WorldWideScience

Sample records for annulus spacer mobility

  1. Recovery of knee mobility after a static or mobile spacer in total knee infection

    NARCIS (Netherlands)

    Brunnekreef, J.J.; Hannink, G.; Mde, W. Malefijt

    2013-01-01

    The purpose of the study was to compare the recovery of knee mobility after two-stage revision of an infected total knee arthroplasty using a static or mobile spacer. At 12 months follow-up, none of the patients had a recurrent infection of their new prosthesis. Knee flexion was lower in the static

  2. Preventing Complications from High-Dose Rate Brachytherapy when Treating Mobile Tongue Cancer via the Application of a Modular Lead-Lined Spacer.

    Directory of Open Access Journals (Sweden)

    Shumei Murakami

    Full Text Available To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients.First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations.With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant distances to the source.The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.

  3. Advantages of the AlGaN spacer in InAlN high-electron-mobility transistors grown using metalorganic vapor phase epitaxy

    Science.gov (United States)

    Yamada, Atsushi; Ishiguro, Tetsuro; Kotani, Junji; Tomabechi, Shuichi; Nakamura, Norikazu; Watanabe, Keiji

    2016-05-01

    We demonstrate the advantages of an AlGaN spacer layer in an InAlN high-electron-mobility transistor (HEMT). We investigated the effects of the growth parameters of the spacer layer on electron mobility in InAlN HEMTs grown by metalorganic vapor phase epitaxy, focusing on the surface roughness of the spacer layer and sharpness of the interface with the GaN channel layer. The electron mobility degraded, as evidenced by the formation of a graded AlGaN layer at the top of the GaN channel layer and the surface roughness of the AlN spacer layer. We believe that the short migration length of aluminum atoms is responsible for the observed degradation. An AlGaN spacer layer was employed to suppress the formation of the graded AlGaN layer and improve surface morphology. A high electron mobility of 1550 cm2 V-1 s-1 and a low sheet resistance of 211 Ω/sq were achieved for an InAlN HEMT with an AlGaN spacer layer.

  4. Cervical spine annulus vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Bohrer, S.P.; Chen, Y.M.

    1988-07-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  5. Cervical spine annulus vacuum.

    Science.gov (United States)

    Bohrer, S P; Chen, Y M

    1988-01-01

    Thirty-eight annulus vacuums in 27 patients were analyzed with regard to location, configuration, and associated vertebral abnormalities such as degenerative changes, absent and compressed anterosuperior vertebral body corners, and annulus calcification. It is concluded that most annulus vacuums are a degenerative phenomenon at the attachment of the annulus to bone. These vacuums may be associated with other degenerative changes such as osteophytes and annulus calcification. Vacuums have a strong association with compressed anterosuperior corners. These deformed corners are thought to be early osteophytes and may be related to previous trauma, a vertebra with an absent corner, and/or normal motion. Small annulus vacuums adjacent to vertebral corners with a normal appearance are more likely to result from acute trauma.

  6. The Annulus Property of Simple Holomorphic Discs

    CERN Document Server

    Zehmisch, Kai

    2010-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the involved almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  7. The annulus property of simple holomorphic discs

    OpenAIRE

    Zehmisch, Kai

    2013-01-01

    We show that any simple holomorphic disc admits the annulus property, i.e., each interior point is surrounded by an arbitrary small annulus consisting entirely of injective points. As an application we show that interior singularities of holomorphic discs can be resolved after slight perturbation of the almost complex structure. Moreover, for boundary points the analogue notion, the half-annulus property, is introduced and studied in detail.

  8. Structural Stator Spacers

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andreasen, Jens H.; Pijanowski, J. M.

    2001-01-01

    This paper presents a powerful new design aspect to reduce acoustic noise and vibration of electro-magnetic origin for electrical machines, by introducing improved slot wedges referred to as "Structural Stator Spacers". These spacers, by using a very stiff dielectric and non magnetic material...... drawbacks usually associated with other noise reduction methods or interdict other noise control methods. Design models and practical prototypes are detailed which are used to verify the effectiveness of the spacers......., a modified shape and small modifications to the stator laminations not only secure the windings and reduce windage losses but also make it possible to increase the stiffness of the stator structure significantly thereby reducing the generation of audible noise. This new method does not incur the significant...

  9. Functional myelographic differentiation of lumbar bulging annulus

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choong Ki; Kim, Hong Kil; Park, Sang Gyu; Lee, Young Jung; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1988-08-15

    Herniated disk and bulging annulus are the major causes of lower back pain. It is necessary to differentiate bulging annulus from herniated disk because of their different methods of treatment. Myelography is one of the useful diagnostic methods for disk diseases even though advanced diagnostic modalities such as CT and MRI are more accurate. Functional myelography is not a new technology expect for two additional views, flexion and extension, are obtained with conventional myelography. Differentiation between bulging annulus and herniated disk by conventional myelography is based on the extent and multiplicity of extradural deformity of the contrast filled dural sac and neural sleeve as well as the changes of nerve root. There is no previous report about differential points between bulging annulus and herniated disk according to functional myelography. It is the purpose of this study to find any additional differential points on functional myelography between bulging annulus and herniated disk over convectional myelography. Authors analysed functional myelographic findings of 152 cases from July 1986 to July 1987. Among them, 22 cases who had been suffered from cervical abnormality or vague lower back pain were diagnosed as normal by myelography, and 30 cases of L4-5 herniated disk and 21 cases of L4-5 bulging annulus which had been finally diagnosed by operation were studied. The results were as follows. 1. In normal group, anterior epidural space was gradually widened from the upper lumbar vertebra downward. And anterior epidural space was more sidened at the disk level in extension view than in flexion except for L5-S1 lever. 2. In bulging annulus group, the shape of anterior epidural space in flexion state was as similar as normal. Anoterior epidural space in extension state was more sidened at the buldging annulus than normal, but lesser than herniated disk. 3. In herniated disk group, widening of anterior epidural space at the herniated disk level was

  10. 可活动间隔垫(articulating spacer,mobile spacer,articulated spacer)

    Institute of Scientific and Technical Information of China (English)

    严广斌

    2007-01-01

    @@ 可活动间隔垫包括由骨水泥或金属制成的股骨和胫骨假体样部件构成的关节面连接,及股骨和胫骨与相应假体样部件之间含抗生素的骨水泥.在膝关节置换术后感染的一期彻底清创后置入膝关节腔内,以保存膝关节腔间隙,维持膝周围软组织平衡,并可允许患肢在间隔期内有一定的活动和部分负重.

  11. Rarefied gas flow in a cylindrical annulus

    Science.gov (United States)

    Lo, S. S.; Loyalka, S. K.; Storvick, T. S.

    1983-09-01

    The Hansen-Morse model of the linearized Wang Chang-Uhlenbeck equation is used to study the thermal transpiration and mechanocaloric effects for rarefied polyatomic gases in a cylindrical annulus, where boundary conditions are characterized by diffuse reflection. Phenomenological coefficients at all degrees of rarefaction are reported for physical parameters that represent helium, hydrogen, carbon dioxide, and air. Comparisons with isothermal flow data are given.

  12. Mechanisms for mechanical damage in the intervertebral disc annulus fibrosus.

    Science.gov (United States)

    Iatridis, J C James C; ap Gwynn, Iolo

    2004-08-01

    Intervertebral disc degeneration results in disorganization of the laminate structure of the annulus that may arise from mechanical microfailure. Failure mechanisms in the annulus were investigated using composite lamination theory and other analyses to calculate stresses in annulus layers, interlaminar shear stress, and the region of stress concentration around a fiber break. Scanning electron microscopy (SEM) was used to evaluate failure patterns in the annulus and evaluate novel structural features of the disc tissue. Stress concentrations in the annulus due to an isolated fiber break were localized to approximately 5 microm away from the break, and only considered a likely cause of annulus fibrosus failure (i.e., radial tears in the annulus) under extreme loading conditions or when collagen damage occurs over a relatively large region. Interlaminar shear stresses were calculated to be relatively large, to increase with layer thickness (as reported with degeneration), and were considered to be associated with propagation of circumferential tears in the annulus. SEM analysis of intervertebral disc annulus fibrosus tissue demonstrated a clear laminate structure, delamination, matrix cracking, and fiber failure. Novel structural features noted with SEM also included the presence of small tubules that appear to run along the length of collagen fibers in the annulus and a distinct collagenous structure representative of a pericellular matrix in the nucleus region.

  13. Modeling mantle convection in the spherical annulus

    Science.gov (United States)

    Hernlund, John W.; Tackley, Paul J.

    2008-12-01

    Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.

  14. Asymptotic Analysis of Transport Equation in Annulus

    Science.gov (United States)

    Wu, Lei; Yang, Xiongfeng; Guo, Yan

    2016-09-01

    We consider the diffusive limit of a steady neutron transport equation with one-speed velocity in a two-dimensional annulus. A classical theorem in Bensoussan et al. (Publ Res Inst Math Sci 15:53-157, 1979) states that the solution can be approximated in L^{∞} by the sum of the interior solution and Knudsen layer derived from Milne problem. However, this result was disproved in Wu and Guo (Commun Math Phys 336:1473-1553, 2015) in a plate via a different boundary layer expansion with geometric correction. In this paper, we established the diffusive limit and provide a counterexample to Bensoussan et al. (1979) in non-convex domains.

  15. Absence of annulus in human asthenozoospermia: case report.

    Science.gov (United States)

    Lhuillier, P; Rode, B; Escalier, D; Lorès, P; Dirami, T; Bienvenu, T; Gacon, G; Dulioust, E; Touré, A

    2009-06-01

    The annulus is a septin-based ring structure located at the junction of the midpiece (MP) and the principal piece (PP) of spermatozoa flagellum. In the mouse, deletion of Septin 4, a structural component of the sperm annulus, prevents annulus formation and leads to MP-PP disjunction, flagellar bending, asthenozoospermia and male sterility. Testis anion transporter 1 (Tat1) is a germ cell-specific member of the SLC26 anion transporter family and is co-expressed with Septin 4 at the sperm annulus. Interestingly, Tat1 null sperm bear an atrophic annulus, causing a phenotype similar to that of Sept4 null sperm. We searched for Tat1 misexpression and/or mislocalization in spermatozoa from asthenozoospermic subjects (n = 75) and controls by performing an immunofluorescence detection assay on sperm smear preparations. We found one patient showing moderate asthenozoospermia, with 97% of sperm lacking Tat1, Septin 4 and Septin 7 proteins at the annulus. We confirmed the absence of the annulus structure by transmission electron microscopy and observed that spermatozoa from the patient displayed MP-PP disjunction and abnormal mitochondrial organization. We show that the structural defects in sperm are not caused by abnormal transcription or point mutations of the TAT1 and SEPT4 genes; however, although both proteins are expressed, they are not properly localized at sperm annulus. The case we studied, so far unreported in human, confirms the involvement of Tat1 and Septin proteins in the constitution of the annulus, but also raises questions about the function of this structure in human sperm motility.

  16. COMPARISON OF PREOPERATIVE NONINVASIVE AND INTRAOPERATIVE MEASUREMENTS OF AORTIC ANNULUS

    Directory of Open Access Journals (Sweden)

    Manish Hinduja

    2016-10-01

    Full Text Available BACKGROUND Precise preoperative assessment of aortic annulus diameter is essential for sizing of aortic valve especially in patients planned for transcatheter aortic valve replacement. Computed Tomographic (CT and echocardiographic measurements of the aortic annulus vary because of elliptical shape of aortic annulus. This study was undertaken to compare the measurement of aortic annulus intraoperatively with preoperative noninvasive methods in patients undergoing aortic valve replacement. MATERIALS AND METHODS Aortic annulus diameter was measured with cardiac CT and Transesophageal Echocardiography (TEE prior to open aortic valve replacement in 30 patients with aortic valve stenosis. In CT, aortic annulus dimensions were measured in coronal plane, sagittal oblique plane and by planimetry. Both 2-dimensional and 3-dimensional TEE were used. These were compared with intraoperative measurements done by valve sizers and Hegar dilators. Pearson analysis was applied to test for degree of correlation. RESULTS CT in coronal and sagittal oblique plane tends to overestimate the diameter of aortic annulus when compared with intraoperative measurements (coefficient of relation, r = 0.798 and 0.749, respectively. CT measurements in single oblique plane showed a weaker correlation with intraoperative measurements than 3D TEE and 2D TEE (r = 0.917 and 0.898, respectively. However, CT measurements by planimetry method were most correlating with the intraoperative measurements (r = 0.951. CONCLUSION Noninvasive investigations with 3-dimensional views (CT-based measurement employing calculated average diameter assessment by planimetry and 3-dimensional TEE showed better correlation with intraoperative measurement of aortic annulus. CT-based aortic annulus measurement by planimetry seems to provide adequate dimensions most similar to operative measurements.

  17. Small aortic valve annulus in children with fixed subaortic stenosis.

    Science.gov (United States)

    Thilenius, O G; Campbell, D; Bharati, S; Lev, M; Arcilla, R A

    1989-01-01

    Twenty-one hearts with fixed subaortic stenosis (FSAS) were examined pathologically. Thirty children with no hemodynamically significant heart disease, 31 children with valvar aortic stenosis, and 25 children with FSAS were studied by echo- and angiocardiography. The following conclusions were drawn: (1) Patients with FSAS often have abnormal aortic valve leaflets as well as small aortic valve annulus. (2) A small aortic annulus/descending aorta ratio is probably present at birth, and may decrease with increasing age. (3) In some patients with FSAS the aortic valve annulus is too small for simple resection of the fibroelastic tissue. A Konno operation is needed for these patients. (4) M-mode echocardiography has not been useful in identifying abnormally small aortic valve annulus in FSAS patients.

  18. Spacer lock of roof bolting

    Energy Technology Data Exchange (ETDEWEB)

    Shirokov, A.P.; Boronov, N.N.; Isachenko, V.M.; Kuntsevich, V.I.

    1980-04-05

    The object of the invention is a spacer joint of anchor bolting, which includes a wedge-shaped head and half-coupling, which are beveled on the inner side of the walls, and have ribs on the outer sides of the walls. It is characterized in that in order to reduce cost of the joint by reducing the amount of steel and manufacturing costs, the walls of the half-couplings hae identical thickness lengthwise, and the ribs are of varying height with corresponding projections on the inner side of the half-couplings.

  19. Mobilities

    DEFF Research Database (Denmark)

    to social networks, personal identities, and our relationship to the built environment. The omnipresence of mobilities within everyday life, high politics, technology, and tourism (to mention but a few) all point to a key insight harnessed by the ‘mobilities turn’. Namely that mobilities is much more than...... simple movements of people, goods, and information from A to B. The ‘mobilities turn’ has made it its hallmark to explore the ‘more than’ effects of a world increasingly on the move. This new title in the Routledge Series ‘Critical Concepts in Built Environment’ creates a state-of-the-art reference work...... will cover diverse topics such as theories, concepts, methods, and approaches as well as it will explore various modes of mobilities and the relationship to everyday life practices. The selection also covers the ‘politics of mobilities’ from local urban planning schemes to geopolitical issues of refugees...

  20. Role of Mitral Annulus Diastolic Geometry on Intraventricular Filling Dynamics.

    Science.gov (United States)

    Okafor, Ikechukwu U; Santhanakrishnan, Arvind; Raghav, Vrishank S; Yoganathan, Ajit P

    2015-12-01

    The mitral valve (MV) is a bileaflet valve positioned between the left atrium and ventricle of the heart. The annulus of the MV has been observed to undergo geometric changes during the cardiac cycle, transforming from a saddle D-shape during systole to a flat (and less eccentric) D-shape during diastole. Prosthetic MV devices, including heart valves and annuloplasty rings, are designed based on these two configurations, with the circular design of some prosthetic heart valves (PHVs) being an approximation of the less eccentric, flat D-shape. Characterizing the effects of these geometrical variations on the filling efficiency of the left ventricle (LV) is required to understand why the flat D-shaped annulus is observed in the native MV during diastole in addition to optimizing the design of prosthetic devices. We hypothesize that the D-shaped annulus reduces energy loss during ventricular filling. An experimental left heart simulator (LHS) consisting of a flexible-walled LV physical model was used to characterize the filling efficiency of the two mitral annular geometries. The strength of the dominant vortical structure formed and the energy dissipation rate (EDR) of the measured fields, during the diastolic period of the cardiac cycle, were used as metrics to quantify the filling efficiency. Our results indicated that the O-shaped annulus generates a stronger (25% relative to the D-shaped annulus) vortical structure than that of the D-shaped annulus. It was also found that the O-shaped annulus resulted in higher EDR values throughout the diastolic period of the cardiac cycle. The results support the hypothesis that a D-shaped mitral annulus reduces dissipative energy losses in ventricular filling during diastole and in turn suggests that a symmetric stent design does not provide lower filling efficiency than an equivalent asymmetric design.

  1. Stability of fluid flow in a cylindrical annulus

    Science.gov (United States)

    Ludwieg, H.

    1984-01-01

    Helical flow in an annulus between two coaxial cylinders is investigated with regard to its stability against the formation of helical vortices of the type known as Taylor's annular vortices. Assuming the annulus to be small and the velocities to vary linearly with radius, it is shown that the problem can be reduced to the classical case of flow between two rotating cylinders. An appropriate stability criterion for helical flows is derived from Rayleigh's stability criterion applicable to such flows.

  2. Caseous Necrosis of Mitral Annulus: A Rare Cause of Stroke

    Directory of Open Access Journals (Sweden)

    Jérôme Corre

    2013-01-01

    Full Text Available The current report describes a rare case of a caseous necrosis presenting as a pseudotumor in ventricle, revealed by stroke. Cerebral MRI, showing multiples lacunes, evocates a cardioembolic mechanism. Transthoracic and transesophageal echocardiography demonstrate a large hyperechogenic mass fixed to the posterior mitral valve and annulus while thoracic tomography revealed a fully calcified lesion, at the mitral annulus, evocative of caseus necrosis. Medical therapy was preferred (anticoagulation, because of her age and the decaying nature of surgery.

  3. Loewner Theory in annulus II: Loewner chains

    CERN Document Server

    Contreras, Manuel D; Gumenyuk, Pavel

    2011-01-01

    Loewner Theory, based on dynamical viewpoint, proved itself to be a powerful tool in Complex Analysis and its applications. Recently Bracci et al [Bracci et al, to appear in J. Reine Angew. Math. Available on ArXiv 0807.1594; Bracci et al, Math. Ann. 344(2009), 947--962; Contreras et al, Revista Matematica Iberoamericana 26(2010), 975--1012] have proposed a new approach bringing together all the variants of the (deterministic) Loewner Evolution in a simply connected reference domain. This paper is devoted to the construction of a general version of Loewner Theory for the annulus launched in [ArXiv 1011.4253]. We introduce the general notion of a Loewner chain over a system of annuli and obtain a 1-to-1 correspondence between Loewner chains and evolution families in the doubly connected setting similar to that in the Loewner Theory for the unit disk. Futhermore, we establish a conformal classification of Loewner chains via the corresponding evolution families and via semicomplete weak holomorphic vector fields...

  4. CRISPR interference directs strand specific spacer acquisition.

    Directory of Open Access Journals (Sweden)

    Daan C Swarts

    Full Text Available BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS: The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the

  5. Development of a High Performance Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kee Nam; Song, K. N.; Yoon, K. H. (and others)

    2007-03-15

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 18 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates 16 are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models.

  6. Tricuspid annulus: A spatial and temporal analysis

    Directory of Open Access Journals (Sweden)

    Ziyad O Knio

    2016-01-01

    Full Text Available Background: Traditional two-dimensional (2D echocardiographic evaluation of tricuspid annulus (TA dilation is based on single-frame measurements of the septolateral (S-L dimension. This may not represent either the axis or the extent of dynamism through the entire cardiac cycle. In this study, we used real-time 3D transesophageal echocardiography (TEE to analyze geometric changes in multiple axes of the TA throughout the cardiac cycle in patients without right ventricular abnormalities. Materials and Methods: R-wave-gated 3D TEE images of the TA were acquired in 39 patients undergoing cardiovascular surgery. The patients with abnormal right ventricular/tricuspid structure or function were excluded from the study. For each patient, eight points along the TA were traced in the 3D dataset and used to reconstruct the TA at four stages of the cardiac cycle (end- and mid-systole, end- and mid-diastole. Statistical analyses were applied to determine whether TA area, perimeter, axes, and planarity changed significantly over each stage of the cardiac cycle. Results: TA area (P = 0.012 and perimeter (P = 0.024 both changed significantly over the cardiac cycle. Of all the axes, only the posterolateral-anteroseptal demonstrated significant dynamism (P < 0.001. There was also a significant displacement in the vertical axis between the points and the regression plane in end-systole (P < 0.001, mid-diastole (P = 0.014, and mid-systole (P < 0.001. Conclusions: The TA demonstrates selective dynamism over the cardiac cycle, and its axis of maximal dynamism is different from the axis (S-L that is routinely measured with 2D TEE.

  7. Mobilization

    Science.gov (United States)

    1987-01-01

    istic and romantic emotionalism that typifies this genre. Longino, James C., et al. “A Study of World War Procurement and Industrial Mobilization...States. Harrisburg, PA: Military Service Publishing Co., 1941. CARL 355.22 J72b. Written in rough prose , this World War II era document explains the

  8. Flow of viscoplastic fluids in a rotating concentric annulus

    DEFF Research Database (Denmark)

    Hassager, Ole; Bittleston, Simon H.

    1992-01-01

    pressure gradient is small compared to the yield stress of the fluid then the full solution predicts the existence of plugs attached to the outer wall of the annulus. The slot approximation fails to predict this feature. For larger pressure gradients the two solutions are in good agreement. The analytical......A difficulty in any flow calculation with viscoplastic fluids such as Bingham fluids is the determination of possible plug zones in which no deformation occurs. This paper investigates the flow in a concentric annulus when there is both an axial and tangential flow, the tangent flow arising from...... rotation of the inner cylinder of the annulus. The flow is analyzed by considering flow in a slot, for which an analytical solution is given, and by solving the full problem numerically. It is shown that when the boundary is set in motion an applied pressure gradient will always cause flow. If the applied...

  9. Nucleate boiling pressure drop in an annulus: Book 2

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. Nineteen test series and a total of 178 tests were performed. Testing addressed the effects of: Heat flux; pressure; helium gas; power tilt; ribs; asymmetric heat flux.

  10. Nucleate boiling pressure drop in an annulus: Book 3

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of data plots and summary files of temperature measurements.

  11. Nucleate boiling pressure drop in an annulus: Book 4

    Energy Technology Data Exchange (ETDEWEB)

    Block, J.A.; Crowley, C.; Dolan, F.X.; Sam, R.G.; Stoedefalke, B.H.

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The annulus has a full-scale geometry, and in fat uses SRL dummy hardware for the inner annulus wall in the ribbed geometry. The materials aluminum. The annulus is uniformly heated in the axial direction, but the circumferential heat flux can be varied to provide ``power tilt`` or asymmetric heating of the inner and outer annulus walls. The test facility uses H{sub 2}O rather than D{sub 2}O, but it includes the effects of dissolved helium gas present in the reactor. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. This document consists of data plots and summary files of temperature measurements.

  12. Radius ratio effects on natural heat transfer in concentric annulus

    DEFF Research Database (Denmark)

    Alipour, M.; Hosseini, R.; Kolaei, Alireza Rezania

    2013-01-01

    This paper studies natural convection heat transfer in vertical and electrically heated annulus. The metallic cylinders mounted concentrically in a parallel tube. Measurements are carried out for four input electric powers and three radius ratios with an apparatus immersed in stagnant air....... This experimental work develops correlations of the average Nusselt number dependency on the Rayleigh number in the annulus, where this dependency promotes as the radius ratio increases from 0.1 to 0.2. Moreover, a correlation is proposed to determine the average Nusselt number based on the variation of the radius...

  13. Flow in a small annulus between concentric cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, M.; Mihelcic, M.; Wingerath, K. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Festkoerperforschung); Pfister, G. (Kiel Univ. (Germany, F.R.). Inst. fuer Angewandte Physik)

    1984-03-01

    Rotationally symmetric vortex flows between concentric cylinders with the inner one rotating and the outer one at rest have been investigated by numerical simulation and by laser-Doppler velocimetry for an annulus of aspect ratio GAMMA = 1.05 with a radius ratio eta = 0.5066. Stationary states and relaxation towards them were explored close to the transition from the primary flow, which is mirror symmetric with respect to the midplane of the annulus, to a flow which gradually loses the symmetry. Detailed comparison of numerically simulated and measured velocity fields is made.

  14. Reproducibility of aortic annulus measurements by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); University of Giessen, Department of Cardiology, Giessen (Germany); Pflederer, Tobias; Marwan, Mohamed; Schmid, Jasmin; Arnold, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany); Nef, Holger; Rixe, Johannes; Hecker, Franziska [University of Giessen, Department of Cardiology, Giessen (Germany); Schneider, Christian [University of Giessen, Department of Radiology, Giessen (Germany); Lell, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany)

    2014-08-15

    To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography. CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers. Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (k = 0.86 for mean, k = 0.84 for area-derived and k = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10 for fluoroscopic projection angle was achieved in 84.3 % of patients. A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification. (orig.)

  15. [Aortic valve replacement for the small aortic annulus].

    Science.gov (United States)

    Oshima, H; Usui, A; Akita, T; Ueda, Y

    2006-04-01

    Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.

  16. Stability of Unsteady Mixed Convection in a Horizontal Concentric Annulus

    Directory of Open Access Journals (Sweden)

    Kamil Kahveci

    2016-01-01

    Full Text Available In this study, stability of unsteady mixed convection in a horizontal annulus between two concentric cylinders was investigated numerically. The surfaces of the cylinders were considered to be at fixed temperatures and it was assumed that the hot inner cylinder is rotating at a constant angular velocity. The buoyancy forces were formulated utilizing the Boussinesq approximation. The governing equations of fluid flow and heat transfer in the annulus were solved with a finite element method for different values of the geometric (radius ratio and transport parameters (Rayleigh number and Reynolds number. Development of the convective flow and heat transfer was expressed by the average Nusselt number for the outer cylinder. The results show that, for a narrow gap annulus, convective flow induces flow bifurcation and becomes unstable for high values of the Rayleigh number. Flow becomes more unstable with an increase in the Reynolds number. For a wide gap annulus, flow is stable for all values of the Rayleigh number if the rotation effects are small. On the other hand, convective flow becomes unstable for the modest and high values of the Ra number with an increase in the Re number.

  17. Hyperelastic anisotropic microplane constitutive model for annulus fibrosus.

    Science.gov (United States)

    Caner, Ferhun C; Guo, Zaoyang; Moran, Brian; Bazant, Zdenek P; Carol, Ignacio

    2007-10-01

    In a recent paper, Peng et al. (2006, "An Anisotropic Hyperelastic Constitutive Model With Fiber-Matrix Interaction for the Human Annulus Fibrosis," ASME J. Appl. Mech., 73(5), pp. 815-824) developed an anisotropic hyperelastic constitutive model for the human annulus fibrosus in which fiber-matrix interaction plays a crucial role in simulating experimental observations reported in the literature. Later, Guo et al. (2006, "A Composites-Based Hyperelastic Constitutive Model for Soft Tissue With Application to the Human Fibrosis," J. Mech. Phys. Solids, 54(9), pp. 1952-1971) used fiber reinforced continuum mechanics theory to formulate a model in which the fiber-matrix interaction was simulated using only composite effect. It was shown in these studies that the classical anisotropic hyperelastic constitutive models for soft tissue, which do not account for this shear interaction, cannot accurately simulate the test data on human annulus fibrosus. In this study, we show that the microplane model for soft tissue developed by Caner and Carol (2006, "Microplane Constitutive Model and Computational Framework for Blood Vessel Tissue," ASME J. Biomech. Eng., 128(3), pp. 419-427) can be adjusted for human annulus fibrosus and the resulting model can accurately simulate the experimental observations without explicit fiber-matrix interaction because, in microplane model, the shear interaction between the individual fibers distributed in the tissue provides the required additional rigidity to explain these experimental facts. The intensity of the shear interaction between the fibers can be adjusted by adjusting the spread in the distribution while keeping the total amount of the fiber constant. A comparison of results obtained from (i) a fiber-matrix parallel coupling model, which does not account for the fiber-matrix interaction, (ii) the same model but enriched with fiber-matrix interaction, and (iii) microplane model for soft tissue adapted to annulus fibrosus with two

  18. Growth of mitral annulus in the pediatric patient after suture annuloplasty of the entire posterior mitral annulus.

    Science.gov (United States)

    Komoda, Takeshi; Huebler, Michael; Berger, Felix; Hetzer, Roland

    2009-08-01

    When mitral annuloplasty is performed in small children, room for annular growth should be allowed. However, it has not been reported how the valve develops after mitral annuloplasty of the entire posterior annulus. We report a case showing traces of annular growth at redo surgery. A female patient suffering from mitral valve insufficiency due to annular dilatation underwent modified Paneth plasty with Kay-Wooler commissural plication annuloplasty at the age of two years one month. In redo surgery 8.4 years after initial repair, enlargement of the commissural portion of the posterior annulus in addition to enlargement of the anterior leaflet and anterior annulus was observed. Modified Paneth plasty reinforced with a pericardial strip and Kay-Wooler annuloplasty of the posteromedial commissure were performed. Mitral orifice size measured with the Hegar dilator was 18 mm after the re-repair, increasing from 16 mm after the initial repair. Taking into account the normal mitral annulus diameter related to body surface area (BSA) of 16 mm at initial operation and 20 mm at redo surgery, the increase in mitral orifice size from 16 mm to 18 mm in this patient may be regarded as the annular growth in 8.4 years.

  19. Formation of the Terrestrial Planets from a Narrow Annulus

    CERN Document Server

    Hansen, Brad

    2009-01-01

    We show that the assembly of the Solar System terrestrial planets can be successfully modelled with all of the mass initially confined to a narrow annulus between 0.7 and 1.0 AU. With this configuration, analogues of Mercury and Mars often form from the collisional evolution of material diffusing out of the annulus under the scattering of the forming Earth and Venus analogues. The final systems also possess eccentricities and inclinations that match the observations, without recourse to dynamical friction from remnant small body populations. Finally, the characteristic assembly timescale for Earth analogues is rapid in this model, and consistent with cosmochemical models based on the $^{182}$Hf--$^{182}$W isotopes. The agreement between this model and the observations suggests that terrestrial planet systems may also be formed in `planet traps', as has been proposed recently for the cores of giant planets in our solar system and others.

  20. A numerical study of natural convection in a narrow annulus

    Science.gov (United States)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area does not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was used to solve these models. The results indicate that the natural convective effects are small.

  1. Instability of diverging and converging flows in an annulus

    CERN Document Server

    Ilin, Konstantin

    2012-01-01

    The stability of two-dimensional diverging and converging flows in an annulus between two permeable cylinders is examined. The basic flow is irrotational and has both the radial and azimuthal components. It is shown that for a wide range of the parameters of the problem, the basic flow is unstable to small two-dimensional perturbations. The instability is inviscid and oscillatory and persists if the viscosity of the fluid is taken into consideration.

  2. A numerical study of natural convection in a narrow annulus

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area do not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was sued to solve these models. The results indicate that the natural convective effects are small. 6 refs.

  3. Simple annulus power balance in EBT-I

    Energy Technology Data Exchange (ETDEWEB)

    Borowski, S.K.; Uckan, N.A.; Jaeger, E.F.; Kammash, T.

    1979-09-01

    An essential feature of the ELMO Bumpy Torus (EBT) concept is the presence of a relativistic electron annulus in each of the toroidal mirror sectors. These high beta annuli are formed and sustained by microwave heating and are of sufficient density and temperature that diamagnetic currents produce the necessary minimum in the magnetic field required for MHD stability of the toroidal core plasma. Because electron rings play an important role in confinement characteristics and performance of EBT, the trade-off between the quality of the confinement afforded by the rings and the power required to sustain the rings represents an important problem in a fusion reactor. Theoretical estimates of the microwave power required to sustain the annulus are found to be within a factor of 2 of the experimentally determined value. Scaling projections that are shown for both EBT-I and EBT-S enable one to examine the sensitivity of the annulus electron temperature as a function of core plasma density for various microwave power levels. The results are found to be sensitive to the details of the hot electron distribution function as well as geometric and scaling parameters. Improvements to the model are under way in order to increase its capability and accuracy in assessing the overall power balance.

  4. Separator-spacer for electrochemical systems

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Newby, Kenneth R.; Bellows, Richard J.

    1983-08-02

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  5. Project W-320 high vacuum 241-AY-102 annulus ventilation system operability test report

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J.W.

    1998-03-12

    This report documents the test results of OTP-320-001, Tank 241-AY-102 Annulus Ventilation System Testing. Included in the appendices are: (1) Supporting documentation prepared to demonstrate the structural integrity of the tank at high annulus vacuum (<20 INWG), and (2) a report that identifies potential cross connections between the primary and annulus ventilation systems. These cross connections were verified to be eliminated prior to the start of testing.

  6. A technique of aortic annulus enlargement with a Freestyle stentless bioprosthesis.

    Science.gov (United States)

    Bical, Olivier M; Nutu, Ovidiu; Deleuze, Philippe

    2012-02-01

    We describe our surgical technique to manage a small aortic annulus during aortic valve replacement. Starting with the posterior annular enlargement incision described by Manouguian, a stentless porcine aortic root, with excision of the left and right porcine coronary segments and conservation of the mural wall (Freestyle MS design, Medtronic, Minneapolis, MN ), was used. The Freestyle bioprosthesis enlarges the aortic annulus using a direct suture of the valve on the enlarged annulus, and the aorta is closed by a direct suture of the mural wall of the bioprosthesis. Therefore, the aortic annulus enlargement is made only using the aortic bioprosthesis, without other material.

  7. Magnetorotational Instability in a Rotating Liquid Metal Annulus

    Energy Technology Data Exchange (ETDEWEB)

    Hantao Ji; Jeremy Goodman; Akira Kageyama

    2001-03-10

    Although the magnetorotational instability (MRI) has been widely accepted as a powerful accretion mechanism in magnetized accretion disks, it has not been realized in the laboratory. The possibility of studying MRI in a rotating liquid-metal annulus (Couette flow) is explored by local and global stability analysis and magnetohydrodynamic (MHD) simulations. Stability diagrams are drawn in dimensionless parameters, and also in terms of the angular velocities at the inner and outer cylinders. It is shown that MRI can be triggered in a moderately rapidly rotating table-top apparatus, using easy-to-handle metals such as gallium. Practical issues of this proposed experiment are discussed.

  8. Heterogeneous diversity of spacers within CRISPR

    Science.gov (United States)

    Deem, Michael; He, Jiankui

    2011-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of anti-viral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement with recent experiments. Our results show that the CRISPR spacer structure is influenced by and provides a record of the viral challenges that bacteria face. 1) J. He and M. W. Deem, Phys. Rev. Lett. 105 (2010) 128102

  9. Nucleate boiling pressure drop in an annulus: Book 5

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The application of the work described in this report is the production reactors at the Savannah River Site, and the context is nuclear reactor safety. The Loss of Coolant Accident (LOCA) scenario considered involves a double-ended break of a primary coolant pipe in the reactor. During a LOCA, the flow through portions of the reactor may reverse direction or be greatly reduced, depending upon the location of the break. The reduced flow rate of coolant (D{sub 2}O) through the fuel assembly channels of the reactor -- downflow in this situation -- can lead to boiling and to the potential for flow instabilities which may cause some of the fuel assembly channels to overheat and melt. That situation is to be avoided. The experimental approach is to provide a test annulus which simulates geometry, materials, and flow conditions in a Mark-22 fuel assembly (Coolant Channel 3) to the extent possible. The key analysis approaches are: To compare the minima in the measured demand curves with analytical criteria, in particular the Saha-Zuber (1974) model; and to compare the pressure and temperature as a function of length in the annulus with an integral model for flow boiling in a heated channel. Nineteen test series and a total of 178 tests were performed. Testing addressed the effects of: Heat flux; pressure; helium gas; power tilt; ribs; asymmetric heat flux. This document consists solely of the plato file index from 11/87 to 11/90.

  10. Ultrasonic defect detection and size approximation using thin annulus probes

    Energy Technology Data Exchange (ETDEWEB)

    Light, G.M.; Fisher, J.L.; Tennis, R.F.; Stolte, J.S.; Hendrix, G.J. [Southwest Research Inst., San Antonio, TX (United States)

    1994-12-31

    Concern has been generated recently about the capabilities of performing nondestructive evaluation (NDE) of the closure head penetrations in nuclear-reactor pressure vessels (PV). These penetrations, primarily for instrumentation and control rod drive mechanisms (CRDMs), are usually thick-walled Inconel tubes, shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through wall cracks in the CRDM penetration or CRDM weld could lead to loss of PV coolant. The penetration presents a complex geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for control-rod operation, is inserted into the penetration so that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. SwRI has developed and evaluated ultrasonic techniques for sizing defects in this area. Long, thin probes were designed to fit into the annulus to carry irrigated ultrasonic transducers into the region of interest. The probes were used to detect cracks in the penetration and to estimate remaining wall thickness.

  11. Fibre-matrix interaction in the human annulus fibrosus.

    Science.gov (United States)

    Guo, Zaoyang; Shi, Xiaohao; Peng, Xiongqi; Caner, Ferhun

    2012-01-01

    Although the mechanical behaviour of the human annulus fibrosus has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models. The objective of this study is to identify the significance of the fibre-matrix interaction in the human annulus fibrosus by careful investigation of the experimental data, the theoretical constitutive models, and the numerical simulation results in the literature. Based on the experimental results from biaxial and uniaxial tests, it is shown that the mechanical behaviour of the matrix can be well simulated by an incompressible neo-Hookean type model, but the effective stiffness of the matrix depends on fibre stretch ratio, which can only be explained by fibre-matrix interaction. Furthermore, we find that this interaction takes place anisotropically between the matrix and the fibres distributed in different proportions in different directions. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by this fibre orientation dispersion.

  12. Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement.

    Science.gov (United States)

    Kazama, S; Kurata, A; Yamashita, Y

    1999-10-01

    An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

  13. Design and analysis of annulus core few mode EDFA for modal gain equalization

    CERN Document Server

    Gaur, Ankita

    2016-01-01

    Few-mode fiber amplifier is widely under study to overcome the issue of internet traffic in optical communication. This article proposes annulus core few-mode erbium doped fiber (FM-EDF) with annulus or extra annulus doping for amplification of the LP01, LP11, LP21, and LP31 signal mode groups with low differential modal gain (DMG). Our simulations confirm that extra annulus doping helps in reducing DMG of higher order mode groups. We have achieved less than 2.2 dB DMG over C-band for 4-mode groups using extra annulus doping. The proposed EDF would be useful for space division multiplexing (SDM) based optical fiber communication system.

  14. Design and Analysis of Annulus Core Few Mode EDFA for Modal Gain Equalization

    Science.gov (United States)

    Gaur, Ankita; Rastogi, Vipul

    2016-05-01

    Few-mode fiber amplifier is widely under study to overcome the issue of internet traffic in optical communication. This article proposes annulus core few-mode erbium doped fiber (FM-EDF) with annulus or extra annulus doping for amplification of the LP01, LP11, LP21, and LP31 signal mode groups with low differential modal gain (DMG). Our simulations confirm that extra annulus doping helps in reducing DMG of higher order mode groups. We have achieved less than 2.2 dB DMG over C-band for 4-mode groups using extra annulus doping. The proposed EDF would be useful for space division multiplexing (SDM) based optical fiber communication system.

  15. In vivo dynamic deformation of the mitral valve annulus.

    Science.gov (United States)

    Eckert, Chad E; Zubiate, Brett; Vergnat, Mathieu; Gorman, Joseph H; Gorman, Robert C; Sacks, Michael S

    2009-09-01

    Though mitral valve (MV) repair surgical procedures have increased in the United States [Gammie, J. S., et al. Ann. Thorac. Surg. 87(5):1431-1437, 2009; Nowicki, E. R., et al. Am. Heart J. 145(6):1058-1062, 2003], studies suggest that altering MV stress states may have an effect on tissue homeostasis, which could impact the long-term outcome [Accola, K. D., et al. Ann. Thorac. Surg. 79(4):1276-1283, 2005; Fasol, R., et al. Ann. Thorac. Surg. 77(6):1985-1988, 2004; Flameng, W., P. Herijgers, and K. Bogaerts. Circulation 107(12):1609-1613, 2003; Gillinov, A. M., et al. Ann. Thorac. Surg. 69(3):717-721, 2000]. Improved computational modeling that incorporates structural and geometrical data as well as cellular components has the potential to predict such changes; however, the absence of important boundary condition information limits current efforts. In this study, novel high definition in vivo annular kinematic data collected from surgically implanted sonocrystals in sheep was fit to a contiguous 3D spline based on quintic-order hermite shape functions with C(2) continuity. From the interpolated displacements, the annular axial strain and strain rate, bending, and twist along the entire annulus were calculated over the cardiac cycle. Axial strain was shown to be regionally and temporally variant with minimum and maximum values of -10 and 4%, respectively, observed. Similarly, regionally and temporally variant strain rate values, up to 100%/s contraction and 120%/s elongation, were observed. Both annular bend and twist data showed little deviation from unity with limited regional variations, indicating that most of the energy for deformation was associated with annular axial strain. The regionally and temporally variant strain/strain rate behavior of the annulus are related to the varied fibrous-muscle structure and contractile behavior of the annulus and surrounding ventricular structures, although specific details are still unavailable. With the high resolution

  16. On the flow in an annulus surrounding a whirling cylinder

    Science.gov (United States)

    Brennen, C.

    1976-01-01

    When fluid in an annulus between two cylinders is set in motion by whirling movements of one or both of the cylinders, dynamic forces are imposed by the fluid on the cylinders. Knowledge of these forces is frequently important, indeed often critical, to the engineer designing rotor systems or journal bearings. Quite general solutions of the Navier-Stokes equations are presented for this problem and are limited only by restrictions on the amplitude of the whirl motion. From these solutions, the forces are derived under a wide variety of circumstances, including large and small annular widths, high and low Reynolds numbers, and the presence and absence of a mean flow created by additional net rotation of one or both of the cylinders.

  17. Dispersion phenomena in helical flow in a concentric annulus.

    Science.gov (United States)

    Song, Young Seok; Brenner, Howard

    2009-12-14

    We examined dispersion phenomena of solutes in helical flow in a concentric annulus through a multiscale approach. The helical flow was developed by the combination of the Poiseuille flow and Couette flow. Here, we present an analytic model that can address the multidimensional Taylor dispersion in the helical flow under a lateral field of thermophoresis (or thermal diffusion) in the gapwise direction. Macroscopic parameters including the average solute velocity and dispersivity were analyzed using relevant microscopic physicochemical properties. The mathematically obtained results were validated by the numerical simulation carried out in this study. The findings show that macrotransport processes are robust and straightforward to handle multidimensional dispersion phenomena of solutes in helical flow. This study is expected to provide a theoretical platform for applications of helical flow such as tube exchangers, oil drilling, and multidimensional field flow fractionations (e.g., helical flow field flow fractionation).

  18. Opposing flow in square porous annulus: Influence of Dufour effect

    Science.gov (United States)

    Athani, Abdulgaphur; Al-Rashed, Abdullah A. A. A.; Khaleed, H. M. T.

    2016-06-01

    Heat and mass transfer in porous medium is very important area of research which is also termed as double diffusive convection or thermo-solutal convection. The buoyancy ratio which is the ratio of thermal to concentration buoyancy can have negative values thus leading to opposing flow. This article is aimed to study the influence of Dufour effect on the opposing flow in a square porous annulus. The partial differential equations that govern the heat and mass transfer behavior inside porous medium are solved using finite element method. A three node triangular element is used to divide the porous domain into smaller elements. Results are presented with respect to geometric and physical parameters such as duct diameter ratio, Rayleigh number, radiation parameter etc. It is found that the heat transfer increase with increase in Rayleigh number and radiation parameter. It is observed that Dufour coefficient has more influence on velocity profile.

  19. Effect of Spacer and the Enzyme-Linked Immunosorbent Assay

    Directory of Open Access Journals (Sweden)

    Manisha Sathe

    2016-09-01

    Full Text Available The effect of spacers and the enzyme-linked immunosorbent assay (ELISA formats on the functional parameters of assays such as lower detection limit, inhibitory concentration at 50 per cent (IC50, and specificity were studied. Enzyme conjugates having hydrophobic and hydrophilic spacers were prepared using O-isopropyl methylphosphonic acid (IMPA and horseradish peroxidase (HRP as an enzyme label. Comparison was made with reference to enzyme conjugate without any spacer. The present investigation revealed that the presence of a hydrophilic spacer in the enzyme conjugate significantly improves the sensitivity of assays. An enhanced IC50 value achieved was 0.01 μg mL−1 for free antigen detection by direct immunoassay using hydrophilic spacers and precoating of ELISA plates by secondary antibody. The use of a hydrophilic spacer might have helped in projecting the hapten in the aqueous phase, leading to enhanced antibody binding signal and improved sensitivity of the assay.

  20. Application of Regent mechanical valve in patients with small aortic annulus: 3-year follow-up

    OpenAIRE

    Zhao Dong; Wang Chunsheng; Hong Tao; Pan Cuizhen; Guo Changfa

    2012-01-01

    Abstract Background Aortic valve replacement (AVR) with a small aortic annulus is always challenging for the cardiac surgeon. In this study, we sought to evaluate the midterm performance of implantation with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent) mechanical valve in retrospective consecutive cohort of patients with small aortic annulus (diameter ≤ 19 mm). Methods From January 2008 to April 2011, 40 patients (31 female, mean age = 47.2 ± 5.8 years) with small aortic annulus (≤19...

  1. Nephila clavipes Flagelliform silk-like GGX motifs contribute to extensibility and spacer motifs contribute to strength in synthetic spider silk fibers.

    Science.gov (United States)

    Adrianos, Sherry L; Teulé, Florence; Hinman, Michael B; Jones, Justin A; Weber, Warner S; Yarger, Jeffery L; Lewis, Randolph V

    2013-06-10

    Flagelliform spider silk is the most extensible silk fiber produced by orb weaver spiders, though not as strong as the dragline silk of the spider. The motifs found in the core of the Nephila clavipes flagelliform Flag protein are GGX, spacer, and GPGGX. Flag does not contain the polyalanine motif known to provide the strength of dragline silk. To investigate the source of flagelliform fiber strength, four recombinant proteins were produced containing variations of the three core motifs of the Nephila clavipes flagelliform Flag protein that produces this type of fiber. The as-spun fibers were processed in 80% aqueous isopropanol using a standardized process for all four fiber types, which produced improved mechanical properties. Mechanical testing of the recombinant proteins determined that the GGX motif contributes extensibility and the spacer motif contributes strength to the recombinant fibers. Recombinant protein fibers containing the spacer motif were stronger than the proteins constructed without the spacer that contained only the GGX motif or the combination of the GGX and GPGGX motifs. The mechanical and structural X-ray diffraction analysis of the recombinant fibers provide data that suggests a functional role of the spacer motif that produces tensile strength, though the spacer motif is not clearly defined structurally. These results indicate that the spacer is likely a primary contributor of strength, with the GGX motif supplying mobility to the protein network of native N. clavipes flagelliform silk fibers.

  2. Mobilities Mobilities

    Directory of Open Access Journals (Sweden)

    César Pompeyo

    2011-12-01

    Full Text Available Urry, John (2007 Mobilities.Oxford: Polity Press.Urry, John (2007 Mobilities.Oxford: Polity Press.John Urry (1946-, profesor en la Universidad de Lancaster, es un sociólogo de sobra conocido y altamente reputado en el panorama internacional de las ciencias sociales. Su dilatada carrera, aparentemente dispersa y diversificada, ha seguido senderos bastante bien definidos dejando tras de sí un catálogo extenso de obras sociológicas de primer nivel. Sus primeros trabajos se centraban en el campo de la teoría social y la filosofía de las ciencias sociales o de la sociología del poder [...

  3. APPLICATIONS OF SPACERS MADE WITH DOUBLE BAR RASCHEL MACHINE

    Directory of Open Access Journals (Sweden)

    DÍAZ-GARCÍA Pablo

    2016-05-01

    Full Text Available Nowadays, textile technologies develop to adapt their different techniques for creating new products for the different sectors of application every day. Particularly, warp knitted fabrics and warp-knitting technology have applications in all different groups of technical textiles. It could be the most applied technique, the most versatile technology to develop new textile products for the new textile market. Warp knitted fabrics play the most important role among the technical textile fabrics. This technology is used in different product groups such as mobile textiles (car seat covers, dashboard cover, industrial textiles (composites, medical textiles (anti-decubitus blankets, sports textiles and foundation garments (bra cups, pads for swimwear. This study presents some examples of the application of this technology in some markets Within the market of technical textile, medical textile has an increasing relevance and knitted fabrics and knitting technology, at the same time, play a very important role in the fields of technical and medical textiles. Studies have demonstrated that knitted structures possess excellent mechanical properties and can promote more effective regenerative medicine, tissue repair, ligament, tendon cartilage, reconstruction, etc. The aim of this paper is to present different possibilities of textiles developed with this kind of structures, to present different alternatives, different examples of products obtained with this kind of textile structure combined with the correct kind of textile fiber. In this kind of technology, double-bar Raschel machines used for producing three-dimensional textiles, spacers, play an important role.

  4. Molecular recordings by directed CRISPR spacer acquisition.

    Science.gov (United States)

    Shipman, Seth L; Nivala, Jeff; Macklis, Jeffrey D; Church, George M

    2016-07-29

    The ability to write a stable record of identified molecular events into a specific genomic locus would enable the examination of long cellular histories and have many applications, ranging from developmental biology to synthetic devices. We show that the type I-E CRISPR (clustered regularly interspaced short palindromic repeats)-Cas system of Escherichia coli can mediate acquisition of defined pieces of synthetic DNA. We harnessed this feature to generate records of specific DNA sequences into a population of bacterial genomes. We then applied directed evolution so as to alter the recognition of a protospacer adjacent motif by the Cas1-Cas2 complex, which enabled recording in two modes simultaneously. We used this system to reveal aspects of spacer acquisition, fundamental to the CRISPR-Cas adaptation process. These results lay the foundations of a multimodal intracellular recording device.

  5. The Cyclicity of the Period Annulus Around the Quadratic Isochronous Center

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The number of the limit cycles bifurcating in small quadratic perturbations of quadratic systems with an isochronous center is studied, it turns out that the cyclicity of the period annulus around one kind of quadratic isochronous center is two.

  6. Annulus electromagnetic stirring for preparing semisolid A357 aluminum alloy slurry

    Institute of Scientific and Technical Information of China (English)

    BAI Yue-long; XU Jun; ZHANG Zhi-feng; SHI Li-kai

    2009-01-01

    The effects of pouring temperature and annulus gap width on the microstructure of the semi-solid A357 aluminum alloy slurry prepared by annulus electromagnetic stirring(AEMS) technology were investigated. The results show that low pouring temperature and narrow annulus gap are advantageous to obtaining the small spherical primary α(Al) phase. The lower the pouring temperature is and the smaller the annulus gap width is, the more uniform, the smaller and the more spherical the microstructure is. The microstructures obtained by the ordinary electromagnetic stirring and AEMS were compared. The results indicate that the primary α(Al) particles are globular, small and distribute homogeneously in the slurry obtained by AEMS. But in the slurry obtained by the ordinary electromagnetic stirring, the primary α(Al) particles are small dendrites in the edge of the slurry and they are large and rosette-like or dendritic in the inner of the slurry.

  7. Aortic valve replacement with concomitant annular enlargement for small aortic annulus of less than 19 mm.

    Science.gov (United States)

    Takakura, H; Sasaki, T; Hashimoto, K; Hachiya, T; Onoguchi, K; Oshiumi, M; Takeuchi, S

    2000-06-01

    Three female patients with aortic stenosis associated with a severely small annulus underwent aortic valve replacement. In intraoperative measurements, a 19-mm obtulator could not pass through the aortic annulus in each case. We therefore concluded that it would be difficult to implant an appropriate-sized prosthesis in a routine fashion, so we performed an annular enlargement in a modified Nicks procedure. By using a wide teardrop-shaped patch for enlargement and slightly tilting insertion of a prosthesis, a 21 mm bileaflet mechanical prosthesis could be inserted into the enlarged annulus. Despite being a simpler method than other enlarging procedures, a two- or three-sizes larger prosthesis than the native annulus can be inserted with relative ease. Thus, the use of a 19 mm mechanical prosthesis may be avoidable in most adult cases.

  8. Orthognathic model surgery with LEGO key-spacer.

    Science.gov (United States)

    Tsang, Alfred Chee-Ching; Lee, Alfred Siu Hong; Li, Wai Keung

    2013-12-01

    A new technique of model surgery using LEGO plates as key-spacers is described. This technique requires less time to set up compared with the conventional plaster model method. It also retains the preoperative setup with the same set of models. Movement of the segments can be measured and examined in detail with LEGO key-spacers.

  9. Stress Analysis of Single Spacer Grid Support considering Fuel Rod

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y. G.; Jung, D. H.; Kim, J. H. [Chungnam National University, Daejeon (Korea, Republic of); Park, J. K.; Jeon, K. L. [Korea Nuclear Fuel, Daejeon (Korea, Republic of)

    2010-10-15

    Pressurized water reactor (PWR) nuclear fuel assembly is mainly composed of a top-end piece, a bottom-end piece, lots of fuel rods, and several spacer grids. Among them, the main function of spacer grid is protecting fuel rods from Fluid Induced Vibration (FIV). The cross section of spacer grid assembled by laser welding in upper and lower point. When the fuel rod inserted in spacer gird, spring and dimple and around of welded area got a stresses. The main hypothesis of this analysis is the boundary area of HAZ and base metal can get a lot of damage than other area by FIV. So, design factors of spacer grid mainly considered to preventing the fatigue failure in HAZ and spring and dimple of spacer grid. From previous researching, the environment in reactor verified. Pressure and temperature of light water observed 15MPa and 320 .deg. C, and vibration of the fuel rod observed within 0 {approx} 50Hz. In this study, mechanical properties of zirconium alloy that extracted from the test and the spacer grid model which used in the PWR were applied in stress analyzing. General-purpose finite element analysis program was used ANSYS Workbench 12.0.1 version. 3-D CAD program CATIA was used to create spacer grid model

  10. Some exploratory experiments with a new type of rotating, differentially-heated fluid annulus

    OpenAIRE

    Davies, Peter A; Walin, Gösta

    2011-01-01

    Some experiments with a rotating differentially heated annulus are presented. It is demonstrated that with suitable construction of the annulus the strength of the zonal baroclinic motion may be chosen independently of the basic density stratification. In the experiment reported it was found that baroclinic instability occurred in a state characterized by small isotherm slopes. Certain aspects of the observed flow and temperature fields—in particular the basic stratification and the slope of ...

  11. Assessment of the frequency of sperm annulus defects in a large cohort of patients presenting asthenozoospermia

    OpenAIRE

    Dirami, Thassadite; Rode, Baptiste; Wolf, Jean-Philippe; Gacon, Gérard; Dulioust, Emmanuel; Touré, Aminata

    2015-01-01

    International audience; Background: The annulus is a ring-shaped structure located beneath the plasma membrane that connects the midpiece and the principal piece of mammalian sperm flagellum. It has been suggested that the annulus acts as a morphological organizer, guiding flagellum assembly during spermiogenesis, and as a diffusion barrier, confining proteins to distinct compartments of the flagellum in mature sperm. Previous studies on small cohorts of patients have attempted to correlate a...

  12. Collagen fibrillogenesis in the development of the annulus fibrosus of the intervertebral disc.

    Science.gov (United States)

    Hayes, Anthony J; Isaacs, Marc D; Hughes, C; Caterson, B; Ralphs, J R

    2011-10-11

    The annulus fibrosus of the intervertebral disc is a complex, radial-ply connective tissue consisting of concentric lamellae of oriented collagen. Whilst much is known of the structure of the mature annulus, less is known of how its complex collagenous architecture becomes established; an understanding of which could inform future repair/regenerative strategies. Here, using a rat disc developmental series, we describe events in the establishment of the collagenous framework of the annulus at light and electron microscopic levels and examine the involvement of class I and II small leucine rich proteoglycans (SLRPs) in the matrix assembly process. We show that a period of sustained, ordered matrix deposition follows the initial cellular differentiation/orientation phase within the foetal disc. Fibrillar matrix is deposited from recesses within the plasma membrane into compartments of interstitial space within the outer annulus - the orientation of the secreted collagen reflecting the initial cellular orientation of the laminae. Medially, we demonstrate the development of a reinforcing 'cage' of collagen fibre bundles around the foetal nucleus pulpous. This derives from the fusion of collagen bundles between presumptive end-plate and inner annulus. By birth, the distinct collagenous architectures are established and the disc undergoes considerable enlargement to maturity. We show that fibromodulin plays a prominent role in foetal development of the annulus and its attachment to vertebral bodies. With the exception of keratocan, the other SLRPs appear associated more with cartilage development within the vertebral column, but all become more prominent within the disc during its growth and differentiation.

  13. Quantifying the contributions of structure to annulus fibrosus mechanical function using a nonlinear, anisotropic, hyperelastic model.

    Science.gov (United States)

    Guerin, Heather Lynch; Elliott, Dawn M

    2007-04-01

    The annulus fibrosus of the intervertebral disc is comprised of concentric lamella of oriented collagen fibers embedded in a hydrated proteoglycan matrix with smaller amounts of minor collagens, elastin, and small proteoglycans. Its structure and composition enable the disc to withstand complex loads and result in inhomogeneous, anisotropic, and nonlinear mechanical behaviors. The specific contributions of the annulus fibrosus constituent structures to mechanical function remain unclear. Therefore, the objective of this study was to use a structurally motivated, anisotropic, nonlinear strain energy model of annulus fibrosus to determine the relative contributions of its structural components to tissue mechanical behavior. A nonlinear, orthotropic hyperelastic model was developed for the annulus fibrosus. Terms to describe fibers, matrix, and interactions between annulus fibrosus structures (shear and normal to the fiber directions) were explicitly included. The contributions of these structures were analyzed by including or removing terms and determining the effect on the fit to multidimensional experimental data. Correlation between experimental and model-predicted stress, a Bland-Altman analysis of bias and standard deviation of residuals, and the contribution of structural terms to overall tissue stress were calculated. Both shear and normal interaction terms were necessary to accurately model multidimensional behavior. Inclusion of shear interactions more accurately described annulus fibrosus nonlinearity. Fiber stretch and shear interactions dominated contributions to circumferential direction stress, while normal and shear interactions dominated axial stress. The results suggest that interactions between fibers and matrix, perhaps facilitated by crosslinks, elastin, or minor collagens, augment traditional (i.e., fiber-uncrimping) models of nonlinearity.

  14. Thermoconvective vortices in a cylindrical annulus with varying inner radius.

    Science.gov (United States)

    Castaño, D; Navarro, M C; Herrero, H

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

  15. Loewner Theory in annulus I: evolution families and differential equations

    CERN Document Server

    Contreras, Manuel D; Gumenyuk, Pavel

    2010-01-01

    Loewner Theory, based on dynamical viewpoint, is a powerful tool in Complex Analysis, which plays a crucial role in such important achievements as the proof of famous Bieberbach's conjecture and well-celebrated Schramm's Stochastic Loewner Evolution (SLE). Recently Bracci et al [Bracci et al, to appear in J. Reine Angew. Math. Available on ArXiv 0807.1594; Bracci et al, Math. Ann. 344(2009), 947--962; Contreras et al, Revista Matematica Iberoamericana 26(2010), 975--1012] have proposed a new approach bringing together all the variants of the (deterministic) Loewner Evolution in a simply connected reference domain. We construct an analogue of this theory for the annulus. In this paper, the first of two articles, we introduce a general notion of an evolution family over a system of annuli and prove that there is a 1-to-1 correspondence between such families and semicomplete weak holomorphic vector fields. Moreover, in the non-degenerate case, we establish a constructive characterization of these vector fields a...

  16. Design, Synthesis and Hydrolytic Behavior of Mutual Prodrugs of NSAIDs with Gabapentin Using Glycol Spacers

    Directory of Open Access Journals (Sweden)

    Hiba Najeh Alsaad

    2012-10-01

    Full Text Available The free –COOH present in NSAIDs is thought to be responsible for the GI irritation associated with all traditional NSAIDs. Exploitation of mutual prodrugs is an approach wherein the NSAID is covalently bounded to a second pharmacologically active carrier/drug with the ultimate aim of reducing the gastric irritation. In this study some NSAIDs were conjugated with gabapentin via ester bonds using glycol spacers with the expectation of reducing gastric adverse effects and obtaining synergistic analgesic effects. The kinetics of ester hydrolysis were studied in two different non enzymatic buffer solutions at pH 1.2 and 7.4, as well as in 80% human plasma using HPLC with chloroform -methanol as mobile phase. Compounds 9a–c with ethylene glycol spacers showed significant stability at buffer solutions with half lives ranging from about 8–25 h, while the underwent a reasonable plasma hydrolysis (49%–88% in 2 h. Compound 9d with a propylene glycol spacer shows a higher rate of enzymatic hydrolysis than the corresponding ethylene glycol compound 9c. The result of compounds 9a-c indicate that these compounds may be stable during their passage through the GIT until reaching the blood circulation.

  17. Spacer effect on nanostructures and self-assembly in organogels via some bolaform cholesteryl imide derivatives with different spacers

    Science.gov (United States)

    Jiao, Tifeng; Gao, Fengqing; Zhang, Qingrui; Zhou, Jingxin; Gao, Faming

    2013-10-01

    In this paper, new bolaform cholesteryl imide derivatives with different spacers were designed and synthesized. Their gelation behaviors in 23 solvents were investigated, and some of them were found to be low molecular mass organic gelators. The experimental results indicated that these as-formed organogels can be regulated by changing the flexible/rigid segments in spacers and organic solvents. Suitable combination of flexible/rigid segments in molecular spacers in the present cholesteryl gelators is favorable for the gelation of organic solvents. Scanning electron microscopy and atomic force microscopy observations revealed that the gelator molecules self-assemble into different aggregates, from wrinkle and belt to fiber with the change of spacers and solvents. Spectral studies indicated that there existed different H-bond formations between imide groups and assembly modes, depending on the substituent spacers in molecular skeletons. The present work may give some insight into the design and character of new organogelators and soft materials with special molecular structures.

  18. Knockdown of asporin affects transforming growth factor-β1-induced matrix synthesis in human intervertebral annulus cells

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2016-10-01

    Conclusion: Our results have verified a functional feedback loop between TGF-β1 and asporin in human intervertebral annulus cells indicating that TGF-β1-induced annulus matrix biosynthesis can be significantly upregulated by knockdown of asporin. Therefore, asporin could be a potential new therapeutic target and inhibition of asporin could be adopted to enhance the anabolic effect of TGF-β1 in human intervertebral annulus cells in degenerative IVD diseases.

  19. Preclinical Evaluation of Bioabsorbable Polyglycolic Acid Spacer for Particle Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Akasaka, Hiroaki [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Sasaki, Ryohei, E-mail: rsasaki@med.kobe-u.ac.jp [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Miyawaki, Daisuke; Mukumoto, Naritoshi; Sulaiman, Nor Shazrina Binti [Division of Radiation Oncology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Nagata, Masaaki [Division of Gastroenterology, Kobe University Graduate School of Medicine, Hyogo Japan (Japan); Yamada, Shigeru [Research Center Hospital, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Murakami, Masao [Radiation Oncology Center, Dokkyo Medical University, Tochigi (Japan); Demizu, Yusuke [Department of Radiology, Hyogo Ion Beam Medical Center, Hyogo (Japan); Fukumoto, Takumi [Division of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Hyogo Japan (Japan)

    2014-12-01

    Purpose: To evaluate the efficacy and safety of a polyglycolic acid (PGA) spacer through physical and animal experiments. Methods and Materials: The spacer was produced with surgical suture material made of PGA, forming a 3-dimensional nonwoven fabric. For evaluation or physical experiments, 150-MeV proton or 320-MeV carbon-ion beams were used to generate 60-mm width of spread-out Bragg peak. For animal experiments, the abdomens of C57BL/6 mice, with or without the inserted PGA spacers, were irradiated with 20 Gy of carbon-ion beam (290 MeV) using the spread-out Bragg peak. Body weight changes over time were scored, and radiation damage to the intestine was investigated using hematoxylin and eosin stain. Blood samples were also evaluated 24 days after the irradiation. Long-term thickness retention and safety were evaluated using crab-eating macaques. Results: No chemical or structural changes after 100 Gy of proton or carbon-ion irradiation were observed in the PGA spacer. Water equivalency of the PGA spacer was equal to the water thickness under wet condition. During 24 days' observation after 20 Gy of carbon-ion irradiation, the body weights of mice with the PGA spacer were relatively unchanged, whereas significant weight loss was observed in those mice without the PGA spacer (P<.05). In mice with the PGA spacer, villus and crypt structure were preserved after irradiation. No inflammatory reactions or liver or renal dysfunctions due to placement of the PGA spacer were observed. In the abdomen of crab-eating macaques, thickness of the PGA spacer was maintained 8 weeks after placement. Conclusions: The absorbable PGA spacer had water-equivalent, bio-compatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to stop proton or carbon-ion beams and to separate normal tissues from the radiation field.

  20. Flow dynamics and concentration polarisation in spacer-filled channels

    DEFF Research Database (Denmark)

    Lipnizki, Jens; Jonsson, Gunnar Eigil

    2002-01-01

    been shown that the mass transport along the membrane is not fully described by the Sherwood correlation, which describes a decreasing mass transfer with an increasing distance from the inlet. It was observed that in open channel without spacers, the slope of the Sherwood correlation is decreasing...... by increasing pressure. This effect is combined with regular stripes on the membrane depending on the crossflow velocity and pressure when using coloured particles. An explanation could be a mass transfer perpendicular to the flow direction due to vortices, which is not covered by the Sherwood correlation....... This phenomenon was also observed in spacer-filled channels. In this case the stripes on the surface depended on the spacer geometry. Furthermore, the experiments were used to calculate the energy consumption vs. the mass transfer coefficient for different spacers. This research can be used as a foundation...

  1. Response of an electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Rerup, T; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...

  2. Technique for adapting a spacer for a custom impression tray.

    Science.gov (United States)

    Kaur, Harsimran; Nanda, Aditi; Verma, Mahesh; Koli, Dheeraj

    2016-12-01

    A method of adapting a spacer for the custom trays used to make a definite impression for complete dentures is presented. The technique can be used under a variety of conditions and offers several advantages.

  3. Simultaneous PIV and thermography measurements of partially blocked flow in a differentially heated rotating annulus

    Energy Technology Data Exchange (ETDEWEB)

    Harlander, Uwe; Alexandrov, Kiril; Wang, Yongtai; Egbers, Christoph [Brandenburg University of Technology Cottbus, Department of Aerodynamics and Fluid Mechanics, Cottbus (Germany); Wenzel, Julia [University of Leipzig, Institute of Meteorology, Leipzig (Germany)

    2012-04-15

    A radial barrier has been mounted in a differentially heated rotating annulus that partially blocks the azimuthal flow component. The experiment can be seen as an analog to geophysical flows with constrictions, e.g., the Antarctic Circumpolar Current. However, the experiment has been carried out without a particular natural flow in mind. The main interest was to observe a baroclinic annulus flow that does not become saturated. Hence, in contrast to the annulus flow without a barrier, the partially blocked flow remains transient and surface heat fluxes associated with baroclinic life cycles can be studied. The annulus can be subdivided into the upstream half of the barrier, where waves amplify, and the downstream half of the barrier, where waves decay. In the upstream half, the azimuthal mean flow is moderate but with a significant positive eddy radial heat flux. In the downstream half, we find a strong jet in the mean azimuthal flow and furthermore an increased radial mean temperature gradient. The latter points to a weakened or even reversed radial eddy heat flux in the lee side of the barrier. Temperature anomalies appear as large bulges in the outer part of the annulus. Moreover, an outward shift of vortex centers can be observed with respect to centers of temperature anomalies. This phase shift between pressure and temperature anomalies differs from that of classical Eady modes of baroclinic instability. (orig.)

  4. Aortic valve leaflet replacement with bovine pericardium to preserve native dynamic capabilities of the aortic annulus.

    Science.gov (United States)

    Kim, Kyung Hwa; Choi, Jong Bum; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn

    2014-02-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations.

  5. Study on Flow Characteristic of Non-Newtonian fluid in Eccentric Annulus

    Directory of Open Access Journals (Sweden)

    Li Mingzhong

    2013-08-01

    Full Text Available This study studied the flow characteristic of non-newtonian in eccentric annulus of highly-deviated well. On the basis of dimensionless analysis of motion equations and continuity equation, Hele-Shaw model suitable for fluid flow in the annulus was derived. Combined with H-B rheological model, velocity and stream distribution model were founded and calculated by numerical method. Furthermore, two-dimensional flow characteristic in eccentric annulus was got and the influence of different factors (such as yield stress, pressure gradient or eccentricity on velocity distribution in condition of laminar flow was analyzed. Width of flow core in the annular is proportional to yield stress and inversely proportional to pressure gradient. In eccentric annulus, eccentricity influences the stream distribution remarkably: with the increment of eccentricity, the contour lines of stream function gradually centralize in the widest annular gap, however distribute the most loosely in the narrowest annular gap. Axial velocity is the largest in the widest gap. The larger eccentricity is, the larger contrast of axial velocity between in the widest gap and in the narrowest gap is. There is the largest azimuthal velocity in an annular gap of a certain azimuthal angle, however which equals to zero in the widest and narrowest annular gap separately. The larger eccentricity is, the more homogeneous azimuthal velocity is. The velocity contrast in the entire annulus can be smoothed by increasing pressure gradient, power law index or decreasing yield stress.

  6. Bioinformatics analyses of Shigella CRISPR structure and spacer classification.

    Science.gov (United States)

    Wang, Pengfei; Zhang, Bing; Duan, Guangcai; Wang, Yingfang; Hong, Lijuan; Wang, Linlin; Guo, Xiangjiao; Xi, Yuanlin; Yang, Haiyan

    2016-03-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are inheritable genetic elements of a variety of archaea and bacteria and indicative of the bacterial ecological adaptation, conferring acquired immunity against invading foreign nucleic acids. Shigella is an important pathogen for anthroponosis. This study aimed to analyze the features of Shigella CRISPR structure and classify the spacers through bioinformatics approach. Among 107 Shigella, 434 CRISPR structure loci were identified with two to seven loci in different strains. CRISPR-Q1, CRISPR-Q4 and CRISPR-Q5 were widely distributed in Shigella strains. Comparison of the first and last repeats of CRISPR1, CRISPR2 and CRISPR3 revealed several base variants and different stem-loop structures. A total of 259 cas genes were found among these 107 Shigella strains. The cas gene deletions were discovered in 88 strains. However, there is one strain that does not contain cas gene. Intact clusters of cas genes were found in 19 strains. From comprehensive analysis of sequence signature and BLAST and CRISPRTarget score, the 708 spacers were classified into three subtypes: Type I, Type II and Type III. Of them, Type I spacer referred to those linked with one gene segment, Type II spacer linked with two or more different gene segments, and Type III spacer undefined. This study examined the diversity of CRISPR/cas system in Shigella strains, demonstrated the main features of CRISPR structure and spacer classification, which provided critical information for elucidation of the mechanisms of spacer formation and exploration of the role the spacers play in the function of the CRISPR/cas system.

  7. Effect of the spacer group nature on the optical and electrical properties of confined poly( p-phenylene vinylene) derivatives

    Science.gov (United States)

    Benzarti-Ghédira, Maha; Zahou, Imen; Hrichi, Haikel; Jaballah, Nejmeddine; Ben Chaâbane, Rafik; Majdoub, Mustapha; Ben Ouada, Hafedh

    2015-09-01

    This study is an investigation about the effect of chemical modification on the morphological, optical and electrical properties of semiconducting organic thin films. Two confined poly( p-phenylene vinylene) (PPV)-type polymers containing different spacer groups were studied: P1 has an isopropylidene spacer group and P2 with hexafluoroisopropylidene spacer. The UV-Vis absorption and PL analysis showed a stronger π- π interaction in the P1 film; in P2, the π-stacking is limited by the introduction of a bulky trifluoromethyl (CF3) groups on the spacer units. The P2 exhibits a better film quality as illustrated by the atomic force microscopy. The HOMO and LUMO energy levels and electrochemical band gap of the polymers were determinate by the cyclic voltammetry. The electrical properties of ITO/PPV derivative/Al diodes were investigated by means of current-voltage and show a space-charge-limited current conduction mechanism with higher mobility in the P2 thin layer. The impedance spectra of the devices can be discussed in terms of an equivalent circuit model designed as a parallel resistance ( R p) and capacitance ( C p) network in series with a resistance.

  8. Sidewall spacer optimization for steep switching junctionless transistors

    Science.gov (United States)

    Gupta, Manish; Kranti, Abhinav

    2016-06-01

    In this work, we analyze the impact of a high permittivity (high-κ) sidewall spacer and gate dielectric on the occurrence of sub-60 mV/decade subthreshold swing (S-swing) in symmetrical junctionless (JL) double gate (DG) transistors. It is shown that steep S-swing values (≤10 mV/decade) can be achieved in JL devices with a combination of a high permittivity (high-κ) gate dielectric and a narrow low permittivity (low-κ) sidewall spacer. Implementation of a wider high-κ spacer will diminish the degree of impact ionization by the influence of the fringing component of the gate electric field, and will not be useful for steep off-to-on current transition. A wider spacer with low-κ and a narrow spacer with high-κ permittivity will be useful to limit the latching effect that can occur at lower temperatures (250 K). For high temperature operation, the decrease in the impact ionization rate can be compensated by designing a JL transistor with a thicker silicon film. The work demonstrates opportunities to enhance impact ionization at sub bandgap voltages, and proposes optimal guidelines for selecting a sidewall spacer to facilitate steep switching in JL transistors.

  9. [Surgical technique of aortic valve replacement for small aortic annulus in elderly patients].

    Science.gov (United States)

    Hata, T; Fujiwara, K; Furukawa, H; Tsushima, Y; Yoshitaka, H; Kuinose, M; Minami, H; Ishida, A; Tamura, K; Totsugawa, T; Kanemitsu, H; Ozawa, M

    2006-04-01

    Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

  10. Flow resistance characteristics of water in narrow annulus during heat exchange

    Institute of Scientific and Technical Information of China (English)

    SUN Li-cheng; YAN Chang-qi; SUN Zhong-ning; ZHANG Qing-hua

    2003-01-01

    Considering the special resistance characteristics of fluids flowing through ducts with small gaps, experiments are performed to investigate the resistance characteristics of single-phase water, which is forced to flow through vertical annuli. The gap sizes are 0.9, 1.4 and 2.4mm, respectively. The experiments are conducted under condition of 1atm. The water in the annuli is heated by high temperature water reversely flowing through the inner tube and the outer annulus. The results show that the flow pattern begin to change from laminar to turbulent before Reynolds number approaches 2000, the flow resistance in annulus has little relations with the temperature difference and ways of being heated, but mainly depends on the ratio of mass flux to the width of annulus.

  11. Technical Information to Support Double Shell Tank (DST) Emergency Annulus Pumping [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    REBERGER, D.W.

    2000-09-14

    This document provides the design calculations for the DST Annulus Emergency Pumping Project. This document also contains essential information relative to DST annulus emergency pumping that may not be found in other documents. This information consists of the following: Index drawing for annulus pumping; References to the Acceptance Test Report, DST Emergency Pumping Guide, Time Deployment study, etc.; Statements of work; and Reference CEIS and RMIS numbers. A Vendor Information document, VI-50121, is not included in this document, but a copy can be obtained by contacting Document Control Services. This document contains various information regarding the Hydrostar pumps, such as the air motor, cylinder size, pump installation and operation manual. It also contains information regarding the Flygt BS2060 submersible pump, such as parts list, pump handling, preventative maintenance, overhaul and repair. In addition, this document also has information on 3-way PM ball valves, electrical skid components and the alternate Gurman-Rupp stainless steel submersible pump.

  12. The potential of standard and modified feed spacers for biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The impact of feed spacers on initial feed channel pressure (FCP) drop, FCP increase and biomass accumulation has been studied in membrane fouling simulators using feed spacers applied in commercially available nanofiltration and reverse osmosis spiral wound membrane modules. All spacers had a similar geometry.Our studies showed that biofouling was not prevented by (i) variation of spacer thickness, (ii) feed spacer orientation, (iii) feed spacer coating with silver, copper or gold and (iv) using a biostatic feed spacer. At constant feed flow, a lower FCP and FCP increase were observed for a thicker feed spacer. At constant linear flow velocity, roughly the same FCP development and biomass accumulation were found irrespective of the feed spacer thickness: hydrodynamics and substrate load were more important for development and impact of biofouling than the thickness of currently applied spacers. Use of biostatic and metal coated spacers were not effective for biofouling control. The same small reduction of biofouling rate was observed with copper and silver coated spacers as well as uncoated 45° rotated spacers.The studied modified spacers were not effective for biofouling prevention and control. The impact of biofouling on FCP increase was reduced significantly by a lower linear flow velocity, while spacer orientation and spacer thickness in membrane modules had a smaller but still significant effect. © 2012 Elsevier B.V.

  13. Collagen fibrillogenesis in the development of the annulus fibrosus of the intervertebral disc

    Directory of Open Access Journals (Sweden)

    AJ Hayes

    2011-10-01

    Full Text Available The annulus fibrosus of the intervertebral disc is a complex, radial-ply connective tissue consisting of concentric lamellae of oriented collagen. Whilst much is known of the structure of the mature annulus, less is known of how its complex collagenous architecture becomes established; an understanding of which could inform future repair/regenerative strategies. Here, using a rat disc developmental series, we describe events in the establishment of the collagenous framework of the annulus at light and electron microscopic levels and examine the involvement of class I and II small leucine rich proteoglycans (SLRPs in the matrix assembly process. We show that a period of sustained, ordered matrix deposition follows the initial cellular differentiation/orientation phase within the foetal disc. Fibrillar matrix is deposited from recesses within the plasma membrane into compartments of interstitial space within the outer annulus – the orientation of the secreted collagen reflecting the initial cellular orientation of the laminae. Medially, we demonstrate the development of a reinforcing ‘cage’ of collagen fibre bundles around the foetal nucleus pulpous. This derives from the fusion of collagen bundles between presumptive end-plate and inner annulus. By birth, the distinct collagenous architectures are established and the disc undergoes considerable enlargement to maturity. We show that fibromodulin plays a prominent role in foetal development of the annulus and its attachment to vertebral bodies. With the exception of keratocan, the other SLRPs appear associated more with cartilage development within the vertebral column, but all become more prominent within the disc during its growth and differentiation.

  14. Two-Dimensional Echo-cardiographic Estimation of the Size of the Mitral Valve Annulus

    Directory of Open Access Journals (Sweden)

    Shigenobu,Masaharu

    1982-12-01

    Full Text Available The diameter of the mitral annulus as measured on the long axis by two-dimensional echocardiogram was found to correlate well with the size of the sewing ring used to replace the mitral valve in 35 consecutive patients. The size of the prosthesis which was used could be predicted within 1 mm of error in 83% of the mitral stenosis (MS patients and in 76% of the mitral regurgitation (MR patients in the study. Preoperative echocardiographic estimation of the size of the mitral valve annulus and prediction of the sewing ring size of the prosthetic valve used could reduce the incidence of valve prosthesis-patient mismatch.

  15. Final design of a spacer grid using axiomatic design

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gyung-Jin; Lee, Hyun-Ah; Kim, Chong-Ki [Hanyang Univ., Seoul (Korea, Republic of); Song, Gi-Nam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-03-15

    The spacer grid set is a component in the nuclear fuel assembly. The set supports the fuel rod safely. The spacer grid set must have enough strength to sustain external loads such as earthquake. The fretting wear occurs between the spring of the fuel rod and the spacer grid due to the flow-induced vibration after the fuel rod is inserted to the spacer grid set. Design of the spring is carried out by using the independence axiom in axiomatic design to solve the two problems. The spacer grid is divided into two parts for sustaining the impact load and reducing fretting wear based on the function requirements. The design for the impact load is performed through non-linear analysis and the homology theory is adopted to reduce fretting wear achieved for shape optimization. The objective function to be minimized ids the maximum stress and constraints are defined to increase the contact area between the fuel rod and the spring using the homology theory. In the design results, the contact area becomes large and it is conformed by nonlinear static analysis. The final design shows that larger impact loads can be sustained compared to the current model.

  16. CRISPR interference and priming varies with individual spacer sequences.

    Science.gov (United States)

    Xue, Chaoyou; Seetharam, Arun S; Musharova, Olga; Severinov, Konstantin; Brouns, Stan J J; Severin, Andrew J; Sashital, Dipali G

    2015-12-15

    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems allow bacteria to adapt to infection by acquiring 'spacer' sequences from invader DNA into genomic CRISPR loci. Cas proteins use RNAs derived from these loci to target cognate sequences for destruction through CRISPR interference. Mutations in the protospacer adjacent motif (PAM) and seed regions block interference but promote rapid 'primed' adaptation. Here, we use multiple spacer sequences to reexamine the PAM and seed sequence requirements for interference and priming in the Escherichia coli Type I-E CRISPR-Cas system. Surprisingly, CRISPR interference is far more tolerant of mutations in the seed and the PAM than previously reported, and this mutational tolerance, as well as priming activity, is highly dependent on spacer sequence. We identify a large number of functional PAMs that can promote interference, priming or both activities, depending on the associated spacer sequence. Functional PAMs are preferentially acquired during unprimed 'naïve' adaptation, leading to a rapid priming response following infection. Our results provide numerous insights into the importance of both spacer and target sequences for interference and priming, and reveal that priming is a major pathway for adaptation during initial infection.

  17. Impact of spacer thickness on biofouling in forward osmosis.

    Science.gov (United States)

    Valladares Linares, R; Bucs, Sz S; Li, Z; AbuGhdeeb, M; Amy, G; Vrouwenvelder, J S

    2014-06-15

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46 mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux.

  18. Impact of spacer thickness on biofouling in forward osmosis

    KAUST Repository

    Valladares Linares, Rodrigo

    2014-06-01

    Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. © 2014 Elsevier Ltd.

  19. A non-electrostatic spacer for aerosol delivery

    DEFF Research Database (Denmark)

    Bisgaard, H; Anhøj, J; Klug, B;

    1995-01-01

    A pear shaped non-electrostatic spacer, composed of steel with a volume of 250 ml and equipped with a facemask containing integrated inlet and outlet valves for inspiration and expiration, was compared with three plastic spacers. The plastic spacers were primed with repeated puffs from a budesonide...... pressurised metered dose inhaler (p-MDI) to minimise the electrostatic charge on the plastic. The procedure prolonged the half life (t1/2) of the aerosol in the Nebuhaler from nine to 32 seconds. A normal cleaning procedure reduced the aerosol t1/2 back to baseline. The t1/2 of the aerosol in the metal spacer...... was 27 seconds and independent of the use of p-MDI. In vitro the maximum dose of budesonide from a p-MDI, expressed as a percentage of the nominal dose, was 56% from the non-electrostatic spacer, 61% from the Nebuhaler, 45% from the Babyhaler, and 30% from the AeroChamber. In 124 children, age 6 months...

  20. Heat Transfer in Tubing-Casing Annulus during Production Process of Geothermal Systems

    Institute of Scientific and Technical Information of China (English)

    Fuzong Zhou; Xiuhua Zheng

    2015-01-01

    In geothermal systems, the temperature distribution of heat flow in the wellbore is de-pendent on the well structure and the geological conditions of the surrounding formation. Under-standing of heat transfer in the tubing-casing annulus can reduce the heat losses of wellbore fluid during the production process. The present study discusses the possible means of heat transfer in the annulus, and develops a piecewise equation for estimating the convective heat transfer coefficient with a wider valid condition of 0annulus. The results indicate that the annulus filled with gas can be utilized as a good thermal barrier for the fluid in the wellbore. Additionally, the contribution of radiation will increase to occupy a majority proportion in the total thermal conductivity when the annular size increases and the materials have high emissivity. Otherwise, thermal radiation is just the second fac-tor.

  1. On the Use of Biaxial Properties in Modeling Annulus as a Holzapfel-Gasser-Ogden Material

    Directory of Open Access Journals (Sweden)

    Narjes eMomeni Shahraki

    2015-06-01

    Full Text Available Besides the biology, stresses and strains within the tissue greatly influence the location of damage initiation and mode of failure in an intervertebral disc. Finite element models of a functional spinal unit (FSU that incorporate reasonably accurate geometry and appropriate material properties are suitable to investigate such issues. Different material models and techniques have been used to model the anisotropic annulus fibrosus, but the abilities of these models to predict damage initiation in the annulus and to explain clinically observed phenomena are unclear. In this study a hyperelastic anisotropic material model for the annulus with two different sets of material constants, experimentally determined using uniaxial and biaxial loading conditions, were incorporated in a 3D finite element model of a ligamentous FSU. The purpose of the study was to highlight the biomechanical differences (e.g., intradiscal pressure, motion, forces, stresses and strains, etc. due to the dissimilarity between the two sets of material properties (uniaxial and biaxial. Based on the analyses, the biaxial constants simulations resulted in better agreements with the in-vitro and in-vivo data, and thus are more suitable for future damage analysis and failure prediction of the annulus under complex multiaxial loading conditions.

  2. Mechanical restoration and failure analyses of a hydrogel and scaffold composite strategy for annulus fibrosus repair

    NARCIS (Netherlands)

    Long, Rose G.; Buerki, Alexander; Zysset, Philippe; Eglin, David; Grijpma, Dirk W.; Blanquer, Sebastien B. G.; Hecht, Andrew C.; Iatridis, James C.

    2016-01-01

    Unrepaired defects in the annulus fibrosus of intervertebral disks are associated with degeneration and persistent back pain. A clinical need exists for a disk repair strategy that can seal annular defects, be easily delivered during surgical procedures, and restore biomechanics with low risk of her

  3. A combined biomaterial and cellular approach for annulus fibrosus rupture repair

    NARCIS (Netherlands)

    Pirvu, Tatiana; Blanquer, Sebastien B. G.; Benneker, Lorin M.; Grijpma, Dirk W.; Richards, Robert G.; Alini, Mauro; Eglin, David; Grad, Sibylle; Li, Zhen

    2015-01-01

    Recurrent intervertebral disc (IVD) herniation and degenerative disc disease have been identified as the most important factors contributing to persistent pain and disability after surgical discectomy. An annulus fibrosus (AF) closure device that provides immediate closure of the AF rupture, restore

  4. An annulus fibrosus closure device based on a biodegradable shape-memory polymer network

    NARCIS (Netherlands)

    Sharifi, Shahriar; van Kooten, Theo G.; Kranenburg, Hendrik-Jan C.; Meij, Bjorn P.; Behl, Marc; Lendlein, Andreas; Grijpma, Dirk W.

    2013-01-01

    Injuries to the intervertebral disc caused by degeneration or trauma often lead to tearing of the annulus fibrosus (AF) and extrusion of the nucleus pulposus (NP). This can compress nerves and cause lower back pain. In this study, the characteristics of poly(D,L-lactide-co-trimethylene carbonate) ne

  5. Measurement of the aortic annulus size by real-time three-dimensional transesophageal echocardiography.

    Science.gov (United States)

    Jánosi, Rolf Alexander; Kahlert, Philipp; Plicht, Björn; Wendt, Daniel; Eggebrecht, Holger; Erbel, Raimund; Buck, Thomas

    2011-04-01

    We sought to determine the level of agreement and the reproducibility of two-dimensional (2D) transthoracic (2D-TTE), 2D transesophageal (2D-TEE) and real-time three-dimensional (3D) transesophageal echocardiography (RT3D-TEE) for measurement of aortic annulus size in patients referred for transcatheter aortic valve implantation (TAVI). Accurate preoperative assessment of the dimensions of the aortic annulus is critical for patient selection and successful implantation in those undergoing TAVI for severe aortic stenosis (AS). Annulus size was measured using 2D-TTE, 2D-TEE and RT3D-TEE in 105 patients with severe AS referred for TAVI. Agreement between echocardiographic methods and interobserver variability was assessed using the Bland-Altman method and regression analysis, respectively. The mean aortic annuli were 21,7 ± 3 mm measured with 2D-TTE, 22,6 ± 2,8 mm with 2D-TEE and 22,3 ± 2,9 mm with RT3D-TEE. The results showed a small but significant mean difference and a strong correlation between the three measurement techniques (2D-TTE vs. 2D-TEE mean difference 0,84 ± 1,85 mm, r = 0,8, p annulus measured by 2D-TTE, 2D-TEE and RT3D-TEE. Thus, in patients referred for TAVI, the echocardiographic method used may have an impact on TAVI strategy.

  6. Genipin-crosslinked fibrin hydrogels as a potential adhesive to augment intervertebral disc annulus repair.

    Science.gov (United States)

    Schek, R M; Michalek, A J; Iatridis, J C

    2011-04-18

    Treatment of damaged intervertebral discs is a significant clinical problem and, despite advances in the repair and replacement of the nucleus pulposus, there are few effective strategies to restore defects in the annulus fibrosus. An annular repair material should meet three specifications: have a modulus similar to the native annulus tissue, support the growth of disc cells, and maintain adhesion to tissue under physiological strain levels. We hypothesized that a genipin crosslinked fibrin gel could meet these requirements. Our mechanical results showed that genipin crosslinked fibrin gels could be created with a modulus in the range of native annular tissue. We also demonstrated that this material is compatible with the in vitro growth of human disc cells, when genipin:fibrin ratios were 0.25:1 or less, although cell proliferation was slower and cell morphology more rounded than for fibrin alone. Finally, lap tests were performed to evaluate adhesion between fibrin gels and pieces of annular tissue. Specimens created without genipin had poor handling properties and readily delaminated, while genipin crosslinked fibrin gels remained adhered to the tissue pieces at strains exceeding physiological levels and failed at 15-30%. This study demonstrated that genipin crosslinked fibrin gels show promise as a gap-filling adhesive biomaterial with tunable material properties, yet the slow cell proliferation suggests this biomaterial may be best suited as a sealant for small annulus fibrosus defects or as an adhesive to augment large annulus repairs. Future studies will evaluate degradation rate, fatigue behaviors, and long-term biocompatibility.

  7. Structural analysis and evaluation of the 241SY101 tank annulus heat-up

    Energy Technology Data Exchange (ETDEWEB)

    Ziada, H.H.

    1994-10-19

    This document provides the structural analysis (static and thermal loads) of the 241SY101 tank to determine the maximum allowable temperature and rate of heating that could be applied to tank 241SY101 through annulus air heating without detrimental effects to the structural integrity of the concrete and steel liner of the tank.

  8. Three-Dimensional Numerical Simulation of Natural Convection Heat Transfer in an Inclined Cylindrical Annulus

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    A numerical study of natural convection beat transfer in an inclined cylindrical annulus has been conducted.The inner cylinder of the annulus is maintained at uniform heat flux and the outer cylinder at constant temperature.the two end walls are assumed to be insulated.A numerical code has been developed to calculate the steady state three-dimensional natural convection in an inclined cylindrical annulus,and the research emphasis is placed on the influences of inclination angle α and modified Rayleigh number Ra on the natural convection heat transfer in the annulus.Computations were carried out in the ranges of 0°≤α≤90*,2.5×105≤Ra*≤7and Pr=0.7 with fixed aspect ratio of H=28.97 and radius ratio of K=3.33,The numerical results are compared with the experimental correlations from the literature and the inclination angle effect on heat transfer is found to be insignificant.Detailed results of heat transfer rate,temperature,and velocity fields are presented for the case of α=45° and discussion is also made concerning the comparison between the numerical and experimental results for the specific case of α=90°。

  9. Background Independent Open String Field Theory with Constant B field On the Annulus

    CERN Document Server

    Rashkov, R; Yang, Y

    2001-01-01

    We study Witten's background independent open-string field theory in the presence of a constant B-field at one loop level. The Green's function and the partition function with a constant B-field are evaluated for an annulus.

  10. Aortic annulus and ascending aorta: Comparison of preoperative and periooperative measurement in patients with aortic stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Smid, Michal [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: kosvin@seznam.cz; Ferda, Jiri [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: ferda@fnplzen.cz; Baxa, Jan [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: baxaj@fnplzen.cz; Cech, Jakub [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: cechj@fnplzen.cz; Hajek, Tomas [Department of Cardiac Surgery, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: hajekt@fnplzen.cz; Kreuzberg, Boris [Department of Radiology, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: kreuzberg@fnplzen.cz; Rokyta, Richard [Cardiology Department of Internal Medicine, School of Medicine Plzen, Charles University Prague and University Hospital Plzen, alej Svobody 80, 304 60 Plzen (Czech Republic)], E-mail: rokyta@fnplzen.cz

    2010-04-15

    Background: Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. Methods and results: A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. Conclusion: In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis.

  11. Surface hydrogenation regulated wrinkling and torque capability of hydrogenated graphene annulus under circular shearing

    Science.gov (United States)

    Li, Yinfeng; Liu, Silin; Datta, Dibakar; Li, Zhonghua

    2015-11-01

    Wrinkles as intrinsic topological feature have been expected to affect the electrical and mechanical properties of atomically thin graphene. Molecular dynamics simulations are adopted to investigate the wrinkling characteristics in hydrogenated graphene annulus under circular shearing at the inner edge. The amplitude of wrinkles induced by in-plane rotation around the inner edge is sensitive to hydrogenation, and increases quadratically with hydrogen coverage. The effect of hydrogenation on mechanical properties is investigated by calculating the torque capability of annular graphene with varying hydrogen coverage and inner radius. Hydrogenation-enhanced wrinkles cause the aggregation of carbon atoms towards the inner edge and contribute to the critical torque strength of annulus. Based on detailed stress distribution contours, a shear-to-tension conversion mechanism is proposed for the contribution of wrinkles on torque capacity. As a result, the graphane annulus anomalously has similar torque capacity to pristine graphene annulus. The competition between hydrogenation caused bond strength deterioration and wrinkling induced local stress state conversion leads to a U-shaped evolution of torque strength relative to the increase of hydrogen coverage from 0 to 100%. Such hydrogenation tailored topological and mechanical characteristics provides an innovative mean to develop novel graphene-based devices.

  12. Injectable, high-density collagen gels for annulus fibrosus repair: An in vitro rat tail model.

    Science.gov (United States)

    Borde, Brandon; Grunert, Peter; Härtl, Roger; Bonassar, Lawrence J

    2015-08-01

    A herniated intervertebral disc often causes back pain when disc tissue is displaced through a damaged annulus fibrosus. Currently, the only methods available for annulus fibrosus repair involve mechanical closure of defect, which does little to address biological healing in the damaged tissue. Collagen hydrogels are injectable and have been used to repair annulus defects in vivo. In this study, high-density collagen hydrogels at 5, 10, and 15 mg/mL were used to repair defects made to intact rat caudal intervertebral discs in vitro. A group of gels at 15 mg/mL were also cross-linked with riboflavin at 0.03 mM, 0.07 mM, or 0.10 mM. These cross-linked, high-density collagen gels maintained their presence in the defect under loading and contributed positively to the mechanical response of damaged discs. Discs exhibited increases to 95% of undamaged effective equilibrium and instantaneous moduli as well as up to fourfold decreases in effective hydraulic permeability from the damaged discs. These data suggest that high-density collagen gels may be effective at restoring mechanical function of injured discs as well as potential vehicles for the delivery of biological agents such as cells or growth factors that may aid in the repair of the annulus fibrosus.

  13. Effect of a spacer moiety on radiometal labelled Neurotensin derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Mascarin, A.; Valverde, I.E.; Mindt, T.L. [Univ. of Basel Hospital (Switzerland). Div. of Radiopharmaceutical Chemistry

    2013-07-01

    The binding sequence of the regulatory peptide Neurotensin, NT(8-13), represents a promising tumour-specific vector for the development of radiopeptides useful in nuclear oncology for the diagnosis (imaging) and therapy of cancer. A number of radiometal-labelled NT(8-13) derivatives have been reported, however, the effect of the spacer which connects the vector with the radiometal complex has yet not been investigated systematically. Because a spacer moiety can influence potentially important biological characteristics of radiopeptides, we synthesized three [DOTA({sup 177}Lu)]-X-NT(8-13) derivatives and evaluated the effect of a spacer (X) on the physico-chemical properties of the conjugate including lipophilicity, stability, and in vitro receptor affinity and cell internalization. (orig.)

  14. Impact of AlN Spacer on Analog Performance of Lattice-Matched AlInN/AlN/GaN MOSHEMT

    Science.gov (United States)

    Jena, Kanjalochan; Swain, Raghunandan; Lenka, T. R.

    2016-04-01

    In this work, a detailed investigation of the impact of spacer layer thickness on analog performance of an AlInN/AlN/GaN metal oxide semiconductor high electron mobility transistor (MOSHEMT) is carried out. A thorough analysis of the key figure-of-merits such as threshold voltage (V th), two-dimensional electron gas sheet charge density (n s), drain current (I d), transconductance (g m), and gate leakage current are performed for various spacer thicknesses ranging from 0.5 nm to 1.8 nm. From the two-dimensional ATLAS device simulation results, it is observed that the performance of AlInN/AlN/GaN MOSHEMT is affected by the variation of spacer thickness. Also, we have developed mathematical expressions for the evaluation of V th , n s , I d , g m and gate leakage current for the proposed device. The model results and technology computer-aided design simulation results are verified and also found to be satisfactory. Improved sheet charge density and superior analog performance is observed due to the insertion of the AlN spacer. Suppression in the forward gate current is observed due to the insertion of the AlN spacer which made it possible to apply a high gate voltage in the transistor operation. From the fabrication point of view, it is also feasible to utilize the existing complementary metal-oxide-semiconductor process flows to fabricate the proposed device.

  15. The Lawn Hill annulus: An Ordovician meteorite impact into water-saturated dolomite

    Science.gov (United States)

    Darlington, Vicki; Blenkinsop, Tom; Dirks, Paul; Salisbury, Jess; Tomkins, Andrew

    2016-12-01

    The Lawn Hill Impact Structure (LHIS) is located 250 km N of Mt Isa in NW Queensland, Australia, and is marked by a highly deformed dolomite annulus with an outer diameter of 18 km, overlying low metamorphic grade siltstone, sandstone, and shale, along the NE margin of the Georgina Basin. This study provides detailed field observations from sections of the Lawn Hill annulus and adjacent areas that demonstrate a clear link between the deformation of the dolomite and the Lawn Hill impact. 40Ar-39Ar dating of impact-related melt particles provides a time of impact in the Ordovician (472 ± 8 Ma) when the Georgina Basin was an active depocenter. The timing and stratigraphic thickness of the dolomite sequence in the annulus suggest that there was possibly up to 300 m of additional sedimentary rocks on top of the currently exposed Thorntonia Limestone at the time of impact. The exposed annulus is remarkably well preserved, with preservation attributed to postimpact sedimentation. The LHIS has an atypical crater morphology with no central uplift. The heterogeneous target materials at Lawn Hill were probably low-strength, porous, and water-saturated, with all three properties affecting the crater morphology. The water-saturated nature of the carbonate unit at the time of impact is thought to have influenced the highly brecciated nature of the annulus, and restricted melt production. The impact timing raises the possibility that the Lawn Hill structure may be a member of a group of impacts resulting from an asteroid breakup that occurred in the mid-Ordovician (470 ± 6 Ma).

  16. Role of calcium signaling in down-regulation of aggrecan induced by cyclic tensile strain in annulus fibrosus cells

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; ZHOU Yue; LI Hua-zhuang; CAO Guo-yong; TENG Hai-jun

    2006-01-01

    Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods :The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results:EGTA, gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.

  17. CRISPR interference and priming varies with individual spacer sequences

    NARCIS (Netherlands)

    Xue, Chaoyou; Seetharam, Arun S.; Musharova, Olga; Severinov, Konstantin; Brouns, Stan J.J.; Severin, Andrew J.; Sashital, Dipali G.

    2015-01-01

    CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems allow bacteria to adapt to infection by acquiring 'spacer' sequences from invader DNA into genomic CRISPR loci. Cas proteins use RNAs derived from these loci to target cognate sequences for destructio

  18. Filter holder assembly having extended collar spacer ring

    Science.gov (United States)

    Alvin, Mary Anne; Bruck, Gerald J.

    2002-01-01

    A filter holder assembly is provided that utilizes a fail-safe regenerator unit with an annular spacer ring having an extended metal collar for containment and positioning of a compliant ceramic gasket used in the assembly. The filter holder assembly is disclosed for use with advanced composite, filament wound, and metal candle filters.

  19. Most recent developments for monitoring and controlling the annulus conditions of Marlim-Sul flexible risers

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, Alexandre S.; Motta, Antonio; Romero, Antonio; Nunes, Joao P.; Zaganelli Junior, Jose L.; Brack, Marcelo [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The main objective of this paper is to present the recent developments for monitoring and controlling the annulus conditions of flexible risers. PETROBRAS has been monitoring the pressure of permeated gas in the annulus region of some risers in order to infer the eventual occurrence of non-conformities as damage on the riser external sheath, for example. Such occurrence would affect the permeated gas flow pattern, the gas pressurization period and the relief valve opening frequencies. Furthermore, the mentioned occurrence would increase the susceptibility of the steel armors to experience the potential failure mechanism of corrosion. In PETROBRAS, the current monitoring method is characterized by visual and periodic manometer readings from a manometer set installed near each riser end-fitting. The data is recorded in a daily report and analyzed by personnel onshore, who are in charge of comparing data and requesting relief valve's actuation, whenever necessary. The paper illustrates Marlim-Sul Asset experience on monitoring and data processing to control the annulus conditions of flexible risers during operation. It presents the in-house developed methodology to data management and processing. This methodology is based on a daily analysis of the permeated gas data worksheet. Some examples are given to illustrate it. The paper also summarizes current developments, in progress, in order to improve riser integrity management. The first development is being done to implement, in the future, automatic data acquisition and control systems. The purpose of automating this process is to improve methods and techniques for data acquisition, transmission and processing. The second development focuses on applications in which riser top end-fittings are submerged. In this particular scenario, a special system - with a quick connection sub sea device - is under development to allow the connection, by divers, after the riser pull-in, of the riser annulus to the platform gas

  20. Implementation of spacer therapy for acute asthma in children.

    LENUS (Irish Health Repository)

    Vandeleur, M

    2009-09-01

    The aim was to develop and implement an evidence based guideline for the treatment of acute asthma using a metered dose inhaler and spacer combination. Children admitted to Cork University Hospital Paediatric Department with acute asthma were identified during two identical 2 month seasonal periods before (2005) and after (2006) implementation of the new guidelines in September 2006. Pre-intervention and post-intervention audits by case note review were performed to determine the impact of and compliance with this evidence-based guideline emphasising patient assessment, spacer delivered bronchodilator and specific discharge criteria. Patients had similar characteristics during the two study periods. There was a raised threshold for admission after guideline implementation with 11\\/52 patients having mild exacerbations in 2006, compared to 21\\/36 in 2005. Duration of admission was less in the post-implementation group for equivalent exacerbation severity e.g. for moderate severity; 28 hours in 2005, 23 hours in 2006. Duration of bronchodilator therapy was shorter in 2006 and more likely to be given by spacer device earlier for equivalent levels of severity e.g. for moderate exacerbations, in 2006 the average length of salbutamol therapy was 18 hours with 12 hours by spacer device, in 2005 the average length of therapy was 25 hours with 3 hours by spacer. There was earlier initiation of oral corticosteroids; the average time to administration was 56 minutes in 2006 and 227 minutes in 2005. There was an improved documentation of asthma education in 2006 e.g. inhaler technique was reviewed in 37\\/52 in 2006, 21\\/35 in 2005 and better use of written action plans.

  1. HYDROELASTIC VIBRATIONS AND LIQUID SLOSHING SUPPRESSION IN A RECTANGULAR TANK WITH ELASTIC SPACER

    Institute of Scientific and Technical Information of China (English)

    CHENG Xu-duo; LIANG Yong; WEN Ji-hua

    2004-01-01

    In this paper, the couple vibration of liquid and elastic spacer in a rectangular tank is investigated. Two different velocity potential functions corresponding respectively to the liquid above and below the elastic spacer are assumed. Complicated boundary conditions corresponding to two velocity potential functions and vibrations of elastic spacer are given. Using the method of energy, the equation of couple frequency is obtained. Through numerical computation the natural frequencies that change according to the location and stiffness of the spacer are shown.

  2. Laboratory experiments in a baroclinic annulus with heating and cooling on the horizontal boundaries

    Science.gov (United States)

    Miller, T. L.; Fowlis, W. W.

    1986-01-01

    Experiments have been performed in a cylindrical annulus with horizontal temperature gradients imposed upon the horizontal boundaries and in which the vertical depth was smaller than the width of the annulus. Qualitative observations were made by the use of small, suspended, reflective flakes in the liquid (water). Four basic regimes of flow were observed: (1) axisymmetric flow, (2) deep cellular convection, (3) boundary layer convective rolls, and (4) baroclinic waves. In some cases there was a mix of baroclinic and convective instabilities present. As a 'mean' interior Richardson number was decreased from a value greater than unity to one less than zero, axisymmetric baroclinic instability of the Solberg type was never observed. Rather, the transition was from non-axisymmetric baroclinic waves, to a mix of baroclinic and convective instability, to irregular cellular convection.

  3. Staging Mobilities / Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2015-01-01

    In recent years, urban research has taken a ‘mobilities turn’. There has been a developing realisation that mobilities do not ‘just happen.’ Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed and lived...... as people are ‘staging themselves’ (from below). Staging mobilities is a dynamic process between ‘being staged’ (for example, being stopped at traffic lights) and the ‘mobile staging’ of interacting individuals (negotiating a passage on the pavement). Staging mobilities is about the fact that mobility...... asks: what are the physical, social, technical, and cultural conditions to the staging of contemporary urban mobilities? The theoretical framing in the Staging mobilities book is applied to four in-depth cases in the accompanying volume Designing mobilities.This book explore how places, sites...

  4. The cyclicity of the period annulus of a quadratic reversible system with one center of genus one

    OpenAIRE

    PENG, Linping; Sun, Yannan

    2014-01-01

    This paper is concerned with a quadratic reversible and non-Hamiltonian system with one center of genus one. By using the properties of related elliptic integrals and the geometry of some planar curves defined by them, we prove that the cyclicity of the period annulus of the considered system under small quadratic perturbations is two. This verifies Gautier's conjecture about the cyclicity of the related period annulus.

  5. The cyclicity of the period annulus of a quadratic reversible system with one center of genus one

    OpenAIRE

    PENG, Linping; Sun, Yannan

    2011-01-01

    This paper is concerned with a quadratic reversible and non-Hamiltonian system with one center of genus one. By using the properties of related elliptic integrals and the geometry of some planar curves defined by them, we prove that the cyclicity of the period annulus of the considered system under small quadratic perturbations is two. This verifies Gautier's conjecture about the cyclicity of the related period annulus.

  6. The Influence of Horizontal Boundaries on Ekman Circulation and Angular Momentum Transport in a Cylindrical Annulus

    OpenAIRE

    Obabko, Aleksandr V.; Cattaneo, Fausto; Fischer, Paul F.

    2008-01-01

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton MRI liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow struc...

  7. A Fast Stble Marching Scheme for Calculating Mixed Convection in a Vertical Rotating Annulus

    Institute of Scientific and Technical Information of China (English)

    Chao-MinZhang; Zeng-YuanGuo

    1993-01-01

    An iterative simultanous solution method is developed to efficiently solve the Newton-Raphson linear equation set for velocity in three dimensions,pressure and temperature,The proposed method is demonstrated for several cases of the thermal drive in a vertical rotating annulus,and is shown to be insensitive to dimensionless time step,requiring significantly less computational effort to converge to the desired accuracy than SIMPLEC,even for low Prandtl number fluid flows.

  8. Genipin-crosslinked fibrin hydrogels as a potential adhesive to augment intervertebral disc annulus repair

    Directory of Open Access Journals (Sweden)

    RM Schek

    2011-04-01

    Full Text Available Treatment of damaged intervertebral discs is a significant clinical problem and, despite advances in the repair and replacement of the nucleus pulposus, there are few effective strategies to restore defects in the annulus fibrosus. An annular repair material should meet three specifications: have a modulus similar to the native annulus tissue, support the growth of disc cells, and maintain adhesion to tissue under physiological strain levels. We hypothesized that a genipin crosslinked fibrin gel could meet these requirements. Our mechanical results showed that genipin crosslinked fibrin gels could be created with a modulus in the range of native annular tissue. We also demonstrated that this material is compatible with the in vitro growth of human disc cells, when genipin:fibrin ratios were 0.25:1 or less, although cell proliferation was slower and cell morphology more rounded than for fibrin alone. Finally, lap tests were performed to evaluate adhesion between fibrin gels and pieces of annular tissue. Specimens created without genipin had poor handling properties and readily delaminated, while genipin crosslinked fibrin gels remained adhered to the tissue pieces at strains exceeding physiological levels and failed at 15-30%. This study demonstrated that genipin crosslinked fibrin gels show promise as a gap-filling adhesive biomaterial with tunable material properties, yet the slow cell proliferation suggests this biomaterial may be best suited as a sealant for small annulus fibrosus defects or as an adhesive to augment large annulus repairs. Future studies will evaluate degradation rate, fatigue behaviors, and long-term biocompatibility.

  9. [Evaluation of aortic valve replacement involving small severely calcified aortic annulus in elderly patients].

    Science.gov (United States)

    Iwahashi, M; Nishimura, Y; Hiramatsu, K; Komori, S; Shibata, M; Yuzaki, M; Okamura, Y

    2006-04-01

    We performed aortic valve replacement in 24 patients aged over 70 with small calcified valves. The surgical management of such patients remains controversial as the extensive calcification compromises implantation. Hence, we used an ultrasonic debridement instrument to remove calcium and selected a small prosthesis with the largest possible orifice without enlargement of the aortic annulus. Echocardiography showed significant reductions in left ventricular mass index compared with preoperative values. Early and mid-term prognosis has been relatively good.

  10. Hysteresis and the transition between axisymmetric flow and wave flow in the baroclinic annulus

    Science.gov (United States)

    Miller, Timothy L.; Butler, Karen A.

    1991-01-01

    A numerical model is employed to establish the transitions between axisymmetric flow and wave flow in the rotating, differentially heated annulus experiments of Fein for both rigid lid and free surface cases. It is shown that, for most of the transitions, the method of computing a steady axisymmetric flow and then testing its linear stability to wave disturbance results in good agreement with the experiments. Implications for the investigation of the dynamics of the earth's atmosphere are considered.

  11. Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

    KAUST Repository

    Siddiqui, Amber

    2016-12-01

    High-quality drinking water can be produced with membrane-based filtration processes like reverse osmosis and nanofiltration. One of the major problems in these membrane systems is biofouling that reduces the membrane performance, increasing operational costs. Current biofouling control strategies such as pre-treatment, membrane modification, and chemical cleaning are not sufficient in all cases. Feed spacers are thin (0.8 mm), complex geometry meshes that separate membranes in a module. The main objective of this research was to evaluate whether feed spacer modification is a suitable strategy to control biofouling. Membrane fouling simulator studies with six feed spacers showed differences in biofouled spacer performance, concluding that (i) spacer geometry influences biofouling impact and (ii) biofouling studies are essential for evaluation of spacer biofouling impact. Computed tomography (CT) was found as a suitable technique to obtain three-dimensional (3D) measurements of spacers, enabling more representative mathematical modeling of hydraulic behavior of spacers in membrane systems. A strategy for developing, characterizing, and testing of spacers by numerical modeling, 3D printing of spacers and experimental membrane fouling simulator studies was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral-wound membrane systems.

  12. Identification of Carnobacterium Species by Restriction Fragment Length Polymorphism of the 16S-23S rRNA Gene Intergenic Spacer Region and Species-Specific PCR

    OpenAIRE

    Rachman, Cinta; Kabadjova, Petia; Valcheva, Rosica; Prévost, Hervé; Dousset, Xavier

    2004-01-01

    The genus Carnobacterium is currently divided into the following eight species: Carnobacterium piscicola, C. divergens, C. gallinarum, C. mobile, C. funditum, C. alterfunditum, C. inhibens, and C. viridans. An identification tool for the rapid differentiation of these eight Carnobacterium species was developed, based on the 16S-23S ribosomal DNA (rDNA) intergenic spacer region (ISR). PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of this 16S-23S rDNA ISR was performed in ord...

  13. SMV1 virus-induced CRISPR spacer acquisition from the conjugative plasmid pMGB1 in Sulfolobus solfataricus P2.

    Science.gov (United States)

    Erdmann, Susanne; Shah, Shiraz A; Garrett, Roger A

    2013-12-01

    Organisms of the crenarchaeal order Sulfolobales carry complex CRISPR (clustered regularly interspaced short palindromic repeats) adaptive immune systems. These systems are modular and show extensive structural and functional diversity, especially in their interference complexes. The primary targets are an exceptional range of diverse viruses, many of which propagate stably within cells and follow lytic life cycles without producing cell lysis. These properties are consistent with the difficulty of activating CRISPR spacer uptake in the laboratory, but appear to conflict with the high complexity and diversity of the CRISPR immune systems that are found among the Sulfolobales. In the present article, we re-examine the first successful induction of archaeal spacer acquisition in our laboratory that occurred exclusively for the conjugative plasmid pMGB1 in Sulfolobus solfataricus P2 that was co-infected with the virus SMV1 (Sulfolobus monocaudavirus 1). Although we reaffirm that protospacer selection is essentially a random process with respect to the pMGB1 genome, we identified single spacer sequences specific for each of CRISPR loci C, D and E that, exceptionally, occurred in many sequenced clones. Moreover, the same sequence was reproducibly acquired for a given locus in independent experiments, consistent with it being the first protospacer to be selected. There was also a small protospacer bias (1.6:1) to the antisense strand of protein genes. In addition, new experiments demonstrated that spacer acquisition in the previously inactive CRISPR locus A could be induced on freeze-thawing of the infected cells, suggesting that environmental stress can facilitate activation. Coincidentally with spacer acquisition, a mobile OrfB element was deleted from pMGB1, suggesting that interplay can occur between spacer acquisition and transposition.

  14. Hydraulic resistance of plane channels and annulus with different roughness on opposite walls

    Science.gov (United States)

    Korsun, A. S.; Kutsenko, K. V.; Pisarevsky, M. I.; Fedoseev, V. N.; Balberkina, Y. N.

    2017-03-01

    A new method for prediction of hydraulic resistance for a turbulent flow in plane channels and annulus is proposed. In spite of the importance of this issue, only very few publications devoted to the investigation into hydrodynamics in these channels are available, and there are no methods for predicting hydraulic resistance of a flow in these channels at all. The flow in channels with different roughness on the walls is described using the Prandtl semiempirical theory of a turbulent boundary layer. The flow in a channel cross-section is divided into two noninteracting layers of different thickness flowing along the walls with different roughness. The basic balance correlations are derived for a plane channel. To match the velocity profiles of both layers at the interface point, a logarithmic velocity profile is used. This yields a closed system of equations for predicting hydraulic resistance in plane channels with a given different roughness on opposite walls. It is demonstrated that the obtained correlation may be used for predicting hydraulic resistance in annulus as well. Experiments were carried out with a water flow in an annulus. Each annuli consisted of a pipe having a smooth wall into which a rod with artificial roughness on the surface was inserted coaxially. Two types of roughness were investigated: trapezoid and threadlike ones. Comparison of the predictions with the experimental data confirmed the validity of the proposed method. It can be used in designing flowpaths of various power installations.

  15. Cubic autocatalysis in a reaction-diffusion annulus: semi-analytical solutions

    Science.gov (United States)

    Alharthi, M. R.; Marchant, T. R.; Nelson, M. I.

    2016-06-01

    Semi-analytical solutions for cubic autocatalytic reactions are considered in a circularly symmetric reaction-diffusion annulus. The Galerkin method is used to approximate the spatial structure of the reactant and autocatalyst concentrations. Ordinary differential equations are then obtained as an approximation to the governing partial differential equations and analyzed to obtain semi-analytical results for this novel geometry. Singularity theory is used to determine the regions of parameter space in which the different types of steady-state diagram occur. The region of parameter space, in which Hopf bifurcations can occur, is found using a degenerate Hopf bifurcation analysis. A novel feature of this geometry is the effect, of varying the width of the annulus, on the static and dynamic multiplicity. The results show that for a thicker annulus, Hopf bifurcations and multiple steady-state solutions occur in a larger portion of parameter space. The usefulness and accuracy of the semi-analytical results are confirmed by comparison with numerical solutions of the governing partial differential equations.

  16. Localized strain measurements of the intervertebral disc annulus during biaxial tensile testing.

    Science.gov (United States)

    Karakolis, Thomas; Callaghan, Jack P

    2015-01-01

    Both inter-lamellar and intra-lamellar failures of the annulus have been described as potential modes of disc herniation. Attempts to characterize initial lamellar failure of the annulus have involved tensile testing of small tissue samples. The purpose of this study was to evaluate a method of measuring local surface strains through image analysis of a tensile test conducted on an isolated sample of annular tissue in order to enhance future studies of intervertebral disc failure. An annulus tissue sample was biaxial strained to 10%. High-resolution images captured the tissue surface throughout testing. Three test conditions were evaluated: submerged, non-submerged and marker. Surface strains were calculated for the two non-marker conditions based on motion of virtual tracking points. Tracking algorithm parameters (grid resolution and template size) were varied to determine the effect on estimated strains. Accuracy of point tracking was assessed through a comparison of the non-marker conditions to a condition involving markers placed on tissue surface. Grid resolution had a larger effect on local strain than template size. Average local strain error ranged from 3% to 9.25% and 0.1% to 2.0%, for the non-submerged and submerged conditions, respectively. Local strain estimation has a relatively high potential for error. Submerging the tissue provided superior strain estimates.

  17. Exogenous thymosin beta4 prevents apoptosis in human intervertebral annulus cells in vitro.

    Science.gov (United States)

    Tapp, H; Deepe, R; Ingram, J A; Yarmola, E G; Bubb, M R; Hanley, E N; Gruber, H E

    2009-12-01

    Loss of cells in the human disc due to programmed cell death (apoptosis) is a major factor in the aging and degenerating human intervertebral disc. Our objective here was to determine if thymosin beta(4) (TB4), a small, multifunctional 5 kDa protein with diverse activities, might block apoptosis in human annulus cells cultured in monolayer or three-dimensional (3D) culture. Apoptosis was induced in vitro using hydrogen peroxide or serum starvation. Annulus cells were processed for identification of apoptotic cells using the TUNEL method. The percentage of apoptotic cells was determined by cell counts. Annulus cells also were treated with TB4 for determination of proliferation, and proteoglycan production was assessed using cell titer and 1,2 dimethylmethylamine (DMB) assays and histological staining. A significant reduction in disc cell apoptosis occurred after TB4 treatment. The percentage of cells undergoing apoptosis decreased significantly in TB4 treated cells in both apoptosis induction designs. TB4 exposure did not alter proteoglycan production as assessed by either DMB measurement or histological staining. Our results indicate the need for further studies of the anti-apoptotic effect of TB4 and suggest that TB4 may have therapeutic application in future biological therapies for disc degeneration.

  18. Radiofrequency catheter ablation of idiopathic ventricular tachycardia and symptomatic premature ventricular contraction originating from valve annulus

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-yu; LIANG Zhao-guang; TAN Zhen; GU Hong-yue; ZHANG Shu; LI Wei-min

    2008-01-01

    Background Radiofrequency catheter ablation (RFCA) has been established as an effective and curative therapy for ventricular tachycardia (VT) and severely symptomatic premature ventricular contraction (PVC) from the outflow tract in structurally normal hearts.This study aimed to investigate electrophysiologic characteristics and effects of RFCA for patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Methods Characteristics of body surface electrocardiogram (ECG) and endocardiogram in a successful RFCA target were analyzed in 16 patients with idiopathic VT and symptomatic PVC originating from the valve annulus.Additionally,the ECG characteristics of vr or PVC were compared with those of manifest Wolff-Parkinson-White (WPW) syndrome originating from the same site of origin in 15 patients.Results Thirteen patients were successful,2 recurrent and 1 failed.The recurrent cases underwent successful ablation the second time guided by the Ensite 3000 mapping system.In all patients with the WPW syndrome,the characteristics of QRS morphology were well matched with those of the VT and PVC that originated from corresponding sites of origin.Conclusions RFCA is an effective curative therapy for VT and symptomatic PVC originating from the valve annulus.There are specific characteristics in ECG and the ablation site could be located by means of the WPW syndrome accessory pathway's algorithm.

  19. Annulus formation on scales of four species of coregonids reared under artificial conditions

    Science.gov (United States)

    Hogman, Walter J.

    1968-01-01

    Scales from known-age coregonids reared in the laboratory were examined to determine when annuli formed and to learn possible factors of their formation. Scales were taken monthly from marked fish for periods up to 21 months. Scales were also examined from fish that died and from preserved specimens of young-of-the-year for each species. Two marks formed on almost all scales each calender year. The stronger formed during March-April and the weaker in October-November. Both marks had all the usual characteristics of an annulus but the spring mark was considered the annulus and the fall mark an accessory check. The annulus formed during a period of constant temperatures and of little change in growth or increasing growth. The accessory check formed during a period of declining temperatures (1-5 degrees F, or 0.6-2.8 degrees C, per month) and of little change in growth or declining growth. Most fish grew throughout the winter; the only exceptions were one bloater (Coregonus hoyi) and several of the largest lake whitefish (C. clupeaformis). Fish were always given all the food they would eat to eliminate availability of food as a factor of mark formation. The temperature of the water during the winter (50 ±. 0.3 F; 10.0 ±. 0.2 C) did not arrest metabolic activity. The growth rate was related more closely to day length than to other variables examined.

  20. Interobserver variability of CT angiography for evaluation of aortic annulus dimensions prior to transcatheter aortic valve implantation (TAVI)

    Energy Technology Data Exchange (ETDEWEB)

    Schmidkonz, C., E-mail: christian.schmidkonz@gmail.com [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany); Marwan, M.; Klinghammer, L.; Mitschke, M.; Schuhbaeck, A.; Arnold, M. [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany); Lell, M. [Radiological Institute, University of Erlangen, Maximiliansplatz 1, D-91054 Erlangen (Germany); Achenbach, S.; Pflederer, T. [Department of Internal Medicine 2 (Cardiology), University of Erlangen, Ulmenweg 18, D-91054 Erlangen (Germany)

    2014-09-15

    Highlights: • Cardiac CT provides highly reproducible measurements of aortic annulus and root dimensions prior to TAVI. • The perimeter-derived aortic annulus diameter shows the lowest interobserver variability. • If all three CT sizing methods are considered and stated as a “consensus result”, mismatches in prosthesis size selection can be further reduced. - Abstract: Objective: Assessment of aortic annulus dimensions prior to transcatheter aortic valve implantation (TAVI) is crucial for accurate prosthesis sizing in order to avoid prosthesis–annulus-mismatch possibly resulting in complications like valve dislodgement, paravalvular regurgitation or annulus rupture. Contrast-enhanced multidetector computed tomography allows 3-dimensional assessment of aortic annulus dimensions. Only limited data exist about its interobserver variability. Methods: In 100 consecutive patients with symptomatic severe aortic stenosis (51 male, BMI 27 ± 5 kg/m{sup 2}, age 81 ± 7 years, heart rate 72 ± 15 bpm, Logistic Euroscore 31 ± 14%, STS-Score 7 ± 4%), pre-interventional aortic annulus assessment was performed by dual source computed tomography (collimation 2 × 128 × 0.6 mm, high pitch spiral data acquisition mode, 40–60 ml contrast agents, radiation dose 3.5 ± 0.9 mSv). The following aortic annulus characteristics were determined by three independent observers: aortic annulus maximum, minimum and mean diameters (D{sub max}, D{sub min}, D{sub mean}), eccentricity index (EI), effective aortic annulus diameter according to its circumference (D{sub circ}), effective aortic annulus diameter according to its area (D{sub area}), distance from the aortic annulus plane to the left (LCA) and right coronary artery (RCA) ostia, maximum (D{sub max}AR) and minimum aortic root diameter (D{sub min}AR), maximum (D{sub max}STJ) and minimum diameter of the sinotubular junction (D{sub min}STJ). Subsequently, interobserver variabilities were assessed. Results: Correlation between

  1. Intergenic spacer length variants in Old Portuguese bread wheat cultivars

    Indian Academy of Sciences (India)

    Ana Carvalho; Henrique Guedes-Pinto; José Lima-Brito

    2011-08-01

    The intergenic spacer of the ribosomal DNA is highly variable, but is location specific in the nucleolar organizer region of the chromosomes. This study provides an event of high level of polymorphism / size variation and occurrence of 14 unique phenotypes in 48 landraces of Portuguese bread wheat cultivars for IGS-amplified products obtained by PCR-RFLP technique performed with TaqI. The attendant IGS polymorphism has been used to deduce affinities between landraces. Some of the high molecular weight IGS allelic variants were also probed for their chromosomal localization by sequential silver nitrate staining and fluorescence in situ hybridization. However, only the intergenic spacer allelic variant of 3.1 kb could be successfully hybridized, and was observed to be physically located on the chromosome pair 1B in the NOR loci of the cultivar ‘Magueija’.

  2. Flow regime transition criteria for two-phase flow in a vertical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J. Enrique, E-mail: bolivar@emc.uji.es [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I., Campus de Riu Sec, 12071 Castellon (Spain); Hibiki, Takashi [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States)

    2011-10-15

    Highlights: > Flow regime transition model is presented for two-phase flows in a vertical annulus. > The transition criteria is easy to be implemented in computational codes. > Final equations do not need experimental input. > New developed model shows better predicting capabilities than existing correlations. > New developed model shows good predicting capabilities in boiling flow. - Abstract: In this work, a new flow regime transition model is proposed for two-phase flows in a vertical annulus. Following previous works, the flow regimes considered are bubbly (B), slug (S) or cap-slug (CS), churn (C) and annular (A). The B to CS transition is modeled using the maximum bubble package criteria of small bubbles. The S to C transition takes place for small annulus perimeter flow channels and it is assumed to occur when the mean void fraction over the entire region exceeds that over the slug-bubble section. If the annulus perimeter is larger that the distorted bubble limit the cap-slug flow regime will be considered since in these conditions it is not possible to distinguish between cap and partial-slug bubbles. The CS to C transition is modeled using the maximum bubble package criteria. However, this transition considers the coalescence of cap and spherical bubbles in order to take into account the flow channel geometry. Finally, the C to A transition is modeled assuming two different mechanisms, (a) flow reversal in the liquid film section along large bubbles; (b) destruction on liquid slugs or large waves by entrainment or deformation. In the S to C and C to A flow regime transitions the annulus flow channel is considered as a rectangular flow channel with no side walls. In all the modeled transitions the drift-flux model is used to obtain the final correlations. The final equations for every flow regime transition are easy to be implemented in computational codes and not experimental input is needed. The prediction accuracy of the newly developed model has been

  3. Surgical spacer placement and proton radiotherapy for unresectable hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shohei; Komatsu; Yuichi; Hori; Takumi; Fukumoto; Masao; Murakami; Yoshio; Hishikawa; Yonson; Ku

    2010-01-01

    Few potentially curative treatment options exist apart from hepatic resection for patients with huge hepatocellular carcinoma (HCC). Proton radiotherapy is a promising new modality which has an inherent antitumor effect against HCC. However, the application of proton radiotherapy for tumors adjacent to the gastrointestinal tract is restricted because the tolerance dose of the intestine is extremely low. A novel two-step treatment was developed with surgical spacer placement and subsequent proton radiotherap...

  4. Effects of interspinous spacers on lumbar degenerative disease.

    Science.gov (United States)

    Zhou, Dong; Nong, Lu-Ming; DU, Rui; Gao, Gong-Ming; Jiang, Yu-Qing; Xu, Nan-Wei

    2013-03-01

    The present study aimed to evaluate the early effects of interspinous spacers on lumbar degenerative disease. The clinical outcomes of 23 patients with lumbar degenerative disease, treated using interspinous spacer implantation alone or combined with posterior lumbar fusion, were retrospectively studied and assessed with a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Pre-operative and post-operative interspinous distance, disc space height, foraminal width and height and segmental lordosis were determined. The early effects and complications associated with the interspinous spacers were recorded. The surgical procedures performed with the in-space treatment were easy and minimally invasive. The VAS scores and ODI were improved post-operatively compared with pre-operatively. Significant changes in the interspinous distance, disc space height, foraminal width and height and segmental lordosis were noted. In-space treatment for degenerative lumbar disease is easy and safe, with good early effects. The in-space system provides an alternative treatment for lumbar degenerative disease.

  5. Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

    KAUST Repository

    Araújo, Paula A.

    2012-06-01

    The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

  6. Effect of plastic spacer handling on salbutamol lung deposition in asthmatic children

    DEFF Research Database (Denmark)

    Lipworth, Brian J; Lee, Daniel K C; Anhøj, Jacob

    2002-01-01

    on separate days. Blood samples were taken for plasma salbutamol at 5, 10, 15 and 20 min after inhalation to measure lung bioavailability as a surrogate for relative lung dose. With immediate inhalation following actuation, a new rinsed spacer (NewRinsed ) was compared with a used spacer after repeated daily......AIMS: To study the effects of electrostatics in a plastic spacer on the lung deposition of salbutamol in asthmatic children. METHODS: Twenty-five children (5-12 years) with mild asthma were given salbutamol hydrofluoroalkane pressurized metered dose inhaler 400 micro g via a 750 ml plastic spacer.......14 fold (1.24, 3.69), or vs RinsedDelay 3.28 fold (2.13, 5.04). CONCLUSIONS: The relative lung dose of salbutamol from a plastic spacer may differ considerably depending on spacer handling suggesting that nonelectrostatic spacers may be the best way forward....

  7. Mobile marketing for mobile games

    OpenAIRE

    Vu, Giang

    2016-01-01

    Highly developed mobile technology and devices enable the rise of mobile game industry and mobile marketing. Hence mobile marketing for mobile game is an essential key for a mobile game success. Even though there are many articles on marketing for mobile games, there is a need of highly understanding mobile marketing strategies, how to launch a mobile campaign for a mobile game. Besides that, it is essential to understand the relationship between mobile advertising and users behaviours. There...

  8. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems

    KAUST Repository

    Siddiqui, Amber Siddiqui Shahnawaz

    2016-01-02

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydraulic behavior of various feed spacer geometries suggested that the impact of spacers on hydraulics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydraulic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydraulic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of biofilm formation on

  9. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems.

    Science.gov (United States)

    Siddiqui, Amber; Farhat, Nadia; Bucs, Szilárd S; Linares, Rodrigo Valladares; Picioreanu, Cristian; Kruithof, Joop C; van Loosdrecht, Mark C M; Kidwell, James; Vrouwenvelder, Johannes S

    2016-03-15

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydrodynamic behavior of various feed spacer geometries suggested that the impact of spacers on hydrodynamics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as the first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydrodynamic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydrodynamic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of

  10. Multi-detector computed tomography is equivalent to trans-oesophageal echocardiography for the assessment of the aortic annulus before transcatheter aortic valve implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rixe, Johannes; Schmitt, Joern; Neumann, Thomas; Hamm, Christian W.; Rolf, Andreas [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Schuhbaeck, Annika; Nef, Holger M.; Achenbach, Stephan [University Hospital of Giessen and Marburg, Site Giessen, Department of Internal Medicine I (Cardiology, Angiology), Giessen (Germany); Liebetrau, Christoph; Moellmann, Helge; Szardien, Sebastian; Brandt, Roland [Kerckhoff Heart and Thorax Center, Department of Cardiology, Bad Nauheim (Germany); Schneider, Christian; Krombach, Gabriele [University Hospital of Giessen and Marburg, Department of Radiology, Giessen (Germany)

    2012-12-15

    In transcatheter aortic valve implantation (TAVI), assessment of the aortic annulus is mandatory. We sought to investigate the correlation between trans-oesophageal echocardiography (TEE) and multi-detector computed tomography (MDCT) for annulus diameter assessment before TAVI. A total of 122 patients (67 male, mean age 84 {+-} 6 years) underwent MDCT and TEE for TAVI planning. In TEE annulus diameters were obtained in a long-axis view at diastole. MDCT data were evaluated using MPR images, and corresponding projections were adjusted for MDCT and TEE. Patients were classified by the predominant localisation of aortic valve calcifications, and annulus diameters between TEE and MDCT were correlated. Additionally, the eccentricity of the aortic annulus was calculated. Mean eccentricity of the aortic annulus determined by MDCT was 0.34 {+-} 0.17, with no difference according to valve calcification. Regarding the aortic annulus diameter, the mean values measured were 24.3 {+-} 2.1 mm in MDCT and 24.0 {+-} 2.5 mm in TEE (P < 0.0001 for agreement). Independent of the pattern of aortic valve calcification, close correlation is found between CT and TEE measurements of the aortic annulus diameter. In addition, CT demonstrates the non-circular shape of the aortic annulus. (orig.)

  11. Comparison of aortic annulus diameter measurement between multi-detector computed tomography and echocardiography: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ruifang Zhang

    Full Text Available BACKGROUND AND PURPOSE: Accurate measurement of aortic annulus diameter is crucial for choosing suitable prosthetic size for transcatheter aortic valve implantation (TAVI. Several imaging methods are available for the measurement, but significant variability between different modalities has been observed. The purpose of this study was to systematically compare the measurements of aortic annulus diameter between multi-detector computed tomography (MDCT, transthoracic echocardiography (TTE, and transesophegeal echocardiography (TEE. METHODS: PubMed and EMBASE databases between January 2000 and January 2012 were searched. We extracted data from eligible studies evaluating the aortic annulus diameter by MDCT and echocardiography (TTE, TEE, or both. We performed a random-effects meta-analysis to calculate the weighted mean differences of aortic annulus diameter measurement between MDCT, TTE, and TEE. RESULTS: A total of 10 eligible studies involving 581 subjects with aortic valve stenosis were included. Aortic annulus diameter measured on coronal view by MDCT (25.3±0.52 mm was respectively larger than that measured on sagittal view by MDCT (22.7±0.37 mm, TTE (22.6±0.28 mm, and TEE (23.1±0.32 mm. The weighted mean difference of aortic annulus diameter between coronal view by MDCT and TTE these two methods was 2.97 mm, followed by the weighted mean difference of 2.53 mm between coronal view and sagittal view by MDCT, and the mean difference of 1.74 mm between coronal view on MDCT and TEE (P<0.0001 for all. The weighted mean difference of aortic annulus diameter measurement between TEE and TTE was significant but somewhat small (0.45 mm, P = 0.007. CONCLUSION: Aortic annulus diameter measured on coronal view by MDCT was robustly and significantly larger than that obtained on sagittal view by MDCT, TTE, or TEE. Such variability of aortic annulus diameter measurement by different imaging modalities cannot be ignored when developing optimal

  12. ANNULUS CLOSURE TECHNOLOGY DEVELOPMENT INSPECTION/SALT DEPOSIT CLEANING MAGNETIC WALL CRAWLER

    Energy Technology Data Exchange (ETDEWEB)

    Minichan, R; Russell Eibling, R; James Elder, J; Kevin Kane, K; Daniel Krementz, D; Rodney Vandekamp, R; Nicholas Vrettos, N

    2008-06-01

    The Liquid Waste Technology Development organization is investigating technologies to support closure of radioactive waste tanks at the Savannah River Site (SRS). Tank closure includes removal of the wastes that have propagated to the tank annulus. Although amounts and types of residual waste materials in the annuli of SRS tanks vary, simple salt deposits are predominant on tanks with known leak sites. This task focused on developing and demonstrating a technology to inspect and spot clean salt deposits from the outer primary tank wall located in the annulus of an SRS Type I tank. The Robotics, Remote and Specialty Equipment (RRSE) and Materials Science and Technology (MS&T) Sections of the Savannah River National Laboratory (SRNL) collaborated to modify and equip a Force Institute magnetic wall crawler with the tools necessary to demonstrate the inspection and spot cleaning in a mock-up of a Type I tank annulus. A remote control camera arm and cleaning head were developed, fabricated and mounted on the crawler. The crawler was then tested and demonstrated on a salt simulant also developed in this task. The demonstration showed that the camera is capable of being deployed in all specified locations and provided the views needed for the planned inspection. It also showed that the salt simulant readily dissolves with water. The crawler features two different techniques for delivering water to dissolve the salt deposits. Both water spay nozzles were able to dissolve the simulated salt, one is more controllable and the other delivers a larger water volume. The cleaning head also includes a rotary brush to mechanically remove the simulated salt nodules in the event insoluble material is encountered. The rotary brush proved to be effective in removing the salt nodules, although some fine tuning may be required to achieve the best results. This report describes the design process for developing technology to add features to a commercial wall crawler and the results of the

  13. CHARACTERIZATION OF TANK 16H ANNULUS SAMPLES PART II: LEACHING RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; Reboul, S.

    2012-06-19

    The closure of Tank 16H will require removal of material from the annulus of the tank. Samples from Tank 16H annulus were characterized and tested to provide information to evaluate various alternatives for removing the annulus waste. The analysis found all four annulus samples to be composed mainly of Si, Na, and Al and lesser amounts of other elements. The XRD data indicate quartz (SiO{sub 2}) and sodium aluminum nitrate silicate hydrate (Na{sub 8}(Al{sub 6}Si{sub 6}O{sub 24})(NO{sub 3}){sub 2}.4H{sub 2}O) as the predominant crystalline mineral phases in the samples. The XRD data also indicate the presence of crystalline sodium nitrate (NaNO{sub 3}), sodium nitrite (NaNO{sub 2}), gibbsite (Al(OH){sub 3}), hydrated sodium bicarbonate (Na{sub 3}H(CO{sub 3}){sub 2}.2H{sub 2}O), and muscovite (KAl{sub 2}(AlSi{sub 3}O{sub 10})(OH){sub 2}). Based on the weight of solids remaining at the end of the test, the water leaching test results indicate 20-35% of the solids dissolved after three contacts with an approximately 3:1 volume of water at 45 C. The chemical analysis of the leachates and the XRD results of the remaining solids indicate sodium salts of nitrate, nitrite, sulfate, and possibly carbonate/bicarbonate make up the majority of the dissolved material. The majority of these salts were dissolved in the first water contact and simply diluted with each subsequent water contact. The water leaching removed large amounts of the uranium in two of the samples and approximately 1/3 of the {sup 99}Tc from all four samples. Most of the other radionuclides analyzed showed low solubility in the water leaching test. The oxalic acid leaching test result indicate approximately 34-47% of the solids in the four annulus samples will dissolve after three contacts with an approximately 3:1 volume of acid to solids at 45 C. The same sodium salts found in the water leaching test comprise the majority of dissolved material in the oxalic acid leaching test. However, the oxalic acid was

  14. Impact of ZnO embedded feed spacer on biofilm development in membrane systems.

    Science.gov (United States)

    Ronen, Avner; Semiat, Raphael; Dosoretz, Carlos G

    2013-11-01

    The concept of suppressing biofouling formation using an antibacterial feed spacer was investigated in a bench scale-cross flow system mimicking a spiral wound membrane configuration. An antibacterial composite spacer containing zinc oxide-nanoparticles was constructed by modification of a commercial polypropylene feed spacer using sonochemical deposition. The ability of the modified spacers to repress biofilm development on membranes was evaluated in flow-through cells simulating the flow conditions in commercial spiral wound modules. The experiments were performed at laminar flow (Re = 300) with a 200 kDa molecular weight cut off polysulfone ultrafiltration membrane using Pseudomonas putida S-12 as model biofilm bacteria. The modified spacers reduced permeate flux decrease at least by 50% compared to the unmodified spacers (control). The physical properties of the modified spacer and biofilm development were evaluated using high resolution/energy dispersive spectrometry-scanning electron microscopy, atomic force microscopy and confocal laser scanning microscopy imaging (HRSEM, EDS, AFM and CLSM). HRSEM images depicted significantly less bacteria attached to the membranes exposed to the modified spacer, mainly scattered and in a sporadic monolayer structure. AFM analysis indicated the influence of the modification on the spacer surface including a phase change on the upper surface. Dead-live staining assay by CLSM indicated that most of the bacterial cells attached on the membranes exposed to the modified spacer were dead in contrast to a developed biofilm which was predominant in the control samples.

  15. Cardiac valve annulus manual segmentation using computer assisted visual feedback in three-dimensional image data.

    Science.gov (United States)

    Casero, Ramon; Burton, Rebecca A B; Quinn, T; Bollensdorff, Christian; Hales, Patrick; Schneider, Jurgen E; Kohl, Peter; Grau, Vicente

    2010-01-01

    Annulus manual segmentation is an important tool for the study of valve anatomy and physiology, for the four main valves of the heart (mitral, tricuspid, aortic and pulmonary). In this paper we review two traditional manual segmentation approaches: slice-by-slice and interpolating a sparse set of landmarks with a spline curve. We propose a new Spline Tool for the open source software platform Seg3D, that is fast and improves spatial coherence by providing visual feedback of the segmentation in real time. The Spline Tool was tested successfully on 14 rat hearts, on all four valves.

  16. The Influence of Horizontal Boundaries on Ekman Circulation and Angular Momentum Transport in a Cylindrical Annulus

    CERN Document Server

    Obabko, Aleksandr V; Fischer, Paul F

    2008-01-01

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton MRI liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow structure, Ekman circulation and associated transport of angular momentum through the onset of unsteadiness and three-dimensionality. A mechanism for the explanation of the dependence of the Ekman flows and circulation on horizontal boundary conditions is proposed.

  17. Mixed convection aiding flow in a vertical porous annulus-two temperature model

    Science.gov (United States)

    Salman Ahmed, N. J.; AAAl-Rashed, Abdullah A.; Kamangar, Sarfaraz; Khaleed, H. M. T.; YunusKhan, T. M.; Athani, Abdulgaphur

    2016-09-01

    The effect of convective heat transfer on mixed convection flow in a vertical porous annulus embedded with fluid saturated porous medium for aiding flow is studied. The inner surface of the annular cylinder is heated with constant temperature whereas the outer surface remains at ambient temperature. The governing partial differential equations are solved using Finite Element Method (FEM). It is assumed that the Darcy law is applicable and thermal nonequilibrium TNE exists between solid and fluid phases of porous medium. The aiding flow behavior of heat transfer with respect to Radius ratioRr, Aspect ratio ArandRadiation parameter Rd for different values of Peclet number Peare investigated.

  18. The influence of horizontal boundaries on Ekman circulation and angular momentum transport in a cylindrical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Obabko, Aleksandr V; Cattaneo, Fausto [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); F Fischer, Paul [Division of Mathematics and Computer Science, Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: obabko@uchicago.edu

    2008-12-15

    We present numerical simulations of circular Couette flow in axisymmetric and fully three-dimensional geometry of a cylindrical annulus inspired by Princeton magnetorotational instability (MRI) liquid gallium experiment. The incompressible Navier-Stokes equations are solved with the spectral element code Nek5000 incorporating realistic horizontal boundary conditions of differentially rotating rings. We investigate the effect of changing rotation rates (Reynolds number) and of the horizontal boundary conditions on flow structure, Ekman circulation and associated transport of angular momentum through the onset of unsteadiness and three-dimensionality. A mechanism for the explanation of the dependence of the Ekman flows and circulation on horizontal boundary conditions is proposed.

  19. Transportation of MHD nanofluid free convection in a porous semi annulus using numerical approach

    Science.gov (United States)

    Sheikholeslami, M.; Ganji, D. D.

    2017-02-01

    Nanofluid free convection in presence of Lorentz forces in a permeable semi annulus is simulated using Control Volume based Finite Element Method. Impact of porous media on governing equations is considered by means of Darcy law. Brownian motion impact on properties of nanofluid is taken into account using Koo-Kleinstreuer-Li (KKL) model. Important parameters are inclination angle (ξ) , CuO-water volume fraction (ϕ) , Hartmann (Ha) and Rayleigh (Ra) numbers for porous medium. A formula for Nuave is provided. Results indicated that temperature gradient detracts with enhance of Ha but it enhances with rise of ξ, Ra . Heat transfer augmentation enhances with rise of Lorentz forces.

  20. An annulus fibrosus closure device based on a biodegradable shape-memory polymer network.

    Science.gov (United States)

    Sharifi, Shahriar; van Kooten, Theo G; Kranenburg, Hendrik-Jan C; Meij, Björn P; Behl, Marc; Lendlein, Andreas; Grijpma, Dirk W

    2013-11-01

    Injuries to the intervertebral disc caused by degeneration or trauma often lead to tearing of the annulus fibrosus (AF) and extrusion of the nucleus pulposus (NP). This can compress nerves and cause lower back pain. In this study, the characteristics of poly(D,L-lactide-co-trimethylene carbonate) networks with shape-memory properties have been evaluated in order to prepare biodegradable AF closure devices that can be implanted minimally invasively. Four different macromers with (D,L-lactide) to trimethylene carbonate (DLLA:TMC) molar ratios of 80:20, 70:30, 60:40 and 40:60 with terminal methacrylate groups and molecular weights of approximately 30 kg mol(-1) were used to prepare the networks by photo-crosslinking. The mechanical properties of the samples and their shape-memory properties were determined at temperatures of 0 °C and 40 °C by tensile tests- and cyclic, thermo-mechanical measurements. At 40 °C all networks showed rubber-like behavior and were flexible with elastic modulus values of 1.7-2.5 MPa, which is in the range of the modulus values of human annulus fibrosus tissue. The shape-memory characteristics of the networks were excellent with values of the shape-fixity and the shape-recovery ratio higher than 98 and 95%, respectively. The switching temperatures were between 10 and 39 °C. In vitro culture and qualitative immunocytochemistry of human annulus fibrosus cells on shape-memory films with DLLA:TMC molar ratios of 60:40 showed very good ability of the networks to support the adhesion and growth of human AF cells. When the polymer network films were coated by adsorption of fibronectin, cell attachment, cell spreading, and extracellular matrix production was further improved. Annulus fibrosus closure devices were prepared from these AF cell-compatible materials by photo-polymerizing the reactive precursors in a mold. Insertion of the multifunctional implant in the disc of a cadaveric canine spine showed that these shape-memory devices could be

  1. Definitive Treatment of Infected Shoulder Arthroplasty With a Cement Spacer.

    Science.gov (United States)

    Mahure, Siddharth A; Mollon, Brent; Yu, Stephen; Kwon, Young W; Zuckerman, Joseph D

    2016-09-01

    Infection in the setting of shoulder arthroplasty can result in significant pain, loss of function, and the need for additional surgery. As the use of shoulder arthroplasty increases, the medical and economic burdens of periprosthetic joint infection increase as well. The ideal management of infected shoulder prostheses has not been established. This report describes 9 patients from a single institution who had an infected shoulder arthroplasty that was definitively managed with a cement spacer. All patients had a minimum of 2 years of follow-up. Of the 9 patients in this study, 6 were men. Mean age was 73±9 years. Of the study patients, 1 had diabetes, 2 presented with Parkinson's disease, and 5 had a history of tobacco use. Average body mass index was 27.9±7 kg/m(2). After mean follow-up of 4 years, none of the patients had clinical or radiographic evidence of infection. Functional outcomes, as measured by American Shoulder and Elbow Surgeons scores, were good or fair in 89% of patients, and the average American Shoulder and Elbow Surgeons score was 57. A review of recent literature suggested that the current findings were similar to those in studies reporting 1- or 2-stage revision procedures. Although cement spacers are typically used as part of a 2-stage revision procedure, the current findings suggest that cement spacers can be used effectively to eradicate infection and allow for acceptable functional recovery and range of motion in patients who have severe medical comorbidities and cannot tolerate additional surgery. [Orthopedics. 2016; 39(5):e924-e930.].

  2. An insulating grid spacer for large-area MICROMEGAS chambers

    CERN Document Server

    Bernard, D; D'Enterria, D G; Le Guay, M; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y; Gandi, A; De Oliveira, R

    2002-01-01

    We present an original design for large area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides an uniform 200 $\\mu$m amplification gap. The uniformity of the amplification gap thickness has been verified under several experimental conditions. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.

  3. Synthesis and properties of novel gemini surfactant with short spacer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cationic gemini surfactant dimethylene-1,2-bis(dodecyldiethylammonium bromide), referred to as C12C2C12(Et) was synthesized, and its surface property and aggregation behavior in aqueous solution were studied. The value of γat the critical micelle concentration (γcmc) is much smaller than that of the surfactant homologues with longer spacer. Spherical and elongated micelles were formed in the aqueous solution of this gemini surfactant,and the spherical micelles were absolutely dominant compared to the elongated micelles at our studied concentration quantitatively.

  4. Does the mitral annulus shrink or enlarge during systole? A real-time 3D echocardiography study.

    Science.gov (United States)

    Kwan, Jun; Jeon, Min-Jae; Kim, Dae-Hyeok; Park, Keum-Soo; Lee, Woo-Hyung

    2009-04-01

    This study was conducted to explore the geometrical changes of the mitral annulus during systole. The 3D shape of the mitral annulus was reconstructed in 13 normal subjects who had normal structure of the mitral apparatus using real-time 3D echocardiography (RT3DE) and 3D computer software. The two orthogonal (antero-posterior and commissure-commissure) dimensions, the areas (2D projected and 3D surface) and the non-planarity of the mitral annulus were estimated during early, mid and late systole. We demonstrated that the MA had a "saddle shape" appearance and it consistently enlarged mainly in the antero-posterior direction from early to late systole with lessening of its non-planarity, as was determined by 3D reconstruction using RT3DE and 3D computer software.

  5. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    DEFF Research Database (Denmark)

    Liu, Tao; Li, Yingjun; Wang, Xiaodi

    2015-01-01

    Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I......, it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci...... in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence...

  6. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition

    DEFF Research Database (Denmark)

    Liu, Tao; Li, Yingjun; Wang, Xiaodi;

    2015-01-01

    , it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci......Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I...... in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence...

  7. Creeping gaseous flows through elastic tube and annulus micro-configurations

    Science.gov (United States)

    Elbaz, Shai; Jacob, Hila; Gat, Amir

    2016-11-01

    Gaseous flows in elastic micro-configurations is relevant to biological systems (e.g. alveolar ducts in the lungs) as well as to applications such as gas actuated soft micro-robots. We here examine the effect of low-Mach-number compressibility on creeping gaseous axial flows through linearly elastic tube and annulus micro-configurations. For steady flows, the leading-order effects of elasticity on the pressure distribution and mass-flux are obtained. For transient flow in a tube with small deformations, elastic effects are shown to be negligible in leading order due to compressibility. We then examine transient flows in annular configurations where the deformation is significant compared with the gap between the inner and outer cylinders defining the annulus. Both compressibility and elasticity are obtained as dominant terms interacting with viscosity. For a sudden flux impulse, the governing non-linear leading order diffusion equation is initially approximated by a porous-medium-equation of order 2.5 for the pressure square. However, as the fluid expand and the pressure decreases, the governing equation degenerates to a porous-medium-equation of order 2 for the pressure.

  8. Melting of a phase change material in a horizontal annulus with discrete heat sources

    Directory of Open Access Journals (Sweden)

    Mirzaei Hooshyar

    2015-01-01

    Full Text Available Phase change materials have found many industrial applications such as cooling of electronic devices and thermal energy storage. This paper investigates numerically the melting process of a phase change material in a two-dimensional horizontal annulus with different arrangements of two discrete heat sources. The sources are positioned on the inner cylinder of the annulus and assumed as constant-temperature boundary conditions. The remaining portion of the inner cylinder wall as well as the outer cylinder wall is considered to be insulated. The emphasis is mainly on the effects of the arrangement of the heat source pair on the fluid flow and heat transfer features. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The results are obtained at Ra=104 and presented in terms of streamlines, isotherms, melting phase front, liquid fraction and dimensionless heat flux. It is observed that, depending on the arrangement of heat sources, the liquid fraction increases both linearly and non-linearly with time but will slow down at the end of the melting process. It can also be concluded that proper arrangement of discrete heat sources has the great potential in improving the energy storage system. For instance, the arrangement C3 where the heat sources are located on the bottom part of the inner cylinder wall can expedite the melting process as compared to the other arrangements.

  9. Posterior enlargement of the small annulus during aortic valve replacement versus implantation of a small prosthesis.

    Science.gov (United States)

    Pugliese, P; Bernabei, M; Santi, C; Pasqué, A; Eufrate, S

    1984-07-01

    Twenty-two patients with a small aortic annulus were identified among 196 consecutive patients undergoing aortic valve replacement (AVR). The 11 patients in Group 1 underwent posterior enlargement aortic annuloplasty, and the 11 in Group 2 received a small aortic prosthesis (less than or equal to 21 mm). The two groups were unselected. Core hypothermia, cardioplegia, and local cooling were employed for all operations. Isolated AVR was performed in 3 patients in each group. In Group 1, the mean increase in diameter of the annulus was 4.82 mm, which resulted in a mean area increase of 169.91 mm2 (51.7%). Mean aortic cross-clamp times were 140.4 minutes and 93.5 minutes in Groups 1 and 2, respectively. There were 2 operative deaths in Group 1, and 1 operative and 1 late death in Group 2. Mean follow-up was 26.5 months for Group 1 and 43.4 months for Group 2. No thomboembolic or bleeding episodes have been recorded. Considerations and conclusions are offered from the study of this small series of patients.

  10. Three dimensional evaluation of the aortic annulus using multislice computer tomography: Are manufacturer's guidelines for sizing for percutaneous aortic valve replacement helpful?

    NARCIS (Netherlands)

    C.J. Schultz (Carl); A. Moelker (Adriaan); N. Piazza (Nicolo); A. Tzikas (Apostolos); A. Otten (Amber); R-J.M. Nuis (Rutger-Jan); L.A.E. Neefjes (Lisan); R.J.M. van Geuns (Robert Jan); P.J. de Feyter (Pim); G.P. Krestin (Gabriel); P.W.J.C. Serruys (Patrick); P.P.T. de Jaegere (Peter)

    2010-01-01

    textabstractAimsTo evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection.Methods and resultsMultislice computer tomography annulus diameters [minimum: Dmin; maximum: Dmax; mean: Dmea

  11. Application of Regent mechanical valve in patients with small aortic annulus: 3-year follow-up

    Directory of Open Access Journals (Sweden)

    Zhao Dong

    2012-09-01

    Full Text Available Abstract Background Aortic valve replacement (AVR with a small aortic annulus is always challenging for the cardiac surgeon. In this study, we sought to evaluate the midterm performance of implantation with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent mechanical valve in retrospective consecutive cohort of patients with small aortic annulus (diameter ≤ 19 mm. Methods From January 2008 to April 2011, 40 patients (31 female, mean age = 47.2 ± 5.8 years with small aortic annulus (≤19 mm in diameter underwent aortic valve replacement with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent mechanical valve. Preoperative mean body surface area, New York Heart Association class, and mean aortic annulus were 1.61 ± 0.26 m2, 3.2 ± 0.4, and 18 ± 1.4 mm respectively. Patients were divided into two groups, according to the implantation of 17 mm SJM Regent mechanical valve (group 1, n = 18 or 19 mm SJM Regent valve (group 2, n = 22. All patients underwent echocardiography examination preoperatively and at one year post-operation. Results There were no early deaths in either group. Follow-up time averaged 36 ± 17.6 months. The mean postoperative New York Heart Association class was 1.3 ± 0.6 (p 2/m2 to 69.8 ± 9.3%, 41.4 ± 8.3%, and 0.92 ± 0.10 cm2/m2 respectively (P 2, 46.1 ± 8.5 mmHg to 86.7 ± 18.2 g/m2 , 13.7 ± 5.2 mmHg respectively. In group 2, the LVEF, LVFS and EOAI increased from 45.9% ± 9.7%, 30.7% ± 8.0%, and 0.81 ± 0.09 cm2/m2 to 77.4% ± 9.7%, 44.5% ± 9.6%, and 1.27 ± 0.11 cm2/m2 respectively, while the LVMI, and the aortic transvalvular pressure gradient decreased from 118.3 ± 27.6 g/m2, 44.0 ± 6.7 mmHg to 80.1 ± 19.7 g/m2, 10.8 ± 4.1 mmHg as well. The prevalence of PPM was documented in 2 patients in Group 1. Conclusions Patients with small aortic annulus and body surface

  12. Nanoparticle-Based Brachytherapy Spacers for Delivery of Localized Combined Chemoradiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajiv, E-mail: r.kumar@neu.edu [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Belz, Jodi [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Markovic, Stacey [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Jadhav, Tej; Fowle, William [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Niedre, Mark [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts (United States); Cormack, Robert; Makrigiorgos, Mike G. [Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States); Sridhar, Srinivas [Nanomedicine Science and Technology Center, Northeastern University, Boston, Massachusetts (United States); Department of Radiation Oncology, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: In radiation therapy (RT), brachytherapy-inert source spacers are commonly used in clinical practice to achieve high spatial accuracy. These implanted devices are critical technical components of precise radiation delivery but provide no direct therapeutic benefits. Methods and Materials: Here we have fabricated implantable nanoplatforms or chemoradiation therapy (INCeRT) spacers loaded with silica nanoparticles (SNPs) conjugated containing a drug, to act as a slow-release drug depot for simultaneous localized chemoradiation therapy. The spacers are made of poly(lactic-co-glycolic) acid (PLGA) as matrix and are physically identical in size to the commercially available brachytherapy spacers (5 mm × 0.8 mm). The silica nanoparticles, 250 nm in diameter, were conjugated with near infrared fluorophore Cy7.5 as a model drug, and the INCeRT spacers were characterized in terms of size, morphology, and composition using different instrumentation techniques. The spacers were further doped with an anticancer drug, docetaxel. We evaluated the in vivo stability, biocompatibility, and biodegradation of these spacers in live mouse tissues. Results: The electron microscopy studies showed that nanoparticles were distributed throughout the spacers. These INCeRT spacers remained stable and can be tracked by the use of optical fluorescence. In vivo optical imaging studies showed a slow diffusion of nanoparticles from the spacer to the adjacent tissue in contrast to the control Cy7.5-PLGA spacer, which showed rapid disintegration in a few days with a burst release of Cy7.5. The docetaxel spacers showed suppression of tumor growth in contrast to control mice over 16 days. Conclusions: The imaging with the Cy7.5 spacer and therapeutic efficacy with docetaxel spacers supports the hypothesis that INCeRT spacers can be used for delivering the drugs in a slow, sustained manner in conjunction with brachytherapy, in contrast to the rapid clearance of the drugs when

  13. Vibration of the Package of Rods Linked by Spacer Grids

    Science.gov (United States)

    Zeman, V.; Hlaváč, Z.

    This paper deals with modelling and vibration analysis of the large package of identical parallel rods which are linked by transverse springs (spacer grids) placed on several level spacings. The vibration of rods is caused by the support plate motion. The rod discretization by FEM is based on Rayleigh beam theory. With respect to cyclic and central package rod symmetry, the system is decomposed to identical revolved rod segments. The modal synthesis method with condensation of the rod segments is used for modelling and determination of steady forced vibration of the whole system. The presented method is the first step to modelling of the nuclear fuel assembly vibration caused by kinematical excitation determined by motion of the support plates which are part of the reactor core.

  14. Transesophageal echocardiography measurements of aortic annulus diameter using biplane mode in patients undergoing transcatheter aortic valve implantation

    Directory of Open Access Journals (Sweden)

    Shahgaldi Kambiz

    2013-01-01

    Full Text Available Abstract Background Aortic stenosis (AS is a relevant common valve disorder. Severe AS and symptoms and/or left ventricular dysfunction (EF Aim of the study is to assess the aortic annulus diameter in patients undergoing TAVI by biplane (BP mode using transesophageal echocardiography (TEE and compare it to two-dimensional (2D transthoracic echocardiography (TTE and 2DTEE using three-dimensional (3D TEE as reference method. Methods The study population consisted of 50 patients retrospectively (24 men and 26 women, mean age 85±8 years of age who all had undergone echocardiography examination prior to TAVI. Results The mean aortic annulus diameter was 20.4±2.2 mm with TTE, 22.3±2.5 mm with 2DTEE, 22.9±1.9 mm with BP-mode and 23.1±1.9 mm with 3DTEE. TTE underestimated the mean aortic annulus diameter in comparison to transesophageal imaging modalities (p Conclusion A multi-dimensional method is preferred to assess aortic annulus diameter in TAVI patients since there is risk of underestimation using single plane. Biplane mode is the method of choice in view of speedy post-processing with no need for expensive dedicated software. Lastly, single plane methods lead to misclassification of patients as unsuitable for TAVI. This may be of major clinical importance.

  15. Penetrating annulus fibrosus injuries affect dynamic compressive behaviors of the intervertebral disc via altered fluid flow: an analytical interpretation.

    Science.gov (United States)

    Michalek, Arthur J; Iatridis, James C

    2011-08-01

    Extensive experimental work on the effects of penetrating annular injuries indicated that large injuries impact axial compressive properties of small animal intervertebral discs, yet there is some disagreement regarding the sensitivity of mechanical tests to small injury sizes. In order to understand the mechanism of injury size sensitivity, this study proposed a simple one dimensional model coupling elastic deformations in the annulus with fluid flow into and out of the nucleus through both porous boundaries and through a penetrating annular injury. The model was evaluated numerically in dynamic compression with parameters obtained by fitting the solution to experimental stress-relaxation data. The model predicted low sensitivity of mechanical changes to injury diameter at both small and large sizes (as measured by low and high ratios of injury diameter to annulus thickness), with a narrow range of high sensitivity in between. The size at which axial mechanics were most sensitive to injury size (i.e., critical injury size) increased with loading frequency. This study provides a quantitative hypothetical model of how penetrating annulus fibrosus injuries in discs with a gelatinous nucleus pulposus may alter disc mechanics by changing nucleus pulposus fluid pressurization through introduction of a new fluid transport pathway though the annulus. This model also explains how puncture-induced biomechanical changes depend on both injury size and test protocol.

  16. Aortic valve replacement for aortic stenosis with a small aortic annulus in a patient having Werner's syndrome and liver cirrhosis.

    Science.gov (United States)

    Sogawa, M; Kasuya, S; Yamamoto, K; Koshika, M; Oguma, F; Hayashi, J

    2001-12-01

    Werner's syndrome is a rare genetic disease characterized by premature aging and scleroderma-like involvement of the skin. We report a case of aortic valve replacement for severely calcified aortic valve stenosis with a small annulus in a patient suffering from Werner's syndrome and liver cirrhosis

  17. Burn-out, Circumferential Film Flow Distribution and Pressure Drop for an Eccentric Annulus with Heated Rod

    DEFF Research Database (Denmark)

    Andersen, P. S.; Jensen, A.; Mannov, G.

    1974-01-01

    Measurements of (1) burn-out, (2) circumferential film flow distribution, and (3) pressure drop in a 17 × 27.2 × 3500 mm concentric and eccentric annulus geometry are presented. The eccentric displacement was varied between 0 and 3 mm. The working fluid was water. Burn-out curves at 70 bar...... flow variation on burn-out is discussed....

  18. Ertapenem Articulating Spacer for the Treatment of Polymicrobial Total Knee Arthroplasty Infection

    Directory of Open Access Journals (Sweden)

    Dragan Radoicic

    2016-01-01

    Full Text Available Introduction. Periprosthetic joint infections (PJIs are the primary cause of early failure of the total knee arthroplasty (TKA. Polymicrobial TKA infections are often associated with a higher risk of treatment failure. The aim of the study was to assess the efficacy of ertapenem loaded spacers in the treatment of polymicrobial PJI. Methods. There were 18 patients enrolled; nine patients with polymicrobial PJI treated with ertapenem loaded articulating spacers were compared to the group of 9 patients treated with vancomycin or ceftazidime loaded spacers. Results. Successful reimplantation with revision implants was possible in 66.67%. Ertapenem spacers were used in 6 cases in primary two-stage procedure and in 3 cases in secondary spacer exchange. Successful infection eradication was achieved in all cases; final reimplantation with revision knee arthroplasty implants was possible in 6 cases. Conclusion. Ertapenem can be successfully used as antimicrobial addition to the cement spacers in two-stage revision treatment of polymicrobial PJIs. However, this type of spacer may also be useful in the treatment of infections caused by monomicrobial extended spectrum beta-lactamases producing gram-negative bacilli. Further clinical studies are required to evaluate the efficacy and safety of ertapenem spacers in the treatment of polymicrobial and monomicrobial PJIs.

  19. Curvature effects on axisymmetric instability of conduction regime in a tall air-filled annulus

    Science.gov (United States)

    Pécheux, J.; Le Quéré, P.; Abcha, F.

    1994-10-01

    This paper numerically studies curvature effects on the instability of the conduction regime of natural convection in a tall air-filled differentially heated annulus of vertical aspect ratio 16 by integrating the two-dimensional axisymmetric Navier-Stokes equations in the Boussinesq approximation. The numerical algorithm combines a pseudospectral Chebyshev space discretization with a second-order time-stepping scheme. It is shown that, in contrast with linear stability analysis of the conduction solution, the time-periodic cross-roll instability does not take place in finite aspect ratio cavities for small values of the radius ratio. For all values of the radius ratio transition to unsteadiness occurs through supercritical Hopf bifurcations. Extensive computations show very complex behaviors of the unsteady solutions depending on the radius ratio. The nature of the reverse transition to steady state that occurs for increasing value of the Rayleigh number is also found to depend strongly on the value of the radius ratio.

  20. Mixed Convection Opposing Flow in a Vertical Porous Annulus-Two Temperature Model

    Science.gov (United States)

    Al-Rashed, Abdullah A. AA; J, Salman Ahmed N.; Khaleed, H. M. T.; Yunus Khan, T. M.; NazimAhamed, K. S.

    2016-09-01

    The opposing flow in a porous medium refers to a condition when the forcing velocity flows in opposite direction to thermal buoyancy obstructing the buoyant force. The present research refers to the effect of opposing flow in a vertical porous annulus embedded with fluid saturated porous medium. The thermal non-equilibrium approach with Darcy modal is considered. The boundary conditions are such that the inner radius is heated with constant temperature Tw the outer radius is maintained at constant temperature Tc. The coupled nonlinear partial differential equations such as momentum equation, energy equation for fluid and energy equation for solid are solved using the finite element method. The opposing flow variation of average Nusselt number with respect to radius ratio Rr, Aspect ratioAr and Radiation parameter Rd for different values of Peclet number Pe are investigated. It is found that the flow behavior is quite different from that of aiding flow.

  1. A linear analysis of the transition curve for the baroclinic annulus

    Science.gov (United States)

    Miller, T. L.; Gall, R. L.

    1983-01-01

    A primitive equation linear model is shown to be capable of quantitatively predicting the neutral curve for a baroclinic annulus. Flows unstable to small nonaxisymmetric perturbations are assumed to lie on the nonaxisymmetric side of a transition curve, while the stable flows are on the axisymmetric side. The stability in the presence of perturbations is tested with linearized hydrostatic primitive equations. Attention is given to the fastest growing eigenmodes, demonstrating that the linear and nonlinear wave have similar structures at a particular point in the nonaxisymmetric regime. All the waves are similar to the Eddy wave except at the extreme to the transition curve, where the waves maintain little structure with height. The eddy kinetic energy is baroclinic with a potential energy suppresed by the large static stability of the basic state. Eddy dissipation is noted to be significant near all boundaries.

  2. Double-diffusive convection in a rotating cylindrical annulus with conical caps

    CERN Document Server

    Simitev, R D

    2011-01-01

    Double-diffusive convection driven by both thermal and compositional buoyancy in a rotating cylindrical annulus with conical caps is considered with the aim to establish whether a small fraction of compositional buoyancy added to the thermal buoyancy (or vice versa) can significantly reduce the critical Rayleigh number and amplify convection in planetary cores. It is shown that the neutral surface describing the onset of convection in the double-buoyancy case is essentially different from that of the well-studied purely thermal case, and does indeed allow the possibility of low-Rayleigh number convection. In particular, isolated islands of instability are formed by an additional "double-diffusive" eigenmode in certain regions of the parameter space. However, the amplitude of such low-Rayleigh number convection is relatively weak. At similar flow amplitudes purely compositional and double-diffusive cases are characterized by a stronger time dependence compared to purely thermal cases, and by a prograde mean zo...

  3. Numerical simulation of solidification in a horizontal cylindrical annulus charged with an aqueous salt solution

    Science.gov (United States)

    Neilson, D. G.; Incropera, F. D.; Bennon, W. D.

    1990-01-01

    A computational study of solidification of a binary Na2CO3 solution in a horizontal cylindrical annulus is performed using a continuum formulation with a control-volume based, finite-difference scheme. The initial conditions were selected to facilitate the study of counter thermal and solutal convection, accompanied by extensive mushy region growth. Numerical results are compared with experimental data with mixed success. Qualitative agreement is obtained for the overall solidification process and associated physical phenomena. However, the plume thickness calculated for the solutally-driven convective upflow is substantially smaller than the observed value. Evolution of double-diffusive layers is predicted, but over a time scale much smaller than that observed experimentally. Good agreement is obtained between predicted and measured results for solid growth, but the mushy region thickness is significantly overpredicted.

  4. Hydromagnetic convection in a rotating annulus with an azimuthal magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kurt, E.; Busse, F.H.; Pesch, W. [University of Bayreuth, Institute of Physics, Bayreuth (Germany)

    2004-11-01

    The problem of convection induced by radial buoyancy in an electrically conducting fluid contained by a rotating cylindrical annulus (angular frequency, {omega}) in the presence of a homogeneous magnetic field (B) in the azimuthal direction is considered. The small gap approximation is used together with rigid cylindrical boundaries. The onset of convection occurs in the form of axial, axisymmetric or oblique rolls. The angle {psi} between the roll axis and the axis of rotation depends of the ratio between the Chandrasekhar number, Q{proportional_to}B{sup 2}, and the Coriolis number, {tau}{proportional_to}{omega}. Fully three-dimensional numerical simulations as well as Galerkin representations for roll patterns including the subsequent stability analysis are used in the theoretical investigation. At finite amplitudes, secondary transitions to 3D-hexarolls and to spatio-temporal chaos are found. Overlapping regions of pattern stability exist such that the asymptotically realized state may depend on the initial conditions. (orig.)

  5. Experimental study on convective boiling heat transfer in narrow-gap annulus tubes

    Institute of Scientific and Technical Information of China (English)

    LI Bin; ZHAO Jian-Fu; ZHOU Fang-De; TANG Ze-Mei; HU Wen-Rui

    2004-01-01

    Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are required to explain and verify the forced convection heat transfer phenomenon in narrow channels. In this experimental study, we model the convective boiling behavior of water with low latent heat substance Freon 113 (R-113), with the purpose of saving power consumption and visualizing experiments. Both heat transfer and pressure drop characteristics were measured in subcooled and saturated concentric narrow gap forced convection boiling. Data were obtained to qualitatively identify the effects of gap size, pressure, flow rate and wall superheat on boiling regimes and the transition between various regimes. Some significant differences from unconfined forced convection boiling were found,and also, the flow patterns in narrow vertical annulus tubes have been studied quantitatively.

  6. Effects of nanoparticles on the peristaltic motion of tangent hyperbolic fluid model in an annulus

    Directory of Open Access Journals (Sweden)

    S. Nadeem

    2015-12-01

    Full Text Available In the present article, effects of nanoparticles on the peristaltic flow of tangent hyperbolic fluid in an annulus are described. The two-dimensional equations of tangent hyperbolic fluid are solved by using the assumptions of low Reynolds number and long wavelength. Analytical solution is obtained with the help of homotopy perturbation and Adomian decomposition method for velocity, temperature and nanoparticles concentration. Solutions are discussed through graphs. Solutions for pressure rise, temperature, nanoparticles concentration, pressure gradient and streamlines are plotted for various emerging parameters. It is found that the temperature profile increases with increase in Brownian motion and thermophoresis parameter. It is also found that the size of the trapped bolus in triangular wave is smaller as compared to other waves. Further, the comparison of both analytical solutions is presented.

  7. A numerical study of entrance region in a curved annulus with an inward and outward eccentricity

    Directory of Open Access Journals (Sweden)

    M.R.H. Nobari

    2016-09-01

    Full Text Available In this article, developing incompressible fluid flow in a curved annulus with inward and outward eccentricities is studied numerically. To do so, a second order finite difference method based on the projection algorithm is employed to solve the governing equations written in a general bipolar–toroidal coordinate system using a three-dimensional staggered uniform grid. The effects of the governing dimensionless parameters such as the Dean number, Reynolds number, curvature ratio, aspect ratio, and eccentricity on the flow field pattern and friction factor are studied in the entrance region. The numerical results obtained indicate that the outward eccentricity significantly deforms the secondary flows and axial velocity profiles. Furthermore, as the eccentricity increases, the friction factor decreases due to the reduction of secondary flow intensity.

  8. Outcome of total knee replacement following explantation and cemented spacer therapy

    Directory of Open Access Journals (Sweden)

    Ghanem, Mohamed

    2016-03-01

    Full Text Available Background: Infection after total knee replacement (TKR is one of the serious complications which must be pursued with a very effective therapeutic concept. In most cases this means revision arthroplasty, in which one-setting and two-setting procedures are distinguished. Healing of infection is the conditio sine qua non for re-implantation. This retrospective work presents an assessment of the success rate after a two-setting revision arthroplasty of the knee following periprosthetic infection. It further considers drawing conclusions concerning the optimal timing of re-implantation.Patients and methods: A total of 34 patients have been enclosed in this study from September 2005 to December 2013. 35 re-implantations were carried out following explantation of total knee and implantation of cemented spacer. The patient’s group comprised of 53% (18 males and 47% (16 females. The average age at re-implantation time was 72.2 years (ranging from 54 to 85 years. We particularly evaluated the microbial spectrum, the interval between explantation and re-implantation, the number of surgeries that were necessary prior to re-implantation as well as the postoperative course. Results: We reported 31.4% (11 reinfections following re-implantation surgeries. The number of the reinfections declined with increasing time interval between explantation and re-implantation. Patients who developed reinfections were operated on (re-implantation after an average of 4.47 months. Those patients with uncomplicated course were operated on (re-implantation after an average of 6.79 months. Nevertheless, we noticed no essential differences in outcome with regard to the number of surgeries carried out prior to re-implantation. Mobile spacers proved better outcome than temporary arthrodesis with intramedullary fixation.Conclusion: No uniform strategy of treatment exists after peri-prosthetic infections. In particular, no optimal timing can be stated concerning re

  9. Pulmonary annulus preservation lowers the risk of late postoperative pulmonary valve implantation after the repair of tetralogy of Fallot.

    Science.gov (United States)

    Kim, Gwan Sic; Han, Seungbong; Yun, Tae-Jin

    2015-02-01

    The long-term benefits of pulmonary annulus preservation in tetralogy of Fallot (ToF) repair in patients with a marginally small pulmonary annulus are controversial. We sought to determine whether pulmonary annulus preservation (AP) is superior to transannular patching (TAP) in lowering the risk of pulmonary valve implantation (PVI) long after the repair of ToF. Of the 255 patients who underwent total correction of ToF during infancy between January 1989 and December 2005, 114 patients (AP group = 57, TAP group = 57) were selected by propensity score matching for various preoperative variables, such as age and body weight at operation, sex, pulmonary artery size, pre-repair palliation, anatomical types of ventricular septal defect, and Z-score of pulmonary valve annulus diameter (PVA-Z). The PVA-Z of the AP and TAP groups were -2.3 ± 1.3 and -2.1 ± 1.3, respectively (p = 0.547). The time to PVI was compared between the two groups. The median follow-up duration was 146 months (AP group: 141 months, TAP group: 147 months; p = 0.191). During the follow-up periods, there were 12 reoperations for the relief of right ventricular outflow tract obstruction (RVOTO), eight PVIs, and three late deaths. While freedom from reoperation for RVOTO was comparable between the two groups (p = 0.182), freedom from PVI at postoperative 15 years was significantly lower in the TAP group than in the AP group (74 and 100 %, p = 0.015). In repairing ToF with marginally small pulmonary valve annulus, AP is associated with a lower risk of late postoperative PVI.

  10. A Study of Neutronics Effects of the Spacer Grids in a Typical PWR via Monte Carlo Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Tran Xuan; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    Neutronics analysis, the spacer grids which support fuel rods are not explicitly described, but they are homogenized with coolant. However, the effects of neglecting or simplifying the spacer grids are not reported in the literature to the best of our knowledge. In this paper, to investigate the effects of spacer grids in neutronics analysis, a detailed description of spacer grids is added to the KAIST benchmark problem 1B. Then, the effective multiplication factor, spatial distributions of neutron flux, and its energy spectrum are obtained for the two cases (with and without spacer grids). Numerical results show that the effects of spacer grids are not negligible. In this paper, to investigate the effect of spacer grids, the spacer grid geometry is described in detail in the Monte Carlo calculation. In the numerical test, the two cases are compared in the context of a modified KAIST benchmark problem 1B. Case 1 does not have spacer grids, while the space is filled by coolant instead. Case 2 includes the spacer grids. The difference in neutron flux spectra is also observed. Thus, the effect of the spacer grids should be considered in the whole-core reactor analysis. In practice, the spacer grids are homogenized into coolant to consider its effect. As a further study, therefore, it would be worthwhile to investigate the differences between the homogenization and the explicit description of the spacer grids.

  11. Association of mitral annulus calcification, aortic valve calcification with carotid intima media thickness

    Directory of Open Access Journals (Sweden)

    Scuteri Angelo

    2004-10-01

    Full Text Available Abstract Background Mitral annular calcification (MAC and aortic annular calcification (AVC may represent a manifestation of generalized atherosclerosis in the elederly. Alterations in vascular structure, as indexed by the intima media thickness (IMT, are also recognized as independent predictors of adverse cardiovascular outcomes. Aim To examine the relationship between the degree of calcification at mitral and/or aortic valve annulus and large artery structure (thickness. Methods We evaluated 102 consecutive patients who underwent transthoracic echocardiography and carotid artery echoDoppler for various indications; variables measured were: systemic blood pressure (BP, pulse pressure (PP=SBP-DBP, body mass index (BMI, fasting glucose, total, HDL, LDL chlolesterol, triglycerides, cIMT. The patients were divided according to a grading of valvular/annular lesions independent scores based on acoustic densitometry: 1 = annular/valvular sclerosis/calcification absence; 2 = annular/valvular sclerosis; 3 = annular calcification; 4 = annular-valvular calcification; 5 = valvular calcification with no recognition of the leaflets. Results Patient score was the highest observed for either valvular/annulus. Mean cIMT increased linearly with increasing valvular calcification score, ranging from 3.9 ± 0.48 mm in controls to 12.9 ± 1.8 mm in those subjects scored 5 (p 0.0001. Conclusion MAC and AVC score can identify subgroups of patients with different cIMT values which indicate different incidence and prevalence of systemic artery diseases. This data may confirm MAC-AVC as a useful important diagnostic parameter of systemic atherosclerotic disease.

  12. Risk of Cerebral Embolization with Caseous Calcification of the Mitral Annulus: Review Article

    Science.gov (United States)

    Dietl, Charles A.; Hawthorn, Christopher M.; Raizada, Veena

    2016-01-01

    Background: Caseous calcification of the mitral annulus (CCMA) is believed to have a benign prognosis. Several authors have recommended conservative management in asymptomatic patients. However, the prevalence of cerebrovascular events (CVE) in patients with CCMA has never been evaluated before. The aims of this study are to investigate whether patients with CCMA are at increased risk of cerebral embolization, and to determine whether elective surgical resection of CCMA should be considered to prevent a cardioembolic stroke. Methods: A comprehensive literature search was obtained from MEDLINE via PubMed.gov, ScienceDirect.com, and Google Scholar using the following search queries: caseous calcification of the mitral annulus, intracardiac pseudotumor, mitral annular calcification, and cardioembolic stroke. Results: From our initial search that yielded 1,502 articles, we identified a total of 130 patients with CCMA reported in 86 publications. Literature review revealed that the prevalence of CVE associated with CCMA is 19.2% (25 of 130) which is significantly higher than the prevalence of CVE reported with mitral annular calcification (MAC), 11.8% (214 of 1818) (range 4.8% to 24.1%) (P = 0.01796) (odds ratio = 1.78; 0.95 confidence interval = 1.1278 – 2.8239). Only four of 25 (16.0%) patients with CCMA who suffered a CVE had history of atrial fibrillation (AF). Conclusion: Based on our review, it would be reasonable to consider elective surgical resection of CCMA in asymptomatic patients who are good surgical candidates, because patients with CCMA may be at increased risk of embolic strokes, which are unrelated to AF. PMID:27990181

  13. The effect of inertia and angular momentum of a fluid annulus on lateral transversal rotor vibrations

    Science.gov (United States)

    Jansson, Ida; Åkerstedt, Hans O.; Aidanpää, Jan-Olov; Lundström, T. Staffan

    2012-01-01

    An extensive amount of work exists on experimental and theoretical analysis of unsteady flow phenomena in hydraulic turbines. Still, resonance phenomena and self-excited vibrations of the rotor of hydropower machines are not considered as a major problem during normal operation conditions. Nevertheless, in development and research it is not sufficient to rely on earlier experience. An accurate predictive rotor model is crucial in risk assessment of rotor vibrations of hydraulic generator units. This paper discusses the effects of inertia and the rotational energy of the fluid in the turbine on lateral transversal shaft vibrations of hydraulic generator units. There is a lack of agreement among engineers upon how fluid inertia of the turbine should be included in rotor models. The rotational energy of the fluid has a potential risk of feeding self-excited vibrations. A fluid-rotor model is presented that captures the effect of inertia and angular momentum of a fluid annulus on vibrations of an inner rigid cylinder. The purpose of the model is to gain physical understanding of the phenomena at work and it is not applicable to specific turbines. The linearized equation of motion of the cylinder surrounded by a fluid annulus is solved for by one single complex equation. The constrained cylinder has two degrees of freedom in the plane perpendicular to its axis. By the assumption of irrotational cyclic flow, the fluid motion is described by a complex potential function. The motion of the cylinder is described by three parameters. Two surfaces are defined that splits the parameter space into regions with different qualitative behaviour. One surface defines the limit of stability whereas the other defines a limit when the eigenvalues have opposite signs or are both positive. The response to an external periodic rotating force is visualized by the magnitude of the inverse of the complex dynamic stiffness.

  14. Targeting the annulus fibrosus of the intervertebral disc: Col1a2-Cre(ER)T mice show specific activity of Cre recombinase in the outer annulus fibrosus.

    Science.gov (United States)

    Bedore, Jake; Quesnel, Katherine; Quinonez, Diana; Séguin, Cheryle A; Leask, Andrew

    2016-06-01

    Degeneration of the intervertebral disc (IVD) is a major underlying contributor to back pain-the single leading cause of disability worldwide. However, we possess a limited understanding of the etiology underlying IVD degeneration. To date, there are a limited number of mouse models that have been used to target proteins in specific compartments of the IVD to explore their functions in disc development, homeostasis and disease. Furthermore, the majority of reports exploring the composition and function of the outer encapsulating annulus fibrosus (AF) of the IVD have considered it as one tissue, without considering the numerous structural and functional differences existing between the inner and outer AF. In addition, no mouse models have yet been reported that enable specific targeting of genes within the outer AF. In the current report, we discuss these issues and demonstrate the localized activity of Cre recombinase in the IVD of Col1a2-Cre(ER)T;ROSA26mTmG mice possessing a tamoxifen-dependent Cre recombinase driven by a Cola2 promoter and distal enhancer and the mTmG fluorescent reporter. Following tamoxifen injection of 3-week-old Col1a2-Cre(ER)T;ROSA26mTmG mice, we show Cre activity specifically in the outer AF of the IVD, as indicated by expression of the GFP reporter. Thus, Col1a2-Cre(ER)T;ROSA26mTmG mice may prove to be a valuable tool in delineating the function of proteins in this unique compartment of the IVD, and in further exploring the compositional differences between the inner and outer AF in disc homeostasis, aging and disease.

  15. Modeling of sheet carrier density and microwave frequency characteristics in Spacer based AlGaN/AlN/GaN HEMT devices

    Science.gov (United States)

    Mohanbabu, A.; Anbuselvan, N.; Mohankumar, N.; Godwinraj, D.; Sarkar, C. K.

    2014-01-01

    In this paper, we present a physics-based model for two-dimensional electron gas (2DEG) sheet carrier density ns and various microwave characteristics such as transconductance, cut-off frequency (ft) of the proposed Spacer layer based AlxGa1-xN/AlN/GaN High Electron Mobility Transistors (HEMTs) is modeled by considering the quasi-triangular quantum well. To obtain charge density ns, the variation of Fermi level with supply voltage and the formation of various energy sub-bands E0, E1 are considered. The obtained results are simple and easy to analyze the sheet carrier density, DC model and microwave frequency performance analysis for nanoscale Spacer layer based AlxGa1-xN/AlN/GaN HEMT power devices. The Spacer layer based AlGaN/AlN/GaN heterostructure HEMTs shows excellent promise as one of the candidates to substitute present AlGaN/GaN HEMTs for future high speed and high power applications. Derived model results for drain current, transconductance, current-gain cutoff frequency for different short and long gate length device are calibrated and verified with experimental data over a full range for gate and drain applied voltages and is useful for nanoscale and microwave analysis for circuit design.

  16. Mobile Learning Using Mobile Phones

    Science.gov (United States)

    Vicente, Paula

    2013-01-01

    The participation in mobile learning programs is conditioned by having/using mobile communication technology. Those who do not have or use such technology cannot participate in mobile learning programs. This study evaluates who are the most likely participants of mobile learning programs by examining the demographic profile and mobile phone usage…

  17. In vitro performance of three combinations of spacers and pressurized metered dose inhalers for treatment in children

    DEFF Research Database (Denmark)

    Berg, E; Madsen, J; Bisgaard, H

    1998-01-01

    The performance of pressurized metered dose inhalers (pMDIs) and spacers in correct dose recommendations is important, but limited information on dose delivery and fine-particle dose from different combinations of spacers and pMDIs is available. In this study, three combinations of spacers and pM...

  18. Characterization of feed channel spacer performance using geometries obtained by X-ray computed tomography

    KAUST Repository

    Haaksman, Viktor A.

    2016-09-09

    Spiral-wound membrane modules used in water treatment for water reuse and desalination make use of spacer meshes for keeping the membrane leaves apart and for enhancing the mass transfer. Computational fluid dynamics (CFD) has gained importance in the design of new spacers with optimized hydrodynamic characteristics, but this requires a precise description of the spacer geometry. This study developed a method to obtain accurate three-dimensional (3-D) geometry representations for any given spacer design from X-ray computed tomography (CT) scans. The method revealed that the filaments of industrial spacers have a highly variable cross-section size and shape, which impact the flow characteristics in the feed channel. The pressure drop and friction factors were calculated from numerical simulations on five commercially available feed spacers used in practice. Model solutions compared well to experimental data measured using a flow cell for average velocities up to 0.2 m/s, as used in industrial reverse osmosis and nanofiltration membrane operations. A newly-proposed spacer geometry with alternating strand thickness was tested, which was found to yield a lower pressure drop while being highly efficient in converting the pumping power into membrane shear. Numerical model solutions using CFD with geometries from CT scans were closer to measurements than those obtained using the traditional circular cross-section strand simplification, indicating that CT scans are very well suitable to approximate real feed spacer geometries. By providing detailed insight on the spacer filament shape, CT scans allow better quantification of local distribution of velocity and shear, possibly leading to more accurate estimations of fouling and concentration polarization. © 2016 Elsevier B.V.

  19. Modulation of porphyrin photoluminescence by nanoscale spacers on silicon substrates

    Science.gov (United States)

    Fang, Y. C.; Zhang, Y.; Gao, H. Y.; Chen, L. G.; Gao, B.; He, W. Z.; Meng, Q. S.; Zhang, C.; Dong, Z. C.

    2013-11-01

    We investigate photoluminescence (PL) properties of quasi-monolayered tetraphenyl porphyrin (TPP) molecules on silicon substrates modulated by three different nanoscale spacers: native oxide layer (NOL), hydrogen (H)-passivated layer, and Ag nanoparticle (AgNP) thin film, respectively. In comparison with the PL intensity from the TPP molecules on the NOL-covered silicon, the fluorescence intensity from the molecules on the AgNP-covered surface was greatly enhanced while that for the H-passivated surface was found dramatically suppressed. Time-resolved fluorescence spectra indicated shortened lifetimes for TPP molecules in both cases, but the decay kinetics is believed to be different. The suppressed emission for the H-passivated sample was attributed to the weaker decoupling effect of the monolayer of hydrogen atoms as compared to the NOL, leading to increased nonradiative decay rate; whereas the enhanced fluorescence with shortened lifetime for the AgNP-covered sample is attributed not only to the resonant excitation by local surface plasmons, but also to the increased radiative decay rate originating from the emission enhancement in plasmonic "hot-spots".

  20. Optimization of Radiation Therapy Techniques for Prostate Cancer With Prostate-Rectum Spacers: A Systematic Review

    Energy Technology Data Exchange (ETDEWEB)

    Mok, Gary [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Department of Radiation Oncology, Centre Intégré de Cancérologie de Laval, Centre de Santé et de Services Sociaux de Laval, Laval, Québec (Canada); Department of Radiology, Radiation Oncology, and Nuclear Medicine, Centre Hospitalier Universitaire de Montréal, Montréal, Québec (Canada); Benz, Eileen [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Vallee, Jean-Paul [Department of Radiology, Geneva University Hospital, Geneva (Switzerland); Miralbell, Raymond [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Zilli, Thomas, E-mail: Thomas.Zilli@hcuge.ch [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland)

    2014-10-01

    Dose-escalated radiation therapy for localized prostate cancer improves disease control but is also associated with worse rectal toxicity. A spacer placed between the prostate and rectum can be used to displace the anterior rectal wall outside of the high-dose radiation regions and potentially minimize radiation-induced rectal toxicity. This systematic review focuses on the published data regarding the different types of commercially available prostate-rectum spacers. Dosimetric results and preliminary clinical data using prostate-rectum spacers in patients with localized prostate cancer treated by curative radiation therapy are compared and discussed.

  1. Mobility management in mobile IP

    Science.gov (United States)

    Medidi, Sirisha; Golshani, Forouzan

    2002-07-01

    There is an emerging interest in integrating mobile wireless communication with the Internet based on the Ipv6 technology. Many issues introduced by the mobility of users arise when such an integration is attempted. This paper addresses the problem of mobility management, i.e., that of tracking the current IP addresses of mobile terminals and sustaining active IP connections as mobiles move. The paper presents some architectural and mobility management options for integrating wireless access to the Internet. We then present performance results for Mobile IPv4, route optimization and Mobile IPv6.

  2. Biaxial testing of canine annulus fibrosus tissue under changing salt concentrations

    Directory of Open Access Journals (Sweden)

    Jacques M. Huyghe

    2010-03-01

    Full Text Available The in vivo mechanics of the annulus fibrosus of the intervertebral disc is one of biaxial rather than uniaxial loading. The material properties of the annulus are intimately linked to the osmolarity in the tissue. This paper presents biaxial relaxation experiments of canine annulus fibrosus tissue under stepwise changes of external salt concentration. The force tracings show that stresses are strongly dependent on time, salt concentration and orientation. The force tracing signature of are sponse to a change instrain, is one of a jumpin stress that relaxes partly as the new strain is maintained. The force tracing signature of a stepwise change in salt concentration is a progressive monotonous change in stress towards a new equilibrium value. Although the number of samples does not allow any definitive quantitative conclusions, the trends may shed light on the complex interaction among the directionality of forces, strains and fiber orientation on one hand, and on the other hand, the osmolarity of the tissue. The dual response to a change in strain is understood as an immediate response before fluid flows in or out of the tissue, followed by a progressive readjustment of the fluid content in time because of the gradient in fluid chemical potential between the tissue and the surrounding solution.A mecânica in vivo do anel fibroso do disco intervertebral é baseada em carregamento biaxial ao invés de uniaxial. As propriedades materiais do anel estão intimamente ligadas à osmolaridade no tecido. O artigo apresenta experimentos de relaxação biaxiais do anel fibroso de um tecido canino sob mudanças abruptas na concentração externa de sal. A assinatura da força devido à mudança brusca de salinidade resulta em uma progressiva e monótona mudança na tensão em direção a um novo valor de equilíbrio. Embora o número de amostras não permita nenhuma conclusão quantitativa, as tendências podem abrir uma luz no entendimento das intera

  3. Flow regime development analysis in adiabatic upward two-phase flow in a vertical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Julia, J. Enrique [Departamento de Ingenieria Mecanica y Construccion, Universitat Jaume I, Campus de Riu Sec, Castellon 12071 (Spain); Ozar, Basar [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States); Jeong, Jae-Jun [Korea Atomic Energy Research Institute, 150 Dukjin, Yuseong, Daejeon 305-353 (Korea, Republic of); Hibiki, Takashi [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States); Ishii, Mamoru, E-mail: ishii@purdue.ed [School of Nuclear Engineering, Purdue University, 400 Central Dr., West Lafayette, IN 47907-2017 (United States)

    2011-02-15

    In this work radial and axial flow regime development in adiabatic upward air-water two-phase flow in a vertical annulus has been investigated. Local flow regimes have been identified using conductivity probes and neural networks techniques. The inner and outer diameters of the annulus are 19.1 mm and 38.1 mm, respectively. The equivalent hydraulic diameter of the flow channel, D{sub H}, is 19.0 mm and the total length is 4.37 m. The flow regime map includes 1080 local flow regimes identifications in 72 flow conditions within a range of 0.01 m/s < < 30 m/s and 0.2 m/s < < 3.5 m/s where and are, respectively, superficial gas and liquid velocities. The local flow regime has been classified into four categories: bubbly, cap-slug, churn-turbulent and annular flows. In order to study the radial and axial development of flow regime the measurements have been performed at five radial locations. The three axial positions correspond to z/D{sub H} = 52, 149 and 230, where z represents the axial position. The flow regime indicator has been chosen as some statistical parameters of local bubble chord length distributions and self-organized neural networks have been used as mapping system. This information has been also used to compare the results given by the existing flow regime transition models. The local flow regime is characterized basically by the void fraction and bubble chord length. The radial development of flow regime shows partial and complete local flow regime combinations. The radial development is controlled by axial location and superficial liquid velocity. The radial flow regime transition is always initiated in the center of the flow channel and it is propagated towards the channel boundaries. The axial development of flow regime is observed in all the flow maps and it is governed by superficial liquid velocity and radial location. The prediction results of the models are compared for each flow regime transition.

  4. Multivariate statistical data analysis methods for detecting baroclinic wave interactions in the thermally driven rotating annulus

    Science.gov (United States)

    von Larcher, Thomas; Harlander, Uwe; Alexandrov, Kiril; Wang, Yongtai

    2010-05-01

    Experiments on baroclinic wave instabilities in a rotating cylindrical gap have been long performed, e.g., to unhide regular waves of different zonal wave number, to better understand the transition to the quasi-chaotic regime, and to reveal the underlying dynamical processes of complex wave flows. We present the application of appropriate multivariate data analysis methods on time series data sets acquired by the use of non-intrusive measurement techniques of a quite different nature. While the high accurate Laser-Doppler-Velocimetry (LDV ) is used for measurements of the radial velocity component at equidistant azimuthal positions, a high sensitive thermographic camera measures the surface temperature field. The measurements are performed at particular parameter points, where our former studies show that kinds of complex wave patterns occur [1, 2]. Obviously, the temperature data set has much more information content as the velocity data set due to the particular measurement techniques. Both sets of time series data are analyzed by using multivariate statistical techniques. While the LDV data sets are studied by applying the Multi-Channel Singular Spectrum Analysis (M - SSA), the temperature data sets are analyzed by applying the Empirical Orthogonal Functions (EOF ). Our goal is (a) to verify the results yielded with the analysis of the velocity data and (b) to compare the data analysis methods. Therefor, the temperature data are processed in a way to become comparable to the LDV data, i.e. reducing the size of the data set in such a manner that the temperature measurements would imaginary be performed at equidistant azimuthal positions only. This approach initially results in a great loss of information. But applying the M - SSA to the reduced temperature data sets enable us to compare the methods. [1] Th. von Larcher and C. Egbers, Experiments on transitions of baroclinic waves in a differentially heated rotating annulus, Nonlinear Processes in Geophysics

  5. Characteristics of turbulent heat transfer in an annulus at supercritical pressure

    Science.gov (United States)

    Peeters, J. W. R.; Pecnik, R.; Rohde, M.; van der Hagen, T. H. J. J.; Boersma, B. J.

    2017-02-01

    Heat transfer to fluids at supercritical pressure is different from heat transfer at lower pressures due to strong variations of the thermophysical properties with the temperature. We present and analyze results of direct numerical simulations of heat transfer to turbulent CO2 at 8 MPa in an annulus. Periodic streamwise conditions are imposed so that mean streamwise acceleration due to variations in the density does not occur. The inner wall of the annulus is kept at a temperature of 323 K, while the outer wall is kept at a temperature of 303 K. The pseudocritical temperature Tp c=307.7 K, which is the temperature where the thermophysical properties vary the most, can be found close to the inner wall. This work is a continuation of an earlier study, in which turbulence attenuation due to the variable thermophysical properties of a fluid at supercritical pressure was studied. In the current work, the direct effects of variations in the specific heat capacity, thermal diffusivity, density, and the molecular Prandtl number on heat transfer are investigated using different techniques. Variations in the specific heat capacity cause significant differences between the mean nondimensionalized temperature and enthalpy profiles. Compared to the enthalpy fluctuations, temperature fluctuations are enhanced in regions with low specific heat capacity and diminished in regions with a large specific heat capacity. The thermal diffusivity causes local changes to the mean enthalpy gradient, which in turn affects molecular conduction of thermal energy. The turbulent heat flux is directly affected by the density, but it is also affected by the mean molecular Prandtl number and attenuated or enhanced turbulent motions. In general, enthalpy fluctuations are enhanced in regions with a large mean molecular Prandtl number, which enhances the turbulent heat flux. While analyzing the Nusselt numbers under different conditions it is found that heat transfer deterioration or enhancement can

  6. INVESTIGATION ON THE FLOW STABILITY OF NEWTONIAN FLUID IN ECCENTRIC ANNULUS VIA THE AXIAL RECIPROCATION OF THE INNER TUBE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The governing equation, together with the formulas of the averaged flux and the stability parameter for Newtonian fluid flowing in eccentric annulus via the axial reciprocation of the inner tube was established in the bipolar coordinate system. Numerical calculation was conducted for the measurement of water flow using the formulas above, of which the results agree well with the experimental data. It is shown that the flow instability can be induced by the increase of the stroke, the frequency, and the eccentricity of annulus, making the sucker rod more susceptible to partial abrasion. Some protecting methods, including adding centralizers, adjusting the stroke and frequency, are proposed to protect the sucker rod from the partial abrasion, and satisfactory results have been achieved in the oilfields.

  7. Recurrent discrete subaortic stenosis and small aortic annulus successfully repaired by the Konno procedure in a young woman.

    Science.gov (United States)

    Kashima, Ichiro; Ueda, Toshihiko; Katogi, Toshiyuki; Taguchi, Shinichi; Inoue, Yoshito; Koizumi, Kiyoshi

    2006-10-01

    A 24-year-old woman who had undergone excision of the membrane for discrete subaortic stenosis when 6 years old displayed recurrent subaortic stenosis and had a small aortic annulus, with a peak pressure gradient of 60mmHg. We chose to perform the Konno operation with a mechanical valve. This released the left ventricular outflow tract obstruction adequately, and she recovered uneventfully with New York Heart Association functional class I. In our experience, an aggressive strategy such as myectomy is an appropriate initial procedure for preventing recurrence when the geometry of the problem may lead to recurrence in the left ventricular outflow tract. The Konno operation is a good option for recurrent subaortic stenosis with small aortic annulus.

  8. Experimental research on heat transfer to liquid sodium and its incipient boiling wall superheat in an annulus

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Liquid sodium is mainly used as a cooling fluid in the liquid metal fast breeder reactor (LMFBR), whose heat transfer, whether convective heat transfer or boiling heat transfer, is different from that of water. So it is important for both normal and accidental operations of LMFBR to perform experimental research on heat transfer to liquid sodium and its boiling heat transfer. This study deals with heat transfer with high temperature (300-700℃) and low Pe number (20~70) and heat transfer with low temperature (250~270℃) and high Pe number (125~860), and its incipient boiling wall superheat in an annulus. Research on heat transfer involves theoretical research and experiments on heat transfer to liquid sodium. It also focuses on the theoretical analysis and experimental research on its incipient boiling wall superheat at positive pressure in an annulus. Semiempirical correlations were obtained and they were well coincident with the experimental data.

  9. Penetrating Annulus Fibrosus Injuries Affect Dynamic Compressive Behaviors of the Intervertebral Disc Via Altered Fluid Flow: An Analytical Interpretation

    OpenAIRE

    Michalek, Arthur J.; Iatridis, James C.

    2011-01-01

    Extensive experimental work on the effects of penetrating annular injuries indicated that large injuries impact axial compressive properties of small animal intervertebral discs, yet there is some disagreement regarding the sensitivity of mechanical tests to small injury sizes. In order to understand the mechanism of injury size sensitivity, this study proposed a simple one dimensional model coupling elastic deformations in the annulus with fluid flow into and out of the nucleus through both ...

  10. Effects of grid spacer with mixing vane on entrainments and depositions in two-phase annular flows

    Directory of Open Access Journals (Sweden)

    Akimaro Kawahara

    2015-06-01

    Full Text Available The effects of mixing vanes (MVs attached to a grid spacer on the characteristics of air–water annular flows were experimentally investigated. To know the effects, a grid spacer with or without MV was inserted in a vertical circular pipe of 16-mm internal diameter. For three cases (i.e., no spacer, spacer without MV, and spacer with MV, the liquid film thickness, liquid entrainment fraction, and deposition rate were measured by the constant current method, single liquid film extraction method, and double liquid film extraction method, respectively. The MVs significantly promote the re-deposition of liquid droplets in the gas core flow into the liquid film on the channel walls. The deposition mass transfer coefficient is three times higher for the spacer with MV than for the spacer without MV, even for cases 0.3-m downstream from the spacer. The liquid film thickness becomes thicker upstream and downstream for the spacer with MV, compared with the thickness for the spacer without MV and for the case with no spacer.

  11. CRISPR Spacer Arrays for Detection of Viral Signatures from Acidic Hot Springs

    Science.gov (United States)

    Snyder, J. C.; Bateson, M. M.; Suciu, D.; Young, M. J.

    2010-04-01

    Viruses are the most abundant life-like entities on the planet Earth. Using CRISPR spacer sequences, we have developed a microarray-based approach to detecting viral signatures in the acidic hot springs of Yellowstone.

  12. Cholesterol-containing liquid crystal dimmers with ether linkages between the spacer and mesogenic units

    NARCIS (Netherlands)

    Marcelis, A.T.M.; Koudijs, A.; Karczmarzyk, Z.; Sudhölter, E.J.R.

    2003-01-01

    Three series of chiral liquid crystalline dimers were investigated, having a cholesteryl and a cyanobiphenylyl, butoxybiphenylyl or hexyloxybiphenylyl group connected to a variable alkyl spacer through ether linkages. Their properties were compared with those of the corresponding ester derivatives.

  13. Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Li Xinxin

    2016-06-01

    Full Text Available Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.

  14. Spacer geometry and particle deposition in spiral wound membrane feed channels

    KAUST Repository

    Radu, A.I.

    2014-11-01

    Deposition of microspheres mimicking bacterial cells was studied experimentally and with a numerical model in feed spacer membrane channels, as used in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane systems. In-situ microscopic observations in membrane fouling simulators revealed formation of specific particle deposition patterns for different diamond and ladder feed spacer orientations. A three-dimensional numerical model combining fluid flow with a Lagrangian approach for particle trajectory calculations could describe very well the in-situ observations on particle deposition in flow cells. Feed spacer geometry, positioning and cross-flow velocity sensitively influenced the particle transport and deposition patterns. The deposition patterns were not influenced by permeate production. This combined experimental-modeling approach could be used for feed spacer geometry optimization studies for reduced (bio)fouling. © 2014 Elsevier Ltd.

  15. Enhanced charge trapping in bipolar spacer oxides during low-dose-rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fleetwood, D.M.; Reber, R.A. Jr.; Winokur, P.S. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L.; Schrimpf, R.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Nowlin, R.N. [Air Force Phillips Laboratory, Albuquerque, NM (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); DeLaus, M. [Analog Devices, Wilmington, MA (United States)

    1994-03-01

    Thermally-stimulated-current and capacitance-voltage measurements reveal enhanced hole trapping in bipolar spacer-oxide capacitors irradiated at 0 V at low dose rates. Possible mechanisms and implications for bipolar low-rate response are discussed.

  16. Structure of recombinant capsids formed by the beta-annulus deletion mutant -- rCP (Delta48-59) of Sesbania mosaic virus.

    Science.gov (United States)

    Pappachan, Anju; Subashchandrabose, Chinnathambi; Satheshkumar, P S; Savithri, H S; Murthy, M R N

    2008-05-25

    A unique feature of several T=3 icosahedral viruses is the presence of a structure called the beta-annulus formed by extensive hydrogen bonding between protein subunits related by icosahedral three-fold axis of symmetry. This unique structure has been suggested as a molecular switch that determines the T=3 capsid assembly. In order to examine the importance of the beta-annulus, a deletion mutant of Sesbania mosaic virus coat protein in which residues 48-59 involved in the formation of the beta-annulus were deleted retaining the rest of the residues in the amino terminal segment (rCP (Delta48-59)) was constructed. When expressed in Escherichia coli, the mutant protein assembled into virus like particles of sizes close to that of the wild type virus particles. The purified capsids were crystallized and their three dimensional structure was determined at 3.6 A resolution by X-ray crystallography. The mutant capsid structure closely resembled that of the native virus particles. However, surprisingly, the structure revealed that the assembly of the particles has proceeded without the formation of the beta-annulus. Therefore, the beta-annulus is not essential for T=3 capsid assembly as speculated earlier and may be formed as a consequence of the particle assembly. This is the first structural demonstration that the virus particle morphology with and without the beta-annulus could be closely similar.

  17. The Development of a Gas-Liquid Two-Phase Flow Sensor Applicable to CBM Wellbore Annulus.

    Science.gov (United States)

    Wu, Chuan; Wen, Guojun; Han, Lei; Wu, Xiaoming

    2016-11-18

    The measurement of wellbore annulus gas-liquid two-phase flow in CBM (coalbed methane) wells is of great significance for reasonably developing gas drainage and extraction processes, estimating CBM output, judging the operating conditions of CBM wells and analyzing stratum conditions. Hence, a specially designed sensor is urgently needed for real-time measurement of gas-liquid two-phase flow in CBM wellbore annulus. Existing flow sensors fail to meet the requirements of the operating conditions of CBM wellbore annulus due to such factors as an inapplicable measurement principle, larger size, poor sealability, high installation accuracy, and higher requirements for fluid media. Therefore, based on the principle of a target flowmeter, this paper designs a new two-phase flow sensor that can identify and automatically calibrate different flow patterns of two-phase flows. Upon the successful development of the new flow sensor, lab and field tests were carried out, and the results show that the newly designed sensor, with a measurement accuracy of ±2.5%, can adapt to the operating conditions of CBM wells and is reliable for long-term work.

  18. The CRISPRdb database and tools to display CRISPRs and to generate dictionaries of spacers and repeats

    OpenAIRE

    Vergnaud Gilles; Grissa Ibtissem; Pourcel Christine

    2007-01-01

    Abstract Background In Archeae and Bacteria, the repeated elements called CRISPRs for "clustered regularly interspaced short palindromic repeats" are believed to participate in the defence against viruses. Short sequences called spacers are stored in-between repeated elements. In the current model, motifs comprising spacers and repeats may target an invading DNA and lead to its degradation through a proposed mechanism similar to RNA interference. Analysis of intra-species polymorphism shows t...

  19. The effect of flexible spacers on the h-shaped dimesogenic liquid crystalline compounds

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joo Hoon; Lee, Hwan Myoung; Choi, Ok Byung; Lee, Chang Joon [Hoseo Univ., Asan (Korea, Republic of); So, Bong Keun; Lee, Soo Min [Hannam Univ., Daejon (Korea, Republic of)

    2001-12-01

    A homologous series of new H-shaped twin liquid crystal molecules (PPPA-n) with flexible spacers, oxypolymethyleneoxy, has been prepared by esterification of acid chloride of {alpha}, {omega}-bis(2,5-dicar-boxyphenoxy)alkanes with p-phenylphenol. The length of spacer was varied from oxyethyleneoxy (n=2) to oxydecamethyleneoxy (n=10). Their thermodynamic data were measured by differential scanning calorimetry and liquid crystalline properties were investigated by a hot-stage polarizing microscope.

  20. Radiation effects on bifurcation and dual solutions in transient natural convection in a horizontal annulus

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kang; Yi, Hong-Liang, E-mail: yihongliang@hit.edu.cn; Tan, He-Ping, E-mail: tanheping@hit.edu.cn [School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2014-05-15

    Transitions and bifurcations of transient natural convection in a horizontal annulus with radiatively participating medium are numerically investigated using the coupled lattice Boltzmann and direct collocation meshless (LB-DCM) method. As a hybrid approach based on a common multi-scale Boltzmann-type model, the LB-DCM scheme is easy to implement and has an excellent flexibility in dealing with the irregular geometries. Separate particle distribution functions in the LBM are used to calculate the density field, the velocity field and the thermal field. In the radiatively participating medium, the contribution of thermal radiation to natural convection must be taken into account, and it is considered as a radiative term in the energy equation that is solved by the meshless method with moving least-squares (MLS) approximation. The occurrence of various instabilities and bifurcative phenomena is analyzed for different Rayleigh number Ra and Prandtl number Pr with and without radiation. Then, bifurcation diagrams and dual solutions are presented for relevant radiative parameters, such as convection-radiation parameter Rc and optical thickness τ. Numerical results show that the presence of volumetric radiation changes the static temperature gradient of the fluid, and generally results in an increase in the flow critical value. Besides, the existence and development of dual solutions of transient convection in the presence of radiation are greatly affected by radiative parameters. Finally, the advantage of LB-DCM combination is discussed, and the potential benefits of applying the LB-DCM method to multi-field coupling problems are demonstrated.

  1. Photobiomodulation on human annulus fibrosus cells during the intervertebral disk degeneration: extracellular matrix-modifying enzymes.

    Science.gov (United States)

    Hwang, Min Ho; Kim, Kyoung Soo; Yoo, Chang Min; Shin, Jae Hee; Nam, Hyo Geun; Jeong, Jin Su; Kim, Joo Han; Lee, Kwang Ho; Choi, Hyuk

    2016-05-01

    Destruction of extracellular matrix (ECM) leads to degeneration of the intervertebral disk (IVD), which is a major contributor to many spine disorders. IVD degeneration is induced by pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), which are secreted by immune cells, including macrophages and neutrophils. The cytokines modulate ECM-modifying enzymes such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human annulus fibrosus (AF) cells. The resulting imbalance in catabolic and anabolic enzymes can cause generalized back, neck, and low back pain (LBP). Photobiomodulation (PBM) is known to regulate inflammatory responses and wound healing. The aim of this study was to mimic the degenerative IVD microenvironment, and to investigate the effect of a variety of PBM conditions (wavelength: 635, 525, and 470 nm; energy density: 16, 32, and 64 J/cm(2)) on the production of ECM-modifying-enzymes by AF cells under degenerative conditions induced by macrophage-conditioned medium (MCM), which contains pro-inflammatory cytokines such as TNF-α and IL-β secreted by macrophage during the development of intervertebral disk inflammation. We showed that the MCM-stimulated AF cells express imbalanced ratios of TIMPs (TIMP-1 and TIMP-2) and MMPs (MMP-1 and MMP-3). PBM selectively modulated the production of ECM-modifying enzymes in AF cells. These results suggest that PBM can be a therapeutic tool for degenerative IVD disorders.

  2. Mechanics of oriented electrospun nanofibrous scaffolds for annulus fibrosus tissue engineering.

    Science.gov (United States)

    Nerurkar, Nandan L; Elliott, Dawn M; Mauck, Robert L

    2007-08-01

    Engineering a functional replacement for the annulus fibrosus (AF) of the intervertebral disc is contingent upon recapitulation of AF structure, composition, and mechanical properties. In this study, we propose a new paradigm for AF tissue engineering that focuses on the reconstitution of anatomic fiber architecture and uses constitutive modeling to evaluate construct function. A modified electrospinning technique was utilized to generate aligned nanofibrous polymer scaffolds for engineering the basic functional unit of the AF, a single lamella. Scaffolds were tested in uniaxial tension at multiple fiber orientations, demonstrating a nonlinear dependence of modulus on fiber angle that mimicked the nonlinearity and anisotropy of native AF. A homogenization model previously applied to native AF successfully described scaffold mechanical response, and parametric studies demonstrated that nonfibrillar matrix, along with fiber connectivity, are key contributors to tensile mechanics for engineered AF. We demonstrated that AF cells orient themselves along the aligned scaffolds and deposit matrix that contributes to construct mechanics under loading conditions relevant to the in vivo environment. The homogenization model was applied to cell-seeded constructs and provided quantitative measures for the evolution of matrix and interfibrillar interactions. Finally, the model demonstrated that at fiber angles of the AF (28 degrees -44 degrees ), engineered material behaved much like native tissue, suggesting that engineered constructs replicate the physiologic behavior of the single AF lamella. Constitutive modeling provides a powerful tool for analysis of engineered AF neo-tissue and native AF tissue alike, highlighting key mechanical design criteria for functional AF tissue engineering.

  3. Subcooled flow boiling heat transfer of ethanol aqueous solutions in vertical annulus space

    Directory of Open Access Journals (Sweden)

    Sarafraz M.M.

    2012-01-01

    Full Text Available The subcooled flow boiling heat-transfer characteristics of water and ethanol solutions in a vertical annulus have been investigated up to heat flux 132kW/m2. The variations in the effects of heat flux and fluid velocity, and concentration of ethanol on the observed heat-transfer coefficients over a range of ethanol concentrations implied an enhanced contribution of nucleate boiling heat transfer in flow boiling, where both forced convection and nucleate boiling heat transfer occurred. Increasing the ethanol concentration led to a significant deterioration in the observed heat-transfer coefficient because of a mixture effect, that resulted in a local rise in the saturation temperature of ethanol/water solution at the vapor-liquid interface. The reduction in the heat-transfer coefficient with increasing ethanol concentration is also attributed to changes in the fluid properties (for example, viscosity and heat capacity of tested solutions with different ethanol content. The experimental data were compared with some well-established existing correlations. Results of comparisons indicate existing correlations are unable to obtain the acceptable values. Therefore a modified correlation based on Gnielinski correlation has been proposed that predicts the heat transfer coefficient for ethanol/water solution with uncertainty about 8% that is the least in comparison to other well-known existing correlations.

  4. Two dimensional analysis of low pressure flows in the annulus region between two concentric cylinders.

    Science.gov (United States)

    Al-Kouz, Wael; Alshare, Aiman; Alkhalidi, Ammar; Kiwan, Suhil

    2016-01-01

    A numerical simulation of the steady two-dimensional laminar natural convection heat transfer for the gaseous low-pressure flows in the annulus region between two concentric horizontal cylinders is carried out. This type of flow occurs in "evacuated" solar collectors and in the receivers of the solar parabolic trough collectors. A finite volume code is used to solve the coupled set of governing equations. Boussinesq approximation is utilized to model the buoyancy effect. A correlation for the thermal conductivity ratio (k r = k eff/k) in terms of Knudsen number and the modified Rayleigh number is proposed for Prandtl number (Pr = 0.701). It is found that as Knudsen number increases then the thermal conductivity ratio decreases for a given Rayleigh number. Also, it is shown that the thermal conductivity ratio k r increases as Rayleigh number increases. It appears that there is no consistent trend for varying the dimensionless gap spacing between the inner and the outer cylinder ([Formula: see text]) on the thermal conductivity ratio (k r) for the considered spacing range.

  5. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    Science.gov (United States)

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

  6. [Long-term results of conventional aortic valve replacement for small aortic annulus].

    Science.gov (United States)

    Miura, Y; Miyairi, T; Kitamura, T; Kigawa, I; Fukuda, S

    2006-04-01

    We studied cardiac function, clinical outcome and quality of life (QOL) long after aortic valve replacement for pure aortic stenosis. Forty-four patients in small group [St. Jude Medical (SJM) 17 HP, 19 A], and 69 patients in non-small group (19 HP, 21 A, 23 A) operated on from 1984 to 2004 were enrolled in this study. We assessed the clinical data, aortic pressure gradient, left ventricular mass index (LVMI), and ejection fraction (EF) by preoperative and postoperative echocardiography. Moreover to evaluate QOL after the operation, we performed SF-36 used for the evaluation of health and QOL worldwide. Mean follow-up is 7.1 +/- 4.8 years in small group, and 6.8 +/- 4.6 years in non-small group. There were 2 hospital deaths in small group, and 1 in non-small group. The actual survival rate at 10-year were 89.2% in small group, and 85.6% in non-small group. There was no significant difference in hospital mortality, LVMI, long-term survival rate, and the scores of SF-36 between the 2 groups. The use of small sized prosthetic valves in patients with small aortic annulus might be justified when there is no patient-prosthesis mismatch.

  7. Enlargement of the aortic annulus during aortic valve replacement: a review.

    Science.gov (United States)

    Bortolotti, Uberto; Celiento, Michele; Milano, Aldo D

    2014-01-01

    The main goal of aortic valve replacement (AVR) is to obtain relief from the fixed left ventricular (LV) obstruction by replacing the aortic valve with a prosthesis, either mechanical or biological, of adequate size. Most currently available prostheses provide satisfactory hemodynamic performance, but small-sized prostheses may be associated with high transvalvular gradients and suboptimal effective orifice area that result in prosthesis-patient mismatch (PPM), and thus are far from ideal for use in young, active patients. The avoidance of PPM is advisable as it has been repeatedly associated with increased mortality, decreased exercise tolerance and an impaired regression of LV hypertrophy after AVR for severe aortic stenosis. Enlargement of the aortic annulus (EAA) has proved to be a valuable method to prevent PPM in the presence of a diminutive aortic root. This review outlines the various techniques described for EAA, presenting technical details, long-term results and major procedure-related complications, and discussing the current role of EAA in patients requiring AVR.

  8. Experiments on transitions of baroclinic waves in a differentially heated rotating annulus

    Directory of Open Access Journals (Sweden)

    Th. von Larcher

    2005-01-01

    Full Text Available Experiments of baroclinic waves in a rotating, baroclinic annulus of fluid are presented for two gap widths. The apparatus is a differentially heated cylindrical gap, rotated around its vertical axis of symmetry, cooled from within, with a free surface, and filled with de-ionised water as working fluid. The surface flow was observed with visualisation technique while thermographic measurements gave a detailed understanding of the temperature distribution and its time-dependent behaviour. We focus in particular on transitions between different flow regimes. Using a wide gap, the first transition from axisymmetric flow to the regular wave regime was characterised by complex flows. The transition to irregular flows was smooth, where a coexistence of the large-scale jet-stream and small-scale vortices was observed. Furthermore, temperature measurements showed a repetitive separation of cold vortices from the inner wall. Experiments using a narrow gap showed no complex flows but strong hysteresis in the steady wave regime, with up to five different azimuthal wave modes as potential steady and stable solutions.

  9. Age estimation for shovelnose sturgeon: A cautionary note based on annulus formation in pectoral fin rays

    Science.gov (United States)

    Whiteman, K.W.; Travnichek, V.H.; Wildhaber, M.L.; DeLonay, A.; Papoulias, D.; Tillett, D.

    2004-01-01

    Numerous studies have examined the age and growth of shovelnose sturgeon Scaphirhynchus platorynchus, but only one study attempted to validate age estimation techniques. Therefore, our objective was to use marginal increment analysis to validate annulus formation in pectoral fin rays of shovelnose sturgeon collected from the Missouri River. We also compared the precision of age estimates between two different readers. Marginal increment distance indicated that for most of the populations an opaque band was laid down in pectoral fin rays during the summer. However, opaque bands were formed throughout the year in some individuals, which could be problematic when using fin rays for age estimation. The agreement of age estimates by two readers for shovelnose sturgeon was only 18%, and differences in ages between the two readers increased for older fish. The presence of split annuli, false annuli, spawning bands, imbedded rays, and deteriorating sections made individual growth rings difficult to separate. Our findings verified that opaque bands are formed annually during the summer in the pectoral fin rays of most shovelnose sturgeon, but some individuals form opaque bands during other times. Pectoral fin rays will probably continue to be the most practical method of age estimation in shovelnose sturgeon, but ages estimated by this method should be used with caution.

  10. Identification of Mitral Annulus Hinge Point Based on Local Context Feature and Additive SVM Classifier

    Directory of Open Access Journals (Sweden)

    Jianming Zhang

    2015-01-01

    Full Text Available The position of the hinge point of mitral annulus (MA is important for segmentation, modeling and multimodalities registration of cardiac structures. The main difficulties in identifying the hinge point of MA are the inherent noisy, low resolution of echocardiography, and so on. This work aims to automatically detect the hinge point of MA by combining local context feature with additive support vector machines (SVM classifier. The innovations are as follows: (1 designing a local context feature for MA in cardiac ultrasound image; (2 applying the additive kernel SVM classifier to identify the candidates of the hinge point of MA; (3 designing a weighted density field of candidates which represents the blocks of candidates; and (4 estimating an adaptive threshold on the weighted density field to get the position of the hinge point of MA and exclude the error from SVM classifier. The proposed algorithm is tested on echocardiographic four-chamber image sequence of 10 pediatric patients. Compared with the manual selected hinge points of MA which are selected by professional doctors, the mean error is in 0.96 ± 1.04 mm. Additive SVM classifier can fast and accurately identify the MA hinge point.

  11. Effect of Yield Power Law Fluid Rheological Properties on Cuttings Transport in Eccentric Horizontal Narrow Annulus

    Directory of Open Access Journals (Sweden)

    Titus Ntow Ofei

    2016-01-01

    Full Text Available Narrow annular drilling such as casing-while-drilling technique is gaining popularity due to its ability to mitigate nonproductive time during oil and gas drilling operations. However, very little is known about the flow dynamics in narrow annular drilling. In this study, the Eulerian-Eulerian two-fluid model was used to examine the influence of Yield Power Law fluid rheological properties on cuttings transport in eccentric horizontal narrow annulus. The flow was assumed as fully developed, laminar, and transient state. The present simulation model was validated against experimental data, where a mean percent error of −1.2% was recorded. Results revealed an increase in the radial distribution of cuttings transport velocity in the wide annular region as the consistency index, K, and the flow behavior index, n, increase. Nonetheless, increasing the yield stress, τo, had insignificant effect on the cuttings transport velocity. Three-dimensional profiles showed how cuttings preferred to travel in less resistant flow area, whereas cuttings concentration builds up in the narrow annular region. Furthermore, annular frictional pressure losses also increased as K, n, and τo increased. This study serves as a guide to properly optimize drilling fluid rheological properties for efficient cuttings transport and equivalent circulating density (ECD management in narrow annular drilling.

  12. Chaotic micromixer utilizing electro-osmosis and induced charge electro-osmosis in eccentric annulus

    Science.gov (United States)

    Feng, Huicheng; Wong, Teck Neng; Che, Zhizhao; Marcos

    2016-06-01

    Efficient mixing is of significant importance in numerous chemical and biomedical applications but difficult to realize rapidly in microgeometries due to the lack of turbulence. We propose to enhance mixing by introducing Lagrangian chaos through electro-osmosis (EO) or induced charge electro-osmosis (ICEO) in an eccentric annulus. The analysis reveals that the created Lagrangian chaos can achieve a homogeneous mixing much more rapidly than either the pure EO or the pure ICEO. Our systematic investigations on the key parameters, ranging from the eccentricity, the alternating time period, the number of flow patterns in one time period, to the specific flow patterns utilized for the Lagrangian chaos creation, present that the Lagrangian chaos is considerably robust. The system can obtain a good mixing effect with wide ranges of eccentricity, alternating time period, and specific flow patterns utilized for the Lagrangian chaos creation as long as the number of flow patterns in one time period is two. As the electric field increases, the time consumption for homogenous mixing is reduced more remarkably for the Lagrangian chaos of the ICEO than that of the EO.

  13. 3D segmentation of annulus fibrosus and nucleus pulposus from T2-weighted magnetic resonance images

    Science.gov (United States)

    Castro-Mateos, Isaac; Pozo, Jose M.; Eltes, Peter E.; Del Rio, Luis; Lazary, Aron; Frangi, Alejandro F.

    2014-12-01

    Computational medicine aims at employing personalised computational models in diagnosis and treatment planning. The use of such models to help physicians in finding the best treatment for low back pain (LBP) is becoming popular. One of the challenges of creating such models is to derive patient-specific anatomical and tissue models of the lumbar intervertebral discs (IVDs), as a prior step. This article presents a segmentation scheme that obtains accurate results irrespective of the degree of IVD degeneration, including pathological discs with protrusion or herniation. The segmentation algorithm, employing a novel feature selector, iteratively deforms an initial shape, which is projected into a statistical shape model space at first and then, into a B-Spline space to improve accuracy. The method was tested on a MR dataset of 59 patients suffering from LBP. The images follow a standard T2-weighted protocol in coronal and sagittal acquisitions. These two image volumes were fused in order to overcome large inter-slice spacing. The agreement between expert-delineated structures, used here as gold-standard, and our automatic segmentation was evaluated using Dice Similarity Index and surface-to-surface distances, obtaining a mean error of 0.68 mm in the annulus segmentation and 1.88 mm in the nucleus, which are the best results with respect to the image resolution in the current literature.

  14. Identification of Mitral Annulus Hinge Point Based on Local Context Feature and Additive SVM Classifier.

    Science.gov (United States)

    Zhang, Jianming; Liu, Yangchun; Xu, Wei

    2015-01-01

    The position of the hinge point of mitral annulus (MA) is important for segmentation, modeling and multimodalities registration of cardiac structures. The main difficulties in identifying the hinge point of MA are the inherent noisy, low resolution of echocardiography, and so on. This work aims to automatically detect the hinge point of MA by combining local context feature with additive support vector machines (SVM) classifier. The innovations are as follows: (1) designing a local context feature for MA in cardiac ultrasound image; (2) applying the additive kernel SVM classifier to identify the candidates of the hinge point of MA; (3) designing a weighted density field of candidates which represents the blocks of candidates; and (4) estimating an adaptive threshold on the weighted density field to get the position of the hinge point of MA and exclude the error from SVM classifier. The proposed algorithm is tested on echocardiographic four-chamber image sequence of 10 pediatric patients. Compared with the manual selected hinge points of MA which are selected by professional doctors, the mean error is in 0.96 ± 1.04 mm. Additive SVM classifier can fast and accurately identify the MA hinge point.

  15. Forced Convective Condensation of Nonazeotropic Refrigerant Mixtures in Horizontal Annulus with Petal Shaped Fin Tubes

    Institute of Scientific and Technical Information of China (English)

    WangShiping; ZhouXinqiu; 等

    1995-01-01

    In this paper,condensation performance in horizontal annulus was compared with a smooth tube,one Saw-Tooth Finned tube(STF tube),four Petal Shaped Fin tubes(PF tubes),using R113,R11 and their mixtures(vapor molar fractions of R11 at the test section inlet were 0.384,0.588and 0.809) as working fluid.The mass flux at the test section ranged from 15-220/m2s。Camera and video camera were used to shoot the flow pattern and condensation phenomena.The condensation transfer coefficient(hc) of mixtures were considerably lower than those of pure fluid,and did not change linearly with composition.The maximum degradation of measured hc from the ideal value were 23% for the smooth tube,65%for STF tube,67% for PF tubes,which occurred in the composition range of 0.4-0.6 vapor molar fraction of R11.For the condensation of mixture,R11 molar fraction from 38%to 81%,the PF tubes had the highest value of hc.which were 10-25% higher than those of STF tubes,and 480-580% higher than that of smooth tube,because the petal shaped fins of PF tubes could promote strong turbulence in the two phase flow,and reduce the mass transfer resistance.

  16. INFLUENCE OF ELECTRICAL AND STRUCTURAL PARAMETERS ON THE PERFORMANCE OF THE SPACERS IN HOPFED

    Institute of Scientific and Technical Information of China (English)

    Zhong Xuefei; Wilbert van der Poel; Daniel den Engelsen; Yin Hanchun

    2006-01-01

    The HOPping Field Emission Display (HOPFED) is a new architecture for field emission displays.The main difference between a conventional Field Emission Display (FED) device and a HOPFED lies in the spacer structure. In a HOPFED, two dielectric plates, named hop and flu spacer, are sandwiched between the emitter and the front plate. The objective of this spacer structure is to improve the performance of a FED substantially with notable contrast, color purity and luminance uniformity. In order to optimize the structure of the device and to make the electron spot on the screen match the requirement of the phosphor dot dimension,the influence of electrical and structural parameters of the device on the electron spot profile was studied by numerical simulation in this paper. Monte Carlo method was employed to calculate the potential distribution inside hop and flu spacers due to secondary electrons mechanism plays an important role in HOPFED. The results indicated that the potential distribution in the spacers and spot profile depended strongly on the hop voltage, anode voltage and spacer's layout. This study may provide a useful theoretical support for optimizing the structure in HOPFED.

  17. Shape memory alloy smart knee spacer to enhance knee functionality: model design and finite element analysis.

    Science.gov (United States)

    Gautam, Arvind; Rani, A Bhargavi; Callejas, Miguel A; Acharyya, Swati Ghosh; Acharyya, Amit; Biswas, Dwaipayan; Bhandari, Vasundhra; Sharma, Paresh; Naik, Ganesh R; Gautam, Arvind; Rani, A Bhargavi; Callejas, Miguel A; Acharyya, Swati Ghosh; Acharyya, Amit; Biswas, Dwaipayan; Bhandari, Vasundhra; Sharma, Paresh; Naik, Ganesh R; Acharyya, Swati Ghosh; Sharma, Paresh; Bhandari, Vasundhra; Rani, A Bhargavi; Gautam, Arvind; Biswas, Dwaipayan; Callejas, Miguel A; Acharyya, Amit

    2016-08-01

    In this paper we introduce Shape Memory Alloy (SMA) for designing the tibial part of Total Knee Arthroplasty (TKA) by exploiting the shape-memory and pseudo-elasticity property of the SMA (e.g. NiTi). This would eliminate the drawbacks of the state-of-the art PMMA based knee-spacer including fracture, sustainability, dislocation, tilting, translation and subluxation for tackling the Osteoarthritis especially for the aged people of 45-plus or the athletes. In this paper a Computer Aided Design (CAD) model using SolidWorks for the knee-spacer is presented based on the proposed SMA adopting the state-of-the art industry-standard geometry that is used in the PMMA based spacer design. Subsequently Ansys based Finite Element Analysis is carried out to measure and compare the performance between the proposed SMA based model with the state-of-the art PMMA ones. 81% more bending is noticed in the PMMA based spacer compared to the proposed SMA that would eventually cause fracture and tilting or translation of spacer. Permanent shape deformation of approximately 58.75% in PMMA based spacer is observed compared to recoverable 11% deformation in SMA when same load is applied on both separately.

  18. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    that of ‘mobilities design’. The book revolves around the following research question: How are design decisions and interventions staging mobilities? It builds upon the Staging Mobilities model (Jensen 2013) in an explorative inquiry into the problems and potentials of the design of mobilities. The exchange value...... between mobilities and design research is twofold. To mobilities research this means getting closer to the ‘material’, and to engage in the creative, explorative and experimental approaches of the design world which offer new potentials for innovative research. Design research, on the other hand, might...... enter into a fruitful relationship with mobilities research, offering a relational and mobile design thinking and a valuable base for a reflective design practice around the ubiquitous structures, spaces and systems of mobilities....

  19. Time spans and spacers : Molecular phylogenetic explorations in the Cladophora complex (Chlorophyta) from the perspective of rDNA gene and spacer sequences

    NARCIS (Netherlands)

    Bakker, Frederik Theodoor

    1995-01-01

    In this study, phylogenetic relationships among genera, species and biogeographic representatives of single Cladophora species within the Cladophorales were analyzed using rDNA gene and spacer sequences. Based on phylogenetic analysis of 18S rRNA gene sequences, the Cladophora complex is shown to be

  20. Mobile payment

    CERN Document Server

    Lerner, Thomas

    2013-01-01

    Paying with mobile devices such as mobile phones or smart phones will expand worldwide in the coming years. This development provides opportunities for various industries (banking, telecommunications, credit card business, manufacturers, suppliers, retail) and for consumers.

  1. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2015-01-01

    Mobile phones are ubiquitous and have completely transformed the way we live, work, learn and conduct our everyday activities. Mobile phones have also changed the way users access lexicographic data. In fact, it can be argued that mobile phones and lexicography are not yet compatible. Modern users...... are already mobile – but lexicography is not yet fully ready for the mobile challenge, mobile users and mobile user situations. The article is based on empirical data from two surveys comprising 10 medical doctors, who were asked to look up five medical substances with the medical dictionary app Medicin...... and that lexicographic innovation is needed. A new type of users, new user situations and new access methods call for new lexicographic solutions, and this article proposes a six-pointed hexagram model, which can be used during dictionary app design to lexicographically calibrate the six dimensions in mobile...

  2. Mobility Divides

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Contemporary mobilities are cultural and social manifestations, and the mobile practices in the everyday life of billions of humans are re-configuring senses of place, self, other and relationships to the built environment. The way ‘mobile situations’ are staged in designed and built environments...... are increasingly becoming ‘second nature’ but also expressions of power, exclusion, and difference. In this talk I will be applying a perspective of ‘mobile situationism’ illustrating how mobile everyday life practices are staged ‘from above’ in planning and policy frameworks, design codes and architectural...... designs, but also how the situated and embodied mobile everyday life practices are staged ‘from below’ in concrete acts of choice concerning modes of mobilities, ways of moving and interacting. The ‘staging mobilites’ framework opens up to an understanding of the meaning of ‘mobilities design...

  3. Predicting the impact of feed spacer modification on biofouling by hydraulic characterization and biofouling studies in membrane fouling simulators

    KAUST Repository

    Siddiqui, A.

    2016-12-22

    Feed spacers are an essential part of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane modules. Geometric modification of feed spacers is a potential option to reduce the impact of biofouling on the performance of membrane systems. The objective of this study was to evaluate the biofouling potential of two commercially available reference feed spacers and four modified feed spacers. The spacers were compared on hydraulic characterization and in biofouling studies with membrane fouling simulators (MFSs). The virgin feed spacer was characterized hydraulically by their resistance, measured in terms of feed channel pressure drop, performed by operating MFSs at varying feed water flow rates. Short-term (9 days) biofouling studies were carried out with nutrient dosage to the MFS feed water to accelerate the biofouling rate. Long-term (96 days) biofouling studies were done without nutrient dosage to the MFS feed water. Feed channel pressure drop was monitored and accumulation of active biomass was quantified by adenosine tri phosphate (ATP) determination. The six feed spacers were ranked on pressure drop (hydraulic characterization) and on biofouling impact (biofouling studies). Significantly different trends in hydraulic resistance and biofouling impact for the six feed spacers were observed. The same ranking for biofouling impact on the feed spacers was found for the (i) short-term biofouling study with nutrient dosage and the (ii) long-term biofouling study without nutrient dosage. The ranking for hydraulic resistance for six virgin feed spacers differed significantly from the ranking of the biofouling impact, indicating that hydraulic resistance of clean feed spacers does not predict the hydraulic resistance of biofouled feed spacers. Better geometric design of feed spacers can be a suitable approach to minimize impact of biofouling in spiral wound membrane systems.

  4. Mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, W.J.; Marquina, N.

    1986-01-01

    This book presents papers given at a conference on mobile robots. Topics the conference included are the following: mobility systems for robotic vehicles; detection and control of mobile robot motion by real-time computer vision, obstacle avoidance algorithms for an autonomous land vehicle; hierarchical processor and matched filters for range image processing; asynchronous distributed control system for a mobile robot, and, planning in a hierarchical nested autonomous control system.

  5. Educing the emission mechanism of internal gravity waves in the differentially heat rotating annulus

    Science.gov (United States)

    Rolland, Joran; Hien, Steffen; Achatz, Ulrich; Borchert, Sebastian; Fruman, Mark

    2016-04-01

    Understanding the lifecycle of gravity waves is fundamental to a good comprehension of the dynamics of the atmosphere. In this lifecycle, the emission mechanisms may be the most elusive. Indeed, while the emission of gravity waves by orography or convection is well understood, the so-called spontaneous emission is still a quite open topic of investigation [1]. This type of emission usually occur very near jet-front systems in the troposphere. In this abstract, we announce our numerical study of the question. Model systems of the atmosphere which can be easily simulated or built in a laboratory have always been an important part of the study of atmospheric dynamics, alongside global simulations, in situ measurements and theory. In the case of the study of the spontaneous emission of gravity waves near jet-front systems, the differentially heated rotating annulus set up has been proposed and extensively used. It comprises of an annular tank containing water: the inner cylinder is kept at a cold temperature while the outer cylinder is kept at a warm temperature. The whole system is rotating. Provided the values of the control parameters (temperature, rotation rate, gap between the cylinders, height of water) are well chosen, the resulting flow mimics the troposphere at midlatitudes: it has a jet stream, and a baroclinic lifecycle develops on top of it. A very reasonable ratio of Brunt-Väisälä frequency over rotation rate of the system can be obtained, so as to be as close to the atmosphere as possible. Recent experiments as well as earlier numerical simulations in our research group have shown that gravity waves are indeed emitted in this set up, in particular near the jet front system of the baroclinic wave [2]. After a first experimental stage of characterising the emitted wavepacket, we focused our work on testing hypotheses on the gravity wave emission mechanism: we have tested and validated the hypothesis of spontaneous imbalance generated by the flow in

  6. Empirical singular vectors of baroclinic flows deduced from experimental data of a differentially heated rotating annulus

    Directory of Open Access Journals (Sweden)

    Michael Hoff

    2015-01-01

    Full Text Available Instability is related to exponentially growing eigenmodes. Interestingly, when finite time intervals are considered, growth rates of certain initial perturbations can exceed the growth rates of the most unstable modes. Moreover, even when all modes are damped, such particular initial perturbations can still grow during finite time intervals. The perturbations with the largest growth rates are called singular vectors (SVs or optimal perturbations. They not only play an important role in atmospheric ensemble predictions, but also for the theory of instability and turbulence. Starting point for a classical SV-analysis is a linear dynamical system with a known system matrix. In contrast to this traditional approach, measured data are used here to estimate the linear propagator. For this estimation, a method is applied that uses the covariances of the measured time series to find the principal oscillation patterns (POPs that are the empirically estimated linear eigenmodes of the system. By using the singular value decomposition (SVD, we can estimate the modes of maximal growth of the propagator which are thus the empirically estimated SVs. These modes can be understood as a superposition of POPs that form a complete but in general non-orthogonal basis. The data used, originate from a differentially heated rotating annulus laboratory experiment. This experiment is an analogue of the earth's atmosphere and is used to study the development of baroclinic waves in a well controlled and reproducible way without the need of numerical approximations. Baroclinic waves form the background for many studies on SV growth and it is thus straight forward to apply the technique of empirical SV estimation to these laboratory data. To test the method of SV estimation, we use a quasi-geostrophic barotropic model and compare the known SVs from that model with SVs estimated from a surrogate data set that was generated with the help of the exact model propagator and some

  7. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2014-01-01

    Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation and the mob...

  8. The Safe Removal of Frozen Air from the Annulus of an LH2 Storage Tank

    Science.gov (United States)

    Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

    2015-01-01

    Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modeling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

  9. The safe removal of frozen air from the annulus of an LH2 storage tank

    Science.gov (United States)

    Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

    2015-12-01

    Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modelling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

  10. A novel culture platform for fast proliferation of human annulus fibrosus cells.

    Science.gov (United States)

    Xiao, Li; Ding, Mengmeng; Saadoon, Osama; Vess, Eric; Fernandez, Andrew; Zhao, Ping; Jin, Li; Li, Xudong

    2017-02-01

    Tissue engineering provides a promising approach to treat degenerative disc disease, which usually requires a large quantity of seed cells. A simple and reliable in vitro culture system to expand seed cells in a timely fashion is necessary to implement the application clinically. Here, we sought to establish a cost-effective culture system for expanding human annulus fibrosus cells using extracellular matrix (ECM) proteins as culture substrates. Cells were cultured onto a plastic surface coated with various types of ECMs, including fibronectin, vitronectin, collagen type I, gelatin and cell-free matrix deposited by human nucleus pulposus cells. AF cell morphology, growth, adhesion and phenotype (anabolic and catabolic markers) were assessed by microscopy, real-time RT-PCR, western blotting, zymography, immunofluorescence staining and biochemical assays. Fibronectin, collagen and gelatin promoted cell proliferation and adhesion in a dose-dependent manner. Fibronectin elevated mRNA expression of proteoglycan and enhanced glycosaminoglycan production. Both collagen and gelatin increased protein expression of type II collagen. Consistent with increased cell adhesion, collagen and fibronectin promoted formation of focal adhesion complexes in the cell-matrix junction, suggesting enhanced binding of the actin network with both ECM substrates. On the other hand, fibronectin, collagen and gelatin decreased expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in media. Finally, a mixture of fibronectin (1.7 μg/mL) and collagen (1.3 μg/mL) was identified as the most promising in vitro culture substrate system in promoting proliferation and maintaining anabolic-catabolic balance. Our method provides a simple and cost-effective platform for tissue engineering applications in intervertebral disc research.

  11. Fully automated software for mitral annulus evaluation in chronic mitral regurgitation by 3-dimensional transesophageal echocardiography

    Science.gov (United States)

    Aquila, Iolanda; Fernández-Golfín, Covadonga; Rincon, Luis Miguel; González, Ariana; García Martín, Ana; Hinojar, Rocio; Jimenez Nacher, Jose Julio; Indolfi, Ciro; Zamorano, Jose Luis

    2016-01-01

    Abstract Three-dimensional (3D) transesophageal echocardiography (TEE) is the gold standard for mitral valve (MV) anatomic and functional evaluation. Currently, dedicated MV analysis software has limitations for its use in clinical practice. Thus, we tested here a complete and reproducible evaluation of a new fully automatic software to characterize MV anatomy in different forms of mitral regurgitation (MR) by 3D TEE. Sixty patients were included: 45 with more than moderate MR (28 organic MR [OMR] and 17 functional MR [FMR]) and 15 controls. All patients underwent TEE. 3D MV images obtained using 3D zoom were imported into the new software for automatic analysis. Different MV parameters were obtained and compared. Anatomic and dynamic differences between FMR and OMR were detected. A significant increase in systolic (859.75 vs 801.83 vs 607.78 mm2; P = 0.002) and diastolic (1040.60 vs. 1217.83 and 859.74 mm2; P < 0.001) annular sizes was observed in both OMR and FMR compared to that in controls. FMR had a reduced mitral annular contraction compared to degenerative cases of OMR and to controls (17.14% vs 32.78% and 29.89%; P = 0.007). Good reproducibility was demonstrated along with a short analysis time (mean 4.30 minutes). Annular characteristics and dynamics are abnormal in both FMR and OMR. Full 3D software analysis automatically calculates several significant parameters that provide a correct and complete assessment of anatomy and dynamic mitral annulus geometry and displacement in the 3D space. This analysis allows a better characterization of MR pathophysiology and could be useful in designing new devices for MR repair or replacement. PMID:27930514

  12. 主动脉瓣环扩大术在主动脉瓣置换术中的应用%Aortic annulus enlargement in aortic valve replacement for small aortic annulus

    Institute of Scientific and Technical Information of China (English)

    朱水波; 殷桂林; 胡健才; 张殿堂; 张晓明; 王荣平; 谭焱; 高旭辉; 刘勇

    2012-01-01

    Objective To summarize the experiences of aortic annulus enlargement in aortic valve replacement for small aortic annulus. Methods From Jan. 2000 to Sept,2010,18 cases of aortic valve disease with small aortic annulus received improved Manouguian procedure to enlarge the small aortic annulus before implanting appropriate mechanical aortic valve. Complicated heart lesion were treated surgically simultaneously. Results Complications in early stage including ventricular arrhythmia, severe low cardiac output syndrome and cardiac tamponade were cured. All cases were discharged without operative mortality. All cases were improved in cardiac function and ventricular wall mass. No death or other severe events occurred in follow - up. Conclusion Aortic annulus enlargement with improved Manougnian method is effective and safe in patients with small aortic annulus in order to implant appropriate mechanical aortic valve.%目的 总结主动脉瓣置换术中处理小主动脉瓣环的体会.方法 我院在2000年至2010年期间收治主动脉瓣环细小的主动脉瓣病变18例,均采取改良Manouguian方法扩大主动脉瓣环,再置入较合适的机械主动脉瓣.同期行二尖瓣置换6例,室间隔修补1例,三尖瓣成形5例.结果 17例有效开口面积指数(EOAI)均达到0.85cm2/m2以上,1例0.80cm2/m2.术后严重低心排综合征1例,室性心律失常3例,心脏压塞1例.18例痊愈出院,随访1~10年,术后6个月复查发现EOAI为0.80cm2/m2的患者主动脉跨瓣压差较高,室间隔及左室壁厚度恢复较慢,左室射血分数较低;而比值在0.85~1.0之间与大于1.0的患者相比,主动脉跨瓣压差、室间隔及左室壁厚度平均值稍高,但差异无统计学意义.2例术后6年因身高、体重增加EOAI分别下降到0.79、0.81cm2/m2,出现活动后心慌,心电图提示左室高电压,经扩管等药物治疗和一般处理,症状明显改善.结论 改良Manouguian方法扩大主动脉瓣环安全、有效,可置入

  13. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided......In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

  14. Residential mobility

    DEFF Research Database (Denmark)

    Morris, Tim; Manley, David; Sabel, Clive

    2016-01-01

    Research into health disparities has long recognised the importance of residential mobility as a crucial factor in determining health outcomes. However, a lack of connectivity between the health and mobility literatures has led to a stagnation of theory and application on the health side, which...... lacks the detail and temporal perspectives now seen as critical to understanding residential mobility decisions. Through a critical re-think of mobility processes with respect to health outcomes and an exploitation of longitudinal analytical techniques we argue that health geographers have the potential...... to better understand and identify the relationship that residential mobility has with health....

  15. Mobile Semiotics

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2013-01-01

    This chapter aims to understand the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The chapter explores the potentials of semiotics and its relationship to the new mobilities literature. What takes place...... is a ‘mobile sense making’ where signs and materially situated meanings connect to the moving human body and thus create particular challenges and complexities of making sense of the world. The chapter includes notions of mobility systems and socio-technical networks in order to show how a ‘semiotic layer’ may...... work to afford or restrict mobile practices....

  16. Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Li Xiaoying

    2015-09-01

    Full Text Available This paper introduces a knitting technique for making innovative curved three-dimensional (3D spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns, and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

  17. Development of an innovative spacer grid model utilizing computational fluid dynamics within a subchannel analysis tool

    Science.gov (United States)

    Avramova, Maria

    In the past few decades the need for improved nuclear reactor safety analyses has led to a rapid development of advanced methods for multidimensional thermal-hydraulic analyses. These methods have become progressively more complex in order to account for the many physical phenomena anticipated during steady state and transient Light Water Reactor (LWR) conditions. The advanced thermal-hydraulic subchannel code COBRA-TF (Thurgood, M. J. et al., 1983) is used worldwide for best-estimate evaluations of the nuclear reactor safety margins. In the framework of a joint research project between the Pennsylvania State University (PSU) and AREVA NP GmbH, the theoretical models and numerics of COBRA-TF have been improved. Under the name F-COBRA-TF, the code has been subjected to an extensive verification and validation program and has been applied to variety of LWR steady state and transient simulations. To enable F-COBRA-TF for industrial applications, including safety margins evaluations and design analyses, the code spacer grid models were revised and substantially improved. The state-of-the-art in the modeling of the spacer grid effects on the flow thermal-hydraulic performance in rod bundles employs numerical experiments performed by computational fluid dynamics (CFD) calculations. Because of the involved computational cost, the CFD codes cannot be yet used for full bundle predictions, but their capabilities can be utilized for development of more advanced and sophisticated models for subchannel-level analyses. A subchannel code, equipped with improved physical models, can be then a powerful tool for LWR safety and design evaluations. The unique contributions of this PhD research are seen as development, implementation, and qualification of an innovative spacer grid model by utilizing CFD results within a framework of a subchannel analysis code. Usually, the spacer grid models are mostly related to modeling of the entrainment and deposition phenomena and the heat

  18. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2014-01-01

    Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation...... and the mobile user situation. The analysis is based on an empirical survey involving ten medical doctors and a monolingual app designed to support cognitive lexicographic functions, cf. (Tarp 2006:61-64). In test A the doctors looked up five medical terms while sitting down at a desk and in test B the doctors......:565), and it was found that the information access success of the mobile user situation is lower than that of the stationary user situation, primarily because users navigate in the physical world and in the mobile device at the same time. The data also suggest that the mobile user situation is not fully compatible...

  19. Using cathode spacers to minimize reactor size in air cathode microbial fuel cells

    KAUST Repository

    Yang, Qiao

    2012-04-01

    Scaling up microbial fuel cells (MFCs) will require more compact reactor designs. Spacers can be used to minimize the reactor size without adversely affecting performance. A single 1.5mm expanded plastic spacer (S1.5) produced a maximum power density (973±26mWm -2) that was similar to that of an MFC with the cathode exposed directly to air (no spacer). However, a very thin spacer (1.3mm) reduced power by 33%. Completely covering the air cathode with a solid plate did not eliminate power generation, indicating oxygen leakage into the reactor. The S1.5 spacer slightly increased columbic efficiencies (from 20% to 24%) as a result of reduced oxygen transfer into the system. Based on operating conditions (1000ς, CE=20%), it was estimated that 0.9Lh -1 of air would be needed for 1m 2 of cathode area suggesting active air flow may be needed for larger scale MFCs. © 2012 Elsevier Ltd.

  20. Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

    KAUST Repository

    Bucs, Szilard

    2014-06-01

    Feed spacers and hydrodynamics have been found relevant for the impact of biofouling on performance in reverse osmosis (RO) and nanofiltration (NF) membrane systems.The objectives of this study on biofouling development were to determine the impact of (i) linear flow velocity and bacterial cell load, (ii) biomass location and (iii) various feed spacer geometries as applied in practice as well as a modified geometry spacer.A three-dimensional mathematical model for biofouling of feed spacer channels including hydrodynamics, solute mass transport and biofilm formation was developed in COMSOL Multiphysics and MATLAB software.Results of this study indicate that the feed channel pressure drop increase caused by biofilm formation can be reduced by using thicker and/or modified feed spacer geometry and/or a lower flow rate in the feed channel. The increase of feed channel pressure drop by biomass accumulation is shown to be strongly influenced by the location of biomass. Results of numerical simulations are in satisfactory agreement with experimental data, indicating that this micro-scale mechanistic model is representative for practice. The developed model can help to understand better the biofouling process of spiral-wound RO and NF membrane systems and to develop strategies to reduce and control biofouling. © 2013 Elsevier B.V.

  1. Influence of length and flexibility of spacers on the binding affinity of divalent ligands

    Directory of Open Access Journals (Sweden)

    Susanne Liese

    2015-05-01

    Full Text Available We present a quantitative model for the binding of divalent ligand–receptor systems. We study the influence of length and flexibility of the spacers on the overall binding affinity and derive general rules for the optimal ligand design. To this end, we first compare different polymeric models and determine the probability to simultaneously bind to two neighboring receptor binding pockets. In a second step the binding affinity of divalent ligands in terms of the IC50 value is derived. We find that a divalent ligand has the potential to bind more efficiently than its monovalent counterpart only, if the monovalent dissociation constant is lower than a critical value. This critical monovalent dissociation constant depends on the ligand-spacer length and flexibility as well as on the size of the receptor. Regarding the optimal ligand-spacer length and flexibility, we find that the average spacer length should be equal or slightly smaller than the distance between the receptor binding pockets and that the end-to-end spacer length fluctuations should be in the same range as the size of a receptor binding pocket.

  2. Influence of length and flexibility of spacers on the binding affinity of divalent ligands.

    Science.gov (United States)

    Liese, Susanne; Netz, Roland R

    2015-01-01

    We present a quantitative model for the binding of divalent ligand-receptor systems. We study the influence of length and flexibility of the spacers on the overall binding affinity and derive general rules for the optimal ligand design. To this end, we first compare different polymeric models and determine the probability to simultaneously bind to two neighboring receptor binding pockets. In a second step the binding affinity of divalent ligands in terms of the IC50 value is derived. We find that a divalent ligand has the potential to bind more efficiently than its monovalent counterpart only, if the monovalent dissociation constant is lower than a critical value. This critical monovalent dissociation constant depends on the ligand-spacer length and flexibility as well as on the size of the receptor. Regarding the optimal ligand-spacer length and flexibility, we find that the average spacer length should be equal or slightly smaller than the distance between the receptor binding pockets and that the end-to-end spacer length fluctuations should be in the same range as the size of a receptor binding pocket.

  3. In Silico Study of Spacer Arm Length Influence on Drug Vectorization by Fullerene C60

    Directory of Open Access Journals (Sweden)

    Haifa Khemir

    2015-01-01

    Full Text Available This work studies theoretically the effect of spacer arm lengths on the characteristics of a fullerene C60-based nanovector. The spacer arm is constituted of a carbon chain including a variable number of methylene groups (n = 2–11. To improve the ability of the fullerene carriage, two arms are presented simultaneously through a malonyl bridge. Then the evolution of selected physicochemical parameters is monitored as a function of the spacer arm length and the angle between the two arms. We show here that while the studied characteristics are almost independent of the spacer arm length or vary monotonically with it, the dipole moment and its orientation vary periodically with the parity of the number of carbon atoms. This periodicity is related to both modules and orientations of dipole moments of the spacer arms. In the field of chemical synthesis, these results highlight the importance of theoretical calculations for the optimization of operating conditions. In the field of drug discovery, they show that theoretical calculations of the chemical properties of a drug candidate can help predict its in vivo behaviour, notably its bioavailability and biodistribution, which are known to be tightly dependent of its polarity.

  4. Detection and characterization of spacer integration intermediates in type I-E CRISPR-Cas system.

    Science.gov (United States)

    Arslan, Zihni; Hermanns, Veronica; Wurm, Reinhild; Wagner, Rolf; Pul, Ümit

    2014-07-01

    The adaptation against foreign nucleic acids by the CRISPR-Cas system (Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated proteins) depends on the insertion of foreign nucleic acid-derived sequences into the CRISPR array as novel spacers by still unknown mechanism. We identified and characterized in Escherichia coli intermediate states of spacer integration and mapped the integration site at the chromosomal CRISPR array in vivo. The results show that the insertion of new spacers occurs by site-specific nicking at both strands of the leader proximal repeat in a staggered way and is accompanied by joining of the resulting 5'-ends of the repeat strands with the 3'-ends of the incoming spacer. This concerted cleavage-ligation reaction depends on the metal-binding center of Cas1 protein and requires the presence of Cas2. By acquisition assays using plasmid-located CRISPR array with mutated repeat sequences, we demonstrate that the primary sequence of the first repeat is crucial for cleavage of the CRISPR array and the ligation of new spacer DNA.

  5. CFD study of isothermal water flow in rod bundle with split-type spacer grid

    Science.gov (United States)

    Batta, A.; Class, A. G.

    2014-06-01

    The design of rod bundles in nuclear application nowadays is assessed by CFD (computational fluid dynamics). The accuracy of CFD models need validation. Within the OECD/NEA benchmark MATiS-H (Measurement and Analysis of Turbulent Mixing in Sub-channels - Horizontal) a single-phase water flow in a 5x5 rod bundle is studied. In the benchmark, two types of spacer grids are tested, the swirl type and the split type, where the current study focuses on the split type spacer grid. Comparison of CFD results obtained at Karlsruhe Institut of Technology (KIT) with experimental results of KAERI (Korea Atomic Energy Research Institute) are presented. In the benchmark velocities components along selected lines downstream of the spacer grid are measured and compared to CFD results. The CFD code STAR CCM+ with the Realized k-ɛ model is used. Comparisons with experimental results show quantitative and qualitative agreement for the averaged values of velocity components. Comparisons of results to other benchmark partners using different modeling show that the selected mesh size and models for the analysis of the current case gives relatively accurate results. However, the used turbulent model (Realized k-ɛ does not capture the turbulent intensity correctly. Computation shows that the flow has very high mixing due to the spacer grid, which does not decay within the measurements domain (z/ DH =0-10 downstream of spacer grid). The same conclusion can be drawn from experimental data.

  6. Numerical investigation on the characteristics of two-phase flow in fuel assemblies with spacer grid

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.; Yang, Z.; Zhong, Y.; Xiao, Y.; Hu, L. [Chongqing Univ. (China). Key Lab. of Low-grade Energy Utilization Technologies and Systems

    2016-07-15

    In pressurized water reactors (PWRs), the spacer grids of the fuel assembly has significant impact on the thermal-hydraulic performance of the fuel assembly. Particularly, the spacer grids with the mixing vanes can dramatically enhance the secondary flow and have significant effect on the void distribution in the fuel assembly. In this paper, the CFD study has been carried out to analyze the effects of the spacer grid with the steel contacts, dimples and mixing vanes on the boiling two-phase flow characteristics, such as the two-phase flow field, the void distribution, and so on. Considered the influence of the boiling phase change on two-phase flow, a boiling model was proposed and applied in the CFD simulation by using the UDF (User Defined Function) method. Furthermore, in order to analyze the effects of the spacer grid with mixing vanes, the adiabatic (without boiling) two-phase flow has also been investigated as comparison with the boiling two-phase flow in the fuel assembly with spacer grids. The CFD simulation on two-phase flow in the fuel assembly with the proposed boiling model can predict the characteristics of two-phase flow better.

  7. Towards a rational spacer design for bivalent inhibition of estrogen receptor

    Science.gov (United States)

    Bujotzek, Alexander; Shan, Min; Haag, Rainer; Weber, Marcus

    2011-03-01

    Estrogen receptors are known drug targets that have been linked to several kinds of cancer. The structure of the estrogen receptor ligand binding domain is available and reveals a homodimeric layout. In order to improve the binding affinity of known estrogen receptor inhibitors, bivalent compounds have been developed that consist of two individual ligands linked by flexible tethers serving as spacers. So far, binding affinities of the bivalent compounds do not surpass their monovalent counterparts. In this article, we focus our attention on the molecular spacers that are used to connect the individual ligands to form bivalent compounds, and describe their thermodynamic contribution during the ligand binding process. We use computational methods to predict structural and entropic parameters of different spacer structures. We find that flexible spacers introduce a number of effects that may interfere with ligand binding and possibly can be connected to the low binding affinities that have been reported in binding assays. Based on these findings, we try to provide guidelines for the design of novel molecular spacers.

  8. [New technique of concomitant replacement of the aortic valve and the ascending aorta with enlargement of the aortic annulus for congenital bicuspid aortic valve].

    Science.gov (United States)

    Takahara, Shingo; Fukasawa, Manabu; Kawahara, Yu; Suzuki, Kotaro; Kobayashi, Yuriko

    2012-12-01

    Congenital bicuspid aortic valve (BAV) is one of the most common congenital heart diseases, with a high incidence of associated valvular lesions and aortic abnormalities including aortic stenosis( AS), aortic regurgitation, aortic dilatation, and aortic dissection. Patients with BAV and AS often have a small aortic annulus. We encountered a case of BAV in which a 51-year-old woman with severe AS having a small aortic annulus and a dilated ascending aorta required surgical intervention. We performed the surgery using new technique that involved concomitant replacement of the aortic valve and the ascending aorta with enlargement of the aortic annulus using a single uniquely-shaped graft to avoid prosthesis patient mismatch. We trimmed the proximal end of the straight graft in shape of 2 teardrops hanging on it to fit the cut annulus. It requires only a single suture line to replace the ascending aorta and enlarge the aortic annulus, which entails a decreased risk of bleeding during surgery. We believe that it could be applicable to many cases requiring concomitant surgery.

  9. Aortic annulus eccentricity before and after transcatheter aortic valve implantation: Comparison of balloon-expandable and self-expanding prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Schuhbaeck, Annika, E-mail: annika.schuhbaeck@uk-erlangen.de [Department of Cardiology, University of Erlangen, Erlangen (Germany); Weingartner, Christina [Department of Cardiology, University of Gießen, Giessen (Germany); Arnold, Martin; Schmid, Jasmin; Pflederer, Tobias; Marwan, Mohamed [Department of Cardiology, University of Erlangen, Erlangen (Germany); Rixe, Johannes; Nef, Holger [Department of Cardiology, University of Gießen, Giessen (Germany); Schneider, Christian [Department of Radiology, University of Gießen, Giessen (Germany); Lell, Michael; Uder, Michael [Department of Radiology, University of Erlangen, Erlangen (Germany); Ensminger, Stephan [Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum, Bad Oeynhausen (Germany); Feyrer, Richard; Weyand, Michael [Department of Cardiothoracic Surgery, University of Erlangen, Erlangen (Germany); Achenbach, Stephan [Department of Cardiology, University of Erlangen, Erlangen (Germany)

    2015-07-15

    Highlights: • Post-implant geometry of catheter-based aortic valve prostheses is influenced by aortic valve calcification. • Balloon-expandable prostheses are more circular as compared to self-expanding prostheses. • The impact of post-implant geometry on valve function needs to be investigated. - Abstract: Introduction: The geometry of the aortic annulus and implanted transcatheter aortic valve prosthesis might influence valve function. We investigated the influence of valve type and aortic valve calcification on post-implant geometry of catheter-based aortic valve prostheses. Methods: Eighty consecutive patients with severe aortic valve stenosis (mean age 82 ± 6 years) underwent computed tomography before and after TAVI. Aortic annulus diameters were determined. Influence of prosthesis type and degree of aortic valve calcification on post-implant eccentricity were analysed. Results: Aortic annulus eccentricity was reduced in patients after TAVI (0.21 ± 0.06 vs. 0.08 ± 0.06, p < 0.0001). Post-TAVI eccentricity was significantly lower in 65 patients following implantation of a balloon-expandable prosthesis as compared to 15 patients who received a self-expanding prosthesis (0.06 ± 0.05 vs. 0.15 ± 0.07, p < 0.0001), even though the extent of aortic valve calcification was not different. After TAVI, patients with a higher calcium amount retained a significantly higher eccentricity compared to patients with lower amounts of calcium. Conclusions: Patients undergoing TAVI with a balloon-expandable prosthesis show a more circular shape of the implanted prosthesis as compared to patients with a self-expanding prosthesis. Eccentricity of the deployed prosthesis is affected by the extent of aortic valve calcification.

  10. Interference-driven spacer acquisition is dominant over naive and primed adaptation in a native CRISPR–Cas system

    Science.gov (United States)

    Staals, Raymond H. J.; Jackson, Simon A.; Biswas, Ambarish; Brouns, Stan J. J.; Brown, Chris M.; Fineran, Peter C.

    2016-01-01

    CRISPR–Cas systems provide bacteria with adaptive immunity against foreign nucleic acids by acquiring short, invader-derived sequences called spacers. Here, we use high-throughput sequencing to analyse millions of spacer acquisition events in wild-type populations of Pectobacterium atrosepticum. Plasmids not previously encountered, or plasmids that had escaped CRISPR–Cas targeting via point mutation, are used to provoke naive or primed spacer acquisition, respectively. The origin, location and order of spacer acquisition show that spacer selection through priming initiates near the site of CRISPR–Cas recognition (the protospacer), but on the displaced strand, and is consistent with 3′–5′ translocation of the Cas1:Cas2-3 acquisition machinery. Newly acquired spacers determine the location and strand specificity of subsequent spacers and demonstrate that interference-driven spacer acquisition (‘targeted acquisition') is a major contributor to adaptation in type I-F CRISPR–Cas systems. Finally, we show that acquisition of self-targeting spacers is occurring at a constant rate in wild-type cells and can be triggered by foreign DNA with similarity to the bacterial chromosome. PMID:27694798

  11. Influence factors on stress corrosion cracking of P110 tubing steel under CO2 injection well annulus environment

    Institute of Scientific and Technical Information of China (English)

    刘然克; 贾静焕; 杜翠薇; 李晓刚

    2016-01-01

    Stress corrosion cracking (SCC) behavior of P110 tubing steel in simulated CO2 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease of pH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.

  12. NUMERICAL SIMULATION OF UNSTEADY FLOW FOR VISCO-ELASTIC FLUID IN AN ECCENTRIC ANNULUS WITH INNER ROD RECIPROCATION

    Institute of Scientific and Technical Information of China (English)

    HE Feng-yun; YANG Shu-ren

    2008-01-01

    The equation governing the unsteady flow of viscoelastic fluids in an eccentric annulus was derived by using the common conversion Maxwell fluid constitutive equation and then discretized by the control volume method. The velocity distribution of flow field was computed by using the ADI method. The influences of the pressure gradient, eccentricity, stroke length, and stroke frequency on the velocity and flow capacity in the flow field was analyzed. The foundation for further research of the eccentric wear problem of the pumping rod in polymer-flood well was laid.

  13. Effects of Slotted Structures on Nonlinear Characteristics of Natural Convection in a Cylinder with an Internal Concentric Slotted Annulus

    CERN Document Server

    Shen, Chunyun; Zhang, Yuwen; Li, Zheng

    2016-01-01

    Natural convection in a cylinder with an internally slotted annulus was solved by SIMPLE algorithm, and the effects of different slotted structures on nonlinear characteristics of natural convection were investigated. The results show that the equivalent thermal conductivity Keq increases with Rayleigh number, and reaches the maximum in the vertical orientation. Nonlinear results were obtained by simulating the fluid flow at different conditions. With increasing Rayleigh number, heat transfer is intensified and the state of heat transfer changes from the steady to unsteady. We investigated different slotted structures effects on natural convection, and analyze the corresponding nonlinear characteristics.

  14. Custom Anatomical 3D Spacer for Temporomandibular Joint Resection and Reconstruction

    Science.gov (United States)

    Green, John Marshall; Lawson, Sarah T.; Liacouras, Peter C.; Wise, Edward M.; Gentile, Michael A.; Grant, Gerald Thomas

    2015-01-01

    Two cases are presented using a two-stage approach and a custom antibiotic spacer placement. Temporomandibular reconstruction can be very demanding and accomplished with a variety of methods in preparation of a total joint and ramus reconstruction with total joint prostheses (TMJ Concepts, Ventura, CA). Three-dimensional reconstructions from diagnostic computed tomography were used to establish a virtually planned resection which included the entire condyle-ramus complex. From these data, digital designs were used to manufacture molds to facilitate intraoperative fabrication of precise custom anatomic spacers from rapidly setting antibiotic-impregnated polymethyl methacrylate. Molds were manufactured using vat polymerization (stereolithography) with a photopolymer in the first case and powder bed fusion (electron beam melting) with Ti6AL4V for the second. Surgical methodology and the use of molds for intraoperative spacer fabrication for each case are discussed. PMID:26889353

  15. Binding of Streptavidin to Surface-attached Biotin with Different Spacer Thicknesses

    Institute of Scientific and Technical Information of China (English)

    LI Yifei; ZHANG Haining

    2015-01-01

    The specific binding of receptor to ligand covalently attached to surface with different surface densities was studied using streptavidin-biotin model pair. Biotinylated substrates with different spacer thicknesses as formed through a simple reaction between amine immobilized surfaces and N-hydroxysucciimide groups at the end of biotin modiifed PEG in anhydrous organic solutions (“grafting to”technique). The amount of the speciifcally adsorbed protein was measured as a function of spacer thickness between hard surface and biotin moieties. It has been shown that the amount of specifically adsorbed streptavidin decreases with the increase spacer thickness and the protein adsorbs onto the functionalized surfaces in a single molecular manner. It provides an interesting model system for studying single molecular interactions.

  16. RISSC: a novel database for ribosomal 16S-23S RNA genes spacer regions.

    Science.gov (United States)

    García-Martínez, J; Bescós, I; Rodríguez-Sala, J J; Rodríguez-Valera, F

    2001-01-01

    A novel database, under the acronym RISSC (Ribosomal Intergenic Spacer Sequence Collection), has been created. It compiles more than 1600 entries of edited DNA sequence data from the 16S-23S ribosomal spacers present in most prokaryotes and organelles (e.g. mitochondria and chloroplasts) and is accessible through the Internet (http://ulises.umh.es/RISSC), where systematic searches for specific words can be conducted, as well as BLAST-type sequence searches. Additionally, a characteristic feature of this region, the presence/absence and nature of tRNA genes within the spacer, is included in all the entries, even when not previously indicated in the original database. All these combined features could provide a useful documentation tool for studies on evolution, identification, typing and strain characterization, among others.

  17. Staged Custom, Intramedullary Antibiotic Spacers for Severe Segmental Bone Loss in Infected Total Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Atul F. Kamath

    2011-01-01

    Full Text Available Introduction. Total hip arthroplasty (THA infections with severe bone loss pose significant reconstructive challenges. We present our experience with two-stage hip reimplantation using an intramedullary, antibiotic-impregnated nail. Methods. Three patients with infected THA with severe proximal femoral bone loss (Mallory type IIIB or greater were treated using a custom antibiotic spacer. Clinical outcomes and any complications were recorded. Average followup was 49 months from final reimplantation. Results. Mean age at spacer placement (stage 1 was 53 years. The mean Harris Hip Score at final followup was 80. Two patients had asymptomatic heterotopic ossification, and one patient had a 2 cm leg-length discrepancy. Conclusions. A custom intramedullary nail antibiotic spacer is a reliable option in the staged management of the infected THA with severe proximal femoral bone loss. Benefits of this technique include limb salvage with maintenance of leg length, soft tissue tension, and functional status.

  18. Effect of Weld Properties on the Crush Strength of the PWR Spacer Grid

    Directory of Open Access Journals (Sweden)

    Kee-nam Song

    2012-01-01

    Full Text Available Mechanical properties in a weld zone are different from those in the base material because of different microstructures. A spacer grid in PWR fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of the spacer grid was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of the spacer grid recently obtained by an instrumented indentation technique, the strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results were compared with the previous research.

  19. New clustered regularly interspaced short palindromic repeat locus spacer pair typing method based on the newly incorporated spacer for Salmonella enterica.

    Science.gov (United States)

    Li, Hao; Li, Peng; Xie, Jing; Yi, Shengjie; Yang, Chaojie; Wang, Jian; Sun, Jichao; Liu, Nan; Wang, Xu; Wu, Zhihao; Wang, Ligui; Hao, Rongzhang; Wang, Yong; Jia, Leili; Li, Kaiqin; Qiu, Shaofu; Song, Hongbin

    2014-08-01

    A clustered regularly interspaced short palindromic repeat (CRISPR) typing method has recently been developed and used for typing and subtyping of Salmonella spp., but it is complicated and labor intensive because it has to analyze all spacers in two CRISPR loci. Here, we developed a more convenient and efficient method, namely, CRISPR locus spacer pair typing (CLSPT), which only needs to analyze the two newly incorporated spacers adjoining the leader array in the two CRISPR loci. We analyzed a CRISPR array of 82 strains belonging to 21 Salmonella serovars isolated from humans in different areas of China by using this new method. We also retrieved the newly incorporated spacers in each CRISPR locus of 537 Salmonella isolates which have definite serotypes in the Pasteur Institute's CRISPR Database to evaluate this method. Our findings showed that this new CLSPT method presents a high level of consistency (kappa = 0.9872, Matthew's correlation coefficient = 0.9712) with the results of traditional serotyping, and thus, it can also be used to predict serotypes of Salmonella spp. Moreover, this new method has a considerable discriminatory power (discriminatory index [DI] = 0.8145), comparable to those of multilocus sequence typing (DI = 0.8088) and conventional CRISPR typing (DI = 0.8684). Because CLSPT only costs about $5 to $10 per isolate, it is a much cheaper and more attractive method for subtyping of Salmonella isolates. In conclusion, this new method will provide considerable advantages over other molecular subtyping methods, and it may become a valuable epidemiologic tool for the surveillance of Salmonella infections.

  20. Flunisolide hydrofluoroalkane with integrated spacer for treating asthma: an updated review.

    Science.gov (United States)

    Berger, William E; Tashkin, Donald P

    2015-01-01

    Flunisolide hydrofluoroalkane (HFA) with integrated spacer is the most recent reformulated inhaled corticosteroid (ICS) for asthma available in the United States. It is the only product that combines a corticosteroid extrafine aerosol with a built-in spacer. The potential clinical benefit of the flunisolide HFA formulation and its integrated spacer for treating persistent asthma was assessed through a comprehensive review of the published literature and data from the past 10 years focusing on (1) flunisolide, the molecule, and the impact of the HFA reformulation; (2) updated information on the anti-inflammatory response to flunisolide HFA, particularly in the distal airways; and (3) the usefulness of an integrated spacer. Flunisolide HFA was found effective and safe in clinical studies and comparable with the chlorofluorocarbon (CFC) formulation, but at about one-third the dose of flunisolide CFC, likely reflecting both the device and the particle size of the reformulated product. Compared with the CFC formulation, the extrafine aerosol and smaller particle size of flunisolide HFA substantially increased pulmonary deposition and decreased oropharyngeal deposition. The integrated spacer further enhanced the pulmonary/oropharyngeal deposition ratio. Examination of lung biopsy specimens indicated a favorable anti-inflammatory response to flunisolide HFA in peripheral airways. Pediatric studies showed no significant effects on growth. The data indicate that flunisolide HFA is a safe and effective maintenance therapy for asthma patients. The integrated spacer may provide an added advantage for patients, especially those who may be more likely to experience adverse effects of ICSs, both local and systemic, including children susceptible to adverse effects on growth.

  1. Constant-flux discrete heating in a unit aspect-ratio annulus

    Science.gov (United States)

    Lopez, J. M.; Sankar, M.; Do, Younghae

    2012-10-01

    Natural convection in an annulus with a discrete heat source on the inner cylinder is studied numerically. The outer cylinder is isothermally cooled at a fixed low temperature, and the top wall, the bottom wall and unheated portions of the inner cylinder are thermally insulated. For low applied heat flux through the heater, as measured non-dimensionally by a Grashof number, Gr, the flow in the annular gap consists of a single-cell overturning meridional flow driven by the radial temperature gradient between the heater on the inner cylinder and the cold outer cylinder. In this regime, the flow is very weak and heat is transported primarily via conduction. The flow structure does not change until Gr ˜ 104, although the flow strength steadily increases with Gr. As the nonlinear convection terms become more important, the meridional circulation sweeps the isotherms from being almost vertical near the outer cylinder to almost horizontal near the bottom wall. By the end of the transition from the conduction-dominated regime (Gr vertical levels below that of the bottom of the heater, an essentially cold stagnant pool develops, with the heat flux through the outer cylinder dropping to zero. (ii) At vertical levels between the bottom and the top of the heater, most of the region in between the two cylinders is stably stratified with a relatively weak radial flow from the cold to the heated cylinder. The horizontal isotherms adjust to the temperatures on the cylinders in thin buoyancy boundary layers which drive fluid down the cold cylinder and up the heated cylinder segment. The boundary layer on the heater is about half as thick as that on the cold cylinder, but about twice as intense. (iii) The third region is above the heater top. The boundary layer flow from the heater continues upward where it meets the top endwall and bounces off of it. A wavy jet bounces on its way radially outward between the top insulated wall and the stably stratified region below. Flow

  2. INTERLEUKIN-6 PROTECTS ANNULUS FIBROSUS CELL FROM APOPTOSIS INDUCED BY INTERLEUKIN-1 IN VITRO

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To investigate the effect of interleukin-6 (IL-6) on the apoptosis of annulus fibrosus (AF) cell induced by interleukin-1 β (IL-1 β).Methods Cultured AF cells were divided into 6 groups and treated with no drug, 10 ng/mL IL-6, 10 ng/mL IL1β, 10 ng/mL IL-1β and Z-VAD-FMK (a caspase-9 inhibitor), 10 ng/mL IL-1β and 10 ng/mL IL-6, 10 ng/mL IL-1β and 100 ng/mL IL-6, respectively. After three days of culture, the apoptosis rate, the positive rates of caspase3, -8, and -9 of AF cells were detected with flow cytometry.Results The apoptosis rates of cells in group 1 to 6 were 2. 67%±1.08%, 2.71%±0.53%, 20.37%±1.57%, 11.34%±0.67%, 18.17%±0.74%, and 9.42%±1.08%, respectively. There was no significant difference between group 1 and 2, while the apoptosis rates of group 4, 5, and 6 were significantly lower than group 3 (P=0.001, P=0.172, and P=0.001, respectively). Positive rates of caspase-3 in group 5 (12.35%± 0.64%) and 6(9.26%±0.36%) were significantly lower than group 3 (17.14%±0.72%; P=0.001 and P<0.001, respectively). And positive rates of caspase-9 in group 5 (15.13%±1.45%) and 6 (10.17%±2.50%) were significantly lower than group 3 (19.4%±0.98%;P=0.014 and P=0.004, respectively). But there was not obvious change of caspase-8 activity after IL-6 was added.Conclusion IL-6 is capable of protecting AF cells from IL-1 β induced apoptosis in vitro. Mechanism of the protection is related with the inhibition of caspase-3 and -9 activities.

  3. Fibrin-genipin annulus fibrosus sealant as a delivery system for anti-TNFα drug

    Science.gov (United States)

    Likhitpanichkul, Morakot; Kim, Yesul; Torre, Olivia M; See, Eugene; Kazezian, Zepur; Pandit, Abhay; Hecht, Andrew C

    2015-01-01

    Background context Intervertebral discs (IVD) are attractive targets for local drug delivery because they are avascular structures with limited transport. Painful IVDs are in a chronic inflammatory state. While anti-inflammatories show poor performance in clinical trials their efficacy treating IVD cells suggests that sustained, local drug delivery directly to painful IVDs may be beneficial. Purpose To determine if genipin crosslinked fibrin (FibGen) with collagen type I hollow spheres (CHS) can serve as a drug delivery carrier for the anti-TNFα drug, infliximab. Infliximab was chosen as a model drug because of the known role of TNFα in increasing downstream production of several pro-inflammatory cytokines and pain mediators. FibGen was used as drug carrier because it is adhesive injectable, slowly degrading hydrogel with potential to seal annulus fibrosus (AF) defects. CHS allow simple and non-damaging drug loading and could act as a drug reservoir to improve sustained delivery. Study Design/Setting Biomaterials and human AF cell culture study to determine drug release kinetics and efficacy. Methods Infliximab was delivered at low and high concentrations using FibGen with and without CHS. Gels were analyzed for structure, drug release kinetics, and efficacy treating human AF cells following release. This work was funded by grants from the NIAMS/NIH (R01 AR057397), AO Foundation, and from the Icahn School of Medicine at Mount Sinai. Results Fibrin showed rapid infliximab drug release but degraded quickly. CHS alone showed a sustained release profile but the small spheres may not remain in a degenerated IVD with fissures. FibGen showed steady and low levels of infliximab release that was increased when loaded with higher drug concentrations. Infliximab was bound in CHS when delivered within FibGen and was only released following enzymatic degradation. The infliximab released over 20 days retained its bioactivity as confirmed by the sustained reduction of IL-1

  4. Mobility Work

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bossen, Claus

    2005-01-01

    We posit the concept of Mobility Work to describe efforts of moving about people and things as part of accomplishing tasks. Mobility work can be seen as a spatial parallel to the concept of articulation work proposed by the sociologist Anselm Strauss. Articulation work describes efforts...... of coordination necessary in cooperative work, but focuses, we argue, mainly on the temporal aspects of cooperative work. As a supplement, the concept of mobility work focuses on the spatial aspects of cooperative work. Whereas actors seek to diminish the amount of articulation work needed in collaboration...... by constructing Standard Operation Procedures (SOPs), actors minimise mobility work by constructing Standard Operation Configurations (SOCs). We apply the concept of mobility work to the ethnography of hospital work, and argue that mobility arises because of the need to get access to people, places, knowledge and...

  5. Mobile Semiotics

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2013-01-01

    This chapter aims to understand the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The chapter explores the potentials of semiotics and its relationship to the new mobilities literature. What takes place is a ‘mob......This chapter aims to understand the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The chapter explores the potentials of semiotics and its relationship to the new mobilities literature. What takes place...... is a ‘mobile sense making’ where signs and materially situated meanings connect to the moving human body and thus create particular challenges and complexities of making sense of the world. The chapter includes notions of mobility systems and socio-technical networks in order to show how a ‘semiotic layer’ may...

  6. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    of departure in the sociological perspective termed ‘Staging Mobilities’ (Jensen 2013a) and utilizes this as an analytical frame for exploring cases of mobility design. The paper put focus on how the material shape, design and architectures of technologies, spaces and sites influence mobilities practices......, mobilitiy technologies or urban sites of movement we get much closer to understanding the meaning of mobilities to social interaction and culture. The cases are still representing work-in-progress but will be reported in the book ‘Designing Mobilites’ (Jensen 2013b) and will cover the four cases of......Within the so-called ‘mobilities turn’ (Adey 2010; Cresswell 2006; Urry 2007) much research has taken place during the last decade bringing mobilities into the centre of sociological analysis. However, the materiality and spatiality of artefacts, infrastructures, and sites hosting mobilities...

  7. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix; Wind, Simon

    2016-01-01

    In this paper, we identify the nexus between design (architecture, urban design, service design, etc.) and mobilities as a new and emerging research field. In this paper, we apply a “situational mobilities” perspective and take point of departure in the pragmatist question: “What design decisions...... and interventions affords this particular mobile situation?” The paper presents the contours of an emerging research agenda within mobilities research. The advent of “mobilities design” as an emerging research field points towards a critical interest in the material as well as practical consequences of contemporary......-making. The paper proposes that increased understanding of the material affordances facilitated through design provides important insight to planning and policymaking that at times might be in risk of becoming too detached from the everyday life of the mobile subject within contemporary mobilities landscapes....

  8. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix; Wind, Simon

    2016-01-01

    In this paper, we identify the nexus between design (architecture, urban design, service design, etc.) and mobilities as a new and emerging research field. In this paper, we apply a “situational mobilities” perspective and take point of departure in the pragmatist question: “What design decisions...... and interventions affords this particular mobile situation?” The paper presents the contours of an emerging research agenda within mobilities research. The advent of “mobilities design” as an emerging research field points towards a critical interest in the material as well as practical consequences of contemporary...... sites of mobilities and technology. Furthermore, the paper argues that heightened material sensitivity with an acute focus on situations and the multi-sensorial dimensions of human mobilities is largely under-prioritised within much contemporary city planning and transport planning as well as policy...

  9. Heterogeneous Diversity of Spacers within CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)

    Science.gov (United States)

    He, Jiankui; Deem, Michael W.

    2010-09-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) in bacterial and archaeal DNA have recently been shown to be a new type of antiviral immune system in these organisms. We here study the diversity of spacers in CRISPR under selective pressure. We propose a population dynamics model that explains the biological observation that the leader-proximal end of CRISPR is more diversified and the leader-distal end of CRISPR is more conserved. This result is shown to be in agreement with recent experiments. Our results show that the CRISPR spacer structure is influenced by and provides a record of the viral challenges that bacteria face.

  10. Microbial fuel cells with an integrated spacer and separate anode and cathode modules

    KAUST Repository

    He, Weihua

    2016-01-01

    A new type of scalable MFC was developed based on using alternating graphite fiber brush array anode modules and dual cathode modules in order to simplify construction, operation, and maintenance of the electrodes. The modular MFC design was tested with a single (two-sided) cathode module with a specific surface area of 29 m2 m−3 based on a total liquid volume (1.4 L; 20 m2 m−3 using the total reactor volume of 2 L), and two brush anode modules. Three different types of spacers were used in the cathode module to provide structural stability, and enhance air flow relative to previous cassette (combined anode–cathode) designs: a low-profile wire spacer; a rigid polycarbonate column spacer; and a flexible plastic mesh spacer. The best performance was obtained using the wire spacer that produced a maximum power density of 1100 ± 10 mW m−2 of cathode (32 ± 0.3 W m−3 based on liquid volume) with an acetate-amended wastewater (COD = 1010 ± 30 mg L−1), compared to 1010 ± 10 mW m−2 for the column and 650 ± 20 mW m−2 for the mesh spacers. Anode potentials were unaffected by the different types of spacers. Raw domestic wastewater produced a maximum of 400 ± 8 mW m−2 under fed batch conditions (wire-spacers), which is one of the highest power densities for this fuel. Over time the maximum power was reduced to 300 ± 10 mW m−2 and 275 ± 7 mW m−2 for the two anode compartments, with only slightly less power of 250 ± 20 mW m−2 obtained under continuous flow conditions. In fixed-resistance tests, the average COD removal was 57 ± 5% at a hydraulic retention time of 8 h. These results show that this modular MFC design can both simplify reactor construction and enable relatively high power generation from even relatively dilute wastewater.

  11. The Effect of Various Fabric Parameters on the Sound Absorption Properties of Circular Knitted Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Arzu Marmaralı

    2014-07-01

    Full Text Available Spacer fabrics which can be produced through weaving or nonwoven technique beside warp knitting and weft knitting processes, can be used for functional applications such as automotive textiles, medical textiles, geotextiles, sportswear, protective textiles and composites due to the possibility of using a variety of different materials, flexible product range and the three dimensional construction. Additionally they can also be used for sound absorption applications with different pore geometry. In this study, the effect of fabric parameters like material type, fabric thickness and surface structures on the sound absorption properties of circular knitted spacer fabrics was investigated and aimed to determine the optimum fabric parameters for better sound absorption.

  12. Role of the conjugated spacer in the optimization of second-order nonlinear chromophores

    Science.gov (United States)

    Pérez-Moreno, Javier; Clays, Koen; Kuzyk, Mark G.

    2009-08-01

    We investigate the role of the conjugated spacer in the optimization of the first hyperpolarizability of organic chromophores. We propose a novel strategy for the optimization of the first hyperpolarizability that is based on the variation of the degree of conjugation for the bridge that separates the donor and acceptors at the end of push-pull type chromophores. The correlation between the type of conjugated spacer and the experimental nonlinear performance of the chromophores is investigated and interpreted in the context of the quantum limits.

  13. Mobile museology

    DEFF Research Database (Denmark)

    Baggesen, Rikke Haller

    Drawing together perspectives from museology, digital culture studies and fashion theory, this thesis considers changes in and challenges for current - day museums as related to ‘mobile museology’. This concept is developed for and elucidated in the thesis to describe an orientation towards...... the fashionable, the ephemeral, and towards an (ideal) state of change and changeability. This orientation is characterised with the triplet concepts of mobile, mobility, and mobilisation, as related to mobile media and movability; to ‘trans - museal’ mediation; and to the mobilisation of collections, audiences...

  14. Hole-transfer induced energy transfer in perylene diimide dyads with a donor-spacer-acceptor motif.

    Science.gov (United States)

    Kölle, Patrick; Pugliesi, Igor; Langhals, Heinz; Wilcken, Roland; Esterbauer, Andreas J; de Vivie-Riedle, Regina; Riedle, Eberhard

    2015-10-14

    We investigate the photoinduced dynamics of perylene diimide dyads based on a donor-spacer-acceptor motif with polyyne spacers of varying length by pump-probe spectroscopy, time resolved fluorescence, chemical variation and quantum chemistry. While the dyads with pyridine based polyyne spacers undergo energy transfer with near-unity quantum efficiency, in the dyads with phenyl based polyyne spacers the energy transfer efficiency drops below 50%. This suggests the presence of a competing electron transfer process from the spacer to the energy donor as the excitation sink. Transient absorption spectra, however, reveal that the spacer actually mediates the energy transfer dynamics. The ground state bleach features of the polyyne spacers appear due to the electron transfer decay with the same time constant present in the rise of the ground state bleach and stimulated emission of the perylene energy acceptor. Although the electron transfer process initially quenches the fluorescence of the donor it does not inhibit energy transfer to the perylene energy acceptor. The transient signatures reveal that electron and energy transfer processes are sequential and indicate that the donor-spacer electron transfer state itself is responsible for the energy transfer. Through the introduction of a Dexter blocker unit into the spacer we can clearly exclude any through bond Dexter-type energy transfer. Ab initio calculations on the donor-spacer and the donor-spacer-acceptor systems reveal the existence of a bright charge transfer state that is close in energy to the locally excited state of the acceptor. Multipole-multipole interactions between the bright charge transfer state and the acceptor state enable the energy transfer. We term this mechanism coupled hole-transfer FRET. These dyads represent a first example that shows how electron transfer can be connected to energy transfer for use in novel photovoltaic and optoelectronic devices.

  15. Characterization of mechanics and cytocompatibility of fibrin-genipin annulus fibrosus sealant with the addition of cell adhesion molecules.

    Science.gov (United States)

    Guterl, Clare C; Torre, Olivia M; Purmessur, Devina; Dave, Khyati; Likhitpanichkul, Morakot; Hecht, Andrew C; Nicoll, Steven B; Iatridis, James C

    2014-09-01

    There is an unmet clinical need for a biomaterial sealant capable of repairing small annulus fibrosus (AF) defects. Causes of these defects include painful intervertebral disc herniations, microdiscectomy procedures, morbidity associated with needle puncture injury from discography, and future nucleus replacement procedures. This study describes the enhancements of a fibrin gel through genipin crosslinking (FibGen) and the addition of the cell adhesion molecules (CAMs), fibronectin and collagen. The gel's performance as a potential AF sealant is assessed using a series of in vitro tests. FibGen gels with CAMs had equivalent adhesive strength, gene expression, cytomorphology, and cell proliferation as fibrin alone. However, FibGen gels had enhanced material behaviors that were tunable to higher shear stiffness values and approximated human annulus tissue as compared with fibrin alone, were more dimensionally stable, and had a slower in vitro degradation rate. Cytomorphology of human AF cells cultured on FibGen gels exhibited increased elongation compared with fibrin alone, and the addition of CAMs to FibGen did not significantly affect elongation. This FibGen gel offers the promise of being used as a sealant material to repair small AF defects or to be used in combination with other biomaterials as an adhesive for larger defects.

  16. New Annulus Testing Pipe String Development%新型环空测试工艺管柱研制

    Institute of Scientific and Technical Information of China (English)

    于洋洋; 高翔; 刘宇飞

    2016-01-01

    Annulus logging technology has the following advantage,less working procedure,high data accuracy,so it was favored by the oil field.With the development of oil field,but with the in-crease of the deepening of oilfield development and deep deviated well,the inadaptability of the annulus test technology is gradually emerging,cable winding has appeared,a crescent shaped space is insufficient,decentralized wellhead rebound and other issues.To solve these problems, small tubing ring empty testing pipe string was designed,and three kinds of supporting tools are researched,especially the downhole tubing rotator,effective solve the pipe string rotation prob-lems in deviated well.%针对环空测试工艺技术出现电缆缠绕、“月牙形”空间不足、偏心井口反弹等问题,设计了小油管环空测试工艺管柱,并研发了3种配套工具,特别是井下油管旋转器,有效解决了斜井管柱转不动的问题。

  17. Simultaneous effects of single wall carbon nanotube and effective variable viscosity for peristaltic flow through annulus having permeable walls

    Science.gov (United States)

    Shahzadi, Iqra; Nadeem, S.; Rabiei, Faranak

    The current article deals with the combine effects of single wall carbon nanotubes and effective viscosity for the peristaltic flow of nanofluid through annulus. The nature of the walls is assumed to be permeable. The present theoretical model can be considered as mathematical representation to the motion of conductive physiological fluids in the existence of the endoscope tube which has many biomedical applications such as drug delivery system. The outer tube has a wave of sinusoidal nature that is travelling along its walls while the inner tube is rigid and uniform. Lubrication approach is used for the considered analysis. An empirical relation for the effective variable viscosity of nanofluid is proposed here interestingly. The viscosity of nanofluid is the function of radial distance and the concentration of nanoparticles. Exact solution for the resulting system of equations is displayed for various quantities of interest. The outcomes show that the maximum velocity of SWCNT-blood nanofluid enhances for larger values of viscosity parameter. The pressure gradient in the more extensive part of the annulus is likewise found to increase as a function of variable viscosity parameter. The size of the trapped bolus is also influenced by variable viscosity parameter. The present examination also revealed that the carbon nanotubes have many applications related to biomedicine.

  18. Mobile Semiotics - signs and mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    This paper is about how to comprehend the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The paper explores the potentials of semiotics and its relationship to the new mobilities literature. The theoretical scope...... is therefore an attempt to mobilize semiotics by drawing on a central body of theory within and adjacent to the discipline. For instance the founding works of C. S. Peirce will be related to the contemporary notions of ‘geosemiotics’ by Scollon & Scollon. The paper’s theoretical claim is that semiotics hold...... a potential for mobilities studies if the awareness of seeing the environment as a semiotic layer and system can be sensitized to the insights of the ‘mobilities turn’. Empirically the paper tentatively explores the usefulness of a mobile semiotics approach to cases such as street signage, airport design...

  19. Mobile phones and mobile communication

    DEFF Research Database (Denmark)

    Ling, Richard; Donner, Jonathan

    With staggering swiftness, the mobile phone has become a fixture of daily life in almost every society on earth. In 2007, the world had over 3 billion mobile subscriptions. Prosperous nations boast of having more subscriptions than people. In the developing world, hundreds of millions of people who...... could never afford a landline telephone now have a mobile number of their own. With a mobile in our hand many of us feel safer, more productive, and more connected to loved ones, but perhaps also more distracted and less involved with things happening immediately around us. Written by two leading...... researchers in the field, this volume presents an overview of the mobile telephone as a social and cultural phenomenon. Research is summarized and made accessible though detailed descriptions of ten mobile users from around the world. These illustrate popular debates, as well as deeper social forces at work...

  20. PRESSURE DISTRIBUTION ON THE WALL OF THE INNER CYLINDER RECIPROCATING AXIALLY TO THE UNSTEADY FLOW OF VISCOELASTIC FLUID IN ECCENTRIC ANNULUS

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; CUI Hai-qing; YANG Yuan-jian; GUO Jun-hui; LI Nan

    2006-01-01

    In this article, the governing equations for the unsteady flow of viscoelastic fluid in the eccentric annulus with the inner cylinder reciprocating axially and the expression of the pressure distribution on the wall of the inner cylinder of the annulus are established and derived, respectively, under the bipolar coordinate system.The equations and the expression are solved and calculated numerically using the finite difference method, respectively.The curves of the pressure distribution on the wall of the inner cylinder of the aqueous solution of Hydrolyzed Polyacrylamide (HPAM) are plotted and the influences of annular eccentricity, stroke, and stroke frequency on the pressure distribution are analyzed.

  1. Histological observation of a gelatin sponge transplant loaded with bone marrow-derived mesenchymal stem cells combined with platelet-rich plasma in repairing an annulus defect

    Science.gov (United States)

    Xu, Xiang; Hu, Jianzhong; Lu, Hongbin

    2017-01-01

    Objective To research the histological characteristics of a gelatin sponge transplant loaded with goat BMSCs (bone marrow-derived mesenchymal stem cells) combined with PRP (platelet-rich plasma) in repairing an annulus defect. Method BMSCs were separated from the iliac crest of goats, sub-cultured and identified after the third generation. Then, PRP was obtained using blood from the jugular vein of goats via two degrees of centrifugation. In the animal experiments, the goats were divided into the following three groups: a sham group, an injury group and a therapeutic group. In the sham group, we decompressed the lamina and exposed the annulus fibrosus. In the injury group, we exposed the annulus fibrosus after decompression of the lamina and created a 1 × 1 cm defect in the annulus using surgical instruments. In the therapeutic group, after decompression of the lamina, we exposed the annulus, created a 1 × 1 cm defect using surgical instruments, and placed a gelatin sponge combined with BMSCs and PRP into the defect for a combined method of repair. Three, six and twelve weeks after the surgery, the previously damaged or undamaged annulus tissue was removed from the three groups. Then, the above tissue was assayed using HE (hematoxylin-eosin) staining, Masson trichrome staining, AB-PAS (Alcian blue-periodic acid Schiff) staining, and type II collagen staining and observed by microscopy. Results From the HE staining, we observed that the number of repair cells gradually increased. Compared to the injury group, the cell density and gross morphology of cells in the therapeutic group were closer to those of the sham group. As observed by Masson trichrome gelatin staining, many of the fibroblast cells or tissues were under repair, and as time progressed, the number of fibroblast cells and amount of tissue gradually increased. The results of the AB-PAS staining suggest that chondrocytes participated in the repair of the annulus. The level of type II collagen gradually

  2. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    examples of mobile clouds applications, based on both existing commercial initiatives as well as proof-of-concept test-beds. Visions and prospects are also discussed, paving the way for further development. As mobile networks and social networks become more and more reliant on each other, the concept...

  3. Effect of electrostatic charge in plastic spacers on the lung delivery of HFA-salbutamol in children

    DEFF Research Database (Denmark)

    Anhøj, J; Bisgaard, H; Lipworth, B J

    1999-01-01

    was delivered on 3 different study days from plastic spacers with mouthpiece. Pre-treatment of the spacers differed between study days: (a) Non-electrostatic 350 ml Babyhaler (coated with benzalkonium chloride) (b) New 350 ml Babyhaler (rinsed in water), and (c) New 145 ml AeroChamber (rinsed in water). Plasma...

  4. Unusual low-energy near-infrared bands for ferrocenyl-naphthalimide donor-acceptor dyads with aromatic spacer groups

    DEFF Research Database (Denmark)

    Tagg, Tei; Kjærgaard, Henrik Grum; Lane, Joseph R.

    2015-01-01

    Time-dependent density functional theory (TDDFT) calculations for a series of donor-spacer-acceptor (D-S-A) molecules with phenyl (1), biphenyl (2), and anthryl (3) spacers interpolated between the ferrocenylalkene donor and -C≡C-4-naphthalimido acceptor components predicted the presence of weak,...

  5. Interference-driven spacer acquisition is dominant over naive and primed adaptation in a native CRISPR-Cas system

    NARCIS (Netherlands)

    Staals, Raymond H.J.; Jackson, Simon A.; Biswas, Ambarish; Brouns, Stan J.J.; Brown, Chris M.; Fineran, Peter C.

    2016-01-01

    CRISPR-Cas systems provide bacteria with adaptive immunity against foreign nucleic acids by acquiring short, invader-derived sequences called spacers. Here, we use high-throughput sequencing to analyse millions of spacer acquisition events in wild-type populations of Pectobacterium atrosepticum.

  6. Sequence analysis of rDNA intergenic spacer region (IGS) as a tool for phylogenetic studies in Trichoderma spp.

    Institute of Scientific and Technical Information of China (English)

    Mercatelli Elisabetta; Pecchia Susanna; Ciliegi Sandro; Vannacci Giovanni

    2004-01-01

    @@ Different from ribosomal genes, which contain highly conserved sequences that are detected in all organisms, the intergenic spacer of rDNA (IGS) appears to be the most rapidly-evolving spacer region. For this reason we tested this region for phylogenetic studies.

  7. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    How is the width of the pavement shaping the urban experience? How is the material design of transport infrastructure and mobile technology affording social interaction in everyday life spaces? How do people inhabit these spaces with their bodies and in accordance to social and cultural norms......? These are some of the questions that this book raises in order to explore how the design of mobile sites and situations affect people's everyday life. The book takes point of departure in the author's book 'Staging Mobilities' (Routledge, 2013) in which it is argued that mobility is much more than simple...... acts of moving in the city. 'Designing Mobilities' is based on more than a decade of academic research by Professor of Urban Theory, Ole B. Jensen and a must-read for students and scholars with an interest in urban studies, urban design, architecture, urban planning, transport planning and geography...

  8. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    In recent years, the social sciences have taken a “mobilities turn.” There has been a developing realisation that mobilities do not “just happen.” Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed...... that mobility is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments......, the book asks: what are the physical, social, technical, and cultural conditions to the staging of contemporary urban mobilities?...

  9. Development and Evaluation of a New Nanometer Based Spacer NMS-I

    Institute of Scientific and Technical Information of China (English)

    Cheng Rongchao; Wang Ruihe; Cao Huilian; Bu Yuhuan; Cheng Yuanfang

    2007-01-01

    In view of the inadequate cementing quality in the cementation for long isolation intervals of oil and gas wells,and considering the field practice in Tarim Oilfield,a nanometer material LC-212 was introduced as the base stock to experimentally develop a new spacer system NMS-I,in combination with other materials,including a chemical gel plugging agent,carboxymethyl cellulose and barite. Experimental results indicated that the system had a wide adjustable range of density,good rheological property,static stability and compatibility with cement slurry. It also showed no flocculating or thickening effect on the water-base drilling fluid and low-density cement system. Meanwhile,the capacity of lost circulation control and the influence of the spacer on the second interfacial cementing strength were evaluated by a self-made lost circulation simulator and shearing test facility. The results showed that the spacer had favorable plugging and flushing effect,and the second interfacial cementing strength can be greatly improved. Moreover,based on the experiments,the mechanisms of spacer function were analyzed. The results obtained from the investigation offer a novel approach to resolving some practical problems in cementing jobs.

  10. Usefulness of a radiolucent spacer in radiation therapy for cancer of the tongue

    Energy Technology Data Exchange (ETDEWEB)

    Yokoi, Motoo (Nagoya City Univ. (Japan). Hospital); Ito, Yoshiyuki; Fuwa, Nobukazu; Kato, Eriko; Murao, Takayuki; Morita, Kozo

    1993-05-01

    For the purpose of preventing osteonecrosis following interstitial irradiation for tongue cancer, a Radiolucent Spacer was prepared with the intention of reducing bone dose by keeping the mandible at a distance from the source. Because of its radiolucency, the Spacer made of silicone enables to perform X-P while inserted, and more exact dose calculation. For 6 cases in which 8 mm-spacer was used, dose reduction rate for surface of lower gingiva corresponded to 42.3%, average of tumor dose for TDF. For 51 cases in which the observation of course was practicable for 2 years--9 years and 4 months, averaging 5 years and 7 months, the incidence of osteonecrosis was 0%, and therefore, Spacer of not less than 8 mm-thickness is thought useful as prosthesis. Extraction of the tooth was done at the start of irradiation, but the healing course was always favorable. The most aseptic possible alveolectomy and complete closure of the wound are necessary for tooth extraction. (author).

  11. Development of Finite Element Model for the Static Buckling Behavior of the Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Young Ik; Park, Nam Gyu; Kim, Kyoung Ju; Suh, Jung Min [Kepco Nuclear Fuel, Daejeon (Korea, Republic of)

    2013-10-15

    In this study, finite element model was proposed to evaluate the buckling characteristics and structural behavior of partial spacer grids. A two-dimensional model was developed to simplify a real spacer gird model and save analysis time. And it was validated for comparison with experimental tests. A non-linear analysis method was introduced to perform realistic simulation. Later, the buckling analysis of the full size grid will be performed based on the analysis results of partial spacer grids. A study was conducted to develop the simplified model of a spacer grid and provide a prediction of buckling behavior. The FE analysis results are quite similar to the experimental tests. · The deformed geometry of FE model after compression is consistent and very similar to that of real situation, and the non-linear analysis method used in this model can simulate buckling and post-buckling behavior well. · The buckling strength obtained by FEM shows a very good agreement with the physical tests.

  12. Electrochemical behavior and dioxygen reactivity of tripodal dinuclear copper complexes linked by unsaturated rigid spacers.

    Science.gov (United States)

    Gomila, Antoine; Le Poul, Nicolas; Kerbaol, Jean-Michel; Cosquer, Nathalie; Triki, Smaïl; Douziech, Bénédicte; Conan, Françoise; Le Mest, Yves

    2013-02-14

    New dinucleating ligands based on two tripodal tris(2-pyridylmethyl)amine (TMPA) units linked by a series of delocalized π-electrons spacers have been synthesized. Their di-Cu(II) complexes have been prepared and structurally characterized. As compared to the corresponding monotopic complexes, these dinuclear Cu(II) complexes reveal spectroscopic and voltammetric features ascribable to weakly perturbed electronic interactions. In the case of the anthracenyl spacer, observation both in the solid and in solution suggests that the existence of intramolecular π-π stacking interactions influences the geometry of the complex and hence its electronic properties. The bis-Cu(I) complexes were prepared electrochemically. In the specific case of the complex bearing a mono-alkyne spacer, addition of dioxygen in acetonitrile leads to the slow formation of a trans-μ-1,2 peroxo Cu(2) complex which shows good stability at 268 K (t(1/2) = 240 s). Analysis of the kinetics of the peroxo formation by UV-vis spectroscopy suggests that the increased activation barrier for intramolecular binding of dioxygen is due to the rigidity of the spacer.

  13. The Interspinous Spacer: A New Posterior Dynamic Stabilization Concept for Prevention of Adjacent Segment Disease

    Directory of Open Access Journals (Sweden)

    Antoine Nachanakian

    2013-01-01

    Full Text Available Introduction. Posterior Dynamic stabilization using the interspinous spacer device is a known to be used as an alternative to rigid fusion in neurogenic claudication patients in the absence of macro instability. Actually, it plays an important in the management of adjacent segment disease in previously fused lumbar spine. Materials and Method. We report our experience with posterior dynamic stabilization using an interspinous spacer. 134 cases performed in our institution between September 2008 and August 2012 with different lumbar spine pathologies. The ages of our patients were between 40 and 72 years, with a mean age of 57 years. After almost 4 years of follow up in our patient and comparing their outcome to our previous serious we found that in some case the interspinous distracter has an important role not only in the treatment of adjacent segment disease but also in its prevention. Results and Discussion. Clinical improvement was noted in ISD-treated patients, with high satisfaction rate. At first, radicular pain improves with more than 3/10 reduction of the mean score on visual analog scale (VAS. In addition, disability score as well as disc height and lordotic angle showed major improvement at 3 to 6 months post operatively. And, no adjacent segment disease was reported in the patient operated with interspinous spacer. Conclusion. The interspinous spacer is safe and efficient modality to be used not only as a treatment of adjacent segment disease but also as a preventive measure in patients necessitating rigid fusion.

  14. A New Pyrene-Spacer-Maleimide Dyad for Sensing Molecules with One or Two Thiol Groups

    Institute of Scientific and Technical Information of China (English)

    WANG,Zhuo; ZHANG,De-Qing; ZHU,Dao-Ben

    2006-01-01

    A new pyrene-spacer-maleimide dyad 1 was used to selectively detect cysteine in the presence of other amino acids, and sequentially react with dithiols to generate the molecule with two pyrene units showing typical excimer fluorescence. Accordingly, dyad 1 was able to differentiate molecules with one or two thiol groups.

  15. Response of an annular electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Johansson, Torben; MacAllister, I. W.

    2002-01-01

    The response of an annular electrostatic probe mounted in an electrode is examined with reference to a right cylindrical spacer. The study involves using the probe λ function to derive characteristic parameters. These parameters enable the response of the probe to different charge distributions...

  16. Dynamic simulation of universal spacer in Dynesys dynamic stabilization system for human vertebra

    Institute of Scientific and Technical Information of China (English)

    Sung-Min KIM; In-Chul YANG; Seung-Yeol LEE; Sung-Youn CHO

    2009-01-01

    The aim of this study is to analyze the simulated behavior of universal spacer in Dynesys dynamic stabilization system inserted in human vertebra. Dynesys, so-called "Dynamic neutralization system for the spine", dynamic stabilization system is a new concept in the surgical treatment of lower back pain recently. Universal spacer used as flexible material is to stabilize the spine and the material property of universal spacer is polycarbonate urethane. Universal spacer may apply different kinematic behaviors at implanted level in vertebra. Spinal range of motion(SROM) of inter-vertebra with installed Dynesys dynamic stabilization system was studied using Adams+LifeMOD as simulation software package. The vertebra model was set up to closely resemble the in-vivo conditions. Inter-vertebra rotations were measured by post processor of Adams and compared with the intact values. SROMs of the flexion, extension, lateral bending, and axial rotation of human virtual models were measured, where three spinal fixation systems such as rigid system, Dynesys system, and fused system were installed. As a result, the value of SROM is decreased in flexion-extension and lateral bending when the spinal fixation system is implanted. The movement of Dynesys system is similar to that of intact model by allowing the movement of lumbar. This means that the Dynesys system is proved to be safe and effective in the treatment of unstable spinal condition.

  17. Investigations in Number, Data, and Space[R]. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2013

    2013-01-01

    "Investigations in Number, Data, and Space"[R], published by Pearson Scott Foresman, is an activity-based K-5 mathematics curriculum designed to help students understand number and operations, geometry, data, measurement, and early algebra. Each instructional unit focuses on a particular content area and lasts from two to five-and-a-half…

  18. Investigations in Number, Data, and Space[R]. WWC Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2009

    2009-01-01

    Investigations in Number, Data, and Space[R], published by Pearson Scott Foresman, is an activity-based K-5 mathematics curriculum designed to help students understand the fundamental ideas of number and operations, geometry, data, measurement, and early algebra. The curriculum encourages students to use prior knowledge to develop an understanding…

  19. Structural analysis of two length variants of the rDNA intergenic spacer from Eruca sativa.

    Science.gov (United States)

    Lakshmikumaran, M; Negi, M S

    1994-03-01

    Restriction enzyme analysis of the rRNA genes of Eruca sativa indicated the presence of many length variants within a single plant and also between different cultivars which is unusual for most crucifers studied so far. Two length variants of the rDNA intergenic spacer (IGS) from a single individual E. sativa (cv. Itsa) plant were cloned and characterized. The complete nucleotide sequences of both the variants (3 kb and 4 kb) were determined. The intergenic spacer contains three families of tandemly repeated DNA sequences denoted as A, B and C. However, the long (4 kb) variant shows the presence of an additional repeat, denoted as D, which is a duplication of a 224 bp sequence just upstream of the putative transcription initiation site. Repeat units belonging to the three different families (A, B and C) were in the size range of 22 to 30 bp. Such short repeat elements are present in the IGS of most of the crucifers analysed so far. Sequence analysis of the variants (3 kb and 4 kb) revealed that the length heterogeneity of the spacer is located at three different regions and is due to the varying copy numbers of repeat units belonging to families A and B. Length variation of the spacer is also due to the presence of a large duplication (D repeats) in the 4 kb variant which is absent in the 3 kb variant. The putative transcription initiation site was identified by comparisons with the rDNA sequences from other plant species.

  20. Aerosol delivery from spacers in wheezy infants: a daily life study

    NARCIS (Netherlands)

    H.M. Janssens (Hettie); E.M. Heijnen; V.M. de Jong; W.C.J. Hop (Wim); W.P. Holland (Wim); J.C. de Jongste (Johan); H.A.W.M. Tiddens (Harm)

    2000-01-01

    textabstractThe aims of this study were to assess and compare dose delivery and dose variability of pressurized metered dose inhalers (pMDI)/spacers in wheezy infants in daily life and to investigate factors influencing aerosol delivery. In an open randomized crossover

  1. Mechanical Properties Of 3D-Structure Composites Based On Warp-Knitted Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Chen Si

    2015-06-01

    Full Text Available In this paper, the mechanical properties (compression and impact behaviours of three-dimension structure (3D-structure composites based on warp-knitted spacer fabrics have been thoroughly investigated. In order to discuss the effect of fabric structural parameters on the mechanical performance of composites, six different types of warp-knitted spacer fabrics having different structural parameters (such as outer layer structure, diameter of spacer yarn, spacer yarn inclination angle and thickness were involved for comparison study. The 3D-structure composites were fabricated based on a flexible polyurethane foam. The produced composites were characterised for compression and impact properties. The findings obtained indicate that the fabric structural parameters have strong influence on the compression and impact responses of 3D-structure composites. Additionally, the impact test carried out on the 3D-structure composites shows that the impact loads do not affect the integrity of composite structure. All the results reveal that the product exhibits promising mechanical performance and its service life can be sustained.

  2. Effect of spacer dielectric engineering on Asymmetric Source Underlapped Double Gate MOSFET using Gate Stack

    Science.gov (United States)

    Chattopadhyay, Ankush; Dasgupta, Arpan; Das, Rahul; Kundu, Atanu; Sarkar, Chandan K.

    2017-01-01

    In this paper, the use of high-k spacers in a source underlapped nMOSFET is explored. The effects have been reported by varying the dielectric constant of the spacer from 3.9 to 22.5 and the study includes a comparison of analog parameters such as transconductance, transconductance generation factor, intrinsic gain, and RF parameters such as parasitic capacitances, resistances, and cut-off frequency. The RF parameters are calculated using the Non-Quasi Static (NQS) Approach which is required for sub 20 nm technology node. The device with high-k spacers features an improvement of 33% in DIBL, significantly increases the on current and reducing the off current by 60%. However, there is a slight compromise in the RF performance of the device, owing to an increase in intrinsic capacitance by about 0.35 fF. The Voltage Transfer Characteristics (VTC) and AC gain analysis of the circuit is also done in this paper. The circuit performance using single stage amplifier with the proposed device as the driver MOS has been analysed. High-k spacers also account for 19% improvement in small signal gain when used in a single stage amplifier circuit.

  3. Genotyping of Histomonas meleagridis isolates based on Internal Transcribed Spacer-1 sequences

    NARCIS (Netherlands)

    H.M.J.F. van der Heijden; W.J.M. Landman; S. Greve; R. Peek

    2006-01-01

    C-profiling is a novel genotyping method for protozoan pathogens, based on polymerase chain reaction and sequencing of AT-rich Internal Transcribed Spacer-1 sequences. It was applied to various Histomonas meleagridis isolates originating from outbreaks of histomoniasis in six Dutch turkey and chicke

  4. Treatment of an old infection in a total hip replacement with an interim spacer prosthesis.

    Science.gov (United States)

    Zilkens, K W; Casser, H R; Ohnsorge, J

    1990-01-01

    When treating a septic hip-joint prosthesis with bone loss of the proximal femur secondary to osteomyelitis, we implanted a specially designed prosthesis to act as a local antibiotic and spacer between the acetabulum and femur until the infection abated. Arthroplasty could then be carried out with no trouble and there was no recurrence of infection.

  5. Influence of the spacer on the inhibitory effect of different polycarbophil-protease inhibitor conjugates.

    Science.gov (United States)

    Marschütz, M K; Veronese, F M; Bernkop-Schnürch, A

    2001-09-01

    Within the present study various polycarbophil (PCP)-serine protease inhibitor conjugates were synthesized and the influence of different spacers on their inhibitory efficacy was evaluated in vitro. Results demonstrated that 4.2+/-0.15 units (n=3; +/-SD) of alpha-chymotrypsin were inhibited by 50% utilizing 0.86% (w/v) of a PCP-tetramethylenediamine (TMDA)-chymostatin 20:1 conjugate. In contrast, only 0.6+/-0.05 units (n=3; +/-SD) of alpha-chymotrypsin were inhibited by a corresponding PCP-poly(ethylene glycol) (PEG)-chymostatin conjugate. Inhibitory effects of PCP-TMDA-antipain and -elastatinal conjugates towards trypsin and elastase, respectively, were also significantly higher (P<0.05) than those of corresponding PCP-PEG-inhibitor conjugates. Hence, the great impact of the molecular size as well as the structure of the spacer on resulting polymer-inhibitor conjugates could be demonstrated. The small and rigid C4-spacer TMDA (molecular weight (MW) 161.1) was thereby shown to be highly advantageous over a long, hydrophilic and flexible PEG-diamine spacer (MW 3400). Results obtained should provide helpful basic knowledge for the development of mucoadhesive polymer-inhibitor conjugates used as auxiliary agents for the oral administration of peptide drugs.

  6. Bending of the Flexible Spacer Chain of Gemini Surfactant Induced by Hydrophobic Interaction

    Institute of Scientific and Technical Information of China (English)

    YOU,Yi; JIANG,Rong; LING,Tingting; ZHAO,Jianxi

    2009-01-01

    In order to understand the special role of the flexible alkylene spacer of gemini surfactant in the self-assembly,three gemini surfactants,alkylene-α,ω-bis(didodecylmethylammonium bromide)that is designated as 2C12-s-2C12·2Br (s=3,6,8),were synthesized.When the spread films of 2C12-s-2C12·2Br on the surface of water were con-structed,they form the dense layer of the alkyl tails owing to four dodecyl chains per molecule.This induced the bending of the spacer chain toward the air-side at the s smaller than that of C12-s-C12·2Br adsorbed on the air/water interface owing to the enhanced hydrophobic interaction between the alkyl tails and the spacer chain, where C12-s-C12·2Br has only two alkyl tails per molecule. Conclusively.,the enhanced hydrophobic interaction between the alkyl tails and the spacer chain can effectively induce the bending of the latter toward the air-side.

  7. Modeling the effect of spacers and biofouling on forward osmosis performance

    KAUST Repository

    Mosqueira Santillán, María José

    2014-11-01

    Currently, the most utilized desalination technology is reverse osmosis (RO), where a membrane is used as a physical barrier to separate the salts from the seawater, using high hydraulic pressure as driving force. A major problem in RO systems is biofouling, caused by severe growth of bacterial biofilms. Both, the need of an external energy input, as well as biofouling, impose a high cost on RO operation. Forward osmosis (FO) is an alternative membrane process that uses an osmotic pressure difference as driving force. FO uses a concentrated draw solution to generate high osmotic pressure, which extracts water across a semi permeable membrane from a feed solution. One of the main advantages of FO is the limited amount of external energy required to extract water from the feed solution. The objective of this research is the assessment of the impact of spacers, separating the membrane sheets, and biofouling on the FO system performance. This type of studies allow the optimization of membrane devices and operational conditions. For this, a two dimensional numerical model for FO systems was developed using computational fluid dynamics (CFD). This model allowed the evaluation of the impact of (i) spacers and (ii) biofilm, and (iii) the combined impact of spacers and biofilm on the performance of FO systems. The results obtained showed that the presence of spacers improved the performance of FO systems. Cavity configuration spacer gave the higher water flux across the membrane in clean systems; whereas for biofouled systems, the submerged configuration showed a better performance. In absence of spacers, the thickness or amount of biofilm is inversely proportional with the water flux. Furthermore, membrane surface coverage of the biofilm is more important than the amount of biofilm in terms of the impact on the performance. The numerical model can be adapted with other parameters (e.g. membrane and spacer thickness, feed and draw solution, solution concentration, etc.) to

  8. Velocity and turbulence distributions in wall subchannels of a road bundle in three axial planes downstream of a spacer grid

    Science.gov (United States)

    Rehme, K.

    1987-03-01

    The velocity, turbulence, and temperature distributions in nuclear fuel element bundles of nuclear reactors were investigated. The mean velocity, the wall shear stresses, and the turbulence were measured in two wall subchannels of a rod bundle of four parallel rods, arranged in a rectangular channel, for three axial planes. A spacer grid was inserted in the rod bundle, for ratios between the distance spacer grid/measuring plane and the hydraulic diameter (LIDh) of 40.4, 32.8 and 16.9. The Reynolds number was 145,000. The results show that the distributions of the velocity and the turbulence are affected by the spacer grid, already for LIDh = 40.4. The effects of the spacer grid increase with decreasing distance to the spacer grid.

  9. DYNAMIC CHARACTERISTICS OF LIQUID SLOSHING IN A TRANS-VERSELY VIBRATING SPHERICAL TANK WITH A SPACER UNDER LOW GRAVITY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The dynamic characteristics of liquid sloshing in a transversely vibrating spherical tank with spacer under low gravity were investigated. By expanding the characteristic functions, the frequencies and velocity potentials of liquid free-sloshing were obtained. The dynamic equations and boundary conditions of liquid sloshing in the traverse vibrational spherical tank with spacer under low gravity were derived. By modifying the velocity potentials of liquid free-sloshing, the velocity potentials of liquid sloshing in the traverse vibrating spherical tank with a spacer were obtained. Furthermore, the forces and the moments acting on tank wall were given. The numerical results show when a spacer is inserted in the tank, the sloshing frequencies of liquid and the forces acting on tank wall will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.

  10. 3D laser inspection of fuel assembly grid spacers for nuclear reactors based on diffractive optical elements

    Science.gov (United States)

    Finogenov, L. V.; Lemeshko, Yu A.; Zav'yalov, P. S.; Chugui, Yu V.

    2007-06-01

    Ensuring the safety and high operation reliability of nuclear reactors takes 100% inspection of geometrical parameters of fuel assemblies, which include the grid spacers performed as a cellular structure with fuel elements. The required grid spacer geometry of assembly in the transverse and longitudinal cross sections is extremely important for maintaining the necessary heat regime. A universal method for 3D grid spacer inspection using a diffractive optical element (DOE), which generates as the structural illumination a multiple-ring pattern on the inner surface of a grid spacer cell, is investigated. Using some DOEs one can inspect the nomenclature of all produced grids. A special objective has been developed for forming the inner surface cell image. The problems of diffractive elements synthesis, projecting optics calculation, adjusting methods as well as calibration of the experimental measuring system are considered. The algorithms for image processing for different constructive elements of grids (cell, channel hole, outer grid spacer rim) and the experimental results are presented.

  11. Effect of a spacer on pulmonary aerosol deposition from a jet nebuliser during mechanical ventilation.

    Science.gov (United States)

    Harvey, C. J.; O'Doherty, M. J.; Page, C. J.; Thomas, S. H.; Nunan, T. O.; Treacher, D. F.

    1995-01-01

    BACKGROUND--Several factors have been identified which improve nebulised aerosol delivery in vitro. One of these is the addition of a spacer to the ventilator circuit which improves aerosol delivery from a jet nebuliser to a model lung by approximately 30%. The current study was designed to demonstrate whether similar improvements could be demonstrated in vivo. METHODS--Ten patients (seven men) were studied during mechanical ventilation (Siemens Servo 900C) after open heart surgery. Aerosol was delivered using a Siemens Servo 945 nebuliser system (high setting) driving a System 22 Acorn jet nebuliser (Medic-Aid) containing 3 ml technetium-99m labelled human serum albumin (99mTc-HSA (50 micrograms); activity in the first nebulisation, 90 MBq; in the second nebulisation, 185 MBq). Central and peripheral lung aerosol deposition and the time to complete deposition were measured using a gamma camera and compared when the nebuliser was connected to the inspiratory limb using a simple T-piece or a 600 ml spacer. RESULTS--The addition of the spacer increased total lung deposition (mean (SD) percentage initial nebuliser activity) from 2.2 (0.7)% to 3 (0.8)%. There was no difference in the time required to complete nebulisation (18.2 min v 18.3 min respectively for T-piece and spacer) or in the retention of activity in the nebuliser (46.2% v 47.1% respectively). CONCLUSIONS--The combination of a spacer with a jet nebuliser increased lung deposition by 36% in mechanically ventilated patients and is a simple way of increasing drug deposition or reducing the amount of an expensive drug required for nebulisation. Images PMID:7886649

  12. Barriers and supports to implementation of MDI/spacer use in nine Canadian pediatric emergency departments: a qualitative study

    Directory of Open Access Journals (Sweden)

    Graham Ian D

    2009-10-01

    Full Text Available Abstract Background Despite recent research supporting the use of metered dose inhalers with spacer devices (MDI/spacers in pediatric emergency departments (PEDs for acute exacerbations of asthma, uptake of this practice has been slow. The objectives of this study were to determine the barriers and supports to implementing MDI/spacer research and to identify factors associated with early and late adoption of MDI/spacers in Canadian PEDs. Methods Using a comparative case study design, we classified nine tertiary care pediatric hospital PEDs based on their stage of implementation. Data were collected using focus group interviews with physicians, registered nurses (RNs, and respiratory therapists (RTs, and individual interviews with both patient care and medical directors at each site. Initial coding was based on the Ottawa Model of Research Use (OMRU categories of elements known to influence the uptake of innovations. Results One hundred and fifty healthcare professionals from nine different healthcare institutions participated in this study. Lack of leadership in the form of a research champion, a lack of consensus about the benefits of MDI/spacers among staff, perceived resistance from patients/parents, and perceived increased cost and workload associated with MDI/spacer use were the most prevalent barriers to the adoption of the MDI/spacer. Common strategies used by early-adopting sites included the active participation of all professional groups in the adoption process in addition to a well-planned and executed educational component for staff, patients, and families. Early adopter sites were also more likely to have the MDI/spacer included in a clinical protocol/pathway. Conclusion Potential barriers and supports to implementation have been identified that will help EDs adopt MDI/spacer use. Future interventions intended to increase MDI/spacer use in PEDs will need to be sensitive to the barriers identified in this study.

  13. Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate Image Guided Intensity Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mariados, Neil, E-mail: nmariados@ampofny.com [Associated Medical Professionals of New York, Syracuse, New York (United States); Sylvester, John [21st Century Oncology, East Bradenton, Florida (United States); Shah, Dhiren [Western New York Urology Associates, Cancer Care of WNY, Cheektowaga, New York (United States); Karsh, Lawrence [The Urology Center of Colorado, Denver, Colorado (United States); Hudes, Richard [Chesapeake Urology Research Associates, The Prostate Center, Owings Mills, Maryland (United States); Beyer, David [Arizona Oncology Services Foundation, Phoenix, Arizona (United States); Kurtzman, Steven [Urological Surgeons of Northern California, Campbell, California (United States); Bogart, Jeffrey [The Research Foundation of State University of New York, SUNY Upstate Medical University, Syracuse, New York (United States); Hsi, R. Alex [Peninsula Cancer Center, Poulsbo, Washington (United States); Kos, Michael [Urology Nevada, Reno, Nevada (United States); Ellis, Rodney [University Hospitals Case Medical Center, Cleveland, Ohio (United States); Logsdon, Mark [Sutter Health Sacramento Sierra Region, Sutter Institute for Medical Research, Sacramento, California (United States); Zimberg, Shawn [Advanced Radiation Centers of New York, Lake Success, New York (United States); Forsythe, Kevin [Oregon Urology Institute, Springfield, Oregon (United States); Zhang, Hong [University of Rochester, Rochester, New York (United States); Soffen, Edward [CentraState Medical Center, Freehold, New Jersey (United States); Francke, Patrick [Carolina Regional Cancer Center, 21st Century Oncology, Myrtle Beach, South Carolina (United States); Mantz, Constantine [21st Century Oncology, Fort Meyers, Florida (United States); Rossi, Peter [Emory University, Atlanta, Georgia (United States); DeWeese, Theodore [The Johns Hopkins University, Baltimore, Maryland (United States); and others

    2015-08-01

    Purpose: Perirectal spacing, whereby biomaterials are placed between the prostate and rectum, shows promise in reducing rectal dose during prostate cancer radiation therapy. A prospective multicenter randomized controlled pivotal trial was performed to assess outcomes following absorbable spacer (SpaceOAR system) implantation. Methods and Materials: Overall, 222 patients with clinical stage T1 or T2 prostate cancer underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans for treatment planning, followed with fiducial marker placement, and were randomized to receive spacer injection or no injection (control). Patients received postprocedure CT and MRI planning scans and underwent image guided intensity modulated radiation therapy (79.2 Gy in 1.8-Gy fractions). Spacer safety and impact on rectal irradiation, toxicity, and quality of life were assessed throughout 15 months. Results: Spacer application was rated as “easy” or “very easy” 98.7% of the time, with a 99% hydrogel placement success rate. Perirectal spaces were 12.6 ± 3.9 mm and 1.6 ± 2.0 mm in the spacer and control groups, respectively. There were no device-related adverse events, rectal perforations, serious bleeding, or infections within either group. Pre-to postspacer plans had a significant reduction in mean rectal V70 (12.4% to 3.3%, P<.0001). Overall acute rectal adverse event rates were similar between groups, with fewer spacer patients experiencing rectal pain (P=.02). A significant reduction in late (3-15 months) rectal toxicity severity in the spacer group was observed (P=.04), with a 2.0% and 7.0% late rectal toxicity incidence in the spacer and control groups, respectively. There was no late rectal toxicity greater than grade 1 in the spacer group. At 15 months 11.6% and 21.4% of spacer and control patients, respectively, experienced 10-point declines in bowel quality of life. MRI scans at 12 months verified spacer absorption. Conclusions: Spacer

  14. Automated 3D Analysis of Pre-Procedural MDCT to Predict Annulus Plane Angulation and C-Arm Positioning Benefit on Procedural Outcome in Patients Referred for TAVR

    NARCIS (Netherlands)

    Samim, Mariam; Stella, Pieter R.; Agostoni, Pierfrancesco; Kluin, Jolanda; Ramjankhan, Faiez; Budde, Ricardo P. J.; Sieswerda, Gertjan; Algeri, Emanuela; van Belle, Camille; Elkalioubie, Ahmed; Juthier, Francis; Belkacemi, Anouar; Bertrand, Michel E.; Doevendans, Pieter A.; Van Belle, Eric

    2013-01-01

    OBJECTIVES The aim of this study was to determine whether pre-procedural analysis of multidetector row computed tomography (MDCT) scans could accurately predict the "line of perpendicularity" (LP) of the aortic annulus and corresponding C-arm angulations required for prosthesis delivery and impact t

  15. Mobile museology

    DEFF Research Database (Denmark)

    Baggesen, Rikke Haller

    posts from the research project blog with three research articles: ‘Museum metamorphosis à la mode’, proposing a fashion perspective on ongoing museum developments; ‘Augmenting the agora: media and civic engagement in museums’, questioning the idea of social media holding a vital potential......Drawing together perspectives from museology, digital culture studies and fashion theory, this thesis considers changes in and challenges for current - day museums as related to ‘mobile museology’. This concept is developed for and elucidated in the thesis to describe an orientation towards...... the fashionable, the ephemeral, and towards an (ideal) state of change and changeability. This orientation is characterised with the triplet concepts of mobile, mobility, and mobilisation, as related to mobile media and movability; to ‘trans - museal’ mediation; and to the mobilisation of collections, audiences...

  16. Mobility Challenges

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lassen, Claus

    2011-01-01

    This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part of th...... mobilities. In particular the article discusses 1) the physical city, its infrastructures and technological hardware/software, 2) policies and planning strategies for urban mobility and 3) the lived everyday life in the city and the region.......This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part...... of the so-called ‘mobility turn’ within social science. The perspective is illustrative for the research efforts at the Centre for Mobility and Urban Studies (C-MUS), Aalborg University. The article presents the contours of a theoretical perspective meeting the challenges to research into contemporary urban...

  17. Calculation of Annulus Pressure on Managed Pressure Drilling in Daqing Oil Field%大庆油田控压钻井作业环空压力的计算

    Institute of Scientific and Technical Information of China (English)

    李士斌; 周艳; 邸百英; 宋瑞宏

    2011-01-01

    根据Beggs-Brill的流动型态模型推导出了控制压力钻井环空多相流的压力计算公式;并提出了井口回压对环空流态的影响.提出的计算模型已通过现场试验的验证.试验结果表明其误差只有3%左右,能够指导现场作业.为控制压力钻井技术在大庆油田的应用和发展提供理论依据.%According to the mobile state model of Beggs-Brill to infer the multiphase calculation formula of manage pressure drilling, the well head back pressure influence the annulus state is proposed. The computation model is proposed through the field test confirmation. The test result has indicated its error only then about 3%, could instruct the field operation. The theory basis for MPD in the Daqing Oil Field application and the development is provided.

  18. The transmembrane heparan sulphate proteoglycan syndecan-4 is involved in establishment of the lamellar structure of the annulus fibrosus of the intervertebral disc.

    Science.gov (United States)

    Beckett, M C; Ralphs, J R; Caterson, B; Hayes, A J

    2015-08-14

    The annulus fibrosus of the intervertebral disc unites adjacent vertebral bodies along the length of the spine and provides tensile resistance towards compressive, twisting and bending movements arising through gait. It consists of a nested series of oriented collagenous lamellae, arranged in cross-ply circumferentially around the nucleus pulposus. The organisation of oriented collagen in the annulus is established during foetal development by an identical arrangement of oriented fibroblasts that are precisely organised into cell sheets, or laminae. These provide a template for ordered deposition of extracellular matrix material on cell surfaces, by means of a poorly understood mechanism involving the actin cytoskeleton. In this study, we investigate the role of two cell surface heparan sulphate proteoglycans (HSPGs), glypican-6 and syndecan-4, in the matrix assembly process in the developmental rat intervertebral disc. We compare their expression patterns with those of heparan sulphate and the interactive, cell-surface adhesive glycoprotein, fibronectin, and relate these to the stage-specific collagenous architectures present within the annulus at both light and electron microscopic levels. We show that both proteoglycans are strongly associated with the development, growth and aging of the intervertebral disc. Furthermore, the immunohistochemical labelling patterns suggest that syndecan-4, in particular, plays a potentially-significant role in annulus formation. We propose that this HSPG mediates interaction between the actin cytoskeleton and nascent extracellular matrix in the lamellar organisation of annulus tissue. These data add considerably towards an understanding of how cells organise and maintain complex, oriented extracellular matrices and has particular clinical relevance to the fields of tissue engineering and repair.

  19. Three-dimensional development of tensile pre-strained annulus fibrosus cells for tissue regeneration: An in-vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Chuah, Yon Jin [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Lee, Wu Chean [University Hospital Conventry & Warwickshire NHS Trust, Clifford Bridge Road, West Midlands CV2, 2DX (United Kingdom); Wong, Hee Kit [Department of Orthopedic Surgery, National University Health System, NUHS Tower Block Level 11, 1E Kent Ridge Road, Singapore 119228 (Singapore); Kang, Yuejun, E-mail: yuejun.kang@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Hee, Hwan Tak, E-mail: HTHee@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Pinnacle Spine & Scoliosis Centre, 3 Mount Elizabeth, Mount Elizabeth Medical Centre, #04-07, Singapore 228510 (Singapore); School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637459 (Singapore)

    2015-02-01

    Prior research has investigated the immediate response after application of tensile strain on annulus fibrosus (AF) cells for the past decade. Although mechanical strain can produce either catabolic or anabolic consequences to the cell monolayer, little is known on how to translate these findings into further tissue engineering applications. Till to date, the application and effect of tensile pre-strained cells to construct a three-dimensional (3D) AF tissue remains unknown. This study aims to investigate the effect of tensile pre-strained exposure of 1 to 24 h on the development of AF pellet culture for 3 weeks. Equibiaxial cyclic tensile strain was applied on AF monolayer cells over a period of 24 h, which was subsequently developed into a cell pellet. Investigation on cellular proliferation, phenotypic gene expression, and histological changes revealed that tensile pre-strain for 24 h had significant and lasting effect on the AF tissue development, with enhanced cell proliferation, and up-regulation of collagen type I, II, and aggrecan expression. Our results demonstrated the regenerative ability of AF cell pellets subjected to 24 h tensile pre-straining. Knowledge on the effects of tensile pre-strain exposure is necessary to optimize AF development for tissue reconstruction. Moreover, the tensile pre-strained cells may further be utilized in either cell therapy to treat mild disc degeneration disease, or the development of a disc construct for total disc replacement. - Highlights: • Establishment of tensile pre-strained cell line population for annulus development. • Tensile strain limits collagen gene expression declination in monolayer culture. • Tensile pre-strained cells up-regulate their matrix protein in 3D pellet culture.

  20. Quality of life after intensity-modulated radiotherapy for prostate cancer with a hydrogel spacer. Matched-pair analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pinkawa, M.; Piroth, M.D.; Holy, R.; Escobar-Corral, N.; Caffaro, M.; Djukic, V.; Klotz, J.; Eble, M.J. [RWTH Aachen Univ. (Germany). Dept. of Radiation Oncology

    2012-10-15

    Background: Hydrogel spacer is an innovative method to protect the rectal wall during prostate cancer radiotherapy. Clinical effects are not well known. Methods: Patients have been surveyed before, at the last day, and 2-3 months after radiotherapy using a validated questionnaire (Expanded Prostate Cancer Index Composite). Median dose to the prostate in the spacer subgroup (SP) was 78 Gy in 2 Gy fractions. The results were independently compared with two matched-pair subgroups (treated conventionally without spacer): 3D conformal 70.2 Gy in 1.8 Gy fractions (3DCRT) and intensity-modulated radiotherapy (IMRT) 76 Gy in 2 Gy fractions. There were 28 patients in each of the three groups. Results: Baseline mean bowel bother scores were 96 points in all subgroups. Similar mean changes (SP 16, 3DCRT 14, IMRT 17 points) were observed at the end of radiotherapy. The smallest difference resulted in the spacer subgroup 2-3 months after radiotherapy (SP 2, 3DCRT 8, IMRT 6 points). Bowel bother scores were only significantly different in comparison to baseline levels in the spacer subgroup. The percentage of patients reporting moderate/big bother with specific symptoms did not increase for any item (urgency, frequency, diarrhoea, incontinence, bloody stools, pain). Conclusion: Moderate bowel quality-of-life changes can be expected during radiotherapy irrespective of spacer application or total dose. Advantages with a spacer can be expected a few weeks after treatment. (orig.)

  1. A comparative evaluation of application techniques of a paint-on die spacer in grooves: an in vitro study.

    Science.gov (United States)

    Vaishali, K; Prasad, D Krishna; Shetty, Manoj

    2013-12-01

    The use of paint-on die spacer to improve the seating of casting has become quite popular in the recent years. The generally accepted range of paint-on die spacer is approximately 20-40 μm, which suggests a range of tolerance. The painting of the retentive grooves with die spacer has always been a subject of debate. The primary purpose of this study was to determine if there was a tendency for the paint-on die spacer to accumulate in grooves of tooth preparation in sufficient thickness to exceed this accepted range of tolerance when applied using two different techniques. Eight die stone blocks with three grooves each were prepared. Half the samples were painted in unidirectional method and the other halves were painted using the haphazard method of application. The thickness of the die spacer was measured at different positions using 200× magnification and the mean and standard deviations were calculated. On analysis it was seen that the thickness of the paint-on die spacer in grooves was in the range of 20-40 μm for unidirectional method of application, whereas in haphazard method of application the thickness of the paint-on die spacer was in the range of 28-132 μm. From the above study it was concluded that the method of application influenced the thickness of the paint-on die spacer. The recommended thickness of the die spacer was achieved on unidirectional method of application.

  2. Development and Manufacture of the Coil End Spacers of the LHC Pre-series Dipoles

    CERN Document Server

    Farina, E; Perini, D; Schiappapietra, A; Seneé, L

    2002-01-01

    The coil end spacers play an important role in the performance of superconducting coils, as their shape and location determine the mechanical stability of the conductors in the coil ends (and hence the overall coil training performance) and the local field quality. The dipole end spacers are often of a size and a geometry difficult to be industrially series manufactured and measured. Efficiency of the production and related costs are a key issue to achieve the required production rate of the LHC main dipoles at an affordable price. For the latter reasons, a design approach integrating state-of-the-art CAD/CAM optimization techniques allowing to considerably decrease design and machining time was implemented. This paper gives examples and describes the design criteria, the computation methods, the machining and measuring procedures adopted to carry out the pre-series production.

  3. Transcriptome changes in STSV2-infected Sulfolobus islandicus REY15A undergoing continuous CRISPR spacer acquisition

    DEFF Research Database (Denmark)

    León-Sobrino, Carlos; Kot, Witold P; Garrett, Roger A

    2016-01-01

    A transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich and basal media over a 6 day period. Spacer acquisition preceded strong host growth retardation, altered transcriptional activity...... of four different CRISPR-Cas modules and changes in viral copy numbers, and with significant differences in the two media. Transcript levels of proteins involved in the cell cycle were reduced, while those of DNA replication, DNA repair, transcriptional regulation, and some antitoxin-toxin pairs...... and transposases were unchanged or enhanced. Antisense RNAs were implicated in the transcriptional regulation of adaptation and interference modules of the type I-A CRISPR-Cas system and evidence was found for the occurrence of functional coordination between the single CRISPR-Cas adaptation module...

  4. Metagenomic data of fungal internal transcribed spacer from serofluid dish, a traditional Chinese fermented food.

    Science.gov (United States)

    Chen, Peng; Zhao, Yang; Wu, Zhengrong; Liu, Ronghui; Xu, Ruixiang; Yan, Lei; Li, Hongyu

    2016-03-01

    Serofluid dish (or Jiangshui, in Chinese), a traditional food in the Chinese culture for thousands of years, is made from vegetables by fermentation. In this work, microorganism community of the fermented serofluid dish was investigated by the culture-independent method. The metagenomic data in this article contains the sequences of fungal internal transcribed spacer (ITS) regions of rRNA genes from 12 different serofluid dish samples. The metagenome comprised of 50,865 average raw reads with an average of 8,958,220 bp and G + C content is 45.62%. This is the first report on metagenomic data of fungal ITS from serofluid dish employing Illumina platform to profile the fungal communities of this little known fermented food from Gansu Province, China. The Metagenomic data of fungal internal transcribed spacer can be accessed at NCBI, SRA database accession no. SRP067411.

  5. Metagenomic data of fungal internal transcribed spacer from serofluid dish, a traditional Chinese fermented food

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2016-03-01

    Full Text Available Serofluid dish (or Jiangshui, in Chinese, a traditional food in the Chinese culture for thousands of years, is made from vegetables by fermentation. In this work, microorganism community of the fermented serofluid dish was investigated by the culture-independent method. The metagenomic data in this article contains the sequences of fungal internal transcribed spacer (ITS regions of rRNA genes from 12 different serofluid dish samples. The metagenome comprised of 50,865 average raw reads with an average of 8,958,220 bp and G + C content is 45.62%. This is the first report on metagenomic data of fungal ITS from serofluid dish employing Illumina platform to profile the fungal communities of this little known fermented food from Gansu Province, China. The Metagenomic data of fungal internal transcribed spacer can be accessed at NCBI, SRA database accession no. SRP067411.

  6. Automatic actuation of a dry powder inhaler into a nonelectrostatic spacer

    DEFF Research Database (Denmark)

    Bisgaard, H

    1998-01-01

    This article describes a new "automatic spacer" device, which has been developed to improve the delivery of inhaled medication to young children. In the device, a dry powder inhaler (DPI) is mechanically actuated into a nonelectrostatic spacer, producing an aerosol cloud of fine drug particles...... of the patient to the additives and propellants used in pressurized metered dose inhalers. Studies with the prototype device show a high yield of fine drug particles in the aerosol (mass median aerodynamic diameter, 2.8 microm), a high repeatability of drug delivery owing to the mechanical nature...... of the actuation (relative standard deviation, 12%), and a prolonged residence time of the fine particle aerosol (half-life of the fallout of the fine particles, 82 s). These features should prove advantageous in the treatment of young children with inhaled medication....

  7. The sequence of spacers between the consensus sequences modulates the strength of procaryotic promoters

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Hammer, Karin

    1998-01-01

    than 2000 relative units, which is among the strongest promoters known for this organism. The ranking of the promoter activities was somewhat different when assayed in E. coli, but the promoters are efficient for modulating gene expression in this bacteria as well. DNA sequencing revealed...... the spacers, at least a 400 fold change in activity can be obtained. Interestingly, the entire range of promoter activities is covered in small steps of activity increase, which makes these promoters very suitable for quantitative physiological studies and for fine tuning of gene expression in industrial bio......A library of synthetic promoters for Lactococcus lactis was constructed, in which the known consensus sequences were kept constant while the sequences of the separating spacers were randomized. The library consists of 38 promoters which differ in strength from 0.3 relative units, and up to more...

  8. Effect of spacer layer on the magnetization dynamics of permalloy/rare-earth/permalloy trilayers

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Chen, E-mail: ronanluochen@gmail.com; Yin, Yuli; Zhang, Dong; Jiang, Sheng; Yue, Jinjin; Zhai, Ya, E-mail: yazhai@seu.edu.cn [Physics Department, Southeast University, Nanjing 211189 (China); Du, Jun; Zhai, Hongru [National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-05-07

    The permalloy/rare-earth/permalloy trilayers with different types (Gd and Nd) and thicknesses of spacer layer are investigated using frequency dependence of ferromagnetic resonance (FMR) measurements at room temperature, which shows different behaviors with different rare earth spacer layers. By fitting the frequency dependence of the FMR resonance field and linewidth, we find that the in-plane uniaxial anisotropy retains its value for all samples, the perpendicular anisotropy remains almost unchanged for different thickness of Gd layer but the values are tailored by different thicknesses of Nd layer. The Gilbert damping is almost unchanged with different thicknesses of Gd; however, the Gilbert damping is significantly enhanced from 8.4×10{sup −3} to 20.1×10{sup −3} with 6 nm of Nd and then flatten out when the Nd thickness rises above 6 nm.

  9. MOLECULAR FIELD THEORY FOR NEMATIC LIQUID CRYSTAL POLYMER COMPRISING FLEXIBLE SPACER

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaogong; LIU Deshan; ZHOU Qixiang

    1993-01-01

    Based on the new model and concept of intramolecular orientational order parameter, a molecular field theory was built up for main chain liquid crystalline polymer (MC-LCPs) with flexible spacers. The theory takes account of orientational correlation among all mesogens in a polymer chain and the relationship between the intramolecular orientation and spatial orientation of the mesogens. The free energy, temperature and entropy of the nematic-isotropic transition were determined with the theory and compared with experiments in current work. It was found that many unique transition properties of the MC-LCPs comprising flexible spacer are correctly predicted by the theory and the agreement of the theory with the experiments is impressive.

  10. Influence of Spacer Grid Outer Strap on Fuel Assembly Thermal Hydraulic Performance

    Directory of Open Access Journals (Sweden)

    Jingwen Yan

    2014-01-01

    Full Text Available The outer strap as a typical structure of a spacer grid enhances the mechanical strength, decreases hang-up susceptibility, and also influences thermal hydraulic performance, for example, pressure loss, mixing performance, and flow distribution. In the present study, a typical grid spacer with different outer strap designs is adopted to investigate the influence of outer strap design on fuel assembly thermal hydraulic performance by using a commercial computational fluid dynamics (CFD code, ANSYS CFX, and a subchannel analysis code, FLICA. To simulate the outer straps’ influence between fuel assemblies downstream, four quarter-bundles from neighboring fuel assemblies are constructed to form the computational domain. The results show that the outer strap design has a major impact on cross-flow between fuel assemblies and temperature distribution within the fuel assembly.

  11. Numerical Simulation for Flow Distribution in ACE7 Fuel Assemblies affected by a Spacer Grid Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jongpil; Jeong, Ji Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In spite of various efforts to understand hydraulic phenomena in a rod bundle containing deformed rods due to swelling and/or ballooning of clad, the studies for flow blockage due to spacer grid deformation have been limited. In the present work, 3D CFD analysis for flow blockage was performed to evaluate coolant flow within ACE7 fuel assemblies (FAs) containing a FA affected by a spacer grid deformation. The real geometry except for inner grids was used in the simulation and the region including inner grid was replaced by porous media. In the present work, the numerical simulation was performed to predict coolant flow within ACE7 FAs affected by a Mid grid deformation. The 3D CFD result shows that approximately 60 subchannel hydraulic diameter is required to fully recover coolant flow under normal operating condition.

  12. Transcriptome changes in STSV2-infected Sulfolobus islandicus REY15A undergoing continuous CRISPR spacer acquisition

    DEFF Research Database (Denmark)

    León Sobrino, Carlos; Kot, W.P.; Garrett, Roger Antony

    2016-01-01

    and transposases were unchanged or enhanced. Antisense RNAs were implicated in the transcriptional regulation of adaptation and interference modules of the type I-A CRISPR-Cas system and evidence was found for the occurrence of functional coordination between the single CRISPR-Cas adaptation module......A transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich and basal media over a 6 day period. Spacer acquisition preceded strong host growth retardation, altered transcriptional activity...... of four different CRISPR-Cas modules and changes in viral copy numbers, and with significant differences in the two media. Transcript levels of proteins involved in the cell cycle were reduced, while those of DNA replication, DNA repair, transcriptional regulation, and some antitoxin-toxin pairs...

  13. SYNTHESIS OF NOVEL LIQUID CRYSTALLINE POLY(METH)ACRYLATES CONTAINING SILOXANE SPACER AND TERPHENYLENE MESOGENIC UNIT

    Institute of Scientific and Technical Information of China (English)

    Zhi-qian Zang; Yu-fei Luo; Dong Zhang; Xin-hua Wan; Qi-feng Zhou

    2000-01-01

    Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3-hydroxyl-propyl)-3-[(4"cyano-p-terphenyloxycarbonyl)alkyl]-1, 1,3,3-tetramethyldisiloxane as the key intermediate. The polymers used a disiloxane moiety as decoupling spacer with cyano-p-terphenyl as mesogenic unit. The products were characterized by NMR, GPC,DSC and polarizing optical microscopy. All the polymers with cyano-p-terphenyl mesogens formed a stable mesophase.However, if the mesogenic unit is replaced by cyano-p-biphenyl, the liquid crystalline character will be lost. The results also showed that the decoupling is incomplete even if a complex and very flexible decoupling spacer is deliberately incorporated to obtain the highest possible decoupling effect.

  14. Analysis of sound absorption of tuck spacer fabrics to reduce automotive noise

    Science.gov (United States)

    Dias, Tilak; Monaragala, Ravindra; Needham, Peter; Lay, Edward

    2007-08-01

    Textiles are widely used in the automotive industry to provide both comfort to the passengers and an aesthetic appearance to the automotive interior. They can also be used to reduce automotive interior noise, which can make automotive travel safer and more comfortable. Knitted fabrics are used widely in automotive upholstery; however, the sound absorbency of a single layer of a knitted fabric is inadequate for the reduction of automotive interior noise. This paper investigates the sound absorbency of a novel knitted spacer fabric, which can be used in automotive upholstery and has the potential for greater sound absorbency than a conventional plain knitted fabric and its derivatives. The spacer fabric is modelled as a porous sound absorber and its sound absorbency is studied with regard to its structural parameters.

  15. TiNi Shape Memory Alloy Foams Synthesized by Spacer Sintering and their Properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Titanium (Ti) andnickel (Ni) elemental powders were blended by ball milling and the ball milled powders were employed to fabricate TiNi shape memory alloy (SMA) foams by spacer sintering. Effect of ball milling time on phase constitutes of the sintered TiNi alloy foams was studied by X-ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) was used to characterize the porous structure, and compressive tests were carried out to evaluate the mechanical properties ofthe foams. Results indicate that porosities of the TiNi alloy foams can be controlled by using the spacer sintering method, and the porosities show a significant effect on the mechanical properties and shape memory effect (SME).

  16. Intensive mobilities:

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of facto....... By exploring how experiences of long-distance workers become constituted by a range of different material forces enables us to more sensitively consider the practical, technical, and political implications of this increasingly prevalent yet underexplored regime of work....... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance mobilities have not received the attention that they deserve within geographical research on mobilities. This paper combines ideas from mobilities research and contemporary social theory...... with fieldwork conducted in Canada, Denmark and Australia to develop our understanding of the experiential politics of long distance workers. Rather than focusing on the extensive dimensions of mobilities that are implicated in patterns and trends, our paper turns to the intensive dimensions of this experience...

  17. Mobile healthcare.

    Science.gov (United States)

    Morgan, Stephen A; Agee, Nancy Howell

    2012-01-01

    Mobile technology's presence in healthcare has exploded over the past five years. The increased use of mobile devices by all segments of the US population has driven healthcare systems, providers, and payers to accept this new form of communication and to develop strategies to implement and leverage the use of mobile healthcare (mHealth) within their organizations and practices. As healthcare systems move toward a more value-driven model of care, patient centeredness and engagement are the keys to success. Mobile healthcare will provide the medium to allow patients to participate more in their care. Financially, mHealth brings to providers the ability to improve efficiency and deliver savings to both them and the healthcare consumer. However, mHealth is not without challenges. Healthcare IT departments have been reluctant to embrace this shift in technology without fully addressing security and privacy concerns. Providers have been hesitant to adopt mHealth as a form of communication with patients because it breaks with traditional models. Our healthcare system has just started the journey toward the development of mHealth. We offer an overview of the mobile healthcare environment and our approach to solving the challenges it brings to healthcare organizations.

  18. Stimulation of the mouse rRNA gene promoter by a distal spacer promoter.

    OpenAIRE

    Paalman, M H; Henderson, S L; Sollner-Webb, B

    1995-01-01

    We show that the mouse ribosomal DNA (rDNA) spacer promoter acts in vivo to stimulate transcription from a downstream rRNA gene promoter. This augmentation of mammalian RNA polymerase I transcription is observed in transient-transfection experiments with three different rodent cell lines, under noncompetitive as well as competitive transcription conditions, over a wide range of template concentrations, whether or not the enhancer repeats alone stimulate or repress expression from the downstre...

  19. Fluid dynamics evaluation of split vane grid spacer in a small modular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nazififard, Mohammad [Kashan Univ (Iran, Islamic Republic of). Dept. of Energy System Engineering; Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering; Philosophia, Seoul (Korea, Republic of); Nematollahi, Mohammadreza [Shiraz Univ. (Iran, Islamic Republic of). Dept. of Nuclear Engineering; Suh, Kune Y. [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering; Philosophia, Seoul (Korea, Republic of)

    2015-12-15

    This paper numerically evaluates the effect of a split vane grid spacer on thermohydrodynamics in a subchannel of a typical small modular pressurized water reactor. The turbulent convective heat transfer and pressure drop are numerically calculated. Thermohydrodynamics and neutronics coupling would indeed be interesting for more quantitative analyses of the fuel assembly design, heat transfer correlation and mixing coefficient for the System-Integrated Modular Advanced Reactor (SMART) being developed by the Korea Atomic Energy Research Institute (KAERI).

  20. Treatment of persistent extraarticular infection using a temporary cement spacer on the tibia after ACL reconstruction.

    Science.gov (United States)

    Jung, Kwang Am; Lee, Soo Chan; Song, Moon Bok; Lee, Choon Key

    2008-01-01

    Postoperative infection after anterior cruciate ligament (ACL) reconstruction is an uncommon but serious complication. Although several treatments for intraarticular infection have been reported, no report has been recorded on the treatment of persistent extraarticular infections. The authors experienced reconstructed graft removal due to a refractory extraarticular infection on tibia. Early ACL reimplantation was performed using a temporary cement spacer containing antibiotics and a irradiated bone patellar tendon bone allograft.

  1. Heat transfer enhancement with mixing vane spacers using the field synergy principle

    Science.gov (United States)

    Yang, Lixin; Zhou, Mengjun; Tian, Zihao

    2017-01-01

    The single-phase heat transfer characteristics in a PWR fuel assembly are important. Many investigations attempt to obtain the heat transfer characteristics by studying the flow features in a 5 × 5 rod bundle with a spacer grid. The field synergy principle is used to discuss the mechanism of heat transfer enhancement using mixing vanes according to computational fluid dynamics results, including a spacer grid without mixing vanes, one with a split mixing vane, and one with a separate mixing vane. The results show that the field synergy principle is feasible to explain the mechanism of heat transfer enhancement in a fuel assembly. The enhancement in subchannels is more effective than on the rod's surface. If the pressure loss is ignored, the performance of the split mixing vane is superior to the separate mixing vane based on the enhanced heat transfer. Increasing the blending angle of the split mixing vane improves heat transfer enhancement, the maximum of which is 7.1%. Increasing the blending angle of the separate mixing vane did not significantly enhance heat transfer in the rod bundle, and even prevented heat transfer at a blending angle of 50°. This finding testifies to the feasibility of predicting heat transfer in a rod bundle with a spacer grid by field synergy, and upon comparison with analyzed flow features only, the field synergy method may provide more accurate guidance for optimizing the use of mixing vanes.

  2. Role of spacer lengths of gemini surfactants in the synthesis of silver nanorods in micellar media.

    Science.gov (United States)

    Bhattacharya, Santanu; Biswas, Joydeep

    2011-07-01

    In this work, we have prepared Ag-nanorods using biscationic gemini surfactant micelles as the media by a seed-mediated wet synthesis method. Towards this end, we first synthesized Ag-nanoseeds of diameter ~7 nm stabilized by trisodium citrate (as the capping agent). Then these Ag-nanoseeds were used to synthesize Ag-nanorods of different aspect ratios. With decreasing Ag-nanoseed concentration, the aspect ratios of the Ag-nanorods stabilized by these gemini surfactants increased gradually. Various Ag-nanoseeds and Ag-nanospecies were characterized using UV-Vis spectroscopy (to know the surface plasmon bands), transmission electron microscopy (to find out their particle sizes and distribution), energy-dispersive X-ray spectroscopy and X-ray diffraction. When we used micelles derived from gemini surfactants of shorter spacer -(CH(2))(n)- (n = 2 or 4) to stabilize the Ag-nanorods, the λ(max) of the longitudinal band shifted more towards the blue region compared to that of the gemini surfactant micelles with a longer spacer -(CH(2))(n)- (n = 5, 12) at a given amount of the Ag-nanoseed solution. So, the growth of Ag-nanorods in the gemini micellar solutions depends on the spacer-chain length of gemini surfactants employed.

  3. Investigation of DNA-cationic bolaform surfactants interaction with different spacer length.

    Science.gov (United States)

    Sohrabi, Beheshteh; Khani, Vahid; Moosavi-Movahedi, Ali Akbar; Moradi, Parviz

    2013-10-01

    In this paper interaction of DNA with cationic bolaform surfactants is investigated. The structural formula for synthesized bolaforms is as follows: bolaform B1 with structural formula Br(-)(CH3)3N(+)(CH2)3N(+)(CH3)Br(-) and bolaform B2 with structural formula of Br(-)(CH3)3N(+)(CH2)12N(+)(CH3)Br(-). There are stronger electrostatic interactions in bolaform B1 due to shorter spacer length, while there are stronger hydrophobic interactions in bolaform B2 compared to bolaform B1 due to existence of 12 carbons in hydrocarbonic chain. The structure of bolaforms consists of two polar head groups which play important role in DNA compaction. Surface tension change in aqueous solution of bolaform surfactants is measured using tensiometer. Electrical conductivity of surfactants aqueous solution is examined with and without DNA. DNA compaction is tracked in the presence of bolaforms by dynamic light scattering (DLS) technique. Results of DLS indicate bolaforms with shorter spacer length (dominant electrostatic interactions) are more influential in compressing DNA compared to bolaforms with longer spacer length (stronger hydrophobic interactions). UV-vis and fluorescence spectroscopies specify the binding mechanism of bolaform surfactants to DNA.

  4. Relative lung bioavailability of generic sodium cromoglycate inhalers used with and without a spacer device.

    Science.gov (United States)

    Aswania, O; Chrystyn, H

    2001-01-01

    The relative lung bioavailability of sodium cromoglycate following inhalation has been evaluated using urinary drug excretion in nine healthly volunteers. Each inhaled four 5 mg sodium cromoglycate doses from a generic metered dose inhaler (MDI) and when it was attached to large volume spacer (MDI + VOL). A breath-actuated MDI was also evaluated either used on its own (EB) or attached to a small volume spacer tube (EBO). The mean (SD) urinary excretion of sodium cromoglycate in the first 30 min post-inhalation was 34.1 (20.2), 211.7 (123.5), 29.3 (19.5) and 52.8 (36.0) microg following MDI, MDI+VOL, EB and EBO, respectively. The cumulative mean (SD) urinary excretion of sodium cromoglycate over the 24 h post-inhalation was 364.7 (266.2), 1227.1 (459.0), 280.2 (155.4) and 429.5 (176.7) microg. A metered dose inhaler attached to a large volume spacer delivers more sodium cromoglycate to the lungs than any other inhalation method.

  5. FIVPET Flow-Induced Vibration Test Report (1) - Candidate Spacer Grid Type I (Optimized H Type)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Hee; Kang, Heung Seok; Yoon, Kyung Ho; Song, Kee Nam; Kim, Jae Yong

    2006-03-15

    The flow-induced vibration (FIV) test using a 5x5 partial fuel assembly was performed to evaluate mechanical/structural performance of the candidate spacer grid type I (Optimized H shape). From the measured vibration response of the test bundle and the flow parameters, design features of the spacer strap can be analyzed in the point of vibration and hydraulic aspect, and also compared with other spacer strap in simple comparative manner. Furthermore, the FIV test will contributes to understand behaviors of nuclear fuel in operating reactor. The FIV test results will be used to verify the theoretical model of fuel rod and assembly vibration. The aim of this report is to present the results of the FIV test of partial fuel assembly and to introduce the detailed test methodology and analysis procedure. In chapter 2, the overall configuration of test bundle and instrumented tube is remarked and chapter 3 will introduce the test facility (FIVPET) and test section. Chapter 4 deals with overall test condition and procedure, measurement and data acquisition devices, instrumentation equipment and calibration, and error analysis. Finally, test result of vibration and pressure fluctuation is presented and discussed in chapter 5.

  6. Mobile Usability

    DEFF Research Database (Denmark)

    Aryana, Bijan; Clemmensen, Torkil

    2013-01-01

    In this article, a country specific comparative mobile usability study is presented, using Iran and Turkey as the two chosen emerging/emergent nation exemplars of smartphone usage and adoption. In a focus group study, three mobile applications were selected by first-time users of smartphones....... In both countries, the music player application was tested, wherein common patterns of accessing and sorting songs emerged. Whereas the Iranian users appeared to be more interested in social networking via use of an SMS service, the Turkish users tended to prefer to apply hierarchies to their own daily...

  7. Mobile Agents

    Science.gov (United States)

    Satoh, Ichiro

    Mobile agents are autonomous programs that can travel from computer to computer in a network, at times and to places of their own choosing. The state of the running program is saved, by being transmitted to the destination. The program is resumed at the destination continuing its processing with the saved state. They can provide a convenient, efficient, and robust framework for implementing distributed applications and smart environments for several reasons, including improvements to the latency and bandwidth of client-server applications and reducing vulnerability to network disconnection. In fact, mobile agents have several advantages in the development of various services in smart environments in addition to distributed applications.

  8. Mobile Misfortune

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2015-01-01

    for themselves and their families, it shows how involvement in the cocaine trade is both a curse and a catalyst. Though trading the drug may facilitate migration and mobility, generating social being and worth in the process, it is an activity that is haunted by the threat of deportation and the termination...... of the mobility it enables. This article, thus, looks at the motives and manners in which young men in Bissau become caught up in transnational flows of cocaine. It shows how motion is emotively anchored and affectively bound: tied to and directed toward a feeling of worth and realisation of being, and how...

  9. Review of the correlation developments and a new concept based on mixing mechanism for heat transfer enhancement of spacer grids

    Energy Technology Data Exchange (ETDEWEB)

    Mao, H.; Yang, B.W.; Liu, X. [Xi' an Jiaotong Univ., Shaanxi (China). Science and Technology Center for Advanced Nuclear Fuel Research

    2016-07-15

    Spacer grids could cause heat transfer enhancement both at the spacer grid regions and downstream of the spacer grids as a result of mixing promoted by the spacer grids in the rod bundle. This phenomenon has been demonstrated by many experiments, and several correlations have been developed based on these experimental data. This paper gives a review of the grid-enhanced heat transfer correlation developments in single phase flow. Following the exploration of the correlation development history, a predictive formulation of grid-enhanced heat transfer in single phase flow is established taking into account the effect of both swirl flow and crossflow. With emphasis on modeling of the mixing mechanism associated with the mixing vane grid, the new correlation could better reflect the physical process of the heat transfer augmentation, while a large number of experimental data are needed to determine the coefficients of the new correlation.

  10. Spacer Thickness-Dependent Electron Transport Performance of Titanium Dioxide Thick Film for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Reda E. El-Shater

    2015-01-01

    Full Text Available A titanium dioxide (P25 film was deposited by cast coating as conductive photoelectrode and subsequently immersed in dye solution (N719 to fabricate the photoanode of dye-sensitized solar cells (DSSCs. A plastic spacer was used as a separation and sealant layer between the photoanode and the counter electrode. The effect of the thickness of this spacer on the transfer of electrons in the liquid electrolyte of the DSSCs was studied by means of both IV curves and electrochemical impedance. Using a spacer thickness range of 20 μm to 50 μm, efficiency ranges from 3.73% to 7.22%. The highest efficiency of 7.22% was obtained with an optimal spacer thickness of 40 μm.

  11. Binding of 12-s-12 dimeric surfactants to calf thymus DNA: Evaluation of the spacer length influence.

    Science.gov (United States)

    Sarrión, Beatriz; Bernal, Eva; Martín, Victoria Isabel; López-López, Manuel; López-Cornejo, Pilar; García-Calderón, Margarita; Moyá, María Luisa

    2016-08-01

    Several cationic dimeric surfactants have shown high affinity towards DNA. Bis-quaternary ammonium salts (m-s-m) have been the most common type of dimeric surfactants investigated and it is generally admitted that those that posses a short spacer (s≤3) show better efficiency to bind or compact DNA. However, experimental results in this work show that 12-s-12 surfactants with long spacers make the surfactant/ctDNA complexation more favorable than those with short spacers. A larger contribution of the hydrophobic interactions, which control the binding Gibbs energy, as well as a higher average charge of the surfactant molecules bound to the nucleic acid, which favors the electrostatic attractions, could explain the experimental observations. Dimeric surfactants with intermediate spacer length seem to be the less efficient for DNA binding.

  12. Visible light dynamical diffraction in a 1-D photonic crystal-based interferometer with an extremely thin spacer layer

    Science.gov (United States)

    Prudnikov, I. R.

    2016-01-01

    Properties of light diffraction in a Fabry-Pérot-like interferometer composed of two 1-D photonic crystals and a nanometer-thick spacer layer are analytically investigated. It is shown that the resonant enhancement of light wave intensity in such a layer is possible because of light dynamical diffraction from the photonic crystals of the interferometer. Numerical simulations of (i) light reflectivity and transmittance curves of the interferometer having an ultra-thin spacer layer (its thickness changes from less than 1 nm to about 10 nm) and (ii) the resonant distribution of the light wave intensity in the vicinity of the layer are performed. Based on the numerical simulations, potentialities for the determination of the structural parameters (e.g., thicknesses and refraction indexes) of ultra-thin spacer films are discussed. A difference is found to appear in resonant intensity enhancements inside the ultra-thin spacer layers between s- and p-polarized light waves.

  13. INFLUENCE OF THE SIZE OF METHYLENE SPACERS ON THE THERMAL BEHAVIOR OF SEVERAL ALIPHATIC-AROMATIC POLYESTERS

    Directory of Open Access Journals (Sweden)

    NATALIA HURDUC

    2014-04-01

    Full Text Available Polyesters have a wide range of technical applications and therefore their processing is of the utmost importance. Since polyesters are usually processed by melting, their thermal stability is an extremely important characteristic for the exact determination of the operational parameters. The thermal analysis was carried out using a MOM-Budapest derivatograph at the 10 C/min heating speed, aluminum oxide the reference material, and the air conditions were static. The study lead to conclusions on the thermal stability and degradation mechanism depending on the number of methylene groups in the spacer. Thermal stability is supported by the increase in the number of methylene groups in the spacer. The degradation mechanism is complex through successive reactions. The spacer size influences the nature of the micromolecules formed by spacer fragmenting and by the number of carbon atoms, respectively.

  14. Distribution of CRISPR spacer matches in viruses and plasmids of crenarchaeal acidothermophiles and implications for their inhibitory mechanism

    DEFF Research Database (Denmark)

    Shah, Shiraz Ali; Hansen, Niels R; Garrett, Roger A

    2009-01-01

    Transcripts from spacer sequences within chromosomal repeat clusters [CRISPRs (clusters of regularly interspaced palindromic repeats)] from archaea have been implicated in inhibiting or regulating the propagation of archaeal viruses and plasmids. For the crenarchaeal thermoacidophiles, the chromo......Transcripts from spacer sequences within chromosomal repeat clusters [CRISPRs (clusters of regularly interspaced palindromic repeats)] from archaea have been implicated in inhibiting or regulating the propagation of archaeal viruses and plasmids. For the crenarchaeal thermoacidophiles...

  15. Preclinical investigations towards the first spacer gel application in prostate cancer treatment during particle therapy at HIT

    OpenAIRE

    Ruciński, Antoni; Bauer, Julia; Campbell, Patrick; Brons, Stephan; Unholtz, Daniel; Habl, Gregor; Herfarth, Klaus; Debus, Jürgen; Bert, Christoph; Parodi, Katia; Jäkel, Oliver; Haberer, Thomas

    2013-01-01

    Background The application of spacer gel represents a promising approach to reliably spare the rectal frontal wall during particle therapy (IJROBP 76:1251-1258, 2010). In order to qualify the spacer gel for the clinical use in particle therapy, a variety of measurements were performed in order to ensure the biological compatibility of the gel, its physical stability during and after the irradiation, and a proper definition of the gel in terms of the Hounsfield Unit (HU) values for the treatme...

  16. Mobile IP

    NARCIS (Netherlands)

    Heijenk, Geert; Sallent, S.; Pras, A.

    1999-01-01

    The Internet is growing exponentially, both in the amount of traffic carried, and in the amount of hosts connected. IP technology is becoming more and more important, in company networks (Intranets), and also in the core networks for the next generation mobile networks. Further, wireless access to I

  17. Mobil nationalisme

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin

    2006-01-01

    , varer, mennesker og kapital men derimod en integreret del af disse tendenser. Gennem begrebet mobil nationalisme argumenteres der for en analytisk optik, hvor nationalisme forstås som en proces hvorigennem skiftende relationer og bevægelser mellem forskellige socio-rumlige skalaer som kroppen...

  18. Sustainable Mobility

    DEFF Research Database (Denmark)

    Kjærulff, Aslak Aamot

    This paper combines strands of mobilities theory and planning theory, and develops a qualitative approach to look across emerging planning practices. By actively following 8 Danish urban and transport planners, over the course of 2 years, we learn how their practices have changed, inspired...

  19. Mobile Phone

    Institute of Scientific and Technical Information of China (English)

    籍万杰

    2004-01-01

    Your mobile phone rings.and instead of usual electronic signals,it's playing your favorite music.A friend sends your favorite song to cheer you up.One day,a record company might forward new records and music videos to your phone.

  20. A Rationale for Going Back to the Future: Use of Disposable Spacers for Pressurised Metered Dose Inhalers

    Directory of Open Access Journals (Sweden)

    Mark Sanders

    2015-01-01

    Full Text Available The introduction of pressurised metered dose inhalers (MDIs in the mid-1950s completely transformed respiratory treatment. Despite decades of availability and healthcare support and development of teaching aids and devices to promote better use, poor pMDI user technique remains a persistent issue. The main pMDI user aid is the spacer/valved holding chamber (VHC device. Spacer/chamber features (size, shape, configuration, construction material, and hygiene considerations can vie with clinical effectiveness (to deliver the same dose as a correctly used pMDI, user convenience, cost, and accessibility. Unsurprisingly, improvised, low-cost alternatives (plastic drink bottles, paper cups, and paper towel rolls have been pressed into seemingly effective service. A UK law change permitting schools to hold emergency inhalers and spacers has prompted a development project to design a low-cost, user-friendly, disposable, and recyclable spacer. This paper spacer requires neither preuse priming nor washing, and has demonstrated reproducible lung delivery of salbutamol sulphate pMDI, comparable to an industry-standard VHC, an alternative paperboard VHC, and pMDI alone. This new device appears to perform better than these other VHC devices at the low flow rates thought achievable by paediatric patients. The data suggest that this disposable spacer may have a place in the single-use emergency setting.

  1. A Comparison of Flow Field Characteristics from PIV Experiment Measurement to Numerical Simulation behind a Spacer in a Vertical Pipe

    Directory of Open Access Journals (Sweden)

    Lávička D.

    2010-07-01

    Full Text Available This paper describes the topic of measurement using a modern laser method (PIV in an annular channel of very small dimensions. The annular channel simulates the flow area around a model of a fuel rod in the VVER nuclear reactor. The annular channel holds spacers which create obstacles to fluid flow. The spacers serve a number of important purposes. In the real nuclear reactor, the spacer holds a fuel rod in the fuel rod bundle. Another important function of the spacer is to influence the flow field characteristics, especially turbulence size, by the shape of the spacer. The value of the turbulence regulates the intensity of heat transfer between the fuel rod and the fluid. Therefore, it is very important to provide a correct description and analysis of the flow field behind the obstacle the spacer generates. The paper further looks into the solution of the same task using numerical simulation. The solution of this task consisted of setting the suitable boundary conditions and of setting the turbulence model for the numerical simulation. The result is a comparison of the flow field characteristics from the experimental measurement and the findings of the numerical simulation. The numerical simulation was carried out using commercial CFD software package, FLUENT.

  2. [A case report of aortic valvuloplasty by rasping technique for aortic stenosis with small annulus simultaneously performed with mitral valve replacement].

    Science.gov (United States)

    Taniyasu, N; Kou, E; Hiramatsu, T; Yokoyama, S; Takenaka, A; Ikawa, O

    1997-02-01

    The patient was a 48-year-old woman with aortic stenosis and regurgitation and mitral stenosis. Preoperative cardiac catheterization revealed LV-Ao pressure gradient of 30 mmHg and regurgitation of Sellers III. The aortic annulus was measured less than 19 mm. As operative findings, the aortic annulus seemed to be too small to be replaced with 19 mm prosthetic valve. Aortic valvuloplasty (AVP) with rasping technique was performed for the aortic valve and valve replacement was carried out for the mitral valve. After aortic declamping and occurring her beat, the transesophageal echocardiographic evaluation for AVP was effective. Postoperative course was uneventful. Postoperative cardiac catheterization have shown decreased transvalvular pressure gradient up to 10 mmHg and aortic regurgitation of Sellers I.

  3. AN EXPERIMENTAL STUDY ON EFFECTS OF THE BETA TOPOGRAPHY ON SURFACE FLOWS IN A ROTATING ANNULUS SUBJECT TO RADIAL TEMPERATURE GRADIENT

    Institute of Scientific and Technical Information of China (English)

    LIN Shang-jing; WEI Gang; LIU Li-long; LIU Yu-di

    2005-01-01

    Beta effects on surface flows in a rotating annulus with a radial temperature gradient and a sloping bottom were studied experimentally. An azimuthal jet was produced by the action of the Coriolis force in the convective region between the two side walls of the annulus. Propagating velocity and patterns of the baroclinic wave on the surface were obtained by using a frequency-meter and a streak photograph respectively. It is shown that there exists the nonlinear interaction between the baroclinic and beta effects. The beta effect exerts little influence on the stratification flows and constrains the baroclinic instability, and it prompts the instability of the weak stratification flows and results in the surface pattern of waves with higher frequency. It is also indicated that the beta effect can reduce the propagating speed of the surface waves in the jet, and increase the thermal Rossby number for those same surface patterns under a given Taylor number.

  4. Mobile-to-mobile wireless channels

    CERN Document Server

    Zajic, Alenka

    2013-01-01

    Present-day mobile communications systems can be classified as fixed-to-mobile because they allow mobility on only one end (e.g. the mobile phone to a fixed mobile operator's cell tower). In answer to the consumer demand for better coverage and quality of service, emerging mobile-to-mobile (M-to-M) communications systems allow mobile users or vehicles to directly communicate with each other. This practical book provides a detailed introduction to state-of-the-art M-to-M wireless propagation. Moreover, the book offers professionals guidance for rapid implementation of these communications syste

  5. Effect of Thermo-Diffusion and Chemical Reaction on Mixed Convective Heat And Mass Transfer Through A Porous Medium In Cylindrical Annulus With Heat Source.

    Directory of Open Access Journals (Sweden)

    Dr.K.Gnaneswar

    2014-09-01

    Full Text Available A finite element study of combined heat and mass transfer flow through a porous medium in a circular cylindrical annulus with Soret and Dufour effects in the presence of heat sources has been analyzed. The coupled velocity, energy, and diffusion equations are solved numerically by using Galerkin- finite element technique. Shear stress, Nusslet number and Sherwood number are evaluated numerically for different values of the governing parameters under consideration and are shown in tabular form.

  6. CT-angiography-based evaluation of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI-predictive value and optimal thresholds for major anatomic parameters.

    Directory of Open Access Journals (Sweden)

    Florian Schwarz

    Full Text Available BACKGROUND/OBJECTIVES: To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI and to calculate optimal cutoff values for the selection of various prosthesis sizes. METHODS: The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67. In the remaining 351 patients, the CoreValve (Medtronic and the Edwards Sapien XT valve (Edwards Lifesciences were implanted in 235 and 116 patients. Optimal prosthesis size was determined during TAVI by inflation of a balloon catheter at the aortic annulus. All patients had undergone CT-angiography of the heart or body trunk prior to TAVI. Using these datasets, the diameter of the long and short axis as well as the circumference and the area of the aortic annulus were measured. Multi-Class Receiver-Operator-Curve analyses were used to determine the predictive value of all variables and to define optimal cutoff-values. RESULTS: Differences between patients who underwent implantation of the small, medium or large prosthesis were significant for all except the large vs. medium CoreValve (all p's<0.05. Furthermore, mean diameter, annulus area and circumference had equally high predictive value for prosthesis size for both manufacturers (multi-class AUC's: 0.80, 0.88, 0.91, 0.88, 0.88, 0.89. Using the calculated optimal cutoff-values, prosthesis size is predicted correctly in 85% of cases. CONCLUSION: CT-based aortic root measurements permit excellent prediction of the prosthesis size considered optimal during TAVI.

  7. Inspection and Gamma-Ray Dose Rate Measurements of the Annulus of the VSC-17 Concrete Spent Nuclear Fuel Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    P. L. Winston

    2007-09-01

    The air cooling annulus of the Ventilated Storage Cask (VSC)-17 spent fuel storage cask was inspected using a Toshiba 7 mm (1/4”) CCD video camera. The dose rates observed in the annular space were measured to provide a reference for the activity to which the camera(s) being tested were being exposed. No gross degradation, pitting, or general corrosion was observed.

  8. Performance of transonic fan stage with weight flow per unit annulus area of 208 kilograms per second per square meter (42.6 (lb/sec)/sq ft)

    Science.gov (United States)

    Urasek, D. C.; Kovich, G.; Moore, R. D.

    1973-01-01

    Performance was obtained for a 50-cm-diameter compressor designed for a high weight flow per unit annulus area of 208 (kg/sec)/sq m. Peak efficiency values of 0.83 and 0.79 were obtained for the rotor and stage, respectively. The stall margin for the stage was 23 percent, based on equivalent weight flow and total-pressure ratio at peak efficiency and stall.

  9. Indirect decompression and vertebral body endplate strength after lateral interbody spacer impaction: cadaveric and foam-block models.

    Science.gov (United States)

    Kwon, Anthony J; Hunter, William D; Moldavsky, Mark; Salloum, Kanaan; Bucklen, Brandon

    2016-05-01

    OBJECTIVE The lateral transpsoas approach to the lumbar spine is a well-defined procedure for the management of discogenic spinal pathology necessitating surgical intervention. Intervertebral device subsidence is a postoperative clinical risk that can lead to recurrence of symptomatic pathology and the need for surgical reintervention. The current study was designed to investigate static versus expandable lateral intervertebral spacers in indirect decompression for preserving vertebral body endplate strength. METHODS Using a cadaveric biomechanical study and a foam-block vertebral body model, researchers compared vertebral body endplate strength and distraction potential. Fourteen lumbar motion segments (7 L2-3 and 7 L4-5 specimens) were distributed evenly between static and expandable spacer groups. In each specimen discectomy was followed by trialing and spacer impaction. Motion segments were axially sectioned through the disc, and a metal stamp was used to apply a compressive load to superior and inferior vertebral bodies to quantify endplate strength. A paired, 2-sample for means t-test was performed to determine statistically significant differences between groups (p ≤ 0.05). A foam-block endplate model was used to control simulated disc tension when a spacer with 2- and 3-mm desired distraction was inserted. One-way ANOVA and a post hoc Student Newman-Keuls test were performed (p ≤ 0.05) to determine differences in distraction. RESULTS Both static and expandable spacers restored intact neural foramen and disc heights after device implantation (p > 0.05). Maximum peak loads at endplate failure for static and expandable spacers were 1764 N (± 966 N) and 2284 N (± 949 N), respectively (p ≤ 0.05). The expandable spacer consistently produced greater desired distraction than was created by the static spacer in the foam-block model (p ≤ 0.05). Distraction created by fully expanding the spacer was significantly greater than the predetermined goals of 2 mm

  10. Use of the Konno procedure in an 80-year-old woman with aortic stenosis, a narrow left ventricular outflow tract, and a small aortic annulus.

    Science.gov (United States)

    Misumi, Hiroyasu; Katayama, Yukihiro; Takaji, Kentaro; Oshitomi, Takashi; Uesugi, Hideyuki; Hirayama, Touitsu; Takeuchi, Takamasa

    2014-01-01

    This report describes a technique for repairing an aortic stenosis in an elderly patient with a small aortic annulus and a narrow left ventricular outflow tract. Preoperative echocardiography in an 80-year-old woman showed severe aortic stenosis with a narrow outflow tract: the aortic valve area was 0.48 cm(2), the aortic annular diameter was 14 mm, and the left ventricular outflow tract diameter was 14 mm. The Konno procedure was used to enlarge both the small aortic annulus and the left ventricular outflow tract, and a 19-mm Carpentier-Edwards bioprosthetic valve was implanted. The patient's postoperative course was uneventful. The left ventricular mass decreased from a preoperative value of 236 g to 96 g, 3 years after surgery. Only a few reports have described the use of the Konno operation in adult patients. In the present case, the Konno operation was demonstrated to be a good option for aortic stenosis accompanied by a small aortic annulus and a narrow left ventricular outflow tract, even in an elderly patient.

  11. Iterative Learning of Transcatheter Mitral Valve Replacement in Mitral Valve Annulus Calcification: Management and Prevention of Transcatheter Mitral Valve Replacement Dislocation.

    Science.gov (United States)

    Hulman, Michal; Bena, Martin; Artemiou, Panagiotis; Gasparovic, Ivo; Hudec, Vladan; Rajani, Ronak; Bapat, Vinayak

    2016-10-01

    Transcatheter mitral valve replacement using balloon-expandable valves is an emerging technique for the treatment of patients with significant mitral regurgitation who have been judged to be inoperable owing to significant mitral valve annulus calcification. Although initial reports have been promising, there remains a lack of consensus as to how to plan for transcatheter mitral valve replacement deployment in terms of appropriateness, sizing, and positioning to mitigate the risks of valve displacement and paravalvular regurgitation. We describe two cases of transcatheter mitral valve replacement in patients with significant mitral valve annulus calcification. The first was complicated by valve displacement into the left atrium, which was successfully managed by surgical redeployment and fixation. The second case was thereafter performed successfully using iterative learning and the application of specific preprocedural planning techniques acquired from a root cause analysis of the first case. We describe our experience with both cases and the specific planning principles required to prevent transcatheter mitral valve replacement displacement in patients with mitral valve annulus calcification.

  12. Numerical Study of Laminar Forced Convection of Water/Al2o3 Nanofluid in an Annulus with Constant Wall Temperature

    Directory of Open Access Journals (Sweden)

    Amin Kashani

    2013-04-01

    Full Text Available Laminar forced convection of a nanofluid consisting of water and Al2O3 in a horizontal annulus has been studied numerically. Two-phase mixture model has been used to investigate thermal behaviors of the nanofluid over constant temperature thermal boundary condition and with different volume concentration of nanoparticles. Comparisons with previously published experimental and analytical works on flow behavior in horizontal annulus show good agreements between the results as volume fraction is zero. In general convective heat transfer coefficient increases with nanoparticle concentration. ABSTRAK: Kertaskerja ini mengkaji secara numerik olakan paksa bendalir lamina yang menganduangi air dan Al2O3 didalam anulus mendatar. Model campuran dua fasa digunakan bagi mengkaji tingkah laku haba bendalir nano pada keadaan suhu malar dengan kepekatan nanopartikel berbeza. Perbandingan dengan karya eksperimen dan analitikal yang telah diterbitkan menunjukkan bahawa kelakuan aliran didalm anulus mendatar adalah baik apabila pecahan isipadu adalah sifar. Pada amnya, pekali pemindahan haba olakan meningkat dengan kepekatan nanopartikel. KEYWORDS: nanofluid; volume concentration; heat transfer enhancement; laminar flow convection; annulus

  13. The African Mobile Story

    DEFF Research Database (Denmark)

    This book identifies the factors that has enabled the growth of mobile telephony in Africa. The book covers the regulatory factors, the development and usage of mobile application, mobile security and sustainable power source for mobile networks......This book identifies the factors that has enabled the growth of mobile telephony in Africa. The book covers the regulatory factors, the development and usage of mobile application, mobile security and sustainable power source for mobile networks...

  14. Mobility Bibliography.

    Science.gov (United States)

    1981-11-01

    military vehicle mobility; shock absorbers; springs; suspension systems; vehicle performance; wheels 44. AU - Singh, D.V. TI - Stability of Rajdoot Scooter ...1972 IT - computer simulation; snow vehicles; suspension systems; vehicle dynamics; vibration 81 IJ 222. AU - Hazzard, H.I. TI - The McCulloch BP-399... suspension - a high speed motion picture study SO - Society of Automotive Engineers Technical Paper No. 710667 IT - snow vehicles; suspension systems

  15. Robotique Mobile

    OpenAIRE

    Filliat, David

    2011-01-01

    1 Introduction I Les bases de la navigation 2 Les différents types de navigation 3 Les sources d'information 4 Matériels courants en robotique mobile II Navigation réactive 5 Navigation vers un but 6 Évitement d'obstacles 7 Apprentissage par renforcement III Navigation utilisant une carte 8 Localisation, Cartographie et Planification 9 Les représentations de l'environne 10 Localisation 11 Cartographie 12 Planification; Engineering school

  16. Going mobile

    Science.gov (United States)

    Brus, Eric

    1987-12-01

    By 1990, all metropolitan areas in the U.S. and rural areas close to major cities or towns are expected to have cellular telephone service; 22 Canadian cities also feature cellular service. To supply mobile telecommunication services to sparsely-populated rural areas, a mobile satellite service (MSS) is now being developed. In this paper the projected possibilities of the MSS system are discussed, including a possibility that a piggyback-MSS payload be added to the GSTAR-4 satellite which is scheduled for a launch in 1988 or 1989; one in which some of the hardware from aborted direct-broadcast satellites would be used; and the possibility of building a new MSS satellite with large servicing capacity. Canada is planning to launch its own mobile satellite, MSAT, in the early 1990s. The MSS is expected to be 'generic', serving not only people on land but maritime and aeronautical users as well. It will also offer major benefits to truck and automobile drivers, making it possible for them to conduct business or to call for assistance from locations beyond the range of cellular systems.

  17. Network Mobiles

    Directory of Open Access Journals (Sweden)

    Alhamali Masoud Alfrgani .Ali

    2015-07-01

    Full Text Available Mobile devices are becoming increasingly popular for delivering multimedia content, particularly by means of streaming. The main disadvantage of these devices is their limited battery life. Unfortunately, streaming of multimedia content causes the battery of the device to discharge very fast, often causing the battery to deplete before the streaming task finishes, resulting in user dissatisfaction. It is generally not possible to charge the device while on the go as electricity socket and charger are required. Therefore, to avoid this user dissatisfaction, it is necessary to find ways to prolong the battery lifetime and to support the completion of the multimedia streaming tasks. A typical architecture for mobile multimedia streaming is presented In this architecture, a wired server streams multimedia content over a wireless IP network to a number of client devices. These devices could be PDAs, smartphones or any other mobile device with 802.11 connectivity. In relation to possible power savings, the multimedia streaming process can be described as consisting of three stages: reception, decoding and playing. Other researchers have shown that energy savings can be made in each stage, for example by using pre-buffering in the reception stage, feedback control during decoding and backlight adjustment for playing. However, it is not a common practice to combine energy savings in the three stages in order to achieve the best

  18. Application of a hydrogel spacer for postoperative salvage radiotherapy of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pinkawa, Michael; Schubert, Carolin; Escobar-Corral, Nuria; Holy, Richard; Eble, Michael J. [RWTH Aachen University, Department of Radiation Oncology, Aachen (Germany)

    2015-04-01

    In contrast to primary radiotherapy, no reports are available for a hydrogel spacer application in postoperative salvage radiotherapy for prostate cancer. A 77-year-old patient presented 20 years after radical prostatectomy with a digitally palpable local recurrence at the urethrovesical anastomosis (PSA 5.5 ng/ml). The hydrogel spacer (10 ml, SpaceOAR trademark) was injected between the local recurrence and rectal wall under transrectal ultrasound guidance. Treatment planning was performed with an intensity-modulated technique up to a total dose of 76 Gy in 2-Gy fractions. The same planning was performed based on computed tomography before spacer injection for comparison. The local recurrence, initially directly on the rectal wall, could be displaced more than 1 cm from the rectal wall after hydrogel injection. With a mean total dose of 76 Gy to the planning target volume, rectal wall volumes included in the 70 Gy, 60 Gy, 50 Gy isodoses were 0 cm{sup 3}, 0 cm{sup 3}, and 0.4 cm{sup 3} with a spacer and 2.9 cm{sup 3}, 4.5 cm{sup 3}, and 6.2 cm{sup 3} without a spacer, respectively. The patient reported rectal urgency during radiotherapy, completely resolving after the end of treatment. The PSA level was 5.4 ng/ml a week before the end of radiotherapy and dropped to 0.9 ng/ml 5 months after radiotherapy. A hydrogel spacer was successfully applied for dose-escalated radiotherapy in a patient with macroscopic local prostate cancer recurrence at the urethrovesical anastomosis to decrease the dose at the rectal wall. This option can be considered in specifically selected patients. (orig.) [German] Im Gegensatz zum Einsatz bei der primaeren Radiotherapie gibt es bisher keine Berichte zum Einsatz eines Hydrogel-Abstandhalters bei der postoperativen Salvage-Radiotherapie des Prostatakarzinoms. Ein 77-jaehriger Patient stellte sich 20 Jahre nach radikaler Prostatektomie mit einem digital palpablem Lokalrezidiv im Bereich der urethrovesikalen Anastomose vor (PSA 5,5 ng

  19. Calculation Analysis of Pressure Wave Velocity in Gas and Drilling Mud Two-Phase Fluid in Annulus during Drilling Operations

    Directory of Open Access Journals (Sweden)

    Yuanhua Lin

    2013-01-01

    Full Text Available Investigation of propagation characteristics of a pressure wave is of great significance to the solution of the transient pressure problem caused by unsteady operations during management pressure drilling operations. With consideration of the important factors such as virtual mass force, drag force, angular frequency, gas influx rate, pressure, temperature, and well depth, a united wave velocity model has been proposed based on pressure gradient equations in drilling operations, gas-liquid two-fluid model, the gas-drilling mud equations of state, and small perturbation theory. Solved by adopting the Runge-Kutta method, calculation results indicate that the wave velocity and void fraction have different values with respect to well depth. In the annulus, the drop of pressure causes an increase in void fraction along the flow direction. The void fraction increases first slightly and then sharply; correspondingly the wave velocity first gradually decreases and then slightly increases. In general, the wave velocity tends to increase with the increase in back pressure and the decrease of gas influx rate and angular frequency, significantly in low range. Taking the virtual mass force into account, the dispersion characteristic of the pressure wave weakens obviously, especially at the position close to the wellhead.

  20. Transient critical heat flux under flow coast-down in vertical annulus with non-uniform heat flux distribution

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.K.; Chun, S.Y.; Choi, K.Y.; Yang, S.K. [Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

    2001-07-01

    An experimental study on transient critical heat flux (CHF) under flow coast-down has been performed for water flow in a non-uniformly heated vertical annulus under low flow and a wide range of pressure conditions. The objectives of this study are to systematically investigate the effect of the flow transient on the CHF and to compare the transient CHF with steady state CHF. The transient CHF experiments have been performed for three kinds of flow transient modes based on the coast-down data of the Kori 3/4 nuclear power plant reactor coolant pump. Most of the CHFs occurred in the annular-mist flow regime. Thus, it means that the possible CHF mechanism might be the liquid film dryout in the annular-mist flow regime. For flow transient mode with the smallest flow reduction rate, the time-to-CHF is the largest. At the same inlet subcooling, system pressure and heat flux, the effect of the initial mass flux on the critical mass flux can be negligible. However, the effect of the initial mass flux on the time-to-CHF becomes large as the heat flux decreases. Usually, the critical mass flux is large for slow flow reduction. There is a pressure effect on the ratio of the transient CHF data to steady state CHF data. Some conventional correlations show relatively better CHF prediction results for high system pressure, high quality and slow transient modes than for low system pressure, low quality and fast transient modes. (author)

  1. Structure and mechanical function of the inter-lamellar matrix of the annulus fibrosus in the disc.

    Science.gov (United States)

    Tavakoli, Javad; Elliott, Dawn M; Costi, John J

    2016-08-01

    The inter-lamellar matrix (ILM) has an average thickness of less than 30 µm and lies between adjacent lamellae in the annulus fibrosus (AF). The microstructure and composition of the ILM have been studied in various anatomic regions of the disc; however, their contribution to AF mechanical properties and structural integrity is unknown. It was suggested that the ILM components, mainly elastic fibers and cross-bridges, play a role in providing mechanical integrity of the AF. Therefore, the manner in which they respond to different loadings and stabilize adjacent lamellae structure will influence AF tear formation and subsequent herniation. This review paper summarizes the composition, microstructure, and potential role of the ILM in the progression of disc herniation, clarifies the micromechanical properties of the ILM, and proposes critical areas for future studies. There are a number of unknown characteristics of the ILM, such as its mechanical role, impact on AF integrity, and ultrastructure of elastic fibers at the ILM-lamella boundary. Determining these characteristics will provide important information for tissue engineering, repair strategies, and the development of more-physiological computational models to study the initiation and propagation of AF tears that lead to herniation and degeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1307-1315, 2016.

  2. A Novel Dynamic Model for Predicting Pressure Wave Velocity in Four-Phase Fluid Flowing along the Drilling Annulus

    Directory of Open Access Journals (Sweden)

    Xiangwei Kong

    2015-01-01

    Full Text Available A dynamic pressure wave velocity model is presented based on momentum equation, mass-balance equation, equation of state, and small perturbation theory. Simultaneously, the drift model was used to analyze the flow characteristics of oil, gas, water, and drilling fluid multiphase flow. In addition, the dynamic model considers the gas dissolution, virtual mass force, drag force, and relative motion of the interphase as well. Finite difference and Newton-Raphson iterative are introduced to the numerical simulation of the dynamic model. The calculation results indicate that the wave velocity is more sensitive to the increase of gas influx rate than the increase of oil/water influx rate. Wave velocity decreases significantly with the increase of gas influx. Influenced by the pressure drop of four-phase fluid flowing along the annulus, wave velocity tends to increase with respect to well depth, contrary to the gradual reduction of gas void fraction at different depths with the increase of backpressure (BP. Analysis also found that the growth of angular frequency will lead to an increase of wave velocity at low range. Comparison with the calculation results without considering virtual mass force demonstrates that the calculated wave velocity is relatively bigger by using the presented model.

  3. A comparison between porcine, ovine, and bovine intervertebral disc anatomy and single lamella annulus fibrosus tensile properties.

    Science.gov (United States)

    Monaco, Lauren A; DeWitte-Orr, Stephanie J; Gregory, Diane E

    2016-02-01

    This project aimed to compare gross anatomical measures and biomechanical properties of single lamellae from the annulus fibrosus of ovine and porcine lumbar vertebrae, and bovine tail vertebrae. The morphology of the vertebrae of these species differ significantly both from each other and from human, yet how these differences alter biomechanical properties is unknown. Geometric parameters measured in this study included: 1) absolute and relative intervertebral (IVD) and vertebral body height and 2) absolute and relative intervertebral disc (IVD) anterior-posterior (AP) and medial-lateral (ML) widths. Single lamella tensile properties included toe-region stress and stretch ratio, stiffness, and tensile strength. As expected, the bovine tail IVD revealed a more circular shape compared with both the ovine and porcine lumbar IVD. The bovine tail also had the largest IVD to vertebral body height ratio (due to having the highest absolute IVD height). Bovine tail lamellae were also found to be strongest and stiffest (in tension) while ovine lumbar lamellae were weakest and most compliant. Histological analysis revealed the greatest proportion of collagen in the bovine corroborating findings of increased strength and stiffness. The observed differences in anatomical shape, connective tissue composition, and tensile properties need to be considered when choosing an appropriate model for IVD research.

  4. Comparison of phenotype characteristics of rat annulus fibrosus cells cultured on flexible silicone membrane and in plastic plate

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; CHENG Min; CAO Guo-yong; LI Hua-zhuang; TENG Hai-jun; ZHOU Yue

    2006-01-01

    Objective:To compare the phenotype characteristics of rat annulus fibrosus (AF) cells cultured on flexible silicone membranes and those in plastic plates. Methods :The morphology of AF cells cultured in different substrates was examined. Proteoglycan was stained by toluidine blue. Contents of collagen type I , collagen type Ⅱ and aggrecan mRNAs were determined by reverse transcription-polymerase chain reaction (RT-PCR). The expression of integrin β1 was monitored by flow cytometry. By using propidium iodide (PI), the cell cycle in AF cells was analyzed. Cell adhesion to silicone membrane was also measured. Results:The AF cells cultured on different substrates were morphologically undistinguishable.Toluidine blue staining showed that there was also no difference between AF cells cultured on these 2 substrates. They still had the same expression levels of collagen type Ⅰ , collagen type Ⅱ , aggrecan mRNAs,and integrin β1. No significant difference was observed in the distribution of the cell cycle. AF cells grew well on silicone membrane. Conclusion:AF cells cultured on flexible silicone membrane maintain the stability of phenotype and may be appropriate for further studying the metabolic responses to mechanical stimuli at the cellular level.

  5. Protective effect of niacinamide on interleukin-1beta-induced annulus fibrosus type II collagen degeneration in vitro.

    Science.gov (United States)

    Duan, Deyu; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiong, Xiaoqian

    2007-02-01

    The protective effect of niacinamide on interleukin-1beta (IL-1beta)-induced annulus fibrosus (AF) type II collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebral disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type II collagen degneration group (IL-1beta) and treatment group (niacinamide+IL-1beta). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type II collagen immunohistochemical examination, and type II collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type II collagen degeneration group (Pniacinamide could effectively inhibit IL-1beta stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1beta-caused destruction and synthesis inhibition of type II collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  6. Inclusion of Zinc Oxide Nanoparticles into Virus-Like Peptide Nanocapsules Self-Assembled from Viral β-Annulus Peptide

    Directory of Open Access Journals (Sweden)

    Seiya Fujita

    2014-09-01

    Full Text Available A viral β-annulus peptide connected with a zinc oxide (ZnO-binding sequence (HCVAHR at its N-terminal was synthesized, and the inclusion behavior of quantum-sized ZnO nanoparticles into the peptide nanocapsules formed by self-assembly of the peptide in water was investigated. Dynamic light scattering (DLS measurements showed that ZnO nanoparticles (approximately 10 nm in the presence of the peptide (0.1 mM formed assemblies with an average size of 48 ± 24 nm, whereas ZnO nanoparticles in the absence of the peptide formed large aggregates. Transmission electron microscopy (TEM observations of the ZnO nanoparticles in the presence of the peptide revealed that ZnO nanoparticles were encapsulated into the peptide nanocapsules with a size of approximately 50 nm. Fluorescence spectra of a mixture of the peptide and ZnO nanoparticles suggested that the ZnO surface and the peptide interact. Template synthesis of ZnO nanoparticles with the peptide nanocapsules afforded larger nanoparticles (approximately 40 nm, which are not quantum-sized ZnO.

  7. The CRISPRdb database and tools to display CRISPRs and to generate dictionaries of spacers and repeats

    Directory of Open Access Journals (Sweden)

    Vergnaud Gilles

    2007-05-01

    Full Text Available Abstract Background In Archeae and Bacteria, the repeated elements called CRISPRs for "clustered regularly interspaced short palindromic repeats" are believed to participate in the defence against viruses. Short sequences called spacers are stored in-between repeated elements. In the current model, motifs comprising spacers and repeats may target an invading DNA and lead to its degradation through a proposed mechanism similar to RNA interference. Analysis of intra-species polymorphism shows that new motifs (one spacer and one repeated element are added in a polarised fashion. Although their principal characteristics have been described, a lot remains to be discovered on the way CRISPRs are created and evolve. As new genome sequences become available it appears necessary to develop automated scanning tools to make available CRISPRs related information and to facilitate additional investigations. Description We have produced a program, CRISPRFinder, which identifies CRISPRs and extracts the repeated and unique sequences. Using this software, a database is constructed which is automatically updated monthly from newly released genome sequences. Additional tools were created to allow the alignment of flanking sequences in search for similarities between different loci and to build dictionaries of unique sequences. To date, almost six hundred CRISPRs have been identified in 475 published genomes. Two Archeae out of thirty-seven and about half of Bacteria do not possess a CRISPR. Fine analysis of repeated sequences strongly supports the current view that new motifs are added at one end of the CRISPR adjacent to the putative promoter. Conclusion It is hoped that availability of a public database, regularly updated and which can be queried on the web will help in further dissecting and understanding CRISPR structure and flanking sequences evolution. Subsequent analyses of the intra-species CRISPR polymorphism will be facilitated by CRISPRFinder and the

  8. CFD Verification of 5x5 Rod Bundle with Mixing Vane Spacer Grids

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sungkew; Jang, Hyungwook; Lim, Jongseon; Park, Eungjun; Nahm, Keeyil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Results of the CHF test are used for determining the CHF correlation, which is used to evaluate the thermal margin in the reactor core. Computational fluid dynamics (CFD) has been used to save the time and cost for experimental tests, components design and complicated phenomena in all industries including the reactor coolant system. L. D. Smith et al. applied the CFD methodology in a 5x5 rod bundle with the mixing vane spacer grid using the renormalization group (RNG) k-epsilon model. This CFD model agreed reasonably well with the test data. M. E. Conner et al. conducted experiments to validate the CFD methodology for the single-phase flow conditions in PWR fuel assemblies. In this validation case, the CFD code predicted very similar flow field structures as the test data. In this study, a CFD simulation under single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with some mixing vane spacer grids. In this study, a CFD simulation under a single-phase flow condition was conducted for one specific condition in a thermal mixing flow test of 5x5 rod bundle with the mixing vane spacer grids to verify the applicability of the CFD model for predicting the outlet temperature distribution. FLUENT 14.5 Version was used in this CFD analysis. For the successful prediction of the wall bounded turbulent flows, the y+ with 3 prism layers was determined within 5. At this time, k-epsilon standard turbulence model was used. The temperature distribution of CFD for each sub-channel at the outlet region of test bundle showed the difference approximately within 1.1% and 0.2% while comparing to that of test and sub-channel analysis code, respectively.

  9. Diversity in a Polymicrobial Community Revealed by Analysis of Viromes, Endolysins and CRISPR Spacers

    Science.gov (United States)

    Treangen, Todd J.; Koren, Sergey; Pop, Mihai; Bhaya, Devaki

    2016-01-01

    The polymicrobial biofilm communities in Mushroom and Octopus Spring in Yellowstone National Park (YNP) are well characterized, yet little is known about the phage populations. Dominant species, Synechococcus sp. JA-2-3B'a(2–13), Synechococcus sp. JA-3-3Ab, Chloroflexus sp. Y-400-fl, and Roseiflexus sp. RS-1, contain multiple CRISPR-Cas arrays, suggesting complex interactions with phage predators. To analyze phage populations from Octopus Spring biofilms, we sequenced a viral enriched fraction. To assemble and analyze phage metagenomic data, we developed a custom module, VIRITAS, implemented within the MetAMOS framework. This module bins contigs into groups based on tetranucleotide frequencies and CRISPR spacer-protospacer matching and ORF calling. Using this pipeline we were able to assemble phage sequences into contigs and bin them into three clusters that corroborated with their potential host range. The virome contained 52,348 predicted ORFs; some were clearly phage-like; 9319 ORFs had a recognizable Pfam domain while the rest were hypothetical. Of the recognized domains with CRISPR spacer matches, was the phage endolysin used by lytic phage to disrupt cells. Analysis of the endolysins present in the thermophilic cyanophage contigs revealed a subset of characterized endolysins as well as a Glyco_hydro_108 (PF05838) domain not previously associated with sequenced cyanophages. A search for CRISPR spacer matches to all identified phage endolysins demonstrated that a majority of endolysin domains were targets. This strategy provides a general way to link host and phage as endolysins are known to be widely distributed in bacteriophage. Endolysins can also provide information about host cell wall composition and have the additional potential to be used as targets for novel therapeutics. PMID:27611571

  10. A new device designed for direct yield stress measurements of cement spacer

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, C.L.; Tonmukayakul, P.; Morgan, R.L. [Halliburton Energy Services, Houston, TX (United States)

    2007-07-01

    The rheological properties of spacer fluids and cement slurries have a significant impact on the hydraulic shear stress of well casing walls. This paper described experimental studies and numerical models of a device designed to measure the yield stress and rheological properties of spacer and cement samples. The device was designed using the Couette principle for rheological measurements, and measured the yield stress of particle-laden samples between 4 and 150 degrees C. A sample contained in a gap between a stator and a blade located along the inside wall of a steel cup was analyzed using the device. A stator was attached to a torque device and remained static during the rheological measurement. Yield stress was measured by rotating the device at a low speed at 3 rpm and at steady state torque. Torque was recorded when the rotation stopped. Two aqueous mixtures of titanium oxide (TiO{sub 2}) particles were used for the experiment. A cement spacer comprised of a blend of barite, citric acid and water was also measured. A volume-averaged shear method was used to calculate shear rate and shear stress. Key dimensionless variables were the impeller Reynolds number; the Froude number; the Weber number; and the Weissenberg number. Accuracy was assessed by examining the data obtained with a model fluid where yield stress data was already determined. Results of the comparison showed that values obtained using the device were consistent and comparable with results obtained using other techniques. It was concluded that further research is needed to characterize the elastic fluids in the device. 13 refs., 2 tabs., 3 figs.

  11. Phylogenetics of early branching eudicots: Comparing phylogenetic signal across plastid introns, spacers, and genes

    Institute of Scientific and Technical Information of China (English)

    Anna-Magdalena BARNISKE; Thomas BORSCH; Kai M(U)LLER; Michael KRUG; Andreas WORBERG; Christoph NEINHUIS; Dietmar QUANDT

    2012-01-01

    Recent phylogenetic analyses revealed a grade with Ranunculales,Sabiales,Proteales,Trochodendrales,and Buxales as first branching eudicots,with the respective positions of Proteales and Sabiales still lacking statistical confidence.As previous analyses of conserved plastid genes remain inconclusive,we aimed to use and evaluate a representative set of plastid introns (group Ⅰ:trnL; group Ⅱ:petD,rpll6,trnK) and intergenic spacers (trnL-F,petB-petD,atpB-rbcL,rps3-rpll6) in comparison to the rapidly evolving matK and slowly evolving atpB and rbcL genes.Overall patterns of microstructural mutations converged across genomic regions,underscoring the existence of a general mutational pattern throughout the plastid genome.Phylogenetic signal differed strongly between functionally and structurally different genomic regions and was highest in matK,followed by spacers,then group Ⅱ and group Ⅰ introns.The more conserved atpB and rbcL coding regions showed distinctly lower phylogenetic information content.Parsimony,maximum likelihood,and Bayesian phylogenetic analyses based on the combined dataset of non-coding and rapidly evolving regions (>14 000 aligned characters) converged to a backbone topology ofeudicots with Ranunculales branching first,a Proteales-Sabiales clade second,followed by Trochodendrales and Buxales.Gunnerales generally appeared as sister to all remaining core eudicots with maximum support.Our results show that a small number of intron and spacer sequences allow similar insights into phylogenetic relationships of eudicots compared to datasets of many combined genes.The non-coding proportion of the plastid genome thus can be considered an important information source for plastid phylogenomics.

  12. PairWise Neighbours database: overlaps and spacers among prokaryote genomes

    Directory of Open Access Journals (Sweden)

    Garcia-Vallvé Santiago

    2009-06-01

    Full Text Available Abstract Background Although prokaryotes live in a variety of habitats and possess different metabolic and genomic complexity, they have several genomic architectural features in common. The overlapping genes are a common feature of the prokaryote genomes. The overlapping lengths tend to be short because as the overlaps become longer they have more risk of deleterious mutations. The spacers between genes tend to be short too because of the tendency to reduce the non coding DNA among prokaryotes. However they must be long enough to maintain essential regulatory signals such as the Shine-Dalgarno (SD sequence, which is responsible of an efficient translation. Description PairWise Neighbours is an interactive and intuitive database used for retrieving information about the spacers and overlapping genes among bacterial and archaeal genomes. It contains 1,956,294 gene pairs from 678 fully sequenced prokaryote genomes and is freely available at the URL http://genomes.urv.cat/pwneigh. This database provides information about the overlaps and their conservation across species. Furthermore, it allows the wide analysis of the intergenic regions providing useful information such as the location and strength of the SD sequence. Conclusion There are experiments and bioinformatic analysis that rely on correct annotations of the initiation site. Therefore, a database that studies the overlaps and spacers among prokaryotes appears to be desirable. PairWise Neighbours database permits the reliability analysis of the overlapping structures and the study of the SD presence and location among the adjacent genes, which may help to check the annotation of the initiation sites.

  13. MOLECULAR PHYLOGENETIC ANALYSIS OF MONASCUS FUNGI BASED ON INTERNAL TRANSCRIBED SPACER REGION

    OpenAIRE

    Kikuchi, Y.; N. SUHARNA; Fukatsu, T

    2005-01-01

    A molecular analysis of internal transcribed spacer region has been carried out to reveal the relationship among 16 strains of Monascus spp. A primer set comprised primer ITS1 and ITS4 was used to amplify this region in which they were cloned and scqucnccd. We also compared the sequence result with M. purpureus AF458473, M.ruber AF458470, M. kaoliang AF451859, M. araneous AF458471 and M. pilosus AF451856 and one outgroup species Thermoascus crustaceus U18353. The result showed that 16 M...

  14. NETWORK MOBILITY SUPPORTED PROXY MOBILE IPV6

    Directory of Open Access Journals (Sweden)

    Ananthi Jebaseeli SamuelRaj

    2014-01-01

    Full Text Available Proxy Mobile IPV6 (PMIPV6 is a network-based mobility management protocol, designed to keep track of individual mobile node’s movement. So a mobile node can easily roam in PMIPV6 network without changing it’s IP address. Network Mobility-Basic Support Protocol (NEMO-BSP, based on MIPV6, is the protocol designed for mobility management of NEMO in MPIV6 network. But NEMO-BSP cannot be directly used in PMIPV6 due to differences in the underlying protocols. To make PMIPV6 as a complete mobility management protocol, functionality of PMIPV6 should be enhanced to support network mobility in PMIPV6. This work enhances functionality of PMIPV6 and NEMO-BSP protocols and proposes a new architecture called NEMO supported PMIPV6 that supports movement of mobile nodes as well as network mobility in PMIPV6 network.

  15. The Construction of Chimeric T-Cell Receptor with Spacer Base of Modeling Study of VHH and MUC1 Interaction

    Directory of Open Access Journals (Sweden)

    Nazanin Pirooznia

    2011-01-01

    Full Text Available Adaptive cell immunotherapy with the use of chimeric receptors leads to the best and most specific response against tumors. Chimeric receptors consist of a signaling fragment, extracellular spacer, costimulating domain, and an antibody. Antibodies cause immunogenicity; therefore, VHH is a good replacement for ScFv in chimeric receptors. Since peptide sequences have an influence on chimeric receptors, the effect of peptide domains on each other's conformation were investigated. CD3Zeta, CD28, VHH and CD8α, and FcgIIα are used as signaling moieties, costimulating domain, antibody, and spacers, respectively. To investigate the influence of the ligation of spacers on the conformational structure of VHH, models of VHH were constructed. Molecular dynamics simulation was run to study the influence of the presence of spacers on the conformational changes in the binding sites of VHH. Root mean square deviation and root mean square fluctuation of critical segments in the binding site showed no noticeable differences with those in the native VHH. Results from molecular docking revealed that the presence of spacer FcgIIα causes an increasing effect on VHH with MUC1 interaction. Each of the constructs was transformed into the Jurkat E6.1. Expression analysis and evaluation of their functions were examined. The results showed good expression and function.

  16. Effect of Charging and Position of Metallic Particle Adhered to Spacer on PDIV and PRPD Characteristics in GIS

    Directory of Open Access Journals (Sweden)

    Y. Khan

    2014-07-01

    Full Text Available Gas Insulated Switchgears (GIS are widely used due to their many benefits. The reliability of GIS is challenged due to the presence of spacer defects and/or metallic particles. Free metallic particles can tremendously reduce the insulation strength of GIS especially when they enter the triple junction region (consisting of the spacer, the electrode and the gaseous medium interface around the spacer. Therefore, there a need to investigate the effect of charged metallic particle on the field intensification produced along the spacer surface and its consequences on the Partial Discharge Inception Voltage (PDIV. In this study, simulation and experimental results are reported for metallic particles adhering to a cylindrical spacer. The effect of particle charging on the resulting field intensification, particle initiated partial discharge inception voltage as well as Phase Resolved Partial Discharge (PRPD characteristics are presented in this study. The particle adversely affects the electric field uniformity in the area between the two electrodes. A particle in contact with the electrode causes the most severe intensification in the electric field, while the effect caused by the particle at the gap centre is the least severe.

  17. Impact of Asymmetric Dual-k Spacer in the Underlap Regions of Sub 20 nm NMOSFET with Gate Stack

    Science.gov (United States)

    Chakraborty, Shramana; Dasgupta, Arpan; Das, Rahul; Kundu, Atanu; Sarkar, Chandan K.

    2016-10-01

    This paper shows the systematic study of underlap double gate (U-DG) NMOSFETs with Gate Stack (GS) under the influence of dual-k spacers at the different underlap regions. In highly scaled devices, underlap is used at the Source and Drain side so as to reduce the short channel effects (SCE's) but at the cost of low on current (ION) and increased channel resistance. The high-k spacers are used to counter this problem. The ION is improved but at the cost of highly enhanced parasitic capacitances. This paper explores the possibility of using asymmetric dual-k spacer at the source underlap side so as to counter the shortcomings of high-k spacers in highly scaled devices on the basis of analog parameters: ION, gm, gm/ID, and intrinsic gain, gmRo and RF performance in terms of parasitic gate capacitance (Cgs, Cgd and Cgg),gate to source/drain resistances (Rgs and Rgd), transport delay (τm), the unity current gain cut-off frequency (fT) and the maximum frequency of oscillation (fmax). A single stage amplifier performance is also analyzed where it has been seen that the asymmetric dual-k spacer at the source underlap side gives better performance as compared to the other devices under comparison.

  18. CFD analysis on mixing effects of spacer grids with different dimples and sizes for advanced fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.W.; Zhang, H.; Han, B.; Zha, Y.D.; Shan, J.Q. [Xi' an Jiaotong Univ. (China). School of Nuclear Science and Technology

    2016-07-15

    The thermal hydraulic characteristics of a mixing vane grid are largely dependent on the structure of key components, such as strip, spring, dimple, weld nugget, as well as the mixing vane configuration. In this paper, several types of spacer grids with different dimple shapes are modeled under subcooled boiling conditions. Prior to the application of CFD on the dimple shape analysis, the mixing effects of spacer grids were studied. After the dimple shape analysis, the side channel effect is discussed by comparing the simulation results of a 3 x 3 and a 5 x 5 spacer grid. The two phase flow CFD models in this study are validated through simple geometry showing that the calculated void fraction is in good agreement with the experimental data. The dimple comparison result shows that varying dimple structures can result in different temperatures, lateral velocities and void fraction distributions downstream of the spacer grids. Comparison of two sizes of spacer grids demonstrate that the side channel generates different flow distribution pattern in the center channel.

  19. Pyrocarbon spacer as a trapezium replacement for arthritis of the trapeziometacarpal joint; a follow-up study of 60 cases.

    Science.gov (United States)

    Szalay, Gabor; Meyer, Christof; Scheufens, Tanja; Schnettler, Reinhard; Christ, Ralph; Schleicher, Iris

    2013-12-01

    Rhizarthrosis is the most common degenerative joint disease of the hand, affecting about 10% of the population. We report our results with trapezium replacement using a pyrocarbon spacer. Between January 2005 and April 2010, 70 patients underwent trapeziectomy with interposition of a pyrocarbon spacer. Sixty patients were examined at an average follow-up of 23.6 (5-64) months after the operation. Six (8.6%) of the 70 implanted pyrocarbon spacers dislocated. Based on the assessment scale devised by Buck-Gramcko, 19 patients achieved a very good outcome (31.6%), 31 patients (51.6%) had a good outcome, six results were satisfactory (10%) and four patients (6.6%) had a poor result. In this study, trapeziectomy and implantation of a pyrocarbon spacer achieved good or very good results in 83.2% of cases. The high cost of the implant and the observed rate of spacer dislocation should however be considered critically. While the short-term results of this method are encouraging, long-term outcomes will show whether this technique can keep up with the good results of suspension arthroplasty.

  20. DYNAMIC CHARACTERISTICS OF LIQUID FORCED SLOSHING IN A TURNING SPHERICAL TANK WITH A SPACER UNDER LOW GRAVITY

    Institute of Scientific and Technical Information of China (English)

    CHENG Xu-duo; HU Mei-zhu; WEN Ji-hua

    2008-01-01

    Under the condition of low gravity the characteristics of liquid forced sloshing in a turning spherical tank with a spacer were investigated. The static shape of the liquid surface was analyzed. By expanding the characteristic functions, the frequencies and velocity potential of liquid free-sloshing were derived. The governing equations and boundary conditions for the forced sloshing of liquid under the tank turning were established. The transverse force of liquid acting on the tank and the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer were given. Numerical results were compared with the ones of the spherical tank without a spacer. The results show that when a spacer is inserted in the tank, the sloshing frequency of liquid and the transverse force of liquid acting on the tank will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.

  1. Analysis of high-k spacer on symmetric underlap DG-MOSFET with Gate Stack architecture

    Science.gov (United States)

    Das, Rahul; Chakraborty, Shramana; Dasgupta, Arpan; Dutta, Arka; Kundu, Atanu; Sarkar, Chandan K.

    2016-09-01

    This paper shows the systematic study of underlap double gate (U-DG) NMOSFETs with Gate Stack (GS) under the influence of high-k spacers. In highly scaled devices, underlap is used at the Source and Drain side so as to reduce the short channel effects (SCE's), however, it significantly reduces the on current due to the increased channel resistance. To overcome these drawbacks, the use of high-k spacers is projected as one of the remedies. In this paper, the analog performance of the devices is studied on the basis of parameters like transconductance (gm), transconductance generation factor (gm/Id) and intrinsic gain (gmro). The RF performance is analyzed on the merits of intrinsic capacitance (Cgd, Cgs), resistance (Rgd, Rgs), transport delay (τm), inductance (Lsd), cutoff frequency (fT), and the maximum frequency of oscillation (fmax). The circuit performance of the devices are studied by implementing the device as the driver MOSFET in a Single Stage Common Source Amplifier. The Gain Bandwidth Product (GBW) has been analyzed from the frequency response of the circuit.

  2. Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

    Directory of Open Access Journals (Sweden)

    Yuchun Ren

    2015-06-01

    Full Text Available A series of azobenzene–cholesterol organogel compounds (M0–M12 with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.

  3. Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

    Science.gov (United States)

    Ren, Yuchun; Zhang, Xiuqing

    2015-01-01

    Summary A series of azobenzene–cholesterol organogel compounds (M 0 –M 12) with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M 6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure. PMID:26199664

  4. Spacer engineered Trigate SOI TFET: An investigation towards harsh temperature environment applications

    Science.gov (United States)

    Mallikarjunarao; Ranjan, Rajeev; Pradhan, K. P.; Artola, L.; Sahu, P. K.

    2016-09-01

    In this paper, a novel N-channel Tunnel Field Effect Transistor (TFET) i.e., Trigate Silicon-ON-Insulator (SOI) N-TFET with high-k spacer is proposed for better Sub-threshold swing (SS) and OFF-state current (IOFF) by keeping in mind the sensitivity towards temperature. The proposed model can achieve a Sub-threshold swing less than 35 mV/decade at various temperatures, which is desirable for designing low power CTFET for digital circuit applications. In N-TFET source doping has a significant effect on the ON-state current (ION) level; therefore more electrons will tunnel from source to channel region. High-k Spacer i.e., HfO2 is used to enhance the device performance and also it avoids overlapping of transistors in an integrated circuits (IC's). We have designed a reliable device by performing the temperature analysis on Transfer characteristics, Drain characteristics and also on various performance metrics like ON-state current (ION), OFF-state current (IOFF), ION/IOFF, Trans-conductance (gm), Trans-conductance Generation Factor (TGF), Sub-threshold Swing (SS) to observe the applications towards harsh temperature environment.

  5. Unexpected Temperature Behavior of Polyethylene Glycol Spacers in Copolymer Dendrimers in Chloroform

    Science.gov (United States)

    Markelov, Denis A.; Matveev, Vladimir V.; Ingman, Petri; Nikolaeva, Marianna N.; Penkova, Anastasia V.; Lahderanta, Erkki; Boiko, Natalia I.; Chizhik, Vladimir I.

    2016-04-01

    We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoate mesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers are additional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. The dendrimer macromolecules were investigated in a dilute chloroform solution by 1H NMR methods (spectra and relaxations). It was found that the PEG layer in G = 5 generations dendrimer is “frozen” at high temperatures (above 260 K), but it unexpectedly becomes “unfrozen” at temperatures below 250 K (i.e., melting when cooling). The transition between these two states occurs within a small temperature range (~10 K). Such a behavior is not observed for smaller dendrimer generations (G = 1 and 3). This effect is likely related to the low critical solution temperature (LCST) of PEG and is caused by dendrimer conformations, in which the PEG group concentration in the layer increases with growing G. We suppose that the unusual behavior of PEG fragments in dendrimers will be interesting for practical applications such as nanocontainers or nanoreactors.

  6. Cationic gemini surfactants with cleavable spacer: chemical hydrolysis, biodegradation, and toxicity.

    Science.gov (United States)

    Tehrani-Bagha, A R; Holmberg, K; van Ginkel, C G; Kean, M

    2015-07-01

    The paper describes synthesis and characterization of a new type of cationic gemini surfactant, which has dodecyl tails and a spacer that contains an ester bond. The nomenclature used to describe the structure is 12Q2OCO1Q12, with Q being a quaternary ammonium group and the numbers indicating the number of methylene or methyl groups. Due to the close proximity to the two quaternary ammonium groups, the ester bond is very stable on the acid side and very labile already at slightly alkaline conditions. The hydrolysis products are two single chain surfactants (i.e. 12Q2OH and 12Q1COOH) which are less surface active than the intact gemini surfactant. 12Q2OCO1Q12 was found to be readily biodegradable, i.e. it gave more than 60% biodegradation after 28 days. This is interesting because similar gemini surfactants but with ester bonds in the tails instead of the spacer, have previously been found not to be readily biodegradable. The gemini surfactant was found to be toxic to aquatic organisms (ErC50 value of 0.27 mg/l), although less toxic than the two hydrolysis products.

  7. Role of spacer length in interaction between novel gemini imidazolium surfactants and Rhizopus oryzae lipase.

    Science.gov (United States)

    Adak, Sunita; Datta, Sougata; Bhattacharya, Santanu; Banerjee, Rintu

    2015-11-01

    An insight into the effects of new ionic liquid-type gemini imidazolium cationic surfactants on the structure and function of the lipases is of prime importance for their potential application. Changes in the activity, stability and structure of Rhizopus oryzae lipase in the presence of novel gemini surfactants, [C16-3-C16im]Br2 and [C16-12-C16im]Br2 were probed in the present study. Surfactant with shorter spacer length, [C16-3-C16im]Br2 was found to be better in improving the hydrolytic activity and thermal stability of the lipase. For both the surfactants, activation was concentration dependent. CD spectroscopy results showed a decrease in α-helix and an increase in β-sheet content in the presence of these surfactants. A higher structural change observed in presence of [C16-12-C16im]Br2 correlated with lower enzyme activity. Isothermal titration calorimetric studies showed the binding to be spontaneous in nature based on sequential two site binding model. The forces involved in binding were found to differ for the two surfactants proving that the spacer length is an important factor which governs the interaction. These surfactants could be used as promising components both in enzyme modification and media engineering for attaining the desired goals in biocatalytic reactions.

  8. π-Spacer effect in dithiafulvenyl-π-phenothiazine dyes for dye-sensitized solar cells

    Science.gov (United States)

    Zhang, Xiaofeng; Gou, Faliang; Zhao, Dongning; Shi, Jian; Gao, Hong; Zhu, Zhenping; Jing, Huanwang

    2016-08-01

    New dithiafulvenyl-π-phenothiazine dyes have been devised and prepared for dye-sensitized solar cells. Various π-spacers have been successfully introduced into the skeleton of dithiafulvenyl and phenothiazine unit to generate novel D-π-D-A dyes (DPP-1 ∼ 4). All dyes have been characterized with NMR, HRMS, UV-vis and fluorescence spectra, and taken into cyclic voltammetry measurements. The devices of new dyes have been determined by photoelectrochemical experiments (IV, IPCE and EIS), in which, solar cell of DPP-4 with biphenyl ring π-spacer enhances obviously its photoelectric conversion efficiency to 7.66% reaching 94% of N719-based standard cell and displays good long-term stability with quasi-solid-state electrolyte. Density functional theory (DFT) calculations of new dyes provide further insight into the molecular geometries and the impacts of the torsion angles on their photovoltaic performance. Large dihedral angles in DPP dyes induce good charge separation for efficient unidirectional flow of electron from donor to acceptor.

  9. INTERSPINOUS SPACER IN PERSISTENT DISCOGENIC PAIN: PERCUTANEOUS APPROACH OR OPEN TECHNIQUE

    Directory of Open Access Journals (Sweden)

    José Antonio Cruz Ricardez

    Full Text Available ABSTRACT Objective: To compare the postoperative clinical course of placement of interspinous spacer with open technique (ISO with percutaneous interspinous spacer (PIS. Methods: Quasi-experimental, longitudinal study of 42 patients with discogenic pain uncontrolled with analgesics, aged 35-55 years old, 21 women, and 21 men. Clinical history, location of pain, VAS scale before and after surgery, Oswestry Disability Index and Macnab modified scale at 6 months were used. Results: When performing quantitative analysis statistical significance (p = 0.0478, 0.0466, 0.0399 was demonstrated with Student's t test between the results according to VAS scale; in the qualitative analysis with the Oswestry index and Macnab modified scale it was demonstrated the hypothesis that the results is dependent of the surgical technique. Conclusions: According to the results, we can conclude that there is a statistically significant difference depending on the surgical technique used with respect to the rate of disability and functionality in daily life as well as in the improvement of pain symptoms.

  10. Green Synthesis, Molecular Characterization and Associative Behavior of Some Gemini Surfactants without a Spacer Group

    Directory of Open Access Journals (Sweden)

    Eugenio Caponetti

    2013-04-01

    Full Text Available A series of new gemini surfactants without a spacer group, disodium 2,3-dialkyl-1,2,3,4-butanetetracarboxylates, were synthesized in a green chemistry context minimizing the use of organic solvents and applying microwaves (MW when activation energy was required. Once the desired architecture was confirmed by means of the nuclear magnetic resonance technique (1H-NMR, 1H-1H COSY for all the studied surfactants, the critical micellization concentration was determined by conductance measurements. The diffusion coefficient of micelles formed by the four compounds was characterized using pulsed field gradient (PFG-NMR. Diffusion coefficients were found to be dependent on the concentration and on the number of carbon atoms in the alkyl chain. The absence of the spacer group, peculiar to this new series of gemini surfactants, may confer relatively low flexibility to the molecules, with potential implications on the interfacial properties, namely on micellization. These gemini surfactants might have interesting applications in the preparation of composite materials, in nanotechnology, in gene transfection and mainly, due to the low CMCs, as new interesting ingredients of cosmetics and toiletries.

  11. Mobile Transporter

    Science.gov (United States)

    2001-01-01

    The Space Shuttle Atlantis, STS-110 mission, deployed this railcar, called the Mobile Transporter, and an initial 43-foot section of track, the S0 (S-zero) truss, preparing the International Space Station (ISS) for future spacewalks. The first railroad in space, the Mobile Transporter will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The 27,000-pound S0 truss is the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002. STS-110's Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver spacewalkers around the Station.

  12. Parylene C-on-photoresist (POP): a low temperature spacer scheme for polymer/metal nanowire fabrication

    Science.gov (United States)

    Li, Yuanhui; Xie, Quan; Wang, Wei; Zheng, Mingxin; Zhang, Hao; Lei, Yinhua; Zhang, Haixia Alice; Wu, Wengang; Li, Zhihong

    2011-06-01

    This work introduced a novel spacer scheme for polymer/metal nanowire preparation by combining Parylene C and photoresist (Parylene C on photoresist, POP, process), both of which possess a low temperature fabrication essence. Adhesion between the Parylene C and the substrate with photoresist onside was improved by introducing a modified silanization pretreatment. Parylene C filled in an undercut generated by regular lithography on a dual-layered photoresist was left as nanometer-sized residues after an isotropic oxygen plasma etching. Parylene C nanowires with the minimal width down to 200 nm were successfully obtained by this POP-based spacer technique, and were then utilized as the etching mask for ion milling of the metal films beneath to realize corresponding chromium/gold nanowires. The present POP scheme will expand the application of the spacer technique in polymer/metal nanowire fabrication for integrated micro/nanoelectromechanical systems.

  13. Optimization of spacers placement in metal oxide surge arresters due to the thermal stability increment using genetic algorithm

    Directory of Open Access Journals (Sweden)

    Seyed Meysam Seyedbarzegar

    2015-03-01

    Full Text Available Abstract: in this paper the optimal placement of spacers in surge arrester column is presented in order to achieve temperature reduction and surge arrester thermal stability against power losses due to the overvoltage in power system. The simulation is done by using genetic algorithm in MATLAB software that it is linked by numerical analysis, i.e., Finite Element Method (FEM. First, electro thermal analysis is performed according to the IEC60099-4 standard on selected population in certain interval and, then the required data is applied to the genetic algorithm for the optimal placement of spacers. Simulation results show that the placement of spacers has great influence on surge arrester temperature variations. Finally, the optimal model of surge arrester is simulated in COMSOL software and the results of this model are compared with conventional model results.

  14. Invariance of the magnetic behavior and AMI in ferromagnetic biphase films with distinct non-magnetic metallic spacers

    Science.gov (United States)

    Silva, E. F.; Gamino, M.; Andrade, A. M. H. de; Vázquez, M.; Correa, M. A.; Bohn, F.

    2017-02-01

    We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices.

  15. Beta1 integrin inhibits apoptosis induced by cyclic stretch in annulus fibrosus cells via ERK1/2 MAPK pathway.

    Science.gov (United States)

    Zhang, Kai; Ding, Wei; Sun, Wei; Sun, Xiao-jiang; Xie, You-zhuan; Zhao, Chang-qing; Zhao, Jie

    2016-01-01

    Low back pain is associated with intervertebral disc degeneration (IVDD) due to cellular loss through apoptosis. Mechanical factors play an important role in maintaining the survival of the annulus fibrosus (AF) cells and the deposition of extracellular matrix. However, the mechanisms that excessive mechanical forces lead to AF cell apoptosis are not clear. The present study was to look for how AF cells sense mechanical changes. In vivo experiments, the involvement of mechanoreceptors in apoptosis was examined by RT-PCR and/or immunoblotting in the lumbar spine of rats subjected to unbalanced dynamic and static forces. In vitro experiments, we investigated apoptotic signaling pathways in untransfected and transfected AF cells with the lentivirus vector for rat β1 integrin overexpression after cyclic stretch. Apoptosis in AF cells was assessed using flow cytometry, Hoechst 33258 nuclear staining. Western blotting was used to analyze expression of β1 integrin and caspase-3 and ERK1/2 MAPK signaling molecules. In the rat IVDD model, unbalanced dynamic and static forces induced apoptosis of disc cells, which corresponded to decreased expression of β1 integrin. Cyclic stretch-induced apoptosis in rat AF cells correlated with the activation of caspase-3 and with decreased levels of β1 integrin and the phosphorylation levels of ERK1/2 activation level. However, the overexpression of β1 integrin in AF cells ameliorated cyclic stretch-induced apoptosis and decreased caspase-3 activation. Furthermore, ERK1/2-specific inhibitor promotes apoptosis in vector β1-infected AF cells. These results suggest that the disruption of β1 integrin signaling may underlie disc cell apoptosis induced by mechanical stress. Further work is necessary to fully elucidate the pathophysiological mechanisms that underlie IVDD caused by unbalanced dynamic and static forces.

  16. Formation of lamellar cross bridges in the annulus fibrosus of the intervertebral disc is a consequence of vascular regression.

    Science.gov (United States)

    Smith, Lachlan J; Elliott, Dawn M

    2011-05-01

    Cross bridges are radial structures within the highly organized lamellar structure of the annulus fibrosus of the intervertebral disc that connect two or more non-consecutive lamellae. Their origin and function are unknown. During fetal development, blood vessels penetrate deep within the AF and recede during postnatal growth. We hypothesized that cross bridges are the pathways left by these receding blood vessels. Initially, the presence of cross bridges was confirmed in cadaveric human discs aged 25 and 53 years. Next, L1-L2 intervertebral discs (n=4) from sheep ranging in age from 75 days fetal gestation to adult were processed for paraffin histology. Mid-sagittal sections were immunostained for endothelial cell marker PECAM-1. The anterior and posterior AF were imaged using differential interference contrast microscopy, and the following parameters were quantified: total number of distinct lamellae, total number of cross bridges, percentage of cross bridges staining positive for PECAM-1, cross bridge penetration depth (% total lamellae), and PECAM-1 positive cross bridge penetration depth. Cross bridges were first observed at 100 days fetal gestation. The overall number peaked in neonates then remained relatively unchanged. The percentage of PECAM-1 positive cross bridges declined progressively from almost 100% at 100 days gestation to less than 10% in adults. Cross bridge penetration depth peaked in neonates then remained unchanged at subsequent ages. Depth of PECAM-1 positive cross bridges decreased progressively after birth. Findings were similar for both the anterior and posterior. The AF lamellar architecture is established early in development. It later becomes disrupted as a consequence of vascularization. Blood vessels then recede, perhaps due to increasing mechanical stresses in the surrounding matrix. In this study we present evidence that the pathways left by receding blood vessels remain as lamellar cross bridges. It is unclear whether the presence

  17. Protective Effect of Niacinamide on interleukin-1β-induced Annulus Fibrosus Type Ⅱ Collagen Degeneration in vitro

    Institute of Scientific and Technical Information of China (English)

    DUAN Deyu; YANG Shuhua; SHAO Zengwu; WANG Hong; XIONG Xiaoqian

    2007-01-01

    The protective effect of niacinamide on interleukin-1β (IL-1β)-induced annulus fibrosus (AF) type Ⅱ collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebrai disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type Ⅱ collagen degneration group (IL-1β) and treatment group (niacinamide+IL-1β). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type Ⅱ collagen immunohistochemical examination, and type Ⅱ collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type Ⅱ collagen degeneration group (P<0.01). Rate of Caspase-3 positive staining AF cells in the 4 groups was 3.4%, 4.2%, 17.6% and 10.3% respectively. The positive rate in treatment group was lower than in the type Ⅱ collagen degeneration group (P<0.01). Type Ⅱ collagen staining demonstrated that lamellar structure and continuity of collagen in treatment group was better reversed than in the degeneration group. RT-PCR revealed that the expression of type Ⅱ collagen in treatment group was significantly stronger than that in type Ⅱ collagen degeneration group (P<0.01). It was concluded that niacinamide could effectively inhibit IL-1β stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1β-caused destruction and synthesis inhibition of type Ⅱ collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  18. Aortic annulus dimension assessment by computed tomography for transcatheter aortic valve implantation: differences between systole and diastole.

    Science.gov (United States)

    Bertaso, Angela G; Wong, Dennis T L; Liew, Gary Y H; Cunnington, Michael S; Richardson, James D; Thomson, Viji S; Lorraine, Brett; Kourlis, George; Leech, Diana; Worthley, Matthew I; Worthley, Stephen G

    2012-12-01

    Accurate assessment of aortic annular dimensions is essential for successful transcatheter aortic valve implantation (TAVI). Annular dimensions are conventionally measured in mid-systole by multidetector computed tomography (MDCT), echocardiography and angiography. Significant differences in systolic and diastolic aortic annular dimensions have been demonstrated in cohorts without aortic stenosis (AS), but it is unknown whether similar dynamic variation in annular dimensions exists in patients with severe calcific AS in whom aortic compliance is likely to be substantially reduced. We investigated the variation in aortic annular dimensions between systole and diastole in patients with severe calcific AS. Patients with severe calcific AS referred for TAVI were evaluated by 128-slice MDCT. Aortic annular diameter was measured during diastole and systole in the modified coronal, modified sagittal, and basal ring planes (maximal, minimal and mean diameters). Differences between systole and diastole were analysed by paired t test. Fifty-nine patients were included in the analysis. Three of the five aortic dimensions measured increased significantly during systole. The largest change was a 0.75 mm (3.4%) mean increase in the minimal diameter of the basal ring during systole (p = 0.004). This corresponds closely to the modified sagittal view, which also increased by mean 0.42 mm (1.9%) during systole (p = 0.008). There was no significant change in the maximal diameter of the basal ring or the modified coronal view during systole (p > 0.05). There is a small magnitude but statistically significant difference in aortic annulus dimensions of patients with severe AS referred for TAVI when measured in diastole and systole. This small difference is unlikely to alter clinical decisions regarding prosthesis size or suitability for TAVI.

  19. Do mechanical strain and TNF-α interact to amplify pro-inflammatory cytokine production in human annulus fibrosus cells?

    Science.gov (United States)

    Likhitpanichkul, Morakot; Torre, Olivia M; Gruen, Jadry; Walter, Benjamin A; Hecht, Andrew C; Iatridis, James C

    2016-05-03

    During intervertebral disc (IVD) injury and degeneration, annulus fibrosus (AF) cells experience large mechanical strains in a pro-inflammatory milieu. We hypothesized that TNF-α, an initiator of IVD inflammation, modifies AF cell mechanobiology via cytoskeletal changes, and interacts with mechanical strain to enhance pro-inflammatory cytokine production. Human AF cells (N=5, Thompson grades 2-4) were stretched uniaxially on collagen-I coated chambers to 0%, 5% (physiological) or 15% (pathologic) strains at 0.5Hz for 24h under hypoxic conditions with or without TNF-α (10ng/mL). AF cells were treated with anti-TNF-α and anti-IL-6. ELISA assessed IL-1β, IL-6, and IL-8 production and immunocytochemistry measured F-actin, vinculin and α-tubulin in AF cells. TNF-α significantly increased AF cell pro-inflammatory cytokine production compared to basal conditions (IL-1β:2.0±1.4-84.0±77.3, IL-6:10.6±9.9-280.9±214.1, IL-8:23.9±26.0-5125.1±4170.8pg/ml for basal and TNF-α treatment, respectively) as expected, but mechanical strain did not. Pathologic strain in combination with TNF-α increased IL-1β, and IL-8 but not IL-6 production of AF cells. TNF-α treatment altered F-actin and α-tubulin in AF cells, suggestive of altered cytoskeletal stiffness. Anti-TNF-α (infliximab) significantly inhibited pro-inflammatory cytokine production while anti-IL-6 (atlizumab) did not. In conclusion, TNF-α altered AF cell mechanobiology with cytoskeletal remodeling that potentially sensitized AF cells to mechanical strain and increased TNF-α-induced pro-inflammatory cytokine production. Results suggest an interaction between TNF-α and mechanical strain and future mechanistic studies are required to validate these observations.

  20. Electron exchange in conformationally restricted donor-spacer-acceptor dyads: angle dependence and involvement of upper-lying excited States.

    Science.gov (United States)

    Benniston, Andrew C; Harriman, Anthony; Li, Peiyi; Patel, Pritesh V; Sams, Craig A

    2008-01-01

    The rate constant for triplet energy transfer (k(TET)) has been measured in fluid solution for a series of mixed-metal Ru-Os bis(2,2':6',2''-terpyridine) complexes built around a tethered biphenyl-based spacer group. The length of the tether controls the central torsion angle for the spacer, which can be varied systematically from 37 to 130 degrees . At low temperature, but still in fluid solution, the spacer adopts the lowest-energy conformation and k(TET) shows a clear correlation with the torsion angle. A similar relationship holds for the inverse quantum yield for emission from the Ru-terpy donor. Triplet energy transfer is more strongly activated at higher temperature and the kinetic data require analysis in terms of two separate processes. The more weakly activated step involves electron exchange from the first-excited triplet state on the Ru-terpy donor and the size of the activation barrier matches well with that calculated from spectroscopic properties. The pre-exponential factor derived for this process correlates remarkably well with the torsion angle and there is a large disparity in electronic coupling through pi and sigma orbitals on the spacer. The more strongly activated step is attributed to electron exchange from an upper-lying triplet state localized on the Ru-terpy donor. Here, the pre-exponential factor is larger but shows the same dependence on the geometry of the spacer. Strangely, the difference in coupling through pi and sigma orbitals is much less pronounced. Despite internal flexibility around the spacer, k(TET) shows a marked dependence on the torsion angle computed for the lowest-energy conformation.

  1. Mobile video with mobile IPv6

    CERN Document Server

    Minoli, Daniel

    2012-01-01

    Increased reliance on mobile devices and streaming of video content are two of the most recent changes that have led those in the video distribution industry to be concerned about the shifting or erosion of traditional advertising revenues. Infrastructure providers also need to position themselves to take advantage of these trends. Mobile Video with Mobile IPv6provides an overview of the current mobile landscape, then delves specifically into the capabilities and operational details of IPv6. The book also addresses 3G and 4G services, the application of Mobile IPv6 to streaming and other mobil

  2. The spacer arm length in cell-penetrating peptides influences chitosan/siRNA nanoparticle delivery for pulmonary inflammation treatment

    Science.gov (United States)

    Jeong, Eun Ju; Choi, Moonhwan; Lee, Jangwook; Rhim, Taiyoun; Lee, Kuen Yong

    2015-11-01

    Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of R9Gn-chitosan/siRNA nanoparticles were investigated in vitro. Increasing the spacing arm length did not significantly affect the complex formation between R9Gn-chitosan and siRNA. However, R9G10-chitosan was much more effective in delivering genes both in vitro and in vivo compared with non-modified chitosan (without the peptide) and R9-chitosan (without the spacer arm). Chitosan derivatives modified with oligoarginine containing a spacer arm can be considered as potential delivery vehicles for various genes.Although chitosan and its derivatives have been frequently utilized as delivery vehicles for small interfering RNA (siRNA), it is challenging to improve the gene silencing efficiency of chitosan-based nanoparticles. In this study, we hypothesized that controlling the spacer arm length between a cell-penetrating peptide (CPP) and a nanoparticle could be critical to enhancing the cellular uptake as well as the gene silencing efficiency of conventional chitosan/siRNA nanoparticles. A peptide consisting of nine arginine units (R9) was used as a CPP, and the spacer arm length was controlled by varying the number of glycine units between the peptide (R9Gn) and the nanoparticle (n = 0, 4, and 10). Various physicochemical characteristics of

  3. Phylogenetic Study of Mangifera laurina and its Related Species Using cpDNA trnL-F Spacer Markers

    Directory of Open Access Journals (Sweden)

    FITMAWATI

    2010-03-01

    Full Text Available Phylogenetic study of cpDNA intergenic spacer trnL-F of Mangifera laurina and their related species within the genus Mangifera in Indonesia was conducted using Rutaceae as the outgroup. This study was to reconstruct phylogenetic relationships and to understand infraspecific relationships within Mangifera based on cpDNA trnL-F intergenic spacer sequences. The results showed that Mangifera sp. Hiku (mangga hiku as the basic cultivar in the clade, and it supported the monophyletic group in Mangifera. And phylogenetic construction indicated that Mangifera sp. Hiku was the progenitor of M. laurina and their related species.

  4. Safety and Efficacy of Bioabsorbable Cervical Spacers and Low-Dose rhBMP-2 in Multi-Level ACDF

    OpenAIRE

    2014-01-01

    Introduction Many options for interbody spacer and graft biologic exist for multilevel anterior cervical discectomy and fusion (ACDF). The objective of this study is to evaluate the safety and efficacy of a bioabsorbable cervical spacer (BCS) (Cornerstone HSR, Medtronic Sofamor Danek) filled with low-dose rhBMP-2 (INFUSE, Medtronic Sofamor Danek) in multilevel ACDF. Methods 72 consecutive patients treated with a multi-level ACDF using BCS and rhBMP-2 (dosage between 0.5 to 0.7 mg per level) a...

  5. CHIRAL CONJUGATED OLIGOMER BASED ON 1,1'-BINOL WITH 3,3'-ACETYLENE-PHENYLENE-ACETYLENE SPACER

    Institute of Scientific and Technical Information of China (English)

    Tian-jun Liu; Ke-shen Zhang; Yong-jun Chen; Dong Wang; Chao-jun Li

    2001-01-01

    The 1,1'-binaphthol based oligomers 3 and 7 with 3,3'-acetylene-phenylene-acetylene spacer were prepared from BINOL 1. The high optical rotation value and CD spectra demonstrated the main chain chirality of the oligomer molecule. The UV-VIS and fluorescent spectra evidence the characteristics of conjugated structure. In comparison with oligomer 2 bearing 3,3'-acetylene spacer, the oligomers 3 and 7 have longer efficient conjugation segment, and their fluorescent quantum yields (φ) increased (0.60-0.65 versus 0.14). Extending the effective conjugation segment would improve the photophysical properties of chiral conjugated polymers.``

  6. Cas1–Cas2 complex formation mediates spacer acquisition during CRISPR–Cas adaptive immunity

    OpenAIRE

    Nuñez, James K.; Kranzusch, Philip J.; Noeske, Jonas; Wright, Addison V.; Davies, Christopher W; Doudna, Jennifer A.

    2014-01-01

    The initial stage of CRISPR–Cas immunity involves the acquisition of foreign DNA spacer segments into the host genomic CRISPR locus. The nucleases Cas1 and Cas2 are the only proteins conserved amongst all CRISPR–Cas systems, yet the molecular functions of these proteins during immunity are unknown. Here we show that Cas1 and Cas2 from Escherichia coli form a stable complex that is essential for spacer acquisition and determine the 2.3-Å resolution crystal structure of the Cas1–Cas2 complex. M...

  7. Role of methylene spacer in the excitation energy transfer in europium 1- and 2- naphthylcarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravlev, K. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Tsaryuk, V., E-mail: vit225@ire216.msk.s [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Kudryashova, V.; Pekareva, I. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation); Sokolnicki, J. [Faculty of Chemistry, University of WrocLaw, 14 F. Joliot-Curie str., WrocLaw 50-383 (Poland); Yakovlev, Yu. [V.A. Kotelnikov Institute of Radioengineering and Electronics of RAS, 1 Vvedenskii sq., Fryazino Moscow reg. 141190 (Russian Federation)

    2010-08-15

    A series of compounds Ln(RCOO){sub 3}.Phen (Ln=Eu, Gd, Tb; RCOO{sup -}-1- and 2-naphthoate, 1- and 2-naphthylacetate, 1- and 2-naphthoxyacetate anions, Phen-1,10-phenanthroline) was investigated by methods of optical spectroscopy. Compounds of composition Ln(RCOO){sub 3}.nH{sub 2}O with the same carboxylate ligands are also considered. Results of studies of the effects of methylene spacer decoupling the {pi}-{pi}- or p-{pi}-conjugation in the naphthylcarboxylate ligand on the structure of Eu{sup 3+} coordination centre, on the lifetime of {sup 5}D{sub 0} (Eu{sup 3+}) state, and on processes of the excitation energy transfer to Eu{sup 3+} or Tb{sup 3+} ions are presented. Introduction of the methylene bridge in the ligand weakens the influence of the steric hindrances in forming of a crystal lattice and results in lowering the distortion of the Eu{sup 3+} luminescence centre, and in elongation of the observed {sup 5}D{sub 0} lifetime {tau}{sub obs}. The latter is caused by decrease in contribution of the radiative processes rate 1/{tau}{sub r}. This is confirmed by the correlation between the lifetimes {tau}{sub obs} and the quantities '{tau}{sub r}.const' inversely proportional to the total integral intensities of Eu(RCOO){sub 3}.Phen luminescence spectra. The methylene spacer performs a role of regulator of sensitization of the Ln{sup 3+} luminescence efficiency by means of an influence on mutual location of lowest triplet states of the ligands, the ligand-metal charge transfer (LMCT) states, and the emitting states of Ln{sup 3+} ions. The lowest triplet state in lanthanide naphthylcarboxylate adducts with Phen is related to carboxylate anion. A presence of the methylene spacer in naphthylcarboxylate ligand increases the triplet state energy. At the same time, the energy of 'carboxylic group-Eu{sup 3+} ion' charge transfer states falls, which can promote the degradation of excitation energy. In naphthylcarboxylates investigated a range of the

  8. Minimally invasive treatment of lumbar spinal stenosis with a novel interspinous spacer

    Directory of Open Access Journals (Sweden)

    Shabat S

    2011-09-01

    Full Text Available Shay Shabat1, Larry E Miller2,3, Jon E Block3, Reuven Gepstein11Spinal Care Unit, Sapir Medical Center, Kfar Saba, Israel; 2Miller Scientific Consulting, Inc, Biltmore Lake, NC, USA; 3Jon E Block, PhD, Inc, San Francisco, CA, USAPurpose: To assess the safety and effectiveness of a novel, minimally invasive interspinous spacer in patients with moderate lumbar spinal stenosis (LSS.Methods: A total of 53 patients (mean age, 70 ± 11 years; 45% female with intermittent neurogenic claudication secondary to moderate LSS, confirmed on imaging studies, were treated with the Superion® Interspinous Spacer (VertiFlex, Inc, San Clemente, CA and returned for follow-up visits at 6 weeks, 1 year, and 2 years. Study endpoints included axial and extremity pain severity with an 11-point numeric scale, Zurich Claudication Questionnaire (ZCQ, back function with the Oswestry Disability Index (ODI, health-related quality of life with the Physical Component Summary (PCS and Mental Component Summary (MCS scores from the SF-12, and adverse events.Results: Axial and extremity pain each decreased 54% (both P < 0.001 over the 2-year follow-up period. ZCQ symptom severity scores improved 43% (P < 0.001 and ZCQ physical function improved 44% (P < 0.001 from pre-treatment to 2 years post-treatment. A statistically significant 50% improvement (P < 0.001 also was noted in back function. PCS and MCS each improved 40% (both P < 0.001 from pre-treatment to 2 years. Clinical success rates at 2 years were 83%–89% for ZCQ subscores, 75% for ODI, 78% for PCS, and 80% for MCS. No device infection, implant breakage, migration, or pull-out was observed, although two (3.8% patients underwent explant with subsequent laminectomy.Conclusion: Moderate LSS can be effectively treated with a minimally invasive interspinous spacer. This device is appropriate for select patients who have failed nonoperative treatment measures for LSS and meet strict anatomical criteria.Keywords: Superion, axial

  9. Improvement in sodium cromoglycate delivery from a spacer device by use of an antistatic lining, immediate inhalation, and avoiding multiple actuations of drug.

    Science.gov (United States)

    O'Callaghan, C; Lynch, J; Cant, M; Robertson, C

    1993-01-01

    BACKGROUND--Aerosols generated from metered dose inhalers may be highly charged. The aim of this study was to determine whether lining the walls of a polycarbonate spacer device with an antistatic agent would result in an increase in drug output. The effects of multiple actuations of drug into the spacer device and increasing residence time of drug within the spacer were also determined. METHODS--The amount of sodium cromoglycate contained in particles of various size available for inhalation (per 5 mg actuation) from a 750 ml polycarbonate spacer was determined by impinger measurement and spectrophotometric assay. RESULTS--Lining the spacer with an antistatic agent increased the mean (SD) amount of sodium cromoglycate in particles < 5 microns available for inhalation (per 5 mg actuation) by 244% from (0.59 (0.03) to 1.44 (0.2) mg). When there was a 20 second interval between actuation into the spacer device and inhalation, sodium cromoglycate available for inhalation in particles < 5 micrograms decreased by 67% (from 0.59 (0.03) mg to 0.2 (0.01) mg). Use of the spacer device increased sodium cromoglycate available for inhalation in respirable particles (< 5 microns) by 18% compared with direct delivery by metered dose inhaler. Multiple actuations into the spacer decreased the amount of sodium cromoglycate available for inhalation in particles < 5 microns by 31% after two actuations and 56% after three acutations. CONCLUSIONS--Multiple actuations of sodium cromoglycate into a spacer device before inhalation should be avoided, and inhalation from spacer devices should take place immediately after actuation to ensure maximum dose. Lining of a standard spacer device with an antistatic agent significantly increased output of sodium cromoglycate. This may have implications for improved therapeutic response and drug cost. Images PMID:8346488

  10. Mobile Inquiry Based Learning

    OpenAIRE

    Specht, Marcus

    2012-01-01

    Specht, M. (2012, 8 November). Mobile Inquiry Based Learning. Presentation given at the Workshop "Mobile inquiry-based learning" at the Mobile Learning Day 2012 at the Fernuniversität Hagen, Hagen, Germany.

  11. MOBILITY: A SYSTEMS APPROACH

    Directory of Open Access Journals (Sweden)

    Mykola I. Striuk

    2015-10-01

    Full Text Available A comprehensive study on the problem of mobility in the socio-educational and technical systems was carried out: the evolution of the concept of mobility in scientific sources of XIX–XXI centuries was analyzed and the new sources on the issue of mobility introduced into scientific circulation, the interrelation of the types of mobility in the socio-pedagogical and technical systems are theoretically grounded, an integrative model of mobility in the information society is proposed. The major trends in academic mobility are identified (the transition from student mobility to mobility programs and educational services providers, the new mobility programs (franchising, double/joint degrees, combinations, nostrification etc. are characterized. The new types of mobility providers are reviewed and attention is focused on virtual universities that are now the basis of virtual mobility of students and activities which are based on the use of new ICT in higher education, especially – the Internet and mobile learning environments.

  12. Influence of St. Jude medical valve in patients with aortic stenosis and small aortic annulus on cardiac function and late survival result.

    Science.gov (United States)

    Natsuaki, Masafumi; Itoh, Tsuyoshi; Okazaki, Yukio; Takarabe, Kyoumi; Furukawa, Koujirou; Rikitake, Kazuhisa; Ohtubo, Satoshi

    2002-10-01

    This clinical study analyzes our experience of postoperative cardiac function and long-term survival rate in patients with aortic stenosis and small-size St. Jude Medical (SJM) valve. Sixty-eight patients who underwent aortic valve replacement by SJM valve were divided into two groups by preoperative aortic annulus diameter. Group 1 consisted of 44 patients with small aortic annulus and small-size SJM valve (19 mm or 21 mm). In Group 1, small SJM standard valves were implanted in 16 patients, and small SJM Hemodynamic Plus (HP) valves were implanted in 28 patients. Group 2 consisted of 24 patients with large-size SJM standard valve (23 mm or larger). Preoperative left ventricular mass index, left ventricular dimension, the dimension of ascending aorta, and body surface area were significantly smaller in Group 1 than in Group 2. Average age at surgery was older in Group 1 than in Group 2. Effective orifice area index of the SJM valve measured by the manufacturer's data was smaller in Group 1 than in Group 2. Postoperative left ventricular mass indexes of Group 1 (standard valve or HP valve) and Group 2 significantly decreased in comparison with the preoperative mass indexes. Postoperative left ventricular ejection fraction and the peak ejection rate of Group 1 were not different from those of Group 2. The 10 year survival rate of Group 1 was 79%, and the rate of Group 2 was 77%. At 10 years after surgery, freedom from valve-related complication of Group 1 was 80%, and freedom from complication of Group 2 was 81%. Our results demonstrated that small-size SJM valve afforded satisfactory long-term survival rate and valve-related event-free rate for elderly patients with small body surface area and small aortic annulus.

  13. CFD prediction of flow and phase distribution in fuel assemblies with spacers

    Energy Technology Data Exchange (ETDEWEB)

    Anglart, H.; Nylund, O. [ABB Atom AB, Vasteras (Switzerland); Kurul, N. [Rensselaer Polytechnic Institute, Troy, NY (United States)] [and others

    1995-09-01

    This paper is concerned with the modeling and computation of multi-dimensional two-phase flows in BWR fuel assemblies. The modeling principles are presented based on using a two-fluid model in which lateral interfacial effects are accounted for. This model has been used to evaluate the velocity fields of both vapor and liquid phases, as well as phase distribution, between fuel elements in geometries similar to BWR fuel bundles. Furthermore, this model has been used to predict, in a detailed mechanistic manner, the effects of spacers on flow and phase distribution between, and pressure drop along, fuel elements. The related numerical simulations have been performed using a CFD computer code, CFDS-FLOW3D.

  14. Selection of enzymes for terminal restriction fragment length polymorphism analysis of fungal internally transcribed spacer sequences.

    Science.gov (United States)

    Alvarado, Pablo; Manjón, Jose L

    2009-07-01

    Terminal restriction fragment length polymorphism (TRFLP) profiling of the internally transcribed spacer (ITS) ribosomal DNA of unknown fungal communities is currently unsupported by a broad-range enzyme-choosing rationale. An in silico study of terminal fragment size distribution was therefore performed following virtual digestion (by use of a set of commercially available 135 type IIP restriction endonucleases) of all published fungal ITS sequences putatively annealing to primers ITS1 and ITS4. Different diversity measurements were used to rank primer-enzyme pairs according to the richness and evenness that they showed. Top-performing pairs were hierarchically clustered to test for data dependency. The enzyme set composed of MaeII, BfaI, and BstNI returned much better results than randomly chosen enzyme sets in computer simulations and is therefore recommended for in vitro TRFLP profiling of fungal ITSs.

  15. Imidacloprid and Thiamethoxam Induced Mutations in Internal Transcribed Spacer 2 (ITS2) of Anopheles stephensi.

    Science.gov (United States)

    Bhinder, Preety; Chaudhry, Asha; Barna, Bhupinder; Kaur, Satvinderjeet

    2012-05-01

    The present article deals with the polymerase chain reaction (PCR)-based genotoxicity evaluation of neonicotinoid pesticides, imidacloprid and thiamethoxam, by using the genome of a mosquito Anopheles stephensi taken as an experimental model. After treatment of the second instar larvae with LC(20) of the pesticides for 24 h, the induced nucleotide sequence variations in the internal transcribed spacer 2 (ITS2) of freshly hatched unfed control and treated individuals was studied from the sequence alignment data and the mutations in the form of insertion, deletion and substitution of bases were recorded. Measurable differences, indicative of the genetic damage due to imidacloprid and thiamethoxam were observed when ITS2 sequences of control and treated individuals were compared. It was found that imidacloprid-treated individual had 8 deletions, 29 insertions, 18 transitions and 33 transversions, whereas thiamethoxam-treated individual had 10 deletions, 8 insertions, 47 transitions and 68 transversions.

  16. Immobilization of heparin on a silicone surface through a heterobifunctional PEG spacer.

    Science.gov (United States)

    Chen, Hong; Chen, Yang; Sheardown, Heather; Brook, Michael A

    2005-12-01

    A novel method of immobilizing heparin on a silicone surface through a heterobifunctional PEG spacer was used yield well defined surfaces with highly active surface immobilized heparin and low non-specific protein adsorption. The heparin surface density achieved using this technique was 0.68 microg/cm2. Sessile drop water contact angles showed increased hydrophilicity of the silicone surface after PEG modification and a further decrease in the contact angles following the grafting of heparin. High specificity for ATIII with little fibrinogen adsorption was noted in plasma adsorption studies. This ATIII adsorption was mediated by the heparin layer, since surfaces modified with PEG only did not adsorb significant quantities of AT. The thrombin resistance of the heparin modified surfaces was demonstrably greater as measured by a chromogenic thrombin generation assay. The results suggest that the heterbifunctional PEG linker results in a high density of active heparin on the surfaces.

  17. Development and Investigation of Evacuated Windows Based on Monolithic Silica Xerogel Spacers

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Svendsen, Sv Aa Højgaard

    will be approximately 0.013 W/(m K) which is approximately 33% of the value for commonly used insulation materials, e.g. mineral wool. Monolithic silica xerogel is a highly porous material (pore volume up to 90%) with a solar transmittance of 50% (thickness = 20 mm). However, if the silica xerogel is not made...... and 3) application for insulating glazings.Scientific developments have made it possible to prepare low density monolithic silica xerogels, only from about 1990, and developments in both the production process as well as size of the samples are necessary for a commercial use of the material...... for insulating glazings. Using the material as spacer between two layers of glass with a vacuum tight sealing of the rim combined with an internal gas pressure below 50-100 hPa result in an insulating glazing having a heat loss coefficient comparable with that of the surrounding walls, but at the same time...

  18. IMMOBILIZATION OF POTENTIALLY BIOACTIVE MOIETIES ONTO POLYETHER WITH POLY(ETHYLENE GLYCOL)-SULFONATE SPACER

    Institute of Scientific and Technical Information of China (English)

    JI Jian; FENG Linxian; QIU Yongxin; YU Xiaojie; YANG Shilin

    1997-01-01

    A new reactive graft copolymer, poly(tetramethylene glycol)-graft-ω-propyl sodium sulfonate-poly(ethylene glycol) (PTMG-g-PEG-CH2CH2CH2SO-3Na+), was synthesized by the cationic polymerization of α-ω-bifunctional PEG macromonomer ((o)CH2-PEG--CH2CH2CH2SO3Na ) and THF. The obtained copolymer exhibits the expected structure as indicated by the result of characterization. Two amino acids (L-arginine, L-tyrosine) were covalently attached to the copolymer after converting the sulfonate group to sulfonyl chloride. So the new reactive graft copolymer (PTMG-g-PEG-CH2CH2CH2SO-3Na+) is expected to be very useful in attachment of potentially bioactive moieties to polymer via a hydrophilic PEG spacer.

  19. The effect of spacers on the performance of Micromegas detectors: a numerical investigation

    CERN Document Server

    Bhattacharya, Purba; Majumdar, Nayana; Bhattacharya, Sudeb

    2016-01-01

    Micromegas detector is considered to be a promising candidate for a large variety of high-rate experiments. Micromegas of various geometries have already been established as appropriate for these experiments for their performances in terms of gas gain uniformity, energy and space point resolution, and their capability to efficiently pave large read-out surfaces with minimum dead zone. The present work investigates the effect of spacers on different detector characteristics of Micromegas detectors having various amplification gaps and mesh hole pitches. Numerical simulation has been used as a tool of exploration to evaluate the effect of such dielectric material on detector performance. Some of the important and fundamental characteristics such as electron transparency, gain and signal of the Micromegas detector have been estimated.

  20. Sequence analysis of the rDNA intergenic spacer of Metarhizium strains isolated in Brazil

    Directory of Open Access Journals (Sweden)

    Fabiana Y. Yanaka-Schäfer

    2008-01-01

    Full Text Available To assess the extent of genetic variability of rDNA intergenic spacer (IGS in Metarhizium sp., 34 strains (27 isolated in Brazil were sequenced and analyzed together with an additional 20 Metarhizium anisopliae var. anisopliae sequences retrieved from GenBank. Overall, the global nucleotide diversity for the region under study was of 0.090, while for the Brazilian isolates it was only 0.016. Phylogenetic analyses showed four well-supported groups (A, B, C, and D, one of which (D has not been previously identified. All but one of the Brazilian strains cluster in this novel D phylogroup, suggesting that the genetic variation found in Brazil is a subset of the worldwide M. anisopiliae var. anisopliae variation.

  1. PHOTOPHYSICAL BEHAVIORS OF OLIGOMER BASED ON 1,1'-BINAPHTHOL WITH 3,3'-ACETYLENE SPACER

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The photophysical behaviors of the oligomer based on 1,1'-binaphthol with 3,3'-acetylene spacer were investigated. The oligomer molecule has a naphthyl-acetylenenaphthyl effective conjugation segment. The atropic of the 1,1'-binaphthyl moiety led to twisted and rigid main chain in the oligomer. With the changes of the external environment such as solvents used, solvent viscosity and ambient temperature, the wavelengths of absorption and the intensities of fluorescence and absorption are changed slightly, but the fluorescent intensity and quantum yield can be influenced. The luminescent behaviors of the oligomer exhibit twisted intramolecular charge transfer characteristics, which could have a potential application in wavelength-stable light emitting material adaptable to ambient temperature and the solvents used in wide range.

  2. -pyrrole substituted porphyrin-pyrene dyads using vinylene spacer: Synthesis, characterization and photophysical properties

    Indian Academy of Sciences (India)

    P Silviya Reeta; Ravi Kumar Kanaparthi; L Giribabu

    2013-03-01

    We have designed and synthesized donor-acceptor conjugates having donor pyrene at the pyrrole- position of either free-base porphyrin or Zn(II) porphyrin using vinylene spacer. Both the dyads have been completely characterized by elemental analysis,MALDI-MS, UV-Vis., and fluorescence (steady state and timeresolved) spectroscopies as well as cyclic voltammetry. The absorption maxima of both dyads are red-shifted by 8-12 nm. The ground state properties showed that there exist minimum - interaction between the aromatic subunits of these D-A systems. Quenched emission was observed in both the dyads when excited at 290 nm. The quenched emission explained in terms of intramolecular excitation energy transfer competes with the photo-induced electron transfer reaction in these D-A system.

  3. Trends in Mobile Marketing

    OpenAIRE

    Chocholová, Petra

    2010-01-01

    The principal aim of this thesis is to assess the state of the mobile marketing as of the first quarter of 2011 and to discuss various scenarios of the future development. This thesis defines the terms "mobile marketing" and "mobile advertising" and identifies the main players in the industry. It explores the main categories of mobile advertising such as mobile messaging, in-content and mobile internet advertising. Later, it analyzes the latest trends in the industry and describes in detail t...

  4. Cooperating mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, John J.; Eskridge, Steven E.; Hurtado, John E.; Byrne, Raymond H.

    2004-02-03

    A miniature mobile robot provides a relatively inexpensive mobile robot. A mobile robot for searching an area provides a way for multiple mobile robots in cooperating teams. A robotic system with a team of mobile robots communicating information among each other provides a way to locate a source in cooperation. A mobile robot with a sensor, a communication system, and a processor, provides a way to execute a strategy for searching an area.

  5. Preparation of the spacer for narrow electrode gap configuration in ionization-based gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Saheed, Mohamed Shuaib Mohamed; Mohamed, Norani Muti; Burhanudin, Zainal Arif [Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Tronoh, Perak. (Malaysia); Fundamental and Applied Science, Universiti Teknologi PETRONAS, Seri Iskandar, Tronoh, Perak. (Malaysia); Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Tronoh, Perak. (Malaysia)

    2012-09-26

    Carbon nanotubes (CNTs) have started to be developed as the sensing element for ionization-based gas sensors due to the demand for improved sensitivity, selectivity, stability and other sensing properties beyond what can be offered by the conventional ones. Although these limitations have been overcome, the problems still remain with the conventional ionization-based gas sensors in that they are bulky and operating with large breakdown voltage and high temperature. Recent studies have shown that the breakdown voltage can be reduced by using nanostructured electrodes and narrow electrode gap. Nanostructured electrode in the form of aligned CNTs array with evenly distributed nanotips can enhance the linear electric field significantly. The later is attributed to the shorter conductivity path through narrow electrode gap. The paper presents the study on the design consideration in order to realize ionization based gas sensor using aligned carbon nanotubes array in an optimum sensor configuration with narrow electrode gap. Several deposition techniques were studied to deposit the spacer, the key component that can control the electrode gap. Plasma spray deposition, electron beam deposition and dry oxidation method were employed to obtain minimum film thickness around 32 {mu}m. For plasma spray method, sand blasting process is required in order to produce rough surface for strong bonding of the deposited film onto the surface. Film thickness, typically about 39 {mu}m can be obtained. For the electron beam deposition and dry oxidation, the film thickness is in the range of nanometers and thus unsuitable to produce the spacer. The deposited multilayer film consisting of copper, alumina and ferum on which CNTs array will be grown was found to be removed during the etching process. This is attributed to the high etching rate on the thin film which can be prevented by reducing the rate and having a thicker conductive copper film.

  6. Theoretical investigation of triphenylamine-based sensitizers with different π-spacers for DSSC.

    Science.gov (United States)

    Li, Wei; Wang, Jian; Chen, Jie; Bai, Fu-Quan; Zhang, Hong-Xing

    2014-01-24

    The molecular geometries, electronic structures, and absorption spectra of two organic dyes, 3-(5-(4-(IDB)phenyl)thiophene-2-yl)-2-cyanoacrylic acid (IDB-1), and 3-(5-(4-(IDB)styryl) thiophene-2-yl)-2-cyanoacrylic acid (IDB-2), before and after binding to TiO2 cluster were investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) methods to understand the effect of enhanced π-conjugation of organic dye on the energy-to-electricity conversion efficiency (η) of dye-sensitized solar cell (DSSC), where, IDB=10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl. The introduction of vinyl unit into the π-spacer enhances the coplanarity and subsequently red-shifts, intensifies, and broadens the absorption spectrum of IDB-2, resulting in the stronger electronic coupling between dye and TiO2 conduction band, thus the more efficient electron transfer. From the theoretical evaluation of electron injection driving force (D), light-harvesting efficiency (LHE), and shift of TiO2 conduction band (ΔEcb), we successfully interpreted the experimentally observed efficiency difference between IDB-1 and IDB-2. Under this theoretical procedure, several novel D-π-A dyes namely IDB-3, IDB-4, and IDB-5, were designed. Our calculated results reveal that IDB-5 has the improved Jsc and Voc compared with IDB-2 because it performs nicely on the three key parameters (D, LHE, and ΔEcb). This work highlight the importance of using dimethyl-substituted cyclopentadithiophene group as π-spacer in achieving more efficient dyes for DSSC. We hope these discussions can provide fundamental guidelines for the optimization of existing cell efficiency as well as the design of novel high-efficiency organic dyes.

  7. Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

    Science.gov (United States)

    Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2016-08-01

    Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

  8. Performance of transonic fan stage with weight flow per unit annulus area of 198 kilograms per second per square meter (40.6(lb/sec)/sq ft)

    Science.gov (United States)

    Kovich, G.; Moore, R. D.; Urasek, D. C.

    1973-01-01

    The overall and blade-element performance are presented for an air compressor stage designed to study the effect of weight flow per unit annulus area on efficiency and flow range. At the design speed of 424.8 m/sec the peak efficiency of 0.81 occurred at the design weight flow and a total pressure ratio of 1.56. Design pressure ratio and weight flow were 1.57 and 29.5 kg/sec (65.0 lb/sec), respectively. Stall margin at design speed was 19 percent based on the weight flow and pressure ratio at peak efficiency and at stall.

  9. AN EXPERIMENTAL STUDY ON THREE-DIMENSIONAL STRUCTURE OF BAROCLINIC WAVY JET STREAM IN A ROTATING ANNULUS SUBJECT TO RADIAL TEMPERATURE GRADIENT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three-dimensional structure of baroclinic wavy jet was experimentally studied in rotating annulus subject to a negative radial temperature gradient.General features of wavy surface jet in the system were obtained.Based on the precise measurements of velocity distribution of the jet with LDV and the three-dimensional temperature field in the convective system, three-dimensional thermodynamic structures of jet were gained, and by using a correlation of three-dimensional disturbed temperature, the unstable mechanism of disturbed temperature of baroclinic fluid in a rotating system was further discussed.

  10. Mobile Schools for a Mobile World

    Science.gov (United States)

    Booth, Susan

    2013-01-01

    Overwhelmingly, independent schools are embracing mobile devices--laptops, iPads or other tablets, and smartphones--to enhance teaching and learning. This article describes the results of the "NAIS 2012 Mobile Learning Survey." Among its findings were that 75 percent of NAIS-member schools currently use mobile learning devices in at…

  11. Investigation of optical spacer layers from solution based precursors for polymer solar cells using X-ray reflectometry

    DEFF Research Database (Denmark)

    Andersen, Philip Hvidthøft Delff; Skårhøj, Jakob; Andreasen, Jens Wenzel

    2009-01-01

    Optical spacer layers based on titaniumalkoxide precursor solutions were prepared by spin-coating on top of bulk heterojunction layers based on poly-3-hexylthiophene (P3HT) and phenyl-C61-butyric acid methylester (PCBM). Models and experiment have shown that the performance of polymer solar cells...

  12. Pyrosequencing analysis of 20 nucleotides of internal transcribed spacer 2 discriminates Candida parapsilosis, Candida metapsilosis, and Candida orthopsilosis.

    Science.gov (United States)

    Borman, Andrew M; Linton, Christopher J; Oliver, Debra; Palmer, Michael D; Szekely, Adrien; Odds, Frank C; Johnson, Elizabeth M

    2009-07-01

    Two new cryptic sister species, Candida orthopsilosis and Candida metapsilosis, were recently identified by consistent DNA sequence differences among several genes within the genetically heterogeneous Candida parapsilosis complex. Here, we present data demonstrating that Pyrosequencing analysis of 20 nucleotides of internal transcribed spacer region 2 rapidly and robustly distinguishes between these three closely related Candida species.

  13. Epitope DNA vaccines against tuberculosis: spacers and ubiquitin modulates cellular immune responses elicited by epitope DNA vaccine

    Institute of Scientific and Technical Information of China (English)

    Wang QM; Sun SH; Hu ZL; Zhou FJ; Yin M; Xiao CJ; Zhang JC

    2005-01-01

    Cell-mediated immune responses are crucial in the protection against tuberculosis. In this study, we constructed epitope DNA vaccines (p3-M-38) encoding cytotoxic T lymphocyte (CTL) epitopes of MPT64 and 38 kDa proteins of Mycobacterium tuberculosis. In order to observe the influence of spacer sequence (Ala-Ala-Tyr) or ubiquitin (UbGR) on the efficacy of the two CTL epitopes, we also constructed DNA vaccines, p3-M-S(spacer)-38, p3-Ub (UbGR)-M-S-38 and p3-Ub-M-38. The immune responses elicited by the four DNA vaccines were tested in C57BL/6 (H-2b) mice. The cytotoxicity of T cells was detected by LDH-release method and by enzyme-linked immunospot assay for epitope-specific cells secreting interferon-gamma. The results showed that DNA immunization with p3-M-38 vaccine could induce epitope-specific CD8+ CTL response and that the spacer sequence (AAY) only enhanced M epitope presentation. The protein-targeting sequence (UbGR) enhanced the immunogenicity of the two epitopes. The finding that defined spacer sequences at C-terminus and protein-targeting degradation modulated the immune response of epitope string DNA vaccines will be of importance for the further development of multi-epitope DNA vaccines against tuberculosis.

  14. The utility of internally transcribed spacer 2 DNA sequences of the nuclear ribosomal gene for distinguishing sibling species of Trichogramma

    NARCIS (Netherlands)

    Stouthamer, R.; Hu, J.; Kan, van F.J.P.M.; Platner, G.R.; Pinto, J.D.

    1999-01-01

    The usefulness of the internally transcribed spacer 2 (ITS2) of the nuclear ribosomal gene complex is tested for providing taxonomic characters to identify Trichogramma species. The ITS2 sequences of a group of sibling species of the T. deion/T. pretiosum complexes were determined. A simple and prec

  15. An improved PCR method for direct identification of Porphyra (Bangiales, Rhodophyta) using conchocelis based on a RUBISCO intergenic spacer

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; DONG Dong; WANG Guangce; ZHANG Baoyu; PENG Guang; XU Pu; TANG Xiaorong

    2009-01-01

    An improved method of PCR in which the small segment of conchocelis is amplified directly without DNA extraction was used to amplify a RUBISCO intergenic spacer DNA fragment from nine species of red algal genus Porphyra (Bangiales, Rhodophyta), including Porphyra yezoensis (Jiangsu, China), P. haitanensis (Fujian, China), P. oligospermatangia (Qingdao, China), P. katadai (Qingdao, China), P. tenera (Qingdao, China), P. suborboculata (Fujian, China), P. pseudolinearis (Kogendo, Korea), P. linearis (Devon, England), and P. fallax (Seattle, USA). Standard PCR and the method developed here were both conducted using primers specific for the RUBISCO spacer region, after which the two PCR products were sequenced. The sequencing data of the amplicons obtained using both methods were identical, suggesting that the improved PCR method was functional. These findings indicate that the method developed here may be useful for the rapid identification of species of Porphyra in a germplasm bank. In addition, a phylogenetic tree was constructed using the RUBISCO spacer and partial rbcS sequence, and the results were in concordant with possible alternative phylogenies based on traditional morphological taxonomic characteristics, indicating that the RUBISCO spacer is a useful region for phylogenetic studies.

  16. The effect of spacer grid critical component on pressure drop under both single and two phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Han, B.; Yang, B.W.; Zhang, H.; Mao, H.; Zha, Y. [Xi' an Jiaotong Univ., Shaanxi (China). Science and Technology Center for Advanced Nuclear Fuel Research

    2016-07-15

    As pressure drop is one of the most critical thermal hydraulic parameters for spacer grids the accurate estimation of it is the key to the design and development of spacer grids. Most of the available correlations for pressure drop do not contain any real geometrical parameters that characterize the grid effect. The main functions for spacer grid are structural support and flow mixing. Once the boundary sublayer near the rod bundle is disturbed, the liquid forms swirls or flow separation that affect pressure drop. However, under two phase flow conditions, due to the existence of steam bubble, the complexity for spacer grid are multiplied and pressure drop calculation becomes much more challenging. The influence of the dimple location, distance of mixing vane to the nearest strip, and the effect of inter-subchannel mixing among neighboring subchannels on pressure drop and downstream flow fields are analyzed in this paper. Based on this study, more detailed space grid geometry parameters are recommended for adding into the correlation when predicting pressure drop.

  17. A simulation study on the variation of virtual NMR signals by winding, bobbin, spacer error of HTS magnet

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Seong; Lee, Woo Seung; Kim, Jin Sub; Song, Seung Hyun; Nam, Seok Ho; Jeon, Hae Ryong; Beak, Geon Woo; Ko, Tae Kuk [Yonsei University, Seoul (Korea, Republic of)

    2016-09-15

    Recently, production technique and property of the High-Temperature Superconductor (HTS) tape have been improved. Thus, the study on applying an HTS magnet to the high magnetic field application is rapidly increased. A Nuclear Magnetic Resonance (NMR) spectrometer requires high magnitude and homogeneous of central magnetic field. However, the HTS magnet has fabrication errors because shape of HTS is tape and HTS magnet is manufactured by winding HTS tape to the bobbin. The fabrication errors are winding error, bobbin diameter error, spacer thickness error and so on. The winding error occurs when HTS tape is departed from the arranged position on the bobbin. The bobbin diameter and spacer thickness error occur since the diameter of bobbin and spacer are inaccurate. These errors lead magnitude and homogeneity of central magnetic field to be different from its ideal design. The purpose of this paper is to investigate the effect of winding error, bobbin diameter error and spacer thickness error on the central field and field homogeneity of HTS magnet using the virtual NMR signals in MATLAB simulation.

  18. Aortic valve annulus and sinus-tube joint diameters in normal adults of Chinese Han ethnic group

    Institute of Scientific and Technical Information of China (English)

    ZHU Dan; ZHAO Qiang

    2008-01-01

    Background The anatomic value of the aortic root is important for aortic valve repair.This study was to determine the normaI diameters of the aortic valve annulus (AVA) and sinus-tube ioint (STJ) in the healthy adults of Chinese Han ethnic group,and to provide a morphological foundation for potential clinical application.Methods Echocardiography was performed in 326 normal subjects,who were divided into 5 groups according to their age.The diameters of the AVA and STJ were measured in the parasternal long-axis view.and normalized to body surface area (BSA).They were averaged for each age group and for each gender.Differences were then determined between the normalized diameters for each age group and for both genders.Pearson's product-moment correlation coefficient was used to determine the differences between AVA and STJ diameters.It was also used to determine any positive or neqative correlations between the above two variables and age,BSA,weight,and height.Results The diameters of the AVA and STJ of Han nationality patients increased with an increase in age,BSA,weight,and height.The correlation coefficient between AVA diameter and BSA was 0.4944 (P<0.0001),between AVA diameter and age,0.1138 (P<0.05),between AVA diameter and weight,0.4521 (P<0.001),and between AVAdiameter and height,0.471 3 (P<0.001).The correlation coefficient between STJ diameter and BSA was 0.3910 (P<0.0001),between STJ diameter and age,0.3667 (P<0.0001),between STJ diameter and weight,0.4586 (P<0.0001),and between STJ diameter and height,0.3736 (P<0.0001).The difference between the above two diameters was statistically significant at 2.42±2.45 mm (paired t-test:t=-17.25;P<0.0001).AVA and STJ diameters were similar in both genders of each group when indexed to BSAConclusions The diameters of the AVA and STJ of adults of Chinese Han ethnic group increase with age,BSA,weight,and height.The diameters of the AVA and the STJ are similar in both genders.when indexed to BSA

  19. Turbulent mixing in a rod bundle with vaned spacer grids: OECD/NEA–KAERI CFD benchmark exercise test

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Seok-Kyu; Kim, Seok; Song, Chul-Hwa, E-mail: chsong@kaeri.re.kr

    2014-11-15

    Highlights: • Detailed velocity profiles have been examined in a rod bundle with mixing spacer grids. • Mixing characteristics strongly depend on the type of the mixing vane on a spacer grid. • The swirl in subchannels is elliptic and the cross-flow in gaps is vigorous in the split-type. • Swirl-type vanes generate a circular swirl in a subchannel and a weak cross-flow in gaps. • Mixing performance is superior in the case of the split-type compared to the swirl-type. - Abstract: An experimental study titled the 2nd International Benchmark Exercise (IBE-2) has been conducted to provide high-precision data of detailed turbulent flow mixing in a rod bundle for validating the CFD codes being used widely in the nuclear power industry. A 5 × 5 rod bundle having mixing spacer grids was adopted as a test rig, and was contained in a square flow housing with a 170 mm side length and 4670 mm length. The 25 rods in a bundle have dimensions of 25.4 mm in outer diameter and a 3863 mm length. The benchmark experiments have been performed at the MATiS-H water loop facility in KAERI. The axial bulk velocity in a rod bundle was maintained at about 1.50 m/s (equivalent to Re ∼50,000) with loop conditions of 35 °C and 1.57 bar measured upstream of the spacer during the experiments. Detailed measurements of the turbulent flow in the subchannels were accomplished using 2-D LDA at four different distances (0.5, 1, 4 and 10 D{sub H}) from the downstream of the mixing spacer grid. The upstream flow profiles also have been measured at the inlet of the mixing spacer grid for the inlet boundary condition. Precise measurements of the lateral and axial velocities in the subchannels are presented at four downstream distances, as well as the inlet from the mixing spacer grid of two types. Turbulence intensities and vorticities in the subchannels are also evaluated from the velocity measurements.

  20. The effect of polyethylene glycol spacer chain length on the tumor-targeting potential of folate-modified PPI dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Shrikant [Dr. Hari Singh Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India); Tekade, Rakesh K., E-mail: rakeshtekade@yahoo.com [University of Hawai' i at Hilo, College of Pharmacy (United States); Kesharwani, Prashant, E-mail: prashant_pharmacy04@rediffmail.com; Jain, Narendra K., E-mail: jnarendr@yahoo.co.in [Dr. Hari Singh Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

    2013-05-15

    The objective of the present investigation was to assess the tumor-targeting potential of ligand-spacer-engineered poly (propylene imine) (PPI) dendrimers as nanoscale drug delivery units for site-specific delivery of a model anticancer agent, docetaxel (DTX). PPI dendrimers were engineered by direct and indirect conjugation of folic acid (FA) via different types of polyethylene glycols (PEGs) [Mw (molecular weight): 1,000, 4,000, 6,000, 7,500] as spacers. The synthesized nanoconjugates (PPIFA, PPIP1FA, PPIP4FA, PPIP6FA, and PPIP7.5FA) were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance ({sup 1}H-NMR) and transmission electron microscopic (TEM) studies. Nanoconjugates were evaluated for entrapment, in vitro drug release (under various pH conditions) and hemolytic studies. Cell uptake and cytotoxicity studies were performed on human malignant cell lines (MCF-7) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT] assay. This debut study explored the effect of PEG spacer length on the targeting potential of folate-conjugated 5.0 G PPI dendrimer. DTX entrapment and in vitro drug release from nanoconjugates augmented, and hemolytic toxicity of nanoconjugates slashed with the molecular weight of PEGs. Further, nanoconjugates with PEG 4000 displayed highest tumor-targeting potential as compared to other spacer conjugated nanoconjugates due to optimized steric hindrance and receptor mediated endocytosis among other PEGs. This work is expected to shed new light on the role of spacer chain length in targeting potential of folate-anchored dendrimer.Graphical Abstract.

  1. Experimental and numerical characterization of the water flow in spacer-filled channels of spiral-wound membranes

    KAUST Repository

    Bucs, Szilard S.

    2015-09-25

    Micro-scale flow distribution in spacer-filled flow channels of spiral-wound membrane modules was determined with a particle image velocimetry system (PIV), aiming to elucidate the flow behaviour in spacer-filled flow channels. Two-dimensional water velocity fields were measured in a flow cell (representing the feed spacer-filled flow channel of a spiral wound reverse osmosis membrane module without permeate production) at several planes throughout the channel height. At linear flow velocities (volumetric flow rate per cross-section of the flow channel considering the channel porosity, also described as crossflow velocities) used in practice (0.074 and 0.163 m∙s-1) the recorded flow was laminar with only slight unsteadiness in the upper velocity limit. At higher linear flow velocity (0.3 m∙s-1) the flow was observed to be unsteady and with recirculation zones. Measurements made at different locations in the flow cell exhibited very similar flow patterns within all feed spacer mesh elements, thus revealing the same hydrodynamic conditions along the length of the flow channel. Three-dimensional (3-D) computational fluid dynamics simulations were performed using the same geometries and flow parameters as the experiments, based on steady laminar flow assumption. The numerical results were in good agreement (0.85-0.95 Bray-Curtis similarity) with the measured flow fields at linear velocities of 0.074 and 0.163 m∙s-1, thus supporting the use of model-based studies in the optimization of feed spacer geometries and operational conditions of spiral wound membrane systems.

  2. Flows in Concentric Annulus

    Directory of Open Access Journals (Sweden)

    Shuichi Torii

    1998-01-01

    stress turbulence model is employed to determine three normal components of the Reynolds stress and its off-diagonal one. The turbulent heat flux is expressed by Boussinesq approximation in which the eddy diffusivity.for heat is given as functions of the temperature variance t2¯ and the dissipation rate of temperate fluctuations εt. The governing boundarylayer equations are discretized by means of a control volume finite-difference technique and numerically solved using the marching procedure. An inner core rotation causes an amplification of the three normal components of the Reynolds stress over the whole cross section, resulting in a substantial enhancement in the Nusselt number.

  3. TYPOLOGIES OF MOBILE APPLICATIONS

    OpenAIRE

    Ion Ivan; Alin Zamfiroiu; Dragoş Palaghiţă3

    2013-01-01

    Mobile applications and their particularities are analyzed. Mobile application specific characteristics are defined. Types of applications are identified and analyzed. The paper established differences between mobile applications and mobile application categories. For each identified type the specific structures and development model are identified.

  4. Next generation mobile broadcasting

    CERN Document Server

    Gómez-Barquero, David

    2013-01-01

    Next Generation Mobile Broadcasting provides an overview of the past, present, and future of mobile multimedia broadcasting. The first part of the book-Mobile Broadcasting Worldwide-summarizes next-generation mobile broadcasting technologies currently available. This part covers the evolutions of the Japanese mobile broadcasting standard ISDB-T One-Seg, ISDB-Tmm and ISDB-TSB; the evolution of the South Korean T-DMB mobile broadcasting technology AT-DMB; the American mobile broadcasting standard ATSC-M/H; the Chinese broadcasting technologies DTMB and CMMB; second-generation digital terrestrial

  5. Intensity Modulated Proton and Photon Therapy for Early Prostate Cancer With or Without Transperineal Injection of a Polyethylen Glycol Spacer: A Treatment Planning Comparison Study

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Damien C., E-mail: damien.weber@unige.ch [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Zilli, Thomas [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Vallee, Jean Paul [Department of Diagnostic Radiology, Geneva University Hospital, Geneva (Switzerland); Rouzaud, Michel; Miralbell, Raymond [Department of Radiation Oncology, Geneva University Hospital, Geneva (Switzerland); Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona (Switzerland)

    2012-11-01

    Purpose: Rectal toxicity is a serious adverse effect in early-stage prostate cancer patients treated with curative radiation therapy (RT). Injecting a spacer between Denonvilliers' fascia increases the distance between the prostate and the anterior rectal wall and may thus decrease the rectal radiation-induced toxicity. We assessed the dosimetric impact of this spacer with advanced delivery RT techniques, including intensity modulated RT (IMRT), volumetric modulated arc therapy (VMAT), and intensity modulated proton beam RT (IMPT). Methods and Materials: Eight prostate cancer patients were simulated for RT with or without spacer. Plans were computed for IMRT, VMAT, and IMPT using the Eclipse treatment planning system using both computed tomography spacer+ and spacer- data sets. Prostate {+-} seminal vesicle planning target volume [PTV] and organs at risk (OARs) dose-volume histograms were calculated. The results were analyzed using dose and volume metrics for comparative planning. Results: Regardless of the radiation technique, spacer injection decreased significantly the rectal dose in the 60- to 70-Gy range. Mean V{sub 70Gy} and V{sub 60Gy} with IMRT, VMAT, and IMPT planning were 5.3 {+-} 3.3%/13.9 {+-} 10.0%, 3.9 {+-} 3.2%/9.7 {+-} 5.7%, and 5.0 {+-} 3.5%/9.5 {+-} 4.7% after spacer injection. Before spacer administration, the corresponding values were 9.8 {+-} 5.4% (P=.012)/24.8 {+-} 7.8% (P=.012), 10.1 {+-} 3.0% (P=.002)/17.9 {+-} 3.9% (P=.003), and 9.7 {+-} 2.6% (P=.003)/14.7% {+-} 2.7% (P=.003). Importantly, spacer injection usually improved the PTV coverage for IMRT. With this technique, mean V{sub 70.2Gy} (P=.07) and V{sub 74.1Gy} (P=0.03) were 100 {+-} 0% to 99.8 {+-} 0.2% and 99.1 {+-} 1.2% to 95.8 {+-} 4.6% with and without Spacer, respectively. As a result of spacer injection, bladder doses were usually higher but not significantly so. Only IMPT managed to decrease the rectal dose after spacer injection for all dose levels, generally with no

  6. Mobile platform security

    CERN Document Server

    Asokan, N; Dmitrienko, Alexandra

    2013-01-01

    Recently, mobile security has garnered considerable interest in both the research community and industry due to the popularity of smartphones. The current smartphone platforms are open systems that allow application development, also for malicious parties. To protect the mobile device, its user, and other mobile ecosystem stakeholders such as network operators, application execution is controlled by a platform security architecture. This book explores how such mobile platform security architectures work. We present a generic model for mobile platform security architectures: the model illustrat

  7. LTE mobile network technology

    OpenAIRE

    Sladič, Klemen

    2012-01-01

    The main purpose of this thesis is an introduction to long term evolution of fourth generation mobile networks based on LTE mobile network standard. Fourth generation mobile networks are currently one of the most developed technology in the world of mobile communications and are somewhere already available for commercial use. At the beginning is a short history of mobile networks evolution, for easier understanding. In the history you can find information from first researches of magnetic...

  8. MOBILE AGENT: EMERGING TECHNOLOGY

    OpenAIRE

    RAJGURU P. V. DR. DESHMUKH S. D

    2011-01-01

    Mobile agent technology has been promoted as an emerging technology that makes it much easier to design, implement, and maintain distributed systems, introduction to basic concepts of mobile agents like agent mobility, agent types and places and agent communication. Then benefits of the usage of mobile agents are summarized and illustrated by selected applications. The next section lists requirements and desirable properties for mobile agent languages and systems. We study the main features, ...

  9. ON MOBILE MESH NETWORKS

    OpenAIRE

    2015-01-01

    With the advances in mobile computing technologies and the growth of the Net, mobile mesh networks are going through a set of important evolutionary steps. In this paper, we survey architectural aspects of mobile mesh networks and their use cases and deployment models. Also, we survey challenging areas of mobile mesh networks and describe our vision of promising mobile services. This paper presents a basic introductory material for Masters of Open Information Technologies Lab, interested in m...

  10. ANALISIS KEANEKARAGAMAN KULTIVAR PISANG MENGGUNAKAN PENANDA PCR-RFLP PADA INTERNAL TRANSCRIBED SPACER (ITS DNA RIBOSOM

    Directory of Open Access Journals (Sweden)

    T.W.D. Ekasari

    2012-09-01

    Full Text Available Pisang merupakan bahan makanan pokok keempat terpenting di negara berkembang yang memiliki keanekaragaman sangat tinggi. Penanda DNA mikrosatelit dapat membedakan kultivar pisang yang memiliki genom A dengan kultivar pisang bergenom B. Namun penanda mikrosatelit memiliki beberapa keterbatasan, yaitu membutuhkan primer spesifik dan membutuhkan preparasi yang lebih rumit, sehingga membutuhkan waktu dan biaya yang cukup mahal. Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP terhadap DNA internal transcribed spacer (ITS ribosom mampu mengklasifikasikan kultivar-kultivar pisang berdasarkan pita restriksi daerah ITS yang dipotong dengan enzim RsaI. Koleksi DNA dari 15 kultivar pisang di Laboratorium Genetika dan Molekular Jurusan Biologi UNNES sudah diklasifikasikan genomnya berdasarkan mikrosatelit. DNA kultivar pisang diamplifikasi menggunakan primer ITS L dan ITS 4 menghasilkan fragmen ITS sebesar 700 pb. Pemotongan fragmen ITS DNA ribosom dengan enzim RsaI menghasilkan fragmen  530 pb yang spesifik untuk genom A, fragmen 350 pb dan 180 pb spesifik untuk genom B. Hasil perbandingan klasifikasi genomik berdasarkan mikrosatelit dan PCR-RFLP dari daerah ITS DNA ribosom menunjukkan bahwa klasifikasi genomnya serupa. Banana is the fourth most important staple foods in developing countries which has very high diversity. Microsatellite markers can be able to differentiate bananas cultivars which have A and B genomes, but this marker has restrictions. It requires a specific primer which is takes time and the costs expensive enough. Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP of the ribosomal DNA internal transcribed spacer (ITS was able to classify banana cultivars based on the restriction band ITS regions cut by RsaI enzyme. The DNA collection from 15 banana cultivars from the Laboratory of Genetics and Molecular Biology Department of Biological Science UNNES have been classified its

  11. Interspinous spacer versus traditional decompressive surgery for lumbar spinal stenosis: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ai-Min Wu

    Full Text Available BACKGROUND: Dynamic interspinous spacers, such as X-stop, Coflex, DIAM, and Aperius, are widely used for the treatment of lumbar spinal stenosis. However, controversy remains as to whether dynamic interspinous spacer use is superior to traditional decompressive surgery. METHODS: Medline, Embase, Cochrane Library, and the Cochrane Controlled Trials Register were searched during August 2013. A track search was performed on February 27, 2014. Study was included in this review if it was: (1 a randomized controlled trial (RCT or non-randomized prospective comparison study, (2 comparing the clinical outcomes for interspinous spacer use versus traditional decompressive surgery, (3 in a minimum of 30 patients, (4 with a follow-up duration of at least 12 months. RESULTS: Two RCTs and three non-randomized prospective studies were included, with 204 patients in the interspinous spacer (IS group and 217 patients in the traditional decompressive surgery (TDS group. Pooled analysis showed no significant difference between the IS and TDS groups for low back pain (WMD: 1.2; 95% CI: -10.12, 12.53; P = 0.03; I2 = 66%, leg pain (WMD: 7.12; 95% CI: -3.88, 18.12; P = 0.02; I2 = 70%, ODI (WMD: 6.88; 95% CI: -14.92, 28.68; P = 0.03; I2 = 79%, RDQ (WMD: -1.30, 95% CI: -3.07, 0.47; P = 0.00; I2 = 0%, or complications (RR: 1.39; 95% CI: 0.61, 3.14; P = 0.23; I2 = 28%. The TDS group had a significantly lower incidence of reoperation (RR: 3.34; 95% CI: 1.77, 6.31; P = 0.60; I2 = 0%. CONCLUSION: Although patients may obtain some benefits from interspinous spacers implanted through a minimally invasive technique, interspinous spacer use is associated with a higher incidence of reoperation and higher cost. The indications, risks, and benefits of using an interspinous process device should be carefully considered before surgery.

  12. Use of a polymethacrylate radial head spacer in temporary reconstruction of complex radial head fracture with associated elbow instability.

    Science.gov (United States)

    Capomassi, Miguel Angel; Clembosky, Gabriel Adrián

    2010-12-01

    Radial head replacement in complex elbow fractures (Mason III) with either bony or ligamentous injuries or interosseous membrane rupture is unquestionable. Actual modular and metallic prosthesis ease the mounting technique and ensure durability. Nevertheless, these types of prostheses are not always available in a short time in our daily practice. We present the use of a transient polymethacrylate spacer as an alternative in nonreconstructable complex radial head fractures with a unstable elbow. We assessed 38 patients between 2006 and 2007, with a median follow-up of 53.8 months. We included 14 Mason IV; 8 Monteggia (posterior); 7 Mason III with either associated medial collateral ligament or interosseous membrane injury; 6 elbow triads; and 3 Essex-Lopresti lesions. With the Mayo elbow performance score and the disabilities of the arm, shoulder, and hand score questionnaire, we assessed the functionality. Anatomic results were evaluated with x-ray scans of the elbow and wrist using the Broberg and Morrey and the Knirk and Jupiter scales. Functional results were as follows: 14--excellent, 14--good, 8--fair, and 2--poor. Assessment through disabilities of the arm, shoulder, and hand score questionnaire was 18.7% in average. There was a statistically significant relationship between joint stability and motion. Of the patients, 70% showed mild or moderate chondromalacia of the capitellum and 90% showed osteolysis on the proximal metaphysis of the radius, both events related to follow-up time but not to pain or range of movement. Of the cases, 30% showed heterotopic calcifications and 35% showed moderate arthrosis between the ulna and the humerus. None of the patients presented wrist arthrosis. Complications were 1 deep infection and 1 spacer luxation because of fatigue and ulna plate rupture (Monteggia posterior). In 6 patients, we had to remove the spacer because of pain and/or functional limitation, and 2 of these patients remained with moderate valgus instability

  13. Abrechnung mobiler Dienste im Mobile-Payment-Referenzmodell

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  14. Charging of mobile services by mobile payment reference model

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  15. Priming in the Type I-F CRISPR-Cas system triggers strand-independent spacer acquisition, bi-directionally from the primed protospacer.

    Science.gov (United States)

    Richter, Corinna; Dy, Ron L; McKenzie, Rebecca E; Watson, Bridget N J; Taylor, Corinda; Chang, James T; McNeil, Matthew B; Staals, Raymond H J; Fineran, Peter C

    2014-07-01

    Clustered regularly interspaced short palindromic repeats (CRISPR), in combination with CRISPR associated (cas) genes, constitute CRISPR-Cas bacterial adaptive immune systems. To generate immunity, these systems acquire short sequences of nucleic acids from foreign invaders and incorporate these into their CRISPR arrays as spacers. This adaptation process is the least characterized step in CRISPR-Cas immunity. Here, we used Pectobacterium atrosepticum to investigate adaptation in Type I-F CRISPR-Cas systems. Pre-existing spacers that matched plasmids stimulated hyperactive primed acquisition and resulted in the incorporation of up to nine new spacers across all three native CRISPR arrays. Endogenous expression of the cas genes was sufficient, yet required, for priming. The new spacers inhibited conjugation and transformation, and interference was enhanced with increasing numbers of new spacers. We analyzed ∼ 350 new spacers acquired in priming events and identified a 5'-protospacer-GG-3' protospacer adjacent motif. In contrast to priming in Type I-E systems, new spacers matched either plasmid strand and a biased distribution, including clustering near the primed protospacer, suggested a bi-directional translocation model for the Cas1:Cas2-3 adaptation machinery. Taken together these results indicate priming adaptation occurs in different CRISPR-Cas systems, that it can be highly active in wild-type strains and that the underlying mechanisms vary.

  16. Phage-host interactions in Streptococcus thermophilus: Genome analysis of phages isolated in Uruguay and ectopic spacer acquisition in CRISPR array

    Science.gov (United States)

    Achigar, Rodrigo; Magadán, Alfonso H.; Tremblay, Denise M.; Julia Pianzzola, María; Moineau, Sylvain

    2017-01-01

    Three cos-type virulent Streptococcus thermophilus phages were isolated from failed mozzarella production in Uruguay. Genome analyses showed that these phages are similar to those isolated elsewhere around the world. The CRISPR1 and CRISPR3 arrays of the three S. thermophilus host strains from Uruguay were also characterized and similarities were noted with previously described model strains SMQ-301, LMD-9 and DGCC7710. Spontaneous bacteriophage-insensitive S. thermophilus mutants (BIMs) were obtained after challenging the phage-sensitive wild-type strain Uy02 with the phage 128 and their CRISPR content was analyzed. Analysis of 23 BIMs indicated that all of them had acquired at least one new spacer in their CRISPR1 array. While 14 BIMs had acquired spacer at the 5′-end of the array, 9 other BIMs acquired a spacer within the array. Comparison of the leader sequence in strains Uy02 and DGCC7710 showed a nucleotide deletion at position -1 in Uy02, which may be responsible for the observed ectopic spacer acquisition. Analysis of the spacer sequences upstream the newly acquired ectopic spacer indicated presence of a conserved adenine residue at position -2. This study indicates that natural strains of S. thermophilus can also acquire spacers within a CRISPR array. PMID:28262818

  17. Molecular Phylogenetic Screening of Withania somnifera Relative From Indonesia Based on Internal Transcribed Spacer Region

    Directory of Open Access Journals (Sweden)

    Topik Hidayat

    2016-04-01

    Full Text Available Withania somnifera (family Solanaceae, known commonly as Ashwaganda, is one of the important medicinal plants, and recent studies reported that Withanone, one of the chemical components in this plant, has ability to kill cancer cell. Because of endemic state of this plant to South Asia, exploring plant species under the same family which grow well in Indonesia has been of interest. The purpose of this study was to screen the Indonesian plant which has strong phylogenetic relationship with Ashwaganda. Thus, phylogenetic analysis using DNA sequences of internal transcribed spacer (ITS region was conducted. Thus, 19 species of Solanaceae and two species of Convolvulaceae as outgroup were examined. Five ITS regions of Ashwaganda retrieved from GenBank were included in the phylogenetic analysis. Parsimony analysis showed that Indonesia Solanaceae comprises seven groups which is consistent with the global Solanaceae relationship as previously reported. Furthermore, our study revealed that two species, Physalis angulata and Physalis peruviana, are relative to W. somnifera. Morphologically, they share characters of flower and fruit. This result indicated that these two species are potential to have similar chemical properties as Ashwaganda, thus we can have new variants of Withanone originated from Indonesia with similar effect.

  18. Endangered Uyghur Medicinal Plant Ferula Identification through the Second Internal Transcribed Spacer.

    Science.gov (United States)

    Fan, Congzhao; Li, Xiaojin; Zhu, Jun; Song, Jingyuan; Yao, Hui

    2015-01-01

    The medicinal plant Ferula has been widely used in Asian medicine, especially in Uyghur medicine in Xinjiang, China. Given that various substitutes and closely related species have similar morphological characteristics, Ferula is difficult to distinguish based on morphology alone, thereby causing confusion and threatening the safe use of Ferula. In this study, internal transcribed spacer 2 (ITS2) sequences were analyzed and assessed for the accurate identification of two salable Ferula species (Ferula sinkiangensis and Ferula fukangensis) and eight substitutes or closely related species. Results showed that the sequence length of ITS2 ranged from 451 bp to 45 bp, whereas guanine and cytosine contents (GC) were from 53.6% to 56.2%. A total of 77 variation sites were detected, including 63 base mutations and 14 insertion/deletion mutations. The ITS2 sequence correctly identified 100% of the samples at the species level using the basic local alignment search tool 1 and nearest-distance method. Furthermore, neighbor-joining tree successfully identified the genuine plants F. sinkiangensis and F. fukangensis from their succedaneum and closely related species. These results indicated that ITS2 sequence could be used as a valuable barcode to distinguish Uyghur medicine Ferula from counterfeits and closely related species. This study may broaden DNA barcoding application in the Uyghur medicinal plant field.

  19. Heterogeneity of the internal transcribed spacer region in Leishmania tropica isolates from southern Iran.

    Science.gov (United States)

    Ghatee, Mohammad Amin; Sharifi, Iraj; Kuhls, Katrin; Kanannejad, Zahra; Harandi, Majid Fasihi; de Almeida, Marcos E; Hatam, Gholamreza; Mirhendi, Hossein

    2014-09-01

    Most of cutaneous leishmaniasis cases occur in only 7 countries, including Iran. Leishmania tropica is the main cause of anthroponotic cutaneous leishmaniasis in Iran. In order to study the heterogeneity and phylogeny of L. tropica in southern Iran, a total of 61 isolates were obtained from Bam district and the cities Kerman and Shiraz. The internal transcribed spacer (ITS) from the ribosomal DNA locus was amplified and then analysed by sequencing. Analysis of the ITS sequences showed four haplotypes in the isolates, including 3 haplotypes among the 58 isolates from the south eastern region, including Bam district and Kerman city, and 2 haplotypes among the 3 isolates from Shiraz city. The results showed a monophyletic structure for the south eastern population. In comparison to GenBank sequences of L. tropica from different countries, most of the southeast Iranian and Indian isolates are comprised in one cluster, while isolates from other countries and few other Iranian isolates group in a different cluster. Analysis of ITS sequences of south eastern L. tropica showed a homogeneous population which could be the basis for other molecular epidemiology studies using more discriminative markers and tracing possible changes in the population structure of L. tropica.

  20. Diffraction-based overlay for spacer patterning and double patterning technology

    Science.gov (United States)

    Lee, Byoung Hoon; Park, JeongSu; Lee, Jongsu; Park, Sarohan; Lim, ChangMoon; Yim, Dong-Gyu; Park, Sungki; Ryu, Chan-Ho; Morgan, Stephen; van de Schaar, Maurits; Fuchs, Andreas; Bhattacharyya, Kaustuve

    2011-03-01

    Overlay performance will be increasingly important for Spacer Patterning Technology (SPT) and Double Patterning Technology (DPT) as various Resolution Enhancement Techniques are employed to extend the resolution limits of lithography. Continuous shrinkage of devices makes overlay accuracy one of the most critical issues while overlay performance is completely dependent on exposure tool. Image Based Overlay (IBO) has been used as the mainstream metrology for overlay by the main memory IC companies, but IBO is not suitable for some critical layers due to the poor Tool Induced Shift (TIS) values. Hence new overlay metrology is required to improve the overlay measurement accuracy. Diffraction Based Overlay (DBO) is regarded to be an alternative metrology to IBO for more accurate measurements and reduction of reading errors. Good overlay performances of DBO have been reported in many articles. However applying DBO for SPT and DPT layers poses extra challenges for target design. New vernier designs are considered for different DPT and SPT schemes to meet overlay target in DBO system. In this paper, we optimize the design of the DBO target and the performance of DBO to meet the overlay specification of sub-3x nm devices which are using SPT and DPT processes. We show that the appropriate vernier design yields excellent overlay performance in residual and TIS. The paper also demonstrated the effects of vernier structure on overlay accuracy from SEM analysis.