ATPases are required for cohesin to bind DNA. Cohesin’s DNA binding activity is also promoted by the Eco1 acetyltransferase and inhibited by Wpl1. Recently we showed that after cohesin stably binds DNA, a second step is required for DNA tethering. This second step is also controlled by Eco1 acetylation. Here, we use genetic and biochemical analyses to show that this second DNA tethering step is regulated by cohesin ATPase. Furthermore, our results also suggest that Eco1 promotes cohesion by modulating the ATPase cycle of DNA-bound cohesin in a state that is permissive for DNA tethering and refractory to Wpl1 inhibition. DOI: http://dx.doi.org/10.7554/eLife.11315.001 PMID:26583750

The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

Energy Technology Data Exchange (ETDEWEB)

Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A. [Department of Mechanical Engineering, University of Sheffield, Mappin St., Sheffield, S1 3JD, England (United Kingdom)

2014-12-10

The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design.

The mechanics of motorised momentum exchange tethers when applied to active debris removal from LEO

International Nuclear Information System (INIS)

Caldecott, Ralph; Kamarulzaman, Dayangku N. S.; Kirrane, James P.; Cartmell, Matthew P.; Ganilova, Olga A.

2014-01-01

The concept of momentum exchange when applied to space tethers for propulsion is well established, and a considerable body of literature now exists on the on-orbit modelling, the dynamics, and also the control of a large range of tether system applications. The authors consider here a new application for the Motorised Momentum Exchange Tether by highlighting three key stages of development leading to a conceptualisation that can subsequently be developed into a technology for Active Debris Removal. The paper starts with a study of the on-orbit mechanics of a full sized motorised tether in which it is shown that a laden and therefore highly massasymmetrical tether can still be forced to spin, and certainly to librate, thereby confirming its possible usefulness for active debris removal (ADR). The second part of the paper concentrates on the modelling of the centripetal deployment of a symmetrical MMET in order to get it initialized for debris removal operations, and the third and final part of the paper provides an entry into scale modelling for low cost mission design and testing. It is shown that the motorised momentum exchange tether offers a potential solution to the removal of large pieces of orbital debris, and that dynamic methodologies can be implemented to in order to optimise the emergent design

Electrodynamic Tethers and E-Sails as Active Experiment Testbeds and Technologies in Space

Science.gov (United States)

Gilchrist, B. E.; Wiegmann, B.; Johnson, L.; Bilen, S. G.; Habash Krause, L.; Miars, G.; Leon, O.

2017-12-01

The use of small-to-large flexible structures in space such as tethers continues to be studied for scientific and technology applications. Here we will consider tether electrodynamic and electrostatic interactions with magneto-plasmas in ionospheres, magnetospheres, and interplanetary space. These systems are enabling fundamental studies of basic plasma physics phenomena, allowing direct studies of the space environment, and generating technological applications beneficial for science missions. Electrodynamic tethers can drive current through the tether based on the Lorenz force adding or extracting energy from its orbit allowing for the study of charged bodies or plasma plumes moving through meso-sonic magnetoplasmas [1]. Technologically, this also generates propulsive forces requiring no propellant and little or no consumables in any planetary system with a magnetic field and ionosphere, e.g., Jupiter [2]. Further, so called electric sails (E-sails) are being studied to provide thrust through momentum exchange with the hypersonic solar wind. The E-sail uses multiple, very long (10s of km) charged, mostly bare rotating conducting tethers to deflect solar wind protons. It is estimated that a spacecraft could achieve a velocity over 100 km/s with time [3,4]. 1. Banks, P.M., "Review of electrodynamic tethers for space plasma science," J. Spacecraft and Rockets, vol. 26, no. 4, pp. 234-239, 1989. 2. Talley, C., J. Moore, D. Gallagher, and L. Johnson, "Propulsion and power from a rotating electrodynamic tether at Jupiter," 38th AIAA Aerospace Sciences Meeting and Exhibit, January 2000. 3. Janhunen, P., "The electric sail—A new propulsion method which may enable fast missions to the outer solar system," J. British Interpl. Soc., vol. 61, no. 8, pp. 322-325, 2008. 4. Wiegman, B., T. Scheider, A. Heaton, J. Vaughn, N. Stone, and K. Wright, "The Heliopause Electrostatic Rapid Transit System (HERTS)—Design, trades, and analyses performed in a two-year NASA investigation

Tethered Aerostat Effects on Nearby Seismometers

Energy Technology Data Exchange (ETDEWEB)

Bowman, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-12-01

This report assesses seismic interference generated by a tethered aerostat. The study was motivated by a planned aerostat deployment within the footprint of the Dry Alluvium Geology seismic network. No evidence was found for seismic interference generated by the aerostat, and thus the e ects on the Dry Alluvium Geology sensors will be negligible.

Template-directed ligation of tethered mononucleotides by t4 DNA ligase for kinase ribozyme selection.

Directory of Open Access Journals (Sweden)

David G Nickens

Full Text Available BACKGROUND: In vitro selection of kinase ribozymes for small molecule metabolites, such as free nucleosides, will require partition systems that discriminate active from inactive RNA species. While nucleic acid catalysis of phosphoryl transfer is well established for phosphorylation of 5' or 2' OH of oligonucleotide substrates, phosphorylation of diffusible small molecules has not been demonstrated. METHODOLOGY/PRINCIPAL FINDINGS: This study demonstrates the ability of T4 DNA ligase to capture RNA strands in which a tethered monodeoxynucleoside has acquired a 5' phosphate. The ligation reaction therefore mimics the partition step of a selection for nucleoside kinase (deoxyribozymes. Ligation with tethered substrates was considerably slower than with nicked, fully duplex DNA, even though the deoxynucleotides at the ligation junction were Watson-Crick base paired in the tethered substrate. Ligation increased markedly when the bridging template strand contained unpaired spacer nucleotides across from the flexible tether, according to the trends: A(2>A(1>A(3>A(4>A(0>A(6>A(8>A(10 and T(2>T(3>T(4>T(6 approximately T(1>T(8>T(10. Bridging T's generally gave higher yield of ligated product than bridging A's. ATP concentrations above 33 microM accumulated adenylated intermediate and decreased yields of the gap-sealed product, likely due to re-adenylation of dissociated enzyme. Under optimized conditions, T4 DNA ligase efficiently (>90% joined a correctly paired, or TratioG wobble-paired, substrate on the 3' side of the ligation junction while discriminating approximately 100-fold against most mispaired substrates. Tethered dC and dG gave the highest ligation rates and yields, followed by tethered deoxyinosine (dI and dT, with the slowest reactions for tethered dA. The same kinetic trends were observed in ligase-mediated capture in complex reaction mixtures with multiple substrates. The "universal" analog 5-nitroindole (dNI did not support ligation when

Pain and spinal cord imaging measures in children with demyelinating disease

Directory of Open Access Journals (Sweden)

Nadia Barakat

2015-01-01

Full Text Available Pain is a significant problem in diseases affecting the spinal cord, including demyelinating disease. To date, studies have examined the reliability of clinical measures for assessing and classifying the severity of spinal cord injury (SCI and also to evaluate SCI-related pain. Most of this research has focused on adult populations and patients with traumatic injuries. Little research exists regarding pediatric spinal cord demyelinating disease. One reason for this is the lack of reliable and useful approaches to measuring spinal cord changes since currently used diagnostic imaging has limited specificity for quantitative measures of demyelination. No single imaging technique demonstrates sufficiently high sensitivity or specificity to myelin, and strong correlation with clinical measures. However, recent advances in diffusion tensor imaging (DTI and magnetization transfer imaging (MTI measures are considered promising in providing increasingly useful and specific information on spinal cord damage. Findings from these quantitative imaging modalities correlate with the extent of demyelination and remyelination. These techniques may be of potential use for defining the evolution of the disease state, how it may affect specific spinal cord pathways, and contribute to the management of pediatric demyelination syndromes. Since pain is a major presenting symptom in patients with transverse myelitis, the disease is an ideal model to evaluate imaging methods to define these regional changes within the spinal cord. In this review we summarize (1 pediatric demyelinating conditions affecting the spinal cord; (2 their distinguishing features; and (3 current diagnostic and classification methods with particular focus on pain pathways. We also focus on concepts that are essential in developing strategies for the detection, monitoring, treatment and repair of pediatric myelitis.

STICS: surface-tethered iterative carbohydrate synthesis.

Science.gov (United States)

Pornsuriyasak, Papapida; Ranade, Sneha C; Li, Aixiao; Parlato, M Cristina; Sims, Charles R; Shulga, Olga V; Stine, Keith J; Demchenko, Alexei V

2009-04-14

A new surface-tethered iterative carbohydrate synthesis (STICS) technology is presented in which a surface functionalized 'stick' made of chemically stable high surface area porous gold allows one to perform cost efficient and simple synthesis of oligosaccharide chains; at the end of the synthesis, the oligosaccharide can be cleaved off and the stick reused for subsequent syntheses.

Hierarchical Structure in Semicrystalline Polymers Tethered to Nanospheres

KAUST Repository

Kim, Sung A; Archer, Lynden A.

2014-01-01

We report on structural and dynamic transitions of polymers tethered to nanoparticles. In particular, we use X-ray diffraction, vibrational spectroscopy, and thermal measurements to investigate multiscale structure and dynamic transitions of poly

Biomechanical simulations of costo-vertebral and anterior vertebral body tethers for the fusionless treatment of pediatric scoliosis.

Science.gov (United States)

Aubin, Carl-Éric; Clin, Julien; Rawlinson, Jeremy

2018-01-01

Compression-based fusionless tethers are an alternative to conventional surgical treatments of pediatric scoliosis. Anterior approaches place an anterior (ANT) tether on the anterolateral convexity of the deformed spine to modify growth. Posterior, or costo-vertebral (CV), approaches have not been assessed for biomechanical and corrective effectiveness. The objective was to biomechanically assess CV and ANT tethers using six patient-specific, finite element models of adolescent scoliotic patients (11.9 ± 0.7 years, Cobb 34° ± 10°). A validated algorithm simulated the growth and Hueter-Volkmann growth modulation over a period of 2 years with the CV and ANT tethers at two initial tensions (100, 200 N). The models without tethering also simulated deformity progression with Cobb angle increasing from 34° to 56°, axial rotation 11° to 13°, and kyphosis 28° to 32° (mean values). With the CV tether, the Cobb angle was reduced to 27° and 20° for tensions of 100 and 200 N, respectively, kyphosis to 21° and 19°, and no change in axial rotation. With the ANT tether, Cobb was reduced to 32° and 9° for 100 and 200 N, respectively, kyphosis unchanged, and axial rotation to 3° and 0°. While the CV tether mildly corrected the coronal curve over a 2-year growth period, it had sagittal lordosing effect, particularly with increasing initial axial rotation (>15°). The ANT tether achieved coronal correction, maintained kyphosis, and reduced the axial rotation, but over-correction was simulated at higher initial tensions. This biomechanical study captured the differences between a CV and ANT tether and indicated the variability arising from the patient-specific characteristics. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:254-264, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Manipulating neuronal circuits with endogenous and recombinant cell-surface tethered modulators

Directory of Open Access Journals (Sweden)

Mandë Holford

2009-10-01

Full Text Available Neuronal circuits depend on the precise regulation of cell-surface receptors and ion channels. An ongoing challenge in neuroscience research is deciphering the functional contribution of specific receptors and ion channels using engineered modulators. A novel strategy, termed “tethered toxins”, was recently developed to characterize neuronal circuits using the evolutionary derived selectivity of venom peptide toxins and endogenous peptide ligands, such as lynx1 prototoxins. Herein, the discovery and engineering of cell-surface tethered peptides is reviewed, with particular attention given to their cell-autonomy, modular composition, and genetic targeting in different model organisms. The relative ease with which tethered peptides can be engineered, coupled with the increasing number of neuroactive venom toxins and ligand peptides being discovered, imply a multitude of potentially innovative applications for manipulating neuronal circuits and tissue-specific cell networks, including treatment of disorders caused by malfunction of receptors and ion channels.

Neurogenic bladder in Hunter's syndrome.

Science.gov (United States)

Koyama, K; Moda, Y; Sone, A; Tanaka, H; Hino, Y

1994-01-01

We encountered a rare patient with Hunter's syndrome who exhibited urinary retention as a result of a neurogenic bladder, uninhibited detrusor contractions, and detrusor-sphincter dyssynergia. Neurological findings were consistent with cervical myelopathy and cervical MR imaging showed very narrow segments at the cord level C2-4. We speculate that this Hunter's syndrome patient has cervical myelopathy and that this neurological dysfunction causes the neurogenic bladder. PMID:8014981

Position Control of an X4-Flyer Using a Tether

Directory of Open Access Journals (Sweden)

Yusuke Ouchi

2016-05-01

Full Text Available In Japan, aging of infrastructures, such as roads,bridges, and water and sewer services, etc. poses a problem, andit is required to extend the life-span of such infrastructures bymaintenance. Among infrastructures, especially bridges areperiodically inspected by short range visual observations, whichcheck the damage and deterioration of the surface. However,since there are some cases where the short range visualobservation is difficult, an alternative method is required so as toreplace the short range visual observation with it. So, "X4-Flyer"is very attractive because of realizing a movement at high altitudeeasily. The objective of this study is to develop a tethered X4-Flyer, so that the conventional short range visual observation ofbridges is replaced by it. In this paper, a method for themeasurement and control of the position is described by using atether for controlling the position of the X4-Flyer. In addition, itis checked whether the tethered X4-Flyer can control the positionusing the proposed method or not, letting it fly in a state in whicha tether is being attached

Tethered elevator: A unique opportunity for space processing

Science.gov (United States)

Monti, R.

1986-01-01

The latest fluid dynamic and material science experiments in the microgravity environment have emphasized the importance of the residual gravity level and of the g-jitter on fluid physics phenomena. The tethered elevator presents the possibility of providing variable g-levels (both steady and g-jitter) around a very low steady g-level (that can be realized when the elevator is near the center of mass of the space station-tether complex). When positioning a variable periodic oscillation to the payload a clean g-jitter disturbance can be obtained that would not be otherwise obtainable by other systems. These two possibilities make the elevator a facility to help resolve a number of still open questions that are preventing wider utilization of the space environment in the microgravity area.

Spinal cord contusion.

Science.gov (United States)

Ju, Gong; Wang, Jian; Wang, Yazhou; Zhao, Xianghui

2014-04-15

Spinal cord injury is a major cause of disability with devastating neurological outcomes and limited therapeutic opportunities, even though there are thousands of publications on spinal cord injury annually. There are two major types of spinal cord injury, transaction of the spinal cord and spinal cord contusion. Both can theoretically be treated, but there is no well documented treatment in human being. As for spinal cord contusion, we have developed an operation with fabulous result.

Tethered Nanoparticle–Polymer Composites: Phase Stability and Curvature

KAUST Repository

Srivastava, Samanvaya; Agarwal, Praveen; Archer, Lynden A.

2012-01-01

different small-angle X-ray scattering signatures in comparison to phase-separated composites comprised of bare or sparsely grafted nanoparticles. A general diagram for the dispersion state and phase stability of polymer tethered nanoparticle-polymer

Dynamics Model for a Multi-Tethered Space-Based Interferometer

National Research Council Canada - National Science Library

Gates, Stephen

2000-01-01

.... Tether constitutive behavior is discussed. Prescribed motion of any system degrees of freedom is treated, and expressions for the corresponding constraint force/torque components are established.

Genetics Home Reference: Meckel syndrome

Science.gov (United States)

... when a structure called the neural tube, a layer of cells that ultimately develops into the brain and spinal cord, fails to close completely during the first few weeks of embryonic development. Meckel syndrome can also cause problems with ...

Ionic-Liquid-Tethered Nanoparticles: Hybrid Electrolytes

KAUST Repository

Moganty, Surya S.

2010-10-22

A new class of solventless electrolytes was created by tethering ionic liquids to hard inorganic ZrO2 nanostructures (see picture; NIM=nanoscale ionic material). These hybrid fluids exhibit exceptional redox stability windows, excellent thermal stability, good lithium transference numbers, long-term interfacial stability in the presence of a lithium anode and, when doped with lithium salt, reasonable ionic conductivities.

System Dynamics and Feedforward Control for Tether-Net Space Robot System

Directory of Open Access Journals (Sweden)

Guang Zhai

2009-06-01

Full Text Available A new concept using flexible tether-net system to capture space debris is presented in this paper. With a mass point assumption the tether-net system dynamic model is established in orbital frame by applying Lagrange Equations. In order to investigate the net in-plane trajectories during after cast, the non-control R-bar and V-bar captures are simulated with ignoring the out-of-plane libration, the effect of in-plane libration on the trajectories of the capture net is demonstrated by simulation results. With an effort to damp the in-plane libration, the control scheme based on tether tension is investigated firstly, after that an integrated control scheme is proposed by introduced the thrusters into the system, the nonlinear close-loop dynamics is linearised by feedforward strategy, the simulation results show that feedforward controllor is effective for in-plane libration damping and enable the capture net to track an expected trajectory.

Application of the NASCAP Spacecraft Simulation Tool to Investigate Electrodynamic Tether Current Collection in LEO

Science.gov (United States)

Adams, Mitzi; HabashKrause, Linda

2012-01-01

Recent interest in using electrodynamic tethers (EDTs) for orbital maneuvering in Low Earth Orbit (LEO) has prompted the development of the Marshall ElectroDynamic Tether Orbit Propagator (MEDTOP) model. The model is comprised of several modules which address various aspects of EDT propulsion, including calculation of state vectors using a standard orbit propagator (e.g., J2), an atmospheric drag model, realistic ionospheric and magnetic field models, space weather effects, and tether librations. The natural electromotive force (EMF) attained during a radially-aligned conductive tether results in electrons flowing down the tether and accumulating on the lower-altitude spacecraft. The energy that drives this EMF is sourced from the orbital energy of the system; thus, EDTs are often proposed as de-orbiting systems. However, when the current is reversed using satellite charged particle sources, then propulsion is possible. One of the most difficult challenges of the modeling effort is to ascertain the equivalent circuit between the spacecraft and the ionospheric plasma. The present study investigates the use of the NASA Charging Analyzer Program (NASCAP) to calculate currents to and from the tethered satellites and the ionospheric plasma. NASCAP is a sophisticated set of computational tools to model the surface charging of three-dimensional (3D) spacecraft surfaces in a time-varying space environment. The model's surface is tessellated into a collection of facets, and NASCAP calculates currents and potentials for each one. Additionally, NASCAP provides for the construction of one or more nested grids to calculate space potential and time-varying electric fields. This provides for the capability to track individual particles orbits, to model charged particle wakes, and to incorporate external charged particle sources. With this study, we have developed a model of calculating currents incident onto an electrodynamic tethered satellite system, and first results are shown

Spinal cheiro-oral syndrome: a common neurological entity in an unusual site.

Science.gov (United States)

Lin, Hung-Sheng; Yin, Hsin-Ling; Chui, Chi; Lui, Chun-Chung; Chen, Wei-Hsi

2011-01-01

Cheiro-oral syndrome (COS) is an established neurological entity characterized by a sensory impairment confined to the mouth angle and ipsilateral finger(s)/ hand. The current understanding of localization is a concomitant involvement of the spinothalamic and trigeminothalamic tract between the cortex and pons. The cervical spinal cord has not been mentioned in this situation yet, and this unusual location may heretofore increase the risk of misdiagnosis. Six patients who presented with unilateral COS due to cervical cord disorder are reported. All patients were women and their age ranged between 42 and 70 years. Their neurological deficits included unilateral paraesthesiae restricted to cheirooral distribution, positive radicular sign, and mild change of tendon reflex. Cervical spinal stenosis at middle/lower cervical spine with variable magnitude of cord compression and intrinsic cord damage was found. A diagnostic dilemma obviously arises from the lack of tangible neurological signs or typical pattern of myelopathy, in addition to the previous concept of cerebral involvement. A benign course ensued in all reported patients. Cheiro-oral syndrome can be an early neurological sign for cervical cord disorder; it further suggests that it is a strong neurological but weak localizing sign. A reciprocal influence of multiple factors is considered to generate COS at the cervical cord. Therefore, an absence of brain pathology should lead to a thorough examination of the cervical cord in case of COS.

Long distance cell communication using spherical tether balloons

Science.gov (United States)

Manchanda, R. K.; Rajagopalan, Vasudevan; Vasudevan, Rajagopalan; Mehrotra, R. K.; Sreenivasan, S.; Pawaskar, M.; Subba Rao Jonnalagadda, Venkata; Buduru, Suneelkumar; Kulkarni, P. M.

A proof-of-concept experiment was conducted for long-range cell communication for rural tele-phony and internet. We designed and fabricated a spherical tether balloon to carry the con-ventional micro base transceiver station (BTS) along with three slotted antenna to cover 2-pi radius. AC power and optical fiber were anchored along with the tether line. A special fre-quency license was obtained from Wireless Planning Commission (WPC) wing of Department of Telecommunication (DoT), India for the period of experiment so as not to affect the opera-tional networks. The experiments were carried out for different BTS heights up to 500 meter. Signal measurement both in data mode and voice quality were done in different quadrant using mobile vans. This paper describes the methodology (under patenting) and utility of technique for operational application.

Tethered "kiteplane" design for the Laddermill project

NARCIS (Netherlands)

Breukels, J.; Ockels, W.

2005-01-01

The Laddermill is an innovative concept for generating energy from wind using large kite-like wings on a tether. The wings are able to fly in both the regime of airplanes and kites. We therefore call these structures "kiteplanes". By providing a recurring motion with a large lift during ascending

Acute Thoracolumbar Spinal Cord Injury: Relationship of Cord Compression to Neurological Outcome.

Science.gov (United States)

Skeers, Peta; Battistuzzo, Camila R; Clark, Jillian M; Bernard, Stephen; Freeman, Brian J C; Batchelor, Peter E

2018-02-21

Spinal cord injury in the cervical spine is commonly accompanied by cord compression and urgent surgical decompression may improve neurological recovery. However, the extent of spinal cord compression and its relationship to neurological recovery following traumatic thoracolumbar spinal cord injury is unclear. The purpose of this study was to quantify maximum cord compression following thoracolumbar spinal cord injury and to assess the relationship among cord compression, cord swelling, and eventual clinical outcome. The medical records of patients who were 15 to 70 years of age, were admitted with a traumatic thoracolumbar spinal cord injury (T1 to L1), and underwent a spinal surgical procedure were examined. Patients with penetrating injuries and multitrauma were excluded. Maximal osseous canal compromise and maximal spinal cord compression were measured on preoperative mid-sagittal computed tomography (CT) scans and T2-weighted magnetic resonance imaging (MRI) by observers blinded to patient outcome. The American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades from acute hospital admission (≤24 hours of injury) and rehabilitation discharge were used to measure clinical outcome. Relationships among spinal cord compression, canal compromise, and initial and final AIS grades were assessed via univariate and multivariate analyses. Fifty-three patients with thoracolumbar spinal cord injury were included in this study. The overall mean maximal spinal cord compression (and standard deviation) was 40% ± 21%. There was a significant relationship between median spinal cord compression and final AIS grade, with grade-A patients (complete injury) exhibiting greater compression than grade-C and D patients (incomplete injury) (p compression as independently influencing the likelihood of complete spinal cord injury (p compression. Greater cord compression is associated with an increased likelihood of severe neurological deficits (complete injury) following

Variation in anisotropy and diffusivity along the medulla oblongata and the whole spinal cord in adolescent idiopathic scoliosis: a pilot study using diffusion tensor imaging.

Science.gov (United States)

Kong, Y; Shi, L; Hui, S C N; Wang, D; Deng, M; Chu, W C W; Cheng, J C Y

2014-08-01

Disturbed somatosensory evoked potentials have been demonstrated in patients with adolescent idiopathic scoliosis (but this functional delay was found to originate above the C5-6 level, while the lower cord level was unaffected). Together with MR imaging observation of tonsillar ectopia and a relatively tethered cord, we hypothesized that there is disturbed mean diffusivity integrity along the spinal cord. In this study, advanced DTI was used to evaluate whether there was underlying decreased WM integrity within the brain stem and spinal cord in adolescent idiopathic scoliosis and any relationship to cerebellar tonsillar ectopia. Clinical impact on balance testing was also correlated. Thirteen girls with adolescent idiopathic scoliosis with right thoracic curves were compared with 13 age-matched healthy girls. DTI of the brain and whole spinal cord was performed. ROIs were manually defined for the medulla oblongata and along each intervertebral segment of the cord. Mean values of fractional anisotropy and mean diffusivity were computed at the defined regions. Between-group comparisons were performed by 1-way ANOVA. Significantly decreased fractional anisotropy values and increased mean diffusivity values were found at the medulla oblongata and C1-2, C2-3, C3-4, and C4-5 segments in patients with adolescent idiopathic scoliosis compared with healthy subjects. No significant difference was found in the lower cord levels. Significant correlation was found between the tonsillar level and fractional anisotropy value at the C4-5 level in patients with adolescent idiopathic scoliosis only. The findings from this study are in agreement with previous findings showing abnormal somatosensory evoked potential readings occurring only above the C5-6 level in patients with adolescent idiopathic scoliosis; these findings might partially explain the pathophysiology of the neural pathway involved. © 2014 by American Journal of Neuroradiology.

Lumbosacral lipoma : gadolinium-enhanced fat saturation T1 weighted MR image is necessary?

International Nuclear Information System (INIS)

Yoon, Man Won; Kim, Hyun Chul; Chung, Tae Woong; Seo, Jeong Jin; Chung, Gwang Woo; Kim, Yun Hyeon; Kim, Jae Kyu; Park, Jin Gyoon; Kang, Heoung Keun

1999-01-01

To evaluate the usefulness of contrast-enhanced fat saturation T1-weighted imaging for the evaluation of spinal lipoma, compared with clinical symptoms and surgical findings. Ten patients with lipomyelomeningocele, confirmed by surgery, were included in this study. In all cases, conventional spin echo T1-and T2-weighted MR imaging, and contrast-enhanced fat saturation T1-weighted imaging was performed to evaluate clinical symptoms, the position of the conus medullaris, the presence of cord tethering, and associated anomalies, and to compare the relative usefulness of the techniques. All ten patients were suffering from lipomyelomeningocele without filum terminale fibrolipoma or intradural lipoma. All cases were associated with cord tethering. As associated anomalies, there were seven cases of syringomyelia without hydrocephalus or anorectal anomaly. To evaluate the position of the spinal conus and the presence of cord tethering, conventional T1-weighted imaging was more useful than the contrast-enhanced fat saturation equivalent. In patients with early-stage spinal lipoma, MRI is useful for evaluation of the causes and position of cord tethering and associated anomalies Our results suggest that contrast-enhanced fat saturation T1-weighted images do not provide additional information concerning spinal lipoma, and that for the diagnosis of this condition, conventional T1 and T2-weighted images are more useful than those obtained by contrast-enhanced fat saturation T1-weighted imaging

Measurement of calcium influx in tethered rings of rabbit aorta under tension

International Nuclear Information System (INIS)

Gleason, M.M.; Ratz, P.H.; Flaim, S.F.

1985-01-01

Calcium (Ca) influx in vascular smooth muscle is routinely measured in untethered preparations not under passive stretch, and Ca influx data are correlated with data for steady-state isometric tension obtained under parallel conditions from tethered preparations under passive stretch. The validity of this method was tested by simultaneous measurement of Ca influx and tension in tethered rings of rabbit thoracic aorta. Ca influx ( 45 Ca 3-min pulse) and tension were measured at 3 and 30 min after norepinephrine (NE) or KCl and under control (no agonist) conditions. Active tension was significantly altered by variations in passive tension. Ca influx was unaffected by passive tension under control, NE, or KCl conditions, and results were similar at 3 and 30 min. The results confirm the validity of correlating Ca influx data from untethered rings with steady-state contractile response data obtained from tethered rings under similar experimental conditions

Differential Regulation of Synaptic Vesicle Tethering and Docking by UNC-18 and TOM-1.

Science.gov (United States)

Gracheva, Elena O; Maryon, Ed B; Berthelot-Grosjean, Martine; Richmond, Janet E

2010-01-01

The assembly of SNARE complexes between syntaxin, SNAP-25 and synaptobrevin is required to prime synaptic vesicles for fusion. Since Munc18 and tomosyn compete for syntaxin interactions, the interplay between these proteins is predicted to be important in regulating synaptic transmission. We explored this possibility, by examining genetic interactions between C. elegans unc-18(Munc18), unc-64(syntaxin) and tom-1(tomosyn). We have previously demonstrated that unc-18 mutants have reduced synaptic transmission, whereas tom-1 mutants exhibit enhanced release. Here we show that the unc-18 mutant release defect is associated with loss of two morphologically distinct vesicle pools; those tethered within 25 nm of the plasma membrane and those docked with the plasma membrane. In contrast, priming defective unc-13 mutants accumulate tethered vesicles, while docked vesicles are greatly reduced, indicating tethering is UNC-18-dependent and occurs in the absence of priming. C. elegans unc-64 mutants phenocopy unc-18 mutants, losing both tethered and docked vesicles, whereas overexpression of open syntaxin preferentially increases vesicle docking, suggesting UNC-18/closed syntaxin interactions are responsible for vesicle tethering. Given the competition between vertebrate tomosyn and Munc18, for syntaxin binding, we hypothesized that C. elegans TOM-1 may inhibit both UNC-18-dependent vesicle targeting steps. Consistent with this hypothesis, tom-1 mutants exhibit enhanced UNC-18 plasma membrane localization and a concomitant increase in both tethered and docked synaptic vesicles. Furthermore, in tom-1;unc-18 double mutants the docked, primed vesicle pool is preferentially rescued relative to unc-18 single mutants. Together these data provide evidence for the differential regulation of two vesicle targeting steps by UNC-18 and TOM-1 through competitive interactions with syntaxin.

Differential regulation of synaptic vesicle tethering and docking by UNC-18 and TOM-1

Directory of Open Access Journals (Sweden)

Elena O Gracheva

2010-10-01

Full Text Available The assembly of SNARE complexes between syntaxin, SNAP-25 and synaptobrevin is required to prime synaptic vesicles for fusion. Since Munc18 and tomosyn compete for syntaxin interactions, the interplay between these proteins is predicted to be important in regulating synaptic transmission. We explored this possibility, by examining genetic interactions between C. elegans unc-18(Munc18, unc-64(syntaxin and tom-1(tomosyn. We have previously demonstrated that unc-18 mutants have reduced synaptic transmission, whereas tom-1 mutants exhibit enhanced release. Here we show that the unc-18 mutant release defect is associated with loss of two morphologically distinct vesicle pools; those tethered within 25nm of the plasma membrane and those docked with the plasma membrane. In contrast, priming defective unc-13 mutants accumulate tethered vesicles, while docked vesicles are greatly reduced, indicating tethering is UNC-18-dependent and occurs in the absence of priming. C. elegans unc-64 mutants phenocopy unc-18 mutants, losing both tethered and docked vesicles, whereas overexpression of open syntaxin preferentially increases vesicle docking, suggesting UNC-18/closed syntaxin interactions are responsible for vesicle tethering. Given the competition between vertebrate tomosyn and Munc18, for syntaxin binding, we hypothesized that C. elegans TOM-1 may inhibit both UNC-18-dependent vesicle targeting steps. Consistent with this hypothesis, tom-1 mutants exhibit enhanced UNC-18 plasma membrane localization and a concomitant increase in both tethered and docked synaptic vesicles. Furthermore, in tom-1;unc-18 double mutants the docked, primed vesicle pool is preferentially rescued relative to unc-18 single mutants. Together these data provide evidence for the differential regulation of two vesicle targeting steps by UNC-18 and TOM-1 through competitive interactions with syntaxin

Acquisition of Ice-Tethered Profilers with Velocity (ITP-V) Instruments for Future Arctic Studies

Science.gov (United States)

2016-11-15

San Diego, CA, IEEE Xplore . Toole, J. M., R. A. Krishfield, M.-L. Timmennans, and A. Proshutinsky, 2011: The Ice-Tethered Profiler: Argo ofthe Arctic, Oceanogr., 24, 126-135. 4 ...observations from Ice-Tethered Profilers, MTS/ IEEE Oceans’ 2015, Washington DC, 1-10. Krishfield, R., J. Toole, A. Proshutinsky, and M.-L. Timmennans, 2008

Orbital Propagation of Momentum Exchange Tether Systems

Science.gov (United States)

Westerhoff, John

2002-01-01

An advanced concept in in-space transportation currently being studied is the Momentum-Exchange/Electrodynamic Reboost Tether System (MXER). The system acts as a large momentum wheel, imparting a Av to a payload in low earth orbit (LEO) at the expense of its own orbital energy. After throwing a payload, the system reboosts itself using an electrodynamic tether to push against Earth's magnetic field and brings itself back up to an operational orbit to prepare for the next payload. The ability to reboost itself allows for continued reuse of the system without the expenditure of propellants. Considering the cost of lifting propellant from the ,ground to LEO to do the same Av boost at $10000 per pound, the system cuts the launch cost of the payload dramatically, and subsequently, the MXER system pays for itself after a small number of missions.1 One of the technical hurdles to be overcome with the MXER concept is the rendezvous maneuver. The rendezvous window for the capture of the payload is on the order of a few seconds, as opposed to traditional docking maneuvers, which can take as long ets necessary to complete a precise docking. The payload, therefore, must be able to match its orbit to meet up with the capture device on the end of the tether at a specific time and location in the future. In order to be able to determine that location, the MXER system must be numerically propagated forward in time to predict where the capture device will be at that instant. It should be kept in mind that the propagation computation must be done faster than real-time. This study focuses on the efforts to find and/or build the tools necessary to numerically propagate the motion of the MXER system as accurately as possible.

Space webs based on rotating tethered formations

Science.gov (United States)

Palmerini, Giovanni B.; Sgubini, Silvano; Sabatini, Marco

2009-07-01

Several on-going studies indicate the interest for large, light orbiting structures, shaped as fish nets or webs: along the ropes of the web small spacecraft can move like spiders to position and re-locate, at will, pieces of hardware devoted to specific missions. The concept could be considered as an intermediate solution between the large monolithic structure, heavy and expensive to realize, but easy to control, and the formations of satellites, where all system members are completely free and should manoeuvre in order to acquire a desired configuration. Instead, the advantage of having a "hard-but-light" link among the different grids lays in the partition of the tasks among system components and in a possible overall reduction of the control system complexity and cost. Unfortunately, there is no stable configuration for an orbiting, two-dimensional web made by light, flexible tethers which cannot support compression forces. A possible solution is to make use of centrifugal forces to pull the net, with a reduced number of simple thrusters located at the tips of the tethers to initially acquire the required spin. In this paper a dynamic analysis of a simplified rotating web is performed, in order to evaluate the spinning velocity able to satisfy the requirement for the stability of the system. The model adopted overlaps simpler elements, each of them given by a tether (made up of a number of linear finite elements) connecting two extreme bodies accommodating the spinning thrusters. The combination of these "diameter-like" elements provides the web, shaped according to the specific requirements. The net is primarily considered as subjected to Keplerian attraction and J2 and drag perturbations only, but its behaviour under thermal inputs is also investigated.

Cervical disc herniation manifesting as a Brown-Sequard syndrome

Directory of Open Access Journals (Sweden)

Kunio Yokoyama

2012-01-01

Full Text Available Brown-Sequard syndrome is commonly seen in the setting of spinal trauma or an extramedullary spinal neoplasm. The clinical picture reflects hemisection of the spinal cord. We report a rare case of Brown-Sequard syndrome caused by a large cervical herniated disc. A 63-year-old man presented with progressive right hemiparesis and disruption of pain and temperature sensation on the left side of the body. Magnetic resonance imaging showed large C3-C4 disc herniation compressing the spinal cord at that level, with severe canal stenosis from C4 through C7. Decompressive cervical laminoplasty was performed. After surgery, complete sensory function was restored and a marked improvement in motor power was obtained.

Cord Blood and Transplants

Science.gov (United States)

... donate their baby’s umbilical cord blood to a public cord blood bank. We have more than 249,000 cord blood ... stored as a cord blood unit at a public cord blood bank for future use. It can then be listed ...

The shear flow processing of controlled DNA tethering and stretching for organic molecular electronics.

Science.gov (United States)

Yu, Guihua; Kushwaha, Amit; Lee, Jungkyu K; Shaqfeh, Eric S G; Bao, Zhenan

2011-01-25

DNA has been recently explored as a powerful tool for developing molecular scaffolds for making reproducible and reliable metal contacts to single organic semiconducting molecules. A critical step in the process of exploiting DNA-organic molecule-DNA (DOD) array structures is the controlled tethering and stretching of DNA molecules. Here we report the development of reproducible surface chemistry for tethering DNA molecules at tunable density and demonstrate shear flow processing as a rationally controlled approach for stretching/aligning DNA molecules of various lengths. Through enzymatic cleavage of λ-phage DNA to yield a series of DNA chains of various lengths from 17.3 μm down to 4.2 μm, we have investigated the flow/extension behavior of these tethered DNA molecules under different flow strengths in the flow-gradient plane. We compared Brownian dynamic simulations for the flow dynamics of tethered λ-DNA in shear, and found our flow-gradient plane experimental results matched well with our bead-spring simulations. The shear flow processing demonstrated in our studies represents a controllable approach for tethering and stretching DNA molecules of various lengths. Together with further metallization of DNA chains within DOD structures, this bottom-up approach can potentially enable efficient and reliable fabrication of large-scale nanoelectronic devices based on single organic molecules, therefore opening opportunities in both fundamental understanding of charge transport at the single molecular level and many exciting applications for ever-shrinking molecular circuits.

Calculating Payload for a Tethered Balloon System

Science.gov (United States)

Charles D. Tangren

1980-01-01

A graph method to calculate payload for a tethered balloon system, with the supporting helium lift and payload equations. is described. The balloon system is designed to collect emissions data during the convective-lift and no-convective-lift phases of a forest fire. A description of the balloon system and a list of factors affecting balloon selection are included....

Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

Science.gov (United States)

Shen, Haijun; Roithmayr, Carlos M.

2015-01-01

Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

Stability control of a flexible maneuverable tethered space net robot

Science.gov (United States)

Zhang, Fan; Huang, Panfeng

2018-04-01

As a promising solution for active space debris capture and removal, a maneuverable Tethered Space Net Robot (TSNR) is proposed as an improved Space Tethered Net (TSN). In addition to the advantages inherit to the TSN, the TSNR's maneuverability expands the capture's potential. However, oscillations caused by the TSNR's flexibility and elasticity of make higher requests of the control scheme. Based on the dynamics model, a modified adaptive super-twisting sliding mode control scheme is proposed in this paper for TSNR stability control. The proposed continuous control force can effectively suppress oscillations. Theoretical verification and numerical simulations demonstrate that the desired trajectory can be tracked steadily and efficiently by employing the proposed control scheme.

Evidence-based and heuristic approaches for customization of care in cardiometabolic syndrome after spinal cord injury.

Science.gov (United States)

Nash, Mark S; Cowan, Rachel E; Kressler, Jochen

2012-09-01

Component and coalesced health risks of the cardiometabolic syndrome (CMS) are commonly reported in persons with spinal cord injuries (SCIs). These CMS hazards are also co-morbid with physical deconditioning and elevated pro-atherogenic inflammatory cytokines, both of which are common after SCI and worsen the prognosis for all-cause cardiovascular disease. This article describes a systematic procedure for individualized CMS risk assessment after SCI, and emphasizes evidence-based and intuition-centered countermeasures to disease. A unified approach will propose therapeutic lifestyle intervention as a routine plan for aggressive primary prevention in this risk-susceptible population. Customization of dietary and exercise plans then follow, identifying shortfalls in diet and activity patterns, and ways in which these healthy lifestyles can be more substantially embraced by both stakeholders with SCI and their health care providers. In cases where lifestyle intervention utilizing diet and exercise is unsuccessful in countering risks, available pharmacotherapies and a preferred therapeutic agent are proposed according to authoritative standards. The over-arching purpose of the monograph is to create an operational framework in which existing evidence-based approaches or heuristic modeling becomes best practice. In this way persons with SCI can lead more active and healthy lives.

Dopaminergic treatment of restless legs syndrome in spinal cord injury patients with neuropathic pain.

Science.gov (United States)

Kumru, Hatice; Albu, Sergiu; Vidal, Joan; Barrio, Manuela; Santamaria, Joan

2016-01-01

Recent studies report high incidence of restless legs syndrome (RLS) in patients with spinal cord injury (SCI), who may also present pain and sensory disturbances. In the present manuscript, we examine and discuss diagnostic and treatment challenges of comorbid RLS and neuropathic pain (NP) in SCI. We evaluated seven men with a mean age of 55.6 (s.d.=14.0) years, with chronic complete or incomplete SCI at the thoracic or lumbar level, for complaints of sensory disturbances in the legs, which initially were attributed to drug-resistant NP. Because overlapped RLS was suspected, clinical evaluation of NP and RLS, serum ferritin and iron level assessment, and video polysomnographic (VPSG) studies were conducted. Pramipexole (0.18 mg q.d. -1 ) was added to treat RLS, and a follow-up was performed at 2 months. We found that in six subjects the RLS was comorbid with NP and in one subject the symptoms of RLS were misdiagnosed as NP. VPSG revealed periodic limb movements (PLMs) in all patients, including PLMs of the legs, arms or both. Serum ferritin was patients. RLS improved significantly after 2 months with pramipexole. On the basis of current findings, we recommend physicians to be aware of the comorbidity between RLS and NP secondary to SCI to include suitable diagnostic procedures and effective treatments.

Operator's Manual for SHEBA Powered Tether Balloon System

Science.gov (United States)

Lappen, Cara-Lyn; Randall, David A.

1998-01-01

The Surface Heat and Energy Budget of the Arctic (SHEBA) was an intensive field project which took place in the Arctic Ocean from October 1997 through October 1998. Its purpose was to measure as many facets of the Arctic environment as possible so that we would be able to better understand the interaction between the ice, atmosphere, and ocean and their interactions with global climate. One aspect of the atmospheric field component was launching tethered balloons to monitor the profiles of temperature, wind, pressure, and humidity, as well as examine the vertical structure of cloud droplet sizes and distributions. The tethered balloon that we used was one specially designed for use in freezing climates by SPEC Corporation in Boulder, Colorado. A special winch that was able to withstand Arctic temperature and weather became necessary when the testing of simple winch systems used in warmer climates failed under these extreme conditions. The purpose of this manual is to acquaint any new user to the powered tethered balloon system deployed at the The Surface Heat and Energy Budget of the Arctic (SHEBA ice camp. It includes a description of the preparations necessary to get ready for a launch, the mechanics of the actual launch, and an account of the proper procedure for taking down the equipment when finished. It will also include tips on how to minimize potential equipment failures, some trouble shooting, and some safety ideas. This manual is designed so that new operators can use the system with minimal previous training. At the end of this manual, the reader will find a quick checklist.

Four-dimensional real-time sonographically guided cauterization of the umbilical cord in a case of twin-twin transfusion syndrome.

Science.gov (United States)

Timor-Tritsch, Ilan E; Rebarber, Andrei; MacKenzie, Andrew; Caglione, Christopher F; Young, Bruce K

2003-07-01

In the past decade, three-dimensional (3D) sonographic technology has matured from a static imaging modality to near-real-time imaging. One of the more notable improvements in this technology has been the speed with which the imaged volume is acquired and displayed. This has enabled the birth of the near-real-time or four-dimensional (4D) sonographic concept. Using the 4D feature of the current 3D sonography machines allows us to follow moving structures, such as fetal motion, in almost real time. Shortly after the emergence of 3D and 4D technology as a clinical imaging tool, its use in guiding needles into structures was explored by other investigators. We present a case in which we used the 4D feature of our sonographic equipment to follow the course and motion of an instrument inserted into the uterus to occlude the umbilical cord of a fetus in a case of twin-twin transfusion syndrome.

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal ... Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal ...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Cord Injury Rehabilitation Pediatric Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal ... Cord Injury Rehabilitation Pediatric Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal ...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation Pediatric Spinal ... Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation Pediatric Spinal ...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation ... Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation ...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Animated Spinal Cord Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal ... Animated Spinal Cord Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal ...

The Cost-Effectiveness of Spinal Cord Stimulation for Complex Regional Pain Syndrome

NARCIS (Netherlands)

Kemler, Marius A.; Raphael, Jon H.; Bentley, Anthony; Taylor, Rod S.

2010-01-01

Objectives: Health-care policymakers and payers require cost-effectiveness evidence to inform their treatment funding decisions. The aims of this study were to assess the cost-effectiveness of the addition of spinal cord stimulation (SCS) compared with conventional management alone (CMM) in patients

Spinal Cord Diseases

Science.gov (United States)

Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back ... of the spine, this can also injure the spinal cord. Other spinal cord problems include Tumors Infections such ...

Spinal Cord Injury 101

Medline Plus

Full Text Available menu Understanding Spinal Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal Cord Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal ...

Electromechanical engineering in SnO2 nanoparticle tethered hybrid ionic liquid

Science.gov (United States)

Deb, Debalina; Bhattacharya, Subhratanu

2017-05-01

Challenge of developing electrolytes comprising synergic properties of high mechanical strength with superior electrical and electrochemical properties has so far been unmet towards the application of secondary storage devices. In this research, we have engineered the electromechanical properties of 2-(trimethylamino) ethyl methacrylate bis(trifluoromethylsulfonyl) imide [TMEM]TFSI ionic liquid by tethering silane modified SnO2 nanoparticles within it. Different percentages of tethering are employed to achieve improved ionic conductivity, better discharge/ charging ratio (40%) along with gel like mechanical properties. Our findings appear to provide an optimal solution towards the future prospects in application in a number of areas, notably in energy-related technologies.

Stationary Tether Device for Buoy Apparatus and System for Using

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A rigid, neutrally buoyant hydrodynamicaly-faired tether and associated fastening hardware that loosely holds a bathymetric float at a predetermined distance from a...

Fiber Optic Shape Sensing for Tethered Marsupial Rovers, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Building upon the successful proof of concept work in Phase I, Luna Innovations Incorporated is proposing to design, build, and test a sensing tether for marsupial...

[Case report : usefulness of the airwayscope for difficult intubations in a pediatric patients with Coffin-Siris syndrome].

Science.gov (United States)

Sakugawa, Yoko; Kamizato, Kota; Miyata, Yuji; Kakinohana, Manabu; Sugahara, Kazuhiro

2013-05-01

We experienced management of general anesthesia in a patients with Coffin-Siris syndrome (CS syndrome) which is an autosomal dominant disorder characterized by mental retardation, growth failure, hypoplasia of the fifth finger's distal phalanx and limb, and syndrome-specific facial appearance. Anesthesia was induced by sevoflurane by mask. After obtaining muscle relaxation by rocuronium, laryngoscopy by Machintosh #2 failed to reveal the vocal cord. However, the vocal cord was revealed by AirwayScope (AWS) for the pediatrics and then tracheal intubation was successful. Surgical procedures and anes-thetic management were performed uneventfully. This case demonstrates usefulness of AWS in pediatric patients with difficult intubation.

Spinal Cord Injuries

Science.gov (United States)

... forth between your body and your brain. A spinal cord injury disrupts the signals. Spinal cord injuries usually begin with a blow that fractures or ... down on the nerve parts that carry signals. Spinal cord injuries can be complete or incomplete. With a complete ...

75 FR 47316 - Centennial Challenges 2010 Strong Tether Challenge

Science.gov (United States)

2010-08-05

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Centennial Challenges 2010 Strong Tether Challenge... teams that wish to compete may register. Centennial Challenges is a program of prize competitions to..., please visit: http://www.spaceward.org/elevator2010-ts . For general information on the NASA Centennial...

Torakal Ventral Cord Herniation

Directory of Open Access Journals (Sweden)

Sermin Tok

2015-11-01

Full Text Available  Ventral cord herniation is a rare cause of focal myelopathy due to herniation of the thoracic cord through a dural defect.It is also known by a variety of other terms such as spontaneous thoracic cord herniation or idiopathic spinal cord herniation.The key feature is focal distortion and rotation of the cord with no CSF seen between it and the ventral theca.

Clustering of tethered satellite system simulation data by an adaptive neuro-fuzzy algorithm

Science.gov (United States)

Mitra, Sunanda; Pemmaraju, Surya

1992-01-01

Recent developments in neuro-fuzzy systems indicate that the concepts of adaptive pattern recognition, when used to identify appropriate control actions corresponding to clusters of patterns representing system states in dynamic nonlinear control systems, may result in innovative designs. A modular, unsupervised neural network architecture, in which fuzzy learning rules have been embedded is used for on-line identification of similar states. The architecture and control rules involved in Adaptive Fuzzy Leader Clustering (AFLC) allow this system to be incorporated in control systems for identification of system states corresponding to specific control actions. We have used this algorithm to cluster the simulation data of Tethered Satellite System (TSS) to estimate the range of delta voltages necessary to maintain the desired length rate of the tether. The AFLC algorithm is capable of on-line estimation of the appropriate control voltages from the corresponding length error and length rate error without a priori knowledge of their membership functions and familarity with the behavior of the Tethered Satellite System.

Spinal cord stimulation for treatment of pain in a patient with post thoracotomy pain syndrome.

Science.gov (United States)

Graybill, Jordan; Conermann, Till; Kabazie, Abraham J; Chandy, Sunil

2011-01-01

Post Thoracotomy Pain Syndrome (PTPS) is defined as pain that occurs or persists in the area of the thoracotomy incision for at least 2 months following the initial procedure.  The true incidence of PTPS is hard to define as literature reports a wide range of occurrence from 5% to 90%.  Thoracotomy is associated with a high risk of severe chronic postoperative pain.  Presenting symptoms include both neuropathic pain in the area of the incision, as well as myofascial pain commonly in the ipsilateral scapula and shoulder.  Pain management can be challenging in these patients.  Multiple treatments have been described including conservative treatments with oral nonsteroidal anti-inflammatory drugs (NSAIDs); topically applied, peripherally acting drugs; neuromodulating agents; physical therapy; transcutaneous electrical nerve stimulation as well as more invasive treatments including intercostal nerve blocks, trigger point steroid injections, epidural steroid injections, radiofrequency nerve ablation, cryoablation, and one case report of spinal cord stimulation.  Unfortunately, a portion of these patients will have persistent pain in spite of multiple treatment modalities, and in some cases will experience worsening of pain. This case report describes the novel utility and complete resolution of symptoms with spinal cord stimulation (SCS) in treatment of a patient with persistent PTPS. In the operating room, a percutaneous octet electrode lead was placed using sterile technique under fluoroscopic guidance and loss-of-resistance technique.  The octet electrode lead was subsequently advanced with the aid of fluoroscopy to the level of the T3 superior endplate just right of midline.  The patient's pain distribution was captured optimally with stimulation at this level.  With the assistance of a neurosurgeon, the lead was anchored, tunneled, and connected to a generator, which was implanted over the right iliac crest.  The patient tolerated the procedure well with

Tethered balloon operation for wintering aerosol measurements in the lower troposphere at Syowa Station, Antarctica

OpenAIRE

Keiichiro Hara; Kazuo Osada; Takashi Yamanouchi

2007-01-01

The 46th Japanese Antarctic Research Expedition (JARE-46) carried out twenty seven tethered-balloon-borne aerosol measurements at Syowa Station for better understanding of aerosol chemical and physical properties in the lower troposphere from 6th January 2005 until 11 December 2005. This report summarizes the plan, preparation, field activities and some troubles/problems in the tethered-balloon observations.

Tethered balloon operation for wintering aerosol measurements in the lower troposphere at Syowa Station, Antarctica

Directory of Open Access Journals (Sweden)

Keiichiro Hara

2007-03-01

Full Text Available The 46th Japanese Antarctic Research Expedition (JARE-46 carried out twenty seven tethered-balloon-borne aerosol measurements at Syowa Station for better understanding of aerosol chemical and physical properties in the lower troposphere from 6th January 2005 until 11 December 2005. This report summarizes the plan, preparation, field activities and some troubles/problems in the tethered-balloon observations.

Lifting options for stratospheric aerosol geoengineering: advantages of tethered balloon systems.

Science.gov (United States)

Davidson, Peter; Burgoyne, Chris; Hunt, Hugh; Causier, Matt

2012-09-13

The Royal Society report 'Geoengineering the Climate' identified solar radiation management using albedo-enhancing aerosols injected into the stratosphere as the most affordable and effective option for geoengineering, but did not consider in any detail the options for delivery. This paper provides outline engineering analyses of the options, both for batch-delivery processes, following up on previous work for artillery shells, missiles, aircraft and free-flying balloons, as well as a more lengthy analysis of continuous-delivery systems that require a pipe connected to the ground and supported at a height of 20 km, either by a tower or by a tethered balloon. Towers are shown not to be practical, but a tethered balloon delivery system, with high-pressure pumping, appears to have much lower operating and capital costs than all other delivery options. Instead of transporting sulphuric acid mist precursors, such a system could also be used to transport slurries of high refractive index particles such as coated titanium dioxide. The use of such particles would allow useful experiments on opacity, coagulation and atmospheric chemistry at modest rates so as not to perturb regional or global climatic conditions, thus reducing scale-up risks. Criteria for particle choice are discussed, including the need to minimize or prevent ozone destruction. The paper estimates the time scales and relatively modest costs required if a tethered balloon system were to be introduced in a measured way with testing and development work proceeding over three decades, rather than in an emergency. The manufacture of a tether capable of sustaining the high tensions and internal pressures needed, as well as strong winds, is a significant challenge, as is the development of the necessary pumping and dispersion technologies. The greatest challenge may be the manufacture and launch of very large balloons, but means have been identified to significantly reduce the size of such balloons or aerostats.

Sensory Loss Mimicking Cauda Equina Syndrome due to Cervical Spinal Lesion in a Patient with Clinically Isolated Syndrome

OpenAIRE

Vinceti, Giulia; Zini, Andrea; Nichelli, Paolo; Mandrioli, Jessica

2012-01-01

We describe the case of a 39-year-old woman with signs and symptoms suggesting cauda equina syndrome. Lumbosacral magnetic resonance imaging (MRI) demonstrated no lesion at this level, while cervical MRI showed a T2-hyperintense lesion in the middle-right anterolateral region of the cervical spinal cord, which may explain the symptoms by involving the anterior spinothalamic tract. We suggest that in cases with cauda equina syndrome presentation and normal lumbosacral MRI, a cervicodorsal lesi...

Stabilization of periodic solutions in a tethered satellite system by damping injection

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2009-01-01

presents a control design for stabilizing these periodic solutions. The design consists of a control law for stabilizing the open-loop equilibrium and a bias term which forces the system trajectory away from the equilibrium. The tether needs to be positioned away from open-loop equilibrium for the tether...... to affect the orbit parameters. An approximation of the periodic solutions of the closed loop system is found as a series expansion in the parameter plane spanned by the controller gain and the bias term. The stability of the solutions is investigated using linear Floquet analysis of the variational...

Crowded, Confined, and Frustrated: Dynamics of Molecules Tethered to Nanoparticles

KAUST Repository

Agarwal, Praveen; Kim, Sung A.; Archer, Lynden A.

2012-01-01

Above a critical chemistry-dependent molecular weight, all polymer molecules entangle and, as a result, exhibit slow dynamics, enhanced viscosity, and elasticity. Herein we report on the dynamics of low molecular weight polymers tethered

Disaster Coverage Predication for the Emerging Tethered Balloon Technology: Capability for Preparedness, Detection, Mitigation, and Response.

Science.gov (United States)

Alsamhi, Saeed H; Samar Ansari, Mohd; Rajput, Navin S

2018-04-01

A disaster is a consequence of natural hazards and terrorist acts, which have significant potential to disrupt the entire wireless communication infrastructure. Therefore, the essential rescue squads and recovery operations during a catastrophic event will be severely debilitated. To provide efficient communication services, and to reduce casualty mortality and morbidity during the catastrophic events, we proposed the Tethered Balloon technology for disaster preparedness, detection, mitigation, and recovery assessment. The proposed Tethered Balloon is applicable to any type of disaster except for storms. The Tethered Balloon is being actively researched and developed as a simple solution to improve the performance of rescues, facilities, and services of emergency medical communication in the disaster area. The most important requirement for rescue and relief teams during or after the disaster is a high quality of service of delivery communication services to save people's lives. Using our proposed technology, we report that the Tethered Balloon has a large disaster coverage area. Therefore, the rescue and research teams are given higher priority, and their performance significantly improved in the particular coverage area. Tethered Balloon features made it suitable for disaster preparedness, mitigation, and recovery. The performance of rescue and relief teams was effective and efficient before and after the disaster as well as can be continued to coordinate the relief teams until disaster recovery. (Disaster Med Public Health Preparedness. 2018;12:222-231).

Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors.

Science.gov (United States)

Poirier, Luke A; Gilbert, Shane T C; St-Hilaire, Sophie; Davidson, Jeff; Cox, Ruth; Quijón, Pedro A

2018-02-01

Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters (Crassostrea virginica) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isothermal pumping analysis for high-altitude tethered balloons.

Science.gov (United States)

Kuo, Kirsty A; Hunt, Hugh E M

2015-06-01

High-altitude tethered balloons have potential applications in communications, surveillance, meteorological observations and climate engineering. To maintain balloon buoyancy, power fuel cells and perturb atmospheric conditions, fluids could be pumped from ground level to altitude using the tether as a hose. This paper examines the pumping requirements of such a delivery system. Cases considered include delivery of hydrogen, sulfur dioxide (SO2) and powders as fluid-based slurries. Isothermal analysis is used to determine the variation of pressures and velocities along the pipe length. Results show that transport of small quantities of hydrogen to power fuel cells and maintain balloon buoyancy can be achieved at pressures and temperatures that are tolerable in terms of both the pipe strength and the current state of pumping technologies. To avoid solidification, transport of SO2 would require elevated temperatures that cannot be tolerated by the strength fibres in the pipe. While the use of particle-based slurries rather than SO2 for climate engineering can reduce the pipe size significantly, the pumping pressures are close to the maximum bursting pressure of the pipe.

[Correlation analysis of the pre-pregnant body mass index, the gestational weight gain and umbilical cord blood C peptide].

Science.gov (United States)

Chen, X L; Han, Y; Zhao, X M; Liu, Y; Lü, J J

2017-01-03

Objective: To explore the correlation among the pre-pregnant body mass index (BMI), gestational weight gain (GWG) and umbilical cord blood C peptide, and to investigate the influence of maternal weight management on the incidence of baby long-term metabolic syndrome. Methods: During May to Aug.2015, 485 pregnant women in Zhejiang Taizhou first people's hospital and Taizhou Huangyan maternal &child care service centre were selected in random and divided into four groups according to pre-pregnant BMI: low body mass, normal body mass, over body mass and obese group, and also divided into two groups for getting gestational diabetes mellitus (GDM) or not. According to the gestational weight gain (GWG), all the cases were divided into two groups: above the Institute Of Medicine (IMO) 2009 recommendations or not. According to the outcome, the GDM group which had received weight control treatment, was divided into successful treat group or not. At last, we tested the umbilical cord blood C peptide and birth weight of each newborn and compared the difference in all subgroups. The correlation between the umbilical cord blood C peptide and birth weight were analysed. Results: (1) In the pre-pregnant BMI groups, there were significant differences of incidence of GDM ( P 0.05). (2) Newborn birth weight and the umbilical cord blood C peptide were positively correlated ( r =0.673, P newborn birth weight in all subgroups. (4) All groups showed correlations with neonatal umbilical cord blood C peptide, the GDM mostly (β=0.58), pre-pregnant BMI secondly (β: 0.36, 0.38) , and GWG weakly (β=0.17). (5) By stratification analysis, in GDM group, low body mass was negatively correlated with umbilical cord blood C peptide ( P gestational weight gain and umbilical cord blood C peptide. Suitable maternal weight control especially pre-pregnant body mass index control will lower the baby long-term metabolic syndrome incidence.

Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report

International Nuclear Information System (INIS)

Lee, Susan C.; Geannette, Christian; Sneag, Darryl B.; Wolfe, Scott W.; Feinberg, Joseph H.

2017-01-01

This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed - and consequently scar tethered - the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy. (orig.)

Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report.

Science.gov (United States)

Lee, Susan C; Geannette, Christian; Wolfe, Scott W; Feinberg, Joseph H; Sneag, Darryl B

2017-08-01

This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed-and consequently scar tethered-the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy.

Associative visual learning by tethered bees in a controlled visual environment.

Science.gov (United States)

Buatois, Alexis; Pichot, Cécile; Schultheiss, Patrick; Sandoz, Jean-Christophe; Lazzari, Claudio R; Chittka, Lars; Avarguès-Weber, Aurore; Giurfa, Martin

2017-10-10

Free-flying honeybees exhibit remarkable cognitive capacities but the neural underpinnings of these capacities cannot be studied in flying insects. Conversely, immobilized bees are accessible to neurobiological investigation but display poor visual learning. To overcome this limitation, we aimed at establishing a controlled visual environment in which tethered bees walking on a spherical treadmill learn to discriminate visual stimuli video projected in front of them. Freely flying bees trained to walk into a miniature Y-maze displaying these stimuli in a dark environment learned the visual discrimination efficiently when one of them (CS+) was paired with sucrose and the other with quinine solution (CS-). Adapting this discrimination to the treadmill paradigm with a tethered, walking bee was successful as bees exhibited robust discrimination and preferred the CS+ to the CS- after training. As learning was better in the maze, movement freedom, active vision and behavioral context might be important for visual learning. The nature of the punishment associated with the CS- also affects learning as quinine and distilled water enhanced the proportion of learners. Thus, visual learning is amenable to a controlled environment in which tethered bees learn visual stimuli, a result that is important for future neurobiological studies in virtual reality.

Cervical Cord-Canal Mismatch: A New Method for Identifying Predisposition to Spinal Cord Injury.

Science.gov (United States)

Nouri, Aria; Montejo, Julio; Sun, Xin; Virojanapa, Justin; Kolb, Luis E; Abbed, Khalid M; Cheng, Joseph S

2017-12-01

The risk for spinal cord injuries (SCIs) ranging from devastating traumatic injuries, compression because of degenerative pathology, and neurapraxia is increased in patients with congenital spinal stenosis. Classical diagnostic criteria include an absolute anteroposterior diameter of spinal cord, which varies across patients, independent of canal size. Recent large magnetic resonance imaging studies of population cohorts have allowed newer methods to emerge that account for both cord and canal size by measuring a spinal cord occupation ratio (SCOR). A SCOR defined as ≥70% on midsagittal imaging or ≥80% on axial imaging appears to be an effective method of identifying cord-canal mismatch, but requires further validation. Cord-canal size mismatch predisposes patients to SCI because of 1) less space within the canal lowering the amount of degenerative changes needed for cord compression, and 2) less cerebrospinal fluid surrounding the spinal cord decreasing the ability to absorb kinetic forces directed at the spine. Patients with cord-canal mismatch have been reported to be at a substantially higher risk of traumatic SCI, and present with degenerative cervical myelopathy at a younger age than patients without cord-canal mismatch. However, neurologic outcome after SCI has occurred does not appear to be different in patients with or without a cord-canal mismatch. Recognition that canal and cord size are both factors which predispose to SCI supports that cord-canal size mismatch rather than a narrow cervical canal in isolation should be viewed as the underlying mechanism predisposing to SCI. Copyright © 2017. Published by Elsevier Inc.

A Fiber-Optic Tether for the Hull Search UUV System Documentation

National Research Council Canada - National Science Library

Buescher, J. G

2006-01-01

...) conducting ship hull inspection missions, defines the required specifications that will allow the integration and installation of a FO tether system on UUVs with ship hull inspection capability...

Bing-Neel Syndrome: Illustrative Cases and Comprehensive Review of the Literature

OpenAIRE

Varettoni, Marzia; Defrancesco, Irene; Diamanti, Luca; Marchioni, Enrico; Farina, Lisa Maria; Pichiecchio, Anna

2017-01-01

The Bing-Neel syndrome is a rare neurological complication of Waldenström’s Macroglobulinemia which results from a direct involvement of central nervous system by malignant lymphoplasmacytic cells. The clinical suspicion of Bing-Neel syndrome may be difficult because neurologic symptoms are heterogeneous, non specific and sometimes underhand. A definitive diagnosis of Bing-Neel syndrome can be confidently made using brain and spinal cord magnetic resonance imaging as well as histopathology an...

Spinal Cord Independence Measure, version III: applicability to the UK spinal cord injured population.

Science.gov (United States)

Glass, Clive A; Tesio, Luigi; Itzkovich, Malka; Soni, Bakul M; Silva, Pedro; Mecci, Munawar; Chadwick, Raymond; el Masry, Waghi; Osman, Aheed; Savic, Gordana; Gardner, Brian; Bergström, Ebba; Catz, Amiram

2009-09-01

To examine the validity, reliability and usefulness of the Spinal Cord Independence Measure for the UK spinal cord injury population. Multi-centre cohort study. Four UK regional spinal cord injury centres. Eighty-six people with spinal cord injury. Spinal Cord Independence Measure and Functional Independence Measure on admission analysed using inferential statistics, and Rasch analysis of Spinal Cord Independence Measure. Internal consistency, inter-rater reliability, discriminant validity; Spinal Cord Independence Measure subscale match between distribution of item difficulty and patient ability measurements; reliability of patient ability measures; fit of data to Rasch model; unidimensionality of subscales; hierarchical ordering of categories within items; differential item functioning across patient groups. Scale reliability (kappa coefficients range 0.491-0.835; (p Spinal Cord Independence Measure subscales compatible with stringent Rasch requirements; mean infit indices high; distinct strata of abilities identified; most thresholds ordered; item hierarchy stable across clinical groups and centres. Misfit and differences in item hierarchy identified. Difficulties assessing central cord injuries highlighted. Conventional statistical and Rasch analyses justify the use of the Spinal Cord Independence Measure in clinical practice and research in the UK. Cross-cultural validity may be further improved.

A simplified tether model for molecular motor transporting cargo

International Nuclear Information System (INIS)

Fang-Zhen, Li; Li-Chun, Jiang

2010-01-01

Molecular motors are proteins or protein complexes which function as transporting engines in biological cells. This paper models the tether between motor and its cargo as a symmetric linear potential. Different from Elston and Peskin's work for which performance of the system was discussed only in some limiting cases, this study produces analytic solutions of the problem for general cases by simplifying the transport system into two physical states, which makes it possible to discuss the dynamics of the motor–cargo system in detail. It turns out that the tether strength between motor and cargo should be greater than a threshold or the motor will fail to transport the cargo, which was not discussed by former researchers yet. Value of the threshold depends on the diffusion coefficients of cargo and motor and also on the strength of the Brownian ratchets dragging the system. The threshold approaches a finite constant when the strength of the ratchet tends to infinity. (general)

Phase 3 study of selected tether applications in space. Volume 2: Study results

Science.gov (United States)

1986-01-01

Engineering designs were developed relative to a tethered launch assist from the Shuttle for payloads up to 10,000 kg mass and the tethering of a 15,000 kg science platform from the space station. These designs are used for a cost benefit analysis which assesses the feasibility of using such systems as a practical alternative to what would otherwise be accomplished by conventional means. The term conventional as related to both these applications is intended to apply to the use of some form(s) of chemical propulsion system.

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

International Nuclear Information System (INIS)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T.

2013-01-01

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded

Tethered Contactless Mobile Nuclear Environment Monitoring Robot

Energy Technology Data Exchange (ETDEWEB)

Choi, S. Y.; Lee, E. S.; Lee, Kun J.; Kim, Su H.; Rim, C. T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

In fact, the nuclear environment monitoring is significantly crucial for early detection of NPP accident, radiological emergency, the estimation of radiation exposure to nearby residents as well as the long term radioactivity. In the UAE, the nuclear environment monitoring is, however, quite challenging because sampling locations are far from NPPs and the outdoor temperature and humidity are very high for NPP workers to collect soil, air, and water samples. Therefore, nuclear environment monitoring robots (Nubos) are strongly needed for the NPPs in the UAE. The Nubos can be remotely controlled to collect samples in extreme environment instead of NPP workers. Moreover, the Nubos can be unmanned ground vehicles (UGVs), unmanned aerial vehicles (UAVs) and unmanned marine vehicles (UMVs) to collect soil, air, and water samples, respectively. In this paper, the prototype development of UGV type Nubos using power cable for a long distance power delivery, called Tethered contactless mobile Nubo is introduced and validated by experiments. In this paper, the prototype development of Tethered Contactless Mobile (TeCoM) Nubo, which can be powered continuously within several km distance and avoid tangled cable, and the indoor test are finished. As further works, outdoor demonstration and a grand scale R and D proposal of practical Nubo will be proceeded.

Stability analysis and trend study of a balloon tethered in a wind, with experimental comparisons

Science.gov (United States)

Redd, L. T.; Bland, S. R.; Bennett, R. M.

1973-01-01

A stability analysis and trend study for a balloon tethered in a steady wind are presented. The linearized, stability-derivative type analysis includes balloon aerodynamics, buoyancy, mass (including apparent mass), and static forces resulting from the tether cable. The analysis has been applied to a balloon 7.64 m in length, and the results are compared with those from tow tests of this balloon. This comparison shows that the analysis gives reasonable predictions for the damping, frequencies, modes of motion, and stability boundaries exhibited by the balloon. A trend study for the 7.64-m balloon was made to illustrate how the stability boundaries are affected by changes in individual stability parameters. The trends indicated in this study may also be applicable to many other tethered-balloon systems.

Tethered by Self-Generated Flow: Mucus String Augmented Feeding Current Generation in Larval Oysters

Science.gov (United States)

Jiang, H.; Wheeler, J.; Anderson, E.

2016-02-01

Marine zooplankton live in a nutritionally dilute environment. To survive, they must process an enormous volume of water relative to their own body volume for food. To achieve this, many zooplankters including copepods, invertebrate larvae, and protists create a feeding current to concentrate and transport food items to their food gathering structures. To enhance the efficiency of the feeding current, these zooplankters often rely on certain "tethering" mechanisms to retard their translational motion for producing a strong feeding current. The tethering force may include excess weight due to gravity, force from attachment to solid surfaces, and drag experienced by strategically placed morphological structures. Larval oysters are known from previous studies to release mucus strings during feeding, presumably for supplying a tethering force to enhance their feeding-current efficiency. But the underlying mechanism is unclear. In this study, we used a high-speed microscale imaging system (HSMIS) to observe the behavior of freely swimming and feeding larval oysters. We also used HSMIS to measure larval imposed feeding currents via a micro-particle image velocimetry (µPIV) technique. HSMIS allows observations along a vertically oriented focal plane in a relatively large water vessel with unprecedented spatial and temporal resolutions. Our high-speed videos show that a feeding larval oyster continuously released a long mucus string into its feeding current that flows downward; the feeding current subsequently dragged the mucus string downward. Analysis of our µPIV data combined with a hydrodynamic model further suggests that the drag force experienced by the mucus string in the feeding current contributes significantly to the tethering force required to generate the feeding current. Thus, mucus strings in larval oysters act as "anchors" in larval self-generated flow to actively tether the feeding larvae.

Microdialysis to optimize cord perfusion and drug delivery in spinal cord injury.

OpenAIRE

Phang, I; Zoumprouli, A; Papadopoulos, MC; Saadoun, S

2016-01-01

OBJECTIVE: There is lack of monitoring from the injury site to guide management of patients with acute traumatic spinal cord injury. Here we describe a bedside microdialysis monitoring technique for optimizing spinal cord perfusion and drug delivery at the injury site. METHODS: 14 patients were recruited within 72 hours of severe spinal cord injury. We inserted intradurally at the injury site a pressure probe, to monitor continuously spinal cord perfusion pressure, and a microdialysis cathete...

Spinal Cord Injury 101

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Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 Adult Injuries Spinal Cord Injury 101 ...

Myocardial Infarction Alters Adaptation of the Tethered Mitral Valve

NARCIS (Netherlands)

Dal-Bianco, Jacob P; Aikawa, Elena; Bischoff, Joyce; Guerrero, J Luis; Hjortnaes, Jesper; Beaudoin, Jonathan; Szymanski, Catherine; Bartko, Philipp E; Seybolt, Margo M; Handschumacher, Mark D; Sullivan, Suzanne; Garcia, Michael L; Mauskapf, Adam; Titus, James S; Wylie-Sears, Jill; Irvin, Whitney S; Chaput, Miguel; Messas, Emmanuel; Hagège, Albert A; Carpentier, Alain; Levine, Robert A

2016-01-01

BACKGROUND: In patients with myocardial infarction (MI), leaflet tethering by displaced papillary muscles induces mitral regurgitation (MR), which doubles mortality. Mitral valves (MVs) are larger in such patients but fibrosis sets in counterproductively. The investigators previously reported that

Spinal Cord Injury 101

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Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 Adult Injuries Spinal Cord Injury 101 David ...

MR imaging of the spine in children

Energy Technology Data Exchange (ETDEWEB)

Duthoy, M.J.; Lund, G.

1988-08-01

MR imaging was reviewed in 66 pediatric spinal cord patients with diagnoses of posterior fossa tumor, primary spinal cord tumor, metastatic disease, neuroectodermal disorder, congenital malformation, trauma, and demyelinating, neurodegenerative, or metabolic disorders. MR proved to be useful in delineating the extent of posterior fossa and cord tumor including metastasis to the cord. MR was of limited value in demyelinating and metabolic disorders. Arnold Chiari malformations, syringomyelia, tethered cord and meningoceles were all easily evaluated using MR.

Development of a Tethered Formation Flight Testbed for ISS, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The development of a testbed for the development and demonstration of technologies needed by tethered formation flying satellites is proposed. Such a testbed would...

Materials for advancement of MXER tether design (1000-371), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — There exist a need to develop, identify, and classify various materials that can be used in the fabrication of electrodynamic tethers for various applications. These...

Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

Science.gov (United States)

Bilen, Sven G.; Johnson, C. Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael; Stone, Nobie

2014-01-01

The PROPEL ("Propulsion using Electrodynamics") flight demonstration mission concept will demonstrate the use of an electrodynamic tether (EDT) for generating thrust, which will allow the propulsion system to overcome the limitations of the rocket equation. The mission concept has been developed by a team of government, industry, and academia partners led by NASA Marshall Space Flight Center (MSFC). PROPEL is being designed for versatility of the EDT system with multiple end users in mind and to be flexible with respect to platform. Previously, we reported on a comprehensive mission design for PROPEL with a mission duration of six months or longer with multiple mission goals including demonstration of significant boost, deboost, inclination change, and drag make-up activities. To explore a range of possible configurations, primarily driven by cost considerations, other mission concept designs have been pursued. In partnership with the NASA's Office of Chief Technologist (OCT) Game Changing Program, NASA MSFC Leadership, and the MSFC Advanced Concepts Office, a mission concept design was developed for a near-term EDT propulsion flight validation mission. The Electrodynamic Tether Propulsion Study (ETPS) defined an EDT propulsion system capable of very large delta-V for use on future missions developed by NASA, DoD, and commercial customers. To demonstrate the feasibility of an ETPS, the study focused on a space demonstration mission concept design with configuration of a pair of tethered satellite busses, one of which is the Japanese H-II Transfer Vehicle (HTV). The HTV would fly its standard ISS resupply mission. When resupply mission is complete, the ISS reconfigures and releases the HTV to perform the EDT experiment at safe orbital altitudes below the ISS. Though the focus of this particular mission concept design addresses a scenario involving the HTV or a similar vehicle, the propulsion system's capability is relevant to a number of applications, as noted above

A 2-center Comparative Study on Tonic Versus Burst Spinal Cord Stimulation: Amount of Responders and Amount of Pain Suppression

NARCIS (Netherlands)

Ridder, D.M.D.; Lenders, M.W.P.M.; de Vos, Cecilia Cecilia Clementine; Dijkstra-Scholten, C.R.N.; Wolters, R.R.N.; Vancamp, T.P.T.; Van Looy, P.R.N.; Van Havenbergh, T.M.D.; Vanneste, S.

2015-01-01

Introduction: Spinal cord stimulation is a safe and effective procedure applied for medically intractable neuropathic pain and failed back surgery syndrome. Recently, a novel stimulation paradigm was developed, called burst stimulation consisting of intermittent packets of closely spaced

Folding of multidomain proteins: biophysical consequences of tethering even in apparently independent folding.

Science.gov (United States)

Arviv, Oshrit; Levy, Yaakov

2012-12-01

Most eukaryotic and a substantial fraction of prokaryotic proteins are composed of more than one domain. The tethering of these evolutionary, structural, and functional units raises, among others, questions regarding the folding process of conjugated domains. Studying the folding of multidomain proteins in silico enables one to identify and isolate the tethering-induced biophysical determinants that govern crosstalks generated between neighboring domains. For this purpose, we carried out coarse-grained and atomistic molecular dynamics simulations of two two-domain constructs from the immunoglobulin-like β-sandwich fold. Each of these was experimentally shown to behave as the "sum of its parts," that is, the thermodynamic and kinetic folding behavior of the constituent domains of these constructs seems to occur independently, with the folding of each domain uncoupled from the folding of its partner in the two-domain construct. We show that the properties of the individual domains can be significantly affected by conjugation to another domain. The tethering may be accompanied by stabilizing as well as destabilizing factors whose magnitude depends on the size of the interface, the length, and the flexibility of the linker, and the relative stability of the domains. Accordingly, the folding of a multidomain protein should not be viewed as the sum of the folding patterns of each of its parts, but rather, it involves abrogating several effects that lead to this outcome. An imbalance between these effects may result in either stabilization or destabilization owing to the tethering. Copyright © 2012 Wiley Periodicals, Inc.

Spinal Cord Injury 101

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Full Text Available ... Cord Injury Diane M. Rowles, MS, NP How Family Life Changes After Spinal Cord Injury Nancy Rosenberg, ... Children with Spinal Cord Injury Patricia Mucia, RN Family Life After Pediatric Spinal Injury Dawn Sheaffer, MSW ...

Spinal Cord Injury 101

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Full Text Available ... spinal cord injury? play_arrow What kind of surgery is common after a spinal cord injury? play_ ... How soon after a spinal cord injury should surgery be performed? play_arrow Is it common to ...

Spinal Cord Stimulation in Failed Back Surgery Syndrome: Effects on Posture and Gait—A Preliminary 3D Biomechanical Study

Directory of Open Access Journals (Sweden)

L. Brugliera

2017-01-01

Full Text Available We studied 8 patients with spinal cord stimulation (SCS devices which had been previously implanted to treat neuropathic chronic pain secondary to Failed Back Surgery Syndrome. The aim of our study was to investigate the effects of SCS on posture and gait by means of clinical scales (Short Form Health Survey-36, Visual Analogue Scale for pain, and Hamilton Depression Rating Scale and instrumented evaluation with 3D Gait Analysis using a stereophotogrammetric system. The latter was performed with the SCS device turned both OFF and ON. We recorded gait and posture using the Davis protocol and also trunk movement during flexion-extension on the sagittal plane, lateral bending on the frontal plane, and rotation on the transversal plane. During and 30 minutes after the stimulation, not only the clinical scales but also spatial-temporal gait parameters and trunk movements improved significantly. Improvement was not shown under stimulation-OFF conditions. Our preliminary data suggest that SCS has the potential to improve posture and gait and to provide a window of pain-free opportunity to optimize rehabilitation interventions.

Utility of spinal MRI in children with anorectal malformation

Energy Technology Data Exchange (ETDEWEB)

Miyasaka, Mikiko; Nosaka, Shunsuke; Tsutsumi, Yoshiyuki [National Centre for Child Health and Development, Radiology, Tokyo (Japan); Kitano, Yoshihiro [Saitama Children' s Medical Centre, Paediatric Surgery, Saitama (Japan); Ueoka, Katsuhiko [National Centre for Child Health and Development, Paediatric Urology, Tokyo (Japan); Kuroda, Tatsuo; Honna, Toshiroh [National Centre for Child Health and Development, Paediatric Surgery, Tokyo (Japan)

2009-08-15

The association between spinal cord anomalies and imperforate anus is well recognized. Until now, the incidence of tethered cord has been assumed to be higher in patients with high-type imperforate anus. However, recent reports suggest that tethered cord is as common in patients with a low lesion as in those with a high lesion. To review the incidence of spinal cord anomalies in those with a low lesion and those with a high (including intermediate) anorectal malformation (ARM), and to determine the best diagnostic imaging strategy. A group of 50 consecutive patients with postoperative ARM and in whom spinal MRI had been performed were identified retrospectively. We reviewed and compared the following factors between those with a high lesion and those with a low lesion: (1) clinical symptoms, (2) spinal cord anomalies, and (3) vertebral anomalies. The incidence of spinal cord anomalies was no different between those with a high lesion and those with a low lesion, and spinal cord anomalies were present regardless of the presence of vertebral anomalies or symptoms. Owing to the high incidence of spinal cord anomalies in patients with imperforate anus, MRI is the best imaging tool for detecting such anomalies regardless of the level of the lesion. (orig.)

Biomimetic chimeric peptide-tethered hydrogels for human mesenchymal stem cell delivery.

Science.gov (United States)

Shim, Gayong; Kim, Gunwoo; Choi, Junhyeok; Yi, TacGhee; Cho, Yun Kyoung; Song, Sun Uk; Byun, Youngro; Oh, Yu-Kyoung

2015-12-01

Here, we report a chimeric peptide-tethered fibrin hydrogel scaffold for delivery of human mesenchymal stem cells (hMSC). Osteopontin-derived peptide (OP) was used as an hMSC-tethering moiety. OP showed hMSC adhesion properties and enhanced hMSC proliferation. A natural fibrin-binding protein-derived peptide (FBP) was tested for its ability to tether hMSC to the fibrin gel matrix. FBP loading on fibrin gels was 8.2-fold higher than that of a scrambled peptide (scFBP). FBP-loaded fibrin gels were retained at injection sites longer than scFBP-loaded fibrin gels, showing a 15.9-fold higher photon intensity of fluorescent FBP-grafted fibrin gels than fluorescent scFBP-loaded fibrin gels 48 h after injection. On the basis of the fibrin gel-binding properties of FBP and the hMSC-binding and proliferation-supporting properties of OP, we constructed chimeric peptides containing FBP and OP linked with a spacer (FBPsOP). Four days after transplantation, the survival of hMSC in FBPsOP-grafted fibrin gels was 3.9-fold higher than hMSC in fibrin gels alone. Our results suggest the potential of FBPsOP-grafted fibrin gels as a bioactive delivery system for enhanced survival of stem cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Spinal Cord Injury 101

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Spinal Cord Injury 101

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Acquisition of Human Operation Characteristics for Kite-based Tethered Flying Robot using Human Operation Data

OpenAIRE

Todoroki, Chiaki; Takahashi, Yasutake; Nakamura, Takayuki

2015-01-01

This paper shows human skill acquisition systems to control the kite-based tethered flying robot. The kite-based tethered flying robot has been proposed as a flying observation system with long-term activity capability[1]. It is a relatively new system and aimed to complement other information gathering systems using a balloon or an air vehicle. This paper shows some approaches of human operation characteristics acquisition based on fuzzy learning controller, knearest neighbor algorithm, and ...

Synergistic impact of acute kidney injury and high level of cervical spinal cord injury on the weaning outcome of patients with acute traumatic cervical spinal cord injury.

Science.gov (United States)

Yu, Wen-Kuang; Ko, Hsin-Kuo; Ho, Li-Ing; Wang, Jia-Horng; Kou, Yu Ru

2015-07-01

Respiratory neuromuscular impairment severity is known to predict weaning outcome among patients with cervical spinal cord injury; however, the impact of non-neuromuscular complications remains unexplored. This study was to evaluate possible neuromuscular and non-neuromuscular factors that may negatively impact weaning outcome. From September 2002 to October 2012, acute traumatic cervical spinal cord injury patients who had received mechanical ventilation for >48h were enrolled and divided into successful (n=54) and unsuccessful weaning groups (n=19). Various neuromuscular, non-neuromuscular factors and events during the intensive care unit stay were extracted from medical charts and electronic medical records. Variables presenting with a significant difference (pspinal cord injury (C1-3), lower pulse rates, and lower Glasgow Coma Scale score on admission, higher peak blood urea nitrogen, lower trough albumin, and lower trough blood leukocyte counts. Furthermore, unsuccessful weaning patients had a higher incidence of pneumonia, acute respiratory distress syndrome, shock and acute kidney injury during the intensive care unit stay. Multivariate logistic regression analysis revealed acute kidney injury and high level of cervical spinal cord injury were independent risk factors for failure of weaning. Importantly, patients with both risk factors showed a large increase in odds ratio for unsuccessful weaning from mechanical ventilation (pinjury during the intensive care unit stay and high level of cervical spinal injury are two independent risk factors that synergistically work together producing a negative impact on weaning outcome. Copyright © 2015 Elsevier Ltd. All rights reserved.

Schiff-Sherrington syndrome in a horse - Case report

Directory of Open Access Journals (Sweden)

Cibele Lima Lhamas

2015-06-01

Full Text Available ABSTRACT. Lhamas C.L., Anjos B.L., Pfingstag K.G., Quevedo L.S. & Duarte C.A. [Schiff-Sherrington syndrome in a horse - Case report.] Síndrome de Schiff-Sherrington em equino - Relato de caso. Revista Brasileira de Medicina Veterinária, 37(2:163-166, 2015. Curso de Pós-Graduação em Ciência Animal, Universidade Federal do Pampa, Campus Uruguaiana, BR 472, Km 585, Uruguaiana, RS 97500-970, Brasil. E-mail: claudiaduarte@unipampa.edu.br Schiff-Sherrington syndrome clinically corresponds to a manifestation of rigidity extensor or hypertonia of the forelimb and hypotonic paralysis of the hind limbs. It is a common condition in dogs, however, rarely described in large animals. It can be caused by trauma and spinal cord compression conditions. The aim of this study was to describe the case of a two-year-old male horse with Schiff-Sherrington syndrome. The animal was sent with signs of paresis and ataxia of the hind limbs, and during the necropsy, multiple fractures were observed in the 1st and 2nd lumbar vertebrae and spinal cord compression.

Control by damping Injection of Electrodynamic Tether System in an Inclined Orbit

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Blanke, Mogens

2009-01-01

dynamical system. Based on this model, a nonlinear controller is designed that will make the system asymptotically stable around its open-loop equilibrium. The control scheme handles the time-varying nature of the system in a suitable manner resulting in a large operational region. The performance...... of the closed loop system is treated using Floquet theory, investigating the closed loop properties for their dependency of the controller gain and orbit inclination.......Control of a satellite system with an electrodynamic tether as actuator is a time-periodic and underactuated control problem. This paper considers the tethered satellite in a Hamiltonian framework and determines a port-controlled Hamiltonian formulation that adequately describes the nonlinear...

A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

Science.gov (United States)

Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

2016-03-01

Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers. © Georg Thieme Verlag KG Stuttgart · New York.

Primary biliary cirrhosis complicated by transverse myelitis in a patient without Sjögren's syndrome

Directory of Open Access Journals (Sweden)

Micheli A

2005-01-01

Full Text Available Transverse myelitis is an acute inflammatory process, affecting one or more segments of the spinal cord. Its association with primary biliary cirrhosis has been documented in only four cases - all along with Sjögren's syndrome. Herein, we report for the first time, a patient who developed recurrent acute transverse myelitis in association with primary biliary cirrhosis without any clinical or histological indication of Sjögren's syndrome. A 42-year-old woman with primary biliary cirrhosis developed acute onset quadriparesis and urinary retention. Diagnostic evaluation excluded the presence of Sjögren's syndrome, other autoimmune syndromes, infections and multiple sclerosis. Magnetic resonance imaging of the spinal cord disclosed signal intensity abnormalities from C1 to T2 after gadolinium enhancement. As diagnosis of acute transverse myelitis was prominent, the patient was treated with intravenous methylprednisolone. The patient had a fair outcome despite an early recurrence of the symptoms after treatment withdrawal.

[Spinal cord stimulation (SCS) as a treatment for the spread phenomenon related to complex regional pain syndrome type- I (CRPS-I )].

Science.gov (United States)

Goto, Shinichi; Taira, Takaomi; Hori, Tomokatsu

2009-09-01

The authors describe an experience of spinal cord stimulation (SCS) in a 30-year-old woman who developed complex regional pain syndrome type-I (CRPS-I) with spread phenomenon. She had received lumbar SCS under a diagnosis of CRPS-I in her left leg for 8 years. She had refractory pain in her right arm for the recent two years. There was no new lesion explaining her refractory pain on physical or radiological examination. Thus, the pain in her right upper arm was considered as spread phenomenon of CRPS-I. Test stimulation with cervical epidural spinal electrode showed good results and the pulse generator was implanted. It is suggested that the symptom of CRPS-I involving spread phenomenon was possibly due to a cortical reorganization. But a certain effect of SCS may be contributing to the favorable results of test stimulation for the treatment of CRPS-I with spread phenomenon in this case.

Spinal cord stimulators and radiotherapy: First case report and practice guidelines

Directory of Open Access Journals (Sweden)

Walsh Lorraine

2011-10-01

Full Text Available Abstract Spinal cord stimulators (SCS are a well-recognised treatment modality in the management of a number of chronic neuropathic pain conditions, particularly failed back syndrome and radiculopathies. The implantable pulse generator (IPG component of the SCS is designed and operates in a similar fashion to that of a cardiac pacemaker. The IPG consists of an electrical generator, lithium battery, transmitter/receiver and a minicomputer. When stimulated, it generates pulsed electrical signals which stimulate the dorsal columns of the spinal cord, thus alleviating pain. Analogous to a cardiac pacemaker, it can be potentially damaged by ionising radiation from a linear accelerator, in patients undergoing radiotherapy. Herein we report our clinical management of the first reported case of a patient requiring adjuvant breast radiotherapy who had a SCS in situ. We also provide useful practical recommendations on the management of this scenario within a radiation oncology department.

Spinal cord stimulators and radiotherapy: First case report and practice guidelines

International Nuclear Information System (INIS)

Walsh, Lorraine; Guha, Daipayan; Purdie, Thomas G; Bedard, Philippe; Easson, Alexandra; Liu, Fei-Fei; Hodaie, Mojgan

2011-01-01

Spinal cord stimulators (SCS) are a well-recognised treatment modality in the management of a number of chronic neuropathic pain conditions, particularly failed back syndrome and radiculopathies. The implantable pulse generator (IPG) component of the SCS is designed and operates in a similar fashion to that of a cardiac pacemaker. The IPG consists of an electrical generator, lithium battery, transmitter/receiver and a minicomputer. When stimulated, it generates pulsed electrical signals which stimulate the dorsal columns of the spinal cord, thus alleviating pain. Analogous to a cardiac pacemaker, it can be potentially damaged by ionising radiation from a linear accelerator, in patients undergoing radiotherapy. Herein we report our clinical management of the first reported case of a patient requiring adjuvant breast radiotherapy who had a SCS in situ. We also provide useful practical recommendations on the management of this scenario within a radiation oncology department

Pain Relief in CRPS-II after Spinal Cord and Motor Cortex Simultaneous Dual Stimulation.

Science.gov (United States)

Lopez, William Oc; Barbosa, Danilo C; Teixera, Manoel J; Paiz, Martin; Moura, Leonardo; Monaco, Bernardo A; Fonoff, Erich T

2016-05-01

We describe a case of a 30-year-old woman who suffered a traumatic injury of the right brachial plexus, developing severe complex regional pain syndrome type II (CRPS-II). After clinical treatment failure, spinal cord stimulation (SCS) was indicated with initial positive pain control. However, after 2 years her pain progressively returned to almost baseline intensity before SCS. Additional motor cortex electrode implant was then proposed as a rescue therapy and connected to the same pulse generator. This method allowed simultaneous stimulation of the motor cortex and SCS in cycling mode with independent stimulation parameters in each site. At 2 years follow-up, the patient reported sustained improvement in pain with dual stimulation, reduction of painful crises, and improvement in quality of life. The encouraging results in this case suggests that this can be an option as add-on therapy over SCS as a possible rescue therapy in the management of CRPS-II. However, comparative studies must be performed in order to determine the effectiveness of this therapy. Chronic neuropathic pain, Complex regional pain syndrome Type II, brachial plexus injury, motor cortex stimulation, spinal cord stimulation.

Single-Molecule Tethered Particle Motion: Stepwise Analyses of Site-Specific DNA Recombination

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Hsiu-Fang Fan

2018-05-01

Full Text Available Tethered particle motion/microscopy (TPM is a biophysical tool used to analyze changes in the effective length of a polymer, tethered at one end, under changing conditions. The tether length is measured indirectly by recording the Brownian motion amplitude of a bead attached to the other end. In the biological realm, DNA, whose interactions with proteins are often accompanied by apparent or real changes in length, has almost exclusively been the subject of TPM studies. TPM has been employed to study DNA bending, looping and wrapping, DNA compaction, high-order DNA–protein assembly, and protein translocation along DNA. Our TPM analyses have focused on tyrosine and serine site-specific recombinases. Their pre-chemical interactions with DNA cause reversible changes in DNA length, detectable by TPM. The chemical steps of recombination, depending on the substrate and the type of recombinase, may result in a permanent length change. Single molecule TPM time traces provide thermodynamic and kinetic information on each step of the recombination pathway. They reveal how mechanistically related recombinases may differ in their early commitment to recombination, reversibility of individual steps, and in the rate-limiting step of the reaction. They shed light on the pre-chemical roles of catalytic residues, and on the mechanisms by which accessory proteins regulate recombination directionality.

Quinine-Promoted, Enantioselective Boron-Tethered Diels-Alder Reaction by Anomeric Control of Transition State Conformation.

Science.gov (United States)

Scholl, Katie; Dillashaw, John; Timpy, Evan; Lam, Yu-Hong; DeRatt, Lindsey; Benton, Tyler R; Powell, Jacqueline P; Houk, Kendall N; Morgan, Jeremy B

2018-05-01

Diels-Alder reactions of tethered vinyl-metal species offer the opportunity to fashion highly functionalized diol intermediates for synthesis. We have developed the first enantioselective boron-tethered Diels-Alder reaction using quinine as a chiral promoter. Quinine recovery, enantioselectivity enhancement, and manipulation of the cyclohexene core are also investigated. DFT modeling calculations confirm the role of quinine as a bidentate ligand enhancing reaction rates. The enantioselectivity of the cycloaddition is proposed to originate from a boron-centered anomeric effect.

Epidural tumour (calcified fibroma) as cause of a 'Cervical Syndrome'

Energy Technology Data Exchange (ETDEWEB)

Piotrowski, W P

1983-01-01

A calcified fibroma caused a so called Cervical Syndrome not responding to medical treatment. In the computerized tomography a compression of the cervical spinal cord could be demonstrated. From this the indication for the operation was given.

COMPARISON OF EARLY AND DELAYED UMBILICAL CORD CLAMPING IN THE THIRD STAGE OF LABOUR

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Tamara Serdinšek

2015-09-01

Full Text Available Background: Umbilical cord clamping in the third stage of labour is still controversial. Early cord clamping is defined as clamping at 10, 15, 30 or 60 seconds after delivery and delayed as clamping after 60 seconds or at 2-5 minutes after delivery, when the cord stops pulsating or when the placenta is visible within the birth canal. Early clamping is one of the three components of active management of the third stage of labour, which has been used widely in modern obstetrics during the last century. However, in some northern European countries, various parts of the USA and Canada and in developing countries physiological management is preferred.Conclusions: After publication of several trials describing advantages of delayed clamping, this has recently been progressively replacing early clamping. The most important advantages of delayed cord clamping are higher haemoglobin and ferritin levels, higher iron stores, lower incidence of iron deficiency anaemia, better cardiopulmonary adaptation, lower rate of respiratory distress syndrome, and longer duration of early breastfeeding in term neonates, while there is no increase in the incidence of postpartum haemorrhage. Delayed clamping seems to bring some advantages for preterm neonates as well. However, caution is still advised because of the potential adverse effects, especially polycythaemia with hyperviscosity, hyperbilirubinaemia and respiratory distress.

UV-Curable Hybrid Nanocomposite Coating to Protect Tether Polymer Materials, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address the NASA need for coatings to protect and strengthen tether materials for Momentum-exchange Electrodynamic Reboost (MXER) technology, Luminit, LLC,...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... arrow What is the “Spinal Cord Injury Model Systems” program? play_arrow What are the most promising new treatments for spinal cord injuries? play_arrow What are the latest developments in the use of electrical stimulation for spinal cord injuries? play_arrow ...

Spinal Cord Injury 101

Medline Plus

Full Text Available ... Abuse and Spinal Cord Injury Allen Heinemann, PhD How Peer Counseling Works Julie Gassaway, MS, RN Pediatric Injuries Pediatric Spinal ... What is a spinal cord injury? play_arrow How does the spinal cord work? play_arrow Why is the level of a ...

Epidural tumour (calcified fibroma) as cause of a 'Cervical Syndrome'

International Nuclear Information System (INIS)

Piotrowski, W.P.

1983-01-01

A calcified fibroma caused a so called cervical syndrome not responding to medical treatment. In the computerized tomography a compression of the cervical spinal cord could be demonstrated. From this the indication for the operation was given. (Author)

Spinal cord stimulation paresthesia and activity of primary afferents.

Science.gov (United States)

North, Richard B; Streelman, Karen; Rowland, Lance; Foreman, P Jay

2012-10-01

A patient with failed back surgery syndrome reported paresthesia in his hands and arms during a spinal cord stimulation (SCS) screening trial with a low thoracic electrode. The patient's severe thoracic stenosis necessitated general anesthesia for simultaneous decompressive laminectomy and SCS implantation for chronic use. Use of general anesthesia gave the authors the opportunity to characterize the patient's unusual distribution of paresthesia. During SCS implantation, they recorded SCS-evoked antidromic potentials at physiologically relevant amplitudes in the legs to guide electrode placement and in the arms as controls. Stimulation of the dorsal columns at T-8 evoked potentials in the legs (common peroneal nerves) and at similar thresholds, consistent with the sensation of paresthesia in the arms, in the right ulnar nerve. The authors' electrophysiological observations support observations by neuroanatomical specialists that primary afferents can descend several (in this case, at least 8) vertebral segments in the spinal cord before synapsing or ascending. This report thus confirms a physiological basis for unusual paresthesia distribution associated with thoracic SCS.

Tuning peptide self-assembly by an in-tether chiral center

Science.gov (United States)

Hu, Kuan; Xiong, Wei; Li, Hu; Zhang, Pei-Yu; Yin, Feng; Zhang, Qianling; Jiang, Fan; Li, Zigang

2018-01-01

The self-assembly of peptides into ordered nanostructures is important for understanding both peptide molecular interactions and nanotechnological applications. However, because of the complexity and various self-assembling pathways of peptide molecules, design of self-assembling helical peptides with high controllability and tunability is challenging. We report a new self-assembling mode that uses in-tether chiral center-induced helical peptides as a platform for tunable peptide self-assembly with good controllability. It was found that self-assembling behavior was governed by in-tether substitutional groups, where chirality determined the formation of helical structures and aromaticity provided the driving force for self-assembly. Both factors were essential for peptide self-assembly to occur. Experiments and theoretical calculations indicate long-range crystal-like packing in the self-assembly, which was stabilized by a synergy of interpeptide π-π and π-sulfur interactions and hydrogen bond networks. In addition, the self-assembled peptide nanomaterials were demonstrated to be promising candidate materials for applications in biocompatible electrochemical supercapacitors.

Spinal Cord Injury 101

Medline Plus

Full Text Available ... the spinal cord work? play_arrow Why is the level of a spinal cord injury important? play_arrow What role does “compression” play in a spinal cord injury? play_arrow Why are high-dose steroids often used right after an injury? play_arrow What is meant ...

Spinal cord stimulation

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

Prospective double-blind preoperative pain clinic screening before microsurgical denervation of the spermatic cord in patients with testicular pain syndrome.

Science.gov (United States)

Oomen, Robert J A; Witjens, Annemijke C; van Wijck, Albert J M; Grobbee, Diederik E; Lock, Tycho M T W

2014-09-01

Testicular pain syndrome (TPS), defined as an intermittent or constant pain in one or both testicles for at least 3 months, resulting in significant reduction of daily activities, is common. Microsurgical denervation of the spermatic cord (MDSC) has been suggested as an effective treatment option. The study population comprised 180 TPS patients admitted to our outpatient urology clinic between 1999 and 2011. On 3 different occasions, patients were offered a double-blind, placebo-controlled temporary blockade of the spermatic cord. A single blockade consisted of 10 mL 2% lidocaine, 10 mL 0.25% bupivacaine, or 10 mL 0.9% sodium chloride. If the results of these blockades were positive, MDSC was offered. All MDSCs were performed by a single urologist (M.T.W.T.L.) using an inguinal approach. Pain reduction was determined at prospective follow-up. This study evaluated 180 patients. Most patients (61.1%) had undergone a scrotal or inguinal procedure. Patients had complaints during sexual activities (51.7%), sitting (37.5%), and/or cycling (36.7%); 189 randomized blockades were offered to all patients. There was a positive response in 37% and a negative response in 51%. MDSC was performed on 58 testicular units, including 3 patients with a negative outcome of the blockades. At mean follow-up of 42.8 months, 86.2% had a ≥ 50% reduction of pain and 51.7% were completely pain free. MDSC is a valuable treatment option for TPS patients because in this study 86.2% experienced a ≥ 50% reduction of pain. To prevent superfluous diagnostics and treatment, it is mandatory to follow a systematic protocol in the treatment of TPS. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

Energy Technology Data Exchange (ETDEWEB)

Sund, James B., E-mail: jim@jamessund.com [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Causey, Corey P. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Wolter, Scott D. [Department of Physics, Elon University, Elon, NC 27244 (United States); Parker, Charles B., E-mail: charles.parker@duke.edu [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Stoner, Brian R. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States); Research Triangle Institute (RTI) International, Research Triangle Park, NC (United States); Toone, Eric J. [Departments of Chemistry and Biochemistry, Duke University, Durham, NC (United States); Glass, Jeffrey T. [Department of Electrical and Computer Engineering, Duke University, Durham, NC (United States)

2014-05-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

Diamond surface functionalization with biomimicry – Amine surface tether and thiol moiety for electrochemical sensors

International Nuclear Information System (INIS)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-01-01

Highlights: • Diamond surfaces were functionalized with organic molecules using a novel approach. • Used biomimicry to select a molecule to bind NO, similar to the human body. • Molecular orbital theory predicted the molecule-analyte oxidation behavior. • A thiol moiety was attached to an amine surface tether on the diamond surface. • XPS analysis verified each surface functionalization step. - Abstract: The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen–oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis

MRI in Lyme disease of the spinal cord

Energy Technology Data Exchange (ETDEWEB)

Mantienne, C.; Catalaa, I.; Sevely, A.; Cognard, C.; Manelfe, C. [Dept. of Diagnostic and Therapeutic Neuroradiology, Hopital Purpan, Toulouse (France); Albucher, J.F. [Dept. of Neurology, Hopital Purpan, Toulouse (France)

2001-06-01

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case. (orig.)

MRI in Lyme disease of the spinal cord

International Nuclear Information System (INIS)

Mantienne, C.; Catalaa, I.; Sevely, A.; Cognard, C.; Manelfe, C.; Albucher, J.F.

2001-01-01

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case. (orig.)

Technical and economical assessment on tethered wind-energy systems (TWES)

Energy Technology Data Exchange (ETDEWEB)

Furuya, O.; Maekawa, S.

1982-06-01

The objective of the work reported was to establish the potential of tethered wind energy systems for energy conversion in the upper atmosphere. Of the concepts investigated, the Vertical Takeoff and Landing (VTOL) lift generation concept had the highest potential as compared to balloon, wind and hybrid concepts.

Spinal Cord Injury 101

Medline Plus

Full Text Available ... injury? play_arrow How does the spinal cord work? play_arrow Why is the level of a spinal cord injury important? play_arrow What role does “compression” play in a spinal cord injury? play_arrow Why are high-dose steroids often used right after an injury? play_arrow What is meant ...

Diamond surface functionalization with biomimicry - Amine surface tether and thiol moiety for electrochemical sensors

Science.gov (United States)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-05-01

The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen-oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

Guillain-Barré Syndrome as First Presentation of Non-Hodgkin's Lymphoma

Directory of Open Access Journals (Sweden)

Abolhassan Ertiaei

2016-07-01

Full Text Available We present a woman referred with underlying non-Hodgkin's lymphoma (NHL masquerading clinically with Guillain-Barré syndrome (GBS like syndrome. At first evaluation, chest CT-Scan along with brain and whole spine MRI were normal. Electrodiagnostic studies were in favor of acute generalized polyradiculoneuropathy. Laboratory evaluation revealed hypoglycorrhachia. She treated with plasmapheresis after two weeks; she was discharged from hospital, but neurological recovery was not complete. After 6 months, she came back with acute onset of weakness in lower limbs, back pain, fever and urinary incontinence. Pinprick and light touch complete sensory loss was found beneath umbilicus. Thoracic MRI with contrast revealed a dorsal epidural mass extending smoothly from T8 to T12 (10 cm with spinal cord compression. She underwent urgent laminectomy for spinal cord decompression. Histological examination revealed small round cell tumor suggestive of malignant T-cell type lymphoma. In cases with Guillain-Barré syndrome presentation, systemic hematologic disorders such as non-Hodgkin's lymphoma should be considered as one of the differential diagnosis of underlying disease.

Cord Blood Chimerism And Relapse After Haplo-Cord Transplantation

Science.gov (United States)

van Besien, Koen; Koshy, Nebu; Gergis, Usama; Mayer, Sebastian; Cushing, Melissa; Rennert, Hannah; Slotky, Ronit; Mark, Tomer; Pearse, Roger; Rossi, Adriana; Phillips, Adrienne; Vasovic, Liljana; Ferrante, Rosanna; Hsu, Michael; Shore, Tsiporah

2018-01-01

Haplo-cord stem cell transplantation combines the infusion of CD34 selected hematopoietic progenitors from a haplo-identical donor with an umbilical cord blood graft from an unrelated donor and allows faster count recovery, with low rates of disease recurrence and chronic GVHD. But the contribution of the umbilical cord blood graft to long-term transplant outcome remains unclear. We analyzed 39 recipients of haplo-cord transplants with AML and MDS, engrafted and in remission at 2 months. Median age was 66 (18-72) and all had intermediate, high, or very high risk disease. Less than 20% UCB chimerism in the CD33 lineage was associated with an increased rate of disease recurrence (54% vs 11% Pdisease recurrence (46% vs 12%, P=0.007) Persistent haplo-chimerism in the CD3 lineage was associated with an increased rate of disease recurrence (40% vs 15%, P=0.009) Chimerism did not predict for treatment related mortality. The cumulative incidence of acute GVHD by day 100 was 43%. The cumulative incidence of moderate/severe chronic GVHD was only 5%. Engraftment of the umbilical cord blood grafts provides powerful GVL effects which protect against disease recurrence and is associated with low risk of chronic GVHD. Engraftment of CD34 selected haplo-identical cells can lead to rapid development of circulating T-cells, but when these cells dominate, GVL-effects are limited and rates of disease recurrence are high. PMID:27333804

Fixed cord in spinal stenosis

International Nuclear Information System (INIS)

Levy, L.M.; Wang, H.; Francomano, C.; Hurko, O.; Carson, B.; Heffez, D.S.; DiChiro, G.; Bryan, R.N.

1990-01-01

This paper evaluates patients with cervical spinal canal compromise due to congenital anomalies (achondroplasia, Chiari malformation) and degenerative diseases using MR cord motion and cerebrospinal fluid (CSF) flow studies. Pulsatile longitudinal motion of the cervical cord was determined by means of cardiac-gated velocity phase contrast methods, including cine. Pathology included dwarfism (n = 15), Chiari malformation (n = 10), spondylosis (n = 10), and acute cord compression (n = 9). Symptomatic cases of congenital cervical stenosis had decreased cord motion, although CSF flow was not always significantly compromised. Postoperative cases demonstrated good cord and CSF motion, unless compression or obstruction was present

Rhabdomyolysis resulting in concurrent Horner's syndrome and brachial plexopathy: a case report

Energy Technology Data Exchange (ETDEWEB)

Lee, Susan C.; Geannette, Christian; Sneag, Darryl B. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Wolfe, Scott W. [Hospital for Special Surgery, Hand and Upper Extremity, Department of Orthopedics, New York, NY (United States); Feinberg, Joseph H. [Hospital for Special Surgery, Physical Medicine and Rehabilitation, New York, NY (United States)

2017-08-15

This case report describes a 29-year-old male who presented with immediate onset of Horner's syndrome and ipsilateral brachial plexopathy after sleeping with his arm dangling outside a car window for 8 h. Outside workup and imaging revealed rhabdomyolysis of the left neck musculature. Subsequent electrodiagnostic testing and high-resolution brachial plexus magnetic resonance imaging at the authors' institution attributed the Horner's syndrome and concurrent brachial plexopathy to rhabdomyolysis of the longus colli and scalene musculature, which had compressed - and consequently scar tethered - the cervical sympathetic trunk and brachial plexus. This case of co-existent Horner's syndrome and brachial plexopathy demonstrates the role of high-resolution brachial plexus MRI in diagnosing plexopathy and the importance of being familiar with plexus and paravertebral muscle anatomy. (orig.)

Phase coupling of a circadian neuropeptide with rest/activity rhythms detected using a membrane-tethered spider toxin.

Directory of Open Access Journals (Sweden)

Ying Wu

2008-11-01

Full Text Available Drosophila clock neurons are self-sustaining cellular oscillators that rely on negative transcriptional feedback to keep circadian time. Proper regulation of organismal rhythms of physiology and behavior requires coordination of the oscillations of individual clock neurons within the circadian control network. Over the last decade, it has become clear that a key mechanism for intercellular communication in the circadian network is signaling between a subset of clock neurons that secrete the neuropeptide pigment dispersing factor (PDF and clock neurons that possess its G protein-coupled receptor (PDFR. Furthermore, the specific hypothesis has been proposed that PDF-secreting clock neurons entrain the phase of organismal rhythms, and the cellular oscillations of other clock neurons, via the temporal patterning of secreted PDF signals. In order to test this hypothesis, we have devised a novel technique for altering the phase relationship between circadian transcriptional feedback oscillation and PDF secretion by using an ion channel-directed spider toxin to modify voltage-gated Na(+ channel inactivation in vivo. This technique relies on the previously reported "tethered-toxin" technology for cell-autonomous modulation of ionic conductances via heterologous expression of subtype-specific peptide ion channel toxins as chimeric fusion proteins tethered to the plasma membrane with a glycosylphosphatidylinositol (GPI anchor. We demonstrate for the first time, to our knowledge, the utility of the tethered-toxin technology in a transgenic animal, validating four different tethered spider toxin ion channel modifiers for use in Drosophila. Focusing on one of these toxins, we show that GPI-tethered Australian funnel-web spider toxin delta-ACTX-Hv1a inhibits Drosophila para voltage-gated Na(+ channel inactivation when coexpressed in Xenopus oocytes. Transgenic expression of membrane-tethered delta-ACTX-Hv1a in vivo in the PDF-secreting subset of clock neurons

Computer Programs for Calculating and Plotting the Stability Characteristics of a Balloon Tethered in a Wind

Science.gov (United States)

Bennett, R. M.; Bland, S. R.; Redd, L. T.

1973-01-01

Computer programs for calculating the stability characteristics of a balloon tethered in a steady wind are presented. Equilibrium conditions, characteristic roots, and modal ratios are calculated for a range of discrete values of velocity for a fixed tether-line length. Separate programs are used: (1) to calculate longitudinal stability characteristics, (2) to calculate lateral stability characteristics, (3) to plot the characteristic roots versus velocity, (4) to plot the characteristic roots in root-locus form, (5) to plot the longitudinal modes of motion, and (6) to plot the lateral modes for motion. The basic equations, program listings, and the input and output data for sample cases are presented, with a brief discussion of the overall operation and limitations. The programs are based on a linearized, stability-derivative type of analysis, including balloon aerodynamics, apparent mass, buoyancy effects, and static forces which result from the tether line.

Use of Tethered Enzymes as a Platform Technology for Rapid Analyte Detection.

Directory of Open Access Journals (Sweden)

Roy Cohen

Full Text Available Rapid diagnosis for time-sensitive illnesses such as stroke, cardiac arrest, and septic shock is essential for successful treatment. Much attention has therefore focused on new strategies for rapid and objective diagnosis, such as Point-of-Care Tests (PoCT for blood biomarkers. Here we use a biomimicry-based approach to demonstrate a new diagnostic platform, based on enzymes tethered to nanoparticles (NPs. As proof of principle, we use oriented immobilization of pyruvate kinase (PK and luciferase (Luc on silica NPs to achieve rapid and sensitive detection of neuron-specific enolase (NSE, a clinically relevant biomarker for multiple diseases ranging from acute brain injuries to lung cancer. We hypothesize that an approach capitalizing on the speed and catalytic nature of enzymatic reactions would enable fast and sensitive biomarker detection, suitable for PoCT devices.We performed in-vitro, animal model, and human subject studies. First, the efficiency of coupled enzyme activities when tethered to NPs versus when in solution was tested, demonstrating a highly sensitive and rapid detection of physiological and pathological concentrations of NSE. Next, in rat stroke models the enzyme-based assay was able in minutes to show a statistically significant increase in NSE levels in samples taken 1 hour before and 0, 1, 3 and 6 hours after occlusion of the distal middle cerebral artery. Finally, using the tethered enzyme assay for detection of NSE in samples from 20 geriatric human patients, we show that our data match well (r = 0.815 with the current gold standard for biomarker detection, ELISA-with a major difference being that we achieve detection in 10 minutes as opposed to the several hours required for traditional ELISA.Oriented enzyme immobilization conferred more efficient coupled activity, and thus higher assay sensitivity, than non-tethered enzymes. Together, our findings provide proof of concept for using oriented immobilization of active

Endogenous opioids are involved in abnormal stereotyped behaviour of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, van J.M.

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

Endogenous opioids are involved in abnormal stereotyped behaviours of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, J.M. van

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

TETHERED BALLOON MEASUREMENTS OF BIOGENIC VOCS IN THE ATMOSPHERIC BOUNDARY LAYER

Science.gov (United States)

Measurements of biogenic volatile organic compounds (BVOCs) have been made on a tethered balloon platform in eleven field deployments between 1985 and 1996. A series of balloon sampling packages have been developed for these campaigns and they have been used to describe boundary ...

Primary ciliary dyskinesia: Kartagener syndrome in a family with a ...

African Journals Online (AJOL)

Makia J. Marafie

2014-12-22

Dec 22, 2014 ... flagella of sperm tail, brain and spinal cord ependyma [2]. Many syndromes are linked to ... VC) to left sided superior caval vein (right sided inferior caval vein), and with S/P left .... east: nature versus nurture. Open Complement ...

Analytical investigation of the dynamics of tethered constellations in Earth orbit, phase 2

Science.gov (United States)

Lorenzini, E. C.; Arnold, D. A.; Cosmo, M.; Grossi, M. D.

1986-10-01

The following topics related to the dynamics of the 4-mass tethered system are addressed: (1) the development of damping algorithms for damping the out-of-plane libration of the system and the interaction of the out-of-plane control with the other degrees of freedom; and (2) the development of environmental models to be added to the dynamics simulation computer code. The environmental models are specifically a new drag routine based on the Jacchia's 1977 model, a J(2) model and an accurate thermal model of the wire. Regarding topic (1) a survey of various out-of-plane libration control laws was carried out. Consequently a yo-yo control law with amplitude of the tether length variation proportional to the amplitude of the out-of-game libration has been selected. This control law provides good damping when applied to a (theoretical) two-dimensional system. In the actual 3-dimensional 4-mass tethered system, however, energy is transferred to the least damped degrees of freedom (the out-of-plane lateral deflections are still undamped in the present simulations) in such a way as to decrease the effectiveness of the algorithm for out-of-plane libration control. The addition of damping algorithms for the out-of-plane lateral deflections is therefore necessary.

Compact, planar, translational piezoelectric bimorph actuator with Archimedes’ spiral actuating tethers

International Nuclear Information System (INIS)

Yang, Chenye; Liu, Sanwei; Livermore, Carol; Xie, Xin

2016-01-01

The design, analytical modelling, finite element analysis (FEA), and experimental characterization of a microelectromechanical system (MEMS) out-of-plane (vertical) translational piezoelectric lead–zirconate–titanate (PZT) bimorph actuator supported on Archimedes’ spiral tethers are presented. Three types of bimorph actuators with different electrode patterns (with spiral tethers half actuated, fully actuated with uniform polarity, or fully actuated with reversed polarity) are designed and modelled. The two actuators with the highest predicted performance (half actuated and fully actuated with uniform polarity) are implemented and characterized. Both designs are fabricated by commercial processes and are compatible with integration into more complex MEMS systems. Analytical modelling and FEA are used to analyze and predict the actuators’ displacements and blocking forces. Experimental measurements of the deflections and blocking forces of actuators with full uniform actuation and half actuation validate the design. At an applied voltage of 110 V, the out-of-plane deflections of the actuators with half actuation and full uniform actuation are measured at about 17 µ m and 29 µ m respectively, in good agreement with analytical predictions of 17.3 µ m and 34.2 µ m and FEA predictions of 17.1 µ m and 25.8 µ m. The blocking force for devices with half-actuated tethers is predicted to be 12 mN (analytical) and 10 mN (FEA), close to the experimental value of 9 mN. The blocking force for devices with full uniform actuation is predicted to be 23 mN (analytical) and 17 mN (FEA), as compared with 15 mN in experiments. (paper)

Experimental study of effectiveness of local application of electroneurostimulation, cortexin and methylprednisolone in acute spinal cord injury

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Tsymbaliuk V.I.

2014-09-01

Full Text Available The tasks were to investigate the effect of topical electroneurostimulation, cortexin and methy¬lprednisolone in acute spinal cord injury in electrophysiological experiments on laboratory rats. The animals un¬derwent half transection of the spinal cord in the lower-thoracic area to simulate Brown-Sequard’s syndrome. Drugs were administered subdurally once daily in the dose of 0.03 mg for cortexin and 0.7 mg for methylprednisolone during 72 hours. Electrophysiological studies were carried out using standard electrophysiological apparatus. Reliable changes of bioelectric indicators in neuromuscular complex during topical application of electrical stimulation, as well as in administered methylprednisolone, failed to be found. However, local application of cortexin in terms of traumatic spinal cord injury due the antioxidant and neurotrophic effect results in improvement of bioelectrical indicators; this is manifested in reliable (p<0.05 increase of amplitude of the background electromyogram impulses at rest by 33% and increase of spontaneous oscillations frequency by 29.82%.

Optimal method for collection of umbilical cord blood: an Egyptian trial for a public cord blood bank.

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Bassiouny, M R; El-Chennawi, F; Mansour, A K; Yahia, S; Darwish, A

2015-06-01

Umbilical cord blood (UCB) contains stem cells and can be used as an alternative to bone marrow transplantation. Engraftment is dependent on the total nucleated cell (TNC) and CD34+ cell counts of the cord blood units. This study was designed to evaluate the effect of the method of collection of the UCB on the yield of the cord blood units. Informed consent was obtained from 100 eligible mothers for donation of cord blood. Both in utero and ex utero methods were used for collection. The cord blood volume was measured. The TNC and the CD34+ cell counts were enumerated. We have found that in utero collection gave significantly larger volumes of cord blood and higher TNC counts than ex utero collection. There was no significant difference between both methods regarding the CD34+ cell counts. This study revealed a significant correlation between the volume of the collected cord blood and both TNC and CD34+ cell counts. It is better to collect cord blood in utero before placental delivery to optimize the quality of the cord blood unit. © 2015 AABB.

The secret life of tethers: the role of tethering factors in SNARE complex regulation

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Michelle L Dubuke

2016-05-01

Full Text Available Trafficking in eukaryotic cells is a tightly regulated process to ensure correct cargo delivery to the proper destination organelle or plasma membrane. In this review, we focus on how the vesicle fusion machinery, the SNARE complex, is regulated by the interplay of the multisubunit tethering complexes (MTC with the SNAREs and Sec1/Munc18 (SM proteins. Although these factors are used in different stages of membrane trafficking, e.g. Golgi to plasma membrane transport vs vacuolar fusion, and in a variety of diverse eukaryotic cell types, many commonalities between their functions are being revealed. We explore the various protein-protein interactions and findings from functional reconstitution studies in order to highlight both their common features and the differences in their modes of regulation. These studies serve as a starting point for mechanistic explorations in other systems.

Case report

African Journals Online (AJOL)

abp

27 déc. 2017 ... bone marrow of thoracolumbar vertebrae in two hemi-cords without bone spur separating the two hemi-marrows, compatible with type 1 diastematomyelia. It was associated with low tethered spinal cord with syringomyelic cavity involving the left hemi-marrow and with biloculated fibrotic lesion at the level of ...

Tethered Lubricants for Small Systems

Energy Technology Data Exchange (ETDEWEB)

Lynden A. Archer

2006-01-09

The objective of this research project is two-fold. First, to fundamentally understand friction and relaxation dynamics of polymer chains near surfaces; and second, to develop novel self-lubricated substrates suitable for MEMS devices. During the three-year performance period of this study the PI and his students have shown using theory and experiments that systematic introduction of disorder into tethered lubricant coatings (e.g. by using self-assembled monolayer (SAM) mixtures or SAMs with nonlinear, branched architectures) can be used to significantly reduce the friction coefficient of a surface. They have also developed a simple procedure based on dielectric spectroscopy for quantifying the effect of surface disorder on molecular relaxation in lubricant coatings. Details of research accomplishments in each area of the project are described in the body of the report.

Theseus: tethered distributed robotics (TDR)

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Digney, Bruce L.; Penzes, Steven G.

2003-09-01

The Defence Research and Development Canada's (DRDC) Autonomous Intelligent System's program conducts research to increase the independence and effectiveness of military vehicles and systems. DRDC-Suffield's Autonomous Land Systems (ALS) is creating new concept vehicles and autonomous control systems for use in outdoor areas, urban streets, urban interiors and urban subspaces. This paper will first give an overview of the ALS program and then give a specific description of the work being done for mobility in urban subspaces. Discussed will be the Theseus: Thethered Distributed Robotics (TDR) system, which will not only manage an unavoidable tether but exploit it for mobility and navigation. Also discussed will be the prototype robot called the Hedgehog, which uses conformal 3D mobility in ducts, sewer pipes, collapsed rubble voids and chimneys.

Spinal cord stimulation: Current applications for treatment of chronic pain.

Science.gov (United States)

Vannemreddy, Prasad; Slavin, Konstantin V

2011-01-01

Spinal cord stimulation (SCS) is thought to relieve chronic intractable pain by stimulating nerve fibers in the spinal cord. The resulting impulses in the fibers may inhibit the conduction of pain signals to the brain, according to the pain gate theory proposed by Melzack and Wall in 1965 and the sensation of pain is thus blocked. Although SCS may reduce pain, it will not eliminate it. After a period of concern about safety and efficacy, SCS is now regaining popularity among pain specialists for the treatment of chronic pain. The sympatholytic effect of SCS is one of its most interesting therapeutic properties. This effect is considered responsible for the effectiveness of SCS in peripheral ischemia, and at least some cases of complex regional pain syndrome. The sympatholytic effect has also been considered part of the management of other chronic pain states such as failed back surgery syndrome, phantom pain, diabetic neuropathy, and postherpetic neuralgia. In general, SCS is part of an overall treatment strategy and is used only after the more conservative treatments have failed. The concept of SCS has evolved rapidly following the technological advances that have produced leads with multiple contact electrodes and battery systems. The current prevalence of patients with chronic pain requiring treatment other than conventional medical management has significantly increased and so has been the need for SCS. With the cost benefit analysis showing significant support for SCS, it may be appropriate to offer this as an effective alternative treatment for these patients.

Cholesterol tethered bioresponsive polycation as a candidate for gene delivery

Energy Technology Data Exchange (ETDEWEB)

Zhu Ying [Second Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310009 (China); Wang Youxiang, E-mail: yx_wang@zju.edu.cn [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Zhejiang University, Hangzhou 310027 (China); Hu Qiaoling; Shen Jiacong [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Zhejiang University, Hangzhou 310027 (China)

2009-04-30

The efficient unpacking of viral protein shell gave the inspiration for the synthesized vectors. In this research, novel cholesterol tethered bioresponsive polyethylenimine (PEI) was specially designed via disulfide-containing cross-linker. The cholesterol lipid had proved to increase the permeability of gene vector through cell membrane. The acid-base titration indicated that the synthesized polycation possessed efficient proton sponge effect, which was suggested to increase endosomal release of pDNA complexes into the cytoplasm. The cholesterol tethered polycation could effectively induce DNA condensation and form spherical particles with diameter about 200 nm at N/P ratio of 10. At glutathione concentration of 3 mM, the polyplexes were unpacked due to the bioresponsive cleavage of the disulfide bonds. The in-vitro experiment indicated that the polyplexes showed efficient transfection efficiency to HEK293T cells. All the results indicated that the bioresponsive polycation could be served as an effective trigger to control the release of DNA at the intracellular environment. The novel bioresponsive polycation might have great potential in non-viral gene delivery research and application.

The nasogastric tube syndrome: two case reports and review of the literature.

Science.gov (United States)

Apostolakis, L W; Funk, G F; Urdaneta, L F; McCulloch, T M; Jeyapalan, M M

2001-01-01

The nasogastric tube syndrome is a potentially life-threatening complication of an indwelling nasogastric (NG) tube. The syndrome is thought to result from ulceration and infection of the posterior cricoid region with subsequent dysfunction of vocal cord abduction. This dysfunction may present as complete loss of vocal cord abduction manifested as serious airway compromise. Reports of this syndrome are infrequent, with only 29 cases published to date. Two additional cases of nasogastric tube syndrome diagnosed at the University of Iowa Hospitals and Clinics over a 2-year period are presented. A search of MEDLINE (1966 through February 1999), including review of those articles' references identified seven previous publications, including 29 case reports. These 29 cases are reviewed and the findings summarized. Twenty-nine cases of NG tube syndrome are identified, with 16 of these occurring in the preantibiotic period. Including the two cases presented here, 15 contemporary patients are examined. Among these 15 cases, 10 required tracheostomy, on average 8.5 days after NG tube placement. Although the fully manifested syndrome presents quite dramatically, we suspect that a clinical spectrum of severity exists with less severe cases going unrecognized. Consistent with previous reports, we found that direct visualization of the postcricoid region is required to rule out the diagnosis and recommend such action be taken whenever the diagnosis is suspected. Treatment should include establishment of a safe airway, removal of the tube whenever possible, antibiotic therapy, and antireflux therapy.

Effect of mass variation on dynamics of tethered system in orbital maneuvering

Science.gov (United States)

Sun, Liang; Zhao, Guowei; Huang, Hai

2018-05-01

In orbital maneuvering, the mass variation due to fuel consumption has an obvious impact on the dynamics of tethered system, which cannot be neglected. The contributions of the work are mainly shown in two aspects: 1) the improvement of the model; 2) the analysis of dynamics characteristics. As the mass is variable, and the derivative of the mass is directly considered in the traditional Lagrange equation, the expression of generalized force is complicated. To solve this problem, the coagulated derivative is adopted in the paper; besides, the attitude dynamics equations derived in this paper take into account the effect of mass variation and the drift of orbital trajectory at the same time. The bifurcation phenomenon, the pendular motion angular frequency, and amplitudes of tether vibration revealed in this paper can provide a reference for the parameters and controller design in practical engineering. In the article, a dumbbell model is adopted to analyze the dynamics of tethered system, in which the mass variation of base satellite is fully considered. Considering the practical application, the case of orbital transfer under a transversal thrust is mainly studied. Besides, compared with the analytical solutions of librational angles, the effects of mass variation on stability and librational characteristic are studied. Finally, in order to make an analysis of the effect on vibrational characteristic, a lumped model is introduced, which reveals a strong coupling of librational and vibrational characteristics.

Arterial Blood Supply to the Spinal Cord in Animal Models of Spinal Cord Injury. A Review.

Science.gov (United States)

Mazensky, David; Flesarova, Slavka; Sulla, Igor

2017-12-01

Animal models are used to examine the results of experimental spinal cord injury. Alterations in spinal cord blood supply caused by complex spinal cord injuries contribute significantly to the diversity and severity of the spinal cord damage, particularly ischemic changes. However, the literature has not completely clarified our knowledge of anatomy of the complex three-dimensional arterial system of the spinal cord in experimental animals, which can impede the translation of experimental results to human clinical applications. As the literary sources dealing with the spinal cord arterial blood supply in experimental animals are limited and scattered, the authors performed a review of the anatomy of the arterial blood supply to the spinal cord in several experimental animals, including pigs, dogs, cats, rabbits, guinea pigs, rats, and mice and created a coherent format discussing the interspecies differences. This provides researchers with a valuable tool for the selection of the most suitable animal model for their experiments in the study of spinal cord ischemia and provides clinicians with a basis for the appropriate translation of research work to their clinical applications. Anat Rec, 300:2091-2106, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Calculating the electromagnetic field on the earth due to an electrodynamic tethered system in the ionosphere

Science.gov (United States)

Estes, Robert D.

1989-01-01

A method is presented for calculating the electromagnetic wave field on the earth's surface associated with the operation of an electrodynamic tethered satellite system of constant or slowly varying current in the upper ionosphere. The wave field at the ionospheric boundary and on the earth's surface is obtained by numerical integration. The results suggest that the ionospheric waves do not propagate into the atmosphere and that the image of the Alfven wings from a steady-current tether should be greatly broadened on the earth's surface.

Elasticity of Hard-Spheres-And-Tether Systems

International Nuclear Information System (INIS)

Farago, O.; Kantor, Y.

1999-01-01

Physical properties of a large class of systems ranging from noble gases to polymers and rubber are primarily determined by entropy, while the internal energy plays a minor role. Such systems can be conveniently modeled and numerically studied using ''hard' (i.e., ''infinity-or-zero'') potentials, such as hard sphere repulsive interactions, or inextensible (''tether'') bonds which limit the distance between the bonded monomers, but have zero energy at all permitted distances. The knowledge of elastic constants is very important for understanding the behavior of entropy-dominated systems. Computational methods for determination of the elastic constants in such systems are broadly classified into ''strain'' methods and (fluctuation methods. In the former, the elastic constants are extracted from stress-strain relations, while in the latter they are determined from measurements of stress fluctuations. The fluctuation technique usually enables more accurate and well-controlled determination of the elastic constants since in this method the elastic constants are computed directly from simulations of the un strained system with no need to deform the simulation cell and perform numerical differentiations. For central forces systems, the original ''fluctuation'' formalism can be applied provided the pair potential is twice differentiable. We have extended this formalism to apply to hard-spheres-and-tether models in which this requirement is not fulfilled. We found that for such models the components of the tensor of elastic constants can be related to (two-, three- and four-point) probability densities of contacts between hard spheres and stretched bonds. We have tested our formalism on simple (phantom networks and three-dimensional hard spheres systems

SPINAL CORD- A CADAVERIC STUDY

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Vijayamma K. N

2018-01-01

Full Text Available BACKGROUND Spinal cord is situated within the vertebral canal extending from the lower end of the medulla oblongata at the upper border of first cervical vertebra. In early foetal life, it extends throughout the length of the vertebral canal, and at the time of birth, it reaches the level of third lumbar vertebra. In adult, it ends at the lower border of first lumbar vertebra and thereafter continued as filum terminale, which gets attached to tip of coccyx. Spinal cord is covered by three protective membranes called spinal meninges, diameter, arachnoid and pia mater. The diameter and arachnoid mater extent up to second sacral vertebra and the pia mater forms filum terminale and extend at the tip of coccyx. MATERIALS AND METHODS Forty spinal cord cadaveric specimen were studied by dissection method after exposing the vertebral canal. The roots of spinal nerve were sectioned on both sides and the cord is released along with its coverings. The dura and arachnoid mater were incised longitudinally and the subarachnoid space, blood vessels, nerve roots, ligament denticulata, cervical and lumbar enlargements were observed. The blood vessels including radicular arteries were also studied photographed. RESULTS The spinal cord is a highly vascular structure situated within the vertebral canal, covered by diameter, arachnoid mater and pia mater. Spinal dura is thicker anteriorly than posteriorly. The pia mater forms linea splendens, which extend along the whole length of the cord in front of the anterior median fissure. The average length of the cord is 38 cm. The length and breadth of cervical enlargement was more compared to lumbar enlargement. The number of rootlets in both dorsal and ventral roots accounts more in cervical compared to other regions of the cord. The ligament denticulata is a thin transparent bands of pia mater attached on either sides of the cord between the dorsal and ventral roots of spinal nerves. The tooth like extensions are well

Optogenetics of the Spinal Cord: Use of Channelrhodopsin Proteins for Interrogation of Spinal Cord Circuits.

Science.gov (United States)

Rahman, Habibur; Nam, Youngpyo; Kim, Jae-Hong; Lee, Won-Ha; Suk, Kyoungho

2017-12-29

Spinal cord circuits play a key role in receiving and transmitting somatosensory information from the body and the brain. They also contribute to the timing and coordination of complex patterns of movement. Under disease conditions, such as spinal cord injury and neuropathic pain, spinal cord circuits receive pain signals from peripheral nerves, and are involved in pain development via neurotransmitters and inflammatory mediators released from neurons and glial cells. Despite the importance of spinal cord circuits in sensory and motor functions, many questions remain regarding the relationship between activation of specific cells and behavioral responses. Optogenetics offers the possibility of understanding the complex cellular activity and mechanisms of spinal cord circuits, as well as having therapeutic potential for addressing spinal cord-related disorders. In this review, we discuss recent findings in optogenetic research employing the channelrhodopsin protein to assess the function of specific neurons and glia in spinal cord circuits ex vivo and in vivo. We also explore the possibilities and challenges of employing optogenetics technology in future therapeutic strategies for the treatment of spinal disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Vocal cord dysfunction in children.

Science.gov (United States)

Noyes, Blakeslee E; Kemp, James S

2007-06-01

Vocal cord dysfunction is characterised by paradoxical vocal cord adduction that occurs during inspiration, resulting in symptoms of dyspnoea, wheeze, chest or throat tightness and cough. Although the condition is well described in children and adults, confusion with asthma often triggers the use of an aggressive treatment regimen directed against asthma. The laryngoscopic demonstration of vocal cord adduction during inspiration has been considered the gold standard for the diagnosis of vocal cord dysfunction, but historical factors and pulmonary function findings may provide adequate clues to the correct diagnosis. Speech therapy, and in some cases psychological counselling, is often beneficial in this disorder. The natural course and prognosis of vocal cord dysfunction are still not well described in adults or children.

Spinal Cord Dysfunction (SCD)

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Department of Veterans Affairs — The Spinal Cord Dysfunction (SCD) module supports the maintenance of local and national registries for the tracking of patients with spinal cord injury and disease...

Spinal cord swelling and candidiasis

International Nuclear Information System (INIS)

Ho, K.; Gronseth, G.; Aldrich, M.; Williams, A.

1982-01-01

Fusiform swelling of the spinal cord was noted myelographically in a patient with Hodgkin's disease. Autopsy revealed that the swelling was cauused by Candida infection of the spinal cord. It is suggested that fungal infection be included in the differential diagnosis of spinal cord swelling in the immunsupporessed cancer patient. (orig.)

Spinal Cord Injury 101

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Full Text Available ... Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation Pediatric Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal Experiences ...

Synthesis and characterization of macromolecular rhodamine tethers and their interactions with P-glycoprotein.

Science.gov (United States)

Crawford, Lindsey; Putnam, David

2014-08-20

Rhodamine dyes are well-known P-glycoprotein (P-gp) substrates that have played an important role in the detection of inhibitors and other substrates of P-gp, as well as in the understanding of P-gp function. Macromolecular conjugates of rhodamines could prove useful as tethers for further probing of P-gp structure and function. Two macromolecular derivatives of rhodamine, methoxypolyethylene glycol-rhodamine6G and methoxypolyethylene glycol-rhodamine123, were synthesized through the 2'-position of rhodamine6G and rhodamine123, thoroughly characterized, and then evaluated by inhibition with verapamil for their ability to interact with P-gp and to act as efflux substrates. To put the results into context, the P-gp interactions of the new conjugates were compared to the commercially available methoxypolyethylene glycol-rhodamineB. FACS analysis confirmed that macromolecular tethers of rhodamine6G, rhodamine123, and rhodamineB were accumulated in P-gp expressing cells 5.2 ± 0.3%, 26.2 ± 4%, and 64.2 ± 6%, respectively, compared to a sensitive cell line that does not overexpress P-gp. Along with confocal imaging, the efflux analysis confirmed that the macromolecular rhodamine tethers remain P-gp substrates. These results open potential avenues for new ways to probe the function of P-gp both in vitro and in vivo.

MR imaging and spinal cord injury

International Nuclear Information System (INIS)

Azar-Kia, B.; Fine, M.; Naheedy, M.; Elias, D.

1987-01-01

MR imaging has significantly improved diagnostic capability of spinal cord injuries. Other available diagnostic modalities such as plain films, myelography, CT, and post-CT myelography have failed to consistently show the secific evidence of spinal cord injuries and their true extent. The authors are presenting our experiences with MR imaging in spinal column injury. They have found MR imaging to be the procedure of choice for prognostic evaluation of spinal cord trauma. They are showing examples of recent and old spinal cord injury such as hematomyelia, myelomalacia, transection, spinal cord edema, and cavitation

Self-consistent field theory of tethered polymers: one dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions.

Science.gov (United States)

Suo, Tongchuan; Whitmore, Mark D

2014-11-28

We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a "mushroom" regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ(1/3) scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ(1/3). In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ(1/3). We also compare the results for two different solvents with each other, and with earlier Θ solvent results.

Self-consistent field theory of tethered polymers: One dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions

International Nuclear Information System (INIS)

Suo, Tongchuan; Whitmore, Mark D.

2014-01-01

We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a “mushroom” regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ 1/3 scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ 1/3 . In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ 1/3 . We also compare the results for two different solvents with each other, and with earlier Θ solvent results

Spinal cord swelling and candidiasis

Energy Technology Data Exchange (ETDEWEB)

Ho, K.; Gronseth, G.; Aldrich, M.; Williams, A.

1982-11-01

Fusiform swelling of the spinal cord was noted myelographically in a patient with Hodgkin's disease. Autopsy revealed that the swelling was caused by Candida infection of the spinal cord. It is suggested that fungal infection be included in the differential diagnosis of spinal cord swelling in the immunosuppressed cancer patient.

Spinal-cord swelling in acute multiple sclerosis

International Nuclear Information System (INIS)

Kikuchi, Seiji; Tashiro, Kunio; Naganuma, Mutsuo; Hida, Kazutoshi; Iwasaki, Yoshinobu; Abe, Hiroshi; Miyasaka, Kazuo

1986-01-01

Despite the frequent involvement of the spinal cord by multiple sclerosis, reports concerning neuroradiological findings regarding these lesions have been limited; most of them have demonstrated a normal or small spinal cord. Two cases of acute paraparesis showed evidence of spinal-cord swelling on myelography and CT myelography, initially suggesting the diagnosis of an intramedullary tumor. Spinal-cord swelling was demonstrated more clearly on CT myelography than on conventional myelography. The diagnosis of multiple sclerosis was made with the aid of the CSF findings, the clinical course, and the contracting-cord sign. The ''contracting-cord sign'' means the diminution of the spinal-cord diameter in the chronic stage. Since acute multiple sclerosis may produce spinal-cord swelling simulating a tumor, careful investigations are necessary to avoid unwarranted surgical interventions. (author)

Cholesterol-Induced Buckling in Physisorbed Polymer-Tethered Lipid Monolayers

Directory of Open Access Journals (Sweden)

Christoph A. Naumann

2013-04-01

Full Text Available The influence of cholesterol concentration on the formation of buckling structures is studied in a physisorbed polymer-tethered lipid monolayer system using epifluorescence microscopy (EPI and atomic force microscopy (AFM. The monolayer system, built using the Langmuir-Blodgett (LB technique, consists of 3 mol % poly(ethylene glycol (PEG lipopolymers and various concentrations of the phospholipid, 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC, and cholesterol (CHOL. In the absence of CHOL, AFM micrographs show only occasional buckling structures, which is caused by the presence of the lipopolymers in the monolayer. In contrast, a gradual increase of CHOL concentration in the range of 0–40 mol % leads to fascinating film stress relaxation phenomena in the form of enhanced membrane buckling. Buckling structures are moderately deficient in CHOL, but do not cause any notable phospholipid-lipopolymer phase separation. Our experiments demonstrate that membrane buckling in physisorbed polymer-tethered membranes can be controlled through CHOL-mediated adjustment of membrane elastic properties. They further show that CHOL may have a notable impact on molecular confinement in the presence of crowding agents, such as lipopolymers. Our results are significant, because they offer an intriguing prospective on the role of CHOL on the material properties in complex membrane architecture.

Focal Anterior Displacement of the Thoracic Spinal Cord without Evidence of Spinal Cord Herniation or an Intradural Mass

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Yoon; Lee, Joon Woo; Lee, Guen Young; Kang, Heung Sik [Department of Radiology, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of)

2014-07-01

We report magnetic resonance imaging (MRI) findings on focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass. We identified 12 patients (male:female = 6:6; mean age, 51.7; range, 15-83 years) between 2007 and 2011, with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MRI findings in consensus. An asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord in all patients, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (thoracic vertebrae 1-6). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and they showed no focal T2-hyperintensity in the spinal cord with the exception of one patient. In addition, cerebrospinal fluid (CSF) flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. Computed tomography myelography revealed preserved CSF flow in the two available patients. Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass.

Focal Anterior Displacement of the Thoracic Spinal Cord without Evidence of Spinal Cord Herniation or an Intradural Mass

International Nuclear Information System (INIS)

Lee, Jong Yoon; Lee, Joon Woo; Lee, Guen Young; Kang, Heung Sik

2014-01-01

We report magnetic resonance imaging (MRI) findings on focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass. We identified 12 patients (male:female = 6:6; mean age, 51.7; range, 15-83 years) between 2007 and 2011, with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MRI findings in consensus. An asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord in all patients, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (thoracic vertebrae 1-6). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and they showed no focal T2-hyperintensity in the spinal cord with the exception of one patient. In addition, cerebrospinal fluid (CSF) flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. Computed tomography myelography revealed preserved CSF flow in the two available patients. Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass

Spinal Cord Injury 101

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Full Text Available ... spinal cord injuries? play_arrow What does stem-cell research on animals tell us? play_arrow When can we expect stem-cell treatments to become available for spinal cord injuries? ...

Use of Tethered Enzymes as a Platform Technology for Rapid Analyte Detection

Science.gov (United States)

Cohen, Roy; Lata, James P.; Lee, Yurim; Hernández, Jean C. Cruz; Nishimura, Nozomi; Schaffer, Chris B.; Mukai, Chinatsu; Nelson, Jacquelyn L.; Brangman, Sharon A.; Agrawal, Yash; Travis, Alexander J.

2015-01-01

Background Rapid diagnosis for time-sensitive illnesses such as stroke, cardiac arrest, and septic shock is essential for successful treatment. Much attention has therefore focused on new strategies for rapid and objective diagnosis, such as Point-of-Care Tests (PoCT) for blood biomarkers. Here we use a biomimicry-based approach to demonstrate a new diagnostic platform, based on enzymes tethered to nanoparticles (NPs). As proof of principle, we use oriented immobilization of pyruvate kinase (PK) and luciferase (Luc) on silica NPs to achieve rapid and sensitive detection of neuron-specific enolase (NSE), a clinically relevant biomarker for multiple diseases ranging from acute brain injuries to lung cancer. We hypothesize that an approach capitalizing on the speed and catalytic nature of enzymatic reactions would enable fast and sensitive biomarker detection, suitable for PoCT devices. Methods and findings We performed in-vitro, animal model, and human subject studies. First, the efficiency of coupled enzyme activities when tethered to NPs versus when in solution was tested, demonstrating a highly sensitive and rapid detection of physiological and pathological concentrations of NSE. Next, in rat stroke models the enzyme-based assay was able in minutes to show a statistically significant increase in NSE levels in samples taken 1 hour before and 0, 1, 3 and 6 hours after occlusion of the distal middle cerebral artery. Finally, using the tethered enzyme assay for detection of NSE in samples from 20 geriatric human patients, we show that our data match well (r = 0.815) with the current gold standard for biomarker detection, ELISA—with a major difference being that we achieve detection in 10 minutes as opposed to the several hours required for traditional ELISA. Conclusions Oriented enzyme immobilization conferred more efficient coupled activity, and thus higher assay sensitivity, than non-tethered enzymes. Together, our findings provide proof of concept for using

Spinal Cord Injury 101

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Spinal cord compression caused by anaplastic large cell lymphoma in an HIV infected individual

Directory of Open Access Journals (Sweden)

Kumar Susheel

2010-01-01

Full Text Available Lymphomas occur with an increased frequency in patients with Human Immunodeficiency Virus (HIV infection. These are usually high-grade immunoblastic lymphomas and primary central nervous system lymphomas. Anaplastic large cell lymphoma (ALCL is a distinct type of non-Hodgkin′s lymphoma. It is uncommon in HIV infected individuals. We describe here an uncommon presentation of this relatively rare lymphoma in the form of spinal cord compression syndrome in a young HIV infected individual.

Flail arm-like syndrome associated with HIV-1 infection

Directory of Open Access Journals (Sweden)

Nalini A

2009-01-01

Full Text Available During the last 20 years at least 23 cases of motor neuron disease have been reported in HIV-1 seropositive patients. In this report we describe the clinical picture of a young man with HIV-1 clade C infection and flail arm-like syndrome, who we were able to follow-up for a long period. We investigated and prospectively monitored a 34-year-old man with features of flail arm syndrome, who developed the weakness and wasting 1 year after being diagnosed with HIV-1 infection after a routine blood test. He presented in 2003 with progressive, symmetrical wasting and weakness of the proximal muscles of the upper limb of 2 years′ duration. He had severe wasting and weakness of the shoulder and arm muscles. There were no pyramidal signs. He has been on HAART for the last 4 years and the weakness or wasting has not worsened. At the last follow-up in July 2007, the patient had the same neurological deficit and no other symptoms or signs of HIV-1 infection. MRI of the spinal cord in 2007 showed characteristic T2 hyperintense signals in the central part of the spinal cord, corresponding to the central gray matter. Thus, our patient had HIV-1 clade C infection associated with a ′flail arm-like syndrome.′ The causal relationship between HIV-1 infection and amyotrophic lateral sclerosis (ALS-like syndrome is still uncertain. The syndrome usually manifests as a lower motor neuron syndrome, as was seen in our young patient. It is known that treatment with antiretroviral therapy (ART stabilizes/improves the condition. In our patient the weakness and atrophy remained stable over a period of 3.5 years after commencing HAART regimen.

On the effect of tether composition on cis/trans selectivity in intramolecular Diels-Alder reactions.

Science.gov (United States)

Paddon-Row, Michael N; Longshaw, Alistair I; Willis, Anthony C; Sherburn, Michael S

2009-01-05

Intramolecular Diels-Alder (IMDA) transition structures (TSs) and energies have been computed at the B3LYP/6-31+G(d) and CBS-QB3 levels of theory for a series of 1,3,8-nonatrienes, H(2)C=CH-CH=CH-CH(2)-X-Z-CH=CH(2) [-X-Z- = -CH(2)-CH(2)- (1); -O-C(=O)- (2); -CH(2)-C(=O)- (3); -O-CH(2)- (4); -NH-C(=O)- (5); -S-C(=O)- (6); -O-C(=S)- (7); -NH-C(=S)- (8); -S-C(=S)- (9)]. For each system studied (1-9), cis- and trans-TS isomers, corresponding, respectively, to endo- and exo-positioning of the -C-X-Z- tether with respect to the diene, have been located and their relative energies (E(rel) (TS)) employed to predict the cis/trans IMDA product ratio. Although the E(rel) (TS) values are modest (typically NH or S), the IMDA cis stereoselectivity diminishes. The predicted stereochemical reaction preferences are explained in terms of two opposing effects operating in the cis-TS, namely (1) unfavorable torsional (eclipsing) strain about the C4-C5 bond, that is caused by the -C-X-C(=Y)- group's strong tendency to maintain local planarity; and (2) attractive electrostatic and secondary orbital interactions between the endo-(thio)carbonyl group, C=Y, and the diene. The former interaction predominates when X is weakly electronegative (X=N, S), while the latter is dominant when X is more strongly electronegative (X=O), or a methylene group (X=CH(2)) which increases tether flexibility. These predictions hold up to experimental scrutiny, with synthetic IMDA reactions of 1, 2, 3, and 4 (published work) and 5, 6, and 8 (this work) delivering ratios close to those calculated. The reactions of thiolacrylate 5 and thioamide 8 represent the first examples of IMDA reactions with tethers of these types. Our results point to strategies for designing tethers, which lead to improved cis/trans-selectivities in IMDAs that are normally only weakly selective. Experimental verification of the validity of this claim comes in the form of fumaramide 14, which undergoes a more trans-selective IMDA reaction

Spinal Cord Injury 101

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Cord blood buffy coat DNA methylation is comparable to whole cord blood methylation.

Science.gov (United States)

Dou, John; Schmidt, Rebecca J; Benke, Kelly S; Newschaffer, Craig; Hertz-Picciotto, Irva; Croen, Lisa A; Iosif, Ana-Maria; LaSalle, Janine M; Fallin, M Daniele; Bakulski, Kelly M

2018-01-01

Cord blood DNA methylation is associated with numerous health outcomes and environmental exposures. Whole cord blood DNA reflects all nucleated blood cell types, while centrifuging whole blood separates red blood cells, generating a white blood cell buffy coat. Both sample types are used in DNA methylation studies. Cell types have unique methylation patterns and processing can impact cell distributions, which may influence comparability. We evaluated differences in cell composition and DNA methylation between cord blood buffy coat and whole cord blood samples. Cord blood DNA methylation was measured with the Infinium EPIC BeadChip (Illumina) in eight individuals, each contributing buffy coat and whole blood samples. We analyzed principal components (PC) of methylation, performed hierarchical clustering, and computed correlations of mean-centered methylation between pairs. We conducted moderated t-tests on single sites and estimated cell composition. DNA methylation PCs were associated with individual (P PC1 = 1.4 × 10 -9 ; P PC2 = 2.9 × 10 -5 ; P PC3 = 3.8 × 10 -5 ; P PC4 = 4.2 × 10 -6 ; P PC5 = 9.9 × 10 -13 , P PC6 = 1.3 × 10 -11 ) and not with sample type (P PC1-6 >0.7). Samples hierarchically clustered by individual. Pearson correlations of mean-centered methylation between paired samples ranged from r = 0.66 to r = 0.87. No individual site significantly differed between buffy coat and whole cord blood when adjusting for multiple comparisons (five sites had unadjusted Pcoat and whole cord blood are much lower than inter-individual variation, demonstrating that both sample preparation types can be analytically combined and compared.

Unrelated cord blood transplantation in adults with myelodysplasia or secondary acute myeloblastic leukemia: a survey on behalf of Eurocord and CLWP of EBMT

NARCIS (Netherlands)

Robin, M.; Sanz, G.F.; Ionescu, I.; Rio, B.; Sirvent, A.; Renaud, M.; Carreras, E.; Milpied, N.; Mohty, M.; Beguin, Y.; Bordigoni, P.; Witte, T.J.M. de; Picardi, A.; Purtill, D.; Gluckman, E.; Kroger, N.; Rocha, V.

2011-01-01

The aim of our study was to evaluate, through the Eurocord and European Group for Blood and Marrow Transplantation (EBMT) registries, outcomes and risk factors for outcomes in adult patients who underwent single or double unrelated cord blood transplantation (UCBT) for myelodysplastic syndrome (MDS)

Experimental spinal cord trauma: a review of mechanically induced spinal cord injury in rat models.

Science.gov (United States)

Abdullahi, Dauda; Annuar, Azlina Ahmad; Mohamad, Masro; Aziz, Izzuddin; Sanusi, Junedah

2017-01-01

It has been shown that animal spinal cord compression (using methods such as clips, balloons, spinal cord strapping, or calibrated forceps) mimics the persistent spinal canal occlusion that is common in human spinal cord injury (SCI). These methods can be used to investigate the effects of compression or to know the optimal timing of decompression (as duration of compression can affect the outcome of pathology) in acute SCI. Compression models involve prolonged cord compression and are distinct from contusion models, which apply only transient force to inflict an acute injury to the spinal cord. While the use of forceps to compress the spinal cord is a common choice due to it being inexpensive, it has not been critically assessed against the other methods to determine whether it is the best method to use. To date, there is no available review specifically focused on the current compression methods of inducing SCI in rats; thus, we performed a systematic and comprehensive publication search to identify studies on experimental spinalization in rat models, and this review discusses the advantages and limitations of each method.

The effect of particle size on the morphology and thermodynamics of diblock copolymer/tethered-particle membranes

International Nuclear Information System (INIS)

Zhang, Bo; Edwards, Brian J.

2015-01-01

A combination of self-consistent field theory and density functional theory was used to examine the effect of particle size on the stable, 3-dimensional equilibrium morphologies formed by diblock copolymers with a tethered nanoparticle attached either between the two blocks or at the end of one of the blocks. Particle size was varied between one and four tenths of the radius of gyration of the diblock polymer chain for neutral particles as well as those either favoring or disfavoring segments of the copolymer blocks. Phase diagrams were constructed and analyzed in terms of thermodynamic diagrams to understand the physics associated with the molecular-level self-assembly processes. Typical morphologies were observed, such as lamellar, spheroidal, cylindrical, gyroidal, and perforated lamellar, with the primary concentration region of the tethered particles being influenced heavily by particle size and tethering location, strength of the particle-segment energetic interactions, chain length, and copolymer radius of gyration. The effect of the simulation box size on the observed morphology and system thermodynamics was also investigated, indicating possible effects of confinement upon the system self-assembly processes

The effect of particle size on the morphology and thermodynamics of diblock copolymer/tethered-particle membranes.

Science.gov (United States)

Zhang, Bo; Edwards, Brian J

2015-06-07

A combination of self-consistent field theory and density functional theory was used to examine the effect of particle size on the stable, 3-dimensional equilibrium morphologies formed by diblock copolymers with a tethered nanoparticle attached either between the two blocks or at the end of one of the blocks. Particle size was varied between one and four tenths of the radius of gyration of the diblock polymer chain for neutral particles as well as those either favoring or disfavoring segments of the copolymer blocks. Phase diagrams were constructed and analyzed in terms of thermodynamic diagrams to understand the physics associated with the molecular-level self-assembly processes. Typical morphologies were observed, such as lamellar, spheroidal, cylindrical, gyroidal, and perforated lamellar, with the primary concentration region of the tethered particles being influenced heavily by particle size and tethering location, strength of the particle-segment energetic interactions, chain length, and copolymer radius of gyration. The effect of the simulation box size on the observed morphology and system thermodynamics was also investigated, indicating possible effects of confinement upon the system self-assembly processes.

Otolith tethering in the zebrafish otic vesicle requires Otogelin and α-Tectorin.

Science.gov (United States)

Stooke-Vaughan, Georgina A; Obholzer, Nikolaus D; Baxendale, Sarah; Megason, Sean G; Whitfield, Tanya T

2015-03-15

Otoliths are biomineralised structures important for balance and hearing in fish. Their counterparts in the mammalian inner ear, otoconia, have a primarily vestibular function. Otoliths and otoconia form over sensory maculae and are attached to the otolithic membrane, a gelatinous extracellular matrix that provides a physical coupling between the otolith and the underlying sensory epithelium. In this study, we have identified two proteins required for otolith tethering in the zebrafish ear, and propose that there are at least two stages to this process: seeding and maintenance. The initial seeding step, in which otolith precursor particles tether directly to the tips of hair cell kinocilia, fails to occur in the einstein (eis) mutant. The gene disrupted in eis is otogelin (otog); mutations in the human OTOG gene have recently been identified as causative for deafness and vestibular dysfunction (DFNB18B). At later larval stages, maintenance of otolith tethering to the saccular macula is dependent on tectorin alpha (tecta) function, which is disrupted in the rolling stones (rst) mutant. α-Tectorin (Tecta) is a major constituent of the tectorial membrane in the mammalian cochlea. Mutations in the human TECTA gene can cause either dominant (DFNA8/12) or recessive (DFNB21) forms of deafness. Our findings indicate that the composition of extracellular otic membranes is highly conserved between mammals and fish, reinforcing the view that the zebrafish is an excellent model system for the study of deafness and vestibular disease. © 2015. Published by The Company of Biologists Ltd.

Tethered Balloon Operations at ARM AMF3 Site at Oliktok Point, AK

Science.gov (United States)

Dexheimer, D.; Lucero, D. A.; Helsel, F.; Hardesty, J.; Ivey, M.

2015-12-01

Oliktok Point has been the home of the Atmospheric Radiation Measurement Program's (ARM) third ARM Mobile Facility, or AMF3, since October 2013. The AMF3 is operated through Sandia National Laboratories and hosts instrumentation collecting continuous measurements of clouds, aerosols, precipitation, energy, and other meteorological variables. The Arctic region is warming more quickly than any other region due to climate change and Arctic sea ice is declining to record lows. Sparsity of atmospheric data from the Arctic leads to uncertainty in process comprehension, and atmospheric general circulation models (AGCM) are understood to underestimate low cloud presence in the Arctic. Increased vertical resolution of meteorological properties and cloud measurements will improve process understanding and help AGCMs better characterize Arctic clouds. SNL is developing a tethered balloon system capable of regular operation at AMF3 in order to provide increased vertical resolution atmospheric data. The tethered balloon can be operated within clouds at altitudes up to 7,000' AGL within DOE's R-2204 restricted area. Pressure, relative humidity, temperature, wind speed, and wind direction are recorded at multiple altitudes along the tether. These data were validated against stationary met tower data in Albuquerque, NM. The altitudes of the sensors were determined by GPS and calculated using a line counter and clinometer and compared. Wireless wetness sensors and supercooled liquid water content sensors have also been deployed and their data has been compared with other sensors. This presentation will provide an overview of the balloons, sensors, and test flights flown, and will provide a preliminary look at data from sensor validation campaigns and test flights.

Imaging of Spinal Cord Injury: Acute Cervical Spinal Cord Injury, Cervical Spondylotic Myelopathy, and Cord Herniation.

Science.gov (United States)

Talekar, Kiran; Poplawski, Michael; Hegde, Rahul; Cox, Mougnyan; Flanders, Adam

2016-10-01

We review the pathophysiology and imaging findings of acute traumatic spinal cord injury (SCI), cervical spondylotic myelopathy, and briefly review the much less common cord herniation as a unique cause of myelopathy. Acute traumatic SCI is devastating to the patient and the costs to society are staggering. There are currently no "cures" for SCI and the only accepted pharmacologic treatment regimen for traumatic SCI is currently being questioned. Evaluation and prognostication of SCI is a demanding area with significant deficiencies, including lack of biomarkers. Accurate classification of SCI is heavily dependent on a good clinical examination, the results of which can vary substantially based upon the patient׳s condition or comorbidities and the skills of the examiner. Moreover, the full extent of a patients׳ neurologic injury may not become apparent for days after injury; by then, therapeutic response may be limited. Although magnetic resonance imaging (MRI) is the best imaging modality for the evaluation of spinal cord parenchyma, conventional MR techniques do not appear to differentiate edema from axonal injury. Recently, it is proposed that in addition to characterizing the anatomic extent of injury, metrics derived from conventional MRI and diffusion tensor imaging, in conjunction with the neurological examination, can serve as a reliable objective biomarker for determination of the extent of neurologic injury and early identification of patients who would benefit from treatment. Cervical spondylosis is a common disorder affecting predominantly the elderly with a potential to narrow the spinal canal and thereby impinge or compress upon the neural elements leading to cervical spondylotic myelopathy and radiculopathy. It is the commonest nontraumatic cause of spinal cord disorder in adults. Imaging plays an important role in grading the severity of spondylosis and detecting cord abnormalities suggesting myelopathy. Copyright © 2016 Elsevier Inc. All rights

Evolution of spinal cord injuries due to cervical canal stenosis without radiographic evidence of trauma (SCIWORET): a prospective study.

Science.gov (United States)

Lamothe, G; Muller, F; Vital, J-M; Goossens, D; Barat, M

2011-06-01

Traumatic spinal cord injuries on cervical canal stenosis represent a steadily increasing pathology, of which clinical and functional outcomes remain largely unknown. We present the results of a prospective study of 20 patients followed for one year who had presented with traumatic spinal cord injury involving initially acute neurological symptoms and cervical canal stenosis defined in the imaging by a Torg ratio0.65, without vertebral fracture. Traumatic spinal cord injuries on cervical canal stenosis are caused mainly by falls in the elderly population and by unsafe behaviour among younger subjects. Most of the patients present with initially incomplete tetraplegia, and two thirds have centromedullary syndrome. Association of complete tetraplegia with advanced age would seem to be a predictive factor of death in the early post-traumatic period. For incomplete tetraplegics, the main phase of neurological and functional recovery is observed over the first six months. Radiological data and timing of surgery do not appear to affect the prognosis. This study underlines the need for individualized specialized care of patients with spinal cord injuries on cervical canal stenosis, particularly according to their demographic and lesional characteristics. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Dexmedetomidine for an awake fiber-optic intubation of a parturient with Klippel-Feil syndrome, Type I Arnold Chiari malformation and status post released tethered spinal cord presenting for repeat cesarean section

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Tanmay H. Shah

2011-08-01

Full Text Available Patients with Klippel-Feil Syndrome (KFS have congenital fusion of their cervical vertebrae due to a failure in the normal segmentation of the cervical vertebrae during the early weeks of gestation and also have myriad of other associated anomalies. Because of limited neck mobility, airway management in these patients can be a challenge for the anesthesiologist. We describe a unique case in which a dexmedetomidine infusion was used as sedation for an awake fiber-optic intubation in a parturient with Klippel-Feil Syndrome, who presented for elective cesarean delivery. A 36-yearold female, G2P1A0 with KFS (fusion of cervical vertebrae who had prior cesarean section for breech presentation with difficult airway management was scheduled for repeat cesarean delivery. After obtaining an informed consent, patient was taken in the operating room and non-invasive monitors were applied. Dexmedetomidine infusion was started and after adequate sedation, an awake fiberoptic intubation was performed. General anesthetic was administered after intubation and dexmedetomidine infusion was continued on maintenance dose until extubation. Klippel-Feil Syndrome (KFS is a rare congenital disorder for which the true incidence is unknown, which makes it even rare to see a parturient with this disease. Patients with KFS usually have other congenital abnormalities as well, sometimes including the whole thoraco-lumbar spine (Type III precluding the use of neuraxial anesthesia for these patients. Obstetric patients with KFS can present unique challenges in administering anesthesia and analgesia, primarily as it relates to the airway and dexmedetomidine infusion has shown promising result to manage the airway through awake fiberoptic intubation without any adverse effects on mother and fetus.

Spinal Cord Injury 101

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The Tethered Balloon Current Generator - A space shuttle-tethered subsatellite for plasma studies and power generation

Science.gov (United States)

Williamson, P. R.; Banks, P. M.

1976-01-01

The objectives of the Tethered Balloon Current Generator experiment are to: (1) generate relatively large regions of thermalized, field-aligned currents, (2) produce controlled-amplitude Alfven waves, (3) study current-driven electrostatic plasma instabilities, and (4) generate substantial amounts of power or propulsion through the MHD interaction. A large balloon (a diameter of about 30 m) will be deployed with a conducting surface above the space shuttle at a distance of about 10 km. For a generally eastward directed orbit at an altitude near 400 km, the balloon, connected to the shuttle by a conducting wire, will be positive with respect to the shuttle, enabling it to collect electrons. At the same time, the shuttle will collect positive ions and, upon command, emit an electron beam to vary current flow in the system.

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Multidisciplinary approach for management of dentofacial deformity of a patient with goldenhar syndrome

Directory of Open Access Journals (Sweden)

Usha Shenoy

2018-01-01

Full Text Available Goldenhar syndrome is a rare congenital craniofacial deformity, associated with anomalies of the head and spinal cord. The syndrome may affect the eyes, ears, face, and mouth and can also differ greatly in the degree of seriousness. The precise etiology of this syndrome is still not identified. Adult patients with dentoskeletal deformities usually need orthodontic and surgical corrections, requiring an integrated approach, patient cooperation, and systemized treatment planning. A poor facial appearance is often the patient's chief complaint, but it may be accompanied by functional problems, temporomandibular joints disorders, or psychosocial handicaps. The present case report highlights the orthodontic and surgical management of a patient with Goldenhar syndrome.

Nuclear pore complex tethers to the cytoskeleton.

Science.gov (United States)

Goldberg, Martin W

2017-08-01

The nuclear envelope is tethered to the cytoskeleton. The best known attachments of all elements of the cytoskeleton are via the so-called LINC complex. However, the nuclear pore complexes, which mediate the transport of soluble and membrane bound molecules, are also linked to the microtubule network, primarily via motor proteins (dynein and kinesins) which are linked, most importantly, to the cytoplasmic filament protein of the nuclear pore complex, Nup358, by the adaptor BicD2. The evidence for such linkages and possible roles in nuclear migration, cell cycle control, nuclear transport and cell architecture are discussed. Copyright © 2017. Published by Elsevier Ltd.

Pericytes Make Spinal Cord Breathless after Injury.

Science.gov (United States)

Almeida, Viviani M; Paiva, Ana E; Sena, Isadora F G; Mintz, Akiva; Magno, Luiz Alexandre V; Birbrair, Alexander

2017-09-01

Traumatic spinal cord injury is a devastating condition that leads to significant neurological deficits and reduced quality of life. Therapeutic interventions after spinal cord lesions are designed to address multiple aspects of the secondary damage. However, the lack of detailed knowledge about the cellular and molecular changes that occur after spinal cord injury restricts the design of effective treatments. Li and colleagues using a rat model of spinal cord injury and in vivo microscopy reveal that pericytes play a key role in the regulation of capillary tone and blood flow in the spinal cord below the site of the lesion. Strikingly, inhibition of specific proteins expressed by pericytes after spinal cord injury diminished hypoxia and improved motor function and locomotion of the injured rats. This work highlights a novel central cellular population that might be pharmacologically targeted in patients with spinal cord trauma. The emerging knowledge from this research may provide new approaches for the treatment of spinal cord injury.

Approaching control for tethered space robot based on disturbance observer using super twisting law

Science.gov (United States)

Hu, Yongxin; Huang, Panfeng; Meng, Zhongjie; Wang, Dongke; Lu, Yingbo

2018-05-01

Approaching control is a key mission for the tethered space robot to perform the task of removing space debris. But the uncertainties of the TSR such as the change of model parameter have an important effect on the approaching mission. Considering the space tether and the attitude of the gripper, the dynamic model of the TSR is derived using Lagrange method. Then a disturbance observer is designed to estimate the uncertainty based on STW control method. Using the disturbance observer, a controller is designed, and the performance is compared with the dynamic inverse controller which turns out that the proposed controller performs better. Numerical simulation validates the feasibility of the proposed controller on the position and attitude tracking of the TSR.

Cord Blood Banking for Potential Future Transplantation.

Science.gov (United States)

Shearer, William T; Lubin, Bertram H; Cairo, Mitchell S; Notarangelo, Luigi D

2017-11-01

This policy statement is intended to provide information to guide pediatricians, obstetricians, and other medical specialists and health care providers in responding to parents' questions about cord blood donation and banking as well as the types (public versus private) and quality of cord blood banks. Cord blood is an excellent source of stem cells for hematopoietic stem cell transplantation in children with some fatal diseases. Cord blood transplantation offers another method of definitive therapy for infants, children, and adults with certain hematologic malignancies, hemoglobinopathies, severe forms of T-lymphocyte and other immunodeficiencies, and metabolic diseases. The development of universal screening for severe immunodeficiency assay in a growing number of states is likely to increase the number of cord blood transplants. Both public and private cord blood banks worldwide hold hundreds of thousands of cord blood units designated for the treatment of fatal or debilitating illnesses. The procurement, characterization, and cryopreservation of cord blood is free for families who choose public banking. However, the family cost for private banking is significant and not covered by insurance, and the unit may never be used. Quality-assessment reviews by several national and international accrediting bodies show private cord blood banks to be underused for treatment, less regulated for quality control, and more expensive for the family than public cord blood banks. There is an unquestionable need to study the use of cord blood banking to make new and important alternative means of reconstituting the hematopoietic blood system in patients with malignancies and blood disorders and possibly regenerating tissue systems in the future. Recommendations regarding appropriate ethical and operational standards (including informed consent policies, financial disclosures, and conflict-of-interest policies) are provided for physicians, institutions, and organizations that

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The adult spinal cord injury without radiographic abnormalities syndrome: magnetic resonance imaging and clinical findings in adults with spinal cord injuries having normal radiographs and computed tomography studies.

Science.gov (United States)

Kasimatis, Georgios B; Panagiotopoulos, Elias; Megas, Panagiotis; Matzaroglou, Charalambos; Gliatis, John; Tyllianakis, Minos; Lambiris, Elias

2008-07-01

Spinal cord injury without radiographic abnormalities (SCIWORA) is thought to represent mostly a pediatric entity and its incidence in adults is rather underreported. Some authors have also proposed the term spinal cord injury without radiologic evidence of trauma, as more precisely describing the condition of adult SCIWORA in the setting of cervical spondylosis. The purpose of the present study was to evaluate adult patients with cervical spine injuries and radiological-clinical examination discrepancy, and to discuss their characteristics and current management. During a 16-year period, 166 patients with a cervical spine injury were admitted in our institution (Level I trauma center). Upper cervical spine injuries (occiput to C2, 54 patients) were treated mainly by a Halo vest, whereas lower cervical spine injuries (C3-T1, 112 patients) were treated surgically either with an anterior, or posterior procedure, or both. Seven of these 166 patients (4.2%) had a radiologic-clinical mismatch, i.e., they presented with frank spinal cord injury with no signs of trauma, and were included in the study. Magnetic resonance imaging was available for 6 of 7 patients, showing intramedullary signal changes in 5 of 6 patients with varying degrees of compression from the disc and/or the ligamentum flavum, whereas the remaining patient had only traumatic herniation of the intervertebral disc and ligamentum flavum bulging. Follow-up period was 6.4 years on average (1-10 years). This retrospective chart review provides information on adult patients with cervical spinal cord injuries whose radiographs and computed tomography studies were normal. It furthers reinforces the pathologic background of SCIWORA in an adult population, when evaluated by magnetic resonance imaging. Particularly for patients with cervical spondylosis, special attention should be paid with regard to vascular compromise by predisposing factors such as smoking or vascular disease, since they probably contribute in

Broken Heart Syndrome – An intra operative complication

Directory of Open Access Journals (Sweden)

Zara Wani

2018-03-01

Full Text Available We report a case of Broken Heart Syndrome in a 56 year old Postmenopausal woman suffered while undergoing simple biopsy procedure for vocal cord polyp that lead to physical, mental and financial burden both for the patient as well as the doctors. A team of cardiologists based on clinical and echocardiographic findings made the diagnosis of this case.

CT-myelography of cervical cord injury

International Nuclear Information System (INIS)

Koyanagi, Izumi; Isu, Toyohiko; Iwasaki, Yoshinobu

1986-01-01

We reported seven cases of acute cervical cord injuries who were examined by CT-Myelography (CTM) within 7 days after trauma. The presence or absence of spinal cord enlargement, the initial neurological status and the neurological prognosis of these patients were studied. The neurological status of each patient was graded by the method of Frankel who defined five grades from A to E according to the severity of neurological deficits. Seven patients were all males. The youngest was 18 and the oldest was 73 years old, with a mean age of 40.7 years. Follows up periods ranged from 7 to 23 months. Result: CTM revealed the enlargement of spinal cord in two cases, who had severe neurological deficits and were graded to A. No neurological improvements were obtained in these cases. Five cases without cord enlargement were graded to A in one patient, B in one patient and C in three patients. Four of these five patients improved neurologically. One grade C patient remained grade C. Complete block of subarachnoid space was observed in two out of seven cases. Cord enlargement was present in one of them. Another case of complete block improved from C to D. Conclusion: We consider the presence of cord enlargement which can be demonstrated by CTM well correlates the severity of the cord damage and presume poor neurological prognosis. Internal decompression, such as posterior longitudinal myelotomy may be recommended to the case of cord enlargement. When the cord enlargement is absent, improvement of neurological grade is expected although the initial neurological status shows severe deficits. (author)

Ortner’s syndrome: a case report and literature review

Directory of Open Access Journals (Sweden)

Bruno Landim Dutra

2015-08-01

Full Text Available AbstractThe authors report the case of a 55-year-old female, hypertensive, smoker patient presenting with dysphonia, dysphagia and persistent dry cough. Laryngoscopy diagnosed left vocal cord paralysis. Computed tomography demonstrated saccular aneurysm of the inferior wall of the aortic arch, stretching the left recurrent laryngeal nerve, a finding compatible with Ortner’s syndrome.

A Quantitative Study of Tethered Chains in Various Solution Conditions Using Langmuir Diblock Copolymer Monolayers

Energy Technology Data Exchange (ETDEWEB)

Kent, Michael S.

1999-08-13

This article summarizes our investigations of tethered chain systems using Langmuir monolayer of polydimethysiloxane-poly styrene (PDMS-PS) diblock copolymers on organic liquids. In this system, the PDMS block adsorbs to the air surface while the PS block dangles into the subphase liquid. The air surface can be made either repulsive or attractive for the tethered PS chain segments by choosing a subphase liquid which has a surface tension lower or greater than that of PS, respectively. The segment profile of the PS block is determined by neutron reflection as a function of the surface density, the molecular weights of the PS and PDMS blocks, and the solution conditions. We cover the range of reduced surface density (SIGMA) characteristic of the large body of data in the literature for systems of chains tethered onto solid surfaces from dilute solution in good or theta solvent conditions (SIGMA < 12). We emphasize quantitative comparisons with analytical profile forms and scaling predictions. We find that the strong-stretching limit invoked in analytical SCF and scaling theories is not valid over this Z range. On the other hand, over a large portion of this range (SIGMA < 5) tethered layers are well described by a renormalization group theory addressing weakly interacting or noninteracting chains. Simultaneous with the study of the profile form, the free energy of the chains is examined through the surface tension. A strong increase in the surface pressure is observed with increasing surface density which determines the maximum surface density which can be achieved. This apparently nonequilibrium effect is attributed to steric interactions and limited lateral interpenetration. This effect may explain several outstanding discrepancies regarding the adsorption of end-functionalized chains and diblock copolymers onto solid surfaces.

Multifocal spinal hemangioblastoma in von Hippel-Lindau syndrome: A case report and literature review

Energy Technology Data Exchange (ETDEWEB)

Kim, Ok Hwa [Dept. of Radiology, Inje University College of Medicine, Haeundae Paik Hospital, Busan (Korea, Republic of)

2015-03-15

Hemangioblastoma is a benign vascular neoplasm of the central nervous system that occurs frequently in the cerebellum and other areas of the central nervous system including spinal cord and brainstem. Spinal hemangioblastoma can present as a sporadic isolated lesion or as a component of von Hippel-Lindau syndrome. The author presents a case of 32-year-old man with von Hippel-Lindau syndrome and spinal hemangioblastomas represented by multiple small spinal lesions, with an emphasis on the magnetic resonance imaging findings and clinical characteristics of von Hippel-Lindau syndrome-associated spinal hemangioblastomas.

Multifocal spinal hemangioblastoma in von Hippel-Lindau syndrome: A case report and literature review

International Nuclear Information System (INIS)

Kim, Ok Hwa

2015-01-01

Hemangioblastoma is a benign vascular neoplasm of the central nervous system that occurs frequently in the cerebellum and other areas of the central nervous system including spinal cord and brainstem. Spinal hemangioblastoma can present as a sporadic isolated lesion or as a component of von Hippel-Lindau syndrome. The author presents a case of 32-year-old man with von Hippel-Lindau syndrome and spinal hemangioblastomas represented by multiple small spinal lesions, with an emphasis on the magnetic resonance imaging findings and clinical characteristics of von Hippel-Lindau syndrome-associated spinal hemangioblastomas.

Piperidinium tethered nanoparticle-hybrid electrolyte for lithium metal batteries

KAUST Repository

Korf, Kevin S.

2014-06-23

We report on the synthesis of novel piperidinium-based ionic liquid tethered nanoparticle hybrid electrolytes and investigate their physical and electrochemical properties. Hybrid electrolytes based on the ionic liquid 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfone) imide covalently tethered to silica nanoparticles (SiO2-PP-TFSI) were blended with propylene carbonate-1 M lithium bis(trifluoromethanesulfone) imide (LiTFSI). We employed NMR analysis to confirm the successful creation of the hybrid material. Dielectric and rheological measurements show that these electrolytes exhibit exceptional room-temperature DC ionic conductivity (10-2 to 10 -3 S cm-1) as well as high shear mechanical moduli (105 to 106 Pa). Lithium transference numbers were found to increase with particle loading and to reach values as high as 0.22 at high particle loadings where the particle jam to form a soft glassy elastic medium. Analysis of lithium electrodeposits obtained in the hybrid electrolytes using SEM and EDX spectra show that the SiO2-PP-TFSI nanoparticles are able to smooth lithium deposition and inhibit lithium dendrite proliferation in Li metal batteries. LTOSiO2-PP-TFSI/PC in 1 M LiTFSILi half-cells based on the SiO2-PP-TFSI hybrid electrolytes exhibit attractive voltage profiles and trouble-free extended cycling behavior over more than 1000 cycles of charge and discharge. This journal is © the Partner Organisations 2014.

The Protective Effect of Spinal Cord Stimulation Postconditioning Against Spinal Cord Ischemia/Reperfusion Injury in Rabbits.

Science.gov (United States)

Li, Huixian; Dong, Xiuhua; Jin, Mu; Cheng, Weiping

2018-01-18

Delayed paraplegia due to spinal cord ischemia/reperfusion injury (IRI) remains one of the most severe complications of thoracoabdominal aneurysm surgery, for which effective prevention and treatment is still lacking. The current study investigates whether spinal cord stimulation (SCS) postconditioning has neuroprotective effects against spinal cord IRI. Ninety-six New Zealand white male rabbits were randomly divided into four groups as follows: a sham group and three experimental groups (C group, 2 Hz group, and 50 Hz group) n = 24/group. Spinal cord ischemia was induced by transient infrarenal aortic balloon occlusion for 28 min, after which rabbits in group C underwent no additional intervention, while rabbits in the other two experimental groups underwent 2 Hz or 50 Hz epidural SCS for 30 min at the onset of reperfusion and then daily until sacrifice. Hind limb neurologic function of rabbits was assessed using Jacob scale. Lumbar spinal cords were harvested immediately after sacrifice for histological examination and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The number of viable α-motor neurons in ventral horn was counted and TUNEL-positive rate of α-motor neurons was calculated. Spinal cord IRI was caused by transient infrarenal aorta occlusion for 28 min. Both 2 Hz and 50 Hz SCS postconditioning had neuroprotective effects, particularly the 2 Hz SCS postconditioning. Comparing to C group and 50 Hz group, rabbits in the 2 Hz group demonstrated better hind limb motor function and a lower rate of TUNEL-positive α-motor neuron after eight hours, one day, three days, and seven days of spinal cord reperfusion. More viable α-motor neurons were preserved after one and three days of spinal cord reperfusion in 2 Hz group rabbits than in C group and 50 Hz group rabbits. SCS postconditioning at 2 Hz protected the spinal cord from IRI. © 2018 International Neuromodulation Society.

The radiation budget of stratocumulus clouds measured by tethered balloon instrumentation: Variability of flux measurements

Science.gov (United States)

Duda, David P.; Stephens, Graeme L.; Cox, Stephen K.

1990-01-01

Measurements of longwave and shortwave radiation were made using an instrument package on the NASA tethered balloon during the FIRE Marine Stratocumulus experiment. Radiation data from two pairs of pyranometers were used to obtain vertical profiles of the near-infrared and total solar fluxes through the boundary layer, while a pair of pyrgeometers supplied measurements of the longwave fluxes in the cloud layer. The radiation observations were analyzed to determine heating rates and to measure the radiative energy budget inside the stratocumulus clouds during several tethered balloon flights. The radiation fields in the cloud layer were also simulated by a two-stream radiative transfer model, which used cloud optical properties derived from microphysical measurements and Mie scattering theory.

Energy dissipation/transfer and stable attitude of spatial on-orbit tethered system

Science.gov (United States)

Hu, Weipeng; Song, Mingzhe; Deng, Zichen

2018-01-01

For the Tethered Satellite System, the coupling between the platform system and the solar panel is a challenge in the dynamic analysis. In this paper, the coupling dynamic behaviors of the Tethered Satellite System that is idealized as a planar flexible damping beam-spring-mass composite system are investigated via a structure-preserving method. Considering the coupling between the plane motion of the system, the oscillation of the spring and the transverse vibration of the beam, the dynamic model of the composite system is established based on the Hamiltonian variational principle. A symplectic dimensionality reduction method is proposed to decouple the dynamic system into two subsystems approximately. Employing the complex structure-preserving approach presented in our previous work, numerical iterations are performed between the two subsystems with weak damping to study the energy dissipation/transfer in the composite system, the effect of the spring stiffness on the energy distribution and the effect of the particle mass on the stability of the composite system. The numerical results show that: the energy transfer approach is uniquely determined by the initial attitude angle, while the energy dissipation speed is mainly depending on the initial attitude angle and the spring stiffness besides the weak damping. In addition, the mass ratio between the platform system and the solar panel determines the stable state as well as the time needed to reach the stable state of the composite system. The numerical approach presented in this paper provides a new way to deal with the coupling dynamic system and the conclusions obtained give some useful advices on the overall design of the Tethered Satellite System.

Reliable and fast volumetry of the lumbar spinal cord using cord image analyser (Cordial).

Science.gov (United States)

Tsagkas, Charidimos; Altermatt, Anna; Bonati, Ulrike; Pezold, Simon; Reinhard, Julia; Amann, Michael; Cattin, Philippe; Wuerfel, Jens; Fischer, Dirk; Parmar, Katrin; Fischmann, Arne

2018-04-30

To validate the precision and accuracy of the semi-automated cord image analyser (Cordial) for lumbar spinal cord (SC) volumetry in 3D T1w MRI data of healthy controls (HC). 40 3D T1w images of 10 HC (w/m: 6/4; age range: 18-41 years) were acquired at one 3T-scanner in two MRI sessions (time interval 14.9±6.1 days). Each subject was scanned twice per session, allowing determination of test-retest reliability both in back-to-back (intra-session) and scan-rescan images (inter-session). Cordial was applied for lumbar cord segmentation twice per image by two raters, allowing for assessment of intra- and inter-rater reliability, and compared to a manual gold standard. While manually segmented volumes were larger (mean: 2028±245 mm 3 vs. Cordial: 1636±300 mm 3 , p<0.001), accuracy assessments between manually and semi-automatically segmented images showed a mean Dice-coefficient of 0.88±0.05. Calculation of within-subject coefficients of variation (COV) demonstrated high intra-session (1.22-1.86%), inter-session (1.26-1.84%), as well as intra-rater (1.73-1.83%) reproducibility. No significant difference was shown between intra- and inter-session reproducibility or between intra-rater reliabilities. Although inter-rater reproducibility (COV: 2.87%) was slightly lower compared to all other reproducibility measures, between rater consistency was very strong (intraclass correlation coefficient: 0.974). While under-estimating the lumbar SCV, Cordial still provides excellent inter- and intra-session reproducibility showing high potential for application in longitudinal trials. • Lumbar spinal cord segmentation using the semi-automated cord image analyser (Cordial) is feasible. • Lumbar spinal cord is 40-mm cord segment 60 mm above conus medullaris. • Cordial provides excellent inter- and intra-session reproducibility in lumbar spinal cord region. • Cordial shows high potential for application in longitudinal trials.

Umbilical Cord Blood: Counselling, Collection, and Banking.

Science.gov (United States)

Armson, B Anthony; Allan, David S; Casper, Robert F

2015-09-01

To review current evidence regarding umbilical cord blood counselling, collection, and banking and to provide guidelines for Canadian health care professionals regarding patient education, informed consent, procedural aspects, and options for cord blood banking in Canada. Selective or routine collection and banking of umbilical cord blood for future stem cell transplantation for autologous (self) or allogeneic (related or unrelated) treatment of malignant and non-malignant disorders in children and adults. Cord blood can be collected using in utero or ex utero techniques. Umbilical cord blood counselling, collection, and banking, education of health care professionals, indications for cord blood collection, short- and long-term risk and benefits, maternal and perinatal morbidity, parental satisfaction, and health care costs. Published literature was retrieved through searches of Medline and PubMed beginning in September 2013 using appropriate controlled MeSH vocabulary (fetal blood, pregnancy, transplantation, ethics) and key words (umbilical cord blood, banking, collection, pregnancy, transplantation, ethics, public, private). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date limits, but results were limited to English or French language materials. Searches were updated on a regular basis and incorporated in the guideline to September 2014. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, and national and international medical specialty societies. The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Umbilical cord blood is a readily available source of hematopoetic stem cells used with increasing frequency as an alternative to

The urgency of surgical decompression in acute central cord injuries with spondylosis and without instability.

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Lenehan, Brian; Fisher, Charles G; Vaccaro, Alex; Fehlings, Michael; Aarabi, Bizhan; Dvorak, Marcel F

2010-10-01

Systematic review, ambispective analysis of observational data. To make recommendations as to whether or not urgent surgical decompression is ever indicated as the optimal treatment for enhancing neurologic recovery in a patient with acute central cord injury without fracture or instability. There are currently no standards regarding the role and timing of decompression in acute traumatic central cord syndrome. In the setting of TCCS without spinal column instability, much controversy exists. We have performed a thorough literature search based on the following question: "Is there a role for urgent (within 24 hours from injury to surgery) surgical decompression in acute central cord syndrome without fracture or instability specifically to enhance neurologic recovery?" Data including patient demographics, mechanism of injury, comorbidities, neurologic status, and surgical treatment was analyzed from a multicenter STSG observational database. Outcome measured included ASIA Motor Score, ASIA Grade, Functional Independence Measure (FIM) Score, SF-36, Sphincter Disturbance, and Ambulatory status. Measures were recorded on admission, discharge, 6 months and 1 year. At 12-month follow-up, early surgery resulted in a 6.31 point greater improvement in total motor score than did the late surgery group, with a P = 0.0358. At 6-month follow-up, early surgery result in higher chance of improvement in ASIA Grade than late surgery, with an odds ratio = 3.39, while at 12-month follow-up early surgery resulted in a higher chance of improvement in ASIA Grade, with an odds ratio of 2.81. Patients who were operated on within 24 hours had 7.79 U more improvement in FIM Total Score than late surgery at 6 month follow-up, with P = 0.0474. The consensus of experts following review of relevant and examination of observational dataset concluded that it is reasonable and safe to consider early surgical decompression in patients with profound neurologic deficit (ASIA = C) and persistent

Distribution of elements in human spinal cord

International Nuclear Information System (INIS)

Yukawa, Masae; Kobayashi, T.; Qiu, Y.; Kameda, N.; Ito, Y.; Otomo, E.

1992-01-01

The distribution of elements in human spinal cord was investigated on unfixed frozen cord material using PIXE technique. Distribution of Cu, Zn and Fe were not uniform in the cross section of the spinal cord and concentrations of these elements were higher in the anterior gray horn than in the other areas, while K and Cl distributed uniformly. The content of K changed along the spinal cord from the cervical to the lumbar level. These findings are discussed in relation to current understanding of the physiology of the spinal cord. (author)

Reverse cope elimination of hydroxylamines and alkenes or alkynes: theoretical investigation of tether length and substituent effects.

Science.gov (United States)

Krenske, Elizabeth H; Davison, Edwin C; Forbes, Ian T; Warner, Jacqueline A; Smith, Adrian L; Holmes, Andrew B; Houk, K N

2012-02-01

Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes ("reverse Cope eliminations"). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. © 2012 American Chemical Society

Radiation treatment of spinal cord neoplasms

International Nuclear Information System (INIS)

Smirnov, R.V.

1982-01-01

Results of radiation treatment of spinal cord neoplasms are presented. The results of combined (surgical and radiation) treatment of tumors are studied. On the whole it is noted that radiation treatment of initial spinal cord tumours is not practised on a large scale because of low radiostability of spinal cord

Spinal cord involvement in tuberculous meningitis.

Science.gov (United States)

Garg, R K; Malhotra, H S; Gupta, R

2015-09-01

To summarize the incidence and spectrum of spinal cord-related complications in patients of tuberculous meningitis. Reports from multiple countries were included. An extensive review of the literature, published in English, was carried out using Scopus, PubMed and Google Scholar databases. Tuberculous meningitis frequently affects the spinal cord and nerve roots. Initial evidence of spinal cord involvement came from post-mortem examination. Subsequent advancement in neuroimaging like conventional lumbar myelography, computed tomographic myelography and gadolinium-enhanced magnetic resonance-myelography have contributed immensely. Spinal involvement manifests in several forms, like tuberculous radiculomyelitis, spinal tuberculoma, myelitis, syringomyelia, vertebral tuberculosis and very rarely spinal tuberculous abscess. Frequently, tuberculous spinal arachnoiditis develops paradoxically. Infrequently, spinal cord involvement may even be asymptomatic. Spinal cord and spinal nerve involvement is demonstrated by diffuse enhancement of cord parenchyma, nerve roots and meninges on contrast-enhanced magnetic resonance imaging. High cerebrospinal fluid protein content is often a risk factor for arachnoiditis. The most important differential diagnosis of tuberculous arachnoiditis is meningeal carcinomatosis. Anti-tuberculosis therapy is the main stay of treatment for tuberculous meningitis. Higher doses of corticosteroids have been found effective. Surgery should be considered only when pathological confirmation is needed or there is significant spinal cord compression. The outcome in these patients has been unpredictable. Some reports observed excellent recovery and some reported unfavorable outcomes after surgical decompression and debridement. Tuberculous meningitis is frequently associated with disabling spinal cord and radicular complications. Available treatment options are far from satisfactory.

Association of cord blood chemokines and other biomarkers with neonatal complications following intrauterine inflammation.

Directory of Open Access Journals (Sweden)

Yoshikazu Otsubo

Full Text Available Intrauterine inflammation has been associated with preterm birth and neonatal complications. Few reports have comprehensively investigated multiple cytokine profiles in cord blood and precisely identified surrogate markers for intrauterine inflammation.To identify the cytokines and surrogate markers associated with intrauterine inflammation and subsequent neonatal complications.We analyzed cord blood samples from 135 patients admitted to the neonatal intensive care unit at Sasebo City General Hospital. We retrospectively determined the associations between the presence of neonatal complications and cord blood cytokines, prenatal factors, and laboratory data at birth. A total of 27 cytokines in the cord blood were measured using a bead-based array sandwich immunoassay.Both Th1 and Th2 cytokine levels were low, whereas the levels of growth factors and chemokines were high. In particular, chemokines IL-8, MCP-1, and MIP-1α were significantly higher in very premature neonates when compared with more mature neonates. In addition, some have been shown to be associated with multiple neonatal complications, including patent ductus arteriosus (PDA, respiratory distress syndrome (RDS, and chronic lung disease (CLD. Similarly, the levels of N-terminal pro-brain natriuretic peptide, nucleated RBC, and urinary β2-microglobulin were associated with these complications and chemokine levels.Our results suggest the association of inflammatory chemokines IL-8, MCP-1, and MIP-1α with intrauterine inflammation, premature birth, and neonatal complications in these perinatal subjects. Furthermore, the association of the aforementioned biomarkers with PDA, RDS, and CLD may help establish early diagnostic measures to predict such neonatal complications following intrauterine inflammation.

[Key-Gaskell syndrome in a cat in Switzerland].

Science.gov (United States)

Litschi, B; Dieth, V

1989-01-01

As far as the authors know this is the first case of Key-Gaskell-syndrome being described in Switzerland. The clinical signs of megaoesophagus, anorexia, constipation, dryness of all mucous membranes, reduced tear production, protrusion of the membrana nictitans, mydriasis, regurgitation and bradycardia are pathognomonic and can't be mistaken by any other disease. The subject of the Key-Gaskell-syndrome is a dysfunction of the autonomic nervous system. Histopathological changes are exclusively related to the autonomic nervous system and to neurons of some nuclei in the cranial nerves. Less severe changes can be found in the neurons of the spinal cord or in the dorsal root ganglia. The etiology remains still unclear. There is a relationship to the grass sickness syndrome in horses and to dysautonomia of man and dog.

Therapeutic approaches for spinal cord injury

Directory of Open Access Journals (Sweden)

Alexandre Fogaça Cristante

2012-10-01

Full Text Available This study reviews the literature concerning possible therapeutic approaches for spinal cord injury. Spinal cord injury is a disabling and irreversible condition that has high economic and social costs. There are both primary and secondary mechanisms of damage to the spinal cord. The primary lesion is the mechanical injury itself. The secondary lesion results from one or more biochemical and cellular processes that are triggered by the primary lesion. The frustration of health professionals in treating a severe spinal cord injury was described in 1700 BC in an Egyptian surgical papyrus that was translated by Edwin Smith; the papyrus reported spinal fractures as a ''disease that should not be treated.'' Over the last biological or pharmacological treatment method. Science is unraveling the mechanisms of cell protection and neuroregeneration, but clinically, we only provide supportive care for patients with spinal cord injuries. By combining these treatments, researchers attempt to enhance the functional recovery of patients with spinal cord injuries. Advances in the last decade have allowed us to encourage the development of experimental studies in the field of spinal cord regeneration. The combination of several therapeutic strategies should, at minimum, allow for partial functional recoveries for these patients, which could improve their quality of life.

Umbilical cord blood for unrelated bone marrow replacement; Asia bank and Japan cord blood bank network update.

Science.gov (United States)

Mugishima, Hideo; Takahashi, Tuneo; Nagamura, Tokiko; Asano, Sigetaka; Saito, Hidehiko

2002-08-01

Cord blood offers many advantages including a high concentration of hematopoietic stem cells, a large number of potential donors, and ease of harvest. Furthermore, since there is no risk for either the mother or baby, few people refuse to donate. There is thought to be a low risk for virus contamination and also probably a low incidence and severity of GVHD. Cord blood can be obtained quickly without the assistance of a coordinator and one or 2 locus-mismatched HLA is usually acceptable. In Japan, there are 10 cord blood banks supported by the government. Between 1996 and June 2002, 9,500 units were registered with the Japan cord blood bank network (JCBBN). 630 units were delivered and most of these were transplanted. The status of registered cord blood units worldwide is shown. 59,081 units have been registered by NETCORD. The Japan cord blood bank network accounts for 13% of these units. I will discuss the Tokyo cord blood tank (TCBB). The bank at Tokyo, to which we belong, is one of the largest banks in Japan. We helped to establish Asia CORD in 2000 and have held annual conferences and meetings in Tokyo to exchange information. So far, China, Korea, Taiwan, Thailand, Viet Nam and Japan have participated. We accepted three trainees from the Ho Chi Minh City Blood Transfusion and Hematology Center for training in cord blood transplantation in May 2001. In January 2002, a patient with ALL received cord blood and was successfully engrafted at Ho Chi Minh City Blood Transfusion and Hematology Center. We present here the clinical outcome of these patients through Tokyo cord blood bank and Japan cord blood bank network. First, the number of CB units stored and registered at JCBBN and TCBB has increased rapidly over the past two years. Second, the survival rate of acute leukemia patients in release was significantly lower than that in patients in CR. Third, the engraftment rate in patients with metabolic disease (50%) was lower than that in patients with leukemia

Trauma: Spinal Cord Injury.

Science.gov (United States)

Eckert, Matthew J; Martin, Matthew J

2017-10-01

Injuries to the spinal column and spinal cord frequently occur after high-energy mechanisms of injury, or with lower-energy mechanisms, in select patient populations like the elderly. A focused yet complete neurologic examination during the initial evaluation will guide subsequent diagnostic procedures and early supportive measures to help prevent further injury. For patients with injury to bone and/or ligaments, the initial focus should be spinal immobilization and prevention of inducing injury to the spinal cord. Spinal cord injury is associated with numerous life-threatening complications during the acute and long-term phases of care that all acute care surgeons must recognize. Published by Elsevier Inc.

Diseases of the spine, spinal cord, and extremities

International Nuclear Information System (INIS)

Tanaka, H.

1983-01-01

This paper covers the following topics: acupuncture needle in the spinal canal of the neck; thoracic tuberculous spondylitis: cold abscess; comminuted fracture of the fifth cervical vertebra; lumbar spondylolysis; lumbar spondylosis; ossification of the posterior longitudinal ligament; disk herniation of the cervical spine: narrowing of the root tunnel; ankylosing spondylitis: narrowing of the root tunnel; ossification of the ligamentum flavum; narrow spinal canal syndrome; syringomyelia; epidural neurinoma of the cervical spine; neurofibromatosis; spinal arteriovenous malformation; atrophy of the thoracic spinal cord; osteomyelitis tuberculosa of the rib; osteomyelitis tuberculosa of the left femur; chronic osteomyelitis of the left humerus; malignant giant cell tumor of the left femur; rheumatoid arthritis of the left hip joint; arthrosis deformans of the left hip joint; and enchondroma of the left index finger: Proximal Phalanx

Umbilical cord cell banking-implications for the future

International Nuclear Information System (INIS)

Gunning, Jennifer

2005-01-01

The first successful cord cell transplant to a sibling with Fanconi's anaemia took place 15 years ago. This proven utility of cord blood led to the establishment of cord blood banks both private and public and there are now nearly 100 cord blood banks worldwide. It is estimated that over 200,000 cord blood units (CBU) are held by the private sector and over 160,000 CBU are registered with the largest public cord blood registry. There is a tension between private cord blood banks, which store CBU for autologous or family use, and public banks, which store CBU for unrelated use and the ethics of private cord blood storage has been questioned. But more general ethical questions also arise regarding ownership, consent, confidentiality, costs and quality standards and patenting. In looking at these ethical issues one also needs to look at potential future use of cord blood stem cells. Up until now cord cells have principally been used in the treatment of paediatric blood and immune disorders. Improvements in cell expansion technology will make CBU more appropriate also for treating adults with such disorders. However, it has also been demonstrated that cord blood stem cells have the capacity to differentiate into other types of cells, neuronal, bone, epithelial and muscle which would have a future role to play in cell therapy and regenerative medicine

COMPLEX REGIONAL PAIN SYNDROME: AN UPDATE

Directory of Open Access Journals (Sweden)

Patta

2015-10-01

Full Text Available Complex Regional Pain Syndrome or CRPS is a chronic disabling heterogenous pain disorder due to trauma, resulting in sensory changes, motor function impairment, psychological changes. Diagnosis is based on clinical features and investigations. The patho - physiology is not clearly known. There is no single drug therapy, only combinations work. Treatment is multidisplinary involving medical, psychological and rehabi li tation. Newer modes of spinal cord stimulations, neuraxial mode of analgesics and newe r drugs are promising

Family-directed umbilical cord blood banking.

Science.gov (United States)

Gluckman, Eliane; Ruggeri, Annalisa; Rocha, Vanderson; Baudoux, Etienne; Boo, Michael; Kurtzberg, Joanne; Welte, Kathy; Navarrete, Cristina; van Walraven, Suzanna M

2011-11-01

Umbilical cord blood transplantation from HLA-identical siblings provides good results in children. These results support targeted efforts to bank family cord blood units that can be used for a sibling diagnosed with a disease which can be cured by allogeneic hematopoietic stem cell transplantation or for research that investigates the use of allogeneic or autologous cord blood cells. Over 500 patients transplanted with related cord blood units have been reported to the Eurocord registry with a 4-year overall survival of 91% for patients with non-malignant diseases and 56% for patients with malignant diseases. Main hematologic indications in children are leukemia, hemoglobinopathies or inherited hematologic, immunological or metabolic disorders. However, family-directed cord blood banking is not widely promoted; many cord blood units used in sibling transplantation have been obtained from private banks that do not meet the necessary criteria required to store these units. Marketing by private banks who predominantly store autologous cord blood units has created public confusion. There are very few current validated indications for autologous storage but some new indications might appear in the future. Little effort is devoted to provide unbiased information and to educate the public as to the distinction between the different types of banking, economic models and standards involved in such programs. In order to provide a better service for families in need, directed-family cord blood banking activities should be encouraged and closely monitored with common standards, and better information on current and future indications should be made available.

Nasogastric Tube Syndrome: Why Is It Important in the Intensive Care Unit?

Directory of Open Access Journals (Sweden)

Taehyun Kim

2015-08-01

Full Text Available Although the nasogastric tube (NGT is widely used in critically ill patients, most intensivists do not give much thought to it or its possible complications. NGT syndrome is a rare but fatal complication characterized by throat pain and vocal cord paralysis in the presence of NGT. Recently, we experienced a case of NGT syndrome developed in an 86-year-old female twelve days after NGT insertion. We immediately removed the NGT and secured the airway by tracheostomy. She was treated successfully with an intravenous antibiotic, steroid and proton pump inhibitor and the syndrome did not recur after reinsertion of the NGT.

Ortner's syndrome: a case report and literature review

International Nuclear Information System (INIS)

Dutra, Bruno Landim; Campos, Lenilton da Costa; Marques, Helder de Castro; Vilela, Vagner Moyses; Duque, Andre Geraldo da Silva

2015-01-01

The authors report the case of a 55-year-old female, hypertensive, smoker patient presenting with dysphonia, dysphagia and persistent dry cough. Laryngoscopy diagnosed left vocal cord paralysis. Computed tomography demonstrated saccular aneurysm of the inferior wall of the aortic arch, stretching the left recurrent laryngeal nerve, a finding compatible with Ortner's syndrome. (author)

Ortner's syndrome: a case report and literature review

Energy Technology Data Exchange (ETDEWEB)

Dutra, Bruno Landim; Campos, Lenilton da Costa; Marques, Helder de Castro; Vilela, Vagner Moyses, E-mail: brunolandim@yahoo.com.br [Universidade Federal de Juiz de Fora (HU/UFJF), MG (Brazil). Hospital Universitario. Unidade de Radiologia e Diagnostico por Imagem; Carvalho, Rodolfo Elias Diniz da Silva [Centro de Diagnostico Medico (CRM), Sao Mateus, ES (Brazil); Duque, Andre Geraldo da Silva [Axial Medicina Diagnostica, Belo Horizonte, MG (Brazil)

2015-07-15

The authors report the case of a 55-year-old female, hypertensive, smoker patient presenting with dysphonia, dysphagia and persistent dry cough. Laryngoscopy diagnosed left vocal cord paralysis. Computed tomography demonstrated saccular aneurysm of the inferior wall of the aortic arch, stretching the left recurrent laryngeal nerve, a finding compatible with Ortner's syndrome. (author)

Human born with a tail: A case report

African Journals Online (AJOL)

Sheri-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, India. A H Sarmast ... Advanced imaging technology in recent decades has allowed more thorough ... association of such lesions with spinal dysraphism and tethered spinal cord.

The oblique cord of the forearm in man.

Science.gov (United States)

Tubbs, R Shane; O'Neil, James T; Key, Christopher D; Zarzour, Jessica G; Fulghum, Sarah B; Kim, Eugenia J; Lyerly, Michael J; Shoja, Mohammadali M; George Salter, E; Jerry Oakes, W

2007-05-01

There is minimal and often conflicting data in the literature regarding the oblique cord of the forearm. The current study seeks to elucidate further the anatomy of this structure of the upper extremity. In adult cadavers, the oblique cord was observed for and, when found, measurements were made of it. Ranges of motion were carried out while observation of the oblique cord was made. An oblique cord was found on 52.6% of sides. Gantzer's muscle was found on 55% of sides and, when present, had attachment into the oblique cord on five sides. The oblique cord was present on 13 sides with a Gantzer's muscle. Of the 20 sides with an oblique cord, no Gantzer's muscle was found on 10. The mean length of the oblique cord was 3.4 cm. In the majority of specimens, this cord tapered from proximal to distal. The proximal, middle, and distal widths of this structure had means 9, 7, and 4 mm, respectively. The oblique cord was found to travel approximately 45 degrees from a line drawn through the ulna and more or less traveled perpendicular to the insertion site of the bicipital tendon. This ligament was lax in the neutral position and with pronation became lax in all specimens. The oblique cord progressively became taut with increased supination from the neutral position and was maximally taut with the forearm fully supinated. Tautness of this cord was also found with distal distraction of the radius. Following the transection of the oblique cord, no discernable difference was observed in regard to maximal supination of the forearm or distal distraction of the radius. No obvious instability of the proximal forearm was found following transection of the oblique cord. Functionally, although the oblique cord may resist supination, it is unlikely that this structure affords significant stability to the proximal forearm, as it was often absent, of a very small caliber, and based on our observations, following its transection, the amount of supination of the forearm did not increase

Efficacy of transverse tripolar spinal cord stimulator for the relief of chronic low back pain from failed back surgery.

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Buvanendran, Asokumar; Lubenow, Timothy J

2008-01-01

Failed back surgery syndrome is a common clinical entity for which spinal cord stimulation has been found to be an effective mode of analgesia, but with variable success rates. To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and therefore provide greater analgesia to the back. Case report. We describe a 42-year-old female with failed back surgery syndrome that had greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads, advanced to the T7-T10 vertebral bodies. Tripolar stimulation pattern resulted in more than 70% pain relief in this patient during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain relief. After implantation of a permanent tripolar electrode system with a single rechargeable battery, the pain relief was maintained for one year. This is case report describing a case of a patient with chronic low back pain with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar system consists of a central cathode surrounded by anodes, using 3 leads. This arrangement may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation and provide analgesia to the lower back.

Pregnancy Complications: Umbilical Cord Abnormalities

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... Umbilical cord abnormalities Umbilical cord abnormalities Now playing: E-mail to a friend Please fill in all fields. ... blood supply) to the baby. The two arteries transport waste from the baby to the placenta (where ...

Diffusion tensor imaging in spinal cord injury

International Nuclear Information System (INIS)

Kamble, Ravindra B; Venkataramana, Neelam K; Naik, Arun L; Rao, Shailesh V

2011-01-01

To assess the feasibility of spinal tractography in patients of spinal cord injury vs a control group and to compare fractional anisotropy (FA) values between the groups. Diffusion tensor imaging (DTI) was performed in the spinal cord of 29 patients (18 patients and 11 controls). DTI was done in the cervical region if the cord injury was at the dorsal or lumbar region and in the conus region if cord injury was in the cervical or dorsal region. FA was calculated for the patients and the controls and the values were compared. The mean FA value was 0.550±0.09 in the control group and 0.367±0.14 in the patients; this difference was statistically significant (P=0.001). Spinal tractography is a feasible technique to assess the extent of spinal cord injury by FA, which is reduced in patients of spinal cord injury, suggesting possible Wallerian degeneration. In future, this technique may become a useful tool for assessing cord injury patients after stem cell therapy, with improvement in FA values indicating axonal regeneration

Experimental autoimmune prostatitis induces microglial activation in the spinal cord.

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Wong, Larry; Done, Joseph D; Schaeffer, Anthony J; Thumbikat, Praveen

2015-01-01

The pathogenesis of chronic prostatitis/chronic pelvic pain syndrome is unknown and factors including the host's immune response and the nervous system have been attributed to the development of CP/CPPS. We previously demonstrated that mast cells and chemokines such as CCL2 and CCL3 play an important role in mediating prostatitis. Here, we examined the role of neuroinflammation and microglia in the CNS in the development of chronic pelvic pain. Experimental autoimmune prostatitis (EAP) was induced using a subcutaneous injection of rat prostate antigen. Sacral spinal cord tissue (segments S14-S5) was isolated and utilized for immunofluorescence or QRT-PCR analysis. Tactile allodynia was measured at baseline and at various points during EAP using Von Frey fibers as a function for pelvic pain. EAP mice were treated with minocycline after 30 days of prostatitis to test the efficacy of microglial inhibition on pelvic pain. Prostatitis induced the expansion and activation of microglia and the development of inflammation in the spinal cord as determined by increased expression levels of CCL3, IL-1β, Iba1, and ERK1/2 phosphorylation. Microglial activation in mice with prostatitis resulted in increased expression of P2X4R and elevated levels of BDNF, two molecular markers associated with chronic pain. Pharmacological inhibition of microglia alleviated pain in mice with prostatitis and resulted in decreased expression of IL-1β, P2X4R, and BDNF. Our data show that prostatitis leads to inflammation in the spinal cord and the activation and expansion of microglia, mechanisms that may contribute to the development and maintenance of chronic pelvic pain. © 2014 Wiley Periodicals, Inc.

Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

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Kise, Yuya; Kuniyoshi, Yukio; Inafuku, Hitoshi; Nagano, Takaaki; Hirayasu, Tsuneo; Yamashiro, Satoshi

2015-01-01

During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P flow with and without distal perfusion (r = 0.803, P network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring

Microsurgical DREZotomy in the treatment of chronic pain due to spinal cord and cauda equina injuries: 2 cases report and related literature review

Directory of Open Access Journals (Sweden)

LIU Qing-jun

2013-10-01

Full Text Available Objective The dorsal root entry zone (DREZ is a hyperactive focus in neuropathic pain (NP syndromes, and DREZotomy has been used in selective cases of NP. This study aims to investigate the therapeutic effect of microsurgical DREZotomy in chronic pain due to spinal cord and cauda equina injuries. Methods Two patients suffered with chronic pain due to spinal cord and cauda equina injuries were treated with microsurgical DREZotomy, and postoperative therapeutic effect and complications were observed. Results One patient had great pain, and the pain was alleviated 2 weeks after surgery, while carbamazepine (300 mg/d was administered continously. Another patient was completely free of pain 2 weeks after surgery, and no recurrence occurred during 3-year follow up. No severe complications were found in the 2 patients. Conclusion Microsurgical DREZotomy is an effective approach in treating chronic pain due to spinal cord and cauda equina injuries.

What Is Being Trained? How Divergent Forms of Plasticity Compete To Shape Locomotor Recovery after Spinal Cord Injury.

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Huie, J Russell; Morioka, Kazuhito; Haefeli, Jenny; Ferguson, Adam R

2017-05-15

Spinal cord injury (SCI) is a devastating syndrome that produces dysfunction in motor and sensory systems, manifesting as chronic paralysis, sensory changes, and pain disorders. The multi-faceted and heterogeneous nature of SCI has made effective rehabilitative strategies challenging. Work over the last 40 years has aimed to overcome these obstacles by harnessing the intrinsic plasticity of the spinal cord to improve functional locomotor recovery. Intensive training after SCI facilitates lower extremity function and has shown promise as a tool for retraining the spinal cord by engaging innate locomotor circuitry in the lumbar cord. As new training paradigms evolve, the importance of appropriate afferent input has emerged as a requirement for adaptive plasticity. The integration of kinematic, sensory, and loading force information must be closely monitored and carefully manipulated to optimize training outcomes. Inappropriate peripheral input may produce lasting maladaptive sensory and motor effects, such as central pain and spasticity. Thus, it is important to closely consider the type of afferent input the injured spinal cord receives. Here we review preclinical and clinical input parameters fostering adaptive plasticity, as well as those producing maladaptive plasticity that may undermine neurorehabilitative efforts. We differentiate between passive (hindlimb unloading [HU], limb immobilization) and active (peripheral nociception) forms of aberrant input. Furthermore, we discuss the timing of initiating exposure to afferent input after SCI for promoting functional locomotor recovery. We conclude by presenting a candidate rapid synaptic mechanism for maladaptive plasticity after SCI, offering a pharmacological target for restoring the capacity for adaptive spinal plasticity in real time.

Cost-effectiveness of private umbilical cord blood banking.

Science.gov (United States)

Kaimal, Anjali J; Smith, Catherine C; Laros, Russell K; Caughey, Aaron B; Cheng, Yvonne W

2009-10-01

To investigate the cost-effectiveness of private umbilical cord blood banking. A decision-analytic model was designed comparing private umbilical cord blood banking with no umbilical cord blood banking. Baseline assumptions included a cost of $3,620 for umbilical cord blood banking and storage for 20 years, a 0.04% chance of requiring an autologous stem cell transplant, a 0.07% chance of a sibling requiring an allogenic stem cell transplant, and a 50% reduction in risk of graft-versus-host disease if a sibling uses banked umbilical cord blood. Private cord blood banking is not cost-effective because it cost an additional $1,374,246 per life-year gained. In sensitivity analysis, if the cost of umbilical cord blood banking is less than $262 or the likelihood of a child needing a stem cell transplant is greater than 1 in 110, private umbilical cord blood banking becomes cost-effective. Currently, private umbilical cord blood banking is cost-effective only for children with a very high likelihood of needing a stem cell transplant. Patients considering private blood banking should be informed of the remote likelihood that a unit will be used for a child or another family member. III.

Relationship between anaerobic capacity estimated using a single effort and 30-s tethered running outcomes.

Directory of Open Access Journals (Sweden)

Alessandro Moura Zagatto

Full Text Available The purpose of the current study was to investigate the relationship between alternative anaerobic capacity method (MAODALT and a 30-s all-out tethered running test. Fourteen male recreational endurance runners underwent a graded exercise test, a supramaximal exhaustive effort and a 30-s all-out test on different days, interspaced by 48h. After verification of data normality (Shapiro-Wilk test, the Pearson's correlation test was used to verify the association between the anaerobic estimates from the MAODALT and the 30-s all-out tethered running outputs. Absolute MAODALT was correlated with mean power (r = 0.58; P = 0.03, total work (r = 0.57; P = 0.03, and mean force (r = 0.79; P = 0.001. In addition, energy from the glycolytic pathway (E[La-] was correlated with mean power (r = 0.58; P = 0.03. Significant correlations were also found at each 5s interval between absolute MAODALT and force values (r between 0.75 and 0.84, and between force values and E[La-] (r between 0.73 to 0.80. In conclusion, the associations between absolute MAODALT and the mechanical outputs from the 30-s all-out tethered running test evidenced the importance of the anaerobic capacity for maintaining force during the course of time in short efforts.

Overload control of artificial gravity facility using spinning tether system for high eccentricity transfer orbits

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Gou, Xing-wang; Li, Ai-jun; Tian, Hao-chang; Wang, Chang-qing; Lu, Hong-shi

2018-06-01

As the major part of space life supporting systems, artificial gravity requires further study before it becomes mature. Spinning tether system is a good alternative solution to provide artificial gravity for the whole spacecraft other than additional devices, and its longer tether length could significantly reduce spinning velocity and thus enhance comfortability. An approximated overload-based feedback method is proposed to provide estimated spinning velocity signals for controller, so that gravity level could be accurately controlled without complicated GPS modules. System behavior in high eccentricity transfer orbits is also studied to give a complete knowledge of the spinning stabilities. The application range of the proposed method is studied in various orbit cases and spinning velocities, indicating that it is accurate and reliable for most of the mission phases especially for the final constant gravity level phase. In order to provide stable gravity level for transfer orbit missions, a sliding mode controller based on estimated angular signals is designed for closed-loop control. Numerical results indicate that the combination of overload-based feedback and sliding mode controller could satisfy most of the long-term artificial gravity missions. It is capable of forming flexible gravity environment in relatively good accuracy even in the lowest possible orbital radiuses and high eccentricity orbits of crewed space missions. The proposed scheme provides an effective tether solution for the artificial gravity construction in interstellar travel.

Malignant spinal cord compression in cancer patients may be mimicked by a primary spinal cord tumour.

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Mohammadianpanah, M; Vasei, M; Mosalaei, A; Omidvari, S; Ahmadloo, N

2006-12-01

Although it is quite rare, second primary neoplasms in cancer patients may present with the signs and symptoms of malignant spinal cord compression. Primary spinal cord tumours in the cancer patients may be deceptive and considered as the recurrent first cancer. Therefore, it should be precisely differentiated and appropriately managed. We report such a case of intramedullary ependymoma of the cervical spinal cord mimicking metatstatic recurrent lymphoma and causing cord compression. A 50-year-old man developed intramedullary ependymoma of the cervical spinal cord 1.5 years following chemoradiation for Waldeyer's ring lymphoma. He presented with a 2-month history of neck pain, progressive upper- and lower-extremity numbness and weakness, and bowel and bladder dysfunction. Magnetic resonance imaging revealed an intramedullary expansive lesion extending from C4 to C6 levels of the cervical spinal cord. The clinical and radiological findings were suggestive of malignant process. A comprehensive investigation failed to detect another site of disease. He underwent operation, and the tumour was subtotally resected. The patient's neurological deficits improved subsequently. The development of the intramedullary ependymoma following treating lymphoma has not been reported. We describe the clinical, radiological and pathological findings of this case and review the literature.

Fullerenic structures and such structures tethered to carbon materials

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Goel, Anish; Howard, Jack B.; Vander Sande, John B.

2010-01-05

The fullerenic structures include fullerenes having molecular weights less than that of C.sub.60 with the exception of C.sub.36 and fullerenes having molecular weights greater than C.sub.60. Examples include fullerenes C.sub.50, C.sub.58, C.sub.130, and C.sub.176. Fullerenic structure chemically bonded to a carbon surface is also disclosed along with a method for tethering fullerenes to a carbon material. The method includes adding functionalized fullerene to a liquid suspension containing carbon material, drying the suspension to produce a powder, and heat treating the powder.

Advanced Electrodynamic Tether Systems: Modeling of Scattering and Unsteady Effects

Science.gov (United States)

2008-06-06

spacecraft and satellites. A high altitude nuclear detonation would likely create a new high energy electron belt and increase the radiation risk to...our tether has no reason to roll, making O=0, and thus cosO =1. The y-component of the torque is thus expressed: < = < =< = FF cossin3 222 ’ (S...ions from the integral limits to manageable levels. Our goal is to isolate the permutations of initial velocities and impact parameters such that

The Reverse Cope Elimination of Hydroxylamines and Alkenes or Alkynes: Theoretical Investigation of Tether Length and Substituent Effects

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Krenske, Elizabeth H.; Davison, Edwin C.; Forbes, Ian T.; Warner, Jacqueline A.; Smith, Adrian L.; Holmes, Andrew B.; Houk, K. N.

2012-01-01

Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes (“reverse Cope eliminations”). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. PMID:22280245

Topologically preserving straightening of spinal cord MRI.

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De Leener, Benjamin; Mangeat, Gabriel; Dupont, Sara; Martin, Allan R; Callot, Virginie; Stikov, Nikola; Fehlings, Michael G; Cohen-Adad, Julien

2017-10-01

To propose a robust and accurate method for straightening magnetic resonance (MR) images of the spinal cord, based on spinal cord segmentation, that preserves spinal cord topology and that works for any MRI contrast, in a context of spinal cord template-based analysis. The spinal cord curvature was computed using an iterative Non-Uniform Rational B-Spline (NURBS) approximation. Forward and inverse deformation fields for straightening were computed by solving analytically the straightening equations for each image voxel. Computational speed-up was accomplished by solving all voxel equation systems as one single system. Straightening accuracy (mean and maximum distance from straight line), computational time, and robustness to spinal cord length was evaluated using the proposed and the standard straightening method (label-based spline deformation) on 3T T 2 - and T 1 -weighted images from 57 healthy subjects and 33 patients with spinal cord compression due to degenerative cervical myelopathy (DCM). The proposed algorithm was more accurate, more robust, and faster than the standard method (mean distance = 0.80 vs. 0.83 mm, maximum distance = 1.49 vs. 1.78 mm, time = 71 vs. 174 sec for the healthy population and mean distance = 0.65 vs. 0.68 mm, maximum distance = 1.28 vs. 1.55 mm, time = 32 vs. 60 sec for the DCM population). A novel image straightening method that enables template-based analysis of quantitative spinal cord MRI data is introduced. This algorithm works for any MRI contrast and was validated on healthy and patient populations. The presented method is implemented in the Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1209-1219. © 2017 International Society for Magnetic Resonance in Medicine.

Reduced intensity haplo plus single cord transplant compared to double cord transplant: improved engraftment and graft-versus-host disease-free, relapse-free survival

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van Besien, Koen; Hari, Parameswaran; Zhang, Mei-Jie; Liu, Hong-Tao; Stock, Wendy; Godley, Lucy; Odenike, Olatoyosi; Larson, Richard; Bishop, Michael; Wickrema, Amittha; Gergis, Usama; Mayer, Sebastian; Shore, Tsiporah; Tsai, Stephanie; Rhodes, Joanna; Cushing, Melissa M.; Korman, Sandra; Artz, Andrew

2016-01-01

Umbilical cord blood stem cell transplants are commonly used in adults lacking HLA-identical donors. Delays in hematopoietic recovery contribute to mortality and morbidity. To hasten recovery, we used co-infusion of progenitor cells from a partially matched related donor and from an umbilical cord blood graft (haplo-cord transplant). Here we compared the outcomes of haplo-cord and double-cord transplants. A total of 97 adults underwent reduced intensity conditioning followed by haplo-cord transplant and 193 patients received reduced intensity conditioning followed by double umbilical cord blood transplantation. Patients in the haplo-cord group were more often from minority groups and had more advanced malignancy. Haplo-cord recipients received fludarabine-melphalan-anti-thymocyte globulin. Double umbilical cord blood recipients received fludarabine-cyclophosphamide and low-dose total body irradiation. In a multivariate analysis, haplo-cord had faster neutrophil (HR=1.42, P=0.007) and platelet (HR=2.54, Pdisease (HR=0.26, Pdisease (HR=0.06, Pdisease-free, relapse-free survival was superior with haplo-cord (HR 0.63, P=0.002) but not overall survival (HR=0.97, P=0.85). Haplo-cord transplantation using fludarabine-melphalan-thymoglobulin conditioning hastens hematopoietic recovery with a lower risk of relapse relative to double umbilical cord blood transplantation using the commonly used fludarabine-cyclophosphamide-low-dose total body irradiation conditioning. Graft-versus-host disease-free and relapse-free survival is significantly improved. Haplo-cord is a readily available graft source that improves outcomes and access to transplant for those lacking HLA-matched donors. Trials registered at clinicaltrials.gov identifiers 00943800 and 01810588. PMID:26869630

Haematopoietic transplants combining a single unrelated cord blood unit and mobilized haematopoietic stem cells from an adult HLA-mismatched third party donor. Comparable results to transplants from HLA-identical related donors in adults with acute leukaemia and myelodysplastic syndromes.

Science.gov (United States)

Sebrango, Ana; Vicuña, Isabel; de Laiglesia, Almudena; Millán, Isabel; Bautista, Guiomar; Martín-Donaire, Trinidad; Regidor, Carmen; Cabrera, Rafael; Fernandez, Manuel N

2010-06-01

We describe results of the strategy, developed by our group, of co-infusion of mobilized haematopoietic stem cells as a support for single-unit unrelated cord blood transplant (dual CB/TPD-MHSC transplants) for treatment of haematological malignancies in adults, and a comparative analysis of results obtained using this strategy and transplants performed with mobilized haematopoietic stem cells from related HLA-identical donors (RTD) for treatment of adults with acute leukaemia and myelodysplastic syndromes. Our data show that the dual CB/TPD-MHSC transplant strategy results in periods of post-transplant neutropenia, final rates of full donor chimerism and transplant-related mortality rates comparable to those of the RTD. Final survival outcomes are comparable in adults transplanted because of acute leukaemia, with different incidences of the complications that most influence these: a higher incidence of infections related to late recovery of protective immunity dependent on T cell functions, and a lower incidence of serious acute graft-versus-host disease and relapses. Recent advances in cord blood transplant techniques allow allogeneic haematopoietic stem cell transplantation (HSCT) to be a viable option for almost every patient who may benefit from this therapeutic approach. Development of innovative strategies to improve the post-transplant recovery of T cells function is currently the main challenge to further improving the possibilities of unrelated cord blood transplantation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Triple A (Allgrove) syndrome: an unusual association with syringomyelia

Science.gov (United States)

2013-01-01

Triple A (Allgrove) syndrome was first described by Allgrove in 1978 in two pairs of siblings. Since then, about 100 cases have been reported, all of them displaying an autosomal recessive pattern of inheritance. Clinical picture is characterized by achalasia, alacrimia and ACTH-resistant adrenal failure. A progressive neurological syndrome including central, peripheral and autonomic nervous system impairment, and mild mental retardation is often associated. The triple A syndrome gene, designated AAAS, is localized on chromosome 12q13. It consists of 16 exons, encoding for a 546 aminoacid protein called ALADIN (Alacrimia-Achalasia-aDrenal Insufficiency Neurologic disorder). We report on a 13 year-old boy presenting with Addison’s disease, dysphagia, muscle weakness, excessive fatigue and recent onset gait ataxia. The analysis of the AAAS gene revealed a homozygous missense mutation in exon 12. It was a T > G transversion at nucleotide position 1224, resulting in a change of leucine at amino acid position 381 into arginine (Leu381Arg or L381R). Brain appearance was found normal at magnetic resonance imaging (MRI) and functional spectroscopy analysis showed normal levels of the main metabolites. Spine MRI showed a cystic cavity within the spinal cord (syringomyelia), localized between the sixth cervical vertebra and the first thoracic vertebra. Cerebellar tonsils descended 7 mm caudal to foramen magnum, consistently with a mild type 1 Chiari malformation. Mild posterior inter-vertebral disk protrusions were evident between T9 and T10 and between L4 and L5. To our knowledge, this is the first report describing type 1 Chiari malformation and multiple spinal cord abnormalities in a patient with Allgrove syndrome. PMID:23800107

Risk factors in iatrogenic spinal cord injury.

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Montalva-Iborra, A; Alcanyis-Alberola, M; Grao-Castellote, C; Torralba-Collados, F; Giner-Pascual, M

2017-09-01

In the last years, there has been a change in the aetiology of spinal cord injury. There has been an increase in the number of elderly patients with spinal cord injuries caused by diseases or medical procedures. The aim of this study is to investigate the frequency of the occurrence of iatrogenic spinal cord injury in our unit. The secondary aim is to study what variables can be associated with a higher risk of iatrogenesis. A retrospective, descriptive, observational study of patients with acute spinal cord injury admitted from June 2009 to May 2014 was conducted. The information collected included the patient age, aetiology, neurological level and grade of injury when admitted and when discharged, cardiovascular risk factors, a previous history of depression and any prior treatment with anticoagulant or antiplatelet drugs. We applied a logistic regression. The grade of statistical significance was established as Pinjury was the thoracic level (48%). The main aetiology of spinal cord injury caused by iatrogenesis was surgery for degenerative spine disease, in patients under the age of 30 were treated with intrathecal chemotherapy. Iatrogenic spinal cord injury is a frequent complication. A statistically significant association between a patient history of depression and iatrogenic spinal cord injury was found as well as with anticoagulant and antiplatelet drug use prior to iatrogenic spinal cord injury.

Spinal cord injury arising in anaesthesia practice.