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Sample records for eustachian tube function

  1. Can nasal decongestants improve eustachian tube function?

    Science.gov (United States)

    Ovari, Attila; Buhr, Anne; Warkentin, Mareike; Kundt, Günther; Ehrt, Karsten; Pau, Hans-Wilhelm

    2015-01-01

    To evaluate the effect of nasal decongestants on eustachian tube (ET) opening. A prospective nonrandomized study. A tertiary referral center. Twenty-four patients (44 ears) with intact eardrums, 39 patients (43 ears) having a noninfected eardrum defect, and six patients with an upper airway infection. Nasal or intratympanal (in perforated ears) application of a nasal decongestant (xylometazoline 0.1%). Change of tube opening quality (yes or no; better or worse) measuring tube opening parameters (pressure, latency) using the Estève method and pressure equalization tests (swallowing at negative and positive external ear canal pressures). In most cases, nasal decongestion or intratympanal use of decongestants have no effect on ET opening. Improvement in tube opening is rather an exception and, in a minority of patients, a reduced ET function was evident. Our acute studies revealed no improvement in eustachian ventilatory tube function with the administration of nasal decongestants.

  2. Postpalatoplasty Eustachian tube function in young children with cleft palate.

    Science.gov (United States)

    Alper, Cuneyt M; Losee, Joseph E; Mandel, Ellen M; Seroky, James T; Swarts, J Douglas; Doyle, William J

    2012-07-01

    To characterize Eustachian tube function using the forced response test in young children with cleft palate with or without cleft lip after palatoplasty with tympanostomy tubes inserted prepalatoplasty and compare these results with those of a 1986 study that evaluated a similar population using identical methods. Outpatient research clinic. A total of 34 children with cleft palate were tested at an average age of 18.6 ± 4.0 months. MAIN OUTCOME MEASUREs: Passive and active measures for the forced response test. Of the sample, 13 ears could not be tested, and tests on 24 ears were incomplete. The forced response test showed that the passive Eustachian tube function parameters were similar to those of normal adults and children. The percentage of ears that showed tubal dilation with swallowing was 60%. The active resistance and dilatory efficiency were similar to those of a normal adult population. A 1986 study of Eustachian tube function in postpalatoplasty subjects with cleft palate (37 ears) aged 15 to 26 months documented Eustachian tube dilation with swallowing in 84% of the ears. In the present study, which focused on a similar population, the frequency of tubal dilation was 60%. Nonetheless, both frequencies are significantly greater than the dilation frequency of 27% reported for 56 ears of subjects with cleft palate tested between 3 months and 18 years with tympanostomy tubes inserted for persistent otitis media with effusion. This suggests that dilation during the forced response test may be a prognostic marker for those children with cleft palate who will resolve their ear disease at an early age.

  3. Imaging of the Eustachian tube and its function: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.E.; Tysome, J.R. [Cambridge University Hospitals NHS Foundation Trust, Department of ENT Surgery, Addenbrooke' s Hospital, Cambridge (United Kingdom); Scoffings, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2016-06-15

    The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function. A systematic review of the literature was performed with narrative data analysis. With high-resolution images, the soft and bony anatomy of the Eustachian tube can be assessed in detail. CT and MRI are best suited to identifying features associated with obstructive or patulous Eustachian tube dysfunction, though true assessments of function have only been achieved with contrast enhanced radiographs and scintigraphy. A single modality has yet to provide a complete assessment. No test has entered routine clinical use, but further development and research is underway. Significant information can be gained from imaging the Eustachian tube, and as faster acquisition techniques are developed, it is possible that dynamic imaging of tubal opening could play an important role in the assessment of patients with ET dysfunction. (orig.)

  4. Myringotomy versus ventilation tubes in secretory otitis media: eardrum pathology, hearing, and eustachian tube function 25 years after treatment

    DEFF Research Database (Denmark)

    Caye-Thomasen, P.; Stangerup, S.E.; Jorgensen, G.

    2008-01-01

    , myringosclerosis and late atrophy. The temporary hearing improvement may reduce the risk of detrimental effects on speech and language development. The prevalence and extension of the various subtypes of pathology change over the years after treatment, which implies the existence of intrinsic repair mechanisms......OBJECTIVE: This report documents the dynamics of eardrum pathology, hearing acuity, and eustachian tube function during 25 years after treatment of bilateral secretory otitis media. The included children were treated by myringotomy on the left ear and ventilation tube insertion on the right ear...... not related to treatment. 7) Eustachian tube function at 25 years was not related to treatment. CONCLUSION: The insertion of a ventilation tube after myringotomy leads not only to better hearing until extrusion but also to an increased prevalence of long-term pathologic changes of the eardrum, that is...

  5. Functional MR imaging of the Eustachian tube in patients with clinically proven dysfunction: correlation with lesions detected on MR images

    Energy Technology Data Exchange (ETDEWEB)

    Luekens, Anna; Guenther, Rolf W. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); DiMartino, Ercole [Ev. Diakonie-Krankenhaus, Department of Otolaryngology and Head- and Neck-Surgery, Bremen (Germany); Krombach, Gabriele A. [University Hospital, University of Technology (RWTH) Aachen, Department of Diagnostic Radiology, Aachen (Germany); University Hospital Giessen, University Giessen, Department of Diagnostic and Interventional Radiology, Giessen (Germany)

    2012-03-15

    To visualise the function of the Eustachian tube by MRI and assess the effect of surrounding lesions. Using 1.5 T MRI, 32 Eustachian tubes of 16 patients with clinically proven dysfunction (clinical symptoms, such as autophonia and fullness and non-opening at tympanometry) were investigated. For depiction of the anatomy and associated abnormalities, coronal and axial T2-weighted turbo spin echo sequences and a T1-weighted-2D-gradient echo sequences were acquired. Eustachian tube opening was analysed with real time turbo-gradient echo sequences during a Valsalva manoeuvre. Dysfunction, that is, failure of opening of the Eustachian tube as shown by MRI, correlated in all patients with tympanometry. Lesions detected included nasopharyngeal carcinoma in 4 patients. Mucosal swelling in the paranasal sinus was present in 9 patients. One patient had postoperative defects. In two patients both pharyngotympanic tubes did not open although no structural abnormalities could be depicted. The opening of the Eustachian tubes during the Valsalva manoeuvre is assessable on MRI. Failure of opening may be due to swelling of the mucosa and may be also associated with tumours. MRI assessment may be helpful in patients with chronic otitis media, where the information about tubal function is important in preoperative planning. (orig.)

  6. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects.

    Science.gov (United States)

    Canali, Inesângela; Petersen Schmidt Rosito, Letícia; Siliprandi, Bruno; Giugno, Cláudia; Selaimen da Costa, Sady

    The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver) in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Mean (standard deviation) age was 11 (2.72) years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p=0.012). The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p≥0.05). Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the variations in discrepancy between measurements were higher in ears

  7. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects,

    Directory of Open Access Journals (Sweden)

    Inesângela Canali

    Full Text Available Abstract Introduction The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. Objective To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. Methods An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Results Mean (standard deviation age was 11 (2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p = 0.012. The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p ≥ 0.05. Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the

  8. Multi-scale finite element modeling of Eustachian tube function: influence of mucosal adhesion.

    Science.gov (United States)

    Malik, J E; Swarts, J D; Ghadiali, S N

    2016-12-01

    The inability to open the collapsible Eustachian tube (ET) leads to the development of chronic Otitis Media (OM). Although mucosal inflammation during OM leads to increased mucin gene expression and elevated adhesion forces within the ET lumen, it is not known how changes in mucosal adhesion alter the biomechanical mechanisms of ET function. In this study, we developed a novel multi-scale finite element model of ET function in adults that utilizes adhesion spring elements to simulate changes in mucosal adhesion. Models were created for six adult subjects, and dynamic patterns in muscle contraction were used to simulate the wave-like opening of the ET that occurs during swallowing. Results indicate that ET opening is highly sensitive to the level of mucosal adhesion and that exceeding a critical value of adhesion leads to rapid ET dysfunction. Parameter variation studies and sensitivity analysis indicate that increased mucosal adhesion alters the relative importance of several tissue biomechanical properties. For example, increases in mucosal adhesion reduced the sensitivity of ET function to tensor veli palatini muscle forces but did not alter the insensitivity of ET function to levator veli palatini muscle forces. Interestingly, although changes in cartilage stiffness did not significantly influence ET opening under low adhesion conditions, ET opening was highly sensitive to changes in cartilage stiffness under high adhesion conditions. Therefore, our multi-scale computational models indicate that changes in mucosal adhesion as would occur during inflammatory OM alter the biomechanical mechanisms of ET function. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Diagnostic accuracy of tubomanometry R value in detecting the Eustachian tube pressure equalizing function.

    Science.gov (United States)

    Alper, Cuneyt M; Teixeira, Miriam S; Kim, Jeehong H; Douglas Swarts, J

    2017-04-01

    Tubomanometry is a relatively novel Eustachian tube (ET) function testing method. A number of recent studies have utilized the R value of Tubomanometry as the main objective measure in reporting their outcome in balloon dilation of ET. There is, however, a lack of evidence concerning the reliability or validity of Tubomanometry measurements. The objectives of this study are to determine the accuracy of Tubomanometry for detecting ET opening as compared to tympanometry and determine its usefulness as a measure of ET function. Healthy subjects between ages 8 and 76 years with an intact tympanic membrane and no middle ear (ME) effusion were prospectively tested. Primary outcomes were the ET opening as determined by the Tubomanometry R value and the increase in ME pressure with tympanometry-measured in relation to a swallow at a nasopharyngeal pressure of 300 daPa. The accuracy of the tubomanometry R value for identifying a successful ET opening was made in reference to the change of ME pressure. A total of 280 measurements were available from 258 ears in 137 subjects. The presence of tubomanometry R value showed high sensitivity of detecting ET opening for the criteria of >5 daPa ME pressure increase (187/202) but low specificity for detecting ET non-opening (34/78). The R value criterion described in the original manuscripts on Tubomanometry is sensitive but not specific for ET opening. The need for validation of the tubomanometry test obviates its use as the main objective outcome measure for the balloon dilation of ET procedure.

  10. [Balloon dilation of the Eustachian tube in pediatric chronic obstructive Eustachian tube dysfunction patients].

    Science.gov (United States)

    Maier, S; Tisch, M; Maier, H

    2015-10-01

    Balloon dilation of the Eustachian tube has recently been introduced as a novel and minimally invasive method for treating chronic obstructive Eustachian tube dysfunction. For the first time worldwide, we assessed the role of this technique in a large cohort of children with Eustachian tube dysfunction that did not respond to other treatments and in whom a tumor could be ruled out as the cause. This study is a retrospective analysis. We retrospectively analyzed the medical records of 66 children (mean age 8.12 years, range 4-14 years) who underwent balloon dilation of the Eustachian tube using the Bielefeld balloon catheter. There were no complications during surgery. Clinical symptoms improved in more than 80% of the patients. No patient reported a deterioration of symptoms. Of the participating parents, over 80% were very satisfied or satisfied with the treatment outcome. Balloon dilation is a rapid, simple, and safe method for treatment of both adults and children with Eustachian tube dysfunction that does not respond to other treatments. Further studies, ideally multicenter studies, are required in order to optimize the definition of existing and potential new indications for this treatment approach, as well as to establish this treatment in the management of children with refractory chronic Eustachian tube dysfunction.

  11. Impact of evolution on the eustachian tube.

    Science.gov (United States)

    Bluestone, Charles D

    2008-03-01

    I posit that humans appear to be the only species that develops otitis media. If animals in the wild had developed middle-ear disease to any significant degree, they would have been selected out during evolution because they would not have survived their predators given the associated hearing loss. Why do humans have otitis media? Evolution has had a significant impact. It is well known that humans are born 12 months too early, which is the result of adaptations to bipedalism and our big brain that, over time, resulted in a relatively small female pelvic outlet compared with nonhuman primates. As a consequence of too early a birth, not only is our immune system immature, but the eustachian tube is too short and floppy in the first year of life. But why is otitis media still common in older individuals? What other adaptation is uniquely human? We developed speech that was associated with descent of the larynx and hyoid bone, which, along with a decrease in prognathism (i.e., facial flattening), resulted in a change in palatal morphology as compared with other primates. Comparative anatomic and physiologic studies have demonstrated significant differences between humans and monkeys, especially in the muscles of the eustachian tube. Paradoxic constriction, as apposed to dilation, on swallowing is a common tubal dysfunction in humans and certain monkey models with chronic middle-ear effusion. My hypothesis is that chronic otitis media with effusion in patients with tubal constriction is a consequence of adaptation for speech and that, most likely, the levator veli palatini muscle is the cause.

  12. Panel 2: Anatomy (Eustachian Tube, Middle Ear, and Mastoid-Anatomy, Physiology, Pathophysiology, and Pathogenesis).

    Science.gov (United States)

    Alper, Cuneyt M; Luntz, Michal; Takahashi, Haruo; Ghadiali, Samir N; Swarts, J Douglas; Teixeira, Miriam S; Csákányi, Zsuzsanna; Yehudai, Noam; Kania, Romain; Poe, Dennis S

    2017-04-01

    Objective In this report, we review the recent literature (ie, past 4 years) to identify advances in our understanding of the middle ear-mastoid-eustachian tube system. We use this review to determine whether the short-term goals elaborated in the last report were achieved, and we propose updated goals to guide future otitis media research. Data Sources PubMed, Web of Science, Medline. Review Methods The panel topic was subdivided, and each contributor performed a literature search within the given time frame. The keywords searched included middle ear, eustachian tube, and mastoid for their intersection with anatomy, physiology, pathophysiology, and pathology. Preliminary reports from each panel member were consolidated and discussed when the panel met on June 11, 2015. At that meeting, the progress was evaluated and new short-term goals proposed. Conclusions Progress was made on 13 of the 20 short-term goals proposed in 2011. Significant advances were made in the characterization of middle ear gas exchange pathways, modeling eustachian tube function, and preliminary testing of treatments for eustachian tube dysfunction. Implications for Practice In the future, imaging technologies should be developed to noninvasively assess middle ear/eustachian tube structure and physiology with respect to their role in otitis media pathogenesis. The new data derived from these structure/function experiments should be integrated into computational models that can then be used to develop specific hypotheses concerning otitis media pathogenesis and persistence. Finally, rigorous studies on medical or surgical treatments for eustachian tube dysfunction should be undertaken.

  13. Epithelial differentiation in developing murine eustachian tube and middle ear.

    Science.gov (United States)

    Park, K; Lee, Y D; Park, H J; Chun, Y M

    2000-06-01

    Detailed information on how an epithelial differentiation occurred in the developing eustachian tube and middle ear would be helpful in understanding both normal physiology and pathology of the tubotympanum. This study was undertaken to establish patterns of laminin and E-cadherin in the embryonic mouse eustachian tube and middle ear by use of immunohistochemistry at a stage when epithelial differentiation is taking place. This study was also designed to clarify the role of the middle ear mesenchyme. During the development of the eustachian tube, relatively high immunoreactivity to laminin was observed in the epithelium at gestational days 16 and 17, when the developments of ciliated and secretory cells were first observed. At the time of birth, in contrast to epithelium of the eustachian tube, epithelium of the middle ear cavity showed predominant expression of laminin and E-cadherin. These findings suggest that the expressions of laminin and E-cadherin may be correlated with maturation of the epithelium in the eustachian tube and middle ear and that the epithelial differentiation of the developing murine eustachian tube and middle ear may be controlled by epithelial-mesenchymal interaction and cell-to-cell interaction.

  14. Changes in microvascular permeability of the middle ear mucosa following the occulsion of the eustachian tube of rabbits. The functional investigation using radioisotope

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    Kikuchi, Yasutaka

    1988-12-01

    Serial changes in submucosal microvascular permeability of the middle ear and the response to histamine after occlusion of the eustachian tube were functionally investigated using radioisotope in rabbits with experimentally induced otitis media with effusion. Tritium water was administered through intravenous injection and transference of tritium water into the middle ear cavity was measured by radioactivity of the middle ear perfusate. Morphological changes were concurrently examined for comparison. Vascular permeability, as measured one, 7, and 14 days after occlusion of the eustachian tube, increased with time. A histological study showed an edematous hypertrophy of the submucosal tissue of the middle ear, suggesting a noticeable increase in microvascular permeability. The response of the middle ear mucosa to histamine, which was added to the fluid for perfusion, gradually decreased after occlusion of the eustachian tube, although the effect of histamine tended to persist for a long time, irrespective of the amount of administration. The results indicated that the mucosal membrane of the middle ear has a noticeable permeability at least up to 14 days after occlusion, and that histamine may be responsible for the increase of submucosal microvascular permeability not only in the normal middle ear cavity but also in otitis media with effusion which results in the persistance of the disease. The presence of factors permeable to the blood, other than histamine, caused microvascular peameability to increase, probably resulting in chronic or irreversible inflammation. This may be explained by markedly proliferative or parenchymatous connective tissues observed 7 and l0 weeks after occlusion. It should be noted that surgical treatment be performed as early as possible in the case of otitis media with effusion. (Namekawa, K) 80 refs.

  15. Eustachian tube-tensor veli palatini muscle-cranial base relationships in children and adults: an osteological study.

    Science.gov (United States)

    Doyle, William J; Swarts, J Douglas

    2010-09-01

    The vector relationships between the Eustachian tube, Tensor veli palatini muscle and cranial base constrain the efficiency of middle ear pressure-regulation and are required parameters for computational modeling of Eustachian tube function. Here, those relationships were reconstructed from skulls and compared between children and adults. Reconstructions were made using modifications of previously described techniques for 18 child skulls aged 3-4 years and 20 adult skulls (10 females, 10 males; >18 years). Measured and calculated variables were compared between groups using a Student's t-test. Consistent with previous reports, certain variables for adult skulls exhibited sexual dimorphism. Between children and adults, significant differences were documented for measures of cranial base length and width; hard palate width; nasopharyngeal height, width and depth; Eustachian tube length; the maximum and minimum Tensor veli palatini muscle lengths; the angles of deviation of the Tensor veli palatini muscle from the Eustachian tube, and the surface area of the Tensor veli palatini muscle. There were no between-group differences in the angle of Eustachian tube decent from the cranial base, Eustachian tube deviation from the parasagittal plane or the lateral component of the Tensor veli palatine muscle-Eustachian tube angle. The differences between children and adults that could account for the observed poorer Eustachian tube function in children include their shorter Eustachian tube, lesser Tensor veli palatine muscle-Eustachian tube vectors, and the lesser Tensor veli palatine muscle surface area. Other observed differences are attributable to growth and development of the craniofacial complex. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Morphology and ciliary motion of mucosa in the Eustachian tube of neonatal and adult gerbils.

    Science.gov (United States)

    Li, Yi; Liu, Huizhan; Li, Jun; Zhang, Qian; Gong, Shusheng; He, David

    2014-01-01

    The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms of otitis media, which is common in children. In the present study, we examined the epithelial lining of the Eustachian tube in neonatal and adult gerbils, with a focus on the morphological and functional development of ciliated cells in the mucosa. The length of the tube is ∼8.8 mm in adult gerbils. Scanning electron microscopy showed that the mucosal member near the pharyngeal side contains a higher density of ciliated cells and goblet cells than that near the tympanic side. The cilia beat frequency is 11 Hz. During development, the length of the Eustachian tube increased significantly between postnatal day 1 (P1) and P18. Scanning electron microscopy showed that the mucosa contained a high density of ciliated cells with a few goblet cells at P1. The density of ciliated cells decreased while the density of goblet cells increased during development. At P18, the mucosa appeared to be adult-like. Interestingly, the ciliary beat frequency measured from ciliated cells at P1 was not statistically different from that measured from adult animals. Our study suggests that the Eustachian tube undergoes significant anatomical and histological changes between P1 and P18. The tube is morphologically and functionally mature at P18, when the auditory function (sensitivity and frequency selectivity) is mature in this species.

  17. Morphology and ciliary motion of mucosa in the Eustachian tube of neonatal and adult gerbils.

    Directory of Open Access Journals (Sweden)

    Yi Li

    Full Text Available The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms of otitis media, which is common in children. In the present study, we examined the epithelial lining of the Eustachian tube in neonatal and adult gerbils, with a focus on the morphological and functional development of ciliated cells in the mucosa. The length of the tube is ∼8.8 mm in adult gerbils. Scanning electron microscopy showed that the mucosal member near the pharyngeal side contains a higher density of ciliated cells and goblet cells than that near the tympanic side. The cilia beat frequency is 11 Hz. During development, the length of the Eustachian tube increased significantly between postnatal day 1 (P1 and P18. Scanning electron microscopy showed that the mucosa contained a high density of ciliated cells with a few goblet cells at P1. The density of ciliated cells decreased while the density of goblet cells increased during development. At P18, the mucosa appeared to be adult-like. Interestingly, the ciliary beat frequency measured from ciliated cells at P1 was not statistically different from that measured from adult animals. Our study suggests that the Eustachian tube undergoes significant anatomical and histological changes between P1 and P18. The tube is morphologically and functionally mature at P18, when the auditory function (sensitivity and frequency selectivity is mature in this species.

  18. Expression of water channel proteins (aquaporins) in the rat Eustachian tube and middle ear mucosa.

    Science.gov (United States)

    Kang, Sung-Ho; Chang, Ki-Hong; Ohcho, Shuji; Lee, Haa-Yung; Cha, Kiweon; Moon, Sung-Kyun; Andalibi, Ali; Lim, David J

    2007-07-01

    Diverse expression of the different subtypes of aquaporins in different parts of the Eustachian tube and middle ear suggests region-specific functions of the aquaporins in the normal physiology of the tubotympanum and also suggests that they may play roles in the pathophysiology of otitis media. The epithelial cells of the middle ear and Eustachian tube must maintain adequate water balance for normal function of the mucociliary system. Since aquaporins (AQPs) are known to play critical roles in water homeostasis, we investigated their expression in the tubotympanum of the rat. The expression of AQP subtypes 1, 2, 4, 5, and 7 were examined in the rat Eustachian tube and middle ear using RT-PCR, Western blotting, and immunohistochemistry. Transcripts for AQP 1, 4, and 5 were detected in the Eustachian tube and middle ear. Expression of these molecules at the protein level was confirmed by Western blot analysis. Immunohistochemical analysis demonstrated that AQP 4 was localized to the basolateral membranes of ciliated epithelial cells while AQP 5 was localized to the apical surface of serous gland cells, but not goblet cells, in the rat Eustachian tube. AQP 1 was found to be expressed by the subepithelial fibroblasts.

  19. [Observation of mucosa of eustachian tube with scanning electron microscope on spontaneous otitis media in mice].

    Science.gov (United States)

    Ma, Weijun; Hu, Juan; Cheng, Ying; Wang, Junli; Zhang, Xiaotong; Xu, Min

    2015-07-01

    To investigate the ultrastructural changes of the mucosa of eustachian tube in mice and to reveals the influence of eustachian tube on middle ear function and its relavence with otitis media. 12 wild type and 12 mutant mice were divided into two groups by age to observe the the ultrastructural changes of the mucosa of eustachian tube. Wild type mice exhibited a thick lawn of morphologically normal, distributed cilia in the mucosa of the middle ear at both time points. The cilia of mucosa of middle ear in mutant mice were short, impaired and disrupted. The impairment of the cilia progressed to a much great severity at 6 months compared to 3 months. Otitis media occurs not only the ciliated cells decreased and the goblet cells increased. More importantly, the ciliary structure was damaged, leading to the dysfunction of the mucociliary transport system and causing otitis media.

  20. 3-DIMENSIONAL COMPUTER RECONSTRUCTION OF THE EUSTACHIAN-TUBE AND PARATUBAL MUSCLES

    NARCIS (Netherlands)

    SPAUWEN, PHM; HILLEN, B; LOMMEN, E

    A new method of anatomic dissection and image reconstruction using computer techniques for better understanding of eustachian tube (ET) functioning is presented. Coronal sections of two noncleft fetal skulls were photographed and projected on a graphic tablet. Contours of the pertinent structures

  1. Morphology and Ciliary Motion of Mucosa in the Eustachian Tube of Neonatal and Adult Gerbils

    OpenAIRE

    Yi Li; Huizhan Liu; Jun Li; Qian Zhang; Shusheng Gong; David He

    2014-01-01

    The Eustachian tube is a small canal that connects the tympanic cavity with the nasal part of the pharynx. The epithelial lining of the Eustachian tube contains a ciliated columnar epithelium at the tympanic cavity and a pseudostratified, ciliated columnar epithelium with goblet cells near the pharynx. The tube serves to equalize air pressure across the eardrum and drains mucus away from the middle ear into the nasopharynx. Blockage of the Eustachian tube is the most common cause of all forms...

  2. The evaluation of the angles of Eustachian tubes in the patients with ...

    African Journals Online (AJOL)

    2015-12-02

    Dec 2, 2015 ... between COM with the eustachian tube anatomical and physiological abnormalities has been described in ... tube show us that the differences of the physiology of eustachian tube due to anatomical variants may ..... Descriptive anatomy of the human auditory tube. Surg Radiol Anat. 1998;20:335‑40. 18.

  3. Tensor veli palatini electromyography for monitoring Eustachian tube rehabilitation in otitis media.

    Science.gov (United States)

    Picciotti, P M; Della Marca, G; D'Alatri, L; Lucidi, D; Rigante, M; Scarano, E

    2017-05-01

    The pathogenesis of otitis media is related to Eustachian tube dysfunction. The tensor veli palatini muscle actively opens the Eustachian tube and promotes middle-ear ventilation. This study describes a technique for paratubal electromyography that uses a surface, non-invasive electrode able to record tensor veli palatini muscle activity during swallowing. Twenty otitis media patients and 10 healthy patients underwent tensor veli palatini electromyography. Activity of this muscle before and after Eustachian tube rehabilitation was also assessed. In 78.5 per cent of patients, the electromyography duration phase and/or amplitude were reduced in the affected side. The muscle action potential was impaired in all patients who underwent Eustachian tube rehabilitation. This study confirmed that Eustachian tube muscle dysfunction has a role in otitis media pathogenesis and showed that muscle activity increases after Eustachian tube rehabilitation therapy.

  4. Structural changes in the rat middle ear mucosa due to endotoxin and eustachian tube obstruction.

    Science.gov (United States)

    Nell, M J; Grote, J J

    1999-01-01

    The middle ears of 48 rats were used to examine the effects of endotoxin injection, eustachian tube obstruction or a combination of eustachian tube obstruction and endotoxin injection. Animals were killed after 1, 2, 4, or 12 weeks and the middle ears processed for light and scanning electron microscopy. Compared to the normal middle ear mucosa, the epithelial layer was more pseudostratified, cuboidal or cylindrical after endotoxin injection or obstruction of the eustachian tube. In the early phase, numerous ciliated cells occurred in areas originally almost devoid of these cells. At 3 months, degeneration of ciliated cells was observed. The combination of eustachian tube obstruction and endotoxin injection also induced a more pseudostratified, cuboidal or cylindrical epithelium with an increased number of goblet cells. However, an early decrease occurred in the number of ciliated cells in the tympanic orifice of the eustachian tube. Furthermore, inflammatory cells, mainly PMNs, macrophages and lymphocytes, invaded the subepithelial layer after eustachian tube obstruction and endotoxin injection. These structural changes resulted in an impairment of the mucociliary transport system for clearance of the middle ear cavity. For this reason we believe that both endotoxin and eustachian tube obstruction or dysfunction play an important role in inducing persistent mucosal changes in the middle ear cavity, thereby prolonging otitis media with effusion.

  5. Endonasal dilatation of the Eustachian tube (EET) in children: feasibility and the role of tubomanometry (Estève) in outcomes measurement.

    Science.gov (United States)

    Jenckel, Friederike; Kappo, Natalie; Gliese, Alexandra; Loewenthal, Maureen; Lörincz, Balazs B; Knecht, Rainald; Dalchow, Carsten V

    2015-12-01

    Studies on endonasal dilatation of the Eustachian tube (EET) utilizing a balloon catheter have shown encouraging results over the last years. This retrospective analysis presents our outcomes with EET in children with chronic obstructive dysfunction of the Eustachian tube, as well as the role of tubomanometry (TMM, Estève) as a diagnostic tool in the pre- and postoperative assessment of the Eustachian tube (ET) dysfunction. The data of 33 children, having undergone EET between September 2010 and March 2014, were retrospectively evaluated. They were assessed using tubomanometry before and after the EET. The R-data as the rate of Eustachian tube function in tubomanometry (TMM) were pre- and postoperatively matched with the clinical outcomes. Moreover, the patients' complaints before and after the procedure were analyzed. We did not see any EET-related complications in children. Most patients noticed a relief of their complaints. In the same time, tubomanometry was not able to show improved tube function or favorable postoperative changes in the R-data. Ear-related symptoms (e.g. otorrhea, otalgia, hearing loss) have been improved. EET is a feasible method in adults as well as in children to treat chronic tube dysfunction. However, tubomanometry does not seem to be the adequate tool to evaluate the tube function and thus the success rate of EET in children with chronic dysfunction of the Eustachian tube.

  6. Evidence and evidence gaps in the treatment of Eustachian tube dysfunction and otitis media

    Science.gov (United States)

    Teschner, Magnus

    2016-01-01

    Evidence-based medicine is an approach to medical treatment intended to optimize patient-oriented decision-making on the basis of empirically proven effectiveness. For this purpose, a classification system has been established to categorize studies – and hence therapy options – in respect of associated evidence according to defined criteria. The Eustachian tube connects the nasopharynx with the middle ear cavity. Its key function is to ensure middle ear ventilation. Compromised ventilation results in inflammatory middle ear disorders. Numerous evidence-based therapy options are available for the treatment of impaired middle ear ventilation and otitis media, the main therapeutic approach being antibiotic treatment. More recent procedures such as balloon dilation of the Eustachian tube have also shown initial success but must undergo further evaluation with regard to evidence. There is, as yet, no evidence for some of the other long-established procedures. Owing to the multitude of variables, the classification of evidence levels for various treatment approaches calls for highly diversified assessment. Numerous evidence-based studies are therefore necessary in order to evaluate the evidence pertaining to existing and future therapy solutions for impaired middle ear ventilation and otitis media. If this need is addressed, a wealth of implications can be expected for therapeutic approaches in the years to come. PMID:28025605

  7. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Dirckx, Joris J J; Jacobsen, Henrik

    2010-01-01

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  8. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Jacobsen, Henrik; Tveterås, Kjell

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  9. Polydimethylsiloxane elastomer injection in the management of the patulous eustachian tube.

    Science.gov (United States)

    Mackeith, S A C; Bottrill, I D

    2016-09-01

    To determine the effectiveness of augmentation surgery using polydimethylsiloxane elastomer injection for the management of patulous eustachian tube. All patients were treated with eustachian tube injection augmentation performed via a combined transnasal-transoral endoscopic approach. Clinical presentation, volume of injection, complications and initial response were all prospectively recorded. Longer-term follow up was conducted through structured telephone interviews using previously described patient-reported outcome measures. Overall, 8 of 11 patients (73 per cent) derived complete or significant symptom improvement; 1 patient had significant improvements but was dissatisfied, and in 2 patients the symptoms were unchanged. The eight satisfied patients showed improvement in their quality-of-life scores. This study describes an effective treatment option for patulous eustachian tube. Unlike many prior published reports, previously described patient-reported outcome measures were utilised in order to allow more direct comparison.

  10. Promising results after balloon dilatation of the Eustachian tube for obstructive dysfunction

    DEFF Research Database (Denmark)

    Wanscher, Jens H; Svane-Knudsen, Viggo

    2014-01-01

    INTRODUCTION: As the first ear, nose and throat department in Denmark, we introduced balloon dilatation of the Eustachian tube as a treatment of obstructive dysfunction in the summer of 2012. We present our preliminary experiences with this new treatment in adults. MATERIAL AND METHODS: Preoperat......INTRODUCTION: As the first ear, nose and throat department in Denmark, we introduced balloon dilatation of the Eustachian tube as a treatment of obstructive dysfunction in the summer of 2012. We present our preliminary experiences with this new treatment in adults. MATERIAL AND METHODS...

  11. Simple mass loading of the tympanic membrane to alleviate symptoms of patulous eustachian tube.

    NARCIS (Netherlands)

    Bartlett, C.; Pennings, R.J.E.; Ho, A.; Kirkpatrick, D.; Wijhe, R. Van; Bance, M.

    2010-01-01

    BACKGROUND: Patulous eustachian tube (PET) has a major impact on a patient's quality of life. The purpose of this study was to understand mechanisms behind the symptoms, develop treatments based on these, and develop and use a questionnaire to measure changes in PET symptoms with a novel

  12. Intranasal fluticasone associated with delayed tympanostomy tube placement in children with eustachian tube dysfunction.

    Science.gov (United States)

    Crowson, Matthew G; Ryan, Marisa A; Ramprasad, Vaibhav H; Choi, Kevin J; Raynor, Eileen

    2017-03-01

    Pediatric patient caregivers may prefer to avoid a surgical intervention and request a medical management option for eustachian tube dysfunction (ETD). However, there are limited published data evaluating the efficacy of intranasal fluticasone in the medical management of ETD as an alternative to tympanostomy tube placement. The objectives of this study were to: 1) determine if intranasal fluticasone (INF) prevented tympanostomy tube placement in children with ETD, and 2) describe differences in patient response to INF related to cleft lip and/or palate (CLP) and Down syndrome. Case series with planned chart review at a Tertiary academic hospital. We reviewed pediatric patients treated with INF for ETD. Inclusion criteria included ETD, no prior intranasal or oral steroid therapy, and no prior tympanostomy tube placement. Outcomes included time-to- tympanostomy tube placement with or without INF and therapy compliance. Kaplan-Meier survival analyses with log-rank tests and Fisher's exact tests were used to examine outcome variables. 676 fulfilled inclusion criteria. 393 (58.7%) were male, and 355 (52.5%) Caucasian with mean age of 27.1 months old. 92 (13.6%) had CLP and 46 (6.8%) had Down Syndrome. 266 (39.4%) received INF, and 202 (88.2%) were compliant at their next visit. 474 (70.1%) had tympanostomy tubes placed. Children treated with INF were less likely to have tympanostomy tubes placed than children not treated (52.6% vs. 81.5%; p < 0.0001). Using survival analyses, INF use was associated with significantly longer mean time-to-tympanostomy tube than no INF use (199.4 vs. 133.7 days; p < 0.0001). INF did not reduce time-to-tympanostomy tube in patients with CLP (p = 0.05) or Down Syndrome (p = 0.27). INF significantly reduces the number of children requiring tympanostomy tube placement for ETD. The CLP and Down Syndrome anatomical variants may attenuate INF efficacy. Further in vivo characterization of INF action on eustachian tube tissues will help

  13. An Eustachian Tube Neuroendocrine Carcinoma: A Previously Undescribed Entity and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Gavin J. le Nobel

    2016-01-01

    Full Text Available Primary sinonasal and middle ear neuroendocrine carcinomas are rare malignancies of the head and neck. Owing to the rarity of these tumors, the clinical behavior and optimal management of these tumors are not well defined. We present a case of an incidentally discovered sinonasal neuroendocrine carcinoma that was found to originate from the Eustachian tube, which has not previously been described in the literature. This patient was treated with primary surgical resection using a combination of transnasal and transaural approaches and achieved an incomplete resection. Follow-up imaging demonstrated continued tumor growth in the Eustachian tube as well as a new growth in the ipsilateral cerebellopontine angle and findings suspicious of perineural invasion. However, the tumor exhibited a benign growth pattern and despite continued growth the patient did not receive additional treatment and he remains asymptomatic 35 months following his original surgery.

  14. Cross-platform data integration of paratubal electromyography and sonotubometry for eustachian tube: a pilot study.

    Science.gov (United States)

    Lin, Chenxi; Li, Yanning; Lin, Xin; Zhang, Shaohua; Tang, Anzhou; Nong, Dongxiao

    2016-11-01

    The sensitive sonotubometry and MATLAB provide a new tool to study the eustachian tube (ET) function and contribute more to reliable data and precise analysis. The levator veli palatini muscle (mLVP) and the salpingopharyngeus muscle (mSP) may, respectively, be the most important and least important muscle for ET function. The ET lumen dilation is a result of the contraction of the paratubal muscles, the tensor veli palatini muscle (mTVP), mLVP and mSP. To trace the dynamic ET muscle/lumen activities, the present study aimed to optimize sonotubometry and achieve cross-platform data integration of electromyography (EMG) and sonotubometry using MATLAB (matrix laboratory). Seventeen healthy volunteers (34 ears) were chosen for the concurrent recordings of the paratubal EMG and sonotubogram under dry and water swallowing. The optimized sonotubometry based on computer sound card showed satisfied sensitivity. For both EMGs and sonotubogram, dry swallowing generated significantly greater amplitude and longer duration compared to water swallowing. Moreover, statistically significant differences (p < 0.05) were detected in the comparison of the amplitude, duration, and latency for the mTVP, mLVP, and mSP. The mSP activity was the weakest and even inactive in some cases, the mLVP presented the most powerful and long lasting activity during ET-opening.

  15. The evaluation of the angles of Eustachian tubes in the patients with chronic otitis media on the temporal computerized tomography.

    Science.gov (United States)

    Aksoy, S; Sayin, I; Yazici, Z M; Kayhan, F T; Karahasanoglu, A; Hocaoglu, E; Inci, E

    2016-01-01

    Chronic otitis media (COM), affecting all over the world and in a wide range of age groups in Turkey, is an important cause of ear discharge and hearing loss. The main clinical manifestations are tympanic membrane perforation, ear, nose and throat problems. On the tympanic membrane perforation becomes persistent and cholesteatoma development, there are a lot of opinions today. Especially in the pathology associated with otitis media with effusion eustachian tube, it is known that COM and cholesteatoma develop. In our study, we interpreted 210 patients' temporal computed tomography (CT). Seventy of these 210 patients had otitis media with cholesteatoma, 70 patients had only otitis media without cholesteatoma, and 70 patients had no otitis media. The eustachian tubes were evaluated using temporal CT multiplanar reconstruction method. Angles with the horizontal plane of the eustachian tube and Reid and tubotympanic angles were measured. The angles between eustachian tube and horizontally oriented Reid plane of the patients with cholesteatoma were found to be significantly lower than the patients with otitis media without cholesteatoma and the patients with no history of otitis media. For the tubotympanic angle, no statistically significant differences were observed between the groups. These results suggest that the decrease in the angle with the horizontal plane of Reid in the eustachian tube in adults may play a significant role in the etiology of cholesteatoma.

  16. Treatment of middle ear ventilation disorders: sheep as animal model for stenting the human Eustachian tube--a cadaver study.

    Directory of Open Access Journals (Sweden)

    Felicitas Miller

    Full Text Available Eustachian tube disorders can lead to chronic otitis media with consecutive conductive hearing loss. To improve treatment and to develop new types of implants such as stents, an adequate experimental animal model is required. As the middle ear of sheep is known to be comparable to the human middle ear, the dimensions of the Eustachian tube in two strains of sheep were investigated. The Eustachian tube and middle ear of half heads of heathland and blackface sheep were filled with silicone rubber, blended with barium sulfate to induce X-ray visibility. Images were taken by digital volume tomography. The tubes were segmented, and a three-dimensional model of every Eustachian tube was generated. The lengths, diameters and shapes were determined. Additionally, the feasibility of endoscopic stent implantation and fixation was tested in cadaver experiments. The length of the tube between ostium pharyngeum and the isthmus and the diameters were comparable to published values for the human tube. The tube was easily accessible through the nose, and then stents could be implanted and fixed at the isthmus. The sheep appears to be a promising model for testing new stent treatments for middle ear ventilation disorders.

  17. Developmental anatomy of the eustachian tube and middle ear in mice.

    Science.gov (United States)

    Park, K; Ueno, K; Lim, D J

    1992-01-01

    It is generally accepted that the development of the tubotympanum has significant bearing on the susceptibility to ear infection. A detailed study of the differentiation of ciliated cells in secretory elements will be useful in understanding both the normal physiology and the pathology of the tubotympanum. Serially sectioned temporal bones of 76 mice ranging from gestational age day 11 to postnatal day 21 were examined microscopically. During the period of gestation, the tubotympanic recess was formed at the 12th day and began to extend to form the middle ear between the 13th and 14th days. A rapid increase in the volume of the tubotympanic recess was observed between the 15th and 16th days when a definitive division of the tubotympanic recess into the eustachian tube and middle ear cavity was observed. Postnatally the tubotympanum attained an adult form around day 9, and the maximum change of middle ear volume was noted on day 11, when the mesenchymal tissue in the middle ear cavity disappeared completely. Development of the ciliated cells was observed concurrently in both the eustachian tube and middle ear on the 16th gestational day, one day earlier than the appearance of the epithelial secretory cells in both the eustachian tube and middle ear. The number of ciliated cells and secretory cells increased rapidly after birth. Tubal glands were well developed with evidence of secretory activity around the time of birth. Based on these findings, one can conclude that the mucociliary defense system starts to develop during the fetal stage and is well established immediately after birth.

  18. Identifying eustachian tube dysfunction prior to hyperbaric oxygen therapy: Who is at risk for intolerance?

    Science.gov (United States)

    Cohn, Jason E; Pfeiffer, Michael; Patel, Niki; Sataloff, Robert T; McKinnon, Brian J

    Determine whether specific risk factors, symptoms and clinical examination findings are associated with hyperbaric oxygen therapy (HBOT) intolerance and subsequent tympanotomy tube placement. A retrospective case series with chart review was conducted from 2007 to 2016 of patients undergoing HBOT clearance at a tertiary care university hospital in an urban city. Eighty-one (n=81) patient charts were reviewed for risk factors, symptoms and clinical examination findings related to HBOT eustachian tube dysfunction and middle ear barotrauma. Relative risk was calculated for each variable to determine risk for HBOT intolerance and need for tympanotomy tube placement. Risk factor, symptom, physical examination and HBOT complication-susceptibility scores were calculated for each patient. Mean risk factor, clinical and HBOT complication-susceptibility scores were significantly higher in patients who did not tolerate HBOT compared to patients who tolerated HBOT. Patients reporting a history of otitis media, tinnitus, and prior ear surgery were at a higher risk for HBOT intolerance. Patients reporting a history of pressure intolerance and prior ear surgery were more likely to undergo tympanotomy tube placement. Patients noted to have otologic findings prior to HBOT were at a higher risk for both HBOT intolerance and tympanotomy tube placement. A thorough otolaryngological evaluation can potentially predict and identify patients at risk for HBOT intolerance and tympanotomy tube placement. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. [The treatment effect of eustachian tube atresia with laser and connical plastic tube after radiotherapy for nasopharyngeal carcinoma].

    Science.gov (United States)

    Gao, H G; Tong, J; Chen, W W

    2017-07-07

    Objective: To investigate the method in treatment of Eustschian tube atresia caused by radiotherapy. Methods: Two cases diagnosed of Eustschian tube atresia following radiotherapy were retrospectively analyzed in Department of Otorhinolaryngology, Divided Hospital of Shanghai University Communication Affiliated First People Hospital in Apr. 2014 and Oct. 2015. Both cases were female, 65 and 64 years old, and accepted radiotherapy six and 20 years ago respectively. The pharyngeal orifices of Eustschian tube were found to be totally closed under endoscope. The closed Eustschian tubes were re-opened by laser and re-shaped by a slim and conical plastic tube for more than six months. They were followed up and evaluated over 12 months. Results: At six and 12 months after treatment, round mouths were formed in the pharyngeal orifice of Eustachian tube, and the patients had no resistance in Valsalva's test. No shrink or abnormal opening of orifice was found at follow-up of 20 and 12 months. Conclusion: The method of re-opening by laser and re-shaping by a slim and conical plastic tube is recommended to treat Eustschian tube occlusion caused by radiotherapy.

  20. Assessment of nasal-noise masking audiometry as a diagnostic test for patulous Eustachian tube.

    Science.gov (United States)

    Paradis, Justin; Bance, Manohar

    2015-02-01

    The primary objective is to assess the validity of nasal-noise masking audiometry (NNMA) as a clinical diagnostic tool in our patient population. Retrospective case review. Tertiary ambulatory referral center. Patients with patulous Eustachian tube (PET) were identified from referrals to our Eustachian tube disorders clinic primarily with symptoms including autophony, aural fullness, and hearing their own breathing. The healthy subjects had no history of ear disease. NNMA was measured in 20 ears of 10 healthy subjects as well as in 42 ears of 21 patients with suspected PET. NNMA mean auditory thresholds were measured at frequencies ranging from 250 to 8,000 Hz. When stratified as definitive or probable PET based on observed tympanic membrane movement with breathing, both Definitive and Probable PET groups had significantly higher NNMA mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.003), 1,000 Hz (p = 0.019, p = 0.001), and 6,000 Hz (p = 0.4, p = 0.001). When stratified based on symptoms on the day of testing, both Symptomatic Ears and Non-Symptomatic Ears had significantly higher mean auditory thresholds compared to Normal ears at 250 Hz (p = 0.001, p = 0.015) and at 1,000 Hz (p = 0.002, p = 0.004). Our results demonstrate a larger masking effect in patients with PET compared to normal subjects in the low-frequency region. In clinical practice, the relatively small effect and the wide variability of results between patients have made this test be of little value clinically in our patient population.

  1. The structure of the middle ear epithelium of the rat and the effect of Eustachian tube obstruction.

    Science.gov (United States)

    Kuijpers, W; van der Beek, J M; Jap, P H; Tonnaer, E L

    1984-08-01

    The middle ear cavity of the rat is lined with ciliated and squamous epithelium. The arrangement of the ciliated cells, interspersed with secretory cells, in distinct tracts and their continuity with the ciliated epithelium of the Eustachian tube, suggests the existence of a mucociliary transport system for cleaning the middle ear cleft. The secretory cells produce either neutral or sulphated glycoproteins, dependent on their location. In addition to these secretions, the epithelium of the lower part of the Eustachian tube is bathed with secretory products of seromucous glands. Also in the areas with squamous epithelium, numerous small secretory cells, the character of which is only identifiable with the electronmicroscope, are present. It is concluded that the middle ear lining can be considered as a locally modified respiratory epithelium. Blockade of the mucociliary transport system, supposedly a crucial aetiological factor in secretory otitis media, by obstruction of the Eustachian tube, induces pathogenic behaviour of microorganisms normally present in the middle ear. This results in either a transient or a longstanding infective middle ear disease, associated with a large variety of changes of the mucosa, especially with respect to the secretory activity. The data obtained indicate that the increased secretory activity encountered in secretory otitis media cannot be attributed to the isolated effect of tubal occlusion, but rather to an infective process.

  2. Eustachian Tube Obliteration and its Effect on Rhinoliquorrhea in Translabyrinthine Vestibular Schwannoma Excision.

    Science.gov (United States)

    Moderie, Christophe; Maniakas, Anastasios; Moumdjian, Robert; Alhabib, Salman F; Saliba, Issam

    2017-08-01

    Rhinoliquorrhea is defined as a cerebrospinal fluid leakage from the nose. Our objective in this study is to determine the reduction of rhinoliquorrhea rates by Eustachian tube (ET) obliteration in the context of a translabyrinthine approach performed following vestibular schwannoma (VS) excision. This is a prospective study achieved in a tertiary-care center where the chart review revealed 94 VS operated by the translabyrinthine approach between 2009 and 2015. There were 40 males and 54 females aged from 28-76 years. The only exclusion criterion was a previous history of cranial surgery. ET obliteration was systematically executed when the petrous apex pneumatization level was at least 2 of 4. Our main outcome measure was the development of rhinoliquorrhea. Eighty-eight patients underwent ET obliteration and were followed for an average of 2.6±1.2 years. Rhinoliquorrhea was reported in 1.14% of the patients having had an ET obliteration. When compared to our previous sample of patients operated with a translabyrinthine approach, it represents a reduction of 84%. Obliteration of the ET is a fast and simple procedure that reduces the rate of rhinoliquorrhea. We therefore recommend its use, specifically in cases of petrous apex pneumatization levels 2-4.

  3. Secretory otitis. Histopathology and goblet-cell density in the Eustachian tube and middle ear in children.

    Science.gov (United States)

    Tos, M; Bak-Pedersen, K

    1976-05-01

    The histological changes in the middle ear of four children with incipient or mild chronic secretory otitis are described. They consist in vascular dilatation and proliferation, round-cell infiltration, epithelial metaplasia into pseudostratified, columnar, ciliated epithelium posteriorly in the middle ear, formation of abnormal mucous tubular glands, and an increase in goblet-cell density in the osseous tube and middle ear. The causes of these changes were presumably long-lasting tubal occlusion due to a permanent nasogastric tube and protracted catarrhal diseases. The density of goblet cells was determined in various parts of the Eustachian tube and middle ear. The findings were analysed statistically and compared with the density in prematures and newborns, normal children, and normal adults. In the tympanic orifice and in the osseous Eustachian tube the goblet-cell density was greatly increased, whereas the increase in the middle ear varied individually, but was in conformity with the other findings. These cases illustrate that the histopathological changes in the middle-ear mucosa in secretory otitis must be regarded not only from a qualitative, but certainly also from a quantitative point of view.

  4. Do the angle and length of the eustachian tube influence the development of chronic otitis media?

    Science.gov (United States)

    Dinç, Aykut Erdem; Damar, Murat; Uğur, Mehmet Birol; Öz, Ibrahim Ilker; Eliçora, Sultan Şevik; Bişkin, Sultan; Tutar, Hakan

    2015-09-01

    To compare the eustachian tube (ET) angle (ETa) and length (ETl) of ears with and without chronic otitis media (COM), and to determine the relationship between ET anatomy and the development of COM. A retrospective case-control study. The study group comprised 125 patients (age range, 8-79 years; 64 males and 61 females) with 124 normal ears and 126 diseased ears, including ears with chronic suppurative otitis media (CSOM) with central perforation, intratympanic tympanosclerosis (ITTS), cholesteatoma, and a tympanic membrane with retraction pockets (TMRP). ET angle and length were measured using computed tomography employing the multiplanar reconstruction technique. The ETa was significantly more horizontal in diseased versus normal ears of all study groups (P = .030), and there was no group difference in ETl (P = .160). ETl was shorter in CSOM versus ITTS ears and normal ears (P = .007 and P = .003, respectively) and in cholesteatoma versus TMRP ears (P = .014). In the unilateral COM group, there were no significant differences in the ETa or ETl of diseased versus contralateral normal ears (P = .155 and P = .710, respectively). The ETa was significantly more horizontal in childhood-onset diseased versus normal ears (P = .027), and there was no group difference in ETl (P = .732). The ETa (P = .002) and ETl (P ETl could be contributory (though not significantly) etiological factors in the development of COM. 3b. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  5. Middle ear ventilation status postoperatively after translabyrinthine resection of vestibular schwannoma with mastoid obliteration and Eustachian tube occlusion: is the Eustachian tube enough to ventilate the middle ear without the mastoid air cell system?

    Science.gov (United States)

    Belyea, James; Wickens, Brandon; Bance, Manohar

    2016-08-30

    Gas pressure balance is essential for maintaining normal middle ear function. The mucosal surfaces of the middle ear, the mastoid air cell system (MACS), and the Eustachian tube (ET) play a critical role in this process; however, the extent that each of these factors contributes to overall middle ear ventilation is unknown. The objective of this study was to determine if the ET alone can maintain normal middle ear pressure without the MACS. To do this, we reviewed subjects who had their MACS completely removed with translabyrinthine (TL) surgery for vestibular schwannoma. A retrospective chart review was done to collect pre and postoperative tympanometry data from patients who underwent resection of vestibular schwannoma. Data from the operative side was compared to the non-operative side at 2 years post-op. Twenty-four patients were included in this study. Of these, 63 % achieved a type A tympanogram at 2 years post-op in the TL resection group, implying an ability to maintain middle ear pressure in the absence of a mastoid cavity. Because some had negative pressures post TL resection, the average change in pre and postoperative pressure was -37.5 daPa for the operative side and 7.8 daPa for the non-operative side. This was significantly different. The difference for change in pre and postoperative pressure and compliance between operative and non-operative side might be expected from the ET plugging during TL resection. However, more interesting are those patients in whom the ET presumably reopens, and in these subjects, despite having no mastoid compartment at all, and the space obliterated with fat, they were still able to maintain normal ventilation of the middle ear space. Our findings imply that the ET alone is adequate to ventilate at least the reduced middle ear space following TL surgery in most subjects, and perhaps in 100 % if the ET hadn't been plugged during surgery. Hence, the mastoid air cell system, even when healthy, is not needed to maintain

  6. [The condition of the Eustachian tube and its influence on the middle ear].

    Science.gov (United States)

    Zechner, G

    1979-01-01

    Any functional disturbance in the auditory tube may be documented morphologically. We demonstrated in case of a block changes within the tubal mucosa and in the adjacent salivary glands. Complete obliteration of the lumen is a very rare instance caused only by severe trauma or as a possible result of heavy inflammatory damage to the mucosa. A lack of ventilation produces in the tympanic cleft a vacuum, followed by a typical effusion out of the altered mucosa. Anaerobic conditions favour hyper and metaplastic transformation of the epithelium. The clinical picture resembles the non-purulent, closed form of otitis, serous otitis media. The missing clearance makes the discharge within the tympanic cleft a great challenge to the mucosa. Granulation tissue proliferates, an enzyme production is initiated and phagocytes help to eliminate or to organize the middle ear content. The clinical picture corresponds to otitis media adhaesiva. If the auditory tube is blocked long enough, the healing result leads to the atelectatic tympanon caused by scare tissue, dystrophic calcification, fatty degeneration of granulation tissue, fibrocystic transformation of the mucosa. The ossicular chain, if not destroyed or interrupted, is fixed. A very dangerous condition is caused by retractionpockets within the ear drum membrane. They give rise to secondary acquired cholesteatoma. In the beginning of the whole process we see the nonfunctioning auditory tube, provoked by an infection. The development of the tubal tonsil and the perivascular aggregations of immunocompetent cells lead to the opinion, that the tube is an immunological not only a mechanical barrier against ascending infections. Favoured by antibiotic treatment the inflammation is localized by the body's own defence within the tympanic tube and causes the blockage, the loss of function, which influences heavily the middle ear and its lining.

  7. [The Eustachian tube and its role in the history of otology. Images from the history of otorhinolaryngology, presented by instruments from the collection of the Ingolstadt German History Museum].

    Science.gov (United States)

    Feldmann, H

    1996-12-01

    Even in ancient times the existence of an open pathway between the ear and the respiratory tract was assumed. Up to the middle ages, however, Aristotle's idea that the air in the ear is an innate part of the body prevailed. The first anatomical description of the tube was given by Eustachius (1563). He still adhered to the concept of "innate air" and regarded the tube only as a pathway for draining pathological matter from the tympanic cavity. Duverney (1683) realized that an important function of the tube was replacing and adjusting the pressure of the air in the tympanic cavity. He thought that the tube is permanently open, thus offering a vent to the air, when the tympanic membrane is moving inwards and outwards. Valsalva (1704) discovered a muscle for opening the tube, and he presumed that in hearing this muscle would come into action. He described the maneuver that is named after him as a method to expel pus from the tympanic cavity into the external auditory canal. E.G. Guyot, a postmaster in Versailles, was the first to try catheterization of his own Eustachian tube via the mouth. Cleland (1741) inserted the catheter via the nose, and Wathen (1756) after studies on corpses described in detail the technique how to carry out this procedure. The therapeutic application of Eustachian catheterization as practiced by physicians such as Itard (1821) centered around irrigation with water and medications as well as inflation of various fumes. Deleau (1836) later advocated a douche of pure air and, in analogy to the auscultation of the lung, described the different noises that could be perceived during this procedure. Numerous models of pumps were constructed for this air douche, which became one of the most widely used therapeutical means in otology. There were also lethal incidents caused by cutaneous emphysemata. Toynbee realized that at rest the tube is closed and that there is a constant absorption of air in the tympanic cavity. The tube would be opened only by

  8. Eustachian Tube Dysfunction

    Science.gov (United States)

    ... Reye SyndromeTeenage Pregnancy and Birth Control AccessRead Article >>Teenage Pregnancy and Birth Control Access Check Your Symptoms Find ... harmful to the brain and liver. It often…Teenage Pregnancy and Birth Control AccessRead Article >>Kids and TeensTeenage ...

  9. Do the Angle and Length of the Eustachian Tube Affect the Success Rate of Pediatric Cartilage Type 1 Tympanoplasty?

    Science.gov (United States)

    Yegin, Yakup; Çelik, Mustafa; Altintaş, Ahmet; Çolak, Ceylan; Kayhan, Fatma Tülin

    2017-05-01

    To investigate the relationships between the angle and length of the Eustachian tube (ET) (the ETa and the ETl) and the success rates of pediatric type 1 tympanoplasty. A retrospective clinical chart review. In total, 51 children (31 females and 20 males; average age, 11.92 ± 3.46 years; age range: 7-18 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. In group A, all patients had intact grafts without perforation, retraction, or lateralization, and a dry ear, at 6 months postoperatively. In group B, reperforation of the tympanic membrane was evident 6 months postoperatively. The average ETa and ETl values of each group were measured on computed tomography images using a multiplanar reconstruction technique, and compared. The ETa values of diseased ears of males and females were, respectively, 26.60 ± 6.42° and 23.29 ± 6.51°, compared to 27.25 ± 5.23° and 23.32 ± 4.61° for normal male and female ears, respectively. In group A, the ETa was 26.46 ± 6.82° in males and 22.95 ± 7.50° in females. In group B, the ETa was 26.85 ± 6.12° in males and 23.90 ± 4.45° in females. In group A, the mean ETl was 41.0 mm (29.6-45.3 mm) in males and 37.9 mm (32.0-44.5 mm) in females. In group B, the mean ETl was 40.5 mm (30.5-47.1 mm) in males and 38.0 mm (32.8-45.0 mm) in females. In group A, the ETa value of diseased ears did not differ between females and males, but in normal ears, the ETa was higher in males than females (P = 0.020 and P  0.05). No difference in the ETl values of diseased and normal ears, in either group, was apparent between females and males (both P > 0.05). Neither the ETa nor the ETl affected the success rate of pediatric cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to compare anatomical outcomes

  10. Retrospective results of radiation therapy of the Eustachian tube in chronic otitis media; Retrospektive Ergebnisse der perkutanen Strahlentherapie der Tuba Eustachii bei chronischer Otitis media

    Energy Technology Data Exchange (ETDEWEB)

    Schultze, J.; Reinke, C.; Kimmig, B. [Klinik fuer Strahlentherapie (Radioonkologie), Universitaetsklinikum Kiel (Germany); Frese, K.A. [Klinik fuer Hals-, Nasen- und Ohrenheilkunde, Kopf- und Halschirurgie, Universitaetsklinikum Kiel (Germany)

    2003-01-01

    Background: The treatment results of symptomatic radiation therapy of the Eustachian tube in chronic otitis media had to be evaluated retrospectively. Patients and Methods: Between 1980 and 1997, 66 patients were referred for therapy. The median age was 58 years. In the clinical presentation, all the patients had a hearing impairment, 35 patients complained of pain, 21 had otorrhea. In their history, 20 patients indicated chronic recurrent infections. The complaints lasted for 4.7 years in the median, primary conservative (adstringentia, antibiotics) and surgical treatment (paracentesis, tympanic tubule, tympanoplastic) did not lead to lasting cure. In 40 of 66 patients, finally radiation therapy was done of both Eustachian tubes. With opposed fields and cobalt-60 photons a total dose of 6 Gy at single doses of 1 Gy, three times a week, was applied. Under the causes for exclusion of radiation therapy were non-acceptance of the patients (nine), prior radiation therapies (six) or spontaneous improvement after initial presentation in our department. The treatment results were evaluated by interviews of the patients and regular otorhinolaryngological examinations. Results: There were no side effects noticed. 28 of 40 (70%) patients reported a significant improvement that could be verified by objective otorhinolaryngological examinations. In the group of 26 nonirradiated patients, 22 could be interviewed indicating in 16 cases (72%) that the complaints were unchanged and chronic otitis media was lasting. In a subgroup analysis concerning the duration of otitis media radiation therapy proved more effective in an acute and subacute stadium of disease of up to 5 years duration, while the patients resistant to radiation therapy were entirely in a chronic stage of disease exceeding 5 years duration. (orig.) [German] Hintergrund: Die Behandlungsergebnisse der symptomatischen Radiotherapie bei chronischer Otitis media sollten retrospektiv evaluiert werden. Patienten und

  11. A study of middle ear reconstruction, the degree of functional restoration and causes of graft failure following chronic ear disease

    Directory of Open Access Journals (Sweden)

    Vishnu Prasad

    2014-07-01

    Conclusion: Patients with normal Eustachian tube function, large and medium size mastoids, small and medium size perforations of the tympanic membrane would have a good rate of graft uptake with tympano-ossiculoplasties thereby returning to normal hearing postoperatively.

  12. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  13. Measurement of middle ear pressure changes during balloon eustachian tuboplasty: a pilot study.

    Science.gov (United States)

    Todt, Ingo; Abdel-Aziz, Tarek; Mittmann, Philipp; Lehmann, Martin; Ebmeyer, Jörg; Scholtz, Lars-Uwe; Sudhoff, Holger

    2017-05-01

    The middle ear pressure changes detected during BET can be directly attributed to the balloon inflation and may represent a second, immediate, mechanism of action of BET. BET seems to be safe with respect to the risk of a barotrauma. Further human studies are now necessary to confirm the results and gain more insight into the mechanism of action of BET. Since the introduction of Balloon Eustachian Tuboplasty (BET) as a treatment of chronic Eustachian tube dysfunction, the precise mechanism of action is unknown. Long-term effects of BET may be related to observed microfractures of the Eustachian tube cartilage. However, clinical observations indicate a second, immediate mode of action. Therefore, this study investigated and characterized middle ear pressure changes occurring directly during BET procedure. Using a micro-optical pressure sensor, pressure changes during BET were monitored transtympanically in a cadaveric animal study using heathland sheep. Middle ear pressure amplitudes during BET are dependent on the speed of balloon inflation as well as the maximum inflation pressure. A 10-bar inflation pressure yielded a mean middle ear pressure of 5.34 mmHg (71.0 daPA). Negative pressure amplitudes occurring on withdrawal of the balloon catheter are influenced by the speed of withdrawal. No pressure amplitudes capable of causing barotrauma to membranous ear structures could be detected.

  14. The Functionality of Paratexts on YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2014-01-01

    This chapter investigates paratexts and their functionality on YouTube. It is argued that YouTube content is in fact characterized by its dependence and usage of paratexts as part of YouTube's infrastructure. Paratexts are presented as being either auto-generated by YouTube or created by its users....... They are furthermore identified through a distinction between spatial and temporal relationships. Based on these distinctions, a small survey of some of the most popular videos on YouTube is conducted in order to examine the appearance and functionality of paratexts. A principal argument of the chapter...... is that the functionality of the paratexts can be explained by what Genette characterizes as the paratext's illocutionary force, which is examined in relationship to YouTube's paratexts and, more specifically, the site's implementation of links. The chapter also argues that paratexts may be characterized as a necessary...

  15. [Long-term follow-up after tympanostomy tube insertion in children with serous otitis media].

    Science.gov (United States)

    Fekete-Szabó, Gabriella; Kiss, Fekete; Rovó, László

    2015-11-15

    The authors report about the efficacy of inserted tympanostomy tube in children with serous otitis media. The aim of the authors was to assess the status of eardrum, the function of Eustachian tube and hearing level 10 years after the use of tympanostomy tube. Patients filled out a questionnaire and microscopic examination of tympanic membrane, tympanometry, Eustachian tube function examination, and audiometry tests were performed. In the period of 2003-2004, ventilation tube insertion was performed in 711 patients in the ENT Department of Pediatric Health Center of University of Szeged. In 349 patients adenotomy and tympanostomy tube insertion, in 18 cases tonsillectomy and grommet insertion and in 344 patients only typmanostomy tube insertion were performed. Due to objective difficulties (address change, no phone number) 453 patients were asked for control test and 312 persons accepted the invitation. Normal hearing level was found in 84.6% of patients and normal tympanometry result occurred in 82%. Tympanic ventilation disorder, perforation of tympanic membrane, sensorineural hearing loss and sensorineural hearing loss due to noise exposure were diagnosed. Application of tympanostomy tube is effective in the treatment of serous otitis media resulting from ventilation disorder. The authors draw attention to the importance of tympanometry examination to prevent the adhesive processes and cholesteatoma in chronic ventilation disorder of the middle ear.

  16. Wave function properties of a single and a system of magnetic flux tube(s) oscillations

    Science.gov (United States)

    Esmaeili, Shahriar; Nasiri, Mojtaba; Dadashi, Neda; Safari, Hossein

    2016-10-01

    In this study, the properties of wave functions of the MHD oscillations for a single and a system of straight flux tubes are investigated. Magnetic flux tubes with a straight magnetic field and longitudinal density stratification were considered in zero-β approximation. A single three-dimensional wave equation (eigenvalue problem) is solved for longitudinal component of the perturbed magnetic field using the finite element method. Wave functions (eigenfunction of wave equation) of the MHD oscillations are categorized into sausage, kink, helical kink, and fluting modes. Exact recognition of the wave functions and the frequencies of oscillations can be used in coronal seismology and also helps to the future high-resolution instruments that would be designed for studying the properties of the solar loop oscillations in details. The properties of collective oscillations of nonidentical and identical system of flux tubes and their interactions are studied. The ratios of frequencies, the oscillation frequencies of a system of flux tubes to their equivalent monolithic tube (ω sys/ω mono), are obtained between 0.748 and 0.841 for a system of nonidentical tubes, whereas the related ratios of frequencies for a system of identical flux tubes are fluctuated around 0.761.

  17. Fluoroscopically guided percutaneous gastrostomy: tube function and malfunction.

    Science.gov (United States)

    McLoughlin, R F; Gibney, R G

    1994-01-01

    We describe our experience with fluoroscopically guided percutaneous gastrostomy, assessing in particular the functional performance of inserted tubes. We also examine the ability of radiological investigations to detect intraperitoneal gastrostomy leakage after the procedure. A functioning gastrostomy tube was established and maintained for as long as was required in 34 (89.5%) of 38 patients referred during a 21-month period. This necessitated further gastrostomy tube placements in 13 patients. On average, inserted gastrostomy tubes functioned for 10.75 weeks and during the review period a total of 34 malfunctioning tubes required replacement or removal. This was most commonly due to tube dislodgement, blockage, or intraperitoneal leakage. We found increasing pneumoperitoneum on sequential postprocedure erect chest films a reliable sign in the diagnosis of the latter complication. In conclusion, while we have been disappointed with aspects of individual tube function, our satisfactory overall functional success rate indicates that percutaneous gastrostomy is an effective method for establishing and maintaining enteral feeding. We also propose a protocol for the management of suspected intraperitoneal leakage based on the findings on postprocedure erect chest films.

  18. Determination of eustachius tube ventilation functioning among benign type chronic suppurative otitis media and non-otitis media subjects using sonotubometry

    Science.gov (United States)

    Ikhwan, M.; Hafil, A. F.; Bramanthyo, B.

    2017-08-01

    The Eustachian tube (ET) is responsible for the ventilation, protection, and cleaning of the middle ear. ET dysfunction plays an important role in the pathogenesis of otitis media cases, and thus the treatment and prognosis of these cases is extremely dependent on adequate ET function, which can ultimately affect the success rate of middle ear reconstruction practices. Data research on the ET’s ventilation function is needed to ensure the success of therapy and surgery treatments in the case of Chronic Suppurative Otitis Media (CSOM) patients. This study aims to investigate ET ventilation functioning in benign type CSOM and non-otitis media subjects and to develop another modality to measure ET ventilation functioning in patients with intact and perforated tympanic membranes. A comparative cross-sectional study of 36 benign type CSOM patients and 80 non-otitis media subjects will be conducted using sonotubometry and the rated parameter measurements of ET opening frequency, amplitude and ET opening duration. Malfunctioning ventilation of the ET is more common among benign type CSOM subjects (47%) than among non-otitis media subjects (18.75%). There is a significant difference (p = 0.002) between the ET ventilation functioning of benign type CSOM subjects and non-otitis media subjects—benign type CSOM subjects have rates of malfunctioning ET ventilation that are 3.88 times higher than those of non-otitis media subjects. Patients with benign type CSOM are more likely to experience malfunctioning ET ventilation than are non-otitis media subjects.

  19. Ulipristal acetate resembles mifepristone in modulating human fallopian tube function.

    Science.gov (United States)

    Li, Hang Wun Raymond; Liao, Su-Bin; Yeung, William Shu-Biu; Ng, Ernest Hung-Yu; O, Wai-Sum; Ho, Pak-Chung

    2014-10-10

    Do ulipristal acetate (UPA) and mifepristone have an effect on ciliary beat frequency and muscular contractions in the human Fallopian tube? UPA, in resemblance to mifepristone, inhibits ciliary beat and muscular contraction of the human Fallopian tube, probably through an agonistic effect on the tubal progesterone receptor. UPA, like mifepristone, acts as an emergency contraceptive mainly by inhibiting ovulation. Little is known about its effects on tubal function. This was an in vitro experimental study using Fallopian tube samples collected from 11 women undergoing hysterectomy for benign non-tubal gynaecological conditions. The tubal epithelium and longitudinal smooth muscle fibres were isolated, cultured and treated with UPA at graded concentrations of 0, 20, 200 and 2000 ng/ml, and mifepristone at graded concentrations of 0, 300, 3000 and 30 000 ng/ml, respectively. After treatment, ciliary beat frequency was determined using a photometric method. Basal tone, amplitude and frequency of muscular contraction were recorded through a force transducer. The mRNA expression of progesterone receptor (total and PR-B isoform), glycodelin and adrenomedullin were determined by real-time quantitative PCR. There was an overall dose-dependent suppressive effect on ciliary beat frequency (P < 0.0001) after treatment with UPA at all concentrations and with mifepristone at 3000 ng/ml or above. The basal tone, amplitude and frequency of muscular contractions were significantly reduced (P < 0.05) after treatment with UPA at 200 ng/ml or above, and with mifepristone at 3000 ng/ml or above. UPA treatment at 200 ng/ml or above significantly up-regulated the mRNA expression of progesterone receptor and glycodelin and down-regulated the mRNA expression of adrenomedullin in Fallopian tube tissue (P < 0.05). Whether or not the tubal effect may translate into additional mechanisms for contraceptive action in vivo is uncertain. The clinical relevance of UPA with regard to contraceptive

  20. Morphological distribution of middle-ear epithelium in the Wistar rat: a functional hypothesis.

    Science.gov (United States)

    Scarano, E; Paludetti, G; Frusoni, F; Deli, R; Maurizi, M

    1997-01-01

    The authors studied the overall microscopical anatomy of the middle ear and of the eustachian tube in 20 tympanic bullae of 10 Wistar rats. Large hexagonal epithelial flat cells covered the roof of the bulla, the two upper thirds of both lateral walls, the upper half of the eustachian tube, and the upper third of the tympanic orifice; ciliated and secretory cells lined the inferior thirds of both walls of the bulla while a ciliated epithelium with strong cilia, all directed towards the tubal orifice, located on the floor of the tympanic cavity together with groups of non-ciliated cells was detectable near the tubal and antral areas and on the floor of the eustachian tube. Non-ciliated cells covered by microvilli were found near the pharyngeal orifice. These observations seem to demonstrate the following: (1) the ciliated elements present a well-defined topographic distribution; (2) a preferential pathway for mucociliary clearance made up of strong ciliated cells located on the floor of the bulla is clearly detectable, and (3) the roof of the bulla seems to be mainly involved in the ventilatory function.

  1. Caregiver Quality of Life and Daily Functioning in Relation to Ventilating Tube Treatment

    DEFF Research Database (Denmark)

    Heidemann, Christian Hamilton; Lauridsen, Henrik Hein; Kjeldsen, Anette Drøhse

    2014-01-01

    OBJECTIVE: Caregiver quality of life and daily functioning may improve after ventilating tube treatment in children with otitis media. The aims of this study are to assess possible changes in caregiver quality of life and daily functioning in relation to ventilating tube treatment and to investig...

  2. Biphasic function of focal adhesion kinase in endothelial tube formation induced by fibril-forming collagens.

    Science.gov (United States)

    Nakamura, Junko; Shigematsu, Satoshi; Yamauchi, Keishi; Takeda, Teiji; Yamazaki, Masanori; Kakizawa, Tomoko; Hashizume, Kiyoshi

    2008-10-03

    Migration and tube formation of endothelial cells are important in angiogenesis and require a coordinated response to the extra-cellular matrix (ECM) and growth factor. Since focal adhesion kinase (FAK) integrates signals from both ECM and growth factor, we investigated its role in angiogenesis. Type I and II collagens are fibril-forming collagens and stimulate human umbilical vein endothelial cells (HUVECs) to form tube structure. Although knockdown of FAK restrained cell motility and resulted in inhibition of tube formation, FAK degradation and tube formation occurred simultaneously after incubation with fibril-forming collagens. The compensation for the FAK degradation by a calpain inhibitor or transient over-expression of FAK resulted in disturbance of tube formation. These phenomena are specific to fibril-forming collagens and mediated via alpha2beta1 integrin. In conclusion, our data indicate that FAK is functioning in cell migration, but fibril-forming collagen-induced FAK degradation is necessary for endothelial tube formation.

  3. Transfer function of protoplasmic tubes of Physarum polycephalum.

    Science.gov (United States)

    Whiting, James G H; de Lacy Costello, Ben P J; Adamatzky, Andrew

    2015-02-01

    The slime mould Physarum polycephalum is a large single celled myxomycete; its plasmodium consists of tubes which extend to find sources of food. It has been previously shown that the tubes are conductive with a resistance of approximately 3 MΩ, and have been used in basic DC circuits. Hybrid slime mould-electronic circuits have been proposed, using the protoplasmic tubes, grown between agar, as Physarum wires. This paper aims to evaluate the electrical properties of the protoplasmic tubes with respect to analogue and digital waveforms. The Physarum wires act as low pass filters with a mean cut off frequency of 19kHz (SD 9 KHz); they have a 12.1 dB/decade roll-off (SD 1.9 dB/decade). Mean attenuation across the band-pass range is -6 dB (S.D. 4.5 dB). The mechanism for the frequency dependant attenuation is unknown however a combination of protoplasmic electrolyte and the cytoskeletal structure is the most likely cause. The tubes last approximately 2 weeks before forming a dry sclerotia, when they cease being conductive and is the prevalent limiting factor of their practical use; this is caused by dehydration and lack of nutrition, a limitation which may be overcome. The potential for Physarum wires in hybrid circuits is strengthened; while previous circuits were simple DC circuits, this work demonstrates that they may be used as electronic components or wires in both digital and analogue circuits or even as a computing component in analogue computers. Copyright © 2015. Published by Elsevier Ireland Ltd.

  4. Occurrence, formation and function of organic sheets in the mineral tube structures of Serpulidae (polychaeta, Annelida.

    Directory of Open Access Journals (Sweden)

    Olev Vinn

    Full Text Available A scanning electron microscopy study of organic sheets in serpulid tube mineral structures was carried out to discern their function, formation and evolution. The organic sheets may have some taxonomic value in distinguishing the two major clades of serpulids previously identified. The organic sheets in the mineral tube structure occur only in certain taxa belonging to clade A, but not all species in clade A have them. Organic sheets are best developed in genus Spirobranchus. One could speculate that organic sheets have evolved as an adaption to further strengthen the mechanical properties of the tubes in clade A, which contains serpulids with the most advanced mineral tube microstructures. The organic sheets are presumably secreted with at least some mineral phase.

  5. Occludin as a functional marker of vascular endothelial cells on tube-forming activity.

    Science.gov (United States)

    Kanayasu-Toyoda, Toshie; Ishii-Watabe, Akiko; Kikuchi, Yutaka; Kitagawa, Hiroko; Suzuki, Hiroko; Tamura, Hiroomi; Tada, Minoru; Suzuki, Takuo; Mizuguchi, Hiroyuki; Yamaguchi, Teruhide

    2018-02-01

    Cell therapy using endothelial progenitor cells (EPCs) is a promising strategy for the treatment of ischemic diseases. Two types of EPCs have been identified: early EPCs and late EPCs. Late EPCs are able to form tube structure by themselves, and have a high proliferative ability. The functional marker(s) of late EPCs, which relate to their therapeutic potential, have not been fully elucidated. Here we compared the gene expression profiles of several human cord blood derived late EPC lines which exhibit different tube formation activity, and we observed that the expression of occludin (OCLN) in these lines correlated with the tube formation ability, suggesting that OCLN is a candidate functional marker of late EPCs. When OCLN was knocked down by transfecting siRNA, the tube formation on Matrigel, the S phase + G2 /M phase in the cell cycle, and the spheroid-based sprouting of late EPCs were markedly reduced, suggesting the critical role of OCLN in tube formation, sprouting, and proliferation. These results indicated that OCLN plays a novel role in neovascularization and angiogenesis. © 2017 Wiley Periodicals, Inc.

  6. Late health effects of radiation for eustachian tube dysfunction : a non-concurrent prospective study

    NARCIS (Netherlands)

    P.G. Verduijn

    1988-01-01

    textabstractThe present study is a non-concurrent prospective cohort study on the risks of the Crowe therapy in 2,542 subjects who underwent this treatment compared to 2,380 - similar - non-irradiated control subjects. The study population consisted of patients from five Dutch ENT clinics. The

  7. The evaluation of the angles of Eustachian tubes in the patients with ...

    African Journals Online (AJOL)

    Introduction: Chronic otitis media (COM), affecting all over the world and in a wide range of age groups in Turkey, is an important cause of ear discharge and hearing loss. The main clinical manifestations are tympanic membrane perforation, ear, nose and throat problems. On the tympanic membrane perforation becomes ...

  8. In vitro assessment of some sperm function following exposure to levonorgestrel in human fallopian tubes

    Directory of Open Access Journals (Sweden)

    Hermanny Alexia

    2012-01-01

    Full Text Available Abstract Background The mechanism of action of levonorgestrel (LNG as emergency contraception (EC remains a subject of debate and its effect on sperm function has been only partially explained. The aim of this study was to assess whether LNG at a similar dose to those found in serum following oral intake for EC could affect spermatozoa when exposed to human fallopian tubes in vitro. Methods Fifteen mini-laparotomies were performed, the side on which ovulation occurred was recorded, and both tubes were removed and perfused with a suspension containing 1 × 10(6 motile spermatozoa, with or without LNG. Following 4-hour incubation, the tubes were sectioned to separate the isthmus and the ampulla. Each segment was flushed and the material was evaluated to quantify the number of motile sperm, the number of spermatozoa adhering to the oviductal epithelium and the acrosome reaction (AR rate. Results The addition of LNG did not significantly alter the number of recovered motile spermatozoa either at the isthmus or at the ampulla, nor did it have any effect on the number of recovered spermatozoa adhered to the human tubal epithelium. Furthermore, LNG did not affect the AR rate. No significant differences were found even when the side on which ovulation occurred was taken into account. Conclusions In a similar dose to that observed in serum following oral intake for EC, LNG had no effect on the number of motile spermatozoa recovered from the human fallopian tubes in vitro, on their adhesion to the tubal epithelium, distribution or AR rate. The possible effect of LNG as EC on sperm function remains poorly understood.

  9. Neural Tube Defects

    Science.gov (United States)

    ... vitamin, before and during pregnancy prevents most neural tube defects. Neural tube defects are usually diagnosed before the infant is ... or imaging tests. There is no cure for neural tube defects. The nerve damage and loss of function ...

  10. Green's function solution to heat transfer of a transparent gas through a tube

    Science.gov (United States)

    Frankel, J. I.

    1989-01-01

    A heat transfer analysis of a transparent gas flowing through a circular tube of finite thickness is presented. This study includes the effects of wall conduction, internal radiative exchange, and convective heat transfer. The natural mathematical formulation produces a nonlinear, integrodifferential equation governing the wall temperature and an ordinary differential equation describing the gas temperature. This investigation proposes to convert the original system of equations into an equivalent system of integral equations. The Green's function method permits the conversion of an integrodifferential equation into a pure integral equation. The proposed integral formulation and subsequent computational procedure are shown to be stable and accurate.

  11. Application of mass transfer theory to biomarker capture by surface functionalized magnetic beads in microcentrifuge tubes.

    Science.gov (United States)

    Scherr, Thomas F; Markwalter, Christine F; Bauer, Westley S; Gasperino, David; Wright, David W; Haselton, Frederick R

    2017-08-01

    In many diagnostic assays, specific biomarker extraction and purification from a patient sample is performed in microcentrifuge tubes using surface-functionalized magnetic beads. Although assay binding times are known to be highly dependent on sample viscosity, sample volume, capture reagent, and fluid mixing, the theoretical mass transport framework that has been developed and validated in engineering has yet to be applied in this context. In this work, we adapt this existing framework for simultaneous mass transfer and surface reaction and apply it to the binding of biomarkers in clinical samples to surface-functionalized magnetic beads. We discuss the fundamental fluid dynamics of vortex mixing within microcentrifuge tubes as well as describe how particles and biomolecules interact with the fluid. The model is solved over a wide range of parameters, and we present scenarios when a simplified analytical expression would be most accurate. Next, we review of some relevant techniques for model parameter estimation. Finally, we apply the mass transfer theory to practical use-case scenarios of immediate use to clinicians and assay developers. Throughout, we highlight where further characterization is necessary to bridge the gap between theory and practical application. Copyright © 2017. Published by Elsevier B.V.

  12. The Functional Role of Music in Communicating Death through/in YouTube Videos

    Directory of Open Access Journals (Sweden)

    Panagiotis Pentaris

    2014-09-01

    Full Text Available Since the establishment of thanatology, the science of death, in the early 20th century, death has not only been considered a controversial subject, but it has also been regarded as a taboo topic. Various ways of communicating death have developed over the last few decades. With the advent of different mass and social media and their increasing impact on everyday life in the 21st century, death can now be communicated via a number of media platforms, such as television, radio, and online videos. This type of communication is underpinned by a series of dimensions, in particular music, that shape the conveyed message. Music has been extensively used in the dissemination of information in the wider media outlet. It is widely seen as a means of evoking emotions and of facilitating the process of assimilating information that is communicated via media. This paper seeks to discuss the functional role of music in communicating death in online video platforms. In particular, the example of the YouTube platform is used to identify the links between death, music and video platforms. This paper is part of a large-scale study on the functional role of music in communicating death through YouTube videos. It is suggested that music may serve as a link between media and death. The conclusions that are drawn in this paper are supported by the authors’ current and ongoing study and critical analysis of the deployment of music in the communication of death.

  13. Electrospun micro- and nanofiber tubes for functional nervous regeneration in sciatic nerve transections

    Directory of Open Access Journals (Sweden)

    Amadio Stefano

    2008-04-01

    Full Text Available Abstract Background Although many nerve prostheses have been proposed in recent years, in the case of consistent loss of nervous tissue peripheral nerve injury is still a traumatic pathology that may impair patient's movements by interrupting his motor-sensory pathways. In the last few decades tissue engineering has opened the door to new approaches;: however most of them make use of rigid channel guides that may cause cell loss due to the lack of physiological local stresses exerted over the nervous tissue during patient's movement. Electrospinning technique makes it possible to spin microfiber and nanofiber flexible tubular scaffolds composed of a number of natural and synthetic components, showing high porosity and remarkable surface/volume ratio. Results In this study we used electrospun tubes made of biodegradable polymers (a blend of PLGA/PCL to regenerate a 10-mm nerve gap in a rat sciatic nerve in vivo. Experimental groups comprise lesioned animals (control group and lesioned animals subjected to guide conduits implantated at the severed nerve stumps, where the tubular scaffolds are filled with saline solution. Four months after surgery, sciatic nerves failed to reconnect the two stumps of transected nerves in the control animal group. In most of the treated animals the electrospun tubes induced nervous regeneration and functional reconnection of the two severed sciatic nerve tracts. Myelination and collagen IV deposition have been detected in concurrence with regenerated fibers. No significant inflammatory response has been found. Neural tracers revealed the re-establishment of functional neuronal connections and evoked potential results showed the reinnervation of the target muscles in the majority of the treated animals. Conclusion Corroborating previous works, this study indicates that electrospun tubes, with no additional biological coating or drug loading treatment, are promising scaffolds for functional nervous regeneration. They

  14. Pilot Date on Swallow Function in Nondysphagic Patients Requiring a Tracheotomy Tube

    OpenAIRE

    Brady, Susan L.; Michele Wesling; Joseph Donzelli

    2009-01-01

    Objective. To evaluate the effects of occlusion status (i.e., open, finger, capped) of the tracheotomy tube and removal of the tracheotomy tube that may have upon bolus flow and durational measurements in nondysphagic persons requiring a tracheotomy tube. Study Design. Prospective, single subject, repeated measure design. Methods. Participants had their swallow evaluated with 5 mL pureed boluses using nasal endoscopy with the tracheotomy tube in place, removed, and under the following ...

  15. Heterogeneity of glycoconjugates in the secretory cells of the chinchilla middle ear and eustachian tubal epithelia: a lectin-gold cytochemical study.

    Science.gov (United States)

    Ueno, K; Lim, D J

    1991-01-01

    The present study was conducted to characterize and localize the glycoconjugates in the tubotympanum (auditory or eustachian tube and middle ear cavity) of chinchilla on an ultrastructural level, using lectin-gold complexes with six different lectins: BPA, ConA, RCA-1, WGA, LFA, and SNA. A comparison of the affinity of these lectins demonstrated the heterogeneity of secretory cells. The glandular serous cells and epithelial dark granulated cells produced "serum"-type glycoprotein. The glandular mucous cells and goblet cells produced dominantly "mucin"-type glycoprotein in the light granules, but "serum"-type glycoprotein in the dark cores. The labeling of LFA and SNA showed that sialic acids existed mainly in the mucinous granules of secretory cells and ciliated epithelium glycocalyx, and in the mucous blanket. The results also suggested that the dominant linkage of sialic acids of mucin is a Neu5Ac(alpha 2-6)Gal/GalNAc sequence. Furthermore, the data obtained from ConA and BPA suggested that initial O-glycosylation of mucin took place in the cis side of the Golgi apparatus and that initial N-glycosylation of the serum occurred in the rough endoplasmic reticulum.

  16. Acute effects of continuous nasogastric tube-feeding on gastric function - comparison of a polymeric and a nonpolymeric formula

    NARCIS (Netherlands)

    Kleibeuker, J. H.; Boersma-van Ek, W.

    1991-01-01

    The acute effects of continuous intragastric administration of 1500 ml (4200 kJ/liter) of a polymeric and of a nonpolymeric formula on gastric function were studied in 15 healthy subjects. During 450 min 1500 ml, containing 6300 kJ (1500 kcal), was given through a nasogastric tube. At regular

  17. Maintaining Enteral Nutrition in the Severely Ill using a Newly Developed Nasojejunal Feeding Tube with Gastric Decompression Function.

    Science.gov (United States)

    Toh Yoon, Ezekiel; Nishihara, Kazuki; Murata, Hirohiko

    2016-01-01

    For nutritional support of critically ill patients, the enteral route is preferred over the parenteral route. Although nasojejunal feeding can be superior to gastric feeding when gastrointestinal symptoms occur, it does not necessarily solve the problem of large gastric residual volumes. We report the successful use of a newly developed nasojejunal feeding tube with gastric decompression function in an 84-year-old man with severe pneumonia. After gastric feeding was considered not well tolerated, the use of this tube improved the delivery of nutrition until the patient was stable enough to undergo percutaneous endoscopic gastrostomy.

  18. Maintaining Enteral Nutrition in the Severely Ill using a Newly Developed Nasojejunal Feeding Tube with Gastric Decompression Function

    Science.gov (United States)

    Toh Yoon, Ezekiel Wong; Nishihara, Kazuki; Murata, Hirohiko

    2016-01-01

    For nutritional support of critically ill patients, the enteral route is preferred over the parenteral route. Although nasojejunal feeding can be superior to gastric feeding when gastrointestinal symptoms occur, it does not necessarily solve the problem of large gastric residual volumes. We report the successful use of a newly developed nasojejunal feeding tube with gastric decompression function in an 84-year-old man with severe pneumonia. After gastric feeding was considered not well tolerated, the use of this tube improved the delivery of nutrition until the patient was stable enough to undergo percutaneous endoscopic gastrostomy. PMID:27746430

  19. Designing a spiropyran-based molecular switch for carbon nanotube functionalization: Influence of anchor groups and tube-switch separation

    Energy Technology Data Exchange (ETDEWEB)

    Bluemmel, Pascal; Setaro, Antonio; Reich, Stephanie [Institut fuer Experimentalphysik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Maity, Chandan; Hecht, Stefan [Department of Chemistry, Humboldt-Universitaet zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany)

    2012-12-15

    Molecular switch compounds, consisting of aromatic anchoring groups connected to a spiropyran moiety, are exploited for carbon nanotube functionalization. The effect of the different anchor groups on sample distribution and debundling efficiency is investigated as well as the influence of the anchor-switch distance and hence tube-switch separation. Morphologically similar anchor groups result in similar chiral compositions of the sample. With smaller separation, the tube-switch interaction strength increases as well as the lifetime of the ring opened isomer. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Voice Morphing Using 3D Waveform Interpolation Surfaces and Lossless Tube Area Functions

    Directory of Open Access Journals (Sweden)

    Lavner Yizhar

    2005-01-01

    Full Text Available Voice morphing is the process of producing intermediate or hybrid voices between the utterances of two speakers. It can also be defined as the process of gradually transforming the voice of one speaker to that of another. The ability to change the speaker's individual characteristics and to produce high-quality voices can be used in many applications. Examples include multimedia and video entertainment, as well as enrichment of speech databases in text-to-speech systems. In this study we present a new technique which enables production of a given number of intermediate voices or of utterances which gradually change from one voice to another. This technique is based on two components: (1 creation of a 3D prototype waveform interpolation (PWI surface from the LPC residual signal, to produce an intermediate excitation signal; (2 a representation of the vocal tract by a lossless tube area function, and an interpolation of the parameters of the two speakers. The resulting synthesized signal sounds like a natural voice lying between the two original voices.

  1. Severe Persistant Cyanosis in a Newborn Due to Prominent Eustachian Valve

    Directory of Open Access Journals (Sweden)

    Vehbi Doğan

    2017-03-01

    Full Text Available ABSTRACTThe valves of right horn of systemic venous sinus are prominent structures within the right atrium during early embryonic period. Involution of these structures may not be complete, resulting in a spectrum of anatomical presentations such as cyanosis. A full-term male neonate referred to our hospital for precise evaluation of severe cyanosis on the first day of life. Echocardiographic examination revealed right-to-left interatrial shunting through patent foramen ovale due to prominent eustachian valve with normal estimated right heart pressures from peak tricuspid regurgitation velocity. He was maintained with supplemental oxygen and a PDE-5 inhibitor (sildenafil and subsequently improvement in oxygen saturation was achieved. The patient was discharged after 2 weeks of treatment. In conclusion; the embryologic remmants of the sinus venosus rarely may lead to right-to-left shunting resulting in severe cyanosis. Pulmonary vasodilators such as sildenafil may improve oxygen saturation in these patients even in case of normal right heart pressures.

  2. Evaluation of different sized blood sampling tubes for thromboelastometry, platelet function, and platelet count

    DEFF Research Database (Denmark)

    Andreasen, Jo Bønding; Pistor-Riebold, Thea Unger; Knudsen, Ingrid Hell

    2014-01-01

    Background: To minimise the volume of blood used for diagnostic procedures, especially in children, we investigated whether the size of sample tubes affected whole blood coagulation analyses. Methods: We included 20 healthy individuals for rotational thromboelastometry (RoTEM®) analyses and compa......Background: To minimise the volume of blood used for diagnostic procedures, especially in children, we investigated whether the size of sample tubes affected whole blood coagulation analyses. Methods: We included 20 healthy individuals for rotational thromboelastometry (RoTEM®) analyses...

  3. GEF-H1 functions in apical constriction and cell intercalations and is essential for vertebrate neural tube closure.

    Science.gov (United States)

    Itoh, Keiji; Ossipova, Olga; Sokol, Sergei Y

    2014-06-01

    Rho family GTPases regulate many morphogenetic processes during vertebrate development including neural tube closure. Here we report a function for GEF-H1/Lfc/ArhGEF2, a RhoA-specific guanine nucleotide exchange factor that functions in neurulation in Xenopus embryos. Morpholino-mediated depletion of GEF-H1 resulted in severe neural tube defects, which were rescued by GEF-H1 RNA. Lineage tracing of GEF-H1 morphants at different developmental stages revealed abnormal cell intercalation and apical constriction, suggesting that GEF-H1 regulates these cell behaviors. Molecular marker analysis documented defects in myosin II light chain (MLC) phosphorylation, Rab11 and F-actin accumulation in GEF-H1-depleted cells. In gain-of-function studies, overexpressed GEF-H1 induced Rho-associated kinase-dependent ectopic apical constriction - marked by apical accumulation of phosphorylated MLC, γ-tubulin and F-actin in superficial ectoderm - and stimulated apical protrusive activity of deep ectoderm cells. Taken together, our observations newly identify functions of GEF-H1 in morphogenetic movements that lead to neural tube closure. © 2014. Published by The Company of Biologists Ltd.

  4. [Functional and morphological defects of the mucociliary system in secretory otitis media].

    Science.gov (United States)

    Borkowski, G; Gurr, A; Stark, T; Philippou, S; Sudhoff, H

    2000-03-01

    One of the main functions of the ciliated cells of the middle ear mucosa is the continuous drainage of fluids from the middle ear cavity to the Eustachian tube. Impaired mucociliary clearance is related to disturbed clearance of middle ear secretions and results in otitis media with effusion. The aim of this study was to evaluate the ciliary beat frequency (CBF) and the ultrastructure of cilia in young patients suffering from otitis media with effusion (OME). CBF and ciliary ultrastructure were studied in 36 patients with OME and 10 normal subjects without any history of middle ear effusion. The CBF was significantly decreased in the study group (6.59 Hz, +/- 1.83) compared to the controls (10.68 Hz, +/- 1.87) and the incidence of ultrastructural defects was higher than in controls. The most common defect were compound cilia, random orientation of the ciliary axes, and defects of the central microtubules. Defects of the dynein arms were not observed.

  5. Sodium hyaluronate-functionalized urea-formaldehyde monolithic column for hydrophilic in-tube solid-phase microextraction of melamine.

    Science.gov (United States)

    Wang, Jiabin; Jiang, Nan; Cai, Zhengmiao; Li, Wenbang; Li, Jianhua; Lin, Xucong; Xie, Zenghong; You, Lijun; Zhang, Qiqing

    2017-09-15

    A novel sodium hyaluronate-functionalized urea-formaldehyde (UF) monolithic column has been developed by in-situ polycondensation of urea, formaldehyde and sodium hyaluronate (HA). HA plays both the roles of crosslinking and hydrophilic functionalization. The preparation factors including different molecular weights of HA and different amounts of HA were optimized, and then a uniform monolith with satisfactory permeability and hydrophilic binding capacity was obtained. Due to the excellent hydrophilicity of HA, HA-functionalized UF monolith showed higher hydrophilic extraction efficiency than UF monolith, and was applied for hydrophilic in-tube solid-phase microextraction (SPME) of melamine (MEL). Several factors for hydrophilic in-tube SPME, such as ACN percentage in the sampling solution, salt concentration and pH value of the sampling solution, elution volume, sampling and elution flow rate, were investigated with respect to the extraction efficiency of MEL. Under the optimized SPME conditions, the limit of detection (LOD) of MEL was found to be 0.2ng/mL in the milk formula samples, the recoveries of MEL spiked in milk formula samples ranged from 87.3% to 96.7% with relative standard deviations (RSDs) less than 5.1%. Owing to the excellent hydrophilic extraction ability, the novel HA-functionalized UF monolith could provide a promising tool for the sensitive analysis of polar analytes in complicated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. TUBE TESTER

    Science.gov (United States)

    Gittings, H.T. Jr.; Kalbach, J.F.

    1958-01-14

    This patent relates to tube testing, and in particular describes a tube tester for automatic testing of a number of vacuum tubes while in service and as frequently as may be desired. In it broadest aspects the tube tester compares a particular tube with a standard tube tarough a difference amplifier. An unbalanced condition in the circuit of the latter produced by excessive deviation of the tube in its characteristics from standard actuates a switch mechanism stopping the testing cycle and indicating the defective tube.

  7. Transport behavior of functionalized multi-wall carbon nanotubes in water-saturated quartz sand as a function of tube length.

    Science.gov (United States)

    Wang, Yonggang; Kim, Jae-Hong; Baek, Jong-Beom; Miller, Gary W; Pennell, Kurt D

    2012-09-15

    A series of one-dimensional column experiments was conducted to examine the effects of tube length on the transport and deposition of 4-ethoxybenzoic acid functionalized multi-wall carbon nanotubes (MWCNTs) in water-saturated porous media. Aqueous MWCNTs suspensions were prepared to yield three distributions of tube lengths; 0.02-1.3 μm (short), 0.2-7.5 μm (medium), and 0.2-21.4 μm (long). Results of the column studies showed that MWCNT retention increased with increasing tube length. Nevertheless, more than 76% of the MWCNT mass delivered to the columns was detected in effluent samples under all experimental conditions, indicating that the functionalized MWCNTs were readily transported through 40-50 mesh Ottawa sand. Examination of MWCNT length distributions in the effluent samples revealed that nanotubes with lengths greater than 8 μm were preferentially deposited. In addition, measured retention profiles exhibited the greatest MWCNT deposition near the column inlet, which was most pronounced for the long MWCNTs, and decreased sharply with travel distance. Scanning electron microscope (SEM) images showed that MWCNTs were deposited on sand surfaces over the entire column length, while larger MWCNT bundles were retained at grain intersections and near the column inlet. A mathematical model based on clean bed filtration theory (CBFT) was unable to accurately simulate the measured retention profile data, even after varying the weighting function and incorporating a nonuniform attachment rate coefficient expression. Modification of the mathematical model to account for physical straining greatly improved predictions of MWCNT retention, yielding straining rate coefficients that were four orders-of-magnitude greater than corresponding attachment rate coefficients. Taken in concert, these experimental and modeling results demonstrate the potential importance of, and need to consider, particle straining and tube length distribution when describing MWCNT transport in

  8. Pulse Tube Refrigerator

    Science.gov (United States)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  9. A low tube voltage technique reduces the radiation dose at retrospective ECG-gated cardiac computed tomography for anatomical and functional analyses.

    Science.gov (United States)

    Oda, Seitaro; Utsunomiya, Daisuke; Funama, Yoshinori; Awai, Kazuo; Katahira, Kazuhiro; Nakaura, Takeshi; Yanaga, Yumi; Namimoto, Tomohiro; Yamashita, Yasuyuki

    2011-08-01

    To investigate the effect of low-tube-voltage technique on a cardiac computed tomography (CT) for coronary arterial and cardiac functional analyses and radiation dose in slim patients. We enrolled 80 patients (52women, 28 men; mean age, 68.7 ± 8.9 years) undergoing retrospective electrocardiogram-gated 64-slice cardiac CT. Forty were subjected to the low (80-kV) and 40 to the standard (120-kV) tube-voltage protocol. Quantitative parameters of the coronary arteries (ie, CT attenuation, image noise, and the contrast-to-noise ratio [CNR]) were calculated, as were the effective radiation dose and the figure of merit (FOM). Each coronary artery segment was visually evaluated using a 5-point scale. Cardiac function calculated by using low-tube-voltage cardiac CT was compared with that on echocardiographs. CT attenuation and image noise were significantly higher at 80- than 120-kV (P tube-voltage cardiac CT and echocardiography for cardiac functional analyses. Low-tube-voltage cardiac CT significantly reduced the radiation dose by approximately 55% in slim patients while maintaining anatomical image quality and accuracy of cardiac functional analysis. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  10. Polydopamine-functionalized poly(ether ether ketone) tube for capillary electrophoresis-mass spectrometry.

    Science.gov (United States)

    Zhou, Wei; Zhang, Wenpeng; Liu, Yikun; Yu, Xinhong; Chen, Zilin

    2017-09-22

    Capillary electrophoresis-mass spectrometry (CE-MS) is a hyphenated technique that combines the advantages like low sample consumption, high separation efficiency, short analytical time in CE and high sensitivity, powerful molecular structure elucidation in MS. Polyimide-coated fused silica capillary has become the most dominant capillary for CE, but it suffers from swelling and aminolysis of polyimide coating when treated with organic solvents and alkaline buffer in the CE-MS interface in which the polyimide coating at the end of the capillary is exposed to the solution, and this phenomenon can result in current instability, irregular electrospray and clogging at outlet after prolonged use. In this work, poly(ether ether ketone) (PEEK) capillary was explored as separation capillary for CE-MS. The problems like swelling and aminolysis of polyimide coating were solved due to the high thermal and chemical stability of PEEK material. After modification with polydopamine, PEEK capillary (PD-PEEK) can generate adjustable electroosmotic flow and provide good separation selectivity. The zwitterion polymer of polydopamine can provide cathodic electroosmotic flow (EOF) at high pH value (pH ≥ 5) and anodic EOF at low pH value (pH ≤ 4), and the EOF mobility can also be adjusted by controlling the modification time of polydopamine. Good separation performance was obtained in the analysis for several classes of compounds including amino acids, phenols and plant hormones at rational EOF direction. Repeatability of the PD-PEEK capillary was studied, with relative standard deviations for intra-day, inter-day runs and between tubes less than 4.94%. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The Application of Rapid Prototyping Technology and Quality Functional Deployment (QFD approach in enhancing the Endotracheal Tube Holder Model in Medical Application

    Directory of Open Access Journals (Sweden)

    Way Yusoff

    2015-01-01

    Full Text Available This paper presents a development of a current design the Endotracheal tube holding device. At present, the medical teams have faced a lot of problems when doing the endotracheal intubation. Misplacement of endotracheal tube into the esophagus and extubation due to patient’s movement are among the problems by surgeons during medical treatment. This is important as the successful management of the potential risk can reduce the number of patients who suffer a serious consequence of endtracheal tube therapy such as a potential risk to patient safety, with associated risks varying from minor complications to death. This paper presents a product design specification for endotracheal tube-holding device is translated from user’s requirements by employing Quality Functional Deployment (QFD. Several design concepts are generated by using CATIA software to be evaluated by endotracheal tube-holding device users for concept selection. Selection of design concept was done in two phases which are concept screening and concept scoring. For selecting the design concept for further development, a prototype of endotracheal tube was fabricated by using Fused Deposition Modelling (FDM.

  12. MILDEW RESISTANCE LOCUS O Function in Pollen Tube Reception Is Linked to Its Oligomerization and Subcellular Distribution1[OPEN

    Science.gov (United States)

    Willoughby, Andrew C.; Kumimoto, Emily L.

    2017-01-01

    Sexual reproduction in flowering plants requires communication between synergid cells and a tip-elongating pollen tube (PT) for the successful delivery of sperm cells to the embryo sac. The reception of the PT relies on signaling within the synergid cell that ultimately leads to the degeneration of the receptive synergid and PT rupture, releasing the sperm cells for double fertilization. In Arabidopsis (Arabidopsis thaliana), NORTIA, a member of the MILDEW RESISTANCE LOCUS O (MLO) family of proteins, plays a critical role in the communication processes regulating PT reception. In this study, we determined that MLO function in PT reception is dependent on MLO protein localization into a Golgi-associated compartment before PT arrival, indicating that PT-triggered regulation of the synergid secretory system is important for synergid function during pollination. Additionally, a structure-function analysis revealed that MLO homooligomerization, mediated by the amino-terminal region of the protein, and carboxyl-terminal tail identity both contribute to MLO activity during PT reception. PMID:28724621

  13. "Click" on tubes: a versatile approach towards multimodal functionalization of SWCNTs.

    Science.gov (United States)

    Tuci, Giulia; Vinattieri, Claudia; Luconi, Lapo; Ceppatelli, Matteo; Cicchi, Stefano; Brandi, Alberto; Filippi, Jonathan; Melucci, Manuela; Giambastiani, Giuliano

    2012-07-02

    Organic functionalization of carbon nanotube sidewalls is a tool of primary importance in material science and nanotechnology, equally from a fundamental and an applicative point of view. Here, an efficient and versatile approach for the organic/organometallic functionalization of single-walled carbon nanotubes (SWCNTs) capable of imparting multimodality to these fundamental nanostructures, is described. Our strategy takes advantage of well-established Cu-mediated acetylene-azide coupling (CuAAC) reactions applied to phenylazido-functionalized SWCNTs for their convenient homo-/heterodecoration with a number of organic/organometallic frameworks, or mixtures thereof, bearing terminal acetylene pendant arms. Phenylazido-decorated SWCNTs were prepared by chemoselective arylation of the CNT sidewalls with diazonium salts under mild conditions, and subsequently used for the copper-mediated cycloaddition protocol in the presence of terminal acetylenes. The latter reaction was performed in one step by using either single acetylene derivatives or equimolar mixtures of terminal alkynes bearing either similar functional groups (masked with orthogonally cleavable protecting groups) or easily distinguishable functionalities (on the basis of complementary analytical/spectroscopic techniques). All materials and intermediates were characterized with respect to their most relevant aspects/properties by TEM microscopy, thermogravimetric analysis coupled with MS analysis of volatiles (TG-MS), elemental analysis, cyclic voltammetry (CV), Raman and UV/Vis spectroscopy. The functional loading and related chemical grafting of both primary amino- and ferrocene-decorated SWCNTs were spectroscopically (UV/Vis, Kaiser test) and electrochemically (CV) determined, respectively. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Alkaline direct ethanol fuel cell performance using alkali-impregnated polyvinyl alcohol/functionalized carbon nano-tube solid electrolytes

    Science.gov (United States)

    Huang, Chien-Yi; Lin, Jia-Shiun; Pan, Wen-Han; Shih, Chao-Ming; Liu, Ying-Ling; Lue, Shingjiang Jessie

    2016-01-01

    This study investigates the application of a polyvinyl alcohol (PVA)/functionalized carbon nano-tubes (m-CNTs) composite in alkaline direct ethanol fuel cells (ADEFC). The m-CNTs are functionalized with PVA using the ozone mediation method, and the PVA composite containing the modified CNTs is prepared. Adding m-CNT into the PVA matrix enhances the alkaline uptake and the ionic conductivity of the KOH-doped electrolyte. Meanwhile, the m-CNT-containing membrane exhibited a lower swelling ratio and suppressed ethanol permeability compared to the pristine PVA film. The optimal condition for the ADEFC is determined to be under operation at an anode feed of 3 M ethanol in a 5 M KOH solution (at a flow rate of 5 cm3 min-1) with a cathode feed of moisturized oxygen (with a flow rate of 100 cm3 min-1) and the KOH-doped PVA/m-CNT electrolyte. We achieved a peak power density value of 65 mW cm-2 at 60 °C, which is the highest among the ADEFC literature data and several times higher than the proton-exchange direct ethanol fuel cells using sulfonated membrane electrolytes. Therefore, the KOH-doped PVA/m-CNT electrolyte is a suitable solid electrolyte for ADEFCs and has potential for commercialization in alkaline fuel cell applications.

  15. Evaluation of Carbon Nanotubes Functionalized Polydimethylsiloxane Based Coatings for In-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Neus Jornet-Martínez

    2015-08-01

    Full Text Available In the present work, the performance of carbon nanotubes (c-CNTs functionalized polydimethylsiloxane (PDMS based coatings as extractive phases for in-tube solid phase microextraction (IT-SPME coupled to Capillary LC (CapLC has been evaluated. Carboxylic-single walled carbon nanotubes (c-SWNTs and carboxylic-multi walled carbon nanotubes (c-MWNTs have been immobilized on the activated surface of PDMS capillary columns. The effect of different percentages of diphenyl groups in the PDMS extractive phase has also been evaluated. The extraction capability of the capillary columns has been tested for different organic pollutants, nitrogen heterocyclic compounds and polycyclic aromatic compounds (PAHs. The results indicated that the use of the c-CNTs-PDMS capillary columns improve pyriproxyfen and mainly PAH extraction. Triazines were better extracted by unmodified TRB-35 and modified c-CNTs-PDMSTRB-5. The results showed that the extraction capability of the c-CNT capillary columns depends not only on the polarity of the analytes (as it occurs with PDMS columns but also on the interactions that the analytes can establish with the immobilized c-CNTs on the PDMS columns. The extraction efficiency has been evaluated on the basis of the preconcentration rate that can be achieved, and, in this sense, the best c-CNTs-PDMS capillary column for each group of compounds can be proposed.

  16. Use of percutaneous endoscopic gastrostomy feeding tubes and functional recovery in stroke rehabilitation: a case-matched controlled study.

    Science.gov (United States)

    Iizuka, Masayuki; Reding, Mike

    2005-05-01

    To compare the morbidity, mortality, and functional recovery of patients who require percutaneous endoscopic gastrostomy (PEG) placement for the management of dysphagia after stroke. Retrospective case-matched controlled study. Acute stroke rehabilitation inpatient unit. Patients (N=193) who were admitted for stroke rehabilitation with a PEG tube in place from January 1, 1993, to December 31, 2002, were matched with 193 case controls without PEG. Patients and controls were within 90 days of stroke onset, and were matched for age, sex, type of stroke, FIM instrument score, duration from onset to stroke unit admission, and year of admission. Not applicable. Length of rehabilitation hospital stay, improvement in FIM scores, FIM efficiency score, need for transfer back to acute care hospital, diagnosis for which transfer was required, final discharge destination, and survival status. Significant differences were found between the 2 groups, PEG versus control, respectively, in the following variables: FIM efficiency (.42+/-.57 vs .56+/-.55, P =.016); need for transfer back to acute hospital (58/193 vs 23/193, P =.001); and survival status dead/alive (14/179 vs 3/190, P =.006). Nonsignificant differences were as follows: length of rehabilitation hospital stay (46.9+/-24.8d vs 43.3+/-19.7d, P =.11), improvement in total FIM score from admission to discharge (16.9+/-17.9 vs 21.0+/-15.5, P =.72), and final discharge destination home/institutional care (96/83 vs 101/89, P =.93). Pneumonia was the most frequent reason for transfer to acute care for patients with PEG. Patients who meet criteria for admission to a stroke rehabilitation unit and who have a PEG in place are at increased risk for medical complications and death. Those who survive, however, show similar functional recovery and rate of home discharge as case-matched controls.

  17. Feeding Tubes

    Science.gov (United States)

    ... feeding therapies have been exhausted. Please review product brand and method of placement carefully with your physician ... Total Parenteral Nutrition. Resources: Oley Foundation Feeding Tube Awareness Foundation Children’s Medical Nutrition Alliance APFED’s Educational Webinar ...

  18. Three Tctn proteins are functionally conserved in the regulation of neural tube patterning and Gli3 processing but not ciliogenesis and Hedgehog signaling in the mouse.

    Science.gov (United States)

    Wang, Chengbing; Li, Jia; Meng, Qing; Wang, Baolin

    2017-10-01

    Tctn1, Tctn2, and Tctn3 are membrane proteins that localize at the transition zone of primary cilia. Tctn1 and Tctn2 mutations have been reported in both humans and mice, but Tctn3 mutations have been reported only in humans. It is also not clear whether the three Tctn proteins are functionally conserved with respect to ciliogenesis and Hedgehog (Hh) signaling. In the present study, we report that loss of Tctn3 gene function in mice results in a decrease in ciliogenesis and Hh signaling. Consistent with this, Tctn3 mutant mice exhibit holoprosencephaly and randomized heart looping and lack the floor plate in the neural tube, the phenotypes similar to those of Tctn1 and Tctn2 mutants. We also show that overexpression of Tctn3, but not Tctn1 or Tctn2, can rescue ciliogenesis in Tctn3 mutant cells. Similarly, replacement of Tctn3 with Tctn1 or Tctn2 in the Tctn3 gene locus results in reduced ciliogenesis and Hh signaling, holoprosencephaly, and randomized heart looping. Surprisingly, however, the neural tube patterning and the proteolytic processing of Gli3 (a transcription regulator for Hh signaling) into a repressor, both of which are usually impaired in ciliary gene mutants, are normal. These results suggest that Tctn1, Tctn2, and Tctn3 are functionally divergent with respect to their role in ciliogenesis and Hh signaling but conserved in neural tube patterning and Gli3 processing. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Aeronautical tubes and pipes

    Science.gov (United States)

    Beauclair, N.

    1984-12-01

    The main and subcomponent French suppliers of aircraft tubes and pipes are discussed, and the state of the industry is analyzed. Quality control is essential for tubes with regard to their i.d. and metallurgical compositions. French regulations do not allow welded seam tubes in hydraulic circuits unless no other form is available, and then rustproofed steel must be installed. The actual low level of orders for any run of tubes dictates that the product is only one of several among the manufacturers' line. Automation, both in NDT and quality control, assures that the tubes meet specifications. A total of 10 French companies participate in the industry, serving both civil and military needs, with some companies specializing only in titanium, steel, or aluminum materials. Concerns wishing to enter the market must upgrade their equipment to meet the higher aeronautical specifications and be prepared to furnish tubes and pipes that serve both functional and structural purposes simultaneously. Additionally, pipe-bending machines must also perform to tight specifications. Pipes can range from 0.2 mm exterior diameter to 40 mm, with wall thicknesses from 0.02 mm to 3 mm. A chart containing a list of manufacturers and their respective specifications and characteristics is presented, and a downtrend in production with reduction of personnel is noted.

  20. Shroom3 functions downstream of planar cell polarity to regulate myosin II distribution and cellular organization during neural tube closure

    Directory of Open Access Journals (Sweden)

    Erica M. McGreevy

    2015-01-01

    Full Text Available Neural tube closure is a critical developmental event that relies on actomyosin contractility to facilitate specific processes such as apical constriction, tissue bending, and directional cell rearrangements. These complicated processes require the coordinated activities of Rho-Kinase (Rock, to regulate cytoskeletal dynamics and actomyosin contractility, and the Planar Cell Polarity (PCP pathway, to direct the polarized cellular behaviors that drive convergent extension (CE movements. Here we investigate the role of Shroom3 as a direct linker between PCP and actomyosin contractility during mouse neural tube morphogenesis. In embryos, simultaneous depletion of Shroom3 and the PCP components Vangl2 or Wnt5a results in an increased liability to NTDs and CE failure. We further show that these pathways intersect at Dishevelled, as Shroom3 and Dishevelled 2 co-distribute and form a physical complex in cells. We observed that multiple components of the Shroom3 pathway are planar polarized along mediolateral cell junctions in the neural plate of E8.5 embryos in a Shroom3 and PCP-dependent manner. Finally, we demonstrate that Shroom3 mutant embryos exhibit defects in planar cell arrangement during neural tube closure, suggesting a role for Shroom3 activity in CE. These findings support a model in which the Shroom3 and PCP pathways interact to control CE and polarized bending of the neural plate and provide a clear illustration of the complex genetic basis of NTDs.

  1. THE DETECTION OF THE NECESSARY CONDITIONS OF EFFECTIVE FUNCTIONING OF THE BALL CLEANING SYSTEM OF THE TUBES OF STEAM TURBINE CONDENSERS. Part 1

    Directory of Open Access Journals (Sweden)

    A. G. Gerasimova

    2017-01-01

    Full Text Available A problem of an increase of the power of turbine by improving heat transfer in condensers of steam turbines is considered in the article as a topical one. The analysis of contamination of the internal surfaces of cooling tubes and of the influence of pollution on the process of heat transfer in turbine condensers has been fulfilled. The existing method of cleaning of condenser tubes with the use of porous elastic balls of sponge rubber that is implemented on a number of large thermal power plants and state region power plants of the Republic of Belarus is examined. In the operation of the ball cleaning system a significant drawback has been revealed, viz. a low efficiency of this method due to the failure to comply with preparation the system of circulating water for operation. Also, a certain imperfection of ball cleaning system technology has been determined. One of the prerequisites for the effective functioning of the ball cleaning system is a certain degree of purity of the pipe system of the condenser, characterized by the coefficient of purity. To determine the effectiveness of ball cleaning system a series of experiments on the launching of porous rubber balls in the pipe system of the main and the embedded bunches of the T-250/300-240 UTMZ turbine has been produced. Immediately before the experiments hydraulic cleaning of the tubes of the condenser by a high-pressure installation were carried out. During the experiments, records of the number of downloaded porous rubber balls, of the number of rubber balls captured in a loading chamber, and of the number of rubber balls that remained in a calibration device were kept. A large proportion of default of the balls caused by the presence of residues of the carbonate sediments, that obstruct the movement of porous rubber balls in the tubes of the condenser, was determined. The presence of carbonate deposits in the tubes of the condenser indicates a lack of effectiveness of antiscale treatment

  2. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  3. Better Ear Health

    Science.gov (United States)

    ... requests or policy questions to our media and public relations staff at newsroom@entnet.org . Many medical conditions, ... This condition usually results from poor eustachian tube function concurrent with middle ear infection (otitis media), but ...

  4. Cholesteatoma

    Science.gov (United States)

    ... requests or policy questions to our media and public relations staff at newsroom@entnet.org . An abnormal skin ... cholesteatoma usually occurs because of poor eustachian tube function as well as infection in the middle ear. ...

  5. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  6. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  7. Generation of flux tube waves in stellar convection zones. 1: Longitudinal tube waves

    Science.gov (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.

    1987-01-01

    The source functions and the energy fluxes are derived for wave generation in magnetic flux tubes embedded in an otherwise magnetic- field free, turbulent, and compressible fluid. Specific results for the generation of longitudinal tube waves are presented.

  8. Magnetic resonance imaging of nasopharyngeal carcinoma. Correlation with otitis media with effusion (OME)

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Y.; Tamaki, S.; Kurata, K.; Honjo, I.; Nishimura, K.; Nakano, Y.

    1987-04-01

    Magnetic resonance imaging (MRI) of the nasopharynx, the eustachian tube and the middle ear was performed in nine patients with nasopharyngeal carcinoma. MRI revealed the extent of the tumor more clearly than CT (computed tomography) when the tumor was situated in the parapharyngeal space. But when the tumor extended superficially in the nasopharyngeal mucosa, its margin could not be identified clearly by either MRI or CT because of hypervascularity and long T1 and T2 of the nasopharyngeal mucosa. Seven of the nine patients had unilateral otitis media with effusion. Their eustachian tube ventilation function was evaluated by an inflation-deflation technique. Failure of active equalization of negative pressure applied to the middle ear was found to be a characteristic disorder of their eustachian tube ventilation function. This dysfunction seemed to be correlated with the lateral dislocation of the eustachian tube cartilage caused by the tumor.

  9. Diffusion in Tube Dialyzer

    Directory of Open Access Journals (Sweden)

    Yohannes Nigatie

    2017-09-01

    Full Text Available Nowadays, kidney failure is a problem of many peoples in the world. We know that the main function of kidney is maintaining the chemical quality of blood particularly removing urea through urine. But when they malfunction, the pathologic state known as uremia results in a condition in which the urea is retained in the body. Failure of the kidney results in building up of harmful wastes and excess fluids in the body. Kidney diseases (failures can be due to infections, high blood pressure (hypertension, diabetes, and/or extensive use of medication. The best form of treatment is the implantation of a healthy kidney from a donor. However, this is often not possible due to the limited availability of human organs. Chronic kidney failure requires the treatment using a tube dialyzer called dialysis. Blood is taken out of the body and passes through a special membrane that removes waste and extra fluids. The clean blood is then returned to the body. The process is controlled by a dialysis machine (tube dialyzer which is equipped with a blood pump and monitoring systems to ensure safety. So this article investigates the real application of mathematics (diffusion in medical science, and it also contains the mathematical formulation and interpretation of tube dialyzer in relation to diffusion.

  10. Nasogastric feeding tube

    Science.gov (United States)

    ... of what to do. What to Expect at Home If your child has an NG tube, try to keep your child from touching or pulling on the tube. After your nurse teaches you how to flush the tube and perform skin care around the nose, set up a daily routine for these tasks. Flushing the Tube Flushing the ...

  11. [Enteral feeding tubes for critically ill patients].

    Science.gov (United States)

    Braun, J; Bein, T; Wiese, C H R; Graf, B M; Zausig, Y A

    2011-04-01

    The use of enteral feeding tubes is an important part of early enteral feeding in intensive care medicine. In other faculties with non-critically ill patients, such as (oncologic) surgery, neurology, paediatrics or even in palliative care medicine feeding tubes are used under various circumstances as a temporary or definite solution. The advantage of enteral feeding tubes is the almost physiologic administration of nutrition, liquids and medication. Enteral nutrition is thought to be associated with a reduced infection rate, increased mucosal function, improved immunologic function, reduced length of hospital stay and reduced costs. However, the insertion and use of feeding tubes is potentially dangerous and may be associated with life-threatening complications (bleeding, perforation, peritonitis, etc.). Therefore, the following article will give a summary of the different types of enteral feeding tubes and their range of application. Additionally, a critical look on indication and contraindication is given as well as how to insert an enteral feeding tube.

  12. Why do aged fluorescent tubes flicker?

    Science.gov (United States)

    Plihon, Nicolas; Ferrand, Jérémy; Guyomar, Tristan; Museur, Flavien; Taberlet, Nicolas

    2017-11-01

    Our everyday experience of aged and defective fluorescent tubes or bulbs informs us that they may flicker and emit a clicking sound while struggling to light up. In this article, the physical mechanisms controlling the initial illumination of a functioning fluorescent tube are investigated using a simple and affordable experimental setup. Thermionic emission from the electrodes of the tube controls the startup of fluorescent tubes. The origin of the faulty startup of aged fluorescent tubes is discussed and flickering regimes using functional tubes are artificially produced using a dedicated setup that decreases electron emission by the thermionic effect in a controlled manner. The physical parameters controlling the occurrence of flickering light are discussed, and their temporal statistics are reported.

  13. Fin-tube solar collectors

    Science.gov (United States)

    1980-01-01

    Report presents test procedures and results of thermal-performance evaluation of seven commercial fin tube (liquid) solar collector-absorber plates. Tests were conducted indoors at Marshall Space Flight Center Solar simulator. Results are graphically shown along with supporting test data and summary, indicating efficiency as function of collector inlet temperature.

  14. Biocompatibility of Different Nerve Tubes

    Directory of Open Access Journals (Sweden)

    Hisham Fansa

    2009-09-01

    Full Text Available Bridging nerve gaps with suitable grafts is a major clinical problem. The autologous nerve graft is considered to be the gold standard, providing the best functional results; however, donor site morbidity is still a major disadvantage. Various attempts have been made to overcome the problems of autologous nerve grafts with artificial nerve tubes, which are “ready-to-use” in almost every situation. A wide range of materials have been used in animal models but only few have been applied to date clinically, where biocompatibility is an inevitable prerequisite. This review gives an idea about artificial nerve tubes with special focus on their biocompatibility in animals and humans.

  15. Medication administration through enteral feeding tubes.

    Science.gov (United States)

    Williams, Nancy Toedter

    2008-12-15

    An overview of enteral feeding tubes, drug administration techniques, considerations for dosage form selection, common drug interactions with enteral formulas, and methods to minimize tube occlusion is given. Enteral nutrition through a feeding tube is the preferred method of nutrition support in patients who have a functioning gastrointestinal tract but who are unable to be fed orally. This method of delivering nutrition is also commonly used for administering medications when patients cannot swallow safely. However, several issues must be considered with concurrent administration of oral medications and enteral formulas. Incorrect administration methods may result in clogged feeding tubes, decreased drug efficacy, increased adverse effects, or drug-formula incompatibilities. Various enteral feeding tubes are available and are typically classified by site of insertion and location of the distal tip of the feeding tube. Liquid medications, particularly elixirs and suspensions, are preferred for enteral administration; however, these formulations may be hypertonic or contain large amounts of sorbitol, and these properties increase the potential for adverse effects. Before solid dosage forms are administered through the feeding tube, it should be determined if the medications are suitable for manipulation, such as crushing a tablet or opening a capsule. Medications should not be added directly to the enteral formula, and feeding tubes should be properly flushed with water before and after each medication is administered. To minimize drug-nutrient interactions, special considerations should be taken when administering phenytoin, carbamazepine, warfarin, fluoroquinolones, and proton pump inhibitors via feeding tubes. Precautions should be implemented to prevent tube occlusions, and immediate intervention is required when blockages occur. Successful drug delivery through enteral feeding tubes requires consideration of the tube size and placement as well as careful

  16. Nasoenteric tube complications.

    Science.gov (United States)

    Prabhakaran, S; Doraiswamy, V A; Nagaraja, V; Cipolla, J; Ofurum, U; Evans, D C; Lindsey, D E; Seamon, M J; Kavuturu, S; Gerlach, A T; Jaik, N P; Eiferman, D S; Papadimos, T J; Adolph, M D; Cook, C H; Stawicki, S P A

    2012-01-01

    The use of nasoenteric tubes (NETs) is ubiquitous, and clinicians often take their placement, function, and maintenance for granted. NETs are used for gastrointestinal decompression, enteral feeding, medication administration, naso-biliary drainage, and specialized indications such as upper gastrointestinal bleeding. Morbidity associated with NETs is common, but frequently subtle, mandating high index of suspicion, clinical vigilance, and patient safety protocols. Common complications include sinusitis, sore throat and epistaxis. More serious complications include luminal perforation, pulmonary injury, aspiration, and intracranial placement. Frequent monitoring and continual re-review of the indications for continued use of any NET is prudent, including consideration of changing goals of care. This manuscript reviews NET-related complications and associated topics.

  17. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  18. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  19. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  20. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube......’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within...

  1. Retrograde Gastrojejunostomy Tube Migration

    Directory of Open Access Journals (Sweden)

    Adeleke Adesina

    2014-01-01

    Full Text Available Percutaneous enteral feeding tubes are placed about 250,000 times each year in the United States. Although they are relatively safe, their placement may be complicated by perforation, infection, bleeding, vomiting, dislodgment, and obstruction. There have been numerous reports of antegrade migration of gastrojejunostomy (G-J tubes. We report a case of G-J tube regurgitation following protracted vomiting and discuss the management of this very rare entity.

  2. On the generation of flux tube waves in stellar convection zones. I - Longitudinal tube waves driven by external turbulence

    Science.gov (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.

    1989-01-01

    The source functions and the energy fluxes for wave generation in magnetic flux tubes embedded in an otherwise magnetic field-free, turbulent, and compressible fluid are derived. The calculations presented here assume that the tube interior is not itself turbulent, e.g., that motions within the flux tube are due simply to external excitation. Specific results for the generation of longitudinal tube waves are presented.

  3. Optimizing Tube Precurvature to Enhance Elastic Stability of Concentric Tube Robots.

    Science.gov (United States)

    Ha, Junhyoung; Park, Frank C; Dupont, Pierre E

    2017-02-01

    Robotic instruments based on concentric tube technology are well suited to minimally invasive surgery since they are slender, can navigate inside small cavities and can reach around sensitive tissues by taking on shapes of varying curvature. Elastic instabilities can arise, however, when rotating one precurved tube inside another. In contrast to prior work that considered only tubes of piecewise constant precurvature, we allow precurvature to vary along the tube's arc length. Stability conditions for a planar tube pair are derived and used to formulate an optimal design problem. An analytic formulation of the optimal precurvature function is derived that achieves a desired tip orientation range while maximizing stability and respecting bending strain limits. This formulation also includes straight transmission segments at the proximal ends of the tubes. The result, confirmed by both numerical and physical experiment, enables designs with enhanced stability in comparison to designs of constant precurvature.

  4. Heated Tube Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Heated Tube Facility at NASA GRC investigates cooling issues by simulating conditions characteristic of rocket engine thrust chambers and high speed airbreathing...

  5. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  6. Disinfection of Biofilms in Tubes with Ultraviolet Light

    DEFF Research Database (Denmark)

    Bak, Jimmy; Begovic, Tanja

    2009-01-01

    Bacterial biofilms on long-term catheters are a major source of infection. We demonstrate here the potential of UVC light emitting diodes (LED) for disinfection purposes in catheter like tubes contaminated with biofilm. We show that UVC Light propagation is possible through teflon tubes using...... that the UVC light attenuation inside the tube can be described by an exponential function depending of tube length and various loss mechanisms. The disinfection efficiency of the UVC diodes is demonstrated on tubes contaminated artificially with a Pseudomonas aeruginosa biofilm. The tubes were connected...... the liquid light guiding principle. If the refractive index of the liquid is higher than that of the tube material light is guided inside the tube by internal reflections. To obtain a high refractive index of the liquid sodium chloride in high concentrations is added to the aqueous solution. It is shown...

  7. Pyrotechnic Tubing Connector

    Science.gov (United States)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  8. Neural Tube Defects

    Science.gov (United States)

    ... pregnancies each year in the United States. A baby’s neural tube normally develops into the brain and spinal cord. ... fluid in the brain. This is called hydrocephalus. Babies with this condition are treated with surgery to insert a tube (called a shunt) into the brain. The shunt ...

  9. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  10. Isolated Fallopian Tube Torsion

    Directory of Open Access Journals (Sweden)

    S. Kardakis

    2013-01-01

    Full Text Available Isolated torsion of the Fallopian tube is a rare gynecological cause of acute lower abdominal pain, and diagnosis is difficult. There are no pathognomonic symptoms; clinical, imaging, or laboratory findings. A preoperative ultrasound showing tubular adnexal masses of heterogeneous echogenicity with cystic component is often present. Diagnosis can rarely be made before operation, and laparoscopy is necessary to establish the diagnosis. Unfortunately, surgery often is performed too late for tube conservation. Isolated Fallopian tube torsion should be suspected in case of acute pelvic pain, and prompt intervention is necessary.

  11. Resonant oscillations in open axisymmetric tubes

    Science.gov (United States)

    Amundsen, D. E.; Mortell, M. P.; Seymour, B. R.

    2017-12-01

    We study the behaviour of the isentropic flow of a gas in both a straight tube of constant cross section and a cone, open at one end and forced at or near resonance at the other. A continuous transition between these configurations is provided through the introduction of a geometric parameter k associated with the opening angle of the cone where the tube corresponds to k=0. The primary objective is to find long-time resonant and near-resonant approximate solutions for the open tube, i.e. k→ 0. Detailed analysis for both the tube and cone in the limit of small forcing (O(ɛ 3)) is carried out, where ɛ 3 is the Mach number of the forcing function and the resulting flow has Mach number O(ɛ ). The resulting approximate solutions are compared with full numerical simulations. Interesting distinctions between the cone and the tube emerge. Depending on the damping and detuning, the responses for the tube are continuous and of O(ɛ ). In the case of the cone, the resonant response involves an amplification of the fundamental resonant mode, usually called the dominant first-mode approximation. However, higher modes must be included for the tube to account for the nonlinear generation of higher-order resonances. Bridging these distinct solution behaviours is a transition layer of O(ɛ 2) in k. It is found that an appropriately truncated set of modes provides the requisite modal approximation, again comparing well to numerical simulations.

  12. The ciliary activity of the middle ear lining--functional and morphological observation.

    Science.gov (United States)

    Ohashi, Y; Nakai, Y; Kihara, S; Maruoka, K; Ikeoka, H; Uemura, Y

    1985-01-01

    Since the middle ear lining is an extension and a modification of the respiratory mucosa, it is conceivable that it has a mucociliary system and it plays an important role in clearance of the tympanic cavity. It was already noted in morphological studies that the middle ear lining had ciliated cells. To our knowledge, however, ciliary activity has never been observed directly. In the present paper, the ciliary activity of the middle ear mucosa was investigated directly and quantitatively by the photo-electric method of Ohashi and Nakai. In this work, special reference was made to the frequency of ciliary beating at various sites within the tympanic cavity. Ciliary activity was found to exist in the Eustachian tube and middle ear same as in other respiratory epithelium and this activity by ciliated cells was more active as their location became more distal to the Eustachian tube. Although the present results are preliminary, the techniques used in this study will provide a new avenue of the investigation of pathological middle ear lining.

  13. Tracheostomy tube - eating

    Science.gov (United States)

    Trach - eating ... take your first bites. Certain factors may make eating or swallowing harder, such as: Changes in the ... easier to swallow. Suction the tracheostomy tube before eating. This will keep you from coughing while eating, ...

  14. Bull Moose Tube Company

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against the Bull Moose Tube Company, a business located at 1819 Clarkson Road, Chesterfield, MO, 63017, for alleged violations at the facility located at 406 East Industrial Drive,

  15. Tube-Forming Assays.

    Science.gov (United States)

    Brown, Ryan M; Meah, Christopher J; Heath, Victoria L; Styles, Iain B; Bicknell, Roy

    2016-01-01

    Angiogenesis involves the generation of new blood vessels from the existing vasculature and is dependent on many growth factors and signaling events. In vivo angiogenesis is dynamic and complex, meaning assays are commonly utilized to explore specific targets for research into this area. Tube-forming assays offer an excellent overview of the molecular processes in angiogenesis. The Matrigel tube forming assay is a simple-to-implement but powerful tool for identifying biomolecules involved in angiogenesis. A detailed experimental protocol on the implementation of the assay is described in conjunction with an in-depth review of methods that can be applied to the analysis of the tube formation. In addition, an ImageJ plug-in is presented which allows automatic quantification of tube images reducing analysis times while removing user bias and subjectivity.

  16. Tube Alinement for Machining

    Science.gov (United States)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  17. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  18. Spherical tube hypersurfaces

    CERN Document Server

    Isaev, Alexander

    2011-01-01

    We examine Levi non-degenerate tube hypersurfaces in complex linear space which are "spherical," that is, locally CR-equivalent to the real hyperquadric. Spherical hypersurfaces are characterized by the condition of the vanishing of the CR-curvature form, so such hypersurfaces are flat from the CR-geometric viewpoint. On the other hand, such hypersurfaces are also of interest from the point of view of affine geometry. Thus our treatment of spherical tube hypersurfaces in this book is two-fold: CR-geometric and affine-geometric. As the book shows, spherical tube hypersurfaces possess remarkable properties. For example, every such hypersurface is real-analytic and extends to a closed real-analytic spherical tube hypersurface in complex space. One of our main goals is to provide an explicit affine classification of closed spherical tube hypersurfaces whenever possible. In this book we offer a comprehensive exposition of the theory of spherical tube hypersurfaces, starting with the idea proposed in the pioneering...

  19. Inverse Kinematics of Concentric Tube Steerable Needles.

    Science.gov (United States)

    Sears, Patrick; Dupont, Pierre E

    2007-01-01

    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube displacements and needle tip configuration as well as to the multiplicity of solutions as the number of tubes increases. This paper presents a general approach to solving the inverse kinematics problem using a pseudoinverse solution together with gradients of nullspace potential functions to enforce geometric and mechanical constraints.

  20. Experimental approach on the collapse mechanism of CFRP composite tubes

    Science.gov (United States)

    Kim, Y. N.; Im, K. H.; Park, J. W.; Yang, I. Y.

    2001-04-01

    This study is to investigate the energy absorption characteristics of CFRP(Carbon-Fiber Reinforced Plastics) tubes on static and dynamic tests. Axial static compression tests have been carried out using the static testing machine(Shin-gang buckling testing machine) and dynamic compression tests have been utilized using an vertical crushing testing machine. When such tubes are subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that could control the crushing process. The collapse characteristics and energy absorption have been examined for various tubes. Energy absorption of the tubes are increased as changes in the lay-up which may increase the modulus of tubes. The results have been varied significantly as a function of ply orientation and interlaminar number. In general, the stacking sequence [0/90] CFRP tubes absorbed more energy than the [15/-15] CFRP tubes.

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  2. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  3. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen

    2011-09-01

    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  4. Geiger-Muller tubes

    Energy Technology Data Exchange (ETDEWEB)

    Gair, S.A.; Copleston, R.E.

    1991-01-16

    A Geiger-Muller tube designed for use in an environment (for example, mounted on a rock drill) where subjected to mechanical shock and vibration has a tensioned anode wire secured by welding to securement members between first and second mounts at opposite ends of the tube envelope. The wire tension is adjusted to a high value with a screwable-adjustment means which is locked eg. by a spot-weld or by a locking nut, in the adjusted position, so that the natural frequency of the vibration of the tensioned wire does not resonate with (and may be much higher than) the frequencies to which the tube is subjected in use. The wire frequency is typically in excess of 400Hz and even 500Hz. The adjustment means may be included in the mount via which the envelope is evacuated and back-filled with the ionizible gas, and a gas-tight seal can be provided around this part of the mount, for example by sealing off the gas pump tube. However the adjustment means may be designed into another part of the tube, for example using telescopic parts of the envelope whose sliding junction is made gas tight with a flexible seal. (author).

  5. Fuel cell tubes and method of making same

    Science.gov (United States)

    Borglum, Brian P.

    1999-11-30

    A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost. A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.

  6. BcMF26a and BcMF26b Are Duplicated Polygalacturonase Genes with Divergent Expression Patterns and Functions in Pollen Development and Pollen Tube Formation in Brassica campestris.

    Directory of Open Access Journals (Sweden)

    Meiling Lyu

    Full Text Available Polygalacturonase (PG is one of the cell wall hydrolytic enzymes involving in pectin degradation. A comparison of two highly conserved duplicated PG genes, namely, Brassica campestris Male Fertility 26a (BcMF26a and BcMF26b, revealed the different features of their expression patterns and functions. We found that these two genes were orthologous genes of At4g33440, and they originated from a chromosomal segmental duplication. Although structurally similar, their regulatory and intron sequences largely diverged. QRT-PCR analysis showed that the expression level of BcMF26b was higher than that of BcMF26a in almost all the tested organs and tissues in Brassica campestris. Promoter activity analysis showed that, at reproductive development stages, BcMF26b promoter was active in tapetum, pollen grains, and pistils, whereas BcMF26a promoter was only active in pistils. In the subcellular localization experiment, BcMF26a and BcMF26b proteins could be localized to the cell wall. When the two genes were co-inhibited, pollen intine was formed abnormally and pollen tubes could not grow or stretch. Moreover, the knockout mutants of At4g33440 delayed the growth of pollen tubes. Therefore, BcMF26a/b can participate in the construction of pollen wall by modulating intine information and BcMF26b may play a major role in co-inhibiting transformed plants.

  7. The sizes of Flat Plate and Evacuated Tube Collectors with Heat Pipe area as a function of the share of solar system in the heat demand

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2016-01-01

    Full Text Available The popularity of solar collectors in Poland is still increasing. The correct location of the collectors and a relatively high density of solar radiation allow delivering heat even in spite of relatively low ambient temperature. Moreover, solar systems used for heating domestic heat water (DHW in summer allow nearly complete elimination of conventional energy sources (e.g. gas, coal. That is why more and more house owners in Poland decide to install solar system installations. In Poland the most common types of solar collectors are flat plate collectors (FPC and evacuated tube collectors with heat pipe (ETCHP; both were selected for the analysis. The heat demand related to the preparation of hot water, connected with the size of solar collectors’ area, has been determined. The analysis includes FPC and ETCHP and heat demand of less than 10 000 kWh/year. Simulations were performed with the Matlab software and using data from a typical meteorological year (TMY. In addition, a 126–year period of measurements of insolation for Krakow has been taken into account. The HDKR model (Hay, Davis, Klucher, Reindl was used for the calculation of solar radiation on the absorber surface. The monthly medium temperature of the absorber depends on the amount of solar system heat and on the heat demand. All the previously mentioned data were used to determine solar efficiency. Due to the fact that solar efficiency and solar system heat are connected, the calculations were made with the use of an iterative method. Additionally, the upper limit for monthly useful solar system heat is resulted from the heat demand and thus the authors prepared a model of statistical solar system heat deviations based on the Monte Carlo method. It has been found that an increase in the useful solar system heat in reference to the heat demand is associated with more than proportional increase in the sizes of the analyzed surfaces of solar collector types.

  8. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-01-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  9. Cladding tube manufacturing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. [Kraftwerk Union AG, Mulheim (Germany); Jeong, Y.H.; Baek, B.J.; Kim, K.H.; Kim, S.J.; Choi, B.K.; Kim, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-04-01

    This report gives an overview of the manufacturing routine of PWR cladding tubes. The routine essentially consists of a series of deformation and annealing processes which are necessary to transform the ingot geometry to tube dimensions. By changing shape, microstructure and structure-related properties are altered simultaneously. First, a short overview of the basics of that part of deformation geometry is given which is related to tube reducing operations. Then those processes of the manufacturing routine which change the microstructure are depicted, and the influence of certain process parameters on microstructure and material properties are shown. The influence of the resulting microstructure on material properties is not discussed in detail, since it is described in my previous report 'Alloy Development for High Burnup Cladding.' Because of their paramount importance still up to now, and because manufacturing data and their influence on properties for other alloys are not so well established or published, the descriptions are mostly related to Zry4 tube manufacturing, and are only in short for other alloys. (author). 9 refs., 46 figs.

  10. Jejunostomy feeding tube

    Science.gov (United States)

    ... skin for redness, odor, pain, puss, or swelling. Make sure the stitches are still in place. Use the clean towel or Q-tip to clean the skin around the J-tube 1 to 3 times a day with mild soap and water. Try to remove any drainage or crusting on ...

  11. Evacuated-tube solar collector--performance evaluation

    Science.gov (United States)

    1980-01-01

    Report gives thermal performance test procedures and results for commercially produced, water-filled, 8-tube collectors. Tests include efficiency, time constant for temperature drop after solar flux is cut, change in efficiency as function of sun angle, and test to see if tubes break when filled with hot water.

  12. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth

    Directory of Open Access Journals (Sweden)

    Jean-Claude Mollet

    2013-03-01

    Full Text Available The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  13. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth.

    Science.gov (United States)

    Mollet, Jean-Claude; Leroux, Christelle; Dardelle, Flavien; Lehner, Arnaud

    2013-03-07

    The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  14. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  15. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma ...

  16. Enteral Tube Feeding and Pneumonia

    Science.gov (United States)

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  17. Circumferential cracking of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  18. Vortex tube optimization theory

    Energy Technology Data Exchange (ETDEWEB)

    Lewins, Jeffery [Cambridge Univ., Magdalene Coll., Cambridge (United Kingdom); Bejan, Adrian [Duke Univ., Dept. of Mechanical Engineering and Materials Science, Durham, NC (United States)

    1999-11-01

    The Ranque-Hilsch vortex tube splits a single high pressure stream of gas into cold and warm streams. Simple models for the vortex tube combined with regenerative precooling are given from which an optimisation can be undertaken. Two such optimisations are needed: the first shows that at any given cut or fraction of the cold stream, the best refrigerative load, allowing for the temperature lift, is nearly half the maximum loading that would result in no lift. The second optimisation shows that the optimum cut is an equal division of the vortex streams between hot and cold. Bounds are obtainable within this theory for the performance of the system for a given gas and pressure ratio. (Author)

  19. YouTube Physics

    Science.gov (United States)

    Riendeau, Diane

    2012-09-01

    To date, this column has presented videos to show in class, Don Mathieson from Tulsa Community College suggested that YouTube could be used in another fashion. In Don's experience, his students are not always prepared for the mathematic rigor of his course. Even at the high school level, math can be a barrier for physics students. Walid Shihabi, a colleague of Don's, decided to compile a list of YouTube videos that his students could watch to relearn basic mathematics. I thought this sounded like a fantastic idea and a great service to the students. Walid graciously agreed to share his list and I have reproduced a large portion of it below.

  20. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  1. Performance of pressure tubes in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, D.; Griffiths, M.; Bickel, G.; Buyers, A.; Coleman, C.; Nordin, H.; St Lawrence, S. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    The pressure tubes in CANDU reactors typically operate for times up to about 30 years prior to refurbishment. The in-reactor performance of Zr-2.5Nb pressure tubes has been evaluated by sampling and periodic inspection. This paper describes the behavior and discusses the factors controlling the behaviour of these components. The Zr–2.5Nb pressure tubes are nominally extruded at 815{sup o}C, cold worked nominally 27%, and stress relieved at 400 {sup o}C for 24 hours, resulting in a structure consisting of elongated grains of hexagonal close-packed alpha-Zr, partially surrounded by a thin network of filaments of body-centred-cubic beta-Zr. These beta-Zr filaments are meta-stable and contain about 20% Nb after extrusion. The stress-relief treatment results in partial decomposition of the beta-Zr filaments with the formation of hexagonal close-packed alpha-phase particles that are low in Nb, surrounded by a Nb-enriched beta-Zr matrix. The material properties of pressure tubes are determined by variations in alpha-phase texture, alpha-phase grain structure, network dislocation density, beta-phase decomposition, and impurity concentration that are a function of manufacturing variables. The pressure tubes operate at temperatures between 250 {sup o}C and 310 {sup o}C with coolant pressures up to about 11 MPa in fast neutron fluxes up to 4 x 10{sup 17} n·m{sup -2}·s{sup -1} (E > 1 MeV) and the properties are modified by these conditions. The properties of the pressure tubes in an operating reactor are therefore a function of both manufacturing and operating condition variables. The ultimate tensile strength, fracture toughness, and delayed hydride-cracking properties (velocity (V) and threshold stress intensity factor (K{sub IH})) change with irradiation, but all reach a nearly limiting value at a fluence of less than 10{sup 25} n·m{sup -2} (E > 1 MeV). At this point the ultimate tensile strength is raised about 200 MPa, toughness is reduced by about 50%, V increases

  2. Predictors of recovery of functional swallow after gastrostomy tube placement for Dysphagia in stroke patients after inpatient rehabilitation: a pilot study.

    Science.gov (United States)

    Crisan, Diana; Shaban, Amir; Boehme, Amelia; Dubin, Perry; Juengling, Jenifer; Schluter, Laurie A; Albright, Karen C; Beasley, T Mark; Martin-Schild, Sheryl

    2014-08-01

    To determine predictors of early recovery of functional swallow in patients who had gastrostomy (percutaneous endoscopic gastrostomy [PEG]) placement for dysphagia and were discharged to inpatient rehabilitation (IPR) after stroke. A retrospective study of prospectively identified patients with acute ischemic and hemorrhagic stroke from July 2008 to August 2012 was conducted. Patients who had PEG during stroke admission and were discharged to IPR, were studied. We compared demographics, stroke characteristics, severity of dysphagia, stroke admission events and medications in patients who remained PEG-dependent after IPR with those who recovered functional swallow. Patients who remained PEG dependent were significantly older (73 vs. 54 years, p=0.009). Recovery of swallow was more frequent for hemorrhagic stroke patients (80% vs. 47%, p=0.079). Age, adjusting for side of stroke (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82-0.98; p=0.016) and left-sided strokes, adjusting for age (OR, 15.15; 95% CI, 1.32-173.34; p=0.028) were significant predictors of swallow recovery. Patients who recovered swallowing by discharge from IPR were more likely to be discharged home compared to those who remained PEG-dependent (90% vs. 42%, p=0.009). Younger age and left-sided stroke may be predictive factors of early recovery of functional swallow in patients who received PEG. Prospective validation is important as avoidance of unnecessary procedures could reduce morbidity and healthcare costs.

  3. Reliability of steam generator tubing

    Energy Technology Data Exchange (ETDEWEB)

    Kadokami, E. [Mitsubishi Heavy Industries Ltd., Hyogo-ku (Japan)

    1997-02-01

    The author presents results on studies made of the reliability of steam generator (SG) tubing. The basis for this work is that in Japan the issue of defects in SG tubing is addressed by the approach that any detected defect should be repaired, either by plugging the tube or sleeving it. However, this leaves open the issue that there is a detection limit in practice, and what is the effect of nondetectable cracks on the performance of tubing. These studies were commissioned to look at the safety issues involved in degraded SG tubing. The program has looked at a number of different issues. First was an assessment of the penetration and opening behavior of tube flaws due to internal pressure in the tubing. They have studied: penetration behavior of the tube flaws; primary water leakage from through-wall flaws; opening behavior of through-wall flaws. In addition they have looked at the question of the reliability of tubing with flaws during normal plant operation. Also there have been studies done on the consequences of tube rupture accidents on the integrity of neighboring tubes.

  4. Mechanistic insights from a quantitative analysis of pollen tube guidance

    Directory of Open Access Journals (Sweden)

    Bhimalapuram Prabhakar

    2010-02-01

    Full Text Available Abstract Background Plant biologists have long speculated about the mechanisms that guide pollen tubes to ovules. Although there is now evidence that ovules emit a diffusible attractant, little is known about how this attractant mediates interactions between the pollen tube and the ovules. Results We employ a semi-in vitro assay, in which ovules dissected from Arabidopsis thaliana are arranged around a cut style on artificial medium, to elucidate how ovules release the attractant and how pollen tubes respond to it. Analysis of microscopy images of the semi-in vitro system shows that pollen tubes are more attracted to ovules that are incubated on the medium for longer times before pollen tubes emerge from the cut style. The responses of tubes are consistent with their sensing a gradient of an attractant at 100-150 μm, farther than previously reported. Our microscopy images also show that pollen tubes slow their growth near the micropyles of functional ovules with a spatial range that depends on ovule incubation time. Conclusions We propose a stochastic model that captures these dynamics. In the model, a pollen tube senses a difference in the fraction of receptors bound to an attractant and changes its direction of growth in response; the attractant is continuously released from ovules and spreads isotropically on the medium. The model suggests that the observed slowing greatly enhances the ability of pollen tubes to successfully target ovules. The relation of the results to guidance in vivo is discussed.

  5. The equilibrium structure of thin magnetic flux tubes. II. [in sun and late stars

    Science.gov (United States)

    Kalkofen, W.; Rosner, R.; Ferrari, A.; Massaglia, S.

    1986-01-01

    The thermal structure of the medium inside thin, vertical magnetic flux tubes embedded in a given external atmosphere is investigated, assuming cylindrical symmetry and a depth-independent plasma beta. The variation with tube radius of the temperature on the tube axis is computed and the temperature on the tube wall is estimated. The temperature variation across the flux tube is found to be due to the depth variation of the intensity and to the density stratification of the atmosphere. Since the temperature difference between the axis and the wall is small in thin flux tubes (of the order of 10 percent), the horizontal temperature gradient may often be neglected and the temperature in a tube of given radius may be described by a single function of depth. Thus, a more detailed numerical treatment of the radiative transfer within thin flux tubes can be substantially simplified by neglecting horizontal temperature differences within the flux tube proper.

  6. Allowable temperature rise in tubes of the piles: Precautions against boiling

    Energy Technology Data Exchange (ETDEWEB)

    Woods, W.K.

    1945-09-27

    In the design of the pile, it was considered advisable never to impose so great a heat load on any tube that the available header pressure would be insufficient to sweep the tube free of vapor if boiling should accidentally be initiated in the tube. Figures are given for the maximum temperature rises permissible, as function of header pressure and orifice diameter.

  7. Determining Interest in YouTube Topics for Extension-Authored Video Development

    Science.gov (United States)

    Parish, Jane A.; Karisch, Brandi B.

    2013-01-01

    With an audience of over 1 billion users per month, YouTube is an attractive medium for delivering Extension programming. Amidst growing competition for viewership, determining content that is in demand by Extension clientele on YouTube is a daunting challenge that Extension educators face. The YouTube Search function of Google Trends and…

  8. Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

    Science.gov (United States)

    Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

    2014-09-01

    Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. © 2014 Scandinavian Plant Physiology Society.

  9. Feasibility of protein-sparing modified fast by tube (ProMoFasT) in obesity treatment: a phase II pilot trial on clinical safety and efficacy (appetite control, body composition, muscular strength, metabolic pattern, pulmonary function test).

    Science.gov (United States)

    Sukkar, S G; Signori, A; Borrini, C; Barisione, G; Ivaldi, C; Romeo, C; Gradaschi, R; Machello, N; Nanetti, E; Vaccaro, A L

    2013-01-01

    Anecdotal data in the last few years suggest that protein-sparing modified diet (PSMF) delivered by naso-gastric tube enteral (with continuous feeding) could attain an significant weight loss and control of appetite oral feeding, but no phase II studies on safety and efficacy have been done up to now. To verify the safety and efficacy of a protein-sparing modified fast administered by naso-gastric tube (ProMoFasT) for 10 days followed by 20 days of a low-calorie diet, in patients with morbid obesity (appetite control, fat free mass maintenance, pulmonary function tests and metabolic pattern, side effects), 26 patients with a BMI ≥30 kg/m 2 have been selected. The patients had to follow a protein-sparing fast by enteral nutrition (ProMoFasT) for 24 h/day, for 10 days followed by 20 days of low-calorie diet (LCD). The endpoint was represented by body weight, BMI, abdominal circumference, Haber's appetite test, body composition by body impedance assessment (BIA), handgrip strength test, metabolic pattern, pulmonary function test. Safety was assessed by evaluation of complications and side effects of PSMF and/or enteral nutrition. In this report the results on safety and efficacy are described after 10 and 30 days of treatment. After the recruiting phase, a total of 22 patients out of 26 enrolled [14 (63.6 %) females] were evaluated in this study. Globally almost all clinical parameters changed significantly during first 10 days. Total body weight significantly decreased after 10 days (∆-6.1 ± 2; p  weight loss related to decrease of FM and not to loss of FFM and appetite decreases. It is relevant that the RFT are significantly improved after only 10 days suggesting the efficacy of this regime in short period, too. These preliminary data underline the necessity to increase the number of RCT for this method, which could represent a possible alternative to other methodologies, such as the intragastric balloon, in particular when it is recommended to

  10. Percutaneous endoscopic gastrostomy tube occlusion in malignant peritoneal carcinomatosis-induced bowel obstruction.

    Science.gov (United States)

    Vashi, Pankaj G; Dahlk, Sadie; Vashi, Rohan P; Gupta, Digant

    2011-11-01

    Percutaneous endoscopic gastrostomy (PEG) tube placement for decompression in advanced peritoneal carcinomatosis with bowel obstruction is a safe and feasible palliative procedure. We describe a rare, previously unreported phenomenon of PEG tube occlusion by gastric mucosal herniation. A consecutive case series of 73 patients with advanced abdominal carcinomatosis-induced bowel obstruction from January 2007 to June 2010. All patients had a 28 Fr (Bard) PEG tube placed for drainage. None of them were surgical candidates due to extensive peritoneal involvement. Patients with PEG tube occlusion as a result of gastric mucosal herniation were further evaluated. Nineteen patients were men and 54 were women. The mean age was 53.3 years. The most common cancer types were ovary, pancreas, colon, and stomach. All patients had PEG tube functioning well after the procedure with immediate relief of obstructive symptoms. Subsequently, 10 patients developed acute occlusion of PEG tubes with reoccurrence of obstructive symptoms. The time between the placement of the PEG tube and its occlusion ranged from 5 to 129 days. Repeat endoscopy showed the PEG tube occluded with gastric mucosa from the opposite wall. PEG tube was replaced with a 28 Fr balloon replacement tube leading to symptom improvement in all 10 patients. This rare but correctable phenomenon of obliteration of PEG tube from the gastric mucosa should be considered in any patient who develops intermittent occlusive symptoms. This phenomenon can be corrected by replacing the PEG tube with a ballooned replacement tube as well as occasional manipulation of the tube.

  11. Steam generator tube integrity program

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, D.R.; Shack, W.J. [Argonne National Laboratory, IL (United States); Muscara, J.

    1996-03-01

    A new research program on steam generator tubing degradation is being sponsored by the U.S. Nuclear Regulatory Commission (NRC) at Argonne National Laboratory. This program is intended to support a performance-based steam generator tube integrity rule. Critical areas addressed by the program include evaluation of the processes used for the in-service inspection of steam generator tubes and recommendations for improving the reliability and accuracy of inspections; validation and improvement of correlations for evaluating integrity and leakage of degraded steam generator tubes, and validation and improvement of correlations and models for predicting degradation in steam generator tubes as aging occurs. The studies will focus on mill-annealed Alloy 600 tubing, however, tests will also be performed on replacement materials such as thermally-treated Alloy 600 or 690. An overview of the technical work planned for the program is given.

  12. Characteristics of long size thermosyphons made of corrugated tube

    Science.gov (United States)

    Hirashima, Masao; Nishikawa, Yuuji; Taguchi, Masakazu; Negishi, Kanji; Kanero, Ken-Ichi; Matsuoka, Takayoshi

    1988-03-01

    Two-phase closed thermosyphons made of corrugated tube operating in the gravitational field have different characteristics in comparison with that of smooth tube in some items. The cause depends on the accumulated working fluid in the concave space of corrugated tube which tends to induce a dry out phenomenon in the evaporator section. The difference of these characteristics between thermosyphons of corrugated tube and smooth tube seems to amplify with the increment of the length of the thermosyphon. The temperature distribution along the axis of thermosyphon, the heat transport and the heat transfer coefficient as a function of the inclination angle at a fill charge ratio 50 percent of the working fluid were obtained by the experiments and discussed herein. A correlating equation of the heat transfer coefficient was deduced also from the experiments.

  13. Diffusion in a Curved Tube

    OpenAIRE

    Ogawa, Naohisa

    2011-01-01

    The diffusion of particles in confining walls forming a tube is discussed. Such a transport phenomenon is observed in biological cells and porous media. We consider the case in which the tube is winding with curvature and torsion, and the thickness of the tube is sufficiently small compared with its curvature radius. We discuss how geomerical quantities appear in a quasi-one-dimensional diffusion equation.

  14. Alternate tube plugging criteria for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C.; Aparicio, C.B. [Tecnatom, S.A., Madrid (Spain)

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  15. Genetics and development of neural tube defects

    Science.gov (United States)

    Copp, Andrew J.; Greene, Nicholas D. E.

    2014-01-01

    Congenital defects of neural tube closure (neural tube defects; NTDs) are among the commonest and most severe disorders of the fetus and newborn. Disturbance of any of the sequential events of embryonic neurulation produce NTDs, with the phenotype (e.g. anencephaly, spina bifida) varying depending on the region of neural tube that remains open. While mutation of more than 200 genes is known to cause NTDs in mice, the pattern of occurrence in humans suggests a multifactorial polygenic or oligogenic aetiology. This emphasises the importance of gene-gene and gene-environment interactions in the origin of these defects. A number of cell biological functions are essential for neural tube closure, with defects of the cytoskeleton, cell cycle and molecular regulation of cell viability prominent among the mouse NTD mutants. Many transcriptional regulators and proteins that affect chromatin structure are also required for neural tube closure, although the downstream molecular pathways regulated by these proteins is unknown. Some key signalling pathways for NTDs have been identified: over-activation of sonic hedgehog signalling and loss of function in the planar cell polarity (non-canonical Wnt) pathway are potent causes of NTD, with requirements also for retinoid and inositol signalling. Folic acid supplementation is an effective method for primary prevention of a proportion of NTDs, in both humans and mice, although the embryonic mechanism of folate action remains unclear. Folic acid-resistant cases can be prevented by inositol supplementation in mice, raising the possibility that this could lead to an additional preventive strategy for human NTDs in future. PMID:19918803

  16. YouTube and 'psychiatry'.

    Science.gov (United States)

    Gordon, Robert; Miller, John; Collins, Noel

    2015-12-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed.

  17. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  18. Balloon gastrostomy tubes for long-term feeding in the community.

    Science.gov (United States)

    Ojo, Omorogieva

    Dysphagic patients with functional guts often receive nutritional and hydration support through enteral feeding tubes. These include percutaneous endoscopic gastrostomy (PEG) and radiologically inserted gastrostomy (RIG) tubes. The balloon gastrostomy tube (BGT) as a primary tube of choice in tube-fed patients, including head and neck cancer patients, offers a new approach to enteral tube feeding in the community. There are complications associated with the use of enteral feeding tubes. This study compared the complication rates and the costs of PEG tubes and BGTs in patients on long-term enteral feeding in the community and looked at the possible use of BGTs as an alternative to PEG tubes. The records of all 15 BGT-fed patients on the caseload and 15 randomly selected PEG tube-fed patients were reviewed. The study was based on two consecutive visits to these patients. Tube and stoma complications were clinically scored in order of increasing severity (0-10) and statistically tested. The prevalence of stoma and tube complications was expressed in percentages. There was no significant difference (P>0.05) in the overall clinical scores between BGT-fed and PEG tube-fed patients at both initial and final visits. However, with regard to specific complications-infected sites, tube dislodgement, overgranulation, and infection with overgranulation-significant differences were observed between the two groups of patients at the initial and final visits. In addition, the total costs of inserting and managing BGTs were significantly higher than those for PEG tubes. Although BGTs may be used as analternative to PEG tubes in patients on long-term enteral feeding in the community, the higher cost of using BGTs over PEG tubes should be considered when selecting feeding tubes for these patients.

  19. Learning from YouTube [Video Book

    Science.gov (United States)

    Juhasz, Alexandra

    2011-01-01

    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  20. Infrared imaging of LED lighting tubes and fluorescent tubes

    Science.gov (United States)

    Siikanen, Sami; Kivi, Sini; Kauppinen, Timo; Juuti, Mikko

    2011-05-01

    The low energy efficiency of conventional light sources is mainly caused by generation of waste heat. We used infrared (IR) imaging in order to monitor the heating of both LED tube luminaires and ordinary T8 fluorescent tubes. The IR images showed clearly how the surface temperatures of the fluorescent tube ends quickly rose up to about +50...+70°C, whereas the highest surface temperatures seen on the LED tubes were only about +30...+40°C. The IR images demonstrated how the heat produced by the individual LED chips can be efficiently guided to the supporting structure in order to keep the LED emitters cool and hence maintain efficient operation. The consumed electrical power and produced illuminance were also recorded during 24 hour measurements. In order to assess the total luminous efficacy of the luminaires, separate luminous flux measurements were made in a large integrating sphere. The currently available LED tubes showed efficacies of up to 88 lm/W, whereas a standard "cool white" T8 fluorescent tube produced ca. 75 lm/W. Both lamp types gave ca. 110 - 130 lx right below the ceiling-mounted luminaire, but the LED tubes consume only 40 - 55% of the electric power compared to fluorescent tubes.

  1. Case series

    African Journals Online (AJOL)

    ebutamanya

    2015-01-29

    Jan 29, 2015 ... Myringoplasty in children: retrospective analysis of 35 cases. Braz j otorhinolaryngol. 2009; 75(3): 371. PubMed | Google. Scholar. 2. Bluestone CD, Cantekin EI, Douglas GS. Eustachian tube function related to the results of tympanoplasty in children. Laryngoscope. 1979 Mar;89(3):450-8. PubMed | Google.

  2. Drop tube technical tasks

    Science.gov (United States)

    Workman, G. L.

    1986-01-01

    Criteria, using fundamental thermochemical dynamics, were developed to assist a scientist using the Drop Tube Facility in designing a good experiment. The types of parameters involved in designing the experiments include the type of furnace, the type of atmosphere, and in general which materials are better behaved than others as determined by past experience in the facility. One of the major advantages of the facility lies in its ability to provide large undercoolings in the cooling curve during the drops. A beginning was to consider the effect of oxygen and other gases upon the amount of undercooling observed. The starting point of the thermochemistry was given by Ellingham and later transformed into what is known as the Richardson Chart. The effect of surface oxidations upon the nucleation phenomena can be observed in each specimen.

  3. Piezoelectric Rotary Tube Motor

    Science.gov (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  4. Dynamics of miscible displacements in round tubes

    Energy Technology Data Exchange (ETDEWEB)

    Meiburg, E.; Maxworthy, T.; Chen, C.Y. [Univ. of Southern California, Los Angeles, CA (United States); Petitjeans, P. [Ecole Superieure de Physique et de Chimie Industrielles, Paris (France)

    1995-12-31

    A combined experimental and numerical investigation of miscible two-phase flow in a capillary tube is reported. The fraction of fluid left behind on the wall is obtained as a function of the Peclet, Atwood, and Froude numbers. Scaling arguments are presented for two distinct flow regimes, dominated by diffusion and convection, respectively. In the latter one, an effective surface tension value can be estimated.

  5. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis

    Science.gov (United States)

    Wei, Bin; Chen, Lin

    2015-01-01

    Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine. PMID:26090420

  6. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis.

    Science.gov (United States)

    Hong, Feng; Wei, Bin; Chen, Lin

    2015-01-01

    Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine.

  7. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis

    Directory of Open Access Journals (Sweden)

    Feng Hong

    2015-01-01

    Full Text Available Bacterial nanocellulose (BNC has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine.

  8. An improved automatic computer aided tube detection and labeling system on chest radiographs

    Science.gov (United States)

    Ramakrishna, Bharath; Brown, Matthew; Goldin, Jonathan; Cagnon, Christopher; Enzmann, Dieter

    2012-03-01

    Tubes like Endotracheal (ET) tube used to maintain patient's airway and the Nasogastric (NG) tube used to feed the patient and drain contents of the stomach are very commonly used in Intensive Care Units (ICU). The placement of these tubes is critical for their proper functioning and improper tube placement can even be fatal. Bedside chest radiographs are considered the quickest and safest method to check the placement of these tubes. Tertiary ICU's typically generate over 250 chest radiographs per day to confirm tube placement. This paper develops a new fully automatic prototype computer-aided detection (CAD) system for tube detection on bedside chest radiographs. The core of the CAD system is the randomized algorithm which selects tubes based on their average repeatability from seed points. The CAD algorithm is designed as a 5 stage process: Preprocessing (removing borders, histogram equalization, anisotropic filtering), Anatomy Segmentation (to identify neck, esophagus, abdomen ROI's), Seed Generation, Region Growing and Tube Selection. The preliminary evaluation was carried out on 64 cases. The prototype CAD system was able to detect ET tubes with a True Positive Rate of 0.93 and False Positive Rate of 0.02/image and NG tubes with a True Positive Rate of 0.84 and False Positive Rate of 0.02/image respectively. The results from the prototype system show that it is feasible to automatically detect both tubes on chest radiographs, with the potential to significantly speed the delivery of imaging services while maintaining high accuracy.

  9. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  10. Enteral tube feeding in adults.

    Science.gov (United States)

    Scott, R; Bowling, T E

    2015-03-01

    Enteral tube feeding is usually a relatively straightforward method of nutritional support, and should be facilitated by a multiprofessional team. For short-term use (tube is indicated but if longer term feeding is required then a gastrostomy is appropriate, usually inserted endoscopically (a percutaneous endoscopic gastrostomy tube). The most common serious complication of a nasogastric tube is not identifying a misplaced tube within the lungs: there are clear recommendations from the National Patient Safety Agency as to how to check tube placement. Nasojejunal tubes are required in patients with gastroparesis. Tube blockage is common and is prevented by careful and regular flushing. Diarrhoea is the most complication of feeding and is often related to other medication. Clinicians need an algorithm for systematically dealing with such a problem. Refeeding syndrome may occur in malnourished patients and is characterised by low levels of potassium, phosphate, and/or magnesium, as well as disorders of water and salt balance. Identifying the at-risk patient with careful monitoring is crucial.

  11. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  12. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... National Eye Institute’s mission is to “conduct and support research, training, health information dissemination, and other programs ... search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI ...

  13. 27 CFR 40.352 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette tubes...

  14. Drug administration via nasogastric tube.

    Science.gov (United States)

    Clarke, Sonya

    2008-09-01

    In 2005, the National Patient Safety Agency (NPSA) highlighted concerns about the management of nasogastric tubes following reports of unnecessary deaths because of misplaced feeding tubes in infants, children and adults. During 2006, I investigated the management of nasogastric tubes (NGTs) in children (Clarke and Richardson 2007a, 2007b). This systematic review divided primary papers into three principal themes: enteral feeding via the NGT; confirmation of NGT position and associated incidence of tube placement error; and hydration via the NGT for acute gastroenteritis in children. Findings of the review are summarised here in relation to using the nasogastric tube to administer medication to children with the aim of informing practice and improving safety.

  15. Estimating probable flaw distributions in PWR steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Gorman, J.A.; Turner, A.P.L. [Dominion Engineering, Inc., McLean, VA (United States)

    1997-02-01

    This paper describes methods for estimating the number and size distributions of flaws of various types in PWR steam generator tubes. These estimates are needed when calculating the probable primary to secondary leakage through steam generator tubes under postulated accidents such as severe core accidents and steam line breaks. The paper describes methods for two types of predictions: (1) the numbers of tubes with detectable flaws of various types as a function of time, and (2) the distributions in size of these flaws. Results are provided for hypothetical severely affected, moderately affected and lightly affected units. Discussion is provided regarding uncertainties and assumptions in the data and analyses.

  16. Electronic structures of peanut-shaped fullerene tubes

    Directory of Open Access Journals (Sweden)

    Hiroyuki Nakayama, Tomoya Ono, Hidekazu Goto and Kikuji Hirose

    2007-01-01

    Full Text Available We have investigated electronic structures of the peanut-shaped polymerized fullerene with so-called P55, P56 and P66 tubular linkage structures. The stable atomic configurations in these one-dimensional or two-dimensionally bundled tubes are searched out by a tight-binding calculation, and then their electronic structures are evaluated by using an ab initio density functional calculation. The electronic structures change drastically depending on the bonding interaction between the tubes. The P66 tube can show metallic conduction when it is bundled two-dimensionally.

  17. A shock tube facility to generate blast loading on structures

    OpenAIRE

    Aune, Vegard; Fagerholt, Egil; Langseth, Magnus; Børvik, Tore

    2016-01-01

    This study evaluates the performance of a new shock tube facility used to produce blast loading in controlled laboratory environments. The facility was found to generate a planar shock wave over the tube cross section by measuring the pressure distribution on a massive steel plate located at the end of the tube. The properties of the shock wave proved to be a function of driver length and driver pressure, and the positive phase of the measured pressure–time histories was similar to those gene...

  18. Electronic versus traditional chest tube drainage following lobectomy

    DEFF Research Database (Denmark)

    Lijkendijk, Marike; Licht, Peter B; Neckelmann, Kirsten

    2015-01-01

    was delegated to staff nurses. Data were analysed by Cox proportional hazard regression model adjusting for lung function, gender, age, BMI, video-assisted thoracic surgery (VATS) or open surgery and presence of incomplete fissure or pleural adhesions. Time was distinguished as possible (optimal) and actual.......014). CONCLUSIONS: Electronic drainage systems did not reduce chest tube duration or length of hospitalization significantly compared with traditional water seal drainage when a strict algorithm for chest tube removal was used. This algorithm allowed delegation of chest tube removal to staff nurses, and in some...

  19. EPR UNIFORM FIELD SIGNAL ENHANCEMENT BY DIELECTRIC TUBES IN CAVITIES.

    Science.gov (United States)

    Hyde, James S; Mett, Richard R

    2017-12-01

    The dielectric tube resonator (DTR) for EPR spectroscopy is introduced. It is defined as a metallic cylindrical TE011 microwave cavity that contains a dielectric tube centered on the axis of the cylinder. Contour plots of dimensions of the metallic cylinder to achieve resonance at 9.5 GHz are shown for quartz, sapphire, and rutile tubes as a function of wall thickness and average radius. These contour plots were developed using analytical equations and confirmed by finite element modeling. They can be used in two ways: design of the metallic cylinder for use at 9.5 GHz that incorporates a readily available tube such as a sapphire tube intended for NMR, or design of a custom procured tube for optimized performance for specific sample-size constraints. The charts extend to the limiting condition where the dielectric fills the tube. However, the structure at this limit is not a dielectric resonator due to the metal wall and does not radiate. In addition, the uniform field (UF) DTR is introduced. Development of the UF resonator starting with a dielectric tube resonator is shown. The diameter of the tube remains constant along the cavity axis, and the diameter of the cylindrical metallic enclosure increases at the ends of the cavity to satisfy the uniform field condition. This structure has advantages over the previously developed UF TE011 resonators: higher resonator efficiency parameter Λ, convenient overall size when using sapphire tubes, and higher quality data for small samples. The DTR and UF DTR structures fill the gap between free space and dielectric resonator limits in a continuous manner.

  20. Eddy current signal comparison for tube identification

    Science.gov (United States)

    Glass, S. W.; Vojvodic, R.

    2015-03-01

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  1. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  2. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)

    2016-06-07

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  3. Endoscopic placement of enteral feeding tubes.

    Science.gov (United States)

    Rafferty, Gerard P; Tham, Tony Ck

    2010-05-16

    Malnutrition is common in patients with acute and chronic illness. Nutritional management of these malnourished patients is an essential part of healthcare. Enteral feeding is one component of nutritional support. It is the preferred method of nutritional support in patients that are not receiving adequate oral nutrition and have a functioning gastrointestinal tract (GIT). This method of nutritional support has undergone progression over recent times. The method of placement of enteral feeding tubes has evolved due to development of new feeding tubes and endoscopic technology. Enteral feeding can be divided into methods that provide short-term and long-term access to the GIT. This review article focuses on the current range of methods of gaining access to the GIT to provide enteral feed.

  4. Clean Industrial Room for Drift Tube Assembling

    CERN Document Server

    Glonti, GL; Evtoukhovitch, P G; Kroa, G; Manz, A; Potrap, I N; Rihter, P; Stoletov, G D; Tskhadadze, E G; Chepurnov, V F; Chirkov, A V; Shelkov, G A

    2001-01-01

    Description of a clean industrial room for assembly of drift tubes for the muon spectrometer of the ATLAS experiment is presented. High quality specifications on the detectors to be produced demanded creation of a workplace with stable temperature and humidity, as well as minimum quantity of dust in the room. Checking of parameters of intra-room air during long period of continuous work has been confirmed correctness of the designed characteristics of the climatic system installed in the clean room. The room large volum (\\sim 190 m^3), the powerful and flexible climatic system, and simplicity of service allow assembling of detectors with length up to 5 m. Subsequent checking of functionality of the assembled detectors has shown high quality of assembling (the amount of rejected tubes does not exceed 2 %). It demonstrates conformity to the assembling quality requirements for mass production of drift chambers for the muon spectrometer.

  5. Plugging criteria for WWER SG tubes

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L.; Wilam, M. [Vitkovice NPP Services (Switzerland); Herman, M. [Vuje, Trnava (Slovakia)

    1997-12-31

    At operated Czech and Slovak nuclear power plants the 80 % criteria for crack or other bulk defect depth is used for steam generator heat exchanging tubes plugging. This criteria was accepted as the recommendation of designer of WWER steam generators. Verification of this criteria was the objective of experimental program performed by Vitkovice, J.S.C., UJV Rez, J.S.C. and Vuje Trnava, J.S.C .. Within this program the following factors were studied: (1) Influence of secondary water chemistry on defects initiation and propagation, (2) Statistical evaluation of corrosion defects progression at operated SG, and (3) Determination of critical pressure for tube rupture as a function of eddy current indications. In this presentation items (2) and (3) are considered.

  6. Method of making straight fuel cell tubes

    Science.gov (United States)

    Borglum, Brian P.

    2001-01-01

    A method and an apparatus for making straight fuel cell tubes are disclosed. Extruded tubes comprising powders of fuel cell material and a solvent are dried by rotating the extruded tubes. The rotation process provides uniform circumferential drying which results in uniform linear shrinkage of the tubes. The resultant dried tubes are very straight, thereby eliminating subsequent straightening steps required with conventional processes. The method is particularly useful for forming inner air electrode tubes of solid oxide fuel cells.

  7. Tube Formation in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Yan Chenglin

    2008-01-01

    Full Text Available Abstract The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

  8. Steam generator tubing NDE performance

    Energy Technology Data Exchange (ETDEWEB)

    Henry, G. [Electric Power Research Institute, Charlotte, NC (United States); Welty, C.S. Jr. [Electric Power Research Institute, Palo Alto, CA (United States)

    1997-02-01

    Steam generator (SG) non-destructive examination (NDE) is a fundamental element in the broader SG in-service inspection (ISI) process, a cornerstone in the management of PWR steam generators. Based on objective performance measures (tube leak forced outages and SG-related capacity factor loss), ISI performance has shown a continually improving trend over the years. Performance of the NDE element is a function of the fundamental capability of the technique, and the ability of the analysis portion of the process in field implementation of the technique. The technology continues to improve in several areas, e.g. system sensitivity, data collection rates, probe/coil design, and data analysis software. With these improvements comes the attendant requirement for qualification of the technique on the damage form(s) to which it will be applied, and for training and qualification of the data analysis element of the ISI process on the field implementation of the technique. The introduction of data transfer via fiber optic line allows for remote data acquisition and analysis, thus improving the efficiency of analysis for a limited pool of data analysts. This paper provides an overview of the current status of SG NDE, and identifies several important issues to be addressed.

  9. PEG tubes: dealing with complications.

    Science.gov (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.

  10. Glass Tube Design for CRT(Cathode Ray Tube)

    OpenAIRE

    Junko, ITOH; Keizo, KISHIDA; Koji, NAKAMURA; Masayuki, Miyazaki; Shigeo, OHSUGI; Sumio, YOSHIOKA; Department of Precision Science & Technology, Osaka University; Mitsubishi Elec.Corp.

    2000-01-01

    Stress and deformation of cathode ray tubes(CRTs)under atmospheric pressure and implosion protection band tightening were analyzed using a finite element method(FEM). The stress and deformation of the tubes were measured experimentally by using strain gages and three-dimensional position measuring techniques. The experimental results showed close agreements with those of the simulation. The location of the highest tensile stress and the effects of tightening of the implosion protection bands ...

  11. Magnetic flux tubes as sources of wave generation

    Science.gov (United States)

    Musielak, Z. E.; Rosner, R.; Ulmschneider, P.

    1987-01-01

    The structure of solar, and very likely stellar, surface magnetic fields is highly inhomogeneous: at the photospheric level, the fields are locally strong, and show concentration into a flux tube structure. In this case, the wave energy generated in stellar convection zones may be largely carried away by flux tube waves, which can then become important sources for the heating of the outer atmospheric layers. Such flux tube wave generation may help to explain the UV and X-ray fluxes observed by the IUE and Einstein observatories. The generation of longitudinal tube waves in magnetic flux tubes embedded in an otherwise magnetic field-free, turbulent, and stratified medium was considered. It is shown that compressible tube waves are generated by dipole emission and that the generation efficiency is a strong function of the magnetic field strength. Energy flux calculations are presented for different magnetic flux tubes, and show how the results depend on the magnetic field strength and the characteristics of the convective turbulence.

  12. Advances in Valveless Piezoelectric Pump with Cone-shaped Tubes

    Science.gov (United States)

    Zhang, Jian-Hui; Wang, Ying; Huang, Jun

    2017-07-01

    This paper reviews the development of valveless piezoelectric pump with cone-shaped tube chronologically, which have widely potential application in biomedicine and micro-electro-mechanical systems because of its novel principles and deduces the research direction in the future. Firstly, the history of valveless piezoelectric pumps with cone-shaped tubes is reviewed and these pumps are classified into the following types: single pump with solid structure or plane structure, and combined pump with parallel structure or series structure. Furthermore, the function of each type of cone-shaped tubes and pump structures are analyzed, and new directions of potential expansion of valveless piezoelectric pumps with cone-shaped tubes are summarized and deduced. The historical argument, which is provided by the literatures, that for a valveless piezoelectric pump with cone-shaped tubes, cone angle determines the flow resistance and the flow resistance determines the flow direction. The argument is discussed in the reviewed pumps one by one, and proved to be convincing. Finally, it is deduced that bionics is pivotal in the development of valveless piezoelectric pump with cone-shaped tubes from the perspective of evolution of biological structure. This paper summarizes the current valveless piezoelectric pumps with cone-shaped tubes and points out the future development, which may provide guidance for the research of piezoelectric actuators.

  13. Feasibility of protein-sparing modified fast by tube (ProMoFasT) in obesity treatment: a phase II pilot trial on clinical safety and efficacy (appetite control, body composition, muscular strength, metabolic pattern, pulmonary function test)

    OpenAIRE

    Sukkar, S. G.; Signori, A.; Borrini, C.; Barisione, G.; Ivaldi, C.; Romeo, C; Gradaschi, R.; Machello, N.; Nanetti, E.; Vaccaro, A. L.

    2013-01-01

    Anecdotal data in the last few years suggest that protein-sparing modified diet (PSMF) delivered by naso-gastric tube enteral (with continuous feeding) could attain an significant weight loss and control of appetite oral feeding, but no phase II studies on safety and efficacy have been done up to now. To verify the safety and efficacy of a protein-sparing modified fast administered by naso-gastric tube (ProMoFasT) for 10?days followed by 20?days of a low-calorie diet, in patients with morbid ...

  14. Microtubules, polarity and vertebrate neural tube morphogenesis.

    Science.gov (United States)

    Cearns, Michael D; Escuin, Sarah; Alexandre, Paula; Greene, Nicholas D E; Copp, Andrew J

    2016-07-01

    Microtubules (MTs) are key cellular components, long known to participate in morphogenetic events that shape the developing embryo. However, the links between the cellular functions of MTs, their effects on cell shape and polarity, and their role in large-scale morphogenesis remain poorly understood. Here, these relationships were examined with respect to two strategies for generating the vertebrate neural tube: bending and closure of the mammalian neural plate; and cavitation of the teleost neural rod. The latter process has been compared with 'secondary' neurulation that generates the caudal spinal cord in mammals. MTs align along the apico-basal axis of the mammalian neuroepithelium early in neural tube closure, participating functionally in interkinetic nuclear migration, which indirectly impacts on cell shape. Whether MTs play other functional roles in mammalian neurulation remains unclear. In the zebrafish, MTs are important for defining the neural rod midline prior to its cavitation, both by localizing apical proteins at the tissue midline and by orienting cell division through a mirror-symmetric MT apparatus that helps to further define the medial localization of apical polarity proteins. Par proteins have been implicated in centrosome positioning in neuroepithelia as well as in the control of polarized morphogenetic movements in the neural rod. Understanding of MT functions during early nervous system development has so far been limited, partly by techniques that fail to distinguish 'cause' from 'effect'. Future developments will likely rely on novel ways to selectively impair MT function in order to investigate the roles they play. © 2016 Anatomical Society.

  15. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Grants and Funding Extramural Research Division of Extramural Science Programs Division of Extramural Activities Extramural Contacts NEI ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded ...

  16. Epidemiology of neural tube defects

    National Research Council Canada - National Science Library

    Seidahmed, Mohammed Z; Abdelbasit, Omar B; Shaheed, Meeralebbae M; Alhussein, Khalid A; Miqdad, Abeer M; Khalil, Mohamed I; Al-Enazy, Naif M; Salih, Mustafa A

    2014-01-01

    To find the prevalence of neural tube defects (NTDs), and compare the findings with local and international data, and highlight the important role of folic acid supplementation and flour fortification with folic acid in preventing NTDs...

  17. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Intern Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > ...

  18. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... questions Clinical Studies Publications Catalog Photos and Images Spanish Language Information Grants and Funding Extramural Research Division ... Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video ...

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... and Aging Program African American Program Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision ... DIVRO) Student Training Programs To search for current job openings visit HHS USAJobs Home > NEI YouTube Videos > ...

  20. Examination of gavage tube placement in children.

    Science.gov (United States)

    Ellett, M L; Beckstrand, J

    1999-01-01

    A primary issue in ensuring safe and effective enteral feeding by tube is achieving and maintaining correct tube position. This study was conducted to determine the prevalence of tube placement errors, risk factors associated with these errors, and accuracy of commonly used bedside placement-screening methods. In this descriptive study, 39 hospitalized children having one or more types of enteral tubes were studied prospectively. Tube placement was assessed across time, using three common placement-screening methods compared to radiographs. Tube placement error occurred in 43.5% of tubes at least once during the observation period. Children who were comatose or semicomatose, were inactive, had swallowing problems, or had Argyle tubes were more likely to have tube placement errors. Findings suggest that radiographs to document tube placement may be needed, at least on initial enteral tube insertion.

  1. Dermatology on YouTube.

    Science.gov (United States)

    Boyers, Lindsay N; Quest, Tyler; Karimkhani, Chante; Connett, Jessica; Dellavalle, Robert P

    2014-06-15

    YouTube, reaches upwards of six billion users on a monthly basis and is a unique source of information distribution and communication. Although the influence of YouTube on personal health decision-making is well established, this study assessed the type of content and viewership on a broad scope of dermatology related content on YouTube. Select terms (i.e. dermatology, sun protection, skin cancer, skin cancer awareness, and skin conditions) were searched on YouTube. Overall, the results included 100 videos with over 47 million viewers. Advocacy was the most prevalent content type at 24% of the total search results. These 100 videos were "shared" a total of 101,173 times and have driven 6,325 subscriptions to distinct YouTube user pages. Of the total videos, 35% were uploaded by or featured an MD/DO/PhD in dermatology or other specialty/field, 2% FNP/PA, 1% RN, and 62% other. As one of the most trafficked global sites on the Internet, YouTube is a valuable resource for dermatologists, physicians in other specialties, and the general public to share their dermatology-related content and gain subscribers. However, challenges of accessing and determining evidence-based data remain an issue.

  2. Claudins in morphogenesis: Forming an epithelial tube.

    Science.gov (United States)

    Baumholtz, Amanda I; Gupta, Indra R; Ryan, Aimee K

    2017-10-02

    The claudin family of tetraspan transmembrane proteins is essential for tight junction formation and regulation of paracellular transport between epithelial cells. Claudins also play a role in apical-basal cell polarity, cell adhesion and link the tight junction to the actin cytoskeleton to exert effects on cell shape. The function of claudins in paracellular transport has been extensively studied through loss-of-function and gain-of-function studies in cell lines and in animal models, however, their role in morphogenesis has been less appreciated. In this review, we will highlight the importance of claudins during morphogenesis by specifically focusing on their critical functions in generating epithelial tubes, lumens, and tubular networks during organ formation.

  3. ATLAS muon drift tube production in Seattle

    CERN Document Server

    Zhao, T; Kuykendall, W; Davisson, R

    2004-01-01

    The drift tube production facility that we developed for producing precision drift tubes of the ATLAS forward muon system in our laboratory is described in this paper. The results of quality assurance for approximately 30,000 tube produced are given. Our experience shows that this production facility is very efficient and the quality of produced drift tubes is very high. (2 refs).

  4. 27 CFR 41.35 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 41.35... OF THE TREASURY (CONTINUED) TOBACCO IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Taxes Tax Rates § 41.35 Cigarette tubes. Cigarette tubes are taxed at the following rates...

  5. 21 CFR 872.6570 - Impression tube.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6570 Impression tube. (a) Identification. An impression tube is a device consisting of a hollow copper tube intended to take an impression of a single tooth... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Impression tube. 872.6570 Section 872.6570 Food...

  6. The local clinical validation of a new lithium heparin tube with a barrier: BD Vacutainer® Barricor LH Plasma tube.

    Science.gov (United States)

    Arslan, Fatma Demet; Karakoyun, Inanc; Basok, Banu Isbilen; Aksit, Merve Zeytinli; Baysoy, Anil; Ozturk, Yasemin Kilic; Guclu, Yusuf Adnan; Duman, Can

    2017-10-15

    Although serum-providing blood tubes with a barrier are still widely used due to their significant advantages, the use of blood tubes with a barrier to provide plasma is becoming widespread. We compared 22 analytes in a BD Vacutainer® Barricor LH Plasma tube for local clinical validation of this new lithium heparin tube with a barrier. Samples from 44 volunteers were collected in different tubes (Becton Dickinson and Company): Z tube without additive (reference), clot-activator tube with gel (SST), lithium heparin tube without gel (LiH), and lithium heparin tube with barrier (Barricor). Analyte concentrations in different tubes were compared with the reference tube. All tubes were also evaluated according to additional testing (different centrifugation durations, blood-sampling techniques and individual differences). Aspartate aminotransferase (AST), glucose (Glc), potassium (K), lactate dehydrogenase (LD), sodium (Na), and total protein (TP) had a significant bias in Barricor (9.19%, - 3.24%, - 4.88%, 21.60%, - 0.40%, 5.03%, respectively) relative to the reference tube. There was no statistical difference between different centrifugation durations and individual differences for AST, K and LD in LiH and/or Barricor (P > 0.05). There was a significant bias for LD between LiH and Barricor in terms of blood-sampling techniques (21.2% and 12.4%, respectively). Recently, the use of plasma has become prominent due to some of its advantages. In this study, plasma AST, K, LD, Glc and TP levels in Barricor were clinically different in comparison to serum. The results of additional tests showed that higher levels of LD in Barricor did not result from haemolysis, and they might be related to other factors including number of platelets, cellular fragility, or functional environment.

  7. Knot formation in the feeding jejunostomy tube: A case report and review of the literature

    Science.gov (United States)

    Liao, Guo-Shiou; Hsieh, Huan-Fa; Wu, Meng-Hang; Chen, Teng-Wei; Yu, Jyh-Cherng; Liu, Yao-Chi

    2007-01-01

    Jejunostomy feeding tubes provide surgeons with an excellent method for providing nutritional support, but there are several complications associated with a tube jejunostomy, including complications resulting from placement of the tube, mechanical problems related to the location or function and development of focally thickened small-bowel folds. A 76-year old man who presented with multiple medical diseases was admitted to our hospital due to aspiration pneumonia with acute respiratory failure and septic shock. He underwent exploratory laparotomy with feeding jejunostomy using a 14-French nasogastric tube for nutritional support. However, occlusion of the feeding tube was found 30 d after operation, and a rare complication of knot formation in the tube occurred after a new tube was replaced. On the following day, the tube was removed and replaced with a similar tube, which was placed into the jejunum for only 15 cm. The patient’s feedings were maintained smoothly for two months. Knot formation in the feeding tube seems to be very rare. To our knowledge, this is the third case in the literature review. Its incidence is probably related to the length of the tube inserted into the lumen. PMID:17352035

  8. Physics of magnetic flux tubes

    CERN Document Server

    Ryutova, Margarita

    2015-01-01

    This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and  ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magn...

  9. Propagation of sound waves in tubes of noncircular cross section

    Science.gov (United States)

    Richards, W. B.

    1986-01-01

    Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

  10. Tubing and cable cutting tool

    Science.gov (United States)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)

    1984-01-01

    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  11. On hydraulics of capillary tubes

    Directory of Open Access Journals (Sweden)

    N.G. Aloyan

    2016-03-01

    Full Text Available The article considers the laws of motion of water in the capillary tubes, taken as a model for flowing well, on the analogical net count device. For capillary tube the lower limit value of flow rate is empirically determined above which the total hydraulic resistance of the capillary is practically constant. The specificity of the phenomenon is that the regime of motion, by a Reynolds number, for a given flow rate still remains laminar. This circumstance can perplex the specialists, so the author invites them to the scientific debate on the subject of study. Obviously, to identify the resulting puzzle it is necessary to conduct a series of experiments using capillaries of different lengths and diameters and with different values of overpressure. The article states that in tubes with very small diameter the preliminary magnitude of capillary rise of water in the presence of flow plays no role and can be neglected.

  12. Drift tubes of Linac 2

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

  13. The pollen tube paradigm revisited.

    Science.gov (United States)

    Kroeger, Jens; Geitmann, Anja

    2012-12-01

    The polar growth process characterizing pollen tube elongation has attracted numerous modeling attempts over the past years. While initial models focused on recreating the correct cellular geometry, recent models are increasingly based on experimentally assessed cellular parameters such as the dynamics of signaling processes and the mechanical properties of the cell wall. Recent modeling attempts have therefore substantially gained in biological relevance and predictive power. Different modeling methods are explained and the power and limitations of individual models are compared. Focus is on several recent models that use closed feedback loops in order to generate limit cycles representing the oscillatory behavior observed in growing tubes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. YouTube and Facebook

    DEFF Research Database (Denmark)

    Robertson, Scott P.; Vatrapu, Ravi; Medina, Richard

    This paper examines the links to YouTube from the Facebook “walls” of Barack Obama, Hillary Clinton, and John McCain over two years prior to the 2008 U.S. Presidential election. User-generated linkage patterns show how participants in these politically-related social networking dialogues used...... online video to make their points. We show a strong integration of the Web 2.0 and new media technologies of social networking and online video. We argue that political discussion in social networking environments can no longer be viewed as primarily textual, and that neither Facebook nor YouTube can...

  15. Working session 3: Tubing integrity

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain); Strosnider, J. [NRC, Washington, DC (United States)

    1997-02-01

    Twenty-three individuals representing nine countries (Belgium, Canada, the Czech Republic, France, Japan, the Slovak Republic, Spain, the UK, and the US) participated in the session on tube integrity. These individuals represented utilities, vendors, consultants and regulatory authorities. The major subjects discussed by the group included overall objectives of managing steam generator tube degradation, necessary elements of a steam generator degradation management program, the concept of degradation specific management, structural integrity evaluations, leakage evaluations, and specific degradation mechanisms. The group`s discussions on these subjects, including conclusions and recommendations, are summarized in this article.

  16. Orifice plates and venturi tubes

    CERN Document Server

    Reader-Harris, Michael

    2015-01-01

    This book gives the background to differential-pressure flow measurement and goes through the requirements explaining the reason for them. For those who want to use an orifice plate or a Venturi tube the standard ISO 5167 and its associated Technical Reports give the instructions required.  However, they rarely tell the users why they should follow certain instructions.  This book helps users of the ISO standards for orifice plates and Venturi tubes to understand the reasons why the standards are as they are, to apply them effectively, and to understand the consequences of deviations from the standards.

  17. Development of new nerve guide tube for repair of long nerve defects.

    Science.gov (United States)

    Ichihara, Satoshi; Inada, Yuji; Nakada, Akira; Endo, Katsuaki; Azuma, Takashi; Nakai, Ryusuke; Tsutsumi, Sadami; Kurosawa, Hisashi; Nakamura, Tatsuo

    2009-09-01

    A novel nerve guide tube (poly (L-lactic) acid (PLLA)/ polyglycolic acid (PGA)-c-tube) capable of repairing long peripheral nerve injuries in a canine model has been developed. The tube was created by braiding together PLLA and PGA and then coating it with collagen. PLLA was newly added to the formulation to achieve higher sustainability. The tube was compared with a PGA-collagen tube in clinical use since 2002 having the same structure with a collagen coating but composed of PGA alone (PGA-c-tube). When tested for repair of a 40-mm gap in the left peroneal nerve, using PLLA/PGA-c-tube (n = 15), PGA-c-tube (n = 15), and a negative control group where the cut stump was capped using a silicone cap (n = 15), the lumen structure essential for securing the space for nerve regeneration was maintained in PLLA/PGA-c-tube for over 12 months with a higher number of axons both within the tube and at the distal nerve end. Electrophysiological evaluation revealed that the amplitude of compound muscle action potentials and sensory nerve action potentials after nerve regeneration with PLLA/PGA-c-tube were significantly higher. When assessed using magnetic resonance imaging (MRI), the volume of the tibialis anterior (TA) muscle in dogs that had undergone nerve repair using PLLA/PGA-c-tube was approximately 80% that of the positive control at 12 months. Functional analysis conducted by assessing the ankle angle revealed faster recovery in the PLLA/PGA-c-tube group. Better regeneration was achieved using a PLLA/PGA-c-tube that contains the slowly decomposing fiber material, PLLA. This indicates potential for repair of even longer nerve gaps or defects located near joints, and also clinical application.

  18. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...... pump as mentioned above, thereby acting to generate a fluid flow through the tube upon repeated deformation of the tube between the two valve members. The pump element may comprise a connecting part for coupling to another tube and may comprise a sealing part establishing a fluid tight connection...

  19. Rechargeable biofilm-controlling tubing materials for use in dental unit water lines.

    Science.gov (United States)

    Luo, Jie; Porteous, Nuala; Sun, Yuyu

    2011-08-01

    A simple and practical surface grafting approach was developed to introduce rechargeable N-halamine-based antimicrobial functionality onto the inner surfaces of continuous small-bore polyurethane (PU) dental unit waterline (DUWL) tubing. In this approach, tetrahydrofuran (THF) solution of a free-radical initiator, dicumyl peroxide (DCP), flowed through the PU tubing (inner diameter of 1/16 in., or 1.6 mm) to diffuse DCP into the tubing's inner walls, which was used as initiator in the subsequent grafting polymerization of methacrylamide (MAA) onto the tubing. Upon chlorine bleach treatment, the amide groups of the grafted MAA side chains were transformed into acyclic N-halamines. The reactions were confirmed with attenuated total reflectance infrared (ATR) spectra and iodometric titration. The mechanical properties of the tubing were not significantly affected by the grafting reactions. The biofilm-controlling function of the new N-halamine-based PU tubing was evaluated with Pseudomonas aeruginosa (P. aeruginosa), one of the most isolated water bacteria from DUWLs, in a continuous bacterial flow model. Bacteria culturing and SEM studies showed that the inner surfaces of the new N-halamine-based PU tubing completely prevented bacterial biofilm formation for at least three to four weeks. After that, bacteria began to colonize the tubing surface. However, the lost function was fully regenerated by exposing the tubing inner surfaces to diluted chlorine bleach. The recharging process could be repeated periodically to further extend the biofilm-controlling duration for long-term applications.

  20. The pulsed-gas tube, statement and perspectives; Le tube a gaz pulse, bilan et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Domblides, J.P.; Neveau, P.; Castaing-Lasvignottes, J. [Laboratoire du froid du CNAM, 75 - Paris (France)

    1997-12-31

    The pulsed-gas tube has several advantages with respect to the other types of cryo-refrigerating machineries classically used to reach very low temperatures: no mobile parts moving at very low temperatures and no vibrations. However, this system discovered in 1963 is handicapped by its lack of power and by its low energy efficiency. Todays researches about pulsed-gas tubes concern: the technical adaptation of existing systems to applications where its simplicity makes it competitive, the improvement of its energetic performances (refrigerating power and range of temperatures of use), and the development of numerical models in order to better understand the functioning of the system and to optimize it. (J.S.) 19 refs.

  1. Casimir effect in hemisphere capped tubes

    CERN Document Server

    de Mello, E R Bezerra

    2014-01-01

    In this paper we investigate the vacuum densities for a massive scalar field with general curvature coupling in background of a (2+1)-dimensional spacetime corresponding to a cylindrical tube with a hemispherical cap. A complete set of mode functions is constructed and the positive-frequency Wightman function is evaluated for both the cylindrical and hemispherical subspaces. On the base of this, the vacuum expectation values of the field squared and energy-momentum tensor are investigated. The mean field squared and the normal stress are finite on the boundary separating two subspaces, whereas the energy density and the parallel stress diverge as the inverse power of the distance from the boundary. For a conformally coupled field, the vacuum energy density is negative on the cylindrical part of the space. On the hemisphere, it is negative near the top and positive close to the boundary. In the case of minimal coupling the energy density on the cup is negative. On the tube it is positive near the boundary and ...

  2. Thermal inhomogeneities in vortex tubes

    Science.gov (United States)

    Lemesh, N. I.; Senchuk, L. A.

    An experimental study of the effect of the temperature of the inlet gas on the temperature difference between the hot and cold streams discharged from a Ranque-Hilsch vortex tube is described. The experimental results are presented in graphical form. It is that the temperature difference increases with the temperature of the entering gas.

  3. Working session 1: Tubing degradation

    Energy Technology Data Exchange (ETDEWEB)

    Kharshafdjian, G. [Atomic Energy of Canada, Mississauga, Ontario (Canada); Turluer, G. [IPSN, Fontenay-aux-Roses (France)

    1997-02-01

    A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to {open_quotes}develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.{close_quotes} Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym {open_quotes}MESS{close_quotes} by some of the group members, were noted. The element of time (i.e., evolution of these variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed.

  4. Kundt's Tube Experiment Using Smartphones

    Science.gov (United States)

    Parolin, Sara Orsola; Pezzi, Giovanni

    2015-01-01

    This article deals with a modern version of Kundt's tube experiment. Using economic instruments and a couple of smartphones, it is possible to "see" nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  5. Vitamins and neural tube defects

    OpenAIRE

    Harris, Rodney

    1988-01-01

    The use of vitamin supplements by women around the time of conception was examined and compared in those having babies with neural tube defects, those with still births or some other type of malformation, and in women who had normal babies.

  6. OurTube / David Talbot

    Index Scriptorium Estoniae

    Talbot, David

    2009-01-01

    USA California Ülikooli töötajate Abram Stern'i ja Michael Dale'i poolt 2005. a. algatatud USA kongressis peetud kõnede videoremiksidest ja nende poolt loodud veebisaidist Metavid.org. Ka YouTube keskkonnast ja wikipedia katsetustest muuta oma keskkond multimeedialisemaks

  7. Tube Suction Test for Evaluating

    Science.gov (United States)

    2012-06-01

    In a comprehensive laboratory study, different tests namely, unconfined compressive strength (UCS) at the end of freeze-thaw/wet-dry (F-T/W-D) cycles, resilient modulus (Mr) at the end of F-T/W-D cycles, vacuum saturation, tube suction, and moisture ...

  8. Building your own shock tube

    NARCIS (Netherlands)

    J. Naber (Jorick)

    2005-01-01

    textabstractThis report treats the development of a shock tube solver for the simulation of flows described by the one-dimensional Euler equations. A well-known one-dimensional flow problem is the initial Riemann problem, which treats the development of a flow due to two initially separated

  9. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    3.6 km of welds were required for the 1 km long CERN Neutrinos to Gran Sasso (CNGS) decay tube, in which particles produced in the collision with a proton and a graphite target will decay into muons and muon neutrinos. Four highly skilled welders performed this delicate task.

  10. A new repair criterion for steam generator tubes with axial cracks based on probabilistic integrity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun-Su; Oh, Chang-Kyun [KEPCO Engineering and Construction Company, Inc., 269, Hyeoksin-ro, Gimcheon, Gyeongsangbuk-do 39660 (Korea, Republic of); Chang, Yoon-Suk, E-mail: yschang@khu.ac.kr [Department of Nuclear Engineering, College of Engineering, Kyung Hee University, 1732 Deokyoungdaero, Giheung, Yongin, Gyeonggi 446-701 (Korea, Republic of)

    2017-03-15

    Highlights: • Probabilistic assessment was performed for axially cracked steam generator tubes. • The threshold crack sizes were determined based on burst pressures of the tubes. • A new repair criterion was suggested as a function of operation time. - Abstract: Steam generator is one of the major components in a nuclear power plant, and it consists of thousands of thin-walled tubes. The operating record of the steam generators has indicated that a number of axial cracks due to stress corrosion have been frequently detected in the tubes. Since the tubes are closely related to the safety and also the efficiency of a nuclear power plant, an establishment of the appropriate repair criterion for the defected tubes and its applications are necessary. The objective of this paper is to develop an accurate repair criterion for the tubes with axial cracks. To do this, a thorough review is performed on the key parameters affecting the tube integrity, and then the probabilistic integrity assessment is carried out by considering the various uncertainties. In addition, the sizes of critical crack are determined by comparing the burst pressure of the cracked tube with the required performance criterion. Based on this result, the new repair criterion for the axially cracked tubes is defined from the reasonably conservative value such that the required performance criterion in terms of the burst pressure is able to be met during the next operating period.

  11. Schizophrenia on YouTube.

    Science.gov (United States)

    Nour, Matthew M; Nour, Murraih H; Tsatalou, Olga-Maria; Barrera, Alvaro

    2017-01-01

    YouTube ( www.youtube.com ) is the most popular video-sharing Web site on the Internet and is used by medical students as a source of information regarding mental health conditions, including schizophrenia. The accuracy and educational utility of schizophrenia presentations on YouTube are unknown. The purpose of this study was to analyze the accuracy of depictions of psychosis in the context of a diagnosis of schizophrenia (referred to in this article as "acute schizophrenia") on YouTube and to assess the utility of these videos as educational tools for teaching medical students to recognize the clinical features of acute schizophrenia. YouTube was searched for videos purporting to show acute schizophrenia. Eligible videos were independently rated by two consultant psychiatrists on two separate occasions 22 days apart for diagnostic accuracy, psychopathology, and educational utility. Videos (N=4,200) were assessed against predefined inclusion and exclusion criteria. The majority were not eligible for further analysis, mostly because they did not claim to show a patient with schizophrenia (74%) or contained duplicated content (11%). Of 35 videos that met the eligibility and adequacy criteria, only 12 accurately depicted acute schizophrenia. Accurate videos were characterized by persecutory delusions (83%), inappropriate affect (75%), and negative symptoms (83%). Despite the fact that 83% of accurate videos were deemed to have good educational utility compared with 15% of inaccurate videos, accurate and inaccurate videos had similar view counts (290,048 versus 186,124). Schizophrenia presentations on YouTube offer a distorted picture of the condition.

  12. A case of a 'lost' nasogastric tube.

    Science.gov (United States)

    Sankar, V; Shakeel, M; Keh, S; Ah-See, K W

    2012-12-01

    To present the case of a 'lost' nasogastric tube and to highlight the importance of imaging and/or chest X-ray after nasogastric tube insertion, especially in unreliable patients. A 50-year-old man, undergoing radiotherapy treatment for squamous cell carcinoma of the tongue base, was admitted for pain control and nasogastric tube feeding. This patient required multiple nasogastric tubes over a two-week period. The patient repeatedly denied pulling the nasogastric tube out and we were unable to establish the exact mode of nasogastric tube removal. On one such occasion another tube was inserted and a check X-ray showed two feeding tubes; the latest one was lying in the left main bronchus and the old nasogastric tube was observed in the oesophagus, with its upper end jutting above the hypopharynx. It was apparent that the patient had somehow cut the tube and swallowed it. This case not only illustrates the importance of flexible nasendoscopy and/or chest X-ray for checking the position of the nasogastric tube, but also highlights that some patients are not tolerant of nasogastric tubes. The use of nasogastric tubes should be avoided in these patients to prevent any self-inflicted injury.

  13. Operating a Geiger-Muller Tube Using a PC Sound Card

    Science.gov (United States)

    Azooz, A. A.

    2009-01-01

    In this paper, a simple MATLAB-based PC program that enables the computer to function as a replacement for the electronic scalar-counter system associated with a Geiger-Muller (GM) tube is described. The program utilizes the ability of MATLAB to acquire data directly from the computer sound card. The signal from the GM tube is applied to the…

  14. Small bore ceramic laser tube inspection light table

    Science.gov (United States)

    Updike, Earl O.

    1990-01-01

    Apparatus for inspecting small bore ceramic laser tubes, which includes a support base with one or more support rollers. A fluorescent light tube is inserted within the laser tube and the laser tube is supported by the support rollers so that a gap is maintained between the laser tube and the fluorescent tube to enable rotation of the laser tube. In operation, the ceramic tube is illuminated from the inside by the fluorescent tube to facilitate visual inspection. Centering the tube around the axial light of the fluorescent tube provides information about straightness and wall thickness of the laser tube itself.

  15. The accessory fallopian tube: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Kusum R Gandhi

    2012-01-01

    Full Text Available This paper presents a rare anatomical variation in the form of accessory fallopian tube on right side. The duplication of fallopian tube was observed in a 34-year-old female during routine undergraduate dissection in our department. Fallopian tube is the part of uterus that carries the ovum from the ovary to the uterus. Accessory fallopian tube is the congenital anomaly attached to the ampullary part of main tube. This accessory tube is common site of pyosalpinx, hydrosalpinx, cystic swelling and torsion. The ovum released by the ovary may also be captured by the blind accessory tube leading to infertility or ectopic pregnancy. Hence, all patients of infertility or pelvic inflammatory disease should be screened to rule out the presence of accessory fallopian tube and if encountered should be removed.

  16. Models for Automated Tube Performance Calculations

    Energy Technology Data Exchange (ETDEWEB)

    C. Brunkhorst

    2002-12-12

    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance.

  17. The efficacy of magnetic field on the thermal behavior of MnFe{sub 2}O{sub 4} nanofluid as a functional fluid through an open-cell metal foam tube

    Energy Technology Data Exchange (ETDEWEB)

    Amani, Mohammad [Mechanical and Energy Engineering Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Ameri, Mohammad, E-mail: ameri_m@yahoo.com [Mechanical and Energy Engineering Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of); Kasaeian, Alibakhsh [Department of Renewable Energies Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran (Iran, Islamic Republic of)

    2017-06-15

    Highlights: • Experiments are performed with MnFe{sub 2}O{sub 4} nanofluid through an open-cell metal foam tube. • Effects of concentration, Reynolds number and magnetic field on the nanofluid thermal behavior are examined. • Heat transfer is enhanced in attendance of constant and alternating magnetic fields. - Abstract: In the present experimental study, the influence of permanent and alternating magnetic fields on the flow and thermal behavior of MnFe{sub 2}O{sub 4} magnetic nanofluid flowing through a circular open-cell metal foam tube is investigated under homogeneous heat flux conditions. The experiments are performed at various nanoparticle concentrations, Reynolds numbers and magnetic fields with different strengths and frequencies. According to the observations, the heat transfer rate enhances directly relative to nanoparticle concentration and Reynolds number in attendance of magnetic field, whereas its maximum value of 16.4% is found for 2 wt% nanoparticles at Re = 200 under alternating field with 400 G strength and 20 Hz frequency. Moreover, it is observed that the influence of strength and frequency of magnetic field is insignificant for the pressure drop. Hydrothermal efficiency as the ratio of the Nusselt number to the ratio of the pressure drop is defined in order to evaluate the privilege of using MnFe{sub 2}O{sub 4} nanofluids in practical applications. The maximum efficiency of 1.25 is observed at 2 wt% under magnetic field with 400 G and 20 Hz at Re = 1000.

  18. Insta-Head: An Instant Headgear Tube

    Directory of Open Access Journals (Sweden)

    Rajesh B Kuril

    2011-01-01

    Full Text Available Specialized headgear tubes are required for fabrication of appliances, such as activator-headgear and twin-block with headgear. The common problems with these tubes are that they need to be purchased beforehand and they are expensive. The present article describes the chairside fabrication of a simple, inexpensive headgear tube (insta-head without the need of any specialized armamentarium.

  19. A Novel Mediastinal Drainage Tube for Mediastinitis

    Directory of Open Access Journals (Sweden)

    Jun Ho Yhang

    2015-10-01

    Full Text Available Mediastinitis is a life-threatening disease, and effective drainage is needed to treat mediastinitis with abscess formation. We recommend an alternative drainage method using chest tube binding with a Silastic Penrose drainage tube. The use of a Silastic Penrose drainage tube may help to manage mediastinitis with abscess formation. This method facilitates effective draining and prevents tissue adhesion.

  20. Studies of Degraded Smelt Spout Opening Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R [ORNL; Kish, Joseph R. [Paprican; Willoughby, Adam W [ORNL; Longmire, Hu Foster [ORNL; Singbeil, Douglas [Paprican

    2007-01-01

    Co-extruded type 304L stainless steel/SA210 carbon steel tubes have been used on the floors and lower walls of many black liquor recovery boilers to address the wall thinning problem that had been an issue for boiler owners and operators. Use of these tubes greatly reduced the corrosion issue, but corrosion was still sometimes observed and cracking was discovered in some tubes, particularly those that are bent to form the openings for smelt spouts. Because cracks in the opening tubes were sometimes observed to extend a significant distance into the tube wall and because these cracks were found fairly frequently, tubes made from a number of alternate cladding materials were tried in place of the 304L clad opening tubes. This paper describes the results of examinations of spout opening tubes of the standard 304L/carbon steel and of several of the alternate materials that have been tried. In addition to the corrosion and cracking seen in the spout opening tubes, another issue associated with these tubes has been observed. Preferential corrosion of the cap welds is sometimes seen on butt welds attaching the spout opening tubes made with alternate cladding materials to the standard 304L/carbon steel co-extruded wall tubes. Some information on the observations of this corrosion is also included in this paper.

  1. Radioactive fallout and neural tube defects

    African Journals Online (AJOL)

    Nejat Akar

    2015-07-10

    Jul 10, 2015 ... Neural tube defects;. Anencephaly;. Spina bifida. Abstract Possible link between radioactivity and the occurrence of neural tube defects is a long lasting debate ... Neural tube defects, are one of the common congenital mal- formations ... ent cities of Turkey (˙Izmir/Aegean Region; Trabzon/Black Sea region ...

  2. Clinical Burden of Laparoscopic Feeding Jejunostomy Tubes.

    Science.gov (United States)

    Speer, Emily A; Chow, Simon C; Dunst, Christy M; Shada, Amber L; Halpin, Valerie; Reavis, Kevin M; Cassera, Maria; Swanström, Lee L

    2016-05-01

    Feeding jejunostomies (J tubes) provide enteral nutrition when oral and gastric routes are not options. Despite their prevalence, there is a paucity of literature regarding their efficacy and clinical burden. All laparoscopic J tubes placed over a 5-year period were retrospectively reviewed. Clinical burden was measured by number of clinical contact events (tube-related clinic visits, phone calls, ED visits) and morbidity (dislodgement, clogging, tube fracture, infection, other). Tube replacements were also recorded. One hundred fifty-one patients were included. Fifty-nine percent had associated malignancy, and 35 % were placed for nutritional prophylaxis. Mean time to J tube removal was 146 days. J tubes were expected to be temporary in >90 % but only 50 % had sufficient oral intake for removal. Tubes were removed prematurely due to patient intolerance in 8 %. Mortality was 0 %. Morbidity was 51 % and included clogging (12 %), tube fracture (16 %), dislodgement (25 %), infection (18 %) and "other" (leaking, erosion, etc.) in 17 %. The median number of adverse events per J tube was 2(0-8). Mean number of clinic phone calls was 2.5(0-22), ED visits 0.5(0-7), and clinic visits 1.4(0-13), with 82 % requiring more than one J tube-related clinic visit. Unplanned replacements occurred in 40 %. While necessary for some patients, J tubes are associated with high clinical burden.

  3. Roll-forming tubes to header plates

    Science.gov (United States)

    Kramer, K.

    1976-01-01

    Technique has been developed for attaching and sealing tubes to header plates using a unique roll-forming tool. Technique is useful for attaching small tubes which are difficult to roll into conventional grooves in header plate tube holes, and for attaching when welding, brazing, or soldering is not desirable.

  4. The Fuge Tube Diode Array Spectrophotometer

    Science.gov (United States)

    Arneson, B. T.; Long, S. R.; Stewart, K. K.; Lagowski, J. J.

    2008-01-01

    We present the details for adapting a diode array UV-vis spectrophotometer to incorporate the use of polypropylene microcentrifuge tubes--fuge tubes--as cuvettes. Optical data are presented validating that the polyethylene fuge tubes are equivalent to the standard square cross section polystyrene or glass cuvettes generally used in…

  5. Kundt's Tube: An Acoustic Gas Analyzer

    Science.gov (United States)

    Aristov, Natasha; Habekost, Gehsa; Habekost, Achim

    2011-01-01

    A Kundt tube is normally used to measure the speed of sound in gases. Therefore, from known speeds of sound, a Kundt tube can be used to identify gases and their fractions in mixtures. In these experiments, the speed of sound is determined by measuring the frequency of a standing sound wave at a fixed tube length, temperature, and pressure. This…

  6. Spring/dimple instrument tube restraint

    Science.gov (United States)

    DeMario, Edmund E.; Lawson, Charles N.

    1993-01-01

    A nuclear fuel assembly for a pressurized water nuclear reactor has a spring and dimple structure formed in a non-radioactive insert tube placed in the top of a sensor receiving instrumentation tube thimble disposed in the fuel assembly and attached at a top nozzle, a bottom nozzle, and intermediate grids. The instrumentation tube thimble is open at the top, where the sensor or its connection extends through the cooling water for coupling to a sensor signal processor. The spring and dimple insert tube is mounted within the instrumentation tube thimble and extends downwardly adjacent the top. The springs and dimples restrain the sensor and its connections against lateral displacement causing impact with the instrumentation tube thimble due to the strong axial flow of cooling water. The instrumentation tube has a stainless steel outer sleeve and a zirconium alloy inner sleeve below the insert tube adjacent the top. The insert tube is relatively non-radioactivated inconel alloy. The opposed springs and dimples are formed on diametrically opposite inner walls of the insert tube, the springs being formed as spaced axial cuts in the insert tube, with a web of the insert tube between the cuts bowed radially inwardly for forming the spring, and the dimples being formed as radially inward protrusions opposed to the springs.

  7. Numerical and experimental study of an annular pulse tube used in the pulse tube cooler

    Science.gov (United States)

    Pang, Xiaomin; Chen, Yanyan; Wang, Xiaotao; Dai, Wei; Luo, Ercang

    2017-12-01

    Multi-stage pulse tube coolers normally use a U-type configuration. For compactness, it is attractive to build a completely co-axial multi-stage pulse tube cooler. In this way, an annular shape pulse tube is inevitable. Although there are a few reports about previous annular pulse tubes, a detailed study and comparison with a circular pulse tube is lacking. In this paper, a numeric model based on CFD software is carried out to compare the annular pulse tube and circular pulse tube used in a single stage in-line type pulse tube cooler with about 10 W of cooling power at 77 K. The length and cross sectional area of the two pulse tubes are kept the same. Simulation results show that the enthalpy flow in the annular pulse tube is lower by 1.6 W (about 11% of the enthalpy flow) compared to that in circular pulse tube. Flow and temperature distribution characteristics are also analyzed in detail. Experiments are then conducted for comparison with an in-line type pulse tube cooler. With the same acoustic power input, the pulse tube cooler with a circular pulse tube obtains 7.88 W of cooling power at 77 K, while using an annular pulse tube leads to a cooling power of 7.01 W, a decrease of 0.9 W (11.4%) on the cooling performance. The study sets the basis for building a completely co-axial two-stage pulse tube cooler.

  8. Investigation of phthalate release from tracheal tubes.

    Science.gov (United States)

    Morton, W J; Muller, C T; Goodwin, N; Wilkes, A R; Hall, J E

    2013-04-01

    Phthalates are chemicals used extensively in the manufacture of plastics for their desirable physical characteristics. In addition to enhancing the performance of plastics, phthalates have a number of undesirable effects, principally endocrine disruptor effects, that may have adverse effects on reproductive development and functioning. As a result, they have been banned from the manufacture of children's toys. Despite this, they continue to be used in the manufacture of medical devices, including anaesthetic equipment. This study aimed to assess phthalate release from five brands of tracheal tube. Using gas chromatography-mass spectrometry, we analysed phthalate concentrations from samples of ultra pure water in which tracheal tubes had been submerged. Phthalate concentration increased from 6.7 to 149 μg.l(-1) over a period of 4.8 days. Phthalate release from anaesthetic equipment has not previously been documented over short time periods and raises the possibility of iatrogenic endocrine disruption with routine anaesthesia. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.

  9. Slow viscous flow of two particles in a cylindrical tube

    Science.gov (United States)

    Yao, Xin; Wong, Teck Neng; Marcos, -

    2015-11-01

    The slow viscous flow around two particles in a cylindrical tube is obtained theoretically. We employ the Lamb's general solution based on spherical harmonics and cylindrical harmonics to solve the flow field around the particles and the flow within the tube, respectively. We compute the drag and torque coefficients of the particles which are dependent on the distance among the cylinder wall and the two particles. The hydrodynamic forces are also a function of particle velocities and background velocity. Our results are in agreement with the existing theory of a single particle traveling in the tube when the distance between the two particles increases. We found that particle-particle interactions can be neglected when the separation distance is three times larger than the sum of particles radii. Furthermore, such analysis can give us insights to understand the mechanisms of collision and aggregation of particles.

  10. Unjoined primary and secondary neural tubes: junctional neural tube defect, a new form of spinal dysraphism caused by disturbance of junctional neurulation.

    Science.gov (United States)

    Eibach, Sebastian; Moes, Greg; Hou, Yong Jin; Zovickian, John; Pang, Dachling

    2016-10-29

    Primary and secondary neurulation are the two known processes that form the central neuraxis of vertebrates. Human phenotypes of neural tube defects (NTDs) mostly fall into two corresponding categories consistent with the two types of developmental sequence: primary NTD features an open skin defect, an exposed, unclosed neural plate (hence an open neural tube defect, or ONTD), and an unformed or poorly formed secondary neural tube, and secondary NTD with no skin abnormality (hence a closed NTD) and a malformed conus caudal to a well-developed primary neural tube. We encountered three cases of a previously unrecorded form of spinal dysraphism in which the primary and secondary neural tubes are individually formed but are physically separated far apart and functionally disconnected from each other. One patient was operated on, in whom both the lumbosacral spinal cord from primary neurulation and the conus from secondary neurulation are each anatomically complete and endowed with functioning segmental motor roots tested by intraoperative triggered electromyography and direct spinal cord stimulation. The remarkable feature is that the two neural tubes are unjoined except by a functionally inert, probably non-neural band. The developmental error of this peculiar malformation probably occurs during the critical transition between the end of primary and the beginning of secondary neurulation, in a stage aptly called junctional neurulation. We describe the current knowledge concerning junctional neurulation and speculate on the embryogenesis of this new class of spinal dysraphism, which we call junctional neural tube defect.

  11. Structures of the vorticity tube segment in turbulence

    Science.gov (United States)

    Wang, Lipo

    2012-04-01

    To address the geometrical properties of the turbulent velocity vector field, a new concept named streamtube segment has been developed recently [L. Wang, "On properties of fluid turbulence along streamlines," J. Fluid Mech. 648, 183-203 (2010), 10.1017/S0022112009993041]. According to the vectorial topology, the entire velocity field can be partitioned into the so-called streamtube segments, which are organized in a non-overlapping and space-filling manner. In principle, properties of turbulent fields can be reproduced from those of the decomposed geometrical units with relatively simple structures. A similar idea is implemented to study the turbulent vorticity vector field using the vorticity tube segment structure. Differently from the conventional vortex tubes, vorticity tube segments are space-filling and can be characterized by non-arbitrary parameters, which enables a more quantitative description rather than just an illustrative explanation of turbulence behaviors. From analyzing the direct numerical simulation data, the topological and dynamical properties of vorticity tube segments are explored. The characteristic parameters have strong influence on some conditional statistics, such as the enstrophy production and the probability density function of vorticity stretching. Consequently the common knowledge in turbulence dynamics that vorticity are more stretched than compressed need to be rectified in the vorticity tube segment context.

  12. Navier–Stokes flow in converging–diverging distensible tubes

    Directory of Open Access Journals (Sweden)

    Taha Sochi

    2015-09-01

    Full Text Available We use a method based on the lubrication approximation in conjunction with a residual-based mass-continuity iterative solution scheme to compute the flow rate and pressure field in distensible converging–diverging tubes for Navier–Stokes fluids. We employ an analytical formula derived from a one-dimensional version of the Navier–Stokes equations to describe the underlying flow model that provides the residual function. This formula correlates the flow rate to the boundary pressures in straight cylindrical elastic tubes with constant-radius. We validate our findings by the convergence toward a final solution with fine discretization as well as by comparison to the Poiseuille-type flow in its convergence toward analytic solutions found earlier in rigid converging–diverging tubes. We also tested the method on limiting special cases of cylindrical elastic tubes with constant-radius where the numerical solutions converged to the expected analytical solutions. The distensible model has also been endorsed by its convergence toward the rigid Poiseuille-type model with increasing the tube wall stiffness. Lubrication-based one-dimensional finite element method was also used for verification. In this investigation five converging–diverging geometries are used for demonstration, validation and as prototypes for modeling converging–diverging geometries in general.

  13. ATLS: Catheter and tube placement

    Science.gov (United States)

    Gosbee, John; Krupa, Debra T.; Pepper, L.; Orsak, Debra

    1991-01-01

    The specific objectives of this experiment are: to evaluate the rack mounted equipment and medical supplies necessary for medical procedures; to evaluate the attachments, mounting points, and inner drawer assemblies for the medical supplies; and to evaluate the procedures for performing medical scenarios. The resources available in the HMF miniracks to accomplish medical scenarios and/or procedures include: medical equipment mounted in the racks; a patch panel with places to attach tubing and catheters; self contained drawers full of critical care medical supplies; and an ALS 'backpack' for deploying supplies. The attachment lines, tubing and associated medical supplies will be deployed and used with the equipment and a patient mannequin. Data collection is provided by direct observations by the inflight experimenters, and analysis of still and video photography.

  14. AFRL Ludwieg Tube Initial Performance

    Science.gov (United States)

    2017-11-01

    controls the fill and purge process. A commercial Sylvania 18 kW resistance heater raises the inlet air temperature to 500K prior to filling the...Distribution is unlimited. 3 ms of uniform run conditions between wave passages. The exterior of the driver tube is heated with blanket resistance ...uniformity and noise characteristics, this has not been a major problem with wind tunnels using this type of valve. However, there has been no direct

  15. MARIS plays important roles in Arabidopsis pollen tube and root hair growth.

    Science.gov (United States)

    Liao, Hong-Ze; Zhu, Meng-Meng; Cui, Hong-Hui; Du, Xin-Yu; Tang, Yu; Chen, Li-Qun; Ye, De; Zhang, Xue-Qin

    2016-11-01

    In flowering plants, male gametes are delivered to female gametes for double fertilization through pollen tubes. Therefore, pollen tube growth is crucial for double fertilization. Despite its importance to sexual reproduction, genetic mechanisms of pollen tube growth remain poorly understood. In this study, we characterized the receptor-like cytoplasmic protein kinase (RLCK) gene, MARIS (MRI) that plays critical roles in pollen tube growth. MRI is preferentially expressed in pollen grains, pollen tubes and roots. Mutation in MRI by a Ds insertion led to a burst of pollen tubes after pollen germination. Pollen-rescue assay by pollen and pollen tube-specific expression of MRI in the mri-4 mutant showed that loss of MRI function also severely affected root hair elongation. MRI protein interacted with the protein kinase OXIDATIVE SIGNAL INDUCIBLE1 (OXI1) in the in vitro and in vivo assays, which functions in plant defence and root hair development, and was phosphorylated by OXI1 in vitro. Our results suggest that MRI plays important roles in pollen tube growth and may function in root hair elongation through interaction with OXI1. © 2016 Institute of Botany, Chinese Academy of Sciences.

  16. Method for estimating off-axis pulse tube losses

    Science.gov (United States)

    Fang, T.; Mulcahey, T. I.; Taylor, R. P.; Spoor, P. S.; Conrad, T. J.; Ghiaasiaan, S. M.

    2017-12-01

    Some Stirling-type pulse tube cryocoolers (PTCs) exhibit sensitivity to gravitational orientation and often exhibit significant cooling performance losses unless situated with the cold end pointing downward. Prior investigations have indicated that some coolers exhibit sensitivity while others do not; however, a reliable method of predicting the level of sensitivity during the design process has not been developed. In this study, we present a relationship that estimates an upper limit to gravitationally induced losses as a function of the dimensionless pulse tube convection number (NPTC) that can be used to ensure that a PTC would remain functional at adverse static tilt conditions. The empirical relationship is based on experimental data as well as experimentally validated 3-D computational fluid dynamics simulations that examine the effects of frequency, mass flow rate, pressure ratio, mass-pressure phase difference, hot and cold end temperatures, and static tilt angle. The validation of the computational model is based on experimental data collected from six commercial pulse tube cryocoolers. The simulation results are obtained from component-level models of the pulse tube and heat exchangers. Parameter ranges covered in component level simulations are 0-180° for tilt angle, 4-8 for length to diameter ratios, 4-80 K cold tip temperatures, -30° to +30° for mass flow to pressure phase angles, and 25-60 Hz operating frequencies. Simulation results and experimental data are aggregated to yield the relationship between inclined PTC performance and pulse tube convection numbers. The results indicate that the pulse tube convection number can be used as an order of magnitude indicator of the orientation sensitivity, but CFD simulations should be used to calculate the change in energy flow more accurately.

  17. Tube entrance lens focus control

    Science.gov (United States)

    Weisser, D. C.; Fifield, L. K.; Kitchen, T. F. G.; Tunningley, T. B.; Lobanov, N. R.; Muirhead, A. G.

    2013-02-01

    The entrance of the accelerator tube in a large electrostatic accelerator imposes a strong lens that dominates the beam optics. The magnification of the lens is large because of the low injection energy, the high voltage gradient of the acceleration tube and the long distance to the terminal. In the absence of the acceleration, the magnification would produce an unacceptably large beam spot at the terminal. The tyranny of the lens is especially irksome when the accelerator is required to operate at a lower terminal voltage than the one corresponding to the nominal gradient at high voltage. One way around the difficulty, used in NEC Pelletron accelerators, is to insert a series of nylon and steel rods that short together units of the acceleration structure at the terminal leaving the ones near the entrance close to the nominal gradient for optimum transmission. This operation takes time and risks the loss of insulating gas. Another alternative used in the 25URC at Oak Ridge National Laboratory, is to focus the beam at the tube entrance, substantially diluting the effect of the entrance lens. The beam then diverges and so requires an additional lens part way to the terminal. This solution is only partially effective and still necessitates use of shorting rods for low voltage operation. The fact that these elaborate strategies are used is evidence that the alternative of lowering the injection energy as the terminal voltage is lowered imposes enough problems that it is not used in practice. We have modeled a solution that controls the voltage gradient at the tube entrance using an external power supply. This not only maintains the focusing effect of the lens but provides the opportunity to tune the beam by adjusting the entrance lens. A 150 kV power supply outside the pressure vessel feeds a controllable voltage through a high voltage feed-through to the fifth electrode of the accelerator tube. Thus 150 kV on this electrode creates the nominal gradient of 30 kV per

  18. Gastroenteric tube feeding: Techniques, problems and solutions

    Science.gov (United States)

    Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen

    2014-01-01

    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision. PMID:25024606

  19. Development boiling to sprinkled tube bundle

    Directory of Open Access Journals (Sweden)

    Kracík Petr

    2016-01-01

    Full Text Available This paper presents results of a studied heat transfer coefficient at the surface of a sprinkled tube bundle where boiling occurs. Research in the area of sprinkled exchangers can be divided into two major parts. The first part is research on heat transfer and determination of the heat transfer coefficient at sprinkled tube bundles for various liquids, whether boiling or not. The second part is testing of sprinkle modes for various tube diameters, tube pitches and tube materials and determination of individual modes’ interface. All results published so far for water as the falling film liquid apply to one to three tubes for which the mentioned relations studied are determined in rigid laboratory conditions defined strictly in advance. The sprinkled tubes were not viewed from the operational perspective where there are more tubes and various modes may occur in different parts with various heat transfer values. The article focuses on these processes. The tube is located in a low-pressure chamber where vacuum is generated using an exhauster via ejector. The tube consists of smooth copper tubes of 12 mm diameter placed horizontally one above another.

  20. Comparison of complication rates, types, and average tube patency between jejunostomy tubes and percutaneous gastrostomy tubes in a regional home enteral nutrition support program.

    Science.gov (United States)

    Ao, Peter; Sebastianski, Meghan; Selvarajah, Vijeyakumar; Gramlich, Leah

    2015-06-01

    Percutaneous endoscopic gastrostomy (PEG) tubes are common enteral access devices for long-term enteral nutrition. Jejunostomy tubes (J-tubes) are able to provide postpyloric enteral access in patients who are not PEG tube candidates. There is a scarcity of literature comparing complication rates of J-tubes to PEG tubes. To compare and characterize J-tube and PEG tube complications requiring tube replacement. A retrospective chart review was performed on 560 patients discharged from the Northern Alberta Home Enteral Nutrition Support Program (NAHENSP) from January 2010 to December 2011. Patients were followed for 3 years from initial tube insertion or until discharge from the NAHENSP, whichever was earliest. Comparisons were made in terms of complications requiring tube replacement, tube patency to first replacement, and indications for tube replacement. A total of 64 J-tube patients were identified and compared with 65 PEG tube patients. Tube replacement rates for the J-tube group included 3.2 cases per 1000 patient days compared with 0.86 cases per 1000 patient days in the PEG group (P < .001). The mean ± SEM duration to first tube replacement for J-tube and PEG tube patients was 160 ± 26.3 days and 331 ± 53.6 days, respectively (P = .010). The most common causes for tube replacement in J-tube patients were dislodgement (35.6%) and obstruction (22.2%) compared with routine replacement (54.5%) and dislodgement (27.2%) in the PEG tube group. J-tubes are associated with higher complication rates requiring tube replacement compared with PEG tubes. The main causes of J-tube replacement are dislodgement and obstruction. © 2014 American Society for Parenteral and Enteral Nutrition.

  1. Computational fluid dynamics simulation and geometric design of hydraulic turbine draft tube

    Directory of Open Access Journals (Sweden)

    JB Sosa

    2015-10-01

    Full Text Available Any hydraulic reaction turbine is installed with a draft tube that impacts widely the entire turbine performance, on which its functions are as follows: drive the flux in appropriate manner after it releases its energy to the runner; recover the suction head by a suction effect; and improve the dynamic energy in the runner outlet. All these functions are strongly linked to the geometric definition of the draft tube. This article proposes a geometric parametrization and analysis of a Francis turbine draft tube. Based on the parametric definition, geometric changes in the draft tube are proposed and the turbine performance is modeled by computational fluid dynamics; the boundary conditions are set by measurements performed in a hydroelectric power plant. This modeling allows us to see the influence of the draft tube shape on the entire turbine performance. The numerical analysis is based on the steady-state solution of the turbine component flows for different guide vanes opening and multiple modified draft tubes. The computational fluid dynamics predictions are validated using hydroelectric plant measurements. The prediction of the turbine performance is successful and it is linked to the draft tube geometric features; therefore, it is possible to obtain a draft tube parameter value that results in a desired turbine performance.

  2. Tube-dwelling invertebrates: tiny ecosystem engineers have large effects in lake ecosystems

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans-Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  3. Influence of timing of chest tube removal on early outcome of patients underwent lung resection

    Directory of Open Access Journals (Sweden)

    Ahmed Labib Dokhan

    2016-05-01

    Conclusion: Early removal of chest tube may have beneficial effect on control of post-thoracotomy pain, improvement of pulmonary functions and decreasing the risk of complications after lung resection.

  4. Effect of tube-support interaction on the dynamic responses of heat exchanger tubes. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1977-01-01

    Operating heat exchangers have experienced tube damages due to excessive flow-induced vibration. The relatively small inherent tube-to-baffle hole clearances associated with manufacturing tolerances in heat exchangers affect the tube vibrational characteristics. In attempting a theoretical analysis, questions arise as to the effects of tube-baffle impacting on dynamic responses. Experiments were performed to determine the effects of tube-baffle impacting in vertical/horizontal tube orientation, and in air/water medium on the vibrational characteristics (resonant frequencies, mode shapes, and damping) and displacement response amplitudes of a seven-span tube model. The tube and support conditions were prototypic, and overall length approximately one-third that of a straight tube segment of the steam generator designed for the CRBR. The test results were compared with the analytical results based on the multispan beam with ''knife-edge'' supports.

  5. Multi-tube arrangement for combustor and method of making the multi-tube arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Ziminsky, Willy Steve [Simpsonville, SC

    2012-07-31

    A fuel injector tube includes a one piece, unitary, polygonal tube having an inlet end and an outlet end. The fuel injector tube further includes a fuel passage extending from the inlet end to the outlet end along a longitudinal axis of the polygonal tube, a plurality of air passages extending from the inlet end to the outlet end and surrounding the fuel passage, and a plurality of fuel holes. Each fuel hole connects an air passage with the fuel passage. The inlet end of the polygonal tube is formed into a fuel tube. A fuel injector includes a plurality of fuel injector tubes and a plate. The plurality of fuel tubes are connected to the plate adjacent the inlet ends of the plurality of fuel injector tubes.

  6. Predicting optimum vortex tube performance using a simplified CFD model

    Energy Technology Data Exchange (ETDEWEB)

    Karimi-Esfahani, M; Fartaj, A.; Rankin, G.W. [Univ. of Windsor, Dept. of Mechanical, Automotive and Materials Engineering, Windsor, Ontario (Canada)]. E-mail: mki_60@hotmail.com

    2004-07-01

    The Ranque-Hilsch tube is a particular type of vortex tube device. The flow enters the device tangentially near one end and exits from the open ends of the tube. The inlet air is of a uniform temperature throughout while the outputs are of different temperatures. One outlet is hotter and the other is colder than the inlet air. This device has no moving parts and does not require any additional power for its operation other than that supplied to the device to compress the inlet air. It has, however, not been widely used, mainly because of its low efficiency. In this paper, a simplified 2-dimensional computational fluid dynamics model for the flow in the vortex tube is developed using FLUENT. This model makes use of the assumption of axial symmetry throughout the entire flow domain. Compared to a three-dimensional computational solution, the simplified model requires significantly less computational time. This is important because the model is to be used for an optimization study. A user-defined function is generated to implement a modified version of the k-epsilon model to account for turbulence. This model is validated by comparing a particular solution with available experimental data. The variation of cold temperature drop and efficiency of the device with orifice diameter, inlet pressure and cold mass flow ratio qualitatively agree with experimental results. Variation of these performance indices with tube length did not agree with the experiments for small values of tube length. However, it did agree qualitatively for large values. (author)

  7. The feeding tube of cyst nematodes: characterisation of protein exclusion.

    Directory of Open Access Journals (Sweden)

    Sebastian Eves-van den Akker

    Full Text Available Plant parasitic nematodes comprise several groups; the most economically damaging of these are the sedentary endoparasites. Sedentary endoparasitic nematodes are obligate biotrophs and modify host root tissue, using a suite of effector proteins, to create a feeding site that is their sole source of nutrition. They feed by withdrawing host cell assimilate from the feeding site though a structure known as the feeding tube. The function, composition and molecular characteristics of feeding tubes are poorly characterised. It is hypothesised that the feeding tube facilitates uptake of host cell assimilate by acting as a molecular sieve. Several studies, using molecular mass as the sole indicator of protein size, have given contradictory results about the exclusion limits of the cyst nematode feeding tube. In this study we propose a method to predict protein size, based on protein database coordinates in silico. We tested the validity of these predictions using travelling wave ion mobility spectrometry--mass spectrometry, where predictions and measured values were within approximately 6%. We used the predictions, coupled with mass spectrometry, analytical ultracentrifugation and protein electrophoresis, to resolve previous conflicts and define the exclusion characteristics of the cyst nematode feeding tube. Heterogeneity was tested in the liquid, solid and gas phase to provide a comprehensive evaluation of three proteins of particular interest to feeding tube size exclusion, GFP, mRFP and Dual PI. The data and procedures described here could be applied to the design of plant expressed defence compounds intended for uptake into cyst nematodes. We also highlight the need to assess protein heterogeneity when creating novel fusion proteins.

  8. Routine jejunostomy tube feeding following esophagectomy

    Science.gov (United States)

    van Eden, Hanneke W. J.; Ruurda, Jelle P.; Luyer, Misha D. P.; Steenhagen, Elles; Nieuwenhuijzen, Grard A. P.; van Hillegersberg, Richard

    2017-01-01

    Background Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support. However, specific complications occur, and data are lacking that support its use over other enteral feeding routes. Therefore routine jejunostomy tube feeding and discharge with home-tube feeding was evaluated, with emphasis on weight loss, length of stay and re-admissions. Methods Consecutive patients undergoing esophagectomy for cancer, with gastric tube reconstruction and jejunostomy creation, were analyzed. Two different regimens were compared. Before January 07, 2011 patients were discharged when oral intake was sufficient, without tube feeding. After that discharge with home-tube feeding was routinely performed. Logistic regression analysis corrected for confounders. Results Some 236 patients were included. The median duration of tube feeding was 35 days. Reoperation for a jejunostomy-related complication was needed in 2%. The median body mass index (BMI) remained stable during tube feeding. The BMI decreased significantly after stopping tube feeding: from 25.6 (1st–3rd quartile 23.0–28.6) kg/m2 to 24.4 (22.0–27.1) kg/m2 at 30 days later [median weight loss: 3.0 (1.0–5.3) kg; 3.9% (1.5–6.3%)]. Weight loss was not affected by the duration of tube feeding duration. Routine home-tube feeding did not affect weight loss, admission time or the readmission rate. Conclusions Weight loss following esophagectomy occurs once that tube feeding is stopped, independently from the time interval after esophagectomy. Moreover routine discharge with home-tube feeding does not reduce length of stay or readmissions. These findings question the value of routine jejunostomy placement and emphasize the need for further research. PMID:28815083

  9. Development of INCONEL 600 precision tube (1)

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Yeong Han; Jo, Bong Hyeon; Lee, Dong Hee; Kim, Wan Kyo; Jeong, Pyeong Keun; Yoon, Hwang Lo; Chio, Seok Sik [Sammi Steel Co. Ltd., Changwon (Korea, Republic of)

    1994-07-01

    Steam generator, being connected with nuclear fuel reactor is one of the most important part of nuclear power plant and consists of a large number of INCONEL 600 tubes. Approximately 160 tons of tubes are needed for a single nuclear power plant. All of INCONEL 600 steam generator tubes for domestic nuclear power plants have been imported. The aim of this research is to develop INCONEL 600 precision tubes for steam generator of nuclear power plant. If this research is conducted successfully, we can produce nuclear fuel tubes, Ni-alloy precision tubes and stainless steel precision tubes for many purposes and technology of INCONEL 600 steam generator tubes are similar to those of other tubes above mentioned. In the current study, development of preliminary manufacturing process of INCONEL 600 precision tubes for steam generator and investigation of material`s metallurgical characteristics were conducted. The main scope of this research is as follows. First, the preliminary manufacturing process design was conducted after investigations of foreign manufacturing processes and technical reports. Second, the results of investigations of material`s metallurgical characteristics through the manufacturing process were applied to the production technology of tentative INCONEL 600 precision tubes for sample. Third, preliminary process routes were established and samples of INCONEL 600 precision tube were produced by this process. As the results of this research, 14 pieces of INCONEL 600 precision tubes were produced by preliminary manufacturing process and the material`s metallurgical characteristics were investigated through the processes. But the SCC test could not be conducted due to the absence of equipment. In order to apply the results of SCC test to the manufacturing process, we need a SCC tester which can simulate SCC characteristics under high temperature and high pressurized circulating water. 95 refs., 55 figs., 20 tabs.

  10. Cases of fallopian tube prolapse

    Directory of Open Access Journals (Sweden)

    Sushil Chawla

    2015-01-01

    Full Text Available Fallopian tube prolapse post hysterectomy is rarely reported complication which can lead to doubts in the mind of young and experienced surgeons alike. This leads to patient morbidity and gets different medical treatments ranging from antibiotics to local applications of copper sulphate, without relief. The use of proper surgical technique, prevention of post operative hematoma and infection go a long way in its prevention.We hereby present two cases, which were manged successfully to relieve the patients of their agony.

  11. Comparison of primary jejunostomy tubes versus gastrojejunostomy tubes for percutaneous enteral nutrition.

    Science.gov (United States)

    Kim, Charles Y; Engstrom, Bjorn I; Horvath, Jeffrey J; Lungren, Matthew P; Suhocki, Paul V; Smith, Tony P

    2013-12-01

    To evaluate technical success and long-term outcomes of percutaneous primary jejunostomy tubes for postpyloric enteral feeding compared with percutaneous gastrojejunostomy (GJ) tubes. Over a 25-month interval, 41 consecutive patients (26 male; mean age, 55.9 y) underwent attempted fluoroscopy-guided direct percutaneous jejunostomy tube insertion. Insertions at previous jejunostomy tube sites were excluded. The comparison group consisted of all primary GJ tube insertions performed over a 12-month interval concomitant with the jejunostomy tube interval (N = 169; 105 male; mean age, 59.4 y). Procedural, radiologic, and clinical data were retrospectively reviewed. Intervention rates were expressed as events per 100 catheter-days. The technical success rate for percutaneous jejunostomy tube insertion was 96%, versus 93% for GJ tubes (P = .47). Mean fluoroscopy times were similar for jejunostomy and GJ tubes (9.8 vs 10.0 min, respectively; P value not significant). Jejunostomy tubes exhibited a lower rate of catheter dysfunction than GJ tubes, with catheter exchange rates of 0.24 versus 0.93, respectively, per 100 catheter-days (P = .045). GJ tube tip retraction into the stomach occurred in 9.5% of cases, at a rate of 0.21 per 100 catheter-days. Intervention rates related to leakage were 0.19 and 0.03 for jejunostomy and GJ tubes, respectively (P Jejunostomy and GJ tubes exhibited similar rates of catheter exchange for occlusion and replacement as a result of inadvertent removal. No major complications were encountered in either group. Percutaneous insertion of primary jejunostomy tubes demonstrated technical success and complication rates similar to those of GJ tubes. Jejunostomy tubes exhibited a lower dysfunction rate but a higher leakage rate compared with GJ tubes. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

  12. Narratives From YouTube

    Directory of Open Access Journals (Sweden)

    Mikael Quennerstedt

    2013-10-01

    Full Text Available The aim of this paper is to explore what is performed in students’ and teachers’ actions in physical education practice in terms of “didactic irritations,” through an analysis of YouTube clips from 285 PE lessons from 27 different countries. Didactic irritations are occurrences that Rønholt describes as those demanding “didactic, pedagogical reflections and discussions, which in turn could lead to alternative thinking and understanding about teaching and learning.” Drawing on Barad’s ideas of performativity to challenge our habitual anthropocentric analytical gaze when looking at educational visual data, and using narrative construction, we also aim to give meaning to actions, relations, and experiences of the participants in the YouTube clips. To do this, we present juxtaposing narratives from teachers and students in terms of three “didactic irritations”: (a stories from a track, (b, stories from a game, and (c, stories from a bench. The stories re-present events-of-moving in the data offering insights into embodied experiences in PE practice, making students’ as well as teachers’ actions in PE practice understandable.

  13. An Experimental Study on the Impact Collapse Characteristics of CF/Epoxy Circular Tubes

    Science.gov (United States)

    Kim, Y. N.; Im, K. H.; Park, J. W.; Yang, I. Y.

    2003-03-01

    This study is to investigate the energy absorption characteristics of CF/Epoxy (Carbon-Fiber/Epoxy Resin) circular tubes in static and impact tests. The experimental results varied significantly as a function of interlaminar number, orientation angle of outer and trigger. When a CFRP composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface, and the response is complex and depends on the interaction among the different mechanisms, such as transverse shearing, laminar bending and local buckling. The collapse mode depended upon orientation angle of outer of CFRP tubes and loading status(static/impact). Typical collapse modes of CFRP tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode.

  14. Trach tubes designed to maximize safety may increase risk to ventilated patients.

    Science.gov (United States)

    McCracken, John; Leasa, David

    2010-01-01

    Dual-cannulae tracheostomy tubes with low-pressure cuffs, such as the Shiley LPC, are widely regarded as inherently safer than single lumen tubes with low-volume cuffs. For the patient who undergoes tracheostomy for failure to wean from mechanical ventilation, however, the insertion of a tube that occupies a large amount of space within the trachea can delay subsequent efforts to liberate him from the ventilator. With an aim to promote more timely rehabilitation of ventilated patients, London Ontario's University Hospital has been inserting the Bivona TTS, a single lumen tube with an elastic cuff, during tracheostomy. This allows caregivers to better exploit the benefits of a functional upper airway early during the weaning process, which may reduce complications associated with prolonged mechanical ventilation. We urge clinical studies to determine how the choice of initial tracheostomy tube can affect rehabilitation strategies and important patient outcomes.

  15. DEVELOPMENT OF COILED TUBING STRESS ANALYSIS

    Directory of Open Access Journals (Sweden)

    Davorin Matanović

    1998-12-01

    Full Text Available The use of coiled tubing is increasing rapidly with drilling of horizontal wells. To satisfy all requirements (larger mechanical stresses, larger fluid capacities the production of larger sizes and better material qualities was developed. Stresses due to axial forces and pressures that coiled tubing is subjected are close to its performance limits. So it is really important to know and understand the behaviour of coiled tubing to avoid its break, burst or collapse in the well.

  16. Unique removal of a kinked nasogastric tube

    Directory of Open Access Journals (Sweden)

    Kumar Shwetanshu Narayan

    2017-01-01

    Full Text Available Nasogastric (NG tube insertion is a common clinical procedure used for both diagnostic and therapeutic purposes. As the importance of enteral nutrition is being increasingly recognized; the use of NG tube insertion has steadily increased. Here, we present an interesting case in which a kinked NG tube was removed in a unique manner with “push and pull” technique without untoward trauma.

  17. Preparation of nitrogen-doped carbon tubes

    Science.gov (United States)

    Chung, Hoon Taek; Zelenay, Piotr

    2015-12-22

    A method for synthesizing nitrogen-doped carbon tubes involves preparing a solution of cyanamide and a suitable transition metal-containing salt in a solvent, evaporating the solvent to form a solid, and pyrolyzing the solid under an inert atmosphere under conditions suitable for the production of nitrogen-doped carbon tubes from the solid. Pyrolyzing for a shorter period of time followed by rapid cooling resulted in a tubes with a narrower average diameter.

  18. Inverse Kinematics of Concentric Tube Steerable Needles

    OpenAIRE

    Sears, Patrick; Dupont, Pierre E.

    2007-01-01

    Prior papers have introduced steerable needles composed of precurved concentric tubes. The curvature and extent of these needles can be controlled by the relative rotation and translation of the individual tubes. Under certain assumptions on the geometry and design of these needles, the forward kinematics problem can be solved in closed form by means of algebraic equations. The inverse kinematics problem, however, is not as straightforward owing to the nonlinear map between relative tube disp...

  19. Pro: one-lung ventilation is best accomplished with the Univent endotracheal tube.

    Science.gov (United States)

    Gayes, J M

    1993-02-01

    Over the years, thoracotomy has changed from a procedure that prompted major concern over cross-contamination caused by infection to pulmonary tumors. Assisting the thoracic surgeon by providing OLV is one of the most specialized skills an anesthesiologist can offer. This must be done in a safe, easy, and efficient manner. The Univent tube appears to be a hybrid, combining the best qualities of both the DLT and the single-lumen endotracheal tube with separate Fogarty-like catheter. The Univent tube is a technical improvement over separate endobronchial blocking catheters because its blocker shaft is attached to the main tube and, therefore, displacement is less likely. In addition, the Univent's axial blocker shaft has a lumen that provides for irrigation, suction, oxygen insufflation, CPAP, and HFV. Though equally as effective as the DLT in treatment of intraoperative hypoxemia, the Univent tube presents a unique advantage in the areas of aspiration prevention, prolonged intubation without tube exchange, and selective blockade of lung segments. The Univent tube is also easier to insert and has fewer associated risks compared to the DLT. Is it my purpose to suggest that because the Univent tube is equal to, or better than, the DLT in many areas, we should abandon the use of DLTs? Definitely not. Double-lumen tubes have performed well in the past and will continue to offer specialized functions, such as postoperative independent lung ventilation in single-lung transplant recipients. As with the acquisition of any new medical skill, the use of the Univent tube has a learning curve. It is worth the time and effort to learn to use the Univent tube.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Micro tube heat exchangers for Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...

  1. Failure Analysis of a Service Tube

    Science.gov (United States)

    Xie, Zhongdong; Cai, Weiguo; Li, Zhenxing; Guan, YiMing; Zhang, Baocheng; Yang, XiaoTong

    2017-12-01

    One tube was cracked used in the primary reformer furnace in a fertilizer plant for two and half years. In order to find out the causes of cracking, the methods for chemical composition analysis, macro- and microstructure analysis, penetrant testing, weld analysis, crack and surface damage analysis, mechanics property analysis, high temperature endurance performance analysis, stress and wall thickness calculation were adopted. The integrated assessment results showed that the carbon content of the tube was in the lower limit of the standard range; the tube effective wall thickness was too small; local overheating leads to tube cracking in use process.

  2. Enhanced Evaporation and Condensation in Tubes

    Science.gov (United States)

    Honda, Hiroshi

    A state-of-the-art review of enhanced evaporation and condensation in horizontal microfin tubes and micro-channels that are used for air-conditioning and refrigeration applications is presented. The review covers the effects of flow pattern and geometrical parameters of the tubes on the heat transfer performance. Attention is paid to the effect of surface tension which leads to enhanced evaporation and condensation in the microfin tubes and micro-channels. A review of prior efforts to develop empirical correlations of the heat transfer coefficient and theoretical models for evaporation and condensation in the horizontal microfin tubes and micro-channels is also presented.

  3. Morphologic 3D scanning of fallopian tubes to assist ovarian cancer diagnosis

    Science.gov (United States)

    Madore, Wendy-Julie; De Montigny, Etienne; Deschênes, Andréanne; Benboujja, Fouzi; Leduc, Mikael; Mes-Masson, Anne-Marie; Provencher, Diane M.; Rahimi, Kurosh; Boudoux, Caroline; Godbout, Nicolas

    2016-02-01

    Pathological evaluation of the fallopian tubes is an important diagnostic result but tumors can be missed using routine approaches. As the majority of high-grade serous ovarian cancers are now believed to originate in the fallopian tubes, pathological examination should include in a thorough examination of the excised ovaries and fallopian tubes. We present an dedicated imaging system for diagnostic exploration of human fallopian tubes. This system is based on optical coherence tomography (OCT), a laser imaging modality giving access to sub- epithelial tissue architecture. This system produces cross-sectional images up to 3 mm in depth, with a lateral resolution of ≍15μm and an axial resolution of ≍12μm. An endoscopic single fiber probe was developed to fit in a human fallopian tube. This 1.2 mm probe produces 3D volume data of the entire inner tube within a few minutes. To demonstrate the clinical potential of OCT for lesion identification, we studied 5 different ovarian lesions and healthy fallopian tubes. We imaged 52 paraffin-embedded human surgical specimens with a benchtop system and compared these images with histology slides. We also imaged and compared healthy oviducts from 3 animal models to find one resembling the human anatomy and to develop a functional ex vivo imaging procedure with the endoscopic probe. We also present an update on an ongoing clinical pilot study on women undergoing prophylactic or diagnostic surgery in which we image ex vivo fallopian tubes with the endoscopic probe.

  4. Management of chronic empyema with unexpandable lung in poor surgical risk patients using an empyema tube

    Directory of Open Access Journals (Sweden)

    Abhishek Biswas

    2016-01-01

    Full Text Available Objectives: High preoperative risk precludes decortication and other surgical interventions in some patients with chronic empyema. We manage such patients by converting the chest tube into an "empyema tube," cutting the tube near the skin and securing the end with a sterile clip to allow for open pleural drainage. The patient is followed serially, and the tube gradually withdrawn based on radiological resolution and amount of drainage. Methods: Between 2010 and 2014, patients with chronic empyema and unexpandable lung, deemed high-risk surgical candidates, had staged chest tube removal, and were included for the study. The volume of fluid drained, culture results, duration of drainage, functional status, and comorbidities were recorded. Measurements and Results: Eight patients qualified. All had resolution of infection. The tube was removed after an average of 73.6 ± 49.73 (95% confidence interval [CI] days. The mean duration of antibiotic treatment was 5.37 ± 1.04 (95% CI weeks. None required surgery or experienced complications from an empyema tube. Conclusion: A strategy of empyema tube drainage with staged removal is an option in appropriately selected patients with chronic empyema, unexpandable lung, and poor surgical candidacy.

  5. Real-time Position Control of Concentric Tube Robots.

    Science.gov (United States)

    Dupont, Pierre E; Lock, Jesse; Itkowitz, Brandon

    2010-05-03

    A novel approach to constructing robots is based on concentrically combining pre-curved elastic tubes. By rotating and extending the tubes with respect to each other, their curvatures interact elastically to position and orient the robot's tip, as well as to control the robot's shape along its length. Since these robots form slender curves, they are well suited for minimally invasive medical procedures. A substantial challenge to their practical use is the real-time solution of their kinematics that are described by differential equations with split boundary equations. This paper proposes a numerically efficient approach to real-time position control. It is shown that the forward kinematics are smooth functions that can be pre-computed and accurately approximated using Fourier series. The inverse kinematics can be solved in real time using root finding applied to the functional approximation. Experimental demonstration of real-time position control using this approach is also described.

  6. Sunspots and the physics of magnetic flux tubes. V - Mutual hydrodynamic forces between neighboring tubes

    Science.gov (United States)

    Parker, E. N.

    1979-01-01

    The mutual hydrodynamic forces between parallel cylinders in a moving fluid are illustrated through several formal examples. Parallel tubes in a uniform flow are attracted or repelled depending on whether they are side by side or one ahead of the other, respectively. A pulsating or undulating tube attracts all other neighboring tubes toward itself. These hydrodynamic effects suggest that the separate flux tubes beneath the sunspots exert significant attractive forces on each other.

  7. Working session 2: Tubing inspection

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, J. [Tecnatom, S.A. San Sebastian de los Reyes, Madrid (Spain); Tapping, R.L. [AECL, Chalk River, Ontario (Canada)

    1997-02-01

    This session was attended by delegates from 10 countries, and four papers were presented. A wide range of issues was tabled for discussion. Realizing that there was limited time available for more detailed discussion, three topics were chosen for the more detailed discussion: circumferential cracking, performance demonstration (to focus on POD and sizing), and limits of methods. Two other subsessions were organized: one dealt with some challenges related to the robustness of current inspection methods, especially with respect to leaving cracked tubes in service, and the other with developing a chart of current NDE technology with recommendations for future development. These three areas are summarized in turn, along with conclusions and/or recommendations. During the discussions there were four presentations. There were two (Canada, Japan) on eddy current probe developments, both of which addressed multiarray probes that would detect a range of flaws, one (Spain) on circumferential crack detection, and one (JRC, Petten) on the recent PISC III results.

  8. Paramecium swimming in capillary tube

    CERN Document Server

    Jana, Saikat; Jung, Sunghwan

    2010-01-01

    Swimming organisms in their natural habitat navigate through a wide array of geometries and chemical environments. Interaction with the boundaries is ubiquitous and can significantly modify the swimming characteristics of the organism as observed under ideal conditions. We study the dynamics of ciliary locomotion in Paramecium multimicronucleatum and observe the effect of the solid boundaries on the velocities in the near field of the organism. Experimental observations show that Paramecium executes helical trajectories that slowly transition to straight line motion as the diameter of the capillary tubes decrease. Theoretically this system is modeled as an undulating cylinder with pressure gradient and compared with experiments; showing that such considerations are necessary for modeling finite sized organisms in the restrictive geometries.

  9. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  10. Water calibration for CT scanners with tube voltage modulation

    Science.gov (United States)

    Ritschl, Ludwig; Bergner, Frank; Fleischmann, Christof; Kachelrieß, Marc

    2010-07-01

    X-ray CT measures the attenuation of polychromatic x-rays through an object of interest. The CT data acquired are the negative logarithm of the relative x-ray intensity after absorption. These data must undergo water precorrection to linearize the measured data and convert them into line integrals through the patient that can be reconstructed to yield the final CT image. The function to linearize the measured projection data depends on the tube voltage U. In most circumstances, CT scans are carried out with a constant tube voltage. For those cases there are dozens of different techniques to carry out water precorrection. In our case the tube voltage is rather modulated as a function of the object. We propose an empirical cupping correction (ECCU) algorithm to correct for CT cupping artifacts that are induced by nonlinearities in the projection data. The method is rawdata based, empirical and requires neither knowledge of the x-ray spectrum nor of the attenuation coefficients. It aims at linearizing the attenuation data using a precorrection function of polynomial form in the polychromatic attenuation data q and in the tube voltage U. The coefficients of the polynomial are determined once using a calibration scan of a homogeneous phantom. The coefficients are computed in the image domain by fitting a series of basis images to a template image. The template image is obtained directly from the uncorrected phantom image and no assumptions on the phantom size or of its positioning are made. Rawdata are precorrected by passing them through the once-determined polynomial. Numerical examples are shown to demonstrate the quality of the precorrection. ECCU is achieved to remove the cupping artifacts and to obtain well-calibrated CT values. A combination of ECCU with analytical techniques yielding a hybrid cupping correction method is possible and allows for channel-dependent correction functions.

  11. Water calibration for CT scanners with tube voltage modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ritschl, Ludwig; Bergner, Frank; Kachelriess, Marc [Institute of Medical Physics (IMP), University of Erlangen-Nuernberg, Henkestr. 91, 91052 Erlangen (Germany); Fleischmann, Christof, E-mail: ludwig.ritschl@imp.uni-erlangen.d [Ziehm Imaging GmbH, Donaustrasse 31, 90451 Nuernberg (Germany)

    2010-07-21

    X-ray CT measures the attenuation of polychromatic x-rays through an object of interest. The CT data acquired are the negative logarithm of the relative x-ray intensity after absorption. These data must undergo water precorrection to linearize the measured data and convert them into line integrals through the patient that can be reconstructed to yield the final CT image. The function to linearize the measured projection data depends on the tube voltage U. In most circumstances, CT scans are carried out with a constant tube voltage. For those cases there are dozens of different techniques to carry out water precorrection. In our case the tube voltage is rather modulated as a function of the object. We propose an empirical cupping correction (ECCU) algorithm to correct for CT cupping artifacts that are induced by nonlinearities in the projection data. The method is rawdata based, empirical and requires neither knowledge of the x-ray spectrum nor of the attenuation coefficients. It aims at linearizing the attenuation data using a precorrection function of polynomial form in the polychromatic attenuation data q and in the tube voltage U. The coefficients of the polynomial are determined once using a calibration scan of a homogeneous phantom. The coefficients are computed in the image domain by fitting a series of basis images to a template image. The template image is obtained directly from the uncorrected phantom image and no assumptions on the phantom size or of its positioning are made. Rawdata are precorrected by passing them through the once-determined polynomial. Numerical examples are shown to demonstrate the quality of the precorrection. ECCU is achieved to remove the cupping artifacts and to obtain well-calibrated CT values. A combination of ECCU with analytical techniques yielding a hybrid cupping correction method is possible and allows for channel-dependent correction functions.

  12. Observation of "YouTube" Language Learning Videos ("YouTube" LLVS)

    Science.gov (United States)

    Alhamami, Munassir

    2013-01-01

    This paper navigates into the "YouTube" website as one of the most usable online tools to learn languages these days. The paper focuses on two issues in creating "YouTube" language learning videos: pedagogy and technology. After observing the existing "YouTube" LLVs, the study presents a novel rubric that is directed…

  13. 49 CFR 230.61 - Arch tubes, water bar tubes, circulators and thermic siphons.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.61 Arch tubes, water bar tubes, circulators and thermic siphons. (a) Frequency of cleaning. Each time the boiler is washed, arch tubes and...

  14. Airplane Ear

    Science.gov (United States)

    ... an imbalance in the air pressure in the middle ear and air pressure in the environment prevents your eardrum (tympanic membrane) from vibrating as ... eustachian tube. One end is connected to the middle ear. The other end has a ... in the environment changes rapidly, and your eustachian tube often doesn' ...

  15. Neural Tube Defects: From a Proteomic Standpoint

    Directory of Open Access Journals (Sweden)

    Tania M. Puvirajesinghe

    2015-03-01

    Full Text Available Neural tube defects (NTDs are congenital birth defects classified according to their resulting morphological characteristics in newborn patients. Current diagnosis of NTDs relies largely on the structural evaluation of fetuses using ultrasound imaging, with biochemical characterization used as secondary screening tools. The multigene etiology of NTDs has been aided by genetic studies, which have discovered panels of genes mutated in these diseases that encode receptors and cytoplasmic signaling molecules with poorly defined functions. Animal models ranging from flies to mice have been used to determine the function of these genes and identify their associated molecular cascades. More emphasis is now being placed on the identification of biochemical markers from clinical samples and model systems based on mass spectrometry, which open novel avenues in the understanding of NTDs at protein, metabolic and molecular levels. This article reviews how the use of proteomics can push forward the identification of novel biomarkers and molecular networks implicated in NTDs, an indispensable step in the improvement of patient management.

  16. Broadcast yourself on YouTube - really?

    NARCIS (Netherlands)

    Kruitbosch, G.; Nack, F.

    2008-01-01

    One essential reason for people to publish on the web is to express themselves freely. YouTube facilitates this self-expression by allowing users to upload video content they generated. This paper investigates to what extent the videos on YouTube are self-generated content, instead of amalgamated

  17. Short Communication Tube-forming polychaetes enhance ...

    African Journals Online (AJOL)

    We collected invertebrate samples from an intertidal flat with low onuphid tube density (2.7 m–2) in Mozambique and document that more organisms (70 times higher mollusc abundances) and more species (15 times more mollusc species) were found associated with solitary tubes of an onuphid polychaete compared with ...

  18. Selecting silicone tubing for device applications.

    Science.gov (United States)

    Jahn, D

    2005-10-01

    A number of factors are involved in selecting the most suitable silicone tubing for a given purpose. These include physical chemistry, performance properties, a supplier's quality system and regulatory compliance. This article provides a guide for device developers when selecting silicone tubing for their applications.

  19. Non-uniform tube representation of proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...

  20. Non-Uniform Tube Representation of Proteins

    DEFF Research Database (Denmark)

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X...

  1. Places to Go: YouTube

    Science.gov (United States)

    Downes, Stephen

    2008-01-01

    Founded in 2005 by three former PayPal employees, YouTube has revolutionized the Internet, marking a change from the static Internet to the dynamic Internet. In this edition of Places to Go, Stephen Downes discusses how the rise of a ubiquitous media format--Flash video--has made YouTube's success possible and argues that Flash video has important…

  2. Photomultiplier tubes for Low Level Cerenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O.

    1965-03-15

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a {beta}-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10{sup -12} input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10{sup -12} to 10{sup -9} input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses.

  3. Confined Tube Crimp Using Portable Hand Tools

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Joseph James [Los Alamos National Laboratory; Pereyra, R. A. [LANL Retired; Archuleta, Jeffrey Christopher [Los Alamos National Laboratory; Martinez, Isaac P. [Los Alamos National Laboratory; Nelson, A. M. [MST-16 Summer Student (2007); Allen, Ronald Scott [Los Alamos National Laboratory; Page, R. L. [LANL Retired; Freer, Jerry Eugene [Los Alamos National Laboratory; Dozhier, Nathan Gus [Los Alamos National Laboratory

    2016-04-04

    The Lawrence Radiation Laboratory developed handheld tools that crimp a 1/16 inch OD tube, forming a leak tight seal1 (see Figure 1). The leak tight seal forms by confining the 1/16 inch OD tubing inside a die while applying crimp pressure. Under confined pressure, the tube walls weld at the crimp. The purpose of this study was to determine conditions for fabricating a leak tight tube weld. The equipment was used on a trial-and-error basis, changing the conditions after each attempt until successful welds were fabricated. To better confine the tube, the die faces were polished. Polishing removed a few thousandths of an inch from the die face, resulting in a tighter grip on the tubing wall. Using detergent in an ultrasonic bath, the tubing was cleaned. Also, the time under crimp pressure was increased to 30 seconds. With these modifications, acceptable cold welds were fabricated. After setting the conditions for an acceptable cold weld, the tube was TIG welded across the crimped face.

  4. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

    2009-05-15

    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  5. Isolated Fallopian Tube Torsion in Adolescents

    Directory of Open Access Journals (Sweden)

    S. Rajaram

    2013-01-01

    Full Text Available Background. Fallopian tube torsion is a rare cause of acute abdomen, occurring commonly in females of reproductive age. It lacks pathognomonic symptoms, signs, or imaging features, thus causing delay in surgical intervention. Case. We report two cases of isolated fallopian tube torsion in adolescent girls. In the first case a 19-year-old patient presented with acute pain in the left iliac region associated with episodes of vomiting for one day and mild tenderness on examination. Laparoscopy revealed left sided twisted fallopian tube associated with hemorrhagic cyst of ovary. The tube was untwisted and salvaged. In another case an 18-year-old virgin girl presented with similar complaints since one week, associated with mild tenderness in the lower abdomen and tender cystic mass on per rectal examination. On laparoscopy right twisted fallopian tube associated with a paratubal cyst was found. Salpingectomy was done as the tube was gangrenous. Conclusion. Fallopian tube torsion, though rare, should be considered in women of reproductive age with unilateral pelvic pain. Early diagnostic laparoscopy is important for an accurate diagnosis and could salvage the tube.

  6. A Slot Machine, A Broken Test Tube

    Indian Academy of Sciences (India)

    IAS Admin

    BOOK │ REVIEW. A Slot Machine, A Broken. Test Tube. Vinita Shivakumar and. Dipshikha Chakravortty. A Slot Machine, A Broken Test. Tube – An Autobiography. Salvador Edward Luria. Harper Collins Publishers Inc.,. USA. 1984. 1st edn. 228 pp. (Original from the University of. Michigan). Price: Rs 60/-. Salvador Edward ...

  7. Teaching Shakespeare with YouTube

    Science.gov (United States)

    Desmet, Christy

    2009-01-01

    YouTube, the video sharing website that allows viewers to upload video content ranging from cute dog tricks to rare rock videos, also supports a lively community devoted to the performance of Shakespeare and Shakespearean adaptations. YouTube is also a popular site for student producers of Shakespeare performances, parodies, and other artistic…

  8. Geotextile Tube Structures Guidelines for Contract Specifications

    Science.gov (United States)

    2006-09-01

    Nonwoven fabrics: Diaphragm Bursting Strength Tester Method ASTM D 3884 (1992) Abrasion Resistance of Textile Fabrics (Rotary Platform, Double-Head... filter cloth, excavation of borrow material, transportation of borrow material, filling of the tubes, coating of the completed tubes, disposal of waste

  9. Local Thickening of Stainless Tube Considering Dimension Variation of the Cold Roll Formed Tube Billet

    Science.gov (United States)

    Sheu, Jinn-Jong; Yu, Cheng-Hsien

    2011-01-01

    A stud end consists of tube body and a flange in order to connect two tubes to form a long straight or angled pipe line. The flange is thicker than the tube body to strengthen the pipe connection. A thicker round hollow disk is usually welded to a straight tube to get the flange of the tube end and then machined to the specified dimension of the two-piece type stud end. A one-piece type stud end of tube proposed here is produced via the local thickening of tube end, flaring, and flange forging processes. The roundness of raw tube is not promised in the cold roll forming (CRF) process, which causes the inaccuracy of dimensions, wrinkling, and folding defects during the local thickening process of tube end. In this paper, a preform process was proposed to correct the dimension of the tube to be thickened. The CRF tube billets were measured and preformed to the required dimensions before thickening. The proposed preforming process was able to resize and control the dimensions and roundness of the tube billet to prevent irregular movement of billet. A three-staged punch profile was designed to prevent the folding defect during the thickening process. Experiments of resizing and thickening were carried out to verify the simulation results and the proposed punch profile design. The CAE simulations demonstrated the defects of folding are very sensitive to the dimension variation of tube billet. The experimental results of thickening process were in good agreement with the simulation predictions using the perfect (with preforming process) and the imperfect (original CRF) tube billets. The proposed pre-forming process and the punch profile designs were able to minimize the surface defects of tube local thickening.

  10. Building lab-scale x-ray tube based irradiators

    Science.gov (United States)

    The construction of economical x-ray tube based irradiators in a variety of configurations is described using 1000 Watt x-ray tubes. Single tube, double tube, and four tube designs are described, as well as various cabinet construction techniques. Relatively high dose rates were achieved for small s...

  11. Tubing-for-casing cuts tubular requirements

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, C.W. Jr.

    1974-04-01

    The tight supply of tubular goods has caused many operators to turn to tubingless completions in field wells devoid of critical downhole problems. It is possible to save up to 50% on tubular steel requirements by this technique. Other than the surface casing, the basic idea employs only one string of pipe of tubing dimensions. Such a completion is illustrated. Tubingless completions generally refer to the use of 2-7/8 in. tubing which is run and cemented as the production casing of a well. In this light, the term tubingless is a misnomer and perhaps tubing-for-casing more aptly described the idea. Tubing-for-casing completions should be considered usually for gas wells where future anticipated remedial work is minimal. However, these completions can be squeezed and normal remedial work can be accomplished with a variety of available tools. Some of the problems that should be investigated when considering a tubing-for-casing are listed and described.

  12. The Mashups of YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2013-01-01

    This article focuses on YouTube mashups and how we can understand them as a specific subgenre on YouTube. The Mashups are analysed as audiovisual recontextualizations that are given new meaning, e.g., via collaborative social communities or for individual promotional purposes. This is elaborated......, but rather in its social and communicative abilities within the YouTube community. This leads to the article’s overall argument that the main characteristic of the YouTube Mashup can be explained in terms of connectivity. It is argued that Mashups reveal a double articulation of connectivity; one...... that involves the social mechanisms of the Mashups, and another mode, which concerns the explicit embedding of structural connectivity that accentuates the medium-specific infrastructure of YouTube. This double articulation of connectivity is furthermore elaborated on by including Grusin and Bolter’s concept...

  13. Torsional Kinematic Model for Concentric Tube Robots.

    Science.gov (United States)

    Dupont, Pierre E; Lock, Jesse; Butler, Evan

    2009-05-12

    A recent approach to steerable needle design is based on combining pre-curved tubes concentrically. By rotating and extending the tubes with respect to each other, the position and orientation of the needle tip, as well as the shape of the inserted length, can be controlled. Prior models neglected torsional twisting in the curved portions of the tubes. This paper presents a mechanics model that includes torsion, applies to any number of tubes and allows curvature and stiffness to vary with arc length. While the general model is comprised of differential equations, an analytic solution is given for two tubes of constant curvature. This solution enables analytic prediction of "snap through" instability based on a single dimensionless parameter. Simulation and experiments are used to illustrate the results.

  14. Explosion interaction with water in a tube

    Science.gov (United States)

    Homae, T.; Sugiyama, Y.; Wakabayashi, K.; Matsumura, T.; Nakayama, Y.

    2017-02-01

    As proposed and legislated in Japan, subsurface magazines have an explosive storage chamber, a horizontal passageway, and a vertical shaft for a vent. The authors found that a small amount of water on the floor of the storage chamber mitigated blast pressure remarkably. The mitigation mechanism has been examined more closely. To examine the effect of water, the present study assesses explosions in a transparent, square cross section, and a straight tube. A high-speed camera used to observe the tube interior. Blast pressure in and around the tube was also measured. Images obtained using the high-speed camera revealed that water inside the tube did not move after the explosion. Differences between cases of tubes without water and with water were unclear. Along with blast pressure measurements, these study results suggest that blast pressure mitigation by water occurs because of interaction between the explosion and the water near the explosion point.

  15. 2, 6-dichlorobenzonitrile Causes Multiple Effects on Pollen Tube Growth beyond Altering Cellulose Synthesis in Pinus bungeana Zucc

    Science.gov (United States)

    Hao, Huaiqing; Chen, Tong; Fan, Lusheng; Li, Ruili; Wang, Xiaohua

    2013-01-01

    Cellulose is an important component of cell wall, yet its location and function in pollen tubes remain speculative. In this paper, we studied the role of cellulose synthesis in pollen tube elongation in Pinus bungeana Zucc. by using the specific inhibitor, 2, 6-dichlorobenzonitrile (DCB). In the presence of DCB, the growth rate and morphology of pollen tubes were distinctly changed. The organization of cytoskeleton and vesicle trafficking were also disturbed. Ultrastructure of pollen tubes treated with DCB was characterized by the loose tube wall and damaged organelles. DCB treatment induced distinct changes in tube wall components. Fluorescence labeling results showed that callose, and acidic pectin accumulated in the tip regions, whereas there was less cellulose when treated with DCB. These results were confirmed by FTIR microspectroscopic analysis. In summary, our findings showed that inhibition of cellulose synthesis by DCB affected the organization of cytoskeleton and vesicle trafficking in pollen tubes, and induced changes in the tube wall chemical composition in a dose-dependent manner. These results confirm that cellulose is involved in the establishment of growth direction of pollen tubes, and plays important role in the cell wall construction during pollen tube development despite its lower quantity. PMID:24146903

  16. The relationship between Sonic hedgehog signalling, cilia and neural tube defects

    Science.gov (United States)

    Murdoch, Jennifer N.; Copp, Andrew J.

    2013-01-01

    The Hedgehog signalling pathway is essential for many aspects of normal embryonic development, including formation and patterning of the neural tube. Absence of Shh ligand is associated with the midline defect holoprosencephaly, while increased Shh signalling is associated with exencephaly and spina bifida. To complicate this apparently simple relationship, mutation of proteins required for function of cilia often leads to impaired Shh signalling and to disruption of neural tube closure. In this manuscript, we review the literature on Shh pathway mutants and discuss the relationship between Shh signalling, cilia and neural tube defects. PMID:20544799

  17. The Role of YouTube in Accessing Popular Music in Japan

    OpenAIRE

    GILLIS-FURUTAKA, Amanda

    2014-01-01

     YouTube was launched in 2005 as a site for people to share their home videos, but has expanded to become an unprecedented archive of freely available sound and visual aterial, as well as a platform for accessing the latest pop music releases. YouTube is also a major social networking site and is facilitating the exchange and appreciation of creative work both within and across national borders. These functions of YouTube will be discussed in relation to the findings of a two-stage rese...

  18. Cryogenic Thermal Absorptance Measurements on Small-Diameter Stainless Steel Tubing

    Science.gov (United States)

    Tuttle, James; Jahromi, Amir; Canavan, Edgar; DiPirro, Michael

    2015-01-01

    The Mid Infrared Instrument (MIRI) on the James Webb Space Telescope includes a mechanical cryocooler which cools its detectors to their 6 Kelvin operating temperature. The coolant gas flows through several meters of small-diameter stainless steel tubing, which is exposed to thermal radiation from its environment. Over much of its length this tubing is gold-plated to minimize the absorption of this radiant heat. In order to confirm that the cryocooler will meet MIRI's requirements, the thermal absorptance of this tubing was measured as a function of its environment temperature. We describe the measurement technique and present the results.

  19. Material modeling for multistage tube hydroforming process simulation

    Science.gov (United States)

    Saboori, Mehdi

    The Aerospace industries of the 21st century demand the use of cutting edge materials and manufacturing technology. New manufacturing methods such as hydroforming are relatively new and are being used to produce commercial vehicles. This process allows for part consolidation and reducing the number of parts in an assembly compared to conventional methods such as stamping, press forming and welding of multiple components. Hydroforming in particular, provides an endless opportunity to achieve multiple crosssectional shapes in a single tube. A single tube can be pre-bent and subsequently hydroformed to create an entire component assembly instead of welding many smaller sheet metal sections together. The knowledge of tube hydroforming for aerospace materials is not well developed yet, thus new methods are required to predict and study the formability, and the critical forming limits for aerospace materials. In order to have a better understanding of the formability and the mechanical properties of aerospace materials, a novel online measurement approach based on free expansion test is developed using a 3D automated deformation measurement system (AramisRTM) to extract the coordinates of the bulge profile during the test. These coordinates are used to calculate the circumferential and longitudinal curvatures, which are utilized to determine the effective stresses and effective strains at different stages of the tube hydroforming process. In the second step, two different methods, a weighted average method and a new hardening function are utilized to define accurately the true stress-strain curve for post-necking regime of different aerospace alloys, such as inconel 718 (IN 718), stainless steel 321 (SS 321) and titanium (Ti6Al4V). The flow curves are employed in the simulation of the dome height test, which is utilized for generating the forming limit diagrams (FLDs). Then, the effect of stress triaxiality, the stress concentration factor and the effective plastic

  20. Otitis Media with Effusion: Its Significance in the Deaf Student.

    Science.gov (United States)

    1982-06-01

    normalize tubal function, and cochlear implants which partially correct hear- ing losses thus reducing the devastating effect of OME in the hearing...screening method. Impedance audiometry (tympanometry and assessment of the middle ear reflex): This method stimulates the most controversy in...development of greater penetrating anti-microbials specifically designed for use in the middle ear space, development of scilastic eustachian tube implants to

  1. Barriers to limiting the practice of feeding tube placement in advanced dementia.

    Science.gov (United States)

    Shega, Joseph W; Hougham, Gavin W; Stocking, Carol B; Cox-Hayley, Deon; Sachs, Greg A

    2003-12-01

    In advanced dementia, many difficult decisions may arise as the disease progresses, including whether to use feeding by tube. Several recent articles question the benefit of percutaneous endoscopic gastrostomy (PEG) tube placement in persons with advanced dementia. However, patients with advanced dementia are still referred for PEG tubes. This study attempts to understand more about physician decisions to recommend PEG tube placement in patients with advanced dementia. Mailed survey. Random sample of 500 physicians from the American Medical Association Masterfile. Primary care physicians. Physician knowledge, beliefs, and self-reported practices of PEG tubes in advanced dementia. Of the 416 eligible participants, 195 completed surveys (response rate of 46.9%). A significant number of physicians believe PEG tubes have the following benefits in advanced dementia: reduce aspiration pneumonia (76.4%), and improve pressure ulcer healing (74.6%), survival (61.4%), nutritional status (93.7%), and functional status (27.1%). Most physicians underestimate 30-day mortality in patients who receive a PEG and more than half of physicians believe PEG tubes in advanced dementia are the standard of care. Also, a majority of physicians believe speech therapists, nurses, and nutritional support teams recommend feeding tubes, which influences their decision to recommend a PEG. Last, almost half of these respondents had a nursing home request PEG tube placement, leading physicians to recommend a PEG. We find a notable discord between physician opinion, reported practice, and the literature regarding PEG tubes in advanced dementia that reveals some of the barriers to decreasing the referral of these patients for PEG.

  2. Spina bifida and other neural tube defects.

    Science.gov (United States)

    Northrup, H; Volcik, K A

    2000-01-01

    NTDs, resulting from failure of the neural tube to close during the fourth week of embryogenesis, are the most common severely disabling birth defects in the United States, with a frequency of approximately 1 of every 2000 births. Neural tube malformations involving the spinal cord and vertebral arches are referred to as spina bifida, with severe types of spina bifida involving protrusion of the spinal cord and/or meninges through a defect in the vertebral arch. Depending on the level of the lesion, interruption of the spinal cord at the site of the spina bifida defect causes paralysis of the legs, incontinence of urine and feces, anesthesia of the skin, and abnormalities of the hips, knees, and feet. Two additional abnormalities often seen in children with spina bifida include hydrocephalus and the Arnold-Chiari type II malformation. Despite the physical and particular learning disabilities children with spina bifida must cope with, participation in individualized educational programs can allow these children to develop skills necessary for autonomy in adulthood. Advances in research to uncover the molecular basis of NTDs is enhanced by knowledge of the link between both the environmental and genetic factors involved in the etiology of NTDs. The most recent development in NTD research for disease-causing genes is the discovery of a genetic link to the most well-known environmental cause of neural tube malformation, folate deficiency in pregnant women. Nearly a decade ago, periconceptional folic acid supplementation was proven to decrease both the recurrence and occurrence of NTDs. The study of folate and its association with NTDs is an ongoing endeavor that has led to numerous studies of different genes involved in the folate metabolism pathway, including the most commonly studied thermolabile mutation (C677T) in the MTHFR gene. An additional focus for NTD research involves mouse models that exhibit both naturally occurring NTDs, as well as those created by

  3. The Role of Percutaneous Endoscopic Transgastric Jejunostomy in the Management of Enteral Tube Feeding

    OpenAIRE

    Toh Yoon, Ezekiel Wong

    2016-01-01

    Feeding-related adverse events after percutaneous endoscopic gastrostomy (PEG) such as aspiration pneumonia can impede the use of PEG. Percutaneous endoscopic transgastric jejunostomy (PEG-J) using large-bore jejunal tubes with gastric decompression function may improve outcomes by circumventing gastric passage during enteral nutrition and improving drainage of excessive gastric secretions. This report describes a case where PEG-J was successful in maintaining enteral tube feeding in a 72-yea...

  4. SEORious business: structural proteins in sieve tubes and their involvement in sieve element occlusion.

    Science.gov (United States)

    Knoblauch, Michael; Froelich, Daniel R; Pickard, William F; Peters, Winfried S

    2014-04-01

    The phloem provides a network of sieve tubes for long-distance translocation of photosynthates. For over a century, structural proteins in sieve tubes have presented a conundrum since they presumably increase the hydraulic resistance of the tubes while no potential function other than sieve tube or wound sealing in the case of injury has been suggested. Here we summarize and critically evaluate current speculations regarding the roles of these proteins. Our understanding suffers from the suggestive power of images; what looks like a sieve tube plug on micrographs may not actually impede translocation very much. Recent reports of an involvement of SEOR (sieve element occlusion-related) proteins, a class of P-proteins, in the sealing of injured sieve tubes are inconclusive; various lines of evidence suggest that, in neither intact nor injured plants, are SEORs determinative of translocation stoppage. Similarly, the popular notion that P-proteins serve in the defence against phloem sap-feeding insects is unsupported by empirical facts; it is conceivable that in functional sieve tubes, aphids actually could benefit from inducing a plug. The idea that rising cytosolic Ca(2+) generally triggers sieve tube blockage by P-proteins appears widely accepted, despite lacking experimental support. Even in forisomes, P-protein assemblages restricted to one single plant family and the only Ca(2+)-responsive P-proteins known, the available evidence does not unequivocally suggest that plug formation is the cause rather than a consequence of translocation stoppage. We conclude that the physiological roles of structural P-proteins remain elusive, and that in vivo studies of their dynamics in continuous sieve tube networks combined with flow velocity measurements will be required to (hopefully) resolve this scientific roadblock.

  5. Atmosphere in a Test Tube

    Science.gov (United States)

    Claudi, R.; Pace, E.; Ciaravella, A.; Micela, G.; Piccioni, G.; Billi, D.; Cestelli Guidi, M.; Coccola, L.; Erculiani, M. S.; Fedel, M.; Galletta, G.; Giro, E.; La Rocca, N.; Morosinotto, T.; Poletto, L.; Schierano, D.; Stefani, S.

    The ancestor philosophers' dream of thousand of new world is finally realised: more than 1800 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System. Others orbit the Habitable Zone (HZ) of their parent stars. Space missions, as JWST and the very recently proposed ARIEL, or ground based instruments, like SPHERE@VLT, GPI@GEMINI and EPICS@ELT, have been proposed and built to measure the atmospheric transmission, reflection and emission spectra over a wide wavelength range of these new worlds. In order to interpret the spectra coming out by this new instrumentation, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how those characteristics could be affected by radiation driven photochemical and bio-chemical reaction. Insights in this direction can be achieved from laboratory studies of simulated planetary atmosphere of different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. ''Atmosphere in a Test Tube'' is a collaboration among several Italian astronomical, biological and engineering institutes in order to share their experiencece in performing laboratory experiments on several items concerning extrasolar planet atmospheres.

  6. Dynamic tube movement of Ahmed glaucoma valve.

    Science.gov (United States)

    Law, Simon K; Coleman, Anne L; Caprioli, Joseph

    2009-01-01

    To report the dynamic movement of the tube of the Ahmed glaucoma valve (AGV) in the anterior chamber with eye movement. Three patients (eyes) with dynamic movement of the tube of the AGV out of approximately 1500 AGV implantations over 10 years were identified. Demographic information, management, and patient outcomes were abstracted from the medical records. Possible mechanisms of the tube movement are discussed. In all 3 eyes, the fibrovascular capsule and the plate were noted to be stationary in the superior temporal fornix under the conjunctiva and did not move with movement of the eye. The length of the intraocular portion of the tube varied between 3 and 4 mm, depending on the position of the globe. All 3 eyes had undergone at least 1 intraocular procedure before AGV implantation and 2 of 3 eyes had at least 1 intraocular procedure after the AGV implantation. The dynamic movement of the tube was first observed from 0.5 to 7 years after the AGVs were implanted. It was not associated with any intraocular reaction, damage of intraocular tissue, or decrease of intraocular pressure control, and no additional surgical intervention has been required. Dynamic movement of the tube of AGV results from dissociation of the fibrovascular capsule and the plate in the fornix from the rotation of the globe. The length of the intraocular portion of the tube may vary widely with eye movement.

  7. Miniature acoustic guidance system for endotracheal tubes

    Science.gov (United States)

    Juan, Eduardo J.

    Ensuring that the distal end of an endotracheal tube is properly located within the trachea, and that the tube is not obstructed by mucous deposition, is a major clinical concern in patients that require mechanical ventilation. A novel acoustic system was developed to allow for the continuous monitoring of endotracheal tube position and patency. A miniature sound source and two sensing microphones are placed in-line between the ventilator hose and the proximal end of the endotracheal tube. Reflections of an acoustic pulse from the endotracheal tube lumen and the airways are digitally analyzed to estimate the location and degree of obstruction, as well as the position of the distal end of the tube in the airway. The system was evaluated through computer simulations, in vitro studies, and in a rabbit model. The system noninvasively estimated tube position in vivo to within roughly 4.5 mm, and differentiated between proper tracheal, and erroneous bronchial or esophageal intubation in all cases. In addition, the system estimated the area and location of lumen obstructions in vitro to within 14% and 3.5 mm, respectively. These findings indicate that this miniature technology could improve the quality of care provided to the ventilated adult and infant.

  8. Gas Separation in the Ranque-Hilsch Vortex tube

    DEFF Research Database (Denmark)

    Linderstrøm-Lang, C. U.

    1964-01-01

    is reached that the centrifugation of the air, and only that, creates the gas separation detected in the outgoing streams. Its relation to the well-known temperature difference also produced between the two streams, is discussed. A flow scheme involving the radial and axial flow components, which permit......The gas separation taking place in the vortex tube is studied in detail. Both enrichment and depletion of a given component in any one of the two resultant streams may take place; the sign of this separation effect depends on certain parameters, notably the hot to cold flow ratio. A comparison...... of the data shows how the pattern of the effect curve, i.e. the separation effect as a function of hot flow fraction, varies with constructional parameters. Among these the ratio of the diameters of the two orifices through which the gas escapes from the tube, is of paramount importance. Also their magnitude...

  9. Flexible intramuscular micro tube electrode combining electrical and chemical interface.

    Science.gov (United States)

    Tian, Hong-Chang; Liu, Jing-Quan; Du, Jing-Cheng; Kang, Xiao-Yang; Zhang, Chuan; Yang, Bin; Chen, Xiang; Yang, Chun-Sheng

    2014-01-01

    With the rapidly developed micromachining technology, various kinds of sophisticated microelectrodes integrated with micro fluidic channels are design and fabricated for not only electrophysiological recording and stimulation, but also chemical drug delivery. As many efforts have been devoted to develop rigid microprobes for neural research of brain, few researchers concentrate on fabrication of flexible microelectrodes for intramuscular electrophysiology and chemical interfacing. Since crude wire electrodes still prevail in functional electrical stimulation (FES) and electromyography (EMG) recording of muscle, here we introduce a flexible micro tube electrode combining electrical and chemical pathway. The proposed micro tube electrode is manufactured based on polymer capillary, which provide circumferential electrode site contacting with electro-active tissue and is easy to manufactured with low cost.

  10. Stroke: Ineffective tube securement reduces nutrition and drug treatment

    OpenAIRE

    Brazier, S.; Taylor, S.J.; Allan, K; R. Clemente; Toher, D.

    2017-01-01

    Stroke patients with dysphagia often depend on nutrition, hydration and medication via nasogastric (NG) feeding tubes. Securing tubes using tape was associated with repeated tube loss. We determined cause and effect by auditing tube placement methods, delays incurred, duration and costs. Of 202 NG tube placements in 75 patients, 67 placements occurred in 17 patients over a full course of enteral nutrition (EN) and 40 of these placements were tracked. Tubes were secured by tape in 100%, mitten...

  11. Development of inconel alloys precision tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hee; Lee, D. H.; Shin, Y. S.; Park, J. H. [Changwon Speciality Steel Co., Ltd., Changwon (Korea); Kim, J. S.; Kim, H. P; Lim, Y. S.; Hwang, S. S.; Jung, M. K.; Woo, Y. M.; Han, C. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    1998-04-01

    The purpose of this research is to investigate the mass production facility and evaluation of profitability for steam generator tubing in nuclear power plant. The equipment requirement and capacity, total investment cost, the evaluation of mass production yield and production cost accounting, the manufacturing technique standardization have been investigated. According to the result of evaluation of profitability, the project for SG tubing will be difficult to commercialize, but it can be considered the re-commercialize when the condition for investment is improving. The results of this research can be applicated to commercialize the precision tubes manufacturing which require similar process. 17 refs., 7 figs., 21 tabs. (Author)

  12. Noninflammatory fallopian tube pathology in children

    Energy Technology Data Exchange (ETDEWEB)

    Merlini, Laura; Anooshiravani, Mehrak; Hanquinet, Sylviane [University Hospital HUG, Unit of Pediatric Radiology, Geneva (Switzerland); Vunda, Aaron [University Hospital, Clinic of Pediatric Surgery, Geneva (Switzerland); Borzani, Irene; Napolitano, Marcello [Ospedale Buzzi, Pediatric Radiology, Milan (Italy)

    2008-12-15

    Noninflammatory tubal abnormalities are rare in children and usually not well covered by traditional educational material. The presenting symptoms are nonspecific and are common to many other conditions, so its preoperative diagnosis is rarely made. The purpose of this study was to review the hospital charts and imaging findings in children and sexually inactive adolescents who showed fallopian tube pathology. Understanding of the pertinent findings of previous imaging examinations might assist radiologists in making the correct preoperative diagnosis and increase the likelihood of preserving the fallopian tubes. The clinical entities described in this article include isolated tubal torsion, paratubal cysts, hydrosalpinx, undescended/ectopic fallopian tube, and tubal inguinal hernia. (orig.)

  13. Nervous system examination on YouTube

    OpenAIRE

    Azer Samy A; AlEshaiwi Sarah M; AlGrain Hala A; AlKhelaif Rana A

    2012-01-01

    Abstract Background Web 2.0 sites such as YouTube have become a useful resource for knowledge and are used by medical students as a learning resource. This study aimed at assessing videos covering the nervous system examination on YouTube. Methods A research of YouTube was conducted from 2 November to 2 December 2011 using the following key words “nervous system examination”, “nervous system clinical examination”, “cranial nerves examination”, “CNS examination”, “examination of cerebellum”, “...

  14. Air Liquide Space Pulse Tube Cryocoolers

    Science.gov (United States)

    Tanchon, J.; Trollier, T.; Buquet, J.; Ravex, A.; Crespi, P.

    2008-03-01

    Thanks to important internal development efforts completed and partial ESA funding, AL/DTA is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as MTG, Sentinel 3, etc… The two pulse tube coolers thermo-mechanical units have been qualified against thermal and mechanical environment constraints. To complete these two Pulse Tube coolers, a Cooler Drive Electronic has been developed for active damping and vibration cancellation. The paper presents the current status of these products and associated Cooler Drive Electronics.

  15. Influence of furnace tube shapeon thermal strain of fire-tube boilers

    Directory of Open Access Journals (Sweden)

    Gaćeša Branka

    2014-01-01

    Full Text Available The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011

  16. EFFECT OF TUBE PITCH ON HEAR TRANSFER IN SPRINKLED TUBE BUNDLE

    Directory of Open Access Journals (Sweden)

    Petr Kracík

    2015-10-01

    Full Text Available Water flowing on a sprinkled tube bundle forms three basic modes: the Droplet mode (the liquid drips from one tube to another, the Jet mode (with an increasing flow rate, the droplets merge into a column and the Membrane (Sheet mode (with a further increase in the flow rate of the falling film liquid, the columns merge and create sheets between the tubes. With a sufficient flow rate, the sheets merge at this stage, and the tube bundle is completely covered by a thin liquid film. There are several factors influencing both the individual modes and the heat transfer. Beside the above-mentioned falling film liquid flow rate, these are for instance the tube diameters, the tube pitches in the tube bundle, or the physical conditions of the falling film liquid. This paper presents a summary of data measured at atmospheric pressure, with a tube bundle consisting of copper tubes of 12 millimetres in diameter, and with a studied tube length of one meter. The tubes are situated horizontally one above another at a pitch of 15 to 30 mm, and there is a distribution tube placed above them with water flowing through apertures of 1.0mm in diameter at a 9.2mm span. Two thermal conditions have been tested with all pitches: 15 °C to 40 °C and 15 °C to 45 °C. The temperature of the falling film liquid, which was heated during the flow through the exchanger, was 15 °C at the distribution tube input. The temperature of the heating liquid at the exchanger input, which had a constant flow rate of approx. 7.2. litres per minute, was 40 °C, or alternatively 45 °C.

  17. A compartmental model analysis of integrative and self-regulatory ion dynamics in pollen tube growth.

    Directory of Open Access Journals (Sweden)

    Junli Liu

    2010-10-01

    Full Text Available Sexual reproduction in higher plants relies upon the polarised growth of pollen tubes. The growth-site at the pollen tube tip responds to signalling processes to successfully steer the tube to an ovule. Essential features of pollen tube growth are polarisation of ion fluxes, intracellular ion gradients, and oscillating dynamics. However, little is known about how these features are generated and how they are causally related. We propose that ion dynamics in biological systems should be studied in an integrative and self-regulatory way. Here we have developed a two-compartment model by integrating major ion transporters at both the tip and shank of pollen tubes. We demonstrate that the physiological features of polarised growth in the pollen tube can be explained by the localised distribution of transporters at the tip and shank. Model analysis reveals that the tip and shank compartments integrate into a self-regulatory dynamic system, however the oscillatory dynamics at the tip do not play an important role in maintaining ion gradients. Furthermore, an electric current travelling along the pollen tube contributes to the regulation of ion dynamics. Two candidate mechanisms for growth-induced oscillations are proposed: the transition of tip membrane into shank membrane, and growth-induced changes in kinetic parameters of ion transporters. The methodology and principles developed here are applicable to the study of ion dynamics and their interactions with other functional modules in any plant cellular system.

  18. Design and fabrication of an IPMC-embedded tube for minimally invasive surgery applications

    Science.gov (United States)

    Liu, Jiayu; Wang, Yanjie; Zhao, Dongxu; Zhang, Chi; Chen, Hualing; Li, Dichen

    2014-03-01

    Minimally Invasive Surgery (MIS) is receiving much attention for a number of reasons, including less trauma, faster recovery and enhanced precision. The traditional robotic actuators do not have the capabilities required to fulfill the demand for new applications in MIS. Ionic Polymer-Metal Composite (IPMC), one of the most promising smart materials, has extensive desirable characteristics such as low actuation voltage, large bending deformation and high functionality. Compared with traditional actuators, IPMCs can mimic biological muscle and are highly promising for actuation in robotic surgery. In this paper, a new approach which involves molding and integrating IPMC actuators into a soft silicone tube to create an active actuating tube capable of multi-degree-of-freedom motion is presented. First, according to the structure and performance requirements of the actuating tube, the biaxial bending IPMC actuators fabricated by using solution casting method have been implemented. The silicone was cured at a suitable temperature to form a flexible tube using molds fabricated by 3D Printing technology. Then an assembly based fabrication process was used to mold or integrate biaxial bending IPMC actuators into the soft silicone material to create an active control tube. The IPMC-embedded tube can generate multi-degree-of-freedom motions by controlling each IPMC actuator. Furthermore, the basic performance of the actuators was analyzed, including the displacement and the response speed. Experimental results indicate that IPMC-embedded tubes are promising for applications in MIS.

  19. Tubes of discontinuous solutions of dynamical systems and their stability

    Science.gov (United States)

    Sesekin, A. N.; Zhelonkina, N. I.

    2017-10-01

    The article is devoted to investigation of nonlinear dynamical systems which applies the generalized effect. The generalized effect (or impulses) is the result of the presence on the right part of the system a generalized derivative of the function of bounded variation. Such system contains incorrect operation of multiplication of discontinuous function on the generalized function from the point of view of the theory of distributions. This incorrectness is overcome by the approximation of the generalized functions in the right part of system by the sequence of smooth approximations of the generalized influences by analogy with sequential approach of the theory of the generalized functions. This sequence generates a sequence of smooth solutions. Then limit of a sequence of smooth solutions is considered. If such limit exists it is offered to be used as a solution. The solution is understood as partial pointwise limit of such sequence if a sequence of smooth solutions does not converge. Such partial limits constitute a tube of solutions. The sufficient conditions are received for stability of tubes of discontinuous solutions.

  20. Pneumatosis intestinalis associated with enteral tube feeding

    National Research Council Canada - National Science Library

    Zorgdrager, Marcel; Pol, Robert

    2013-01-01

    ...). Explorative laparotomy showed an omental band adhesion without signs of ischaemia. After a short period of total parenteral nutrition PI resolved almost completely and enteral tube feeding could be continued once again...

  1. Automatic welding of stainless steel tubing

    Science.gov (United States)

    Clautice, W. E.

    1978-01-01

    The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

  2. Caring for Your Percutaneous Nephrostomy Tube

    Science.gov (United States)

    ... and medication through this line.  You will be awake, relaxed, and maybe a little sleepy during the ... tube.  If you have low urine output or dark, foul- Patient Information Procedure 1. Thoroughly wash your ...

  3. Screening for Open Neural Tube Defects.

    Science.gov (United States)

    Krantz, David A; Hallahan, Terrence W; Carmichael, Jonathan B

    2016-06-01

    Biochemical prenatal screening was initiated with the use of maternal serum alpha fetoprotein to screen for open neural tube defects. Screening now includes multiple marker and sequential screening protocols involving serum and ultrasound markers to screen for aneuploidy. Recently cell-free DNA screening for aneuploidy has been initiated, but does not screen for neural tube defects. Although ultrasound is highly effective in identifying neural tube defects in high-risk populations, in decentralized health systems maternal serum screening still plays a significant role. Abnormal maternal serum alpha fetoprotein alone or in combination with other markers may indicate adverse pregnancy outcome in the absence of open neural tube defects. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. The Choking Game on YouTube

    Directory of Open Access Journals (Sweden)

    Ellen K. Defenderfer MS

    2016-03-01

    Full Text Available The choking game (TCG is an adolescent activity in which asphyxiation is used to obtain a “high,” occasionally resulting in seizures or death. A plethora of TCG information is available through YouTube, though this content has not been evaluated recently. The current study described TCG as portrayed in YouTube videos and compared views and ratings of TCG videos to unrelated videos. The TCG videos demonstrated diverse methods of asphyxiation, with a minority showing injury to the participants. TCG videos were less likely to be commented on or rated positively than non–choking game videos. TCG prevention videos differed significantly from actual TCG videos in the way they depicted the social context of TCG. Thus, TCG videos are accessible through YouTube, but the prevention materials available on YouTube are not accurate or representative. Accurate and educational online prevention materials should be created to decrease the occurrence of TCG.

  5. Multimode Traveling-Wave Amplifier Tubes

    Science.gov (United States)

    Buck, E.

    1981-02-01

    The paper examines the recent developments which makes the Traveling Wave Tube (TWT) more powerful and efficient as a microwave amplifier than the solid state devices. Basic workings and efficiency, which can run, but usually do not, to 55%, are examined. The dependence of the performance of a given TWT upon the qualities of the beam and the manner of its focusing is described. Also described is the development of a multistage depressed collector (MDC) and its first application to a Communication Technology Satellite (CTS) tube, a 12 GHz, coupled-cavity, 200 watt TWT, which resulted in being operated in space for nearly four years and was both the most powerful and the most efficient (around 50%) communications TWT ever flown. It is predicted that the application of efficient refocusing and MDCs, made possible by computer simulations, will greatly increase tube efficiency, and thereby make practical, new multimode tubes which operate, as least partly, in a linear fashion.

  6. Gastroenteric tube feeding: Techniques, problems and solutions

    National Research Council Canada - National Science Library

    Irina Blumenstein Yogesh M Shastri Jürgen Stein

    2014-01-01

    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically...

  7. Medical Informatics Idle YouTube Potential.

    Science.gov (United States)

    Hucíková, Anežka; Babic, Ankica

    2017-01-01

    YouTube as an online video-sharing service in the context of Web 2.0 goes beyond the bounds of pure fun, for which the platform was primarily established. Nowadays, commonly to other social media, it serves also educational, informational and last but not least, marketing purposes. The importance of video sharing is supported by several predictions about video reaching over 90% of global internet traffic by 2020. Using qualitative content analysis over selected YouTube videos, paper examines the current situation of the platform's marketing potential usage by medical informatics organizations, researches and other healthcare professionals. Results of the analysis demonstrate several ways in which YouTube is already used to inform, educate or promote above-mentioned medical institutions. However, their engagement in self-promo or spreading awareness of their research projects via YouTube is considered to be low.

  8. YouTube and ‘psychiatry’

    Science.gov (United States)

    Gordon, Robert; Miller, John; Collins, Noel

    2015-01-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of ‘psychiatry’ during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of ‘psychiatry’ on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed. PMID:26755987

  9. A review of pulse tube refrigeration

    Science.gov (United States)

    Radebaugh, Ray

    1990-01-01

    This paper reviews the development of the three types of pulse tube refrigerators: basic, resonant, and orifice types. The principles of operation are given. It is shown that the pulse tube refrigerator is a variation of the Stirling-cycle refrigerator, where the moving displacer is substituted by a heat transfer mechanism or by an orifice to bring about the proper phase shifts between pressure and mass flow rate. A harmonic analysis with phasors is described which gives reasonable results for the refrigeration power, yet is simple enough to make clear the processes which give rise to the refrigeration. The efficiency and refrigeration power are compared with those of other refrigeration cycles. A brief review is given of the research being done at various laboratories on both one- and two-stage pulse tubes. A preliminary assessment of the role of pulse tube refrigerators is discussed.

  10. Opioid Use and Neural Tube Defects

    Science.gov (United States)

    ... CDC.gov . Error processing SSI file Key Findings: Opioid Use and Neural Tube Defects Recommend on Facebook ... new study that looked at the use of opioids during pregnancy and their relationship to having a ...

  11. Routine jejunostomy tube feeding following esophagectomy

    National Research Council Canada - National Science Library

    Weijs, Teus J; van Eden, Hanneke W.J; Ruurda, Jelle P.|info:eu-repo/dai/nl/257561021; Luyer, Misha D P; Steenhagen, Elles|info:eu-repo/dai/nl/304815713; Nieuwenhuijzen, Grard A P; van Hillegersberg, Richard|info:eu-repo/dai/nl/110706242

    2017-01-01

    Background: Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support...

  12. Accidental Decannulation OF TRACHEOSTOMY TUBES - Case Series.

    Science.gov (United States)

    Omokanye, H K; Dunmade, A D; Segun-Busari, S; Afolabi, O A; Habeeb, O G; Adegboye, M B; Alabi, B S

    2016-01-01

    Tracheostomy tube (TT) is usually removed in a planned manner once the patient ceases to have the condition that necessitated the procedure. Accidental decannulation or extubation refers to inadvertent removal of tracheostomy tube out of the stoma. It could prove fatal in an otherwise stable patient. We review a variety of unexpected and often-overlooked causes of accidental decannulation with suggestions on preventive measures. We therefore present three cases of accidental decannulation of tracheostomy tubes in order to report our experiences in the management of the condition. Accidental decannulation occurs both in hospitalized and patient on home care of their tracheostomy tubes. Reduction in neck circumference due to weight loss predisposes to accidental decannulation, which could be prevented by suturing the flange to the skin.

  13. Stabilization Strategies for Drift Tube Linacs

    CERN Document Server

    AUTHOR|(CDS)2085420; Lamehi Rashti, Mohammad

    The average axial electric fields in drift tube linac cavities are known to be sensitive with respect to the perturbation errors. Postcoupler is a powerful stabilizer devices that is used to reduce this sensitivity of average axial field. Postcouplers are the cylindrical rod which is extended from cavity wall toward the drift tube without touching the drift tube surface. Postcouplers need to be adjusted to the right length to stabilize the average axial field. Although postcouplers are used successfully in many projects, there is no straightforward procedure for postcouplers adjustment and it has been done almost based on trial and errors. In this thesis, the physics and characteristics of postcouplers has been studied by using an equivalent circuit model and 3D finite element method calculations. Finally, a straightforward and accurate method to adjust postcouplers has been concluded. The method has been verified by using experimental measurements on CERN Linac4 drift tube linac cavities.

  14. SPECIAL PURPOSE SHOCK TUBE for BLAST ASSESSMENT

    Data.gov (United States)

    Federal Laboratory Consortium — This device is a specially designed shock tube for testing fabric samples in a controlled environment. The device determines the appropriate types of sensors to be...

  15. Metal bellows custom-fabricated from tubing

    Science.gov (United States)

    1965-01-01

    Mandrel assembly mounted in a lathe chuck is used with a forming wheel to roll-form bellows from standard sheet metal tubing. Spacers and mandrels of various sizes custom-fabricate bellows of any desired dimensions.

  16. SNORKEL TRACHEOTOMY TUBE FOR RESPIRATOR USE

    Science.gov (United States)

    Lebo, Charles P.

    1954-01-01

    The Snorkel tracheotomy tube, a simple modification of the standard tube, overcomes many of the mechanical inconveniences usually encountered in the care of patients with tracheotomy who have to be kept in respirators. With it in place, it is not necessary to use special devices to hold the collar of the respirator away from the site of the tracheal incision. Nursing care of the patient is made easier. ImagesFigure 2.Figure 3. PMID:13182610

  17. Accidental Decannulation OF TRACHEOSTOMY TUBES - Case Series

    OpenAIRE

    Omokanye, HK; Dunmade, AD; Segun-Busari, S; Afolabi, OA; Habeeb, OG; Adegboye, MB; Alabi, BS

    2016-01-01

    Tracheostomy tube (TT) is usually removed in a planned manner once the patient ceases to have the condition that necessitated the procedure. Accidental decannulation or extubation refers to inadvertent removal of tracheostomy tube out of the stoma. It could prove fatal in an otherwise stable patient. We review a variety of unexpected and often-overlooked causes of accidental decannulation with suggestions on preventive measures. We therefore present three cases of accidental decannulation of ...

  18. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler....... The CHP system may also be operated in a heating or cooling mode, thus being able to heat or cool water by feeding electricity to the system....

  19. Explosively Bonded Gun Tube Liner Development

    Science.gov (United States)

    2015-04-01

    some concern was the occasional appearance of iron-Ta intermetallics near the liner-steel interface. This is a brittle phase and subject to...Montgomery JS, de Rosset WS. Examination of intermetallic phases and residual stresses resulting from explosive bonding of refractory metal gun tube...caliber smoothbore gun tube. The metallic bond produced by explosive bonding is extremely strong and presumably would keep the liner in place. In Phase

  20. Cyclic strain-mediated regulation of vascular endothelial cell migration and tube formation.

    Science.gov (United States)

    Von Offenberg Sweeney, Nicholas; Cummins, Philip M; Cotter, Eoin J; Fitzpatrick, Paul A; Birney, Yvonne A; Redmond, Eileen M; Cahill, Paul A

    2005-04-08

    Hemodynamic forces exerted by blood flow (cyclic strain, shear stress) affect the initiation and progression of angiogenesis; however, the precise signaling mechanism(s) involved are unknown. In this study, we examine the role of cyclic strain in regulating bovine aortic endothelial cell (BAEC) migration and tube formation, indices of angiogenesis. Considering their well-documented mechanosensitivity, functional inter-dependence, and involvement in angiogenesis, we hypothesized roles for matrix metalloproteinases (MMP-2/9), RGD-dependent integrins, and urokinase plasminogen activator (uPA) in this process. BAECs were exposed to equibiaxial cyclic strain (5% strain, 1Hz for 24h) before their migration and tube formation was assessed by transwell migration and collagen gel tube formation assays, respectively. In response to strain, both migration and tube formation were increased by 1.83+/-0.1- and 1.84+/-0.1-fold, respectively. Pertussis toxin, a Gi-protein inhibitor, decreased strain-induced migration by 45.7+/-32% and tube formation by 69.8+/-13%, whilst protein tyrosine kinase (PTK) inhibition with genistein had no effect. siRNA-directed attenuation of endothelial MMP-9 (but not MMP-2) expression/activity decreased strain-induced migration and tube formation by 98.6+/-41% and 40.7+/-31%, respectively. Finally, integrin blockade with cRGD peptide and siRNA-directed attenuation of uPA expression reduced strain-induced tube formation by 85.7+/-15% and 84.7+/-31%, respectively, whilst having no effect on migration. Cyclic strain promotes BAEC migration and tube formation in a Gi-protein-dependent PTK-independent manner. Moreover, we demonstrate for the first time a putative role for MMP-9 in both strain-induced events, whilst RGD-dependent integrins and uPA appear only to be involved in strain-induced tube formation.

  1. Identification and exploration of pollen tube small proteins encoded by pollination-induced transcripts.

    Science.gov (United States)

    Huang, Jong-Chin; Chang, Liang-Chi; Wang, Min-Long; Guo, Cian-Ling; Chung, Mei-Chu; Jauh, Guang-Yuh

    2011-09-01

    Pollination is composed of cell-cell communication and complicated signaling cascades that regulate pollen tube growth and guidance toward the ovules for double fertilization, and is critical for successful sexual reproduction. Exploring expression profiles of in vivo grown pollen tubes is important. Nevertheless, it is difficult to obtain accessible pollen tubes for profiling studies in most model plants. By taking advantage of the hollow styles of lily (Lilium longiflorum), in vivo pollen tubes harvested from pollinated styles which had been cut open were used here to study their protein and transcript profiles. Pollination quantitatively and qualitatively altered the total protein composition of elongating pollen tubes. cDNAs generated and amplified from total RNAs of 24 h in vivo grown and 12 h in vitro cultured pollen tubes were used for suppression subtractive hybridization analyses and preparation of home-made array chips. Microarray analyses conducted with different probe sets revealed 16 transcripts specifically present and/or enriched in in vivo pollen tubes. Reverse transcription-PCR (RT-PCR), in situ hybridization and Northern blotting were applied to validate their unique pollination-induced expression features. Interestingly, several transcripts were simultaneously detected on the stylar transmitting tract epidermis, where in vivo pollen tubes tightly adhered during pollination. Their deduced amino acid sequences showed that most of them encoded small proteins and could be classified into several families. Transient assay revealed filament-like structures decorated by these proteins and one probably localized in the generative cell. These small peptides might be critical for pollen tube growth during pollination, and further exploration of their biological functions and mechanisms of action are of great interest.

  2. Tube current reduction in pediatric non-ECG-gated heart CT by combined tube current modulation.

    Science.gov (United States)

    Goo, Hyun Woo; Goo, Hyum Woo; Suh, Dong Soo

    2006-04-01

    Dose reduction by combined tube current modulation has not been evaluated in pediatric low-dose CT. This study was performed to evaluate tube current reduction in non-ECG-gated heart CT angiography in children by combined tube current modulation, and to assess the effects of body weight, age, sex, and scan direction on tube current reduction. From September 2004 to January 2005, non-ECG-gated heart CT examinations were performed with combined tube current modulation in 50 children (median age 1 year, range 1 month to 16 years; M/F 29/21) with congenital heart disease. Sixteen-slice spiral CT studies were obtained using a weight-based low-dose protocol (80 kVp, 50-160 effective mA). CT scans were obtained in the craniocaudal direction when leg veins (n=36) were used for IV injection of contrast agent and in the caudocranial direction when arm veins (n=13) were used. In one child who underwent a Fontan operation, both arm and leg veins were used. We calculated tube current reduction by combined tube current modulation and evaluated the effects of body weight, age, sex, and scan technique on tube current reduction. The quality of CT angiography images was visually evaluated by an experienced pediatric radiologist. Overall tube current reduction by combined tube current modulation was 15.8+/-11.1%. The reduction was variable among five body weight groups (9.3+/-7.9% for ECG-gated heart CT by 15.8% without degradation of image quality. With our CT protocol, for body weights up to 39.9 kg, age showed a significant positive correlation with tube current reduction, but there was a lower dose-saving effect in children heavier than 40 kg. Tube current reduction was not affected by sex, but was affected by scan direction.

  3. Investigations on high-pressure ribbed tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kling, G.

    1942-05-01

    During hydrogenation of coal, the reactants (coal paste and hydrogen) had to be heated to reaction temperature partly by heat exchange with products and partly by heating in hairpin tubes of a preheater. These hairpin tubes were heated externally by hot circulating gases. In order to improve heat transfer from the gases to the tubes, various types of metal ribbing were welded to the tubes to catch more heat and transfer it to the tubes. This report detailed some studies on the best shapes and dimensions and numbers of plates to be used. The report was limited to flat, rectangular-cross-section plates attached perpendicularly, instead of including flat circular plates, spiral plates, or other configurations. The advantage of greater surface area to catch more heat had to be balanced off against the disadvantage of greater surface area to absorb more heat in internal resistance to heat flow. The report described the experimental conditions, the modifications tested, and the shape decided upon as best for flat plates. Some of the diagrams illustrating temperature distributions around the tubes and ribs were presented in imitation three-dimenional formats. 16 figures.

  4. Insulation co-ordination and the enlargement law for the GM counter tube

    Directory of Open Access Journals (Sweden)

    Dolićanin Edin Ć.

    2016-01-01

    Full Text Available In this paper we analyze application of contemporary methods of insulation co-ordination and the enlargement law in designing a GM counting tube. It has been shown that by applying insulation co-ordination methods the counting tube can be optimally dimensioned. The application of the enlargement law was demonstrated in generalizing the results of test obtained by the GM tube to those obtained by the counting tube with m-times greater dimensions. The investigations were conducted both theoretically and by experiment. Using theoretical analysis, we derived the expressions that may be applied if a performance function of a random variable breakdown voltage is known. The experiments were conducted on a GM counter model under well controlled laboratory conditions.

  5. Evaluation on mechanical and corrosion properties of steam generator tubing materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Sup; Lee, Byong Whi; Lee, Sang Kyu; Lee, Young Ho; Kim, Jun Whan; Lee, Ju Seok; Kwon, Hyuk Sang; Kim, Su Jung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-06-15

    Steam generator is one of the major components of nuclear reactor pressure boundary. It's main function os transferring heat which generated in the reactor to turbine generator through steam generator tube. In these days, steam generator tubing materials of operating plant are used Inconel 600 alloys. But according to the operation time, there are many degradation phenomena which included mechanical damage due to flow induced vibration and corrosion damage due to PWSCC, IGA/SCC and pitting etc. Recently Inconel 690 alloys are selected as new and replacement steam generator tubes for domestic nuclear power plant. But there are few study about mechanical and corrosion properties of Inconel 600 and 690. The objectives of this study is to evaluate and compare mechanical and corrosion propertied of steam generator tube materials.

  6. Multi objective optimization of foam-filled circular tubes for quasi-static and dynamic responses

    Directory of Open Access Journals (Sweden)

    Fauzan Djamaluddin

    Full Text Available AbstractFuel consumption and safety are currently key aspects in automobile design. The foam-filled thin-walled aluminium tube represents a potentially effective material for use in the automotive industry, due to its energy absorption capability and light weight. Multi-objective crashworthiness design optimization for foam-filled double cylindrical tubes is presented in this paper. The double structures are impacted by a rigid wall simulating quasi-static and dynamic loadings. The optimal parameters under consideration are the minimum peak crushing force and maximum specific energy absorption, using the non-dominated sorting genetic algorithm-II (NSGA-II technique. Radial basis functions (RBF and D-Optimal are adopted to determine the more complex crashworthiness functional objectives. The comparison is performed by finite element analysis of the impact crashworthiness characteristics in tubes under static and dynamic loads. Finally, the optimum crashworthiness performance of empty and foam-filled double tubes is investigated and compared to the traditional single foam-filled tube. The results indicate that the foam-filled double aluminium circular tube can be recommended for crashworthy structures.

  7. Steam Generator tube integrity -- US Nuclear Regulatory Commission perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E.L.; Sullivan, E.J.

    1997-02-01

    In the US, the current regulatory framework was developed in the 1970s when general wall thinning was the dominant degradation mechanism; and, as a result of changes in the forms of degradation being observed and improvements in inspection and tube repair technology, the regulatory framework needs to be updated. Operating experience indicates that the current U.S. requirements should be more stringent in some areas, while in other areas they are overly conservative. To date, this situation has been dealt with on a plant-specific basis in the US. However, the NRC staff is now developing a proposed steam generator rule as a generic framework for ensuring that the steam generator tubes are capable of performing their intended safety functions. This paper discusses the current U.S. regulatory framework for assuring steam generator (SG) tube integrity, the need to update this regulatory framework, the objectives of the new proposed rule, the US Nuclear Regulatory Commission (NRC) regulatory guide (RG) that will accompany the rule, how risk considerations affect the development of the new rule, and some outstanding issues relating to the rule that the NRC is still dealing with.

  8. NEI You Tube Videos: Amblyopia

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    Full Text Available ... and other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and ... National Eye Health Education Program (NEHEP) Diabetic Eye Disease Education Program Glaucoma Education Program Low Vision Education ...

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    Full Text Available ... and other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of ... National Eye Health Education Program (NEHEP) Diabetic Eye Disease Education Program Glaucoma Education Program Low Vision Education ...

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    Full Text Available ... programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health ... Pressroom Contacts Dustin Hays - Chief, Science Communication dustin.hays@nih.gov Anna Harper - Media Relations ...

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    Full Text Available ... to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and requirements of ... Pressroom Contacts Dustin Hays - Chief, Science Communication dustin.hays@nih.gov Anna Harper - Media Relations ...

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    Full Text Available ... to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and requirements of the blind.” ... Health Information Frequently asked questions ...

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    Full Text Available ... eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and ... Clinical Studies Publications Catalog Photos and Images Spanish Language Information Grants and Funding Extramural Research Division of ...

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... of visual function, preservation of sight, and the special health problems and requirements of the blind.” News & ... Emily Y. Chew, M.D., Deputy Clinical Director Education Programs National Eye Health Education Program (NEHEP) Diabetic ...

  15. Biodegradable and Multifunctional Polymer Micro-Tubes for Targeting Photothermal Therapy

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2014-07-01

    Full Text Available We describe an innovative form of polymer micro-tubes with diverse functions including biodegradation, magnetic manipulation, and photothermal effect that employs and activates photothermal therapy to target cancer cells. The micro-tube comprised soybean protein isolate, poly-l-glutamic acid, magnetite nanoparticles, plus gold nanoparticles. Through electrostatic force, these components, with opposite charges, formed pairs of layers in the pores of the template, various bilayers of soybean protein isolate and poly-l-glutamic acid served as the biodegradable building wall to each micro-tube. The layers of magnetite nanoparticle functionalized micro-tubes enabled the micro-tube manipulate to target the cancer cells by using an external magnetic field. The photo-thermal effect of the layer of gold nanoparticles on the outer surface of the micro-tubes, when under irradiation and when brought about by the near infrared radiation, elevated each sample’s temperature. In addition, and when under the exposure of the near infrared radiation, the elevated temperature of the suspension of the micro-tubes, likewise with a concentration of 0.2 mg/mL, and similarly with a power of 2 W and as well maintained for 10 min, elevated the temperature of the suspension beyond 42 °C. Such temperatures induced apoptosis of target cancer cells through the effect of photothermal therapy. The findings assert that structured micro-tubes have a promising application as a photothermal agent. From this assertion, the implications are that this multifunctional agent will significantly improve the methodology for cancer diagnosis and therapy.

  16. Statistical analysis and modelling of in-reactor diametral creep of Zr-2.5Nb pressure tubes

    Energy Technology Data Exchange (ETDEWEB)

    Jyrkama, Mikko I., E-mail: mjyrkama@uwaterloo.ca [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada N2L 3G1 (Canada); Bickel, Grant A., E-mail: grant.bickel@cnl.ca [Canadian Nuclear Laboratories, Chalk River Laboratories, Chalk River, ON, Canada K0J 1J0 (Canada); Pandey, Mahesh D., E-mail: mdpandey@uwaterloo.ca [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada N2L 3G1 (Canada)

    2016-04-15

    Highlights: • New and simple statistical model of pressure tube diametral creep. • Based on surveillance data of 328 pressure tubes from eight different CANDU reactors. • Uses weighted least squares (WLS) to regress out operating conditions. • The shape of the diametral creep profiles are predicted very well. • Provides insight and relative ranking of strain behaviour of in-service tubes. - Abstract: This paper presents the development of a simplified regression approach for modelling the diametral creep over time in Zr-2.5 wt% Nb pressure tubes used in CANDU reactors. The model is based on a large dataset of in-service inspection data of 328 different pressure tubes from eight different CANDU reactor units. The proposed weighted least squares (WLS) regression model is linear in time as a function of flux and temperature, with a temperature-dependent variance function. The model predicts the shape of the observed diametral creep profiles very well, and is useful not merely for prediction, but also for assessing tube-to-tube variability and manufacturing properties among the inspected tubes.

  17. Full penetration current variation of a superconducting tube

    Energy Technology Data Exchange (ETDEWEB)

    Douine, B; Leveque, J; Netter, D [GREEN, University of Nancy, BP 139, F-54506 Vandoeuvre-les-Nancy (France)], E-mail: Bruno.Douine@green.uhp-nancy.fr

    2008-02-01

    It is well known that the critical current density J{sub c} of a superconducting material depends on the magnetic field B. If magnetic independent J{sub c} is chosen for analytical calculation of current distribution, the critical current I{sub c0} corresponds to full penetration current I{sub p}. I{sub c0} is a measured current with 1{mu}V/cm criterion and I{sub p} is a calculated current. The aim of this paper is to present I{sub p} variation of superconducting tube. To calculate I{sub p}, which is depending on the material itself, a linear function J{sub c}(B) is sufficient to obtain realistic values by analytic way. We need to have a linear J{sub c}(B) law (J{sub c}(B)=J{sub C0}.(1-|B|/B{sub J0}) that is close to the measured J{sub c}(B) characteristics presented in this paper. The linear J{sub c}(B) law chosen was used for the calculation of the distribution of both magnetic field B(r, t) and the current density J(r, t). These distributions allow the analytical calculation of I{sub p}. We present the variation of I{sub p} with material characteristics and geometric parameters of the tube. The two main results are presented. I{sub p} decreases when B{sub J0} increases for same J{sub C0}. I{sub p} increases when the tube internal radius R{sub in} increases for same tube section. For AC losses versus current curves, I{sub p} is the frontier between low and high losses. So the present results, allow designing future transport current superconducting cable.

  18. Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development

    Energy Technology Data Exchange (ETDEWEB)

    Pschirer, James [Alstom Power Inc., Windsor, CT (United States); Burgess, Joshua [Alstom Power Inc., Windsor, CT (United States); Schrecengost, Robert [Alstom Power Inc., Windsor, CT (United States)

    2017-08-16

    Alstom Power Inc., a wholly owned subsidiary of the General Electric Company (GE), has completed the project “Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development” under U.S. Department of Energy (DOE) Award Number DE-FE0024076. This project was part of DOE’s Novel Crosscutting Research and Development to Support Advanced Energy Systems program. AUSC Tube Membrane Panel Development was a two and one half year project to develop and verify the manufacturability and serviceability of welded tube membrane panels made from high performance materials suitable for the AUSC steam cycles, defined as high pressure steam turbine inlet conditions of 700-760°C (1292-1400°F) and 24.5-35MPa (3500-5000psi). The difficulty of this challenge lies in the fact that the membrane-welded construction imposes demands on the materials that are unlike any that exist in other parts of the boiler. Tube membrane panels have been designed, fabricated, and installed in boilers for over 50 years with relatively favorable experience when fabricated from carbon and Cr-Mo low alloy steels. The AUSC steam cycle requires membrane tube panels fabricated from materials that have not been used in a weldment with metal temperatures in the range of 582-610°C (1080-1130°F). Fabrication materials chosen for the tubing were Grade 92 and HR6W. Grade 92 is a creep strength enhanced ferritic Cr-Mo alloy and HR6W is a high nickel alloy. Once the materials were chosen, GE performed the engineering design of the panels, prepared shop manufacturing drawings, and developed manufacturing and inspection plans. After the materials were purchased, GE manufactured and inspected the tube membrane panels, determined if post fabrication heat treatment of the tube membrane panels was needed, performed pre- and post-weld heat treatment on the Grade 92 panels, conducted final nondestructive inspection of any heat treated tube membrane panels, conducted destructive inspection of the completed tube

  19. Testing of Colorimetric Tubes for Nitrogen Dioxide and Monomethylhydrazine.

    Science.gov (United States)

    Diamond, Philip

    Colorimetric tubes for nitrogen dioxide (NO2) and monomethylhydrazine (MMH) were tested for accuracy and results indicate that at the levels checked the tubes' average deviation was plus or minus 20 percent. Tube NO2 concentrations all read lower than the analyzed concentrations. MMH tubes read much higher than the analyzed concentration of 0.28…

  20. 16 CFR 1507.12 - Multiple-tube fireworks devices.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Multiple-tube fireworks devices. 1507.12... REGULATIONS FIREWORKS DEVICES § 1507.12 Multiple-tube fireworks devices. (a) Application. Multiple-tube mine and shell fireworks devices with any tube measuring 1.5 inches (3.8 cm) or more in inside diameter and...

  1. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted into...

  2. 46 CFR 153.979 - Gauging with a sounding tube.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Gauging with a sounding tube. 153.979 Section 153.979... Procedures § 153.979 Gauging with a sounding tube. (a) No person may remove the cover of a sounding tube... cargo transfer may not authorize removal of the cover from a sounding tube gauge unless all tank...

  3. 21 CFR 870.4390 - Cardiopulmonary bypass pump tubing.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pump tubing. 870.4390... bypass pump tubing. (a) Identification. A cardiopulmonary bypass pump tubing is polymeric tubing which is... through the cardiopulmonary bypass circuit. (b) Classification. Class II (performance standards). ...

  4. Development, prevention, and treatment of feeding tube dependency

    NARCIS (Netherlands)

    Krom, Hilde; de Winter, J. Peter; Kindermann, Angelika

    2017-01-01

    Enteral nutrition is effective in ensuring nutritional requirements and growth. However, when tube feeding lasts for a longer period, it can lead to tube dependency in the absence of medical reasons for continuation of tube feeding. Tube-dependent children are unable or refuse to start oral

  5. Acoustic Resonance in Cylindrical Tubes with Side Branches

    Science.gov (United States)

    2013-05-01

    branches and tubes that change diameter. 4. Musical Instrument Design A flute is essentially a hollow tube with a way at one end to modulate the...an integer (1,2,3,…). 12 Figure 5. Tube with no holes. The addition of a side branch effectively changes the length of the tube, so in a flute

  6. General tube law for collapsible thin and thick-wall tubes.

    Science.gov (United States)

    Kozlovsky, Pavel; Zaretsky, Uri; Jaffa, Ariel J; Elad, David

    2014-07-18

    Modeling the complex deformations of cylindrical tubes under external pressure is of interest in engineering and physiological applications. The highly non-linear post-buckling behavior of cross-section of the tube during collapse attracted researchers for years. Major efforts were concentrated on studying the behavior of thin-wall tubes. Unfortunately, the knowledge on post-buckling of thick-wall tubes is still incomplete, although many experimental and several theoretical studies have been performed. In this study we systematically studied the effect of the wall thickness on post-buckling behavior of the tube. For this purpose, we utilized a computational model for evaluation of the real geometry of the deformed cross-sectional area due to negative transmural (internal minus external) pressure. We also developed an experimental method to validate the computational results. Based on the computed cross-sections of tubes with different wall thicknesses, we developed a general tube law that accounts for thin or thick wall tubes and fits the numerical data of computed cross-sectional areas versus transmural pressures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Automated Determination of Oxygen-Dependent Enzyme Kinetics in a Tube-in-Tube Flow Reactor

    DEFF Research Database (Denmark)

    Ringborg, Rolf Hoffmeyer; Pedersen, Asbjørn Toftgaard; Woodley, John

    2017-01-01

    and limited oxygen supply. Here, we present a novel method for the collection of such kinetic data using a pressurized tube-in-tube reactor, operated in the low-dispersed flow regime to generate time-series data, with minimal material consumption. Experimental development and validation of the instrument...

  8. Fluid heating by current injection tubes; Chauffage de fluides par tubes a passage de courant

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.S. [Societe Parmilleux (France)

    1999-04-01

    Current injection tube technology may be applied in compact fluid heating installation with a very low level of thermal inertia. The technology is particularly suitable for heating heat-sensitive fluids or those with a tendency to foul other types of installations. Specific advantages of current injection tubes include the elimination of cold spots and their reduced volume requirements. (author)

  9. UNUSUAL SITE OF OBSTRUCTION IN A FLEXOMETALLIC TUBE

    Directory of Open Access Journals (Sweden)

    Habib Rahaman

    2014-12-01

    Full Text Available Maxillofacial procedure such as LeFort I osteotomy requires Transmyelohyoid Intubation. For that initial intubation is done with Flexometallic Endotracheal Tube so that this tube can be easily brought out through transmyelohyoid incision. Frequently Flexometallic tubes are reused after Ethylene Oxide Sterilisation because of high Cost. Here we present an obstruction to endotracheal tube at an unusual location, (Deformity of the tube at the level of Cuff, with intact cuff.

  10. Automated Diagnosis and Classification of Steam Generator Tube Defects

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gabe V. Garcia

    2004-10-01

    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  11. NEI You Tube Videos: Amblyopia

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  13. Development of a photomultiplier tube with high quantum efficiency

    CERN Document Server

    Shima, T

    1999-01-01

    We propose a new method to significantly increase the quantum efficiency of a photomultiplier tube by employing a multi-photocathode and a mirror to produce photoelectrons by reusing photons transmitted by a single photocathode. In order to estimate the expected performance of the new photomultiplier, we studied the spectral responses of the reflectance, transmittance, and quantum efficiency of a K sub 2 CsSb photocathode as a function of the wavelength of incident light. A large enhancement of the quantum efficiency is expected in the regions between lambda=280 and 650 nm. (author)

  14. Overall presentation of the Ranque-Hilsch tube

    Energy Technology Data Exchange (ETDEWEB)

    Sibbertsen, W.; Orlowski, S.; Broers, R.

    1985-07-15

    The structure and functioning of the turbulence tube based on the Ranque effect are described. The influence of the state of the air-injected gas and of the geometry of the turbulence pipe on the temperature separating effect are presented in the form of literature; the definition of the level of effectiveness is explained. Practical applications of the turbulence pipe are indicated. Among others these include on-site cooling in mines, gas liquefaction and air conditioning in super-sonic aircraft. (BR).

  15. Folate receptors and neural tube closure.

    Science.gov (United States)

    Saitsu, Hirotomo

    2017-09-01

    Neural tube defects (NTD) are among the most common human congenital malformations, affecting 0.5-8.0/1000 of live births. Human clinical trials have shown that periconceptional folate supplementation significantly decreases the occurrence of NTD in offspring. However, the mechanism by which folate acts on NTD remains largely unknown. Folate receptor (Folr) is one of the three membrane proteins that mediate cellular uptake of folates. Recent studies suggest that mouse Folr1 (formerly referred to as Fbp1) is essential for neural tube closure. Therefore, we examined spatial and temporal expression patterns of Folr1 in developing mouse embryos, showing a close association between Folr1 and anterior neural tube closure. Transient transgenic analysis was performed using lacZ as a reporter; we identified a 1.1-kb enhancer that directs lacZ expression in the neural tube and optic vesicle in a manner that is similar to endogenous Folr1. The 1.1-kb enhancer sequences were highly conserved between humans and mice, suggesting that human FOLR1 is associated with anterior neural tube closure in humans. Several experimental studies in mice and human epidemiological and genetics studies have suggested that folate receptor abnormalities are involved in a portion of human NTDs, although the solo defect of FOLR1 did not cause NTD. © 2017 Japanese Teratology Society.

  16. Geiger-Muller tubes and their manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Gair, S.A.; Copleston, R.E.

    1991-02-06

    A Geiger-Muller tube designed for use in an environment subjected to mechanical shock and vibration has a tensioned anode wire secured between first and second mounts located at opposite ends of the tube envelope. The wire tension is adjusted, preferably with a screwable-adjustment means which is locked in the adjusted position, so that the natural frequency of vibration of the tensioned wire does not resonate with any frequency to which the tube is subjected in use. The adjustment means may be included in the mount via which the envelope is evacuated and back-filled with the ionizable gas, and a gas-tight seal can be provided around this part of the mount for example by sealing off the gas pump tube. However the adjustment means may be designed into another part of the tube, for example using telescopic parts of the envelope whose sliding junction is made gas tight with a flexible seal. Alternatively, the desired tension may be obtained by welding the wire to the first mount, passing it through the second mount, tensioning it and then crimping it to the second mount. (Author).

  17. Administration of antiretroviral medication via enteral tubes.

    Science.gov (United States)

    Prohaska, Emily S; King, Allison R

    2012-12-15

    Case reports and other published or manufacturer-provided data on the administration of antiretroviral agents through enteral feeding tubes are reviewed. There is very limited published evidence to guide clinicians in the delivery of therapies for human immunodeficiency virus (HIV) infection by feeding tubes, especially crushed tablets and capsule contents. A search of the primary literature (through February 2012) identified a total of nine articles describing the delivery of highly active antiretroviral therapy (HAART) agents via gastrostomy (G), jejunostomy, and other feeding tubes; correspondence with pharmaceutical manufacturers yielded additional information. Most of the published evidence (from two prospective studies, one retrospective study, and six case reports) pertains to the treatment of HIV-infected children (33 of 40 cases). Although not a primary endpoint of any of the reviewed studies, viral suppression was documented in 29 of the 40 patients referenced in the reviewed articles. Manufacturer-provided information indicates that crushed darunavir tablets in suspension, as well as oral solutions of ritonavir and lopinavir-ritonavir, can be administered through G-tubes without significant loss of therapeutic efficacy. Data regarding enteral feeding tube administration are available for 63% of commercially available oral HAART agents and are primarily limited to case reports specific to the pediatric population.

  18. Jejunostomy tube feeding in patients undergoing esophagectomy.

    Science.gov (United States)

    Srinathan, Sadeesh K; Hamin, Tamara; Walter, Stephen; Tan, A Lawrence; Unruh, Helmut W; Guyatt, Gordon

    2013-12-01

    Surgical jejunostomy tubes are a routine part of elective esophagectomies in patients with carcinomas and provide a route for nutritional support in those who experience complications. We wished to determine how frequently oral intake is delayed and the amount of nutrition delivered via the jejunostomy tube. We reviewed the charts of all adults undergoing esophagectomy for carcinoma between January 2000 and June 2008. We determined the proportion of patients unable to resume oral nutrition after 8 days and the amount of nutrition delivered in each of the 8 days. In all, 111 patients underwent elective esophagectomy for carcinoma, and 103 had a jejunostomy tube placed. The mean age was 67 ± 10.8 years. The median time to oral intake was 7 (interquartile range 7-11) days. Seventy-four (67%) patients resumed oral intake within 8 days. The mean nutrition delivered by jejunostomy within the first 8 days as a percentage of the target was 45.6% (95% confidence interval 41.2%-49.9%). Six (5.4%) patients experienced complications attributable solely to the jejunostomy tube; 3 (2.9%) required surgery. Forty (38.8%) patients had abdominal issues serious enough to warrant delaying the progression of feeding. Two-thirds of patients undergoing elective esophagectomy were tolerating oral intake by the end of the eighth postoperative day, and less than half of the target nutrition was delivered over the first 8 days. We now selectively place surgical jejunostomy tubes in patients undergoing elective esophagectomies.

  19. Design and evaluate finned tube bundles

    Energy Technology Data Exchange (ETDEWEB)

    Ganapathy, V. [ABCO Industries, Abilene, TX (United States)

    1996-09-01

    Finned tube bundles are widely used in heat exchangers, air coolers, waste heat boilers and fired heaters where energy transfer occurs between clean flue gases and a fluid with a high heat-transfer coefficient. They have several advantages including compactness, low gas pressure drop and low weight for a given duty compared to bare tube bundles. Choosing a fin type, arrangement and fin configuration requires a thorough analysis and economic evaluation. The solution is not unique since it depends on material and labor costs. Surface areas vary widely in finned tube designs for the same duty and gas pressure drop. Therefore, decisions should not be based on surface area alone. Plant engineers and consultants should consider operating costs in their evaluation because they accrue year after year. Selecting a boiler based on initial costs alone is not prudent. The paper discusses heat transfer and gas pressure drop with finned tubes, determining fin efficiency and effectiveness,g as pressure drop, tube wall and fin top temperatures, an example calculation, the effect of fin configuration on design, the effect of inline versus staggered arrangements and solid versus serrated fins, and concerns with high fin-density designs.

  20. Construction of preheaters with horizontal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Goetze

    1944-09-27

    This report involved construction of preheaters for distillation and cracking plants in the oil industry, particularly in America. The use of heat transmission by radiation was also a consideration here. The recycling of waste gases occurred, but was not the rule. A convection section was often built next to the radiation section, in which the discharge gases were used for heating the incoming product. The general arrangement of the preheaters was discussed. The first form was a rectangular box with fireproof lining with tubes arranged in a single row along the outer walls and sometimes in a double row on the ceiling. It consisted of smooth and finned tubes. From the simple form a double preheater was developed that allowed one or two common discharge flues to provide as large a heating surface as possible within a reasonable space. Other items discussed were recycling of waste gases, reasons for the choice of horizontal preheaters with radiation heating, the use of vertical tubes in the U.S.A. and elsewhere in the oil industry, details of horizontal preheater tubes, end closures, material, suspension, protection against overloading by radiation, circulation heating, burners, use of horizontal radiation preheaters in hydrogenation in the U.S.A., rebuilding I. G. preheaters, construction, tube supports, and masonry. A list of references on cracking, preheaters, heat transmission, and alloyed steels was given.

  1. Mechanical properties of ceramic composite tubes

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, W.A.; Oleksuk, L.L.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Stinton, D.P. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    Results of axial tension tests on SiC/SiC tubular ceramic composite components fabricated by a forced-M technique are presented. Axial elastic modulus measurements on a number of tubes show that the Young`s modulus varies along the length of the tube, with occasional very stiff or very soft regions. Tests to failure on a few tubes show the initiation of non-linear stress-strain behavior to be in the range of 3-9 ksi, followed by extensive non-linear deformation up to failure. For one tube, the failure stress obtained was 20.1 ksi, but the strains to failure at various axial locations varies from 0.19%to 0.24%. The correlation between modulus and proportional limit is considered within the ACK matrix cracking theory and within a model in which matrix cracking between fiber tows occurs, both modified to account for matrix porosity. The crack size required to cause stress concentrations large enough to cause failure at the observed strength is considered. Predictions for both matrix cracking and strength suggest that the current generation of tubes are controlled by microstructural defects.

  2. Air liquide's space pulse tube cryocooler systems

    Science.gov (United States)

    Trollier, T.; Tanchon, J.; Buquet, J.; Ravex, A.

    2017-11-01

    Thanks to important development efforts completed with ESA funding, Air Liquide Advanced Technology Division (AL/DTA), is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as Meteosat Third Generation (MTG), SIFTI, etc… The Miniature Pulse Tube Cooler (MPTC) is lifting up to 2.47W@80K with 50W compressor input power and 10°C rejection temperature. The weight is 2.8 kg. The Large Pulse Tube Cooler (LPTC) is providing 2.3W@50K for 160W input power and 10°C rejection temperature. This product is weighing 5.1 kg. The two pulse tube coolers thermo-mechanical units are qualified against environmental constraints as per ECSS-E-30. They are both using dual opposed pistons flexure bearing compressor with moving magnet linear motors in order to ensure very high lifetime. The associated Cooler Drive Electronics is also an important aspect specifically regarding the active control of the cooler thermo-mechanical unit during the launch phase and the active reduction of the vibrations induced by the compressor (partly supported by the French Agency CNES). This paper details the presentation of the two Pulse Tube Coolers together with the Cooler Drive Electronics aspects.

  3. Detailed Root Cause Analysis of SG Tube ODSCC Indications within the Tube Sheets of NPP Biblis Unit A

    Science.gov (United States)

    Kilian, R.; Beck, J.; Lang, H.; Schönherr, T.; Widera, M.

    Biblis Unit A is a Siemens/KWU type four loop PWR equipped with SG tubing made from Stainless Steel Alloy 800, operating from 1975 until the shutdown in 2011 due to the German political decision of a quick nuclear phase out. During the regular SG tubing inspections using eddy current testing in 2005 and 2006, a few SG tube indications were detected within the tube sheet between upper and lower mechanical tube expansion. These indications were limited to the outer tube bundle periphery. As a consequence two tubes with EC indications were pulled in 2006 for further investigations. The destructive examinations revealed axially oriented cracks starting from the outer tube surface (ODSCC). The analysis of the debris from the upper expansion area clearly indicated the presence of secondary side water in the volume between tube sheet and SG tube. Penetration of secondary side water is only possible by a penetration path along the upper expansion.

  4. MAPLE Fabricated Fe3O4@Cinnamomum verum Antimicrobial Surfaces for Improved Gastrostomy Tubes

    Directory of Open Access Journals (Sweden)

    Alina Georgiana Anghel

    2014-06-01

    Full Text Available Cinnamomum verum-functionalized Fe3O4 nanoparticles of 9.4 nm in size were laser transferred by matrix assisted pulsed laser evaporation (MAPLE technique onto gastrostomy tubes (G-tubes for antibacterial activity evaluation toward Gram positive and Gram negative microbial colonization. X-ray diffraction analysis of the nanoparticle powder showed a polycrystalline magnetite structure, whereas infrared mapping confirmed the integrity of C. verum (CV functional groups after the laser transfer. The specific topography of the deposited films involved a uniform thin coating together with several aggregates of bio-functionalized magnetite particles covering the G-tubes. Cytotoxicity assays showed an increase of the G-tube surface biocompatibility after Fe3O4@CV treatment, allowing a normal development of endothelial cells up to five days of incubation. Microbiological assays on nanoparticle-modified G-tube surfaces have proved an improvement of anti-adherent properties, significantly reducing both Gram negative and Gram positive bacteria colonization.

  5. Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance

    Directory of Open Access Journals (Sweden)

    M.A. Pech-Canul

    Full Text Available An aluminum automotive condenser was designed to exhibit high corrosion resistance in the seawater acetic acid test (SWAAT combining zinc coated microchannel tubes and fins made with AA4343/AA3003(Zn/AA4343 brazing sheet. Electrochemical measurements in SWAAT solution were carried out under laboratory conditions using tube-fin assembly and individual fin and tube samples withdrawn from the condenser core. The aim was to gain information on the protective role of the zinc sacrificial layer and about changes in corrosion behavior as a function of immersion time. External corrosion of the tube-fin system was simulated by immersion of mini-core samples under open circuit conditions. The corrosion rate increased rapidly during the first 6 h and slowly afterwards. The short time behavior was related to the dissolution of the oxide film and fast dissolution of the outermost part of the zinc diffusion layer. With the aid of cross-sectional depth corrosion potential profiles, it was shown that as the sacrificial layer gets dissolved, the surface concentration of zinc decreases and the potential shifts to less negative values. The results of galvanic coupling of tube and fins in a mini-cell showed that the tube became the anode while the fins exhibited cathodic behavior. An evolution in the galvanic interaction was observed, due to the progressive dissolution of the sacrificial zinc layer. The difference of uncoupled potentials between tube and fins decreased from 71 mV to 32 mV after 84 h of galvanic coupling. At the end of such period there was still a part of the zinc sacrificial layer remaining which would serve for protection of the tube material for even longer periods and there were indications of slight corrosion in the fins. Keywords: Aluminum, Automotive, Corrosion, Galvanic, Zn coating

  6. How much does the type of tympanostomy tube matter? A utility-based Markov decision analysis.

    Science.gov (United States)

    Baik, Grace; Brietzke, Scott

    2015-06-01

    To use a utility-based Markov decision analysis model to compare outcomes of short-term grommet tympanostomy tubes (TTs), intermediate-type tubes, and permanent T-Tubes and to use a detailed sensitivity analysis to determine the most important factors influencing outcomes with one type of TT versus another. Markov decision analysis. Hypothetical cohort. A Markov cohort decision analysis model was created using computer software (TreeAge Software, Inc, Williamstown, Massachusetts) comparing the 3 types of TT. Published data were used to determine key baseline model parameters. The model featured potential complications including eardrum perforation, early TT extrusion/blockage, and the need for possible repeat TT placement after extrusion. Outcomes were quantified using a 0.95 (1 procedure, full recovery) to 0.6 (failed myringoplasty) utility scale. Utility values were discounted over time to incorporate real-life inconvenience. The intermediate TT accumulated superior total utility in 2-, 4-, and 6-year models (2.48, 3.96, and 5.27 total utility) compared with grommets (2.32, 3.82, 5.18) and T-Tubes (2.42, 3.86, 5.18). Examining a hypothetically otherwise healthy 3000-child cohort, T-Tubes resulted in an increased overall persistent perforation rate (7.9% vs 0.2%, P placement, the utility assigned to having a functional tube in place, and the inconvenience utility discount factor over time were the driving factors of the model. The intermediate TT may produce optimal outcomes as it combines a balance of a lower perforation rate than T-Tubes and a longer period of ventilation than grommet tubes. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  7. Direct ophthalmoscopy on YouTube

    DEFF Research Database (Denmark)

    Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars

    2016-01-01

    BACKGROUND: Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy...... in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. RESULTS...... the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman's ρ=0.53; P=0.029). CONCLUSION: Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address...

  8. Pneumatosis intestinalis associated with enteral tube feeding.

    Science.gov (United States)

    Zorgdrager, Marcel; Pol, Robert

    2013-12-03

    A 49-year-old man presented with a Hinchey II perforated diverticulitis and underwent laparoscopic peritoneal lavage. During the postoperative course the patient received enteral tube feeding which was followed by a bowel obstruction accompanied with pneumatosis intestinalis (PI). Explorative laparotomy showed an omental band adhesion without signs of ischaemia. After a short period of total parenteral nutrition PI resolved almost completely and enteral tube feeding could be continued once again. In the weeks that followed the patient developed atypical bowel symptoms and recurrent PI which resolved each time the drip feeding was discontinued. Despite the mild clinical course, a CT scan showed massive PI on day 21 after the laparotomy. After excluding life-threatening conditions conservative management was instituted and the patient recovered completely after discontinuing the drip feeding. We present one of the few cases of subclinical PI associated with enteral tube feeding that could be managed conservatively.

  9. Plasmonic band structures in doped graphene tubes.

    Science.gov (United States)

    Zhou, Yu; Zhu, Ying-Ying; Zhang, Kun; Wu, Hong-Wei; Peng, Ru-Wen; Fan, Ren-Hao; Wang, Mu

    2017-05-29

    We present theoretically the transport of plasmonic waves in doped graphene tube, which is made by rolling planar graphene sheet into a cylinder and periodic doping is applied on it. It is shown that periodic modulation of the Fermi level along the tube can open gaps in the dispersion relations of graphene plasmons and eventually create plasmonic band structures. The propagation of graphene plasmons is forbidden within the bandgaps; while within the band, the plasmonic waves present axially-extended field distributions and propagate along the tubes, yet well confined around the curved graphene surface. Furthermore, the bandgaps, propagation constants and propagation lengths of the modes in plasmonic band structures are significantly tuned by varying the Fermi level of graphene, which provides active controls over the plasmonic waves. Our proposed structures here may provide an approach to dynamically control the plasmonic waves in graphene-based subwavelength waveguides.

  10. Sea urchin tube feet are photosensory organs that express a rhabdomeric-like opsin and PAX6.

    Science.gov (United States)

    Lesser, Michael P; Carleton, Karen L; Böttger, Stefanie A; Barry, Thomas M; Walker, Charles W

    2011-11-22

    All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensitivity, respiration, chemoreception and locomotion. In the green sea urchin, the most distal portion of these tube feet contain five ossicles arranged as a light collector with its concave surface facing towards the ambient light. These ossicles are perforated and lined with pigment cells that express a PAX6 protein that is universally involved in the development of eyes and sensory organs in other bilaterians. Polymerase chain reaction (PCR)-based sequencing and real time quantitative PCR (qPCR) also demonstrate the presence and differential expression of a rhabdomeric-like opsin within these tube feet. Morphologically, nerves that could serve to transmit information to the test innervate the tube feet, and the differential expression of opsin transcripts in the tube feet is inversely, and significantly, related to the amount of light that tube feet are exposed to depending on their location on the test. The expression of these genes, the differential expression of opsin based on light exposure and the unique morphological features at the distal portion of the tube foot strongly support the hypothesis that in addition to previously identified functional roles of tube feet they are also photosensory organs that detect and respond to changes in the underwater light field.

  11. A novel vortex tube-based N2-expander liquefaction process for enhancing the energy efficiency of natural gas liquefaction

    Directory of Open Access Journals (Sweden)

    Qyyum Muhammad Abdul

    2017-01-01

    Full Text Available This research work unfolds a simple, safe, and environment-friendly energy efficient novel vortex tube-based natural gas liquefaction process (LNG. A vortex tube was introduced to the popular N2-expander liquefaction process to enhance the liquefaction efficiency. The process structure and condition were modified and optimized to take a potential advantage of the vortex tube on the natural gas liquefaction cycle. Two commercial simulators ANSYS® and Aspen HYSYS® were used to investigate the application of vortex tube in the refrigeration cycle of LNG process. The Computational fluid dynamics (CFD model was used to simulate the vortex tube with nitrogen (N2 as a working fluid. Subsequently, the results of the CFD model were embedded in the Aspen HYSYS® to validate the proposed LNG liquefaction process. The proposed natural gas liquefaction process was optimized using the knowledge-based optimization (KBO approach. The overall energy consumption was chosen as an objective function for optimization. The performance of the proposed liquefaction process was compared with the conventional N2-expander liquefaction process. The vortex tube-based LNG process showed a significant improvement of energy efficiency by 20% in comparison with the conventional N2-expander liquefaction process. This high energy efficiency was mainly due to the isentropic expansion of the vortex tube. It turned out that the high energy efficiency of vortex tube-based process is totally dependent on the refrigerant cold fraction, operating conditions as well as refrigerant cycle configurations.

  12. A novel vortex tube-based N2-expander liquefaction process for enhancing the energy efficiency of natural gas liquefaction

    Science.gov (United States)

    Qyyum, Muhammad Abdul; Wei, Feng; Hussain, Arif; Ali, Wahid; Sehee, Oh; Lee, Moonyong

    2017-11-01

    This research work unfolds a simple, safe, and environment-friendly energy efficient novel vortex tube-based natural gas liquefaction process (LNG). A vortex tube was introduced to the popular N2-expander liquefaction process to enhance the liquefaction efficiency. The process structure and condition were modified and optimized to take a potential advantage of the vortex tube on the natural gas liquefaction cycle. Two commercial simulators ANSYS® and Aspen HYSYS® were used to investigate the application of vortex tube in the refrigeration cycle of LNG process. The Computational fluid dynamics (CFD) model was used to simulate the vortex tube with nitrogen (N2) as a working fluid. Subsequently, the results of the CFD model were embedded in the Aspen HYSYS® to validate the proposed LNG liquefaction process. The proposed natural gas liquefaction process was optimized using the knowledge-based optimization (KBO) approach. The overall energy consumption was chosen as an objective function for optimization. The performance of the proposed liquefaction process was compared with the conventional N2-expander liquefaction process. The vortex tube-based LNG process showed a significant improvement of energy efficiency by 20% in comparison with the conventional N2-expander liquefaction process. This high energy efficiency was mainly due to the isentropic expansion of the vortex tube. It turned out that the high energy efficiency of vortex tube-based process is totally dependent on the refrigerant cold fraction, operating conditions as well as refrigerant cycle configurations.

  13. Sea urchin tube feet are photosensory organs that express a rhabdomeric-like opsin and PAX6

    Science.gov (United States)

    Lesser, Michael P.; Carleton, Karen L.; Böttger, Stefanie A.; Barry, Thomas M.; Walker, Charles W.

    2011-01-01

    All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensitivity, respiration, chemoreception and locomotion. In the green sea urchin, the most distal portion of these tube feet contain five ossicles arranged as a light collector with its concave surface facing towards the ambient light. These ossicles are perforated and lined with pigment cells that express a PAX6 protein that is universally involved in the development of eyes and sensory organs in other bilaterians. Polymerase chain reaction (PCR)-based sequencing and real time quantitative PCR (qPCR) also demonstrate the presence and differential expression of a rhabdomeric-like opsin within these tube feet. Morphologically, nerves that could serve to transmit information to the test innervate the tube feet, and the differential expression of opsin transcripts in the tube feet is inversely, and significantly, related to the amount of light that tube feet are exposed to depending on their location on the test. The expression of these genes, the differential expression of opsin based on light exposure and the unique morphological features at the distal portion of the tube foot strongly support the hypothesis that in addition to previously identified functional roles of tube feet they are also photosensory organs that detect and respond to changes in the underwater light field. PMID:21450733

  14. Digital Radiography Qualification of Tube Welding

    Science.gov (United States)

    Carl, Chad

    2012-01-01

    The Orion Project will be directing Lockheed Martin to perform orbital arc welding on commodities metallic tubing as part of the Multi Purpose Crew Vehicle assembly and integration process in the Operations and Checkout High bay at Kennedy Space Center. The current method of nondestructive evaluation is utilizing traditional film based x-rays. Due to the high number of welds that are necessary to join the commodities tubing (approx 470), a more efficient and expeditious method of nondestructive evaluation is desired. Digital radiography will be qualified as part of a broader NNWG project scope.

  15. Energy absorption of braided composite tubes

    Science.gov (United States)

    Beard, Shawn Joseph

    In this investigation, a model was developed for simulating the crushing behavior and predicting the energy absorption characteristics of braided composite tubes. The crushing model uses the finite element code ABAQUS along with a material module that describes the constitutive behavior of the braid material. The material module contains a three-dimensional description of the braid geometry, which is used to calculate the effective stiffnesses of a representative volume. The stiffness calculations include the effects of nonlinear shear, damage accumulation, and scissoring and jamming of the braider tows. A stiffness reduction scheme, based on the predicted failure mode, is used to account for tow and resin failure throughout the representative volume. Scissoring of the braider tows results in an increase in the overall effective compliance until jamming occurs. To facilitate the model development, extensive coupon tests and tube crushing experiments were conducted. Coupon tests were conducted on braided flat plaques to help characterize the damage mechanisms occurring and to obtain the initial stiffnesses for verifying the proposed model. The braided flat plaques were made using 80k Akzo Nobel Fortafil carbon fiber tows for both the axial and braider tows, and Hetron 922 epoxy-vinyl ester resin for the matrix. Crushing tests were conducted on braided carbon fiber/epoxy-vinyl ester composite tubes with both circular and square cross-sections. All tests were conducted quasi-statically, and plug-type initiators were used to trigger the progressive crushing. The braided tubes were made using 80k Akzo Nobel Fortafil carbon fiber tows for the axial tows, 12k Hercules Grafil 34-700 carbon fiber tows for the braider tows, and Hetron 922 epoxy-vinyl ester resin for the matrix. The energy absorption characteristics are significantly affected by the fiber architecture of the tube and the fillet radius of the initiator plug. In order to verify the proposed model, simulation

  16. Pulse tube coolers for Meteosat third generation

    Science.gov (United States)

    Butterworth, James; Aigouy, Gérald; Chassaing, Clement; Debray, Benoît; Huguet, Alexandre

    2014-01-01

    Air Liquide's Large Pulse Tube Coolers (LPTC) will be used to cool the focal planes of the Infrared Sounder (IRS) and Flexible Combined Imager (FCI) instruments aboard the ESA/Eumetsat satellites Meteosat Third Generation (MTG). This cooler consists of an opposed piston linear compressor driving a pulse tube cold head and the associated drive electronics including temperature regulation and vibration cancellation algorithms. Preparations for flight qualification of the cooler are now underway. In this paper we present results of the optimization and qualification activities as well as an update on endurance testing.

  17. Arrested Bubble Rise in a Narrow Tube

    Science.gov (United States)

    Lamstaes, Catherine; Eggers, Jens

    2017-05-01

    If a long air bubble is placed inside a vertical tube closed at the top it can rise by displacing the fluid above it. However, Bretherton found that if the tube radius, R, is smaller than a critical value Rc=0.918 ℓ _c, where ℓ _c=√{γ /ρ g} is the capillary length, there is no solution corresponding to steady rise. Experimentally, the bubble rise appears to have stopped altogether. Here we explain this observation by studying the unsteady bubble motion for Rmotion.

  18. Nitrous oxide use and endotracheal tube rupture.

    Science.gov (United States)

    Mosby, E L; Schelkun, P M; Vincent, S K

    1988-01-01

    Nitrous oxide is an important and widely used anesthetic agent. However, during lengthy surgical procedures, significant amounts of nitrous oxide diffuse into the endotracheal tube cuff, causing sequelae that may include increased cuff pressures, tracheal trauma, increased postoperative discomfort, and cuff rupture. In this paper, two cases are presented in which the endotracheal tube cuff used to deliver this anesthetic agent ruptured after more than four hours of surgery. Two simple means of limiting the diffusion of nitrous oxide into the cuff and thus preventing this occurrence are described.

  19. Self-assembling segmented coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  20. Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

    2016-12-15

    Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

  1. Geology of selected lava tubes in the Bend Area, Oregon

    Science.gov (United States)

    Greely, R.

    1971-01-01

    Longitudinal profiles representing 5872.5 m of mapped lava tubes and a photogeologic map relating lava tubes to surface geology, regional structure and topography are presented. Three sets of lava tubes were examined: (1) Arnold Lava Tube System (7km long) composed of collapsed and uncollapsed tube segments and lava ponds, (2) Horse Lava Tube System (11 km long) composed of parallel and anastomosing lava tube segments, and (3) miscellaneous lava tubes. Results of this study tend to confirm the layered lava hypothesis of Ollier and Brown (1965) for lava tube formation; however, there are probably several modes of formation for lava tubes in general. Arnold System is a single series of tubes apparently formed in a single basalt flow on a relatively steep gradient. The advancing flow in which the tubes formed was apparently temporarily halted, resulting in the formation of lava ponds which were inflated and later drained by the lava tube system. Horse System probably formed in multiple, interconnected flows. Pre-flow gradient appears to have been less than for Arnold System, and resulted in meandrous, multiple tube networks.

  2. Everything the nurse practitioner should know about pediatric feeding tubes.

    Science.gov (United States)

    Hannah, Erin; John, Rita Marie

    2013-11-01

    To provide an overview of the current feeding tubes in use in the pediatric population including feeding tube complications, and specific guidance for patients at the initiation, throughout the use of, and at the discontinuation of tube feeding. A review of the literature was performed using multiple databases including PubMed, CINAHL, Ovid Medline, and Cochrane Library. Key words used included pediatric gastrostomy (G) tubes, nasogastric (NG) tubes, gastrojejunostomy (GJ) tubes, enteral access, and nurse practitioner (NP). Any child who cannot obtain nutrition orally is a candidate for enteral feeding tube access. Tube feeding is the recommended care guideline for children that are undernourished or unable to safely take-in oral nutrition. Tube feeding has been known to improve health-related quality of life. There are a number of different forms of feeding tubes that can be used in children, including NG, orogastric, G, and GJ tubes. Children are being sent home regularly with enteral feeding tube access and NPs will encounter these patients in everyday practice. It is important that NPs know the risks and benefits of tube feeding as well as the types of tubes currently in use and their indications, advantages, disadvantages, and complications. ©2013 The Author(s) ©2013 American Association of Nurse Practitioners.

  3. Influence of tube spinning on formability of friction stir welded aluminum alloy tubes for hydroforming application

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.S. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hu, Z.L., E-mail: zhilihuhit@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China); State Key Laboratory of Materials Processing and Die and Mould Technology, Huazhong University of Science and Technology (China); Yuan, S.J. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Hua, L. [Hubei Key Laboratory of Advanced Technology of Automobile Parts, Wuhan University of Technology, Wuhan 430070 (China)

    2014-06-01

    Due to economic and ecological reasons, the application of tailor-welded blanks of aluminum alloy has gained more and more attention in manufacturing lightweight structures for automotives and aircrafts. In the study, the research was aimed to highlight the influence of spinning on the formability of FSW tubes. The microstructural characteristics of the FSW tubes during spinning were studied by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The formability of the FSW tubes with different spinning reduction was assessed by hydraulic bulge test. It is found that the spinning process shows a grain refinement of the tube. The grains of the FSW tube decrease with increasing thickness reduction, and the effect of grain refinement is more obvious for the BM compared to that of the weld. The difference of grain size and precipitates between the weld and BM leads to an asymmetric W-type microhardness distribution after spinning. The higher thickness reduction of the tube, the more uniform distribution of grains and precipitates it shows, and consequently results in more significant increase of strength. As compared with the result of tensile test, the tube after spinning shows better formability when the stress state changes from uniaxial to biaxial stress state.

  4. YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery.

    Science.gov (United States)

    Sorensen, Jeffrey A; Pusz, Max D; Brietzke, Scott E

    2014-01-01

    Assess the overall quality of information on adenotonsillectomy and ear tube surgery presented on YouTube (www.youtube.com) from the perspective of a parent or patient searching for information on surgery. The YouTube website was systematically searched on select dates with a formal search strategy to identify videos pertaining to pediatric adenotonsillectomy and ear tube surgery. Only videos with at least 5 (ear tube surgery) or 10 (adenotonsillectomy) views per day were included. Each video was viewed and scored by two independent scorers. Videos were categorized by goal and scored for video/audio quality, accuracy, comprehensiveness, and procedure-specific content. Cross-sectional study. Public domain website. Fifty-five videos were scored for adenotonsillectomy and forty-seven for ear tube surgery. The most common category was educational (65.3%) followed by testimonial (28.4%), and news program (9.8%). Testimonials were more common for adenotonsillectomy than ear tube surgery (41.8% vs. 12.8%, p=0.001). Testimonials had a significantly lower mean accuracy (2.23 vs. 2.62, p=0.02), comprehensiveness (1.71 vs. 2.22, p=0.007), and TA specific content (0.64 vs. 1.69, p=0.001) score than educational type videos. Only six videos (5.9%) received high scores in both video/audio quality and accuracy/comprehensiveness of content. There was no significant association between the accuracy and comprehensive score and views, posted "likes", posted "dislikes", and likes/dislikes ratio. There was an association between "likes" and mean video quality (Spearman's rho=0.262, p=0.008). Parents/patients searching YouTube for information on pediatric adenotonsillectomy and ear tube surgery will generally encounter low quality information with testimonials being common but of significantly lower quality. Viewer perceived quality ("likes") did not correlate to formally scored content quality. Published by Elsevier Ireland Ltd.

  5. Exocyst SEC3 and Phosphoinositides Define Sites of Exocytosis in Pollen Tube Initiation and Growth.

    Science.gov (United States)

    Bloch, Daria; Pleskot, Roman; Pejchar, Přemysl; Potocký, Martin; Trpkošová, Pavlína; Cwiklik, Lukasz; Vukašinović, Nemanja; Sternberg, Hasana; Yalovsky, Shaul; Žárský, Viktor

    2016-10-01

    Polarized exocytosis is critical for pollen tube growth, but its localization and function are still under debate. The exocyst vesicle-tethering complex functions in polarized exocytosis. Here, we show that a sec3a exocyst subunit null mutant cannot be transmitted through the male gametophyte due to a defect in pollen tube growth. The green fluorescent protein (GFP)-SEC3a fusion protein is functional and accumulates at or proximal to the pollen tube tip plasma membrane. Partial complementation of sec3a resulted in the development of pollen with multiple tips, indicating that SEC3 is required to determine the site of pollen germination pore formation. Time-lapse imaging demonstrated that SEC3a and SEC8 were highly dynamic and that SEC3a localization on the apical plasma membrane predicts the direction of growth. At the tip, polar SEC3a domains coincided with cell wall deposition. Labeling of GFP-SEC3a-expressing pollen with the endocytic marker FM4-64 revealed the presence of subdomains on the apical membrane characterized by extensive exocytosis. In steady-state growing tobacco (Nicotiana tabacum) pollen tubes, SEC3a displayed amino-terminal Pleckstrin homology-like domain (SEC3a-N)-dependent subapical membrane localization. In agreement, SEC3a-N interacted with phosphoinositides in vitro and colocalized with a phosphatidylinositol 4,5-bisphosphate (PIP 2 ) marker in pollen tubes. Correspondingly, molecular dynamics simulations indicated that SEC3a-N associates with the membrane by interacting with PIP 2 However, the interaction with PIP 2 is not required for polar localization and the function of SEC3a in Arabidopsis (Arabidopsis thaliana). Taken together, our findings indicate that SEC3a is a critical determinant of polar exocytosis during tip growth and suggest differential regulation of the exocytotic machinery depending on pollen tube growth modes. © 2016 American Society of Plant Biologists. All Rights Reserved.

  6. An Exact Hot-Tube Solution For Thin Tape Helix Traveling-Wave Tube

    Science.gov (United States)

    Wong, Patrick; Lau, Y. Y.; Gilgenbach, Ronald; Chernin, David; Hoff, Brad

    2017-10-01

    The exact hot-tube dispersion relation for a thin tape helix traveling-wave tube (TWT) is derived for the first time, based on its exact cold-tube solution. This is an attempt to provide a reliable determination of the Pierce parameters, in particular the ``AC space-charge'' parameter QC, for a realistic TWT. The determination of QC remains an outstanding issue. The numerical results from the exact formulation will be compared with other approximate models of TWT that were commonly used in the literature for QC. This work was supported by AFOSR Grant No. FA9550-15-1-0097.

  7. Microbial Contamination of Orthodontic Buccal Tubes from Manufacturers

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2010-09-01

    Full Text Available This study aimed to test the sterility of new unused orthodontic buccal tubes received from manufacturers. Four different types of buccal tubes were used straight from the manufactures package without any additional sterilizing step. Of these buccal tubes tested, three genera of bacteria, implicated as opportunistic pathogens, namely Micrococcus luteus, Staphylococcus haemolyticus and Acinetobacter calcoaceticus were recovered from these buccal tubes. Our data showing microbial contamination on buccal tubes highlights the need of sterilization before clinical use. We also suggest that manufacturers should list the sterility state of orthodontic buccal tubes on their packaging or instructions stating the need for sterilization.

  8. Air-side heat transfer characteristics of spiral-type circular fin-tube heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mooyeon; Kang, Taehyung; Kim, Yongchan [Department of Mechanical Engineering, Korea University, Anam-dong, Sungbuk-ku, Seoul 136-713 (Korea)

    2010-03-15

    The objective of this study is to investigate the air-side heat transfer characteristics of spiral-type circular fin-tube heat exchangers used as evaporators in household refrigerators. The j-factors of the tested heat exchangers under non-frosting conditions were measured by varying the fin pitch, number of tube rows, and fin alignment. The j-factors of the spiral-type circular fin-tube heat exchangers were analyzed as a function of heat exchanger geometries and then compared with those of the flat plate fin-tube heat exchangers with discrete fins. Two empirical correlations of the j-factors were developed separately for the inline and the staggered fin alignment as a function of the Reynolds number, number of tube rows, and dimensionless fin pitch normalized by the hydraulic diameter. The mean deviation of the predictions using the present correlations from the measured data was 4.78% for the inline fin alignment and 6.02% for the staggered fin alignment. (author)

  9. Cryogenic Thermal Emittance Measurements on Small-Diameter Stainless Steel Tubing

    Science.gov (United States)

    Jahromi, Amir E.; Tuttle, James G.; Canavan, Edgar R.

    2017-01-01

    The Mid Infrared Instrument aboard the James Webb Space Telescope includes a mechanical cryocooler which cools its detectors to their 6 K operating temperature. The refrigerant flows through several meters of 2 mm diameter 304L stainless steel tubing, with some sections gold plated, and some not, which are exposed to their environment. An issue of water freezing onto the tube surfaces is mitigated by running a warm gas through the lines to sublimate the frozen water. To model the effect of this process on nearby instruments, an accurate measure of the tube emittance is needed. Previously we reported the absorptance of the gold plated stainless steel tubing as a function of source temperature (i.e. its environment). In this work the thermal emittance of the uncoated tubing is measured as a function of its temperature between 100 and 280 K. These values lead to an accurate prediction of the minimum length of time required to thermally recycle the system. We report the technique and present the results.

  10. Shroom induces apical constriction and is required for hingepoint formation during neural tube closure.

    Science.gov (United States)

    Haigo, Saori L; Hildebrand, Jeffrey D; Harland, Richard M; Wallingford, John B

    2003-12-16

    The morphogenetic events of early vertebrate development generally involve the combined actions of several populations of cells, each engaged in a distinct behavior. Neural tube closure, for instance, involves apicobasal cell heightening, apical constriction at hingepoints, convergent extension of the midline, and pushing by the epidermis. Although a large number of genes are known to be required for neural tube closure, in only a very few cases has the affected cell behavior been identified. For example, neural tube closure requires the actin binding protein Shroom, but the cellular basis of Shroom function and how it influences neural tube closure remain to be elucidated. We show here that expression of Shroom is sufficient to organize apical constriction in transcriptionally quiescent, naive epithelial cells but not in non-polarized cells. Shroom-induced apical constriction was associated with enrichment of apically localized actin filaments and required the small GTPase Rap1 but not Rho. Endogenous Xenopus shroom was found to be expressed in cells engaged in apical constriction. Consistent with a role for Shroom in organizing apical constriction, disrupting Shroom function resulted in a specific failure of hingepoint formation, defective neuroepithelial sheet-bending, and failure of neural tube closure. These data demonstrate that Shroom is an essential regulator of apical constriction during neurulation. The finding that a single protein can initiate this process in epithelial cells establishes that bending of epithelial sheets may be patterned during development by the regulation of expression of single genes.

  11. Cryogenic thermal emittance measurements on small-diameter stainless steel tubing

    Science.gov (United States)

    Jahromi, Amir E.; Tuttle, James G.; Canavan, Edgar R.

    2017-12-01

    The Mid Infrared Instrument aboard the James Webb Space Telescope includes a mechanical cryocooler which cools its detectors to their 6 K operating temperature. The refrigerant flows through several meters of ~2 mm diameter 304L stainless steel tubing, with some sections gold plated, and some not, which are exposed to their environment. An issue of water freezing onto the tube surfaces is mitigated by running a warm gas through the lines to sublimate the frozen water. To model the effect of this process on nearby instruments, an accurate measure of the tube emittance is needed. Previously we reported the absorptance of the gold plated stainless steel tubing as a function of source temperature (i.e. its environment). In this work the thermal emittance of the uncoated tubing is measured as a function of its temperature between 100 and 280 K. These values lead to an accurate prediction of the minimum length of time required to thermally recycle the system. We report the technique and present the results.

  12. Contrastive Analysis and Research on Negative Pressure Beam Tube System and Positive Pressure Beam Tube System for Mine Use

    Science.gov (United States)

    Wang, Xinyi; Shen, Jialong; Liu, Xinbo

    2018-01-01

    Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology.

  13. Liquid Oscillations in a U-Tube

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco; Navarro, Luis Barba

    2018-01-01

    In hydrostatics, pressure measurement with U-gauges and their relationship to density is a well-known experiment. Very little is studied or experimented with the dynamics of the movement of a liquid in a U-tube probably due to its theoretical complexity but, after all, it is a simple damped oscillating system. In this paper we present a relatively…

  14. "Fine grain Nb tube for SRF cavities"

    Energy Technology Data Exchange (ETDEWEB)

    Robert E. Barber

    2012-07-08

    Superconducting radio frequency (SRF) cavities used in charged particle linear accelerators, are currently fabricated by deep drawing niobium sheets and welding the drawn dishes together. The Nb sheet has a non-uniform microstructure, which leads to unpredictable cavity shape and surface roughness, and inconsistent "spring-back" during forming. In addition, weld zones cause hot spots during cavity operation. These factors limit linear accelerator performance and increase cavity manufacturing cost. Equal channel angular extrusion (ECAE) can be used to refine and homogenize the microstructure of Nb tube for subsequent hydroforming into SRF cavities. Careful selection of deformation and heat treatment conditions during the processing steps can give a uniform and consistent microstructure in the tube, leading to improved deformability and lower manufacturing costs. Favorable microstructures were achieved in short test samples of RRR Nb tube, which may be particularly suitable for hydroforming into SRF cavity strings. The approach demonstrated could be applicable to microstructure engineering of other tube materials including tantalum, titanium, and zirconium.

  15. Of Slot Machines and Broken Test Tubes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 5. Of Slot Machines and Broken Test Tubes. S Mahadevan. General Article Volume 19 Issue 5 May 2014 pp 395-405. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/019/05/0395-0405. Keywords.

  16. The LI-rings in pollen tubes

    Directory of Open Access Journals (Sweden)

    H. Q. Zhang

    2014-01-01

    Full Text Available Monoclonal antibodies, which recognize the specific epitopes for pectins and arabinogalactan proteins, in connection with confocal laser scanning microscopy demonstrated the presence of a ring-like structure in the cell wall of pollen tubes of flowering plants.

  17. Cotton transformation via pollen tube pathway.

    Science.gov (United States)

    Wang, Min; Zhang, Baohong; Wang, Qinglian

    2013-01-01

    Although many gene transfer methods have been employed for successfully obtaining transgenic cotton, the major constraint in cotton improvement is the limitation of genotype because the majority of transgenic methods require plant regeneration from a single transformed cell which is limited by cotton tissue culture. Comparing with other plant species, it is difficult to induce plant regeneration from cotton; currently, only a limited number of cotton cultivars can be cultured for obtaining regenerated plants. Thus, development of a simple and genotype-independent genetic transformation method is particularly important for cotton community. In this chapter, we present a simple, cost-efficient, and genotype-independent cotton transformation method-pollen tube pathway-mediated transformation. This method uses pollen tube pathway to deliver transgene into cotton embryo sacs and then insert foreign genes into cotton genome. There are three major steps for pollen tube pathway-mediated genetic transformation, which include injection of -foreign genes into pollen tube, integration of foreign genes into plant genome, and selection of transgenic plants.

  18. YouTube in the Science Classroom

    Science.gov (United States)

    Everhart, Jerry

    2009-01-01

    YouTube makes it possible for teachers to capitalize on children's insatiable appetite for visually stimulating learning. Some of these videos attain "viral" status, getting passed on from person to person and by links on other sites. Not only are these popular videos viral, but developing one's own content and posting it for the world's access is…

  19. YouTube: Educational Potentials and Pitfalls

    Science.gov (United States)

    Jones, Troy; Cuthrell, Kristen

    2011-01-01

    The instructional potential of video technology in the classroom is promising, especially in light of the 21st Century Learning Framework (Siegle, 2009). Studies show positive gains in student outcomes as a result of the integration of video technology in instruction. This article explores potential uses of YouTube as an instructional aid in…

  20. YouTube as a Participatory Culture

    Science.gov (United States)

    Chau, Clement

    2010-01-01

    There is an explosion of youth subscriptions to original content-media-sharing Web sites such as YouTube. These Web sites combine media production and distribution with social networking features, making them an ideal place to create, connect, collaborate, and circulate. By encouraging youth to become media creators and social networkers, new…

  1. Steam generator tube integrity flaw acceptance criteria

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, B. [FRAMATOME, Paris la Defense (France)

    1997-02-01

    The author discusses the establishment of a flaw acceptance criteria with respect to flaws in steam generator tubing. The problem is complicated because different countries take different approaches to the problem. The objectives in general are grouped in three broad areas: to avoid the unscheduled shutdown of the reactor during normal operation; to avoid tube bursts; to avoid excessive leak rates in the event of an accidental overpressure event. For each degradation mechanism in the tubes it is necessary to know answers to an array of questions, including: how well does NDT testing perform against this problem; how rapidly does such degradation develop; how well is this degradation mechanism understood. Based on the above information it is then possible to come up with a policy to look at flaw acceptance. Part of this criteria is a schedule for the frequency of in-service inspection and also a policy for when to plug flawed tubes. The author goes into a broad discussion of each of these points in his paper.

  2. Indications and Complications of Tube Thoracostomy with ...

    African Journals Online (AJOL)

    patients were followed up with serial chest X‑rays until certified cured. ... 1‑80 years. The most frequent indication was for malignant/ paramalignant effusion, 46 (27.5%). Others were trauma,. 44 (26.3%), Parapneumonic effusion, 20 (12%), postthoracotomy ... X-rays until certified cured before removal of the chest tube.

  3. Aspergillus DNA contamination in blood collection tubes.

    Science.gov (United States)

    Harrison, Elizabeth; Stalhberger, Thomas; Whelan, Ruth; Sugrue, Michele; Wingard, John R; Alexander, Barbara D; Follett, Sarah A; Bowyer, Paul; Denning, David W

    2010-08-01

    Fungal polymerase chain reaction (PCR)-based diagnostic methods are at risk for contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably Aspergillus fumigatus. Lower proportions of contamination in other vessels were observed. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Aspergillus DNA contamination in blood collection tubes

    OpenAIRE

    Harrison, Elizabeth; Stahlberger, Thomas; Whelan, Ruth; Sugrue, Michele; Wingard, John R.; Alexander, Barbara D.; Follett, Sarah A.; Bowyer, Paul; Denning, David W.

    2010-01-01

    Fungal PCR-based diagnostic methods are at risk of contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably A. fumigatus. Lower proportions of contamination in other vessels were observed.

  5. Kundt’s tube experiment using smartphones

    Science.gov (United States)

    Orsola Parolin, Sara; Pezzi, Giovanni

    2015-07-01

    This article deals with a modern version of Kundt’s tube experiment. Using economic instruments and a couple of smartphones, it is possible to ‘see’ nodes and antinodes of standing acoustic waves in a column of vibrating air and to measure the speed of sound.

  6. Holding Tubes in Place for Brazing

    Science.gov (United States)

    Ambrisco, D.; Arbino, P.

    1983-01-01

    Simple method prevents loosening due to thermal mismatch. Four segment die pushed outward against tubing wall by tapered ram. Boss on each segment of die produces dimple in wall. Ram driven by commercial pneumatic cylinder powered by air at 250 psi. Method applicable to brazing of heat exchanges, thrust chambers, and other assemblies in which thermal expansion coefficients of materials differ significantly.

  7. YouTube and Video Quizzes

    Directory of Open Access Journals (Sweden)

    Kevin YEE

    2010-04-01

    Full Text Available The Internet sensation YouTube (http://www.youtube.com has become such a force online that it was estimated in 2006 to account for a full tenth of the bandwidth by the entire Internet in the United States (WebProNews, 2007, and to use as much bandwidth in 2007 as the entire Internet had done in 2000 (Carter, 2008. Like many technological tools created with entertainment or profit in mind, YouTube can now be easily and usefully adopted by instructors for educational purposes, and indeed many professors use YouTube in their classroom teaching already (Brooks, 2000. This is especially true for passive uses of YouTube; watching videos that are already online and using them in the classroom experience to support a concept and provide another mechanism for students to connect with the topics. It is fruitful to consider Bloom's Taxonomy of Educational Objectives (Bloom & Krathwohl, 1956 when employing video or any media in the classroom to maximize the intentionality of teaching and learning. The use of video for demonstration or modeling corresponds well to Blooms levels of Knowledge, Comprehension, and Application; while case studies offer a chance to demonstrate Analysis and Synthesis, and perhaps even Evaluation, when comparing a video to information from a text book or other content.

  8. Routine jejunostomy tube feeding following esophagectomy

    NARCIS (Netherlands)

    Weijs, Teus J.|info:eu-repo/dai/nl/413993558; van Eden, Hanneke W.J.; Ruurda, Jelle P.|info:eu-repo/dai/nl/257561021; Luyer, Misha D P; Steenhagen, Elles|info:eu-repo/dai/nl/304815713; Nieuwenhuijzen, Grard A P; van Hillegersberg, Richard|info:eu-repo/dai/nl/110706242

    2017-01-01

    Background: Malnutrition is an important problem following esophagectomy. A surgically placed jejunostomy secures an enteral feeding route, facilitating discharge with home-tube feeding and long-term nutritional support. However, specific complications occur, and data are lacking that support its

  9. YouTube, dentistry, and dental education.

    Science.gov (United States)

    Knösel, Michael; Jung, Klaus; Bleckmann, Annalen

    2011-12-01

    The objective of this study was to systematically assess the informational value, intention, source, and bias of videos related to dentistry available on the video-sharing Internet platform YouTube. YouTube (www.youtube.com) was searched for videos related to dentistry, using the system-generated sorts "by relevance" and "most viewed" and two categories (All and Education). Each of the first thirty results was rated by two assessors filling out a questionnaire for each (total: 120). The data were subjected to statistical analysis using Cohen's kappa, Pearson's correlation coefficient tau, Mann-Whitney U-tests, and a nonparametric three-way ANOVA, including an analysis of the interaction between the sorting and category effect, with an α-level of 5 percent. The scan produced 279,000 results in the category All and 5,050 in the category Education. The analysis revealed a wide variety of information about dentistry available on YouTube. The purpose of these videos includes entertainment, advertising, and education. The videos classified under Education have a higher degree of usefulness and informational value for laypersons, dental students, and dental professionals than those found in a broader search category. YouTube and similar social media websites offer new educational possibilities that are currently both underdeveloped and underestimated in terms of their potential value. Dentists and dental educators should also recognize the importance of these websites in shaping public opinion about their profession.

  10. Flow induced pulsations generated in corrugated tubes

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Swindell, R.; Tummers, R.

    2008-01-01

    Corrugated tubes can produce a tonal noise when used for gas transport, for instance in the case of flexible risers. The whistling sound is generated by shear layer instability due to the boundary layer separation at each corrugation. This whistling is examined by investigating the frequency,

  11. Indications and Complications of Tube Thoracostomy with ...

    African Journals Online (AJOL)

    Two perforations are created on the cap approximately 0.4 cm and 0.5 cm, respectively. Through the 0.4 cm perforation is. Indications and Complications of Tube Thoracostomy with Improvised Underwater Seal Bottles. SA Edaigbini, IZ Delia, MB Aminu, AA Orogade1, N Anumenechi, AD Ibrahim. Department of Surgery ...

  12. Tubes, Mono Jets, Squeeze Out and CME

    Energy Technology Data Exchange (ETDEWEB)

    Longacre, R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-10-23

    Glasma Flux Tubes, Mono Jets with squeeze out flow around them plus the Chiral Magnetic Effect(CME) are physical phenomenon that generate two particle correlation with respect to the reaction plane in mid-central 20% to 30% Au-Au collision √sNN = 200.0 GeV measured at RHIC.

  13. Enrichment Monitor for 235U Fuel Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    2001-08-22

    This report describes the performance of this prototype y-monitor of 235 Uranium enrichment. In this proposed method y-rates associated with 235U and 232U are correlated with enrichment. Instrumentation for appraising fuel tubes with this method has been assembled and tested.

  14. Tube thoracostomy: Primary management option for empyema ...

    African Journals Online (AJOL)

    Twenty three (50%) children had history of pneumonia and treatment prior to development of empyema. Thirty five (76.08%) children ... Conclusions: Majority of children with empyema thoracis are manageable with tube thoracostomy, antibiotics, physiotherapy and other supportive treatment. Few of them who fail to above ...

  15. Cutting the L3 torque tube

    CERN Multimedia

    Laurent Guiraud

    2001-01-01

    Workers cut the torque tube, with a plasma-cutting device on the L3 experiment, which closed with the LEP accelerator in 2000. L3 was housed in a huge red solenoid, which will be taken over by the ALICE detector when the new LHC is completed.

  16. Thermocouple installation in thin-walled tubes

    Science.gov (United States)

    Curren, A. N.; Wycoff, K. C.

    1970-01-01

    Brazing process attaches thermocouples to slot in type-347 stainless steel tube flush around its circumference. Electrolytic flashing with gold enhances brazing process. This installation procedure does not significantly change calibration of thermocouples used and does not cause major wear spots in the thin-walled devices.

  17. Experimental investigation of forced-convection in a finned rhombic tube of the flat-plate solar collectors

    DEFF Research Database (Denmark)

    Taherian, Hessam; Yazdanshenas, Eshagh

    2006-01-01

    Due to scarcity of literature on forced-convection heat transfer in a solar collector with rhombic cross-section absorbing tubes, a series of experiments was arranged and conducted to determine heat transfer coefficient. In this study, a typical rhombic cross-section finned tube of flat......-plate collectors used as the test section. Two correlations were proposed for the Nusselt number as a function of the Reynolds number and the Prandtl number based on hydraulic diameter for various heat fluxes. The temperature distribution along the finned tube for the fluid and the wall were also illustrated....

  18. Steam generator tube inspection in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Shigetaka [Japan Power Engineering and Inspection Corp., Tokyo (Japan)

    1997-02-01

    Steam generator tube inspection was first carried out in 1971 at Mihama Unit-1 that is first PWR plant in Japan, when the plant was brought into the first annual inspection. At that time, inspection was made on sampling basis, and only bobbin coil probe was used. After experiencing various kinds of tube degradations, inspection method was changed from sampling to all number of tubes, and various kinds of probes were used to get higher detectability of flaw. At present, it is required that all the tubes shall be inspected in their full length at each annual inspection using standard bobbin coil probe, and some special probes for certain plants that have susceptibility of occurrence of flaw. Sleeve repaired portion is included in this inspection. As a result of analyses of eddy current testing data, all indications that have been evaluated to be 20% wall thickness or deeper shall be repaired by either plugging or sleeving, where flaw morphology is to be a wastage or wear. Other types of flaw such as IGA/SCC are not allowed to be left inservice when those indications are detected. These inspections are performed according to inspection procedures that are approved by regulatory authority. Actual inspections are witnessed by the Japan Power engineering and inspection corporation (JAPEIC)`s inspectors during data acquisition and analysis, and they issue inspection report to authority for review and approval. It is achieved high safety performance of steam generator through this method of inspections, however. some tube leakage problems were experienced in the past. To prevent recurrence of such events, government is conducting development and verification test program for new eddy current testing technology.

  19. Fallopian tube cancer. The Roswell Park experience.

    Science.gov (United States)

    Rose, P G; Piver, M S; Tsukada, Y

    1990-12-15

    Sixty-four patients with primary fallopian tube cancer treated at Roswell Park Memorial Institute from 1964 to 1987 underwent retrospective clinicopathologic review. In 40 patients fallopian tube cancer was the only primary, but in 24 patients primary fallopian tube cancer was part of a multifocal upper genital tract malignancy. Of the 40 patients with unifocal fallopian disease, the median survival was 28 months. Only 15% of patients were alive and disease free with follow-up ranging from 22 to 141 months (median, 90.5 months). Survival was not associated with stage of disease, tumor histology, grade, or depth of invasion in this series. Fourteen patients who received cisplatin-based chemotherapy were evaluable for response. Three patients (21%) responded; two complete and one partial. Twelve patients without clinical evidence of disease underwent second-look procedures, ten laparotomy and two laparoscopy. Four of ten second-look laparotomies were negative. Secondary debulking was done in three of four patients with gross disease, one of which had a negative third-look laparotomy. Negative laparotomy, second-look or third-look, was associated with improved survival (P = 0.016). One of the two laparoscopies was negative, but the patient recurred. In the remaining 24 patients cancer of the fallopian tube was part of a multifocal upper genital tract malignancy. In 12 patients tubal disease was invasive, and in 12, it was in situ. Separate primaries occurred in the ovaries (n = 20); uterus (n = 7); and cervix (n = 2). This represents 1.3% of ovarian malignancies treated at Roswell Park Memorial Institute during the study period. Fallopian tube cancer seems as virulent as ovarian cancer with few long-term survivors. It is frequently associated with other sites of upper genital tract malignancy. Second-look laparotomy is an important predictor of survival. Second-look laparoscopy may be useful if positive.

  20. The Educational Potential of YouTube.

    Science.gov (United States)

    Godwin, Haley T; Khan, Murtaza; Yellowlees, Peter

    2017-12-01

    The objective of this paper was to examine the educational potential and effectiveness of a 3 min video clip of a simulation of schizophrenia published online at YouTube. Researchers examined the 267 public comments published on the video-sharing website YouTube over 8 years by viewers of a schizophrenia simulation video titled "virtual hallucinations" made in the Second Life game platform. Comments were independently categorized into six groupings, then cooperatively finalized, and qualitatively analyzed. The six categories of style of comments were "Emotional" (n = 76), "Identification" (n = 62), "Educational Interest" (n = 45), "Mocking/Displeased" (n = 36), "Game Interest" (n = 32), and "Other" (n = 25). Without any advertising or marketing by the creators, over 194,400 views of the video were recorded in 8 years, an average of about 1500 views per month. The use of YouTube with its viral marketing potential has created a vastly amplified reach for this educational offering that would otherwise have been impossible. Qualitative analysis of publically posted comments in response to the video, which were generally positive, has led to a greater understanding of public reactions to such educational offerings. YouTube videos are already a rich source of data for psychiatric researchers, and psychiatric educators should consider posting high quality video clips on publically available social media platforms such as YouTube in order to reduce public stigma about psychiatric disorders and patients.

  1. Vlasov simulations of auroral flux tubes

    Science.gov (United States)

    Gunell, Herbert; De Keyser, Johan; Mann, Ingrid

    2013-04-01

    Electric fields that are parallel to the earth's magnetic field are known to exist in the auroral zone, where they contribute to the acceleration of auroral electrons. Thus, parallel electric fields form an integral part of the auroral current circuit. Transverse electric fields at high altitude result in parallel electric fields as a consequence of the closure of the field-aligned currents through the conducting ionosphere (L. R. Lyons, JGR, vol. 85, 1724, 1980). These parallel electric fields can be supported by the magnetic mirror field (Alfvén and Fälthammar, Cosmical Electrodynamics, 2nd ed., 1963). The current-voltage characteristics of an auroral flux tube has been studied using stationary kinetic models (Knight, Planet. and Space Sci., vol. 21, 741-750, 1973). Observations have shown that field-aligned potential drops often are concentrated in electric double layers (e.g. Ergun, et al., Phys. Plasmas, vol. 9, 3685-3694, 2002). In the upward current region, 20-50% of the total potential drop has been identified as localised. How the rest of the potential is spread out as function of altitude is not yet known from observations (Ergun et al., J. Geophys. Res., vol. 109, A12220, doi:101.1029/2004JA010545, 2004). We have performed Vlasov simulations, using a model that is one-dimensional in configuration space and two-dimensional in velocity space. In the upward current region, most of the potential drop is found in a thin, stationary, double layer. The rest is in a region, which extends a few earth radii above it. The current-voltage characteristic approximately follows the Knight relation. The altitude of the double layer decreases with an increasing field-aligned potential drop. In the downward current region, the voltage is significantly lower than in the upward current region for the same value of the current. Double layers have been observed also in the downward current region (Andersson et al., Phys. Plasmas, vol. 9, 3600-3609, doi:10

  2. Research on temperature control and influence of the vacuum tubes with inserted tubes solar heater

    Science.gov (United States)

    Xiao, L. X.; He, Y. T.; Hua, J. Q.

    2017-11-01

    A novel snake-shape vacuum tube with inserted tubes solar collector is designed in this paper, the heat transfer characteristics of the collector are analyzed according to its structural characteristics, and the influence of different working temperature on thermal characteristics of the collector is studied. The solar water heater prototype consisting of 14 vacuum tubes with inserted tubes is prepared, and the hot water storage control subsystem is designed by hysteresis comparison algorithm. The heat characteristic of the prototype was experimentally studied under hot water output temperature of 40-45°C, 50-55°C and 60-65°C. The daily thermal efficiency was 64%, 50% and 46%, respectively. The experimental results are basically consistent with the theoretical analysis.

  3. Structural safety of coolant channel components under excessively high pressure tube diametral expansion rate at garter spring location

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, M. [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Sinha, S.K., E-mail: sunilks@barc.gov.in [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2013-08-15

    Structural safety of coolant channel assembly in the event of high diametral expansion of pressure tube in a 220 MWe pressurised heavy water reactor was investigated using axisymmetric and 3-D finite element models. The axisymmetric analyses were performed and stresses were evaluated for pressure tube, girdle wire and calandria tube at different point of time for diametral expansion rates of 0.2%, 0.25% and 0.3% per year of the pressure tube inside diameter. The results of this study indicated that for the case of 0.3% per year of diametral expansion rate (worst case scenario), occurrence of complete circumferential interference of garter spring with calandria tube at the location of maximum expansion would take place much earlier at around 14 years or 4.2% of the total expansion of pressure tube as opposed to its anticipated design life (30 years). This fact was further corroborated by 3-D finite element analysis performed for the actual assembly configuration under actual loadings. The latter analysis revealed that net section yielding of calandria tube occurs in just 1 year after the occurrence of total circumferential interference between calandria tube and garter spring spacer. It has also been observed that the maximum stress intensity in girdle wire does not increase beyond the ultimate tensile strength even when maximum stress intensity in calandria tube reaches its yield strength. These analyses also revealed that the structural as well as functional integrity of pressure tube and the garter spring is not affected as result of this interference.

  4. Development and characterization of sub-100 ps photomultiplier tubes.

    Science.gov (United States)

    Horsfield, C J; Rubery, M S; Mack, J M; Young, C S; Herrmann, H W; Caldwell, S E; Evans, S C; Sedilleo, T J; Kim, Y H; McEvoy, A; Milnes, J S; Howorth, J; Davis, B; O'Gara, P M; Garza, I; Miller, E K; Stoeffl, W; Ali, Z

    2010-10-01

    We describe the evaluation of a microchannel plate (MCP) photomultiplier tube (PMT), incorporating a 3 μm pore MCP and constant voltage anode and cathode gaps. The use of the small pore size results in PMTs with response functions of the order of 85 ps full-width-half-maximum, while the constant electric field across the anode and cathode gaps produces a uniform response function over the entire operating range of the device. The PMT was characterized on a number of facilities and employed on gas Cherenkov detectors fielded on various deuterium tritium fuel (DT) implosions on the Omega Laser Facility at the University of Rochester. The Cherenkov detectors are part of diagnostic development to measure Gamma ray reaction history for DT implosions on the National Ignition Facility.

  5. An Advanced simulation Code for Modeling Inductive Output Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Thuc Bui; R. Lawrence Ives

    2012-04-27

    During the Phase I program, CCR completed several major building blocks for a 3D large signal, inductive output tube (IOT) code using modern computer language and programming techniques. These included a 3D, Helmholtz, time-harmonic, field solver with a fully functional graphical user interface (GUI), automeshing and adaptivity. Other building blocks included the improved electrostatic Poisson solver with temporal boundary conditions to provide temporal fields for the time-stepping particle pusher as well as the self electric field caused by time-varying space charge. The magnetostatic field solver was also updated to solve for the self magnetic field caused by time changing current density in the output cavity gap. The goal function to optimize an IOT cavity was also formulated, and the optimization methodologies were investigated.

  6. The dynamic single-tube concept; Le mono-tube dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Rivet, P. [Ste MC International (France)

    1997-12-31

    In the framework of greenhouse gas emission reduction and the utilization of cooling intermediate fluids with indirect refrigerating systems, a new concept of dynamical single-tube has been developed, which allows for the simultaneous cold distribution from a centralized plant towards various required temperature systems (as for example in a supermarket refrigerating system) with optimized efficiency, fluid flow and defrosting conditions; moreover, the dynamic single-tube concept is very well adapted to two-phase flows

  7. Development and Technology Transfer of the Syncro Blue Tube (Gabriel) Magnetically Guided Feeding Tube

    Science.gov (United States)

    2017-06-01

    placement. Patients who had trauma to the neck that precluded placing the magnet behind the neck and patients with abdominal surgery resulting in...2%), is associated with high mortality rate (50%). Peristalsis will now advance the Gabriel® Feeding Tube into the small intestine. Now advance... high potential for post-pyloric migration without extra skills or costly procedures. The Gabriel feeding tube with balloon was developed with

  8. Distal bronchial tubes damage in patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    M V Sheyanov

    2009-01-01

    Full Text Available Objective. To study prevalence and clinical picture of distal parts of bronchial tree(bronchiolitis in pts with rheumatoid arthritis (RA. Material and methods. 104 nonsmoking pts with RA and 100 pts without RA and chronic diseases of respiratory apparatus were included. General clinical examination, spirometry, bodyplethysmography, examination of lung diffusion capacity (LDC and multispiralcomputed tomography (MSCT of lungs were performed. Results. Direct and indirect bronchiolitis signs were revealed with MSCT in 36 (35% ptswith RA and 1 pt of control group (p<0,01. Pts with signs of bronchiolitis complained of shortness of breath (69% of pts, cough (56%, phlegm discharge (56%, heavy breathing (25%. Obstructive lung ventilation disturbances were revealed in 19 (53% RA pts with bronchiolitis. Restrictive disturbances and LDC decrease were present in 3 (8% pts. High frequency of oligosymptomatic bronchiolitis course was found in RA pts. Bronchiolitis symptoms in RA pts coincided with signs of proximal bronchial tubes damage forming picture of diffuse damage of bronchial tree. Conclusion. Bronchiolitis is a prevalent variant of respiratory apparatus damage in pts with RA. Pts with MSCT signs of bronchiolitis often have cough, phlegm discharge, shortness of breath, heavy breathing. Lung ventilation disturbances of obstructive type are common but part of pts has normal lung functional measures or restriction. Oligosymptomatic forms of distal bronchial tubes damage are prevalent in RA pts. Lung MSCT is the main method of bronchiolitis diagnostics because bronchiolitis induces nonspecific clinical signs and RA pts have multilevel respiratory apparatus damage. MSCT reveals signs of distal bronchial tubes damage in 35% of RA pts.

  9. Mapping Self-Guided Learners' Searches for Video Tutorials on YouTube

    Science.gov (United States)

    Garrett, Nathan

    2016-01-01

    While YouTube has a wealth of educational videos, how self-guided learners use these resources has not been fully described. An analysis of search engine queries for help with the use of Microsoft Excel shows that few users search for specific features or functions but instead use very general terms. Because the same videos are returned in…

  10. A Behavior Analysis Approach toward Chronic Food Refusal in Children with Gastrostomy-Tube Dependency.

    Science.gov (United States)

    Luiselli, James K.; Luiselli, Tracy Evans

    1995-01-01

    This report describes a behavior analysis treatment approach to establishing oral feeding in children with multiple developmental disabilities and gastrostomy-tube dependency. Pretreatment screening, functional assessment, and treatment are reported as implemented within a behavioral consultation model. A case study illustrates the sequence and…

  11. Knotting of a nasogastric feeding tube in a child with head injury: A ...

    African Journals Online (AJOL)

    The complications include trauma, nasal septal abscess and inadvertent entry into the cranial cavity and trachea, ulceration, bleeding from varices and perforation. ... We also challenge the fact that the small sized stomach is a risk factor for knotting of a feeding tube if the functional status and tone are normal, because of the ...

  12. Spirometry using facemask versus conventional tube in patients with neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Taha Taha Abdelgawad

    2017-10-01

    Conclusion: The use of facemask during assessment of spirometric and respiratory pressures measures in patients with NMD and more specifically in patients with bulbar palsy is promising and can be considered a good alternative to conventional tube assessment for functional screening rationale.

  13. LAMINAR FLOW THROUGH A TUBE WITH AN EASILY PENETRABLE ROUGHNESS NEAR AXIS

    Directory of Open Access Journals (Sweden)

    Є.О. Гаєв

    2012-12-01

    Full Text Available  Mathematical model has been suggested and investigation carried out of laminar flow through a round tube with a porous insertion (easily penetrable roughness, EPR in its middle along the axis. Velocity and shear fields have been found analytically for stable flow region, as well as hydraulic resistance as functions of EPR density and its height.

  14. Massive gastric dilatation and anuria resolved with naso-gastric tube decompression.

    Science.gov (United States)

    Peces, Ramón; Vega, Cristina; Peces, Carlos; Trébol, Julio; González, Juan A

    2010-09-01

    We report for the first time a case of acute kidney injury associated with severe gastric distention after a laparoscopic Nissen-Rossetti fundoplication of the stomach for hiatal hernia. An abdominal compartment syndrome secondary to intra-abdominal hypertension was suspected. Naso-gastric tube decompression resulted in immediate resaturation of the diuresis and progressive recovery of renal function.

  15. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening

    Science.gov (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  16. Risks of Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening

    Science.gov (United States)

    ... Screening Research Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening (PDQ®)–Patient Version What is screening? Go to ... ovarian cancer. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer Screening Key Points Tests are used to screen for ...

  17. Gastrostomy tube feeding of children with cerebral palsy

    DEFF Research Database (Denmark)

    Dahlseng, Magnus O; Andersen, Guro L; DA Graca Andrada, Maria

    2012-01-01

    To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries.......To compare the prevalence of gastrostomy tube feeding (GTF) of children with cerebral palsy (CP) in six European countries....

  18. Brushless dc motor uses electron beam switching tube as commutator

    Science.gov (United States)

    Studer, P.

    1965-01-01

    Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.

  19. Helioseismic Effects of Magnetic Flux Tube: 3D Numerical Simulations

    Science.gov (United States)

    Daiffallah, K.; Abdelatif, T.

    2008-09-01

    Observations suggest clearly that there is a significant interaction between solar surface waves and magnetic flux tubes with specific helioseismic signature. Magnetic flux tubes permit the propagation of two types of magnetohydrodynamic waves: The longitudinal tube wave (sausage modes) and the transversal tube wave (kink modes). The response of different magnetic flux tubes embedded in polytropic atmosphere to the propagation of surface gravity wave (f-mode) is studied numerically with the SLiM code (see Cameron et al. 2007). We find that the back scattering wave from different sizes of tubes reveals interesting information about which modes are excited in the tubes. The numerical calculations of the scattering effects (for different frequencies of the incident wave, different tube radius and values of plasma-beta) are compared with theoretical results obtained by Hanasoge et al. 2008.

  20. Glycol/water evacuated-tube solar collector

    Science.gov (United States)

    1980-01-01

    Report describes performance of 8 tube and 10 tube commercially produced solar collectors. Tests include thermal efficiency, time constant for temperature drop after solar flux is cut, change in efficiency with Sun angle, and temperature rise if circulation is stopped.