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Sample records for ureteral iii-v complicado

  1. III-V microelectronics

    CERN Document Server

    Nougier, JP

    1991-01-01

    As is well known, Silicon widely dominates the market of semiconductor devices and circuits, and in particular is well suited for Ultra Large Scale Integration processes. However, a number of III-V compound semiconductor devices and circuits have recently been built, and the contributions in this volume are devoted to those types of materials, which offer a number of interesting properties. Taking into account the great variety of problems encountered and of their mutual correlations when fabricating a circuit or even a device, most of the aspects of III-V microelectronics, from fundamental p

  2. Semiconducting III-V compounds

    CERN Document Server

    Hilsum, C; Henisch, Heinz R

    1961-01-01

    Semiconducting III-V Compounds deals with the properties of III-V compounds as a family of semiconducting crystals and relates these compounds to the monatomic semiconductors silicon and germanium. Emphasis is placed on physical processes that are peculiar to III-V compounds, particularly those that combine boron, aluminum, gallium, and indium with phosphorus, arsenic, and antimony (for example, indium antimonide, indium arsenide, gallium antimonide, and gallium arsenide).Comprised of eight chapters, this book begins with an assessment of the crystal structure and binding of III-V compounds, f

  3. Transformational III-V Electronics

    KAUST Repository

    Nour, Maha A.

    2014-01-01

    Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS

  4. Transformational III-V Electronics

    KAUST Repository

    Nour, Maha A.

    2014-04-01

    Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS) compatible process for transforming traditional III-V materials based electronics into flexible one. The thesis reports releasing 200 nm of Gallium Arsenide (GaAs) from 200 nm GaAs / 300 nm Aluminum Arsenide (AlAs) stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes that contributes to the better transparency (45 % at 724 nm wavelengths) observed. Fabrication of metal oxide semiconductor capacitor (MOSCAPs) on GaAs is followed by releasing it to have devices on flexible 200 nm GaAs. Similarly, flexible GaSb and InP fabrication process is also reported to transform traditional electronics into large-area flexible electronics.

  5. III-V semiconductor materials and devices

    CERN Document Server

    Malik, R J

    1989-01-01

    The main emphasis of this volume is on III-V semiconductor epitaxial and bulk crystal growth techniques. Chapters are also included on material characterization and ion implantation. In order to put these growth techniques into perspective a thorough review of the physics and technology of III-V devices is presented. This is the first book of its kind to discuss the theory of the various crystal growth techniques in relation to their advantages and limitations for use in III-V semiconductor devices.

  6. Hybrid III-V/silicon lasers

    Science.gov (United States)

    Kaspar, P.; Jany, C.; Le Liepvre, A.; Accard, A.; Lamponi, M.; Make, D.; Levaufre, G.; Girard, N.; Lelarge, F.; Shen, A.; Charbonnier, P.; Mallecot, F.; Duan, G.-H.; Gentner, J.-.; Fedeli, J.-M.; Olivier, S.; Descos, A.; Ben Bakir, B.; Messaoudene, S.; Bordel, D.; Malhouitre, S.; Kopp, C.; Menezo, S.

    2014-05-01

    The lack of potent integrated light emitters is one of the bottlenecks that have so far hindered the silicon photonics platform from revolutionizing the communication market. Photonic circuits with integrated light sources have the potential to address a wide range of applications from short-distance data communication to long-haul optical transmission. Notably, the integration of lasers would allow saving large assembly costs and reduce the footprint of optoelectronic products by combining photonic and microelectronic functionalities on a single chip. Since silicon and germanium-based sources are still in their infancy, hybrid approaches using III-V semiconductor materials are currently pursued by several research laboratories in academia as well as in industry. In this paper we review recent developments of hybrid III-V/silicon lasers and discuss the advantages and drawbacks of several integration schemes. The integration approach followed in our laboratory makes use of wafer-bonded III-V material on structured silicon-on-insulator substrates and is based on adiabatic mode transfers between silicon and III-V waveguides. We will highlight some of the most interesting results from devices such as wavelength-tunable lasers and AWG lasers. The good performance demonstrates that an efficient mode transfer can be achieved between III-V and silicon waveguides and encourages further research efforts in this direction.

  7. Thermal oxidation of III-V compounds

    International Nuclear Information System (INIS)

    Monteiro, O.R.; Evans, J.W.

    1988-01-01

    The thermal oxidation of two important III-V compound semiconductor materials, namely GaAs and InP, has been studied between 300 and 600 0 C. In-situ TEM, cross-sectional TEM (XTEM) and SIMS analyses were used to characterize the reaction products. The first technique allows us to access the reactions at the very moment they are occurring. XTEM provides a clearer picture of the distribution of phases in the oxidized samples. SIMS gives us information on the dopant redistribution after oxidation as well as enrichment of group V element at the oxide semiconductor interface. Based on those results, the reaction products were characterized and reaction mechanisms proposed

  8. Progress in III-V materials technology

    Science.gov (United States)

    Grant, Ian R.

    2004-12-01

    Compound semiconductors, in the form of GaAs and InP have achieved major commercial significance in areas of application such as mobile communications, displays and telecoms and offer a versatility of function beyond the capabilities of Si. III-V compounds, and in particular GaAs, have since their early development been the subject of defence related interest. Support from this sector established the basic materials technologies and nurtured development up until their commercial breakthrough into consumer products. GaAs, for example, now provides essential components for mobile phones and CD / DVD players. An overview is presented of the crystal growth and processing methods used in the manufacture of these materials. Current state of the art characteristics on crystal form and quality are discussed, together with the evolution of single crystal growth techniques. Consideration is given to how these principal compounds together with the minor materials, InSb, GaSb and InAs are employed in diverse applications over a broad spectral range, together with information on markets and future perspectives.

  9. Position-controlled epitaxial III-V nanowires on silicon

    NARCIS (Netherlands)

    Roest, A.L.; Verheijen, M.A.; Wunnicke, O.; Serafin, S.N.; Wondergem, H.J.; Bakkers, E.P.A.M.

    2006-01-01

    We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction

  10. Percutaneous Ureteral stent insertion

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yup; Sung, Dong Wook; Choi, Woo Suk; Lee, Dong Ho; Ko, Young Tae; Lee, Sun Wha; Lim, Jae Hoon [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1990-10-15

    Percutaneous ureteral stent insertion is a treatment of permanent or temporary urinary diversion to maintain continuity and function of the obstructed and injured ureter. We performed 31 cases of percutaneous double pig tall ureteral stent insertion in 21 patients, included 13 patients with malignant ureteral obstruction and eight patients with injured ureter as well as benign inflammatory stricture. Satisfactory resulted was obtained in all patients but one, who need percutaneous nephrostomy on week later for urinary diversion. No significant complication was encountered. The authors concluded that percutaneous ureteral stent insertion, an interventional procedure alternative to urologic retrograde method, is an effective method for urinary diversion.

  11. Magnetooptical investigations on ferromagnetic III-V-semiconductors; Magnetooptische Untersuchungen an ferromagnetischen III-V-Halbleitern

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Andreas

    2009-07-23

    Magnetooptical Kerr effect (MOKE) and Magnetic Circular Dichroism (MCD) have been used to investigate magnetic as well as bandstructure properties of diluted magnetic III-V-semiconductors containing Mn. In these ferromagnetic systems it has been found that the strength of the observed effects depends linearly on the magnetization of the samples with no influence of the external magnetic field. The magnetooptical effects allowed the recording of hysteresis loops of GaMnAs, GaMnSb, InMnAs and InMnSb samples for different temperatures and in the case of GaMnAs also for different alignments of the external magnetic field with respect to the easy axis of magnetization. The Stoner-Wohlfahrt-Model has been used to describe the resulting shapes of the loops yielding the magnetic anisotropy parameters of the samples. For magnetically saturated samples, spectra of MOKE and MCD have been recorded. Contrary to pure III-V-semiconductors, which exhibit lots of sharp resonances due to interband transitions between Landau levels, III-Mn-V-semi-conductors how only very few (or just one) considerably broad resonance(s). Their spectral position(s) do(es) neither depend upon the magnetic field as it would be the case for pure III-V-semiconductors nor the magnetization. Only the amplitude increases linearly with the magnetization. Utilizing a kp-theory it has been possible to describe the observed dependencies. Valence- and conduction-band are split into Landau levels by the external magnetic field and, in addition to the Zeeman-effect, the spin-levels are split by the exchange interaction between the localized electrons of the Mn ions and the free carriers which is proportional to the magnetization of the samples. This splitting is much bigger than the Landau level splitting. Due to an inhomogeneous distribution of the Mn ions and due to the high carrier density the Landau levels are strongly broadened and their structure is not observable. Owing to the high carrier-concentration in

  12. Position-controlled epitaxial III-V nanowires on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Roest, Aarnoud L; Verheijen, Marcel A; Wunnicke, Olaf; Serafin, Stacey; Wondergem, Harry; Bakkers, Erik P A M [Philips Research Laboratories, Professor Holstlaan 4, 5656 AA Eindhoven (Netherlands); Kavli Institute of NanoScience, Delft University of Technology, PO Box 5046, 2600 GA Delft (Netherlands)

    2006-06-14

    We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction pole figures and cross-sectional transmission electron microscopy. We show preliminary results of two-terminal electrical measurements of III-V nanowires grown on silicon. E-beam lithography was used to predefine the position of the nanowires.

  13. Position-controlled epitaxial III-V nanowires on silicon

    International Nuclear Information System (INIS)

    Roest, Aarnoud L; Verheijen, Marcel A; Wunnicke, Olaf; Serafin, Stacey; Wondergem, Harry; Bakkers, Erik P A M

    2006-01-01

    We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the VLS mechanism with laser ablation as well as metal-organic vapour phase epitaxy. The hetero-epitaxial growth of the III-V nanowires on silicon was confirmed with x-ray diffraction pole figures and cross-sectional transmission electron microscopy. We show preliminary results of two-terminal electrical measurements of III-V nanowires grown on silicon. E-beam lithography was used to predefine the position of the nanowires

  14. Development of III-V/Si Multijunction Space Photovoltaics

    Data.gov (United States)

    National Aeronautics and Space Administration — High substrate costs, as well as weight, typically play a major role in the high costs of multijunction space solar cell production and deployment. III-V/Si...

  15. Hybrid III-V/SOI Resonant Cavity Photodetector

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol

    2016-01-01

    A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization.......A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization....

  16. Surface passivation technology for III-V semiconductor nanoelectronics

    International Nuclear Information System (INIS)

    Hasegawa, Hideki; Akazawa, Masamichi

    2008-01-01

    The present status and key issues of surface passivation technology for III-V surfaces are discussed in view of applications to emerging novel III-V nanoelectronics. First, necessities of passivation and currently available surface passivation technologies for GaAs, InGaAs and AlGaAs are reviewed. Then, the principle of the Si interface control layer (ICL)-based passivation scheme by the authors' group is introduced and its basic characterization is presented. Ths Si ICL is a molecular beam epitaxy (MBE)-grown ultrathin Si layer inserted between III-V semiconductor and passivation dielectric. Finally, applications of the Si ICL method to passivation of GaAs nanowires and GaAs nanowire transistors and to realization of pinning-free high-k dielectric/GaAs MOS gate stacks are presented

  17. Research progress of III-V laser bonding to Si

    Science.gov (United States)

    Bo, Ren; Yan, Hou; Yanan, Liang

    2016-12-01

    The vigorous development of silicon photonics makes a silicon-based light source essential for optoelectronics' integration. Bonding of III-V/Si hybrid laser has developed rapidly in the last ten years. In the tireless efforts of researchers, we are privileged to see these bonding methods, such as direct bonding, medium adhesive bonding and low temperature eutectic bonding. They have been developed and applied to the research and fabrication of III-V/Si hybrid lasers. Some research groups have made remarkable progress. Tanabe Katsuaki of Tokyo University successfully implemented a silicon-based InAs/GaAs quantum dot laser with direct bonding method in 2012. They have bonded the InAs/GaAs quantum dot laser to the silicon substrate and the silicon ridge waveguide, respectively. The threshold current of the device is as low as 200 A/cm2. Stevan Stanković and Sui Shaoshuai successfully produced a variety of hybrid III-V/Si laser with the method of BCB bonding, respectively. BCB has high light transmittance and it can provide high bonding strength. Researchers of Tokyo University and Peking University have realized III-V/Si hybrid lasers with metal bonding method. We describe the progress in the fabrication of III-V/Si hybrid lasers with bonding methods by various research groups in recent years. The advantages and disadvantages of these methods are presented. We also introduce the progress of the growth of III-V epitaxial layer on silicon substrate, which is also a promising method to realize silicon-based light source. I hope that readers can have a general understanding of this field from this article and we can attract more researchers to focus on the study in this field.

  18. Percutaneous placement of ureteral stent

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyup; Park, Jae Hyung; Han, Joon Koo; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1990-12-15

    Antegrade placement of ureteral stents has successfully achieved in 41 of 46 ureters. When it was difficult to advance ureteral stents through the lesion, it was facilitated by retrograde guide-wire snare technique through urethra. Complications associated with the procedure were non-function of ureteral stent by occlusion, upward migration,and spontaneous fracture of ureteral stent. These complications were managed by percutaneous nephrostomy and removal of ureteral stents by guide-wire snare technique and insertion of a new ureteral stent. While blood cell in urine was markedly increased in about 50% of patients following the procedure.

  19. Epitaxial III-V nanowires on silicon for vertical devices

    NARCIS (Netherlands)

    Bakkers, E.P.A.M.; Borgström, M.T.; Einden, Van Den W.; Weert, van M.H.M.; Helman, A.; Verheijen, M.A.

    2006-01-01

    We show the epitaxial integration of III-V semiconductor nanowires with silicon technology. The wires are grown by the Vapor-Liquid-Solid (VLS) mechanism with laser ablation as well as metal organic vapor phase epitaxy. The VLS growth enables the fabrication of complex axial and radial

  20. Antisites in III-V semiconductors: Density functional theory calculations

    KAUST Repository

    Chroneos, A.; Tahini, Hassan Ali; Schwingenschlö gl, Udo; Grimes, R. W.

    2014-01-01

    as a function of the Fermi level and under different growth conditions. The formation energies of group III antisites (III V q) decrease with increasing covalent radius of the group V atom though not group III radius, whereas group V antisites (V I I I

  1. Long-wavelength III-V/silicon photonic integrated circuits

    NARCIS (Netherlands)

    Roelkens, G.C.; Kuyken, B.; Leo, F.; Hattasan, N.; Ryckeboer, E.M.P.; Muneeb, M.; Hu, C.L.; Malik, A.; Hens, Z.; Baets, R.G.F.; Shimura, Y.; Gencarelli, F.; Vincent, B.; Loo, van de R.; Verheyen, P.A.; Lepage, G.; Campenhout, van J.; Cerutti, L.; Rodriquez, J.B.; Tournie, E.; Chen, X; Nedeljkovic, G.; Mashanovich, G.; Liu, X.; Green, W.S.

    2013-01-01

    We review our work in the field of short-wave infrared and mid-infrared photonic integrated circuits for applications in spectroscopic sensing systems. Passive silicon waveguide circuits, GeSn photodetectors, the integration of III-V and IV-VI semiconductors on these circuits, and silicon nonlinear

  2. [Ureteral stricture after ESWL for ureteral calculi].

    Science.gov (United States)

    Yamauchi, Tomoyuki; Tsukamoto, Takuji; Mori, Yoshiaki; Sugiyama, Ken; Fujioka, Toshio

    2003-01-01

    There are many reports on the effects of ESWL, but few reports on the complications, especially remaining ureteral stricture after this treatment. Therefore we have retrospectively reviewed our cases to define the predisposing factors of this complication. Since 1991 we have treated urolithiasis with ESWL using a Siemens Lithostar for the first therapy. We had 16 cases of ureteral stricture after this treatment. Ureteral stricture is the most common complication after ESWL treatment. To define the risk factor of the stricture we have compared 549 cases that were successfully treated between 1994 and 1996 without this complication. In these two groups we examined ages, sexes, chief complaints, size, position and components of the calculi, the degree of hydronephrosis, the frequency of ESWL, the presence of urinary tract infection, the duration of stone impaction and the after endourological treatment using multiple logistic regression analysis. Patients with the stone incidentally found and those with the UTI seemed to be more frequently associated with ureteral stricture, however there was not a significant difference. The hydronephrosis more than grade 3 (p = 0.025), the frequency of ESWL (p = 0.0325) and the after endourological treatment, especially TUL (p = 0.0184) were statistically significant among the other factors. The stricture occurred in 5 out of 29 patients with the hydronephrosis of grade 4 and 5 between 1994 and 1996. We should carefully treat patients with grade 3 or more hydronephrosis with ESWL. We should not repeatedly treat the patients with ESWL. We should take care of TUL treatment after ESWL.

  3. Cleavage mechanoluminescence in elemental and III-V semiconductors

    International Nuclear Information System (INIS)

    Chandra, B.P.; Patel, R.P.; Gour, Anubha S.; Chandra, V.K.; Gupta, R.K.

    2003-01-01

    The present paper reports the theory of mechanoluminescence (ML) produced during cleavage of elemental and III-V semiconductors. It seems that the formation of crack-induced localized states is responsible for the ML excitation produced during the cleavage of elemental and III-V semiconductors. According to this mechanism, as the atoms are drawn away from each other in an advancing crack tip, the decreasing wave function overlap across the crack may result in localized states which is associated with increasing electron energy. If the energy of these localized states approach that of the conduction band, transition to the conduction band via tunnelling would be possible, creating minority carriers, and consequently the electron-hole recombination may give rise to mechanoluminescence. When an elemental or III-V semiconductor is cleaved, initially the ML intensity increases with time, attains a peak value I m at the time t m corresponding to completion of the cleavage of the semiconductor, and then it decreases following power law decay. Expressions are derived for the ML intensity I m corresponding to the peak of the ML intensity versus time curve and for the total ML intensity I T . It is shown that both I m and I T should increase directly with the area of the newly created surfaces of the crystals. From the measurements of the ML intensity, the velocity of crack propagation in material can be determined by using the relation v=H/t m

  4. Antisites in III-V semiconductors: Density functional theory calculations

    KAUST Repository

    Chroneos, A.

    2014-07-14

    Density functional based simulation, corrected for finite size effects, is used to investigate systematically the formation of antisite defects in III-V semiconductors (III=Al, Ga, and In and V=P, As, and Sb). Different charge states are modelled as a function of the Fermi level and under different growth conditions. The formation energies of group III antisites (III V q) decrease with increasing covalent radius of the group V atom though not group III radius, whereas group V antisites (V I I I q) show a consistent decrease in formation energies with increase in group III and group V covalent radii. In general, III V q defects dominate under III-rich conditions and V I I I q under V-rich conditions. Comparison with equivalent vacancy formation energy simulations shows that while antisite concentrations are always dominant under stoichiometric conditions, modest variation in growth or doping conditions can lead to a significantly higher concentration of vacancies. © 2014 AIP Publishing LLC.

  5. Penetrating ureteral trauma

    Directory of Open Access Journals (Sweden)

    Gustavo P. Fraga

    2007-04-01

    Full Text Available OBJECTIVE: The purpose of this series is to report our experience in managing ureteral trauma, focusing on the importance of early diagnosis, correct treatment, and the impact of associated injuries on the management and morbid-mortality. MATERIALS AND METHODS: From January 1994 to December 2002, 1487 laparotomies for abdominal trauma were performed and 20 patients with ureteral lesions were identified, all of them secondary to penetrating injury. Medical charts were analyzed as well as information about trauma mechanisms, diagnostic routine, treatment and outcome. RESULTS: All patients were men. Mean age was 27 years. The mechanisms of injury were gunshot wounds in 18 cases (90% and stab wounds in two (10%. All penetrating abdominal injuries had primary indication of laparotomy, and neither excretory urography nor computed tomography were used in any case before surgery. The diagnosis of ureteric injury was made intra-operatively in 17 cases (85%. Two ureteral injuries (10% were initially missed. All patients had associated injuries. The treatment was dictated by the location, extension and time necessary to identify the injury. The overall incidence of complications was 55%. The presence of shock on admission, delayed diagnosis, Abdominal Trauma Index > 25, Injury Severity Score > 25 and colon injuries were associated to a high complication rate, however, there was no statistically significant difference. There were no mortalities in this group. CONCLUSIONS: A high index of suspicion is required for diagnosis of ureteral injuries. A thorough exploration of all retroperitoneal hematoma after penetrating trauma should be an accurate method of diagnosis; even though it failed in 10% of our cases.

  6. Subsurface dimerization in III-V semiconductor (001) surfaces

    DEFF Research Database (Denmark)

    Kumpf, C.; Marks, L.D.; Ellis, D.

    2001-01-01

    We present the atomic structure of the c(8 X 2) reconstructions of InSb-, InAs-, and GaAs-(001) surfaces as determined by surface x-ray diffraction using direct methods. Contrary to common belief, group III dimers are not prominent on the surface, instead subsurface dimerization of group m atoms ...... takes place in the second bilayer, accompanied by a major rearrangement of the surface atoms above the dimers to form linear arrays. By varying the occupancies of four surface sites the (001)-c(8 X 2) reconstructions of III-V semiconductors can be described in a unified model....

  7. Radiation Effects in III-V Nanowire Devices

    Science.gov (United States)

    2016-09-01

    fabrication of an in-plane nanowire (NW) GaAs metal-oxide-semiconductor field- effect transistor (MOSFET) by focused -ion beam (FIB) etching and chemical...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-94 Radiation Effects in III-V...5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY

  8. DX centers in III-V semiconductors under hydrostatic pressure

    International Nuclear Information System (INIS)

    Wolk, J.A.

    1992-11-01

    DX centers are deep level defects found in some III-V semiconductors. They have persistent photoconductivity and large difference between thermal and optical ionization energies. Hydrostatic pressure was used to study microstructure of these defects. A new local vibrational mode (LVM) was observed in hydrostatically stressed, Si-doped GaAs. Corresponding infrared absorption peak is distinct from the Si Ga shallow donor LVM peak, which is the only other LVM peak observed in our samples, and is assigned to the Si DX center. Analysis of the relative intensities of the Si DX LVM and the Si shallow donor LVM peaks, combined with Hall effect and resistivity indicate that the Si DX center is negatively charged. Frequency of this new mode provides clues to the structure of this defect. A pressure induced deep donor level in S-doped InP was also discovered which has the properties of a DX center. Pressure at which the new defect becomes more stable than the shallow donor is 82 kbar. Optical ionization energy and energy dependence of the optical absorption cross section was measured for this new effect. Capture barrier from the conduction band into the DX state were also determined. That DX centers can be formed in InP by pressure suggests that DX states should be common in n-type III-V semiconductors. A method is suggested for predicting under what conditions these defects will be the most stable form of the donor impurity

  9. III-V nanoelectronics and related surface/interface issues

    International Nuclear Information System (INIS)

    Hasegawa, Hideki

    2003-01-01

    The conventional logic gate architecture is not suitable for high-density integration of quantum devices which are non-robust and extremely structure- and charge-sensitive. In this paper, our novel hexagonal binary-decision-diagram (BDD) quantum circuit approach for III-V nanoelectronics is reviewed and related critical surface/interface issues for high-density integration are discussed. First, the basic concept and actual implementation method of our approach are explained, giving examples of novel BDD quantum integrated circuits where nanowire networks are controlled by nanoscale Schottky wrap gates. For high-density integration, growth of embedded sub-10 nm III-V quantum wire networks by selective molecular beam epitaxy (MBE) on patterned substrates is described, including effects of atomic hydrogen irradiation and kinetic control of wire width. The key processing issue lies in understanding and control of nanostructure surfaces/interfaces. Behavior of nanoscale Schottky gates, recent scanning tunneling microscopy (STM)/scanning tunneling spectroscopy (STS) studies of surface states, and successful removal of surface states by MBE-grown silicon interface control layer are discussed

  10. Hybrid III-V-on-Si Vertical Cavity laser for Optical Interconnects

    DEFF Research Database (Denmark)

    Park, Gyeong Cheol; Semenova, Elizaveta; Chung, Il-Sug

    2013-01-01

    Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers.......Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers....

  11. Fast optical in situ spectroscopy in III-V MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Kaspari, C.

    2007-09-29

    This work describes the application of optical in situ measurement techniques (reflectance anisotropy spectroscopy, RAS, and spectroscopic ellipsometry, SE) to processes that are important for the growth of III-V semiconductors like GaAs, InP, InAs and GaP in metal-organic vapour phase epitaxy (MOVPE). Special emphasis is placed on the determination of the free carrier concentration (doping level) and the study of the thermal desorption properties of III-V oxides. A large part of this work is concerned with the development and the construction of a multichannel RAS setup that allows the recording of RAS spectra within fractions of a second. On the basis of benchmark measurements it was shown that the spectral resolution is sufficiently accurate for application in epitaxy. To demonstrate the recording of spectra with high temporal resolution, RAS monolayer oscillations during growth of GaAs were studied and it was shown that the surface changes periodically between a relatively smooth morphology with adsorbed methyl groups (type III) and a stepped, gallium-rich surface (type II). Furthermore the non-reversible process of growing InAs quantum dots on GaAs was studied. It was shown that the multichannel RAS is capable of detecting the 2D-3D transition as well as the following morphological change of the surface at high temporal resolution. For the measurement of the doping level, the relationship between the doping-induced internal electric field and the anisotropy of the sample was studied. To understand the effect of the so-called doping oscillations, a theoretical model was developed. For the investigation of the thermal desorption of the III-V oxides in MOVPE, a number of test series were realised. It was also found that the formation of the reconstructed surface is finished a considerable time after the SE transient indicates stable conditions (no further reduction of the oxide layer). The activation energy for oxide desorption from InAs, GaAs and InP was

  12. Organic / IV, III-V Semiconductor Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Pang-Leen Ong

    2010-03-01

    Full Text Available We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V, nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic active material (p-type deposited by coating, printing or spraying technique on the surface of bulk or nanostructured semiconductor (n-type forming a heterojunction between the two materials. Organic components include various photosensitive monomers (e.g., phtalocyanines or porphyrines, conjugated polymers, and carbon nanotubes. Mechanisms of the charge separation at the interface and their transport are discussed. Also, perspectives on the future development of such hybrid cells and comparative analysis with other classes of photovoltaics of third generation are presented.

  13. Ureteral Metastasis from Prostatic Carcinoma with an Associated Ureteral Stone: A Case Report

    Directory of Open Access Journals (Sweden)

    Chia-Chu Liu

    2004-07-01

    Full Text Available Ureteral metastasis is rare, and only a few cases of ureteral metastasis from prostatic carcinoma have been reported. We present a case of ureteral metastasis from prostatic carcinoma that was also associated with a ureteral stone. To our knowledge, this is the second case with a ureteral stone at the site of the metastatic lesion.

  14. Spectroscopic characterization of III-V semiconductor nanomaterials

    Science.gov (United States)

    Crankshaw, Shanna Marie

    III-V semiconductor materials form a broad basis for optoelectronic applications, including the broad basis of the telecom industry as well as smaller markets for high-mobility transistors. In a somewhat analogous manner as the traditional silicon logic industry has so heavily depended upon process manufacturing development, optoelectronics often relies instead on materials innovations. This thesis focuses particularly on III-V semiconductor nanomaterials, detailed characterization of which is invaluable for translating the exhibited behavior into useful applications. Specifically, the original research described in these thesis chapters is an investigation of semiconductors at a fundamental materials level, because the nanostructures in which they appear crystallize in quite atypical forms for the given semiconductors. Rather than restricting the experimental approaches to any one particular technique, many different types of optical spectroscopies are developed and applied where relevant to elucidate the connection between the crystalline structure and exhibited properties. In the first chapters, for example, a wurtzite crystalline form of the prototypical zincblende III-V binary semiconductor, GaAs, is explored through polarization-dependent Raman spectroscopy and temperature-dependent photoluminescence, as well as second-harmonic generation (SHG). The altered symmetry properties of the wurtzite crystalline structure are particularly evident in the Raman and SHG polarization dependences, all within a bulk material realm. A rather different but deeply elegant aspect of crystalline symmetry in GaAs is explored in a separate study on zincblende GaAs samples quantum-confined in one direction, i.e. quantum well structures, whose quantization direction corresponds to the (110) direction. The (110) orientation modifies the low-temperature electron spin relaxation mechanisms available compared to the usual (001) samples, leading to altered spin coherence times explored

  15. Design and Characterisation of III-V Semiconductor Nanowire Lasers

    Science.gov (United States)

    Saxena, Dhruv

    The development of small, power-efficient lasers underpins many of the technologies that we utilise today. Semiconductor nanowires are promising for miniaturising lasers to even smaller dimensions. III-V semiconductors, such as Gallium Arsenide (GaAs) and Indium Phosphide (InP), are the most widely used materials for optoelectronic devices and so the development of nanowire lasers based on these materials is expected to have technologically significant outcomes. This PhD dissertation presents a comprehensive study of the design of III-V semiconductor nanowire lasers, with bulk and quantum confined active regions. Based on the design, various III-V semiconductor nanowire lasers are demonstrated, namely, GaAs nanowire lasers, GaAs/AlGaAs multi-quantum well (MQW) nanowire lasers and InP nanowire lasers. These nanowire lasers are shown to operate at room temperature, have low thresholds, and lase from different transverse modes. The structural and optoelectronic quality of nanowire lasers are characterised via electron microscopy and photoluminescence spectroscopic techniques. Lasing is characterised in all these devices by optical pumping. The lasing characteristics are analysed by rate equation modelling and the lasing mode(s) in these devices is characterised by threshold gain modelling, polarisation measurements and Fourier plane imaging. Firstly, GaAs nanowire lasers that operate at room temperature are demonstrated. This is achieved by determining the optimal nanowire diameter to reduce threshold gain and by passivating nanowires to improve their quantum efficiency (QE). High-quality surface passivated GaAs nanowires of suitable diameters are grown. The growth procedure is tailored to improve both QE and structural uniformity of nanowires. Room-temperature lasing is demonstrated from individual nanowires and lasing is characterised to be from TM01 mode by threshold gain modelling. To lower threshold even further, nanowire lasers with GaAs/AlGaAs coaxial multi

  16. III - V semiconductor structures for biosensor and molecular electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Luber, S M

    2007-01-15

    The present work reports on the employment of III-V semiconductor structures to biosensor and molecular electronics applications. In the first part a sensor based on a surface-near two dimensional electron gas for a use in biological environment is studied. Such a two dimensional electron gas inherently forms in a molecular beam epitaxy (MBE) grown, doped aluminum gallium arsenide - gallium arsenide (AlGaAs-GaAs) heterostructure. Due to the intrinsic instability of GaAs in aqueous solutions the device is passivated by deposition of a monolayer of 4'-substituted mercaptobiphenyl molecules. The influence of these molecules which bind to the GaAs via a sulfur group is investigated by Kelvin probe measurements in air. They reveal a dependence of GaAs electron affinity on the intrinsic molecular dipole moment of the mercaptobiphenyls. Furthermore, transient surface photovoltage measurements are presented which demonstrate an additional influence of mercaptobiphenyl chemisorption on surface carrier recombination rates. As a next step, the influence of pH-value and salt concentration upon the sensor device is discussed based on the results obtained from sensor conductance measurements in physiological solutions. A dependence of the device surface potential on both parameters due to surface charging is deduced. Model calculations applying Poisson-Boltzmann theory reveal as possible surface charging mechanisms either the adsorption of OH- ions on the surface, or the dissociation of OH groups in surface oxides. A comparison between simulation settings and physical device properties indicate the OH- adsorption as the most probable mechanism. In the second part of the present study the suitability of MBE grown III-V semiconductor structures for molecular electronics applications is examined. In doing so, a method to fabricate nanometer separated, coplanar, metallic electrodes based on the cleavage of a supporting AlGaAs-GaAs heterostructure is presented. This is followed by a

  17. III - V semiconductor structures for biosensor and molecular electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Luber, S.M.

    2007-01-15

    The present work reports on the employment of III-V semiconductor structures to biosensor and molecular electronics applications. In the first part a sensor based on a surface-near two dimensional electron gas for a use in biological environment is studied. Such a two dimensional electron gas inherently forms in a molecular beam epitaxy (MBE) grown, doped aluminum gallium arsenide - gallium arsenide (AlGaAs-GaAs) heterostructure. Due to the intrinsic instability of GaAs in aqueous solutions the device is passivated by deposition of a monolayer of 4'-substituted mercaptobiphenyl molecules. The influence of these molecules which bind to the GaAs via a sulfur group is investigated by Kelvin probe measurements in air. They reveal a dependence of GaAs electron affinity on the intrinsic molecular dipole moment of the mercaptobiphenyls. Furthermore, transient surface photovoltage measurements are presented which demonstrate an additional influence of mercaptobiphenyl chemisorption on surface carrier recombination rates. As a next step, the influence of pH-value and salt concentration upon the sensor device is discussed based on the results obtained from sensor conductance measurements in physiological solutions. A dependence of the device surface potential on both parameters due to surface charging is deduced. Model calculations applying Poisson-Boltzmann theory reveal as possible surface charging mechanisms either the adsorption of OH- ions on the surface, or the dissociation of OH groups in surface oxides. A comparison between simulation settings and physical device properties indicate the OH- adsorption as the most probable mechanism. In the second part of the present study the suitability of MBE grown III-V semiconductor structures for molecular electronics applications is examined. In doing so, a method to fabricate nanometer separated, coplanar, metallic electrodes based on the cleavage of a supporting AlGaAs-GaAs heterostructure is presented. This is followed

  18. Wide bandgap collector III-V double heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Flitcroft, R.M.

    2000-10-01

    This thesis is devoted to the study and development of Heterojunction Bipolar Transistors (HBTs) designed for high voltage operation. The work concentrates on the use of wide bandgap III-V semiconductor materials as the collector material and their associated properties influencing breakdown, such as impact ionisation coefficients. The work deals with issues related to incorporating a wide bandgap collector into double heterojunction structures such as conduction band discontinuities at the base-collector junction and results are presented which detail, a number of methods designed to eliminate the effects of such discontinuities. In particular the use of AlGaAs as the base material has been successful in eliminating the conduction band spike at this interface. A method of electrically injecting electrons into the collector has been employed to investigate impact ionisation in GaAs, GaInP and AlInP which has used the intrinsic gain of the devices to extract impact ionisation coefficients over a range of electric fields beyond the scope of conventional optical injection techniques. This data has enabled the study of ''dead space'' effects in HBT collectors and have been used to develop an analytical model of impact ionisation which has been incorporated into an existing Ebers-Moll HBT simulator. This simulator has been shown to accurately reproduce current-voltage characteristics in both the devices used in this work and for external clients. (author)

  19. Ultrabroadband Hybrid III-V/SOI Grating Reflector for On-chip Lasers

    DEFF Research Database (Denmark)

    Park, Gyeong Cheol; Taghizadeh, Alireza; Chung, Il-Sug

    2016-01-01

    We report on a new type of III-V/SOI grating reflector with a broad stopband of 350 nm. This reflector has promising prospects for applications in high-speed III-V/SOI vertical cavity lasers with an improved heat dissipation capability.......We report on a new type of III-V/SOI grating reflector with a broad stopband of 350 nm. This reflector has promising prospects for applications in high-speed III-V/SOI vertical cavity lasers with an improved heat dissipation capability....

  20. Helical CT of ureteral disease

    International Nuclear Information System (INIS)

    Cikman, Pablo; Bengio, Ruben; Bulacio, Javier; Zirulnik, Esteban; Garimaldi, Jorge

    2000-01-01

    Among the new applications of helical CT is the study of the ureteral pathology. The objective of this paper was to evaluate patients with suspected pathology of this organ and the repercussion in the therapeutic plans. We studied 23 patients with a helical CT protocol, without IV contrast injection and performed multiplanar reconstruction (MPR). We called this procedure Pielo CT. Thirteen ureteral stones were detected, 6 calculi, 2 urinary tract tumors, dilatation of the system in a patient with neo-bladder. In 2 patients, in whom ureteral pathology was ruled out, we found other alterations that explained the symptoms, (gallbladder stones, disk protrusion). The Pielo CT let decide a therapeutical approach in 20 or 21 patients with ureteral pathology. (author)

  1. Heterogeneous Silicon III-V Mode-Locked Lasers

    Science.gov (United States)

    Davenport, Michael Loehrlein

    Mode-locked lasers are useful for a variety of applications, such as sensing, telecommunication, and surgical instruments. This work focuses on integrated-circuit mode-locked lasers: those that combine multiple optical and electronic functions and are manufactured together on a single chip. While this allows production at high volume and lower cost, the true potential of integration is to open applications for mode-locked laser diodes where solid state lasers cannot fit, either due to size and power consumption constraints, or where small optical or electrical paths are needed for high bandwidth. Unfortunately, most high power and highly stable mode-locked laser diode demonstrations in scientific literature are based on the Fabry-Perot resonator design, with cleaved mirrors, and are unsuitable for use in integrated circuits because of the difficulty of producing integrated Fabry-Perot cavities. We use silicon photonics and heterogeneous integration with III-V gain material to produce the most powerful and lowest noise fully integrated mode-locked laser diode in the 20 GHz frequency range. If low noise and high peak power are required, it is arguably the best performing fully integrated mode-locked laser ever demonstrated. We present the design methodology and experimental pathway to realize a fully integrated mode-locked laser diode. The construction of the device, beginning with the selection of an integration platform, and proceeding through the fabrication process to final optimization, is presented in detail. The dependence of mode-locked laser performance on a wide variety of design parameters is presented. Applications for integrated circuit mode-locked lasers are also discussed, as well as proposed methods for using integration to improve mode-locking performance to beyond the current state of the art.

  2. Mixing of III-V compound semiconductor superlattices

    International Nuclear Information System (INIS)

    Mei, Ping.

    1989-01-01

    In this work, the methods as well as mechanisms of III-V compound superlattice mixing are discussed, with particular attention on the AlGaAs based superlattice system. Comparative studies of ion-induced mixing showed two distinct effects resulting from ion implantation followed by a thermal anneal; i.e. collisional mixing and impurity induced mixing. It was found that Ga and As ion induced mixing are mainly due to the collisional effect, where the extent of the mixing can be estimated theoretically, with the parameters of ion mass, incident energy and the implant dose. The impurity effect was dominant for Si, Ge, Be, Zn and Te. Quantitative studies of impurity induced mixing have been conducted on samples doped with Si or Te during the growth process. It was discovered that Si induced AlGaAs superlattice mixing yielded an activation energy of approximately 4 eV for the Al diffusion coefficient with a high power law dependence of the prefactor on the Si concentration. In the Te doped AlGaAs superlattice the Al diffusion coefficient exhibited an activation energy of ∼3.0 eV, with a prefactor approximately proportional to the Te concentration. These results are of importance in examining the current diffusion models. Zn and Si induced InP/InGaAs superlattice mixing are examined. It was found that Zn predominantly induces cation interdiffusion, while Si induces comparable cation and anion interdiffusion. In addition, widely dispersed Zn rich islands form with Zn residing in the InP layers in the form of Zn 3 P 2 . With unstrained starting material, the layer bandgap disparity increases due to mixing induced strain, while in the Si diffused sample the mixed region would be expected to exhibit bandgaps intermediate between those of the original layers. Semiconductor superlattice mixing shows technological potential for optoelectronic device fabrication

  3. Relationship between type III-V radio and hard X-ray bursts

    International Nuclear Information System (INIS)

    Stewart, R.T.

    1978-01-01

    Type III-V radio bursts are found to be closely associated with impulsive hard X-ray bursts. Probably 0.1% to 1% of the fast electrons in the X-ray source region escape to heights >0.1 solar radii in the corona and excite the type III-V burst. (Auth.)

  4. Analysis of novel silicon and III-V solar cells by simulation and experiment; Analyse neuartiger Silizium- und III-V-Solarzellen mittels Simulation und Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hermle, Martin

    2008-11-27

    This work presents various simulation studies of silicon and III-V solar cells. For standard silicon solar cells, one of the critical parameters to obtain good performance, is the rear side recombination velocity. The optical and electrical differences of the different cell structures were determined. The optical differences and the effective recombination velocity Sback of the different rear side structures for 1 Ohmcm material were extracted. Beside standard silicon solar cells, back junction silicon solar cells were investigated. Especially the influence of the front surface field and the electrical shading due to the rear side, was investigated. In the last two chapters, III-V solar cells were analysed. For the simulation of III-V multi-junction solar cells, the simulation of the tunneldiode is the basic prerequisite. In this work, the numerical calibration of an GaAs tunneldiode was achieved by using an non-local tunnel model. Using this model, it was possible to successfully simulate a III-V tandem solar cell. The last chapter deals with an optimization of the III-V 3-junction cell for space applications. Especially the influence of the GaAs middle cell was investigated. Due to structural changes, the end-of-life efficiency was drastically increased.

  5. Growth and characterization of manganese doped III-V heterostructures; Herstellung und Charakterisierung von Mangan dotierten III-V Halbleiterheterostrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Wurstbauer, Ursula

    2008-04-15

    Subject of this thesis is the growth of III-V heterostructures doped with manganese by means of molecular beam epitaxy (MBE). The characterization was done primarily by magnetotransport measurements in the temperature range from 300 K to 20 mK and fields up to 19 T. Two different kind of Mn doped materials, ferromagnetic GaMnAs layers and Mn modulation doped magnetic two dimensional hole systems were studied. The first part focuses on the enhancement of the electric and magnetic properties of ferromagnetic properties and the integration of GaMnAs layers in more sophisticated heterostructures. Therefore, the crystal quality and the influence of the buffer layer beneath the magnetic layer are crucial. The MBE-growth of ferromagnetic GaMnAs layers on (001), (311)A and (311)A was successfully achieved with present values of the Curie-temperature (TC). Additionally, the growth of ferromagnetic GaMnAs layers on nonpolar (110) substrates and on cleaved [110] edges was established. An application of the latter was the investigation of magnetic bipolar junctions. Magnetic two dimensional hole gases (M2DHG) has been realized by the use of In0.75Al0.25As/In0.75Ga0.25As/InAs quantum well (QW) structures. It is necessary to grow a buffer layer for strain relaxation due to the lattice mismatch by gradually increasing the In mole fraction. Magnetotransport measurements were carried out on Si doped two-dimensional electron gases (2DEG) and on Mn doped M2DHGs. From magnetotransport measurements on the M2DHGs we see some interesting features, in particular in the mK region. From the 2DEGs and all non inverted doped M2DEGs weak localization and weak antilocalization effects can be observed in the low field region. Whereas all M2DHGs with an inverted doping layer show strong localization effects and a metal insulator transition dependent on the applied magnetic field perpendicular to the QW. In the high field region Shubnikov-de-Haas oscillations in the longitudinal resistance and

  6. 21 CFR 876.4620 - Ureteral stent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ureteral stent. 876.4620 Section 876.4620 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4620 Ureteral stent. (a) Identification. A ureteral stent...

  7. Methods for enhancing P-type doping in III-V semiconductor films

    Science.gov (United States)

    Liu, Feng; Stringfellow, Gerald; Zhu, Junyi

    2017-08-01

    Methods of doping a semiconductor film are provided. The methods comprise epitaxially growing the III-V semiconductor film in the presence of a dopant, a surfactant capable of acting as an electron reservoir, and hydrogen, under conditions that promote the formation of a III-V semiconductor film doped with the p-type dopant. In some embodiments of the methods, the epitaxial growth of the doped III-V semiconductor film is initiated at a first hydrogen partial pressure which is increased to a second hydrogen partial pressure during the epitaxial growth process.

  8. Radionuclide imaging of ureteric peristalsis

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, C.A.; Coptcoat, M.J.; Carter, S.StC.; Hilson, A.W.J.; Wickham, J.E.A.; Shah, P.J.F. (Inst. of Urology and St. Peter' s Hospitals, London (UK))

    1989-02-01

    Dynamic renal scintigraphy is a successful and minimally invasive technique for evaluating renal function. An extension to the basic technique involving fast-frame acquisition and a modified analysis is described which enables ureteric function to be examined. Ureteric peristalsis was assessed in 32 patients using this technique. The results from 5 representative studies are described in detail. Normally functioning ureters exhibit peristaltic contractions at a frequency of up to 3/min. Hyperperistalsis that exceeds 4 contractions/min is associated with obstruction. Peristaltic behaviour in 9 patients examined before and after ESWL was not altered. (author).

  9. Radionuclide imaging of ureteric peristalsis

    International Nuclear Information System (INIS)

    Lewis, C.A.; Coptcoat, M.J.; Carter, S.StC.; Hilson, A.W.J.; Wickham, J.E.A.; Shah, P.J.F.

    1989-01-01

    Dynamic renal scintigraphy is a successful and minimally invasive technique for evaluating renal function. An extension to the basic technique involving fast-frame acquisition and a modified analysis is described which enables ureteric function to be examined. Ureteric peristalsis was assessed in 32 patients using this technique. The results from 5 representative studies are described in detail. Normally functioning ureters exhibit peristaltic contractions at a frequency of up to 3/min. Hyperperistalsis that exceeds 4 contractions/min is associated with obstruction. Peristaltic behaviour in 9 patients examined before and after ESWL was not altered. (author)

  10. Medidas para la normalización del duelo y el abordaje del duelo complicado en cuidadores de pacientes paliativos

    OpenAIRE

    Verdú Rico, Elena Soledad

    2017-01-01

    Introducción: El duelo es un proceso doloroso que ocurre tras la pérdida de una persona, y normalmente presenta una evolución favorable. No obstante, un 10-20% de las personas que han estado cuidando a enfermos paliativos, presentan una constelación de síntomas por un periodo de tiempo prolongado que se define como duelo complicado. Este dolor puede obstaculizar la capacidad de los cuidadores para seguir con su vida, por la cual cosa los profesionales de cuidados paliativos tienen como funció...

  11. The coupling of thermochemistry and phase diagrams for group III-V semiconductor systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.J.

    1998-07-21

    The project was directed at linking the thermochemical properties of III-V compound semiconductors systems with the reported phase diagrams. The solid-liquid phase equilibrium problem was formulated and three approaches to calculating the reduced standard state chemical potential were identified and values were calculated. In addition, thermochemical values for critical properties were measured using solid state electrochemical techniques. These values, along with the standard state chemical potentials and other available thermochemical and phase diagram data, were combined with a critical assessment of selected III-V systems. This work was culminated with a comprehensive assessment of all the III-V binary systems. A novel aspect of the experimental part of this project was the demonstration of the use of a liquid encapsulate to measure component activities by a solid state emf technique in liquid III-V systems that exhibit high vapor pressures at the measurement temperature.

  12. Interpreting Interfacial Structure in Cross-Sectional STM Images of III-V Semiconductor Heterostructures

    National Research Council Canada - National Science Library

    Nosho, B. Z; Barvosa-Carter, W; Yang, M. J; Bennett, B. R; Whitman, L. J

    2000-01-01

    ...) can be used for the study of III-V heterostructure interfaces. The interpretation of interfacial structure in XSTM images is impeded by the fact that only every other III or V plane as grown on the (001...

  13. High Efficiency Quantum Dot III-V Multijunction Solar Cell for Space Power, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We are proposing to utilize quantum dots to develop a super high-efficiency multijunction III-V solar cell for space. In metamorphic triple junction space solar...

  14. Structure of metal-rich (001) surfaces of III-V compound semiconductors

    DEFF Research Database (Denmark)

    Kumpf, C.; Smilgies, D.; Landemark, E.

    2001-01-01

    The atomic structure of the group-III-rich surface of III-V semiconductor compounds has been under intense debate for many years, yet none of the models agrees with the experimental data available. Here we present a model for the three-dimensional structure of the (001)-c(8x2) reconstruction on In......(8 x 2) reconstructions of III-V semiconductor surfaces contain the same essential building blocks....

  15. Vertical group III-V nanowires on si, heterostructures, flexible arrays and fabrication

    Science.gov (United States)

    Wang, Deli; Soci, Cesare; Bao, Xinyu; Wei, Wei; Jing, Yi; Sun, Ke

    2015-01-13

    Embodiments of the invention provide a method for direct heteroepitaxial growth of vertical III-V semiconductor nanowires on a silicon substrate. The silicon substrate is etched to substantially completely remove native oxide. It is promptly placed in a reaction chamber. The substrate is heated and maintained at a growth temperature. Group III-V precursors are flowed for a growth time. Preferred embodiment vertical Group III-V nanowires on silicon have a core-shell structure, which provides a radial homojunction or heterojunction. A doped nanowire core is surrounded by a shell with complementary doping. Such can provide high optical absorption due to the long optical path in the axial direction of the vertical nanowires, while reducing considerably the distance over which carriers must diffuse before being collected in the radial direction. Alloy composition can also be varied. Radial and axial homojunctions and heterojunctions can be realized. Embodiments provide for flexible Group III-V nanowire structures. An array of Group III-V nanowire structures is embedded in polymer. A fabrication method forms the vertical nanowires on a substrate, e.g., a silicon substrate. Preferably, the nanowires are formed by the preferred methods for fabrication of Group III-V nanowires on silicon. Devices can be formed with core/shell and core/multi-shell nanowires and the devices are released from the substrate upon which the nanowires were formed to create a flexible structure that includes an array of vertical nanowires embedded in polymer.

  16. Tratamiento magnético de los traumatismos no complicados: Reportes preliminares Magnetic treatment of noncomplicated traumatisms: Preliminary reports

    Directory of Open Access Journals (Sweden)

    René F Espinosa Álvarez

    2007-12-01

    Full Text Available Se conoce que los traumatismos no complicados son frecuentes a cualquier edad, y es predominante el autotratamiento por parte de los pacientes afectados de aplicarse el hielo envuelto en un tejido. A tal efecto, se escogió desde Enero de 2000 hasta Diciembre de 2005 aquellos pacientes, sin importar la edad y sexo, que presentaron traumatismos no complicados de acuerdo con la región anatómica afectada, y seguir su evolución por espacio de 10 días, para compararlos usando la magnetoterapia versus la terapéutica convencional de baja temperatura (hielo. Se demostró que el tiempo de curación fue más rápido con la aplicación de la magnetoterapia.It is known that noncomplicated traumatisms are frequent at any age, and that it is common that the patients affected treat themselves with a piece of ice wrapped in a cloth. To this end, those patients regardless their age and sex that presented noncomplicated traumatisms according to the affected anatomical region were selected to follow their evolution for 10 days, and to compare them by using magneto therapy versus the low temperature conventional therapy (ice. It was proved that the healing time was faster with the application of magneto therapy.

  17. III-V-on-silicon solar cells reaching 33% photoconversion efficiency in two-terminal configuration

    Science.gov (United States)

    Cariou, Romain; Benick, Jan; Feldmann, Frank; Höhn, Oliver; Hauser, Hubert; Beutel, Paul; Razek, Nasser; Wimplinger, Markus; Bläsi, Benedikt; Lackner, David; Hermle, Martin; Siefer, Gerald; Glunz, Stefan W.; Bett, Andreas W.; Dimroth, Frank

    2018-04-01

    Silicon dominates the photovoltaic industry but the conversion efficiency of silicon single-junction solar cells is intrinsically constrained to 29.4%, and practically limited to around 27%. It is possible to overcome this limit by combining silicon with high-bandgap materials, such as III-V semiconductors, in a multi-junction device. Significant challenges associated with this material combination have hindered the development of highly efficient III-V/Si solar cells. Here, we demonstrate a III-V/Si cell reaching similar performances to standard III-V/Ge triple-junction solar cells. This device is fabricated using wafer bonding to permanently join a GaInP/GaAs top cell with a silicon bottom cell. The key issues of III-V/Si interface recombination and silicon's weak absorption are addressed using poly-silicon/SiOx passivating contacts and a novel rear-side diffraction grating for the silicon bottom cell. With these combined features, we demonstrate a two-terminal GaInP/GaAs//Si solar cell reaching a 1-sun AM1.5G conversion efficiency of 33.3%.

  18. Balloon dilatation of ureteric strictures.

    Directory of Open Access Journals (Sweden)

    Punekar S

    2000-01-01

    Full Text Available AIMS: Evaluation of dilatation as a minimally invasive technique for the treatment of ureteric strictures. MATERIAL AND METHODS: We evaluated this technique in 16 patients with ureteric and secondary pelviureteric junction strictures from June 1998. Of these, 7 were men and 9 were women. The age range was from 14 to 40 years. RESULTS: Balloon dilatation was successful in 69% of patients. Strictures secondary to previous surgery had nearly 100% success. Of the 8 cases diagnosed as genitourinary tuberculosis, success rate was 50%. CONCLUSIONS: Factors affecting success of balloon dilatation are: a age of the stricture b length of the stricture and c etiology of the stricture. In a select group of patients with fresh post-operative or post-inflammatory strictures, balloon dilatation may be an attractive alternative to surgery.

  19. Analysis of ureteral length in adult cadavers

    Directory of Open Access Journals (Sweden)

    Hugo F. F. Novaes

    2013-04-01

    Full Text Available Introduction In some occasions, correlations between human structures can help planning surgical intra-abdominal interventions. The previous determination of ureteral length helps pre-operatory planning of surgeries, reduces costs of auxiliary exams, the correct choice of double-J catheter with low morbidity and fewer symptoms, and an adequate adhesion to treatment. Objective To evaluate ureteral length in adult cadavers and to analyze its correlation with anthropometric measures. Materials and Methods: From April 2009 to January 2012 we determined ureteral length of adult cadavers submitted to necropsy and obtained the following measures: height, distance from shoulder to wrist, elbow-wrist, xiphoid appendix-umbilicus, umbilicus-pubis, xiphoid appendix-pubis and between iliac spines. We analyzed the correlations between ureteral length and those anthropometric measures. Results We dissected 115 ureters from 115 adult corpses from April 2009 to January 2012. Median ureteral length didn't vary between sexes or according to height. It was observed no correlation among ureteral length and all considered anthropometric measures in all analyzed subgroups and in general population. There were no significant differences between right and left ureteral measures. Conclusions There is no difference of ureteral length in relation to height or gender (male or female. There is no significant correlation among ureteral length and the considered anthropometric measures.

  20. Ureteric diverticulum: A diagnostic challenge

    Directory of Open Access Journals (Sweden)

    Rahul Kumar Gupta

    2017-11-01

    Full Text Available Ureteric diverticulum is a rare urological condition with only 47 cases described in the literature till 2013. A full term female infant presented with a huge cystic lump occupying almost the entire right side of the abdomen at 1 month of age. Ultrasonography and Magnetic Resonance Urography (MRU revealed right sided gross hydronephrosis with pelvis appeared folded onto itself along with left sided mild hydronephrosis. On EC scan, differential function of right sided kidney was 0.9%. With working diagnosis of right sided giant hydronephrosis secondary to pelviureteric junction obstruction, the child was posted for Anderson - Hynes pyeloplasty through right flank incision. On exploration we were surprised to find ureteric diverticula. Excision of ureteric diverticulum with proximal ureterostomy was done. Distal part of ureter was transfixed. Histopathological examination of diverticulum showed presence of fibromuscular wall suggestive of true diverticulum. Since ureterostomy was draining only few drops of clear fluid and on repeat EC scan there was no improvement in function of right kidney, right nephroureterectomy was done after 6 months.

  1. Comparison of Pneumatic and Laser Lithotripsy in the Endoscopic Treatment of Upper Ureteral Stones

    Directory of Open Access Journals (Sweden)

    Ozer Guzel

    2016-04-01

    Full Text Available Aim: We aimed to compare the success rate of the use of a pneumatic and a holmium laser lithotripter for endoscopic treatment of upper ureteral calculi with semirigid uretero-renoscopy (URS. Material and Method: A total of 74 patients were included in this study. The patients were divided into two groups; a ballistic lithotripter was used for group 1 containing 33 and a Holmium-YAG laser lithotripter for the remaining 41 patients in group 2. Both groups were compared in terms of stone size the duration of the operation, postoperative hospitalization time, stone-free rate and complications. Results: The mean age of the patients was 47.6. The mean stone size in groups 1 and 2 were 16.4mm and 11.0mm, respectively (p=0.043. The mean stone-free rate groups 1 and 2 were 78.7% and 80.5% respectively at the approximately 1 month follow-up (p=0.391. In group 1 two patients and in group 2 two patients had a minor complication (ClavienI-II. In group 1 three patients had major complications due to ureteral perforation (Clavien 3a and 3b. No major complications (Clavien III-V occurred in Group 2. Discussion: Based on these findings laser lithotripsy can be regarded as safer. If laser lithotripter is available in medical centers, we argue that it should be the first choice for the treatment of upper ureteral stones.

  2. Transferable tight-binding model for strained group IV and III-V materials and heterostructures

    Science.gov (United States)

    Tan, Yaohua; Povolotskyi, Michael; Kubis, Tillmann; Boykin, Timothy B.; Klimeck, Gerhard

    2016-07-01

    It is critical to capture the effect due to strain and material interface for device level transistor modeling. We introduce a transferable s p3d5s* tight-binding model with nearest-neighbor interactions for arbitrarily strained group IV and III-V materials. The tight-binding model is parametrized with respect to hybrid functional (HSE06) calculations for varieties of strained systems. The tight-binding calculations of ultrasmall superlattices formed by group IV and group III-V materials show good agreement with the corresponding HSE06 calculations. The application of the tight-binding model to superlattices demonstrates that the transferable tight-binding model with nearest-neighbor interactions can be obtained for group IV and III-V materials.

  3. III-V/Si wafer bonding using transparent, conductive oxide interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Tamboli, Adele C., E-mail: Adele.Tamboli@nrel.gov; Hest, Maikel F. A. M. van; Steiner, Myles A.; Essig, Stephanie; Norman, Andrew G.; Bosco, Nick; Stradins, Paul [National Center for Photovoltaics, National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401 (United States); Perl, Emmett E. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106-9560 (United States)

    2015-06-29

    We present a method for low temperature plasma-activated direct wafer bonding of III-V materials to Si using a transparent, conductive indium zinc oxide interlayer. The transparent, conductive oxide (TCO) layer provides excellent optical transmission as well as electrical conduction, suggesting suitability for Si/III-V hybrid devices including Si-based tandem solar cells. For bonding temperatures ranging from 100 °C to 350 °C, Ohmic behavior is observed in the sample stacks, with specific contact resistivity below 1 Ω cm{sup 2} for samples bonded at 200 °C. Optical absorption measurements show minimal parasitic light absorption, which is limited by the III-V interlayers necessary for Ohmic contact formation to TCOs. These results are promising for Ga{sub 0.5}In{sub 0.5}P/Si tandem solar cells operating at 1 sun or low concentration conditions.

  4. Perfiles clínicos del paludismo no complicado por Plasmodium falciparum en Córdoba, Colombia

    Directory of Open Access Journals (Sweden)

    Angélica Knudson

    2007-12-01

    Conclusiones. Existe una alta frecuencia (93,3% de fallas a la cloroquina como tratamiento para el paludismo no complicado por P. falciparum en esta región. Las agrupaciones hechas con el análisis por correspondencias múltiples mostraron similitudes con las descripciones clásicas encontradas en la literatura sobre las formas de presentación clínica de la malaria no complicada. La baja frecuencia de individuos con respuesta clínica adecuada impidió el análisis de asociación. El análisis multivariado involucra variables relacionadas con aspectos epidemiológicos y clínicos y permite una interpretación más integral de los hallazgos obtenidos.

  5. Integration, gap formation, and sharpening of III-V heterostructure nanowires by selective etching

    DEFF Research Database (Denmark)

    Kallesoe, C.; Mølhave, Kristian; Larsen, K. F.

    2010-01-01

    Epitaxial growth of heterostructure nanowires allows for the definition of narrow sections with specific semiconductor composition. The authors demonstrate how postgrowth engineering of III-V heterostructure nanowires using selective etching can form gaps, sharpening of tips, and thin sections...... lithography is used for deposition of catalyst particles on trench sidewalls and the lateral growth of III-V nanowires is achieved from such catalysts. The selectivity of a bromine-based etch on gallium arsenide segments in gallium phosphide nanowires is examined, using a hydrochloride etch to remove the III...

  6. Monte-Carlo simulation of crystallographical pore growth in III-V-semiconductors

    International Nuclear Information System (INIS)

    Leisner, Malte; Carstensen, Juergen; Foell, Helmut

    2011-01-01

    The growth of crystallographical pores in III-V-semiconductors can be understood in the framework of a simple model, which is based on the assumption that the branching of pores is proportional to the current density at the pore tips. The stochastic nature of this model allows its implementation into a three-dimensional Monte-Carlo-simulation of pore growth. The simulation is able to reproduce the experimentally observed crysto pore structures in III-V-semiconductors in full quantitative detail. The different branching probabilities for different semiconductors, as well as doping levels, can be deduced from the specific passivation behavior of the semiconductor-electrolyte-interface at the pore tips.

  7. Antegrade balloon dilatation and ureteral stenting for the benign ureteral strictures

    International Nuclear Information System (INIS)

    Kim, Seung Hyup; Park, Jae Hyung; Han, Man Chung

    1994-01-01

    To evaluate the role of antegrade balloon dilatation and ureteral stenting in benign ureteral strictures. Percutaneous antegrade balloon dilatation was attempted in 46 patients with benign ureteral strictures. The underlying causes of the strictures were urinary tract tuberculosis in 20 patients, congenital ureteropelvic junction obstruction in eight, ureteroneocystostomy or ureteroileostomy state in five, postoperative or post-extracorporeal shock wave lithotripsy state for ureteral calculi in eight, ureteral injury during surgery in four, and retroperitoneal fibrosis in one. Antegrade balloon dilatation was performed with initial technical success in 43 patients but the procedure was aborted in the remaining three with urinary tract tuberculosis due to the failure in passing a guidewire through the stenotic lesions. Intravenous urograms obtained 4-76 months after the procedure showed improvements in 76% (13/17) with urinary tract tuberculosis, in 63%(5/8) with congenital ureteropelvic junction obstruction, in 88%(7/8) with strictures associated with ureteral calculi, and in 100%(4/4) with iatrogenic ureteral injury. The results were relatively poor in strictures of the ureteral anastomosis(1/5) and in ureteral strictures associated with retroperitoneal fibrosis (0/1). Antegrade balloon dilatation of the urinary tract combined with ureteral stenting was an effective technique for the management of the benign ureteral strictures

  8. Ureteral sciatic hernia: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Choi, So Young; Han, Hyun Young; Park, Suk Jin; Choe, Hyoung Shim; Kim, Eun Tak [Eulji University Hospital, Daejeon (Korea, Republic of)

    2008-09-15

    A ureteral hernia that occurs through the sciatic foramen is very rare. We present a case of a ureteral sciatic hernia with hydronephrosis. Intravenous urography (IVU) showed the presence of a curved, laterally displaced ureter, and computed tomography (CT) clearly depicted the herniated ureter through the sciatic foramen. The patient was treated transiently with a double J catheter.

  9. Management of ureteric stone in pediatric patients

    Directory of Open Access Journals (Sweden)

    Eugene Minevich

    2010-01-01

    Full Text Available The management of ureteral stones in children is becoming more similar to that in adults. A number of factors must be taken into account when selecting one′s choice of therapy for ureteral stone in children such as the size of the stone, its location, its composition, and urinary tract anatomy. Endoscopic lithotripsy in children has gradually become a major technique for the treatment of ureteral stones. The stone-free rate following urteroscopic lithotripsy for ureteral stones has been reported in as high as 98.5-100%. The safety and efficacy of Holmium:YAG laser lithotripsy make it the intracorporeal lithotriptor of choice. Given its minimally invasive features, extracorporeal shock wave lithotripsy (ESWL has become a primary mode of treatment for the pediatric patients with reno-ureteral stones. Stone-free rates have been reported from 59% to 91% although some patients will require more than one treatment session for stone clearance. It appears that the first-line of therapy in the child with distal and mid-ureteral stones should be ureteroscopic lithotripsy. While ESWL is still widely considered the first-line therapy for proximal ureteral calculi, there is an increasing body of evidence that shows that endoscopic or ESWL are equally safe and efficacious in those clinical scenarios. Familiarity with the full spectrum of endourological techniques facilitates a minimally invasive approach to pediatric ureteral stones.

  10. Emergency management of ureteral stones: Recent advances

    Directory of Open Access Journals (Sweden)

    Luis Osorio

    2008-01-01

    Full Text Available Most ureteral stones can be observed with reasonable expectation of uneventful stone passage. When an active ureteral stone treatment is warranted, the best procedure to choose is dependent on several factors, besides stone size and location, including operators′ experience, patients′ preference, available equipment and related costs. Placement of double-J stent or nephrostomy tube represents the classical procedures performed in a renal colic due to acute ureteral obstruction when the conservative drug therapy does not resolve the symptoms. These maneuvers are usually followed by ureteroscopy or extracorporeal shockwave lithotripsy, which currently represent the mainstay of treatment for ureteral stones. In this review paper a literature search was performed to identify reports dealing with emergency management of renal colic due to ureteral stones. The main aspects related to this debated issue are analyzed and the advantages and disadvantages of each treatment option are carefully discussed.

  11. Emergency management of ureteral stones: Recent advances.

    Science.gov (United States)

    Osorio, Luis; Lima, Estêvão; Autorino, Riccardo; Marcelo, Filinto

    2008-10-01

    Most ureteral stones can be observed with reasonable expectation of uneventful stone passage. When an active ureteral stone treatment is warranted, the best procedure to choose is dependent on several factors, besides stone size and location, including operators' experience, patients' preference, available equipment and related costs. Placement of double-J stent or nephrostomy tube represents the classical procedures performed in a renal colic due to acute ureteral obstruction when the conservative drug therapy does not resolve the symptoms. These maneuvers are usually followed by ureteroscopy or extracorporeal shockwave lithotripsy, which currently represent the mainstay of treatment for ureteral stones. In this review paper a literature search was performed to identify reports dealing with emergency management of renal colic due to ureteral stones. The main aspects related to this debated issue are analyzed and the advantages and disadvantages of each treatment option are carefully discussed.

  12. Photoelectrochemistry of III-V epitaxial layers and nanowires for solar energy conversion

    Science.gov (United States)

    Parameshwaran, Vijay; Enck, Ryan; Chung, Roy; Kelley, Stephen; Sampath, Anand; Reed, Meredith; Xu, Xiaoqing; Clemens, Bruce

    2017-05-01

    III-V materials, which exhibit high absorption coefficients and charge carrier mobility, are ideal templates for solar energy conversion applications. This work describes the photoelectrochemistry research in several IIIV/electrolyte junctions as an enabler for device design for solar chemical reactions. By designing lattice-matched epitaxial growth of InGaP and GaP on GaAs and Si, respectively, extended depletion region electrodes achieve photovoltages which provide an additional boost to the underlying substrate photovoltage. The InGaP/GaAs and GaP/Si electrodes drive hydrogen evolution currents under aqueous conditions. By using nanowires of InN and InP under carefully controlled growth conditions, current and capacitance measurements are obtained to reveal the nature of the nanowire-electrolyte interface and how light is translated into photocurrent for InP and a photovoltage in InN. The materials system is expanded into the III-V nitride semiconductors, in which it is shown that varying the morphology of GaN on silicon yields insights to how the interface and light conversion is modulated as a basis for future designs. Current extensions of this work address growth and tuning of the III-V nitride electrodes with doping and polarization engineering for efficient coupling to solar-driven chemical reactions, and rapid-throughput methods for III-V nanomaterials synthesis in this materials space.

  13. Generic technique to grow III-V semiconductor nanowires in a closed glass vessel

    Directory of Open Access Journals (Sweden)

    Kan Li

    2016-06-01

    Full Text Available Crystalline III-V semiconductor nanowires have great potential in fabrication of nanodevices for applications in nanoelectronics and optoelectronics, and for studies of novel physical phenomena. Sophisticated epitaxy techniques with precisely controlled growth conditions are often used to prepare high quality III-V nanowires. The growth process and cost of these experiments are therefore dedicated and very high. Here, we report a simple but generic method to synthesize III-V nanowires with high crystal quality. The technique employs a closed evacuated tube vessel with a small tube carrier containing a solid source of materials and another small tube carrier containing a growth substrate inside. The growth of nanowires is achieved after heating the closed vessel in a furnace to a preset high temperature and then cooling it down naturally to room temperature. The technique has been employed to grow InAs, GaAs, and GaSb nanowires on Si/SiO2 substrates. The as-grown nanowires are analyzed by SEM, TEM and Raman spectroscopy and the results show that the nanowires are high quality zincblende single crystals. No particular condition needs to be adjusted and controlled in the experiments. This technique provides a convenient way of synthesis of III-V semiconductor nanowires with high material quality for a wide range of applications.

  14. Controlling the emission wavelength in group III-V semiconductor laser diodes

    KAUST Repository

    Ooi, Boon S.

    2016-12-29

    Methods are provided for modifying the emission wavelength of a semiconductor quantum well laser diode, e.g. by blue shifting the emission wavelength. The methods can be applied to a variety of semiconductor quantum well laser diodes, e.g. group III-V semiconductor quantum wells. The group III-V semiconductor can include AlSb, AlAs, Aln, AlP, BN, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, and InP, and group III-V ternary semiconductors alloys such as AlxGai.xAs. The methods can results in a blue shifting of about 20 meV to 350 meV, which can be used for example to make group III-V semiconductor quantum well laser diodes with an emission that is orange or yellow. Methods of making semiconductor quantum well laser diodes and semiconductor quantum well laser diodes made therefrom are also provided.

  15. Predictors of outcome for cats with ureteral obstructions after interventional management using ureteral stents or a subcutaneous ureteral bypass device.

    Science.gov (United States)

    Horowitz, Cara; Berent, Allyson; Weisse, Chick; Langston, Cathy; Bagley, Demetrius

    2013-12-01

    Novel treatment alternatives for feline ureteral obstruction(s) include placement of a double pigtail ureteral stent and a subcutaneous ureteral bypass (SUB) device. This study evaluated parameters for the prediction of hospitalization times, peri-operative survival, renal recovery and long-term survival in cats with benign ureteral obstructions after successful decompression with either a ureteral stent or SUB device. The medical records of 41 cats treated for benign ureteral obstruction(s) were retrospectively reviewed. Preoperative historical, biochemical and imaging parameters, along with intra- and postoperative biochemical parameters and complications were evaluated for predictors of hospitalization length, survival to discharge, 3-, 6- and 9-month post-procedure creatinine, and overall survival time. All patients had successful decompression of their renal pelvis. Hospitalization time was positively associated with presenting creatinine, perioperative complications, post-procedure creatinine and potassium, but was negatively associated with post-procedure sodium. No parameters were associated with survival to discharge. A higher creatinine at discharge was positively associated with a higher creatinine at follow-up. A decreased overall survival was associated with a higher presenting blood urea nitrogen, higher creatinine at hospital discharge and in over-hydrated patients during hospitalization. Cats with International Renal Interest Society stage 1 and 2 kidney disease, versus stage 3 and 4, at 3 months and 6 months post-procedure, lived longer. Cats with ureteral obstruction(s) treated with a ureteral stent or SUB device had an overall good survival and no admitting parameter was associated with survival to discharge. No single parameter was associated with all outcomes in this study, making predicting patient survival and cost prior to ureteral decompression difficult.

  16. Image-guided ureteral reconstruction using rendezvous technique for complex ureteric transection after gunshot injuries.

    Science.gov (United States)

    Arabi, Mohammad; Mat'hami, Abdulaziz; Said, Mohammad T; Bulbul, Muhammad; Haddad, Maurice; Al-Kutoubi, Aghiad

    2016-01-01

    Management of complex ureteric transection poses a significant clinical challenge, particularly after gunshot injuries due to marked distortion of anatomy and associated tissue loss. We report two cases of total ureteric transection due to gunshot injury successfully repaired using fluoroscopy-guided rendezvous procedure and double J stent placement. This minimally invasive approach may offer a safe and effective technique to repair complete ureteral transection and obviate the need for complex surgical procedures.

  17. Ureteritis cystica: A rare benign lesion

    Directory of Open Access Journals (Sweden)

    F. Ibrahim

    2014-09-01

    Full Text Available Ureteritis cystica is an uncommon benign pathology of the ureter. The etiology is unclear but the diagnosis has become much easier to make with the routine use of ureteroscopy for diagnosis of ureteric lesions. We present a case of a 63 year old Sudanese woman with a history of repeated attacks of right loin pain in whom magnetic resonance urography (MRU showed multiple filling defects in the right ureter. These were initially thought to be malignant urothelial lesions. Ureteroscopy revealed cystic smooth walled masses which discharged tiny turbid fluid on biopsy. An intraoperative diagnosis of ureteritis cystica was confirmed. The patient was managed conservatively.

  18. Cr-doped III-V nitrides: Potential candidates for spintronics

    KAUST Repository

    Amin, Bin

    2011-02-19

    Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

  19. Efficient n-type doping of zinc-blende III-V semiconductor nanowires

    Science.gov (United States)

    Besteiro, Lucas V.; Tortajada, Luis; Souto, J.; Gallego, L. J.; Chelikowsky, James R.; Alemany, M. M. G.

    2014-03-01

    We demonstrate that it is preferable to dope III-V semiconductor nanowires by n-type anion substitution as opposed to cation substitution. Specifically, we show the dopability of zinc-blende nanowires is more efficient when the dopants are placed at the anion site as quantified by formation energies and the stabilization of DX-like defect centers. The comparison with previous work on n - type III-V semiconductor nanocrystals also allows to determine the role of dimensionality and quantum confinement on doping characteristics of materials. Our results are based on first-principles calculations of InP nanowires by using the PARSEC code. Work supported by the Spanish MICINN (FIS2012-33126) and Xunta de Galicia (GPC2013-043) in conjunction with FEDER. JRC acknowledges support from DoE (DE-FG02-06ER46286 and DESC0008877). Computational support was provided in part by CESGA.

  20. III-V/Active-Silicon Integration for Low-Cost High-Performance Concentrator Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Ringel, Steven [The Ohio State Univ., Columbus, OH (United States); Carlin, John A [The Ohio State Univ., Columbus, OH (United States); Grassman, Tyler [The Ohio State Univ., Columbus, OH (United States)

    2018-04-17

    This FPACE project was motivated by the need to establish the foundational pathway to achieve concentrator solar cell efficiencies greater than 50%. At such an efficiency, DOE modeling projected that a III-V CPV module cost of $0.50/W or better could be achieved. Therefore, the goal of this project was to investigate, develop and advance a III-V/Si mulitjunction (MJ) CPV technology that can simultaneously address the primary cost barrier for III-V MJ solar cells while enabling nearly ideal MJ bandgap profiles that can yield efficiencies in excess of 50% under concentrated sunlight. The proposed methodology was based on use of our recently developed GaAsP metamorphic graded buffer as a pathway to integrate unique GaAsP and Ga-rich GaInP middle and top junctions having bandgaps that are adjustable between 1.45 – 1.65 eV and 1.9 – 2.1 eV, respectively, with an underlying, 1.1 eV active Si subcell/substrate. With this design, the Si can be an active component sub-cell due to the semi-transparent nature of the GaAsP buffer with respect to Si as well as a low-cost alternative substrate that is amenable to scaling with existing Si foundry infrastructure, providing a reduction in materials cost and a low cost path to manufacturing at scale. By backside bonding of a SiGe, a path to exceed 50% efficiency is possible. Throughout the course of this effort, an expansive range of new understanding was achieved that has stimulated worldwide efforts in III-V/Si PV R&D that spanned materials development, metamorphic device optimization, and complete III-V/Si monolithic integration. Highlights include the demonstration of the first ideal GaP/Si interfaces grown by industry-standard MOCVD processes, the first high performance metamorphic tunnel junctions designed for III-V/Si integration, record performance of specific metamorphic sub-cell designs, the first fully integrated GaInP/GaAsP/Si double (1.7 eV/1.1 eV) and triple (1.95 eV/1.5 eV/1.1 eV) junction solar cells, the first

  1. Coherent-potential approximation for the lattice vibrations of mixed III-V crystals

    International Nuclear Information System (INIS)

    Kleinert, P.

    1984-01-01

    The coherent-potential approximation (CPA) is applied to the lattice dynamics of some III-V mixed crystals. The calculations are based on an eleven-parameter rigid-ion model (RIM 11). Explicit results are reported for the one-mode system In/sub 1-c/Ga/sub c/P and the two mixed-mode crystals In/sub 1-c/Ga/sub c/Sb and GaSb/sub 1-c/As/sub c/. Both, the reflectivity spectra and the composition dependence of vibrations at the GAMMA and X points are compared with existing experimental data. Force-constant changes are considered by the virtual-crystal approximation (VCA). The CPA theory is uniquely successful for III-V mixed-mode systems, which appear to switch from one-mode to two-mode behaviour. (author)

  2. III-V group compound semiconductor light-emitting element having a doped tantalum barrier layer

    International Nuclear Information System (INIS)

    Oanna, Y.; Ozawa, N.; Yamashita, M.; Yasuda, N.

    1984-01-01

    Disclosed is a III-V Group compound semiconductor light-emitting element having a III-V Group compound semiconductor body with a p-n junction and including a p-type layer involved in forming the p-n junction; and a multi-layer electrode mounted on the p-type layer of the semiconductor body. The electrode comprises a first layer of gold alloy containing a small amount of beryllium or zinc and formed in direct contact with the p-type layer of the semiconductor body and an uppermost layer formed of gold or aluminum. A tantalum layer doped with carbon, nitrogen and/or oxygen is formed between the first layer and the uppermost layer by means of vacuum vapor deposition

  3. David Adler Lectureship Award Talk: III-V Semiconductor Nanowires on Silicon for Future Devices

    Science.gov (United States)

    Riel, Heike

    Bottom-up grown nanowires are very attractive materials for direct integration of III-V semiconductors on silicon thus opening up new possibilities for the design and fabrication of nanoscale devices for electronic, optoelectronic as well as quantum information applications. Template-Assisted Selective Epitaxy (TASE) allows the well-defined and monolithic integration of complex III-V nanostructures and devices on silicon. Achieving atomically abrupt heterointerfaces, high crystal quality and control of dimension down to 1D nanowires enabled the demonstration of FETs and tunnel devices based on In(Ga)As and GaSb. Furthermore, the strong influence of strain on nanowires as well as results on quantum transport studies of InAs nanowires with well-defined geometry will be presented.

  4. Cr-doped III-V nitrides: Potential candidates for spintronics

    KAUST Repository

    Amin, Bin; Arif, Suneela K.; Ahmad, Iftikhar; Maqbool, Muhammad; Ahmad, Roshan; Goumri-Said, Souraya; Prisbrey, Keith A.

    2011-01-01

    Studies of Cr-doped III-V nitrides, dilute magnetic alloys in the zincblende crystal structure, are presented. The objective of the work is to investigate half-metallicity in Al 0.75Cr 0.25N, Ga 0.75Cr 0.25N, and In 0.75Cr 0.25N for their possible application in spin-based electronic devices. The calculated spin-polarized band structures, electronic properties, and magnetic properties of these compounds reveal that Al 0.75Cr 0.25N and Ga 0.75Cr 0.25N are half-metallic dilute magnetic semiconductors while In 0.75Cr 0.25N is metallic in nature. The present theoretical predictions provide evidence that some Cr-doped III-V nitrides can be used in spintronics devices. © 2011 TMS.

  5. Blocking of indium incorporation by antimony in III-V-Sb nanostructures

    International Nuclear Information System (INIS)

    Sanchez, A M; Beltran, A M; Ben, T; Molina, S I; Beanland, R; Gass, M H; De la Pena, F; Walls, M; Taboada, A G; Ripalda, J M

    2010-01-01

    The addition of antimony to III-V nanostructures is expected to give greater freedom in bandgap engineering for device applications. One of the main challenges to overcome is the effect of indium and antimony surface segregation. Using several very high resolution analysis techniques we clearly demonstrate blocking of indium incorporation by antimony. Furthermore, indium incorporation resumes when the antimony concentration drops below a critical level. This leads to major differences between nominal and actual structures.

  6. Low Thermal Budget Fabrication of III-V Quantum Nanostructures on Si Substrates

    International Nuclear Information System (INIS)

    Bietti, S; Somaschini, C; Sanguinetti, S; Koguchi, N; Isella, G; Chrastina, D; Fedorov, A

    2010-01-01

    We show the possibility to integrate high quality III-V quantum nanostructures tunable in shape and emission energy on Si-Ge Virtual Substrate. Strong photoemission is observed, also at room temperature, from two different kind of GaAs quantum nanostructures fabricated on Silicon substrate. Due to the low thermal budget of the procedure used for the fabrication of the active layer, Droplet Epitaxy is to be considered an excellent candidate for implementation of optoelectronic devices on CMOS circuits.

  7. Observation of electron polarization above 80% in photoemission from strained III-V compounds

    International Nuclear Information System (INIS)

    Garwin, E.L.; Maruyama, T.; Prepost, R.; Zapalac, G.H.

    1992-02-01

    Spin-polarized electron photoemission has been investigated for strained III--V compounds; (1) strained In x Ga 1-x As epitaxially grown on a GaAs substrate, and (2) strained GaAs grown on a GaAs 1-x P x buffer layer. The lattice mismatched heterostructure results in a highly strained epitaxial layer, and electron spin polarization as high as 90% has been observed

  8. Transferable tight binding model for strained group IV and III-V heterostructures

    Science.gov (United States)

    Tan, Yaohua; Povolotskyi, Micheal; Kubis, Tillmann; Boykin, Timothy; Klimeck, Gerhard

    Modern semiconductor devices have reached critical device dimensions in the range of several nanometers. For reliable prediction of device performance, it is critical to have a numerical efficient model that are transferable to material interfaces. In this work, we present an empirical tight binding (ETB) model with transferable parameters for strained IV and III-V group semiconductors. The ETB model is numerically highly efficient as it make use of an orthogonal sp3d5s* basis set with nearest neighbor inter-atomic interactions. The ETB parameters are generated from HSE06 hybrid functional calculations. Band structures of strained group IV and III-V materials by ETB model are in good agreement with corresponding HSE06 calculations. Furthermore, the ETB model is applied to strained superlattices which consist of group IV and III-V elements. The ETB model turns out to be transferable to nano-scale hetero-structure. The ETB band structures agree with the corresponding HSE06 results in the whole Brillouin zone. The ETB band gaps of superlattices with common cations or common anions have discrepancies within 0.05eV.

  9. III-V quantum light source and cavity-QED on silicon.

    Science.gov (United States)

    Luxmoore, I J; Toro, R; Del Pozo-Zamudio, O; Wasley, N A; Chekhovich, E A; Sanchez, A M; Beanland, R; Fox, A M; Skolnick, M S; Liu, H Y; Tartakovskii, A I

    2013-01-01

    Non-classical light sources offer a myriad of possibilities in both fundamental science and commercial applications. Single photons are the most robust carriers of quantum information and can be exploited for linear optics quantum information processing. Scale-up requires miniaturisation of the waveguide circuit and multiple single photon sources. Silicon photonics, driven by the incentive of optical interconnects is a highly promising platform for the passive optical components, but integrated light sources are limited by silicon's indirect band-gap. III-V semiconductor quantum-dots, on the other hand, are proven quantum emitters. Here we demonstrate single-photon emission from quantum-dots coupled to photonic crystal nanocavities fabricated from III-V material grown directly on silicon substrates. The high quality of the III-V material and photonic structures is emphasized by observation of the strong-coupling regime. This work opens-up the advantages of silicon photonics to the integration and scale-up of solid-state quantum optical systems.

  10. Ureteral valve masquerading as obstructive megaureter

    Directory of Open Access Journals (Sweden)

    Sushmita Bhatnagar

    2017-05-01

    Full Text Available Primary obstructed megaureter is a common urological condition in the pediatric age group. It is one of the differentials for congenital anomalies of the kidney and urinary tract that include a myriad of structural anomalies of the urinary tract. The obstructive conditions are usually managed conservatively unless there is deterioration in renal function, repeated urinary tract infection, or any other symptom such as abdominal pain on ipsilateral side and hypertension. Presented here is a case of left lower ureteral valve that was diagnosed as primary obstructed megaureter with pain in abdomen and reduced ipsilateral renal function wherein ureteral valve was detected incidentally intraoperatively. Excision of the valve with end to end uretero-ureteral anastomoses over a D-J stent, without resorting to ureteric reimplantation was successful in relieving the obstruction and hydronephrosis

  11. Laparoscopic transperitoneal ureterolithotomy for large ureteric stones

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Sayyad

    2012-01-01

    Conclusion: Laparoscopic transperitoneal ureterolithotomy is a safe and effective approach for selected patients with large proximal ureteric stones with reduced postoperative pain and short hospital stay, and should be considered as a treatment option for such stones.

  12. Evaluation of ureteral lesions in ureterorenoscopy

    DEFF Research Database (Denmark)

    Lildal, Søren Kissow; Andreassen, Kim Hovgaard; Jung, Helene

    2018-01-01

    (PULS) classification system. RESULTS: The use of 10/12 Fr UASs resulted in less severe lesions than reported previously with larger diameter UASs. There was a higher risk of superficial lesions in the UAS group, with a calculated crude odds ratio (OR) of 1.84 [95% confidence interval (CI) 1...... with an endoscope alone, but when adjusting for age and gender the incidence of ureteral lesions was comparable between RIRS with and without the use of a 10/12 Fr UAS.......OBJECTIVE: The aim of this study was to evaluate the incidence of ureteral lesions in retrograde intrarenal surgery (RIRS) with and without the use of a 10/12 Fr ureteral access sheath (UAS). A further objective was to search for preoperative factors that could influence the risk of ureteral damage...

  13. Normal ureteral diameter in infancy and childhood

    International Nuclear Information System (INIS)

    Hellstroem, M.; Hjaelmaas, K.; Jacobsson, B.; Jodal, U.; Oden, A.; Oestra Sjukhuset, Goeteborg; Oestra Sjukhuset, Goeteborg; Goeteborg Univ.

    1985-01-01

    Ureteral diameters were estimated on films from intravenous urography in 194 children (100 boys and 94 girls) aged 0-16 years. Children with signs of urinary tract infection, calculi, obstruction, duplication or malformation were excluded. Films obtained without abdominal compression were used for measurements, including only ureters visualized over 50 per cent of their lengths. A good correlation was demonstrated between ureteral diameter and age and between ureteral diameter and the length of a segment of the lumbar spine. The widest part of the ureter was most often located just above the crossing of the iliac vessels. The right ureter was slightly wider than the left one. No difference between boys and girls was noted. The results are in good agreement with those of others obtained at autopsy. Bearing in mind the possible physiologic variations, it would seem that measuring the ureteral diameter can be of value for a more objective differentiation between dilated and non-dilated ureters. (orig.)

  14. Ureteral Stenting after Uncomplicated Ureteroscopy for Distal Ureteral Stones: A Randomized, Controlled Trial

    Directory of Open Access Journals (Sweden)

    Y. El Harrech

    2014-01-01

    Full Text Available Objectives. We compared outcome and complications after uncomplicated ureteroscopic treatment of distal ureteral calculi with or without the use of ureteral stents. Materials and Methods. 117 patients, prospectively divided into three groups to receive a double j stent (group 1, 42 patients, ureteral stent (group 2, 37 patients, or no stent (group 3, 38 patients, underwent ureteroscopic treatment of distal ureteral calculi. Stone characteristics, operative time, postoperative pain, lower urinary tract symptoms (LUTS, analgesia need, rehospitalization, stone-free rate, and late postoperative complications were all studied. Results. There were no significant differences in preoperative data. There was no significant difference between the three groups regarding hematuria, fever, flank pain, urinary tract infection, and rehospitalisation. At 48 hours and 1 week, frequency/urgency and dysuria were significantly less in the nonstented group. When comparing group 1 and group 3, patients with double j stents had statistically significantly more bladder pain (P=0.003, frequency/urgency (P=0.002, dysuria (P=0.001, and need of analgesics (P=0.001. All patients who underwent imaging postoperatively were without evidence of obstruction or ureteral stricture. Conclusions. Uncomplicated ureteroscopy for distal ureteral calculi without intraoperative ureteral dilation can safely be performed without placement of a ureteral stent.

  15. Implications of the Differential Toxicological Effects of III-V Ionic and Particulate Materials for Hazard Assessment of Semiconductor Slurries.

    Science.gov (United States)

    Jiang, Wen; Lin, Sijie; Chang, Chong Hyun; Ji, Zhaoxia; Sun, Bingbing; Wang, Xiang; Li, Ruibin; Pon, Nanetta; Xia, Tian; Nel, André E

    2015-12-22

    Because of tunable band gaps, high carrier mobility, and low-energy consumption rates, III-V materials are attractive for use in semiconductor wafers. However, these wafers require chemical mechanical planarization (CMP) for polishing, which leads to the generation of large quantities of hazardous waste including particulate and ionic III-V debris. Although the toxic effects of micron-sized III-V materials have been studied in vivo, no comprehensive assessment has been undertaken to elucidate the hazardous effects of submicron particulates and released III-V ionic components. Since III-V materials may contribute disproportionately to the hazard of CMP slurries, we obtained GaP, InP, GaAs, and InAs as micron- (0.2-3 μm) and nanoscale (particles for comparative studies of their cytotoxic potential in macrophage (THP-1) and lung epithelial (BEAS-2B) cell lines. We found that nanosized III-V arsenides, including GaAs and InAs, could induce significantly more cytotoxicity over a 24-72 h observation period. In contrast, GaP and InP particulates of all sizes as well as ionic GaCl3 and InCl3 were substantially less hazardous. The principal mechanism of III-V arsenide nanoparticle toxicity is dissolution and shedding of toxic As(III) and, to a lesser extent, As(V) ions. GaAs dissolves in the cell culture medium as well as in acidifying intracellular compartments, while InAs dissolves (more slowly) inside cells. Chelation of released As by 2,3-dimercapto-1-propanesulfonic acid interfered in GaAs toxicity. Collectively, these results demonstrate that III-V arsenides, GaAs and InAs nanoparticles, contribute in a major way to the toxicity of III-V materials that could appear in slurries. This finding is of importance for considering how to deal with the hazard potential of CMP slurries.

  16. Morphology of interior interfaces in dilute nitride III/V material systems; Morphologie innerer Grenzflaechen in verduennt stickstoffhaltigen III/V-Materialsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Oberhoff, S.

    2007-12-03

    This study aims to clarify structure formation processes in dilute N-containing III/V-based material systems, using highly selective etching methods and subsequent atomic force microscopy (AFM) to expose and analyse interior interfaces. In the first part of this study it was directly proved for the first time that adding Sb during growth interruption inhibits the GI-induced structural phase transition and reduces the diffusivity on GaAs and (GaIn)(NAs) surfaces. However, applying Sb during GI does not affect the driving force of the structural phase transition. Therefore a fundamental analysis about the incorporation of Sb into GaAs, Ga(NAs) and (GaIn)(NAs) was carried out in the second part of the study. Using a combination of high resolution X-ray diffraction, transmission electron microscopy and SIMS measurements, it was verified that incorporating Sb into (GaIn)(NAs) causes an increase of the In content and a decrease of the N content. In the third part of the study, novel etching methods for the GaP-based material system Ga(NAsP) are introduced which provide the opportunity to analyse structure formation processes on interior interfaces in this material system by AFM. (orig.)

  17. Hydrogen-Mediated Nitrogen Clustering in Dilute III-V Nitrides

    Science.gov (United States)

    Du, Mao-Hua; Limpijumnong, Sukit; Zhang, S. B.

    2006-08-01

    First-principles calculation reveals multi-N clusters to be the ground states for hydrogenated N in dilute III-V nitrides. While hydrogenation of a single N, forming H2*(N), can relax the large strain induced by the size-mismatched N, formation of the clusters will relax the strain even more effectively. This suppresses the formation of H2*(N), the existence of which has recently been debated. More importantly, postgrowth dehydrogenation of the N-H clusters provides an explanation to the observed metastable bare N clusters in GaAsN grown by gas-source molecular beam epitaxy or metal-organic chemical vapor deposition.

  18. General theory of the transverse dielectric constant of III-V semiconducting compounds

    Science.gov (United States)

    Kahen, K. B.; Leburton, J. P.

    1985-01-01

    A general model of the transverse dielectric constant of III-V compounds is developed using a hybrid method which combines the kp method with a nonlocal pseudopotential calculation. In this method the Brillouin zone is partitioned into three regions by expanding the energy bands and matrix elements about the F, X, and L symmetry points. The real and imaginary parts of the dielectric constant are calculated as a sum of the individual contributions of each region. By using this partition method, it is possible to get good insight into the dependence of the dielectric constant on the shape of the band structure.

  19. Ultracompact electro-optic phase modulator based on III-V-on-silicon microdisk resonator.

    Science.gov (United States)

    Lloret, J; Kumar, R; Sales, S; Ramos, F; Morthier, G; Mechet, P; Spuesens, T; Van Thourhout, D; Olivier, N; Fédéli, J-M; Capmany, J

    2012-06-15

    A novel ultracompact electro-optic phase modulator based on a single 9 μm-diameter III-V microdisk resonator heterogeneously integrated on and coupled to a nanophotonic waveguide is presented. Modulation is enabled by effective index modification through carrier injection. Proof-of-concept implementation involving binary phase shift keying modulation format is assembled. A power imbalance of ∼0.6  dB between both symbols and a modulation rate up to 1.8 Gbps are demonstrated without using any special driving technique.

  20. On the use of the plasma in III-V semiconductor processing

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, G.; Capezzuto, P.; Losurdo, M. [C.N.R.-Centro di Studio per la Chimica dei Plasmi Dipartimento di Chimica-Universita di Bari via Orabona, 4-70126 Bari (Italy)

    1996-03-01

    The manufacture of usable devices based on III-V semiconductor materials is a complex process requiring epilayer growth, anisotropic etching, defect passivation, surface oxidation and substrate preparation processes. The combination of plasma based methods with metalorganic chemical vapor deposition (MOCVD) offers some real advantages: {ital in} {ital situ} production and preactivation of PH{sub 3} and sample preparation using H-atom. The detailed understanding and use of the plasma (using mass spectrometry, optical emission spectroscopy, laser reflectance interferometry and spectroscopic ellipsometry) as applied to InP material is discussed. {copyright} {ital 1996 American Institute of Physics.}

  1. Study of III-V semiconductor band structure by synchrotron photoemission

    International Nuclear Information System (INIS)

    Williams, G.P.; Cerrina, F.; Anderson, J.; Lapeyre, G.J.; Smith, R.J.; Hermanson, J.; Knapp, J.A.

    1982-01-01

    Angle-resolved synchrotron photoemission studies of six III-V semiconductors have been carried out. For emission normal to the (110) plane of these materials, peaks in the experimental spectra were identified with the bands involved in the transitions, and the critical point energies X 3 , X 5 , and Σ 1 /sup min/, were determined. The data indicate that k perpendicular is conserved in the transitions. Comparison of the data with theoretical bands permits an evaluation of k perpendicular associated with the experimentally observed transition, and from this information the bands were plotted out

  2. Increased renal adrenomedullin expression in rats with ureteral obstruction

    DEFF Research Database (Denmark)

    Nørregaard, Rikke; Bødker, Tina; Jensen, Boye L

    2009-01-01

    Ureteral obstruction is characterized by decreased renal blood flow that is associated with hypoxia within the kidney. Adrenomedullin (AM) is a peptide hormone with tissue-protective capacity that is stimulated through hypoxia. We tested the hypothesis that ureteral obstruction stimulates...... increases in response to ureteral obstruction in agreement with expected oxygen gradients. Hypoxia acting through HIF-1alpha accumulation may be an important pathway for the renal response to ureteral obstruction....

  3. Pulsed laser deposition of II-VI and III-V semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Mele, A.; Di Palma, T.M.; Flamini, C.; Giardini Guidoni, A. [Rome, Univ. `La Sapienza` (Italy). Dep. di Chimica

    1998-12-01

    Pulsed laser irradiation of a solid target involves electronic excitation and heating, followed by expansion from the target of the elliptical gas cloud (plume) which can be eventually condensed on a suitable substrate. Pulsed laser ablation has been found to be a valuable technique to prepare II-VI and III-V thin films of semiconductor materials. Pulsed laser ablation deposition is discussed in the light of the results of an investigation on CdS, CdSe, CdTe and CdSe/CdTe multilayers and AIN, GaN and InN together with Al-Ga-In-N heterostructures. [Italiano] L`irradiazione di un target solido, mediante un fascio laser impulsato, genera una serie di processi che possono essere schematizzati come segue: riscaldamento ed eccitazione elettronica del target, da cui consegue l`espulsione di materiale sotto forma di una nube gassosa di forma ellissoidale (plume), che espande e puo` essere fatta depositare su un opportuno substrato. L`ablazione lasersi e` rivelata una tecnica valida per preparare film sottili di composti di elementi del II-VI e del III-V gruppo della tavola periodica. La deposizione via ablazione laser viene discussa alla luce dei risultati ottenuti nella preparazione di film di CdS, CdSe, CdTe e di film multistrato di CdSe/CdTe, di film di AIN, GaN, InN e di eterostrutture di Al-Ga-In-N.

  4. Mechanical properties of some binary, ternary and quaternary III-V compound semiconductor alloys

    International Nuclear Information System (INIS)

    Navamathavan, R.; Arivuoli, D.; Attolini, G.; Pelosi, C.; Choi, Chi Kyu

    2007-01-01

    Vicker's microindentation tests have been carried out on InP/InP, GaAs/InP, InGaAs/InP and InGaAsP/InP III-V compound semiconductor alloys. The detailed mechanical properties of these binary, ternary and quaternary epilayers were determined from the indentation experiments. Microindentation studies of (1 1 1) GaAs/InP both A and B faces show that the hardness value increases with load and attains a constant for further increase in load and the microhardness values were found to lie between 3.5 and 4.0 GPa. The microhardness values of InGaAs/InP epilayers with different thickness were found to lie between 3.93 and 4.312 GPa. The microhardness values of InGaAsP/InP with different elemental composition were found to lie between 5.08 and 5.73 GPa. The results show that the hardness of the quaternary alloy drastically increases, the reason may be that the increase in As concentration hardens the lattice when phosphorous concentration is less and hardness decreases when phosphorous is increased. It was interestingly observed that the hardness value increases as we proceed from binary to quaternary III-V compound semiconductor alloys

  5. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio

    2015-05-25

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Cycloadditions to Epoxides Catalyzed by GroupIII-V Transition-Metal Complexes

    KAUST Repository

    D'Elia, Valerio; Pelletier, Jeremie; Basset, Jean-Marie

    2015-01-01

    Complexes of groupIII-V transition metals are gaining increasing importance as Lewis acid catalysts for the cycloaddition of dipolarophiles to epoxides. This review examines the latest reports, including homogeneous and heterogeneous applications. The pivotal step for the cycloaddition reactions is the ring opening of the epoxide following activation by the Lewis acid. Two modes of cleavage (C-C versus C-O) have been identified depending primarily on the substitution pattern of the epoxide, with lesser influence observed from the Lewis acid employed. The widely studied cycloaddition of CO2 to epoxides to afford cyclic carbonates (C-O bond cleavage) has been scrutinized in terms of catalytic efficiency and reaction mechanism, showing that unsophisticated complexes of groupIII-V transition metals are excellent molecular catalysts. These metals have been incorporated, as well, in highly performing, recyclable heterogeneous catalysts. Cycloadditions to epoxides with other dipolarophiles (alkynes, imines, indoles) have been conducted with scandium triflate with remarkable performances (C-C bond cleavage). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Dense Plasma Focus-Based Nanofabrication of III-V Semiconductors: Unique Features and Recent Advances.

    Science.gov (United States)

    Mangla, Onkar; Roy, Savita; Ostrikov, Kostya Ken

    2015-12-29

    The hot and dense plasma formed in modified dense plasma focus (DPF) device has been used worldwide for the nanofabrication of several materials. In this paper, we summarize the fabrication of III-V semiconductor nanostructures using the high fluence material ions produced by hot, dense and extremely non-equilibrium plasma generated in a modified DPF device. In addition, we present the recent results on the fabrication of porous nano-gallium arsenide (GaAs). The details of morphological, structural and optical properties of the fabricated nano-GaAs are provided. The effect of rapid thermal annealing on the above properties of porous nano-GaAs is studied. The study reveals that it is possible to tailor the size of pores with annealing temperature. The optical properties of these porous nano-GaAs also confirm the possibility to tailor the pore sizes upon annealing. Possible applications of the fabricated and subsequently annealed porous nano-GaAs in transmission-type photo-cathodes and visible optoelectronic devices are discussed. These results suggest that the modified DPF is an effective tool for nanofabrication of continuous and porous III-V semiconductor nanomaterials. Further opportunities for using the modified DPF device for the fabrication of novel nanostructures are discussed as well.

  8. Growth of Ag-seeded III-V Nanowires and TEM Characterization

    DEFF Research Database (Denmark)

    Lindberg, Anna Helmi Caroline

    appropriate, the density and the vertical yield were obtained. The crystal structures for the grown nanowires have been investigated with TEM.We have also performed additional growths to further understand exactly how the nanowire growth proceeds as well as to understand the limitations of using Ag as a seed......This thesis deals with growth and characterization of GaAs and InAs nanowires. Today Au nanoparticle-seeding together with self-catalyzing are the dominating techniques to grow III-V nanowires with molecular beam epitaxy. In this thesis we instead investigate the possibility to use Ag as seed...... particle for growth of GaAs and InAs nanowires. The aim with the experiments performed has been to conclude whether Ag can be used to nucleate and grow nanowires on III-V substrates with molecular beam epitaxy. To investigate this we have performed growths of GaAs nanowires on GaAs(111)B and GaAs(100...

  9. Final Report: Vapor Transport Deposition for Thin Film III-V Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher, Shannon [Univ. of Oregon, Eugene, OR (United States); Greenaway, Ann [Univ. of Oregon, Eugene, OR (United States); Boucher, Jason [Univ. of Oregon, Eugene, OR (United States); Aloni, Shaul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-02-10

    Silicon, the dominant photovoltaic (PV) technology, is reaching its fundamental performance limits as a single absorber/junction technology. Higher efficiency devices are needed to reduce cost further because the balance of systems account for about two-thirds of the overall cost of the solar electricity. III-V semiconductors such as GaAs are used to make the highest-efficiency photovoltaic devices, but the costs of manufacture are much too high for non-concentrated terrestrial applications. The cost of III-V’s is driven by two factors: (1) metal-organic chemical vapor deposition (MOCVD), the dominant growth technology, employs expensive, toxic and pyrophoric gas-phase precursors, and (2) the growth substrates conventionally required for high-performance devices are monocrystalline III-V wafers. The primary goal of this project was to show that close-spaced vapor transport (CSVT), using water vapor as a transport agent, is a scalable deposition technology for growing low-cost epitaxial III-V photovoltaic devices. The secondary goal was to integrate those devices on Si substrates for high-efficiency tandem applications using interface nanopatterning to address the lattice mismatch. In the first task, we developed a CSVT process that used only safe solid-source powder precursors to grow epitaxial GaAs with controlled n and p doping and mobilities/lifetimes similar to that obtainable via MOCVD. Using photoelectrochemical characterization, we showed that the best material had near unity internal quantum efficiency for carrier collection and minority carrier diffusions lengths in of ~ 8 μm, suitable for PV devices with >25% efficiency. In the second task we developed the first pn junction photovoltaics using CSVT and showed unpassivated structures with open circuit photovoltages > 915 mV and internal quantum efficiencies >0.9. We also characterized morphological and electrical defects and identified routes to reduce those defects. In task three we grew epitaxial

  10. Percutaneous balloon dilatation for transplant ureteral strictures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Chul [Chungnam National University School of Medicine, Taechun (Korea, Republic of); Banner, Marc P [University of Pennsylvania School of Medicine, Philadelphia (United States)

    1993-09-15

    We report 10 kidney allografted patients treated for 11 ureteral strictures with standard endourlogic balloon catheter dilatation and internal stenting between August 1979 and December 1991. They have been followed until 2 to 140 months (mean 42). We compared and analyzed the 6 successful strictures (54%) and 5 unsuccessful strictures. There was no statistically significant difference of demographic, clinical and radiologic interventional techniques between two groups. But there was slightly higher success rate in abruptly narrowed shorter fibrotic strictures in ureteroneocystomy sites than smoothly taped longer ones in other sites of the ureter. Longterm stenting by the transplantation team with cystoscopic removal of internal ureteral stents by urologists resulted in 3 cases of stent occlusion, encrustation or fracture. Exact early diagnosis of ureteral stricture with continued close follow up and proper radiologic interventional procedure with optimal stenting period may increase the success rate and still provide an alternative to surgery.

  11. Structural properties of III-V zinc-blende semiconductors under pressure

    International Nuclear Information System (INIS)

    Froyen, S.; Cohen, M.L.

    1983-01-01

    The pseudopotential method within the local-density approximation is used to investigate the static and structural properties of some III-V compound semiconductors. Comparisons of calculated total energies as a function of volume and structure yield information about solid-solid phase transformations. At high pressures the results indicate that several metallic structures are lower in energy than the zinc-blende structure. From our results the compounds (AlP, AlAs, GaP, and GaAs) can be divided into two classes. In the Ga compounds, we find a pressure-induced phase transformation to either rocksalt, β-Sn, or NiAs, whereas in the Al compounds rocksalt and NiAs are stabilized with respect to β-Sn. All structures except zinc blende are metallic. We discuss the electronic structure of each phase and show how it relates to structural stability

  12. New III-V cell design approaches for very high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; Patkar, M.P.; Young, M.P. (Purdue Univ., Lafayette, IN (United States))

    1993-04-01

    This report describes to examine new solar cell desip approaches for achieving very high conversion efficiencies. The program consists of two elements. The first centers on exploring new thin-film approaches specifically designed for M-III semiconductors. Substantial efficiency gains may be possible by employing light trapping techniques to confine the incident photons, as well as the photons emitted by radiative recombination. The thin-film approach is a promising route for achieving substantial performance improvements in the already high-efficiency, single-junction, III-V cell. The second element of the research involves exploring desip approaches for achieving high conversion efficiencies without requiring extremely high-quality material. This work has applications to multiple-junction cells, for which the selection of a component cell often involves a compromise between optimum band pp and optimum material quality. It could also be a benefit manufacturing environment by making the cell's efficiency less dependent on materialquality.

  13. Hydrogen-mediated Nitrogen Clustering in Dilute III-V Nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Du, M.-H.; Limpijumnong, S.; Zhang, S. B

    2006-01-01

    First-principles calculation reveals multi-N clusters to be the ground states for hydrogenated N in dilute III-V nitrides. While hydrogenation of a single N, forming H*{sub 2}(N), can relax the large strain induced by the size-mismatched N, formation of the clusters will relax the strain even more effectively. This suppresses the formation of H*{sub 2}(N), the existence of which has recently been debated. More importantly, postgrowth dehydrogenation of the N-H clusters provides an explanation to the observed metastable bare N clusters in GaAsN grown by gas-source molecular beam epitaxy or metal-organic chemical vapor deposition.

  14. Acousto-optic modulation of III-V semiconductor multiple quantum wells

    International Nuclear Information System (INIS)

    Smith, D.L.; Kogan, S.M.; Ruden, P.P.; Mailhiot, C.

    1996-01-01

    We present an analysis of the effect of surface acoustic waves (SAW close-quote s) on the optical properties of III-V semiconductor multiple quantum wells (MQW close-quote s). Modulation spectra at the fundamental and second harmonic of the SAW frequency are presented. The SAW modulates the optical properties of the MQW primarily by changing optical transition energies. The SAW generates both strains, which modulate the transition energies by deformation potential effects, and electric fields, which modulate the transition energies by the quantum confined Stark effect. We find that modulation of the transition energies by strain effects is usually more important than by electric-field effects. If large static electric fields occur in the MQW, the SAW-generated electric field can mix with the static field to give optical modulation, which is comparable in magnitude to modulation from the deformation potential effect. If there are no large static electric fields, modulation by the SAW-generated fields is negligible. A large static electric field distributes oscillator strength among the various optical transitions so that no single transition is as strong as the primary allowed transitions without a static electric field. To achieve the maximum modulation for fixed SAW parameters, it is best to modulate a strong optical transition. Thus optimum modulation occurs when there are no large static electric fields present and that modulation is primarily from deformation potential effects. We specifically consider Ga x In 1-x As/Ga x Al 1-x As MQW close-quote s grown on (100) and (111) oriented substrates, but our general conclusions apply to other type I MQW close-quote s fabricated from III-V semiconductors. copyright 1996 The American Physical Society

  15. Optical analysis of a III-V-nanowire-array-on-Si dual junction solar cell.

    Science.gov (United States)

    Chen, Yang; Höhn, Oliver; Tucher, Nico; Pistol, Mats-Erik; Anttu, Nicklas

    2017-08-07

    A tandem solar cell consisting of a III-V nanowire subcell on top of a planar Si subcell is a promising candidate for next generation photovoltaics due to the potential for high efficiency. However, for success with such applications, the geometry of the system must be optimized for absorption of sunlight. Here, we consider this absorption through optics modeling. Similarly, as for a bulk dual-junction tandem system on a silicon bottom cell, a bandgap of approximately 1.7 eV is optimum for the nanowire top cell. First, we consider a simplified system of bare, uncoated III-V nanowires on the silicon substrate and optimize the absorption in the nanowires. We find that an optimum absorption in 2000 nm long nanowires is reached for a dense array of approximately 15 nanowires per square micrometer. However, when we coat such an array with a conformal indium tin oxide (ITO) top contact layer, a substantial absorption loss occurs in the ITO. This ITO could absorb 37% of the low energy photons intended for the silicon subcell. By moving to a design with a 50 nm thick, planarized ITO top layer, we can reduce this ITO absorption to 5%. However, such a planarized design introduces additional reflection losses. We show that these reflection losses can be reduced with a 100 nm thick SiO 2 anti-reflection coating on top of the ITO layer. When we at the same time include a Si 3 N 4 layer with a thickness of 90 nm on the silicon surface between the nanowires, we can reduce the average reflection loss of the silicon cell from 17% to 4%. Finally, we show that different approximate models for the absorption in the silicon substrate can lead to a 15% variation in the estimated photocurrent density in the silicon subcell.

  16. Narrow-linewidth Si/III-V lasers: A study of laser dynamics and nonlinear effects

    Science.gov (United States)

    Vilenchik, Yaakov Yasha

    Narrow-linewidth lasers play an important role in a wide variety of applications, from sensing and spectroscopy to optical communication and on-chip clocks. Current narrow-linewidth systems are usually implemented in doped fibers and are big, expensive, and power-hungry. Semiconductor lasers compete favorably in size, cost, and power consumption, but their linewidth is historically limited to the sub-MHz regime. However, it has been recently demonstrated that a new design paradigm, in which the optical energy is stored away from the active region in a composite high-Q resonator, has the potential to dramatically improve the coherence of the laser. This work explores this design paradigm, as applied on the hybrid Si/III-V platform. It demonstrates a record sub-KHz white-noise-floor linewidth. It further shows, both theoretically and experimentally, that this strategy practically eliminates Henry's linewidth enhancement by positioning a damped relaxation resonance at frequencies as low as 70 MHz, yielding truly quantum limited devices at frequencies of interest. In addition to this empirical contribution, this work explores the limits of performance of this platform. Here, the effect of two-photon-absorption and free-carrier-absorption are analyzed, using modified rate equations and Langevin force approach. The analysis predicts that as the intra-cavity field intensity builds up in the high-Q resonator, non-linear effects cause a new domain of performance-limiting factors. Steady-state behavior, laser dynamics, and frequency noise performance are examined in the context of this unique platform, pointing at the importance of nonlinear effects. This work offers a theoretical model predicting laser performance in light of nonlinear effects, obtaining a good agreement with experimental results from fabricated high-Q Si/III-V lasers. In addition to demonstrating unprecedented semiconductor laser performance, this work establishes a first attempt to predict and demonstrate

  17. [Ureteral realignment with the rendezvous procedure in complex ureteral injuries - aspects of technique and our experience].

    Science.gov (United States)

    Brandt, Alexander Sascha; von Rundstedt, F-C; Lazica, D A; Roth, S

    2010-07-01

    The rendezvous procedure for re-establishing ureteral continuity after complex ureteral injuries is introduced and we present our experience with this technique. Aspects of the technique are described in a detailed step-by-step instruction using intraoperative radiographs. We evaluated our patient data from 1998 until 2009 for cases in which the rendezvous procedure was attempted. The rendezvous procedure was used in a total of 11 patients. Realignment was successful in 10 cases (90.9 %) and the initial nephrostomy could be removed. In 3 of 7 cases postoperative removal of the JJ ureteric stent was successful. In 7 patients the final surgical ureter reconstruction was performed after a medium period of 7 months. 5 cases of ureteroneocystostomy and 2 cases of reconstruction of the ureter either with colon or ileum segments were accomplished. In 1 patient a permanent maintenance of the DJ ureteral stent was necessary. Ureteral realignment with the rendezvous procedure enables disposition of the ureteral stent in many cases, exclusively antegrade or retrograde procedures failed. By this means nephrostomy could be spared as a temporary or permanent solution and a better chance of restitutio ad integrum could be realised. Georg Thieme Verlag KG Stuttgart * New York.

  18. Endoscopic placement of ureteral stents for treatment of congenital bilateral ureteral stenosis in a dog.

    Science.gov (United States)

    Lam, Nathaniel K; Berent, Allyson C; Weisse, Chick W; Bryan, Christine; Mackin, Andrew J; Bagley, Demetrius H

    2012-04-15

    A 5-year-old 8.6-kg (18.9-lb) spayed female Pug was evaluated because of chronic hematuria and recurrent urinary tract infections. Excretory urography, ultrasonography, and excretory CT urography were performed. Results indicated that the dog had bilateral hydronephrosis and hydroureter and suspected proximal ureteral stenosis. Retrograde ureteropyelography confirmed the presence of stenosis at the ureteropelvic junction of each ureter, along with a large amount of endoluminal ureteral debris. Clinical findings suggested that the dog had a congenital bilateral anomaly of the upper urinary tract. The dog was anesthetized, and 2 double-pigtail ureteral stents were placed cystoscopically with fluoroscopic guidance for immediate relief of the ureteropelvic junction obstructions. Each stent extended from the left or right renal pelvis to the urinary bladder. The procedures and the patient's recovery from anesthesia were uncomplicated. Continuing improvements in severity of hydronephrosis, hydroureter, and dysuria were evident during routine follow-up examinations at 2, 4, 12, 16, and 45 weeks after stent placement. Over the subsequent 12 months, all clinical signs remained resolved other than a urinary tract infection that was successfully treated with antimicrobials. Ureteral stenosis should be considered as a differential diagnosis for hydronephrosis in dogs, particularly when urinary tract calculi or neoplasia is not present. Chronic hematuria and recurrent urinary tract infections can be associated with this condition. Placement of ureteral stents may be a successful treatment option for ameliorization of congenital ureteral obstructions.

  19. Relationship Between Ureteral Jet Flow, Visual Analogue Scale, and Ureteral Stone Size.

    Science.gov (United States)

    Ongun, Sakir; Teken, Abdurrazak; Yılmaz, Orkun; Süleyman, Sakir

    2017-06-01

    To contribute to the diagnosis and treatment of ureteral stones by investigating the relationship between the ureteral jet flow measurements of patients with ureteral stones and the size of the stones and the patients' pain scores. The sample consisted of patients who presented acute renal colic between December 2014 and 2015 and from a noncontrast computed tomography were found to have a urinary stone. The ureteral jet flow velocities were determined using Doppler ultrasonography. The patients were all assessed in terms of stone size, localization and area, anteroposterior pelvis (AP) diameter, and visual analogue scale (VAS) scores. A total of 102 patients were included in the study. As the VAS score decreased, the peak jet flow velocity on the stone side increased, whereas the flow velocity on the other side, AP diameter, and stone area were reduced (P flow velocity was reduced and the AP diameter increased significantly (P flow was not observed in 17 patients on the stone side. A statistically significant difference was found between these patients and the remaining patients in terms of all parameters (P flow velocity of ureteral jet is low and with a severe level of pain or the peak flow velocity of ureteral jet cannot be measured, there is a low possibility of spontaneous passage and a high possibility of a large stone, and therefore the treatment should be started immediately. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Transperitoneal laparoscopic ureteric reimplantation for lower ...

    African Journals Online (AJOL)

    V. Singh

    2016-07-21

    Jul 21, 2016 ... in Table 1. All the patients had an initial failed retrograde JJ stent .... we found only a single case of recurrence of the stricture or stenosis in the follow up ... scopic ureteral reconstruction for benign stricture disease. Urology.

  1. BILATERAL SINGLE SESSION URETEROSCOPY FOR URETERAL ...

    African Journals Online (AJOL)

    Objectives: To determine the feasibility, safety and success rate of bilateral single session rigid retrograde ureteroscopy (URS) for bilateral ureteral calculi. Patients and Methods: Thirty-five patients underwent bilateral single session ureteroscopic calculus removal. Results: Out of 70 renal units in 35 patients treated, ...

  2. ureteric perforation following laparoscopic assisted vaginal

    African Journals Online (AJOL)

    2011-03-03

    Mar 3, 2011 ... Ureteric injury is one of the most common complications of hysterectomy, both in open and laparoscopic and is a source of serious morbidity. Laparoscopy carries a higher risk because of increased use of electro-surgery close to the ureter when securing the uterine artery and it is more likely to be ...

  3. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Seth

    2012-09-12

    The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong

  4. Analytical Electron Diffraction from Iii-V and II-Vi Semiconductors

    Science.gov (United States)

    Spellward, Paul

    Available from UMI in association with The British Library. This thesis describes the development and evaluation of a number of new TEM-based techniques for the measurement of composition in ternary III-V and II-VI semiconductors. New methods of polarity determination in binary and ternary compounds are also presented. The theory of high energy electron diffraction is outlined, with particular emphasis on zone axis diffraction from well-defined strings. An account of TEM microstructural studies of Cd_{rm x}Hg _{rm 1-x}Te and CdTe epitaxial layers, which provided the impetus for developing the diffraction-based analytical techniques, is given. The wide range of TEM-based compositional determination techniques is described. The use of HOLZ deficiency lines to infer composition from a lattice parameter measurement is evaluated. In the case of Cd_{ rm x}Hg_{rm 1-x}Te, it is found to be inferior to other techniques developed. Studies of dynamical aspects of HOLZ diffraction can yield information about the dispersion surface from which a measure of composition may be obtained. This technique is evaluated for Al_{rm x}Ga_{rm 1-x} As, in which it is found to be of some use, and for Cd_{rm x}Hg _{rm 1-x}Te, in which the large Debye-Waller factor associated with mercury in discovered to render the method of little value. A number of critical voltages may be measured in medium voltage TEMs. The (111) zone axis critical voltage of Cd_{rm x}Hg _{rm 1-x}Te is found to vary significantly with x and forms the basis of an accurate technique for composition measurement in that ternary compound. Other critical voltage phenomena are investigated. In Al _{rm x}Ga_ {rm 1-x}As and other light ternaries, a non-systematic critical voltage is found to vary with x, providing a good indicator of composition. Critical voltage measurements may be made by conventional CBED or by various other techniques, which may also simultaneously yield information on the spatial variation of composition. The

  5. Metallic ureteral stents in malignant ureteral obstruction: clinical factors predicting stent failure.

    Science.gov (United States)

    Chow, Po-Ming; Hsu, Jui-Shan; Huang, Chao-Yuan; Wang, Shuo-Meng; Lee, Yuan-Ju; Huang, Kuo-How; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liang, Po-Chin

    2014-06-01

    To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure. Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure. A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration. Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.

  6. Positron annihilation studies of defects in molecular beam epitaxy grown III-V layers

    International Nuclear Information System (INIS)

    Umlor, M.T.; Keeble, D.J.; Cooke, P.W.

    1994-01-01

    A summary of recent positron annihilation experiments on molecular beam epitaxy (MBE) grown III-V layers is Presented. Variable energy positron beam measurements on Al 0.32 Ga 0.68 As undoped and Si doped have been completed. Positron trapping at a open volume defect in Al 0.32 Ga 0.68 :Si for temperatures from 300 to 25 K in the dark was observed. The positron trap was lost after 1.3 eV illumination at 25K. These results indicate an open volume defect is associated with the local structure of the deep donor state of the DX center. Stability of MBE GaAs to thermal annealing war, investigated over the temperature range of 230 to 700 degrees C, Proximity wafer furnace anneals in flowing argon were used, Samples grown above 450 degrees C were shown to be stable but for sample below this temperature an anneal induced vacancy related defect was produced for anneals between 400 and 500 degrees C. The nature of the defect was shown to be different for material grown at 350 and 230 degrees C. Activation energies of 2.5 eV to 2.3 eV were obtained from isochronal anneal experiments for samples grown at 350 and 230 degrees C, respectively

  7. III-V semiconductors for photoelectrochemical applications: surface preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Fertig, Dominic; Schaechner, Birgit; Calvet, Wofram; Kaiser, Bernhard; Jaegermann, Wolfram [TU Darmstadt, Fachbereich Materialwissenschaft, Fachgebiet Oberflaechenforschung (Germany)

    2011-07-01

    III-V semiconductors are promising reference systems for photoelectrochemical energy conversion. Therefore we have studied the influence of different acids and acidic solutions on the etching of p-doped gallium-arsenide and gallium-phosphide single crystal surfaces. From our experiments we conclude, that etching with HCl and subsequent annealing up to 450 C gives the best results for the removal of the carbonates and the oxides without affecting the quality of the sample. By treating the surfaces with ''piranha''-solution (H{sub 2}SO{sub 4}:H{sub 2}O{sub 2}:H{sub 2}O/7:2:1), the creation of an oxide layer with well defined thickness can be achieved. For the creation of an efficient photoelectrochemical cell, Pt nanoparticles have been deposited from solution. These surfaces are then characterized by photoelectron spectroscopy and AFM. Further electrochemical measurements try to correlate the effect of the surface cleaning and the Pt deposition on the photoactivity of the GaAs- and GaP-semiconductors.

  8. Spin Relaxation in III-V Semiconductors in various systems: Contribution of Electron-Electron Interaction

    Science.gov (United States)

    Dogan, Fatih; Kesserwan, Hasan; Manchon, Aurelien

    2015-03-01

    In spintronics, most of the phenomena that we are interested happen at very fast time scales and are rich in structure in time domain. Our understanding, on the other hand, is mostly based on energy domain calculations. Many of the theoretical tools use approximations and simplifications that can be perceived as oversimplifications. We compare the structure, material, carrier density and temperature dependence of spin relaxation time in n-doped III-V semiconductors using Elliot-Yafet (EY) and D'yakanov-Perel'(DP) with real time analysis using kinetic spin Bloch equations (KSBE). The EY and DP theories fail to capture details as the system investigated is varied. KSBE, on the other hand, incorporates all relaxation sources as well as electron-electron interaction which modifies the spin relaxation time in a non-linear way. Since el-el interaction is very fast (~ fs) and spin-conserving, it is usually ignored in the analysis of spin relaxation. Our results indicate that electron-electron interaction cannot be neglected and its interplay with the other (spin and momentum) relaxation mechanisms (electron-impurity and electron-phonon scattering) dramatically alters the resulting spin dynamics. We use each interaction explicitly to investigate how, in the presence of others, each relaxation source behaves. We use GaAs and GaN for zinc-blend structure, and GaN and AlN for the wurtzite structure.

  9. FREQUENCY DEFORMITY SCOLIOSIS AND FLAT FEET IN PUPILS III, V.VII GRADE SCHOOL

    Directory of Open Access Journals (Sweden)

    Dejаn Gojković

    2013-07-01

    Full Text Available Scoliosis is a lateral deviation of the spine or the angular deviation of the normal position of one or more segmenata.Funkcional curve can be fully corrected until the internal structural scoliosis are bone disorders, muscle nerve elements that support the spine, and complete correction is impossible. Static role is reflected in the foot taking kisses body weight through the bones pop and transmission and distribution of weight on the main point of support of the foot and therefore subject to various changes in the normal foot status.Dinamic role is reflected in walking, running and jumping in different forms. Because of this, the percentage of foot disorders is particularly large in the form of lowering the testing we arche.Perform o.š.Pale Pale deformities in scoliosis and flat feet in students III, V, VII grade. Our aim was to verify the extent to which physical education classes take appropriate measures in the detection and removal of poor posture and physical deformities. For testing we used: clinical method for scoliosis, a method for flat feet -Thomson method.

  10. Growth, structure and phase transitions of epitaxial nanowires of III-V semiconductors

    International Nuclear Information System (INIS)

    Glas, F; Patriarche, G; Harmand, J C

    2010-01-01

    We review and illustrate the impact of TEM on the study of nanowires of non-nitride III-V semiconductors, with particular emphasis on the understanding of the thermodynamics and kinetics of their formation assisted by nano-sized catalyst particles. Besides providing basic information about the morphology of the nanowires and their growth rate as a function of diameter, TEM offers insights into the peculiar crystalline structure that they adopt. We discuss the formation of the unusual wurtzite hexagonal crystalline phase and that of planar stacking defects in these nanowires and show that they are kinetically controlled. We also demonstrate the transformation of wurtzite into cubic sphalerite upon epitaxial burying of the nanowires. Nanowires are particularly interesting in that they allow the fabrication of precisely positioned quantum dots with well-defined geometries. In this respect, we discuss the formation of strained quantum-size inclusions in nanowires, their critical dimensions and the kinetic and thermodynamic factors governing the changes of the crystalline structure that sometimes occur around a hetero-interface.

  11. Long-range ordering of III-V semiconductor nanostructures by shallowly buried dislocation networks

    International Nuclear Information System (INIS)

    Coelho, J; Patriarche, G; Glas, F; Saint-Girons, G; Sagnes, I

    2004-01-01

    We account for lateral orderings of III-V nanostructures resulting from a GaAs/InAs/InGaAs/GaAs sequence grown on GaAs by metallorganic vapour phase epitaxy at two different temperatures. For both samples, the ordering is induced by the stress field of a periodic dislocation network (DN) shallowly buried and parallel to the surface. This DN is a grain boundary (GB) that forms, between a thin GaAs layer (on which growth was performed) and a GaAs substrate joined together by wafer bonding, in order to accommodate a tilt and a twist between these two crystals; both these misorientations are imposed in a controlled manner. This GB is composed of a one-dimensional network of mixed dislocations and of a one-dimensional network of screw dislocations. For both samples, the nanostructures observed by transmission electron microscopy (TEM) and atomic force microscopy are ordered by the underlying DN observed by TEM since they have same dimensions and orientations as the cells of the DN

  12. Patterns of ureteral motion: Data compression and statistics

    International Nuclear Information System (INIS)

    Mueller-Schauenburg, W.

    1981-01-01

    Images of ureteral peristaltics (ureteral kinetography) have been recorded at Tuebingen University Hospital since 1978. These images give a synoptical picture of ureteral motion in highly compressed form. Possibilities of data compression are discussed on the basis of functional path-time images, the ROI series, the in the path-time matrix, and the background subtraction. Particular attention is paid to problems of urethral activity statistics. (WU) [de

  13. Prevention strategies for ureteral stricture following ureteroscopic lithotripsy

    Directory of Open Access Journals (Sweden)

    Hao Dong

    2018-04-01

    Full Text Available Ureteral stricture formation after ureteroscopic lithotripsy is a late complication that can lead to hydronephrosis and a subsequent risk of renal deterioration. The specific incidence is unknown, and the mechanism of stricture formation has not been completely explained. In this review, we summarize the current evidence regarding the incidence of this condition and discuss its pathogenesis. We then list preventive strategies to reduce the morbidity of ureteral strictures. Keywords: Ureteroscopy, Ureteral stricture, Lithotripsy, Complications

  14. A Case of Polyarteritis Nodosa with Bilateral Ureteral Obstruction

    Science.gov (United States)

    Yoo, Bin; Kim, Hong Kyu; Choi, Seung Won; Moon, Hee Bom

    1996-01-01

    We report a case of bilateral ureteral obstruction most likely caused by polyarteritis nodosa. The diagnosis was based upon muscle biopsy which showed typical necrotizing vasculitis in medium size artery in conjunction with microaneurysms in renal angiography. Ureteral obstruction is a rare manifestation of polyarteritis nodosa. This condition is thought to result from vasculitis of periureteral vessels. The patient was managed with prednisolone alone, which resulted in complete resolution of ureteral obstruction on both sides. PMID:8854655

  15. Ureteric transection secondary to penetrating handlebar injury

    Directory of Open Access Journals (Sweden)

    K.P. Debbink

    2017-08-01

    Full Text Available Ureteric trauma is rare, occurring in <1% of all traumas. We present a unique case of a 13 year old female who sustained a penetrating abdominal injury from a bicycle handlebar. Upon initial examination there was herniation of bowel through the abdominal wound, so exploratory laparotomy was performed. A serosal injury of the colon and bleeding mesenteric veins were encountered; the retroperitoneum was not explored at that time. Postoperative course was remarkable for a doubling of the serum creatinine, increasing abdominal distention and pain. Computed tomography on postoperative day five demonstrated a large amount of intra-abdominal fluid. The patient was taken for re-exploration. The left ureter was found to be completely transected. It was repaired over a double-J stent. This case demonstrates the need for a high index of suspicion in the diagnosis of ureteric injury. Keywords: Ureter, Bicycle, Handlebar, Penetrating

  16. Vesical-ureteral reflux in children

    International Nuclear Information System (INIS)

    Desvignes, V.; Palcoux, J.B.; Cochat, P.

    1995-01-01

    The vesical-ureteral reflux is the most frequent uropathy in children. The diagnosis is made by uretero-cystography, often after pyelonephritis, sometimes after ante-natal diagnosis from echographic abnormalities. Spontaneous recovery is possible in 50 to 80% of cases. This is especially true in grade 1, 2 and 3, however complications may occur. They are more frequent in the case of reflux nephropathy with a resulting risk of hypertension and chronic renal failure. The therapeutic choice is between the conservative management with urinary antiseptics ad the surgical treatment with ureters re-implantation or endoscopic treatment. The therapeutic indications take into account vesical-ureteral reflux grades, the child's age, the associated diseases and the child's and parents' compliance. (authors). 22 refs., 2 figs

  17. Ureteral Metastasis Secondary to Prostate Cancer: A Case Report

    Directory of Open Access Journals (Sweden)

    I. Morales

    2016-03-01

    Full Text Available Prostate cancer is very frequent, but secondary ureteral metastasis are extremely rare. We present a 55 year old man with a 2 month history of right flank pain and lower urinary tract symptoms. Prostatic specific antigen of 11.3 ng/mL. Computed tomography showed right hydroureteronephrosis, a developing urinoma and right iliac adenopathies. He underwent right ureteronephrectomy, iliac lymphadenectomy and prostate biopsy. Pathology revealed prostatic carcinoma infiltrating the ureteral muscularis propria, without mucosal involvement. There are 46 reported cases of prostate cancer with ureteral metastases. Ureteral metastasis are a rare cause of renal colic and need of a high index of suspicion.

  18. Combined antegrade and retrograde ureteral stenting: the rendezvous technique

    International Nuclear Information System (INIS)

    Macri, A.; Magno, C.; Certo, A.; Basile, A.; Scuderi, G.; Crescenti, F.; Famulari, C.

    2005-01-01

    Ureteral stenting is a routine procedure in endourology. To increase the success rate in difficult cases, it may be helpful to use the rendezvous technique, a combined antegrade and retrograde approach. We performed 16 urological rendezvous in 11 patients with ureteral strictures or urologic lesions. The combined approach was successful in all patients, without morbidity or mortality. In our experience the rendezvous technique increased the success rate of antegrade ureteral stenting from 78.6 to 88.09% (p>0.05). This procedure is a valid option in case of failure of conventional ureteral stenting

  19. Band structure effects on resonant tunneling in III-V quantum wells versus two-dimensional vertical heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Philip M., E-mail: philip.campbell@gatech.edu [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Electronic Systems Laboratory, Georgia Tech Research Institute, Atlanta, Georgia 30332 (United States); Tarasov, Alexey; Joiner, Corey A.; Vogel, Eric M. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Ready, W. Jud [Electronic Systems Laboratory, Georgia Tech Research Institute, Atlanta, Georgia 30332 (United States)

    2016-01-14

    Since the invention of the Esaki diode, resonant tunneling devices have been of interest for applications including multi-valued logic and communication systems. These devices are characterized by the presence of negative differential resistance in the current-voltage characteristic, resulting from lateral momentum conservation during the tunneling process. While a large amount of research has focused on III-V material systems, such as the GaAs/AlGaAs system, for resonant tunneling devices, poor device performance and device-to-device variability have limited widespread adoption. Recently, the symmetric field-effect transistor (symFET) was proposed as a resonant tunneling device incorporating symmetric 2-D materials, such as transition metal dichalcogenides (TMDs), separated by an interlayer barrier, such as hexagonal boron-nitride. The achievable peak-to-valley ratio for TMD symFETs has been predicted to be higher than has been observed for III-V resonant tunneling devices. This work examines the effect that band structure differences between III-V devices and TMDs has on device performance. It is shown that tunneling between the quantized subbands in III-V devices increases the valley current and decreases device performance, while the interlayer barrier height has a negligible impact on performance for barrier heights greater than approximately 0.5 eV.

  20. Band structure effects on resonant tunneling in III-V quantum wells versus two-dimensional vertical heterostructures

    Science.gov (United States)

    Campbell, Philip M.; Tarasov, Alexey; Joiner, Corey A.; Ready, W. Jud; Vogel, Eric M.

    2016-01-01

    Since the invention of the Esaki diode, resonant tunneling devices have been of interest for applications including multi-valued logic and communication systems. These devices are characterized by the presence of negative differential resistance in the current-voltage characteristic, resulting from lateral momentum conservation during the tunneling process. While a large amount of research has focused on III-V material systems, such as the GaAs/AlGaAs system, for resonant tunneling devices, poor device performance and device-to-device variability have limited widespread adoption. Recently, the symmetric field-effect transistor (symFET) was proposed as a resonant tunneling device incorporating symmetric 2-D materials, such as transition metal dichalcogenides (TMDs), separated by an interlayer barrier, such as hexagonal boron-nitride. The achievable peak-to-valley ratio for TMD symFETs has been predicted to be higher than has been observed for III-V resonant tunneling devices. This work examines the effect that band structure differences between III-V devices and TMDs has on device performance. It is shown that tunneling between the quantized subbands in III-V devices increases the valley current and decreases device performance, while the interlayer barrier height has a negligible impact on performance for barrier heights greater than approximately 0.5 eV.

  1. Cistoadenocarcinoma mucinoso de ovario en estadio terminal, en embarazo complicado con muerte fetal tardía. Presentación de un caso.

    OpenAIRE

    Hansy Díaz Pérez; Rafael Pérez Castro; Juan Carlos Maura Tandrón; Caridad Cordovés Brito; Julio Concepción Bombino

    2007-01-01

    Presentamos un caso de Cistoadenocarcinoma mucinoso de ovario en un embarazo de 36.4 semanas de gestación complicado con muerte fetal tardía. que ingresó en el Hospital Materno Provincial “Isabel María de Valdivia y Salas de Sancti-Spíritus” diagnosticándose el tumor de ovario en un estadío avanzado de la enfermedad con un cuadro clínico florido y múltiples hallazgos al exámen físico que motivó varios planteamientos y dudas en el diagnóstico ,no realizándose el mismo durante la vigilancia pr...

  2. Forgotten Ureteral Stents: An Avoidable Morbidity

    International Nuclear Information System (INIS)

    Murtaza, B.; Alvi, S.

    2016-01-01

    Objective: To assess the clinical presentation of forgotten ureteral stents and highlight the etiological factors resulting in the retention of these stents. Study Design: Observational study. Place and Duration of Study: Department of Urology, Armed Forces Institute of Urology, Rawalpindi, from January 2010 to Jun 2011. Methodology: Thirty-eight patients, with forgotten ureteral stents, retained for more than 6 months duration, were enrolled. A detailed evaluation was performed, along with the questions regarding the patients' opinion about the ureteral stents. They were specially asked whether they knew about the stents or were they formally informed regarding the stents. Subsequently, the patients were managed according to their clinical condition. Results: The male to female ratio was 2.1:1 aged 23 - 69 years, mean being 40.24 ± 12.59 years. The time of presentation after the ureteral stenting was 7 - 180 months (mean = 28.89 ± 33.435 years). Seven patients (18.4 percentage) reported with chronic kidney disease, including ESRD in two cases. Recurrent UTI was seen in 28 cases (73.6 percentage), calculus formed over the stents in 20 cases (52.6 percentage), and stent fragmented in 5 patients (13.1 percentage). Majority of patients, (n = 23, 60.5 percentage), were not even aware of the placement of these stents while 8 (21.0 percentage) knew but were reluctant about its removal. In 3 cases (7.8 percentage), the relatives knew about the stent but never informed the patients. The stent had been removed in 2 cases (5.2 percentage), but the other broken fragment was missed. One case (2.6 percentage) each had a misconception about the permanent placement of the stents like cardiac stents and regarding degradation of the stents in situ. Conclusion: Forgotten ureteral stents produce clinical features ranging from recurrent UTI to ESRD. This preventable urological complication is primarily due to the unawareness or ignorance of the patients and their relatives

  3. Interface formation between hydrocarbon ring molecules and III-V semiconductor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Passmann, Regina

    2008-08-15

    In this work a systematical study to investigate the adsorption structures of small hydrocarbon ring shaped molecules on III-V semiconductor surfaces with Photo-Emission Spectroscopy (PES), Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunneling Microscopy (STM) as well as Low Electron Energy Diffraction (LEED) was performed. To investigate the influence of the surface structure in detail the surface dimer configuration to the adsorption process of organic molecules GaAs(001) surfaces, the c(4 x 4), the (2 x 4) and the (4 x 2) have been investigated as well as the adsorption of cyclopentene on the InP(001)(2 x 4) reconstructed surface. In the direct comparison it is shown that cyclopentene bonds to the InP(001)(2 x 4) surface via a cycloaddition like reaction. During this adsorption the double bond splits which is in contrast to the adsorption of cyclopentene on the GaAs(001) surfaces. Therefrom it is concluded that the surface geometry has an influence on the resulting adsorption structure. In order to investigate the influence of the intra-molecular double bonds, cyclopentene (one double bond), 1,4-cyclohexadiene (two double bonds) and benzene (three double bonds) were used for the characterization of the interface formation. With the investigations on the GaAs(001) reconstructed surfaces it was shown that a dependency of the bonding configuration on the intra-molecular double bonds exists. During the adsorption of cyclopentene no evidence was found that the double bond has to be involved in the interface formation while during the adsorption of 1,4-cyclohexadiene and benzene the double bonds are involved. Furthermore it was found that a bonding to As atoms of the surface is more likely than a bonding to Ga atoms. (orig.)

  4. Protective capping and surface passivation of III-V nanowires by atomic layer deposition

    Directory of Open Access Journals (Sweden)

    Veer Dhaka

    2016-01-01

    Full Text Available Low temperature (∼200 °C grown atomic layer deposition (ALD films of AlN, TiN, Al2O3, GaN, and TiO2 were tested for protective capping and surface passivation of bottom-up grown III-V (GaAs and InP nanowires (NWs, and top-down fabricated InP nanopillars. For as-grown GaAs NWs, only the AlN material passivated the GaAs surface as measured by photoluminescence (PL at low temperatures (15K, and the best passivation was achieved with a few monolayer thick (2Å film. For InP NWs, the best passivation (∼2x enhancement in room-temperature PL was achieved with a capping of 2nm thick Al2O3. All other ALD capping layers resulted in a de-passivation effect and possible damage to the InP surface. Top-down fabricated InP nanopillars show similar passivation effects as InP NWs. In particular, capping with a 2 nm thick Al2O3 layer increased the carrier decay time from 251 ps (as-etched nanopillars to about 525 ps. Tests after six months ageing reveal that the capped nanostructures retain their optical properties. Overall, capping of GaAs and InP NWs with high-k dielectrics AlN and Al2O3 provides moderate surface passivation as well as long term protection from oxidation and environmental attack.

  5. Protective capping and surface passivation of III-V nanowires by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dhaka, Veer, E-mail: veer.dhaka@aalto.fi; Perros, Alexander; Kakko, Joona-Pekko; Haggren, Tuomas; Lipsanen, Harri [Department of Micro- and Nanosciences, Micronova, Aalto University, P.O. Box 13500, FI-00076 (Finland); Naureen, Shagufta; Shahid, Naeem [Research School of Physics & Engineering, Department of Electronic Materials Engineering, Australian National University, Canberra ACT 2601 (Australia); Jiang, Hua; Kauppinen, Esko [Department of Applied Physics and Nanomicroscopy Center, Aalto University, P.O. Box 15100, FI-00076 (Finland); Srinivasan, Anand [School of Information and Communication Technology, KTH Royal Institute of Technology, Electrum 229, S-164 40 Kista (Sweden)

    2016-01-15

    Low temperature (∼200 °C) grown atomic layer deposition (ALD) films of AlN, TiN, Al{sub 2}O{sub 3}, GaN, and TiO{sub 2} were tested for protective capping and surface passivation of bottom-up grown III-V (GaAs and InP) nanowires (NWs), and top-down fabricated InP nanopillars. For as-grown GaAs NWs, only the AlN material passivated the GaAs surface as measured by photoluminescence (PL) at low temperatures (15K), and the best passivation was achieved with a few monolayer thick (2Å) film. For InP NWs, the best passivation (∼2x enhancement in room-temperature PL) was achieved with a capping of 2nm thick Al{sub 2}O{sub 3}. All other ALD capping layers resulted in a de-passivation effect and possible damage to the InP surface. Top-down fabricated InP nanopillars show similar passivation effects as InP NWs. In particular, capping with a 2 nm thick Al{sub 2}O{sub 3} layer increased the carrier decay time from 251 ps (as-etched nanopillars) to about 525 ps. Tests after six months ageing reveal that the capped nanostructures retain their optical properties. Overall, capping of GaAs and InP NWs with high-k dielectrics AlN and Al{sub 2}O{sub 3} provides moderate surface passivation as well as long term protection from oxidation and environmental attack.

  6. Progress in the development of metamorphic multi-junction III-V space solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinharoy, S.; Patton, M.O.; Valko, T.M.; Weizer, V.G. [Essential Research Inc., Cleveland, OH (United States)

    2002-07-01

    Theoretical calculations have shown that highest-efficiency III-V multi-junction solar cells require alloy structures that cannot be grown on a lattice-matched substrate. Ever since the first demonstration of high efficiency metamorphic single-junction 1.1 and 1.2 eV InGaAs solar cells, interest has grown in the development of multi-junction cells of this type, using graded buffer layer technology. Essential Research Incorporated (ERI) is currently developing a dual-junction 1.6 eV InGaP/1.1 eV InGaAs tandem cell (projected practical air-mass zero (AMO), one-sun efficiency of 27%, and 100-sun efficiency of 31.1%) under a Ballistic Missile Defense Command (BMDO) SBIR Phase II program. A second ongoing research effort involves the development of a 2.1 eV A1GaInP/1.6 eV InGaAsP/1.2 eV InGaAs triple-junction concentrator tandem cell (projected practical AMO efficiency 36.5% under 100 suns) under a SBIR Phase II program funded by the Air Force. We are in the process of optimizing the dual-junction cell performance. For the triple-junction cell, we have developed the bottom and the middle cell, and are in the process of developing the layer structures needed for the top cell. A progress report is presented in this paper. (author)

  7. Concomitant glenohumeral pathologies in high-grade acromioclavicular separation (type III - V).

    Science.gov (United States)

    Markel, Jochen; Schwarting, Tim; Malcherczyk, Dominik; Peterlein, Christian-Dominik; Ruchholtz, Steffen; El-Zayat, Bilal Farouk

    2017-11-10

    Acromioclavicular joint (ACJ) dislocations are common injuries of the shoulder associated with physical activity. The diagnosis of concomitant injuries proves complicated due to the prominent clinical symptoms of acute ACJ dislocation. Because of increasing use of minimally invasive surgery techniques concomitant pathologies are diagnosed more often than with previous procedures. The aim of this study was to identify the incidence of concomitant intraarticular injuries in patients with high-grade acromioclavicular separation (Rockwood type III - V) as well as to reveal potential risk constellations. The concomitant pathologies were compiled during routine arthroscopically assisted treatment in altogether 163 patients (147 male; 16 female; mean age 36.8 years) with high-grade acromioclavicular separation (Rockwood type III: n = 60; Rockwood type IV: n = 6; Rockwood type V: n = 97). Acromioclavicular separation occurred less often in women than men (1:9). In patients under 35, the most common cause for ACJ dislocation was sporting activity (37.4%). Rockwood type V was observed significantly more often than the other types with 57.5% (Rockwood type III = 36.8%, Rockwood type IV 3.7%). Concomitant pathologies were diagnosed in 39.3% of the patients with that number rising to as much as 57.3% in patients above 35 years. Most common associated injuries were rotator cuff injuries (32.3%), chondral defects (30.6%) and SLAP-lesions (22.6%). Of all patients, 8.6% needed additional reconstructive surgery. Glenohumeral injuries are a much more common epiphenomenon during acromioclavicular separation than previously ascertained. High risk group for accompanying injuries are patients above 35 years with preexisting degenerative disease. The increasing use of minimally invasive techniques allows for an easier diagnosis and simultaneous treatment of the additional pathologies.

  8. A III-V nanowire channel on silicon for high-performance vertical transistors.

    Science.gov (United States)

    Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

    2012-08-09

    Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

  9. Phenomenological survey on the potential profile evolution in III-V binary compounds

    Directory of Open Access Journals (Sweden)

    Alejandro Mendoza Álvarez

    2011-01-01

    Full Text Available En este artículo se presenta el cambio en el perfil de eficacia potencial de algunos compuestos cuando el bandmixing de huecos ligeros y pesados se altera. Se obtuvieron mediante la aplicación de este teorema generalizado Shur a un problema de valores propios cuadrática obtenidos a partir de un sistema con N ecuaciones de segundo orden, junto en el contexto de la aproximación de masa efectiva multibanda. Se consideraron los valores de energía incidente que fue menor, igual y superior a la altura de la barrera de dispersión potencial de diferentes compuestos de semiconductores III-V binario. La mayoría de las propiedades estándar de los compuestos binarios en este estudio están garantizados, pero no todos los materiales que elegimos, han puesto de manifiesto la evolución que se espera en su perfil de potencial efectivo: algunos de los que constituyen los pozos cuánticos (QW en aplicaciones tecnológicas sólo convertirse en efectiva barrera (B las conductas de los agujeros de luz (LH cuando están en la energía incidente diferente (E se extiende y bandmixing diferentes presentes. Ninguno de los compuestos que constituyen barreras para las aplicaciones tecnológicas en este estudio se convierte en eficaz comportamientos QW válido tanto para la LH y HH. Sorprendentemente, todos los compuestos en este estudio que constituyen barreras estándar en las aplicaciones tecnológicas, las transiciones presente desde CS a B para la LH en el rango donde el valor de E es mayor que la altura de la barrera.

  10. Interface formation between hydrocarbon ring molecules and III-V semiconductor surfaces

    International Nuclear Information System (INIS)

    Passmann, Regina

    2008-01-01

    In this work a systematical study to investigate the adsorption structures of small hydrocarbon ring shaped molecules on III-V semiconductor surfaces with Photo-Emission Spectroscopy (PES), Reflectance Anisotropy Spectroscopy (RAS), Scanning Tunneling Microscopy (STM) as well as Low Electron Energy Diffraction (LEED) was performed. To investigate the influence of the surface structure in detail the surface dimer configuration to the adsorption process of organic molecules GaAs(001) surfaces, the c(4 x 4), the (2 x 4) and the (4 x 2) have been investigated as well as the adsorption of cyclopentene on the InP(001)(2 x 4) reconstructed surface. In the direct comparison it is shown that cyclopentene bonds to the InP(001)(2 x 4) surface via a cycloaddition like reaction. During this adsorption the double bond splits which is in contrast to the adsorption of cyclopentene on the GaAs(001) surfaces. Therefrom it is concluded that the surface geometry has an influence on the resulting adsorption structure. In order to investigate the influence of the intra-molecular double bonds, cyclopentene (one double bond), 1,4-cyclohexadiene (two double bonds) and benzene (three double bonds) were used for the characterization of the interface formation. With the investigations on the GaAs(001) reconstructed surfaces it was shown that a dependency of the bonding configuration on the intra-molecular double bonds exists. During the adsorption of cyclopentene no evidence was found that the double bond has to be involved in the interface formation while during the adsorption of 1,4-cyclohexadiene and benzene the double bonds are involved. Furthermore it was found that a bonding to As atoms of the surface is more likely than a bonding to Ga atoms. (orig.)

  11. Double-blind ureteral duplication: report of two cases

    International Nuclear Information System (INIS)

    Choi, Ja-Young; Kim, Seung Hyup; Kim, Sun Ho

    2002-01-01

    Blind ending of ureteral duplication is one of the most rare anomalies of the upper urinary tract. We report two cases of ureteral duplication with a blind ending both superiorly and inferiorly, and with no definite communication with the urinary tract. (orig.)

  12. Ureteric injuries following laparoscopic hysterectomy: A report of ...

    African Journals Online (AJOL)

    The incidence of ureteric injuries following hysterectomy varies. Raut et al in 1991 documented 12 ureteric injuries (1.34%) following 892 gynaecological procedures (2) while Nawaz et al reported a rate of 0.6% following gynaecological procedures over a 20 year period at the Aga Khan University Hospital,. Karachi (2).

  13. Spontaneous calyceal rupture caused by a ureteral calculus

    African Journals Online (AJOL)

    A. Chaabouni

    Ureteral calculus;. CT;. Ureterel stent. Abstract. Rupture of the urinary collecting system with perirenal and retroperitoneal extravasation of the urine is an unusual condition that is typically caused by ureteral-obstructing calculi. We report a case of calyceal rupture with urinoma formation, due to a stone in the distal ureter.

  14. paediatric ureteric calculi: in-situ extracorporeal shock wave lithotripsy

    African Journals Online (AJOL)

    Objective To evaluate prospectively the efficacy of in-situ extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteric calculi in the paediatric age group. Patients and Methods Twenty children (aged 2.2 16 years) with 22 ureteric stones were evaluated and treated with in-situ ESWL using the Dornier S lithotripter ...

  15. A case of ureteral tumor diagnosed by computed tomography

    International Nuclear Information System (INIS)

    Hirakawa, Shinji; Adachi, Botaro; Hamamoto, Ryuichi; Nishimoto, Kazuhiko; Goto, Hajime

    1980-01-01

    A 66-year-old woman, visited Tottori University Hospital with the chief complaint of asymptomatic macrohematuria on Oct. 4, 1979. RP showed right hydroureteronephrosis due to right lower ureteral stenosis. Computed tomography (CT) was employed to investigate the right lower ureter, which showed a tumor in the right lower ureter, confined within the ureteral wall. Diagnosis of the right ureteral tumor with right hydroureteronephrosis was made and under general anesthesia right complete nephroureterectomy was performed on Oct. 26, 1979. So, the accuracy of the preoperative diagnosis was confirmed by the operation. CT has been supposed to be disadvantageous in the diagnosis of ureteral lesions, since ureter is thin, and the ureteral wall is also thin. However as was demonstrated in this case, a sizeable tumor of ureter could be diagnosed accurately by CT. (author)

  16. Fluids and diuretics for acute ureteric colic.

    Science.gov (United States)

    Worster, Andrew S; Bhanich Supapol, Wendy

    2012-02-15

    Acute ureteric colic is commonly associated with severe and debilitating pain. Theoretically, increasing fluid flow through the affected kidney might expedite stone passage, thereby improving symptoms more quickly. The efficacy and safety of interventions such as high volume intravenous (IV) or oral fluids and diuretics aimed at expediting ureteric stone passage is, however, uncertain. To look at the benefits and harms of diuretics and high volume (above maintenance) IV or oral fluid therapy for treating adult patients presenting with uncomplicated acute ureteric colic. We searched the Cochrane Renal Group's specialised register (3 January 2012). Previously we searched the Cochrane Central Register of Controlled Trials (CENTRAL The Cochrane Library), MEDLINE (from 1966), EMBASE (from 1980) and handsearched reference lists of nephrology and urology textbooks, review articles, relevant studies, and abstracts from nephrology scientific meetings. All randomised controlled trials (RCTs) and quasi-RCTs (including the first period of randomised cross-over studies) looking at diuretics or high volume IV or oral fluids for treating uncomplicated acute ureteric colic in adult patients presenting to the emergency department for the first time during that episode were included. Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model for multiple studies of the same outcomes, otherwise the fixed-effect model was used. Results were expressed as risk ratios (RR) for dichotomous outcomes or as mean differences (MD) for continuous data with 95% confidence intervals (CI). Two studies (enrolling 118 participants) examined the association between intense hydration and ureteric colic outcomes. There was no significant difference in pain at six hours (1 study, 60 participants: RR 1.06, 95% CI 0.71 to 1.57), surgical stone removal (1 study, 60 participants: RR 1.20, 95% CI 0.41 to 3.51) or manipulation by

  17. Appendix vermiformis as a left pyelo-ureteral substitute in a 6-month ...

    African Journals Online (AJOL)

    Extensive ureteral loss in early childhood is a rare but dramatic event. We present the case of a 6-monthold girl with a iatrogenic extensive pyelo-ureteral loss and solitary kidney. She successfully underwent left ureteral substitution using the appendix vermiformis. Left ureteral reconstruction using the appendix vermiformis ...

  18. Accumulation capacitance frequency dispersion of III-V metal-insulator-semiconductor devices due to disorder induced gap states

    International Nuclear Information System (INIS)

    Galatage, R. V.; Zhernokletov, D. M.; Dong, H.; Brennan, B.; Hinkle, C. L.; Wallace, R. M.; Vogel, E. M.

    2014-01-01

    The origin of the anomalous frequency dispersion in accumulation capacitance of metal-insulator-semiconductor devices on InGaAs and InP substrates is investigated using modeling, electrical characterization, and chemical characterization. A comparison of the border trap model and the disorder induced gap state model for frequency dispersion is performed. The fitting of both models to experimental data indicate that the defects responsible for the measured dispersion are within approximately 0.8 nm of the surface of the crystalline semiconductor. The correlation between the spectroscopically detected bonding states at the dielectric/III-V interface, the interfacial defect density determined using capacitance-voltage, and modeled capacitance-voltage response strongly suggests that these defects are associated with the disruption of the III-V atomic bonding and not border traps associated with bonding defects within the high-k dielectric.

  19. Optimization of the silicon subcell for III-V on silicon multijunction solar cells: Key differences with conventional silicon technology

    Science.gov (United States)

    García-Tabarés, Elisa; Martín, Diego; García, Iván; Lelièvre, Jean François; Rey-Stolle, Ignacio

    2012-10-01

    Dual-junction solar cells formed by a GaAsP or GaInP top cell and a silicon (Si) bottom cell seem to be attractive candidates to materialize the long sought-for integration of III-V materials on Si for photovoltaic (PV) applications. Such integration would offer a cost breakthrough for PV technology, unifying the low cost of Si and the efficiency potential of III-V multijunction solar cells. The optimization of the Si solar cells properties in flat-plate PV technology is well-known; nevertheless, it has been proven that the behavior of Si substrates is different when processed in an MOVPE reactor In this study, we analyze several factors influencing the bottom subcell performance, namely, 1) the emitter formation as a result of phosphorus diffusion; 2) the passivation quality provided by the GaP nucleation layer; and 3) the process impact on the bottom subcell PV properties.

  20. Silicon, germanium, and III-V-based tunneling devices for low-power applications

    Science.gov (United States)

    Smith, Joshua T.

    While the scaling of transistor dimensions has kept pace with Moore's Law, the voltages applied to these devices have not scaled in tandem, giving rise to ever-increasing power/heating challenges in state-of-the-art integrated circuits. A primary reason for this scaling mismatch is due to the thermal limit---the 60 mV minimum required at room temperature to change the current through the device by one order of magnitude. This voltage scaling limitation is inherent in devices that rely on the mechanism of thermal emission of charge carriers over a gate-controlled barrier to transition between the ON- and OFF-states, such as in the case of conventional CMOS-based technologies. To overcome this voltage scaling barrier, several steep-slope device concepts have been pursued that have experimentally demonstrated sub-60-mV/decade operation since 2004, including the tunneling-field effect transistor (TFET), impact ionization metal-oxide-semiconductor (IMOS), suspended-gate FET (SG-FET), and ferroelectric FET (Fe-FET). These reports have excited strong efforts within the semiconductor research community toward the realization of a low-power device that will support continued scaling efforts, while alleviating the heating issues prevalent in modern computer chips. Literature is replete with claims of sub-60-mV/decade operation, but often with neglect to other voltage scaling factors that offset this result. Ideally, a low-power device should be able to attain sub-60-mV/decade inverse subthreshold slopes (S) employing low supply and gate voltages with a foreseeable path toward integration. This dissertation describes the experimental development and realization of CMOS-compatible processes to enhance tunneling efficiency in Si and Si/Ge nanowire (NW) TFETs for improved average S (S avg) and ON-currents (ION), and a novel, III-V-based tunneling device alternative is also proposed. After reviewing reported efforts on the TFET, IMOS, and SG-FET, the TFET is highlighted as the

  1. First principles calculation of material properties of group IV elements and III-V compounds

    Science.gov (United States)

    Malone, Brad Dean

    This thesis presents first principles calculations on the properties of group IV elements and group III-V compounds. It includes investigations into what structure a material is likely to form in, and given that structure, what are its electronic, optical, and lattice dynamical properties as well as what are the properties of defects that might be introduced into the sample. The thesis is divided as follows: • Chapter 1 contains some of the conceptual foundations used in the present work. These involve the major approximations which allow us to approach the problem of systems with huge numbers of interacting electrons and atomic cores. • Then, in Chapter 2, we discuss one of the major limitations to the DFT formalism introduced in Chapter 1, namely its inability to predict the quasiparticle spectra of materials and in particular the band gap of a semiconductor. We introduce a Green's function approach to the electron self-energy Sigma known as the GW approximation and use it to compute the quasiparticle band structures of a number of group IV and III-V semiconductors. • In Chapter 3 we present a first-principles study of a number of high-pressure metastable phases of Si with tetrahedral bonding. The phases studied include all experimentally determined phases that result from decompression from the metallic beta-Sn phase, specifically the BC8 (Si-III), hexagonal diamond (Si-IV), and R8 (Si-XII). In addition to these, we also study the hypothetical ST12 structure found upon decompression from beta-Sn in germanium. • Our attention is then turned to the first principles calculations of optical properties in Chapter 4. The Bethe-Salpeter equation is then solved to obtain the optical spectrum of this material including electron-hole interactions. The calculated optical spectrum is compared with experimental data for other forms of silicon commonly used in photovoltaic devices, namely the cubic, polycrystalline, and amorphous forms. • In Chapter 5 we present

  2. Fibroepithelial ureteral polyps presenting as ureteropelvic obstruction

    Science.gov (United States)

    Cusano, Antonio; Abarzua-Cabezas, Fernando; Kesler, Stuart

    2014-01-01

    A 57-year-old woman presented with bilateral abdominal pain and flank discomfort. Imaging studies, consisting of CT scan, diethylene triamine pentaacetic acid renal scan with Lasix and a retrograde pyelogram, indicated an obstruction at the uteropelvic junction (UPJ), possibly due to fibroepithelial polyps within the ureter. A robotic pyeloplasty revealed a ureteral diverticulum and a thin, still-attached fibroepithelial polyp of approximately 2 cm in length. The patient tolerated the procedure well and was discharged one day postpyeloplasty with no reported complications. This rare clinical scenario should be considered when formulating a diagnosis for a UPJ obstruction. PMID:24759168

  3. Endoluminal release of ureteral ligature after hysterectomy

    Directory of Open Access Journals (Sweden)

    Chih-Jen Wang

    2016-01-01

    Full Text Available Iatrogenic ureteral injury is a well-recognized complication of abdominal total hysterectomy. We report a case of a 57-year-old female who underwent abdominal total hysterectomy for a uterine myoma and experienced severe right flank pain postoperatively. The imaging study displayed an obstruction of the right distal ureter. Under ureteroscopy, an extraluminal ligature was released with a holmium:yttrium–aluminum–garnet laser. The stenotic segment was immediately relieved. Two months later, the intravenous urogram illustrated patency of the distal ureter with regression of right hydronephrosis. There was no recurrent hydronephrosis during 1 year of follow-up.

  4. Retrograde placement of double-J ureteral stent with interventional therapy for the treatment of ureteral stricture

    International Nuclear Information System (INIS)

    Kong Jian; Xu Linfeng; Liang Huimin; Zheng Chuansheng; Zheng Jinlong; Feng Gansheng

    2000-01-01

    Objective: To evaluate the retrograde placement of Double-J ureteral stent with interventional therapy for the treatment of ureteral stricture. Methods: Twenty patients with ureteral stricture of various causes were treated with retrograde placing Double-J ureteral stent by interventional therapy. Results: The Double-J stent was successfully performed in all twenty patients. The successful rate of placing stent was 100%. The cure rate was 90% (18/20). The complications such as urinary leakage, wound infection, and bleeding were markedly decreased. The indication, duration of indwelling and complication of the indwelling stent were discussed. Conclusion: Retrograde placing Double-J stent with interventional therapy is simple and less invasive. It is believed to be a safe and effective method for the treatment of ureteral stricture

  5. [The Predictive Factors of Stent Failure in the Treatment of Malignant Extrinsc Ureteral Obstruction Using Internal Ureteral Stents].

    Science.gov (United States)

    Matsuura, Hiroshi; Arase, Shigeki; Hori, Yasuhide; Tochigi, Hiromi

    2017-12-01

    In this study, we retrospectively reviewed the experiences at our single institute in the treatment of malignant extrinsic ureteral obstruction (MUO) using ureteral stents to investigate the clinical outcomes and the predictive factors of stent failure. In 52 ureters of 38 patients who had radiologically significant hydronephrosis due to MUO, internal ureteral stents (The BARD(R) INLAY(TM) ureteral stent set) were inserted. The median follow-up interval after the initial stent insertion was 124.5 days (4-1,120). Stent failure occurred in 8 ureters (15.4%) of the 7 patients. The median interval from the first stent insertion to stent failure was 88 days (1-468). A Cox regression multivariate analysis showed that the significant predictors of stent failure were bladder invasion. Based on the possibility of stent failure, the adaptation of the internal ureteral stent placement should be considered especially in a patient with MUO combined with bladder invasion.

  6. III/V nano ridge structures for optical applications on patterned 300 mm silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Kunert, B.; Guo, W.; Mols, Y.; Pantouvaki, M.; Van Campenhout, J.; Langer, R.; Barla, K. [imec, Kapeldreef 75, 3001 Heverlee (Belgium); Tian, B.; Wang, Z.; Shi, Y.; Van Thourhout, D. [Photonics Research Group, Ghent University, Technologiepark-Zwijnaarde 15, 9052 Gent (Belgium)

    2016-08-29

    We report on an integration approach of III/V nano ridges on patterned silicon (Si) wafers by metal organic vapor phase epitaxy (MOVPE). Trenches of different widths (≤500 nm) were processed in a silicon oxide (SiO{sub 2}) layer on top of a 300 mm (001) Si substrate. The MOVPE growth conditions were chosen in a way to guarantee an efficient defect trapping within narrow trenches and to form a box shaped ridge with increased III/V volume when growing out of the trench. Compressively strained InGaAs/GaAs multi-quantum wells with 19% indium were deposited on top of the fully relaxed GaAs ridges as an active material for optical applications. Transmission electron microcopy investigation shows that very flat quantum well (QW) interfaces were realized. A clear defect trapping inside the trenches is observed whereas the ridge material is free of threading dislocations with only a very low density of planar defects. Pronounced QW photoluminescence (PL) is detected from different ridge sizes at room temperature. The potential of these III/V nano ridges for laser integration on Si substrates is emphasized by the achieved ridge volume which could enable wave guidance and by the high crystal quality in line with the distinct PL.

  7. Electrically driven hybrid Si/III-V Fabry-Pérot lasers based on adiabatic mode transformers.

    Science.gov (United States)

    Ben Bakir, B; Descos, A; Olivier, N; Bordel, D; Grosse, P; Augendre, E; Fulbert, L; Fedeli, J M

    2011-05-23

    We report the first demonstration of an electrically driven hybrid silicon/III-V laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100-nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain. The bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBRs) and a surface-grating coupler. The supermodes of this hybrid structure are controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the device almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side-mode suppression ratio is as high as 20 dB, and the fiber-coupled output power is ~7 mW.

  8. Metabolomic and proteomic biomarkers for III-V semiconductors: Chemical-specific porphyrinurias and proteinurias

    International Nuclear Information System (INIS)

    Fowler, Bruce A.; Conner, Elizabeth A.; Yamauchi, Hiroshi

    2005-01-01

    A pressing need exists to develop and validate molecular biomarkers to assess the early effects of chemical agents, both individually and in mixtures. This is particularly true for new and chemically intensive industries such as the semiconductor industry. Previous studies from this laboratory and others have demonstrated element-specific alterations of the heme biosynthetic pathway for the III-V semiconductors gallium arsenide (GaAs) and indium arsenide (InAs) with attendant increased urinary excretion of specific heme precursors. These data represent an example of a metabolomic biomarker to assess chemical effects early, before clinical disease develops. Previous studies have demonstrated that the intratracheal or subcutaneous administration of GaAs and InAs particles to hamsters produces the induction of the major stress protein gene families in renal proximal tubule cells. This was monitored by 35-S methionine labeling of gene products followed by two-dimensional gel electrophoresis after exposure to InAs particles. The present studies examined whether these effects were associated with the development of compound-specific proteinuria after 10 or 30 days following subcutaneous injection of GaAs or InAs particles in hamsters. The results of these studies demonstrated the development of GaAs- and InAs-specific alterations in renal tubule cell protein expression patterns that varied at 10 and 30 days. At the 30-day point, cells in hamsters that received InAs particles showed marked attenuation of protein expression, suggesting inhibition of the stress protein response. These changes were associated with GaAs and InAs proteinuria patterns as monitored by two-dimensional gel electrophoresis and silver staining. The intensity of the protein excretion patterns increased between the 10- and 30-day points and was most pronounced for animals in the 30-day InAs treatment group. No overt morphologic signs of cell death were seen in renal tubule cells of these animals

  9. Quantitative STEM on indium containing group III-V semiconductor nanostructures

    International Nuclear Information System (INIS)

    Mehrtens, Thorsten

    2013-01-01

    In the framework of this thesis. a method for compositional analysis of semiconductor nanostructures is applied on technologically relevant group III-V alloys. It is based on a quantitative comparison between intensities of experimentally acquired High-Angle Annular Dark Field Scanning Tansmission Electron Microscopy (HAADF-STEM) images and simulated intensities from multislice calculations in the frozen lattice approach. The demonstrated method allows determination of specimen thickness and material composition on subnanometer scale. Since quantitative HAADF-STEM is still a very young technique, its applicability has only been proven for a few materials, yet. Thus, the main goal of this thesis is the simulation of suitable reference datasets for different ternary semiconducting alloys and to test their reliability by complementary analysis. A total of three different semiconducting materials are thereby analyzed (InGaN, InGaAs and InAlN) that have all in common that they contain indium. The main focus of this work lies on InGaN which is due to its bandgap particularly suitable for the fabrication of optoelectronic devices operating in the visible spectrum of the light. In the first part of the presented results, the quality of ultra-thin TEM-specimens prepared by techniques involving ion milling at high energies is optimized. This is done by an additional ion milling step where the impinging ions possess an energy of only 400 eV. It is found that the preparation induced amorphous surface layer that occurs during ion milling can be drastically reduced below 1 nm. The second part concentrates on results obtained on InGaN. Here, different simulations in the frozen lattice approach are carried out under certain conditions. These simulations either include or do not include thermal diffuse scattering and/or static atomic displacement to demonstrate their influence on the amount of intensity measured in the experiment. As the consideration of thermal diffuse scattering

  10. Laparoscopic surgery to treat ureterosciatic herniation after ureteral stent failure

    Directory of Open Access Journals (Sweden)

    Yi-Sheng Tai

    2014-03-01

    Full Text Available We report on a patient who presented with left flank pain for 6 months. Computed tomography and intravenous urography revealed left ureterosciatic herniation with severe hydronephrosis. Antegrade placement of the ureteral double-J stent was performed and her symptoms subsequently subsided. These symptoms recurred after the removal of the stent 1 year later with persistent hydronephrosis and herniation. We performed laparoscopic ureterolysis, ureteral fixation to psoas muscle, and sciatic hernia repair with hyaluronan-containing mesh. The result was encouraging and the follow-up image at 6 months showed no hydronephrosis and no ureteral herniation.

  11. Cistoadenocarcinoma mucinoso de ovario en estadio terminal, en embarazo complicado con muerte fetal tardía. Presentación de un caso.

    Directory of Open Access Journals (Sweden)

    Hansy Díaz Pérez

    2007-06-01

    Full Text Available Presentamos un caso de Cistoadenocarcinoma mucinoso de ovario en un embarazo de 36.4 semanas de gestación complicado con muerte fetal tardía. que ingresó en el Hospital Materno Provincial “Isabel María de Valdivia y Salas de Sancti-Spíritus” diagnosticándose el tumor de ovario en un estadío avanzado de la enfermedad con un cuadro clínico florido y múltiples hallazgos al exámen físico que motivó varios planteamientos y dudas en el diagnóstico ,no realizándose el mismo durante la vigilancia prenatal habitual ni durante la ecografía pélvica que se realiza durante esta, siendo un hallazgo durante la laparotomía exploradora ya cuando la paciente se encontraba en la fase final del cuadro que la lleva al fallecimiento en la Unidad de cuidados intensivos al tercer día del ingreso con asistencia ventilatoria y múltiples complicaciones.

  12. Outcome of retrograde ureteric stenting as a urinary drainage procedure in ureteric obstruction related to malignant lesions.

    Science.gov (United States)

    Wijayarathna, S; Suvendran, S; Ishak, M; Weligamage, A; Epa, A; Munasinghe, S; Abeygunaskera, A M

    2014-12-01

    We investigated the outcome of endoscopic retrograde ureteric stenting (RUS) in patients with ureteric obstruction related to malignant lesions. Data were prospectively collected from patients with ureteric obstruction related to malignant lesions treated at a single urology unit from 1 January 2011 to 30 April 2014. All patients had radiologically significant hydronephrosis by ultrasonography and CT scanning. First choice of urinary drainage was placing a retrograde ureteric stent cystoscopically. Outcome of patients who had stenting were recorded after following them until death or removal of stents. Eighty two patients with ureteric obstruction related to malignant lesions had complete data. In 33 (25%) patients, retrograde ureteric stenting was possible. Fifteen of them had recurrent tumour in the pelvis at the time of stenting and 13 (87%) were dead within 3 months of stenting. Four of the five patients who did not have pelvic tumour recurrence were alive at the end of the study. All eight patients who underwent stenting before surgery as a prophylactic measure and three of the five patients who had retroperitoneal tumour mass and underwent RUS were alive. Stenting was not possible in 42 patients. Thirty eight of them had pelvic tumour recurrences and two were having retroperitoneal tumour masses. Only one did not have tumour in the pelvis.CT evidence of tumour recurrence in the pelvis (OR 12.7; 95% CI 1.3-117.6; p=0.026) and high serum creatinine (OR 4.3; 95% CI 1.6-11.7; p=0.004) were associated with failure to ureteric stenting. Chances of successful RUS were low in patients with ureteric obstruction in the presence of tumour recurrences or elevated serum creatinine. Even if ureteric stenting was successful, their life expectancy was short.

  13. Understanding the vapor-liquid-solid growth and composition of ternary III-V nanowires and nanowire heterostructures

    Science.gov (United States)

    Dubrovskii, V. G.

    2017-11-01

    Based on the recent achievements in vapor-liquid-solid (VLS) synthesis, characterization and modeling of ternary III-V nanowires and axial heterostructures within such nanowires, we try to understand the major trends in their compositional evolution from a general theoretical perspective. Clearly, the VLS growth of ternary materials is much more complex than in standard vapor-solid epitaxy techniques, and even maintaining the necessary control over the composition of steady-state ternary nanowires is far from straightforward. On the other hand, VLS nanowires offer otherwise unattainable material combinations without introducing structural defects and hence are very promising for next-generation optoelectronic devices, in particular those integrated with a silicon electronic platform. In this review, we consider two main problems. First, we show how and by means of which parameters the steady-state composition of Au-catalyzed or self-catalyzed ternary III-V nanowires can be tuned to a desired value and why it is generally different from the vapor composition. Second, we present some experimental data and modeling results for the interfacial abruptness across axial nanowire heterostructures, both in Au-catalyzed and self-catalyzed VLS growth methods. Refined modeling allows us to formulate some general growth recipes for suppressing the unwanted reservoir effect in the droplet and sharpening the nanowire heterojunctions. We consider and refine two approaches developed to date, namely the regular crystallization model for a liquid alloy with a critical size of only one III-V pair at high supersaturations or classical binary nucleation theory with a macroscopic critical nucleus at modest supersaturations.

  14. Histopathological correlations to ureteral lesions visualized during ureteroscopy

    DEFF Research Database (Denmark)

    Lildal, Søren Kissow; Sørensen, Flemming Brandt; Andreassen, Kim Hovgaard

    2017-01-01

    PURPOSE: To correlate ureteral lesions visualized during ureteroscopy with histopathological findings.MATERIALS AND METHODS: Ureteral access sheaths (UAS) sized 13/15 Fr. were inserted bilaterally in 22 laboratory pigs. During retraction of the UAS with a semirigid ureteroscope inside, ureteral......) stained. Histopathological scoring of ureteral wall lesions was subsequently performed according to PULS.RESULTS: In 72.1% of ureters, the highest histopathological score was at least 1 grade higher than the highest endoscopic PULS score. For 12 (27.9%) lesions, the difference was 2 scores higher......, and for 1 (2.3%), it was 3 scores higher. The histopathological PULS grade was higher than the endoscopical PULS grade at all minimum, quartile, and maximum scores. There was a significant difference in the distribution of highest lesional scores between the endoscopic and histopathological PULS (p = 0...

  15. Forgotten ureteral stents: Risk factors, complications and management

    African Journals Online (AJOL)

    A.Y. Abdelaziz

    2018-02-07

    Feb 7, 2018 ... Preoperative non-contrast spiral CT abdomen and pelvis showed encrustations on the stent in 23.5% of patients ... Despite their advantages, ureteral stents are not without possible morbidity. ..... A model to quantify encrusta-.

  16. Acute kidney injury secondary to iatrogenic bilateral ureteric ligation ...

    African Journals Online (AJOL)

    Acute kidney injury secondary to iatrogenic bilateral ureteric ligation following emergency abdominal hysterectomy. Oluseyi A. Adejumo, Olurotimi S. Ogundiniyi, Ayodeji A. Akinbodewa, Lawrence A. Adesunloro, Oladimeji J. Olafisoye ...

  17. Clinical and radiographic characteristics of ureteral polyps in children

    International Nuclear Information System (INIS)

    Niu Zhibing; Wang Changlin; Yang Qi; Hou Ying

    2007-01-01

    Objective: To analyze the clinical and radiographic characterstics of ureteral polyps with hydronephrosis in children. Methods: Thirteen patients with ureteral polyps and hydronephrosis were studied retrospectively. All patients underwent abdominal plain film, intravenous pyelogram (IVP) and ultrasound (US) examinations,contrast-enhanced CT scan was performed in 10 cases. Results: Intermittent or recurrent abdominal pain with painless hematuria was presented in most cases. Hydronephrosis was demonstrated in radiographic images. IVP delineated the dilatation of the ureter and filling defects within the ureteral lumen in 5 cases. Computed tomography (CT) showed all abnormal changes of ureter and irregular intraluminal soft tissue masses in 6 cases. Moderate and low echoic structures were showed in ureters by US in 2 cases. Conclusion: US and CT, as an important imaging modalities, can improve the diagnostic accuracy for ureteral polyps. (authors)

  18. Spontaneous ureteral rupture in a patient with systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Benson, C.H.; Pennebaker, J.B.; Harisdangkul, V.; Songcharoen, S.

    1983-01-01

    A patient with known systemic lupus erythematosus had fever and symptoms of a lower urinary tract infection. Bone scintigraphy showed left ureteral perforation and necrosis with no demonstrable nephrolithiasis. It is speculated that this episode was due to lupus vasculitis

  19. Percutaneous dilatation of benign ureteral stricture -a case report-

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Kyu Bo; Ahn, Jung Sook; Ham, So Hie; Woo, Won Hyung [Koryo General Hospital, Seoul (Korea, Republic of)

    1987-06-15

    Percutaneous ureteral dilatation was done with balloon catheter and ureteral stent. A 40 year old woman had a pelvic surgery due to inflammatory cyst and this surgery was complicated by incidental cutting of right ureter and ureteroureteral anastomosis was done. After 1 month, she was suffered from severe right flank pain, nausea and vomiting, and showed delayed visualization of pelvocalyceal system with dilatation in intravenous pyelography. Percutaneous nephrostomy was done and complete obstruction at lower ureter was seen in antegrade pyelography. 4 mm balloon catheter was introduced through the nephrostomy tract and dilatation was done with a pressure of 5 atm for 1 minute duration for 4 times and no. 7 double J ureteral stent was left across the lesion for prevention of restenosis. Ureteral stent was removed after 2 months, and successful dilatation was seen and no evidence of restenosis in 5 weeks follow up.

  20. III-V Ultra-Thin-Body InGaAs/InAs MOSFETs for Low Standby Power Logic Applications

    Science.gov (United States)

    Huang, Cheng-Ying

    As device scaling continues to sub-10-nm regime, III-V InGaAs/InAs metal- oxide-semiconductor ?eld-e?ect transistors (MOSFETs) are promising candidates for replacing Si-based MOSFETs for future very-large-scale integration (VLSI) logic applications. III-V InGaAs materials have low electron effective mass and high electron velocity, allowing higher on-state current at lower VDD and reducing the switching power consumption. However, III-V InGaAs materials have a narrower band gap and higher permittivity, leading to large band-to-band tunneling (BTBT) leakage or gate-induced drain leakage (GIDL) at the drain end of the channel, and large subthreshold leakage due to worse electrostatic integrity. To utilize III-V MOSFETs in future logic circuits, III-V MOSFETs must have high on-state performance over Si MOSFETs as well as very low leakage current and low standby power consumption. In this dissertation, we will report InGaAs/InAs ultra-thin-body MOSFETs. Three techniques for reducing the leakage currents in InGaAs/InAs MOSFETs are reported as described below. 1) Wide band-gap barriers: We developed AlAs0.44Sb0.56 barriers lattice-match to InP by molecular beam epitaxy (MBE), and studied the electron transport in In0.53Ga0.47As/AlAs 0.44Sb0.56 heterostructures. The InGaAs channel MOSFETs using AlAs0.44Sb0.56 bottom barriers or p-doped In0.52 Al0.48As barriers were demonstrated, showing significant suppression on the back barrier leakage. 2) Ultra-thin channels: We investigated the electron transport in InGaAs and InAs ultra-thin quantum wells and ultra-thin body MOSFETs (t ch ~ 2-4 nm). For high performance logic, InAs channels enable higher on-state current, while for low power logic, InGaAs channels allow lower BTBT leakage current. 3) Source/Drain engineering: We developed raised InGaAs and recessed InP source/drain spacers. The raised InGaAs source/drain spacers improve electrostatics, reducing subthreshold leakage, and smooth the electric field near drain, reducing

  1. Improved Electron Yield and Spin-Polarization from III-V Photocathodes via Bias Enhanced Carrier Drift: Final Report

    International Nuclear Information System (INIS)

    Mulhollan, Gregory A.

    2006-01-01

    In this DOE STTR program, Saxet Surface Science, with the Stanford Linear Accelerator Center as partner, designed, built and tested photocathode structures such that optimal drift-enhanced spin-polarization from GaAs based photoemitters was achieved with minimal bias supply requirements. The forward bias surface grid composition was optimized for maximum polarization and yield, together with other construction parameters including doping profile. This program has culminated in a cathode bias structure affording increased electron spin polarization when applied to III-V based photocathodes. The optimized bias structure has been incorporated into a cathode mounting and biasing design for use in a polarized electron gun.

  2. Factors affecting stress distribution and displacements in crystals III-V grown by Czochralski method with liquid encapsulation

    International Nuclear Information System (INIS)

    Schvezov, C.E.; Samarasekera, I.; Weinberg, F.

    1988-01-01

    A mathematical model based on the finite element method for calculating temperature and shear stress distributions in III-V crystals grown by LEC technique was developed. The calculated temperature are in good agreements with the experimental measurements. The shear stress distribution was calculated for several environmental conditions. The results showed that the magnitude and the distribution of shear stresses are highly sensitive to the crystal environment, including thickness and temperature distribution in boron oxides and the gas. The shear stress is also strongly influenced by interface curvature and cystals radius. (author) [pt

  3. A comprehensive review of nephroblastoma with ureteric involvement

    Directory of Open Access Journals (Sweden)

    Singh S

    2017-12-01

    Full Text Available Ureteric involvement is described rarely in nephroblastoma, the most common pediatric renal tumor. This clinicopathological, descriptive retrospective study was conducted to elucidate the prevalence and histomorphological features of ureteric involvement by nephroblastoma. Of 454 nephroblastomas diagnosed in the 25-year study period, 32 displayed ureteric involvement; 21 and 11 demonstrated prolapse and invasion, respectively. The patient cohort had a mean age of 47.3 months and mainly advanced stage disease. Pre-operative radiological and intra-operative assessments identified ureteric involvement in 4 and 13 patients, respectively, but distinction between ureteric prolapse and invasion was not possible. Histopathological assessment of the primary renal tumor demonstrated exclusive triphasichistomorphology in all 32 nephroblastomas. Favorable histology, diffuse anaplasia and nephroblastomatosis were present in 28, 4 and 7 tumors, respectively. Re-appraisal of 17 post-treated tumors were classified by SIOP criteria as mixed(6, stromal(4, anaplastic(4 and regressive(3 types. The ureteric component displayed triphasic(11, biphasic(5 and monophasic(1histomorphology. The staging profile of patients with ureteric prolapse was stages I(3, II(5, III(6, IV(6 and V(1. The staging profile of patients with ureteric invasion was stages I(0, II(2, III(3, IV(4 and V(2. Distant metastases were present in 10/32 patients. Follow-up of 32 patients confirmed 21 that were tumor-free, 7 with recurrent disease and 4 fatalities; of those that remained tumor-free, 11 had advanced disease. Even in advanced tumor stages, complete excision of the urinary tract tumor and optimal treatment of disseminated malignancy are pivotal to overall patient management and outcome.

  4. Ureteral stent retrieval using the crochet hook technique in females.

    Directory of Open Access Journals (Sweden)

    Takashi Kawahara

    Full Text Available INTRODUCTION: We developed a method for ureteral stent removal in female patients that requires no cystoscopy or fluoroscopic guidance using a crochet hook. In addition, we also investigated the success rate, complications and pain associated with this procedure. METHODS: A total of 40 female patients (56 stents underwent the removal of ureteral stents. All procedures were carried out with the patients either under anesthesia, conscious sedation, or analgesic suppositories as deemed appropriate for each procedure including Shock Wave Lithotripsy (SWL, Ureteroscopy (URS, Percutaneous Nephrolithotomy (PCNL, and ureteral stent removal. At the time of these procedures, fluoroscopy and/or cystoscopy were prepared, but they were not used unless we failed to successfully remove the ureteral stent using the crochet hook. In addition, matched controls (comprising 50 stents which were removed by standard ureteral stent removal using cystoscopy were used for comparison purposes. RESULTS: A total of 47 of the 56 stents (83.9% were successfully removed. In addition, 47 of 52 (90.4% were successfully removed except for two migrated stents and two heavily encrusted stents which could not be removed using cystoscopy. Ureteral stent removal using the crochet hook technique was unsuccessful in nine patients, including two encrustations and two migrations. Concerning pain, ureteral stent removal using the crochet hook technique showed a lower visual analogue pain scale (VAPS score than for the standard technique using cystoscopy. CONCLUSIONS: Ureteral stent removal using a crochet hook is considered to be easy, safe, and cost effective. This technique is also easy to learn and is therefore considered to be suitable for use on an outpatient basis.

  5. Abdominal colic due to ureteric diverticulum with stone formation

    International Nuclear Information System (INIS)

    Roodhooft, A.M.; Boven, K.; Acker, K.J. van; Gentens, P.

    1987-01-01

    In a 15-year-old boy right lower abdominal colicky pain was caused by intermittent obstruction of the ureter by stones which had accumulated in a ureteric diverticulum. As was shown by repeated X-rays, each of these stones had moved to the ureter and back to the diverticulum. Ureteric diverticulum mostly remains asymptomatic in children: stone formation and obstruction of the ureter by the stones is one of the instances which may cause symptoms. (orig.)

  6. The Role of Pharmacology in Ureteral Physiology and Expulsive Therapy

    Science.gov (United States)

    Jerde, Travis J.; Nakada, Stephen Y.

    2007-04-01

    Research in the field of ureteral physiology and pharmacology has traditionally been directed toward relaxation of ureteral spasm as a mechanism of analgesia during painful ureteral obstruction, most often stone-induced episodes. However, interest in this field has expanded greatly in recent years with the expanded use of alpha-blocker therapy for inducing stone passage, a usage now termed "medical expulsive therapy". While most clinical reports involving expulsive therapy have focused on alpha receptor or calcium channel blockade, there are diverse studies investigating pharmacological ureteral relaxation with novel agents including cyclooxygenase inhibitors, small molecule beta receptor agonists, neurokinin antagonists, and phosphodiesterase inhibitors. In addition, cutting edge molecular biology research is revealing promising potential therapeutic targets aimed at specific molecular changes that occur during the acute obstruction that accompanies stone disease. The purpose of this report is to review the use of pharmacological agents as ureteral smooth muscle relaxants clinically, and to look into the future of expulsive therapy by reviewing the available literature of ureteral physiology and pharmacology research.

  7. The forgotten ureteric JJ stent and its prevention: a prospective audit of the value of a ureteric stent logbook.

    Science.gov (United States)

    Thomas, A Z; Casey, R G; Grainger, R; McDermott, T; Flynn, R; Thornhill, J A

    2007-01-01

    Temporary ureteric stent insertion is an integral part of modern endo-urological practice. Delayed stent removal or forgotten stents are associated with increased patient morbidity and complications which are often difficult to manage. We prospectively audited our ureteric stent insertion and removal logbook system to determine the value and effectiveness of our stent follow-up. Over a 1-year period, 210 ureteric stents were inserted in our urological unit. Of these, 47 (22.4%) patients were unaccounted as having their stents removed within the stent logbooks. One patient was lost to follow-up and re-presented with stent encrustation 10 months later. Our results in this audit suggest that our system of ureteric stent follow-up is not effective. We have now introduced a new system that we feel is a safer and a satisfactory alternative to the stent logbooks. This includes a patient education leaflet and removal date scheduling prior to discharge from hospital.

  8. 30 CFR 57.22202 - Main fans (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main fans (I-A, I-B, I-C, II-A, III, V-A, and V... Main fans (I-A, I-B, I-C, II-A, III, V-A, and V-B mines). (a) Main fans shall be— (1) Installed on the... mines, provided with an automatic signal device to give an alarm when the fan stops. The signal device...

  9. Preservation of water samples for arsenic(III/V) determinations: An evaluation of the literature and new analytical results

    Science.gov (United States)

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Maest, A.S.

    2004-01-01

    Published literature on preservation procedures for stabilizing aqueous inorganic As(III/V) redox species contains discrepancies. This study critically evaluates published reports on As redox preservation and explains discrepancies in the literature. Synthetic laboratory preservation experiments and time stability experiments were conducted for natural water samples from several field sites. Any field collection procedure that filters out microorganisms, adds a reagent that prevents dissolved Fe and Mn oxidation and precipitation, and isolates the sample from solar radiation will preserve the As(III/V) ratio. Reagents that prevent Fe and Mn oxidation and precipitation include HCl, H 2SO4, and EDTA, although extremely high concentrations of EDTA are necessary for some water samples high in Fe. Photo-catalyzed Fe(III) reduction causes As(III) oxidation; however, storing the sample in the dark prevents photochemical reactions. Furthermore, the presence of Fe(II) or SO 4 inhibits the oxidation of As(III) by Fe(III) because of complexation reactions and competing reactions with free radicals. Consequently, fast abiotic As(III) oxidation reactions observed in the laboratory are not observed in natural water samples for one or more of the following reasons: (1) the As redox species have already stabilized, (2) most natural waters contain very low dissolved Fe(III) concentrations, (3) the As(III) oxidation caused by Fe(III) photoreduction is inhibited by Fe(II) or SO4.

  10. Towards large size substrates for III-V co-integration made by direct wafer bonding on Si

    Directory of Open Access Journals (Sweden)

    N. Daix

    2014-08-01

    Full Text Available We report the first demonstration of 200 mm InGaAs-on-insulator (InGaAs-o-I fabricated by the direct wafer bonding technique with a donor wafer made of III-V heteroepitaxial structure grown on 200 mm silicon wafer. The measured threading dislocation density of the In0.53Ga0.47As (InGaAs active layer is equal to 3.5 × 109 cm−2, and it does not degrade after the bonding and the layer transfer steps. The surface roughness of the InGaAs layer can be improved by chemical-mechanical-polishing step, reaching values as low as 0.4 nm root-mean-square. The electron Hall mobility in 450 nm thick InGaAs-o-I layer reaches values of up to 6000 cm2/Vs, and working pseudo-MOS transistors are demonstrated with an extracted electron mobility in the range of 2000–3000 cm2/Vs. Finally, the fabrication of an InGaAs-o-I substrate with the active layer as thin as 90 nm is achieved with a Buried Oxide of 50 nm. These results open the way to very large scale production of III-V-o-I advanced substrates for future CMOS technology nodes.

  11. Towards large size substrates for III-V co-integration made by direct wafer bonding on Si

    Energy Technology Data Exchange (ETDEWEB)

    Daix, N., E-mail: dai@zurich.ibm.com; Uccelli, E.; Czornomaz, L.; Caimi, D.; Rossel, C.; Sousa, M.; Siegwart, H.; Marchiori, C.; Fompeyrine, J. [IBM Research - Zürich, Säumerstrasse 4, CH-8803 Rüschlikon (Switzerland); Hartmann, J. M. [CEA, LETI 17, rue des Martyrs, F-38054 Grenoble (France); Shiu, K.-T.; Cheng, C.-W.; Krishnan, M.; Lofaro, M.; Kobayashi, M.; Sadana, D. [IBM T. J. Watson Research Center, 1101 Kitchawan Rd., Route 134 Yorktown Heights, New York 10598 (United States)

    2014-08-01

    We report the first demonstration of 200 mm InGaAs-on-insulator (InGaAs-o-I) fabricated by the direct wafer bonding technique with a donor wafer made of III-V heteroepitaxial structure grown on 200 mm silicon wafer. The measured threading dislocation density of the In{sub 0.53}Ga{sub 0.47}As (InGaAs) active layer is equal to 3.5 × 10{sup 9} cm{sup −2}, and it does not degrade after the bonding and the layer transfer steps. The surface roughness of the InGaAs layer can be improved by chemical-mechanical-polishing step, reaching values as low as 0.4 nm root-mean-square. The electron Hall mobility in 450 nm thick InGaAs-o-I layer reaches values of up to 6000 cm{sup 2}/Vs, and working pseudo-MOS transistors are demonstrated with an extracted electron mobility in the range of 2000–3000 cm{sup 2}/Vs. Finally, the fabrication of an InGaAs-o-I substrate with the active layer as thin as 90 nm is achieved with a Buried Oxide of 50 nm. These results open the way to very large scale production of III-V-o-I advanced substrates for future CMOS technology nodes.

  12. Towards large size substrates for III-V co-integration made by direct wafer bonding on Si

    Science.gov (United States)

    Daix, N.; Uccelli, E.; Czornomaz, L.; Caimi, D.; Rossel, C.; Sousa, M.; Siegwart, H.; Marchiori, C.; Hartmann, J. M.; Shiu, K.-T.; Cheng, C.-W.; Krishnan, M.; Lofaro, M.; Kobayashi, M.; Sadana, D.; Fompeyrine, J.

    2014-08-01

    We report the first demonstration of 200 mm InGaAs-on-insulator (InGaAs-o-I) fabricated by the direct wafer bonding technique with a donor wafer made of III-V heteroepitaxial structure grown on 200 mm silicon wafer. The measured threading dislocation density of the In0.53Ga0.47As (InGaAs) active layer is equal to 3.5 × 109 cm-2, and it does not degrade after the bonding and the layer transfer steps. The surface roughness of the InGaAs layer can be improved by chemical-mechanical-polishing step, reaching values as low as 0.4 nm root-mean-square. The electron Hall mobility in 450 nm thick InGaAs-o-I layer reaches values of up to 6000 cm2/Vs, and working pseudo-MOS transistors are demonstrated with an extracted electron mobility in the range of 2000-3000 cm2/Vs. Finally, the fabrication of an InGaAs-o-I substrate with the active layer as thin as 90 nm is achieved with a Buried Oxide of 50 nm. These results open the way to very large scale production of III-V-o-I advanced substrates for future CMOS technology nodes.

  13. Preservation of water samples for arsenic(III/V) determinations: an evaluation of the literature and new analytical results

    International Nuclear Information System (INIS)

    McCleskey, R.Blaine; Nordstrom, D.Kirk; Maest, Ann S.

    2004-01-01

    Published literature on preservation procedures for stabilizing aqueous inorganic As(III/V) redox species contains discrepancies. This study critically evaluates published reports on As redox preservation and explains discrepancies in the literature. Synthetic laboratory preservation experiments and time stability experiments were conducted for natural water samples from several field sites. Any field collection procedure that filters out microorganisms, adds a reagent that prevents dissolved Fe and Mn oxidation and precipitation, and isolates the sample from solar radiation will preserve the As(III/V) ratio. Reagents that prevent Fe and Mn oxidation and precipitation include HCl, H 2 SO 4 , and EDTA, although extremely high concentrations of EDTA are necessary for some water samples high in Fe. Photo-catalyzed Fe(III) reduction causes As(III) oxidation; however, storing the sample in the dark prevents photochemical reactions. Furthermore, the presence of Fe(II) or SO 4 inhibits the oxidation of As(III) by Fe(III) because of complexation reactions and competing reactions with free radicals. Consequently, fast abiotic As(III) oxidation reactions observed in the laboratory are not observed in natural water samples for one or more of the following reasons: (1) the As redox species have already stabilized, (2) most natural waters contain very low dissolved Fe(III) concentrations, (3) the As(III) oxidation caused by Fe(III) photoreduction is inhibited by Fe(II) or SO 4

  14. An ultrahigh vacuum, low-energy ion-assisted deposition system for III-V semiconductor film growth

    Science.gov (United States)

    Rohde, S.; Barnett, S. A.; Choi, C.-H.

    1989-06-01

    A novel ion-assisted deposition system is described in which the substrate and growing film can be bombarded with high current densities (greater than 1 mA/sq cm) of very low energy (10-200 eV) ions. The system design philosophy is similar to that used in III-V semiconductor molecular-beam epitaxy systems: the chamber is an all-metal ultrahigh vacuum system with liquid-nitrogen-cooled shrouds, Knudsen-cell evaporation sources, a sample insertion load-lock, and a 30-kV reflection high-energy electron diffraction system. III-V semiconductor film growth is achieved using evaporated group-V fluxes and group-III elemental fluxes sputtered from high-purity targets using ions extracted from a triode glow discharge. Using an In target and an As effusion cell, InAs deposition rates R of 2 microns/h have been obtained. Epitaxial growth of InAs was observed on both GaSb(100) and Si(100) substrates.

  15. Development of III-V p-MOSFETs with high-kappa gate stack for future CMOS applications

    Science.gov (United States)

    Nagaiah, Padmaja

    As the semiconductor industry approaches the limits of traditional silicon CMOS scaling, non-silicon materials and new device architectures are gradually being introduced to improve Si integrated circuit performance and continue transistor scaling. Recently, the replacement of SiO2 with a high-k material (HfO2) as gate dielectric has essentially removed one of the biggest advantages of Si as channel material. As a result, alternate high mobility materials are being considered to replace Si in the channel to achieve higher drive currents and switching speeds. III-V materials in particular have become of great interest as channel materials, owing to their superior electron transport properties. However, there are several critical challenges that need to be addressed before III-V based CMOS can replace Si CMOS technology. Some of these challenges include development of a high quality, thermally stable gate dielectric/III-V interface, and improvement in III-V p-channel hole mobility to complement the n-channel mobility, low source/drain resistance and integration onto Si substrate. In this thesis, we would be addressing the first two issues i.e. the development high performance III-V p-channels and obtaining high quality III-V/high-k interface. We start with using the device architecture of the already established InGaAs n-channels as a baseline to understand the effect of remote scattering from the high-k oxide and oxide/semiconductor interface on channel transport properties such as electron mobility and channel electron concentration. Temperature dependent Hall electron mobility measurements were performed to separate various scattering induced mobility limiting factors. Dependence of channel mobility on proximity of the channel to the oxide interface, oxide thickness, annealing conditions are discussed. The results from this work will be used in the design of the p-channel MOSFETs. Following this, InxGa1-xAs (x>0.53) is chosen as channel material for developing p

  16. Can ureteral stones cause pain without causing hydronephrosis?

    Science.gov (United States)

    Song, Yan; Hernandez, Natalia; Gee, Michael S; Noble, Vicki E; Eisner, Brian H

    2016-09-01

    While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p hydronephrosis. In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.

  17. Results of radiotherapy on ureteric obstruction in muscle-invasive bladder cancer

    DEFF Research Database (Denmark)

    Honnens De Lichtenberg, Mette; Miskowiak, J; Rolff, H

    1995-01-01

    To evaluate the effect of radiotherapy on ureteric obstruction due to muscle-invasive bladder cancer.......To evaluate the effect of radiotherapy on ureteric obstruction due to muscle-invasive bladder cancer....

  18. Photon confinement in high-efficiency, thin-film III-V solar cells obtained by epitaxial lift-off

    International Nuclear Information System (INIS)

    Schermer, J.J.; Bauhuis, G.J.; Mulder, P.; Haverkamp, E.J.; Deelen, J. van; Niftrik, A.T.J. van; Larsen, P.K.

    2006-01-01

    Using the epitaxial lift-off (ELO) technique, a III-V device structure can be separated from its GaAs substrate by selective wet etching of a thin release layer. The thin-film structures obtained by the ELO process can be cemented or van der Waals bonded on arbitrary smooth surface carriers for further processing. It is shown that the ELO method, initially able to separate millimetre-sized GaAs layers with a lateral etch rate of about 1 mm/h, has been developed to a process capable to free the entire 2-in. epitaxial structures from their substrates with etch rates up to 30 mm/h. With these characteristics the method has a large potential for the production of high efficiency thin-film solar cells. By choosing the right deposition and ELO strategy, the thin-film III-V cells can be adequately processed on both sides allowing for an entire range of new cell structures. In the present work, the performance of semi-transparent bifacial solar cells, produced by the deposition of metal grid contacts on both sides, was evaluated. Reflection of light at the rear side of the bifacial GaAs solar cells was found to result in an enhanced collection probability of the photon-induced carriers compared to that of regular III-V cells on a GaAs substrate. To enhance this effect, thin-film GaAs cells with gold mirror back contacts were prepared. Even in their present premature stage of development, these single-junction thin-film cells reached a record efficiency of 24.5% which is already very close to the 24.9% efficiency that was obtained with a regular GaAs cell on a GaAs substrate. From this it could be concluded that, as a result of the photon confinement, ELO cells require a significantly thinner base layer than regular GaAs cells while at the same time they have the potential to reach a higher efficiency

  19. Outcome of ureteral stent placement for treatment of benign ureteral obstruction in dogs: 44 cases (2010-2013).

    Science.gov (United States)

    Pavia, Philippa R; Berent, Allyson C; Weisse, Chick W; Neiman, Dana; Lamb, Kenneth; Bagley, Demetrius

    2018-03-15

    OBJECTIVE To describe the technique and short- and long-term outcomes for dogs undergoing double-pigtail ureteral stent placement for treatment of benign ureteral obstruction. DESIGN Retrospective case series. ANIMALS 44 dogs (57 ureters). PROCEDURES Medical records of dogs that underwent ureteral stenting for treatment of benign ureteral obstruction between 2010 and 2013 were reviewed. Signal-ment, history, pertinent diagnostic imaging results, endourologic and post-procedural details, duration of hospitalization, complications, and outcome (short term, 7 to 30 days; long term, > 30 days) were recorded. Ureteral stent placement was performed endoscopically, surgically, or both, with fluoroscopic guidance. RESULTS 57 ureters (44 dogs) underwent stenting because of obstructive ureterolithiasis (n = 48 [84%]), stricture (5 [9%]), or both (4 [7%]). Endoscopic or surgical techniques were successful for stent placement in 45 of 55 and 12 of 12 ureters (34/42 and 10/10 dogs), respectively. Median hospitalization time was 1 day. Median creatinine concentration was 2 mg/dL prior to stenting and 1.3 mg/dL 3 months after the procedure. Urinary tract infections were present in 26 of 44 (59%) dogs prior to stenting and in 11 of 43 dogs (26%) after stenting. One of the 44 (2%) dogs died after undergoing stenting, but the cause of death was not related to the procedure. Median follow-up time was 1,158 days (range, 3 to > 1,555 days), with 30 of 44 dogs alive at the time of last follow-up. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ureteral stenting may be a viable option for first-line treatment of dogs with benign ureteral obstruction. However, patients should be monitored for urinary tract infection following stenting.

  20. Ureteral stenting can be a negative predictor for successful outcome following shock wave lithotripsy in patients with ureteral stones

    Directory of Open Access Journals (Sweden)

    Dong Hyuk Kang

    2016-11-01

    Full Text Available Purpose: To evaluate ureteral stenting as a negative predictive factor influencing ureteral stone clearance and to estimate the probability of one-session success in shock wave lithotripsy (SWL patients with a ureteral stone. Materials and Methods: We retrospectively reviewed the medical records of 1,651 patients who underwent their first SWL. Among these patients, 680 had a ureteral stone measuring 4–20 mm and were thus eligible for our study. The 57 patients who underwent ureteral stenting during SWL were identified. Maximal stone length (MSL, mean stone density (MSD, skin-to-stone distance (SSD, and stone heterogeneity index (SHI were determined by pre-SWL noncontrast computed tomography. Results: After propensity score matching, 399 patients were extracted from the total patient cohort. There were no significant differences between stenting and stentless groups after matching, except for a higher one-session success rate in the stentless group (78.6% vs. 49.1%, p=0.026. In multivariate analysis, shorter MSL, lower MSD, higher SHI, and absence of a stent were positive predictors for one-session success in patients who underwent SWL. Using cutoff values of MSL and MSD obtained from receiver operator curve analysis, in patients with a lower MSD (≤784 HU, the success rate was lower in those with a stent (61.1% than in those without (83.5% (p=0.001. However, in patients with a higher MSL (>10 mm, the success rate was lower in those with a stent (23.6% than in those without (52.2% (p=0.002. Conclusions: Ureteral stenting during SWL was a negative predictor of one-session success in patients with a ureteral stone.

  1. Substrate effects on the formation of flat Ag films on (110) surfaces of III-V compound semiconductors

    International Nuclear Information System (INIS)

    Chao, K.; Zhang, Z.; Ebert, P.; Shih, C.K.

    1999-01-01

    Ag films grown at 135 K on (110) surfaces of III-V compound semiconductors and annealed at room temperature are investigated by scanning tunneling microscopy and low-energy electron diffraction. Ag films on Ga-V semiconductors are well ordered, atomically flat, and exhibit a specific critical thickness, which is a function of the substrate material. Films grown on In-V semiconductors are still rather flat, but significantly more disordered. The (111) oriented Ag films on III-arsenides and III-phosphides exhibit a clear twofold superstructure. Films on III-antimonides exhibit threefold low-energy electron diffraction images. The morphology of the Ag films can be explained on the basis of the electronic growth mechanism. copyright 1999 The American Physical Society

  2. The Role of III-V Substrate Roughness and Deoxidation Induced by Digital Etch in Achieving Low Resistance Metal Contacts

    Directory of Open Access Journals (Sweden)

    Florent Ravaux

    2017-06-01

    Full Text Available To achieve low contact resistance between metal and III-V material, transmission-line-model (TLM structures of molybdenum (Mo were fabricated on indium phosphide (InP substrate on the top of an indium gallium arsenide (InGaAs layer grown by molecular beam epitaxy. The contact layer was prepared using a digital etch procedure before metal deposition. The contact resistivity was found to decrease significantly with the cleaning process. High Resolution Transmission & Scanning Electron Microscopy (HRTEM & HRSTEM investigations revealed that the surface roughness of treated samples was increased. Further analysis of the metal-semiconductor interface using Energy Electron Loss Spectroscopy (EELS showed that the amount of oxides (InxOy, GaxOy or AsxOy was significantly decreased for the etched samples. These results suggest that the low contact resistance obtained after digital etching is attributed to the combined effects of the induced surface roughness and oxides removal during the digital etch process.

  3. Broadband microwave photonic fully tunable filter using a single heterogeneously integrated III-V/SOI-microdisk-based phase shifter.

    Science.gov (United States)

    Lloret, Juan; Morthier, Geert; Ramos, Francisco; Sales, Salvador; Van Thourhout, Dries; Spuesens, Thijs; Olivier, Nicolas; Fédéli, Jean-Marc; Capmany, José

    2012-05-07

    A broadband microwave photonic phase shifter based on a single III-V microdisk resonator heterogeneously integrated on and coupled to a nanophotonic silicon-on-insulator waveguide is reported. The phase shift tunability is accomplished by modifying the effective index through carrier injection. A comprehensive semi-analytical model aiming at predicting its behavior is formulated and confirmed by measurements. Quasi-linear and continuously tunable 2π phase shifts at radiofrequencies greater than 18 GHz are experimentally demonstrated. The phase shifter performance is also evaluated when used as a key element in tunable filtering schemes. Distortion-free and wideband filtering responses with a tuning range of ~100% over the free spectral range are obtained.

  4. Pesan Sosial dalam Foto Jurnalistik (Analisis Semiotika dalam Buku ‘Jakarta Estetika Banal’, Bab I, III, V, dan VII

    Directory of Open Access Journals (Sweden)

    Jaka Priyo Nuswantara

    2014-01-01

    Full Text Available This study aims to determine the meaning of denotation and connotation, and social message in the book 'Aesthetics Jakarta Banal', Chapter I, III, V, and VII. The author uses the theory Semiotics of Roland Barthes. Where Semiotics of Roland Barthes uses two stages of analysis denotation and connotation. The research method used is a Roland Barthes semiotic analysis method on the basis that this study analyzes the messages conveyed in the book 'Aesthetics Jakarta Banal', which gives an explanation and overview of issues related to the formulation. Inferred outline text analysis results indicate that the social life of silence in the city with the concept of light to be seen. Of all the images examined, the object edges and political society into something dominant to be something that should be understood by the reader.

  5. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    International Nuclear Information System (INIS)

    Zhao, W.; Steidl, M.; Paszuk, A.; Brückner, S.; Dobrich, A.; Supplie, O.; Kleinschmidt, P.; Hannappel, T.

    2017-01-01

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H_2. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H_2-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H_2 ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  6. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W.; Steidl, M.; Paszuk, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Brückner, S. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Dobrich, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Supplie, O. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Kleinschmidt, P. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Hannappel, T., E-mail: thomas.hannappel@tu-ilmenau.de [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany)

    2017-01-15

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H{sub 2}. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H{sub 2}-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H{sub 2} ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  7. Intensity of adjuvant chemotherapy regimens and grade III-V toxicities among elderly stage III colon cancer patients.

    Science.gov (United States)

    van Erning, F N; Razenberg, L G E M; Lemmens, V E P P; Creemers, G J; Pruijt, J F M; Maas, H A A M; Janssen-Heijnen, M L G

    2016-07-01

    The aim of this study was to provide insight in the use, intensity and toxicity of therapy with capecitabine and oxaliplatin (CAPOX) and capecitabine monotherapy (CapMono) among elderly stage III colon cancer patients treated in everyday clinical practice. Data from the Netherlands Cancer Registry were used. All stage III colon cancer patients aged ≥70 years diagnosed in the southeastern part between 2005 and 2012 and treated with CAPOX or CapMono were included. Differences in completion of all planned cycles, cumulative dosages and toxicity between both regimens were evaluated. One hundred ninety-three patients received CAPOX and 164 patients received CapMono; 33% (n = 63) of the patients receiving CAPOX completed all planned cycles of both agents, whereas 55% (n = 90) of the patients receiving CapMono completed all planned cycles (P characteristics, CapMono was associated with a lower odds of developing grade III-V toxicity than CAPOX (odds ratio 0.54, 95% confidence interval 0.33-0.89). For patients treated with CAPOX, the most common toxicities were gastrointestinal (29%), haematological (14%), neurological (11%) and other toxicity (13%). For patients treated with CapMono, dermatological (17%), gastrointestinal (13%) and other toxicity (11%) were the most common. CAPOX is associated with significantly more grade III-V toxicities than CapMono, which had a pronounced impact on the cumulative dosage received and completion of all planned cycles. In this light, CapMono seems preferable over CAPOX. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. III-V/Si Tandem Cells Utilizing Interdigitated Back Contact Si Cells and Varying Terminal Configurations: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, Manuel; Klein, Talysa R.; Jain, Nikhil; Essig, Stephanie; Schulte-Huxel, Henning; Warren, Emily; van Hest, Maikel F. A. M.; Geisz, John; Stradins, Paul; Tamboli, Adele; Rienacker, Michael; Merkle, Agnes; Schmidt, Jan; Brendel, Rolf; Peibst, Robby

    2017-07-11

    Solar cells made from bulk crystalline silicon (c-Si) dominate the market, but laboratory efficiencies have stagnated because the current record efficiency of 26.3% is already very close to the theoretical limit of 29.4% for a single-junction c-Si cell. In order to substantially boost the efficiency of Si solar cells we have been developing stacked III-V/Si tandem cells, recently attaining efficiencies above 32% in four-terminal configuration. In this contribution, we use state-of-the-art III-V cells coupled with equivalent circuit simulations to compare four-terminal (4T) to three- and two-terminal (3T, 2T) operation. Equivalent circuit simulations are used to show that tandem cells can be operated just as efficiently using three terminals as with four terminals. However, care must be taken not to overestimate 3T efficiency, as the two circuits used to extract current interact, and a method is described to accurately determine this efficiency. Experimentally, a 4T GaInP/Si tandem cell utilizing an interdigitated back contact cell is shown, exhibiting a 4T efficiency of 31.5% and a 2T efficiency of 28.1%. In 3T configuration, it is used to verify the finding from simulation that 3T efficiency is overestimated when interactions between the two circuits are neglected. Considering these, a 3T efficiency approaching the 4T efficiency is found, showing that 3T operation is efficient, and an outlook on fully integrated high-efficiency 3T and 2T tandem cells is given.

  9. Detection of Vesico-Ureteric Reflux Using Voiding Hippuran Ureterograms

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, J. B.; Palser, R. [Section of Nuclear Medicine, Manitoba Cancer Treatment and Research Foundation, Winnipeg General Hospital, Winnipeg (Canada); Macpherson, R. I. [Children' s Hospital of Winnipeg, Winnipeg (Canada)

    1971-02-15

    Initial results of a technique for the demonstration of vesico-ureteric reflux in children are described. Hippuran-{sup 131}I (15 {mu}Ci) (ortho-iodohippurate) is injected intravenously. A standard renogram is obtained. Additional collimation is added to the recording probes and they are positioned to record the radioactivity from the mid-ureteric region. Recordings of normal and abnormal peristaltic activity during per-ora hydration of the patient are thus obtained. When the child is willing to void, he is placed upright on a bed pan, the probes positioned to record over the lower ureteric region and recordings are made while the child voids. All data are recorded on a 512-channel analyser operated in the multi-scaler node. Data are punched out on paper tape and, after an 11 point computer smoothing program, are displayed graphically. These recordings show different patterns in normal children and those with vesico-ureteric reflux. There are several advantages to this technique over the standard radiological and other radionuclide voiding cystoureterograms. The results are compared with contrast voiding cystourethrograms in both normal children and those with vesico-ureteric reflux. (author)

  10. [Distal ureteral lithiasis. ESWL versus ambulatory URS].

    Science.gov (United States)

    Miján Ortiz, J L; Gutiérrez Tejero, F; López Carmona, F; Nogueras Ocaña, M; Arrabal Martín, M; Zuluaga Gómez, A

    2001-11-01

    To present the results achieved in the treatment of 1802 distal ureteral stones treated at the Lithotripsy Unit of the San Cecilio University Hospital over the last 10 years (1990-2000). Stones were treated by extracorporeal shock wave lithotripsy (ESWL) or ureteroscopy (URS). ESWL was the initial treatment in 81% of the cases (1460 calculi) and URS in the remaining 19% (342 stones). URS was performed for complication or failed ESWL (102 stones) and ESWL was performed for failed URS, basically due to stone migration (24 stones). Ureterolithotomy was required on 7 occasions. Sedation-analgesia with fentanyl and midazolam was routinely used in URS. Sedation was required in only 55% of the ESWL procedures. Elective ESWL resolved 93% of the cases, a percentage which is similar to that achieved with URS as first treatment. The ESWL retreatment rate was 1.3. URS was successful in 98% of the cases of failed ESWL. There are two treatment modalities for stones in the distal ureter: ESWL and URS. We advocate the use of outpatient URS with sedation preferably in the female patient, impacted stones, obstructive uropathy, stones larger than 2 cm and radiotransparent stones.

  11. Post appendectomy acalculus bilateral ureteric obstruction: A rare entity in children

    Directory of Open Access Journals (Sweden)

    Vipul Gupta

    2013-01-01

    Full Text Available Bilateral acalculus ureteric obstruction is described as rare sequelae of acute appendicitis in two paediatric patients aged 6 and 11 years presented with features of anuria. Imaging and endoscopic evaluation confirmed bilateral ureteric obstruction secondary to bladder wall oedema as an inflammatory reaction to appendix. Both cases recovered following bilateral ureteric stenting and are doing well.

  12. Technical and clinical outcomes of ureteral stenting in cats with benign ureteral obstruction: 69 cases (2006-2010).

    Science.gov (United States)

    Berent, Allyson C; Weisse, Chick W; Todd, Kimberly; Bagley, Demetrius H

    2014-03-01

    OBJECTIVE--To evaluate the technical, short-term, and long-term outcomes in cats with benign ureteral obstructions treated by means of double-pigtail ureteral stent placement. DESIGN--Retrospective case series. ANIMALS--69 cats (79 ureters). PROCEDURES--The diagnosis of benign ureteral obstruction was made via abdominal ultrasonography, radiography, and ureteropyelography. Ureteral stent placement was attempted endoscopically, surgically, or both, with fluoroscopic guidance. The medical records were reviewed for pre-, intra-, and postoperative data; complications; and outcome. RESULTS--69 cats (79 ureters) had stent placement attempted for various causes: ureterolithiasis (56/79 [71%]), stricture (10/79 [13%]), both ureterolithiasis and stricture (12/79 [15%]), or a purulent plug (1/79 [1%]). Stent placement was successful in 75 of 79 ureters (95%). Median number of stones per ureter was 4 (range, 0 to > 50), and 67 of 79 (85%) had concurrent nephrolithiasis. Preoperative azotemia was present in 95% (66/69) of cats (median creatinine concentration, 5.3 mg/dL [range, 1.1 to 25.8 mg/dL]), and 71% (49/69) remained azotemic (median, 2.1 mg/dL [range, 1.0 to 11.8 mg/dL]) after successful surgery. Procedure-related, postoperative ( 30 days) complications occurred in 8.7% (6/69; 7/79 ureters), 9.1% (6/66), 9.8% (6/61), and 33% (20/60) of cats, respectively; most of these complications were minor and associated with intermittent dysuria or the need for ureteral stent exchange. The perioperative mortality rate was 7.5% (5/69), and no deaths were procedure related. The median survival time was 498 days (range, 2 to > 1,278 days). For patients with a renal cause of death, median survival time was > 1,262 days, with only 14 of 66 cats (21%) dying of chronic kidney disease. Nineteen (27%) cats needed a stent exchange (stricture in-growth [n = 10], migration [4], ureteritis [2], dysuria [2], pyelonephritis [1], or reflux [1]). No patient died of the procedure or recurrent

  13. High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure.

    Science.gov (United States)

    Chen, Szu-Hung; Liao, Wen-Shiang; Yang, Hsin-Chia; Wang, Shea-Jue; Liaw, Yue-Gie; Wang, Hao; Gu, Haoshuang; Wang, Mu-Chun

    2012-08-01

    A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal-semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials.

  14. Stone Formation and Fragmentation in Forgotten Ureteral Double J Stent

    Directory of Open Access Journals (Sweden)

    Okan Bas

    2014-02-01

    Full Text Available Aim: Nowadays, ureteral stents play an essential role in various endourological and open surgical procedures and common procedures performed in daily urological practice. However, stents can cause significant complications such as migration, infection, fragmentation, stone formation and encrustation, especially when forgotten for a long period. Objectives: We present our experience in endoscopic management of forgotten ureteral stents with a brief review of current literature. Case presentation: A total of 2 patients with forgotten ureteral stents were treated with endourological approaches in our department. Indwelling durations were 18 months and 36 months. After treatment both patients were stone and stent free. Conclusion: An endourological approach is effective for stent and stone removal after a single anesthesia session with minimal morbidity and short hospital stay. However, therapeutic strategy is also determined by the technology available. The best treatment would be the prevention of this complication by providing detailed patient education.

  15. Percutaneous antegrade ureteric stent removal using a rigid alligator forceps.

    LENUS (Irish Health Repository)

    Given, M F

    2008-12-01

    To evaluate the safety and efficacy of percutaneous antegrade ureteric stent removal using a rigid alligator forceps. Twenty patients were included in our study. Indications for ureteric stent insertion included stone disease (n = 7), malignancy (n = 8) and transplant anastomotic strictures (n = 5). Stent retrieval was carried out for proximal stent placement\\/migration in seven patients and encrustation in the remaining 13. Twenty-two stents were successfully retrieved in 20 patients. There was one technical failure (5%). There were no major complications. We had four minor complications, which included nephrostomy site pain (n = 2), periprocedural sepsis (n = 1) and a small urinoma (n = 1). All patients settled with conservative management. Percutaneous radiologically guided antegrade ureteric stent removal with an alligator forceps is safe and effective, particularly when initial surgical removal has failed.

  16. Endometriosis on the uterosacral ligament: a marker of ureteral involvement.

    Science.gov (United States)

    Lima, Raquel; Abdalla-Ribeiro, Helizabet; Nicola, Ana Luisa; Eras, Aline; Lobao, Anna; Ribeiro, Paulo Ayroza

    2017-06-01

    To evaluate the association between ultrasound measurements of endometriosis nodules on the uterosacral ligament (USL) and the risk of ureteral involvement, as well as to assess whether associations with other ultrasound variables increase the sensitivity and specificity of the diagnosis of ureteral endometriosis. Cross-sectional, observational study. University hospital. Four hundred sixty-three women with deep infiltrating endometriosis (DIE). Patients diagnosed with DIE underwent transvaginal ultrasound endometriosis mapping before laparoscopic surgery for full excision of endometriotic lesions. Preoperative ultrasound evaluation, intra- and postoperative assessment, and anatomopathologic confirmation. Of the 463 patients who participated in the study, 111 (23.97%) presented with endometriosis nodules with USL involvement on ultrasound examination conducted by a single radiologist. Receiver operating characteristic curve analysis showed that the size of the USL nodule had a statistically significant association with ipsilateral ureteral involvement. After multivariate logistic regression, the variables reduction in ovarian mobility, ureteral changes on the right side, size of the USL nodule, and presence of endometrioma on the left side were significantly associated with a ureteral endometriosis nodule. However, the combined result for the variables cited was worse than the diagnostic analysis using only the size of the USL nodule. Uterosacral ligament nodules with ultrasound measurements of 1.75 cm and 1.95 cm on the right and left sides, respectively, significantly increase the risk of ureteral involvement. Even with the association of other ultrasound variables, there was no improvement in sensitivity. Therefore, USL nodule size is a key measure for therapeutic planning and consent of the patient. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  17. Fluoroscopic guidance of retrograde exchange of ureteral stents in women.

    Science.gov (United States)

    Chang, Ruey-Sheng; Liang, Huei-Lung; Huang, Jer-Shyung; Wang, Po-Chin; Chen, Matt Chiung-Yu; Lai, Ping-Hong; Pan, Huay-Ben

    2008-06-01

    The purpose of this study was to review our experience with fluoroscopically guided retrograde exchange of ureteral stents in women. During a 48-month period, 28 women (age range, 38-76 years) were referred to our department for retrograde exchange of a ureteral stent. The causes of urinary obstruction were tumor compression in 26 patients and benign fibrotic stricture in two patients. A large-diameter snare catheter (25-mm single loop or 18- to 35-mm triple loop) or a foreign body retrieval forceps (opening width, 11.3 mm) was used to grasp the bladder end of the stent under fluoroscopic guidance. The technique entailed replacement of a patent or occluded ureteral stent with a 0.035- or 0.018-inch guidewire with or without the aid of advancement of an angiographic sheath. A total of 54 ureteral stents were exchanged with a snare catheter in 42 cases or a forceps in 12 cases. One stent misplaced too far up the ureter was replaced successfully through antegrade percutaneous nephrostomy. Ten occluded stents, including one single-J stent, were managed with a 0.018-inch guidewire in three cases, advancement of an angiographic sheath over the occluded stent into the ureter in five cases, and recannulation of the ureteral orifice with a guidewire in two cases. No complications of massive hemorrhage, ureter perforation, or infection were encountered. With proper selection of a snare or forceps catheter, retrograde exchange of ureteral stents in women can be easily performed under fluoroscopic guidance with high technical success and a low complication rate.

  18. Laparoscopic Management of Ureteral Endometriosis and Hydronephrosis Associated With Endometriosis.

    Science.gov (United States)

    Alves, João; Puga, Marco; Fernandes, Rodrigo; Pinton, Anne; Miranda, Ignacio; Kovoor, Elias; Wattiez, Arnaud

    STUDY OBJECTIVE: To evaluate if laparoscopic treatment of ureteral endometriosis is feasible, safe, and effective and to determine if ureteral dilatation and/or the number of incisions increases complications. An institutional review board-approved retrospective cohort study of consecutive patients who underwent surgery for deep infiltrating endometriosis involving the ureter with hydronephrosis (Canadian Task Force classification III). A university hospital. Of 658 patients who had surgery for deep infiltrating endometriosis between November 2004 and December 2013, 198 of the 658 patients had ureteral endometriosis and required ureterolysis, and 28 of the 198 patients were identified with ureteral dilatation and hydronephrosis associated with endometriosis. Of these 28 cases, 15 ureterolyses, 12 reanastomoses, and 1 reimplantation were performed. Medical, operative, and pathological data on the evolution of pain, urinary complaints, fertility, complications, and recurrences were collected from clinical records. Additionally, telephone interviews were performed for the follow-up of long-term outcomes. All 28 patients had concomitant surgical procedures because of endometriosis elsewhere in the pelvis or abdomen; 12 (42.9%) underwent surgery of the bowel, whereas 5 (17.9%) had bladder surgery. The evolution of pain after surgery showed a positive response (mean dysmenorrhea evaluation measured by the Numeric Pain Rating Scale from 0-10 preoperatively at the short-term follow-up and the long-term follow-up: 7.25-1.73 and 0.25, respectively). Three complications were noted in the group of 28 patients with ureterohydronephrosis; 1 required surgical reintervention. Logistic regression analyses found vaginal incision (odds ratio = 2.08; 95% CI 0.92-4.73), bladder incision (odds ratio = 8.77; 95% CI 3.25-23.63), number of incisions (odds ratio = 2.12; 95% CI 1.29-3.47), and number of previous surgeries (odds ratio = 1.26; 95% CI 0.93-1.71) as independent risk

  19. Acute bilateral ureteral obstruction following Dextranomer/hyaluronic acid polymer injection: A case report

    Directory of Open Access Journals (Sweden)

    Arnon Lavi

    2017-05-01

    Full Text Available Ureteral obstruction following bulking agent injection for treatment of vesicoureteral reflux is rare. Herein we report a case of acute bilateral ureteral obstruction following bilateral Dextranomer/hyaluronic acid polymer injection. The obstruction which manifested hours following the injection, was treated with prompt insertion of bilateral ureteral stents. The stents were removed 4 weeks later with complete resolution of the obstruction. We believe that ureteral stenting is an excellent solution for acute ureteral obstruction following Dextranomer/hyaluronic acid polymer injection

  20. High-Throughput Multiple Dies-to-Wafer Bonding Technology and III/V-on-Si Hybrid Lasers for Heterogeneous Integration of Optoelectronic Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Xianshu eLuo

    2015-04-01

    Full Text Available Integrated optical light source on silicon is one of the key building blocks for optical interconnect technology. Great research efforts have been devoting worldwide to explore various approaches to integrate optical light source onto the silicon substrate. The achievements so far include the successful demonstration of III/V-on-Si hybrid lasers through III/V-gain material to silicon wafer bonding technology. However, for potential large-scale integration, leveraging on mature silicon complementary metal oxide semiconductor (CMOS fabrication technology and infrastructure, more effective bonding scheme with high bonding yield is in great demand considering manufacturing needs. In this paper, we propose and demonstrate a high-throughput multiple dies-to-wafer (D2W bonding technology which is then applied for the demonstration of hybrid silicon lasers. By temporarily bonding III/V dies to a handle silicon wafer for simultaneous batch processing, it is expected to bond unlimited III/V dies to silicon device wafer with high yield. As proof-of-concept, more than 100 III/V dies bonding to 200 mm silicon wafer is demonstrated. The high performance of the bonding interface is examined with various characterization techniques. Repeatable demonstrations of 16-III/V-die bonding to pre-patterned 200 mm silicon wafers have been performed for various hybrid silicon lasers, in which device library including Fabry-Perot (FP laser, lateral-coupled distributed feedback (LC-DFB laser with side wall grating, and mode-locked laser (MLL. From these results, the presented multiple D2W bonding technology can be a key enabler towards the large-scale heterogeneous integration of optoelectronic integrated circuits (H-OEIC.

  1. The Effect of Ureteral Stent Placement Before Radical Prostatectomy on the Safety of Ureteral Dissection and the Surgeon’s Comfort

    OpenAIRE

    Fatih Akdemir; Emrah Okulu; Önder Kayıgil

    2017-01-01

    Objective: This study investigated the role of preoperative ureteral stent placement in reducing the risk of ureteral injury, an intraoperative complication of radical retropubic prostatectomy (RRP), and its contribution to the surgeon’s comfort. Materials and Methods: Open RRP was performed in 66 patients diagnosed with localized prostate cancer in our clinic between 2010 and 2015. The patients were divided into two groups; group 1 (n=34) underwent surgery without ureteral stent placement...

  2. New insights into thorium and uranium oxo-arsenic (III/V) and oxo-phosphates (V) crystal chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Na

    2015-12-11

    The fundamental chemistry of actinides is of great interest owing to the diverse number of valence states and complex coordination chemistry of the actinides. The phases based on actinides and oxo-salt fragments have been under thorough investigation in the last decades. These compounds can be widely found in nature and they affect the migration process of actinides in nature. A better understanding of the fundamental coordination chemistry of actinide compounds with oxo-salts of group V elements is not only important for understanding the actinides behavior within the migration process but can also be used to understand actinide properties in phosphate ceramics. Concerning the radioactive issues, the less radioactive early actinides (i.e. U, Th) can be taken as modeling elements to study the crystal chemistry of the transuranic elements (Np, Pu) without the major handling problems. This can be done as Th(IV) has a very similar coordination chemistry with An(IV) and U(VI) can be chosen as a modeling element for transuranic elements in higher valence states. Therefore, a systematic research on the actinides (U, Th) bearing phases with tetrahedral oxo-anions such as phosphates and arsenates have been performed in this work. High temperature (HT) solid state reaction, High pressure high temperature (HP-HT) solid state reaction and the hydrothermal method were the methods of choice for synthesizing actinide bearing oxo-arsenic(III/V) and oxo- phosphorus(V) phases in the past three years. As a result, numerous novel compounds containing actinides were obtained. The structures of all compounds were determined using single crystal X-ray diffraction data. Raman spectroscopy, EDS, DSC and high temperature powder X-ray diffraction (HT-PXRD) measurements were implemented to characterize the chemical and physical properties of the obtained compounds. The core of this dissertation is a fundamental study of the crystal chemistry of actinides (Th, U) oxo-arsenic (III/V) and oxo

  3. New insights into thorium and uranium oxo-arsenic (III/V) and oxo-phosphates (V) crystal chemistry

    International Nuclear Information System (INIS)

    Yu, Na

    2015-01-01

    The fundamental chemistry of actinides is of great interest owing to the diverse number of valence states and complex coordination chemistry of the actinides. The phases based on actinides and oxo-salt fragments have been under thorough investigation in the last decades. These compounds can be widely found in nature and they affect the migration process of actinides in nature. A better understanding of the fundamental coordination chemistry of actinide compounds with oxo-salts of group V elements is not only important for understanding the actinides behavior within the migration process but can also be used to understand actinide properties in phosphate ceramics. Concerning the radioactive issues, the less radioactive early actinides (i.e. U, Th) can be taken as modeling elements to study the crystal chemistry of the transuranic elements (Np, Pu) without the major handling problems. This can be done as Th(IV) has a very similar coordination chemistry with An(IV) and U(VI) can be chosen as a modeling element for transuranic elements in higher valence states. Therefore, a systematic research on the actinides (U, Th) bearing phases with tetrahedral oxo-anions such as phosphates and arsenates have been performed in this work. High temperature (HT) solid state reaction, High pressure high temperature (HP-HT) solid state reaction and the hydrothermal method were the methods of choice for synthesizing actinide bearing oxo-arsenic(III/V) and oxo- phosphorus(V) phases in the past three years. As a result, numerous novel compounds containing actinides were obtained. The structures of all compounds were determined using single crystal X-ray diffraction data. Raman spectroscopy, EDS, DSC and high temperature powder X-ray diffraction (HT-PXRD) measurements were implemented to characterize the chemical and physical properties of the obtained compounds. The core of this dissertation is a fundamental study of the crystal chemistry of actinides (Th, U) oxo-arsenic (III/V) and oxo

  4. Pressure-induced structural change of liquid InAs and the systematics of liquid III-V compounds

    International Nuclear Information System (INIS)

    Hattori, T.; Tsuji, K.; Miyata, Y.; Sugahara, T.; Shimojo, F.

    2007-01-01

    To understand the pressure-induced structural changes of liquid III-V compounds systematically, the pressure dependence of l-InAs was investigated using the synchrotron x-ray diffraction and an ab initio molecular-dynamics simulation (AIMD). The x-ray diffraction experiments revealed that the liquid changes its compression behavior from a nearly uniform type to a nonuniform one around 9 GPa. Corresponding to this change, the coordination number (China), which is maintained up to 9 GPa, markedly increases from 6.0 to 7.5. The AIMD simulation revealed that this change is related to the change in the pressure dependence of all three pair correlations. In particular, a marked change is observed in the As-As correlation; in the low-pressure region, the position of the first peak in g AsAs (r), r AsAs , increases while maintaining the CN AsAs , but in the high-pressure region, the r AsAs stops increasing and the CN AsAs begins to increase. The AIMD simulation also revealed that each partial structure of l-InAs is similar to that for the pure-element liquid with the same valence electron number. Upon compression, each partial structure approaches the respective one for a heavier element in the same group. These findings suggest that the structures of liquid compounds are locally controlled by the number of the valence electrons in each ion pair and that the change in each partial structure obeys the empirical rule that the high-pressure state resembles the ambient state of a heavier element in the same group. Comparing the pressure-induced structural change of l-InAs to those of other liquid III-V compounds (GaSb and InSb) has revealed that, although the high-pressure behaviors of these three liquids are apparently different, their structural changes are systematically understood by a common structural sequence. This systematics originates from the same effect on each partial structure between increasing the atomic number and the pressurization

  5. An unusual case: right proximal ureteral compression by the ovarian vein and distal ureteral compression by the external iliac vein

    Directory of Open Access Journals (Sweden)

    Halil Ibrahim Serin

    2015-12-01

    Full Text Available A 32-years old woman presented to the emergency room of Bozok University Research Hospital with right renal colic. Multidetector computed tomography (MDCT showed compression of the proximal ureter by the right ovarian vein and compression of the right distal ureter by the right external iliac vein. To the best of our knowledge, right proximal ureteral compression by the ovarian vein together with distal ureteral compression by the external iliac vein have not been reported in the literature. Ovarian vein and external iliac vein compression should be considered in patients presenting to the emergency room with renal colic or low back pain and a dilated collecting system.

  6. Study of the transport phenomena in III-V materials by the Monte Carlo method: application to INAS

    International Nuclear Information System (INIS)

    Bouazza, B.; Amer, L.; Guen-Bouazza, A.; Sayeh, C.; Chabanne-Sari, N.E.; Gontrand, C.

    2004-01-01

    Full text.The microelectronic comprehension of the phenomena which describes the behavior of the carriers in semiconductor materials requires the knowledge of energy distribution function. This distribution function is obtained by the resolution of Boltzmann equation which is very hard to solve analytically. Other methods based on modeling are actually successfully used to solve this equation. This Monte Carlo method is among of the most methods used for studying electronics components operations. It consists to follow the evolution of electron packets in real space, where each electron subjected to the electric field present in material goes interact with the crystal lattice. It is therefore an iterative process made up from a whole coasting flights stopped by acoustics interactions, polar and non polar optics, piezoelectric, inter-valley, impurity, ionization and surface. By applying this method to the III-V material: InAs. We can describe the behavior of the carriers from dynamic and energetic point of view (variation speed according to the field). The simulation is applied, taking into account variation of the carriers according to time in the non stationary mode, and the effect of temperature, and measurements doping. Results obtained are shown to be comparable to those of the theory

  7. Proteomic and metabolomic biomarkers for III-V semiconductors: And prospects for application to nano-materials

    International Nuclear Information System (INIS)

    Fowler, Bruce A.; Conner, Elizabeth A.; Yamauchi, Hiroshi

    2008-01-01

    There has been an increased appreciation over the last 20 years that chemical agents at very low dose levels can produce biological responses in protein expression patterns (proteomic responses) or alterations in sensitive metabolic pathways (metabolomic responses). Marked improvements in analytical methodologies, such as 2-D gel electrophoresis, matrix-assisted laser desorption-time of flight (MALDI-TOF) and surface enhanced laser desorption-time of flight (SELDI-TOF) technologies are capable of identifying specific protein patterns related to exposure to chemicals either alone or as mixtures. The detection and interpretation of early cellular responses to chemical agents have also made great advances through correlative ultrastructural morphometric and biochemical studies. Similarly, advances in analytical technologies such as HPLC, proton NMR, MALDI-TOF, and SELDI-TOF have permitted early detection of changes in a number of essential metabolic pathways following chemical exposures by measurement of alterations in metabolic products from those pathways. Data from these approaches are increasingly regarded as potentially useful biomarkers of chemical exposure and early cellular responses. Validation and establishment of linkages to biological outcomes are needed in order for biomarkers of effect to be established. This short review will cover a number of the above techniques and report data from chemical exposures to two binary III-V semiconductor compounds to illustrate gender differences in proteomic responses. In addition, the use of these methodologies in relation to rapid safety evaluations of nanotechnology products will be discussed. (Supported in part by NIH R01-ES4879)

  8. Two Dimensional Effective Electron Mass at the Fermi Level in Quantum Wells of III-V, Ternary and Quaternary Semiconductors.

    Science.gov (United States)

    Chakrabarti, S; Chatterjee, B; Debbarma, S; Ghatak, K P

    2015-09-01

    In this paper we study the influence of strong electric field on the two dimensional (2D)effective electron mass (EEM) at the Fermi level in quantum wells of III-V, ternary and quaternary semiconductors within the framework of k x p formalism by formulating a new 2D electron energy spectrum. It appears taking quantum wells of InSb, InAs, Hg(1-x)Cd(x)Te and In(1-x)Ga(x)As(1-y)P(y) lattice matched to InP as examples that the EEM increases with decreasing film thickness, increasing electric field and increases with increasing surface electron concentration exhibiting spikey oscillations because of the crossing over of the Fermi level by the quantized level in quantum wells and the quantized oscillation occurs when the Fermi energy touches the sub-band energy. The electric field makes the mass quantum number dependent and the oscillatory mass introduces quantum number dependent mass anisotropy in addition to energy. The EEM increases with decreasing alloy composition where the variations are totally band structure dependent. Under certain limiting conditions all the results for all the cases get simplified into the well-known parabolic energy bands and thus confirming the compatibility test. The content of this paper finds three applications in the fields of nano-science and technology.

  9. Atomic scale images of acceptors in III-V semiconductors. Band bending, tunneling paths and wave functions

    Energy Technology Data Exchange (ETDEWEB)

    Loth, S.

    2007-10-26

    This thesis reports measurements of single dopant atoms in III-V semiconductors with low temperature Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy (STS). It investigates the anisotropic spatial distribution of acceptor induced tunneling processes at the {l_brace}110{r_brace} cleavage planes. Two different tunneling processes are identified: conventional imaging of the squared acceptor wave function and resonant tunneling at the charged acceptor. A thorough analysis of the tip induced space charge layers identifies characteristic bias windows for each tunnel process. The symmetry of the host crystal's band structure determines the spatial distribution of the tunneling paths for both processes. Symmetry reducing effects at the surface are responsible for a pronounced asymmetry of the acceptor contrasts along the principal [001] axis. Uniaxial strain fields due to surface relaxation and spin orbit interaction of the tip induced electric field are discussed on the basis of band structure calculations. High-resolution STS studies of acceptor atoms in an operating p-i-n diode confirm that an electric field indeed changes the acceptor contrasts. In conclusion, the anisotropic contrasts of acceptors are created by the host crystal's band structure and concomitant symmetry reduction effects at the surface. (orig.)

  10. Exploiting strain to enhance the Bi incorporation in GaAs-based III/V semiconductors using MOVPE

    Science.gov (United States)

    Nattermann, L.; Ludewig, P.; Sterzer, E.; Volz, K.

    2017-07-01

    Bi containing III/V semiconductors are frequently mentioned for their importance as part of the next generation of optoelectronic devices. Bi containing ternary and quaternary materials like Ga(AsBi), Ga(NAsBi) or Ga(PAsBi) are promising candidates to meet the requirements for new laser structures for telecommunications and solar cell applications. However, in previous studies it was determined that the incorporation of sufficient amounts of Bi still poses a challenge, especially when using MOVPE (metalorganic vapour phase epitaxy) as the growth technique. In order to figure out which mechanisms are responsible for the limitation of Bi incorporation, this work deals with the question of whether there is a relationship between strain, induced by the large Bi atoms, and the saturation level of Bi incorporation in Ga(AsBi). Ga(NAsBi) structures were grown by MOVPE at a low temperature, 400 °C, and compared to Ga(PAsBi) as well as Ga(AsBi) growth. By using the two group V atoms P and N, which have a smaller covalent radius than Bi, the effect of local strain compensation was investigated systematically. The comparison of Bi incorporation in the two quaternary materials systems proved the importance of local strain for the limitation of Bi incorporation, in addition to other effects, like Bi surface coverage and hydrocarbon groups at the growth surface. This, of course, also opens up ways to strain-state-engineer the Bi incorporation in semiconductor alloys.

  11. Controlling and modelling the wetting properties of III-V semiconductor surfaces using re-entrant nanostructures.

    Science.gov (United States)

    Ng, Wing H; Lu, Yao; Liu, Huiyun; Carmalt, Claire J; Parkin, Ivan P; Kenyon, Anthony J

    2018-02-23

    Inorganic semiconductors such as III-V materials are very important in our everyday life as they are used for manufacturing optoelectronic and microelectronic components with important applications span from energy harvesting to telecommunications. In some applications, these components are required to operate in harsh environments. In these cases, having waterproofing capability is essential. Here we demonstrate design and control of the wettability of indium phosphide based multilayer material (InP/InGaAs/InP) using re-entrant structures fabricated by a fast electron beam lithography technique. This patterning technique enabled us to fabricate highly uniform nanostructure arrays with at least one order of magnitude shorter patterning times compared to conventional electron beam lithography methods. We reduced the surface contact fraction significantly such that the water droplets may be completely removed from our nanostructured surface. We predicted the wettability of our patterned surface by modelling the adhesion energies between the water droplet and both the patterned surface and the dispensing needle. This is very useful for the development of coating-free waterproof optoelectronic and microelectronic components where the coating may hinder the performance of such devices and cause problems with semiconductor fabrication compatibility.

  12. Ion beam nanopatterning of III-V semiconductors: consistency of experimental and simulation trends within a chemistry-driven theory.

    Science.gov (United States)

    El-Atwani, O; Norris, S A; Ludwig, K; Gonderman, S; Allain, J P

    2015-12-16

    Several proposed mechanisms and theoretical models exist concerning nanostructure evolution on III-V semiconductors (particularly GaSb) via ion beam irradiation. However, making quantitative contact between experiment on the one hand and model-parameter dependent predictions from different theories on the other is usually difficult. In this study, we take a different approach and provide an experimental investigation with a range of targets (GaSb, GaAs, GaP) and ion species (Ne, Ar, Kr, Xe) to determine new parametric trends regarding nanostructure evolution. Concurrently, atomistic simulations using binary collision approximation over the same ion/target combinations were performed to determine parametric trends on several quantities related to existing model. A comparison of experimental and numerical trends reveals that the two are broadly consistent under the assumption that instabilities are driven by chemical instability based on phase separation. Furthermore, the atomistic simulations and a survey of material thermodynamic properties suggest that a plausible microscopic mechanism for this process is an ion-enhanced mobility associated with energy deposition by collision cascades.

  13. Nonradiative lifetime extraction using power-dependent relative photoluminescence of III-V semiconductor double-heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Walker, A. W., E-mail: alexandre.walker@ise.fraunhofer.de; Heckelmann, S.; Karcher, C.; Höhn, O.; Went, C.; Niemeyer, M.; Bett, A. W.; Lackner, D. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg (Germany)

    2016-04-21

    A power-dependent relative photoluminescence measurement method is developed for double-heterostructures composed of III-V semiconductors. Analyzing the data yields insight into the radiative efficiency of the absorbing layer as a function of laser intensity. Four GaAs samples of different thicknesses are characterized, and the measured data are corrected for dependencies of carrier concentration and photon recycling. This correction procedure is described and discussed in detail in order to determine the material's Shockley-Read-Hall lifetime as a function of excitation intensity. The procedure assumes 100% internal radiative efficiency under the highest injection conditions, and we show this leads to less than 0.5% uncertainty. The resulting GaAs material demonstrates a 5.7 ± 0.5 ns nonradiative lifetime across all samples of similar doping (2–3 × 10{sup 17 }cm{sup −3}) for an injected excess carrier concentration below 4 × 10{sup 12 }cm{sup −3}. This increases considerably up to longer than 1 μs under high injection levels due to a trap saturation effect. The method is also shown to give insight into bulk and interface recombination.

  14. Outcomes of outpatient ureteral stenting without fluoroscopy at ...

    African Journals Online (AJOL)

    for several years, resource limitations in the form of hospital bed ... ureteric stone complicated by non-resolving pain, failure of medical ... The overall success rate for the procedures was 85.4%, independent of gender (p=0.87), age (p=0.13), ...

  15. Intraureteral metallic endoprosthesis in the treatment of ureteral strictures

    Energy Technology Data Exchange (ETDEWEB)

    Daskalopoulos, George; Hatzidakis, Adam; Triantafyllou, Theodosis; Delakas, Dimitrios; Anezinis, Ploutarchos; Metaxari, Maria; Cranidis, Angelos

    2001-09-01

    Objective: We report our experience on intraureteral metallic stents placement for the treatment of malignant and benign ureteral strictures. Methods: Eight patients (six men and two women) with inoperable malignant or benign ureteral strictures, underwent insertion of metallic stents through percutaneous tracts. Six lesions (three malignant, three benign) involved ureterointestinal anastomoses after cystectomy for bladder cancer and ureteroileal urinary diversion or bladder substitution, and two malignant lesions involved the midureter. Self-expandable stents were used in seven cases and a balloon-expandable stent in the remaining one case. One stent was sufficient in seven ureters, and in one ureter, two overlapping stents were placed. Results: Metallic stents were inserted without technical difficulties in all obstructed ureters and patency was achieved in all patients. Ultrasonography revealed resolution of pre-existing hydronephrosis. The duration of follow-up was 6-17 months (mean, 9 months). One ureter was occluded 8 months after stent placement because of ingrowth of tumor and granulation tissue. The other ureters showed no signs of obstruction during follow-up. No major complications directly attributable to the metallic stent occurred. Conclusions: Our results suggest that insertion of a metallic stent in the ureter is feasible and safe for the treatment of benign or malignant ureteral strictures. However, more work needs to be done to establish the use of these stents for the treatment of ureteral obstruction.

  16. Spontaneous calyceal rupture caused by a ureteral calculus ...

    African Journals Online (AJOL)

    Rupture of the urinary collecting system with perirenal and retroperitoneal extravasation of the urine is an unusual condition that is typically caused by ureteral-obstructing calculi. We report a case of calyceal rupture with urinoma formation, due to a stone in the distal ureter. The diagnosis was confirmed by computed ...

  17. The efficacy of tamsulosin in lower ureteral calculi

    Directory of Open Access Journals (Sweden)

    Griwan M

    2010-01-01

    Full Text Available Context: There has been a paradigm shift in the management of ureteral calculi in the last decade with the introduction of new less invasive methods, such as ureterorenoscopy and extracorporeal shock wave lithotripsy (ESWL. Aims: Recent studies have reported excellent results with medical expulsive therapy (MET for distal ureteral calculi, both in terms of stone expulsion and control of ureteral colic pain. Settings and Design: We conducted a comparative study in between watchful waiting and MET with tamsulosin. Materials and Methods: We conducted a comparative study in between watchful waiting (Group I and MET with tamsulosin (Group II in 60 patients, with a follow up of 28 days. Statistical Analysis: Independent ′t′ test and chi-square test. Results: Group II showed a statistically significant advantage in terms of the stone expulsion rate. The mean number of episodes of pain, mean days to stone expulsion and mean amount of analgesic dosage used were statistically significantly lower in Group II (P value is 0.007, 0.01 and 0.007, respectively as compared to Group I. Conclusions: It is concluded that MET should be considered for uncomplicated distal ureteral calculi before ureteroscopy or extracorporeal lithotripsy. Tamsulosin has been found to increase and hasten stone expulsion rates, decrease acute attacks by acting as a spasmolytic, reduces mean days to stone expulsion and decreases analgesic dose usage.

  18. Outcome of ureteroscopy for the management of distal ureteric ...

    African Journals Online (AJOL)

    M. El-Qadhi

    Minimal invasive techniques for management of ureteric cal- culi include extracorporeal shockwave lithotripsy (ESWL), ureteroscopy (URS), and laparoscopic ureterolithotomy. The choice of the procedure depends on location and characteristics of the stone, patient's preference, as well as associated costs. According to.

  19. Cystoscopic temporary ureteral catheterization during radical vaginal and abdominal trachelectomy.

    Science.gov (United States)

    Abu-Rustum, Nadeem R; Sonoda, Yukio; Black, Destin; Chi, Dennis S; Barakat, Richard R

    2006-11-01

    To describe the role of temporary retrograde ureteral catheterization at the time of fertility-sparing radical vaginal or abdominal trachelectomy in women with early-stage cervical cancer. We analyzed a prospectively maintained database of all patients with cervical cancer who were explored for radical vaginal or abdominal trachelectomy at our institution. Cystourethroscopy and ureteral catheterization were performed prior to the vaginal or abdominal operation in all patients, except two pediatric ones. Temporary bilateral retrograde ureteral catheters were planned for all patients as part of our routine procedure to facilitate identification of the distal ureters. 5Fr whistle-tip or open-ended catheters were used and usually advanced to approximately 20 cm. Catheters were removed at the end of the operation in all cases. All catheters were inserted by a gynecologic oncology fellow or attending. Between 11/01 and 12/05, 40 patients were taken to the operating room for planned fertility-sparing radical vaginal or abdominal trachelectomy. We previously reported on two pediatric patients; they are excluded from this report. The median age for adult patients was 32 years (mean, 31.6; range, 23-40). International Federation of Gynecology and Obstetrics (FIGO) stage included IB1 (26), IA2 (6), and IA1 with lymphovascular invasion (6). Thirty-four patients underwent radical vaginal trachelectomy and four underwent a radical abdominal trachelectomy. Two (5%) of 38 patients required immediate completion radical hysterectomy due to extensive endocervical disease (one in the vaginal group and one in the abdominal group). Bilateral ureteral catheters were inserted successfully in 37 (97%) of 38 patients and facilitated identification of the distal ureter during the dissection. In one case, the right ureteral orifice could not be successfully catheterized, and the case was completed with unilateral catheterization. The estimated time to perform this part of the operation was

  20. Error-free Dispersion-uncompensated Transmission at 20 Gb/s over SSMF using a Hybrid III-V/SOI DML with MRR Filtering

    DEFF Research Database (Denmark)

    Cristofori, Valentina; Kamchevska, Valerija; Ding, Yunhong

    2016-01-01

    Error-free 20-Gb/s directly-modulated transmission is achieved by enhancing the dispersion tolerance of a III-V/SOI DFB laser with a silicon micro-ring resonator. Low (∼0.4 dB) penalty compared to back-to-back without ring is demonstrated after 5-km SSMF....

  1. Silicon photonics fiber-to-the-home transceiver array based on transfer-printing-based integration of III-V photodetectors.

    Science.gov (United States)

    Zhang, Jing; De Groote, Andreas; Abbasi, Amin; Loi, Ruggero; O'Callaghan, James; Corbett, Brian; Trindade, António José; Bower, Christopher A; Roelkens, Gunther

    2017-06-26

    A 4-channel silicon photonics transceiver array for Point-to-Point (P2P) fiber-to-the-home (FTTH) optical networks at the central office (CO) side is demonstrated. A III-V O-band photodetector array was integrated onto the silicon photonic transmitter through transfer printing technology, showing a polarization-independent responsivity of 0.39 - 0.49 A/W in the O-band. The integrated PDs (30 × 40 μm 2 mesa) have a 3 dB bandwidth of 11.5 GHz at -3 V bias. Together with high-speed C-band silicon ring modulators whose bandwidth is up to 15 GHz, operation of the transceiver array at 10 Gbit/s is demonstrated. The use of transfer printing for the integration of the III-V photodetectors allows for an efficient use of III-V material and enables the scalable integration of III-V devices on silicon photonics wafers, thereby reducing their cost.

  2. Characteristics of an Electron Cyclotron Resonance Plasma Source for the Production of Active Nitrogen Species in III-V Nitride Epitaxy

    Science.gov (United States)

    Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

    1997-01-01

    A simple analysis is provided to determine the characteristics of an electron cyclotron resonance (ECR) plasma source for the generation of active nitrogen species in the molecular beam epitaxy of III-V nitrides. The effects of reactor geometry, pressure, power, and flow rate on the dissociation efficiency and ion flux are presented. Pulsing the input power is proposed to reduce the ion flux.

  3. The Cost-Effectiveness of Treatment Modalities for Ureteral Stones

    Directory of Open Access Journals (Sweden)

    Justin Ji-Yuen Siu MD

    2016-10-01

    Full Text Available Additional intervention and medical treatment of complications may follow the primary treatment of a ureteral stone. We investigated the cost of the treatment of ureteral stone(s within 45 days after initial intervention by means of retrospective analysis of the National Health Insurance Research Database of Taiwan. All patients of ages ≥20 years diagnosed with ureteral stone(s( International Classification of Diseases, Ninth Revision, Clinical Modification/ICD-9-CM: 592.1 from January 2001 to December 2011 were enrolled. We included a comorbidity code only if the diagnosis appeared in at least 2 separate claims in a patient’s record. Treatment modalities (code included extracorporeal shock-wave lithotripsy (SWL; 98.51, ureteroscopic lithotripsy (URSL; 56.31, percutaneous nephrolithotripsy (PNL; 55.04, (open ureterolithotomy (56.20, and laparoscopy (ie, laparoscopic ureterolithotomy; 54.21. There were 28 513 patients with ureteral stones (13 848 men and 14 665 women in the randomized sample of 1 million patients. The mean cost was 526.4 ± 724.1 United States Dollar (USD. The costs of treatment were significantly increased in patients with comorbidities. The costs of treatment among each primary treatment modalities were 1212.2 ± 627.3, 1146.7 ± 816.8, 2507.4 ± 1333.5, 1533.3 ± 1137.1, 2566.4 ± 2594.3, and 209.8 ± 473.2 USD in the SWL, URSL, PNL, (open ureterolithotomy, laparoscopy (laparoscopic ureterolithotomy, and conservative treatment group, respectively. In conclusion, URSL was more cost-effective than SWL and PNL as a primary treatment modality for ureteral stone(s when the possible additional costs within 45 days after the initial operation were included in the calculation.

  4. Impaction and Prediction: Does Ureteral Wall Thickness Affect the Success of Medical Expulsive Therapy in Pediatric Ureteral Stones?

    Science.gov (United States)

    Tuerxun, Aierken; Batuer, Abudukahaer; Erturhan, Sakip; Eryildirim, Bilal; Camur, Emre; Sarica, Kemal

    2017-01-01

    The study aimed to evaluate the predictive value of ureteral wall thickness (UWT) and stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in pediatric upper ureteral stones. A total of 35 children receiving MET ureteral stones (Hounsfield unit), degree of hydronephrosis, and UWT were evaluated with patient demographics and recorded. The possible predictive value of these parameters in success rates and time to stone expulsion were evaluated in a comparative manner between the 2 groups. The overall mean patient age and stone size values were 5.40 ± 0.51 years and 6.24 ± 0.28 mm, respectively. Regarding the predictive values of these parameters for the success of MET, while stone size and UWT were found to be highly predictive for MET success, patients age, body mass index, stone density, and degree of hydronephrosis had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in pediatric ureteral stones in an effective manner. With this approach, unnecessary use of these drugs that may cause a delay in removing the stone will be avoided, and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized. © 2017 S. Karger AG, Basel.

  5. Comprehension of Postmetallization Annealed MOCVD-TiO2 on (NH42S Treated III-V Semiconductors

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    Ming-Kwei Lee

    2012-01-01

    Full Text Available The electrical characteristics of TiO2 films grown on III-V semiconductors (e.g., p-type InP and GaAs by metal-organic chemical vapor deposition were studied. With (NH42S treatment, the electrical characteristics of MOS capacitors are improved due to the reduction of native oxides. The electrical characteristics can be further improved by the postmetallization annealing, which causes hydrogen atomic ion to passivate defects and the grain boundary of polycrystalline TiO2 films. For postmetallization annealed TiO2 on (NH42S treated InP MOS, the leakage current densities can reach 2.7 × 10−7 and 2.3 × 10−7 A/cm2 at ±1 MV/cm, respectively. The dielectric constant and effective oxide charges are 46 and 1.96 × 1012 C/cm2, respectively. The interface state density is 7.13×1011 cm−2 eV−1 at the energy of 0.67 eV from the edge of valence band. For postmetallization annealed TiO2 on (NH42S treated GaAs MOS, The leakage current densities can reach 9.7×10−8 and 1.4×10−7 at ±1 MV/cm, respectively. The dielectric constant and effective oxide charges are 66 and 1.86×1012 C/cm2, respectively. The interface state density is 5.96×1011 cm−2 eV−1 at the energy of 0.7 eV from the edge of valence band.

  6. Influence of light waves on the thermoelectric power under large magnetic field in III-V, ternary and quaternary materials

    Energy Technology Data Exchange (ETDEWEB)

    Ghatak, K.P. [Department of Electronic Science, The University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Bhattacharya, S. [Post Graduate Department of Computer Science, St. Xavier' s College, 30 Park Street, Kolkata 700 016 (India); Pahari, S. [Department of Administration, Jadavpur University, Kolkata 700 032 (India); De, D. [Department of Computer Science and Engineering, West Bengal University of Technology, B. F. 142, Sector I, Salt Lake, Kolkata 700 064 (India); Ghosh, S.; Mitra, M. [Department of Electronics and Telecommunication Engineering, Bengal Engineering and Science University, Howrah 711 103 (India)

    2008-04-15

    We study theoretically the influence of light waves on the thermoelectric power under large magnetic field (TPM) for III-V, ternary and quaternary materials, whose unperturbed energy-band structures, are defined by the three-band model of Kane. The solution of the Boltzmann transport equation on the basis of this newly formulated electron dispersion law will introduce new physical ideas and experimental findings in the presence of external photoexcitation. It has been found by taking n-InAs, n-InSb, n-Hg{sub 1-x}Cd{sub x}Te and n-In{sub 1-x}Ga{sub x}As{sub y}P{sub 1-y} lattice matched to InP as examples that the TPM decreases with increase in electron concentration, and increases with increase in intensity and wavelength, respectively in various manners. The strong dependence of the TPM on both light intensity and wavelength reflects the direct signature of light waves that is in direct contrast as compared with the corresponding bulk specimens of the said materials in the absence of external photoexcitation. The rate of change is totally band-structure dependent and is significantly influenced by the presence of the different energy-band constants. The well-known result for the TPM for nondegenerate wide-gap materials in the absence of light waves has been obtained as a special case of the present analysis under certain limiting conditions and this compatibility is the indirect test of our generalized formalism. Besides, we have also suggested the experimental methods of determining the Einstein relation for the diffusivity:mobility ratio, the Debye screening length and the electronic contribution to the elastic constants for materials having arbitrary dispersion laws. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  7. Conformal, planarizing and bridging AZ5214-E layers deposited by a 'draping' technique on non-planar III V substrates

    Science.gov (United States)

    Eliás, P.; Strichovanec, P.; Kostic, I.; Novák, J.

    2006-12-01

    A draping technique was tested for the deposition of positive-tone AZ5214-E photo-resist layers on non-planar (1 0 0)-oriented III-V substrates, which had a variety of three-dimensional (3D) topographies micromachined in them that consisted, e.g., of mesa ridges confined to side facets with variable tilt, inverted pyramidal holes and stubs confined to perpendicular side facets. All objects were sharp-edged. In each draping experiment, an AZ5214-E sheet was (1) formed floating on the water surface, (2) lowered onto a non-planar substrate and (3) draped over it during drying to form either self-sustained, or conformal, or planarizing layers over the non-planar substrates. The draping process is based on the depression of the glass transition temperature Tg of AZ5214-E material induced by penetrant water molecules that interact with AZ5214-E. During the process, the molecules are initially trapped under an AZ5214-E sheet and then transported out through the sheet via permeation. The water-AZ5214-E interaction modifies the stiffness κ of the sheet. The magnitude of the effect depends on temperature T and on partial water vapour pressure difference p(T, P, κ): the net effect is that Tg = f(C(T, P), p(T, P, κ)) is lowered as the concentration C of water increases with T and p, where P is the permeability of the sheet. The interaction depressed the Tg of the sheets as low as or lower than 53 °C for 6 µm thick sheets. At room temperature T Tg, the sheet becomes rubbery and mouldable by adhesion and capillary forces. As a result, it can either contour or planarize the topography depending on its geometry and thickness of the sheet.

  8. The Effect of Ureteral Stent Placement Before Radical Prostatectomy on the Safety of Ureteral Dissection and the Surgeon’s Comfort

    Directory of Open Access Journals (Sweden)

    Fatih Akdemir

    2017-09-01

    Full Text Available Objective: This study investigated the role of preoperative ureteral stent placement in reducing the risk of ureteral injury, an intraoperative complication of radical retropubic prostatectomy (RRP, and its contribution to the surgeon’s comfort. Materials and Methods: Open RRP was performed in 66 patients diagnosed with localized prostate cancer in our clinic between 2010 and 2015. The patients were divided into two groups; group 1 (n=34 underwent surgery without ureteral stent placement and group 2 (n=32 had surgery following the placement of a ureteral stent. The cases were preoperatively evaluated by suprapubic and transrectal ultrasonography. Perioperative and postoperative complications of all cases were determined. Both groups were assessed in terms of ureteral injury, operative time, and surgeon’s comfort. Results: The mean age of the patients in group 1 and group 2 was 61.12±5.92 (50-72 years and 63.58±6.2 (51-75 years, respectively. The mean prostate volume was 76.8±2.41 and 72.4±3.53 cc in groups 1 and 2, respectively. The mean operative time was 143.9±3.06 minutes in group 1 and 136.8±2.83 minutes in group 2. Partial ureteral injury occurred in three patients in group 1 and was repaired intraoperatively. Of these patients, two had previously undergone radiotherapy for prostate cancer and it was difficult to perform prostate dissection intraoperatively. The remaining patient had a history of transurethral resection of the prostate. No ureteral injury was observed in any of the patients in group 2. Conclusion: Preoperative ureteral stent placement in selected patients can facilitate ureteral dissection and reduce ureteral injury risk.

  9. Cost analysis of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery.

    Science.gov (United States)

    Fanning, James; Fenton, Bradford; Jean, Geraldine Marie; Chae, Clara

    2011-12-01

    Prophylactic intraoperative ureteral stent placement is performed to decrease operative ureteric injury, though few data are available on the effectiveness of this procedure, and no data are available on its cost. To analyze the cost of prophylactic intraoperative cystoscopic ureteral stents in gynecologic surgery. All cases of prophylactic ureteral stent placement performed in gynecologic surgery during a 1-year period were identified and retrospectively reviewed through the electronic medical records database of Summa Health System. Costs were obtained through the Healthcare Cost Accounting System. The principles of cost-effective analysis were used (ie, explicit and detailed descriptions of costs and cost-effectiveness statistics). Importantly, we evaluated cost and not charges or financial model estimates. In addition, we obtained the contribution margins (ie, the hospital's net profit or loss) for prophylactic ureteral stent placement. Other gynecologic procedures were also analyzed. Among 792 major inpatient gynecologic procedures, 18 cases of prophylactic intraoperative ureteral stents were identified. Median costs were as follows: additional cost of prophylactic intraoperative ureteral stenting, $1580; additional cost of surgical resources, $770; cost of ureteral catheters, $427; cost of surgeons, $383. The contribution margins per case for various gynecologic surgical procedures were as follows: oophorectomy, $2804 profit; abdominal hysterectomy, $2649 profit; laparoscopically assisted vaginal hysterectomy (LAVH), $1760 profit. When intraoperative ureteral stenting was added, the contribution margins changed to the following: oophorectomy, $782 profit; abdominal hysterectomy, $627 profit; LAVH, $262 loss. Overall, the contribution margin profit was decreased by about 85%, from $2400 to $380. Prophylactic intraoperative ureteral stenting in gynecologic surgery decreases a hospital's contribution margin. Because of the expense of this procedure, as well as

  10. US demonstration of pyelitis and ureteritis in children

    International Nuclear Information System (INIS)

    Avni, E.F.; Gansbeke, D. van; Matos, C.; Thoua, Y.; Schulman, C.C.

    1988-01-01

    The authors report a new ultrasonic sign of urinary tract infection in children: thickening of the renal pelvis and/or ureteral wall. This thickening as encountered in 10 children, (10 months to 12 years) all with urinary tract infection, appears to result from inflammatory changes and to correspond to a sonographic sign of pyelitis and ureteritis. These alterations of the walls are similar to striations and folds described in this pathology on intravenous pyelograms. The thickening was the only sign of abnormality of the urinary tract in two cases; it was observed without reflux in four cases. The demonstration of this pattern should lead to further uroradiological investigations and to appropriate treatment. (orig.)

  11. Retroperitoneal fibrosis: A rare cause of both ureteral and small bowel obstruction

    Institute of Scientific and Technical Information of China (English)

    Faisal Aziz; Srinivasulu Conjeevaram; Than Phan

    2006-01-01

    Retroperitoneal fibrosis (RPF) is a rare condition of unclear etiology. It can cause ureteral obstruction. We present the unique case of a 54 years old female, who initially presented with spontaneous perforation of the cecum. Upon exploring the abdomen, the classical glistening white, unyielding retroperitoneal fibrosis was encountered. A right hemicolectomy was performed.Subsequently, the patient presented with bilateral ureteral obstruction, and later on with small bowel obstruction. Ureteral obstruction was treated with stents,and small bowel obstruction was treated with bypass.To our knowledge no case of idiopathic RPF presenting with features of both bilateral ureteral and small bowel obstruction has been reported in the literature.

  12. Role of ureteric stents in relieving obstruction in patients with obstructive uropathy

    Directory of Open Access Journals (Sweden)

    M Shehab

    2013-01-01

    Conclusion: The predictors of renal recoverability revealed that ureteral stents alone can help in regaining renal function and significant improvement of clinical condition in patients with obstructive uropathy.

  13. Medical expulsive therapy for distal ureteric stones: tamsulosin versus silodosin

    Directory of Open Access Journals (Sweden)

    Vittorio Imperatore

    2014-06-01

    Full Text Available Objectives: To compare the efficacy and safety of tamsulosin and silodosin in the context of medical expulsive therapy (MET of distal ureteric stones. Patients and methods: Observational data were collected retrospectively from patients who received silodosin (N = 50 or tamsulosin (N = 50 as MET from January 2012 to January 2013. Inclusion criteria were: patients aged ≥ 18 years with a single, unilateral, symptomatic, radiopaque ureteric stone of 10 mm or smaller in the largest dimension located between the lower border of the sacroiliac joint and the vesico-ureteric junction. Stone expulsion rate, stone expulsion time, number of pain episodes, need for analgesics use, incidence of side effects were compared. Results: Stone-expulsion rate in the silodosin and in the tamsulosin groups were 88% and 82%, respectively (p not significant. Mean expulsion times were 6.7 and 6.5 days in the silodosin and tamsulosin group, respectively (p not significant. Mean number of pain episodes were 1.6 and 1.7 in the silodosin and tamsulosin group, respectively (p not significant. The mean number of analgesic requirement was 0.84 and 0.9 for the silodosin and tamsulosin group, respectively (p not significant. Overall, incidence of side effects was similar in both groups. Patients taking silodosin experienced an higher incidence of retrograde ejaculation but a lower incidence of side effects related to peripheral vasodilation when compared to patients taking tamsulosin. Subgroup analysis demonstrated significantly lower mean expulsion times and pain episodes in patients with stones ≤ 5 mm in both groups. Conclusions: Tamsulosin and silodosin are equally effective as MET for distal ureteric stones sized 10 mm or smaller. MET with silodosin is associatd with a lower incidence of side effects related to peripheral vasodilation but an higher incidence of retrograde ejaculation when compared to tamsulosin.

  14. Medical expulsive therapy for distal ureteric stones: tamsulosin versus silodosin.

    Science.gov (United States)

    Imperatore, Vittorio; Fusco, Ferdinando; Creta, Massimiliano; Di Meo, Sergio; Buonopane, Roberto; Longo, Nicola; Imbimbo, Ciro; Mirone, Vincenzo

    2014-06-30

    To compare the efficacy and safety of tamsulosin and silodosin in the context of medical expulsive therapy (MET) of distal ureteric stones. Observational data were collected retrospectively from patients who received silodosin (N = 50) or tamsulosin (N = 50) as MET from January 2012 to January 2013. Inclusion criteria were: patients aged ≥ 18 years with a single, unilateral, symptomatic, radiopaque ureteric stone of 10 mm or smaller in the largest dimension located between the lower border of the sacroiliac joint and the vesico-ureteric junction. Stone expulsion rate, stone expulsion time, number of pain episodes, need for analgesics use, incidence of side effects were compared. Stone-expulsion rate in the silodosin and in the tamsulosin groups were 88% and 82%, respectively (p not significant). Mean expulsion times were 6.7 and 6.5 days in the silodosin and tamsulosin group, respectively (p not significant). Mean number of pain episodes were 1.6 and 1.7 in the silodosin and tamsulosin group, respectively (p not significant). The mean number of analgesic requirement was 0.84 and 0.9 for the silodosin and tamsulosin group, respectively (p not significant). Overall, incidence of side effects was similar in both groups. Patients taking silodosin experienced an higher incidence of retrograde ejaculation but a lower incidence of side effects related to peripheral vasodilation when compared to patients taking tamsulosin. Subgroup analysis demonstrated significantly lower mean expulsion times and pain episodes in patients with stones ≤ 5 mm in both groups. Tamsulosin and silodosin are equally effective as MET for distal ureteric stones sized 10 mm or smaller. MET with silodosin is associatd with a lower incidence of side effects related to peripheral vasodilation but an higher incidence of retrograde ejaculation when compared to tamsulosin.

  15. Simultaneous Bilateral Ureteral Calculi: A New Paradigm for Management.

    Science.gov (United States)

    Scotland, Kymora B; Hubosky, Scott G; Tanimoto, Ryuta; Cooper, Robert; Healy, Kelly A; Bagley, Demetrius H

    2018-05-21

    To define the need for emergent intervention between patients with simultaneous bilateral ureteral calculi (SBUC) compared to unilateral ureteral calculi (UUC). Patients with SBUC represent a potential urological emergency due to possible anuria or electrolyte imbalance. While conventional practice mandates immediate intervention in these patients, little data exist to define the rate of these events. Records of all patients with ureteral stones treated ureteroscopically over an 11-year period were reviewed to identify those with SBUC. Patient presenting characteristics, time from diagnosis to intervention, and postoperative outcomes were noted. To determine the need for emergent intervention, we compared metabolic and infectious parameters between SBUC patients and age- and sex-matched patients with UUC. A total of 3800 patients presented with ureteral calculi including 42 (1.1%) with SBUC. Two-thirds of patients with SBUC had an established diagnosis of nephrolithiasis. Among the 42 patients with SBUC, 11 (26.2%) were considered emergent due to metabolic (5 of 11, 45.5%), infectious (1 of 11, 9.1%), or both metabolic and infectious indications (5 of 11, 45.5%). No patients required acute dialysis before surgical intervention. Compared to patients with UUC, those with SBUC were significantly more likely to require emergent management (P = .03, odds ratio 2.3). Univariate and multivariate analyses showed this to be due to anuria (P = .001) and acidosis (P = .003). SBUC is an uncommon condition and, in this series, only the minority of patients presented emergently. Therefore, patients with SBUC can often be managed electively if counseled on clinical signs warranting emergent medical attention. Appropriately selected patients have excellent outcomes following single stage bilateral ureteroscopy. Copyright © 2018. Published by Elsevier Inc.

  16. Emergency extracorporeal shock wave lithotripsy (ESWL) for obstructing ureteral stones.

    Science.gov (United States)

    Tligui, M; El Khadime, M R; Tchala, K; Haab, F; Traxer, O; Gattegno, B; Thibault, P

    2003-05-01

    To evaluate emergency treatment of obstructing ureteral stones by in situ extracorporeal shock wave lithotripsy (ESWL) during acute renal colic. From January 1994 to February 2000, 200 patients (mean age: 42 years) were treated by ESWL (EDAP LT-02) for obstructing ureteral stones causing acute renal colic refractory to medical treatment or recurring within 24hours of such treatment. Stones were visualised by fluoroscopic imaging and/or ultrasound. Follow-up included radiological and/or ultrasound examinations and lasted three months. Mean stone size was 7mm (3-20mm). At three months, 164/200 (82%) patients were stone-free. This rate ranged from 79% to 83% according to the location of the stone, and from 75% to 86% according to the size of the stone. These differences in rate were not significant. Two or three ESWL sessions were required in 79 patients. ESWL was well tolerated in 90% of patients. The only complication was a case of pyelonephritis requiring the placement of a JJ stent, administration of antibiotics, and distant ureteroscopy. The 36 patients, in whom ESWL failed, underwent ureteroscopy (n=23) or lithotripsy with a Dornier machine (n=13). Non-deferred ESWL for acute renal colic secondary to obstructing ureteral stones has a satisfactory success rate and very low morbidity.

  17. Diagnosis and management of ureteral complications following renal transplantation

    Directory of Open Access Journals (Sweden)

    Brian D. Duty

    2015-10-01

    Full Text Available When compared with maintenance dialysis, renal transplantation affords patients with end-stage renal disease better long-term survival and a better quality of life. Approximately 9% of patients will develop a major urologic complication following kidney transplantation. Ureteral complications are most common and include obstruction (intrinsic and extrinsic, urine leak and vesicoureteral reflux. Ureterovesical anastomotic strictures result from technical error or ureteral ischemia. Balloon dilation or endoureterotomy may be considered for short, low-grade strictures, but open reconstruction is associated with higher success rates. Urine leak usually occurs in the early postoperative period. Nearly 60% of patients can be successfully managed with a pelvic drain and urinary decompression (nephrostomy tube, ureteral stent, and indwelling bladder catheter. Proximal, large-volume, or leaks that persist despite urinary diversion, require open repair. Vesicoureteral reflux is common following transplantation. Patients with recurrent pyelonephritis despite antimicrobial prophylaxis require surgical treatment. Deflux injection may be considered in recipients with low-grade disease. Grade IV and V reflux are best managed with open reconstruction.

  18. Deep infiltrating ureteral endometriosis with catamenial hydroureteronephrosis: a case report.

    Science.gov (United States)

    Lee, Hyun Jung; Lee, Yoon Soon

    2017-12-13

    This aim of this case report is to raise awareness of ureteral endometriosis in women of reproductive age with hydronephrosis in the absence of urolithiasis to enable early diagnosis and prevent loss of renal function. A 44-year-old Asian woman presented with a 4-year history of cyclic right flank pain and right hydronephrosis during menstruation. Despite several evaluations by physicians, including gynecologists, the cause of her symptoms was not diagnosed. On transvaginal ultrasonography, the uterus was observed deviated to the right, with a nodular lesion at the right uterosacral ligament, and the right ovary was attached to the uterus with no apparent cystic lesion. Magnetic resonance imaging showed a mass in the right uterine wall and mild wall thickening with delayed enhancement of the right distal ureter. Right ureteral endometriosis was suspected. Diagnostic laparoscopy revealed narrowing of the distal right ureter between the right uterosacral ligament and the right ovary with adhesions caused by deep infiltrating endometriosis. The adhesion bands and infiltrating endometriosis around the right ureter were dissected. The nonspecific symptoms of ureteral endometriosis can result in incorrect diagnosis, with renal damage as a result of prolonged hydronephrosis. A high index of suspicion and use of imaging modalities enable earlier diagnosis and preservation of renal function.

  19. III-V-on-Silicon Photonic Integrated Circuits for Spectroscopic Sensing in the 2-4 μm Wavelength Range.

    Science.gov (United States)

    Wang, Ruijun; Vasiliev, Anton; Muneeb, Muhammad; Malik, Aditya; Sprengel, Stephan; Boehm, Gerhard; Amann, Markus-Christian; Šimonytė, Ieva; Vizbaras, Augustinas; Vizbaras, Kristijonas; Baets, Roel; Roelkens, Gunther

    2017-08-04

    The availability of silicon photonic integrated circuits (ICs) in the 2-4 μm wavelength range enables miniature optical sensors for trace gas and bio-molecule detection. In this paper, we review our recent work on III-V-on-silicon waveguide circuits for spectroscopic sensing in this wavelength range. We first present results on the heterogeneous integration of 2.3 μm wavelength III-V laser sources and photodetectors on silicon photonic ICs for fully integrated optical sensors. Then a compact 2 μm wavelength widely tunable external cavity laser using a silicon photonic IC for the wavelength selective feedback is shown. High-performance silicon arrayed waveguide grating spectrometers are also presented. Further we show an on-chip photothermal transducer using a suspended silicon-on-insulator microring resonator used for mid-infrared photothermal spectroscopy.

  20. Multicolor (UV-IR) Photodetectors Based on Lattice-Matched 6.1 A II/VI and III/V Semiconductors

    Science.gov (United States)

    2015-08-27

    copyright information. 13. SUPPLEMENTARY NOTES. Enter information not included elsewhere such as: prepared in cooperation with; translation of; report...II-VI heterojunctions such as multi-color photodetectors and solar cells [2]. Mixing lattice-matched II-VI and III-V semiconductors could be an...at 77 K, further silicon oxide surface passivation can be done to suppress the surface leakage [10] in the future work. Figure 10 The dark I-V

  1. A comprehensive study of g-factors, elastic, structural and electronic properties of III-V semiconductors using hybrid-density functional theory

    Science.gov (United States)

    Bastos, Carlos M. O.; Sabino, Fernando P.; Sipahi, Guilherme M.; Da Silva, Juarez L. F.

    2018-02-01

    Despite the large number of theoretical III-V semiconductor studies reported every year, our atomistic understanding is still limited. The limitations of the theoretical approaches to yield accurate structural and electronic properties on an equal footing, is due to the unphysical self-interaction problem that mainly affects the band gap and spin-orbit splitting (SOC) in semiconductors and, in particular, III-V systems with similar magnitude of the band gap and SOC. In this work, we report a consistent study of the structural and electronic properties of the III-V semiconductors by using the screening hybrid-density functional theory framework, by fitting the α parameters for 12 different III-V compounds, namely, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb, to minimize the deviation between the theoretical and experimental values of the band gap and SOC. Structural relaxation effects were also included. Except for AlP, whose α = 0.127, we obtained α values that ranged from 0.209 to 0.343, which deviate by less than 0.1 from the universal value of 0.25. Our results for the lattice parameter and elastic constants indicate that the fitting of α does not affect those structural parameters when compared with the HSE06 functional, where α = 0.25. Our analysis of the band structure based on the k ṡ p method shows that the effective masses are in agreement with the experimental values, which can be attributed to the simultaneous fitting of the band gap and SOC. Also, we estimate the values of g-factors, extracted directly from the band structure, which are close to experimental results, which indicate that the obtained band structure produced a realistic set of k ṡ p parameters.

  2. [Double Endobutto reconstituting coracoclavicular ligament combined with repairing acromioclavicular ligament at stage I for the treatment of acromioclavicular dislocation with Rockwood type III - V].

    Science.gov (United States)

    Hu, Wen-yue; Yu, Chong; Huang, Zhong-ming; Han, Lei

    2015-06-01

    To explore clinical efficacy of double Endobutto reconstituting coracoclavicular ligament combined with repairing acromioclavicular ligament in stage I in treating acromioclavicular dislocation with Rockwood type III - V . From January 2010 to September 2013, 56 patients with Rockwood type III - V acromioclavicular dislocation were treated by operation, including 20 males and 36 femlaes, aged from 32 to 52 years old with an average of 38.5 years old. Twenty-five patients were on the left side and 31 cases on the right side. The time from injury to operation was from 3 to 14 days, averaged 7 days. All patients were diagnosed as acromioclavicular dislocation with Rockwood type III - V, and double Endobutto were used to reconstituting coracoclavicular ligament, line metal anchors were applied for repairing acromioclavicular ligament. Postoperative complications were observed, Karlsson and Constant-Murley evaluation standard were used to evaluate clinical effects. All patients were followed up from 8 to 24 months with average of 11 months. According to Karlsson evaluation standard at 6 months after operation,42 cases were grade A, 13 were grade B and 1 was grade C. Constant-Murley score were improved from (42.80±5.43) before operation to (91.75±4.27) at 6 months after operation. All items at 6 months after operation were better than that of preoperative items. Forty-eight patients got excellent results, 7 were moderate and only 1 with bad result. No shoulder joint adhesion, screw loosening or breakage were occurred during following up. Double Endobutto reconstituting coracoclavicular ligament combined with repairing acromioclavicular ligament in stage I for the treatment of acromioclavicular dislocation with Rockwood type III - V could obtain early staisfied clinical effects, and benefit for early recovery of shoulder joint function.

  3. InGaAsP Mach-Zehnder interferometer optical modulator monolithically integrated with InGaAs driver MOSFET on a III-V CMOS photonics platform.

    Science.gov (United States)

    Park, Jin-Kown; Takagi, Shinichi; Takenaka, Mitsuru

    2018-02-19

    We demonstrated the monolithic integration of a carrier-injection InGaAsP Mach-Zehnder interferometer (MZI) optical modulator and InGaAs metal-oxide-semiconductor field-effect transistor (MOSFET) on a III-V-on-insulator (III-V-OI) wafer. A low-resistivity lateral PIN junction was formed along an InGaAsP rib waveguide by Zn diffusion and Ni-InGaAsP alloy, enabling direct driving of the InGaAsP optical modulator by the InGaAs MOSFET. A π phase shift of the InGaAsP optical modulator was obtained through the injection of a drain current from the InGaAs MOSFET with a gate voltage of approximately 1 V. This proof-of-concept demonstration of the monolithic integration of the InGaAsP optical modulator and InGaAs driver MOSFET will enable us to develop high-performance and low-power electronic-photonic integrated circuits on a III-V CMOS photonics platform.

  4. Laparoscopic ureteral reimplantation with Boari flap for the management of long- segment ureteral defect: A case series with review of the literature.

    Science.gov (United States)

    Bansal, Ankur; Sinha, Rahul Janak; Jhanwar, Ankur; Prakash, Gaurav; Purkait, Bimalesh; Singh, Vishwajeet

    2017-09-01

    The incidence of ureteral stricture is showing a rising trend due to increased use of laparoscopic and upper urinary tract endoscopic procedures. Boari flap is the preferred method of repairing long- segment ureteral defects of 8-12 cm. The procedure has undergone change from classical open (transperitoneal and retroperitoneal) method to laparoscopic surgery and recently robotic surgery. Laparoscopic approach is cosmetically appealing, less morbid and with shorter hospital stay. In this case series, we report our experience of performing laparoscopic ureteral reimplantation with Boari flap in 3 patients. This prospective study was conducted between January 2011 December 2014. The patients with a long- segment ureteral defect who had undergone laparoscopic Boari flap reconstruction were included in the study. Outcome of laparoscopic ureteral reimplantation with Boari flap for the manangement of long segment ureteral defect was evaluated. The procedure was performed on 3 patients, and male to female ratio was 1:2. One patient had bilateral and other two patient had left ureteral stricture. The mean length of ureteral stricture was 8.6 cm (range 8.2-9.2 cm). The mean operative time was 206 min (190 to 220 min). The average estimated blood loss was 100 mL (range 90-110 mL) and mean hospital stay was 6 days (range 5 to 7 days). The mean follow up was 19 months (range 17-22 months). None of the patients experienced any complication related to the procedure in perioperative period. Laparoscopic ureteral reimplantation with Boari flap is safe, feasible and has excellent long term results. However, the procedure is technically challenging, requires extensive experience of intracorporeal suturing.

  5. Body mass index and buttock circumference are independent predictors of disintegration failure in extracorporeal shock wave lithotripsy for ureteral calculi

    Directory of Open Access Journals (Sweden)

    Teng-Kai Yang

    2013-07-01

    Conclusion: Stone burden is the main predictor of ESWL failure for all patients with ureteral calculi. BC and BMI are independent predictors for ESWL failure for middle/lower and upper ureteral calculi, respectively.

  6. Differences in Ureteroscopic Stone Treatment and Outcomes for Distal, Mid-, Proximal, or Multiple Ureteral Locations

    DEFF Research Database (Denmark)

    Perez Castro, Enrique; Osther, Palle J S; Jinga, Viorel

    2014-01-01

    Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones.......Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones....

  7. Clinical presentation and outcome of cats with circumcaval ureters associated with a ureteral obstruction.

    Science.gov (United States)

    Steinhaus, J; Berent, A C; Weisse, C; Eatroff, A; Donovan, T; Haddad, J; Bagley, D

    2015-01-01

    Circumcaval ureters (CU) are a rare embryological malformation resulting in ventral displacement of the caudal vena cava, which crosses the ureter, potentially causing a ureteral stricture. To evaluate cats with obstructed CU(s) and report the presenting signs, diagnostics, treatment(s), and outcomes. Cats with obstructed CU(s) were compared to ureterally obstructed cats without CU(s). 193 cats; 22 circumcaval obstructed (Group 1); 106 non-circumcaval obstructed (Group 2); 65 non-obstructed necropsy cases (Group 3). Retrospective study, review of medical records for cats treated for benign ureteral obstructions from AMC and University of Pennsylvania between 2009 and 2013. surgical treatment of benign ureteral obstruction, complete medical record including radiographic, ultrasonographic, biochemistry, and surgical findings. Seventeen percent (22/128) of obstructed cats had a CU (80% right-sided) compared to 14% (9/65) non-obstructed necropsy cats (89% right-sided). Clinical presentation, radiographic findings, and creatinine were not statistically different between Groups 1 and 2. Strictures were a statistically more common (40%) cause of ureteral obstruction in Group 1 compared to Group 2 (17%) (P = .01). The MST for Groups 1 and 2 after ureteral decompression was 923 and 762 days, respectively (P = .62), with the MST for death secondary to kidney disease in both groups being >1,442 days. Re-obstruction was the most common complication in Group 1 (24%) occurring more commonly in ureters of cats treated with a ureteral stent(s) (44%) compared to the subcutaneous ureteral bypass (SUB) device (8%) (P = .01). Ureteral obstructions in cats with a CU(s) have a similar outcome to those cats with a ureteral obstruction and normal ureteral anatomy. Long-term prognosis is good for benign ureteral obstructions treated with a double pigtail stent or a SUB device. The SUB device re-obstructed less commonly than the ureteral stent, especially when a ureteral stricture was

  8. Antegrade deligation of iatrogenic distal ureteric obstruction utilising a high pressure balloon dilatation technique.

    LENUS (Irish Health Repository)

    Rajendran, Simon

    2012-02-01

    BACKGROUND: Iatrogenic trauma is the leading cause of ureteric injury with an incidence in abdominal and pelvic surgery varying between 0.4 and 2.5%. CASE: We report a case of ureteric obstruction caused by a haemostatic clip. There was associated rupture of the ureter proximal to the clip with intra-peritoneal leakage of urine. The patient was unfit for surgery and was managed by a novel procedure of endoluminal balloon deligation. CONCLUSION: Ureteric injuries are rare but potentially serious complications. They require prompt diagnosis and management depends on the patients\\' clinical condition, extent of injury and interval from injury to diagnosis. We have successfully demonstrated a new technique to treat ureteric obstruction caused by a haemostatic clip with associated ureteral rupture in a patient unfit for surgery.

  9. The ureteric bud epithelium: morphogenesis and roles in metanephric kidney patterning.

    Science.gov (United States)

    Nagalakshmi, Vidya K; Yu, Jing

    2015-03-01

    The mammalian metanephric kidney is composed of two epithelial components, the collecting duct system and the nephron epithelium, that differentiate from two different tissues -the ureteric bud epithelium and the nephron progenitors, respectively-of intermediate mesoderm origin. The collecting duct system is generated through reiterative ureteric bud branching morphogenesis, whereas the nephron epithelium is formed in a process termed nephrogenesis, which is initiated with the mesenchymal-epithelial transition of the nephron progenitors. Ureteric bud branching morphogenesis is regulated by nephron progenitors, and in return, the ureteric bud epithelium regulates nephrogenesis. The metanephric kidney is physiologically divided along the corticomedullary axis into subcompartments that are enriched with specific segments of these two epithelial structures. Here, we provide an overview of the major molecular and cellular processes underlying the morphogenesis and patterning of the ureteric bud epithelium and its roles in the cortico-medullary patterning of the metanephric kidney. © 2015 Wiley Periodicals, Inc.

  10. Revisiting the tethered ureteral stents in children: a novel modification.

    Science.gov (United States)

    Kajbafzadeh, Abdol-Mohammad; Nabavizadeh, Behnam; Keihani, Sorena; Hosseini Sharifi, Seyed Hossein

    2015-06-01

    To propose a simple noninvasive method for ureteral stent retrieval using an extraction string sutured to the skin in children. A retrospective chart review was performed to gather relevant data from December 2005 to February 2013. After the surgeries, if indicated, a tethered double-J stent was placed in the ureter. A 5-0 non-absorbable Prolene stitch was used as an extraction string passing through the urethra and was sutured to subcoronal skin in boys or inner surface of labia majora in girls. For stent removal, a small amount of 2 % lidocaine jelly was pushed into the urethra 5 min before the procedure. The string was then pulled by continuous and gentle force until the entire stent was out. The suture was then cut to release the stent. No sedation or anesthesia was needed. A total of 378 double-J stents with extraction strings were inserted for a total of 325 patients (61.2 % male). Of the 53 patients with bilateral ureteral stents, one male patient (1.88 %) experienced early stent protrusion from urethral meatus. Two of 272 patients (0.73 %) with unilateral ureteral stent (one male and one female) encountered the same problem. All other stents were extracted successfully using the extraction string without any complications. No upward stent migration or suture site reaction was encountered. This method is a safe, easy-to-use, feasible and noninvasive alternative for cystoscopic stent removal with high success rate and minimal complications. This can lead to considerable saving in time and costs for patients, families and healthcare system.

  11. Medical expulsive treatment of distal ureteral stone using tamsulosin

    International Nuclear Information System (INIS)

    Ahmad, H.; Azim, W.; Akmal, M.; Murtaza, B.

    2015-01-01

    Many minimally invasive interventional techniques as well as expectant treatments exist for the management of lower ureteric calculi. This study was conducted to evaluate the efficacy of tamsulosin as an expulsive pharmacologic therapy for the treatment of distal ureteral stone. Methods: This randomized control trial included 100 patients over 18 years of age with stone Size = 8mm in distal 1/3 of ureter. Patients were randomly assigned into two groups (A and B). Group A Patients were given Capsule Tamsulosin 0.4 mg, 1 daily up to 4 weeks while group B patients were given placebo, 1 Capsule daily up to 4 weeks. The primary endpoint was expulsion rate. A written informed consent was taken from all the patients. Expulsion time, need for analgesics, need for hospitalization and drug side effects were secondary endpoints. Results: A total of 49 patients in group A and 48 patients in group B reported back, therefore 97 out of 100 patients were evaluated. Mean age of the patients was 36.34 years (range 18-57 years). Mean stone size was 5.78 mm (range 4-8 mm) in greatest dimension. A stone expulsion rate of 85.71% (42 patients) was noted in group A and 54.20% (26 patients) in group B. Group A revealed a statistically significant advantage in term of stone expulsion rate (p=0.032). Considering expulsion time in days group A showed statistically significant advantage (p=0.015). Regarding age, sex, stone size and stone lateralization (right/left), there was no significant difference between the group A and B. No drug side effects were noted in both the groups. Conclusion: By using tamsulosin a higher stone expulsion rates can be achieved in a shorter time. More randomized control trials are required to establish tamsulosin as a standard medical expulsive treatment for small distal ureteric calculus. (author)

  12. Molecular Pathology of Murine Ureteritis Causing Obstructive Uropathy with Hydronephrosis

    Science.gov (United States)

    Ichii, Osamu; Otsuka, Saori; Namiki, Yuka; Hashimoto, Yoshiharu; Kon, Yasuhiro

    2011-01-01

    Primary causes of urinary tract obstruction that induces urine retention and results in hydronephrosis include uroliths, inflammation, and tumors. In this study, we analyzed the molecular pathology of ureteritis causing hydronephrosis in laboratory rodents. F2 progenies of C57BL/6 and DBA/2 mice were studied histopathologically and by comprehensive gene expression analysis of their ureters. Incidence of hydronephrosis was approximately 5% in F2 progenies. Histopathologically, this hydronephrosis was caused by stenosis of the proximal ureter, which showed fibrosis and papillary malformations of the proliferative epithelium with infiltrations of B-cell-dominated lymphocytes. Additionally, CD16-positive large granular leukocytes and eosinophils infiltrated from the ureteral mucosa to the muscular layer. Eosinophilic crystals were characteristically observed in the lumen of the ureter and the cytoplasm of large granular leukocytes, eosinophils, and transitional epithelial cells. Comprehensive gene profiling revealed remarkably elevated expression of genes associated with hyperimmune responses through activation of B cells in diseased ureters. Furthermore, diseased ureters showed dramatically higher gene expression of chitinase 3-like 3, known as Ym1, which is associated with formation both of adenomas in the transitional epithelium and of eosinophilic crystals in inflammatory conditions. The Ym1 protein was mainly localized to the cytoplasm of the transitional epithelium, infiltrated cells, and eosinophilic crystals in diseased ureters. We determined that the primary cause of hydronephrosis in F2 mice was ureteritis mediated by the local hyperimmune response with malformation of the transitional epithelium. Our data provide a novel molecular pathogenesis for elucidating causes of aseptic inflammation in human upper urinary tracts. PMID:22114694

  13. Holmium laser lithotripsy (HoLL) of ureteral calculi

    Science.gov (United States)

    Kuntz, Rainer M.; Lehrich, Karin; Fayad, Amr

    2001-05-01

    The effectiveness and side effects of ureteroscopic HoLL of ureteral stones should be evaluated. In 63 patients (17 female, 46 males) a total of 75 stones of 3-20 mm diameter were treated with ureteroscopic HoLL. 18.7 percent of stones were located in the proximal third, 24.0 percent in the middle third and 57.3 percent in the distal third of the ureter. HoLL was performed with small diameter semirigid and flexible ureteroscopes, 220 or 365 nm flexible laser fibers and a holmium:YAG laser at a power of 5-15 W (0.5-1.0 J, 10- 15 Hz). 47 of 63 patients (74.6 percent) were immediately free of stones, and 8 others (12.6 percent) lost their residual fragments spontaneously within two weeks. Another 2 patients received additional chmolitholysis for uric acid stone fragments, i.e. 90.5 percent of patients were stone free by one sitting of ureterscopic HoLL. Of the remaining 6 patients (9.5 percent) who still had residual calculi 4 weeks after HoLL, 2 asymptomatic patients refused any additional treatment, 2 patients preferred treatment with ESWL, and 2 patients had a successful second HoLL, thereby raising the success rate of ureteroscopic HoLL to 93.7 percent. 2 patients showed contrast medium extravasation on retrograde ureterograms, due to guide wire perforation. No ureteral stricture occurred. In conclusion, transurethral ureteroscopic HoLL proved to be a safe and successful minimal invasive treatment of ureteral calculi.

  14. Oxide-Free Bonding of III-V-Based Material on Silicon and Nano-Structuration of the Hybrid Waveguide for Advanced Optical Functions

    Directory of Open Access Journals (Sweden)

    Konstantinos Pantzas

    2015-10-01

    Full Text Available Oxide-free bonding of III-V-based materials for integrated optics is demonstrated on both planar Silicon (Si surfaces and nanostructured ones, using Silicon on Isolator (SOI or Si substrates. The hybrid interface is characterized electrically and mechanically. A hybrid InP-on-SOI waveguide, including a bi-periodic nano structuration of the silicon guiding layer is demonstrated to provide wavelength selective transmission. Such an oxide-free interface associated with the nanostructured design of the guiding geometry has great potential for both electrical and optical operation of improved hybrid devices.

  15. Histochemical Analysis of Renal Dysplasia with Ureteral Atresia

    International Nuclear Information System (INIS)

    Kawate, Toyoko; Kawamura, Ryuki; Uchida, Takenori; Takahashi, Kyosuke; Hasegawa, Tomohiro; Futamata, Haruo; Katoh, Ryohei; Takeda, Sen

    2009-01-01

    Unilateral small kidney with ureteral obstruction was discovered in a 74-year-old female cadaver during an anatomical dissection course. In order to elucidate the histogenesis of renal dysplasia, we carried out histochemical and immunohistochemical analyses. On macroscopic view, the kidney was approximately 3 cm in length, 2 cm in width and weighed only 9 g. Although the ureter ran from the renal hilus to the bladder, its width was under 2 mm. The renal parenchyma was extremely thin and there was a large congested vein in the renal sinus. On microscopic examination of the kidney, we observed that numerous developing renal tubules had cytokeratin-positive epithelia, most of which were surrounded by concentric fibrosis. However, we could not detect any structures resembling the collecting duct, renal tubules, renal pelvis, or glomeruli. The concentric mesencymal fibrous tissue surrounding the immature renal tubules contained the smooth muscles that were positive for h-caldesmon. Serial sections of the ureter revealed several small and discontinuous lacunae lined by cuboidal and transitional epithelium, which did not constitute a patent lumen through the bladder. This case is a rare case of renal dysplasia with defect in recanalization of the ureteral bud during the early developmental stage

  16. Ureteric stricture secondary to unusual extension of prostatic adenocarcinoma.

    Science.gov (United States)

    Chalasani, Venu; Macek, Petr; O'Neill, Gordon F; Barret, Wade

    2010-02-01

    This article describes an unusual finding in a patient who presented with an adenocarcinoma of the prostate and right hydronephrosis. A 68-year-old male presented with right hydronephrosis and a PSA of 96. DRE was consistent with cT3 carcinoma. Cystoscopy showed an exophytic superficial transitional cell carcinoma (TCC) of the bladder and a transrectal biopsy of the prostate confirmed adenocarcinoma Gleason score 4+3. Staging investigations (CT pelvis and bone scan) were negative; androgen deprivation therapy was therefore initiated for the prostatic adenocarcinoma. Upper tract imaging showed multiple filling defects in the proximal ureter. Ureteroscopy showed a stricture at the level of the iliac vessels. With a working diagnosis of upper tract TCC, right open nephroureterectomy was performed. Final histology showed prostatic adenocarcinoma infiltrating the adventitia of the entire ureter up to the level of the renal pelvis. A rare cause of ureteric stricture, contiguous spread of prostatic adenocarcinoma, should be considered in the differential diagnosis of patients presenting with upper tract obstruction and a known history of prostatic adenocarcinoma. Androgen deprivation therapy for several months did not seem to cause resolution of the tumor in the periureteric, ureteric and perihilar tissues.

  17. Incidental diagnosis of diseases on un-enhanced helical computed tomography performed for ureteric colic

    Directory of Open Access Journals (Sweden)

    Ather M Hammad

    2003-03-01

    Full Text Available Abstract Background Patients presenting in the emergency room with flank pain suggestive of acute ureteric colic may have alternative underlying conditions mimicking ureteric stones. An early diagnosis and appropriate treatment for other causes of flank pain is important. The majority of centers around the world are increasingly using un-enhanced helical CT (UHCT for evaluation of ureteric colic. This study was conducted to determine the incidence and spectrum of significant incidental diagnoses established or suggested on UHCT performed for suspected renal/ureteric colic. Methods Urologist and radiologist reviewed 233 consecutive UHCT, performed for suspected renal/ureteral colic along with assessment of the medical records. Radiological diagnoses of clinical entities not suspected otherwise were analyzed. All other relevant radiological, biochemical and serological investigations and per-operative findings were also noted. Results Ureteral calculi were identified in 148 examinations (64%, findings of recent passage of calculi in 10 (4% and no calculus in 75 examinations (32%. Overall the incidental findings (additional or alternative diagnosis were found in 28 (12% CT scans. Twenty (71% of these diagnoses were confirmed by per-operative findings, biopsy, and other radiological and biochemical investigations or on clinical follow up. Conclusion A wide spectrum of significant incidental diagnoses can be identified on UHCT performed for suspected renal/ureteral colic. In the present series of 233 consecutive CT examinations, the incidence of incidental diagnosis was 12%.

  18. Diagnostic accuracy of circulating thyrotropin receptor messenger RNA combined with neck ultrasonography in patients with Bethesda III-V thyroid cytology.

    Science.gov (United States)

    Aliyev, Altay; Patel, Jinesh; Brainard, Jennifer; Gupta, Manjula; Nasr, Christian; Hatipoglu, Betul; Siperstein, Allan; Berber, Eren

    2016-01-01

    The aim of this study was to analyze the usefulness of thyrotropin receptor messenger RNA (TSHR-mRNA) combined with neck ultrasonography (US) in the management of thyroid nodules with Bethesda III-V cytology. Cytology slides of patients with a preoperative fine needle aspiration (FNA) and TSHR-mRNA who underwent thyroidectomy between 2002 and 2011 were recategorized based on the Bethesda classification. Results of thyroid FNA, TSHR-mRNA, and US were compared with the final pathology. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. There were 12 patients with Bethesda III, 112 with Bethesda IV, and 58 with Bethesda V cytology. The sensitivity of TSHR-mRNA in predicting cancer was 33%, 65%, and 79 %, and specificity was 67%, 66%, and 71%, for Bethesda III, IV, and V categories, respectively. For the same categories, the PPV of TSHR-mRNA was 25%, 33%, and 79%, respectively; whereas the NPV was 75%, 88%, and 71%, respectively. The addition of neck US to TSHR-mRNA increased the NPV to 100% for Bethesda III, and 86%, for Bethesda IV, and 82% for Bethesda V disease. This study documents the potential usefulness of TSHR-mRNA for thyroid nodules with Bethesda III-V FNA categories. TSHR-mRNA may be used to exclude Bethesda IV disease. A large sample analysis is needed to determine its accuracy for Bethesda category III nodules. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. A Review of Ultrahigh Efficiency III-V Semiconductor Compound Solar Cells: Multijunction Tandem, Lower Dimensional, Photonic Up/Down Conversion and Plasmonic Nanometallic Structures

    Directory of Open Access Journals (Sweden)

    Katsuaki Tanabe

    2009-07-01

    Full Text Available Solar cells are a promising renewable, carbon-free electric energy resource to address the fossil fuel shortage and global warming. Energy conversion efficiencies around 40% have been recently achieved in laboratories using III-V semiconductor compounds as photovoltaic materials. This article reviews the efforts and accomplishments made for higher efficiency III-V semiconductor compound solar cells, specifically with multijunction tandem, lower-dimensional, photonic up/down conversion, and plasmonic metallic structures. Technological strategies for further performance improvement from the most efficient (AlInGaP/(InGaAs/Ge triple-junction cells including the search for 1.0 eV bandgap semiconductors are discussed. Lower-dimensional systems such as quantum well and dot structures are being intensively studied to realize multiple exciton generation and multiple photon absorption to break the conventional efficiency limit. Implementation of plasmonic metallic nanostructures manipulating photonic energy flow directions to enhance sunlight absorption in thin photovoltaic semiconductor materials is also emerging.

  20. Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies.

    Science.gov (United States)

    Chow, Po-Ming; Hsu, Jui-Shan; Wang, Shuo-Meng; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liu, Kao-Lang

    2014-06-01

    To provide short-term result of the metallic ureteral stent in patients with malignant ureteral obstruction and identify radiological findings predicting stent failure. The records of all patients with non-urological malignant diseases who have received metallic ureteral stents from July 2009 to March 2012 for ureteral obstruction were reviewed. Stent failure was detected by clinical symptoms and imaging studies. Survival analysis was used to estimate patency rates and factors predicting stent failure. A total of 74 patients with 130 attempts of stent insertion were included. A total of 113 (86.9 %) stents were inserted successfully and 103 (91.2 %) achieved primary patency. After excluding cases without sufficient imaging data, 94 stents were included in the survival analysis. The median functional duration of the 94 stents was 6.2 months (range 3-476 days). Obstruction in abdominal ureter (p = 0.0279) and lymphatic metastasis around ureter (p = 0.0398) were risk factors for stent failure. The median functional durations of the stents for abdominal and pelvic obstructions were 4.5 months (range 3-263 days) and 6.5 months (range 4-476 days), respectively. The median durations of the stents with and without lymphatic metastasis were 5.3 months (range 4-398 days) and 7.8 months (range 31-476 days), respectively. Metallic ureteral stents are effective and safe in relieving ureteral obstructions resulting from non-urological malignancies, and abdominal ureteral obstruction and lymphatic metastasis around ureter were associated with shorter functional duration.

  1. Ureteropelvic junction obstruction and ureteral strictures treated by simple high-pressure balloon dilation

    DEFF Research Database (Denmark)

    Osther, P J; Geertsen, U; Nielsen, H V

    1998-01-01

    The long-term results of simple high-pressure balloon dilation in the treatment of ureteropelvic junction obstruction (UPJO) and ureteral strictures were evaluated. A total of 77 consecutive patients were treated: 40 had UPJO and 37 ureteral strictures. The etiology of the obstruction included...... years, success was achieved in only 25% of cases. There were no major complications. It was concluded that simple high-pressure balloon dilation is a safe and reasonably effective technique for the management of most ureteral strictures and congenital UPJO with symptom debut in adult life. Balloon...

  2. Ureteral obstructions treatment with percutaneous translumbar insertion of double J endoprostheses. First remote results

    Energy Technology Data Exchange (ETDEWEB)

    Gandini, G; Asnaghi, R; Righi, D and others

    1987-01-01

    Percutaneous insertion of ureteral stents is a widely accepted method for ureteral obstructions treatment. from 1981 to February 1986, we introduced 78 endoprostheses in 60 patients. Fifty-six with malignant tumours and 4 with benign stenoses. In 48 of those 60 patients follow-up is complete. In the patients with malignant obstructions the mean time of survival was 198 days. Twelve patients were still alive in February 1986, with a mean time of survival over 300 days. In 12 patients (25%) the stent became obstructed in a mean time of 96.8 days. The placement of ureteral stents offers an alternative treatment to the palliative urologic surgery. 27 refs.

  3. The treatment of ureteric calculi before and after the introduction of extracorporeal shockwave lithotripsy

    DEFF Research Database (Denmark)

    Gade, J; Holtveg, H; Nielsen, O S

    1995-01-01

    Indications and treatment results of ureteric calculi one year before and one year after the introduction of ESWL were analysed in 169 consecutive patients. Sex, age, former stone operation, stone localisation and stone size were not significantly different in the two groups. Before ESW1 47...... with ESWL, but not significantly. Judged from the length of the hospital stay there was no major economic benefit from ESWL. In conclusion, ESWL with a second generation lithotriptor is suitable for in situ treatment of ureteric calculi. It should be first choice for ureteric calculi....

  4. Ultrasonographic diagnosis of ureteral stones: Accuracy and factors influencing on diagnostic sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Mi; Han, Sang Seok; Chang, Seung Kuk; Joo, Sang Hoo; Lee, Jeong Sik; Eun, Choong Ki [Pusan Paik Hospital, Inje University College of Medicine, Pusan (Korea, Republic of)

    1999-12-15

    To determine the accuracy of ultrasonographic diagnosis in patients with clinically suspected ureteral stones and to evaluate the factors influencing on the diagnostic sensitivity for the detection of ureteral stone. The patients (115 cases) with proven presence or absence of ureteral stones were included in the study. At first, both sided kidney and proximal ureters were examined on each decubitus position and then middle ureters were done if proximal ureters were visualized. On the supine view, distal ureters and UVJ were scanned through the acoustic window of the filled bladder. KUB (20 cases), IVU (62 cases), AGP (7 cases), RGP (3 cases), ESWL (9 cases), CT (9 cases), and patients' history of spontaneous passage of stones (5 cases) were included as confirmation methods. The sensitivity, specificity, and accuracy of the ultrasonographic diagnosis of ureteral stones were calculated and the factors influencing on the sensitivity on the focus of the position and size of ureteral stone, visibility of ureter, the presence or absence of renal stone and hydronephrosis were analyzed. Of 82 cases with proven ureteral stone, 72 cases were revealed on ultrasonography and there was one false positive examination among 33 cases with proven absence of ureteral stone. The overall diagnostic accuracy was 90%. The ultrasonographic detection rates of ureteral stones as correlated with their locations were 83% (24/29), 100% (11/11), 80% (16/20), and 100% (21/21) of each group of proximal, middle, distal ureter, and UVJ stones. Of 61 stones, those as correlated with their sizes, were 82% (37/45) and 94% (15/16) of each group less than 10 mm and more than 11 mm. Those as correlated with the presence or absence of ureteral visualization on ultrasonography were 92% (69/75) and 43% (3/7) of each group. Those as correlated with presence of absence of renal stones were 85% (41/48) and 91% (31/34) of each group. Those as correlated with presence or absence of hydronephrosis were 89

  5. Renal Transplant Ureteral Stenosis: Treatment by Self-Expanding Metallic Stent

    International Nuclear Information System (INIS)

    Cantasdemir, Murat; Kantarci, Fatih; Numan, Furuzan; Mihmanli, Ismail; Kalender, Betul

    2003-01-01

    We report the use of a metallic stent in a transplant ureteral stenosis. A 28-year-old man with chronic renal failure due to chronic pyelonephritis, who received a living-donor renal transplant, presented with transplant ureteral stenosis. The stenosis was unresponsive to balloon dilation and was treated by antegrade placement of a self-expanding Memotherm stent. The stentedureter stayed patent for 3 years. It may be reasonable to treat post-transplant ureteral stenosis resistant to balloon dilation with self-expanding metallic stents. However, long-term follow-up is required to evaluate the efficacy of this treatment

  6. Use of Self-Expanding Metallic Ureteral Stents in the Secondary Treatment of Ureteral Stenosis Following Kidney Transplantation.

    Science.gov (United States)

    Xu, Guibin; Li, Xun; He, Yongzhong; Zhao, Haibo; Yang, Weiqing; Xie, Qingling

    2015-10-01

    To evaluate the safety and efficacy of self-expanding metal stents in the treatment of ureteral stenosis following kidney transplantation. Seven patients who developed benign stenosis after kidney transplantation were treated by a self-expanding metallic stent implantation from June 2007 to March 2014. All patients had undergone at least one open surgical procedure and one endourologic procedure for treatment of the stenosis. The extent of stenosis varied from 1.2 to 3.7 cm. Ultrasonography, urography, diuretic renography, and urine culture were performed every 3 months after stent insertion. Ureteroscopic examination was performed when needed. Stent placement was technically effective in all cases. The mean operative time was 37 minutes (range, 26-59 minutes). Lower urinary-tract symptoms and the ipsilateral flank pain were common early-stage complications and were greatly relieved after an average of 3 months. The mean follow-up duration was 38 months (range, 13-86 months), and no stent migration or fragmentation was observed. Urothelial hyperplasia occurred in only one patient and was effectively managed with a Double-J stent. Five patients had normal stable renal function; the remaining two had impaired renal function, including one patient with a preoperative renal failure who required dialysis at the end of the follow-up period (36 months). As an alternative to open surgery, implantation of a self-expanding metal stent is a safe and effective treatment for ureteral stenosis in patients who have undergone kidney transplantation.

  7. The impact of ureteral Double-J stent insertion following ureterorenoscopy in patients with ureteral stones accompanied by perirenal fat stranding

    Directory of Open Access Journals (Sweden)

    Ercan Ogreden

    2018-03-01

    Full Text Available Objective: To evaluate the impact of ureteral stent insertion following semirigid ureterorenoscopy (URS in patients with perirenal fat stranding (PFS due to ureteral stones. Material and methods: Data of 600 patients who underwent URS were analyzed retrospectively. Seventy-two patients detected to have PFS accompanying ureteral stone were included. Patients who did not undergo double J (DJ stent insertion following semirigid URS were classified as Group I (n: 52, while those who underwent stent insertion were classified as Group II (n: 20. Side distribution; localization of the stones, stone size, presence of fever, urinary tract infection (UTIs and urosepsis rates were compared in the two groups. Results: The average age of the patients was 44.4 (20-71 years. Male/female ratio and side of the stone location showed similar distribution in both groups (p > 0.05. Fever occurred in 23 cases (44.2% in Group I and in 15 cases (75% in Group II (p = 0.038. UTIs occurred in 15 cases (28.9% in Group I and in 12 cases (60% in Group II (p = 0.03. Urosepsis presented in 3 (5.8% and 5 (25% of the patients in Group I and II, respectively (p = 0.033. Conclusions: According to our results, ureteral DJ stent insertion following URS in patients with PFS due to ureteral stone caused an increase on postoperative infection related complications.

  8. Ureterolithotripsy for a Ureteral Calculus at the Ureteroureterostomy of a Renal-transplant Recipient.

    Science.gov (United States)

    Mitsui, Yosuke; Wada, Koichiro; Araki, Motoo; Yoshioka, Takashi; Ariyoshi, Yuichi; Nishimura, Shingo; Kobayashi, Yasuyuki; Sasaki, Katsumi; Watanabe, Toyohiko; Nasu, Yasutomo

    2017-10-01

    We describe a 40-year-old living-donor renal-transplant recipient who underwent successful ureterolithotripsy. He had been on hemodialysis for >15 years pre-transplant and underwent ureteroureterostomy along with the surgery. One year post-transplant, ultrasound examination demonstrated hydronephrosis, and CT showed a 6-mm ureteral calculus at the ureteroureterostomy site. No pain and no elevated serum creatinine were present. As the ureter was easily accessed, we performed a ureterolithotripsy, which would confirm whether a suture caused the calculus. Despite ureteral tortuosity, laser stone fragmentation succeeded. The calculus was completely removed with an antegrade guidewire. Mild postoperative ureteral stenosis resolved with a temporary ureteral stent without balloon dilation. Ureterolithotripsy is effective even in renal transplant recipients with ureteroureterostomy.

  9. Original article Role of Tamsulosin in Improving Double-J Ureteric ...

    African Journals Online (AJOL)

    2011-10-04

    related symptoms and quality of life (QoL) in patients with double-J (DJ) ureteric stents. Subjects and Methods: A total of 136 patients were prospectively evaluated and distributed randomly in two groups. Group 1 was 69 ...

  10. Results of radiotherapy for ureteric obstruction in muscle-invasive bladder cancer

    International Nuclear Information System (INIS)

    Holm, M.; Miskowiak, J.; Rolff, H.

    1996-01-01

    Retrospective evaluation of the records of 574 patients with muscle-invasive bladder cancer revealed 90 patients (16%) with ureteric obstruction; the obstruction was bilateral in 24%. The effect of radiotherapy was assessed in 55 patients with 68 obstructed kidneys. Six patients with eight obstructed kidneys required percutaneous nephrostomy or ureteric catheters in addition to radiotherapy. Drainage improved in only 20% of kidneys and the diverting catheter could be withdrawn permanently in only one (17%) of the diverted patients. The median survival was 11 months. Irradiation was followed by significant complications in 37 patients (67%). This raises doubts about the assumed beneficial effect of irradiation on ureteric obstruction due to muscle invasive bladder cancer. The short median survival of 11 months confirms that ureteric obstruction is a poor prognostic factor in muscle invasive bladder cancer. (au) 10 refs

  11. Metallic stent in the treatment of ureteral obstruction: Experience of single institute

    Directory of Open Access Journals (Sweden)

    Chien-Chang Li

    2011-10-01

    Conclusion: Patients with ureteral obstructions can be treated sufficiently with the Resonance® metallic stent. Patients who had gynecological malignancies and received radiotherapy had a higher failure rate after Resonance® metallic stent insertion.

  12. A rare complication of acute appendicitis: complete bilateral distal ureteral obstruction

    NARCIS (Netherlands)

    Aronson, D. C.; Moorman-Voestermans, C. G.; Tiel-van Buul, M. M.; Vos, A.

    1994-01-01

    Three children treated for appendicitis developed anuria and acute renal insufficiency several days after appendicectomy. Associated hydronephrosis or hydroureters were present in two. At cystoscopy, marked swelling of the trigonum and ureteric orifices was seen. One patient developed unilateral

  13. Ureteral quintuplication with renal atrophy in an infant after the 1986 Chernobyl nuclear disaster.

    Science.gov (United States)

    Jurkiewicz, Beata; Ząbkowski, Tomasz; Shevchuk, Dmitrij

    2014-01-01

    Ureteral duplication is a comparatively frequent urinary tract anomaly. Ureteral triplication is rare, but quadruplication is extremely rare. In this study, we describe a case of ureteral quintuplication, the first such report in the English-language literature. A newborn female baby was diagnosed with left ureteral quintuplication. The left ureter was divided into 5 ureters with 5 renal pelvises within approximately 3 cm of the urinary bladder, and trace parenchyma of the kidney was noted. The patient was born within 60 km of the epicenter of the 1986 Chernobyl disaster, 24 years after the catastrophic nuclear accident, and is currently aged 3 years. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Laser-welded ureteral anastomoses: experimental studies with three techniques.

    Science.gov (United States)

    Gürpinar, T; Gürer, S; Kattan, M W; Wang, L; Griffith, D P

    1996-01-01

    Tissue welding with laser energy is a new technique for reconstructive surgery. The potential advantages of laser welding are (a) lack of foreign body reaction, (b) decreased operative time, (c) less tissue manipulation, and (d) effective union of tissues equivalent to sutured anastomoses. We have performed ureteral anastomoses in adult mongrel dogs using a KTP 532 nm laser at an intensity of 1.4 W. Multiple "spot welds" of 1-s duration were utilized in a single layer anastomosis. Laser-welded anastomoses were performed with and without protein solder (33% and 50% human albumin) and were compared to sutured anastomoses. The laser-welded anastomoses required less operative time and provided bursting pressure levels similar to those of traditional sutured anastomoses. There was no advantage or disadvantage to the addition of human albumin as a solder in these experimental studies.

  15. Intra-urinoma Rendezvous Using a Transconduit Approach to Re-establish Ureteric Integrity

    International Nuclear Information System (INIS)

    Anderson, Hugh; Alyas, Faisal; Edwin, Patrick Joseph

    2005-01-01

    Ureteric discontinuity following injury has been traditionally treated surgically. With the advent of improved interventional instrumentation it is possible to stent these lesions percutaneously, retrogradely or failing that using a combined (rendezvous) technique. We describe an intra-urinoma rendezvous procedure combining a percutaneous antegrade-transconduit retrograde technique of stent insertion to successfully re-establish ureteric integrity that was used following the failure of a percutaneous retrograde approach. We illustrate its usefulness as an alternative to surgery

  16. Ureteric catheterization via an ileal conduit: technique and retrieval of a JJ stent.

    Science.gov (United States)

    Wah, T M; Kellett, M J

    2004-11-01

    Retrograde ureteric catheterization of a patient with an ileal conduit is difficult, because guide wires and catheters coil in the conduit. A modified loopogram, using a Foley catheter as a fulcrum through which catheters can be advanced to the ureteric anastomosis, is described. This technique was used to remove a JJ stent, which had been inserted previously across a stricture in one ureter, the stent crossing from one kidney to the other.

  17. Robotic Ureteroplasty with Buccal Mucosa Graft for the Management of Complex Ureteral Strictures.

    Science.gov (United States)

    Lee, Ziho; Waldorf, Benjamin T; Cho, Eric Y; Liu, Jeffrey C; Metro, Michael J; Eun, Daniel D

    2017-12-01

    Surgical management of proximal and mid ureteral strictures that are not amenable to primary excision and anastomosis is challenging. Although a buccal mucosa graft is commonly used during substitution urethroplasty, its use in substitution ureteroplasty is limited. We describe our technique of robotic ureteroplasty with a buccal mucosa graft to manage complex ureteral strictures and we report our outcomes. We retrospectively reviewed the records of 12 patients who underwent robotic ureteroplasty with a buccal mucosa graft between September 2014 and June 2016. The indication for the procedure was a proximal or mid ureteral stricture not amenable to primary excision and anastomosis. The primary outcomes were clinical success, absent symptoms on ureteral pathology and radiological success, defined as absent ureteral obstruction on retrograde pyelography, renal scan and/or computerized tomography. Four of the 12 patients (33.3%) had a ureteropelvic junction stricture, 4 (33.3%) had a proximal stricture and 4 (33.3%) had a mid ureteral stricture. Eight of the 12 patients (66.7%) had previously undergone failed ureteral reconstruction. Median stricture length was 3 cm (range 2 to 5). Median operative time was 217 minutes (range 136 to 344) and mean estimated blood loss was 100 ml (range 50 to 200). Median length of stay was 1 day (range 1 to 6). At a median followup of 13 months (range 4 to 30) 10 of the 12 cases (83.3%) were clinically and radiologically successful. Robotic ureteroplasty with a buccal mucosa graft is associated with low inherent morbidity. It is an effective way to manage complex proximal and mid ureteral strictures. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  18. Tamsulosin and the spontaneous passage of ureteral stones in children: A multi-institutional cohort study

    Science.gov (United States)

    Tasian, Gregory E.; Cost, Nicholas G.; Granberg, Candace F.; Pulido, Jose E.; Rivera, Marcelino; Schwen, Zeyad; Schulte, Marion; Fox, Janelle A.

    2014-01-01

    Purpose Tamsulosin is associated with increased passage of ureteral stones in adults, but its effectiveness in children is uncertain. We determined the association between tamsulosin and the spontaneous passage of ureteral stones in children. Methods We performed a multi-institutional retrospective cohort study of children ≤ 18 years who presented between 2007 and 2012 with a ureteral stone ≤ 10 mm and were managed with tamsulosin or oral analgesics alone. The outcome was spontaneous stone passage defined as radiographic clearance and/or patient report of passage. Subjects prescribed tamsulosin were matched with subjects prescribed analgesics alone using nearest neighbor propensity score matching to adjust for treatment selection. Conditional logistic regression models were used to estimate the association between tamsulosin and spontaneous passage of ureteral stones, adjusting for stone size and location. Results Of 449 children with ureteral stones, 334 were eligible for inclusion, and complete data were available for 274 children from 4 institutions (99 tamsulosin; 175 analgesics alone). Following case matching, there were no differences in patient age, gender, weight, height, stone size, or stone location between the 99 subjects prescribed tamsulosin and the 99 propensity-score matched subjects prescribed analgesics alone. In the tamsulosin cohort, 55% of ureteral stones passed versus 44% in the analgesics alone cohort (p = 0.03). In multivariate analysis adjusting for stone size and location, tamsulosin was associated with spontaneous passage of ureteral stones (OR 3.31; 95% CI 1.49–7.34). Conclusions The odds of spontaneous passage of ureteral stones were higher in children prescribed tamsulosin versus analgesics alone. PMID:24518765

  19. Tamsulosin and spontaneous passage of ureteral stones in children: a multi-institutional cohort study.

    Science.gov (United States)

    Tasian, Gregory E; Cost, Nicholas G; Granberg, Candace F; Pulido, Jose E; Rivera, Marcelino; Schwen, Zeyad; Schulte, Marion; Fox, Janelle A

    2014-08-01

    Tamsulosin is associated with increased passage of ureteral stones in adults but its effectiveness in children is uncertain. We determined the association between tamsulosin and the spontaneous passage of ureteral stones in children. We performed a multi-institutional retrospective cohort study of patients 18 years or younger who presented between 2007 and 2012 with ureteral stones up to 10 mm and who were treated with tamsulosin or oral analgesics alone. The outcome was spontaneous stone passage, defined as radiographic clearance and/or patient report of passage. Subjects prescribed tamsulosin were matched with subjects prescribed analgesics alone, using nearest neighbor propensity score matching to adjust for treatment selection. Conditional logistic regression models were used to estimate the association between tamsulosin and spontaneous passage of ureteral stones, adjusting for stone size and location. Of 449 children with ureteral stones 334 were eligible for inclusion, and complete data were available for 274 patients from 4 institutions (99 receiving tamsulosin, 175 receiving analgesics alone). Following case matching, there were no differences in age, gender, weight, height, stone size or stone location between the 99 subjects prescribed tamsulosin and the 99 propensity score matched subjects prescribed analgesics alone. In the tamsulosin cohort 55% of ureteral stones passed, compared to 44% in the analgesics alone cohort (p=0.03). In multivariate analysis adjusting for stone size and location tamsulosin was associated with spontaneous passage of ureteral stones (OR 3.31, 95% CI 1.49-7.34). The odds of spontaneous passage of ureteral stones were greater in children prescribed tamsulosin vs analgesics alone. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Spontaneous rupture of renal pelvis secondary to ureteral obstruction by urothelial tumor

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Daniel Alvarenga; Palma, Ana Laura Gatti; Kido, Ricardo Yoshio Zanetti; Barros, Ricardo Hoelz de Oliveira; Martins, Daniel Lahan; Penachim, Thiago Jose; Caserta, Nelson Marcio Gomes, E-mail: daniel_alvafer@yahoo.com.br, E-mail: daniel_alvafer@icloud.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Medicina. Dept. de Radiologia

    2014-09-15

    Partial spontaneous rupture of the upper urinary tract is rare and usually associated with nephrolithiasis. Other reported causes, apart from instrumentation and trauma, involve obstructive ureteral tumor in the pelvic cavity, retroperitoneal fibrosis, fluid overload, and pregnancy. We report a case of spontaneous rupture of renal pelvis secondary to ureteral obstruction caused by urothelial tumor, clinically suspected and evaluated by CT scans and MRIs, discussing the relevant findings for diagnosis.(author)

  1. Distal Ureteral Diameter Ratio is Predictive of Breakthrough Febrile Urinary Tract Infection.

    Science.gov (United States)

    Arlen, Angela M; Leong, Traci; Guidos, P Joseph; Alexander, Siobhan E; Cooper, Christopher S

    2017-12-01

    Distal ureteral diameter ratio is an objective measure that is prognostic of spontaneous resolution of vesicoureteral reflux. Along with likelihood of resolution, improved identification of children at risk for recurrent febrile urinary tract infections may impact management decisions. We evaluated the usefulness of ureteral diameter ratio as a predictive factor for breakthrough febrile urinary tract infections. Children with primary vesicoureteral reflux and detailed voiding cystourethrogram were identified. Ureteral diameter ratio was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between L1 and L3 vertebral bodies. Demographics, vesicoureteral reflux grade, laterality, presence/absence of bladder-bowel dysfunction, and ureteral diameter ratio were tested in univariate and multivariable analyses. Primary outcome was breakthrough febrile urinary tract infections. We analyzed 112 girls and 28 boys with a mean ± SD age of 2.5 ± 2.3 years at diagnosis. Vesicoureteral reflux was grade 1 to 2 in 64 patients (45.7%), grade 3 in 50 (35.7%), grade 4 in 16 (11.4%) and grade 5 in 10 (7.2%). Mean ± SD followup was 3.2 ± 2.7 years. A total of 40 children (28.6%) experienced breakthrough febrile urinary tract infections. Ureteral diameter ratio was significantly greater in children with (0.36) vs without (0.25) breakthrough febrile infections (p = 0.004). Controlling for vesicoureteral reflux grade, every 0.1 U increase in ureteral diameter ratio resulted in 1.7 times increased odds of breakthrough infection (95% CI 1.24 to 2.26, p urinary tract infections independent of reflux grade. Ureteral diameter ratio provides valuable prognostic information about risk of recurrent pyelonephritis and may assist with clinical decision-making. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  2. Robot-assisted ureteral reconstruction – current status and future directions

    Directory of Open Access Journals (Sweden)

    Paurush Babbar

    2018-01-01

    Full Text Available Robotic surgery in the treatment in certain urological diseases has become a mainstay. With the increasing use of the robotic platform, some surgeries which were historically performed open have transitioned to a minimally invasive technique. Recently, the robotic approach has become more utilized for ureteral reconstruction. In this article, the authors review the surgical techniques for a number of major ureteral reconstuctive surgeries and briefly discuss the outcomes reported in the literature.

  3. Ureteral catheters for colorectal surgery: Influence on operative times and complication outcomes: An observational study

    Directory of Open Access Journals (Sweden)

    Julio T. Chong

    2018-03-01

    Full Text Available Purpose: Placement of pre-operative ureteral catheters for colorectal surgery can aid in the identification of ureteral injuries. This study investigates whether simultaneous ureteral catheterization with surgery skin preparation can minimize operating room times without increasing post-operative complications. Materials and Methods: Patients undergoing simultaneous colorectal surgery skin preparation and placement of pre-operative ureteral catheters (n=21 were compared to those who underwent these events sequentially (n=28. Operative time-points of anesthesia ready (AR, surgery procedure start (PS, dorsal lithotomy and catheter insertion (CI times were compared to assess for differences between groups. Complications were compared between groups. Results: There were no differences in age, gender, body mass index (BMI, American Society of Anesthesiologists (ASA, comorbidities, current procedure terminology (CPT or International Classification of Diseases, 9th revision (ICD-9 codes between groups. Simultaneous catheterization saved 11.82 minutes of operative time between CI to PS (p=0.005, t-test. There was a significant difference in mean time between CI to PS (11.82 minutes, p=0.008 between simultaneous and sequential ureteral catheterization groups in a linear regression multivariate analysis controlling for age, BMI, CPT and ICD-9 codes. There were 4 complications in the simultaneous (19% and 3 in the sequential group (11% (p=0.68. Conclusions: Ureteral catheterization and colorectal surgery skin preparation in a simultaneous fashion decreases the time between CI and PS without significant increase in complications. Mean time saved with simultaneous ureteral catheterization was 11.82 minutes per case. Simultaneous ureteral catheterization may be an option in colorectal surgery and may result in cost savings without additional complications.

  4. Lessons learned over a decade of pediatric robotic ureteral reimplantation

    Directory of Open Access Journals (Sweden)

    Minki Baek

    2017-01-01

    Full Text Available The da Vinci robotic system has improved surgeon dexterity, ergonomics, and visualization to allow for a minimally invasive option for complex reconstructive procedures in children. Over the past decade, robot-assisted laparoscopic ureteral reimplantation (RALUR has become a viable minimally invasive surgical option for pediatric vesicoureteral reflux (VUR. However, higher-thanexpected complication rates and suboptimal reflux resolution rates at some centers have also been reported. The heterogeneity of surgical outcomes may arise from the inherent and underestimated complexity of the RALUR procedure that may justify its reclassification as a complex reconstructive procedure and especially for robotic surgeons early in their learning curve. Currently, no consensus exists on the role of RALUR for the surgical management of VUR. High success rates and low major complication rates are the expected norm for the current gold standard surgical option of open ureteral reimplantation. Similar to how robot-assisted laparoscopic surgery has gradually replaced open surgery as the most utilized option for prostatectomy in prostate cancer patients, RALUR may become a higher utilized surgical option in children with VUR if the adoption of standardized surgical techniques that have been associated with optimal outcomes can be adopted during the second decade of RALUR. A future standard of RALUR for children with VUR whose parents seek a minimally invasive surgical option can arise if widespread achievement of high success rates and low major complication rates can be obtained, similar to the replacement of open surgery with robot-assisted laparoscopic radical prostectomy as the new strandard for men with prostate cancer.

  5. New III-V cell design approaches for very high efficiency. Annual subcontract report, 1 August 1990--31 July 1991

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, M.S.; Melloch, M.R.; Lush, G.B.; O`Bradovich, G.J.; Young, M.P. [Purdue Univ., Lafayette, IN (United States)

    1993-01-01

    This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.

  6. Vortex Laser based on III-V semiconductor metasurface: direct generation of coherent Laguerre-Gauss modes carrying controlled orbital angular momentum.

    Science.gov (United States)

    Seghilani, Mohamed S; Myara, Mikhael; Sellahi, Mohamed; Legratiet, Luc; Sagnes, Isabelle; Beaudoin, Grégoire; Lalanne, Philippe; Garnache, Arnaud

    2016-12-05

    The generation of a coherent state, supporting a large photon number, with controlled orbital-angular-momentum L = ħl (of charge l per photon) presents both fundamental and technological challenges: we demonstrate a surface-emitting laser, based on III-V semiconductor technology with an integrated metasurface, generating vortex-like coherent state in the Laguerre-Gauss basis. We use a first order phase perturbation to lift orbital degeneracy of wavefunctions, by introducing a weak anisotropy called here "orbital birefringence", based on a dielectric metasurface. The azimuthal symmetry breakdown and non-linear laser dynamics create "orbital gain dichroism" allowing selecting vortex handedness. This coherent photonic device was characterized and studied, experimentally and theoretically. It exhibits a low divergence (50 dB vortex purity), and single frequency operation in a stable low noise regime (0.1% rms). Such high performance laser opens the path to widespread new photonic applications.

  7. Ka-band to L-band frequency down-conversion based on III-V-on-silicon photonic integrated circuits

    Science.gov (United States)

    Van Gasse, K.; Wang, Z.; Uvin, S.; De Deckere, B.; Mariën, J.; Thomassen, L.; Roelkens, G.

    2017-12-01

    In this work, we present the design, simulation and characterization of a frequency down-converter based on III-V-on-silicon photonic integrated circuit technology. We first demonstrate the concept using commercial discrete components, after which we demonstrate frequency conversion using an integrated mode-locked laser and integrated modulator. In our experiments, five channels in the Ka-band (27.5-30 GHz) with 500 MHz bandwidth are down-converted to the L-band (1.5 GHz). The breadboard demonstration shows a conversion efficiency of - 20 dB and a flat response over the 500 MHz bandwidth. The simulation of a fully integrated circuit indicates that a positive conversion gain can be obtained on a millimeter-sized photonic integrated circuit.

  8. Reduction of bonding resistance of two-terminal III-V/Si tandem solar cells fabricated using smart-stack technology

    Science.gov (United States)

    Baba, Masaaki; Makita, Kikuo; Mizuno, Hidenori; Takato, Hidetaka; Sugaya, Takeyoshi; Yamada, Noboru

    2017-12-01

    This paper describes a method that remarkably reduces the bonding resistance of mechanically stacked two-terminal GaAs/Si and InGaP/Si tandem solar cells, where the top and bottom cells are bonded using a Pd nanoparticle array. A transparent conductive oxide (TCO) layer, which partially covers the surface of the Si bottom cell below the electrodes of the III-V top cell, significantly enhances the fill factor (FF) and cell conversion efficiency. The partial TCO layer reduces the bonding resistance and thus, increases the FF and efficiency of InGaP/Si by factors of 1.20 and 1.11, respectively. Eventually, the efficiency exceeds 15%. Minimizing the optical losses at the bonding interfaces of the TCO layer is important in the fabrication of high-efficiency solar cells. To help facilitate this, the optical losses in the tandem solar cells are thoroughly characterized through optical simulations and experimental verifications.

  9. Ureteric complications in live related donor renal transplantation - impact on graft and patient survival

    Directory of Open Access Journals (Sweden)

    A Srivastava

    2004-01-01

    Full Text Available Objective : The study was performed with an aim to determine the incidence of ureteric complications in live related donor renal transplantation, and to study the effect of ureteric complications on long term graft and patient survival. Patients And Methods: Records of 1200 consecutive live related renal transplants done from 1989-2002 were reviewed. Twenty-six ureteric complications were noted to occur and treatment modalities employed were documented. In the non complication group sufficient data for evaluation was available in 867 patients. Survival analysis were performed using Kaplan-Meier techniques. Results: The overall incidence of urological complications is 2.9%. Complications occurred at a mean interval of 31.9 days after renal transplantation. Ureteric complications occurred in 2% patients with stented and 7.7% patients with non stented anastomosis (p=0.001. Mean follow up following renal transplantation was 37.4 months. Survival analysis showed that ureteric complications did not increase the risk of graft fai lu re or patient death. Conclusions: Ureteric complications in live related donor renal transplantation occurred in 2.9 % patients and did not impair graft and patient survival.

  10. Antegrade Ureteral Stenting is a Good Alternative for the Retrograde Approach.

    Science.gov (United States)

    van der Meer, Rutger W; Weltings, Saskia; van Erkel, Arian R; Roshani, Hossain; Elzevier, Henk W; van Dijk, Lukas C; van Overhagen, Hans

    2017-07-01

    Double J (JJ) stents for treating obstructive ureteral pathology are generally inserted through a retrograde route with cystoscopic guidance. Antegrade percutaneous insertion using fluoroscopy can be performed alternatively but is less known. Indications, success rate and complications of antegrade ureteral stenting were evaluated. Data of consecutive patients in which antegrade ureteral stenting was performed were retrospectively analysed using the radiology information system and patient records. Patient characteristics, details of the antegrade JJ stent insertion procedure and registered complications were collected. Furthermore, it was investigated if prior to the antegrade procedure a retrograde attempt for JJ stent insertion was performed. Total 130 attempts for antegrade JJ stent insertion were performed in 100 patients. A percutaneous nephrostomy catheter had already been placed in the majority of kidneys (n = 109) for initial treatment of hydronephrosis. Most prevelant indication for a JJ stent was obstructive ureteral pathology due to malignancy (n = 63). A JJ stent was successfully inserted in 125 of 130 procedures. In 21 cases, previous retrograde ureteral stenting had failed but, subsequent antegrade ureteral stenting was successful. There were 8 procedure related complications; 6 infections, 1 false tract and 1 malposition. Antegrade percutaneous insertion of a JJ stent is a good alternative for retrograde insertion.

  11. Comparison of ESWL and ureteroscopic holmium laser lithotripsy in management of ureteral stones.

    Science.gov (United States)

    Cui, Yon; Cao, Wenzhou; Shen, Hua; Xie, Jianjun; Adams, Tamara S; Zhang, Yuanyuan; Shao, Qiang

    2014-01-01

    There are many options for urologists to treat ureteral stones that range from 8 mm to 15 mm, including ESWL and ureteroscopic holmium laser lithotripsy. While both ESWL and ureteroscopy are effective and minimally invasive procedures, there is still controversy over which one is more suitable for ureteral stones. To perform a retrospective study to compare the efficiency, safety and complications using ESWL vs. ureteroscopic holmium laser lithotripsy in management of ureteral stones. Between October 2010 and October 2012, 160 patients who underwent ESWL or ureteroscopic holmium laser lithotripsy at Suzhou municipal hospital for a single radiopaque ureteral stone (the size 8-15 mm) were evaluated. All patients were followed up with ultrasonography for six months. Stone clearance rate, costs and complications were compared. Similarity in stone clearance rate and treatment time between the two procedures; overall procedural time, analgesia requirement and total cost were significantly different. Renal colic and gross hematuria were more frequent with ESWL while voiding symptoms were more frequent with ureteroscopy. Both procedures used for ureteral stones ranging from 8 to 15 mm were safe and minimally invasive. ESWL remains first line therapy for proximal ureteral stones while ureteroscopic holmium laser lithotripsy costs more. To determining which one is preferable depends on not only stone characteristics but also patient acceptance and cost-effectiveness ratio.

  12. Comparison of ESWL and ureteroscopic holmium laser lithotripsy in management of ureteral stones.

    Directory of Open Access Journals (Sweden)

    Yon Cui

    Full Text Available BACKGROUND: There are many options for urologists to treat ureteral stones that range from 8 mm to 15 mm, including ESWL and ureteroscopic holmium laser lithotripsy. While both ESWL and ureteroscopy are effective and minimally invasive procedures, there is still controversy over which one is more suitable for ureteral stones. OBJECTIVE: To perform a retrospective study to compare the efficiency, safety and complications using ESWL vs. ureteroscopic holmium laser lithotripsy in management of ureteral stones. METHODS: Between October 2010 and October 2012, 160 patients who underwent ESWL or ureteroscopic holmium laser lithotripsy at Suzhou municipal hospital for a single radiopaque ureteral stone (the size 8-15 mm were evaluated. All patients were followed up with ultrasonography for six months. Stone clearance rate, costs and complications were compared. RESULTS: Similarity in stone clearance rate and treatment time between the two procedures; overall procedural time, analgesia requirement and total cost were significantly different. Renal colic and gross hematuria were more frequent with ESWL while voiding symptoms were more frequent with ureteroscopy. Both procedures used for ureteral stones ranging from 8 to 15 mm were safe and minimally invasive. CONCLUSION: ESWL remains first line therapy for proximal ureteral stones while ureteroscopic holmium laser lithotripsy costs more. To determining which one is preferable depends on not only stone characteristics but also patient acceptance and cost-effectiveness ratio.

  13. Effect of Diuretics on Ureteral Stone Therapy with Extracorporeal Shock Wave Lithotripsy

    Directory of Open Access Journals (Sweden)

    Zomorrodi A

    2008-01-01

    Full Text Available To evaluate the effect of diuretics on ureteral stone fragmentation and clearance during therapy with extra corporeal shock wave lithotripsy (ESWL, we studied 87 patients with ureteral stone at different levels and treated with ESWL. The patients were randomized into two groups treated by standard ESWL; the treatment protocol included 3500 shock wave per patient in each session, energy of the shock in two groups was 13 to 9 kv per patient, and the number of sessions was 3 per patient. The first group included 43 patients who received only ESWL, while the second group of 44 patients received as well 40 mg of furosemide. Stone fragmentation rate was 81% and 93.1% and stone clearance rate was 68.2% and 88.4% for the first and the second groups, respectively. With diuretics, fragmentation was18.8% more in the middle ureteral stones, 16.9% more in the upper tract stones, and 5.4% more in the distal stones. Moreover, clearance of fragmented stones was 38%, 28%, 15.4% more at middle and upper and distal ureteral stone, respectively. We conclude that the stone fragmentation and clearance were higher with ESWL and diuretics than without diuresis. Diuresis is safe and has some advantage at increasing the effect of ESWL on ureteral stones especially the middle ureteral calculi.

  14. Design and Analysis of CMOS-Compatible III-V Compound Electron-Hole Bilayer Tunneling Field-Effect Transistor for Ultra-Low-Power Applications.

    Science.gov (United States)

    Kim, Sung Yoon; Seo, Jae Hwa; Yoon, Young Jun; Lee, Ho-Young; Lee, Seong Min; Cho, Seongjae; Kang, In Man

    2015-10-01

    In this work, we design and analyze complementary metal-oxide-semiconductor (CMOS)-compatible III-V compound electron-hole bilayer (EHB) tunneling field-effect transistors (TFETs) by using two-dimensional (2D) technology computer-aided design (TCAD) simulations. A recently proposed EHB TFET exploits a bias-induced band-to-band tunneling (BTBT) across the electron-hole bilayer by an electric field from the top and bottom gates. This is in contrast to conventional planar p(+)-p(-)-n TFETs, which utilize BTBT across the source-to-channel junction. We applied III-V compound semiconductor materials to the EHB TFETs in order to enhance the current drivability and switching performance. Devices based on various compound semiconductor materials have been designed and analyzed in terms of their primary DC characteristics. In addition, the operational principles were validated by close examination of the electron concentrations and energy-band diagrams under various operation conditions. The simulation results of the optimally designed In0.533Ga0.47As EHB TFET show outstanding performance, with an on-state current (Ion) of 249.5 μA/μm, subthreshold swing (S) of 11.4 mV/dec, and threshold voltage (Vth) of 50 mV at VDS = 0.5 V. Based on the DC-optimized InGaAs EHB TFET, the CMOS inverter circuit was simulated in views of static and dynamic behaviors of the p-channel device with exchanges between top and bottom gates or between source and drain electrodes maintaining the device structure.

  15. Medical impulsive therapy (MIT): the impact of 1 week of preoperative tamsulosin on deployment of 16-French ureteral access sheaths without preoperative ureteral stent placement.

    Science.gov (United States)

    Kaler, Kamaljot S; Safiullah, Shoaib; Lama, Daniel J; Parkhomenko, Egor; Okhunov, Zhamshid; Ko, Young H; Huynh, Linda; Patel, Roshan M; Landman, Jaime; Clayman, Ralph V

    2018-05-25

    Medical expulsive therapy is based on pharmacologic ureteral relaxation. We hypothesized this concept may facilitate the deployment of the large 16 French (F) ureteral access sheath (UAS) when patients are intentionally pre-treated with oral tamsulosin, i.e., medical impulsive therapy. We retrospectively analyzed our experience with UAS deployment during endoscopic-guided percutaneous nephrolithotomy in prone position in patients pre-treated for 1 week with oral tamsulosin with a contemporary untreated cohort. Between January 2015 and September 2016, seventy-seven patients without a pre-existing ureteral stent met inclusion criteria. Demographic data, tamsulosin usage, UAS size, deployment failure, ureteral injuries, stone-free rates, and complications were recorded. Univariate and multivariate analysis was conducted to assess the impact of tamsulosin on deployment of the 16F UAS. There was no statistical difference between the tamsulosin (n = 40) group and non-tamsulosin (n = 37) group in regard to demographic data. The tamsulosin group had a significantly higher percentage of 16F UAS deployment, 87 vs. 43% (p < 0.001), and no significant difference in ureteral injuries (p = 0.228). Univariate and multivariate analysis revealed that tamsulosin significantly increased the odds ratio (9.3 and 19.4, respectively) for successful passage of a 16F UAS. Despite a larger stone volume, there was no significant difference in computed tomography scan complete stone-free rates (29 vs. 42%; p = 0.277) at median post-operative time of only 3 days. In this retrospective study, 1 week of preoperative tamsulosin was associated with an increase in the deployment of a 16F UAS in patients without preoperative ureteral stent placement.

  16. Endoscopic rendezvous procedure for ureteral iatrogenic detachment: report of a case series with long-term outcomes.

    Science.gov (United States)

    Pastore, Antonio Luigi; Palleschi, Giovanni; Silvestri, Luigi; Leto, Antonino; Autieri, Domenico; Ripoli, Andrea; Maggioni, Cristina; Al Salhi, Yazan; Carbone, Antonio

    2015-04-01

    Injury to the ureter is the most common urologic complication of pelvic surgery, with an incidence that ranges from 1% to 10%. Most cases of ureteral injuries are related to gynecologic procedures. The ureter is particularly vulnerable to detachment or ligation during hysterectomy because of its position from the lateral edge of the cervix. We report a case series of female patients who underwent the ureteral rendezvous procedure for ureteral detachment. Between January 2009 and April 2013, 18 ureteral rendezvous procedures were performed for patients with complete detachment. We assessed the operative and clinical outcomes of these patients over a mean follow-up duration of 26.5 months and describe the three most representative cases. The endoscopic rendezvous technique was performed in all cases to manage ureteral detachment. CT urography at discharge and 6 and 12 months after discharge confirmed the restoration of ureteral integrity without any leakage in 66% (12/18) patients, indicated ureteral stenosis in 22% (4/18) patients, and indicated ureteral leakage in 12% (2/18) patients. The overall long-term success rate for all 18 patients was 78% (14/18) at a mean follow-up of 26.5 months. The endoscopic rendezvous procedure reduces the need for invasive open surgical repair and represents the optimal initial option in patients with iatrogenic ureteral lesions before invasive procedures with higher morbidity are attempted.

  17. What is the risk of urinary tract infection in children with antenatally presenting dilating vesico-ureteric reflux?

    Science.gov (United States)

    Evans, Kathryn; Asimakadou, Maria; Nwankwo, Oluchi; Desai, Divyesh; Cherian, Abraham; Mushtaq, Imran; Cuckow, Peter; Duffy, Patrick; Smeulders, Naima

    2015-04-01

    The incidence of recurrent urinary tract infection (UTI) in children with primary vesico-ureteric reflux (VUR) presenting symptomatically is well documented. The risk of UTI in asymptomatic primary VUR diagnosed on investigation of antenatal hydronephrosis (ANH) is less clear. Paradoxically, several previous studies have suggested a lower risk (1-25%). We ascertain the incidence of UTI amongst antenatally-presenting primary VUR and explore risk factors. All patients UTI, grade of VUR, radioisotope imaging findings (CRN-congenital reflux nephropathy, NRD-new renal defects), evidence of bladder dysfunction, surgical intervention and resolution were recorded. UTI diagnosis was based on positive urine culture with symptoms including fever. SPSS statistical package and Pearson's Chi-squared test were used to explore significance. Of 308 patients with primary VUR aged UTI. The remaining 66 (21%) were initially asymptomatic, and VUR was diagnosed on investigation of ANH. All were given prophylaxis from birth. Six months to 16years (median 6years) follow-up was available for 54 (42 males, 12 females). All but two patients had grade III-V VUR (96%), bilaterally in 41 (76%). CRN was evident in 30 (56%; all male) and bladder dysfunction in 12 (22%; 10 males). Twenty-eight patients (52%) developed a UTI. The risk of UTI was 58% in girls, 33% in boys without CRN and 57% in boys with CRN (p = 0.17). Bladder dysfunction was a significant risk factor for UTI (p = 0.03). All 8 (15%; 7 males) with NRD had had a UTI. A single UTI appeared responsible for the majority of NRD (6/8; 75%). UTI occurred in 6/27 (22%) boys after circumcision compared to 17/25 (68%) prior/without circumcision (p UTI in VUR detected after presentation with ANH was 52%. CRN and bladder dysfunction were risk factors for developing a UTI. Circumcision appears to significantly reduce the risk of infection. Antenatal presentation of primary VUR does not carry a reduced risk of UTI. A single UTI, in half before

  18. 50% dextrose versus normal saline as distension media during cystoscopy for assessment of ureteric patency.

    Science.gov (United States)

    Narasimhulu, Deepa Maheswari; Prabakar, Cheruba; Tang, Nancy; Bral, Pedram

    2016-04-01

    To compare the visualization of ureteric jets when using 50% dextrose (D50) as opposed to normal saline (NS) as distension media during cystoscopy. Cross sectional study. Two patients each had two cystoscopy videos recorded at the time of a ureteric jet; one using NS and the other using D50 resulting in two sets of paired videos (four videos). A fifth cystoscopy video was recorded, as a control, at a time when there was no ureteric-jet. Fifty participants including attending physicians, residents and medical students were recruited at an academic-affiliated community hospital. Participants were blinded to the medium used and viewed each of the five videos. Participants assessed each video for presence of a ureteric-jet, ease of interpretation, and compared the paired D50 and NS videos for clarity of ureteric-jets. Participant's assessment of clarity of the ureteric jets when D50 was used as compared to when NS was used in the paired videos. All 100 observations of the two D50 videos with jets identified the presence of a jet; for the NS videos, 96/100 observations identified a jet, 2/100 did not identify a jet and 2/100 were unsure. 48/50 observations of the video with no jet were correct, while 2/50 were unsure. Participants rated the ureteric-jets to be clearer in videos with D50 (86% vs 14%, Pdextrose was used as the distension medium during cystoscopy as compared to normal saline. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Shock Wave Lithotripsy in Ureteral Stones: Evaluation of Patient and Stone Related Predictive Factors

    Directory of Open Access Journals (Sweden)

    Ozgur Yazici

    2015-08-01

    Full Text Available ABSTRACTPurpose:To evaluate the patient and stone related factors which may influence the final outcome of SWL in the management of ureteral stones.Materials and Methods:Between October 2011 and October 2013, a total of 204 adult patients undergoing SWL for single ureteral stone sizing 5 to 15 mm were included into the study program. The impact of both patient (age, sex, BMI, and stone related factors (laterality, location, longest diameter and density as CT HU along with BUN and lastly SSD (skin to stone distance on fragmentation were analysed by univariate and multivariate analyses. Results: Stone free rates for proximal and distal ureteral stones were 68.8% and 72.7%, respectively with no statistically significant difference between two groups (p=0.7. According to univariate and multivariate analyses, while higher BMI (mean: 26.8 and 28.1, p=0.048 and stone density values (mean: 702 HU and 930 HU, p<0.0001 were detected as statistically significant independent predictors of treatment failure for proximal ureteral stones, the only statistically significant predicting parameter for the success rates of SWL in distal ureteral stones was the higher SSD value (median: 114 and 90, p=0.012.Conclusions:Our findings have clearly shown that while higher BMI and increased stone attenuation values detected by NCCT were significant factors influencing the final outcome of SWL treatment in proximal ureteral stones; opposite to the literature, high SSD was the only independent predictor of success for the SWL treatment of distal ureteral stones.

  20. Doppler visualization of ureteric jets in unilateral hydronephrosis in children and adolescents

    Energy Technology Data Exchange (ETDEWEB)

    Cvitkovic Kuzmic, Andrea E-mail: andreack@workmail.com; Brkljacic, Boris; Rados, Marko; Galesic, Kresimir

    2001-09-01

    Objective: to evaluate Doppler visualization of ureteric jets in the assessment of unilateral kidney collecting system dilatation in children and adolescents. Methods and patients: color Doppler ultrasonography was performed in 27 patients with hydronephrosis (11 female, 16 male, age range 3-21 years, mean age 10.5{+-}4.4). Nine had acute obstruction due to ureteral calculus, seven had obstructive hydronephrosis due to uretero-pelvic junction (UPJ) stenosis, and 11 had non-obstructive hydronephrosis. Doppler was also performed in 32 healthy children (15 boys and 17 girls, age 2-17 years, mean age 7.8{+-}3.9), who represented the control group. Results: in the control group jets were visible in 57 out of 64 ureteric units (89%). The mean frequency of jets in healthy children was 4.1 jets per min. In all children with hydronephrosis, jets were visible in 25 out of 27 normal ureteric units (92.6%), and their mean frequency was 4.5 jets per min. In children with acute unilateral colic, ureteric jets were completely absent in eight of nine patients (89%). In children with obstructive hydronephrosis, due to UPJ stenosis, jets were absent in five out of seven patients (71.4%), and in children with non-obstructive hydronephrosis jets were absent in three out of eleven patients (27.3%). When jets are visible, their frequencies are much lower on the obstructed side as compared with normal side, while in cases of nonobstructive dilatation frequency of jets is similar on both sides. Conclusion: absence of jets in patients with acute obstruction due to ureteral calculus, strongly correlates with high-grade obstruction. In children with UPJ stenosis, presence of ureteric jet does not exclude significant obstruction, but the frequency of jets on the obstructed side is much lower as compared with the unaffected side. When there is absence of jet from the dilated side or significant asymmetry in jet frequency, hydronephrosis is likely to be obstructive.

  1. [The effiectiveness of extracorporeal shock wave lithotripsy in treating proxima ureteral stones].

    Science.gov (United States)

    Kogan, M I; Belousov, I I; Yassine, A M

    2017-10-01

    Extracorporeal shock wave lithotripsy (ESWL) has proven efficacy in the treatment of proximal ureteral stones. The research to date has not been able to establish real time to spontaneous stone clearance after ESWL and the appropriateness and effectiveness of -blockers in stimulating residual stone clearance after ESWL. To conduct a comprehensive assessment of the effectiveness of ESWL in treating proximal ureteral stones and determine the appropriateness of using -blockers to stimulate residual stone clearance. ESWL was performed in 40 patients with X-ray positive proximal ureteral stones. Before ESWL and at 3 months after the treatment all patients underwent multispiral computed tomography. ESWL was considered successful if there was a complete clearance of the stones with no residual fragments on the control MSCT. If a residual ureteral stone was found at 3 months after ESWL, a 2-week course of silodosin was administered. Complete stone clearance was achieved in 37.5% of patients. Silodosin therapy for residual stones resulted in stone clearance in 68.4% of cases. Taken together, ESWL monotherapy and additional 3 months of lithokinetic therapy resulted in stone clearance in 70.0% of patients. The remaining patients underwent contact ureteral lithotripsy. Spontaneous stone passage after ESWL for proximal ureteral stones occurs not in all patients. Most commonly it occurred during the first three weeks after ESWL, and thereafter stone passage was not observed. In half of the patients with residual stones they were asymptomatic. The effectiveness of ESWL as a monotherapy for ureteral stones greater than 15 mm is incomplete. Adding silodosin during the long-term post ESWL period improves the passage of asymptomatic residual stones in 2/3 of patients, which makes its use promising.

  2. Is the Routine Check Nephrostogram Following Percutaneous Antegrade Ureteric Stent Placement Necessary?

    International Nuclear Information System (INIS)

    Soh, Keng Chuan; Tay, Kiang Hiong; Tan, Bien Soo; MM Htoo, Austin; HG Lo, Richard; Lin, Shueh En

    2008-01-01

    Our aim was to review our experience with percutaneous antegrade ureteric stent (PAUS) placement and to determine if the routinely conducted check nephrostogram on the day following ureteric stent placement was necessary. Retrospective review of patients who had undergone PAUS placement between January 2004 and December 2005 was performed. There were 83 subjects (36 males, 47 females), with a mean age of 59.9 years (range, 22-94 years). Average follow-up duration was 7.1 months (range, 1-24 months). The most common indications for PAUS placement were ureteric obstruction due to metastatic disease (n = 56) and urinary calculi (n = 34). Technical success was 93.2% (96/103 attempts), with no major immediate procedure-related complications or mortalities. The Bard 7Fr Urosoft DJ Stent was used in more than 95% of the cases. Eighty-one of 89 (91.0%) check nephrostograms demonstrated a patent ureteric stent with resultant safety catheter removal. Three check nephrostograms revealed distal stent migration requiring repositioning by a goose-snare, while five others showed stent occlusion necessitating permanent external drainage by nephrostomy drainage catheter reinsertion. Following PAUS placement, the serum creatinine level improved or stabilized in 82% of patients. The serum creatinine outcome difference between the groups with benign and malignant indications for PAUS placement was not statistically significant (p = 0.145) but resolution of hydronephrosis was significantly better (p = 0.008) in patients with benign indications. Percutaneous antegrade ureteric stent placement is a safe and effective means of relief for ureteric obstruction. The check nephrostogram following ureteric stent placement was unnecessary in the majority of patients

  3. Effect of ipsilateral ureteric obstruction on contralateral kidney and role of renin angiotensin system blockade on renal recovery in experimentally induced unilateral ureteric obstruction

    Directory of Open Access Journals (Sweden)

    Shasanka S Panda

    2013-01-01

    Full Text Available Aims: To study, the effects of ipsilateral ureteric obstruction on contralateral kidney and the role of renin angiotensin system (RAS blockade on renal recovery in experimentally induced unilateral ureteric obstruction. Materials and Methods: Unilateral upper ureteric obstruction was created in 96 adult Wistar rats that were reversed after pre-determined intervals. Losartan and Enalapril were given to different subgroups of rats following relief of obstruction. Results: The severity of dilatation on the contralateral kidney varied with duration of ipsilateral obstruction longer the duration more severe the dilatation. There is direct correlation between renal parenchymal damage, pelvi-ureteric junction (PUJ fibrosis, inflammation and severity of pelvi-calyceal system dilatation of contralateral kidney with duration of ipsilateral PUJ obstruction. Conclusions: Considerable injury is also inflicted to the contralateral normal kidney while ipsilateral kidney remains obstructed. Use of RAS blocking drugs has been found to significantly improve renal recovery on the contralateral kidney. It can, thus, be postulated that contralateral renal parenchymal injury was mediated through activation of RAS.

  4. Ureteral stents increase risk of postoperative acute kidney injury following colorectal surgery.

    Science.gov (United States)

    Hassinger, Taryn E; Mehaffey, J Hunter; Mullen, Matthew G; Michaels, Alex D; Elwood, Nathan R; Levi, Shoshana T; Hedrick, Traci L; Friel, Charles M

    2018-07-01

    Ureteral stents are commonly placed before colorectal resection to assist in identification of ureters and prevent injury. Acute kidney injury (AKI) is a common cause of morbidity and increased cost following colorectal surgery. Although previously associated with reflex anuria, prophylactic stents have not been found to increase AKI. We sought to determine the impact of ureteral stents on the incidence of AKI following colorectal surgery. All patients undergoing colon or rectal resection at a single institution between 2005 and 2015 were reviewed using American College of Surgeons National Surgical Quality Improvement Program dataset. AKI was defined as a rise in serum creatinine to ≥ 1.5 times the preoperative value. Univariate and multivariate regression analyses were performed to identify independent predictors of AKI. 2910 patients underwent colorectal resection. Prophylactic ureteral stents were placed in 129 patients (4.6%). Postoperative AKI occurred in 335 (11.5%) patients during their hospitalization. The stent group demonstrated increased AKI incidence (32.6% vs. 10.5%; p colorectal surgery including age, procedure duration, and ureteral stent placement. Prophylactic ureteral stents independently increased AKI risk when placed prior to colorectal surgery. These data demonstrate increased morbidity and hospital costs related to usage of stents in colorectal surgery, indicating that placement should be limited to patients with highest potential benefit.

  5. Distal ureteral calculi: the usefulness of transrectal ultrasound and comparison with intravenous urography

    International Nuclear Information System (INIS)

    Choi, Moon Hae; Yoon, Dae Young; Shim, Joo Eun; Kim, Ho Chul; Yi, Jeong Geun; Choi, Chul Sun; Bae, Sang Hoon; Kim, Ha Young

    1996-01-01

    To determine the usefulness of transrectal ultrasound (TRUS) and to compare TRUS with intravenous urography (IVU) in the evaluation of distal ureteral calculi. TRUS and IVU were performed in 24 patients with distal ureteral calculi. Using TRUS, we evaluated the presence and size of calculus, type of ureteral jet at the affected site and diameter of ureter proximal to calculus, and using IVU evaluated the presence and size of calculus, degree of ureteral obstruction, and degree of hydroureter. TRUS and IVU findings, were compared. In each patient, TRUS detected calculus of the distal ureter;in only 18 cases (75%), were the calculi demonstrated with IVU. In 18 cases where calculi were detected by both modalities, average calculus size was 4.5x3.0mm (longest and shortest dimensions) by IVU, and 6.1x3.7mm by TRUS. Between TRUS and IVU(p 0.05). TRUS appears to be a useful adjunctive method for the evaluation of distal ureteral calculus

  6. [Questions of terminology, systematization and grading of complications of contact ureteral lithotripsy].

    Science.gov (United States)

    Dutov, V V; Bazaev, V V; Mamedov, E A; Urenkov, S B; Podoinitsyn, A A

    2017-07-01

    To investigate the advantages and disadvantages of the current variants of systematization and grading of complications of contact ureteral lithotripsy (CULT) and develop a working classification of CULT complications. The study analyzed results of 545 fluoroscopy-guided endoscopic procedures performed at the MRRCI Clinic of Urology from 2008 to 2015 in 506 patients with ureterolithiasis. The proposed and implemented classification and terminology of CULT complications unifies the diagnostic and management algorithm. This tool is more systematic and structured than the classical classification and universal methods of systematization and grading of CULT complications (classifying CULT complications in "major" and "minor", PULS scale, Satava and Clavien-Dindo grading systems). Given the lack of clear grading of ureteral rupture, it was divided into amputation (two-level rupture) and avulsion (one-level rupture). Using such term as extravasation of the contrast media and/or migration of the stone outside of the ureter is groundless because these complications occur only after the perforation of the ureteral wall. Therefore, these conditions are complications not of CULT, but of the ureteral wall perforation. The ureteral perforation was classified into macro- and micro-perforation. The existing terminology, classification and grading of the CULT complications should undergo a more detailed analysis. None of the existing classifications of CULT complications afford them to be fully staged and systematized. The working classification of complications of CULT developed at the M.F. Vladimirsky MRRCI Clinic of Urology warrants a multi-center prospective study to validate it and investigate its effectiveness.

  7. Can tamsulosin facilitate expulsion of ureteral stones? A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Fan, Bo; Yang, Deyong; Wang, Jianbo; Che, Xiangyu; Li, Xiancheng; Wang, Lina; Chen, Feng; Wang, Tiezheng; Song, Xishuang

    2013-08-01

    To determine the efficacy and safety of the adrenergic alpha-antagonist tamsulosin in facilitating ureteral stones expulsion. A literature search was carried out using the PubMed database, Medline via Ovid, Embase and the Cochrane Library database to identify randomized controlled trials evaluating the efficiency of tamsulosin in the treatment of ureteral stones. Meta-analysis and forest plots were carried out by use of Review Manager version 5.1 software (Cochrane Collaboration). Compared with the control group, the tamsulosin group had an increase in expulsion rate of 51% and a decrease in expulsion time of 2.63 days. Furthermore, tamsulosin was found to reduce the risk of ureteral colic during treatment by 40% and also the risk of requirement of auxiliary procedures during follow up by 60%. In terms of safety, the tamsulosin group had a 117% increase in the incidence of side-effects compared with the control group, especially for incidence of dizziness. Tamsulosin facilitates the expulsion of ureteral calculi by providing a higher expulsion rate, a shorter expulsion time, a lower incidence of ureteral colic during treatment and a lower requirement of auxiliary procedures. However, the incidence of dizziness occurring during tamsulosin treatment is significantly higher in this setting. © 2012 The Japanese Urological Association.

  8. [Construction of a capsular tissue-engineered ureteral stent seeded with autologous urothelial cells].

    Science.gov (United States)

    Tan, Haisong; Fu, Weijun; Li, Jianqiang; Wang, Zhongxin; Li, Gang; Ma, Xin; Dong, Jun; Gao, Jiangping; Wang, Xiaoxiong; Zhang, Xu

    2013-01-01

    To investigate the feasibility of constructing a capsular poly L-lactic acid (PLLA) ureteral stent seeded with autologous urothelial cells using tissue engineering methods. The capsular ureteral stent was constructed by subcutaneously embedding PLLA ureteral stent in the back of beagles for 3 weeks to induce the formation of connective tissue on the surfaces. After decellularization of the stent, the expanded autologous urothelial cells were seeded on the stent. The surface structure and cell adhesion of the stent were observed using HE staining, scanning electron microscope (SEM) and immunocytochemical staining. MTT assay was used to evaluate urothelial cell proliferation on the capsular PLLA ureteral stent and on circumferential small intestinal submucosa graft. HE staining and VIII factor immunohistochemistry revealed numerous capillaries in the connective tissue encapsulating the stent without obvious local inflammatory response. The results of SEM and immunocytochemical staining showed that the capsule contained rich collagenic fibers forming three-dimensional structures, and the seeded autologous urothelial cells could adhere and well aligned on the surface. MTT assay showed normal growth of the cells on the stent as compared with the cells grown on circumferential small intestinal submucosa graft. The capsular PLLA ureteral stent allows adhesion and proliferation of autologous urothelial cells and shows a potential in applications of constructing tissue-engineered ureter.

  9. Management of ureteral endometriosis with hydronephrosis: Experience from a tertiary medical center.

    Science.gov (United States)

    Huang, Jing-Zhi; Guo, Hong-Ling; Li, Jin-Bo; Chen, Shu-Qin

    2017-10-01

    We report the clinical characteristics and experience of the surgical management of ureteral endometriosis in our institution. We retrospectively reviewed the data of patients with hydronephrosis resulting from ureteral endometriosis. Forty-six patients with different degrees of hydronephrosis were included in the study; 35% had urinary tract symptoms. Concomitant involvement of the ipsilateral ovary occurred in more than two-thirds of the patients. Four patients had nephrectomy, one of which involved ureterolysis because of hydronephrosis recurrence six months later. Hydronephrosis may be caused by uncommon reasons, such as ureteral endometriosis, which can even cause silent loss of renal function. Routine ultrasound scanning of the upper urinary tract for severe stages of endometriosis is very important in order to detect any potential ureteral lesions. Ureterolysis should be considered as the first surgical step, not only to avoid iatrogenic ureteral injuries but also to better evaluate ureter involvement for further procedures. To warrant tension-free and lesion-free anastomosis, it is wise to perform ureteroneocystostomy for long-term sound results. © 2017 Japan Society of Obstetrics and Gynecology.

  10. CT urograms in pediatric patients with ureteral calculi: do adult criteria work?

    International Nuclear Information System (INIS)

    Smergel, E.; Greenberg, S.B.; Crisci, K.L.; Salwen, J.K.

    2001-01-01

    Background: Secondary signs of urinary obstruction associated with ureteral calculi are useful adjuncts to diagnosis in adults with renal colic evaluated by unenhanced helical CT. Objective: Our purpose was to evaluate the frequency of secondary signs of obstruction in children with renal colic undergoing unenhanced helical CT. Materials and methods: Ureteral calculi were identified in 20 of 61 children with acute flank pain examined by unenhanced helical CT. Each imaging study was evaluated for the presence of secondary signs of urinary obstruction. The frequencies of individual signs were compared with each other by means of the McNemar test. Results: Six children had no secondary sign identified. In the remaining 14 children, proximal ureteral dilatation was seen in 10, renal enlargement in 10, hydronephrosis in 9, tissue rim sign in 6, decreased kidney attenuation in 5, and perinephric stranding in 1. Comparison of the frequencies strongly suggested that perinephric stranding occurs less frequently than proximal ureteral dilatation (P = 0.004), hydronephrosis (P = 0.008), or renal enlargement (P = 0.012). Conclusion: Perinephric stranding, a common secondary sign in adults with ureteral calculi, occurs less frequently in children than other reported secondary signs. (orig.)

  11. CT urograms in pediatric patients with ureteral calculi: do adult criteria work?

    Energy Technology Data Exchange (ETDEWEB)

    Smergel, E.; Greenberg, S.B.; Crisci, K.L.; Salwen, J.K. [Dept. of Radiology, St. Christopher' s Hospital for Children, Philadelphia, PA (United States)

    2001-10-01

    Background: Secondary signs of urinary obstruction associated with ureteral calculi are useful adjuncts to diagnosis in adults with renal colic evaluated by unenhanced helical CT. Objective: Our purpose was to evaluate the frequency of secondary signs of obstruction in children with renal colic undergoing unenhanced helical CT. Materials and methods: Ureteral calculi were identified in 20 of 61 children with acute flank pain examined by unenhanced helical CT. Each imaging study was evaluated for the presence of secondary signs of urinary obstruction. The frequencies of individual signs were compared with each other by means of the McNemar test. Results: Six children had no secondary sign identified. In the remaining 14 children, proximal ureteral dilatation was seen in 10, renal enlargement in 10, hydronephrosis in 9, tissue rim sign in 6, decreased kidney attenuation in 5, and perinephric stranding in 1. Comparison of the frequencies strongly suggested that perinephric stranding occurs less frequently than proximal ureteral dilatation (P = 0.004), hydronephrosis (P = 0.008), or renal enlargement (P = 0.012). Conclusion: Perinephric stranding, a common secondary sign in adults with ureteral calculi, occurs less frequently in children than other reported secondary signs. (orig.)

  12. Experience of extracorporeal shock wave lithotripsy for kidney and upper ureteric stones by electromagnetic lithotripter

    International Nuclear Information System (INIS)

    Wazir, B.G.; Haq, M.I.H.; Faheem-ul-Haq; Nawaz, A.; Nawaz, A.; Ikramullah; Jamil, M.

    2010-01-01

    Background: Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive treatment of urinary stones which breaks them, by using externally applied, focused, high intensity acoustic pulse, into smaller pieces so that they can pass easily through ureter. Shock wave generation, focusing, coupling and stone localisation by fluoroscope or ultrasound are the basic components of ESWL. ESWL has some complications and is contraindicated in certain situations. The aim of this study was to evaluate the effectiveness and safety of ESWL in kidney and upper ureteric stones by Electromagnetic Lithotriptor. Methods: All adult patients with renal and upper ureteric stones having a diameter of up to 1 Cm were included in the study. Basic evaluation such as history, examination, ultrasound and excretory urography were performed. Electromagnetic lithotripsy was done and data were collected on a printed proforma from January 1, 2008 to March 30, 2009 in Institute of Kidney Diseases, Peshawar. Results: Out of a total of 625 patients 463 were male and 162 were female; 67.36% of patients were having renal stones, 23.84% upper ureteric and 8.8% both renal and ureteric stones. Complications noted were renal colic in 9.76%, haematuria in 3.2%, stein strasse in 2.72%, and fever in 1.12% of patients. The stone free rate was 89% and 7% of patients were having stone fragments <4 mm. ESWL failed in 4% of patients. Conclusion: ESWL is a safe and effective way of treating kidney and upper ureteric stones. (author)

  13. INSITU extracorporeal shock- wave lithotripsy as a primary treatment for ureteral stones

    International Nuclear Information System (INIS)

    Maghraby, Hisham

    2003-01-01

    The aim of the sudy was to evaluate the results ofextracorporeal shock-wave lithotripsy (ESWL) as a primary treatment for ureteral calculi at different levels. We treated 166 consecutive patients with solitary ureteral stones (73 at the upper, 4 at the middle and 89 at the lower ureter) by primary in situ ESWL on an outpatient basis. A maximum of three treatments were given individually before adopting ureteroscopy as an alternative treatment. The success rate was calculated on the basis of complete stone clearance and resolution of any associated obstruction. Re-treatment rates ,complications and time to complete stone clearence were recorded. Complete stone clearance was received in 152 patients (91.6%) after an average of 10.2 days ( range1-28). The average treatment rate was 1.3 sessions per patient. As whole groups, lower ureteral stones required more treatment sessions than those in the upper ureter , and the difference was statistically significant.However, differences in the final success rate and time to stone clearence were statistically nonsignificant. When stratified according to size, the success rate was lowest for lower ureteral stones >1 cm in diameter. We believe ESWL is a safe and simple non-invasive option of choice for most ureteral calculi at different levels. Ureteroscopy represents an alternative choice in case of ESWL failure, or in cases of larger stones in the lower ureter when it might be the first option. (author)

  14. Percutaneous Management of Ureteral Injuries that are Diagnosed Late After Cesarean Section

    Energy Technology Data Exchange (ETDEWEB)

    Ustunsoz, Bahri; Ugurel, Sahin; Duru, Namik Kemal; Ozgok, Yasar; Ustunsoz, Ayfer [GATA Medical Faculty, Ankara (Turkmenistan)

    2008-08-15

    We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS). Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 +- 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years. Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%). Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable

  15. Percutaneous Management of Ureteral Injuries that are Diagnosed Late After Cesarean Section

    International Nuclear Information System (INIS)

    Ustunsoz, Bahri; Ugurel, Sahin; Duru, Namik Kemal; Ozgok, Yasar; Ustunsoz, Ayfer

    2008-01-01

    We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS). Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 ± 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years. Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%). Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable

  16. Early release of neonatal ureteral obstruction preserves renal function

    DEFF Research Database (Denmark)

    Shi, Yimin; Pedersen, Michael; Li, Chunling

    2004-01-01

    was left in place or released after 1 or 4 wk. Renal blood flow (RBF) and kidney size were measured sequentially over 24 wk using MRI. In rats in which the obstruction was left in place, RBF of the obstructed kidney was progressively reduced to 0.92 ± 0.17 vs. 1.79 ± 0.12 ml·min−1·100 g body wt−1 (P ...The incidence of congenital hydronephrosis is ∼1% and is often associated with renal insufficiency. It is unknown whether early release is essential to prevent deterioration of renal function. Rats were subjected to partial unilateral ureteral obstruction (PUUO) on postnatal day 2. The obstruction...... downregulation of Na-K-ATPase to 62 ± 7%, aquaporin-1 to 53 ± 3%, and aquaporin-3 to 53 ± 7% of sham levels. Release after 1 wk completely prevented development of hydronephrosis, reduction in RBF and glomerular filtration rate, and downregulation of renal transport proteins, whereas release after 4 wk had...

  17. Chronic partial ureteral obstruction and the developing kidney

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, Robert L. [University of Virginia, Department of Pediatrics, Box 800386, Charlottesville, VA (United States)

    2008-01-15

    Although congenital urinary tract obstruction is a common disorder, its pathophysiology remains poorly understood and clinical practice is controversial. Animal models have been used to elucidate the mechanisms responsible for obstructive nephropathy, and the models reveal that renal growth and function are impaired in proportion to the severity and duration of obstruction. Ureteral obstruction in the neonatal rat or mouse leads to activation of the renin-angiotensin system, renal infiltration by macrophages, and tubular apoptosis. Nephrons are lost by glomerular sclerosis and the formation of atubular glomeruli, and progressive injury leads to tubular atrophy and interstitial fibrosis. Recovery following release of obstruction depends on the timing, severity, and duration of obstruction. Growth factors and cytokines are produced by the hydronephrotic kidney, including MCP-1 and TGF-{beta}1, which are excreted in urine and can serve as biomarkers of renal injury. Because MRI can be used to monitor renal morphology, blood flow, and filtration rate, its use might supplant current imaging modalities (ultrasonography and diuretic renography), which have significant drawbacks. Combined use of MRI and new urinary biomarkers should improve our understanding of human congenital obstructive nephropathy and should lead to new approaches to evaluation and management of this challenging group of patients. (orig.)

  18. Theoretical modeling and optimization of III-V GaInP/GaAs/Ge monolithic triple-junction solar cells

    International Nuclear Information System (INIS)

    Leem, Jung Woo; Yu, Jae Su; Kim, Jong Nam; Noh, Sam Kyu

    2014-01-01

    We design and optimize monolithic III-V GaInP/GaAs/Ge triple-junction (TJ) solar cells by using a commercial software Silvaco ATLAS simulator to obtain the maximum short-circuit current density J sc . The maximum J sc , which is a current matching value between the GaInP top and GaAs middle subcells, can be determined by varying the base thicknesses of the GaInP top and GaAs middle subcells. From the numerical simulation results, a matched maximum J sc value of 13.92 mA/cm 2 is obtained at base thicknesses of 0.57 μm and 3 μm for the GaInP top and GaAs middle subcells, respectively, under 1-sun air mass 1.5 global spectrum illumination, leading to a high power conversion efficiency of 30.72%. The open-circuit voltage and the fill factor are 2.55 V and 86.55%, respectively. For the optimized cell structure, the external quantum efficiency and the photogeneration rate distributions are also investigated. To obtain efficient antireflection coatings (ARCs), we perform optical reflectance calculations by using a rigorous coupled-wave analysis method. For this, a silicon oxide/titanium oxide double-layer is used as an ARC on the TJ solar cell.

  19. Theoretical modeling and optimization of III-V GaInP/GaAs/Ge monolithic triple-junction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Leem, Jung Woo; Yu, Jae Su [Kyung Hee University, Yongin (Korea, Republic of); Kim, Jong Nam [Pukyung National University, Pusan (Korea, Republic of); Noh, Sam Kyu [Korea Research Institute of Standards and Science, Daejon (Korea, Republic of)

    2014-05-15

    We design and optimize monolithic III-V GaInP/GaAs/Ge triple-junction (TJ) solar cells by using a commercial software Silvaco ATLAS simulator to obtain the maximum short-circuit current density J{sub sc}. The maximum J{sub sc}, which is a current matching value between the GaInP top and GaAs middle subcells, can be determined by varying the base thicknesses of the GaInP top and GaAs middle subcells. From the numerical simulation results, a matched maximum J{sub sc} value of 13.92 mA/cm{sup 2} is obtained at base thicknesses of 0.57 μm and 3 μm for the GaInP top and GaAs middle subcells, respectively, under 1-sun air mass 1.5 global spectrum illumination, leading to a high power conversion efficiency of 30.72%. The open-circuit voltage and the fill factor are 2.55 V and 86.55%, respectively. For the optimized cell structure, the external quantum efficiency and the photogeneration rate distributions are also investigated. To obtain efficient antireflection coatings (ARCs), we perform optical reflectance calculations by using a rigorous coupled-wave analysis method. For this, a silicon oxide/titanium oxide double-layer is used as an ARC on the TJ solar cell.

  20. Scattering amplitudes and static atomic correction factors for the composition-sensitive 002 reflection in sphalerite ternary III-V and II-VI semiconductors.

    Science.gov (United States)

    Schowalter, M; Müller, K; Rosenauer, A

    2012-01-01

    Modified atomic scattering amplitudes (MASAs), taking into account the redistribution of charge due to bonds, and the respective correction factors considering the effect of static atomic displacements were computed for the chemically sensitive 002 reflection for ternary III-V and II-VI semiconductors. MASAs were derived from computations within the density functional theory formalism. Binary eight-atom unit cells were strained according to each strain state s (thin, intermediate, thick and fully relaxed electron microscopic specimen) and each concentration (x = 0, …, 1 in 0.01 steps), where the lattice parameters for composition x in strain state s were calculated using continuum elasticity theory. The concentration dependence was derived by computing MASAs for each of these binary cells. Correction factors for static atomic displacements were computed from relaxed atom positions by generating 50 × 50 × 50 supercells using the lattice parameter of the eight-atom unit cells. Atoms were randomly distributed according to the required composition. Polynomials were fitted to the composition dependence of the MASAs and the correction factors for the different strain states. Fit parameters are given in the paper.

  1. Evaluation of symptoms and patients' comfort for JJ-ureteral stents with and without antireflux-membrane valve.

    Science.gov (United States)

    Ecke, Thorsten H; Bartel, Peter; Hallmann, Steffen; Ruttloff, Jürgen

    2010-01-01

    To evaluate safety and patients' comfort by using the ureteral stent symptom questionnaire. Ureteral stents are used to provide upper urinary-tract drainage. A total of 133 JJ-ureteral stents with and without antireflux-membrane valve as consecutive referrals for therapy of hydronephrosis have been inserted. Four weeks after insertion of the ureteral stent, the patients were asked about pain while urination, flank pain due to reflux, and the comparison with former stents. Ultrasound of the kidney for hydronephrosis grade and creatinine value as follow-up have been documented. Statistical analysis included chi(2) test after Pearson correlation computed and performed by SPSS software. We found a high correlation between the JJ-ureteral stent used and the detection of a hydronephrosis (P = .004). More patients who had a JJ-ureteral stent without valve complained of flank pain (P JJ-ureteral stent with valve found this one to be worse than what they had before. JJ-stent related symptoms are a major problem for these patients. New stent designs and materials will be developed in the future to reduce stent-related morbidity and improve patient comfort. JJ-ureteral stents with an antireflux-membrane valve have a lower complication rate and provide a higher patient comfort compared with stents without valve. Crown Copyright 2010. Published by Elsevier Inc. All rights reserved.

  2. A Giant Ureteral Stone without Underlying Anatomic or Metabolic Abnormalities: A Case Report

    Directory of Open Access Journals (Sweden)

    Selcuk Sarikaya

    2013-01-01

    Full Text Available A 28-year old man presented with left flank pain and dysuria. Plain abdominal film and computed tomography showed a left giant ureteral stone measuring 11.5 cm causing ureteral obstruction and other stones 2.5 cm in size in the lower pole of ipsilateral kidney and 7 mm in size in distal part of right ureter. A left ureterolithotomy was performed and then a double J stent was inserted into the ureter. The patient was discharged from the hospital 4 days postoperatively with no complications. Stone analysis was consistent with magnesium ammonium phosphate and calcium oxalate. Underlying anatomic or metabolic abnormalities were not detected. One month after surgery, right ureteral stone passed spontaneously, left renal stone moved to distal ureter, and it was removed by ureterolithotomy. Control intravenous urography and cystography demonstrated unobstructed bilateral ureter and the absence of vesicoureteral reflux.

  3. “Direct modulation of a hybrid III-V/Si DFB laser with MRR filtering for 22.5-Gb/s error-free dispersion-uncompensated transmission over 2.5-km SSMF

    DEFF Research Database (Denmark)

    Cristofori, Valentina; Da Ros, Francesco; Ding, Yunhong

    2016-01-01

    Error-free and penalty-free transmission over 2.5 km SSMF of a 22.5 Gb/s data signal from a directly modulated hybrid III-V/Si DFB laser is achieved by enhancing the dispersion tolerance using a silicon micro-ring resonator....

  4. Primary ureteral carcinoma: MRI diagnosis and comparison with other diagnostic imaging facilities

    International Nuclear Information System (INIS)

    An Ningyu; Jiang Bo; Cai Youquan; Liang Yan

    2004-01-01

    Objective: To investigate MRI examination methods and imaging manifestations of primary ureteral carcinoma, and to evaluate its clinical values when comparing with other diagnostic imaging facilities. Methods: Eighty-seven cases of primary ureteral carcinoma who were operated within recent 8 years came into the study, among which, 35 cases had MRI examinations. For MRI examination, coronal heavy T 2 WI (water imaging) was performed to show the dilated ureter, then axial T 2 WI and T 1 WI were scanned at the obstruction level. 11 cases underwent additional Gd-DTPA dynamic contrast enhanced scans. The original pre-operative diagnostic reports of various imaging facilities were analyzed comparing with the results of operation and pathology. Results: MRI showed ureteral dilatation in 33 of 35 cases, no abnormal appearance in 1 case, and only primary kidney atrophy post renal transplantation in 1 case. Among the 33 cases with ureteral obstruction, soft mass at the obstruction level was detected on axial scans in 32 cases. The lesions showed gradual and homogeneous mild to moderate enhancement on contrast MRI. The overall employment rate of imaging facilities was as follows: ultrasound (94.3%), IVU (59.8%), CT (52.9%), MRI (40.2%), and RUP (35.6%). The accurate diagnostic rate was as follows :MRI (91.4%), RUP (80.6%), CT (63.0%), ultrasound (47.6%), and IVU (11.5%). Conclusion: Combination of MR water imaging and conventional sequences can demonstrate most primary ureteral carcinoma lesions and has a highest diagnostic accuracy among the current diagnostic imaging facilities. It should be taken as the first diagnostic imaging method of choice when primary ureteral carcinoma is suspected after ultrasound screening

  5. Sonography as an initial study in patients with suspected ureteral stone

    International Nuclear Information System (INIS)

    Lee, Jae Gue; Lim, Joo Won; Ko, Young Tae; Lee, Dong Ho; Lee, Hye Won; Oh, Joo Hyeong; Yoon, Yup; Lee, Sun Ju

    1999-01-01

    To evaluate the usefulness of sonography as an initial study in patients with suspected ureteral stone. We have undertaken a prospective study for 106 patients with suspected ureteral stone during 15 months. All the patients subsequently underwent urography at a mean interval of 1.8 days after the abdominopelvic sonography. We had only a clinical impression at the sonography and didn't refer to the other study such as KUB. We observed the degree of hydronephrosis using a grading system by Ellenbogen et aland location and size of stone. Seventy four patients had ureteral stone disease. The sonographic findings of these 74 patients showed a stone with hydronephrosis in 61 patients, a stone without hydronephrosis in 9, only hydronephrosis without stone in 2, and unremarkable finding in 2. In 3 of the remaining 32 patients, sonography showed hydronephrosis without stone. Locations of stone were 9 patients of ureteropelvic junction(UPJ), 19 of proximal ureter, 30 of distal ureter, and 16 of ureterovesical junction(UVJ). The sensitivity of sonography for stone was 95% and the specificity was 100%. When a ureteral stone was present, ipsilateral hydronephrosis was detected in 85% of cases on sonography. When only hydronephrosis without stone was detected on sonography, a ureteral stone was diagnosed in 2(40%) of 5 patients. Mean discrepancy of stone size between sonography and KUB was 3.1mm and stone size on sonography was larger. Grade of hydronephrosis between sonography and urography was the same in 32(59%) of 54 patients, whose stones were not expelled until urography after sonography. Sonography could be used as an initial study in patients with suspected ureteral stone.

  6. Extraction Strings for Ureteric Stents: Is There an Increased Risk for Urinary Tract Infections?

    Science.gov (United States)

    Fröhlich, Maryna; Fehr, Jan; Sulser, Tullio; Eberli, Daniel; Mortezavi, Ashkan

    To evaluate urinary tract infections associated with placement of ureteric stents, we performed a retrospective study and compared rates between patients with and patients without an extraction string attached to the ureteric stent. Indwelling ureteric stents are routinely removed by cystoscopy. If an extraction string has been connected to the stent at the time of placement, however, the removal can be performed without an invasive procedure. Concerns exist regarding the risk for an unintentional dislocation, increased stent-related discomfort, or an increase of the post-operative urinary tract infection rate. All elective transurethral ureteric stent placements performed between November 2011 and December 2012 in our department were included for this investigation. Urinary tract infection was defined according to the Centers for Disease Control and Prevention (CDC)/National Healthcare Safety Network (NHSN) surveillance definition of health-care-associated infections. Patients with an existing urinary tract infection at the time of admission were excluded from the analysis. A total of 342 patients receiving ureteric stents were evaluated regarding post-operative urinary tract infections. Of these patients, 127 (37.1%) had an extraction string and 215 (62.9%) a stent without a string. The total urinary tract infection rate was 6.4% with no significant difference between the two groups (7.9% vs. 5.6%, p = 0.49). In the present study, we did not observe an increased rate of post-operative urinary tract infections in patients with an extraction string attached to the ureteral stent. Extraction string is a good option for patients to avoid cystoscopic stent removal.

  7. Cutting-balloon angioplasty of resistant ureteral stenosis as bridge to stent insertion

    Energy Technology Data Exchange (ETDEWEB)

    Iezzi, R., E-mail: iezzir@virgilio.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, ' A. Gemelli' Hospital - Catholic University, L.go A Gemelli 8, 00168 Rome (Italy); Di Stasi, C.; Simeone, A.; Bonomo, L. [Department of Bioimaging and Radiological Sciences, Institute of Radiology, ' A. Gemelli' Hospital - Catholic University, L.go A Gemelli 8, 00168 Rome (Italy)

    2011-07-15

    Ureteral stenting is a routine, minimally invasive procedure performed for relief of benign or malignant obstruction. In case of ureteral stenosis, to allow a correct insertion of the stent, a predilatation of the ureter stenosis with a conventional balloon catheter can be necessary. In exceptional cases, it can be difficult to advance an 7-8 Fr JJ-catheter over a tight resistant ureter stenosis following unsuccessful high-pressure balloon dilatation. In the present report, we describe two cases of resistant ureter stenosis successfully dilated by a cutting-balloon following the failure of high-pressure balloon dilatation, allowing a correct and uncomplicated antegrade stent insertion.

  8. Cutting-balloon angioplasty of resistant ureteral stenosis as bridge to stent insertion

    International Nuclear Information System (INIS)

    Iezzi, R.; Di Stasi, C.; Simeone, A.; Bonomo, L.

    2011-01-01

    Ureteral stenting is a routine, minimally invasive procedure performed for relief of benign or malignant obstruction. In case of ureteral stenosis, to allow a correct insertion of the stent, a predilatation of the ureter stenosis with a conventional balloon catheter can be necessary. In exceptional cases, it can be difficult to advance an 7-8 Fr JJ-catheter over a tight resistant ureter stenosis following unsuccessful high-pressure balloon dilatation. In the present report, we describe two cases of resistant ureter stenosis successfully dilated by a cutting-balloon following the failure of high-pressure balloon dilatation, allowing a correct and uncomplicated antegrade stent insertion.

  9. Dextranomer/hyaluronic acid copolymer (Deflux) implants mimicking distal ureteral calculi on CT

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Caleb P. [Children' s Hospital Boston, Department of Urology, Boston, MA (United States); Chow, Jeanne S. [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States)

    2008-01-15

    Periureteral or subtrigonal injection of dextranomer/hyaluronic acid (Dx/HA) copolymer (Deflux, Q-Med, Uppsala, Sweden) is an increasingly common endoscopic treatment for vesicoureteral reflux. We report a confusing radiographic finding of bilateral calcified Dx/HA injections initially thought to represent bilateral distal ureteral stones in a boy who presented with intermittent periumbilical pain. Urologists, radiologists, and emergency room physicians should be aware of the potential for calcification of ureteral implants of Dx/HA, and of the potentially confusing radiographic images that may result. (orig.)

  10. Dextranomer/hyaluronic acid copolymer (Deflux) implants mimicking distal ureteral calculi on CT

    International Nuclear Information System (INIS)

    Nelson, Caleb P.; Chow, Jeanne S.

    2008-01-01

    Periureteral or subtrigonal injection of dextranomer/hyaluronic acid (Dx/HA) copolymer (Deflux, Q-Med, Uppsala, Sweden) is an increasingly common endoscopic treatment for vesicoureteral reflux. We report a confusing radiographic finding of bilateral calcified Dx/HA injections initially thought to represent bilateral distal ureteral stones in a boy who presented with intermittent periumbilical pain. Urologists, radiologists, and emergency room physicians should be aware of the potential for calcification of ureteral implants of Dx/HA, and of the potentially confusing radiographic images that may result. (orig.)

  11. Usefulness of Early Extracorporeal Shock Wave Lithotripsy in Colic Patients with Ureteral Stones

    OpenAIRE

    Choi, Hyeung Joon; Jung, Jin-Hee; Bae, Jungbum; Cho, Min Chul; Lee, Hae Won; Lee, Kwang Soo

    2012-01-01

    Purpose To compare efficacy and safety between early extracorporeal shock wave lithotripsy (eESWL) and deferred ESWL (dESWL) in colic patients with ureteral stones and to investigate whether eESWL can play a critical role in improving treatment outcomes. Materials and Methods A total of 279 patients who underwent ESWL for single radio-opaque ureteral stones of 5 to 20 mm in size were included in this retrospective study. The patients were categorized into two groups according to the time betw...

  12. Retroperitoneoscopy for treatment of renal and ureteral stones

    Directory of Open Access Journals (Sweden)

    Rodrigo S. Soares

    2005-04-01

    Full Text Available OBJECTIVE: To assess the efficacy of retroperitoneoscopy for treating stones in the renal pelvis and proximal ureter. MATERIALS AND METHODS: In the period from August 2003 to August 2004, 35 retroperitoneoscopies for treatment of urinary stones were performed on 34 patients. Fifteen patients (42% had stones in the renal pelvis, and in 2 cases, there were associated stones in the upper caliceal group. Twenty patients (58% had ureteral stones, all of them located above the iliac vessel. Twenty-five patients (71% had previously undergone at least one session of extracorporeal lithotripsy and 8 patients (26% also underwent ureteroscopy to attempt to remove the stone. Eight patients underwent retroperitoneoscopy as a primary procedure. Stone size ranged from 0.5 to 6 cm with a mean of 2.1 cm. RESULTS: Retroperitoneoscopy was performed by lumbar approach with initial access conducted by open technique and creation of space by digital dissection. We used a 10-mm Hasson trocar for the optics, and 2 or 3 additional working ports placed under visualization. Following identification, the urinary tract was opened with a laparoscopic scalpel and the stone was removed intact. The urinary tract was closed with absorbable 4-0 suture and a Penrose drain was left in the retroperitoneum. In 17 patients (49%, a double-J stent was maintained postoperatively. Surgical time ranged from 60 to 260 minutes with a mean of 140 minutes. The mean hospital stay was 3 days (1-10 days. The mean length of retroperitoneal urinary drainage was 3 days (1-10 days. There were minor complications in 6 (17.6% patients and 1 case of conversion due to technical difficulty. Thirty-three patients (94% became stone free. CONCLUSION: Retroperitoneoscopy is an effective, low-morbidity alternative for treatment of urinary stones.

  13. Retroperitoneoscopy for treatment of renal and ureteral stones.

    Science.gov (United States)

    Soares, Rodrigo S; Romanelli, Pedro; Sandoval, Marcos A; Salim, Marcelo M; Tavora, Jose E; Abelha, David L

    2005-01-01

    To assess the efficacy of retroperitoneoscopy for treating stones in the renal pelvis and proximal ureter. In the period from August 2003 to August 2004, 35 retroperitoneoscopies for treatment of urinary stones were performed on 34 patients. Fifteen patients (42%) had stones in the renal pelvis, and in 2 cases, there were associated stones in the upper caliceal group. Twenty patients (58%) had ureteral stones, all of them located above the iliac vessel. Twenty-five patients (71%) had previously undergone at least one session of extracorporeal lithotripsy and 8 patients (26%) also underwent ureteroscopy to attempt to remove the stone. Eight patients underwent retroperitoneoscopy as a primary procedure. Stone size ranged from 0.5 to 6 cm with a mean of 2.1 cm. Retroperitoneoscopy was performed by lumbar approach with initial access conducted by open technique and creation of space by digital dissection. We used a 10-mm Hasson trocar for the optics, and 2 or 3 additional working ports placed under visualization. Following identification, the urinary tract was opened with a laparoscopic scalpel and the stone was removed intact. The urinary tract was closed with absorbable 4-0 suture and a Penrose drain was left in the retroperitoneum. In 17 patients (49%), a double-J stent was maintained postoperatively. Surgical time ranged from 60 to 260 minutes with a mean of 140 minutes. The mean hospital stay was 3 days (1-10 days). The mean length of retroperitoneal urinary drainage was 3 days (1-10 days). There were minor complications in 6 (17.6%) patients and 1 case of conversion due to technical difficulty. Thirty-three patients (94%) became stone free. Retroperitoneoscopy is an effective, low-morbidity alternative for treatment of urinary stones.

  14. Emergency room management of ureteral calculi: current practices.

    Science.gov (United States)

    Phillips, Elizabeth; Kieley, Sam; Johnson, Elizabeth B; Monga, Manoj

    2009-06-01

    To evaluate current practice patterns in U.S. emergency departments (EDs) for the diagnosis, treatment, and counseling of patients with ureteral calculi. Hospital-based ED physicians were invited by e-mail to participate in a Survey-Monkey survey. E-mails were delivered in March 2008 by Direct Medical Data using a listserv provided by the American Medical Association. Of the e-mails sent, 173 e-mails were opened, and 135 physicians responded. Physicians were compensated with a $10 Amazon.com gift card. Ninety percent of ED physicians use noncontrast CT as their initial imaging modality, and 63% use alpha-blockers for medical expulsive therapy. Only 13% of evaluated EDs have guidelines for the management of renal colic, and only 58% of these guidelines that recommend the use of an alpha-blocker. Alpha-blocker use was more common with physicians who have been practicing fewer than 5 years (81%) compared with those with more than 10 years of experience (56%). The majority of physicians used ketorolac and morphine to achieve effective analgesia. Although the average responses concerning the chance of spontaneous stone passage for stones 4 mm (44%) were close to evidence-based values, great variation in the answers was noted (standard deviations: 12% and 22%, respectively). Indeed, 38% of respondents stated that stones 95% chance of passage. Twenty-eight percent of ED physicians would arrange follow-up with a primary care physician, while the remainder would arrange follow-up with a urologist. This study establishes a need for educational opportunities for ED physicians in the management of renal colic. The development of collaborative practice guidelines between urology and emergency medicine associations may be warranted.

  15. Uterine Artery Embolization for Ureteric Obstruction Secondary to Fibroids

    International Nuclear Information System (INIS)

    Mirsadraee, Saeed; Tuite, David; Nicholson, Anthony

    2008-01-01

    This case series examines the safety and efficacy of uterine artery embolization (UAE) in the treatment of obstructive nephropathy caused by large fibroids. Between 2004 and 2007, 10 patients referred with symptomatic uterine fibroids that were found to be causing either unilateral (7 patients) or bilateral (3 patients) hydronephrosis were treated by UAE. Presenting complaints included menorrhagia, dysmenorrhea, bulk symptoms, loin pain, postobstructive atrophy, and mild renal impairment. All had posterior intramural dominant fibroids >11 cm in maximum sagittal diameter and uterine volumes between 3776 and 15,625 ml. Outcome measures at between 12 and 36 months included procedural success, repeat intervention, relief of symptoms, resolution of hydronephrosis, stable renal function and size, and avoidance of hysterectomy. In all cases the cause of renal obstruction was confirmed to be a giant fibroid compressing the ureter at the pelvic brim. In all cases UAE was technically successful, though two patients required a repeat procedure. In eight patients hydronephrosis resolved and the obstruction was relieved, though two still had some bulk symptoms not requiring further treatment. Renal function improved or was stable in all cases. Renal size was stable in all cases. Where menorrhagia was part of the symptom complex it was relieved in all cases. Two patients diagnosed as having postobstructive atrophy of one kidney underwent retrograde ureteric stenting on the nonatrophied side prior to UAE. This was unsuccessful in one of the cases due to the distortion caused by the fibroid. Despite improvement in hydronephrosis this patient underwent hysterectomy at 7 months after a renogram demonstrated persistent obstruction at the pelvic brim. In the second patient a double pigtail stent was inserted with difficulty and eventually removed at 8 months. This patient has had stable renal function and size for 3 years post-UAE. We conclude that UAE is safe and effective in

  16. Electron-beam-induced reactivation of Si dopants in hydrogenated two-dimensional AlGaAs heterostructures: a possible new route for III-V nanostructure fabrication

    International Nuclear Information System (INIS)

    Kurowski, Ludovic; Bernard, Dorothee; Constant, Eugene; Decoster, Didier

    2004-01-01

    Hydrogen incorporation in n-type Si-doped GaAs epilayers is a well-known process which leads to the neutralization of the active Si impurities with the formation of SiH complexes. Recently, we have shown that SiH complex dissociation and, consequently, Si-dopant reactivation could occur when the epilayers are exposed to an electron beam. Two epilayers have been studied: the first is a 0.35 μm thick hydrogenated Si-doped GaAs epilayer and the second is Si planar-doped AlGaAs/GaAs/InGaAs heterostructures. Firstly, Hall effect measurements have been carried out on the epilayers exposed, after RF hydrogen plasma exposition, to increasing electron doses with different injection energies. For the 2D heterostructures, we have observed that the free carrier density N s does not vary significantly for weak electron densities. This reactivation presents a threshold value, contrary to the 0.35 μm epilayer in which N s varies quite linearly. It will be shown that such phenomena might be attributed to the filling of surface states as the dopants are progressively reactivated. Then, using a high spatial resolution electron beam lithography system, nanometric conductive patterns have been fabricated starting from hydrogenated epilayers. Electric measurements have been performed and the results obtained show that about 15 nm spatial resolution could be expected. In conclusion, taking into account this spatial resolution, the high spatial contrast of conductivity which could be expected due to the existence of an electron dose threshold, and the high mobility of the AlGaAs/GaAs/InGaAs heterostructure, the effects described in this paper could open a new way for the fabrication of III-V 1D or 2D mesoscopic structures for electronic or optoelectronic applications

  17. Numerical analysis of urine flow through the side holes of a double J stent in a ureteral stenosis.

    Science.gov (United States)

    Kim, Hyoung-Ho; Choi, Young Ho; Lee, Seung Bae; Baba, Yasutaka; Kim, Kyung-Wuk; Suh, Sang-Ho

    2017-07-20

    Ureteral stenosis presents with a narrowing in the ureter, due to an intrinsic or extrinsic ureteral disease, such as ureter cancer or retroperitoneal fibrosis. The placement of a double J stent in the upper urinary system is one of the most common treatments of ureteral stenosis, along with the insertion of a percutaneous nephrostomy tube into the renal pelvis. The effect that the side holes in a double J stent have on urine flow has been evaluated in a few studies using straight ureter models. In this study, urine flow through a double J stent's side holes was analyzed in curved ureter models, which were based on human anatomy. In ureteral stenosis, especially in severe ureteral stenosis, a stent with side holes had a positive effect on the luminal and total flow rates, compared with the rates for a stent without side holes. The more side holes a stent has, the greater the luminal and total flow rates. However, the angular positions of the side holes did not affect flow rate. In conclusion, the side holes in a double J stent had a positive effect on ureteral stenosis, and the effect became greater as the ureteral stenosis became more severe.

  18. Endoscopic placement of double-J ureteric stents in children as a treatment for primary obstructive megaureter

    Directory of Open Access Journals (Sweden)

    Carroll Daniel

    2010-01-01

    Full Text Available Aim: To determine the efficacy and potential complications of double-J ureteric stents in the treatment of persistent or progressive primary obstructive megaureter in pediatric patients within our institution. Materials and Methods: A retrospective case-note review of all patients with double-J ureteric stents, between 1997 and 2004, was performed. In all, 38 stents were inserted in 31 patients aged between 2 months and 15 years of age. Complications and results of follow-up investigations and the need for follow-up investigations were recorded. Patients were followed up clinically and radiologically for a minimum of 2 years following stent insertion. Results: Endoscopic placement of double-J ureteric stents in childhood is straightforward and complications are uncommon (8/38 insertions. In non-resolving or progressive primary non-refluxing megaureter, double-J ureteric stenting alone is effective with resolution of primary non-refluxing megaureter in 66% of cases (25/38 insertions. Conclusions: Ureteric stenting provides an alternative to early surgery in patients with primary non-refluxing megaureter. The youngest patient in our series was 2 months old at the time of endoscopic ureteric double-J stent insertion. Endoscopic placement of ureteric double-J stents should be considered as a first-line treatment in the management of persistent or progressive non-refluxing megaureter leading to progressive hydronephrosis or pyonephrosis.

  19. Self-organisation after embryonic kidney dissociation is driven via selective adhesion of ureteric epithelial cells.

    Science.gov (United States)

    Lefevre, James G; Chiu, Han S; Combes, Alexander N; Vanslambrouck, Jessica M; Ju, Ali; Hamilton, Nicholas A; Little, Melissa H

    2017-03-15

    Human pluripotent stem cells, after directed differentiation in vitro , can spontaneously generate complex tissues via self-organisation of the component cells. Self-organisation can also reform embryonic organ structure after tissue disruption. It has previously been demonstrated that dissociated embryonic kidneys can recreate component epithelial and mesenchymal relationships sufficient to allow continued kidney morphogenesis. Here, we investigate the timing and underlying mechanisms driving self-organisation after dissociation of the embryonic kidney using time-lapse imaging, high-resolution confocal analyses and mathematical modelling. Organotypic self-organisation sufficient for nephron initiation was observed within a 24 h period. This involved cell movement, with structure emerging after the clustering of ureteric epithelial cells, a process consistent with models of random cell movement with preferential cell adhesion. Ureteric epithelialisation rapidly followed the formation of ureteric cell clusters with the reformation of nephron-forming niches representing a later event. Disruption of P-cadherin interactions was seen to impair this ureteric epithelial cell clustering without affecting epithelial maturation. This understanding could facilitate improved regulation of patterning within organoids and facilitate kidney engineering approaches guided by cell-cell self-organisation. © 2017. Published by The Company of Biologists Ltd.

  20. Infusion dynamic ureteroscintigraphy in assessment of ureteral and pelvic contractivity in renal tuberculosis and chronic pyelonephritis

    International Nuclear Information System (INIS)

    Savin, I.B.; Tovstykh, A.M.; Morozov, N.V.

    1995-01-01

    A novel radionuclide method: infusion dynamic ureterscintigraphy was used in examinations of 42 patients with the initial forms of nephrotuberculosis, 18 patients with chronic nonspecific pyelonephritis, and 51 healthy controls. The new method was shown to be highly sensitive in assessment of ureteral and pelvic contractility in specific and nonspecific involvement of the kidneys. 16 refs.; 3 figs

  1. Use of 50% Dextrose as the Distension Medium During Cystoscopy for Visualization of Ureteric Jets.

    Science.gov (United States)

    Narasimhulu, Deepa M; Prabakar, Cheruba; Tang, Nancy; Bral, Pedram

    2016-01-01

    Indigotindisulfonate sodium has been used to color the urine and thereby improve the visualization of ureteric jets during intraoperative cystoscopy. After indigotindisulfonate sodium became unavailable, there has been an ongoing search for an alternate agent to improve visualization of the jets. We used 50% dextrose, which is more viscous than urine, as the distension medium during cystoscopy so that the ureteric efflux is seen as a jet of contrasting viscosity. We instilled 100 mL of 50% dextrose into the bladder through an indwelling catheter, which is then removed and cystoscopy is performed as usual. We observed jets of contrasting viscosity in every patient in whom 50% dextrose was used as compared with coloring agents in which the jet is not always colored at the time of cystoscopy. Visualization of the other structures in the bladder and the bladder wall itself is not altered by 50% dextrose, although the volume of 50% dextrose that we typically use may not provide adequate distension for a complete assessment of the bladder. If additional distension is necessary, normal saline may be used in addition to the 50% dextrose once the ureteric jets have been assessed. Fifty percent dextrose is an effective alternative to indigotindisulfonate sodium for visualization of ureteric jets during cystoscopy.

  2. A case of ectopic ureteral orifice with hypoplastic kidney diagnosed by enhanced computed tomography

    International Nuclear Information System (INIS)

    Kishi, Mikio; Yoshimoto, Jun; Matsumura, Yosuke; Ohmori, Hiroyuki

    1983-01-01

    A case of ectopic ureteral orifice, 6 year old girl with urinary incontinece, is herein reported. Cystoscopy and excretory urogram showed absense of right half of trigone and non visualizing kidney. By enhanced computed tomography, right hypoplastic kidney was found and right nephrectomy was performed. We emphasize that enhanced computed tomography is very usefull for diagnosis of localization of hypoplastic kidney. (author)

  3. Clinical implications and applications of the twinkling sign in ureteral calculus: a preliminary study.

    Science.gov (United States)

    Sharma, Gyanendra; Sharma, Anshu

    2013-06-01

    Twinkling is an artifact seen on color Doppler ultrasound as a rapidly changing mixture of red and blue behind a stationary echogenic structure. We studied the presence or absence of this artifact in ureteral calculi detected on ultrasound and correlated it with clinical parameters. We evaluated 284 ureteral calculi seen on color Doppler ultrasound. The twinkling artifact was graded as 0 to 2 and correlated with the presence or absence of pain, symptom duration, degree of hydronephrosis and passage of a Glidewire® guidewire across the ureteral calculus during ureterorenoscopy. The presence or absence of twinkling was not associated with the degree of hydronephrosis. Twinkling was absent in 92% of patients with significant pain and grade 2 twinkling was seen in 69.5% without significant pain. Twinkling was dominantly absent in patients with a recent colic episode, while 77% who presented 2 to 15 days after a colic episode had grade 2 twinkling. The guidewire was difficult to pass in cases with absent twinkling compared to those with grade 2 twinkling, in which the guidewire and ureteral catheter crossed the calculus easily. Absent twinkling is associated with significant pain, a recent colic episode and difficult guidewire passage across the calculus. These findings suggest that absent twinkling implies significant obstruction, while its presence indicates no significant obstruction. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  4. Editorial comment on: “Ureteritis cystica: A rare benign lesion”

    African Journals Online (AJOL)

    E.O. Kehinde

    This is an interesting rare case of filling defects in the ureter of a. Sudanese lady, proved to be due to ureteritis cystica. The correct diagnosis was made by the finding of filling defects in the ureter on. CT urography and MRU films and at ureteroscopy and biopsy. Nat- urally as clinicians, we think of neoplasms first in such ...

  5. Effect of Flos carthami Extract and α1-Adrenergic Antagonists on the Porcine Proximal Ureteral Peristalsis

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    San-Yuan Wu

    2014-01-01

    Full Text Available Traditional Chinese medicine (TCM has been proposed to prevent urolithiasis. In China, Flos carthami (FC, also known as Carthamus tinctorius (Safflower; Chinese name: Hong Hua/紅花 has been used to treat urological diseases for centuries. We previously performed a screening and confirmed the in vivo antilithic effect of FC extract. Here, ex vivo organ bath experiment was further performed to study the effect of FC extract on the inhibition of phenylepinephrine (PE (10−4 and 10−3 M ureteral peristalsis of porcine ureters with several α1-adrenergic antagonists (doxazosin, tamsulosin, and terazosin as experimental controls. The results showed that doxazosin, tamsulosin, and terazosin dose (approximately 4.5 × 10−6 − 4.5 × 10−1 μg/mL dependently inhibited both 10−4 and 10−3 M PE-induced ureteral peristalsis. FC extract achieved 6.2% ± 10.1%, 21.8% ± 6.8%, and 24.0% ± 5.6% inhibitions of 10−4 M PE-induced peristalsis at doses of 5 × 103, 1 × 104, and 2 × 104 μg/mL, respectively, since FC extract was unable to completely inhibit PE-induced ureteral peristalsis, suggesting the antilithic effect of FC extract is related to mechanisms other than modulation of ureteral peristalsis.

  6. Role of Tamsulosin in Improving Double-J Ureteric Stent-Related ...

    African Journals Online (AJOL)

    Objective: To evaluate the efficacy of tamsulosin in improving stent- related symptoms and quality of life (QoL) in patients with double-J (DJ) ureteric stents. Subjects and Methods: A total of 136 patients were prospectively evaluated and distributed randomly in two groups. Group 1 was 69 patients with mean age 35 years ...

  7. Bilateral transrenal ureteral occlusion by means of n-butyl cyanoacrylate and AMPLATZER vascular plug

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    Rosario F Grasso

    2014-01-01

    Full Text Available AMPLATZER vascular plug is a widely used embolic agent. In the present paper, we present a case of an 86-year-old female patient who underwent bilateral ureteral occlusion by means of AMPLATZER vascular plug II coupled to n-butyl cyanoacrylate (NBCA because of recurring pyelonephritis following cystectomy with subsequent bilateral ureterosigmoidostomy (sec. Mainz type II.

  8. Treatment of pyonephrosis with a subcutaneous ureteral bypass device in four cats.

    Science.gov (United States)

    Cray, Megan; Berent, Allyson C; Weisse, Chick W; Bagley, Demetrius

    2018-03-15

    CASE DESCRIPTION 4 cats were examined because of ureteral obstruction. CLINICAL FINDINGS Clinical and clinicopathologic abnormalities were nonspecific and included anorexia, lethargy, weight loss, anemia, leukocytosis, neutrophilia, lymphopenia, and azotemia. A diagnosis of pyonephrosis was made in all cats. The presence of bacteriuria was confirmed by means of urinalysis in 2 cats, bacterial culture of a urine sample obtained by means of preoperative cystocentesis in 2 cats, and bacterial culture of samples obtained from the renal pelvis intraoperatively in 3 cats. Ureteral obstruction was caused by a urolith in 3 cats; ureteral stricture associated with a circumcaval ureter was identified in 1 cat. TREATMENT AND OUTCOME All 4 cats underwent renal pelvis lavage and placement of a subcutaneous ureteral bypass (SUB) device for treatment of obstructive pyonephrosis. Postoperatively, the cystostomy tube became occluded with purulent material in 1 cat, requiring exchange. The procedure was successful in relieving the obstruction and pyonephrosis in all cats. Three of 4 cats had documented resolution of urinary tract infection. One cat had persistent bacteriuria without clinical signs 1 month after SUB device placement. CLINICAL RELEVANCE Results of this small series suggested that renal pelvis lavage with placement of an SUB device may be a treatment option for cats with obstructive pyonephrosis.

  9. Severity of hydronephrosis correlates with tumour invasiveness and urinary bladder recurrence of ureteric cancer.

    Science.gov (United States)

    Luo, Hao Lun; Kang, Chih Hsiung; Chen, Yen Ta; Chuang, Yao Chi; Lee, Wei Ching; Cheng, Yuan Tso; Chiang, Po Hui

    2013-08-01

    To explore the prognostic role of hydronephrosis grade in patients with pure ureteric cancer. The study included 162 patients with pure ureteric cancer who were treated between January 2005 and December 2010 at a single tertiary referral centre. The association between hydronephrosis grade with pathological findings and oncological outcomes was assessed using multivariate Cox regression analysis. Hydronephrosis grade >2 was independently associated with non-organ-confined ureteric cancer (P = 0.003). Hydronephrosis grade Hydronephrosis grade >2 and bladder cancer history independently predict bladder cancer recurrence (P = 0.021 and P = 0.002, respectively) Hydronephrosis of grade >2 was found to be associated with local and distant recurrence only in univariate analysis; non-organ-confined pathology independently predicted local and distant oncological failure (P ≤ 0.001 and P = 0.002, respectively). Hydronephrosis grade >2 is associated with non-organ-confined ureteric cancer and with bladder cancer recurrence. Non-organ-confined pathology is still the most important predictor for local and distant oncological failure. © 2013 BJU International.

  10. Vesico-ureteral reflux in children with prenatally detected hydronephrosis: a systematic review

    NARCIS (Netherlands)

    van Eerde, A. M.; Meutgeert, M. H.; de Jong, T. P. V. M.; Giltay, J. C.

    2007-01-01

    To investigate the value of prenatally detected hydronephrosis (PNH) as a prognostic factor for vesico-ureteral reflux (VUR). The MEDLINE database was searched for articles on PNH and VUR published between 1980 and 2004. A total of 18 studies were identified and reviewed for various aspects. Results

  11. [Experimental work: reconstruction of the pelvi-ureteric junction and ureter using testicular tunica vaginalis autograft].

    Science.gov (United States)

    Usupbaev, A Ch; Kurbanaliev, R M; Chernetsova, G S; Kolesnichenko, I V; Sultanov, B M; Myrzakanov, N M; Zolotukhin, A O; Vagner, N A

    2017-12-01

    To evaluate the results of surgical reconstruction of the upper urinary tract using an autograft of testicular tunica vaginalis in experimental animals. The article presents the results of partial replacement of the renal pelvis and ureter with an autograft in 25 male dogs. The grafts were harvested by resection of the parietal layer of the testicular tunica vaginalis, which was transplanted into the region of the pelvi-ureteric junction and the proximal ureter. The upper urinary tract was drained using a ureteral stent catheter. The results were evaluated at week 1 and months 1, 3 and six after the operation. The functional state of the kidneys and ureters was analyzed using excretory urography and ultrasound; the autograft biopsy specimens were examined histologically. In all cases, the viability of the autograft was completely preserved, there were no signs of secondary infection, necrosis and impaired patency in the anastomosis zone. Histological examination revealed signs of epithelialization, connective tissue substitution and neovasculogenesis in the implantation zone. The proposed surgical modality is an alternative method to restore normal urine flow in the upper urinary tract in obstructive urological diseases. The group of obstructive urological diseases was studied using the model of the strictures of the pelvi-ureteric junction in the intrarenal pelvis and ureteral strictures measuring up to 3-4 cm in length.

  12. Lumbar Ureteral Stenosis due to Endometriosis: Our Experience and Review of the Literature

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    Salvatore Butticè

    2013-01-01

    Full Text Available Endometriosis is a chronic gynaecological disorder characterized by the presence of endometrial tissue outside the uterus. The disease most often affects the ovaries, uterine ligaments, fallopian tubes, and cervical-vaginal region. Urinary tract involvement is rare, accounting for around 1%-2% of all cases, of which 84% are in the bladder. We report a case of isolated lumbar ureteral stenosis due to endometriosis in a 37-year-old patient. The patient came to our observation complaining from lumbar back pain and presented with severe fever. The urological examination found monolateral left positive sign of Giordano. Blood tests evidenced marked lymphocytosis and increased valued of C-reactive protein. Urologic ultrasound showed hydronephrosis of first degree in the left kidney and absence of images related to stones bilaterally. Uro-CT scan evidenced ureteral stenosis at the transition between the iliac and pelvic tracts. We addressed the patient to surgery, and performed laparoscopic excision of the paraureteral bulk, endoscopic mechanical ureteral dilation, and stenting. The histological examination evidenced glandular structures lined by simple epithelium and surrounded by stroma. Immunohistochemical test of the glandular epithelium showed positivity for estrogen and progesterone receptors and moreover stromal cells were positive for CD10. The finding suggested a very rare diagnosis of isolated lumbar ureteral endometriosis.

  13. Ureteral diameter in low-risk vesicoureteral reflux in infancy and childhood

    International Nuclear Information System (INIS)

    Hellstroem, M.; Hjaelmaas, K.; Jacobsson, B.; Jodal, U.; Oestra Sjukhuset, Goeteborg; Oestra Sjukhuset, Goeteborg

    1986-01-01

    In order to improve the accuracy of the grading of vesicoureteral reflux (VUR), reference values for ureteral diameter at micturition cystourethrography (MCUG) were established in infants and children with low-risk VUR. Low-risk VUR was defined as VUR not associated with infection, obstruction, calculi, duplication, malformations (except for hypospadia) or neurogenic bladder disturbances. Forty-six children (age 1 day - 14 years) were selected by examining the records of 12000 MCUG:s performed 1960-1983. Ureteral diameter was measured at the widest point of the ureter on the films from MCUG:s and urographies. Ureteral diameter was slightly larger at MCUG than at urography in the same individuals but the difference was not significant. The ureteral diameter at MCUG also correlated closely to normal values at urography in a previous study. It is proposed that the reference values obtained at MCUG in the present investigation can be used for the differentiation between dilatation and no dilatation in the grading of VUR. (orig.)

  14. Do stone size and impaction influence therapeutic approach to proximal ureteral stones?

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    Radulović Slobodan

    2009-01-01

    Full Text Available Background/Aim. Primary therapeutic approach to lumbar ureteral stones is still contraversial. The aim of the study was to investigate the influence of stone impaction and size on the effectiveness of proximal ureteral stone lithotripsy. Methods. A total of 123 patients with proximal ureteral stones were investigated in this prospective study performed in a 10- month period. The patients were divided into the group I - 86 patients treated with extracorporeal shock wave lithotripsy (ESWL and the group II - 37 patients treated with 'Swiss' Lithoclast. In the group I, 49 stones (57% were classified as impacted, while 20 stones (23.3% were larger than 100 mm2. In the group II, 26 stones (70.3% were impacted, and 11 stones (29.7% were larger than 100 mm2. Stones were defined as impacted by the radiographic, echosonographic as well as endoscopic findings in the group II of patients. Stone size was presented in mm2. Chemical composition of stones were almost the same in both groups of the patients. Results. Generally, there was no statistically significant difference in the treatment success between the groups. However, stones larger than 100 mm2 were statistically more successfully treated endoscopically, while there was no statistical difference in the treatment success of impacted stones between these two groups. Conclusion. ESWL can by considered as primary first therapeutic approach in treatment of all proximal ureteral stones except for stones larger than 100 mm2 that should primarily be treated endoscopically.

  15. Pattern of Ureteric Pathology Presenting to a Fistula Centre in Western Kenya

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    Anthony Wanjala

    2018-01-01

    Full Text Available Background. Ureteric pathology arises from surgical misadventures, trauma, and congenital anomalies. Early detection and treatment is of the essence. Objectives. To determine the types/etiology and outcome of ureteric pathology presenting to Gynocare Fistula Centre, Eldoret, Kenya. Methods. Descriptive retrospective study that evaluated patients presenting with ureteric pathology at Gynocare between 1st January 2012 and 31st December 2016. We pulled out patient charts and extracted and analyzed relevant data using STATA 13E statistical software. Results. We analyzed 33 charts, and their age ranged from 10 to 58 years. Annual proportion for 2012, 2013, 2014, 2015, and 2016 was 2.5%, 2.8%, 1.2%, 1.4%, and 3.0% respectively among all the fistula patients treated in the hospital. All the patients presented with urinary incontinence, and 7 (21.2% had flank pain. Iatrogenic injuries contributed 84.8% (28, and 3 (9.1% were congenital while trauma and infection had 1 each. Of those resulting from surgical misadventures, 17 (60.7% were from obstetric while 11 (39.2% were from gynecological surgery. All the injuries were in the distal third of the ureter; 5 were bilateral; and 11 were left sided while 17 were right-sided. Repair and/or reimplantation was successful in 31 (93.93% of the patients. Conclusion. Highest proportion of ureteric pathologies was accounted for by iatrogenic causes and surgical repair and/or reimplantation has a high success rate.

  16. Medical expulsive therapy for ureteral stones: where do we go from here?

    NARCIS (Netherlands)

    Somani, Bhaskar K.; Aboumarzouk, Omar; Traxer, Olivier; Baard, Joyce; Kamphuis, Guido; de la Rosette, Jean

    2016-01-01

    Despite two decades of clinical use, the effectiveness of medical expulsive therapy (MET) for the noninvasive management of patients with ureteral stones has, in the past year, been called into in question. The primary aim of MET is to expedite stone passage, although it has also shown effectiveness

  17. The clinical implications of hydronephrosis and the level of ureteral obstruction in stage IIIB cervical cancer

    International Nuclear Information System (INIS)

    Chao, K.S. Clifford; Leung, W.-M.; Grigsby, Perry W.; Mutch, David G.; Herzog, Thomas; Perez, Carlos A.

    1998-01-01

    Purpose: There are two criteria for the diagnosis of Stage IIIB cervical cancer in the FIGO staging system: tumor fixation to the pelvic side wall and/or the presence of hydronephrosis due to tumor. However, we often encounter hydronephrosis without tumor fixed to the pelvic side wall or the level of ureteral obstruction not corresponding to the main tumor mass in the pelvis. The clinical implication of these phenomena remains unclear. We investigated the Stage IIIB population treated at the Mallinckrodt Institute of Radiology and hypothesized that, if hydronephrosis presents without tumor fixation to the pelvic side wall or if the level of ureteral obstruction is above the main pelvic tumor mass, it most likely resulted from external compression of ureter(s) by enlarged lymph nodes and, consequently, a worse outcome is expected. Methods and Materials: From 1959 to 1989, there were 297 patients with Stage IIIB cervical cancer who received definitive radiation therapy at the Mallinckrodt Institute of Radiology and were assessable for the presence of hydronephrosis and the level of ureteral obstruction. There were 281 patients who presented with tumor fixed to the pelvic side wall, and 62 of them were associated with concurrent hydronephrosis. An additional 16 patients presented with hydronephrosis without tumor fixation to the pelvic side wall. Among these 78 documented cases of hydronephrosis, the level of ureteral obstruction was above the true pelvis in 39 patients, and below the true pelvis in the other 39. Radiation therapy was individualized according to tumor extension and configuration; para-aortic lymph nodes were not routinely treated except in patients with clinical evidence of nodal metastasis. Results: The progression-free survival (PFS) at 5 years was 35% in 62 patients with hydronephrosis and tumor fixed to the pelvic side wall vs. 43% in 213 patients with tumor fixed to the pelvic side wall only (p 0.12). However, PFS at 5 years decreased to 23% in

  18. Doppler visualization of ureteric jets in unilateral hydronephrosis in children and adolescents

    International Nuclear Information System (INIS)

    Cvitkovic Kuzmic, Andrea; Brkljacic, Boris; Rados, Marko; Galesic, Kresimir

    2001-01-01

    Objective: to evaluate Doppler visualization of ureteric jets in the assessment of unilateral kidney collecting system dilatation in children and adolescents. Methods and patients: color Doppler ultrasonography was performed in 27 patients with hydronephrosis (11 female, 16 male, age range 3-21 years, mean age 10.5±4.4). Nine had acute obstruction due to ureteral calculus, seven had obstructive hydronephrosis due to uretero-pelvic junction (UPJ) stenosis, and 11 had non-obstructive hydronephrosis. Doppler was also performed in 32 healthy children (15 boys and 17 girls, age 2-17 years, mean age 7.8±3.9), who represented the control group. Results: in the control group jets were visible in 57 out of 64 ureteric units (89%). The mean frequency of jets in healthy children was 4.1 jets per min. In all children with hydronephrosis, jets were visible in 25 out of 27 normal ureteric units (92.6%), and their mean frequency was 4.5 jets per min. In children with acute unilateral colic, ureteric jets were completely absent in eight of nine patients (89%). In children with obstructive hydronephrosis, due to UPJ stenosis, jets were absent in five out of seven patients (71.4%), and in children with non-obstructive hydronephrosis jets were absent in three out of eleven patients (27.3%). When jets are visible, their frequencies are much lower on the obstructed side as compared with normal side, while in cases of nonobstructive dilatation frequency of jets is similar on both sides. Conclusion: absence of jets in patients with acute obstruction due to ureteral calculus, strongly correlates with high-grade obstruction. In children with UPJ stenosis, presence of ureteric jet does not exclude significant obstruction, but the frequency of jets on the obstructed side is much lower as compared with the unaffected side. When there is absence of jet from the dilated side or significant asymmetry in jet frequency, hydronephrosis is likely to be obstructive

  19. Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: a report of five cases.

    Science.gov (United States)

    Dai, L N; Chen, C D; Lin, X K; Wang, Y B; Xia, L G; Liu, P; Chen, X M; Li, Z R

    2015-10-01

    Hydronephrosis is a common disease in children and may be caused by ureteral fibroepithelial polyps (UFP). Ureteral fibroepithelial polyps are rare in children and are difficult to precisely diagnose before surgery. Surgical treatment for symptomatic UFP is recommended. At the present institution, retroperitoneal laparoscopy has been used to treat five boys with UFP since 2006. To highlight the significance of UFP as an etiological factor of hydronephrosis in children and evaluate the applicative value of retroperitoneal laparoscopy in the treatment of children with UFP. Between 2006 and 2013 five boys underwent retroperitoneal laparoscopy at the present institution. They were identified with UFP by review of the clinical database. Detailed data were collected, including: radiographic studies, gross anatomical pathology, and pathology and radiology reports. All boys had been followed up at least every 6 months. All of the boys were aged between 7 and 16 years (mean 9.8 years). The main symptoms were flank pain (all five) and hematuria (three). Radiographic examination showed that all of the boys presented with incomplete ureteral obstruction and hydronephrosis. The ureteral fibroepithelial polyps were located near the left UPJ or the left proximal ureter. All of the boys had the UFP removed: three underwent retroperitoneal laparoscopic dismembered Anderson-Hynes pyeloplasty and polypectomy, and two had retroperitoneal laparoscopic ureteral anastomosis. These polyps were all on the left side and between 15 and 35 mm in length (mean 22 mm) (Figure). All of the boys recovered well and were discharged from hospital. The postoperative histological report confirmed that the specimens were UFP. Hydronephrosis was periodically assessed by ultrasonography (using the same method as pre-surgical ultrasonography) after surgery. Mean follow-up was 33 months (range 6-58 months) and no complications were found afterwards. Ureteral fibroepithelial polyps are rare but rather

  20. Bilateral complete ureteral duplication with calculi obstructing both limbs of left double ureter.

    Science.gov (United States)

    Aiken, William D; Johnson, Peter B; Mayhew, Richard G

    2015-01-01

    A woman with bilateral complete ureteral duplication with stones simultaneously obstructing both limbs of the left double ureter is presented. A search of the English medical literature suggests that this is the first reported case. Based on the initial difficulty accessing the stones via ureteroscopy we make recommendations regarding how this rare problem should be approached if encountered. A 37-year old woman with left-sided flank pain was discovered on CT scan to have bilateral complete ureteral duplication and three stones obstructing both limbs of the left double ureter. Ureteroscopy was initially unsuccessful due to the very small calibre and unyielding nature of the ureters and both ureteral limbs were stented. Repeat ureteroscopy was easily achieved after pre-stenting and the impacted stones were completely cleared with intracorporeal laser lithotripsy. The smaller calibre of both double ureters and their presence in a common adventitial sheath distally, made initial attempts at ureteroscopy difficult. Stenting both limbs increased ureteral compliance, passively dilated both ureters and allowed for improved manoeuvrability and retrograde passage of the ureteroscope. Based on the experience with this first reported case it is recommended that pre-stenting should be routinely performed prior to any attempt at ureteroscopy in cases of stones complicating completely duplicated ureters. We report the first recorded case of bilateral complete ureteral duplication with stones simultaneously obstructing both limbs of the double ureter and recommend that routine pre-stenting be done prior to ureteroscopy to allow easy uncomplicated retrograde passage of the ureteroscope. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. A clinical nomogram to predict the successful shock wave lithotripsy of renal and ureteral calculi.

    Science.gov (United States)

    Wiesenthal, Joshua D; Ghiculete, Daniela; Ray, A Andrew; Honey, R John D'A; Pace, Kenneth T

    2011-08-01

    Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (pstone density (pstone distance (pstone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  2. The Effect of Tamsulosin in the Medical Treatment of Distal Ureteral Stones

    Science.gov (United States)

    Alizadeh, M.; Magsudi, M.

    2014-01-01

    Introduction: Renal stones are common disorders that affect approximately 5% to 10% of the population and the incidence of renal stones is rising. Treatment of ureteral stones is an important part of urologists and minimally invasive procedures such as ESWL and ureteroscopy effectiveness has been proven in various studies. However, these methods are not completely safe and are expensive and can be complicated. Purpose of this study is to evaluate the effectiveness of tamsulosin in the medical treatment of distal ureteral stones. Patients and methods: A total of 96 patients with distal ureteral stones or UVj are randomly divided into two study group (50 patients) and control group (46 patients). Patients in the control group allowed to freely consuming fluids (hydration) and indomethacin 100 mg PRN. Study group in addition to indomethacin and daily analgesic 0.4 mg tamsulosin was administered. All subjects in terms of analgesic dose, duration of expulsion and expulsion were studied. Results: Spontaneous expulsion of stone was occurred in 62.5% (30 patients out of 46) of control group patients and 82% (41 patients out of 50) that there was no significant difference (P>0.05). Average time to fix the stone in control group 4.7±8.03 days (range 2 to 28 days) and in the study group, 3.7±5.70 days (range 1 to 23 days) is significantly different (P>0.05). The average amount of analgesic consumption in the control group was 2.3±4.31and in the study group was 1.48±2.15 that showed significant differences (Ptamsulosin to conservative treatment of distal ureteral stones in the distal ureteral stone expulsion showed no significant difference between the two groups, but the reduction in the duration of expulsion, reduce pain and reduce the need for analgesic has been beneficial. PMID:25363178

  3. Assessment of readability, quality and popularity of online information on ureteral stents.

    Science.gov (United States)

    Mozafarpour, Sarah; Norris, Briony; Borin, James; Eisner, Brian H

    2018-02-12

    To evaluate the quality and readability of online information on ureteral stents. Google.com was queried using the search terms "ureteric stent", "ureteral stent", "double J stent" and, "Kidney stent" derived from Google AdWords. Website popularity was determined using Google Rank and the Alexa tool. Website quality assessment was performed using the following criteria: Journal of the American Medical Association (JAMA) benchmarks, Health on the Net (HON) criteria, and a customized DISCERN questionnaire. The customized DISCERN questionnaire was developed by combining the short validated DISCERN questionnaire with additional stent-specific items including definition, placement, complications, limitations, removal and "when to seek help". Scores related to stent items were considered as the "stent score" (SS). Readability was evaluated using five readability tests. Thirty-two websites were included. The mean customized DISCERN score and "stent score" were 27.1 ± 7.1 (maximum possible score = 59) and 14.6 ± 3.8 (maximum possible score = 24), respectively. A minority of websites adequately addressed "stent removal" and "when to seek medical attention". Only two websites (6.3%) had HON certification (drugs.com, radiologyinfo.org) and only one website (3.3%) met all JAMA criteria (bradyurology.blogspot.com). Readability level was higher than the American Medical Association recommendation of sixth-grade level for more than 75% of the websites. There was no correlation between Google rank, Alexa rank, and the quality scores (P > 0.05). Among the 32 most popular websites on the topic of ureteral stents, online information was highly variable. The readability of many of the websites was far higher than standard recommendations and the online information was questionable in many cases. These findings suggest a need for improved online resources in order to better educate patients about ureteral stents and also should inform physicians that popular websites may

  4. Retrograde or antegrade double-pigtail stent placement for malignant ureteric obstruction?

    International Nuclear Information System (INIS)

    Uthappa, M.C.; Cowan, N.C.

    2005-01-01

    AIM: To determine the optimum approach for double-pigtail stent placement in malignant ureteric obstruction. PATIENTS AND METHODS: Retrograde stent placement was attempted in a consecutive series of patients presenting with malignant ureteric obstruction. If retrograde stent placement was unsuccessful, percutaneous nephrostomy was performed immediately followed by elective antegrade stent placement. Identical digital C-arm fluoroscopy for image-guidance and conditions for anaesthesia and analgesia were employed for both retrograde and antegrade procedures. Identical 8 Fr (20-26 cm) double-pigtail hydrophilic coated stents were used for each approach. RESULTS: Retrograde placement was attempted in 50 ureters in 30 patients {19 male, 11 female, average age 61.4 yr (range 29-90 yr)} over a 24-month period. The success rate for retrograde ureteric stent placement was 50% (n=25/50). Technical failures were due to failure to identify the ureteric orifice (n=22), failure to cross the stricture (n=1), failure to pass the stent (n=1) and failure to pass a 4 Fr catheter (n=1). Antegrade placement was attempted in 25 ureters with a success rate of 96% (n=24/25). Failure in the one case was due to inability to cross an upper third stricture secondary to pyeloureteritis cystica. CONCLUSION: It is suggested that retrograde route should be the initial approach if imaging shows no involvement of ureteric orifice (UO), when nephrostomy is technically very difficult or in cases of solitary kidney. The antegrade route is preferred if imaging shows tumour occlusion of the UO or if there is a tight stricture very close to the uretero-vesical junction (UVJ) making purchase within the ureter difficult for crossing the stricture

  5. Endoscopic placement of double-J ureteric stents in children as a treatment for primary hydronephrosis.

    Science.gov (United States)

    Pogorelić, Zenon; Brković, Tomislava; Budimir, Dražen; Todorić, Jakov; Košuljandić, Đurđica; Jerončić, Ana; Biočić, Mihovil; Saraga, Marijan

    2017-06-01

    The aim of this study was to determine the efficacy and potential complications of double-J ureteric stents in the treatment of primary hydronephrosis in pediatric patients. A retrospective case-records review of 133 patients (45 girls and 88 boys) treated because of primary hydronephrosis with double-J ureteric stents, in Department of Pediatric Surgery, Split University Hospital, between December 1997 and December 2014, was performed. Success of treatment, results of follow up investigations and complications were recorded. Patients were followed up clinically and radiologically for a minimum of 2 years following stent insertion. In all, 133 endoscopic double-J ureteric stents insertions were performed. Of the total number of patients, left-sided hydronephrosis was found in 82 patients, right-sided in 38, and bilateral in 13 patients. The median age of children was 2 years (range 0-17 years). Mean hospital stay was 2 days (range 1-10 days). In primary hydronephrosis, double-J ureteric stenting alone was effective with resolution of hydronephrosis in 73% of cases (97/133 insertions). Regarding the age of the patients the highest success of 83.5% was achieved in age group 0-4 years. Success in groups 5-9 years; 10-14 years and 15-17 years were 47%; 33.5% and 0%, respectively. Several complications have been recorded: symptomatic infections, migration in the renal pelvis and bladder, progression of hydronephrosis, spontaneously prolapse of prosthesis, bleeding and perforation of the renal pelvis. A significant, decreasing trend in success rates by age of participants was observed (p hydronephrosis. Endoscopic placement of ureteric double-J stents should be considered as a first-line treatment in the management of primary hydronephrosis especially in children till 4 years of age, with success rate of 83.5% and without the need for conventional surgery. In a case of failure we are time-consuming to definitive surgery.

  6. Extra-corporeal shock wave lithotripsy (ESWL) versus ureteroscopic management for ureteric calculi.

    Science.gov (United States)

    Nabi, G; Downey, P; Keeley, F; Watson, G; McClinton, S

    2007-01-24

    Ureteral stones frequently cause renal colic and if left untreated can cause obstructive uropathy. Extracorporeal Shock Wave Lithotripsy (ESWL) and ureteroscopy, with or without intracorporeal lithotripsy, are the two most commonly offered interventional procedures in these patients. ESWL treatment is less invasive but has some limitations such as a high retreatment rate and lack of availability in many centres. Advances in ureteroscopy over the past decade have increased the success rate and reduced complication rates. To examine evidence from randomised controlled trials (RCTs) on the outcomes of ESWL or ureteroscopy in the treatment of ureteric calculi. We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library Issue 2, 2006), MEDLINE (1966 - March 2006), EMBASE (1980 - March 2006), reference lists of articles and abstracts from conference proceedings without language restriction. RCTs comparing ESWL with ureteroscopic retrieval of ureteric stones were included. Participants were adults with ureteric stones requiring intervention. Published and unpublished sources were considered. Two authors independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or weighted mean difference (MD) for continuous data with 95% confidence intervals (CI). Six RCTs (833 patients) were included. The stone-free rates were lower in the ESWL group (RR 0.84 95% CI 0.73 to 0.96). The retreatment rates were lower but not significant in the ureteroscopy group (RR 3.34 95% CI 0.82 to 13.62). The rate of complications was lower in the ESWL group (RR 0.48 95% CI 0.26 to 0.91). Length of hospital stay was less for ESWL treatment (MD -2.10 95% CI -2.55 to -1.64). Ureteroscopic removal of ureteral stones achieves a higher stone-free state but with a higher complication rate and a longer hospital stay.

  7. Efficacy of extracorporeal shockwave lithotripsy using Dornier SII in different levels of ureteral stones

    Science.gov (United States)

    Elkholy, Mohamed M.; Ismail, Hassan; Abdelkhalek, Mohamed A.; Badr, Mohamad M.; Elfeky, Mohamed M.

    2014-01-01

    Objective: The objective of this study was to evaluate the efficacy and safety of the Dornier lithotripter S II system in the treatment of ureteral calculi. Patients and Methods: A total of 97 cases which consists of 54 males and 43 females with ureteral stones were treated by extracorporeal shock wave lithotripsy (ESWL). Mean age was 42.6 years. Inclusion criteria were solitary radiopaque ureteral stones of radiological stone size of ≤1 cm. The stones were not impacted, with normal kidney functions. Procedure time, number of shocks, energy used, number of sessions and complications were reported. The outcome of ESWL was also recorded. Results: Stones were in the abdominal (upper ureter) in 50% of patients, in pelvic (middle ureter) in 47% of patients. All patients had unilateral stones and the mean stone size in maximum length was) 10 mm). Good dye excretion passing the stone was noted in all patients. Mild hydronephrosis was found in 85% of cases. A total of 49 cases were treated by a single session, while in 35% of cases two sessions were enough and 16% received three sessions. The average number of shocks per session was 3125. The average number of shocks per patient was 5962.5 shocks and average energy was 204.3 Joules. The overall stone-free rate 3 months after lithotripsy was 94%. After a single session of lithotripsy, 49 patients (49%) became stone-free. Stone free rates after ESWL for upper, middle ureteral stones were 94%, 95.7% respectively. Additional procedures were needed in only 6 cases (6%) to render patients stone-free after lithotripsy. No serious complications occurred. Conclusion: The Dornier lithotripter S II is very effective in the treatment of ureteral calculi with no major complications. PMID:25371614

  8. Large impacted upper ureteral calculi: A comparative study between retrograde ureterolithotripsy and percutaneous antegrade ureterolithotripsy in the modified lateral position

    Directory of Open Access Journals (Sweden)

    Kamal Moufid

    2013-01-01

    Conclusions: In our series, Perc-URS is a safe and efficient treatment option for proximal ureteral stone, especially when the stone size is superior to 15 mm with the presence of moderate or severe hydronephrosis.

  9. Pelvi-ureteric junction obstruction related to crossing vessels: vascular anatomic variations and implication for surgical approaches.

    Science.gov (United States)

    Panthier, Frédéric; Lareyre, Fabien; Audouin, Marie; Raffort, Juliette

    2018-03-01

    Pelvi-ureteric junction obstruction corresponds to an impairment of urinary transport that can lead to renal dysfunction if not treated. Several mechanisms can cause the obstruction of the ureter including intrinsic factors or extrinsic factors such as the presence of crossing vessels. The treatment of the disease relies on surgical approaches, pyeloplasty being the standard reference. The technique consists in removing the pathologic ureteric segment and renal pelvis and transposing associated crossing vessels if present. The vascular anatomy of the pelvi-ureteric junction is complex and varies among individuals, and this can impact on the disease development and its surgical treatment. In this review, we summarize current knowledge on vascular anatomic variations in the pelvi-ureteric junction. Based on anatomic characteristics, we discuss implications for surgical approaches during pyeloplasty and vessel transposition.

  10. Extracorporeal shock wave lithotripsy in the treatment of ureteric stones: Experience from Twam Hospital, United Arab Emirates

    International Nuclear Information System (INIS)

    Ghafoor, M.; Halim, A.

    2002-01-01

    The optimal treatment of ureteric stones, especially the lower ureteric stone, remains controversial. The purpose of this study was to evaluate the role of extracorporeal shock wave lithotripsy (ESWL) in the management of ureteric stones. A total of 99 patients with ureteric stones at different levels were treated with ESWL from 1994 through 1998 at our hospital. All patients were treated using Siemen Lithostar-II Plus Lithotripter. Of 99 patients, 22 were excluded from the study because they had no follow-up records of their stone-free status. The clearance rates for ureteric stones of the other 79 patients treated were stratified according to the site, size and the number of treatment sessions required per stone. The stone size was determined by the widest diameters. Based on stone size, the patients were divided into two groups: A ( 1 0 mm) and B (11-20 mm). The overall all clearance rate for ureteric stones treated with ESWL, irrespective of its site and size, was 78.5%. The overall clearance rate for size A (<-10 mm) stone was 82% and size B (11-20 mm) was 58% regardless of the site of the stone in the ureter. A total of 17 upper ureteric stones were treated with ESWL. The overall clearance rate for upper ureteric stones was 94%. Thirteen patients with mid-ureteric stones were treated with ESWL. The overall clearance rate for the lower ureteric stones was 69.3%. ESWL is safe, effective, noninvasive and a convenient way of treatment for all ureteric stones. The clearance rate for stones in the upper and mid-ureter is above 90%. ESWL being an outpatient procedure without ant need for anesthesia or any pretreatment intervention. It should be considered as the first line of treatment for all stones in the upper and mid-ureter. The clearance for small stones (<1 mm) in the lower third of ureter was 73.8% in our study and for these, ESWL may be considered as a primary therapy. For stones larger than 10 mm in the distal third of ureter, the clearance rate was low

  11. Technological development for super-high efficiency solar cells. Technological development for crystalline compound solar cells (high-efficiency III-V tandem solar cells); Chokokoritsu taiyo denchi no gijutsu kaihatsu. Kessho kagobutsu taiyo denchi no gijutsu kaihatsu (III-V zoku kagobutsu handotai taiyo denchi no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuta, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    This paper reports the study results on technological development of III-V compound semiconductor solar cells in fiscal 1994. (1) On development of epitaxial growth technology of lattice mismatching systems, the optimum structure of InGaAs strain intermediate layers was studied for reducing a dislocation density by lattice mismatching of GaAs layer grown on Si substrate and difference in thermal expansion coefficient. The effect of strain layer on dislocation reduction was found only at 250dyne/cm in strain energy. Growth of GaAs layers on the Si substrate treated by hydrofluoric acid at low temperature was attempted by MBE method. As a dislocation distribution was controlled by laying different atoms at hetero-interface, the dislocation density of growing layer surfaces decreased by concentration of dislocation at hetero-interface. (2) On development of high-efficiency tandem cell structure, tunnel junction characteristics, cell formation process and optimum design method of lattice matching tandem cells were studied, while thin film cell formation was basically studied for lattice mismatching tandem cells. 45 figs., 8 tabs.

  12. Extracorporeal shock wave lithotripsy (ESWL) versus ureteroscopic management for ureteric calculi.

    Science.gov (United States)

    Aboumarzouk, Omar M; Kata, Slawomir G; Keeley, Francis X; McClinton, Samuel; Nabi, Ghulam

    2012-05-16

    Ureteral stones frequently cause renal colic, and if left untreated, can lead to obstructive uropathy. Extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy, with or without intracorporeal lithotripsy, are the most common interventions used to treat ureteral stones. ESWL treatment is less invasive than ureteroscopy, but has some limitations such as a high retreatment rate, and is not available in all centres. Recent advances in ureteroscopy have increased success rates and reduced complication rates. To examine evidence from randomised controlled trials (RCTs) on the outcomes of ESWL or ureteroscopy in the treatment of ureteric calculi. We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library Issue 2, 2011), MEDLINE (1966 to March 2011), EMBASE (1980 to March 2011), CINAHL, Clinicaltrials.gov, Google Scholar, reference lists of articles and abstracts from conference proceedings, all without language restriction. RCTs that compared ESWL with ureteroscopic retrieval of ureteric stones were included in this review. Study participants were adults with ureteric stones requiring intervention. Published and unpublished sources were considered for inclusion. Three authors independently assessed study quality, risk of bias, and extracted data. Statistical analyses were performed using the random-effects model. Results were expressed as risk ratios (RR) for dichotomous outcomes or mean differences (MD) for continuous data, both with 95% confidence intervals (CI). Seven RCTs (1205 patients) were included in the review. Stone-free rates were lower in patients who underwent ESWL (7 studies, 1205 participants: RR 0.84, 95% CI 0.73 to 0.96) but re-treatment rates were lower in ureteroscopy patients (6 studies, 1049 participants: RR 6.18, 95% CI 3.68 to 10.38. ESWL-treated patients had less need for auxiliary treatment (5 studies, 751 participants: RR 0.43, 95% CI 0.25 to 0.74; fewer complications (7 studies, 1205 participants: RR 0

  13. [The thermoformable spiral metallic stents in the treatment of localized ureteral stenosis: an alternative to JJ stent? Prospective multicenter study].

    Science.gov (United States)

    Bonniol, R; Meria, P; Safsaf, A; Albouy, B; Sibert, L

    2011-06-01

    Evaluation of the effectiveness and tolerance of thermoformable metallic spiral stents Memokath(®) 051 (Bard, Pnn Medical) in the treatment of localized ureteral stenosis in non-operable patients who have JJ ureteral stents. Prospective, descriptive and multicenter study of patients with ureteral strictures treated with metallic ureteral stents Memokath(®) 051. Assessment criteria (recurrent stenotic, permeability, tolerance) were measured by clinical, biological and radiological examination at 1 month, and then every 3 months. Fifteen stents (average length: 9.15 cm, range 6-15 cm) were implanted in 14 patients (mean age: 55 years, range: 38-72 years) with secondary suspended ureteral stenosis during 2 years in two centers. The median follow-up was 11 months (range 6 to 24 months). Technical difficulty was observed with two patients. Stents are still up in four patients. The stenosis recurred in four patients with spontaneous progression of stenosis but without endoprosthetics tissue invasion. Two and three migration were observed with spontaneous expulsions. Two lower urinary infections and one high occurred, resolved on antibiotic therapy, no inlay or hematuria, no pain (mean VAS score=3/10) or urinary disorders of the lower unit have been identified. Stents Memokath(®) 051 are well tolered and seem to position themselves as an interesting alternative to JJ ureteral stent in some frails patients. The refinement of contraindication should help to improve the stent's efficacity and to reduce the risk of migration and expulsion. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  14. Relief of chronic partial ureteral obstruction attenuates salt-sensitive hypertension in rats

    DEFF Research Database (Denmark)

    Carlström, M.; Wåhlin, N.; Skøtt, Ole

    2007-01-01

    shown that animals with chronic partial unilateral ureteral obstruction develop salt-sensitive hypertension. In this study, the effects of ipsilateral and contralateral nephrectomy and ureterovesicostomy on blood pressure were studied in hydronephrotic animals. METHODS: Partial unilateral ureteral...... obstruction was created in 3-week-old male Sprague-Dawley rats and blood pressure was measured telemetrically 4-6 weeks later during a normal and high salt diet before and after uninephrectomy or ureterovesicostomy. Plasma samples for renin assay were collected during both diets before and after ipsilateral...... nephrectomy. RESULTS: All hydronephrotic animals developed salt-sensitive hypertension, of different degrees. Before nephrectomy the plasma renin concentration was significantly higher in the hydronephrotic animals than in controls (160 +/- 15 microGU mL(-1) vs. 96 +/- 12 microGU mL(-1), respectively...

  15. Robotic versus open pediatric ureteral reimplantation: Costs and complications from a nationwide sample.

    Science.gov (United States)

    Kurtz, Michael P; Leow, Jeffrey J; Varda, Briony K; Logvinenko, Tanya; Yu, Richard N; Nelson, Caleb P; Chung, Benjamin I; Chang, Steven L

    2016-12-01

    We sought to compare complications and direct costs for open ureteral reimplantation (OUR) versus robot-assisted laparoscopic ureteral reimplantation (RALUR) in a sample of hospitals performing both procedures. Anecdotal reports suggest that use of RALUR is increasing, but little is known of the outcomes and costs nationwide. The aim was to determine the costs and 90-day complications (of any Clavien grade) in a nationwide cohort of pediatric patients undergoing OUR or RALUR. Using the Premier Hospital Database we identified pediatric patients (age robotic experience, and that outcomes for these procedures should be carefully and systematically tracked. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  16. The treatment of the reno-ureteral calculi by extracorporeal shockwave lithotripsy (ESWL).

    Science.gov (United States)

    Ceban, E

    2012-06-12

    Urolithiasis has an important role in the structure of urological pathology, due to its high incidence, frequency of recurrence and complications it might cause. There are many methods of treatment for kidney stones described in the scientific literature as conservative, surgical, laparoscopic, endoscopic, and ESWL. In this study, we have analyzed the ESWL method of treatment of reno-ureteral stones.There are still many controversies about the effectiveness of different models of lithotripters but the lithotripter type Modulith SLK Storz Medical (Germany) used in our clinic has proved to be very effective. ESWL is currently the first-line treatment for the majority of kidney and ureteral stones, which are up to 20 mm in diameter.

  17. Inferior vena cava filter penetration following Whipple surgical procedure causing ureteral injury.

    Science.gov (United States)

    Abdel-Aal, Ahmed Kamel; Ezzeldin, Islam B; Moustafa, Amr Soliman; Ertel, Nathan; Oser, Rachel

    2015-12-01

    We report a case of an indwelling inferior vena cava filter that penetrated the IVC wall after Whipple's pancreatico-duodenectomy procedure performed in a patient with ampullary carcinoma, resulting in right ureteral injury and obstruction with subsequent hydroureter and hydronephrosis. This was incidentally discovered on a computed tomography scan performed as routine follow up to evaluate the results of the surgery. We retrieved the inferior vena cava filter and placed a nephrostomy catheter to relieve the ureteral obstruction. Our case highlights the importance of careful inferior vena cava manipulation during abdominal surgery in the presence of an inferior vena cava filter, and the option of temporary removal of the filter to be placed again after surgery in order to avoid this complication, unless protection is required against clot migration during the surgical procedure.

  18. A case report of ureteral cast stone and giant urethral stone, respectively

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Yung; Rhee, Song Joo; Choi, Ki Chul [School of Medicine, Jeongbug National University, Jeonju (Korea, Republic of)

    1980-12-15

    Urinary lithiasis is one of the most common disease of the urinary tract. It occurs more frequently in men than in women but rare in children and in blacks; a familial predisposition is often encountered. Ureteral stones originate in the kidney. Gravity and peristalis contribute to spontaneous passage into and down the ureter. Ureterovesical junction is the most frequent lodging site of stone. In our hospital one case of ureteral cast stone and giant urethral stone were found respectively and they were confirmed by radiological examination and surgery on Aug. 1978 and Jan. 1979. Ureteral cast stone which had been introduced and named first by Kiyonobu Tari and Kikjiro So in 1972 was very giant unusually. It may be the only one till now. Our patient was 36 years old female who has been suffered from intermittent right flank pain for 10 years. On KUB giant cylindrical radiopaque shadow was shown on RLQ extended to right minor pelvis and this was confirmed as a stone by retrograde ureteral catheterization. A stone measured 13cm x 1.5cm was found above the ureterovesical junction during operation. Follow up excretory urogram one year after operation showed no functional improvement of right kidney. Urethral stone is also unusual urinary lithiasis. This 60 years old male patient was been suffered from non-tender palpable hard mass on scrotal area and intermittent urinary retention. When urinary retention was occurred it was relieved by manipulation of the mass by himself. On plain film oval shaped giant radiopaque shadow was shown on cavernous urethral region. On urethrocystogram anterior urethra was opacified, but posterior urethra and bladder were not opacified and multiple fistulous leakage was identified. A stone measured 6.5cm x 3.5cm was found in cavernous urethra during operation.

  19. A case report of ureteral cast stone and giant urethral stone, respectively

    International Nuclear Information System (INIS)

    Song, Ho Yung; Rhee, Song Joo; Choi, Ki Chul

    1980-01-01

    Urinary lithiasis is one of the most common disease of the urinary tract. It occurs more frequently in men than in women but rare in children and in blacks; a familial predisposition is often encountered. Ureteral stones originate in the kidney. Gravity and peristalis contribute to spontaneous passage into and down the ureter. Ureterovesical junction is the most frequent lodging site of stone. In our hospital one case of ureteral cast stone and giant urethral stone were found respectively and they were confirmed by radiological examination and surgery on Aug. 1978 and Jan. 1979. Ureteral cast stone which had been introduced and named first by Kiyonobu Tari and Kikjiro So in 1972 was very giant unusually. It may be the only one till now. Our patient was 36 years old female who has been suffered from intermittent right flank pain for 10 years. On KUB giant cylindrical radiopaque shadow was shown on RLQ extended to right minor pelvis and this was confirmed as a stone by retrograde ureteral catheterization. A stone measured 13cm x 1.5cm was found above the ureterovesical junction during operation. Follow up excretory urogram one year after operation showed no functional improvement of right kidney. Urethral stone is also unusual urinary lithiasis. This 60 years old male patient was been suffered from non-tender palpable hard mass on scrotal area and intermittent urinary retention. When urinary retention was occurred it was relieved by manipulation of the mass by himself. On plain film oval shaped giant radiopaque shadow was shown on cavernous urethral region. On urethrocystogram anterior urethra was opacified, but posterior urethra and bladder were not opacified and multiple fistulous leakage was identified. A stone measured 6.5cm x 3.5cm was found in cavernous urethra during operation

  20. Tamsulosin versus tadalafil as a medical expulsive therapy for distal ureteral stones: A prospective randomized study.

    Science.gov (United States)

    Kc, Hari Bahadur; Shrestha, Anil; Acharya, Ganesh Bhakta; Basnet, Robin Bahadur; Shah, Arvind Kumar; Shrestha, Parash Mani

    2016-09-01

    This study aimed to compare the safety and efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteral stones. This prospective randomized study was conducted at the Department of Urology of Bir Hospital over a period of 12 months in patients with distal ureteral stones sized 5 to 10 mm. Patients were randomly divided into 2 groups: group A received tamsulosin 0.4 mg and group B received tadalafil 10 mg at bedtime for 2 weeks. Stone expulsion rate, number of ureteric colic episodes and pain score, analgesic requirements, and adverse drug effects were noted in both groups. Statistical analyses were performed by using Student t-test and chi-square test. Altogether 85 patients, 41 in group A and 44 in group B, were enrolled in the study. The patients' average age was 31.72±12.63 years, and the male-to-female ratio was 1.5:1. Demographic profiles, stone size, and baseline investigations were comparable between the 2 groups. The stone expulsion rate was significantly higher in the tadalafil group than in the tamsulosin group (84.1% vs. 61.0%, p=0.017). Although the occurrence of side effects was higher with tadalafil, this difference was not significant (p=0.099). There were no serious adverse effects. Tadalafil has a significantly higher stone expulsion rate than tamsulosin when used as a medical expulsive therapy for distal ureteral stones sized 5-10 mm. Both drugs are safe, effective, and well tolerated with minor side effects.

  1. Diuretic urography in the assessment of obstruction of the pelvi-ureteric junction

    International Nuclear Information System (INIS)

    Nilson, A.E.; Aurell, M.; Bratt, C.G.; Nilsson, S.

    1980-01-01

    Twenty adult patients with urographic evidence of unilateral, moderately wide renal pelves were examined by routine and diuretic urography. Planimetry of the corresponding calyx system of the two examinations was performed. An increase in size by more than 20 per cent following osmotic diuresis indicated an obstruction of the pelvi-ureteric junction in kidneys with moderately wide renal pelves. Diuretic urography may be useful to diagnose obstruction as a cause of moderately wide renal pelves and to assess operative results. (Auth.)

  2. Bedside Ultrasound in the Emergency Department to Detect Hydronephrosis for the Evaluation of Suspected Ureteric Colic.

    Science.gov (United States)

    Shrestha, R; Shakya, R M; Khan A, A

    2016-01-01

    Background Renal colic is a common emergency department presentation. Hydronephrosis is indirect sign of urinary obstruction which may be due to obstructing ureteric calculus and can be detected easily by bedside ultrasound with minimal training. Objective To compare the accuracy of detection of hydronephrosis performed by the emergency physician with that of radiologist's in suspected renal colic cases. Method This was a prospective observational study performed over a period of 6 months. Patients >8 years with provisional diagnosis of renal colic with both the bedside ultrasound and the formal ultrasound performed were included. Presence of hydronephrosis in both ultrasounds and size and location of ureteric stone if present in formal ultrasound was recorded. The accuracy of the emergency physician detection of hydronephrosis was determined using the scan reported by the radiologists as the "gold standard" as computed tomography was unavailable. Statistical analysis was executed using SPSS 17.0. Result Among the 111 included patients, 56.7% had ureteric stone detected in formal ultrasound. The overall sensitivity, specificity, positive predictive value and negative predictive value of bedside ultrasound performed by emergency physician for detection of hydronephrosis with that of formal ultrasound performed by radiologist was 90.8%., 78.3%, 85.5% and 85.7% respectively. Bedside ultrasound and formal ultrasound both detected hydronephrosis more often in patients with larger stones and the difference was statistically significant (p=.000). Conclusion Bedside ultrasound can be potentially used as an important tool in detecting clinically significant hydronephrosis in emergency to evaluate suspected ureteric colic. Focused training in ultrasound could greatly improve the emergency management of these patients.

  3. The incidence of ureteral obstruction secondary to aorto-femoral bypass surgery. A prospective study

    DEFF Research Database (Denmark)

    Henriksen, L O; Mejdahl, Steen; Petersen, F

    1988-01-01

    Hydronephrosis is reported to be an infrequent complication of aorto-femoral bypass operations. To define the true incidence of this complication, renography (131I-Hippuran) and renal scintigraphy (99 Technetium) were performed both pre- and postoperatively on 56 asymptomatic patients following...... successful aortic reconstruction. No patient developed signs of ureteral obstruction. It is concluded that hydronephrosis is a rare complication to aorto-femoral bypass surgery and postoperative control is only indicated in patients with symptoms from the urinary tract....

  4. A case of retrocaval ureter diagnosed by CT scan combined with a ureteral catheter

    International Nuclear Information System (INIS)

    Matsumoto, Atsushi; Iio, Shozo; Toyama, Takashi; Mochizuki, Teruichi

    1986-01-01

    The patient was a 45-year-old male who was admitted for right flank pain, nausea and vomitting. IVP revealed right hydronephrosis and hydroureter with medial distortion at the level of the 3rd lumbar spine. The diagnosis of retrocaval ureter was made with CT scan combined with a ureteral catheter. End to end anastomosis after resection of the retrocaval segment was performed. IVP 21 days after the operation showed that the right hydroureteronephrosis had moderately improved. (author)

  5. Extracorporeal shockwave lithotripsy versus ureteroscopy for distal ureteric calculi: efficacy and patient satisfaction

    Directory of Open Access Journals (Sweden)

    Ibrahim F. Ghalayini

    2006-12-01

    Full Text Available OBJECTIVE: We compared the efficacy of extracorporeal shock wave lithotripsy (ESWL and ureteroscopy (URS for the treatment of distal ureteral calculi with respect to patient satisfaction. MATERIALS AND MHETODS: This is a prospective study where a total of 212 patients with solitary, radiopaque distal ureteral calculi were treated with ESWL (n = 92 using Dornier lithotriptor S (MedTech Europe GmbH or URS (n = 120. Patient and stone characteristics, treatment parameters, clinical outcomes, and patient satisfaction were assessed for each group. RESULTS: The 2 groups were comparable in regard to patient age, sex, stone size, and side of treatment. The stone-free status for ESWL and URS at 3 months was 81.5% and 97.5%, respectively (p < 0.0001. In addition, 88% of patients who underwent ESWL versus 20% who underwent URS were discharged home the day of procedure. Minor complications occurred in 3.3% and 8.3% of the ESWL and URS groups, respectively (p = 0.127. No ureteral perforation or stricture occurred in the URS group. Postoperative flank pain and dysuria were more severe in the URS than ESWL group, although the differences were not statistically significant (p = 0.16. Patient satisfaction was high for both groups, including 94% for URS and 80% for ESWL (p = 0.002. CONCLUSIONS: URS is more effective than ESWL for the treatment of distal ureteral calculi. ESWL was more often performed on an outpatient basis, and showed a trend towards less flank pain and dysuria, fewer complications and quicker convalescence. Patient satisfaction was significantly higher for URS according to the questionnaire used in this study.

  6. Diagnosis and surgical management of obstructive ureteral calculi in cats: 11 cases (1993-1996)

    International Nuclear Information System (INIS)

    Kyles, A.E.; Stone, E.A.; Gookin, J.; Spaulding, K.; Clary, E.M.; Wylie, K.; Spodnick, G.

    1998-01-01

    To evaluate diagnostic methods, surgical treatment, perioperative management, and renal function of cats with obstructive calcium oxalate ureteroliths. Retrospective case series. 11 cats that underwent surgery for removal of calcium oxalate ureteroliths. Medical records were reviewed, and the following information was recorded: signalment; results of physical examination, clinicopathologic analyses, and abdominal imaging; surgical procedure; postoperative management; and results of ureterolith quantitative analysis. Ureteroliths in the proximal portion of the ureter were removed from 5 cats (pyelotomy, 1 cat; unilateral ureterotomy, 2 cats; bilateral ureterotomies, 2 cats). Calculi in the middle and distal part of the ureter were removed by partial ureterectomy and ureteroneocystostomy (6 cats). Ten cats recovered from surgery and were discharged from the hospital. One cat died from unknown causes 4 months after surgery, and 1 cat had a nephrectomy elsewhere 5 weeks after ureterolith removal. Eight cats were evaluated 12 to 20 months after surgery. Of these, 2 cats that were markedly azotemic before surgery improved after surgery, and 2 cats developed nephroliths after surgery. Also, of 5 cats that had nephroliths that were not removed at the time of surgery, 4 still had visible nephroliths. One cat had recurrent ureteral obstruction from a ureterolith and persistent urinary tract infection. Ureteroliths or ultrasonographic evidence of ureteral obstruction were not detected in other cats. A combination of microsurgical techniques and intensive postoperative care is necessary to minimize morbidity of cats after removal of a ureterolith. Renal function may improve or stabilize after removal of the ureteral obstruction

  7. Incidence of Deflux® calcification masquerading as distal ureteric calculi on ultrasound.

    Science.gov (United States)

    Yankovic, Francisca; Swartz, Robert; Cuckow, Peter; Hiorns, Melanie; Marks, Stephen D; Cherian, Abraham; Mushtaq, Imran; Duffy, Patrick; Smeulders, Naima

    2013-12-01

    Dextranomer-hyaluronic acid (Deflux(®)), the most widely used compound in the endoscopic treatment of vesico-ureteric reflux (VUR) today, is believed to provoke only minimal inflammation. Reports of calcification of Deflux(®) are increasing. We ascertain the incidence of Deflux(®) calcification appearing as distal ureteric calculi on ultrasound. Three cases (2 external patients) of ureteroscopy for calcified submucosal Deflux(®) prompted a retrospective review of the notes and imaging of all children treated with Deflux(®) for VUR between December 2000 and January 2011 at Great Ormond Street Hospital. 232 children (M:F = 5:3) received Deflux(®) for VUR at median age 2 years (range 2 months-12 years). Follow-up annual ultrasound, performed in all, identified calcification in 2. The interval between Deflux(®) injection and presentation of its calcification was 4 years. 104 of the 232 children had been followed up for 4-10 years. Considering the observed lag-period, after 4 years the incidence of calcification of Deflux(®) on ultrasound was 2% (2/104). Patients should be warned that calcification of Deflux(®) can occur. Misinterpretation as ureteric stones is common and may lead to unnecessary ureteroscopy. In this series, the incidence of calcification of Deflux(®) on ultrasound after 4 years was 2%. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  8. Useful technique for long-term urinary drainage by inlying ureteral stent. Six-year experience.

    Science.gov (United States)

    Kearney, G P; Mahoney, E M; Brown, H P

    1979-08-01

    Endoscopically placed inlying ureteral stents have proved useful in the conservative management of patients with ureteral obstruction, urinary fistula, and malignancy and have obviated the need for operative intervention. In high-risk symptomatic patients with widespread malignancy, internal urinary diversion offers the opportunity for an improved quality of life without the surgical risk or potential morbidity of supravesical diversion. Potential candidates for this simple, safe, and effective technique include: those with postsurgical obstruction and/or fistula, retroperitoneal fibrosis, metastatic carcinoma, congenital ureteropelvic junction obstruction, as well as those with reversible obstruction from lymphoma and carcinoma of the prostate who are undergoing radiotherapy and/or chemotherapy. The focus of this report is on the technique we have found successful in providing us with stents that fit our individual patients. Readily available fabricated graduated ureteral catheter can be cut and shaped to particular measurements unlike prefabricated catheters. Minimal preparation time is demanded, and there is no need for extensive stocking of various catheter sizes.

  9. Ureteral in situ biocompatibility of L-lactide-glycolic acid copolymer 80:20 stent

    International Nuclear Information System (INIS)

    Hou Yuchuan; Wang Chunxi; Zhang Baogang; Chen Xuesi

    2006-01-01

    Objective: To evaluate the in situ biocompatibility of a new biodegradable ureteral stent made of L-lactide-glycolic acid copolymer 80:20 (PLGA 80:20). Methods: 16 dogs served as experimental animals. Ureteral stents of PLGA 80:20 were inserted in situ into the left ureter after transection at the mid level, then the ureters were routinely anastomosed. Ureters surrounding the stent were taken out 2, 4, 8 and 12 weeks postoperatively. The ureters were dissected to find changes of stents and local ureters. Histological analysis was performed to investigate tissue reactions to the stent and evaluate the biocompatibility. Rods of UROVISION stent served as controls. Results: The PLGA stent was degraded completely within 12 weeks post implantation. In the early stage (2-4 weeks), both stents induced epithelial hyperplasia and inflammatory cell reaction at local ureter (P>0.05). In the later stage (8-12 weeks), the tissue reaction nearly subsided in PLGA stented ureters after degradation of the device. Whereas, the tissue reaction induced by UROVISION stent had lasted throughout the observation period, even deteriorated with time going (P<0.05). Conclusion: The tissue reaction induced by PLGA stent is retrievable. PLGA is regarded highly compatible and can serve as an ideal material for biodegradable ureteral stent. (authors)

  10. The effect of diclofenac (Voltarol) and pethidine on ureteric peristalsis and the isotope renogram

    Energy Technology Data Exchange (ETDEWEB)

    Brough, R.J. [Department of Urology, Withington Hospital, Manchester (United Kingdom); Lancashire, M.J.R. [Department of Virology, The Alexandra Hospital, Redditch (United Kingdom); Prince, J.R. [Department of Medical Physics, Christie Hospital, Manchester (United Kingdom); Rose, M.R.; Prescott, M.C.; Testa, H.J. [Department of Nuclear Medicine, Manchester Royal Infirmary, Manchester (United Kingdom); Payne, S.R. [Department of Urology, Manchester Royal Infirmary, Manchester (United Kingdom)

    1998-11-01

    Diclofenac (a non-steroidal anti-inflammatory drug) and pethidine (a synthetic opiate) are the two analgesics most commonly used to relieve the pain of ureteric colic. Fast frame renography is a non-invasive means of imaging ureteric peristalsis and renal drainage. The aim of this study was to determine the effects of each of these drugs on the drainage pattern of the upper tracts. Twelve normal male volunteers were studied. All underwent a standard fast frame renogram using 75 MBq of technetium-99m-mercaptoacetyltriglycine, and were then administered either 100 mg pethidine or 75 mg diclofenac by intramuscular injection. Fast frame renography was then repeated. Peristalsis was determined from the condensed image of each ureter and the renogram curves were analysed to obtain standard parameters and deconvolution analysis. Diclofenac caused a profound disruption to both ureteric peristalsis and the renogram curve. This effect was not seen after the administration of pethidine. Deconvolution analysis suggests the effects of diclofenac are mediated via a direct effect on drainage rather than by any alteration of blood flow to the kidney. This study suggests that pethidine is the analgesic of choice prior to renography and that inferences about alterations of drainage in the presence of diclofenac should be interpreted with care. (orig.) With 5 figs., 2 tabs., 15 refs.

  11. Renal autotransplantation--a possibility in the treatment of complex renal vascular diseases and ureteric injuries.

    Science.gov (United States)

    Hau, Hans Michael; Bartels, Michael; Tautenhahn, Hans-Michael; Morgul, Mehmet Haluk; Fellmer, Peter; Ho-Thi, Phuc; Benckert, Christoph; Uhlmann, Dirk; Moche, Michael; Thelen, Armin; Schmelzle, Moritz; Jonas, Sven

    2012-12-31

    We report our contemporary experiences with renal autotransplantation in patients with complicated renal vascular diseases and/or complex ureteral injuries. Since its first performance, renal autotransplantation has been steadily improved and become a safe and effective procedure. Between 1998 and 2006, 6 renal autotransplantations in 6 patients were performed at the University Medical Center of Leipzig. After nephrectomy and renal perfusion ex vivo, the kidney was implanted standardized in the fossa iliaca. The vessels were anastomized to the iliac vessels, the ureter was reimplanted in an extravesical tunneled ureteroneocystostomy technique according to Lich-Gregoir. Demographic, clinical, and laboratory data of the patients were collected and analyzed for pre-, intra-, and postoperative period. Indications for renal autotransplantation were complex renovascular diseases in 2 patients (1 with fibromuscular dysplasia and 1 with Takayasu's arteritis) and in 4 patients with complex ureteral injuries. The median duration of follow-up was 9.7 years (range: 5.6-13.3). The laboratory values of our 6 patients showed improvements of creatinine, urea and blood pressure levels in comparison to the preoperative status at the end of follow-up period. The present study reports excellent results of renal autotransplantation in patients with renovascular disease or complex ureteric injuries. After a median follow-up of 9.7 years all 6 patients present with stable renal function as well as normal blood pressure values. Postoperative complications were observed with a rate comparable to other studies.

  12. The effect of diclofenac (Voltarol) and pethidine on ureteric peristalsis and the isotope renogram

    International Nuclear Information System (INIS)

    Brough, R.J.; Lancashire, M.J.R.; Prince, J.R.; Rose, M.R.; Prescott, M.C.; Testa, H.J.; Payne, S.R.

    1998-01-01

    Diclofenac (a non-steroidal anti-inflammatory drug) and pethidine (a synthetic opiate) are the two analgesics most commonly used to relieve the pain of ureteric colic. Fast frame renography is a non-invasive means of imaging ureteric peristalsis and renal drainage. The aim of this study was to determine the effects of each of these drugs on the drainage pattern of the upper tracts. Twelve normal male volunteers were studied. All underwent a standard fast frame renogram using 75 MBq of technetium-99m-mercaptoacetyltriglycine, and were then administered either 100 mg pethidine or 75 mg diclofenac by intramuscular injection. Fast frame renography was then repeated. Peristalsis was determined from the condensed image of each ureter and the renogram curves were analysed to obtain standard parameters and deconvolution analysis. Diclofenac caused a profound disruption to both ureteric peristalsis and the renogram curve. This effect was not seen after the administration of pethidine. Deconvolution analysis suggests the effects of diclofenac are mediated via a direct effect on drainage rather than by any alteration of blood flow to the kidney. This study suggests that pethidine is the analgesic of choice prior to renography and that inferences about alterations of drainage in the presence of diclofenac should be interpreted with care. (orig.)

  13. [Tamsulosin, oxybutynin or their combination in the treatment of ureteral stent-related symptoms].

    Science.gov (United States)

    Maldonado-Alcaraz, Efraín; Moreno-Palacios, Jorge; López-Sámano, Virgilio A; Landa-Salas, Jason D; Torres-Mercado, León O; García-Cruz, Carlos

    2017-01-01

    The aim of this paper is to compare the efficacy of tamsulosin, oxybutynin or their combination for the treatment of symptoms related to double J stent (DJS). Randomized clinical non-blinded trial with three arms (tamsulosin, oxybutynin or combination) to assess the improvement of ureteral related symptoms with DJS with the questionnaire of Ureteral Stent Symptom Questionnaire (USSQ) and the adverse effects of treatment. Evaluations were made at 7 and 21 days after the placement of DJS. The maneuvers were compared using Chi squared test, Kruskall-Wallis, ANOVA and Wilcoxon considering a statistically significant p ≤ 0.05. 170 patients with CJJ were evaluated. A perprotocol analysis was performed in 142 patients, 53 received tamsulosin (37.4%), 42 oxybutynin (29.6%) and 47 the combination of both (33%). At 7 and 21 days the improvement was similar in all three arms. Men with tamsulosin and women with oxybutynin had less general symptoms. Tamsulosin, oxybutynin or its combination similarly improve ureteral stent related symptoms and this improvement becomes more noticeable over time. Men are less symptomatic with tamsulosin and women with oxybutynin.

  14. Usefulness of unenhanced helical CT in patients with suspected ureteral colic

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Soo; Nam Kung, Sook; Kim, Heung Cheol; Hwang, Woo Chul; Lee, In Sun; Hwang, Im Kyung; Kim, Ho Chul; Bae, Sang Hoon; Lee, Sang Kon; Lee, Seong Ho [College of Medicine, Hallym Univ., Chunchon (Korea, Republic of)

    2002-07-01

    To determine the usefulness of unenhanced helical CT in patients with suspected renal colic. One hundred and fourteen patients with suspected ureteral colic, referred by physicians, underwent unenhanced helical CT. Two radiologists prospectively interpreted the results, determining the presence or absence of ureter stone and other diseases the arise outside the urinary tract. In cases of ureteral stone, we retrospectively sought secondary signs of hydronephrosis, perinephric fat stranding, thickening of renal fascia, renal enlargement, and the tissue rim sign. Among the 114 patients, 57 were confirmed as having ureter stones. Unenhanced helical CT depicted 57 of 58 stones in 57 patients, producing one false-negative and one false-positive result. Overall, the results showed 98% sensitivity, 95% specificity, 98% positive predictive value, 95% negative predictive value, and 97% accuracy. The frequencies of secondary signs were as follows: hydronephrosis, 95%(54/57); perinephric fat stranding, 81% (46/57); thickening of renal fascia, 77% (44/57); renal enlargement , 65%(37/57); and the tissure rim sign 72%(21/29). In 20 patients, the diagnoses were not related to stone disease and included one false-negative diagnosis of pyonephrosis. Unenhanced helical CT provides information which is valuable in the accurate diagnosis of ureteral stone as well as other diseases that arise outside the urinary tract in patients with suspected renal colic.

  15. Repair of a common bile duct defect with a decellularized ureteral graft

    Science.gov (United States)

    Cheng, Yao; Xiong, Xian-Ze; Zhou, Rong-Xing; Deng, Yi-Lei; Jin, Yan-Wen; Lu, Jiong; Li, Fu-Yu; Cheng, Nan-Sheng

    2016-01-01

    AIM To evaluate the feasibility of repairing a common bile duct defect with a decellularized ureteral graft in a porcine model. METHODS Eighteen pigs were randomly divided into three groups. An approximately 1 cm segment of the common bile duct was excised from all the pigs. The defect was repaired using a 2 cm long decellularized ureteral graft over a T-tube (T-tube group, n = 6) or a silicone stent (stent group, n = 6). Six pigs underwent bile duct reconstruction with a graft alone (stentless group). The surviving animals were euthanized at 3 mo. Specimens of the common bile ducts were obtained for histological analysis. RESULTS The animals in the T-tube and stent groups survived until sacrifice. The blood test results were normal in both groups. The histology results showed a biliary epithelial layer covering the neo-bile duct. In contrast, all the animals in the stentless group died due to biliary peritonitis and cholangitis within two months post-surgery. Neither biliary epithelial cells nor accessory glands were observed at the graft sites in the stentless group. CONCLUSION Repair of a common bile duct defect with a decellularized ureteral graft appears to be feasible. A T-tube or intraluminal stent was necessary to reduce postoperative complications. PMID:28082809

  16. Yang-Monti Principle in Bridging Long Ureteral Defects: Cases Report and A Systemic Review.

    Science.gov (United States)

    Bao, Jun Sheng; He, Qiqi; Li, Yuzhuo; Shi, Wei; Wu, Gongjin; Yue, Zhongjin

    2017-07-02

    Ureteric substitution using the Yang-Monti principle was reported as a modification of simple ileal ureter replacement. During April 2013 to June in 2015, 2 patients underwent ileal ureteral substitution using a reconfigured ileal segment of Yang Monti principle in our clinical center. Some slight modifications were made and then follow-up were carried out up to 12 months. For these 2 cases, no significant intra/post-operative complications occurred. In 1 year follow up, serum creatinine (Scr) and blood urea nitrogen (BUN) of both patients decreased to normal.Glomerular filtration rate (GFR), renogram and pyelogram showed a stable split renal function. To better understand the Yang-Monti principle and potential risks and complications, we conduct an systemic review by searching PubMed, Google Scholar and the Cochrane Library database from January 1996 through June 2016. 10 out of 644 publications were identified, which included 269 patients from cohort studies. The most usual indications for Yang-monti therapy were iatrogenic stricture and retroperitoneal fibrosis. Infection and ileus were indicated as themain short time postoperative complications while the fistula and re- strictures happened in long-term. In general,we believe Yang-Monti Principle is a safer and efficient technique for clinical partial and complete ureteral defects if patients and potential risks could be well prepared.

  17. Computer aided detection of ureteral stones in thin slice computed tomography volumes using Convolutional Neural Networks.

    Science.gov (United States)

    Längkvist, Martin; Jendeberg, Johan; Thunberg, Per; Loutfi, Amy; Lidén, Mats

    2018-06-01

    Computed tomography (CT) is the method of choice for diagnosing ureteral stones - kidney stones that obstruct the ureter. The purpose of this study is to develop a computer aided detection (CAD) algorithm for identifying a ureteral stone in thin slice CT volumes. The challenge in CAD for urinary stones lies in the similarity in shape and intensity of stones with non-stone structures and how to efficiently deal with large high-resolution CT volumes. We address these challenges by using a Convolutional Neural Network (CNN) that works directly on the high resolution CT volumes. The method is evaluated on a large data base of 465 clinically acquired high-resolution CT volumes of the urinary tract with labeling of ureteral stones performed by a radiologist. The best model using 2.5D input data and anatomical information achieved a sensitivity of 100% and an average of 2.68 false-positives per patient on a test set of 88 scans. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Prediction of vesico-ureteral reflux in children from intravenous urography films

    International Nuclear Information System (INIS)

    Lanning, P.; Seppaenen, U.; Huttunen, N.P.; Uhari, M.

    1979-01-01

    Intravenous urography and voiding urethrocystography were performed on 255 children with urinary tract infection. Eighty-six (34%) of these children has some kind of abnormality of the urinary tract. Vesico-ureteral reflux was observed to 96 ureters (19%) in 69 children (27%). The prediction of vesic-ureteral reflux by two radiologists from urography films only gave 46 (48%) and 51 (53%) false negative results respectively. In cases of clinically important reflux (III to V 0 ), however, the rate of false negative prediction was 0/18 and 1/18 (6%) respectively. The rate for false positive predictions were 45/413 (11%) for both radiologist. In view of the number of pathological findings in this series i.v. urography is recommended as a routine in children undergoing urological work-up after their first urinary tract infection. As the clinically important vesico-ureteral reflux seems to be predictable from urography films alone, voiding urethrocystography seems not to be justified in children with negative i.v. urography, and can be postponed and carried out later if the urinary tract infection recurs. (author)

  19. Treatment of Ureteroarterial Fistulae with Covered Vascular Endoprostheses and Ureteral Occlusion

    International Nuclear Information System (INIS)

    Bilbao, Jose I.; Cosin, Octavio; Bastarrika, Gorka; Rosell, David; Zudaire, Javier; Martinez-Cuesta, Antonio

    2005-01-01

    Background. Ureteroarterial fistulae (UAFs) are a rare entity, often difficult to identify, and associated with a high mortality rate. This fact has been attributed to a delay in diagnosis and treatment. Five conditions that can predispose to the development of this uncommon entity have been described: prior pelvic surgery, prolonged ureteral stenting, radiation therapy, previous vascular surgery and vascular pathology. Methods. We present 4 patients with UAFs and at least three of the above-mentioned conditions. Ureteral ischemia and subsequent necrosis promote the formation of these fistulae. The constant pulsation of the iliac artery is transmitted to an already compromised ureter containing a stiff intraluminal foreign body, resulting in pressure necrosis, most likely where the ureter crosses the iliac artery. Results and Conclusion. Cases were managed percutaneously with a combination of the deployment of a covered prosthesis and, when needed, with mechanical occlusion of the ureter. Hematuria stopped in all the patients with no evidence of immediate rebleeding. One patient presented a new episode of vaginal bleeding 13 months after endograft placement and ureteral embolization. Arteriography showed the presence of a hypogastric artery pseudoaneurysm that was occluded using coils. No new bleeding has occurred in this patient 12 months after the second embolization. At present all 4 patients are alive with follow-up periods of 5, 9, 11 and 25 months since the first procedure

  20. [Comparison of the efficacy of ESWL and ureteroscopy in the treatment of lower ureteric stone].

    Science.gov (United States)

    Petrík, A

    2007-01-01

    The efficacy of ESWL and ureteroscopy in the treatment of lower ureteric stone is still discussed. The aim of the study is to compare efficacy and safeness of both methods. A retrospective study comparing the treatment results of distal ureteric stones was performed. The inclusion criteria were: distal ureteric stones with no previous treatment and an accomplished three months follow-up after the treatment. There were 395 cases (390 patients) included in the ESWL group and 509 cases (501 patients) in the ureteroscopy group. Higher efficacy of ureteroscopy as opposed to ESWL therapy was marked. There is no significant difference in stone free rate in three months after the treatment (97.72% vs. 98.40%, p = 0.4675), but there is a significant difference in EQ according to Rassweiler (43.52 vs. 89.60, p ESWL treatment is accompanied by a higher re-treatment rate (51% vs. 2%, p ESWL. The main advantage of ureteroscopy is the immediate effect, low re-treatment rate and low incidence of auxiliary procedures, except the need of removing the J-J stent. The disadvantage of ureteroscopy is the requirement of general anaesthesia and a higher incidence of complications after the treatment, though only minor ones in most of the cases.

  1. Usefulness of Early Extracorporeal Shock Wave Lithotripsy in Colic Patients with Ureteral Stones

    Science.gov (United States)

    Choi, Hyeung Joon; Jung, Jin-Hee; Bae, Jungbum; Cho, Min Chul; Lee, Hae Won

    2012-01-01

    Purpose To compare efficacy and safety between early extracorporeal shock wave lithotripsy (eESWL) and deferred ESWL (dESWL) in colic patients with ureteral stones and to investigate whether eESWL can play a critical role in improving treatment outcomes. Materials and Methods A total of 279 patients who underwent ESWL for single radio-opaque ureteral stones of 5 to 20 mm in size were included in this retrospective study. The patients were categorized into two groups according to the time between the onset of colic and ESWL: eESWL (ESWL sessions and less time to achieve stone-free status than did the dESWL group. For 241 patients with stones ESWL complication rates were comparable between the two groups. In the multivariate analysis, smaller stone size and a time to ESWL of <48 hours were independent predictors of success. Conclusions Our data suggest that eESWL in colic patients with ureteral stones is an effective and safe treatment with accelerated stone clearance. PMID:23301130

  2. Treatment of lower ureteric stones by ESWL and ICPL: a comparative study.

    Science.gov (United States)

    Islam, M S; Shameem, I A; Alam, A K M K; Kibria, S A M G

    2005-12-01

    This study was carried-out to find-out better and effective treatment option for Lower Ureteric Stones (LUS) by comparing Extracorporeal Shock Wave Lithotripsy (ESWL) with ureterorenoscopic (URS) Intracorporeal Pneumatic Lithotripsy (ICPL). A total of 60 patients attending the outpatient department of Bangabandhu Sheikh Mujib Medical University (BSMMU) with lower ureteric stones were divided into two groups, 30 in group-I (URS + ICPL) and the remaining 30 in group-II (ESWL). In group-I, 60% were male with mean age of 32.76 years and in group-II, 40% were male with mean age of 36.23 years. The ratio of involvement of right to left ureter was 1.7:1. The mean stone size was 10.7 + 2.69 mm (SD) in group-I and 9.9 + 1.97 mm (SD) in group-II. The differences in age, sex and side of involvement of ureter were not significant (p > 0.05) between the two groups. Among the groups 24 (80%) in group-I and 26 (86.61%) of patients in group-II were found stone free. The post procedure loin pain, fever and haematuria were more common in group-I than in group-II. The LUTS and loin pain were significantly more in group-I than in group-II (p ESWL was found effective method than URS + ICPL for the treatment of lower ureteric stones.

  3. Body mass index and buttock circumference are independent predictors of disintegration failure in extracorporeal shock wave lithotripsy for ureteral calculi.

    Science.gov (United States)

    Yang, Teng-Kai; Yang, Hung-Ju; Lee, Liang-Min; Liao, Chun-Hou

    2013-07-01

    Effective stone disintegration by extracorporeal shockwave lithotripsy (ESWL) may depend on patient- and stone-related factors. We investigated predictors of disintegration failure in ESWL for a solitary ureteral calculus. From July 2008 to May 2010, 203 patients who underwent ESWL for a solitary ureteral calculus were enrolled. Clinical and radiologic data were collected, and factors related to ESWL failure were analyzed. Fifty-two patients (25.6%) showed ESWL failure, with a mean follow-up of 41 days. Forty patients (19.7%) required retreatment, including 12 who underwent repeat ESWL and 28 who underwent curative ureteroscopy. Patients with ESWL failure had significantly higher body weight, body mass index (BMI), and buttock circumference (BC) than patients for whom ESWL was successful. Univariate analysis showed that stone burden (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.03-1.06) and BC (OR, 1.06; 95% CI, 1.01-1.11) were predictors of ESWL failure, while BMI was a potential predictor with borderline significance (OR, 1.09; 95% CI, 0.99-1.20). Multivariate analysis showed that stone burden (OR, 1.04; 95% CI, 1.03-1.06) was a significant predictor for all patients. On stratifying patients according to the level of ureteral calculi, BC was found to be an independent predictor (OR, 1.35; 95% CI, 1.02-1.80) for ESWL failure for middle/lower ureteral calculi and BMI (OR, 1.47; 95% CI, 1.13-1.91) for upper ureteral calculi. Stone burden is the main predictor of ESWL failure for all patients with ureteral calculi. BC and BMI are independent predictors for ESWL failure for middle/lower and upper ureteral calculi, respectively. Copyright © 2012. Published by Elsevier B.V.

  4. Effects of PDE5 Inhibitors and sGC Stimulators in a Rat Model of Artificial Ureteral Calculosis.

    Directory of Open Access Journals (Sweden)

    Peter Sandner

    Full Text Available Urinary colics from calculosis are frequent and intense forms of pain whose current pharmacological treatment remains unsatisfactory. New and more effective drugs are needed to control symptoms and improve stone expulsion. Recent evidence suggested that the Nitric Oxide (NO / cyclic guanosine monophosphate (cGMP/phosphodiesterase type 5 (PDE5 system may contribute to ureteral motility influencing stone expulsion. We investigated if PDE5 inhibitors and sGC stimulators influence ureteral contractility, pain behaviour and stone expulsion in a rat model of ureteral calculosis. We investigated: a the sex-specific PDE5 distribution in the rat ureter; b the functional in vitro effects of vardenafil and sildenafil (PDE5 inhibitors and BAY41-2272 (sGC stimulator on induced ureteral contractility in rats and c the in vivo effectiveness of vardenafil and BAY41-2272, alone and combined with ketoprofen, vs hyoscine-N-butylbromide alone or combined with ketoprofen, on behavioural pain indicators and stone expulsion in rats with artificial calculosis in one ureter. PDE5 was abundantly expressed in male and female rats' ureter. In vitro, both vardenafil and BAY41-2272 significantly relaxed pre-contracted ureteral strips. In vivo, all compounds significantly reduced number and global duration of "ureteral crises" and post-stone lumbar muscle hyperalgesia in calculosis rats. The highest level of reduction of the pain behaviour was observed with BAY41-2272 among all spasmolytics administered alone, and with the combination of ketoprofen with BAY41-2272. The percentage of stone expulsion was maximal in the ketoprofen+BAY41-2272 group. The NO/cGMP/PDE5 pathway is involved in the regulation of ureteral contractility and pain behaviour in urinary calculosis. PDE5 inhibitors and sGC stimulators could become a potent new option for treatment of urinary colic pain.

  5. Desarrollo de la tecnología de MOVPE para el crecimiento de semiconductores III-V : fabricación de células solares para concentraciones luminosas elevadas

    OpenAIRE

    Galiana Blanco, Beatriz

    2011-01-01

    El trabajo de estas tesis trata sobre el desarrollo en el IES-UPM de la tecnología de crecimiento epitaxial de fase vapor mediante precursores metalorgánicos (MOVPE) para el crecimiento de células solares de semiconductores III-V para concentraciones luminosas elevadas. En la primera parte de la memoria se presentan los principios de la MOVPE y el estudio de los materiales semiconductores utilizados a lo largo de la tesis: GaAs, AlGaAs, GaInP y AlInP. Para ello, se ha analizado cómo influ...

  6. Caractérisations de matériaux et tests de composants des cellules solaires à base des nitrures des éléments III-V

    OpenAIRE

    Gorge , Vanessa

    2012-01-01

    Among III-V nitrides, the InGaN material has intensively been studied since the year 2000 for photovoltaic applications, in particular for multi-junction solar cells, thanks to its large tunable band gap covering almost the entire solar spectrum. Then, it will be possible to reach high efficiency and low cost. However, one of the problems of InGaN material is the absence of lattice-matched substrate leading to high defect density which limits device performances. We have thus studied the feas...

  7. Comparison of Two Types of Double-J Ureteral Stents that Differ in Diameter and the Existence of Multiple Side Holes along the Straight Portion in Malignant Ureteral Strictures.

    Science.gov (United States)

    Song, Myung Gyu; Seo, Tae-Seok; Lee, Chang Hee; Kim, Kyeong Ah; Kim, Jun Suk; Oh, Sang Cheul; Lee, Jae-Kwan

    2015-06-01

    This study was decided to evaluate the impact of diameter and the existences of multiple side holes along the straight portion of double-J ureteral stents (DJUS) on early dysfunction of stents placed for malignant ureteral strictures. Between April 2007 and December 2011, 141 DJUSs were placed via a percutaneous nephrostomy (PCN) tract in 110 consecutive patients with malignant ureteral strictures. 7F DJUSs with multiple side holes in the straight portion were placed in 58 ureters of 43 patients (Group 1). 8F DJUSs with three side holes in the proximal 2-cm of the straight portion were placed in 83 ureters of 67 patients (Group 2). The incidence of early DJUS dysfunction was compared between the two groups, and nephrostographic findings were evaluated in the cases of early dysfunction. Early dysfunction of the DJUS was noted in 14 of 58 patients (24.1 %) in Group 1, which was significantly higher (p = 0.001) than in Group 2 in which only 1 of 83 patients (1.2 %) had early dysfunction of the DJUS. Nephrostographic findings of early dysfunction included dilatation of the pelvicalyceal system, filling defects in the ureteral stent, and no passage of contrast media into the urinary bladder. In malignant ureteral strictures, multiple side holes in the straight portion of the 7-F DJUS seem to cause early dysfunction. The 8F DJUSs with three side holes in the proximal 2-cm of the straight portion may be superior at preventing early dysfunction.

  8. Tamsulosin hydrochloride vs placebo for management of distal ureteral stones: a multicentric, randomized, double-blind trial.

    Science.gov (United States)

    Vincendeau, Sébastien; Bellissant, Eric; Houlgatte, Alain; Doré, Bertrand; Bruyère, Franck; Renault, Alain; Mouchel, Catherine; Bensalah, Karim; Guillé, François

    2010-12-13

    α-Blockers induce selective relaxation of ureteral smooth muscle with subsequent inhibition of ureteral spasms and dilatation of the ureteral lumen. The aim of the study was to evaluate the efficacy and safety of the α-blocker tamsulosin hydrochloride in patients with ureteral colic owing to a distal ureteral stone. This was a multicenter, placebo-controlled, randomized, double-blind study. Patients with emergency admission for ureteral colic with a 2- to 7-mm-diameter radio-opaque distal ureteral stone were included in the study. They received tamsulosin (0.4 mg/d) or matching placebo until stone expulsion or day 42, whichever came first. The main end point was time to stone expulsion between inclusion and day 42. Sequential statistical analysis was performed using the triangular test. A total of 129 patients with acute renal colic were recruited from emergency wards between February 1, 2002, and December 8, 2006, in 6 French hospitals. Of these 129 randomized patients (placebo, 63; tamsulosin, 66), 7 were excluded from analyses: 5 for major deviations from inclusion criteria, 1 for stone expulsion before the first treatment administration, and 1 for consent withdrawal. At inclusion, mean (SD) stone diameters were 3.2 (1.2) and 2.9 (1.0) mm in the placebo and tamsulosin groups, respectively (P = .23). Expulsion delay distributions during 42 days did not show any difference (P = .30). The numbers of patients who spontaneously expelled their stone within 42 days were 43 of 61 (70.5%) and 47 of 61 (77.0%) in the placebo and tamsulosin groups, respectively (P = .41). Corresponding delays were 10.1 (10.0) and 9.6 (9.8) days (P = .82). Other secondary end points and tolerance were not different between groups. Although well tolerated, a daily administration of 0.4 mg of tamsulosin did not accelerate the expulsion of distal ureteral stones in patients with ureteral colic. clinicaltrials.gov Identifier: NCT00151567.

  9. A randomized controlled trial comparing alpha blocker (tamsulosin) and anticholinergic (solifenacin) in treatment of ureteral stent-related symptoms.

    Science.gov (United States)

    El-Nahas, Ahmed R; Tharwat, Mohamed; Elsaadany, Mohamed; Mosbah, Ahmed; Gaballah, Mohamed A

    2016-07-01

    To compare the effectiveness of tamsulosin and solifenacin in relieving ureteral stents related symptoms. A randomized controlled trial was conducted between January 2013 and July 2014. Inclusion criteria were patients aged 20-50 years who underwent temporary unilateral ureteral stent for drainage of calcular upper tract obstruction or after ureteroscopic lithotripsy. Patients with history of lower urinary tract symptoms before stent placement, stents that were fixed after open or laparoscopic procedures, and those who developed complications related to the primary procedure were not included. Eligible patients were randomly assigned to 1 of 3 groups using computer-generated random tables. Patients in group 1 received placebo, patients in group 2 received tamsulosin 0.4 mg once daily, and those in group 3 received solifenacin 5 mg once daily. Ureteral Stent Symptom Questionnaire (USSQ) was answered by all patients 1-2 weeks after stent placement. The primary outcome was the comparison of total score of USSQ between all groups. The study included 131 patients. All baseline characteristics (age, sex, side, indication, length, and duration of stent) were comparable for all groups. Total USSQ score was 61 in solifenacin group, 76 in tamsulosin group, and 83 in control group (P tamsulosin group (P tamsulosin alone or solifenacin alone in patients with ureteral stents can improve the quality of life by decreasing ureteral stent-related symptoms. Solifenacin was better than tamsulosin. CLINICALTRIAL. NCT01880619.

  10. Evaluation with Decision Trees of Efficacy and Safety of Semirigid Ureteroscopy in the Treatment of Proximal Ureteral Calculi.

    Science.gov (United States)

    Sancak, Eyup Burak; Kılınç, Muhammet Fatih; Yücebaş, Sait Can

    2017-01-01

    The decision on the choice of proximal ureteral stone therapy depends on many factors, and sometimes urologists have difficulty in choosing the treatment option. This study is aimed at evaluating the factors affecting the success of semirigid ureterorenoscopy (URS) using the "decision tree" method. From January 2005 to November 2015, the data of consecutive patients treated for proximal ureteral stone were retrospectively analyzed. A total of 920 patients with proximal ureteral stone treated with semirigid URS were included in the study. All statistically significant attributes were tested using the decision tree method. The model created using decision tree had a sensitivity of 0.993 and an accuracy of 0.857. While URS treatment was successful in 752 patients (81.7%), it was unsuccessful in 168 patients (18.3%). According to the decision tree method, the most important factor affecting the success of URS is whether the stone is impacted to the ureteral wall. The second most important factor affecting treatment was intramural stricture requiring dilatation if the stone is impacted, and the size of the stone if not impacted. Our study suggests that the impacted stone, intramural stricture requiring dilatation and stone size may have a significant effect on the success rate of semirigid URS for proximal ureteral stone. Further studies with population-based and longitudinal design should be conducted to confirm this finding. © 2017 S. Karger AG, Basel.

  11. Renal vein doppler sonography in rabbits with acute ureteral obstruction: usefulness of impedance index of renal vein

    International Nuclear Information System (INIS)

    Sohn, Kyung Myung; Chung, Su Kyo; Lee, Sung Yong

    2004-01-01

    To evaluate the usefulness of the impedance index of the renal vein for the diagnosis of acute obstructive uropathy in rabbits. Ligation of the left ureter was done in 12 rabbits. Doppler sonography of the interlobar veins in both kidneys was checked before and 30 minutes, 1, 3, 6, 9 and 24 hours after ureteral ligation. The venous impedance index [(peak flow signal-least flow signal)/peak flow signal] was compared between the obstructed and non-obstructed kidneys for all periods. The change in the impedance index after ureteral ligation was also compared between the obstructed and non-obstructed kidneys. A decrease in the impedance index of the intrarenal vein was observed starting from 30 mins atter ureteral ligation, and the index remained low up to 24 hours after ureteral ligation. The obstructed kidneys had a significantly lower impedance index than the contralateral kidneys for all six of the postligation measurements (p< 0.05). There were significant differences in the change of impedance index after ureteral ligation between the obstructed and non-obstructed kidneys (p< 0.05). The impedance index of the intrarenal vein was significantly decreased in the obstructed kidneys. The measurement of the impedance index of the intrarenal vein using Doppler sonography could provide a useful method of diagnosing obstructive uropathy

  12. Physics and performances of III-V nanowire broken-gap heterojunction TFETs using an efficient tight-binding mode-space NEGF model enabling million-atom nanowire simulations.

    Science.gov (United States)

    Afzalian, A; Vasen, T; Ramvall, P; Shen, T-M; Wu, J; Passlack, M

    2018-06-27

    We report the capability to simulate in a quantum-mechanical atomistic fashion record-large nanowire devices, featuring several hundred to millions of atoms and a diameter up to 18.2 nm. We have employed a tight-binding mode-space NEGF technique demonstrating by far the fastest (up to 10 000  ×  faster) but accurate (error  <  1%) atomistic simulations to date. Such technique and capability opens new avenues to explore and understand the physics of nanoscale and mesoscopic devices dominated by quantum effects. In particular, our method addresses in an unprecedented way the technologically-relevant case of band-to-band tunneling (BTBT) in III-V nanowire broken-gap heterojunction tunnel-FETs (HTFETs). We demonstrate an accurate match of simulated BTBT currents to experimental measurements in a 12 nm diameter InAs NW and in an InAs/GaSb Esaki tunneling diode. We apply our TB MS simulations and report the first in-depth atomistic study of the scaling potential of III-V GAA nanowire HTFETs including the effect of electron-phonon scattering and discrete dopant impurity band tails, quantifying the benefits of this technology for low-power low-voltage CMOS applications.

  13. As in Real Estate, Location Is What Matters: A Case Report of Transplant Ureteral Obstruction Due to an Inguinal Hernia.

    Science.gov (United States)

    Bugeja, Ann; Clark, Edward G; Sood, Manish M; Ali, Sohrab N

    2018-01-01

    Kidney allograft dysfunction is common and often reversible but can lead to allograft loss if not promptly evaluated. Transplant ureteral obstruction in an inguinal hernia is a rare cause of allograft dysfunction, but early recognition may prevent allograft loss. We present a case of a man with acute kidney allograft dysfunction who received a deceased donor kidney transplant 6 years earlier for end-stage kidney disease secondary to polycystic kidney disease. Abdominal ultrasounds revealed hydronephrosis without full visualization of the transplant ureter. Abdominal computed tomography revealed moderate hydronephrosis of the transplant kidney due to obstructed herniation of the transplant ureter in a right inguinal hernia. A stent was inserted into the transplant ureter to prevent further allograft dysfunction and facilitate hernia repair. Transplant ureteral obstruction is a rare cause of acute kidney allograft dysfunction, and its detection can be challenging. The recognition of transplant ureteral obstruction is vital to timely management for preventing allograft loss.

  14. Combined retrograde flexible ureteroscopic lithotripsy with holmium YAG laser for renal calculi associated with ipsilateral ureteral stones.

    Science.gov (United States)

    Cocuzza, Marcello; Colombo, Jose R; Ganpule, Arvind; Turna, Burak; Cocuzza, Antonio; Dhawan, Divyar; Santos, Bruno; Mazzucchi, Eduardo; Srougi, Miguel; Desai, Mahesh; Desai, Mihir

    2009-02-01

    The purpose of this study was to evaluate the effectiveness of combined ureteroscopic holmium YAG lithotripsy for renal calculi associated with ipsilateral ureteral stones. Between August 2002 and March 2007, retrograde flexible ureteroscopic stone treatment was attempted in 351 cases. Indication for treatment was concurrent symptomatic ureteral stones in 63 patients (group I). Additional operative time and perioperative complication rates were compared to a group of 39 patients submitted to ureteroscopic treatment for ureteral calculi exclusively (group II). Mean ureteral stone size was 8.0 +/- 2.6 mm and 8.1 +/- 3.4 mm for groups I and II, respectively. Mean operative time for group I was 67.9 +/- 29.5 minutes and for group 2 was 49.3 +/- 13.2 minutes (p stone size was 10.7 +/- 6.4 mm, overall stone free rate in group I was 81%. However, considering only patients with renal stones smaller than 15 mm, the stone free rate was 88%. Successful treatment occurred in 81% of patients presenting lower pole stones, but only 76% of patients with multiple renal stones became stone free. As expected, stone free rate showed a significant negative correlation with renal stone size (p = 0.03; r = -0.36). Logistic regression model indicated an independent association of renal stones smaller than 15 mm and stone free rate (OR = 13.5; p = 0.01). Combined ureteroscopic treatment for ureteral and ipsilateral renal calculi is a safe and attractive option for patients presenting for symptomatic ureteral stone and ipsilateral renal calculi smaller than 15 mm.

  15. Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy.

    Science.gov (United States)

    Juan, Hsu-Cheng; Lin, Hung-Yu; Chou, Yii-Her; Yang, Yi-Hsin; Shih, Paul Ming-Chen; Chuang, Shu-Mien; Shen, Jung-Tsung; Juan, Yung-Shun

    2012-08-01

    To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. • Unenhanced CT is now widely used to assess ureteric calculi. • The same CT protocol can provide measurements of abdominal fat distribution. • Ureteric calculi are usually treated by shock wave lithotripsy (SWL). • Greater intra-abdominal fat stores are generally associated with poorer SWL results.

  16. Primary antegrade ureteric stenting: Prospective experience and cost-effectiveness analysis in 50 ureters

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Gillian M.T.; Patel, Uday

    2001-07-01

    AIM: To evaluate the success rate and cost efficiency of primary antegrade ureteric stenting (antegrade ureteric stent insertion as a single procedure without preliminary drainage). MATERIALS AND METHODS: A policy of primary stenting was tested in 38 patients (50 ureters) with obstructive hydronephrosis, of acute or chronic onset and of benign or malignant origin. Patients with suspected pyonephrosis were excluded. Patients successfully primarily stented (group 1) were compared to a group stented as a traditional two-stage procedure (group 2). End point assessments were screening time, equipment used, procedure-related costs, bed occupancy and technical and clinical success rate. Using these cost and outcome measures, a cost-efficiency analysis was performed comparing the two strategies. RESULTS: 40/50 (80%) ureters were considered primary stent successes. The average procedure-related bed occupancy was 2 days (range 1-2 days). Simple equipment alone was successful in 16 cases. Van Andel dilatation catheters and peel-away sheaths were frequently used (23 ureters). Expensive equipment was rarely necessary (four cases) and average extra equipment cost was small (46 pounds/case). The mean screening time was similar for the two groups (13.5 min vs 15.3 min;P {>=} 0.05). There was a minimum saving of 800 pounds per successful primary stent. The cost-effectiveness of a primary antegrade stenting strategy was 1229 pounds vs 2093 pounds for secondary stenting. CONCLUSION: In carefully selected patients, the majority of obstructed ureters can be primarily stented using simple equipment. The reduced hospital stay and overall success rate significantly improves the cost competitiveness of antegrade ureteric stenting. Watson, G.M.T. and Patel, U. (2001)

  17. Impact of Hydronephrosis on Treatment Outcome of Solitary Proximal Ureteral Stone After Extracorporeal Shock Wave Lithotripsy

    Directory of Open Access Journals (Sweden)

    Hsi-Lin Hsiao

    2008-10-01

    Full Text Available The purpose of this study was to investigate the impact of hydronephrosis on the treatment outcome of patients with a solitary proximal ureteral stone after extracorporeal shock wave lithotripsy (ESWL. A total of 182 consecutive patients who underwent ESWL for a solitary proximal ureteral stone of between 5 and 20 mm in size in our institution were included in this study. The degree of hydronephrosis was defined by renal ultrasonography. Patient data, stone size, shock wave numbers and shock wave energy were also recorded. Treatment outcome was evaluated 3 months after the first session of ESWL. In multivariate analysis, only the maximal stone length (odds ratio [OR], 0.15; 95% confidence interval [CI], 0.03–0.91; p = 0.04 and the degree of hydronephrosis (OR, 0.40; 95% CI, 0.16–0.98; p = 0.045 were significant predicting factors for stone-free status 3 months after ESWL. For stones ≤ 10 mm, the stone-free rate decreased from 80% in patients with mild hydronephrosis to 56.4% in those with moderate to severe hydro-nephrosis. For stones > 10 mm, the stone-free rate decreased further, from 65.2% in patients with mild hydronephrosis to 33.3% in those with moderate to severe hydronephrosis. In summary, patients with a solitary proximal ureteral stone and a stone > 10 mm, the treatment outcome after ESWL was not good if moderate to severe hydronephrosis was noted on ultrasonography. Alternative treatments, such as ureteroscopic lithotripsy, may be appropriate as initial treatment or after failure of one session of ESWL.

  18. Pyelo-cystic Reflux in F-18 FDG PET Scan Due to Ureteral Obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Reyhan, Mehmet [Baskent Univ., Adana (Turkmenistan)

    2013-09-15

    A 72-year-old woman with a history of cervical cancer was treated with brachytherapy and chemotherapy. Combined F-18 FDG PET/CT performed for restaging demonstrated increased FDG uptake in a hypodense cystic lesion at the posterior part of the right renal cortex and a hypermetabolic soft tissue mass at the right parailiac region suggestive of a metastatic lymph node causing ureteral obstruction. There had been no FDG uptake in the cystic lesion on the FDG PET/CT study performed 1 year before. These findings suggest that the increased FDG uptake in the cystic lesion was caused by pyelocystic reflux due to ureteral obstruction secondary to parailiac lymph node metastasis (Figs. 1 and 2). Several renal lesions may have increased metabolism, such as renal cell carcinoma, lymphoma, oncocytoma, adult Wilms' tumor, angiomyolipoma, metastatic lesions, xanthogranulo-matous pyelonephritis and infected cyst. Most of these lesions are solid. Some infected renal cysts may be FDG avid, but in this situation increased FDG uptake is observed on the wall of the cyst. In our case, FDG uptake was seen in the entire cystic lesion. The patient had no symptoms or laboratory findings related to infection. Cysts are the most common space-occupying lesions of the kidney. The vast majority of these are simple cysts that are usually unilateral and solitary. Simple cysts are asymptomatic, except when complications exist such as hemorrhage, infection or rupture. There have been a few reports on spontaneous communications between renal cysts and the pyelocaliceal system, in most cases involving ruptures of the cysts into the pyelocaliceal system due to increased intracystic pressure caused by bleeding or infection of the cyst. In the present case, the cause of the connection between the cystic cavity and the pyelocaliceal system is the increased pressure in the renal pelvic cavity due to the ureteral obstruction secondary to parailiac lymph node metastasis.

  19. Can stone density on plain radiography predict the outcome of extracorporeal shockwave lithotripsy for ureteral stones?

    Science.gov (United States)

    Lim, Ki Hong; Jung, Jin-Hee; Kwon, Jae Hyun; Lee, Yong Seok; Bae, Jungbum; Cho, Min Chul; Lee, Kwang Soo

    2015-01-01

    Purpose The objective was to determine whether stone density on plain radiography (kidney-ureter-bladder, KUB) could predict the outcome of extracorporeal shockwave lithotripsy (ESWL) for ureteral stones. Materials and Methods A total of 223 patients treated by ESWL for radio-opaque ureteral stones of 5 to 20 mm were included in this retrospective study. All patients underwent routine blood and urine analyses, plain radiography (KUB), and noncontrast computed tomography (NCCT) before ESWL. Demographic, stone, and radiological characteristics on KUB and NCCT were analyzed. The patients were categorized into two groups: lower-density (LD) group (radiodensity less than or equal to that of the 12th rib, n=163) and higher-density (HD) group (radiodensity greater than that of the 12th rib, n=60). Stone-free status was assessed by KUB every week after ESWL. A successful outcome was defined as stone free within 1 month after ESWL. Results Mean stone size in the LD group was significantly smaller than that in the HD group (7.5±1.4 mm compared with 9.9±2.9 mm, p=0.002). The overall success rates in the LD and HD groups were 82.1% and 60.0%, respectively (p=0.007). The mean duration of stone-free status and average number of SWL sessions required for success in the two groups were 21.7 compared with 39.2 days and 1.8 compared with 2.3, respectively (pESWL since colic and radiodensity of the stone on KUB were independent predictors of successful ESWL. Conclusions Our data suggest that larger stone size, longer time to ESWL, and ureteral stones with a radiodensity greater than that of the 12th rib may be at a relatively higher risk of ESWL failure 1 month after the procedure. PMID:25598937

  20. Clinical protocol levels are required in laboratory animal surgery when using medical devices: experiences with ureteral replacement surgery in goats

    OpenAIRE

    de Jonge, Paul K. J. D.; Sloff, Marije; Janke, Heinz P.; Kortmann, Barbara B. M.; de Gier, Robert P. E.; Geutjes, Paul J.; Oosterwijk, Egbert; Feitz, Wout F. J.

    2017-01-01

    It is common to test medical devices in large animal studies that are or could also be used in humans. In this short report we describe the use of a ureteral J-stent for the evaluation of biodegradable tubular constructs for tissue reconstruction, and the regeneration of ureters in Saanen goats. Similarly to a previous study in pigs, the ureteral J-stent was blindly inserted until some resistance was met. During evaluation of the goats after three months, perforation of the renal cortex by th...

  1. Early Experience Of Pneumatic Lithoclast For The Management Of Ureteric Stones At Peshawar.

    Science.gov (United States)

    Nawaz, Ahmad; Wazir, Bakhtawar Gul; Orakzai, Akhtar Nawaz

    2016-01-01

    Pakistan lies in the Afro-Asia stone belt. Ureteric calculi are common occurrence and a major burden on health care facilities in Pakistan. The objective of this study was to assess the efficacy and safety of pneumatic lithoclast in the management of ureteric calculi. Case series study Department of Urology at Institute of Kidney Diseases Hayatabad Peshawar, from 1st Oct 2010 to 1st Oct 2011. One-hundred adult patients with ureteric calculi ≥ 0.7 cm were evaluated by history, physical examination, routine blood and urine examination after taking their written informed consent and approval of ethical committee. Ultrasound and X-ray KUB were done with IVU if required. All patients underwent ureteroscopy within intracorporeal lithotripsy and JJ stenting. Patients were followed up with post-op X-ray KUB at 24 hours and then weekly intervals till they became stone free. Following parameters were assessed: stone size, site, laterality, degree of fragmentation, success rate, stone migration and complications. Inability to reach the calculus with URS, proximal migration of stone or requirement of another/auxiliary procedure was considered failure. One hundred and ten patients were enrolled with a mean age of 38±10 years. There were 72 males and 28 females. Fifty-eight calculi were on right and 42 on left side. 24, 24 and 52 stones were in upper, middle and lower ureter respectively. Forty stones measured 7-10 mm, 52 measured 11-15 mm and 8 measured 16-20 mm in size. 98 stones were broken while 2 calculi migrated proximally. Overall success rate was 90% (Efficiency Quotient =78.95). Success rate in upper, middle and lower ureter was 83.3%, 83.3% and 96.1% respectively. 10 and 2 patients required ESWL and open ureterolithotomy, respectively, as additional treatment. Mean operative time was 33.5 minutes. There were no major complications.. Pneumatic lithoclast with URS is effective and safe in the management of the ureteric calculi with some limitations in the upper ureter.

  2. Regional changes in renal cortical glucose, lactate and urea during acute unilateral ureteral obstruction

    DEFF Research Database (Denmark)

    Krarup, Peter-Martin; Stolle, Lars B; Rawashdeh, Yazan F

    2007-01-01

    . Furthermore, we investigated regional variations in renal interstitial fluid (RIF) glucose, lactate and urea during acute UUO. MATERIAL AND METHODS: Eight anesthetized pigs were used. Microdialysis probes were inserted in the upper, middle and lower thirds of the left renal cortex and perfused with Ringer...... third. RIF lactate did not change. Interstitial urea increased in all regions of the kidney, but most markedly in the upper and lower poles. CONCLUSIONS: Microdialysis is of potential value for assessing the renal interstitial milieu under different pathophysiological conditions. Ureteral obstruction...

  3. Ureteral Involvement Within an Incarcerated Inguinal Hernia in a Patient With Crossed-fused Renal Ectopia

    Directory of Open Access Journals (Sweden)

    Udit Singhal

    2016-07-01

    Full Text Available Crossed-fused renal ectopy is an uncommon abnormality of the genitourinary tract that results from errors during embryological development. Ureteral herniation represents another rare anatomic event and can often occur from spontaneous, postoperative, and congenital causes (Allam, Johnson, Grewal & Johnson 2015; Pollack, Popky & Blumberg 1975. Here, we discuss the complex clinical course of a patient with crossed-fused renal ectopia who presents with symptoms due to ureteroinguinal herniation and provide a brief overview of the literature. We highlight the clinical considerations in the management of this patient and provide a potential anatomical and embryological explanation for his presentation.

  4. Notas clínicas: Un caso de transplantación ureteral

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    Abelardo Arango A.

    1933-11-01

    Full Text Available Un caso de trasplantación ureteral. Jorge Cavalier / La nueva técnica de histeropexia. Jorge E. Helo / La última epidemia de sarampión en Bogotá. Gerardo Bonilla I. / Patología veminosa del Municipio de Girardota (Antioquia. Gabriel Vélez Vélez / La vacunoterapia en la fiebre tifoidea. Andrés Soriano Lleras / Aglutinaciones como aporte a la investigación de la fiebre ondulante en Colombia. Cupertino Patiño S.

  5. Outcomes of complex robot-assisted extravesical ureteral reimplantation in the pediatric population.

    Science.gov (United States)

    Arlen, Angela M; Broderick, Kristin M; Travers, Curtis; Smith, Edwin A; Elmore, James M; Kirsch, Andrew J

    2016-06-01

    While open ureteral reimplantation remains the gold standard for surgical treatment of vesicoureteral reflux (VUR), minimally invasive approaches offer potential benefits. This study evaluated the outcomes of children undergoing complex robot-assisted laparoscopic ureteral reimplantation (RALUR) for failed previous anti-reflux surgery, complex anatomy, or ureterovesical junction obstruction (UVJO), and compared them with patients undergoing open extravesical repair. Children undergoing complex RALUR or open extravesical ureteral reimplantation (OUR) were identified. Reimplantation was classified as complex if ureters: 1) had previous anti-reflux surgery, 2) required tapering and/or dismembering, or 3) had associated duplication or diverticulum. Seventeen children underwent complex RALUR during a 24-month period, compared with 41 OUR. The mean follow-up was 16.6 ± 6.5 months. The RALUR children were significantly older (9.3 ± 3.7 years) than the OUR patients (3.1 ± 2.7 years; P urinary tract infection compared with a single child (5.9%) undergoing RALUR (P = 1.00). There was no significant difference in complication rate between the two groups (12.2% OUR versus 11.8% RALUR; P = 1.00). A postoperative cystogram was performed in the majority of RALUR patients, with no persistent VUR detected, and one child (6.7%) was diagnosed with contralateral reflux. Reported VUR resolution rates following robot-assisted ureteral reimplantation are varied. In the present series, children undergoing RALUR following failed previous anti-reflux surgery, with complex anatomy, or UVJO experienced a shorter length of stay but had similar analgesic requirements to those undergoing open repair. Radiographic, clinical success rates and complication risk were comparable. This study had several limitations, aside from lack of randomization. Analgesic use was limited to an inpatient setting, and pain scores were not assessed. Not all children underwent a postoperative VCUG, so

  6. Intracorporal Alexandrite-laser lithotripsy in the treatment of ureteral calculi

    Science.gov (United States)

    Zumbe, Juergen; Fischer, Hermann; Kimont, Hans-Georg; Kierfeld, Gerd

    1994-02-01

    Extracorporal shock wave lithotripsy (ESWL) is the standard therapy in the treatment of urinary calculi. the high rate of fragmentation and simultaneous stone selectivity makes laser lithotripsy an alternative method in the treatment of obstructing ureteral calculi. In comparison to the success rate of ESWL, laser lithotripsy as a minimally invasive endoscopic procedure seems to be superior in disintegrating calculi in the distal ureter. Together with the advance of miniaturized semiflexible endoscopes, intracorporal laser lithotripsy presents a new aspect in the treatment of urinary calculi.

  7. Studies on II-VI and III-V semiconductor nanostructures. Introduction of the core/shell/shell structure and development of CdSe nanocrystals in an automatized procedure; Untersuchungen an II-VI und III-V Halbleiternanostrukturen. Einfuehrung der Core/shell/shell-Struktur und Darstellung von CdSe-Nanokristallen in einem automatisierten Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Mekis, I.

    2005-11-15

    The work in this dissertation is focused on the development and characterization of fluorescent II-VI and III-V-Nanomaterials. Highly luminescent and photostable Nanocrystals with narrow size distributions were prepared. It was shown that nearly monodisperse CdSe-Nanocrystals could be prepared from Cd(Ac){sub 2} and TOPSe in a mixture of TOPO/TOP/HDA/TDPA. Nearly monodisperse CdSe/CdS-Core/shell-Nanocrystals have been prepared in a one-pot-synthesis by injection of H{sub 2}S-Gas into a freshly prepared crude solution of CdSe. The passivation of the CdSe-core with an inorganic shell of CdS resulted in the drastic improvement of the photoluminescence-efficiency of the colloidal solution. Reproducible room-temperature quantum yields reached up to a value of 85%. Photostability investigations have proved the enhanced stability of CdSe/CdS-Nanocrystals compared to CdSe-Nanocrystals under illumination with UV-Light. A novel type of luminescent semiconductor nanocrystal structure has been developed, consisting of a CdSe core and two anorganic shells. Highly fluorescent and nearly monodisperse CdSe/CdS/ZnS- and CdSe/ZnSe/ZnS-Core/shell/shell-nanocrystals have been prepared via organometallic- and acetate-precursors. The Core/she ll/shell particles reached reproducible room-temperature quantum yields up to 85%. Photostability investigations among CdSe-core, CdSe/CdS-Core/shell- and CdSe/CdS/ZnS- Core/shell/-shell-nanocrystals under illumination with UV-light have proved the highest photostability of the Core/shell/shell-particles. The photostabilities of CdSe/ZnSe/ZnS-and CdSe/ZnS-nanocrystals were compared under illumination with intense laser-beam in air. Another part of this work focused on the development of an automated synthesis procedure of CdSe-nanocrystals by constructing and implementing a flow-reactor system. The size and structure of prepared nanocrystals depended considerably on the Cd:Se-precursorratio and the flow-rate. The preparation of CdSe using Cd(Ac)2

  8. Gunshot Injury of Pelvi-Ureteric Junction: Management by the Rendezvous Technique.

    Science.gov (United States)

    Sekhon, Virender; Suryavanshi, Manav

    2017-01-01

    Background: Gunshot injury of ureter is common, but isolated injury of pelvi-ureteric junction (PUJ) has not been reported. Moreover, its management is evolving from the traditional urinary diversion, stenting followed later by definitive surgical repair to a more upfront minimally invasive endourologic approach. Case Presentation: An adolescent boy presented with gunshot laceration injury of left PUJ with associated small intestinal injury. Radiological investigations confirmed a contained urinary leak. Retrograde stenting was not effective. The same guidewire was retained into the urinoma and an antegrade percutaneous access was obtained. A snare was used to retrieve the guidewire and obtain a through and through access. A ureteropelvic drainage catheter was inserted over this guidewire and secured in the upper ureter, bypassing the region of injury. Three weeks later, the drainage tube was removed and the same tract was used for antegrade stenting. A retrograde pyelogram done 3 months later during stent removal demonstrated no leak. The patient is asymptomatic for urinary symptoms on 6 months of follow-up. Conclusion: Rendezvous technique is a feasible alternative to open repair of gunshot pelvi-ureteric junction injury. Long-term follow-up is awaited.

  9. A novel ureteral stent material with antibacterial and reducing encrustation properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jing [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cao, Zhiqiang [General Hospital of Shenyang Military Region, Shenyang 110840 (China); Ren, Ling; Chen, Shanshan; Zhang, Bingchun; Liu, Rui [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2016-11-01

    Ureteral stents have been used to relieve ureterostenosis. Complications such as infection and encrustation occur in the long time of stent implantation, which is a clinical problem needs to be resolved. Indwelling ureteral stents have shown to develop microbial biofilm that may lead to recurrent infection and encrustation. This study was aiming to reduce those complications by using a novel material, Cu-bearing antibacterial stainless steel. The antibacterial performance, encrustation property, and biocompatibility were examined by SEM, image analysis, MTT and would healing. The in vitro immersion test showed that 316LCu-bearing stainless steel (316LCu-SS) not only inhibited proliferation of bacteria and formation of biofilm, but also had less encrustation deposition. Its antibacterial effectiveness against Escherichia coli reached to 92.7% in the artificial urine for 24 h and 90.3% in the human urine for 6 h. The encrustation surface coverage percentage was 30.2% by 12 weeks, which was nearly one half of NiTi alloy. The in vitro tests showed that 316LCu-SS had no toxicity, and promoted the migration of urethral epithelial cells. - Highlights: • 316LCu-SS exhibited strong antibacterial performance against E.coli in the urine. • 316LCu-SS had less crystals deposition on its surface compared to NiTi. • 316LCu-SS showed no toxicity and promoted migration of epithelial cells. • 316LCu-SS is prospective to be a new candidate material to relieve UTIs.

  10. Lunar Phases and Emergency Department Visits for Renal Colic Due to Ureteral Calculus.

    Science.gov (United States)

    Yang, Andy W; Johnson, Justin D; Fronczak, Carolyn M; LaGrange, Chad A

    2016-01-01

    Urolithiasis affects an estimated 5% of the population and the lifetime risk of passing a stone in the urinary tract is estimated to be 8-10%. Urinary calculus formation is highly variable and while certain risk factors such as age, gender, seasonality, anatomic abnormality, and metabolic diseases have been identified, not much is known regarding the association of environmental factors such as lunar phases on renal colic. We conducted a retrospective study to test the hypothesis that full moon phase is an environmental factor associated for increased emergency department (ED) visits for renal colic due to ureteral calculus. We analyzed 559 renal colic diagnoses by the ED at the University of Nebraska Medical Center in a 24-month period and compared them with corresponding lunar phases as well as supermoon events. The lunar phases were defined as full moon ± two days, new moon ± two days, and the days in-between as normal days according to the lunar calendar. Supermoon event dates were obtained from NASA. 90 cases (16.1%) were diagnosed during full moon phase, 89 cases (15.9%) were diagnosed during new moon phase, and 380 cases (68.0%) were diagnosed during normal days. The incidence of renal colic showed no statistically significant association with lunar phases or supermoon events. In this retrospective longitudinal study with adequate power, neither full moon phase nor supermoon event exhibited an association with increased renal colic diagnoses due to ureteral calculus by the ED at the University of Nebraska Medical Center.

  11. Is pre-operative imaging essential prior to ureteric stone surgery?

    Science.gov (United States)

    Youssef, F R; Wilkinson, B A; Hastie, K J; Hall, J

    2012-09-01

    The aim of this study was to identify patients not requiring ureteric stone surgery based on pre-operative imaging (within 24 hours) prior to embarking on semirigid ureteroscopy (R-URS) for urolithiasis. The imaging of all consecutive patients on whom R-URS for urolithiasis was performed over a 12-month period was reviewed. All patients had undergone a plain x-ray of the kidney, ureters and bladder (KUB), abdominal non-contrast computed tomography (NCCT-KUB) or both on the day of surgery. A total of 96 patients were identified for the study. Stone sizes ranged from 3 mm to 20 mm. Thirteen patients (14%) were cancelled as no stone(s) were identified on pre-operative imaging. Of the patients cancelled, 8 (62%) required NCCT-KUB to confirm spontaneous stone passage. One in seven patients were stone free on the day of surgery. This negates the need for unnecessary anaesthetic and instrumentation of the urinary tract, with the associated morbidity. Up-to-date imaging prior to embarking on elective ureteric stone surgery is highly recommended.

  12. Effect of Tamsulosin on Stone Passage for Ureteral Stones: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Wang, Ralph C; Smith-Bindman, Rebecca; Whitaker, Evans; Neilson, Jersey; Allen, Isabel Elaine; Stoller, Marshall L; Fahimi, Jahan

    2017-03-01

    Tamsulosin is recommended for patients receiving a diagnosis of a ureteral stone less than 10 mm who do not require immediate urologic intervention. Because of conflicting results from recent meta-analyses and large randomized controlled trials, the efficacy of tamsulosin is unclear. We perform a systematic review and meta-analysis to investigate the effect of tamsulosin on stone passage in patients receiving a diagnosis of ureteral stone. MEDLINE, EMBASE, and CENTRAL databases were searched without language restriction through November 2015 for studies assessing the efficacy of tamsulosin and using a double-blind, randomized, controlled trial design. Meta-analysis was conducted with a random-effects model and subgroup analyses were conducted to determine sources of heterogeneity. Eight randomized controlled trials (N=1,384) contained sufficient information for inclusion. The pooled risk of stone passage in the tamsulosin arm was 85% versus 66% in the placebo arm, but substantial heterogeneity existed across trials (I 2 =80.2%; Ptamsulosin (risk difference=22%; 95% confidence interval 12% to 33%; number needed to treat=5). The meta-analysis of the small stone subgroup (Tamsulosin significantly improves stone passage in patients with larger stones, whereas the effect of tamsulosin is diminished in those with smaller stones, who are likely to pass their stone regardless of treatment. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  13. Comparative efficacy of tamsulosin versus nifedipine for distal ureteral calculi: a meta-analysis.

    Science.gov (United States)

    Wang, Hai; Man, Li Bo; Huang, Guang Lin; Li, Gui Zhong; Wang, Jian Wei

    2016-01-01

    The aim of this study was to systematically compare the therapeutic effect and safety of tamsulosin with nifedipine in medical expulsive therapy for distal ureteral calculi. Databases, including PubMed, EMBASE, the Cochrane Library, and Clinical Trial Register Centers, were comprehensively searched. Relevant randomized controlled trials (RCTs) were selected, and quality assessment was performed according to the Cochrane Handbook. RevMan software was used to analyze the outcome measures, which consisted of expulsion rate, expulsion time, and complications. Twelve RCTs consisting of 4,961 patients were included (tamsulosin group, 2,489 cases; nifedipine group, 2,472 cases). Compared with nifedipine, tamsulosin significantly increased the expulsion rate (risk ratio =1.29, 95% CI [1.25, 1.33], Ptamsulosin was associated with fewer complications than nifedipine (risk ratio =0.45, 95% CI [0.28, 0.72], P=0.0008), and further subgroup analysis showed that tamsulosin was associated with a lower risk of both mild and moderate-to-severe complications. On the bias of current evidence, tamsulosin showed an overall superiority to nifedipine for distal ureteral calculi Tamsulosin was supposed to be the first drug to be recommended to patients willing to receive medical expulsive therapy.

  14. Complications of Percutaneous Nephrostomy, Percutaneous Insertion of Ureteral Endoprosthesis, and Replacement Procedures

    International Nuclear Information System (INIS)

    Kaskarelis, Ioannis S.; Papadaki, Marina G.; Malliaraki, Niki E.; Robotis, Epaminondas D.; Malagari, Katerina S.; Piperopoulos, Ploutarchos N.

    2001-01-01

    Purpose: The aim of the present study was to record and identify the frequency of complications following percutaneous nephrostomy, replacement of nephrostomy drains and percutaneous insertion of ureteral endoprostheses.Methods: During a 10-year period 341 patients were referred to our department with indications for percutaneous nephrostomy and/or percutaneous insertion of a ureteral endoprosthesis, and a total of 1036 interventional procedures were performed (nephrostomy, catheter change, stenting).Results: There were three major complications (0.29%): two patients died during the first 30 days after the procedure, due to aggravation of their condition caused by the procedure, and one patient had retroperitoneal bleeding requiring surgery. There were 76 complications of intermediate severity (7.33%): catheter or stent displacement (n = 37, 3.57%) catheter occlusion (n = 18, 1.73%), hematuria (n = 12, 1.16%), and urinary tract infection (n = 9, 0.87%). The 55 minor complications (5.3%) comprised inflammation of the skin at the site of insertion of the percutaneous catheter.Conclusion: The small number of complications observed during acts of interventional uroradiology prove transcutaneous manipulations to be safe medical procedures

  15. A novel ureteral stent material with antibacterial and reducing encrustation properties

    International Nuclear Information System (INIS)

    Zhao, Jing; Cao, Zhiqiang; Ren, Ling; Chen, Shanshan; Zhang, Bingchun; Liu, Rui; Yang, Ke

    2016-01-01

    Ureteral stents have been used to relieve ureterostenosis. Complications such as infection and encrustation occur in the long time of stent implantation, which is a clinical problem needs to be resolved. Indwelling ureteral stents have shown to develop microbial biofilm that may lead to recurrent infection and encrustation. This study was aiming to reduce those complications by using a novel material, Cu-bearing antibacterial stainless steel. The antibacterial performance, encrustation property, and biocompatibility were examined by SEM, image analysis, MTT and would healing. The in vitro immersion test showed that 316LCu-bearing stainless steel (316LCu-SS) not only inhibited proliferation of bacteria and formation of biofilm, but also had less encrustation deposition. Its antibacterial effectiveness against Escherichia coli reached to 92.7% in the artificial urine for 24 h and 90.3% in the human urine for 6 h. The encrustation surface coverage percentage was 30.2% by 12 weeks, which was nearly one half of NiTi alloy. The in vitro tests showed that 316LCu-SS had no toxicity, and promoted the migration of urethral epithelial cells. - Highlights: • 316LCu-SS exhibited strong antibacterial performance against E.coli in the urine. • 316LCu-SS had less crystals deposition on its surface compared to NiTi. • 316LCu-SS showed no toxicity and promoted migration of epithelial cells. • 316LCu-SS is prospective to be a new candidate material to relieve UTIs.

  16. Anti-fibrotic effect of natural toxin bee venom on animal model of unilateral ureteral obstruction.

    Science.gov (United States)

    An, Hyun Jin; Kim, Kyung Hyun; Lee, Woo Ram; Kim, Jung Yeon; Lee, Sun Jae; Pak, Sok Cheon; Han, Sang Mi; Park, Kwan Kyu

    2015-05-29

    Progressive renal fibrosis is the final common pathway for all kidney diseases leading to chronic renal failure. Bee venom (BV) has been widely used as a traditional medicine for various diseases. However, the precise mechanism of BV in ameliorating the renal fibrosis is not fully understood. To investigate the therapeutic effects of BV against unilateral ureteral obstruction (UUO)-induced renal fibrosis, BV was given intraperitoneally after ureteral ligation. At seven days after UUO surgery, the kidney tissues were collected for protein analysis and histologic examination. Histological observation revealed that UUO induced a considerable increase in the number of infiltrated inflammatory cells. However, BV treatment markedly reduced these reactions compared with untreated UUO mice. The expression levels of TNF-α and IL-1β were significantly reduced in BV treated mice compared with UUO mice. In addition, treatment with BV significantly inhibited TGF-β1 and fibronectin expression in UUO mice. Moreover, the expression of α-SMA was markedly withdrawn after treatment with BV. These findings suggest that BV attenuates renal fibrosis and reduces inflammatory responses by suppression of multiple growth factor-mediated pro-fibrotic genes. In conclusion, BV may be a useful therapeutic agent for the prevention of fibrosis that characterizes progression of chronic kidney disease.

  17. Anti-Fibrotic Effect of Natural Toxin Bee Venom on Animal Model of Unilateral Ureteral Obstruction

    Directory of Open Access Journals (Sweden)

    Hyun Jin An

    2015-05-01

    Full Text Available Progressive renal fibrosis is the final common pathway for all kidney diseases leading to chronic renal failure. Bee venom (BV has been widely used as a traditional medicine for various diseases. However, the precise mechanism of BV in ameliorating the renal fibrosis is not fully understood. To investigate the therapeutic effects of BV against unilateral ureteral obstruction (UUO-induced renal fibrosis, BV was given intraperitoneally after ureteral ligation. At seven days after UUO surgery, the kidney tissues were collected for protein analysis and histologic examination. Histological observation revealed that UUO induced a considerable increase in the number of infiltrated inflammatory cells. However, BV treatment markedly reduced these reactions compared with untreated UUO mice. The expression levels of TNF-α and IL-1β were significantly reduced in BV treated mice compared with UUO mice. In addition, treatment with BV significantly inhibited TGF-β1 and fibronectin expression in UUO mice. Moreover, the expression of α-SMA was markedly withdrawn after treatment with BV. These findings suggest that BV attenuates renal fibrosis and reduces inflammatory responses by suppression of multiple growth factor-mediated pro-fibrotic genes. In conclusion, BV may be a useful therapeutic agent for the prevention of fibrosis that characterizes progression of chronic kidney disease.

  18. Extracorporeal shock wave lithotripsy (ESWL) vs. ureterorenoscopic (URS) manipulation in proximal ureteric stone.

    Science.gov (United States)

    Manzoor, Salman; Hashmi, Altaf Hussain; Sohail, Muhammad Ali; Mahar, Feroz; Bhatti, Shahid; Khuhro, Abdul Qayoom

    2013-10-01

    To compare the stone free rate at one week after extracorporeal shock wave lithotripsy (ESWL) and ureterorenoscopic (URS) manipulation for proximal ureteric stone (10 - 15 mm size). Randomized controlled trial. Sindh Institute of Urology and Transplantation (SIUT), Karachi, from August 2010 to February 2011. One hundred and ninety patients with 10 - 15 mm proximal urteric stone, in each group were treated with ESWL and ureterorenoscopic manipulation by using an 8.0 or 8.5 Fr semi rigid ureteroscope. Intracorporeal lithotripsy was performed by using pneumatic lithoclast. The stone free rate were compared between groups by considering size of stone at one week after procedure. The success rate, retreatment rate, auxiliary procedure and complication rate were compared in each group. Success rate was 49.2% for ESWL and 57.8% for URS (p = 0.008). The re-treatment rate was significantly higher in ESWL group than in URS group (40% vs. 11 and 18% in URS group). Although ESWL is regarded as the preferred choice of treatment for proximal ureteric stone, the present results suggest that ureterorenoscopic manipulation with intracorporeal lithotripsy is a safe alternative, with an advantage of obtaining an earlier or immediate stone-free status. Laparoscopic approaches are reasonable alternatives in cases, where ESWL and URS have failed.

  19. Extracorporeal Shock Wave Lithotripsy (ESWL) vs. Ureterorenoscopic (URS) Manipulation in Proximal Ureteric Stone

    International Nuclear Information System (INIS)

    Manzoor, S.; Khuhro, A.Q.; Hashmi, A.H.; Sohail, M.A.; Mahar, F.; Bhatti, S.

    2013-01-01

    Objective: To compare the stone free rate at one week after extracorporeal shock wave lithotripsy (ESWL) and ureterorenoscopic (URS) manipulation for proximal ureteric stone (10 - 15 mm size). Study Design: Randomized controlled trial. Place and Duration of Study: Sindh Institute of Urology and Transplantation (SIUT), Karachi, from August 2010 to February 2011. Methodology: One hundred and ninety patients with 10 - 15 mm proximal urteric stone, in each group were treated with ESWL and ureterorenoscopic manipulation by using an 8.0 or 8.5 Fr semi rigid ureteroscope. Intracorporeal lithotripsy was performed by using pneumatic lithoclast. The stone free rate were compared between groups by considering size of stone at one week after procedure. The success rate, retreatment rate, auxiliary procedure and complication rate were compared in each group. Results: Success rate was 49.2% for ESWL and 57.8% for URS (p = 0.008). The re-treatment rate was significantly higher in ESWL group than in URS group (40% vs. 11 and 18% in URS group). Conclusion: Although ESWL is regarded as the preferred choice of treatment for proximal ureteric stone, the present results suggest that ureterorenoscopic manipulation with intracorporeal lithotripsy is a safe alternative, with an advantage of obtaining an earlier or immediate stone-free status. Laparoscopic approaches are reasonable alternatives in cases, where ESWL and URS have failed. (author)

  20. Safety and efficacy of silodosin and tadalafil in ease of negotiation of large ureteroscope in the management of ureteral stone: A prosective randomized trial.

    Science.gov (United States)

    Bhattar, Rohit; Jain, Vipin; Tomar, Vinay; Yadav, Sher Singh

    2017-12-01

    To evaluate the safety and efficacy of silodosin and tadalafil in ease of negotiation of large size ureteroscope (8/9.8 Fr) in the management of ureteral stone. Between June 2015 and May 2016, 86 patients presented with ureteral stone of size 6-15 mm were on consent randomly assigned to 1 of 3 outpatient treatment arms: silodosin (Group A), tadalafil (Group B), and placebo (Group C). After two weeks of therapy 67 patients underwent ureteroscopy, and ureteral orifice configuration, ureteroscopic negotiation, ureteral dilatation, operating time, procedural complication and drug related side effects were noted in each group. Ureteral negotiation was significantly better in Groups A (73.9%) and B (69.6%) as compared to Group C (38.1%) (p<0.01). Statistically significant difference was noted in the requirement for dilatation in Group C (71.4%) as compared to Groups A (26.1%) and B (39.1%) (p<0.01). Ureteral orifice was found to be more dilated in Groups A (69.6%) and B (60.9%) as compared to Group C (28.6%). Mean operating time was statistically lower in Groups A (35.2 min) and B (34.91 min) as compared to Group C (41.14 min) (p<0.01). Both silodosin and tadalafil not only relax ureteral smooth muscle but also help in forward propagation of large size ureteroscope (8/9.8 Fr) without any significant risk of adverse events.

  1. Diagnosis of acute flank pain caused by ureteral stones: value of combined direct and indirect signs on IVU and unenhanced helical CT

    International Nuclear Information System (INIS)

    Wang, Li-Jen; Wong, Yon-Cheong; Ng, Chip-Jin; Chen, Jih-Chang; Chiu, Te-Fa

    2004-01-01

    The aim of this study was to assess the usefulness of combined direct and indirect signs on intravenous urography (IVU) and unenhanced helical computed tomography (UHCT) for the diagnosis of ureteral stones in emergency patients with acute flank pain. During an 8-month period, 82 emergency patients with acute flank pain undergoing IVU and UHCT with sufficient clinical follow-up formed the study group. The presence or absence of direct sign (visualization of ureteral stones) and indirect signs on IVU and UHCT was recorded. The diagnostic accuracy of each direct/indirect sign and their combination for the diagnosis of ureteral stones on IVU and UHCT were analyzed and compared. Of the 82 patients, 66 had ureteral stones, four had passed urinary stones prior to imaging and 12 had other diseases. The diagnostic accuracies of direct signs on IVU and UHCT for the diagnosis of ureteral stones were 79.3 and 98.8%, respectively, which was more accurate than that of any single indirect sign on IVU and UHCT. However, the diagnostic accuracy of ureteral stones by IVU increased to 90.2% when using diagnostic criteria requiring the presence of a direct sign or at least three indirect signs, and by UHCT, it increased to 100% when using diagnostic criteria requiring the presence of a direct sign with at least one indirect sign. Therefore, for emergency patients with acute flank pain, the use of the above combinations of direct/indirect signs is useful as the diagnostic criterion for ureteral stones. (orig.)

  2. Comparison of Two Types of Double-J Ureteral Stents that Differ in Diameter and the Existence of Multiple Side Holes along the Straight Portion in Malignant Ureteral Strictures

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myung Gyu, E-mail: acube808@naver.com; Seo, Tae-Seok, E-mail: g1q1papa@korea.ac.kr; Lee, Chang Hee, E-mail: chlee86@korea.ac.kr; Kim, Kyeong Ah, E-mail: kahkim@korea.ac.kr [Korea University College of Medicine, Department of Radiology, Korea University Guro Hospital (Korea, Republic of); Kim, Jun Suk, E-mail: kjs6651@kumc.or.kr; Oh, Sang Cheul, E-mail: sachoh@korea.ac.kr [Korea University College of Medicine, Department of Oncology, Korea University Guro Hospital (Korea, Republic of); Lee, Jae-Kwan, E-mail: jklee38@korea.ac.kr [Korea University College of Medicine, Department of Gynecology, Korea University Guro Hospital (Korea, Republic of)

    2015-06-15

    PurposeThis study was decided to evaluate the impact of diameter and the existences of multiple side holes along the straight portion of double-J ureteral stents (DJUS) on early dysfunction of stents placed for malignant ureteral strictures.MethodsBetween April 2007 and December 2011, 141 DJUSs were placed via a percutaneous nephrostomy (PCN) tract in 110 consecutive patients with malignant ureteral strictures. 7F DJUSs with multiple side holes in the straight portion were placed in 58 ureters of 43 patients (Group 1). 8F DJUSs with three side holes in the proximal 2-cm of the straight portion were placed in 83 ureters of 67 patients (Group 2). The incidence of early DJUS dysfunction was compared between the two groups, and nephrostographic findings were evaluated in the cases of early dysfunction.ResultsEarly dysfunction of the DJUS was noted in 14 of 58 patients (24.1 %) in Group 1, which was significantly higher (p = 0.001) than in Group 2 in which only 1 of 83 patients (1.2 %) had early dysfunction of the DJUS. Nephrostographic findings of early dysfunction included dilatation of the pelvicalyceal system, filling defects in the ureteral stent, and no passage of contrast media into the urinary bladder.ConclusionsIn malignant ureteral strictures, multiple side holes in the straight portion of the 7-F DJUS seem to cause early dysfunction. The 8F DJUSs with three side holes in the proximal 2-cm of the straight portion may be superior at preventing early dysfunction.

  3. Size matters. The width and location of a ureteral stone accurately predict the chance of spontaneous passage

    Energy Technology Data Exchange (ETDEWEB)

    Jendeberg, Johan; Geijer, Haakan; Alshamari, Muhammed; Liden, Mats [Oerebro University Hospital, Department of Radiology, Faculty of Medicine and Health, Oerebro (Sweden); Cierzniak, Bartosz [Oerebro University, Department of Surgery, Faculty of Medicine and Health, Oerebro (Sweden)

    2017-11-15

    To determine how to most accurately predict the chance of spontaneous passage of a ureteral stone using information in the diagnostic non-enhanced computed tomography (NECT) and to create predictive models with smaller stone size intervals than previously possible. Retrospectively 392 consecutive patients with ureteric stone on NECT were included. Three radiologists independently measured the stone size. Stone location, side, hydronephrosis, CRP, medical expulsion therapy (MET) and all follow-up radiology until stone expulsion or 26 weeks were recorded. Logistic regressions were performed with spontaneous stone passage in 4 weeks and 20 weeks as the dependent variable. The spontaneous passage rate in 20 weeks was 312 out of 392 stones, 98% in 0-2 mm, 98% in 3 mm, 81% in 4 mm, 65% in 5 mm, 33% in 6 mm and 9% in ≥6.5 mm wide stones. The stone size and location predicted spontaneous ureteric stone passage. The side and the grade of hydronephrosis only predicted stone passage in specific subgroups. Spontaneous passage of a ureteral stone can be predicted with high accuracy with the information available in the NECT. We present a prediction method based on stone size and location. (orig.)

  4. Clinical protocol levels are required in laboratory animal surgery when using medical devices: experiences with ureteral replacement surgery in goats

    NARCIS (Netherlands)

    Jonge, P.K.J.D. de; Sloff, M.; Janke, H.P.; Kortmann, B.B.M.; Gier, R.P.E. de; Geutjes, P.J.; Oosterwijk, E.; Feitz, W.F.J.

    2017-01-01

    It is common to test medical devices in large animal studies that are or could also be used in humans. In this short report we describe the use of a ureteral J-stent for the evaluation of biodegradable tubular constructs for tissue reconstruction, and the regeneration of ureters in Saanen goats.

  5. Tamsulosin versus tamsulosin plus tadalafil as medical expulsive therapy for lower ureteric stones: a randomized controlled trial.

    Science.gov (United States)

    Jayant, Kumar; Agrawal, Rajendra; Agrawal, Swati

    2014-10-01

    To compare the efficacy of tamsulosin versus tamsulosin plus tadalafil as medical expulsive therapy for lower ureteric stones. Between January 2013 and December 2013, 244 patients presenting with distal ureteric stones (size 5-10 mm) were randomized equally to tamsulosin (group A) or tamsulosin plus tadalafil (group B). Therapy was given for a maximum of 4 weeks. Stone expulsion rate, time to stone expulsion, analgesic use, number of hospital visits for pain, follow up, endoscopic treatment and adverse effects of drugs were recorded. Statistical analyses were carried out using Student's t-test and the χ(2) -test. There was a statistically significant higher expulsion rate in group B compared with group A (83.6% vs 65.5%; P-value = 0.031) and a shorter time to expulsion (14.9 ± 4.4 days vs 16.7 ± 4.8 days; P-value = 0.003). Statistically significant differences were noted in terms of the number of hospital visits and analgesic requirement in favor of group B. There was no serious adverse event. An improvement in erectile function was noted in patients of group B compared with those of group A. Medical expulsive therapy for distal ureteric stones using tamsulosin plus tadalafil is safe, effective and well tolerated. Furthermore, tadalafil provides the additional advantage of improving erectile dysfunction when this condition coexists with a lower ureteric stone. © 2014 The Japanese Urological Association.

  6. Is There Hope for Renal Growth on Imaging Studies Following Ureteral Reimplant for Boys With Fetal Hydronephrosis and Urinary Reflux?

    Directory of Open Access Journals (Sweden)

    Ming-Hsien Wang

    2015-07-01

    Full Text Available Reflux nephropathy is thought to be the etiology for renal maldevelopment. We present two boys with fetal hydronephrosis and sterile vesicoureteral reflux (VUR. There was lack of renal growth of the refluxing renal units on surveillance renal ultrasound. Parents elected to undergo open ureteral reimplants. Post-surgical ultrasounds demonstrated improved renal growth.

  7. Suture-free technique for canine ureteral resection-anastomosis using a microvascular anastomotic system: a cadaveric study.

    Science.gov (United States)

    Wavreille, Vincent; Adin, Christopher A; Arango, Johnattan; Ham, Kathleen L; Byron, Julie K; McLoughlin, Mary A

    2015-01-01

    To describe a suture-free technique for canine ureteral resection-anastomosis using a microvascular anastomotic system (MAS) and to compare surgical time and burst pressure of hand-sewn (HS) ureteral end-to-end anastomosis with the MAS technique. Experimental ex vivo study. Canine cadavers (n = 8). For each cadaver, 1 ureter was randomly assigned to undergo HS anastomosis and the contralateral ureter had MAS anastomosis. The first 3 cadavers (6 ureters) were used to refine the MAS technique. In the other 5 dogs, surgical time and ureteral burst pressure were compared between groups (n = 5 ureters/group). Preliminary procedures showed that selective impaling of the mucosa and submucosa (without muscularis and adventitia) is necessary to allow complete mechanical interlock of the anastomotic rings for the MAS technique. Median anastomotic time was significantly shorter for MAS (7.6 min) than HS (16.6 min; p = .029) and burst pressure higher for MAS (393 cm H2 O) than HS (180 cm H2 O; p = .012). This study demonstrated the feasibility of a suture-free technique of canine ureteral resection-anastomosis using a commercially available MAS. The MAS anastomosis was faster and had higher burst strength compared with the HS anastomosis. © Copyright 2014 by The American College of Veterinary Surgeons.

  8. Anionic and cationic drug secretion in the isolated perfused rat kidney after neonatal surgical induction of ureteric obstruction.

    NARCIS (Netherlands)

    Gier, R.P.E. de; Feitz, W.F.J.; Masereeuw, R.; Wouterse, A.C.; Smits, D.; Russel, F.G.M.

    2003-01-01

    OBJECTIVE: To study the pathophysiological changes of renal tubular drug transport mechanisms in congenital renal obstruction, by developing a model for perfusing the isolated kidney (IPK) after neonatal surgical induction of partial ureteric obstruction in Hanover Wistar rats. MATERIAL AND METHODS:

  9. Terapia Expulsiva Medicamentosa na Litíase Ureteral: Revisão de Literatura/ Medicamental Expulsive Therapy in Ureteral Lithiasis: Literature Review

    Directory of Open Access Journals (Sweden)

    Kenji Maeda Missima

    2014-06-01

    Full Text Available A terapia expulsiva medicamentosa na litíase ureteral tem ganhado importante espaço na prática clínica, visto que é um método não invasivo e de grande eficácia. Como se trata de uma afecção comum, de alta incidência e custo, a terapia expulsiva possibilita um manejo clínico menos dispendioso e invasivo, quando comparada a procedimentos intervencionistas. Há consenso na literatura que a terapia expulsiva medicamentosa é efetiva e deve ser utilizada em cálculos com cerca de 5 milímetros de diâmetro, visto que as drogas utilizadas aumentam a taxa e diminuem o tempo de expulsão, além de diminuir a dor e o número de internações. O tamanho e localização do cálculo são de extrema relevância para que se possa considerar o manejo conservador. As drogas que obtém as melhores taxas expulsivas são os bloqueadores dos receptores alfa-adrenérgicos e os bloqueadores dos canais de cálcio. Analgésicos também são utilizados para o alívio da dor e o uso de corticoides ainda é questionado. Medicamental expulsive therapy for ureteral stones has gained important place in clinical practice, because it is a noninvasive and highly effective method. As it is a common disorder with high incidence and cost, expulsive therapy provides a less costly and invasive clinical management when compared to interventional procedures. There is a consensus that the medicamental expulsive therapy is effective and should be used in calculations with about 5 millimeters in diameter, since the drugs used increase rate and decrease the time of expulsion, in addition to reducing the pain and the number of hospitalizations. The size and location of the calculi are very important for it to be considered conservative management. The drugs that get the best expulsive rates are alpha - adrenergic receptor blockers and calcium channel blockers. Analgesics are also used for pain relief and the use of corticosteroids is still questioned.

  10. Efficacy of tamsulosin hydrochloride in relieving "double-J ureteral stent-related morbidity": a randomized placebo controlled clinical study.

    Science.gov (United States)

    Singh, Iqbal; Tripathy, Sambit; Agrawal, Vivek

    2014-12-01

    To evaluate the efficacy of tamsulosin therapy in reducing ureteral double-J stent morbidity by evaluating USSQ, IPSS, QOL and VAS (primary objective) and to evaluate the morbidity and or complication(s) associated with indwelling double-J ureteral stent(s) and to evaluate the safety of tamsulosin therapy for "morbidity associated with double-J stents" by evaluating its tolerability, side effects and adverse events if any (secondary objective) as per protocol. After institutional review board approval, 60 consecutive patients with a double-J ureteral stent inserted after percutaneous nephrolithotomy or ureteroscopic stone treatment were randomly assigned to receive tamsulosin 0.4 mg, or a placebo for 4 weeks. The validated USSQ, VAS and IPSS were completed before stent insertion, at 3 days and 4 weeks after stent insertion and at 2 weeks after stent removal. Data were statistically analyzed for efficacy and tolerability of one drug over the other using Wilcoxon signed-rank test, Mann-Whitney test and Student's t test. Patients receiving tamsulosin compared with the placebo showed significant decrease in urinary index score, pain index score, work performance score, VAS score at loin area, VAS score at flank, VAS score at suprapubic area, average VAS score, need for antibiotics, number of hospital visits (P tamsulosin but, however, the decrease was not significant. No patients discontinued medication because of side effects. We conclude that ureteral stenting using double-J stents with concomitant tamsulosin therapy was generally well tolerated, safe, effective and significantly beneficial in reducing stent morbidity in the majority of our patients. We advocate the routine use of concomitant tamsulosin therapy in eligible patients undergoing ureteral stenting in order to minimize stent morbidity.

  11. Effect of ureteral reimplantation on prevention of urinary tract infection and renal growth in infants with primary vesicoureteral reflux

    International Nuclear Information System (INIS)

    Matsumoto, Fumi; Tohda, Akira; Shimada, Kenji

    2004-01-01

    We retrospectively reviewed the results of ureteral reimplantation in infants with primary vesicoureteral reflux (VUR) to evaluate the effect on prevention of urinary tract infection (UTI) and renal growth. From July 1991 to December 2001, a total of 205 infants (180 boys and 25 girls) with primary VUR underwent ureteral reimplantation at the Department of Urology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan. Indications for surgery were high-grade reflux (grade IV-V), breakthrough UTI and non-compliance of medical treatment. Age at surgery raged from 1 to 11 months (mean, 6.4 months). Ureteral reimplantation was performed according to Cohen's method. Only two of 336 refluxing ureters required ureteral tailoring. Follow-up ranged from 12 to 110 months (mean, 64 months). Surgical outcome, frequency of UTI and individual renal growth measured by 99m Tc-dimercaptosuccinic acid (DMSA) scintigraphy was evaluated. Postoperative ultrasound and voiding cystourethrography showed neither residual reflux nor ureterovesical obstruction. Contralateral low grade reflux occurred in six of 74 patients (8.1%) who had unilateral reflux preoperatively. After reimplantation, 10 patients documented 13 febrile UTI. Eleven of the 13 episodes occurred early in the postoperative period (<6 months). Frequency of febrile UTI reduced from 0.23538 before surgery to 0.00894 and 0.00081 per patient per month at 6 and 12 months after surgery, respectively. No development of renal scarring was seen in postoperative DMSA scan. Changes of differential renal function was <0.05 in all patients. The present results show ureteral reimplantation in infants is safe and very effective for the prevention of UTI. After surgical treatment in infancy, individual renal growth of children with primary VUR is stable. (authors)

  12. In Vivo and In Vitro Elution of Analgesics from Multilayered Poly(D,L-lactide-co-glycolide Nanofibers Incorporated Ureteral Stents

    Directory of Open Access Journals (Sweden)

    Yi-Chia Lin

    2018-01-01

    Full Text Available We develop novel analgesic-eluting nanofiber-incorporated ureteral stents that offer sustained release of lidocaine and ketorolac for local drug delivery. Lidocaine and poly(D,L-lactide-co-glycolide (PLGA were dissolved in hexafluoroisopropanol and were electrospun into nonwoven nanofibers onto the surface of ureteral stents. This was followed by electrospinning of another layer of PLGA nanofibers containing ketorolac. Electrospun drug-loaded nanofibers were then characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle analysis. In addition, the elution behavior characteristics of the analgesics, both in vivo and in vitro, from the nanofiber-incorporated stents were evaluated. Experimental results indicate that the analgesic-eluting ureteral stents could liberate high strengths of analgesics in vitro and in vivo for at least 50 and 30 days, respectively. The analgesic-eluting nanofiber-incorporated ureteral stents are potentially applicable for alleviating the discomfort associated with stent implant.

  13. Generation of branching ureteric bud tissues from human pluripotent stem cells.

    Science.gov (United States)

    Mae, Shin-Ichi; Ryosaka, Makoto; Toyoda, Taro; Matsuse, Kyoko; Oshima, Yoichi; Tsujimoto, Hiraku; Okumura, Shiori; Shibasaki, Aya; Osafune, Kenji

    2018-01-01

    Recent progress in kidney regeneration research is noteworthy. However, the selective and robust differentiation of the ureteric bud (UB), an embryonic renal progenitor, from human pluripotent stem cells (hPSCs) remains to be established. The present study aimed to establish a robust induction method for branching UB tissue from hPSCs towards the creation of renal disease models. Here, we found that anterior intermediate mesoderm (IM) differentiates from anterior primitive streak, which allowed us to successfully develop an efficient two-dimensional differentiation method of hPSCs into Wolffian duct (WD) cells. We also established a simplified procedure to generate three-dimensional WD epithelial structures that can form branching UB tissues. This system may contribute to hPSC-based regenerative therapies and disease models for intractable disorders arising in the kidney and lower urinary tract. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Impact of Case Volume on Outcomes of Ureteroscopy for Ureteral Stones

    DEFF Research Database (Denmark)

    Kandasami, Sangam V; Mamoulakis, Charalampos; El-Nahas, Ahmed R

    2014-01-01

    of case volume on the outcomes of URS for ureteral stones. DESIGN, SETTING, AND PARTICIPANTS: The URS Global Study collected prospective data on consecutive patients with urinary stones treated with URS at 114 centres worldwide for 1 yr. Centres were identified as low or high volume based on the median...... overall annual case volume. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Pre- and intraoperative characteristics, and postoperative outcomes in patients at low- and high-volume centres were compared. The relationships between case volume and stone-free rate (SFR), stone burden, complications...... SFR was 91.9% and 86.3% at high- and low-volume centres, respectively (pstone-free outcome increased with increasing case volume (p

  15. In Vivo and In Vitro Elution of Analgesics from Multilayered Poly(D,L)-lactide-co-glycolide Nanofibers Incorporated Ureteral Stents

    OpenAIRE

    Lin, Yi-Chia; Liu, Kuo-Sheng; Lee, Demei; Li, Min-Jhan; Liu, Shih-Jung; Ito, Hiroshi

    2018-01-01

    We develop novel analgesic-eluting nanofiber-incorporated ureteral stents that offer sustained release of lidocaine and ketorolac for local drug delivery. Lidocaine and poly(D,L)-lactide-co-glycolide (PLGA) were dissolved in hexafluoroisopropanol and were electrospun into nonwoven nanofibers onto the surface of ureteral stents. This was followed by electrospinning of another layer of PLGA nanofibers containing ketorolac. Electrospun drug-loaded nanofibers were then characterized using scannin...

  16. FIRST EXPERIENCE OF THE URETERO-URETEROANASTOMOSIS (URETEROPYELOANASTOMOSIS IN CHILDREN WITH COMPLETE URETERAL DUPLICATION

    Directory of Open Access Journals (Sweden)

    I. M. Kagantsov

    2017-01-01

    Full Text Available Introduction. The Duplex kidney is one of the most common anomalies of urinary system. Approaches to the surgical management of these conditions significantly differ. Taking into account the preferences of surgeons, heminephroureterectomy is offered to perform openly or laparoscopically, uretero-cysto-anastomosis of ectopic ureter or two ureters en bloc. Some publications about the possibility of ureteroureteral anastomosis have lately begun to appear. We present the experience of ureteroureteral anastomosis performed openly and laparoscopically in 9 clinics of Russia and Belarus.Objective. Improvement of treatment results of ureterohydronephrosis in children with complete ureteral duplication.Material and methods. We retrospectively reviewed medical records of 38 children who underwent ureteroureteral anastomosis surgery from 2007 to 2016. There were 10 boys (26.3% and 28 girls (73.7%. The mean age of patients was 40.2 months. Right duplex kidney was confirmed in 15 (39.5% children, the left one was diagnosed in 23 (60.5% children. All the patients were divided into two groups according to the surgical technique used. Fourteen children 14 (36.8% were included in the first group, in whom the ureteroureteral anastomosis has been performed openly, the second group comprised 24 (63.2% patients with laparoscopically made anastomosis.Results. There weren’t any cases of conversion in this cohort. One patient in each group suffered from acute pyelonephritis. In the early postoperative period, urine leakage along the drainage occurred in 3 (12.5% patients after laparoscopically performed ureteroureteral anastomosis, one (4.2% child had residual ureteral stump. Thus, five (13.2% children had complications, one (2.6% patient required redo surgery.Conclusion. There are few clinics where ureteroureteral anastomosis is performed via open or laparoscopic approach. This operation is at the stage of development and accumulation of experience. It is a safe

  17. Lunar Phases and Emergency Department Visits for Renal Colic Due to Ureteral Calculus.

    Directory of Open Access Journals (Sweden)

    Andy W Yang

    Full Text Available Urolithiasis affects an estimated 5% of the population and the lifetime risk of passing a stone in the urinary tract is estimated to be 8-10%. Urinary calculus formation is highly variable and while certain risk factors such as age, gender, seasonality, anatomic abnormality, and metabolic diseases have been identified, not much is known regarding the association of environmental factors such as lunar phases on renal colic. We conducted a retrospective study to test the hypothesis that full moon phase is an environmental factor associated for increased emergency department (ED visits for renal colic due to ureteral calculus.We analyzed 559 renal colic diagnoses by the ED at the University of Nebraska Medical Center in a 24-month period and compared them with corresponding lunar phases as well as supermoon events. The lunar phases were defined as full moon ± two days, new moon ± two days, and the days in-between as normal days according to the lunar calendar. Supermoon event dates were obtained from NASA.90 cases (16.1% were diagnosed during full moon phase, 89 cases (15.9% were diagnosed during new moon phase, and 380 cases (68.0% were diagnosed during normal days. The incidence of renal colic showed no statistically significant association with lunar phases or supermoon events.In this retrospective longitudinal study with adequate power, neither full moon phase nor supermoon event exhibited an association with increased renal colic diagnoses due to ureteral calculus by the ED at the University of Nebraska Medical Center.

  18. Comparative efficacy of tamsulosin versus nifedipine for distal ureteral calculi: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Wang H

    2016-03-01

    Full Text Available Hai Wang, Li Bo Man, Guang Lin Huang, Gui Zhong Li, Jian Wei WangDepartment of Urology, Beijing Jishuitan Hospital, Beijing, People’s Republic of China Objective: The aim of this study was to systematically compare the therapeutic effect and safety of tamsulosin with nifedipine in medical expulsive therapy for distal ureteral calculi.Methods: Databases, including PubMed, EMBASE, the Cochrane Library, and Clinical Trial Register Centers, were comprehensively searched. Relevant randomized controlled trials (RCTs were selected, and quality assessment was performed according to the Cochrane Handbook. RevMan software was used to analyze the outcome measures, which consisted of expulsion rate, expulsion time, and complications.Results: Twelve RCTs consisting of 4,961 patients were included (tamsulosin group, 2,489 cases; nifedipine group, 2,472 cases. Compared with nifedipine, tamsulosin significantly increased the expulsion rate (risk ratio =1.29, 95% CI [1.25, 1.33], P<0.0001 and reduced the expulsion time (standard mean difference =-0.39, 95% CI [−0.72, −0.05], P=0.02. Regarding safety, tamsulosin was associated with fewer complications than nifedipine (risk ratio =0.45, 95% CI [0.28, 0.72], P=0.0008, and further subgroup analysis showed that tamsulosin was associated with a lower risk of both mild and moderate-to-severe complications.Conclusion: On the bias of current evidence, tamsulosin showed an overall superiority to nifedipine for distal ureteral calculi <10 mm in aspects of expulsion rate, expulsion time, and safety. Tamsulosin was supposed to be the first drug to be recommended to patients willing to receive medical expulsive therapy.Keywords: tamsulosin, nifedipine, medical expulsive therapy, MET, lower urinary calculi

  19. Distal Ureteric Stones and Tamsulosin: A Double-Blind, Placebo-Controlled, Randomized, Multicenter Trial.

    Science.gov (United States)

    Furyk, Jeremy S; Chu, Kevin; Banks, Colin; Greenslade, Jaimi; Keijzers, Gerben; Thom, Ogilvie; Torpie, Tom; Dux, Carl; Narula, Rajan

    2016-01-01

    We assess the efficacy and safety of tamsulosin compared with placebo as medical expulsive therapy in patients with distal ureteric stones less than or equal to 10 mm in diameter. This was a randomized, double-blind, placebo-controlled, multicenter trial of adult participants with calculus on computed tomography (CT). Patients were allocated to 0.4 mg of tamsulosin or placebo daily for 28 days. The primary outcomes were stone expulsion on CT at 28 days and time to stone expulsion. There were 403 patients randomized, 81.4% were men, and the median age was 46 years. The median stone size was 4.0 mm in the tamsulosin group and 3.7 mm in the placebo group. Of 316 patients who received CT at 28 days, stone passage occurred in 140 of 161 (87.0%) in the tamsulosin group and 127 of 155 (81.9%) with placebo, a difference of 5.0% (95% confidence interval -3.0% to 13.0%). In a prespecified subgroup analysis of large stones (5 to 10 mm), 30 of 36 (83.3%) tamsulosin participants had stone passage compared with 25 of 41 (61.0%) with placebo, a difference of 22.4% (95% confidence interval 3.1% to 41.6%) and number needed to treat of 4.5. There was no difference in urologic interventions, time to self-reported stone passage, pain, or analgesia requirements. Adverse events were generally mild and did not differ between groups. We found no benefit overall of 0.4 mg of tamsulosin daily for patients with distal ureteric calculi less than or equal to 10 mm in terms of spontaneous passage, time to stone passage, pain, or analgesia requirements. In the subgroup with large stones (5 to 10 mm), tamsulosin did increase passage and should be considered. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  20. Comparative efficacy of tamsulosin versus tadalafil as medical expulsive therapy for distal ureteric stones.

    Science.gov (United States)

    Goyal, Suresh Kumar; Singh, Vikash; Pandey, Himanshu; Chhabra, Mahaveer Kumar; Aggarwal, Satinder Pal; Bhat, Amilal

    2018-01-01

    The objective of this study was to compare the relative efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteric stones. This was a prospective study performed between December 2014 and February 2016. A total of 123 adult patients (>18 years of age) presenting with distal ureteric stones sized 6-10 mm were randomized to treatment with tamsulosin 0.4 mg once daily (Group A) or tadalafil10 mg once daily (Group B). Therapy was given for a maximum of 4 weeks. The stone expulsion rate was the primary endpoint. Time to stone expulsion, number of colic episodes, analgesic use, number of hospital visits for pain, endoscopic treatment, and adverse effects of the drugs were noted. Statistical analyses were done using Fisher's exact test and Chi-square test. A total of 61 patients were included in tamsulosin group and 62 patients in tadalafil group. A statistically insignificant difference was found for stone clearance rate between both groups as a whole (Group A-73.77%, Group B-69.35%, P = 0.690) as well as when we considered both subgroups (A1-78.05%, B1-75.0%, P = 0.802; A2-65.0%, B2-55.6%, P = 0.741). All the primary and secondary outcome measures were more in favour of stones ≤8 mm size than stones >8 mm size. No statistical difference was found for adverse drug effects except for retrograde ejaculation, which was significantly high in tamsulosin group ( P tamsulosin is more effective for stone clearance than tadalafil, but this difference was not significant ( P = 0.690).

  1. Quality-of-Life Assessment After Palliative Interventions to Manage Malignant Ureteral Obstruction

    International Nuclear Information System (INIS)

    Monsky, Wayne Laurence; Molloy, Chris; Jin, Bedro; Nolan, Timothy; Fernando, Dayantha; Loh, Shaun; Li, Chin-Shang

    2013-01-01

    Purpose: Malignancies may cause urinary tract obstruction, which is often relieved with placement of a percutaneous nephrostomy tube, an internal double J nephro-ureteric stent (double J), or an internal external nephroureteral stent (NUS). We evaluated the affect of these palliative interventions on quality of life (QoL) using previously validated surveys. Methods: Forty-six patients with malignancy related ureteral obstruction received nephrostomy tubes (n = 16), double J stents (n = 15), or NUS (n = 15) as determined by a multidisciplinary team. QoL surveys were administered at 7, 30, and 90 days after the palliative procedure to evaluate symptoms and physical, social, functional, and emotional well-being. Number of related procedures, fluoroscopy time, and complications were documented. Kruskal–Wallis and Friedman’s test were used to compare patients at 7, 30, and 90 days. Spearman’s rank correlation coefficient was used to assess correlations between clinical outcomes/symptoms and QoL. Results: Responses to QoL surveys were not significantly different for patients receiving nephrostomies, double J stents, or NUS at 7, 30, or 90 days. At 30 and 90 days there were significantly higher reported urinary symptoms and pain in those receiving double J stents compared with nephrostomies (P = 0.0035 and P = 0.0189, respectively). Significantly greater fluoroscopy time was needed for double J stent–related procedures (P = 0.0054). Nephrostomy tubes were associated with more frequent minor complications requiring additional changes. Conclusion: QoL was not significantly different. However, a greater incidence of pain in those receiving double J stents and more frequent tube changes in those with nephrostomy tubes should be considered when choosing palliative approaches

  2. LAPAROSCOPIC RECONSTRUCTION OF THE URINARY TRACT IN PATIENTS WITH URETERAL STRICTURE AFTER KIDNEY TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    D. V. Perlin

    2013-01-01

    Full Text Available Aim. Ureteral obstruction secondary to ischemia is the most common urologic complication of kidney trans- plantation. Pyeloureteral anastomosis with recipient ureter has shown most satisfactory long-term results in its management. Existing urinary infection and immunosupression determine the high risk of wound complications. We have experience more than 50 reconstructive procedures of urinary tract after kidney transplantation by open surgery during 25 years. Till last time this procedure has been performed through open surgery. Method. We used pyeloureteral anastomosis with recipient ureter in two patients with ureteral stricture after kidney transplantation by laparoscopic approach. The operations lasted 215 and 275 min respectively. In both cases the surgery was per- formed after percutaneous nephrostomy because of deterioration of transplanted kidney function. Internal stent was indwelled laparoscopicaly. No drain tube was left. Results. The nephrostomy tubes were removed after 10 and 7 days respectively. The stents were removed after 27 and 20 days respectively. No complications were seen during the surgery and postoperative period. Now serum creatinine level is 0.12 mmol/l and 0.15 mmol/l after 15 and 12 months after surgery respectively. Conclusion. In spite of some difficulties related with topographic land- marks and severe tissues fibrosis after transplantation laparoscopic pyeloureterostomy in transplanted kidney is safe and feasible procedure. The main advantage is absence of risk of most serious complications related with wound infection in immune compromised patients. Moreover, early recovery to usual activity and diet facilita- tes to prevent pulmonary infections and to normalize intestinal absorbability of the immunosuppressive drugs. 

  3. Ureteric stent dwelling time: a risk factor for post-ureteroscopy sepsis.

    Science.gov (United States)

    Nevo, Amihay; Mano, Roy; Baniel, Jack; Lifshitz, David A

    2017-07-01

    To evaluate the association between stent dwelling time and sepsis after ureteroscopy, and identify risk factors for sepsis in this setting. The prospectively collected database of a single institution was queried for all patients who underwent ureteroscopy for stone extraction between 2010 and 2016. Demographic, clinical, preoperative and operative data were collected. The primary study endpoint was sepsis within 48 h of ureteroscopy. Logistic regressions were performed to identify predictors of post-ureteroscopy sepsis in the ureteroscopy cohort and specifically in patients with prior stent insertion. Between October 2010 and April 2016, 1 256 patients underwent ureteroscopy for stone extraction. Risk factors for sepsis included prior stent placement, female gender and Charlson comorbidity index. A total of 601 patients had a ureteric stent inserted before the operation and were included in the study cohort, in which the median age was 56 years, 90 patients were women (30%), and 97 patients were treated for positive preoperative urine cultures (16.1%). Postoperative sepsis, Sepsis rates after stent dwelling times of 1, 2, 3 and >3 months were 1, 4.9, 5.5 and 9.2%, respectively. On multivariate analysis, stent dwelling time, stent insertion because of sepsis, and female gender were significantly associated with post-ureteroscopy sepsis in patients with prior stent placement. Patients who undergo ureteroscopy after ureteric stent insertion have a higher risk of postoperative sepsis. Prolonged stent dwelling time, sepsis as an indication for stent insertion, and female gender are independent risk factors. Stent placement should be considered cautiously, and if inserted, ureteroscopy should be performed within 1 month. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  4. Quality-of-Life Assessment After Palliative Interventions to Manage Malignant Ureteral Obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Monsky, Wayne Laurence, E-mail: wemonsky@msn.com [University of Washington Medical Center, Department of Radiology (United States); Molloy, Chris; Jin, Bedro [University of California, Davis, School of Medicine (United States); Nolan, Timothy; Fernando, Dayantha; Loh, Shaun [University of California Davis Medical Center, Department of Radiology (United States); Li, Chin-Shang [University of California, Davis, Division of Biostatistics, Department of Public Health Sciences (Canada)

    2013-10-15

    Purpose: Malignancies may cause urinary tract obstruction, which is often relieved with placement of a percutaneous nephrostomy tube, an internal double J nephro-ureteric stent (double J), or an internal external nephroureteral stent (NUS). We evaluated the affect of these palliative interventions on quality of life (QoL) using previously validated surveys. Methods: Forty-six patients with malignancy related ureteral obstruction received nephrostomy tubes (n = 16), double J stents (n = 15), or NUS (n = 15) as determined by a multidisciplinary team. QoL surveys were administered at 7, 30, and 90 days after the palliative procedure to evaluate symptoms and physical, social, functional, and emotional well-being. Number of related procedures, fluoroscopy time, and complications were documented. Kruskal-Wallis and Friedman's test were used to compare patients at 7, 30, and 90 days. Spearman's rank correlation coefficient was used to assess correlations between clinical outcomes/symptoms and QoL. Results: Responses to QoL surveys were not significantly different for patients receiving nephrostomies, double J stents, or NUS at 7, 30, or 90 days. At 30 and 90 days there were significantly higher reported urinary symptoms and pain in those receiving double J stents compared with nephrostomies (P = 0.0035 and P = 0.0189, respectively). Significantly greater fluoroscopy time was needed for double J stent-related procedures (P = 0.0054). Nephrostomy tubes were associated with more frequent minor complications requiring additional changes. Conclusion: QoL was not significantly different. However, a greater incidence of pain in those receiving double J stents and more frequent tube changes in those with nephrostomy tubes should be considered when choosing palliative approaches.

  5. Hybrid III-V Silicon Lasers

    Science.gov (United States)

    Bowers, John

    2014-03-01

    Abstract: A number of important breakthroughs in the past decade have focused attention on Si as a photonic platform. We review here recent progress in this field, focusing on efforts to make lasers, amplifiers, modulators and photodetectors on or in silicon. We also describe optimum quantum well design and distributed feedback cavity design to reduce the threshold and increase the efficiency and power output. The impact active silicon photonic integrated circuits could have on interconnects, telecommunications and on silicon electronics is reviewed. Biography: John Bowers holds the Fred Kavli Chair in Nanotechnology, and is the Director of the Institute for Energy Efficiency and a Professor in the Departments of Electrical and Computer Engineering and Materials at UCSB. He is a cofounder of Aurrion, Aerius Photonics and Calient Networks. Dr. Bowers received his M.S. and Ph.D. degrees from Stanford University and worked for AT&T Bell Laboratories and Honeywell before joining UC Santa Barbara. Dr. Bowers is a member of the National Academy of Engineering and a fellow of the IEEE, OSA and the American Physical Society. He is a recipient of the OSA/IEEE Tyndall Award, the OSA Holonyak Prize, the IEEE LEOS William Streifer Award and the South Coast Business and Technology Entrepreneur of the Year Award. He and coworkers received the EE Times Annual Creativity in Electronics (ACE) Award for Most Promising Technology for the hybrid silicon laser in 2007. Bowers' research is primarily in optoelectronics and photonic integrated circuits. He has published ten book chapters, 600 journal papers, 900 conference papers and has received 54 patents. He has published 180 invited papers and conference papers, and given 16 plenary talks at conferences. As well as Chong Zhang.

  6. II-VI/III-V Heterojunction Lasers

    National Research Council Canada - National Science Library

    Gunshor, Robert

    1999-01-01

    ... in both. In the second part of the program we studied the growth and the optical evaluation of wide bandgap nitride heterostructures, an effort which included the first reporting of a GaN-based laser to be fabricated...

  7. Efficacy and Safety of Alfuzosin as Medical Expulsive Therapy for Ureteral Stones: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Chenli Liu

    Full Text Available Alfuzosin has been widely used to treat benign prostatic hyperplasia and prostatitis, and is claimed to be a selective agent for the lower urinary tract with low incidence of adverse side-effects and hypotensive changes. Recently, several randomized controlled trials have reported using Alfuzosin as an expulsive therapy of ureteral stones. Tamsulosin, another alpha blocker, has also been used as an agent for the expulsive therapy for ureteral stones. It is unclear whether alfuzosin has similar efficacy as Tamsulosin in the management of ureteral stones.To perform a systematic review and analysis of literatures comparing Alfuzosin with Tamsulosin or standard conservative therapy for the treatment of ureteral stones less than 10 mm in diameter.A systematic literature review was performed in December 2014 using Pubmed, Embase, and the Cochrane library databases to identify relevant studies. All randomized and controlled trials were included. A subgroup analysis was performed comparing Alfuzosin with control therapy on the management of distal ureteral stones.Alfuzosin provided a significantly higher stone-free rate than the control treatments (RR: 1.85; 95% confidence interval [CI], 1.35-2.55; p<0.001, and a shorter stone expulsion time (Weighted mean difference [WMD]: -4.20 d, 95%CI, -6.19 to -2.21; p<0.001, but it has a higher complication rate (RR: 2.02; 95% CI, 1.30-3.15; p<0.01. When Alfuzosin was compared to Tamsulosin, there was no significant difference in terms of stone-free rate (RR: 0.90; 95% CI, 0.79-1.02; p = 0.09 as well as the stone expulsion time (WMD: 0.52 d, 95%CI, -1.61 to 2.64; p = 0.63. The adverse effects of Alfuzosin were similar to those of Tamsulosin (RR: 0.88; 95% CI, 0.61-1.26; p = 0.47.Alfuzosin is a safe and effective agent for the expulsive therapy of ureteral stones smaller than 10 mm in size. It is more effective than therapeutic regiment without alpha blocker. It is equivalent to Tamsulosin in its effectiveness and

  8. The effect and influence of lumen holmium laser lithotripsy on serum oxidative stress proteins and inflammatory factors of ureteral calculi patients

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2016-09-01

    Full Text Available Objective: To investigate the effect and influence of lumen holmium laser lithotripsy on treating serum oxidative stress proteins and inflammatory factors of patients with ureteral calculi. Methods: A total of 120 cases of patients with ureteral calculi treated in our hospital from May 2010 to Nov 2014 were enrolled in this research for an analysis study. The effect and influence on serum oxidative stress proteins and inflammatory factors of lumen holmium laser lithotripsy on ureteral calculi patients were assayed. Then 120 cases of healthy subjects in our hospital at the same period were taken as control. Results: Among the 120 cases of ureteral calculi patients, 113 cases of patients showed successful operation, with a success rate of 94.2%. The average calculi-discharged time was (28.4 ± 11.2 d and the average operation time was (58.9 ± 10.7 min, while the postoperative hospital stay is (3.8 ± 1.2 d. The results also showed that the levels of NOX1. NOX3, NOX4 and NOX5, and levels of interleukin-2 (IL-2, IL-6, IL-10 and TNF-α of patients with ureteral calculi were significantly higher, compared with the control group, and these parameters were normalized greatly after operation with that the levels of them were significantly different from those before operation. Conclusion: Lumen holmium laser lithotripsy exerts a significant effect on ureteral calculi patients and the oxidative stress parameters and inflammatory factor were normalized greatly.

  9. Synthesis, characterization, spectroscopic and catalytic oxidation studies of Fe(III), Ni(II), Co(III), V(IV) and U(VI) Schiff base complexes with N, O donor ligands derived from 2,3-diaminopyridine

    Energy Technology Data Exchange (ETDEWEB)

    Zabardasti, Abedien; Shangaie, Sayed Asad [Lorestan Univ., Khorramabad (Iran, Islamic Republic of). Dept. of Chemistry

    2016-10-15

    Fifteen new complexes of transition metals were designed using three Schiff base ligands and aldol condensation of 2,3-diaminopyridine with 5-R-2-hydroxybenzaldehyde (R = F, Cl, Br) in the 1:2 molar ratio. The tetradentate ligands N,N{sup '}-bis(5-R-2-hydroxybenzaldehyde) pyridine were acquired with the common formula H{sub 2}[(5-R-sal){sub 2}py] and characterized by IR, UV-Vis spectra, {sup 1}H-NMR and elemental analysis. These ligands produce 1:1 complexes M[(5-R-sal){sub 2}py] with Fe(III), Ni(II), Co(III), V(IV) and U(VI) metal ions. The electronic property and nature of complexes were identified by IR, UV-Vis spectra, elemental analysis, X-ray crystallography and cyclic voltammetric methods. The catalytic activity of complexes for epoxidation of styrene with UHP as primary oxidant at minimal temperature (10 C) has been planned. The spectral data of the ligands and their complexes are deliberate in connection with the structural changes which happen due to complex preparation. The electrochemical outcome has good conformability with what suggested for electronic interaction among metal center and ligand by the UV-Vis and IR measurements.

  10. Laparoscopic bilateral nephroureterectomy and bladder cuff excision for native renal pelvic and ureteral transitional cell carcinoma after renal transplantation.

    Directory of Open Access Journals (Sweden)

    Chen C

    2003-01-01

    Full Text Available A 37-years-old female who was suffering from end-stage renal disease for about 6 years received allograft renal transplantation 4 years ago. She has been receiving 50mg of Cyclosporin A orally daily for immuno-suppression since then. Gross haematuria was noted and computerised tomography showed native left renal pelvic and ureteral multi-focal transitional cell carcinoma with severe hydronephrosis. Laparoscopic bilateral nephroureterectomy and bladder cuff excision were performed. In the past, history of previous operation was considered a relative contraindication for laparoscopic surgery. To our knowledge, we present the first case of laparoscopic treatment for native renal pelvic and ureteral transitional cell carcinoma after renal allograft transplantation without a hand-assisted device. This case shows the feasibility of laparoscopic bilateral nephroureterectomy in patients with transplanted kidneys.

  11. Interkinetic nuclear migration in the mouse embryonic ureteric epithelium: Possible implication for congenital anomalies of the kidney and urinary tract.

    Science.gov (United States)

    Motoya, Tomoyuki; Ogawa, Noriko; Nitta, Tetsuya; Rafiq, Ashiq Mahmood; Jahan, Esrat; Furuya, Motohide; Matsumoto, Akihiro; Udagawa, Jun; Otani, Hiroki

    2016-05-01

    Interkinetic nuclear migration (INM) is a phenomenon in which progenitor cell nuclei migrate along the apico-basal axis of the pseudostratified epithelium, which is characterized by the presence of apical primary cilia, in synchrony with the cell cycle in a manner of apical mitosis. INM is suggested to regulate not only stem/progenitor cell proliferation/differentiation but also organ size and shape. INM has been reported in epithelia of both ectoderm and endoderm origin. We examined whether INM exists in the mesoderm-derived ureteric epithelium. At embryonic day (E) 11.5, E12.5 and E13.5, C57BL/6J mouse dams were injected with 5-bromo-2'-deoxyuridine (BrdU) and embryos were killed 1, 2, 4, 6, 8, 10 and 12 h later. We immunostained transverse sections of the ureter for BrdU, and measured the position of BrdU (+) nuclei in the ureteric epithelia along the apico-basal axis at each time point. We analyzed the distribution patterns of BrdU (+) nuclei in histograms using the multidimensional scaling. Changes in the nucleus distribution patterns suggested nucleus movement characteristic of INM in the ureteric epithelia, and the mode of INM varied throughout the ureter development. While apical primary cilia are related with INM by providing a centrosome for the apical mitosis, congenital anomalies of the kidney and urinary tract (CAKUT) include syndromes linked to primary ciliary dysfunction affecting epithelial tubular organs such as kidney, ureter, and brain. The present study showed that INM exists in the ureteric epithelium and suggests that INM may be related with the CAKUT etiology via primary ciliary protein function. © 2015 Japanese Teratology Society.

  12. Current practices in the management of patients with ureteral calculi in the emergency room of a university hospital

    Directory of Open Access Journals (Sweden)

    Oliver Rojas Claros

    2012-01-01

    Full Text Available OBJECTIVE: Urinary lithiasis is a common disease. The aim of the present study is to assess the knowledge regarding the diagnosis, treatment and recommendations given to patients with ureteral colic by professionals of an academic hospital. MATERIALS AND METHODS: Sixty-five physicians were interviewed about previous experience with guidelines regarding ureteral colic and how they manage patients with ureteral colic in regards to diagnosis, treatment and the information provided to the patients. RESULTS: Thirty-six percent of the interviewed physicians were surgeons, and 64% were clinicians. Forty-one percent of the physicians reported experience with ureterolithiasis guidelines. Seventy-two percent indicated that they use noncontrast CT scans for the diagnosis of lithiasis. All of the respondents prescribe hydration, primarily for the improvement of stone elimination (39.3%. The average number of drugs used was 3.5. The combination of nonsteroidal anti-inflammatory drugs and opioids was reported by 54% of the physicians (i.e., 59% of surgeons and 25.6% of clinicians used this combination of drugs (p = 0.014. Only 21.3% prescribe alpha blockers. CONCLUSION: Reported experience with guidelines had little impact on several habitual practices. For example, only 21.3% of the respondents indicated that they prescribed alpha blockers; however, alpha blockers may increase stone elimination by up to 54%. Furthermore, although a meta-analysis demonstrated that hydration had no effect on the transit time of the stone or on the pain, the majority of the physicians reported that they prescribed more than 500 ml of fluid. Dipyrone, hyoscine, nonsteroidal anti-inflammatory drugs, and opioids were identified as the most frequently prescribed drug combination. The information regarding the time for the passage of urinary stones was inconsistent. The development of continuing education programs regarding ureteral colic in the emergency room is necessary.

  13. PERCUTANEOUS NEPHROSTOMY AND DOUBLE PIGTAIL (JJ URETERAL STENTS AS TEMPORARY METHODS IN SOLVING SUPRAVESICAL OBSTRUCTION CAUSED BY STONE

    Directory of Open Access Journals (Sweden)

    Ljubomir Dinić

    2015-08-01

    Full Text Available Percutaneous nephrostomy and ureteral stenting are temporary treatments for the upper urinary tract obstruction. The aim of this study was to evaluate the efficacy of these two methods by comparing complications, placement success, urinary symptoms, urine culture analyses prior to derivation placement and derivation removal and success of stone elimination after extracorporeal shock wave lithotripsy (ESWL. This prospective study included 157 patients with supravesical obstruction caused by ureteral stones. Eighty-one patients underwent percutaneus nephrostomy, and JJ stent was inserted in seventy-six (76 patients. After resolving the obstruction, ESWL was performed in all patients. There were no statistically significant differences in success of the urinary derivation placement, the urine culture results before and after placement and success of ESWL treatment between the two studied groups (p>0.05. Urinary symptoms (dysuria, hematuria, urinary urgency, frequent urination during the day were significantly more present in patients with a JJ stent and this difference was statistically significant for each symptom (p<0.001. Major complications were verified in 2 (2.46% patients with PCN catheter, and in 7 (9.2% patients in the group with the JJ stent. Minor complications were significantly more frequent in the group with the JJ stent compared to the group with PCN catheter (28.39% vs 60.52%, p<0.001. Percutaneous nephrostomy and JJ stenting are optimal methods for temporary treatment of supravesical obstruction caused by ureteral stones, with similar incidence of the following complications, except for the pain, which dominates in patients with the JJ stent. Urinary symptoms and asymptomatic bacteriuria are more common in patients with the JJ stent. If the ESWL treatment of ureteral stone is performed after urinary derivation placement, we can expect greater success in patients with the JJ stent.

  14. Treatment of distal ureteric stones-comparative efficacy of transureteral pneumatic lithotripsy and extracorporeal shock wave lithotripsy

    International Nuclear Information System (INIS)

    Wazir, B.G.; Nawaz, A.; Orakzai, A.N.

    2015-01-01

    Ureteric stones greater than 6mm require intervention. Extracorporeal shockwave lithotripsy (ESWL) and ureteroscopy (URS) with intra-corporeal lithotripsy (ICL) are two least invasive therapies. Both show acceptable stone clearance. What should be the first line of treatment in distal ureteric stones. We conducted this study to compare the efficacy of ESWL and pneumatic ICL in order to develop clear cut treatment guidelines. Methods: This randomized control trial was conducted at Institute of Kidney Diseases, Peshawar from June 2011 to June 2012. Two hundred and twenty-four patients with distal ureteric stones 6-12 mm in size were included. Patients were randomized into two groups. Group-A patients were treated with URS plus ICL and Group-B with ESWL. Patients were evaluated for stone clearance after 2 weeks, with X-ray KUB and ultrasound. All the data were recorded in a proforma and analysed in SPSS 10. Fisher's exact test was applied to compare the efficacy and a p-value of 0.05 was considered significant. Results: Out of 112 patients in Group-A, 75 (67%) were males and 37 (33%) were females while in Group-B 79 (70.5%) were males and 33 (29.5%) were females. The mean age in Group-A was, 48.73 ± 16.23 years whereas it was 6 ± 14.58 years in Group-B. Overall, mean age was 47.36 ± 15.4 years. Mean stone size was 9.18 ± 1.6 mm. At follow up (2 weeks post-operative) URS with ICL was successful in 101 (90.2%) patients while ESWL was successful in 75 (67%) patients (p-value=0.0001). Conclusion: Extracorporeal shockwave lithotripsy shows acceptable stone clearance but ureteroscopy with intra-corporeal lithotripsy shows superior results in distal ureteric stones. (author)

  15. Comparison of secondary signs as shown by unenhanced helical computed tomography in patients with uric acid or calcium ureteral stones

    Directory of Open Access Journals (Sweden)

    Yii-Her Chou

    2012-06-01

    Full Text Available Unenhanced helical computed tomography (UHCT has evolved into a well-accepted diagnostic method in patients with suspected ureterolithiasis. UHCT not only shows stones within the lumen of the ureter, it also permits evaluation of the secondary signs associated with ureteral obstruction from stones. However, there we could find no data on how secondary signs might differ in relation to different compositions of ureteral stones. In this study, we compared the degree of secondary signs revealed by UHCT in uric acid stone formers and in patients forming calcium stones. We enrolled 117 patients with ureteral stones who underwent UHCT examination and Fourier transform infra-red analysis of stone samples. Clinical data were collected as follows: age, sex, estimated glomerular filtration rate (eGFR, urine pH, and radiological data on secondary signs apparent on UHCT. The uric acid stone formers had significantly lower urine pH and eGFR in comparison to calcium stone formers, and on UHCT they also had a higher percentage of the secondary signs, including rim sign (78.9% vs. 60.2%, hydroureter (94.7% vs. 89.8%, perirenal stranding (84.2% vs. 59.2% and kidney density difference (73.7% vs. 50.0%. The radiological difference was statistically significant for perirenal stranding (p=0.041. In conclusion, we found that UHCT scanning reveals secondary signs to be more frequent in patients with uric acid ureteral stones than in patients with calcium stones, a tendency that might result from an acidic urine environment.

  16. Analysis and evaluation for practical application of photovoltaic power generation system. Analysis and evaluation for development of extra-high efficiency solar cells (fundamental research on extra-high efficiency III-V compound semiconductor tandem solar cells); Taiyoko hatsuden system jitsuyoka no tame no kaiseki hyoka. Chokokoritsu taiyo denchi no gijutsu kaihatsu no tame no kaiseki hyoka (chokokoritsu III-V zoku kagobutsu taiyo denchi gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    Sekikawa, T; Kawanami, H; Sakata, I; Nagai, K; Matsumoto, K; Miki, K [Electrotechnical Laboratory, Tsukuba (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for development of extra-high efficiency III-V compound semiconductor tandem solar cells. Heteroepitaxial structures of compound semiconductors, such as GaAs, on silicon substrates are analyzed and evaluated by EXAFS, Raman and RHEED for the initial stage of the film growth and heterointerfaces. The device capable of in-situ observation of the growing surface structures during the period of heteroepitaxial film growth is introduced, to investigate the effects of rise-up and initial growth conditions on defects. The effects of atomic hydrogen on growth of a GaAs film on a silicon substrate are investigated from photoluminescence and solar cell characteristics, to confirm the effects of reducing defects. Heteroepitaxial growth of InGaP, which has the optimum band width for forming multi-junction silicon solar cells, on a silicon substrate is investigated, to find that an interfacial buffer layer is necessary to form a good film. 2 figs.

  17. Symptomatic small non-obstructing lower ureteric calculi: comparison of ureteroscopy and extra corporeal shock wave lithotripsy.

    Directory of Open Access Journals (Sweden)

    Andankar M

    2001-07-01

    Full Text Available OBJECTIVE: To compare the success, efficacy and complications of ureteroscopy (URS and extra corporeal shock wave lithotripsy (ESWL for the treatment of symptomatic small non obstructing lower ureteric calculi. SUBJECTS AND METHODS: This prospective non-randomised study was conducted simultaneously at two urological referral centres, included 280 patients with symptomatic small (4-10 mm lower ureteric calculi (situated below the sacroiliac joint, with good renal function on intravenous urography. Patients were offered both the treatment options. One hundred and sixty patients chose ureteroscopy, whereas 120 patients were treated by ESWL. Standard techniques of ureteroscopy and ESWL were employed. Patients were followed-up to assess the success rates and complications of the two procedures. RESULTS: Ureteroscopy achieved complete stone clearance in one session in 95% of patients. In six patients ureteroscopy had failed initially and was later accomplished in second session improving the success rate to 98.7%. Two patients had a proximal migration of calculus that needed ESWL. Of the 120 patients treated by ESWL, 90% achieved stone free status at three months. Ureteroscopy was needed for twelve patients (10% where ESWL failed to achieve stone clearance. There were no significant ESWL related complications. ESWL was administered on outpatient basis, while patients needed hospitalisation and anaesthesia for ureteroscopy. CONCLUSION: ESWL can be the primary mode of treatment for symptomatic small non-obstructing lower ureteric calculi as it is minimally invasive and safe. Ureteroscopy can be offered to patients who demand immediate relief or when ESWL fails.

  18. Suspected ureteral colic: plain film and sonography vs unenhanced helical CT. A prospective study in 66 patients

    Energy Technology Data Exchange (ETDEWEB)

    Ripolles, Tomas; Agramunt, Marcos; Errando, Jose; Martinez, Maria Jesus [Department of Radiology, Hospital Universitario Dr. Peset, 90 Gaspar Aguilar Avenue, 46017, Valencia (Spain); Coronel, Belen [Department of Urology, Hospital Universitario Dr. Peset, 90 Gaspar Aguilar Avenue, 46017, Valencia (Spain); Morales, Maria [Research Unit, Hospital Universitario Dr. Peset, 90 Gaspar Aguilar Avenue, 46017, Valencia (Spain)

    2004-01-01

    The aim of this study was to compare the sensitivity and specificity of plain abdominal films plus ultrasound, vs nonenhanced CT for the diagnosis of ureteral colic in patients with acute flank pain. During a 4-month period, 66 patients (mean age 48 years) with acute flank pain were prospectively studied by means of plain abdominal film, US, and unenhanced CT. The presence of lithiasis and of obstructive uropathy signs were determined. The plain film was only used as a guide for the US exam. Clinical follow-up of all patients was obtained. Ureteral lithiasis was confirmed in 56 patients. The CT had a greater sensitivity (93 vs 79%) and negative predictive value (71 vs 46%) for the detection of lithiasis. The combination of lithiasis plus obstructive signs showed a sensitivity and a specificity of 100% for CT and of 100 and 90%, respectively, for US. The 11 lithiasis not detected by US were passed spontaneously (10 were <5 mm). Both techniques showed similar extraurinary pathology. Computed tomography is the most accurate technique for the detection of ureteral lithiasis; however, the combination of plain film and US is an alternative to nonenhanced CT with a lower sensitivity and radiation dose that has a good practical value. (orig.)

  19. Non-Contrast Computed Tomography Scan Based Parameters of Ureteric Stones Affecting the Outcome of Extracorporeal Shock Wave Lithotripsy

    Science.gov (United States)

    Ayaz Khan, Mohammad; Waqas Iqbal, Muhammad; Akbar, Mian Khalid; Saqib, Imad-ud-din; Akhter, Saeed

    2017-01-01

    Objective  To compare the non-contrast computed tomography (NCCT) scan-based parameters of ureteric stones affecting the outcome of extracorporeal shock wave lithotripsy (ESWL). Materials and methods We retrospectively evaluated the pre-procedure NCCT of 74 patients who had ESWL for solitary ureteric calculi of 5-20 mm in diameter. We assessed the age, sex, basal metabolic index (BMI), laterality, location, presence of double 'J' (DJ) stent, skin to stone distance (SSD), stone maximum diameter, Hounsfield unit (HU), Hounsfield density (HD), area, and volume. All those who had no stone on follow-up imaging within 30 days were declared successful while those who had residual stone were declared failures. Results The overall success rate was 78% (58/74). Sixty (81.1%) patients were male. The success of ESWL was correlated with lower SSD, Hounsfield units (HU) and Hounsfield density (HD). However, in multivariate analysis, SSD, Hounsfield unit, and stone area showed correlation with success of procedure but Hounsfield density failed to show correlation. The success rate in patients with stone HU 1000 were 93.9%, 69%, and 58.3%, respectively. Patients with lower BMI (30 kg/m2) and higher HD (>76 HU/mm). Conclusion BMI, SSD, stone Hounsfield units and Hounsfield unit density were strong predictors of outcome of ESWL for ureteric stone. PMID:28589076

  20. Efficacy and Safety of Tamsulosin in Medical Expulsive Therapy for Distal Ureteral Stones with Renal Colic: A Multicenter, Randomized, Double-blind, Placebo-controlled Trial.

    Science.gov (United States)

    Ye, Zhangqun; Zeng, Guohua; Yang, Huan; Tang, Kun; Zhang, Xiaochun; Li, Hong; Li, Weibing; Wu, Zhong; Chen, Lingwu; Chen, Xingfa; Liu, Xiankui; Deng, Yaoliang; Pan, Tiejun; Xing, Jinchun; Wang, Shusheng; Cheng, Yue; Gu, Xiaojian; Gao, Wenxi; Yang, Jianggen; Zhang, Yonghai; Mi, Qiwu; Qi, Lin; Li, Jiongming; Hu, Weilie; Liang, Peiyu; Sun, Zhaolin; Xu, Changbao; Long, Yongfu; Liao, Yongbin; Liu, Siping; Liu, Guoqing; Xu, Xun; He, Wei; Chen, Zhiqiang; Xu, Hua

    2017-11-12

    Recent large high-quality trials have questioned the clinical effectiveness of medical expulsive therapy using tamsulosin for ureteral stones. To evaluate the efficacy and safety of tamsulosin for distal ureteral stones compared with placebo. We conducted a double-blind, placebo-controlled study of 3296 patients with distal ureteral stones, across 30 centers, to evaluate the efficacy and safety of tamsulosin. Participants were randomly assigned (1:1) into tamsulosin (0.4mg) or placebo groups for 4 wk. The primary end point of analysis was the overall stone expulsion rate, defined as stone expulsion, confirmed by negative findings on computed tomography, over a 28-d surveillance period. Secondary end points included time to stone expulsion, use of analgesics, and incidence of adverse events. Among 3450 patients randomized between September 1, 2011, and August 31, 2013, 3296 (96%) were included in the primary analysis. Tamsulosin benefits from a higher stone expulsion rate than the placebo (86% vs 79%; ptamsulosin for the treatment of large distal ureteral stones (>5mm). Considering the secondary end points, tamsulosin-treated patients reported a shorter time to expulsion (ptamsulosin use benefits distal ureteral stones in facilitating stone passage and relieving renal colic. Subgroup analyses find that tamsulosin provides a superior expulsion rate for stones >5mm, but no effect for stones ≤5mm. In this report, we looked at the efficacy and safety of tamsulosin for the treatment of distal ureteral stones. We find that tamsulosin significantly facilitates the passage of distal ureteral stones and relieves renal colic. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.