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Sample records for junction upj obstruction

  1. Congenital right sided ureteropelvic junction obstruction in right ...

    African Journals Online (AJOL)

    V. Singh

    Congenital right sided ureteropelvic junction obstruction in right crossed ... Peer review under responsibility of Pan African Urological Surgeons' Asso- ciation. ... There was large gap between the UPJ and the .... relationship to renal disease.

  2. Laparoscopic treatment of UPJ obstruction in ectopic pelvic kidneys in children

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    A. Marte

    2012-10-01

    Full Text Available Aims: to assess the feasibility and safety of a laparoscopic approach to uPJ obstruction (uPJo in ectopic pelvic kidneys. Material and Methods: in a retrospective analysis we selected 14 children, aged 6months to 17 years, 12 males, 2 females, who had been treated in our department between January 2004 and June 2011. 9 patients presented ureteropelvic junction obstruction (in 3 cases pelvic stones coexisted with normal/moderately reduced (≥25% relative function at radionuclide scan (MAg3, 3 nonfunctioning kidneys associated or not to hypertension, 2 congenital hypo-dysplastic kidneys. the evaluation of each patient involved the medical history, ultrasound examination, VCug, MAg3 diuresis renogram and Mri in some cases. of the patients presenting uPJo, 5 underwent dismembered pyeloplasty with pyelolithotomy, if required, and 4 pelvic derotation with straightening of the uretero-pelvic junction. A previous cystoscopic placement of a double J stent was utilized. this facilitated the identification and dissection around the pelvis. With the patient in trendelenburg position we utilized an umbilical trocar and two trocar in the right and left iliac fossae; an additional trocar, when required, was inserted more cephalad on the midclavear line contralaterally to the lesion. the derotation of ureteropelvic junction was obtained by freeing the kidney’s lower pole and by placing intraperitoneally the junction protected with a double J stent. this was obtained by suturing the peritoneum behind the ureteropelvic junction resulting in a forward rotation of the major axis of the kidney and a straightening of the junction. the 5 patients presenting nonfunctioning ectopic kidneys underwent laparoscopic nephrectomy. While the removal of congenital hypoplasic kidneys resulted easy, the removal of nonfunctioning kidneys was more difficult due to their complex vascular situation and for the embryonic disposition. Results: the operating time varied between 40 to

  3. UPJ obstruction

    Science.gov (United States)

    ... chap 40. Read More Abdominal mass Acute kidney failure Fever Hydronephrosis of one kidney Renal Ultrasound pregnancy Urinary tract infection - adults Urine - bloody Review Date 6/29/2015 Updated by: Jennifer Sobol, ...

  4. Pediatric ureteropelvic junction obstruction: can magnetic resonance urography identify crossing vessels?

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    Parikh, Kushal R.; Kraft, Kate H.; Ivancic, Vesna; Smith, Ethan A.; Dillman, Jonathan R. [Section of Pediatric Radiology, Mott Children' s Hospital, Department of Radiology, University of Michigan Health System, Ann Arbor, MI (United States); Hammer, Matthew R. [University of Texas Southwestern, Department of Radiology, Dallas, TX (United States)

    2015-11-15

    MR Urography (MRU) is an increasingly used imaging modality for the evaluation of pediatric genitourinary obstruction. To determine whether pediatric MR urography (MRU) reliably detects crossing vessels in the setting of suspected ureteropelvic junction (UPJ) obstruction. The clinical significance of these vessels was also evaluated. We identified pediatric patients diagnosed with UPJ obstruction by MRU between May 2009 and June 2014. MRU studies were evaluated by two pediatric radiologists for the presence or absence of crossing vessels. Ancillary imaging findings such as laterality, parenchymal thinning/scarring, trapped fluid in the proximal ureter, and presence of renal parenchymal edema were also evaluated. Imaging findings were compared to surgical findings. We used the Mann-Whitney U test to compare continuous data and the Fisher exact test to compare proportions. Twenty-four of 25 (96%) UPJ obstructions identified by MRU were surgically confirmed. MRU identified crossing vessels in 10 of these cases, with 9 cases confirmed intraoperatively (κ = 0.92 [95% CI: 0.75, 1.0]). Crossing vessels were determined to be the primary cause of UPJ obstruction in 7/9 children intraoperatively, while in two children the vessels were deemed incidental and noncontributory to the urinary tract obstruction. There was no significant difference in age or the proportions of ancillary findings when comparing children without and with obstructing vessels. MRU allows detection of crossing vessels in pediatric UPJ obstruction. Although these vessels are the primary cause of obstruction in some children, they are incidental and non-contributory in others. Our study failed to convincingly identify any significant predictors (e.g., age or presence of renal parenchymal edema) that indicate when a crossing vessel is the primary cause of obstruction. (orig.)

  5. Pediatric ureteropelvic junction obstruction: can magnetic resonance urography identify crossing vessels?

    Science.gov (United States)

    Parikh, Kushal R; Hammer, Matthew R; Kraft, Kate H; Ivančić, Vesna; Smith, Ethan A; Dillman, Jonathan R

    2015-11-01

    MR Urography (MRU) is an increasingly used imaging modality for the evaluation of pediatric genitourinary obstruction. To determine whether pediatric MR urography (MRU) reliably detects crossing vessels in the setting of suspected ureteropelvic junction (UPJ) obstruction. The clinical significance of these vessels was also evaluated. We identified pediatric patients diagnosed with UPJ obstruction by MRU between May 2009 and June 2014. MRU studies were evaluated by two pediatric radiologists for the presence or absence of crossing vessels. Ancillary imaging findings such as laterality, parenchymal thinning/scarring, trapped fluid in the proximal ureter, and presence of renal parenchymal edema were also evaluated. Imaging findings were compared to surgical findings. We used the Mann-Whitney U test to compare continuous data and the Fisher exact test to compare proportions. Twenty-four of 25 (96%) UPJ obstructions identified by MRU were surgically confirmed. MRU identified crossing vessels in 10 of these cases, with 9 cases confirmed intraoperatively (κ = 0.92 [95% CI: 0.75, 1.0]). Crossing vessels were determined to be the primary cause of UPJ obstruction in 7/9 children intraoperatively, while in two children the vessels were deemed incidental and noncontributory to the urinary tract obstruction. There was no significant difference in age or the proportions of ancillary findings when comparing children without and with obstructing vessels. MRU allows detection of crossing vessels in pediatric UPJ obstruction. Although these vessels are the primary cause of obstruction in some children, they are incidental and non-contributory in others. Our study failed to convincingly identify any significant predictors (e.g., age or presence of renal parenchymal edema) that indicate when a crossing vessel is the primary cause of obstruction.

  6. Concurrent management of bilateral ureteropelvic junction obstruction in children using robotic-assisted laparoscopic surgery

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    Drew A. Freilich

    2008-03-01

    Full Text Available INTRODUCTION: Bilateral ureteropelvic junction (UPJ obstruction occurs infrequently. When surgical management is deemed necessary, staged pyeloplasties traditionally have been recommended to minimize the morbidity associated with performing procedures concurrently. With the advent of robotic-assistance, concurrent surgical management can more readily be performed laparoscopically. In this report, we evaluated the safety and outcome of managing patients with bilateral UPJ obstruction with concurrent robotic-assisted laparoscopic pyeloplasty. MATERIALS AND METHODS: We performed a retrospective review of five patients with bilateral ureteropelvic junction obstruction who underwent concurrent bilateral robotic-assisted pyeloplasties at our institution between October 2003 and April 2007. Technical consideration for patient positioning, robotic set-up, port placement, and the use of a hitch stitches was assessed. The operative time, complications, analgesic needs, length of hospitalization, and overall success of the procedure were evaluated. RESULTS: Operative time ranged from 235 to 541 minutes (mean = 384. Estimated blood loss was 5-100 cc (mean = 48.0. Length of hospitalization ranged from 1.3 to 3.6 days (mean = 2.4. Ureteral stents were removed 3-8 weeks postoperatively. There were no complications. All kidneys demonstrated decreased hydronephrosis on postoperative ultrasound or improved drainage parameters on diuretic renography or IVP. CONCLUSIONS: Simultaneous bilateral robotic-assisted laparoscopic pyeloplasties utilizing 4-port access is feasible and safe. It provides an effective method of managing patients with bilateral UPJ obstruction, avoiding the burden and morbidity of performing staged surgeries.

  7. Contrast-enhanced magnetic resonance angiography for the detection of crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with operative findings

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    Calder, Alistair D.; Hiorns, Melanie P.; Olsen, Oystein E. [Hospital for Children NHS Trust, Department of Radiology, London (United Kingdom); Abhyankar, Aruna; Mushtaq, Imran [Hospital for Children NHS Trust, Department of Urology, London (United Kingdom)

    2007-04-15

    Crossing renal vessels (CRV) are associated with ureteropelvic junction (UPJ) obstruction, particularly when presentation is beyond the neonatal period. Their presence may influence surgical management. To evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in the identification of CRV in children requiring surgical treatment of symptomatic UPJ obstruction, against a gold standard of laparoscopic or open surgical findings. We reviewed CE-MRA studies (3-D T2-weighted turbo spin-echo and multiphase 3-D spoiled gradient echo following intravenous gadolinium administration) of 14 children, age range 6-15 years, performed prior to surgery for suspected CRV-related UPJ obstruction. Consensus reviews of the CE-MRA studies were compared with surgical findings. CE-MRA demonstrated CRV at the level of the obstruction in nine and no crossing vessels in five children. These were all verified intraoperatively ({chi}{sup 2} = 14.0; P < 0.001). In eight of the nine patients with CRV there was no evidence of intrinsic obstruction at surgery. In the remaining patient there was fibrosis of the upper ureter. CE-MRA is an accurate means of identifying CRV in children older than 6 years with symptomatic UPJ obstruction. (orig.)

  8. Minimally Invasive Pyeloplasty in Horseshoe Kidneys with Ureteropelvic Junction obstruction: A case series

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    Stephen Faddegon

    2013-04-01

    Full Text Available Background and Purpose Horseshoe kidney is an uncommon renal anomaly often associated with ureteropelvic junction (UPJ obstruction. Advanced minimally invasive surgical (MIS reconstructive techniques including laparoscopic and robotic surgery are now being utilized in this population. However, fewer than 30 cases of MIS UPJ reconstruction in horseshoe kidneys have been reported. We herein report our experience with these techniques in the largest series to date. Materials and Methods We performed a retrospective chart review of nine patients with UPJ obstruction in horseshoe kidneys who underwent MIS repair at our institution between March 2000 and January 2012. Four underwent laparoscopic, two robotic, and one laparoendoscopic single-site (LESS dismembered pyeloplasty. An additional two pediatric patients underwent robotic Hellstrom repair. Perioperative outcomes and treatment success were evaluated. Results Median patient age was 18 years (range 2.5-62 years. Median operative time was 136 minutes (range 109-230 min. and there were no perioperative complications. After a median follow-up of 11 months, clinical (symptomatic success was 100%, while radiographic success based on MAG-3 renogram was 78%. The two failures were defined by prolonged t1/2 drainage, but neither patient has required salvage therapy as they remain asymptomatic with stable differential renal function. Conclusions MIS repair of UPJ obstruction in horseshoe kidneys is feasible and safe. Although excellent short-term clinical success is achieved, radiographic success may be lower than MIS pyeloplasty in heterotopic kidneys, possibly due to inherent differences in anatomy. Larger studies are needed to evaluate MIS pyeloplasty in this population.

  9. [Retroperitoneoscopic assisted pyeloplasty for ureteropelvic junction obstruction in children].

    Science.gov (United States)

    Luque Mialdea, R; Martin-Crespo Izquierdo, R; Díaz Gómez, L; Moreno, L; Carrero, C; Cebrian, J

    2007-04-01

    Description of the retroperitoneoscopic approach in the conventional pyeloplasty for ureteropelvic junction obstruction in children. From 1998 pyeloplasty assisted by retroperitoneoscopic approach (PARA) was performed in 30 patients. Position in latero-dorsal decubitus and incision of 1 cm in angle costolumbar. We made retroperitoneoscopic space by ball dissection technique and 11 mm Hg pressure. The ureteropelvic junction was extracted through the incision of the port. The UPJ was resected in all patients and Anderson-Hynes pyeloplasty with double PDS 6/0 continuous sutures was performed. In all patients a drainage type Penrose in perirenal space was used. In the last 18 patients a 4F double-J stent was placed. The mean follow-up time was 42 months (range between 6 and 84 months). Operative time, hospital stay, handling of postoperative pain and the postoperative studies have been revised. In all the cases the retroperitoneoscopic approach was good for the identification and dissection of the ureteropelvic junction facilitating the extraction and reconstruction (pyeloplasty) through the mini-incision of the entrance port. The mean operative time was 90 min. (range between 65 and 128 min). We highlight the absence of intraoperative complications. The only postoperative complication has been a pyohydronephrosis in a patient not having internal drainage that was solved by percutaneous pyelostomy and didn't need reintervention. The postoperative handling of the pain was good by means of caudal locorregional anesthesia or by infiltration of the wound with local anesthesic and a dose of Ibuprofeno previous to leave the hospital. The mean hospital stay was 2 days (1-3 days) excluding the complicated case. Postoperative diuretic renograms at the 6 and 18 have shown absence of obstruction in all cases. In the long term follow-up, in 1 case nephrectomy was performed. The PARA for UPJ obstruction is a safe and effective procedure with the advantage of a minimal invasive

  10. [Retroperitoneoscopic dismembered pyeloplasty for pediatric ureteropelvic junction obstruction: a report of 85 cases].

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    Chen, Zhi; Chen, Xiang; Qi, Lin; Chen, Liang; Luo, Yancheng; He, Yao; Li, Nannan; Xie, Chaoqun

    2011-05-01

    To investigate the clinical application of retroperitoneoscopic dismembered pyeloplasty for pediatric ureteropelvic junction obstruction (UPJO). Of the 85 pediatric patients with UPJO, 56 were boys and 29 were girls. The age of the patients ranged from 2.5 to 11 years (mean = 4.6 years).B-ultrasonography showed hydronephrosis 8 d ).Urine leakage occurred in 1 patient and with a good drainage, urine leakage disappeared in 1 week. Follow-up ranged 3-24 months (mean = 11 months).IVU showed on UPJ stricture, and good imaging in 75 patients within 30 min, light imaging in 10 at 30-120 min. Hydronephrosis was remitted:hydronephrosis resolution in 51 patients, mild in 6 and moderate in 3. Retroperitoneoscopic dismembered pyeloplasty is a safe, effective and mini-invasive procedure for pediatric ureteropelvic junction obstruction, with a rapid postoperative recovery. It will be the ideal treatment for UPJO in pediatric patients.

  11. Utilizing ultrasonography in the diagnosis of pediatric fibroepithelial polyps causing ureteropelvic junction obstruction.

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    Wang, Xiao Man; Jia, Li Qun; Wang, Yu; Wang, Ning

    2012-09-01

    Fibroepithelial polyps are a rare cause of ureteropelvic junction (UPJ) obstruction in children. Preoperative US diagnosis of fibroepithelial polyps is infrequently reported, with intravenous pylogram and retrograde pyelography being most commonly used for diagnosis. To recommend the most accurate process for diagnosing this disease in children by assessing a modified ultrasonographic procedure for the diagnosis of fibroepithelial polyps. A retrospective review of US and IVP imaging studies performed in surgically and histologically confirmed cases of fibroepithelial polyps in children. Each child was asked to drink as much water as possible 30 min before the US testing. For US, the renal pelvis, UPJ and the proximal ureter were inspected for an echogenic mass resulting in hydronephrosis. For IVP studies, abdominal plain films were performed at 7, 15 and 30 min following contrast injection. Thirty-five children, 34 boys and 1 girl, had confirmed fibroepithelial polyps. The children ranged in age from 3 to 14 years (mean age 9 years). Clinical presentation included intermittent vague abdominal pain (100%) and/or hematuria (9.7%) for a period ranging from 1 month to 5 years. Of the 35 children (37 polyps), 21 (23 polyps) were correctly diagnosed preoperatively with US, establishing a 62.2% (23/37) US accuracy rate. Twenty polyps were seen on the left, three on the right and two children had bilateral polyps. The masses were all mildly echogenic with defined edges. Eight children (9 polyps) had an IVP consistent with fibroepithelial polyps giving IVP an accuracy rate of 24.3% (9/37). US is an effective screening tool for identifying fibroepithelial polyps causing UPJ obstruction in children.

  12. Spontaneous large renal pelvis hematoma in ureteropelvic junction obstruction presenting as an acute abdomen: Rare case report.

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    Sawant, Ajit; Kasat, Gaurav; Pawar, Prakash; Tamhankar, Ashwin

    2016-01-01

    Patients with ureteropelvic junction (UPJ) obstruction can present with flank pain or hematuria. We present 20-year-old male presenting with acute pain in lumbar and right fossa with tenderness and guarding, this case was clinically mimicking general surgical emergency. On computed tomography with urography and angiography, there was 15 cm × 11 cm × 10 cm size non-enhancing hyperdense lesion (average Hounsfield units - +64) in right renal pelvis suggestive of hematoma. Patient's diethylenetriaminepentaacetic acid diuretic renography was suggestive of right kidney glomerular function rate of 48.4 ml/min with the relative function of 43%, Peak to half peak was not achieved. The patient was managed by retrograde ureteropyelography and double J stenting. After 1 month, clot size decreased to 4 cm × 3 cm × 2 cm. The patient had undergone open reduction Anderson hynes dismembered pyeloplasty with the removal of pelvis clot after 6 weeks. We report the first case of UPJ obstruction presenting as an acute abdomen and spontaneous hematuria with large pelvis clot without rupture of the renal pelvis.

  13. Spontaneous large renal pelvis hematoma in ureteropelvic junction obstruction presenting as an acute abdomen: Rare case report

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    Ajit Sawant

    2016-01-01

    Full Text Available Patients with ureteropelvic junction (UPJ obstruction can present with flank pain or hematuria. We present 20-year-old male presenting with acute pain in lumbar and right fossa with tenderness and guarding, this case was clinically mimicking general surgical emergency. On computed tomography with urography and angiography, there was 15 cm × 11 cm × 10 cm size non-enhancing hyperdense lesion (average Hounsfield units - +64 in right renal pelvis suggestive of hematoma. Patient's diethylenetriaminepentaacetic acid diuretic renography was suggestive of right kidney glomerular function rate of 48.4 ml/min with the relative function of 43%, Peak to half peak was not achieved. The patient was managed by retrograde ureteropyelography and double J stenting. After 1 month, clot size decreased to 4 cm × 3 cm × 2 cm. The patient had undergone open reduction Anderson hynes dismembered pyeloplasty with the removal of pelvis clot after 6 weeks. We report the first case of UPJ obstruction presenting as an acute abdomen and spontaneous hematuria with large pelvis clot without rupture of the renal pelvis.

  14. Renal pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function

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    Chavhan, Govind; Daneman, Alan; Lim, Ruth; Traubici, Jeffrey [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Moineddin, Rahim [University of Toronto, Department of Family and Community Medicine, Toronto (Canada); Langlois, Valerie [University of Toronto, Division of Nephrology, Department of Pediatrics, Hospital for Sick Children, Toronto (Canada)

    2008-10-15

    Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis. To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ({sup 99m}Tc-MAG3) scan. Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by {sup 99m}Tc-MAG3 scan, of the obstructed kidney of {>=}45% was considered normal and of {<=}44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids. In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294). We observed that in obstructed kidneys

  15. Urothelial Defects from Targeted Inactivation of Exocyst Sec10 in Mice Cause Ureteropelvic Junction Obstructions.

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    Ben Fogelgren

    Full Text Available Most cases of congenital obstructive nephropathy are the result of ureteropelvic junction obstructions, and despite their high prevalence, we have a poor understanding of their etiology and scarcity of genetic models. The eight-protein exocyst complex regulates polarized exocytosis of intracellular vesicles in a large variety of cell types. Here we report generation of a conditional knockout mouse for Sec10, a central component of the exocyst, which is the first conditional allele for any exocyst gene. Inactivation of Sec10 in ureteric bud-derived cells using Ksp1.3-Cre mice resulted in severe bilateral hydronephrosis and complete anuria in newborns, with death occurring 6-14 hours after birth. Sec10 FL/FL;Ksp-Cre embryos developed ureteropelvic junction obstructions between E17.5 and E18.5 as a result of degeneration of the urothelium and subsequent overgrowth by surrounding mesenchymal cells. The urothelial cell layer that lines the urinary tract must maintain a hydrophobic luminal barrier again urine while remaining highly stretchable. This barrier is largely established by production of uroplakin proteins that are transported to the apical surface to establish large plaques. By E16.5, Sec10 FL/FL;Ksp-Cre ureter and pelvic urothelium showed decreased uroplakin-3 protein at the luminal surface, and complete absence of uroplakin-3 by E17.5. Affected urothelium at the UPJ showed irregular barriers that exposed the smooth muscle layer to urine, suggesting this may trigger the surrounding mesenchymal cells to overgrow the lumen. Findings from this novel mouse model show Sec10 is critical for the development of the urothelium in ureters, and provides experimental evidence that failure of this urothelial barrier may contribute to human congenital urinary tract obstructions.

  16. Urothelial Defects from Targeted Inactivation of Exocyst Sec10 in Mice Cause Ureteropelvic Junction Obstructions.

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    Fogelgren, Ben; Polgar, Noemi; Lui, Vanessa H; Lee, Amanda J; Tamashiro, Kadee-Kalia A; Napoli, Josephine Andrea; Walton, Chad B; Zuo, Xiaofeng; Lipschutz, Joshua H

    2015-01-01

    Most cases of congenital obstructive nephropathy are the result of ureteropelvic junction obstructions, and despite their high prevalence, we have a poor understanding of their etiology and scarcity of genetic models. The eight-protein exocyst complex regulates polarized exocytosis of intracellular vesicles in a large variety of cell types. Here we report generation of a conditional knockout mouse for Sec10, a central component of the exocyst, which is the first conditional allele for any exocyst gene. Inactivation of Sec10 in ureteric bud-derived cells using Ksp1.3-Cre mice resulted in severe bilateral hydronephrosis and complete anuria in newborns, with death occurring 6-14 hours after birth. Sec10 FL/FL;Ksp-Cre embryos developed ureteropelvic junction obstructions between E17.5 and E18.5 as a result of degeneration of the urothelium and subsequent overgrowth by surrounding mesenchymal cells. The urothelial cell layer that lines the urinary tract must maintain a hydrophobic luminal barrier again urine while remaining highly stretchable. This barrier is largely established by production of uroplakin proteins that are transported to the apical surface to establish large plaques. By E16.5, Sec10 FL/FL;Ksp-Cre ureter and pelvic urothelium showed decreased uroplakin-3 protein at the luminal surface, and complete absence of uroplakin-3 by E17.5. Affected urothelium at the UPJ showed irregular barriers that exposed the smooth muscle layer to urine, suggesting this may trigger the surrounding mesenchymal cells to overgrow the lumen. Findings from this novel mouse model show Sec10 is critical for the development of the urothelium in ureters, and provides experimental evidence that failure of this urothelial barrier may contribute to human congenital urinary tract obstructions.

  17. Robotic dismembered pyeloplasty for the treatment of ureteropelvic junction obstruction.

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    Vipul Patel

    2005-01-01

    Full Text Available Objective: Laparoscopic pyeloplasty has been shown to have equivalent surgical outcomes with less surgical morbidity when compared to the open approach. The laparoscopic approach has traditionally been performed in a few specialized training centers because of the advanced technical skills required to perform this complex reconstructive procedure. The introduction of robotic technology into the modern day operating suite has brought on a new era and has simplified complex urologic reconstructive procedures. The daVinci robot provides the advantages of three-dimensional vision, magnification, and a robotic articulating wrist. These features allow precise dissection and suturing capabilities. We used the daVinci robot to perform robotic assisted laparoscopic pyeloplasty. We studied its feasibility, utility, and efficacy. Methods: Between July 2002 and April 2003, 12 patients with a mean age of 29.2 years (16-56 underwent robotic assisted laparoscopic dismembered pyeloplasty. Each patient had presented with flank pain (six left and right and had been diagnosed with a ureteropelvic junction (UPJ obstruction by either IVP or MAG3 renal scan. A retrograde pyelogram was performed preoperatively to delineate the anatomy and a stent was placed. Robotic dismembered pyeloplasty was performed. Eight of 12 patients had crossing vessels only five of which were shown on preoperative CT scan. The crossing vessels were preserved in all cases. The UPJ was dismembered at the point of obstruction and the scar excised. The ureter was spatulated medially and the renal pelvis fashioned appropriately. Ureteropelvic reconstruction was performed with eight-interrupted 4-0 monocryl sutures on an RB-1 needle in the first five cases. In the other seven cases the anastomosis was performed with two running semicircular sutures. Stents were removed at 14-28 days. An IVP was performed prior to stent removal and a renal scan at 3 and 6 months. Results: Each patient underwent a

  18. Renal trauma in occult ureteropelvic junction obstruction: CT findings

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    Sebastia, M.C.; Rodriguez-Dobao, M.; Quiroga, S.; Pallisa, E.; Martinez-Rodriguez, M.; Alvarez-Castells, A. [Dept. of Radiology, Hospital General Universitari Vall d`Hebron, Barcelona (Spain)

    1999-05-01

    The aim of this study was to present CT findings of occult ureteropelvic junction obstruction in patients with renal trauma and to describe the clinical signs and singular CT features that are characteristically observed with trauma and are relevant to management of these patients. We retrospectively reviewed 82 helical CT studies in patients with renal trauma referred to our institution. We found 13 cases of occult preexisting renal pathology, six of which were occult ureteropelvic junction obstructions. The clinical presentation, radiologic findings of trauma according to the Federle classification, and CT findings of obstructed ureteropelvic junction are presented. We found three category-I lesions (one in a horseshoe kidney), two of them treated with nephrostomy because of increased ureteropelvic junction obstruction due to pelvic clots; two category-II lesions (parenchymal and renal pelvis lacerations) that had presented only with microhematuria; and one category-IV lesion (pelvic laceration alone). Pelvic extension was demonstrated in all the cases with perirenal collections. The CT studies in all the cases with suspected ureteropelvic junction obstruction showed decreased parenchymal thickness and enhancement, and dilatation of the renal pelvis and calyx, with a normal ureter. Computed tomography can provide information to confidently diagnose underlying ureteropelvic junction obstruction in renal trauma, categorize the traumatic injury (at times clinically silent) and facilitate proper management according to the singularities observed, such us rupture of the renal pelvis alone (Federle category IV) and increasing ureteropelvic obstruction due to clots which can be decompressed by nephrostomy. (orig.) With 6 figs., 3 tabs., 13 refs.

  19. Agreement between static magnetic resonance urography and diuretic renal scintigraphy in patients with ureteropelvic junction obstruction after pyeloplasty.

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    Mazdak, Hamid; Karam, Mehdi; Ghassami, Fatemeh; Malekpour, Alireza

    2015-01-01

    Ureteropelvic junction obstruction (UPJO) is the most common cause of hydronephrosis within childhood that usually treat by surgery. According to anatomical variations in different individuals, scheduling similar procedures for all patients is not suitable, and thus the best decision for an appropriate surgical technique should be considered separately for each patient. Regardless of the type of applied technique, creating a funnel-shape UPJ with a suitable size is a successful treatment. In this context, the assessment of a successful surgical treatment in a short-term follow-up means repairing revealed anatomical defects. The present study aimed to compare the diagnostic value of static magnetic resonance urography (MRU) and diuretic-based renalscintigraphy (DRS) in patients with UPJO after pyeloplasty. A total of 30 consecutive patients with UPJO, who underwent unilateral pyeloplasty between 2012 and 2013 were assessed. All subjects underwent DRS and also MRU about 1-month after the former procedure. The Kendall's tau correlation showed a very strong correlation between results of MRU and diuretic renal scintigraphy (r = 0.932, P MRU to assess UPJO. MRU static fluid has a high accuracy for assessment of renal system anatomy. Due to the lack of dangerous consequences of contrast materials, MRU can be the best option instead of DRS.

  20. Efficacy of Magnetic Resonance urography in detecting crossing renal vessels in children with ureteropelvic junction obstruction.

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    Pavicevic, Polina K; Saranovic, Djordjije Z; Mandic, Marija J; Vukadinovic, Vojkan M; Djordjevic, Miroslav Lj; Radojicic, Zoran I; Petronic, Ivana; Cirovic, Dragana; Nikolic, Dejan

    2015-01-01

    An aberrant or accessory crossing renal vessel (CV) leading to the lower pole of the kidney is the most common extrinsic cause of uretero pelvic obstruction(UPJ) obstruction in a child and young adolescent.There is still controversy regarding there functional significance in obstruction Preoperative identification of such vessels may influence surgical management. First aim is to determine the value of magnetic resonance (MR) urography in detecting crossing vessels in children with UPJ obstruction,comparing the data with postoperative findings and the second one is to evaluate morphologic and functional parameters in these hydronephrotic kidneys. Between June 2009 and December 2012 we retrospectively reviewed MR urography records of one hundred and nine children with unilateral hydronephrosis at the University Children's Hospital. 68 (62.4%) were male and 41 (37.6%) were female,median age was 6.5 ± 5.7. Of the total number of patients, 30 (27%) underwent pyeloplasty, while 79 (72.5%) did not. The age at surgery ranged from 0.3 to 18 years (median 6.6 years). The indication for surgery was based on standard criteria (obstructed renal transit time with or without altered renal function of vDRF MRU, there was no crossing vessel in 21 kidneys, confirmed at surgery in 18. A crossing vessel was detected with MRU in 9 kidneys and confirmed at surgery in 6. Thus, the sensitivity of MRU was 66.7%, the specificity was 85.7%, the positive predictive value was 66.7%, the negative predictive value was 85.7% and the accuracy was 80%. There was no statistically significant difference in the detection of crossing vessels between MR urography and surgery (p = 0.004 and p MRU and surgery showed good agreement (κ = 0.524). Based on our results we suggest that MR urography is a reliable and safe diagnostic tool to determine crossing vessels in selected children with UPJ obstruction. Thus, MRU can substitute for other imaging modalities and provide detailed information about the

  1. Postnatal evaluation of intrauterine hydronephrosis due to ureteropelvic junction obstruction Avaliação pós-natal de hidronefrose intra-uterina por estenose da junção ureteropiélica

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Fernandes Molina

    2013-01-01

    Full Text Available PURPOSE: Fetal hydronephrosis is a frequent finding due to advances in prenatal ultrasonography. The definition of fetal and neonatal urinary tract obstruction is a very difficult task requiring confirmation of reduced renal function and hydronephrosis. In this study we followed a series of consecutive patients with intrauterine hydronephrosis that persisted during post-natal life. METHODS: 116 newborns with antenatal hydronephrosis diagnosed by ultrasound and submitted to a specific post-natal evaluative protocol with a follow-up period of 6 years. RESULTS: In 45 (38.8% of 116 patients, ureteropelvic junction (UPJ obstruction was confirmed and surgical correction of the UPJ obstruction was done in 19 patients. From 26 children who were initially submitted to non-surgical treatment, only 6 (23% needed a surgical approach during follow up. Overall analysis showed that surgery was performed in 25 patients with UPJ obstruction, and the others 20 patients were kept under clinical observation, since normal renal function was confirmed by scintigraphy scans. CONCLUSION: Fetal hydronephrosis due to UPJ obstruction deserves careful postnatal evaluation. UPJ obstruction is the most frequent anomaly and its surgical treatment has very precise indications. The evaluative protocol was useful in identify patients that could be followed-up with a non-surgical approach.OBJETIVO: Com a ampla utilização dos exames ultrassonográficos na avaliação pré-natal, é frequente o diagnóstico da hidronefrose fetal. A definição de obstrução do trato urinário no periodo pós-natal necessita da confirmação de redução da função renal além da hidronefrose. Neste estudo, acompanhamos uma série de pacientes consecutivos com hidronefrose intra-útero que persistiu no periodo pós-natal. MÉTODOS: 116 recém-nascidos com hidronefrose pré-natal diagnosticada pela ultrassonografia foram submetidos a protocolo específico de avaliação e companhados pelo periodo

  2. Acute obstructive hydrocephalus complicating decompression surgery of the craniovertebral junction

    Science.gov (United States)

    Ohya, Junichi; Chikuda, Hirotaka; Nakatomi, Hirofumi; Sakamoto, Ryuji; Saito, Nobuhito; Tanaka, Sakae

    2016-01-01

    Obstructive hydrocephalus has been described as a rare complication following foramen magnum decompression for Chiari malformation. However, there are few reports of obstructive hydrocephalus after spinal surgery for other pathologies of the craniovertebral junction (CVJ). The authors herein report a 52-year-old female with achondroplasia presenting with an 8-month history of myelopathy due to spinal cord compression at CVJ. She underwent resection of the C1 posterior arch and part of the edge of the occipital bone. A computed tomography (CT) scan obtained 1-week after the surgery revealed bilateral infratentorial fluid collection. The patient was first managed conservatively; however, on the 17th day, her consciousness level showed sudden deterioration. Emergency CT demonstrated marked hydrocephalus due to obstruction of the cerebral aqueduct. Acute obstructive hydrocephalus can occur late after decompression surgery at the CVJ, and thus should be included in the differential diagnosis of a deteriorating mental status. PMID:27366268

  3. Forming a stone in pelviureteric junction obstruction: cause or effect?

    Science.gov (United States)

    Stasinou, Theodora; Bourdoumis, Andreas; Masood, Junaid

    2017-01-01

    ABSTRACT Objectives To investigate a possible causal relationship for stone formation in pelviureteric junction obstruction and to outline management options. Materials and Methods A literature search and evidence synthesis was conducted via electronic databases in the English language using the key words pelviureteric junction obstruction; urolithiasis; hyperoxaluria; laparoscopic pyeloplasty; flexible nephroscopy; percutaneous nephrolithotomy, alone or in combination. Relevant articles were analysed to extract conclusions. Results Concomitant pelviureteric junction obstruction (PUJO) and renal lithiasis has been reported only scarcely in the literature. Although PUJO has been extensively studied throughout the years, the presence of calculi in such a patient has not received equal attention and there is still doubt surrounding the pathophysiology and global management. Conclusions Metabolic risk factors appear to play an important role, enough to justify metabolic evaluation in these patients. Urinary stasis and infection are well known factors predisposing to lithiasis and contribute to some extent. The choice for treatment is not always straightforward. Management should be tailored according to degree of obstruction, renal function, patient symptoms and stone size. Simultaneous treatment is feasible with the aid of minimally invasive operative techniques and laparoscopy in particular.

  4. Ureteropelvic junction obstruction: the effect of pyeloplasty on renal function

    Energy Technology Data Exchange (ETDEWEB)

    Dowling, K.J.; Harmon, E.P.; Ortenberg, J.; Polanco, E.; Evans, B.B.

    1988-11-01

    We studied preoperatively and postoperatively 41 children who underwent pyeloplasty for correction of unilateral ureteropelvic junction obstruction. Conventional radiological studies and quantitative radioiodine hippurate renal scans were obtained to assess the effect of pyeloplasty on the appearance of the kidney and its function. Analysis of the data suggests that the degree of improvement in renal function is related primarily to the age at which the surgical correction is accomplished and whether infection has occurred preoperatively.

  5. Imaging of uretero-pelvic junction obstruction with stimulated diuresis

    Energy Technology Data Exchange (ETDEWEB)

    Ebel, K.D.; Bliesener, J.A.; Gharib, M.

    1988-01-01

    Eighty-nine kidneys of 81 infants and children with uretero-pelvic junction obstruction were investigated using ultrasonography (US), diuretic urography (DUR) and diuretic renography (DREN). Results of the US were false-negative in 14%. This can be avoided by ensuring that the patients get an amount of fluid appropriate to their age before the examination or by performing diuretic ultrasonography with frusemide. False-positive results were found with US in 15%, but obstruction was excluded by using the DUR and/or the DREN. During post-operative follow-up the DUS is useful and after 6 months the clearance with 123-iodine hippurate combined with the DREN should be performed. The administration of the Whitaker-test is unnecessary.

  6. Immunohistochemistry in ureteropelvic junction obstruction and its correlation to postoperative outcome

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    Anusiri Inugala

    2017-01-01

    Conclusion: This is the first study which correlates the status of ICC in UPJ with the outcome of pyeloplasty in pediatric patients. Both the cases with bad outcome had no ICC at the lower margin of the resected specimen and one case had no ICC at the UPJ. There is a statistically significant difference (P = 0.001 in the number of ICC at the UPJ and the resected margin.

  7. Double Trouble: A Rare Case of Bilateral Upper Pole Ureteropelvic Junction Obstruction

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    Craig A. Peters

    2014-09-01

    Full Text Available A 16-year-old girl presented with bilateral back pain caused by bilateral upper pole ureteropelvic junction obstructions; an extremely rare phenomenon. Bilateral robotically assisted upper pole pyeloplasties were preformed at the same setting with an excellent clinical response. Although rare, upper pole ureteropelvic junction obstruction is a defined entity that urologists should be aware of.

  8. The results of 15 years of consistent strategy in treating antenatally suspected pelvi-ureteric junction obstruction

    DEFF Research Database (Denmark)

    Thorup, Jørgen Mogens; Jokela, R; Cortes, Dina;

    2003-01-01

    To determine how to select patients for surgery among those with antenatally detected pelvi-ureteric junction (PUJ) obstruction.......To determine how to select patients for surgery among those with antenatally detected pelvi-ureteric junction (PUJ) obstruction....

  9. Transperitoneal laparoscopic pyeloplasty in the treatment of ureteropelvic junction obstruction

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    Luis Hidalgo Togores

    2013-07-01

    Full Text Available Introduction. Laparoscopic pyeloplasty was first described by Schuessler. During the last decade, this technique has been developed in order to achieve the same results as open surgery, with lower rates of morbidity and complications. In this study we review our experience using laparoscopic pyeloplasty as the gold standard for the treatment of the ureteropelvic junction obstruction (UPJO.Material and methods. We performed a retrospective review of 62 laparoscopic pyeloplasties carried out at our center. In the last 2 years we used 3 mm and 5 mm ports in order to achieve better cosmetics results. Demographic data is described and the functionality of the affected kidney and surgical data, among others were analyzed statistically. In the case of bilateral statistical tests were considered significant as those with p values <0.05.Results. The most frequent reason for consultation was ureteral pain. Patients mean age was 40 years and 94% of them had preoperative renogram showing a full or partial obstructive pattern. The right side was affected in 61% of cases and the left in the remaining 39%. The presence of stones was observed in 12 patients and crossing vessels in 58% of cases. The average stay was 3.72 days. Post–surgery complications were observed in two patients. The operative time was 178 minutes. Mean follow–up was 45 months and a success was achieved in 91%.Conclusions. The transperitoneal laparoscopic pyeloplasty has become the gold standard for the treatment of ureteropelvic junction stenosis in our center because of high success rate, shorter postoperative stay, and low intra and postoperative complications.

  10. Non-contrast-enhanced MR angiography using time-spin labelling inversion pulse technique for detecting crossing renal vessels in children with symptomatic ureteropelvic junction obstruction: comparison with surgical findings.

    Science.gov (United States)

    Brucher, Nicolas; Vial, Julie; Baunin, Christiane; Labarre, David; Meyrignac, Olivier; Juricic, Michel; Bouali, Ourdia; Abbo, Olivier; Galinier, Philippe; Sans, Nicolas

    2016-08-01

    Investigate the feasibility and evaluate the accuracy of non-contrast-enhanced MR angiography (NC-MRA) using time-spin labelling inversion pulse (time-SLIP)to identify crossing renal vessels (CRVs) in children requiring surgical treatment of ureteropelvic junction (UPJ) obstructionand compare to laparoscopic findings. Nineteen children ranging from 6 to 16 years of age underwent NC-MRA using the time-SLIP technique before surgery. Two independent readers analysed the MRA images. Number of renal arteries and presence or absence of CRVs were identified and compared with surgicalfindings. Image quality was assessed, as well as the presence of CRVs and measurement of renal pelvis diameter. Intra and inter-reader agreement was calculated using Cohen's kappa coefficient and Bland-Altman plots. The overall image quality was fair or good in 88% of cases. NC-MRA demonstrated CRVs at the level of the obstruction in 10 children and no CRV in 9 children. All were confirmed intra-operatively except in one of the nine children. Sensitivity, specificity, NPV, PPV for predicting CRVs were 92%, 100%, 100% and 87.5%, respectively, for both readers. NC-MRA is a good alternative to contrast-enhanced MRA and CT scanning for identifying CRVs in children with symptomatic UPJ. • Time-SLIP technique offers acceptable imaging quality for identifying crossing renal vessel. • Time-SLIP technique is easy to apply to the renal MRA examination. • Time-SLIP technique is an alternative to contrast-enhanced MRA and CT scanning.

  11. Spontaneous Perirenal Urinoma Associated with Ureteropelvic Junction Obstruction in a Child: A Case Report

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    Po-Chang Tseng

    2009-06-01

    Full Text Available We report a case of a 10-year-old Taiwanese boy with a perinephric urinoma, whose health had previously been good, but who experienced a sudden onset of severe left flank pain. Radiological examination revealed ureteropelvic junction obstruction with grade IV hydronephrosis and perinephric urinoma of the left kidney. Percutaneous drainage was performed successfully to relieve these symptoms. Urinoma is a rare complication of congenital obstruction of the urinary tract, and it occurs most commonly following renal trauma.

  12. Pyelonephritis caused by Actinobaculum schaalii in a child with pyeloureteral junction obstruction.

    NARCIS (Netherlands)

    Pajkrt, D.; Simoons - Smit, A.M.; Savelkoul, P.H.M.; Hoek, van den J.; Hack, WW; Furth, van A.M.

    2003-01-01

    Reported here is the case of a 5-year old boy with a pyeloureteral junction (PUJ) obstruction and pyelonephritis caused by Actinobaculum schaalii, an Actinomyces-like organism. Pyelonephritis or any other urinary tract infection caused by Actinobaculum schaalii has not been described in children

  13. Splenic torsion and ureteropelvic junction obstruction - a case report; Torcao esplenica e estenose da juncao ureteropielica - relato de um caso

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Vivian Alvim; Bauab Junior, Tufik [Instituto de Radiodiagnostico Rio Preto, Sao Jose do Rio Preto, SP (Brazil); Barroso Junior, Ubirajara [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina. Div. de Urologia

    2000-04-01

    We report a case of a 13-year-old boy with a pedicle splenic torsion associated with ureteropelvic junction obstruction. The symptoms, clinical outcome and the imaging findings are presented. (author)

  14. Evaluating the Upset Protrusion Joining (UPJ) Method to Join Magnesium Castings to Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen [FCA US LLC

    2016-02-24

    This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparing performance results of the joints made with the UPJ process to those made with the SPR process. Key results presented include: • The benchmark SPR process can produce good joints in the MgAM60B-Al 6013 joint configuration with minimal cracking in the Mg coupons if the rivet is inserted from the Mg side into the Al side. • Numerous bare Mg to bare Al joints made with the SPR process separated after only 6-wks of accelerated corrosion testing due to fracture of the rivet as a result of hydrogen embrittlement • For the same joint configurations, UPJ demonstrated substantially higher pre-corrosion joint strengths and post-corrosion joint strengths, primarily because of the larger diameter protrusion compared to smaller SPR rivet diameter and reduced degradation due to accelerated corrosion exposure • As with the SPR process, numerous bare Mg to bare Al joints made with the UPJ process also separated after 6-wks of accelerated corrosion testing, but unlike the SPR experience, the UPJ joints experienced degradation of the boss and head because of galvanic corrosion of the Mg casting, not hydrogen embrittlement of the steel rivet. • In the configuration where both the Mg and Al were pretreated with Alodine 5200 prior to joining and the complete

  15. Evaluating the Upset Protrusion Joining (UPJ) Method to Join magnesium Castings to Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen D. [FCA US LLC

    2015-08-19

    This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparing performance results of the joints made with the UPJ process to those made with the SPR process.

  16. 经皮肾“三明治”腔内肾盂成形术治疗肾盂输尿管连接部梗阻%Percutaneous "sandwich" endopyeloplasty technique: a new endourological measure for ureteropelvic junction obstruction

    Institute of Scientific and Technical Information of China (English)

    杨波; 胡浩; 王佳; 徐涛; 黄晓波; 王晓峰

    2015-01-01

    目的:报道一种新的腔内成形技术——经皮肾“三明治”腔内肾盂成形术治疗肾盂输尿管连接部梗阻(ureteropelvic junction obstruction,UPJO)的临床疗效和安全性.方法:选取2012年1月至2013年12月期间使用经皮肾“三明治”腔内肾盂成形术治疗UPJO患者71例,其中先天性UPJO 12例,医源性UPJ059例;平均狭窄段长度为(1.4±0.8) mm,5例为肾盂输尿管连接部(ureteropelvic junction,UPJ)完全闭锁,患肾平均肾小球滤过率(glomerular filtration rate,GFR)为(19.8±10.8) mL/min.超声引导下建立皮肾通道后,UPJO狭窄段使用21 F(1 F=0.33 mm)或24F输尿管扩张球囊采用球囊扩张-切开-球囊扩张的“三明治”技术扩大流出道,所有患者留置加强型输尿管支架管(7/14 F)作为狭窄段成形后的支撑.术后2个月撤除输尿管支架管,随访12 ~24个月.结果:一期手术成功69例,余2例因UPJ完全闭锁行二期手术成功,手术时间(39.3±24.2) min,术后肾周血肿1例,结石残余2例,无需要输血和发生尿源性败血症病例,无需要干预的尿外渗和体腔积液病例.随访期间,64例未再次出现UPJO的临床症状和影像学变化,7例撤除支架管后出现UPJ的再狭窄,其中6例为医源性UPJO,1例为先天性UPJO患者.结论:经皮肾“三明治”腔内肾盂成形术治疗UPJO,具有操作简便、微创、安全、有效等特点,对于具有适应证的患者可以作为一线的治疗选择.

  17. Double layered self-expanding metal stents for malignant esophageal obstruction, especially across the gastroesophageal junction

    Institute of Scientific and Technical Information of China (English)

    Min Dae Kim; Su Bum Park; Dae Hwan Kang; Jae Hyung Lee; Cheol Woong Choi; Hyung Wook Kim; Chung Uk Chung

    2012-01-01

    AIM:TO evaluate the clinical outcomes of double-layered self-expanding metal stents (SEMS) for treatment of malignant esophageal obstruction according to whether SEMS crosses the gastroesophageal junction (GEJ).METHODS:Forty eight patients who underwent the SEMS insertion for malignant esophageal obstruction were enrolled.Patients were classified as GEJ group (SEMS across GEHm 18 patients) and non-GEJ group (SEMS above GEJ,30 patients) according to SEMS position.Double layered (outer uncovered and inner covered stent) esophageal stents were placed.RESULTS:The SEMS insertion and the clinical improvement were achieved in all patients in both groups.Stent malfunction occurred in seven patients in the GEJ group and nine patients in the non-GEJ group.Tumor overgrowth occurred in five and eight patients,respectively,food impaction occurred in one patient in each group,and stent migration occurred in one and no patient,respectively.There were no significant differences between the two groups.Reflux esophagitis occurred more frequently in the GEJ group (eight vs five patients,P =0.036) and was controlled by proton pump inhibitor.Aspiration pneumonia occurred in zero and five patients,respectively,and tracheoesophageal fistula occurred in zero and two patients,respectively.CONCLUSION:Double-layered SEMS are a feasible and effective treatment when placed across the GEJ for malignant esophageal obstruction.Double-layered SEMS provide acceptable complications,especially migration,although reflux esophagitis is more common in the GEJ group.

  18. Transforming growth factor-β1 in congenital ureteropelvic junction obstruction: diagnosis and follow-up

    Directory of Open Access Journals (Sweden)

    Cristian Sager

    2009-06-01

    Full Text Available OBJECTIVE: To assess the role of transforming growth factor-β1 (TGF-β1 in congenital ureteropelvic junction obstruction at diagnosis and during postoperative follow-up. MATERIAL AND METHODS: We conducted a case-control study including 19 patients with a mean age of 6.7 years and 19 matched controls. All patients presented negative voiding cystourethrography, obstructive diuretic renogram and underwent dismembered pyeloplasty. Urinary TGF-β1 and other markers were measured pre-, intra- and postoperatively. RESULTS: The mean bladder urine TGF-β1 concentration in obstructed patients prior to pyeloplasty was higher than in controls (92.5 pg/mL ± 16.8 vs. 35.8 pg/mL ± 16.2; p = 0.0001. The mean renal pelvic urine TGF-β1 concentration in the hydronephrotic kidney was higher than in the preoperative bladder urine sample (122.3 pg/mL ± 43.9 vs. 92.5 pg/mL ± 16.8; p = 0.036. Postoperative mean TGF-β1 concentration was significantly lower than preoperative TGF-β1 (48.7 pg/mL ± 13.1 vs. 92.5 pg/mL ± 16.8; p = 0.0001. CONCLUSION: TGF-β1 is a cytokine leading to renal fibrosis. The measurement of urinary TGF-β1 could become a useful tool for the diagnosis of obstructive hydronephrosis and the evaluation of the parenchyma function status, pre and postoperatively.

  19. An audit of routine grey scale sonograghic imaging for pelviureteric junction obstruction: Do they identify lower polar vessels?

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    Chapman Stephen

    2010-01-01

    Full Text Available Background: Aberrant lower polar vessels are uncommon causes of pelviureteric junction (PUJ obstruction. Preoperative identifi cation would help in planning the appropriate procedure. We attempted to determine whether routine investigations would predict crossing lower polar vessels. Materials and Methods: This was a retrospective study of 20 patients that either had ultrasonographic investigation by a radiologist who was blinded to the aetiology of PUJ obstruction, or underwent minimal access surgery for PUJ obstruction, from 2005 to 2007, in the Birmingham Children′s Hospital, UK. Results: There were 20 patients with PUJ obstruction, 8 were found at operation to have crossing lower polar vessels causing PUJ obstruction. The sonography correctly identifi ed crossing vessels in only one, with a sensitivity of 12.5%, specifi city of 66.6%, positive predictive value of 20%, and negative predictive value of 53%. Conclusion: Preliminary results showed that none of these investigations could reliably identify lower polar vessels.

  20. Delayed Recognition of an Ureteropelvic Junction Obstruction in a Young Adult Female

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    Ariel Schulman

    2015-01-01

    Full Text Available A percentage of ureteropelvic junction obstruction cases are clinically silent in childhood and manifest symptoms in adults. Herein we present a 25-year-old female with several years of intermittent flank pain and abdominal symptoms with prior inconclusive diagnostic workup including abdominal imaging without hydronephrosis. Ultimately, a CT scan performed during an acute pain crisis clearly identified right-sided hydronephrosis. The keys to diagnosis are awareness of this entity, a detailed history, and obtaining imaging studies during a crisis. The patient subsequently underwent a right robotic-assisted laparoscopic pyeloplasty with preservation of a lower pole crossing vessel. We highlight noteworthy features of the clinical presentation and surgical repair.

  1. Sonographic Renal Parenchymal Measurements for the Evaluation and Management of Ureteropelvic Junction Obstruction in Children

    Directory of Open Access Journals (Sweden)

    Jeremy C Kelley

    2016-05-01

    Full Text Available Purpose: To correlate sonographic renal parenchymal measurements among patients with ureteropelvic junction obstruction (UPJO labeled Society of Fetal Urology (SFU hydronephrosis grades 1 to 4 and to examine whether sonographic renal parenchymal measurements could be used to differentiate conservative versus surgical management.Materials and Methods: Retrospective chart review and sonographic renal parenchymal measurements (renal length, medullary pyramid thickness, and renal parenchymal thickness were performed in patients with SFU grades 1 to 4 hydronephrosis secondary to UPJO managed between 2009 and 2014. Exclusion criteria included other concomitant genitourinary pathology or incomplete follow-up. Anterior-posterior renal pelvic diameter (APRPD and radionuclide renography were also evaluated when available. Results: 104 patient with ureteropelvic junction obstruction underwent 244 RBUS (1,464 sonographic renal parenchymal measurements in 488 kidneys. Medullary pyramid thickness and renal parenchymal thickness progressively decreased from SFU grades 1 to 4 (p<0.05. A similar trend was appreciated when comparing SFU grades 1 and 2 vs. 3 and 4, as well as SFU grades 3 vs. 4 (p<0.05. SFU grade 3 and 4 patients who underwent pyeloplasty had longer renal length in comparison to those who were managed conservatively (p<0.02.Conclusions: This is the first study that evaluates these objective, quantifiable sonographic renal parenchymal measurements in children with unilateral UPJO. These sonographic renal parenchymal measurements correlate closely with worsening of hydronephrosis graded by the SFU and APRPD classification systems. Prospective studies are needed to elucidate the role of sonographic renal parenchymal measurements in the management of children with UPJO.□

  2. Antenatally detected pelviureteric junction obstruction: Safety of conservative management by our protocol

    Directory of Open Access Journals (Sweden)

    D K Gupta

    2000-01-01

    Full Text Available The present study was carried out by evaluate the safety and effectiveness of the selective conservative manage-ment of antenatally detected unilateral pelviureteric junc-tion obstruction (ADPUJ in children who were diagnosed to have unequivocal obstruction upon DTPA renograms performed at 6 weeks of age. The study comprised of 28 patients with ADPUJ. The selective conservative manage-ment was applied to the patients with unilateral ADPUJ who were asymptomatic, had split renal function (SRF above 40% and had the anterior posterior diameter of the pelvis less than 20 mm at 6 weeks of life. 20 of the 28 patients fulfilled the above criteria and were followed up at 3-monthly intervals with nuclear renograms and ultra-sonography (US. Prophylactic antibiotics were not pres-cribed to these patients. The remaining 8 patients underwent pyeloplasty. None of the patients followed up without surgical intervention deteriorated enough to the SRF of 40% or below during the mean follow-up period of 30 months. Only I of these 20 patients had an episode of urinary tract infection. In conclusion, unilateral ADPUJ managed by selective conservative treatment is safe and these patients do not require any antibiotic chemo-prophylaxis.

  3. Ureteropelvic junction obstruction in children: two variants of the same congenital anomaly?

    Directory of Open Access Journals (Sweden)

    Braga Luis H.P.

    2003-01-01

    Full Text Available OBJECTIVE: To compare the characteristics of prenatally and postnatally diagnosed ureteropelvic junction obstruction (UPJO in children. PATIENTS AND METHODS: We reviewed the records of 74 children who underwent pyeloplasty or nephrectomy for UPJO between 1995 and 2000. The patients were divided into 2 groups: prenatally and postnatally diagnosed UPJO. In each group, we compared age at surgery, gender, affected side, anteroposterior diameter (APD of the renal pelvis, surgical findings, and renal function as determined by creatinine clearance. RESULTS: Of the 74 children, 44 (59.4% had a prenatal diagnosis of UPJO and 30 (40.6% had a postnatal diagnosis despite the fact that all had had a fetal ultrasonography. Median age at the time of surgery was 6.3 years (4 months to 16 years for children with postnatal UPJO and 3.6 months (1 month to 4 years for the prenatal group. Forty-three percent of the children in the postnatal group and 25% in the prenatal group were females. Clinical manifestations in children with postnatal UPJO included abdominal pain in 13 (43% patients, pyelonephritis in 7 (23%, urinary tract infection in 5 (16.6%, and occasional findings upon ultrasound in 5 (16.6%. Excretory urography suggested obstruction in most children. The surgical findings included ureteral kinks due to adhesions in 93.3% of postnatally diagnosed UPJO cases and in 27.3% of prenatal cases (p < 0.01. A reduction in mean creatinine clearance of hydronephrotic kidneys was observed for both groups when compared to reference values for the respective ages, but this difference was not statistically significant. CONCLUSIONS: Postnatally diagnosed UPJO may be considered, at least in part, an entity different from prenatally detected obstruction due to its peculiar characteristics, i.e., postnatal UPJO more frequently affects females, manifests later in life with urinary infection or abdominal pain, and is frequently associated with ureteral kinking.

  4. Comparison Between Diuretic Urography (IVP and Diuretic Renography for Diagnosis of Ureteropelvic Junction Obstruction in Children

    Directory of Open Access Journals (Sweden)

    Mohammad Esmaeili

    2016-01-01

    Full Text Available Background: Ureteropelvic junction obstruction (UPJO is one of the most common causes of urinary tract obstruction in children. Several methods are used to diagnose upper urinary tract obstruction including renal ultrasonography (US, intravenous pyelogram (IVP, diuretic renography (DR, magnetic resonance urography (MRU and antegrade or retrograde pyelography. Nowadays it is suggested to use diuretic renography as the best method for diagnosing of UPJO. There is no comparative study between IVP and DR scan for diagnosis of UPJO in children. Objectives: The aim of the present study was to compare IVP with furosemide injection and diuretic renography in diagnosis of clinically significant UPJO. Patients and Methods: This was a cross sectional study performed in 153 UPJO suspected children (121 boys, 32 girls based on US findings in cases presented with urinary tract infection (UTI, prenatal hydronephrosis, abdominal/flank pain, abdominal mass and hematuria. Renal ultrasound was used as an initial screening tool for detection of urinary tract abnormality. Vesicoureteral reflux (VUR was ruled out by voiding cystourethrography (VCUG. Serum creatinin, blood urea nitrogen, urinalysis and urine culture was screened in all cases. IVP with furosemide and DR were performed as soon as possible after the mentioned workup. Results: During a five year period, 46 out of 153 patients were diagnosed as UPJO based on diuretic renography: the age ranged from 4 months to 13 years (mean: 3.1 ± 0.78 years. There was a significant higher (76% proportion of UPJO in the boys and in the left side (78%. The sensitivity of IVP with furosemide injection in diagnosis of UPJO was 91.3% whereas DR was accepted as standard for diagnostic procedure in diagnosis of UPJO. Conclusions: Although DR is accepted as the best method for diagnosis of UPJO, we found a small sensitivity difference between IVP and DR in kidneys with normal or near normal function. In many settings such as

  5. Congenital ureteropelvic junction obstruction: physiopathology, decoupling of tout court pelvic dilatation-obstruction semantic connection, biomarkers to predict renal damage evolution.

    Science.gov (United States)

    Alberti, C

    2012-02-01

    The widespread use of fetal ultrasonography results in a frequent antenatally observation of hydronephrosis, ureteropelvic junction obstruction (UPJO) accounting for the greatest fraction of congenital obstructive nephropathy. UPJO may be considered, in most cases, as a functional obstructive condition, depending on defective fetal smooth muscle/nerve development at this level, with lack of peristaltic wave propagation--aperistaltic segment--and, therefore, poor urine ejection from the renal pelvis into the ureter. The UPJO-related physiopathologic events are, at first, the compliant dilatation of renal pelvis that, acting as hydraulic buffer, protects the renal parenchyma from the rising intrapelvic pressure-related potential damages, and, subsequently, beyond such phase of dynamic balance, the tubular cell stretch-stress induced by increased intratubular pressure and following parenchymal inflammatory lesions: inflammatory infiltrates, fibroblast proliferation, activation of myofibroblasts, tubulo-interstitial fibrosis. Reactive oxygen species (ROS), nitric oxide (NO), several chemo- and cytokines, growth factors, prostaglandins and eicosanoids, angiotensin-II are the main pathogenetic mediators of the obstructive nephropathy. Apoptosis of tubular cells is the major cause of the tubular atrophy, together with epithelial-mesenchymal transdifferentiation. Some criticisms on tout court semantic renal pelvis dilatation-obstruction connection have been raised considering that the renal pelvis expansion isn't, in any case, linked to an ostructive condition, as it may be verified by diuretic (furosemide) renogram together with scintiscan-based evaluation of differential renal function. In this regard, rather than repetitive invasive nuclear procedures that expose the children to ionizing radiations, an intriguing noninvasive strategy, based on the evaluation of urinary biomarkers and urinary proteome, can define the UPJO-related possible progress of parenchymal lesions

  6. PERANCANGAN SISTEM INFORMASI PENGADUAN PELANGGAN BAGIAN CATER PT PLN CABANG UPJ BEKASI KOTA

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    Eddy Sutedjo

    2007-10-01

    Full Text Available Article discusses the design of user complaint information system on Cater PLN Company Branch UPJ CityBekasi. The design systems consist of complaint acceptance module, scheduled module, field team determinationmodule, and complaint report module. This information system application program testing of user complaint isusing black-box testing method. Black-box testing method was done by giving a number of inputs to the applicationprogram that later processed suitable with the functional needs to produce the needed output. The research resultis the program able to give information about the complaint faster, accurate, and up to date compared to the use ofmanual document.Keywords: information system, customer

  7. Robot-assisted pyeloplasty for pelvi-ureteric junction obstruction of lower moiety in partial duplex system: A technical challenge

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    Girdhar S Bora

    2016-01-01

    Full Text Available Management of pelvi-ureteric junction obstruction (PUJO in a duplex system is technically challenging as dissection at the pelvis may jeopardize the vascularity of the normal moiety ureter. Anastomosing the pelvis to the one single ureter will have a risk of future development of stricture which then will risk both the moieties. Robotic assistance enables appropriate tissue dissection; minimal handling of normal ureter and precision in suturing, overcoming the potential challenges involved in the minimally invasive management of such complex cases. We report the feasibility and efficacy of robot-assisted laparoscopic pyeloplasty in such case.

  8. Detection of crossing vessels in pediatric ureteropelvic junction obstruction: Clinical patterns and imaging findings.

    Science.gov (United States)

    Weiss, Dana A; Kadakia, Sagar; Kurzweil, Rebecca; Srinivasan, Arun K; Darge, Kassa; Shukla, Aseem R

    2015-08-01

    Pediatric ureteropelvic junction obstruction (UPJO) is caused by congenital intrinsic narrowing and/or a lower pole-crossing renal artery. When a crossing renal vessel (CRV) is missed at the time of pyeloplasty, a redo-pyeloplasty is often required. The aims were to analyze clinical predictors for the presence of a CRV in UPJO and the utility of functional magnetic resonance urography (fMRU) in preoperative identification of a crossing vessel. Using an Institutional Review Board approved registry database, we identified 166 patients from July of 2007 until January of 2014 who had undergone open, laparoscopic, or robotic assisted laparoscopic pyeloplasty at our institution. We abstracted data including age at surgery, preoperative symptoms, preoperative imaging findings, and whether or not a CRV was identified intraoperatively. Statistical analysis was performed on SPSS using the Mann-Whitney U test. Of the 166 patients identified, 78 were found to have a CRV at the time of surgery and 88 did not. The surgical approach was distributed as 104 robotic assisted laparoscopic, 51 open, and 11 pure laparoscopic. On univariate analysis, older age at presentation and pain at presentation predicted the presence of a CRV; antenatal hydronephrosis was a negative predictor, though 20 of 68 (25.6%) infants diagnosed with UPJO antenatally did have a CRV. Subgroup analysis of patients undergoing preoperative MRU showed a sensitivity of 88.2% and specificity of 91.7% for the detection of CRVs. This study confirmed the importance of looking for a crossing vessel in all cases, with the knowledge that increased age and pain at presentation were more likely to be associated with a crossing vessel. In addition, fMRU is a valuable source of information in the preoperative identification of the presence of a crossing vessel. The study has limitations including being retrospective in nature, and that the sensitivity of fMRU to identify CRVs was based on the read of an experienced

  9. Anderson-Hynes pyeloplasty with isthmotomy and lateropexy in horseshoe kidneys with pelviureteric junction obstruction in children

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    Shasanka Shekhar Panda

    2014-01-01

    Full Text Available Objective: The objective of this study was to evaluate the results of Anderson-Hynes pyeloplasty with isthmotomy and lateropexy in horseshoe kidney with pelviureteric junction obstruction (PUJO. Materials and Methods: Medical records of patients of horseshoe kidney with PUJO operated in our institute between June 1998 and June 2012 were reviewed. Anderson-Hynes pyeloplasty with isthmotomy and lateropexy was performed in all patients. The surgical outcome was evaluated with emphasis on the changes in degree of hydronephrosis by ultrasonography, renal drainage and function assessed by diuretic renal scans. Results: We studied the records of eight children of horseshoe kidney having unilateral PUJO. Obstruction was caused by a crossing lower-pole vessel in two cases, a high ureteral insertion in three and narrowing of the PUJ in three cases. Post-operative follow-up (median 4.4 years, range 18 months to 10 years revealed improved renal function and good drainage in all cases. Hydronephrosis disappeared in 3, 4 showed Grade 1 and one showed Grade 2 hydronephrosis. All children are doing well and have no symptoms. Conclusion: Anderson-Hynes pyeloplasty with isthmotomy and lateropexy is a highly effective and safe procedure for treating PUJO in horseshoe kidney in children.

  10. Evaluation of Renal Histopathological Changes, as a Predictor of Recoverability of Renal Function Following Pyeloplasty for Ureteropelvic Junction Obstruction

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    Kumar

    2015-07-01

    Full Text Available Background Pyeloplasty is a widely accepted treatment for ureteropelvic junction obstruction (UPJO. However, the renal function recoverability after pyeloplasty is still a matter of debate. Different parameters have been used to predict renal functional recoverability after corrective surgery, with conflicting results. Objectives In this study, renal biopsy was carried on a series of cases of UPJO, during pyeloplasty, to study the extent of histological alterations in renal parenchyma, as a result of obstruction, and its predictive value in renal function recoverability after pyeloplasty. Patients and Methods We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 53 adult patients. Histopathological changes were graded on a scale of 1 to 3, according to their severity, and compared with the differential renal function (DRF revealed on the preoperative and postoperative follow up diethylene triamine pentaacetic acid (DTPA renal scan. A Fischer’s t test was used to evaluate statistical differences between values. Results This study showed a linear relationship between the severity of histological changes and renal function recovery, after pyeloplasty. Out of 24 obstructed renal units (ORU, with minimal histopathological changes (grade I, 21 ORU (87.5%, with > 35% DRF preoperatively, showed significant improvement in renal function after 12 months of pyeloplasty (P 0.05. Renal function deterioration after pyeloplasty was not observed in any of the cases. Conclusions The severity of pathological changes in renal parenchyma, due to UPJO, is a good predictor of renal function recoverability, after pyeloplasty. The ORUs, with DRF > 35%, usually have normal (grade I renal biopsy and might be expected to present better functional recoverability after pyeloplasty.

  11. Benign Fibroepithelial Polyps: A Rare Cause of Ureteropelvic Junction Obstruction in Children

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    Anitha Ezekiel

    2015-07-01

    Full Text Available FEPs are rare, benign mucosal growths that may cause urinary tract obstruction in both adults and children. We present the case of a ten year old Hispanic male with recurring urinary tract infections and hydronephrosis diagnosed with fibroepithelial polyps (FEPs. Despite multiple radiographic procedures, we were unable to accurately preoperatively diagnose FEPs. Here we demonstrate the difficulties in preoperative diagnosis and suggest that perhaps a combination of US and MRI in the setting of persistent urinary tract infections and flank pain may be the best approach for early diagnosis and conservative management, including less invasive treatment protocols.

  12. Comparison of Retrograde Balloon Dilatation and Laparoscopic Pyeloplasty for Treatment of Ureteropelvic Junction Obstruction: Results of a 2-Year Follow-Up

    OpenAIRE

    Ning Xu; Shao-Hao Chen; Xue-Yi Xue; Qing-Shui Zheng; Yong Wei; Tao Jiang; Xiao-Dong Li; Jin-Bei Huang; Hai Cai

    2016-01-01

    Objective To evaluate the efficacy of laparoscopic pyeloplasty relative to retrograde balloon dilatation for the treatment of ureteropelvic junction obstruction (UPJO). Methods This retrospective study enrolled UPJO patients with stricture length < 2 cm who had been treated with laparoscopic pyeloplasty (LP; 44 cases) or balloon dilatation (BD; 38 cases) from Jan 2010 to Jan 2012, according to patients’ preference after consultation. Demographics and clinical parameters were collected. Patien...

  13. Closed External End Double J Catheter as a Nephrostent in Pyeloplasty for Infants with Uretero-Pelvic Junction Obstruction

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    Seyed Mohammad Reza Rabani

    2010-12-01

    Full Text Available Uretero-Pelvic Junction Obstruction (UPJO is a common congenitalanomaly that may need pyeloplasty to prevent renalfunction deterioration. The purpose of this study was to describea modified use of jj stent catheter in pyeloplasty for infantwith UPJO. A series of 12 children, between 3 and 10months, underwent stenting open pyeloplasty. In each patient a6 French Foley catheter was placed within the bladder. One mlsterile methylene blue was instilled into the catheter, which wasclamped during the operation time. During a dismembered pyeloplasty,a small (3F double j stent was placed through theflank into renal pelvis, passing the flank skin, muscles and enteringvia lower pole posteriorly to pass the anastomosis andentering the ureter and urinary bladder, confirmed by observingmethylene blue within the wound. The external end of the jjcatheter was doubled up and sutured to the flank skin and thenremoved 4 weeks later. No procedure related complication(ssuch as extravasation, infection, and stent displacement wasseen. The duration of follow up was 6 months to 3 years. Thismethod of stenting pyeloplasty is easily tolerated and causes noneed for endoscopic removal of the catheter. It is an invaluabletechnique of pyeloplasty with stenting in very small children,and needs no external appliance.Iran J Med Sci 2010; 35(4: 319-322.Keywords ● Hydronephrosis ● newborn infant

  14. Comparison of intravenous urography and magnetic resonance urography in preoperative evaluation of pelvi-ureteric junction obstruction in children.

    Science.gov (United States)

    Sharma, Alok; Sodhi, Kushaljit Singh; Saxena, Akshay Kumar; Bhatia, Anmol; Menon, Prema; Rao, Katragadda L N; Khandelwal, Niranjan

    2016-01-01

    To compare intravenous urography (IVU) and magnetic resonance urography (MRU) in the preoperative evaluation of pelvi-ureteric junction obstruction (PUJO) in children. A total of 35 children up to 10 years of age in whom unilateral or bilateral PUJO were suspected on ultrasonography were enrolled in this prospective study. All children underwent IVU and MRU, and the findings were compared. Of the 70 kidneys evaluated, 14 (20%) were not visualized on IVU because of nonexcretion of contrast, whereas all the 70 (100%) kidneys were visualized on MRU. On IVU, nephrogram was not visualized in 66 (94.2%) of the 70 kidneys, whereas MRU showed prompt and homogeneous nephrogram in 68 (97.1%) of the 70 kidneys. No evidence of PUJO was seen in 31 (44.2%) kidneys on both IVU and MRU. IVU showed PUJO in 26 (37.1%) kidneys, whereas MRU showed it in 38 (54.2%) kidneys. MRU detected two duplex systems that were missed on IVU. A focal renal lesion and two incidental extra renal abnormalities were detected on MRU, which were not visualized on IVU. MRU is better than IVU, especially in case of poorly functioning kidneys which are not visualized on IVU. MRU also provides anatomic details of the ureter and vessels with better evaluation of renal parenchyma. It also has an additional advantage of detecting incidental extra renal abnormalities, if present.

  15. Minimal invasive treatment of ureteropelvic junction obstruction in low volume pelvis: A comparative study of endopyelotomy and laparoscopic nondismembered pyeloplasty

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    Pratipal Singh

    2009-01-01

    Full Text Available Objective: To evaluate the role of nondismembered laparoscopic pyeloplasty and percutaneous endopyelotomy for ureteropelvic junction obstruction (UPJO with low volume renal pelvis. Material and Methods: Retrospective acquired data of 34 patients of laparoscopic nondismembered pyeloplasty was compared with 26 patients of UPJO with pelvic volume less than 50 ml undergoing antegrade endopyelotomy and analyzed for clinical parameters, operative outcomes and success of procedures. All patients were followed up clinically and with diuretic renogram at regular intervals. Results: Mean age, renal pelvic volume and preoperative glomerular filtration rate (GFR was 25 years, 43.6 ml and 42.5 ml/min, respectively in endopyelotomy group and 21 years, 34.4 ml and 39.9 ml/min, respectively in laparoscopic pyeloplasty group. Mean operative time, postoperative analgesic requirement and mean hospital stay was 100min, 250 mg and 4 days, respectively in endopyelotomy group and 210 min, 300 mg and 4 days, respectively in laparoscopic pyeloplasty group. Only operative time was significantly different between two groups (P < 0.05. Mean follow-up was 36 and 39 months and success rates were 91.2% and 88.8% in laparoscopy and endopyelotomy group, respectively (P < 0.05. No significant complication was seen in endopyelotomy group while two patients had hematuria (one requiring blood transfusion and three had increased drain output for more than 3 days in laparoscopy group. Conclusion: Percutaneous endopyelotomy is associated with significantly less operative time and postoperative complication rate and provides equivalent success in comparison to nondismembered laparoscopic pyeloplasty in patients with UPJO and low volume pelvis. It can be a preferred minimally invasive treatment modality for such patients.

  16. Transverse comparisons between ultrasound and radionuclide parameters in children with presumed antenatally detected pelvi-ureteric junction obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Duong, Hong Phuoc; Janssen, Francoise; Hall, Michelle; Ismaili, Khalid [Universite Libre de Bruxelles (ULB), Department of Pediatric Nephrology, Hopital Universitaire des Enfants Reine Fabiola, Brussels (Belgium); Piepsz, Amy [Hopital Universitaire Saint-Pierre, Department of Radioisotopes, Ghent (Belgium); Khelif, Karim; Collier, Frank [Universite Libre de Bruxelles (ULB), Department of Pediatric Urology, Hopital Universitaire des Enfants Reine Fabiola, Brussel (Belgium); Man, Kathia de [University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium); Damry, Nash [Universite Libre de Bruxelles (ULB), Department of Pediatric Radiology, Hopital Universitaire des Enfants Reine Fabiola, Brussel (Belgium)

    2015-05-01

    The main criteria used for deciding on surgery in children with presumed antenatally detected pelviureteric junction obstruction (PPUJO) are the level of hydronephrosis (ultrasonography), the level of differential renal function (DRF) and the quality of renal drainage after a furosemide challenge (renography), the importance of each factor being far from generally agreed. Can we predict, on the basis of ultrasound parameters, the patient in whom radionuclide renography can be avoided? We retrospectively analysed the medical charts of 81 consecutive children with presumed unilateral PPUJO detected antenatally. Ultrasound and renographic studies performed at the same time were compared. Anteroposterior pelvic diameter (APD) and calyceal size were both divided into three levels of dilatation. Parenchymal thickness was considered either normal or significantly decreased. Acquisition of renograms under furosemide stimulation provided quantification of DRF, quality of renal drainage and cortical transit. The percentages of patients with low DRF and poor drainage were significantly higher among those with major hydronephrosis, severe calyceal dilatation or parenchymal thinning. Moreover, impaired cortical transit, which is a major risk factor for functional decline, was seen more frequently among those with very severe calyceal dilatation. However, none of the structural parameters obtained by ultrasound examination was able to predict whether the level of renal function or the quality of drainage was normal or abnormal. Alternatively, an APD <30 mm, a calyceal dilatation of <10 mm and a normal parenchymal thickness were associated with a low probability of decreased renal function or poor renal drainage. In the management strategy of patients with prenatally detected PPUJO, nuclear medicine examinations may be postponed in those with an APD <30 mm, a calyceal dilatation of <10 mm and a normal parenchymal thickness. On the contrary, precise estimation of DRF and renal

  17. Significance of MR angiography in the diagnosis of aberrant renal arteries as the cause of ureteropelvic junction obstruction in children; Stellenwert der MR-Angiografie in der Diagnostik aberrierender Nierenarterien als Ursache einer Ureterabgangsstenose bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, L.; Sorge, I.; Hirsch, F.W.; Vieweger, A. [Leipzig Univ. (Germany). Dept. of Pediatric Radiology; Goetz, G.; Lehnert, T.; Buehligen, U.; Geyer, C. [Leipzig Univ. (Germany). Dept. of Pediatric Surgery

    2015-01-15

    To determine the importance of MRI with contrast-enhanced MRA for the detection or exclusion of aberrant or obstructing renal arteries in ureteropelvic junction obstruction in children. Key word-based search in RIS database (ureteropelvic junction obstruction/MRI) and retrospective comparison of arterial findings from preoperative contrast-enhanced MRA and intra-operative inspection. From 2007 to 2013, 19 children with ureteropelvic junction obstruction underwent contrast-enhanced MRA. Based on the results of the MRI scan and MAG3 scintigraphy, the children were referred to surgery (Anderson-Hynes-pyeloplasty). An aberrant renal artery was diagnosed with MRI in 14 of 19 children, and intra-operative inspection confirmed 13 of those 14. In the remaining 5 children, no aberrant vessel could be observed in MRI and this was confirmed intra-operatively in 3 of the 5 cases, while in the remaining 2, an aberrant vessel was found. Of the 14 children with aberrant vessels, 12 underwent surgery due to assumed ureteral obstruction, which was confirmed by surgery in 11 cases. In one case, an aberrant artery was found intra-operatively, but obstruction could not be confirmed. In one of the 14 children, the vessel was found in MRI, but its obstructing character was negated via MRA, which was confirmed intra-operatively. In the diagnosis of aberrant and obstructing renal arteries, contrast-enhanced MRA presents 85 % sensitivity and 80 % specificity, with a positive predictive value of 0.8. MRI with contrast-enhanced MRA is suitable to detect aberrant and obstructing renal arteries. An obstructive effect of the aberrant vessel is to be assumed if the vessel has a close relationship to the ureteropelvic junction and if it is linearly stretched.

  18. Spontaneous Perforation of the UPJ: A Case Report and Review of the Literature

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    K. Searvance

    2017-01-01

    Full Text Available Spontaneous rupture of the ureter is an uncommon condition defined by non-traumatic extravasation of urine. Causative factors leading to rupture include urinary calculi, malignancies, instrumentation or trauma. Ureteral rupture can lead to numerous complications, including abscess formation, urinomas, and urosepsis. Minimal literature is available regarding spontaneous ureteral perforation, especially at the ureteropelvic junction. We present a rare case of spontaneous perforation of the ureter at the ureteropelvic junction caused by an undiagnosed non-compliant bladder. This case illustrates a previously undescribed cause of spontaneous ureteral perforation and the importance of prompt identification and treatment.

  19. Simultaneous laparoscopic management of ureteropelvic junction obstruction and renal lithiasis: the combined experience of two academic centers and review of the literature

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    Stravodimos KG

    2014-05-01

    Full Text Available Konstantinos G Stravodimos,1 Stilianos Giannakopoulos,2 Stavros I Tyritzis,1 Aristeides Alevizopoulos,1 Stefanos Papadoukakis,1 Stavros Touloupidis,2 Constantinos A Constantinides11Department of Urology, Athens University Medical School, Laiko Hospital, Athens, 2Department of Urology, Democritus University of Thrace, Alexandroupolis, GreeceIntroduction: Approximately one out of five patients with ureteropelvic junction obstruction (UPJO present lithiasis in the same setting. We present our outcomes of simultaneous laparoscopic management of UPJO and pelvic or calyceal lithiasis and review the current literature.Methods: Thirteen patients, with a mean age of 42.8±13.3 years were diagnosed with UPJO and pelvic or calyceal lithiasis. All patients were subjected to laparoscopic dismembered Hynes–Anderson pyeloplasty along with removal of single or multiple stones, using a combination of laparoscopic graspers, irrigation, and flexible nephroscopy with nitinol baskets.Results: The mean operative time was 218.8±66 minutes. In two cases, transposition of the ureter due to crossing vessels was performed. The mean diameter of the largest stone was 0.87±0.25 cm and the mean number of stones retrieved was 8.2 (1–32. Eleven out of 13 patients (84.6% were rendered stone-free. Complications included prolonged urine output from the drain in one case (Clavien grade I and urinoma formation requiring drainage in another case (Clavien grade IIIa. The mean postoperative follow-up was 30.2 (7–51 months. No patient has experienced stone or UPJO recurrence.Conclusion: Laparoscopy for the management of UPJO along with renal stone removal seems a very appealing treatment, with all the advantages of minimally invasive surgery. Concomitant renal stones do not affect the outcome of laparoscopic pyeloplasty, at least in the midterm. According to our results and the latest literature data, we advocate laparoscopic management as the treatment of choice for these cases

  20. Comparison of Retrograde Balloon Dilatation and Laparoscopic Pyeloplasty for Treatment of Ureteropelvic Junction Obstruction: Results of a 2-Year Follow-Up.

    Directory of Open Access Journals (Sweden)

    Ning Xu

    Full Text Available To evaluate the efficacy of laparoscopic pyeloplasty relative to retrograde balloon dilatation for the treatment of ureteropelvic junction obstruction (UPJO.This retrospective study enrolled UPJO patients with stricture length < 2 cm who had been treated with laparoscopic pyeloplasty (LP; 44 cases or balloon dilatation (BD; 38 cases from Jan 2010 to Jan 2012, according to patients' preference after consultation. Demographics and clinical parameters were collected. Patients were followed-up at 3, 6, 12, and 24 months. Ultrasonography, intravenous urography, and diuretic renography were applied to evaluate the remission of hydronephrosis.Both groups were comparable with respect to age, UPJO location, gender, and other baseline parameters. Compared to the LP group, patients receiving BD experienced significantly shorter operative time, analgesia time, hospital stay, and urethral catheter indwelling time, and less cost (P<0.001. Three and 6 months after their respective procedures, the success rates of the LP (97.7%, both and BD (94.7% and 86.8% groups were similar, and at 12 and 24 months the long-term success rate of LP (95.5%, both was better than that of BD (78.9% and 71.0%.LP showed better long-term success rate than did BD in the management of UPJO with length of stricture < 2 cm. Considering that BD is more minimally invasive, simpler and easier to perform, and costs less, we recommend it for some selective UPJO patients as the first-line therapy.

  1. Obstructive Uropathy in Sudanese Patients

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    El Imam M

    2006-01-01

    Full Text Available In this paper we describe the causes, patterns of presentation, and management of obstructive uropathy in Sudanese patients in a retrospective multi-center audit. All patients who presented with obstructive uropathy during 2005 were included in this study. All of the patients were subjected to serial investigations including imaging and tests of renal function. Diversion, stenting, and/or definitive surgery were performed in order to relieve the obstruction. Five hundred twenty patients were diagnosed with obstructive uropathy during this period; 345 (66% patients presented with chronic obstruction and 175 (34% with acute obstruction. Of the study patients, 210 (40% presented with significant renal impairment; 50 (23% of them required emergent dialysis. The patterns of clinical presentation of the obstructed patients included pain at the site of obstruction in 48%, lower urinary tract symptoms in 42%, urine retention in 36.5%, mass effect in 22%, and anuria in 4%. Patients in the pediatric age group constituted 4% of the total. The common causative factors of obstruction included congenital urethral valves, pelvi-ureteral junction obstruction, urolithiasis, and iatrogenic trauma, especially in the obstetric practice. Renal function was completely recovered with early management in 100% of patients with acute obstruction and was stabilized in 90% of patients with chronic obstruction. Four patients were diagnosed with end-stage renal failure; two of them were transplanted. The mortality rate in this study was less than 0.3%.

  2. Laparoscopically assisted pyeloplasty for ureteropelvic junction ...

    African Journals Online (AJOL)

    junction obstruction: a transperitoneal versus a retroperitoneal approach ... laparoscopic-assisted dismembered pyeloplasty (TLADP) ... to an open technique for two patients of the TLADP group; ... Annals of Pediatric Surgery 2012, 8:29–31.

  3. Assessment of Pelvo- ureteric Junction Obstruction in Children with Diuretic Ultrasound%利尿B超诊断小儿肾盂输尿管连接部梗阻

    Institute of Scientific and Technical Information of China (English)

    文建国; 申涛; 孙雁龄; 王明太; 文兰田; 黄敏

    1995-01-01

    In order to evaluate the reliability of the diuretic ultrasound diagnosis of the pelvi- ureteric junction obstruction ( PUJO ), 25 patients ( 34 kidneys ) with hydronephrosis (Hn) were examined with diuretic ultrasound. Being compared with those of IVU, the Whitaker test, the operative findings, and the diuretic ultrasound examination in healthy children, the results in children with PUJO showed significantly increasing of pyelotasis (average increased by 105%) as the failure of returning to the original condition within 90 minutes after diuresis. The results of PUJO were significantly different from those of hydronephrosis due to reflux, lower ureteric or lower urinary obstruction, or The normal kidneys (P< 0.05). Diuretic ultrasound will play a useful role in the investigation of PUJO.%为了解利尿B超诊断小儿肾盂输尿管连接部梗阻(PUJO)的意义,对25例(34侧)小儿肾积水进行利尿B超检查,将检查结果与IVU、肾盂测压、手术中所见病理改变及正常肾脏检查结果进行比较.结果显示利尿后PUJO患儿肾脏集合系统明显扩大,平均较利尿前扩大105%,利尿后90 min仍不能恢复.同返流、输尿管远端或下尿路梗阻引起的肾积水及正常肾脏检查结果比较有显著性差异(P<0.05).利尿B超可作为判断PUJO的方法之一.

  4. Theoretical Analysis and Simulation of BJFET Obstructive Characteristics

    Institute of Scientific and Technical Information of China (English)

    ZENG Yun; YAN Min; YAN Yong-hong; FAN Wei

    2005-01-01

    A new bipolar junction field-effect transistor (BJFET) was described. The theoretical analysis and computer simulation of BJFET obstructive characteristic are achieved. The gate bias voltage affects the BJFET obstructive voltage greatly. The BJFET obstructive characteristic is relevant to structure parameters of channel width W and channel length L.The decrease-bias-voltage operation can weaken the device obstructive characteristic. The forward turn in device forward obstructive region can also affect the BJFET obstructive characteristic. BJFET has a good high temperature obstructive characteristic and can be applying to high temperature status as high voltage switch devices.

  5. Cervicomedullary neurocysticercosis causing obstructive hydrocephalus.

    Science.gov (United States)

    Wang, Doris D; Huang, Michael C

    2015-09-01

    We present a 45-year-old man with tussive headache and blurred vision found to have obstructive hydrocephalus from a neurocysticercal cyst at the cervicomedullary junction who underwent surgical removal of the cyst. We performed a suboccipital craniectomy to remove the cervicomedullary cyst en bloc. Cyst removal successfully treated the patient's headaches without necessitating permanent cerebrospinal fluid diversion. Neurocysticercosis is the most common parasite infection of the central nervous system causing seizures and, less commonly, hydrocephalus. Intraventricular cysts or arachnoiditis usually cause hydrocephalus in neurocysticercosis but craniocervical junction cysts causing obstructive hydrocephalus are rare. Neurocysticercosis at the craniocervical junction may cause Chiari-like symptoms. In the absence of arachnoiditis and leptomeningeal enhancement, surgical removal of the intact cyst can lead to favorable outcomes.

  6. Intestinal obstruction

    Science.gov (United States)

    Paralytic ileus; Intestinal volvulus; Bowel obstruction; Ileus; Pseudo-obstruction - intestinal; Colonic ileus ... objects that are swallowed and block the intestines) Gallstones (rare) Hernias Impacted stool Intussusception (telescoping of 1 ...

  7. Obstructive Sleep Apnea

    Science.gov (United States)

    ... to find out more. Obstructive Sleep Apnea Obstructive Sleep Apnea Obstructive sleep apnea (OSA) is a serious ... to find out more. Obstructive Sleep Apnea Obstructive Sleep Apnea Obstructive sleep apnea (OSA) is a serious ...

  8. Gap Junctions

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  9. Gap junctions.

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2012-07-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1853-1872, 2012.

  10. Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients.

    Science.gov (United States)

    Turrà, Francesco; Escolino, Maria; Farina, Alessandra; Settimi, Alessandro; Esposito, Ciro; Varlet, François

    2016-10-01

    Hydronephrosis is the most common presentation of ureteropelvic junction (UPJ) obstruction. We reviewed literature, collecting data from Medline, to evaluate the current status of minimally invasive surgery (MIS) approach to pyeloplasty. Since the first pyeloplasty was described in 1939, several techniques has been applied to correct UPJ obstruction, but Anderson-Hynes dismembered pyeloplasty is established as the gold standard, to date also in MIS technique. According to literature several studies underline the safety and effectiveness of this approach for both trans- and retro-peritoneal routes, with a success rate between 81-100% and an operative time between 90-228 min. These studies have demonstrated the safety and efficacy of this procedure in the management of UPJ obstruction in children. Whether better the transperitoneal, than the retroperitoneal approach is still debated. A long learning curve is needed especially in suturing and knotting.

  11. Double obstruction of ureter: A diagnostic challenge

    Directory of Open Access Journals (Sweden)

    Pankaj Halder

    2014-01-01

    Full Text Available Introduction: Isolated obstruction of the ureteropelvic junction and the vesico-ureteric junction are the two most common causes of hydronephrosis in a pediatric population. [1] They do not pose diagnostic difficulties when are present alone but when together can be difficult to diagnose. Here, we discuss the problems we faced when we encountered these two anomalies in the same ureter and the way in which we managed them. Aim: To assess the difficulties in diagnosis of pediatric patients who present with both ureteropelvic junction obstruction (UPJO and vesico-ureteric junction obstruction (VUJO in the ipsilateral ureter and their management protocol. Materials and Methods: This is a retrospective study. The study period is from 1 January 2004 to 31 December 2011. Out of 254 children who were diagnosed to have hydronephrosis due to UPJO in our institute, 5 patients (in the age range of 5 to 10 years had both UPJO and VUJO in the ipsilateral ureter. The problems we faced in diagnosing the two conditions are mentioned with a literature review. Results: Operative intervention was used in four out of five patients; none of the patients had an accurate diagnosis before surgery. All patients were suspected of having double obstruction during pyeloplasty when appropriate size double J stent could not be negotiated through the vesicoureteric junction into the bladder. Postoperative nephrostogram confirmed the diagnosis in all patients. Conclusion: Children with double obstruction of the ipsilateral ureter present as a diagnostic dilemma. Because of the rarity of this condition it can escape the eye of even an astute clinician. Early diagnosis can be made if this condition is kept in mind while treating any hydronephrosis due to UPJO or UVJO.

  12. 继发性输尿管梗阻对大鼠肾盂输尿管交界处ICC样细胞的影响%The effects of artificial ureteral obstruction on interstitial cell of Cajal-like cells in rats

    Institute of Scientific and Technical Information of China (English)

    张洪宪; 马潞林; 陆敏; 赵磊; 田晓军; 王国良; 黄毅

    2011-01-01

    目的 探讨继发性输尿管梗阻后大鼠肾盂输尿管交界处ICC样细胞形态和密度的变化规律.方法 清洁级SD大鼠35只,随机分为7组,每组5只.大鼠被分为三个大组,5只作为正常对照组(C),5只作为假手术组(S),其余作为实验组:梗阻3 d组(S1)、梗阻1周组(S2)、梗阻2周组(S3)、梗阻4周组(S4)、梗阻8周组(S5).实验组动物建立左侧输尿管完全梗阻模型.取肾盂输尿管交界处上下各0.2 cm输尿管采用免疫组织化学显色,光镜下计数ICC样细胞密度并观察形态.结果 所有实验组大鼠左肾盂及输尿管均见明显扩张积水,动物模型建立成功.各组ICC样间质细胞的密度分别为:C(7.20±2.29)个/视野,S(7.02±2.68)个/视野,S1(3.54±1.85)个/视野,S2(6.30±1.19)个/视野,S3(4.30±0.67)个/视野,S4(4.42±1.45)个/视野,S5(4.70±1.09)个/视野.除了S2组以外的各实验组ICC样间质细胞的密度较正常对照组(C)和假手术组(S)有所下降(P均<0.05),但呈现出先下降后上升再下降的趋势,这种差异在各个实验组之间无统计学意义.结论 大鼠肾盂输尿管交界处ICC样间质细胞的密度变化与输尿管蠕动活性关系密切,为将来研究ICC样间质细胞在泌尿系统中的作用奠定了一定的基础.%Objective To determine the changes in density and moiphology of interstitial cells of Cajal (ICC)-like cells (ICC-LC) at the ureteropelvic junction ( UPJ) of rats after artificial distal ureteral ohstruction. Materials and Methods Of a total of 35 rats,5 served as controls ( C) ,5 underwent shamoperations (SH) and 25 were in the study (S) groups. The UPJs were extracted initially in the C and SH groups , and 3 ,7 ,14 ,28 ,56 days after ligation of the distal ureter in the study groups ( S1 , S2 , S3 , S4 and S5 ,respectively). The sections stained by c-kit anticore were studied under a light microscope .Results Ureterohydronephrosis was observed in all the rats after the obstruction was

  13. Obstructive uropathy

    Science.gov (United States)

    ... uropathy URL of this page: //medlineplus.gov/ency/article/000507.htm Obstructive uropathy To use the sharing ... cancer Colon cancer Cervical cancer Uterine cancer Any ... blockage. A Foley catheter, placed through the urethra into the bladder, may also be help urine ...

  14. Obstructed uterus

    Energy Technology Data Exchange (ETDEWEB)

    Scott, W.W.; Rosenshein, N.B.; Siegelman, S.S.; Sanders, R.C.

    1981-12-01

    Eleven patients with an obstructed, fluid-filled uterus, due to carcinoma of the uterus or to its treatment by radiation therapy, were examined with computed tomography (CT) and/or ultrasound. It is important to recognize this abnormality to differentiate it from other causes of pelvic mass and to ensure prompt treatment of pyometra, should it develop. Both CT and ultrasound reliably identified this condition and differentiated it from other pelvic masses.

  15. 磁共振尿路成像技术在诊断新生儿先天性肾盂输尿管连接部梗阻中的应用%Clinical applications of magnetic resonance urography technique in diagnosing congenital ureteropelvic junction obstruction in the newborn

    Institute of Scientific and Technical Information of China (English)

    戈明媚; 刘志钦; 王秋良; 吴新淮; 张宗丽

    2012-01-01

    Objective To evaluate the magnetic resonance urography ( MRU ) on the diagnosis of congenital ureteropelvic junction obstruction( CUJO )in the neonatess. Methods MRU imaging data and surgical results of the newborns who underwent surgery at the Beijing Military General Hospital from 2010 to 2011 were retrospectively studied . The sequences of MRU included 3D MRU, conventional axial fast recovery fast spin-echo( FRFSE ) T2WI and fast imaging employing steady acquisition( FIESTA ). The 3D-MRU were reconstructed on AW4. 2 workstation with maximum intensity projection( MIP ), volume rendering( VR ) and Reformat methods. Results A total of 21 patients were enrolled, and fetal hydronephrosis were diagnosed using ultrasound during pregnancy and became more severe after birth with or without clinical signs. MRU showed 1 case with bilateral hydronephrosis, 7 cases with right-side hydronephrosis and ureteropelvic junction obstruction, and 13 cases with left-side hydronephrosis and ureteropelvic junction obstruction. All patients underwent surgical treatment, including thirteen left laparoscopic pyeloplasty and cystoscopy, six right laparoscopic pyeloplasty and cystoscopy, one umbilical one-trocar laparoscopic nephroureterectomy of the right kidney, and one bilateral laparoscopic pyeloplasty and cystoscopy. All postoperative diagnosis were consistent with the MRU diagnosis. Conclusion As a multi-angle, multi-faceted, multi-parameter imaging technique with no radiation exposure, MRU has become an important method on the diagnosis, differential diagnosis and the preparation of surgery of neonatal CUJO.%目的 探讨磁共振尿路成像(MRU)技术在诊断新生儿先天性肾盂输尿管连接部梗阻(CUJO)中的应用价值.方法 回顾性分析2010-2011年在我院行MRU检查的新生儿影像资料及手术结局.MRU检查序列包括3D尿路成像、常规轴位快速恢复快速自旋回波T2WI和稳态采集快速成像.所有图像在AW4.2工作

  16. Low morbidity after palliation of obstructing gastro-oesophageal adenocarcinoma to restore swallowing function

    DEFF Research Database (Denmark)

    Kofoed, Steen Christian; Lundsgaard, Martin; Ellemann, Ann-Camilla;

    2012-01-01

    This study describes the procedure-related complications and survival after deployment of self-expanding metal stents (SEMS) or use of argon plasma coagulation (APC) in patients with obstructing gastro-oesophageal junction (GEJ) adenocarcinoma.......This study describes the procedure-related complications and survival after deployment of self-expanding metal stents (SEMS) or use of argon plasma coagulation (APC) in patients with obstructing gastro-oesophageal junction (GEJ) adenocarcinoma....

  17. Quantitative Assessment of Obstructive Uropathy with Diuretic Renography in children

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Ho; Lee, Dong Soo; Kwark, Cheol Eun; Lee, Kyung Han; Choi, Chang Woon; Chung, June Key; Lee, Myung Chul; Koh, Chang Soon; Choi, Yong; Choi, Hwang [Seoul National University Hospital, Seoul (Korea, Republic of)

    1993-07-15

    Differentiating the various causes of hydronephrosis from that of obstruction can be very difficult. The decision-marking process for those instances of urinary tract dilatation that require surgical correction and those that do not is based in part on the findings of diuresis renography. The methodology for performing this test has differed among nuclear medicine practitioners and the surgical findings are occasionally discrepant from the diuretic renogram interpretation. Consequently we made an automatic computer software program that calculates the slope of the response curve. The quantitative indices, such as the injection and response t1/2 by linear-fitting and monoexponential-fitting, were compared with the visual assessment of the diuretic cinerenography and clinical outcome in 50 children (62 kidneys) with ureteropelvic junction obstruction. Pooled diuresis renogram data indicated that: (1) Visual evaluation of the diuretic cinerenography is a sensitive (87%, 54/62) tool to differentiate obstruction in suspected ureteropelvic junction obstruction. (2) The cut-off value (maximum washout t1/2 with non-obstruction) of injection and response t1/2 by linear-fitting were 40 min. (3) The sensitivity and specificity using injection and response t1/2 by linear-fitting for obstruction were 89%(23/26) and 100%(30/30), respectively. (4) Response t1/2 as well as injection t1/2 by monoexponential-fitting do not stratify children with possible ureteropelivic junction obstruction. In conclusion, quantitative assessment of diuretic renography as well as visual assessment of diuretic cinerenography correlate well with surgical and clinical outcome of suspected ureteropelvic junction obstruction.

  18. 继发性输尿管梗阻对大鼠活体输尿管蠕动规律及ICC样间质细胞的影响%The Effects of Artificial Ureteral Obstruction on Ureteral Peristalsis in Vivo and Interstitial Cell of Cajal-like Cells in Rats

    Institute of Scientific and Technical Information of China (English)

    张洪宪; 马潞林; 陆敏; 赵磊; 田晓军; 王国良; 黄毅

    2011-01-01

    Objective The aim of this study was to evaluate the ureteral motility of rats in vivo and to determine the changes in density and morphology of interstitial cells of Cajal ( ICC ) -like cells (ICC-LC ) at the ureteropelvic junction (UPJ) of rats after artificial distal ureteral obstruction. Then, the correlationship was assessed between these two aspects. Methods Of a total of 35 rats, 5 served as controls (C) , 5 underwent sham-operations ( SH ) and 25 were in the study (S) groups. The left ureters of the rats in the S groups were tied with 5-zero silk ligature approximately 3 mm proximal to the ureterovesical junction ( UVJ). The ureteral motility of rats was measured by external pressure transducers. The UPJs were extracted initially in the C and SH groups, and 3, 7, 14, 28, 56 days after ligation of the distal ureter in the study groups (SI, S2, S3, S4 and S5, respectively). The sections stained by c-kit anticore were studied under a light microscope. Results Ureterohydronephrosis was observed in all the rats after the obstruction was established. The mean number of ureteral peristaltic rate was ( 19. 6 ±4. 037)/ min in C, (18.8 ±2. 168)/min in S, (4.6 ±1. 140)/min in SI, (8. 0 ± 2. 345)/min in S2, (5.4 ±1.673)/ min in S3, (5. 4 ± 1. 517/min in S4, and (6. 2 ± 1. 789)/min S5. There was a statistically significant decrease in ureteral peristaltic rate in the study groups compared to the C and SH groups. The mean number of ICC-LC was (7. 20±2. 29)/HP in C, (7.02 ±2.68)/HP in SH, (3.54 ± 1.85)/HP in SI, (6.30 ±1. 19)/HP in S2, (4. 30 ±0. 67)/HP in S3, (4.42 ± 1. 45)/HP in S4, and (4. 70 ± 1. 09)/HP in S5. There was a statistically significant decrease in ICC-LC density in the study groups, except S2, compared to the C and SH groups. No significant difference was detected in Cajal cell morphology between groups. Conclusion Based on the changes in density of ICC-LC at the UPJ after obstruction of the distal ureter, we suggest that ICC-LC have a close

  19. An unusual cause of chronic abdominal pain after laparoscopic Roux en Y gastric bypass: Case report of a penetrating fish bone causing adhesions at the biliary-digestive junction resulting in partial obstruction and chronic symptoms

    Science.gov (United States)

    Ochieng, Vincent; Hendrickx, Leo; Valk, Jody

    2016-01-01

    Background The management of chronic abdominal pain after laparoscopic Roux-en-Y gastric bypass (LRYGP) is complex and challenging. Foreign body intestinal perforation including that caused by fish bones has previously been reported in the literature and if clinically unrecognized, can cause significant morbidity and mortality. Fish bone perforation as a cause of chronic abdominal pain after LRYGP has rarely been reported. Summary The unusual case of a 54 year old female presenting with recurrent episodes of postprandial pain 2 years after LRYGP is reported. Previous radiological and endoscopic investigations did not reveal any abnormality and after the most recent clinical presentation, a laparoscopic exploration was performed. A protruding fish bone at the biliary-digestive junction was discovered intra-operatively and successfully extracted. Dense adhesions between the involved intestinal loops were lysed in an attempt to improve intestinal transit and subsequently relieve post-prandial pain. Conclusion This case highlights the possibility of a missed fish bone perforation causing chronic postprandial abdominal pain and discomfort in a patient with a Roux-en-Y gastric bypass anatomy. Foreign body perforation is a rare cause of abdominal pain after gastric bypass that should be considered when evaluating chronic abdominal pain symptoms after LRYGP. PMID:27107305

  20. 补片整形术治疗小儿先天性肾盂输尿管连接处梗阻%Pyeloueteroplasty Using a Pelvic Patch for the Treatment of Congenital Obstruction of the Pelviureteric Junction

    Institute of Scientific and Technical Information of China (English)

    李衷初; 葛人铨; 郑玉衡

    1985-01-01

    @@ 先天性肾盂输尿管连接处梗阻是造成小儿肾积水最常见的原因,由于小儿特别是5岁以下的幼儿肾功能的代偿和修复能力很强,故目前的治疗观点是一致的,即尽可能采用保留肾的整形术.作者于1976年设计了一种补片整形手术,至1982年已施行了10例,效果良好.%From 1976 to 1982.10 pediatric cases of hydronephrosis due to pelviureteric obstruction were surgically treated by pyeloureteroplasty using a piece of pelvic patch with satisfactory result.The procedure was designed by the authors in 1976.The success rate was almost 100 percent.This new method has advantages as follows:(1)retainning the intact pelvic funnel,which can better conform with physiology of unination;(2)making it feasible to resect the majority of the dilated and nonelastic pelvis so as to diminish dead cavity;(3)being easy to do,as the pelvis-to-pelvis anastomosis is easier than that between pelvis and ureter,with little risk of resultant stricture of anastomosis,and tension;(4)peristalsis can be seen on the patch on television screen during the intravenous pyelography,which demonstrates this pyeloureteroplasty has contributed to transporting urine.

  1. Molecular electronic junction transport

    DEFF Research Database (Denmark)

    Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

    2012-01-01

    Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

  2. Pancreatic ductal system obstruction and acute recurrent pancreatitis

    Institute of Scientific and Technical Information of China (English)

    M Delhaye; C Matos; M Arvanitakis; J Devière

    2008-01-01

    Acute recurrent pancreatitis is a clinical entity largely associated with pancreatic ductal obstruction.This latter includes congenital variants,of which pancreas divisum is the most frequent but also controversial,chronic pancreatitis,tumors of the pancreaticobiliary junction and sphincter of Oddi dysfunction.This review summarizes current knowledge about diagnostic work-up and therapy of these conditions.

  3. Intestinal obstruction repair

    Science.gov (United States)

    Repair of volvulus; Intestinal volvulus - repair; Bowel obstruction - repair ... Intestinal obstruction repair is done while you are under general anesthesia . This means you are asleep and DO NOT feel pain. ...

  4. Obstructive sleep apnea - adults

    Science.gov (United States)

    Sleep apnea - obstructive - adults; Apnea - obstructive sleep apnea syndrome - adults; Sleep-disordered breathing - adults; OSA - adults ... When you sleep, all of the muscles in your body become more relaxed. This includes the muscles that help keep your ...

  5. Doppler sonographic renal resistance index and resistance index ratio in children and adolescents with unilateral hydronephrosis

    Energy Technology Data Exchange (ETDEWEB)

    Brkljacic, Boris [Department of Radiology, University Hospital ' ' Dubrava' ' , Av. G. Suska 6, 10000 Zagreb (Croatia); Kuzmic, Andrea Cvitkovic; Dmitrovic, Romana [Department of Pediatric Nephrology, Children' s Hospital, Klaiceva 16, 10000 Zagreb (Croatia); Rados, Marko [Department of Radiology, University Hospital Center, Kispaticeva 12, 10000 Zagreb (Croatia); Vidjak, Vinko [Department of Radiology, University Hospital ' ' Merkur' ' , Zajceva 19, 10000 Zagreb (Croatia)

    2002-11-01

    The aim of this study was to evaluate Doppler renal resistance index (RI) and RI ratio (RIR) in differentiating between obstructive and nonobstructive hydronephrosis in children and adolescents. The RI and RIR were measured in 32 healthy examinees (control group) and 29 patients with unilateral hydronephrosis. Ten patients had acute obstruction caused by a ureteric stone. Seven had obstructive hydronephrosis due to uretero-pelvic junction (UPJ) obstruction. Twelve patients had nonobstructive hydronephrosis. In controls the mean RI{+-}S.D. was 0.615{+-}0.04, and RIR 1.045{+-}0.033. In children with acute obstruction RI was 0.692{+-}0.035 and RIR 1.148{+-}0.037. In UPJ obstruction RI was 0.631{+-}0.054 and RIR 1.059{+-}0.047. In nonobstructive dilatation RI was 0.61{+-}0.038 and RIR 1.043{+-}0.042. The RI and RIR differences were statistically significant between controls and patients with acute colic (p<0.01), and between patients with acute obstruction and with nonobstructive hydronephrosis (p<0.01). In detecting acute obstruction RI{>=}0.70 was found to have a 70% sensitivity and a 92% specificity. The RIR{>=}1.10 was found optimal to distinguish obstructive from nonobstructive dilatation (sensitivity 90%, specificity 83%). Both RI and RIR are significantly elevated in patients with acute obstruction. Renal Doppler seems to be useful in children and adolescents for the detection of acute renal obstruction, although it cannot differentiate chronic obstruction due to the UPJ obstruction and nonobstructive renal collecting system dilatation. (orig.)

  6. Magnetic tunnel junctions (MTJs)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We review the giant tunnel magnetoresistance (TMR) in ferromagnetic-insulator-ferromagnetic junctions discovered in recent years, which is the magnetoresistance (MR) associated with the spin-dependent tunneling between two ferromagnetic metal films separated by an insulating thin tunnel barrier. The theoretical and experimental results including junction conductance, magnetoresistance and their temperature and bias dependences are described.

  7. Stacked Josephson Junctions

    DEFF Research Database (Denmark)

    Madsen, Søren Find; Pedersen, Niels Falsig; Christiansen, Peter Leth

    2010-01-01

    Long Josephson junctions have for some time been considered as a source of THz radiation. Solitons moving coherently in the junctions is a possible source for this radiation. Analytical computations of the bunched state and bunching-inducing methods are reviewed. Experiments showing THz radiation...

  8. Obstructive Colitis Proximal to Obstructive Colorectal Carcinoma

    Directory of Open Access Journals (Sweden)

    Hye Kyung Chang

    2009-01-01

    Full Text Available The term “obstructive colitis” refers to ulceroinflammatory lesions occurring in the colon proximal to a completely or partially obstructing lesion. It has been referred to by various terms in the literature. This entity differs from the carcinoma of the colon that complicates true ulcerative colitis where there is involvement distal to the neoplasm as well as proximal to it. Although it has appeared in the literature over several decades, it remains an uncommon and troublesome disease. In Yonsei University Medical Center, for 11 years from January 1996 to December 2006 we encountered seven patients with obstructing colorectal carcinoma complicated by obstructive colitis. Here we report our cases to share our experience and to review the literature to facilitate the recognition and proper management of this rare disease entity.

  9. Gallstone impacted in the rectosigmoid junction causing a biliary ileus and a sigmoid perforation.

    Science.gov (United States)

    Van Kerschaver, O; Van Maele, V; Vereecken, L; Kint, M

    2009-01-01

    A gallstone ileus is an unusual form of bowel obstruction. Colonic gallstone ileus is rare, difficult to diagnose, and still has a high mortality rate. We present a case of biliary ileus caused by an impacted gallstone, causing necrosis and perforation of the rectosigmoid junction. A Hartmann's procedure was performed to treat the perforation and the obstruction. Cholecystectomy and closure of the cholecysto-colonic fistula were delayed until restoration of the intestinal continuity.

  10. Equivalent Josephson junctions

    Science.gov (United States)

    Boyadjiev, T. L.; Semerdjieva, E. G.; Shukrinov, Yu. M.

    2008-01-01

    The magnetic field dependences of critical current are numerically constructed for a long Josephson junction with a shunt-or resistor-type microscopic inhomogeneities and compared to the critical curve of a junction with exponentially varying width. The numerical results show that it is adequate to replace the distributed inhomogeneity of a long Josephson junction by an inhomogeneity localized at one of its ends, which has certain technological advantages. It is also shown that the critical curves of junctions with exponentially varying width and inhomogeneities localized at the ends are unaffected by the mixed fluxon-antifluxon distributions of the magnetic flow. This fact may explain the improvement of the spectra of microwave radiation noted in the literature.

  11. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  12. Benign segmental bronchial obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Loercher, U.

    1988-09-01

    The benigne segmental bronchial obstruction - mostly discovered on routine chest films - can well be diagnosed by CT. The specific findings in CT are the site of the bronchial obstruction, the mucocele and the localized empysema of the involved segment. Furthermore CT allows a better approach to the underlying process.

  13. Obstructive sleep apnea therapy

    NARCIS (Netherlands)

    Hoekema, A.; Stegenga, B.; Wijkstra, P. J.; van der Hoeven, J. H.; Meinesz, A. F.; de Bont, L. G. M.

    2008-01-01

    In clinical practice, oral appliances are used primarily for obstructive sleep apnea patients who do not respond to continuous positive airway pressure (CPAP) therapy. We hypothesized that an oral appliance is not inferior to CPAP in treating obstructive sleep apnea effectively. We randomly assigned

  14. Pathophysiology of increased intestinal permeability in obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal dysfunction. The key event in the pathophysiology of obstructive jaundice-associated complications is endotoxemia of gut origin because of intestinal barrier failure. This breakage of the gut barrier in obstructive jaundice is multi-factorial, involving disruption of the immunologic, biological and mechanical barrier.Experimental and clinical studies have shown that obstructive jaundice results in increased intestinal permeability. The mechanisms implicated in this phenomenon remain unresolved, but growing research interest during the last decade has shed light in our knowledge in the field. This review summarizes the current concepts in the pathophysiology of obstructive jaundice-induced gut barrier dysfunction, analyzing pivotal factors, such as altered intestinal tight junctions expression, oxidative stress and imbalance of enterocyte proliferation and apoptosis. Clinicians handling patients with obstructive jaundice should not neglect protecting the intestinal barrier function before, during and after intervention for the relief of this condition, which may improve their patients' outcome.

  15. 输尿管不全梗阻致兔肾积水动物模型的肾功能MR相关评估%The renal function study of MR perfusion of hydronephrosis due to ureteropelvic junction obstruction in the rabbit model

    Institute of Scientific and Technical Information of China (English)

    杨洋; 张潍平; 彭芸; 温洋; 杨吉刚

    2011-01-01

    Objective To study the feasibility of MR perfusion imaging in assessing renal function of hydronephrosis in animal model.Methods Ten New Zealand rabbits(10-week-old,Male) underwent ureteropelvic junction obstruction by embolied the right ureter of ureteropelvic junction into a plastic cannula.Before and two months after the surgery,the animals were performed both on SPECT and MR perfusion,MR perfusion parameters were assessed,and statistical analyses were performed on the GFR of SPECT and MR perfusion parameters.Results Majority MR perfusion parameters,such as volume of renal parenchyma(7608.00±951.29 mm3) and pSRF(0.3455±0.1226 ml/min) after operation were decreased than those before operation(8400.82±1082.25 mm3,0.5709±0.1472 ml/min,respectively).Statistic analysis showed that pSRF had good statistically relationship with GFR of SPECT(preoperation r=0.712,p=0.041,postoperation r=0.633,p=0.037).However,there were no obvious relation of volume of renal parenchyma with GFR after operation(r=0.312,p=0.079).Conclusions MR perfusion imaging can accurately assess animal model' renal function in hydronephrosis.MR perfusion nephrogram can provide the sufficient message which may have statistically relation with GFR of SPECT.%目的 探讨MR灌注成像技术对积水肾脏肾功能的评估价值.方法 应用塑料套管压迫法建立肾盂输尿管连接部梗阻致肾积水动物模型10只.模型建立前后分别对样本行核医学肾动态显像(单光子发射计算机体层成像SPECT)及MR灌注成像,并以病理检查为佐证,观察样本手术前后各项参数的变化,进行MR灌注参数与核素GFR的统计学相关性分析.结论 积水肾脏皮髓质MR灌注参数,包括积水肾脏的肾实质体积,术前(8400.82±1082.25)mm3,术后(7608.00±951.29)mm3 (P=0.021);基于Patlak技术推算出的分肾功能(Patlak SRF,pSRF),术前(0.5709±0.1472)ml/min,术后(0.3455±0.1226)ml/min(P=0.0092)以及核素扫描测得的GFR,术前(277.6±214.5)ml

  16. Esophagogastric junction distensibility in the management of achalasia patients: relation to treatment outcome

    NARCIS (Netherlands)

    Smeets, F.G.; Masclee, A.A.M.; Keszthelyi, D.; Tjwa, E.T.; Conchillo, J.M.

    2015-01-01

    BACKGROUND: Achalasia is characterized by a functional esophagogastric junction (EGJ) obstruction. The functional luminal imaging probe (EndoFLIP) is a method to assess EGJ distensibility. In a homogeneous group of newly diagnosed achalasia patients treated with pneumatic dilation (PD), we aimed (i)

  17. Wrecks and Obstructions

    Data.gov (United States)

    Department of Homeland Security — In 1981, NOAA�s National Ocean Service (NOS) implemented the Automated Wreck and Obstruction Information System (AWOIS) to assist in planning hydrographic survey...

  18. OBSTRUCTIVE NEPHROPATHY: ITS PHYSIOPATHOLOGY

    Directory of Open Access Journals (Sweden)

    Musso C

    2011-01-01

    Full Text Available Obstructive nephropathy is the functional and /or parenchymal renal damage secondary to the urinary tract occlusion at any part of it. The inducing urinary obstruction diseases can vary depending on the patient´s age and gender. There are many renal dysfunction inducing mechanisms involved in this entity: increase in the intra-luminal pressure, ureteral dilatation with ineffective ureteral peristalsis, glomerular ultrafiltration net pressure reduction, intra-renal glomerular blood flux reduction due to vasoconstriction, and local disease of chemotactic substances. Obstructive nephropathy can also lead to hypertension (vasoconstriction-hypervolemia, hyperkalemia, metabolic acidosis (aldosterone resistance, diabetes insipidus (vasopressine resistance. In conclusion, since obstructive nephropathy is a potentially reversible cause of renal dysfunction, it should always be taken into account among the differential diagnosis of renal failure inducing mechanisms.

  19. [Obstructive anuria. Thirty cases].

    Science.gov (United States)

    Bennani, S; Debbagh, A; Joual, A; el Mrini, M; Benjelloun, S

    1995-01-01

    The authors report 30 cases of obstructive anuria during the last fifteen years. The anuria was secondary to lithiasis in 60 per cent, in 26.6 per cent to pelvic cancer and in 13.4 per cent to retroperitoneal fibrosis. The diagnosis was facilitated by ultrasonography. Emergency treatment of obstructive anuria is based on urinary diversion by ureteral stent or by percutaneous nephrostomy under ultrasound control. Later the treatment depend of etiology.

  20. [Non obstructive retrocaval ureter].

    Science.gov (United States)

    Cao Avellaneda, E; Server Pastor, G; López López, A I; Maluff Torres, A; López Cubillana, P; Rigabert Montiel, M; Pérez Albacete, M

    2005-01-01

    We report a case on circumcavum ureter without obstruction or type two, according the Batenson and Atkinson's classification, in a forty-nine year old man. It was diagnosticated for a gross haematuria and renoureteral pain, because of a simultaneous urinary tract infection. We emphasize its absence of the typical morphology and obstruction signs. After twelve months the patient is still asymptomatic, without any medical or surgical treatment.

  1. Chronic obstructive pulmonary disease

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008430 Effect of gas exchange at maximal intensity on exercise capacity in patients with chronic obstructive pulmonary disease. WANG Haoyan(王浩彦), et al. Dept Respir Dis, Beijing Friendship Hosp, Capital Med Sci Univ, Beijing 100050. Chin J Tuberc Respir Dis 2008;31(6):414-416. Objective To investigate the effect of gas exchange at maximal intensity on exercise capacity in patients with chronic obstructive pulmonary disease (COPD).

  2. Imaging of obstructed defecation

    Energy Technology Data Exchange (ETDEWEB)

    Ganeshan, A. [Radiology Department, John Radcliffe Hospital, Oxford (United Kingdom); Anderson, E.M. [Radiology Department, John Radcliffe Hospital, Oxford (United Kingdom)], E-mail: eanderson@doctors.org.uk; Upponi, S.; Planner, A.C.; Slater, A.; Moore, N.; D' Costa, H.; Bungay, H. [Radiology Department, John Radcliffe Hospital, Oxford (United Kingdom)

    2008-01-15

    Constipation is a common problem in the western world, which occurs as a consequence of impaired colonic transit and/or due to obstructed defecation. Imaging plays an important role in distinguishing structural from functional causes of constipation. In this article a description of common imaging techniques for diagnosing structural causes of constipation with illustrations of abnormal defecographic findings in patients with obstructive defecation are presented.

  3. The human myotendinous junction

    DEFF Research Database (Denmark)

    Knudsen, A B; Larsen, M; Mackey, Abigail

    2015-01-01

    The myotendinous junction (MTJ) is a specialized structure in the musculotendinous system, where force is transmitted from muscle to tendon. Animal models have shown that the MTJ takes form of tendon finger-like processes merging with muscle tissue. The human MTJ is largely unknown and has never ...

  4. Doped semiconductor nanocrystal junctions

    Energy Technology Data Exchange (ETDEWEB)

    Borowik, Ł.; Mélin, T., E-mail: thierry.melin@isen.iemn.univ-lille1.fr [Institut d’Electronique, de Microélectronique et de Nanotechnologie, CNRS-UMR8520, Avenue Poincaré, F-59652 Villeneuve d’Ascq (France); Nguyen-Tran, T.; Roca i Cabarrocas, P. [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS-UMR7647, Ecole Polytechnique, F-91128 Palaiseau (France)

    2013-11-28

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (N{sub D}≈10{sup 20}−10{sup 21}cm{sup −3}) silicon nanocrystals (NCs) in the 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as N{sub D}{sup −1/3}, and depleted charge linearly increasing with the NC diameter and varying as N{sub D}{sup 1/3}. We thus establish a “nanocrystal counterpart” of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

  5. Junction trees of general graphs

    Institute of Scientific and Technical Information of China (English)

    Xiaofei WANG; Jianhua GUO

    2008-01-01

    In this paper,we study the maximal prime subgraphs and their corresponding structure for any undirected graph.We introduce the notion of junction trees and investigate their structural characteristics,including junction properties,induced-subtree properties,running-intersection properties and maximum-weight spanning tree properties.Furthermore,the characters of leaves and edges on junction trees are discussed.

  6. 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

    AIM: The incidence of hydronephrosis due to ureteropelvic junction obstruction is approx. 0.5%. During the last decade, the management of non-symptomatic hydronephrosis has become much more conservative, but the long-term physiological consequences of this policy are not clear. Previously, we hav...

  7. Holliday junction resolvases.

    Science.gov (United States)

    Wyatt, Haley D M; West, Stephen C

    2014-09-02

    Four-way DNA intermediates, called Holliday junctions (HJs), can form during meiotic and mitotic recombination, and their removal is crucial for chromosome segregation. A group of ubiquitous and highly specialized structure-selective endonucleases catalyze the cleavage of HJs into two disconnected DNA duplexes in a reaction called HJ resolution. These enzymes, called HJ resolvases, have been identified in bacteria and their bacteriophages, archaea, and eukaryotes. In this review, we discuss fundamental aspects of the HJ structure and their interaction with junction-resolving enzymes. This is followed by a brief discussion of the eubacterial RuvABC enzymes, which provide the paradigm for HJ resolvases in other organisms. Finally, we review the biochemical and structural properties of some well-characterized resolvases from archaea, bacteriophage, and eukaryotes. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  8. Wireless Josephson Junction Arrays

    Science.gov (United States)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  9. Occupational chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Omland, Oyvind; Würtz, Else Toft; Aasen, Tor Børvig

    2014-01-01

    Occupational-attributable chronic obstructive pulmonary disease (COPD) presents a substantial health challenge. Focusing on spirometric criteria for airflow obstruction, this review of occupational COPD includes both population-wide and industry-specific exposures.......Occupational-attributable chronic obstructive pulmonary disease (COPD) presents a substantial health challenge. Focusing on spirometric criteria for airflow obstruction, this review of occupational COPD includes both population-wide and industry-specific exposures....

  10. Nasal obstruction and human communication.

    Science.gov (United States)

    Malinoff, R; Moreno, C

    1989-04-01

    Nasal obstruction may cause a variety of communication disorders, particularly in children. The effects of nasal obstruction on hearing, speech, language, and voice are examined. Methods for assessing the effects of nasal obstruction are delineated, and recommendations for therapeutic interventions are described.

  11. Resistive Index in Obstructive Uropathy

    NARCIS (Netherlands)

    A.A. Shokeir

    1999-01-01

    textabstractThe diagnosis of urinary tract obstruction is a difficult and perplexing problem particularly in children. Pyelocalyectasis is seen not only in obstruction but also in other conditions, such as residual dilatation afler relief of obstruction, vesicoureteral reflux and pyelonephritis.

  12. Inducible laryngeal obstruction

    DEFF Research Database (Denmark)

    Halvorsen, Thomas; Walsted, Emil Schwarz; Bucca, Caterina

    2017-01-01

    Inducible laryngeal obstruction (ILO) describes an inappropriate, transient, reversible narrowing of the larynx in response to external triggers. ILO is an important cause of a variety of respiratory symptoms and can mimic asthma. Current understanding of ILO has been hampered by imprecise nomenc...

  13. [Ureteropelvic junction syndrome in adults. 108 cases in 102 adults].

    Science.gov (United States)

    Joual, A; Aboutaeib, R; Rabii, R; el Mrini, M; Benjelloun, S

    1996-01-01

    We report 108 cases of ureteropelvic junction obstruction corresponding 54 males and 48 females, with a mean age of 33 years. Pain was the commonest symptom. Delay in diagnosis was 3 and a half years. The diagnosis was made by IVP allowing our patients to be in different stages : Stage I (12 cases), stage II (39 cases), stage III (25 cases), stage IV (32 cases). We did not operate on 10 patients presenting with allow stage. 61 patients were operated by a conservative procedure : dismembered pyeloplasty (58 cases), YV pyeloplasty (3 cases). Nephrectomy was performed in 37 patients (34%). This high nephrectomy rate was due to be delayed in diagnosis.

  14. 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.

  15. An induced junction photovoltaic cell

    Science.gov (United States)

    Call, R. L.

    1974-01-01

    Silicon solar cells operating with induced junctions rather than diffused junctions have been fabricated and tested. Induced junctions were created by forming an inversion layer near the surface of the silicon by supplying a sheet of positive charge above the surface. Measurements of the response of the inversion layer cell to light of different wavelengths indicated it to be more sensitive to the shorter wavelengths of the sun's spectrum than conventional cells. The greater sensitivity occurs because of the shallow junction and the strong electric field at the surface.

  16. Genitourinary tuberculosis: a rare cause of obstructive uropathy in pregnancy.

    Science.gov (United States)

    Adhikari, Emily H; Duryea, Elaine L; Rac, Martha W F; Sheffield, Jeanne S

    2014-01-01

    Background. A rare but morbid form of extrapulmonary tuberculosis (TB), genitourinary TB is an important cause of obstructive uropathy and is likely underdiagnosed in pregnancy. Case. A 30-year-old primigravida undergoing treatment for active pulmonary TB presented with anuria at 13-14-weeks gestation. Bilateral ureteral strictures above the level of the ureterovesicular junctions were seen on imaging studies. Given her pulmonary disease, her obstructive uropathy was attributed to genitourinary TB. Bilateral percutaneous nephrostomy tubes were placed during pregnancy with successful ureteral reimplantation postpartum. Conclusion. Genitourinary TB should be considered as an etiology of urinary tract pathology during pregnancy, especially in foreign-born and immunocompromised persons. Early recognition resulting in prompt treatment can prevent further deterioration of maternal renal function and optimize pregnancy outcomes.

  17. Genitourinary Tuberculosis: A Rare Cause of Obstructive Uropathy in Pregnancy

    Directory of Open Access Journals (Sweden)

    Emily H. Adhikari

    2014-01-01

    Full Text Available Background. A rare but morbid form of extrapulmonary tuberculosis (TB, genitourinary TB is an important cause of obstructive uropathy and is likely underdiagnosed in pregnancy. Case. A 30-year-old primigravida undergoing treatment for active pulmonary TB presented with anuria at 13-14-weeks gestation. Bilateral ureteral strictures above the level of the ureterovesicular junctions were seen on imaging studies. Given her pulmonary disease, her obstructive uropathy was attributed to genitourinary TB. Bilateral percutaneous nephrostomy tubes were placed during pregnancy with successful ureteral reimplantation postpartum. Conclusion. Genitourinary TB should be considered as an etiology of urinary tract pathology during pregnancy, especially in foreign-born and immunocompromised persons. Early recognition resulting in prompt treatment can prevent further deterioration of maternal renal function and optimize pregnancy outcomes.

  18. Mixing in T-junctions

    NARCIS (Netherlands)

    Kok, Jacobus B.W.; van der Wal, S.

    1996-01-01

    The transport processes that are involved in the mixing of two gases in a T-junction mixer are investigated. The turbulent flow field is calculated for the T-junction with the k- turbulence model by FLOW3D. In the mathematical model the transport of species is described with a mixture fraction

  19. Endoscopic Removal of a Nitinol Mesh Stent from the Ureteropelvic Junction after 15 Years

    Directory of Open Access Journals (Sweden)

    Tomaž Smrkolj

    2015-01-01

    Full Text Available We report a rare case of a patient with a large stone encrusted on a nitinol mesh stent in the ureteropelvic junction. The stent was inserted in the year 2000 after failure of two pyeloplasty procedures performed due to symptomatic ureteropelvic junction stenosis. By combining minimally invasive urinary stone therapies—extracorporeal shock wave lithotripsy, semirigid ureterorenoscopy with laser lithotripsy, and percutaneous nephrolithotomy—it was possible to completely remove the encrusted stone and nitinol mesh stent that was implanted for 15 years, rendering the patient symptom and obstruction free.

  20. [Obstructive sleep apnea syndromes].

    Science.gov (United States)

    Poirrier, R

    1993-01-01

    Snoring and excessive sleepiness are the hallmarks of obstructive sleep apnea syndrome but other clinical manifestations are present and a precise assessment of the disease involves clear definitions of the various kinds of apnea. Several pathogenetic factors (functional, anatomical, neurological, genetical) are still being discussed. However new insights of the pathophysiology of apneas allow more reliable treatments. Central nervous and cardiovascular complications as well as the traumatic morbidity, associated with excessive daytime sleepiness, make it a major public health problem.

  1. Airflow obstruction and exercise.

    Science.gov (United States)

    Cooper, Christopher B

    2009-03-01

    The primary abnormality in chronic obstructive pulmonary disease (COPD) is chronic airway inflammation which results in airflow limitation. Disease progression is usually depicted as an accelerated decline in FEV(1) over time. However, COPD patients also manifest progressive static hyperinflation due to the combined effects of reduced lung elastic recoil and increased airway resistance. Superimposed on static hyperinflation are further increases in operational lung volumes (dynamic hyperinflation) brought on during exercise, exacerbations or tachypnea. An important consequence of exertional dyspnea is activity limitation. COPD patients have been shown to spend only a third of the day walking or standing compared with age-matched healthy individuals who spend more than half of their time in these activities. Furthermore, the degree of activity limitation measured by an accelerometer worsens with disease progression. COPD patients have been shown to have an accelerated loss of aerobic capacity (VO(2)max) and this correlates with mortality just as is seen with hypertension, diabetes and obesity. Thus physical inactivity is an important therapeutic target in COPD. Summarizing; airflow obstruction leads to progressive hyperinflation, activity limitation, physical deconditioning and other comorbidities that characterize the COPD phenotype. Targeting the airflow obstruction with long-acting bronchodilator therapy in conjunction with a supervised exercise prescription is currently the most effective therapeutic intervention in earlier COPD. Other important manifestations of skeletal muscle dysfunction include muscle atrophy and weakness. These specific problems are best addressed with resistance training with consideration of anabolic supplementation.

  2. Minimally Invasive Approach of a Retrocaval Ureter

    Science.gov (United States)

    Pinheiro, Hugo; Ferronha, Frederico; Morales, Jorge; Campos Pinheiro, Luís

    2016-01-01

    The retrocaval ureter is a rare congenital entity, classically managed with open pyeloplasty techniques. The experience obtained with the laparoscopic approach of other more frequent causes of ureteropelvic junction (UPJ) obstruction has opened the method for the minimally invasive approach of the retrocaval ureter. In our paper, we describe a clinical case of a right retrocaval ureter managed successfully with laparoscopic dismembered pyeloplasty. The main standpoints of the procedure are described. Our results were similar to others published by other urologic centers, which demonstrates the safety and feasibility of the procedure for this condition. PMID:27635277

  3. Metallic Junction Thermoelectric Device Simulations

    Science.gov (United States)

    Duzik, Adam J.; Choi, Sang H.

    2017-01-01

    Thermoelectric junctions made of semiconductors have existed in radioisotope thermoelectric generators (RTG) for deep space missions, but are currently being adapted for terrestrial energy harvesting. Unfortunately, these devices are inefficient, operating at only 7% efficiency. This low efficiency has driven efforts to make high-figure-of-merit thermoelectric devices, which require a high electrical conductivity but a low thermal conductivity, a combination that is difficult to achieve. Lowered thermal conductivity has increased efficiency, but at the cost of power output. An alternative setup is to use metallic junctions rather than semiconductors as thermoelectric devices. Metals have orders of magnitude more electrons and electronic conductivities higher than semiconductors, but thermal conductivity is higher as well. To evaluate the viability of metallic junction thermoelectrics, a two dimensional heat transfer MATLAB simulation was constructed to calculate efficiency and power output. High Seebeck coefficient alloys, Chromel (90%Ni-10%Cr) and Constantan (55%Cu-45%Ni), produced efficiencies of around 20-30%. Parameters such as the number of layers of junctions, lateral junction density, and junction sizes for both series- and parallel-connected junctions were explored.

  4. Late endovascular removal of Günther-Tulip inferior vena cava filter and stent reconstruction of chronic post-thrombotic iliocaval obstruction after 4753 days of filter dwell time: a case report with review of literature.

    Science.gov (United States)

    Doshi, Mehul Harshad; Narayanan, Govindarajan

    2016-12-01

    Chronic post-thrombotic obstruction of the inferior vena cava (IVC) or iliocaval junction is an uncommon complication of long indwelling IVC filter. When such an obstruction is symptomatic, endovascular treatment options include stent placement with or without filter retrieval. Filter retrieval becomes increasingly difficult with longer dwell times. We present a case of symptomatic post-thrombotic obstruction of the iliocaval junction related to Günther-Tulip IVC filter (Cook Medical Inc, Bloomington, IN) with dwell time of 4753 days, treated successfully with endovascular filter removal and stent reconstruction. Filter retrieval and stent reconstruction may be a treatment option in symptomatic patients with filter-related chronic IVC or iliocaval junction obstruction, even after prolonged dwell time.

  5. Deliberate Perspectival Obstructions

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard; Rasmussen, Anders Emil

    2016-01-01

    to a radical shift in perspective that allows partly for the invisible and absent to emerge as visible and present, and for different potentialities of persons and social relations to be brought to light. Hence the article demonstrates how obstruction and intervention as parts of the ethnographic methodology...... may help elicit perspectives that are otherwise kept hidden (deliberately or not), such as power-relations or the occluded side of a friendship or a kinship relation. This, in turn, also poses a danger to the otherwise collaborative ideal of modern ethnographic fieldwork in literally challenging...

  6. Obstructive Sleep Apnea

    OpenAIRE

    Brass, Steven D.; Ho, Matthew L.

    2006-01-01

    Obstructive sleep apnea (OSA) affects millions of Americans and is estimated to be as prevalent as asthma and diabetes. Given the fact that obesity is a major risk factor for OSA, and given the current global rise in obesity, the prevalence of OSA will increase in the future. Individuals with sleep apnea are often unaware of their sleep disorder. It is usually first recognized as a problem by family members who witness the apneic episodes or is suspected by their primary care doctor because o...

  7. Combined transnasal and transoral endoscopic approaches to the craniovertebral junction

    Directory of Open Access Journals (Sweden)

    I H El-Sayed

    2010-01-01

    Full Text Available Objectives: To describe and evaluate a new technique of a combined endoscope-assisted transnasal and transoral approach to decompress the craniovertebral junction. Materials and Methods: A retrospective cohort of patients requiring an anterior decompression at the craniovertebral junction over a 12-month period was studied. Eleven patients were identified and included in the study. Eight of the patients had an endoscopic approach [endonasal (2, endooral (2, and combined (4]. Four of the 8 patients in the endoscopic group had a prior open transoral procedure at other institutions. These 8 patients were compared with a contemporary group of 3 patients who had an open, transoral-transpalatal approach. Charts, radiographic images, and pathologic diagnosis were reviewed. We evaluated the following issues: airway obstruction, dysphagia, velopharyngeal insufficiency (VPI, length of hospital stay (LOS, adequate decompression, and the need for revision surgery. Results: Adequate anterior decompression was achieved in all the patients. The endoscopic cohort had a reduced LOS (P = 0.014, reduced need for prolonged intubation/tracheotomy (P =0.024 and a trend toward reduced VPI (P = 0.061 when compared with the open surgery group. None of the patients required a revision surgery. Conclusion: Proper choice of endoscopic transnasal, transoral, or combined approaches allows anterior decompression at the craniovertebral junction, while avoiding the need to split the palate. A combined transnasal-transoral approach appears to reduce procedure-related morbidity compared with open, transoral, and transpalatal surgeries.

  8. Imaging of cervicothoracic junction trauma

    Directory of Open Access Journals (Sweden)

    Wongwaisayawan S

    2013-01-01

    Full Text Available Sirote Wongwaisayawan,1 Ruedeekorn Suwannanon,2 Rathachai Kaewlai11Department of Radiology, Ramathibodi Hospital and Mahidol University, Bangkok, Thailand; 2Department of Radiology, Faculty of Medicine, Prince of Songkla University, Hat Yai, ThailandAbstract: Cervicothoracic junction trauma is an important cause of morbidity and mortality in trauma patients. Imaging has played an important role in identifying injuries and guiding appropriate, timely therapy. Computed tomography is currently a method of choice for diagnosing cervicothoracic junction trauma, in which the pattern of injuries often suggests possible mechanisms and potential injuries. In this article, the authors describe and illustrate common and uncommon injuries that can occur in the cervicothoracic junction.Keywords: cervicothoracic junction, cervical spine, trauma, imaging, radiology

  9. Chronic obstructive pulmonary disease - adults - discharge

    Science.gov (United States)

    COPD - adults - discharge; Chronic obstructive airways disease - adults - discharge; Chronic obstructive lung disease - adults - discharge; Chronic bronchitis - adults - discharge; Emphysema - adults - discharge; Bronchitis - ...

  10. Demonstrated Anomalous Pancreaticobiliary Ductal Junction

    OpenAIRE

    Koçkar, Cem; ?ENOL, Altu?; BA?TÜRK, Abdulkadir; AYDIN, Bünyamin; Cüre, Erkan

    2015-01-01

    Anomalies of the pancreaticobiliary junction are rare. Clinically anomalies of the pancreaticobiliary junction are uncommonly symptomatic but may present themselves with associated conditions ranging from benign acute abdominal pain to carcinomas. A 52 years old man was admitted to gastroenterology service with complaints of fever, nausea, vomiting and recurrent epigastric pain. He was diagnosed with biliary pancreatitis. Endoscopic retrograde cholangiopancreato-graphy was performed. Papilla ...

  11. Josephson junctions with ferromagnetic interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Wild, Georg Hermann

    2012-03-04

    We report on the fabrication of superconductor/insulator/ferromagnetic metal/superconductor (Nb/AlO{sub x}/Pd{sub 0.82}Ni{sub 0.18}/Nb) Josephson junctions (SIFS JJs) with high critical current densities, large normal resistance times area products, and high quality factors. For these junctions, a transition from 0- to {pi}-coupling is observed for a thickness d{sub F}=6 nm of the ferromagnetic Pd{sub 0.82}Ni{sub 0.18} interlayer. The magnetic field dependence of the critical current of the junctions demonstrates good spatial homogeneity of the tunneling barrier and ferromagnetic interlayer. Magnetic characterization shows that the Pd{sub 0.82}Ni{sub 0.18} has an out-of-plane anisotropy and large saturation magnetization indicating negligible dead layers at the interfaces. A careful analysis of Fiske modes up to about 400 GHz provides valuable information on the junction quality factor and the relevant damping mechanisms. Whereas losses due to quasiparticle tunneling dominate at low frequencies, at high frequencies the damping is explained by the finite surface resistance of the junction electrodes. High quality factors of up to 30 around 200 GHz have been achieved. They allow to study the junction dynamics, in particular the switching probability from the zero-voltage into the voltage state with and without microwave irradiation. The experiments with microwave irradiation are well explained within semi-classical models and numerical simulations. In contrast, at mK temperature the switching dynamics without applied microwaves clearly shows secondary quantum effects. Here, we could observe for the first time macroscopic quantum tunneling in Josephson junctions with a ferromagnetic interlayer. This observation excludes fluctuations of the critical current as a consequence of an unstable magnetic domain structure of the ferromagnetic interlayer and affirms the suitability of SIFS Josephson junctions for quantum information processing.

  12. Electronic thermometry in tunable tunnel junction

    Energy Technology Data Exchange (ETDEWEB)

    Maksymovych, Petro

    2016-03-15

    A tunable tunnel junction thermometry circuit includes a variable width tunnel junction between a test object and a probe. The junction width is varied and a change in thermovoltage across the junction with respect to the change in distance across the junction is determined. Also, a change in biased current with respect to a change in distance across the junction is determined. A temperature gradient across the junction is determined based on a mathematical relationship between the temperature gradient, the change in thermovoltage with respect to distance and the change in biased current with respect to distance. Thermovoltage may be measured by nullifying a thermoelectric tunneling current with an applied voltage supply level. A piezoelectric actuator may modulate the probe, and thus the junction width, to vary thermovoltage and biased current across the junction. Lock-in amplifiers measure the derivatives of the thermovoltage and biased current modulated by varying junction width.

  13. Confocal Annular Josephson Tunnel Junctions

    Science.gov (United States)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  14. Octagonal Defects at Carbon Nanotube Junctions

    Science.gov (United States)

    Jaskólski, W.; Pelc, M.; Chico, Leonor; Ayuela, A.

    2013-01-01

    We investigate knee-shaped junctions of semiconductor zigzag carbon nanotubes. Two dissimilar octagons appear at such junctions; one of them can reconstruct into a pair of pentagons. The junction with two octagons presents two degenerate localized states at Fermi energy (EF). The reconstructed junction has only one state near EF, indicating that these localized states are related to the octagonal defects. The inclusion of Coulomb interaction splits the localized states in the junction with two octagons, yielding an antiferromagnetic system. PMID:24089604

  15. Wound healing in a suction blister model:an experimental study with special reference to healing in patients with diabetes and patients with obstructive jaundice

    OpenAIRE

    Koivukangas, V

    2004-01-01

    Abstract The expression intensities of cytokeratins and tight junction proteins were determined on re-epithelization. Experimental blister wound healing was studied in patients with diabetes mellitus and in patients with obstructive jaundice. Suction blisters were induced on healthy volunteers, and the healing blisters were biopsied at different time points. Cytokeratin expression and the tight junction proteins ZO-1 and occludin were studied immunohistochemically. Blisters were ...

  16. Spectrum of Lesions Affecting the Renal Pelvis and Pelviureteric Junction: A 13-Year Retrospective Analysis

    Science.gov (United States)

    Kini, Hema; Suresh, Pooja Kundapur; Guni, Laxman Prabhu Gurupur; Bhat, Shaila; Kini, Jyoti Ramanath

    2016-01-01

    Introduction Both, the renal pelvis and the ureter, are affected by developmental, reactive and neoplastic disorders, though rare in incidence. Aim This series of cases were analysed to study the clinicopathological characteristics of the common and comparatively rare lesions involving the renal pelvis and pelviureteric junction. Materials and Methods A retrospective collection of 476 nephrectomies and pelviureteric junction resections, received over a period of 13 years from 2001 to 2013 was done. The patients’ clinical details were obtained and the histopathological findings reviewed. The lesions were classified into non-neoplastic and neoplastic categories. Results Primary involvement of the renal pelvis and pelviureteric junction was seen in 105 of 476 specimens. The mean age was 54.5 years with a male to female ratio of 2.2:1. The non-neoplastic lesions accounted for 76.2% of cases with a majority being pelviureteric junction obstruction due to inflammation induced fibromuscular hypertrophy (68.6%) causing hydronephrosis. Urothelial carcinomas were encountered in 20% of the cases. A majority of the urothelial carcinomas were infiltrative (81%) and high grade (71%) tumours. Conclusion Renal pelvis, a conduit to propel urine, can be the site for numerous disorders. Non-neoplastic lesions were more common than neoplasms. Pelviureteric junction obstruction due to inflammation induced fibromuscular hypertrophy was the commonest lesion in our study. In the neoplastic category, urothelial carcinoma was most common. However, rare lesions such as hamartomatous fibroepithelial polyp, Von Brunn’s nests, flat urothelial hyperplasia and intramuscular haemangioma of upper ureter at the pelviureteric junction were encountered along with occasional cases of tuberculosis and squamous cell carcinomas. PMID:27042468

  17. Childhood Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    R Dayal

    2014-03-01

    Full Text Available Obstructive sleep apnea (OSA is a common condition in childhood and can result insevere complications if left untreated. It is showing a rising trend in India. A significantassociation with obesity has been observed; however, some children with enlargedtonsils and/or adenoids may even be underweight. The patient usually presents withsnoring and other respiratory problems like mouth breathing, choking and gaspingepisodes in night. Poor school performance and neurocognitive deficits have beenreported. Pulmonary hypertension and cor pulmonale are seen in severe cases. Besidesthe history and clinical examination, for definitive diagnosis an overnightpolysomnographic evaluation is the gold standard. In all cases, the specific treatmentranges from simple lifestyle modifications and medications to surgeries likeadenotonsillectomy. Early diagnosis is vital.Key words: Childhood OSA, Obesity, adenotonsillar hypertrophy

  18. Chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    V K Vijayan

    2013-01-01

    Full Text Available The global prevalence of physiologically defined chronic obstructive pulmonary disease (COPD in adults aged >40 yr is approximately 9-10 per cent. Recently, the Indian Study on Epidemiology of Asthma, Respiratory Symptoms and Chronic Bronchitis in Adults had shown that the overall prevalence of chronic bronchitis in adults >35 yr is 3.49 per cent. The development of COPD is multifactorial and the risk factors of COPD include genetic and environmental factors. Pathological changes in COPD are observed in central airways, small airways and alveolar space. The proposed pathogenesis of COPD includes proteinase-antiproteinase hypothesis, immunological mechanisms, oxidant-antioxidant balance, systemic inflammation, apoptosis and ineffective repair. Airflow limitation in COPD is defined as a postbronchodilator FEV1 (forced expiratory volume in 1 sec to FVC (forced vital capacity ratio <0.70. COPD is characterized by an accelerated decline in FEV1. Co morbidities associated with COPD are cardiovascular disorders (coronary artery disease and chronic heart failure, hypertension, metabolic diseases (diabetes mellitus, metabolic syndrome and obesity, bone disease (osteoporosis and osteopenia, stroke, lung cancer, cachexia, skeletal muscle weakness, anaemia, depression and cognitive decline. The assessment of COPD is required to determine the severity of the disease, its impact on the health status and the risk of future events (e.g., exacerbations, hospital admissions or death and this is essential to guide therapy. COPD is treated with inhaled bronchodilators, inhaled corticosteroids, oral theophylline and oral phosphodiesterase-4 inhibitor. Non pharmacological treatment of COPD includes smoking cessation, pulmonary rehabilitation and nutritional support. Lung volume reduction surgery and lung transplantation are advised in selected severe patients. Global strategy for the diagnosis, management and prevention of Chronic Obstructive Pulmonary Disease

  19. Chronic obstructive pulmonary disease.

    Science.gov (United States)

    Vijayan, V K

    2013-02-01

    The global prevalence of physiologically defined chronic obstructive pulmonary disease (COPD) in adults aged >40 yr is approximately 9-10 per cent. Recently, the Indian Study on Epidemiology of Asthma, Respiratory Symptoms and Chronic Bronchitis in Adults had shown that the overall prevalence of chronic bronchitis in adults >35 yr is 3.49 per cent. The development of COPD is multifactorial and the risk factors of COPD include genetic and environmental factors. Pathological changes in COPD are observed in central airways, small airways and alveolar space. The proposed pathogenesis of COPD includes proteinase-antiproteinase hypothesis, immunological mechanisms, oxidant-antioxidant balance, systemic inflammation, apoptosis and ineffective repair. Airflow limitation in COPD is defined as a postbronchodilator FEV1 (forced expiratory volume in 1 sec) to FVC (forced vital capacity) ratio disease and chronic heart failure), hypertension, metabolic diseases (diabetes mellitus, metabolic syndrome and obesity), bone disease (osteoporosis and osteopenia), stroke, lung cancer, cachexia, skeletal muscle weakness, anaemia, depression and cognitive decline. The assessment of COPD is required to determine the severity of the disease, its impact on the health status and the risk of future events (e.g., exacerbations, hospital admissions or death) and this is essential to guide therapy. COPD is treated with inhaled bronchodilators, inhaled corticosteroids, oral theophylline and oral phosphodiesterase-4 inhibitor. Non pharmacological treatment of COPD includes smoking cessation, pulmonary rehabilitation and nutritional support. Lung volume reduction surgery and lung transplantation are advised in selected severe patients. Global strategy for the diagnosis, management and prevention of Chronic Obstructive Pulmonary Disease guidelines recommend influenza and pneumococcal vaccinations.

  20. Modelling of Dual-Junction Solar Cells including Tunnel Junction

    Directory of Open Access Journals (Sweden)

    Abdelaziz Amine

    2013-01-01

    Full Text Available Monolithically stacked multijunction solar cells based on III–V semiconductors materials are the state-of-art of approach for high efficiency photovoltaic energy conversion, in particular for space applications. The individual subcells of the multi-junction structure are interconnected via tunnel diodes which must be optically transparent and connect the component cells with a minimum electrical resistance. The quality of these diodes determines the output performance of the solar cell. The purpose of this work is to contribute to the investigation of the tunnel electrical resistance of such a multi-junction cell through the analysis of the current-voltage (J-V characteristics under illumination. Our approach is based on an equivalent circuit model of a diode for each subcell. We examine the effect of tunnel resistance on the performance of a multi-junction cell using minimization of the least squares technique.

  1. Obstructive sleep apnea in chronic obstructive pulmonary disease patients.

    LENUS (Irish Health Repository)

    Lee, Ruth

    2011-03-01

    Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) represent two of the most prevalent chronic respiratory disorders and cardiovascular diseases are major co-morbidities in both. Co-existence of both disorders (overlap syndrome) occurs in 1% of adults and overlap patients have worse nocturnal hypoxemia and hypercapnia than COPD and OSA patients alone. The present review discusses recent data concerning the pathophysiological and clinical significance of the overlap syndrome.

  2. CT of gastro-duodenal obstruction.

    Science.gov (United States)

    Millet, I; Doyon, F Curros; Pages, E; Faget, C; Zins, M; Taourel, P

    2015-10-01

    Gastro-duodenal obstruction encompasses a spectrum of benign and malignant disease. Historically, chronic peptic ulcer disease was the main cause of gastro-duodenal obstruction, whereas now malignant cause with gastric carcinomas for gastric obstruction and pancreatic tumors for duodenal obstruction predominate. This paper reviews the role of CT in diagnosing gastro-duodenal obstruction, its level, its cause by identifying intraluminal, parietal, or extrinsic process, and the presence of complication.

  3. Obstructive Sleep Apnea Hypopnea Syndrome

    African Journals Online (AJOL)

    hanumantp

    and is seen in both central sleep apnea (CSA) and obstructive sleep apnea .... weight.[1]. Perioperative and postoperative. Patients with OSAHS may have an increased perioperative risks. ... deprivation, and adjustment of sleeping positions.

  4. Gap junctions - guards of excitability.

    Science.gov (United States)

    Stroemlund, Line Waring; Jensen, Christa Funch; Qvortrup, Klaus; Delmar, Mario; Nielsen, Morten Schak

    2015-06-01

    Cardiomyocytes are connected by mechanical and electrical junctions located at the intercalated discs (IDs). Although these structures have long been known, it is becoming increasingly clear that their components interact. This review describes the involvement of the ID in electrical disturbances of the heart and focuses on the role of the gap junctional protein connexin 43 (Cx43). Current evidence shows that Cx43 plays a crucial role in organizing microtubules at the intercalated disc and thereby regulating the trafficking of the cardiac sodium channel NaV1.5 to the membrane.

  5. Obstructive sleep apnea.

    Science.gov (United States)

    Ho, Matthew L; Brass, Steven D

    2011-11-29

    Obstructive sleep apnea (OSA) affects millions of Americans and is estimated to be as prevalent as asthma and diabetes. Given the fact that obesity is a major risk factor for OSA, and given the current global rise in obesity, the prevalence of OSA will increase in the future. Individuals with sleep apnea are often unaware of their sleep disorder. It is usually first recognized as a problem by family members who witness the apneic episodes or is suspected by their primary care doctor because of the individual's risk factors and symptoms. The vast majority remain undiagnosed and untreated, despite the fact that this serious disorder can have significant consequences. Individuals with untreated OSA can stop breathing hundreds of times a night during their sleep. These apneic events can lead to fragmented sleep that is of poor quality, as the brain arouses briefly in order for the body to resume breathing. Untreated, sleep apnea can have dire health consequences and can increase the risk of hypertension, diabetes, heart disease, and heart failure. OSA management has also become important in a number of comorbid neurological conditions, including epilepsy, stroke, multiple sclerosis, and headache. Diagnosis typically involves use of screening questionnaires, physical exam, and an overnight polysomnography or a portable home study. Treatment options include changes in lifestyle, positive airway pressure, surgery, and dental appliances.

  6. Obstructed Thickenings and Supermanifolds

    CERN Document Server

    Bettadapura, Kowshik

    2016-01-01

    Associated to any supermanifold is a filtration by spaces, referred to as thickenings. It is the objective of this paper to study them up to a certain equivalence and then up to isomorphism in the complex-analytic setting. We study them both in the presence and absence of a complex supermanifold and will be guided by the goal to clarify and address the question: when does a given thickening come from a supermanifold? Such a question was, in principle, first studied by Eastwood and LeBrun. In this paper we begin with a pedagogical account of their study, after which we further develop the theory of thickenings in the context of supergeometry. Our intent will be in recovering results reminiscent of those one finds in studies on deformation theory. As a complement to our study here, we comment on the moduli problem for complex supermanifolds and consider the analogous problem for thickenings. Finally, we conclude with some illustrations of obstructed thickenings on the complex projective plane.

  7. Obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Steven D. Brass

    2011-11-01

    Full Text Available Obstructive sleep apnea (OSA affects millions of Americans and is estimated to be as prevalent as asthma and diabetes. Given the fact that obesity is a major risk factor for OSA, and given the current global rise in obesity, the prevalence of OSA will increase in the future. Individuals with sleep apnea are often unaware of their sleep disorder. It is usually first recognized as a problem by family members who witness the apneic episodes or is suspected by their primary care doctor because of the individual’s risk factors and symptoms. The vast majority remain undiagnosed and untreated, despite the fact that this serious disorder can have significant consequences. Individuals with untreated OSA can stop breathing hundreds of times a night during their sleep. These apneic events can lead to fragmented sleep that is of poor quality, as the brain arouses briefly in order for the body to resume breathing. Untreated, sleep apnea can have dire health consequences and can increase the risk of hypertension, diabetes, heart disease, and heart failure. OSA management has also become important in a number of comorbid neurological conditions, including epilepsy, stroke, multiple sclerosis, and headache. Diagnosis typically involves use of screening questionnaires, physical exam, and an overnight polysomnography or a portable home study. Treatment options include changes in lifestyle, positive airway pressure, surgery, and dental appliances.

  8. Control over Rectification in Supramolecular Tunneling Junctions

    NARCIS (Netherlands)

    Wimbush, K.S.; Wimbush, Kim S.; Reus, William F.; van der Wiel, Wilfred Gerard; Reinhoudt, David; Whitesides, George M.; Nijhuis, C.A.; Velders, Aldrik

    2010-01-01

    In complete control: The magnitude of current rectification in well-defined supramolecular tunneling junctions can be controlled by changing the terminal functionality (red spheres) of dendrimers (gray spheres) immobilized on a supramolecular platform (see picture). Junctions containing biferrocene

  9. Nano-Molecular Junctions on STM Tips

    Institute of Scientific and Technical Information of China (English)

    Chun Huang∗; Jianshu Yang

    2011-01-01

    We present a technique for building metal-organic-metal junctions, which contain ten or fewer conjugated molecules between each of such junction, and the investigations of the I-V response of these junctions. The junctions are made by self assembling thiolated molecules onto gold coated tips for use in scanning tunneling microscopy. We show that this easy technique probes the qualitative properties of the molecules. Current-voltage characteristics of a Tour wire and a new molecular rectifier are presented.

  10. Nano-Molecular Junctions on STM Tips

    Institute of Scientific and Technical Information of China (English)

    Chun Huang; Jianshu Yang

    2011-01-01

    We present a technique for building metal-organic-metal junctions, which contain ten or fewer conjugated molecules between each of such junction, and the investigations of the I-V response of these junctions.The junctions are made by self assembling thiolated molecules onto gold coated tips for use in scanning tunneling microscopy. We show that this easy technique probes the qualitative properties of the molecules. Currentvoltage characteristics of a Tour wire and a new molecular rectifier are presented.

  11. Current noise in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

    2017-06-15

    We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  13. Stability of large-area molecular junctions

    NARCIS (Netherlands)

    Akkerman, Hylke B.; Kronemeijer, Auke J.; Harkema, Jan; van Hal, Paul A.; Smits, Edsger C. P.; de Leeuw, Dago M.; Blom, Paul W. M.

    The stability of molecular junctions is crucial for any application of molecular electronics. Degradation of molecular junctions when exposed to ambient conditions is regularly observed. In this report the stability of large-area molecular junctions under ambient conditions for more than two years

  14. Soliton bunching in annular Josephson junctions

    DEFF Research Database (Denmark)

    Vernik, I.V; Lazarides, Nickos; Sørensen, Mads Peter

    1996-01-01

    By studying soliton (fluxon) motion in long annular Josephson junctions it is possible to avoid the influence of the boundaries and soliton-soliton collisions present in linear junctions. A new experimental design consisting of a niobium coil placed on top of an annular junction has been used...

  15. Long Range Magnetic Interaction between Josephson Junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1995-01-01

    A new model for magnetic coupling between long Josephson junctions is proposed. The coupling mechanism is a result of the magnetic fields outside the junctions and is consequently effective over long distances between junctions. We give specific expressions for the form and magnitude of the inter...

  16. Dynamics of pi-junction interferometer circuits

    DEFF Research Database (Denmark)

    Kornkev, V.K.; Mozhaev, P.B.; Borisenko, I.V.;

    2002-01-01

    The pi-junction superconducting circuit dynamics was studied by means of numerical simulation technique. Parallel arrays consisting of Josephson junctions of both 0- and pi-type were studied as a model of high-T-c grain-boundary Josephson junction. The array dynamics and the critical current...

  17. Dynamics of pi-junction interferometer circuits

    DEFF Research Database (Denmark)

    Kornkev, V.K.; Mozhaev, P.B.; Borisenko, I.V.

    2002-01-01

    The pi-junction superconducting circuit dynamics was studied by means of numerical simulation technique. Parallel arrays consisting of Josephson junctions of both 0- and pi-type were studied as a model of high-T-c grain-boundary Josephson junction. The array dynamics and the critical current...

  18. Bronchoscopic management of malignant airway obstruction.

    Science.gov (United States)

    Mitchell, Patrick D; Kennedy, Marcus P

    2014-05-01

    Approximately one-third of patients with lung cancer will develop airway obstruction and many cancers lead to airway obstruction through meta stases. The treatment of malignant airway obstruction is often a multimodality approach and is usually performed for palliation of symptoms in advanced lung cancer. Removal of airway obstruction is associated with improvement in symptoms, quality of life, and lung function. Patient selection should exclude patients with short life expectancy, limited symptoms, and an inability to visualize beyond the obstruction. This review outlines both the immediate and delayed bronchoscopic effect options for the removal of airway obstruction and preservation of airway patency with endobronchial stenting.

  19. [Secretory eosinophilia and obstructive rhinitis].

    Science.gov (United States)

    Rouvier, P; Mondain, M; Elkhoury, J

    1992-01-01

    Detecting eosinophilia in the nasal secretions of patients complaining of nasal obstruction makes it possible to identify a group of high risk patients. Hosty use of surgery in these patients carries a high risk of iatrogenic complications and little potential for improvement. The 2 most frequently used methods of obtaining cytologic specimens (swabbing versus washing) were compared in 37 patients with obstructive rhinitis (early stage polyposis and nonallergic rhinitis with eosinophilia syndrome, NARES). Swabbing gave reliable results. Eosinophilia was negligible in a group of 25 control subjects. The mean eosinophil count was 2.5% and only 1 patient had a positive cystogram. The 220 patients which nasal obstruction were classed in 5 groups according to the severity of clinical signs and symptoms. The mean eosinophil count and the percentage of patients with positive cystogram increased with increased severity of the clinical syndrome. 28 patients had uncomplicated obstructive rhinitis, 10 had NARES, 43 had allergic rhinitis, 52 had chronic obstructive rhinitis, and 87 had nasosinal polyposis. The respective mean eosinophil counts were 6.42%, 10.3%, 13.8% 16.8% and 31.4%. The percentage of patients with positive cytograms was respectively, 10.8%, 20%, 23.3%, 28.8% and 54%.

  20. Octagonal Defects at Carbon Nanotube Junctions

    Directory of Open Access Journals (Sweden)

    W. Jaskólski

    2013-01-01

    Full Text Available We investigate knee-shaped junctions of semiconductor zigzag carbon nanotubes. Two dissimilar octagons appear at such junctions; one of them can reconstruct into a pair of pentagons. The junction with two octagons presents two degenerate localized states at Fermi energy (EF. The reconstructed junction has only one state near EF, indicating that these localized states are related to the octagonal defects. The inclusion of Coulomb interaction splits the localized states in the junction with two octagons, yielding an antiferromagnetic system.

  1. Fabrication of high quality ferromagnetic Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Weides, M. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany) and CNI-Center of Nanoelectronic Systems for Information Technology, Research Centre Juelich, D-52425 Juelich (Germany)]. E-mail: m.weides@fz-juelich.de; Tillmann, K. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany); Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich, D-52425 Juelich (Germany); Kohlstedt, H. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany); CNI-Center of Nanoelectronic Systems for Information Technology, Research Centre Juelich, D-52425 Juelich (Germany); Department of Material Science and Engineering and Department of Physics, University of Berkeley, CA 94720 (United States)

    2006-05-15

    We present ferromagnetic Nb/Al{sub 2}O{sub 3}/Ni{sub 60}Cu{sub 40}/Nb Josephson junctions (SIFS) with an ultrathin Al{sub 2}O{sub 3} tunnel barrier. The junction fabrication was optimized regarding junction insulation and homogeneity of current transport. Using ion-beam-etching and anodic oxidation we defined and insulated the junction mesas. The additional 2 nm thin Cu-layer below the ferromagnetic NiCu (SINFS) lowered interface roughness and ensured very homogeneous current transport. A high yield of junctional devices with j {sub c} spreads less than 2% was obtained.

  2. Improvement of renal function after relief of chronic partial upper urinary tract obstruction

    Directory of Open Access Journals (Sweden)

    HA Davari

    2005-03-01

    Full Text Available Background: Kidney's functional and anatomical changes reversibility of after treatment of partial ureteropelvic junction obstruction (UPJO is not defined well. Therefore, in this clinical trial study, we've evaluated these changes. Methods: In a clinical trial study with non randomized-simple sampling, 32 patients with chronic partial obstruction of urinary tract due to unilateral UPJO were studied. In each patient, IVU, DMSA, DTPA, and bilateral kidney sonography were down pre and post operatively. Paired t-test, Wilcoxon, and McNemar tests analyzed data. P-value less than 0.05 was considered significant. Results: Mean age of the patients was 5.44 ± 0.47 years old and 40.6 % of the patients were male. Split function mean in DMSA had significant difference, comparing pre and post operatively (P<0.05. There also was a significant difference in mean of retention time and T1/2 of DTPA (P<0.05, comparing pre and post operatively (P<0.05. Mean of kidney pelvis diameter had significant difference, comparing pre and post operatively (P<0.05. Conclusion: Our study showed that operation of chronic partial obstruction of kidney, could improve kidney function. We also showed that sonographic evaluation of kidneys could help to evaluate kidney function in these patients. Keywords: obstructive uropathy, kidney reversibility, ureter obstruction

  3. Selective permeability of gap junction channels.

    Science.gov (United States)

    Goldberg, Gary S; Valiunas, Virginijus; Brink, Peter R

    2004-03-23

    Gap junctions mediate the transfer of small cytoplasmic molecules between adjacent cells. A family of gap junction proteins exist that form channels with unique properties, and differ in their ability to mediate the transfer of specific molecules. Mutations in a number of individual gap junction proteins, called connexins, cause specific human diseases. Therefore, it is important to understand how gap junctions selectively move molecules between cells. Rules that dictate the ability of a molecule to travel through gap junction channels are complex. In addition to molecular weight and size, the ability of a solute to transverse these channels depends on its net charge, shape, and interactions with specific connexins that constitute gap junctions in particular cells. This review presents some data and interpretations pertaining to mechanisms that govern the differential transfer of signals through gap junction channels.

  4. Small bowel obstruction- a surprise.

    Science.gov (United States)

    Mathew, Jeffrey Daniel; Cp, Ganesh Babu; M, Balachandar; M, Ramanathan

    2015-01-01

    Trans - omental hernia is very rare, accounting to 1-4% of all internal hernias which is an unusual cause of small bowel obstruction. Here we present a case report of a small bowel obstruction in a female due to trans - omental hernia presenting with central abdominal pain, distension and bilious vomiting. She had no previous history of trauma, surgery. Plain X-ray abdomen erect showed multiple air fluid levels with dilated small bowel loops. Emergency laparotomy revealed a segment of congested small bowel loop (ileum) through a defect in greater omentum. On table the herniated bowel loop was reduced and the defect in greater omentum was closed primarily. There was no necessity for bowel resection as it regained normal colour after reduction. Postoperative period was uneventful with complete resolution of symptoms. This case is presented for its rarity and its importance in clinical differential diagnosis of acute abdomen due to small bowel obstruction.

  5. Ureterosciatic Hernia Causes Obstructive Uropathy

    Directory of Open Access Journals (Sweden)

    Ping-Ju Tsai

    2008-09-01

    Full Text Available Obstructive uropathy can be caused by urolithiasis, fibrotic ureteral stricture, inflammatory ureteritis with polyp formations, ureteral malignancy and various forms of external compression. Ureteral herniation is a relatively rare cause of obstructive uropathy and has been reported with herniation sites including inguinal canal, femoral canal and sciatic foramen. Most ureteral herniations occur in the inguinal area. In the literature, previous cases of sciatic ureter have been treated with observation in asymptomatic patients or with surgery in patients with obstructive uropathy or clinical symptomatology. We report the case of a 91-year-old female with asymptomatic hydronephrosis of the left kidney due to extremely rare ureterosciatic herniation. Her global renal function was acceptable. As she was elderly and a poor surgical candidate, watchful waiting was recommended after discussion with the patient and her family.

  6. Seebeck effect in molecular junctions

    Science.gov (United States)

    Zimbovskaya, Natalya A.

    2016-05-01

    Advances in the fabrication and characterization of nanoscale systems presently allow for a better understanding of their thermoelectric properties. As is known, the building blocks of thermoelectricity are the Peltier and Seebeck effects. In the present work we review results of theoretical studies of the Seebeck effect in single-molecule junctions and similar systems. The behavior of thermovoltage and thermopower in these systems is controlled by several factors including the geometry of molecular bridges, the characteristics of contacts between the bridge and the electrodes, the strength of the Coulomb interactions between electrons on the bridge, and of electron-phonon interactions. We describe the impact of these factors on the thermopower. Also, we discuss a nonlinear Seebeck effect in molecular junctions.

  7. Electron transport in molecular junctions

    DEFF Research Database (Denmark)

    Jin, Chengjun

    This thesis addresses the electron transport in molecular junctions, focusing on the energy level alignment and correlation effects. Various levels of theory have been applied to study the structural and electronic effects in different molecular junctions, starting from the single particle density...... charge position are in quantitative agreement with the experiments, while pure DFT is not. This is the consequence of the accurate energy level alignment, where the DFT+∑ method corrects the self-interaction error in the standard DFT functional and uses a static image charge model to include the image...... charge effect on the energy level renormalization. Additionally, the gating of the 4,4’-bipyridine (44BP) molecule contacted to either Ni or Au electrodes has been investigated. Here it is found that the gating mechanism is conceptually different between two cases. In the case of Ni contacts where...

  8. How coherent are Josephson junctions?

    CERN Document Server

    Paik, Hanhee; Bishop, Lev S; Kirchmair, G; Catelani, G; Sears, A P; Johnson, B R; Reagor, M J; Frunzio, L; Glazman, L; Schoelkopf, R J

    2011-01-01

    Attaining sufficient coherence is a requirement for realizing a large-scale quantum computer. We present a new implementation of a superconducting transmon qubit that is strongly coupled to a three-dimensional superconducting cavity. We observe a reproducible increase in the coherence times of qubit (both $T_1$ and $T_2$ > 10 microseconds) and cavity ($T_{cav}$ ~ 50 microseconds) by more than an order of magnitude compared to the current state-of-art superconducting qubits. This enables the study of the stability and quality of Josephson junctions at precisions exceeding one part per million. Surprisingly, we see no evidence for $1/f$ critical current noise. At elevated temperatures, we observe the dissipation due to a small density (< 1 - 10 ppm) of thermally-excited quasiparticles. The results suggest that the overall quality of Josephson junctions will allow error rates of a few $10^{-4}$, approaching the error correction threshold.

  9. Morphogenesis of rat myotendinous junction.

    Science.gov (United States)

    Curzi, Davide; Ambrogini, Patrizia; Falcieri, Elisabetta; Burattini, Sabrina

    2013-10-01

    Myotendinous junction (MTJ) is the highly specialized complex which connects the skeletal muscle to the tendon for transmitting the contractile force between the two tissues. The purpose of this study was to investigate the MTJ development and rat EDL was chosen as a model. 1, 15, 30 day animals were considered and the junctions were analyzed by light and electron microscopy. The MTJ interface architecture increased during the development, extending the interaction between muscle and tendon. 1-day-old rats showed disorganized myofibril bundles, spread cytosol and incomplete rough endoplasmic reticulum, features partially improved in 15-day-old rats, and completely developed in 30-day-old animals. These findings indicate that muscle-tendon interface displays, during rat lifetime, numerically increased and longer tendon interdigitations, correlated with an improved organization of both tissues and with a progressive acquirement of full functionality.

  10. Adhesive bowel obstruction? Not always

    Directory of Open Access Journals (Sweden)

    Mittapalli D

    2011-01-01

    Full Text Available A 58-year-old man presented acutely with features of post-surgical adhesive small bowel obstruction. Following an unsuccessful trial of conservative management, computed tomography (CT of the abdomen was performed. This revealed a mass in the ileocaecal region, for which he underwent a subsequent right hemicolectomy. Histology revealed diffuse B-cell Non-Hodgkin′s lymphoma of the terminal ileum. Confounding obstructive lesion of the intestine in patients with a history of previous laparotomy is extremely uncommon. Early high resolution imaging may predict diagnosis and consolidate clinical management plans.

  11. Thermoelectric efficiency of molecular junctions

    Science.gov (United States)

    Perroni, C. A.; Ninno, D.; Cataudella, V.

    2016-09-01

    Focus of the review is on experimental set-ups and theoretical proposals aimed to enhance thermoelectric performances of molecular junctions. In addition to charge conductance, the thermoelectric parameter commonly measured in these systems is the thermopower, which is typically rather low. We review recent experimental outcomes relative to several junction configurations used to optimize the thermopower. On the other hand, theoretical calculations provide estimations of all the thermoelectric parameters in the linear and non-linear regime, in particular of the thermoelectric figure of merit and efficiency, completing our knowledge of molecular thermoelectricity. For this reason, the review will mainly focus on theoretical studies analyzing the role of not only electronic, but also of the vibrational degrees of freedom. Theoretical results about thermoelectric phenomena in the coherent regime are reviewed focusing on interference effects which play a significant role in enhancing the figure of merit. Moreover, we review theoretical studies including the effects of molecular many-body interactions, such as electron-vibration couplings, which typically tend to reduce the efficiency. Since a fine tuning of many parameters and coupling strengths is required to optimize the thermoelectric conversion in molecular junctions, new theoretically proposed set-ups are discussed in the conclusions.

  12. Subtotal obstruction of the male reproductive tract

    NARCIS (Netherlands)

    Pierik, F.H.; Dohle, G.R.; Roijen, J.H. van; Vreeburg, J.T.M.; Weber, R.F.A.

    2003-01-01

    Bilateral obstruction of the male reproductive tract is suspected in men with azoospermia, normal testicular volume and normal FSH. A testicular biopsy is required to differentiate between an obstruction and a testicular insufficiency. Unilateral or subtotal bilateral obstructions and epididymal dys

  13. Chaos induced by coupling between Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Azemtsa-Donfack, H.; Botha, A. E.

    2015-02-01

    It is found that, in a stack of intrinsic Josephson junctions in layered high temperature superconductors under external electromagnetic radiation, the chaotic features are triggered by interjunction coupling, i.e., the coupling between different junctions in the stack. While the radiation is well known to produce chaotic effects in the single junction, the effect of interjunction coupling is fundamentally different and it can lead to the onset of chaos via a different route to that of the single junction. A precise numerical study of the phase dynamics of intrinsic Josephson junctions, as described by the CCJJ+DC model, is performed. We demonstrate the charging of superconducting layers, in a bias current interval corresponding to a Shapiro step subharmonic, due to the creation of a longitudinal plasma wave along the stack of junctions. With increase in radiation amplitude chaotic behavior sets in. The chaotic features of the coupled Josephson junctions are analyzed by calculations of the Lyapunov exponents. We compare results for a stack of junctions to the case of a single junction and prove that the observed chaos is induced by the coupling between the junctions. The use of Shapiro step subharmonics may allow longitudinal plasma waves to be excited at low radiation power.

  14. [Remodeling of cardiac gap junctions and arrhythmias].

    Science.gov (United States)

    Yu, Zhi-Bin; Sheng, Juan-Juan

    2011-12-25

    In the heart, gap junctions mediate electrical and chemical coupling between adjacent cardiomyocytes, forming the cell-to-cell pathways for orderly spread of the wave of electrical excitation responsible for a functional syncytium. Three principal connexins are expressed in cardiomyocytes, connexin 43 (CX43), CX40, and CX45. CX43 predominates in ventricular muscle cells. Most of the gap junctions, assembled from CX43, are located at the intercalated discs, often with larger junctional plaques at the disc periphery. The gap junctions are rarely distributed to the sides of the cardiomyocyte. The ischemia-reperfusion, cardiac hypertrophy, heart failure, hypercholesterolemia, and diabetes mellitus induce gap junction remodeling. The gap junction remodeling induced by above-mentioned diseases shows similar characteristics, including down-regulation of CX43, reduction in gap junction plaque size, increased heterogeneity and lateralization of gap junction distribution, and dephosphorylation of CX43. The elevated angiotensin II concentration in local myocardium may play an important role in the gap junction remodeling. The down-regulation of CX43 and lateralization of gap junction distribution alter anisotropic spread of the impulse of ventricular myocardium. The dephosphorylation of CX43 not only reduces electrical conductance, but also decreases permeability of chemicals between cardiomyocytes. The lateralization of gap junctions may increase the number of hemichannels formed by CX43. The opening of hemichannels induces ATP efflux and Na(+) influx, which forms a delayed after-depolarization. The gap junction remodeling in pathological condition produces arrhythmia substrate in the ventricles. In this review, the current knowledge on the relationship between the remodeling of cardiac gap junctions and arrhythmias were summarized.

  15. Oxidative stress in obstructive nephropathy

    NARCIS (Netherlands)

    Dendooven, Amelie; Ishola, David A.; Nguyen, Tri Q.; Van der Giezen, Dionne M.; Kok, Robbert Jan; Goldschmeding, Roel; Joles, Jaap A.

    P>Unilateral ureteric obstruction (UUO) is one of the most commonly applied rodent models to study the pathophysiology of renal fibrosis. This model reflects important aspects of inflammation and fibrosis that are prominent in human kidney diseases. In this review, we present an overview of the

  16. Intestinal anisakiasis as a rare cause of small bowel obstruction.

    Science.gov (United States)

    Kojima, Gotaro; Usuki, Shinichiro; Mizokami, Ken; Tanabe, Marianne; Machi, Junji

    2013-09-01

    Anisakiasis, a parasitic infection by larvae of the nematode Anisakis found in raw or undercooked saltwater fish, mostly involves stomach but rarely small intestine. We report a rare case of a 61-year-old man who presented with abdominal pain and developed small bowel obstruction caused by intestinal anisakiasis. Abdominal computed tomography revealed segmental edema of the intestinal wall with proximal dilatation. The patient underwent urgent laparotomy because strangulated small bowel obstruction was suspected. A localized portion of the intestine around jejunoileal junction was found to be erythematous, edematous, and hardened, which was resected. The resected specimen showed a linear whitish worm, Anisakis simplex, penetrating into the intestinal mucosa. It is often clinically challenging to consider intestinal anisakiasis in the differential diagnosis because of its nonspecific abdominal symptoms and findings. Although gastrointestinal anisakiasis is still rare in the United States, the incidence is expected to rise given the growing popularity of Japanese cuisine such as sushi or sashimi. Anisakiasis should be considered as one of the differential diagnoses in patients with nonspecific abdominal symptoms after consumption of raw or undercooked fish.

  17. Airflow obstruction in young adults in Canada

    DEFF Research Database (Denmark)

    Al-Hazmi, Manal; Wooldrage, Kate; Anthonisen, Nicholas R.;

    2007-01-01

    OBJECTIVE: Airflow obstruction is relatively uncommon in young adults, and may indicate potential for the development of progressive disease. The objective of the present study was to enumerate and characterize airflow obstruction in a random sample of Canadians aged 20 to 44 years. SETTING......% were nonsmokers with asthma and 17% were nonsmokers with no history of asthma. Bronchial hyper-responsiveness increased the prevalence of airflow obstruction in each of these groups. CONCLUSION: Smoking and asthma, jointly and individually, are major determinants of obstructive disorders in young...... adults. Bronchial hyper-responsiveness contributes to obstruction in both groups....

  18. Hook Phenomenon: Intermittent distal ureteral obstruction following reimplantation

    Directory of Open Access Journals (Sweden)

    M. Mehdizadeh "

    2003-06-01

    Full Text Available Background/Objectives: To evaluate the child with intermittent ureteral obstruction following antireflux surgery and to introduce a new imaging technique for diagnosis of the socalled “hook” phenomenon, the most serious complication of antireflux surgery. Patients and Methods: Twenty-five children with a history of antireflux surgery who were referred for either persistent urinary tract infection (UTI or progressive hydronephrosis were included in the study. All the children with signs and symptoms of voiding dysfunction or persistent reflux were excluded. A new imaging technique was devised to evaluate these patients for the presence of “hook phenomenon”, in which a renal ultrasound was performed both on a full bladder and after voiding. If dilatation of the urinary tract was detected on full bladder, and this dilatation decreased dramatically following micturition, then a catheter was passed into the bladder and was filled with normal saline (based on the estimated bladder capacity in order to avoid over-distension. An intravenous urogram and saline cystogram were performed simultaneously. After 20 minutes, 2 abdominal radiographs were obtained on full and emptied bladder, both. Results: On the intravenous urogram, some children showed typical “J- hook-shaped” ureters. In all the cases marked hydronephrosis was noted, with no contrast material seen entering the bladder on the 20 minute radiogram. Upon evacuation of the bladder, both ureters promptly drained into the bladder and the”J-hooking” of the ureters and hydronephrosis resolved. Conclusion: "J- hook phenomenon” is one of the most common causes of hydronephrosis and hydroureter following ureteral re-implantation is intermittent ureteral obstruction from creation of the new ureteral hiatus at an inappropriate site. This complication is frequently misdiagnosed as irreversible uretero-vesical junction obstruction from ischemia or fibrosis. Once the diagnosis of “J- hook

  19. Clinical characteristics and management of children with ...

    African Journals Online (AJOL)

    Clinical characteristics and management of children with ureteropelvic ... structural changes in predisposed children. ... or secondary changes of the ureteral barrier at the UPJ. However .... higher resistance at the ureterovesical junction when.

  20. Physics and Applications of NIS Junctions

    Energy Technology Data Exchange (ETDEWEB)

    Ullom, J N

    2001-08-24

    This paper reviews the physics and applications of Normal-Insulator-Superconductor (NIS) tunnel junctions. The current-voltage properties of NIS junctions are diode-like with a strong temperature dependence. Hence, these structures can be used as sensitive thermometers at temperatures well below the energy gap, {Delta}, of the superconducting electrode. For junction voltages comparable to {Delta}/q, current flow removes energy from the normal electrode. This property has been exploited to build refrigerators capable of cooling thin-film circuits from 0.3 K to 0.1 K. Calorimeters and bolometers for the detection of X-rays and millimeter-wave radiation, respectively, have successfully been built from NIS junctions. NIS junctions have also been used to probe the superconducting state. Finally, recent ideas for the use of NIS junctions as simple circuit elements are described.

  1. Algorithms for Junctions in Directed Acyclic Graphs

    CERN Document Server

    Ferreira, Carlos Eduardo

    2012-01-01

    Given a pair of distinct vertices u, v in a graph G, we say that s is a junction of u, v if there are in G internally vertex disjoint directed paths from s to u and from s to v. We show how to characterize junctions in directed acyclic graphs. We also consider the two problems in the following and derive efficient algorithms to solve them. Given a directed acyclic graph G and a vertex s in G, how can we find all pairs of vertices of G such that s is a junction of them? And given a directed acyclic graph G and k pairs of vertices of G, how can we preprocess G such that all junctions of k given pairs of vertices could be listed quickly? All junctions of k pairs problem arises in an application in Anthropology and we apply our algorithm to find such junctions on kinship networks of some brazilian indian ethnic groups.

  2. When transcription goes on Holliday: Double Holliday junctions block RNA polymerase II transcription in vitro.

    Science.gov (United States)

    Pipathsouk, Anne; Belotserkovskii, Boris P; Hanawalt, Philip C

    2017-02-01

    Non-canonical DNA structures can obstruct transcription. This transcription blockage could have various biological consequences, including genomic instability and gratuitous transcription-coupled repair. Among potential structures causing transcription blockage are Holliday junctions (HJs), which can be generated as intermediates in homologous recombination or during processing of stalled replication forks. Of particular interest is the double Holliday junction (DHJ), which contains two HJs. Topological considerations impose the constraint that the total number of helical turns in the DNA duplexes between the junctions cannot be altered as long as the flanking DNA duplexes are intact. Thus, the DHJ structure should strongly resist transient unwinding during transcription; consequently, it is predicted to cause significantly stronger blockage than single HJ structures. The patterns of transcription blockage obtained for RNA polymerase II transcription in HeLa cell nuclear extracts were in accordance with this prediction. However, we did not detect transcription blockage with purified T7 phage RNA polymerase; we discuss a possible explanation for this difference. In general, our findings implicate naturally occurring Holliday junctions in transcription arrest. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Molecular junctions: can pulling influence optical controllability?

    Science.gov (United States)

    Parker, Shane M; Smeu, Manuel; Franco, Ignacio; Ratner, Mark A; Seideman, Tamar

    2014-08-13

    We suggest the combination of single molecule pulling and optical control as a way to enhance control over the electron transport characteristics of a molecular junction. We demonstrate using a model junction consisting of biphenyl-dithiol coupled to gold contacts. The junction is pulled while optically manipulating the dihedral angle between the two rings. Quantum dynamics simulations show that molecular pulling enhances the degree of control over the dihedral angle and hence over the transport properties.

  4. Loss models for long Josephson junctions

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1984-01-01

    A general model for loss mechanisms in long Josephson junctions is presented. An expression for the zero-field step is found for a junction of overlap type by means of a perturbation method. Comparison between analytic solution and perturbation result shows good agreement.......A general model for loss mechanisms in long Josephson junctions is presented. An expression for the zero-field step is found for a junction of overlap type by means of a perturbation method. Comparison between analytic solution and perturbation result shows good agreement....

  5. Obstructive sleep apnea in chronic obstructive pulmonary disease patients.

    LENUS (Irish Health Repository)

    Lee, Ruth

    2012-02-01

    PURPOSE OF REVIEW: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) represent two of the most prevalent chronic respiratory disorders and cardiovascular diseases are major co-morbidities in both. Co-existence of both disorders (overlap syndrome) occurs in 1% of adults and overlap patients have worse nocturnal hypoxemia and hypercapnia than COPD and OSA patients alone. The present review discusses recent data concerning the pathophysiological and clinical significance of the overlap syndrome. RECENT FINDINGS: The severity of obstructive ventilatory impairment and hyperinflation, especially the inspiratory capacity to total lung capacity (TLC) ratio, correlates with the severity of sleep-related breathing disturbances. Early treatment with continuous positive airway pressure (CPAP) improves survival, reduces hospitalization and pulmonary hypertension, and also reduces hypoxemia. Evidence of systemic inflammation and oxidative stress in COPD and sleep apnea provides insight into potential interactions between both disorders that may predispose to cardiovascular disease. Long-term outcome studies of overlap patients currently underway should provide further evidence of the clinical significance of the overlap syndrome. SUMMARY: Studies of overlap syndrome patients at a clinical, physiological and molecular level should provide insight into disease mechanisms and consequences of COPD and sleep apnea, in addition to identifying potential relationships with cardiovascular disease.

  6. Coagulability in Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Christina Liak

    2011-01-01

    Full Text Available BACKGROUND: Obstructive sleep apnea (OSA is a common disorder that affects both quality of life and cardiovascular health. The causal link between OSA and cardiovascular morbidity/mortality remains elusive. One possible explanation is that repeated episodes of nocturnal hypoxia lead to a hypercoagulable state that predisposes patients to thrombotic events. There is evidence supporting a wide array of hematological changes that affect hemostasis (eg, increased hematocrit, blood viscosity, platelet activation, clotting factors and decreased fibrinolytic activity.

  7. Magnetic resonance urography (MRU) versus intravenous urography (IVU) in obstructive uropathy: a prospective study of 30 cases.

    Science.gov (United States)

    Khanna, P C; Karnik, N D; Jankharia, B G; Merchant, S A; Joshi, Anagha R; Kukreja, K U

    2005-06-01

    Intravenous Urography (IVU) as a diagnostic modality has limitations in patients of obstructive uropathy with impaired renal function. Our aim was to study the technique and diagnostic accuracy of Magnetic Resonance Urography (MRU) in obstructive uropathy and to correlate the findings with IVU. Forty-eight patients, selected over a six-month period, based on mild to severe pelvicalyceal dilatation on screening ultrasonography, underwent an IVU; those having non-obstructive dilatation were excluded (18 patients). Thirty patients (age range 10 to 75 years) with definite obstructive dilatation underwent MRU. These were obtained using an open MRI unit (Siemens Magnetom Open Viva) with low-dose gadolinium-DTPA (0.01 mmol/kg body weight) using various MRI sequences. MRU studies were classified as 'excellent' or 'diagnostic' and data generated was compared with that of IVU. MRU studies were 'excellent' in twelve and 'diagnostic' in eighteen patients. Of the sixty pelvicalyceal systems (PCS) evaluated in thirty patients, there were thirty-seven calculi, nine pelvi-ureteric junction (PUJ) obstructions, six with impaired renal function, four malrotated kidneys and one each of horseshoe kidney, pancake kidney, pelvic mass (endometriomas), duplex moieties, ureterocele and vesico-ureteric reflux. MRU better depicted moderate-severe PCS dilatation, staghorn and urethral calculi, impaired renal function, extrinsic ureteric and PUJ obstruction. IVU better depicted small calculi and mild PCS dilatation. In these thirty patients of obstructive uropathy, low magnetic field, open MRI units and low-dose Gd-DTPA provided cost-effective MRU studies with excellent diagnostic utility. MRU scored over IVU in patients with moderate-severe dilatation, staghorn and urethral calculi, impaired renal function, extrinsic ureteric and PUJ obstruction.

  8. Obstructive Sleep Apnea in MPS

    Directory of Open Access Journals (Sweden)

    Abhijit Ricky Pal MBBChir, MA, MD, FRCS(ORL-HNS

    2015-11-01

    Full Text Available The mucopolysaccharidoses (MPSs are a group of inherited, metabolic disorders characterized by progressive multisystem accumulation of partially degraded glycosaminoglycans. This manifests with multilevel airway obstruction, presenting with obstructive sleep apnea (OSA. We systematically reviewed the literature to determine the severity and prevalence of OSA in MPS based on polysomnography analysis. Fifteen studies with 294 participants met the inclusion criteria for review. The pretreatment prevalence of OSA in MPS was 81% with a mean apnea–hypopnea index (AHI of 10.4. Patients with MPS I are most significantly affected, with 75% suffering with moderate to severe OSA (mean AHI, 16.6. Enzyme replacement therapy (ERT results in an almost significant reduction in OSA in MPS I ( P = .06, while adenotonsillar surgery significantly improves AHI ( P = .002. Obstructive sleep apnea least affects MPS III. There is a lack of long-term post-ERT and hematopoietic stem cell transplant data relating to OSA outcomes in this population, with further prospective studies required to determine the ongoing response to treatment.

  9. Obstructive Sleep Apnea in MPS

    Directory of Open Access Journals (Sweden)

    Abhijit Ricky Pal MBBChir, MA, MD, FRCS(ORL-HNS

    2015-11-01

    Full Text Available The mucopolysaccharidoses (MPSs are a group of inherited, metabolic disorders characterized by progressive multisystem accumulation of partially degraded glycosaminoglycans. This manifests with multilevel airway obstruction, presenting with obstructive sleep apnea (OSA. We systematically reviewed the literature to determine the severity and prevalence of OSA in MPS based on polysomnography analysis. Fifteen studies with 294 participants met the inclusion criteria for review. The pretreatment prevalence of OSA in MPS was 81% with a mean apnea–hypopnea index (AHI of 10.4. Patients with MPS I are most significantly affected, with 75% suffering with moderate to severe OSA (mean AHI, 16.6. Enzyme replacement therapy (ERT results in an almost significant reduction in OSA in MPS I (P = .06, while adenotonsillar surgery significantly improves AHI (P = .002. Obstructive sleep apnea least affects MPS III. There is a lack of long-term post-ERT and hematopoietic stem cell transplant data relating to OSA outcomes in this population, with further prospective studies required to determine the ongoing response to treatment.

  10. Stents for malignant ureteral obstruction

    Directory of Open Access Journals (Sweden)

    Kristina Pavlovic

    2016-07-01

    Full Text Available Malignant ureteral obstruction can result in renal dysfunction or urosepsis and can limit the physician's ability to treat the underlying cancer. There are multiple methods to deal with ureteral obstruction including regular polymeric double J stents (DJS, tandem DJS, nephrostomy tubes, and then more specialized products such as solid metal stents (e.g., Resonance Stent, Cook Medical and polyurethane stents reinforced with nickel-titanium (e.g., UVENTA stents, TaeWoong Medical. In patients who require long-term stenting, a nephrostomy tube could be transformed subcutaneously into an extra-anatomic stent that is then inserted into the bladder subcutaneously. We outline the most recent developments published since 2012 and report on identifiable risk factors that predict for failure of urinary drainage. These failures are typically a sign of cancer progression and the natural history of the disease rather than the individual type of drainage device. Factors that were identified to predict drainage failure included low serum albumin, bilateral hydronephrosis, elevated C-reactive protein, and the presence of pleural effusion. Head-to-head studies show that metal stents are superior to polymeric DJS in terms of maintaining patency. Discussions with the patient should take into consideration the frequency that exchanges will be needed, the need for externalized hardware (with nephrostomy tubes, or severe urinary symptoms in the case of internal DJS. This review will highlight the current state of diversions in the setting of malignant ureteral obstruction.

  11. Appendico-ileal knotting resulting in closed-loop obstruction in a child

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Albert D. [Department of Radiology, Changhua Christian Hospital, 135 Nan Siau Street, Changhua, Taiwan 50050 (Taiwan); Lee, Chien-Hsing [Department of Paediatric Surgery, Changhua Christian Hospital, Taiwan (Taiwan)

    2002-12-01

    A 1-year 7-month-old boy presented with sudden onset of severe vomiting and abdominal pain. Barium enema revealed the caecum was elevated by a mass and the ileocaecal junction was visualised with a very short segment of terminal ileum showing a 'bird's-beak' appearance. At surgery, an unusually long necrotic appendix knotting the terminal ileum resulted in strangulation of a segment of the terminal ileum. There was no evidence of torsion of the terminal ileum or appendix. To our knowledge, this is the first case of the appendix knotting the terminal ileum resulting in a strangulated closed-loop obstruction. (orig.)

  12. Gap junctions and connexin-interacting proteins

    NARCIS (Netherlands)

    Giepmans, Ben N G

    2004-01-01

    Gap junctions form channels between adjacent cells. The core proteins of these channels are the connexins. Regulation of gap junction communication (GJC) can be modulated by connexin-associating proteins, such as regulatory protein phosphatases and protein kinases, of which c-Src is the best-studied

  13. Gap junctions and connexin-interacting proteins

    NARCIS (Netherlands)

    Giepmans, Ben N G

    2004-01-01

    Gap junctions form channels between adjacent cells. The core proteins of these channels are the connexins. Regulation of gap junction communication (GJC) can be modulated by connexin-associating proteins, such as regulatory protein phosphatases and protein kinases, of which c-Src is the

  14. Gap junctions and connexin-interacting proteins

    NARCIS (Netherlands)

    Giepmans, Ben N G

    2004-01-01

    Gap junctions form channels between adjacent cells. The core proteins of these channels are the connexins. Regulation of gap junction communication (GJC) can be modulated by connexin-associating proteins, such as regulatory protein phosphatases and protein kinases, of which c-Src is the best-studied

  15. Shot noise in YBCO bicrystal Josephson junctions

    DEFF Research Database (Denmark)

    Constantinian, K.Y.; Ovsyannikov, G.A.; Borisenko, I.V.;

    2003-01-01

    We measured spectral noise density in YBCO symmetric bicrystal Josephson junctions on sapphire substrates at bias voltages up to 100 mV and T 4.2 K. Normal state resistance of the Josephson junctions, R-N = 20-90 Omega and ICRN up to 2.2 mV have been observed in the experimental samples. Noise...

  16. Shear zone junctions: Of zippers and freeways

    Science.gov (United States)

    Passchier, Cees W.; Platt, John P.

    2017-02-01

    Ductile shear zones are commonly treated as straight high-strain domains with uniform shear sense and characteristic curved foliation trails, bounded by non-deforming wall rock. Many shear zones, however, are branched, and if movement on such branches is contemporaneous, the resulting shape can be complicated and lead to unusual shear sense arrangement and foliation geometries in the wall rock. For Y-shaped shear zone triple junctions with three joining branches and transport direction at a high angle to the branchline, only eight basic types of junction are thought to be stable and to produce significant displacement. The simplest type, called freeway junctions, have similar shear sense in all three branches. The other types show joining or separating behaviour of shear zone branches similar to the action of a zipper. Such junctions may have shear zone branches that join to form a single branch (closing zipper junction), or a single shear zone that splits to form two branches, (opening zipper junction). All categories of shear zone junctions show characteristic foliation patterns and deflection of markers in the wall rock. Closing zipper junctions are unusual, since they form a non-active zone with opposite deflection of foliations in the wall rock known as an extraction fault or wake. Shear zipper junctions can form domains of overprinting shear sense along their flanks. A small and large field example are given from NE Spain and Eastern Anatolia. The geometry of more complex, 3D shear zone junctions with slip parallel and oblique to the branchline is briefly discussed.

  17. Retrograde ureteroscopic holmium laser endopyelotomy in a selected population of patients with ureteropelvic junction obstruction

    DEFF Research Database (Denmark)

    Stilling, Nicolaj; Jung, Helene; Nørby, Bettina;

    2009-01-01

    follow-up 110 weeks). Success criteria were defined as symptom relief and improved or preserved renal function. Results. Twenty-nine patients (66%) experienced complete symptom resolution and 10 patients (23%) had significant symptom improvement (i.e. no need for pain-killing medication). Five patients...

  18. Plasma rennin activity: Early indicator of renal injury in bilateral pelviureteric junction obstruction in children

    Directory of Open Access Journals (Sweden)

    Amit Singh

    2014-01-01

    Conclusion: In bilateral PUJO where DRF and SFU grading of hydronephrosis did not correctly reflect renal injury, PRA showed a significant relationship with renal histopathologic grade and could be an early indicator of renal injury in bilateral PUJO.

  19. Renal pelvis rupture in a kidney with ureteropelvic junction obstruction and extrarenal calyces.

    Science.gov (United States)

    Ransford, George; Young, Ezekiel; Castellan, Miguel; Labbie, Andrew

    2013-06-01

    The extrarenal calyx (ERC) is a rare congenital anomaly, associated with various other abnormalities of the urogenital system. We report a unique case of ERC in a solitary functioning kidney with a massively dilated pelvis that developed spontaneous rupture. A dismembered pyeloplasty was performed at the time of rupture. The patient did well post-operatively with a stable creatinine and stable SFU grade 2 hydronephrosis.

  20. 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

    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...... dilation seems to have no place in the treatment of primary congenital UPJO in children....

  1. Appendicular Tourniquet: A Cause of Intestinal Obstruction

    Science.gov (United States)

    Shivashankar, Santhosh Chikkanayakanahalli; Gangappa, Rajashekara Babu; Varghese, Edison Vadakkenchery

    2016-01-01

    Intestinal obstruction is one of the common surgical emergencies seen in daily practice. Postoperative adhesions are notorious for being the most common cause for intestinal obstruction. Occasionally, laparotomy findings do come as a surprise to surgeons. Here one such case is discussed. A patient was operated on with suspicion of intestinal obstruction secondary to postoperative adhesions. However, laparotomy revealed the appendix to be inflamed, curled around the terminal ileum and acting as a tourniquet. PMID:27437300

  2. Junction conditions of cosmological perturbations

    CERN Document Server

    Tomita, K

    2004-01-01

    The behavior of perturbations is studied in cosmological models which consist of two different homogeneous regions connected in a spherical shell boundary. The junction conditions for the metric perturbations and the displacements of the shell boundary are analyzed and the surface densities of the perturbed energy and momentum in the shell are derived, using Mukohyama's gauge-invariant formalism and the Israel discontinuity condition. In both homogeneous regions the perturbations of scalar, vector and tensor types are expanded using the 3-dimensional harmonic functions, but the model coupling among them is caused in the shell by the inhomogeneity. By treating the perturbations with odd and even parities separately, it is found, however, that we can have consistent displacements and surface densities for given metric parturbations

  3. Obstructive Lesions of the Pediatric Subglottis

    OpenAIRE

    Ida, Jonathan B.; Guarisco, J. Lindhe; Rodriguez, Kimsey H.; Amedee, Ronald G.

    2008-01-01

    Purpose: To compile information regarding obstructive subglottic lesions in children, including anatomy, pathogenesis, prevention, evaluation, and treatment options, required for implementation of a multi-faceted treatment plan.

  4. Obstructive Lesions of the Pediatric Subglottis

    OpenAIRE

    Ida, Jonathan B.; Guarisco, J. Lindhe; Rodriguez, Kimsey H.; Amedee, Ronald G.

    2008-01-01

    Purpose: To compile information regarding obstructive subglottic lesions in children, including anatomy, pathogenesis, prevention, evaluation, and treatment options, required for implementation of a multi-faceted treatment plan.

  5. Coordinate transformation in the model of long Josephson junctions: geometrically equivalent Josephson junctions

    Science.gov (United States)

    Semerdzhieva, E. G.; Boyadzhiev, T. L.; Shukrinov, Yu. M.

    2005-10-01

    The transition from the model of a long Josephson junction of variable width to the model of a junction with a coordinate-dependent Josephson current amplitude is effected through a coordinate transformation. This establishes the correspondence between the classes of Josephson junctions of variable width and quasi-one-dimensional junctions with a variable thickness of the barrier layer. It is shown that for a junction of exponentially varying width the barrier layer of the equivalent quasi-one-dimensional junction has a distributed resistive inhomogeneity that acts as an attractor for magnetic flux vortices. The curve of the critical current versus magnetic field for a Josephson junction with a resistive microinhomogeneity is constructed with the aid of a numerical simulation, and a comparison is made with the critical curve of a junction of exponentially varying width. The possibility of replacing a distributed inhomogeneity in a Josephson junction by a local inhomogeneity at the end of the junction is thereby demonstrated; this can have certain advantages from a technological point of view.

  6. Severe Obstructive Sleep Apnea Due to Massive Cervical Lipohypertrophy.

    Science.gov (United States)

    Ugurlu, Alper Mete; Ersozlu, Tolga; Basat, Salih Onur; Ceran, Fatih

    2015-09-01

    Obstructive sleep apnea is a difficult problem to deal with. Many studies on the pathogenesis of obstructive sleep apnea were performed in the past, and we present cervical lipohypertrophy causing severe obstructive sleep apnea in this article.

  7. Atomically Abrupt Topological p-n Junction.

    Science.gov (United States)

    Kim, Sung Hwan; Jin, Kyung-Hwan; Kho, Byung Woo; Park, Byeong-Gyu; Liu, Feng; Kim, Jun Sung; Yeom, Han Woong

    2017-08-24

    Topological insulators (TI's) are a new class of quantum matter with extraordinary surface electronic states, which bear great potential for spintronics and error-tolerant quantum computing. In order to put a TI into any practical use, these materials need to be fabricated into devices whose basic units are often p-n junctions. Interesting electronic properties of a 'topological' p-n junction were proposed theoretically such as the junction electronic state and the spin rectification. However, the fabrication of a lateral topological p-n junction has been challenging because of materials, process, and fundamental reasons. Here, we demonstrate an innovative approach to realize a p-n junction of topological surface states (TSS's) of a three-dimensional (3D) topological insulator (TI) with an atomically abrupt interface. When a ultrathin Sb film is grown on a 3D TI of Bi2Se3 with a typical n-type TSS, the surface develops a strongly p-type TSS through the substantial hybridization between the 2D Sb film and the Bi2Se3 surface. Thus, the Bi2Se3 surface covered partially with Sb films bifurcates into areas of n- and p-type TSS's as separated by atomic step edges with a lateral electronic junction of as short as 2 nm. This approach opens a different avenue toward various electronic and spintronic devices based on well-defined topological p-n junctions with the scalability down to atomic dimensions.

  8. Gap junction communication in myelinating glia.

    Science.gov (United States)

    Nualart-Marti, Anna; Solsona, Carles; Fields, R Douglas

    2013-01-01

    Gap junction communication is crucial for myelination and axonal survival in both the peripheral nervous system (PNS) and central nervous system (CNS). This review examines the different types of gap junctions in myelinating glia of the PNS and CNS (Schwann cells and oligodendrocytes respectively), including their functions and involvement in neurological disorders. Gap junctions mediate intercellular communication among Schwann cells in the PNS, and among oligodendrocytes and between oligodendrocytes and astrocytes in the CNS. Reflexive gap junctions mediating transfer between different regions of the same cell promote communication between cellular compartments of myelinating glia that are separated by layers of compact myelin. Gap junctions in myelinating glia regulate physiological processes such as cell growth, proliferation, calcium signaling, and participate in extracellular signaling via release of neurotransmitters from hemijunctions. In the CNS, gap junctions form a glial network between oligodendrocytes and astrocytes. This transcellular communication is hypothesized to maintain homeostasis by facilitating restoration of membrane potential after axonal activity via electrical coupling and the re-distribution of potassium ions released from axons. The generation of transgenic mice for different subsets of connexins has revealed the contribution of different connexins in gap junction formation and illuminated new subcellular mechanisms underlying demyelination and cognitive defects. Alterations in metabolic coupling have been reported in animal models of X-linked Charcot-Marie-Tooth disease (CMTX) and Pelizaeus-Merzbarcher-like disease (PMLD), which are caused by mutations in the genes encoding for connexin 32 and connexin 47 respectively. Future research identifying the expression and regulation of gap junctions in myelinating glia is likely to provide a better understanding of myelinating glia in nervous system function, plasticity, and disease. This

  9. Fluxon dynamics in three stacked Josephson junctions

    DEFF Research Database (Denmark)

    Gorria, Carlos; Christiansen, Peter Leth; Gaididei, Yuri Borisovich

    2002-01-01

    /sub -/, the coupling between junctions leads to a repulsion of the fluxons with the same polarity. Above this critical velocity a fluxon will induce radiation in the neighboring junctions, leading to a bunching of the fluxons in the stacked junctions. Using the Sakai-Bodin-Pedersen model, three coupled perturbed sine......-Gordon equations are numerically studied for different values of coupling, damping, and bias parameters. In a narrow range of velocities bunching occurs. Outside this interval the fluxons split and new fluxons may be created. I-V characteristics are presented...

  10. Temperature dependence of thermopower in molecular junctions

    Science.gov (United States)

    Kim, Youngsang; Lenert, Andrej; Meyhofer, Edgar; Reddy, Pramod

    2016-07-01

    The thermoelectric properties of molecular junctions are of considerable interest due to their promise for efficient energy conversion. While the dependence of thermoelectric properties of junctions on molecular structure has been recently studied, their temperature dependence remains unexplored. Using a custom built variable temperature scanning tunneling microscope, we measured the thermopower and electrical conductance of individual benzenedithiol junctions over a range of temperatures (100 K-300 K). We find that while the electrical conductance is independent of temperature, the thermopower increases linearly with temperature, confirming the predictions of the Landauer theory.

  11. Phase qubits fabricated with trilayer junctions

    Energy Technology Data Exchange (ETDEWEB)

    Weides, M; Bialczak, R C; Lenander, M; Lucero, E; Mariantoni, Matteo; Neeley, M; O' Connell, A D; Sank, D; Wang, H; Wenner, J; Yamamoto, T; Yin, Y; Cleland, A N; Martinis, J, E-mail: martin.weides@nist.gov, E-mail: martinis@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2011-05-15

    We have developed a novel Josephson junction geometry with minimal volume of lossy isolation dielectric, suitable for higher quality trilayer junctions implemented in qubits. The junctions are based on in situ deposited trilayers with thermal tunnel oxide, have micron-sized areas and a low subgap current. In qubit spectroscopy only a few avoided level crossings are observed, and the measured relaxation time of T{sub 1{approx}}400 ns is in good agreement with the usual phase qubit decay time, indicating low loss due to the additional isolation dielectric.

  12. Multidetector row computed tomography in bowel obstruction. Part 2. Large bowel obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, R. [Department of Radiology, Glenfield Hospital, Leicester (United Kingdom)]. E-mail: rakesh.sinha@uhl-tr.nhs.uk; Verma, R. [Department of Radiology, Glenfield Hospital, Leicester (United Kingdom)

    2005-10-01

    Large bowel obstruction may present as an emergency as high-grade colonic obstruction and can result in perforation. Perforated large bowel obstruction causes faecal peritonitis, which can result in high morbidity and mortality. Multidetector row computed tomography (MDCT) has the potential of providing an accurate diagnosis of large bowel obstruction. The rapid acquisition of images within one breath-hold reduces misregistration artefacts than can occur in critically ill or uncooperative patients. The following is a review of the various causes of large bowel obstruction with emphasis on important pathogenic factors, CT appearances and the use of multiplanar reformatted images in the diagnostic workup.

  13. Increasing gap junctional coupling: a tool for dissecting the role of gap junctions.

    Science.gov (United States)

    Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin; Kjølbye, Anne-Louise; Hennan, James K; Holstein-Rathlou, Niels-Henrik; Petersen, Jørgen Søberg; Nielsen, Morten Schak

    2007-03-01

    Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes. In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs and by interfering with the gating of gap junctional channels.

  14. Osteoporosis in chronic obstructive pulmonary disease patients

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye; Schwarz, Peter

    2008-01-01

    The purpose of this review is to examine the state of knowledge and clinical practice in the association of chronic obstructive pulmonary disease to osteoporosis and fracture incidence.......The purpose of this review is to examine the state of knowledge and clinical practice in the association of chronic obstructive pulmonary disease to osteoporosis and fracture incidence....

  15. 36 CFR 1004.13 - Obstructing traffic.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio Trust...

  16. 36 CFR 4.13 - Obstructing traffic.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic. ...

  17. Airflow Obstruction in Young Adults in Canada

    Directory of Open Access Journals (Sweden)

    Manal Al-Hazmi

    2007-01-01

    Full Text Available OBJECTIVE: Airflow obstruction is relatively uncommon in young adults, and may indicate potential for the development of progressive disease. The objective of the present study was to enumerate and characterize airflow obstruction in a random sample of Canadians aged 20 to 44 years.

  18. Retrospective study to characterize post-obstructive diuresis in cats with urethral obstruction.

    Science.gov (United States)

    Francis, Brenda J; Wells, Raegan J; Rao, Sangeeta; Hackett, Timothy B

    2010-08-01

    Urethral obstruction is a common medical emergency in cats. Frequency of post-obstruction diuresis in cats following resolution of urethral obstruction is unknown. The objective of this study was to document frequency and associated clinical features of post-obstruction diuresis in cats. The records of 32 cats undergoing 33 admissions to the Colorado State University Veterinary Hospital for urethral obstruction were reviewed. Signalment, admission blood values, fluid therapy, and urine output were recorded. Diuresis was defined as urine output greater than 2ml/kg/h. Post-obstructive diuresis occurred in 46% (13/28) of cats within the first 6h of treatment. Occurrence of post-obstructive diuresis was statistically more likely in cats with venous pHdiuresis.

  19. Management of Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    V K Vijayan

    2014-03-01

    Full Text Available Obstructive Sleep Apnea (OSA is an important public health problem and is associatedwith considerable morbidity and mortality. Therefore, treatment of this condition is ofparamount importance. The treatment of OSA includes general and behaviouralmeasures, mechanical measures including continuous positive airway pressure(CPAP, Bilevel positive airway pressure (BiPAP and Oral Appliances (OA,pharmacological treatment and surgical procedures. Continuous positive airwaypressure (CPAP treatment reverses the repetitive upper airway obstruction of sleepapnea and associated daytime sleepiness and is the most effective treatment for OSA.However maintaining patient adherence to CPAP therapy is a challenge. Weight lossshould be recommended to overweight patients with OSA, as it has been shown thatweight reduction has additional health benefits. Treatment of underlying medicalconditions such as hypothyroidism or acromegaly has profound effect onapnea/hypopnea index. A subset of patients with OSA may benefit from supplementaloxygen and positional therapy. Presently, there are no effective pharmacotherapeuticagents for treatment of patients with OSA and the role of surgical treatment in OSA iscontroversial. However, pharmacological treatment of persisting residual sleepiness,despite adequate positive airway pressure therapy delivery and adherence, is indicatedand may improve daytime sleepiness.Key words : CPAP, Oral appliances, Modafinil, CPAP complianceUvulopalatopharyngoplasty, positional therapy

  20. Hypertension and obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Phillips CL

    2013-05-01

    Full Text Available Craig L Phillips,1–3 Denise M O'Driscoll4,51Department of Respiratory and Sleep Medicine, Royal North Shore Hospital, Sydney, Australia; 2National Health and Medical Research Council Center for Integrated Research and Understanding of Sleep, Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia; 3Discipline of Sleep Medicine, Sydney Medical School, University of Sydney, Sydney, Australia; 4Monash Lung and Sleep, Monash Medical Centre, Monash University, Melbourne, Australia; 5Department of Medicine, Southern Clinical School, Monash University, Melbourne, AustraliaAbstract: Obstructive sleep apnea (OSA is increasingly being recognized as a major health burden with strong focus on the associated cardiovascular risk. Studies from the last two decades have provided strong evidence for a causal role of OSA in the development of systemic hypertension. The acute physiological changes that occur during apnea promote nocturnal hypertension and may lead to the development of sustained daytime hypertension via the pathways of sympathetic activation, inflammation, oxidative stress, and endothelial dysfunction. This review will focus on the acute hemodynamic disturbances and associated intermittent hypoxia that characterize OSA and the potential pathophysiological mechanisms responsible for the development of hypertension in OSA. In addition the epidemiology of OSA and hypertension, as well as the role of treatment of OSA, in improving blood pressure control will be examined.Keywords: obstructive sleep apnea, hypertension, intermittent hypoxia, ambulatory blood pressure, sympathetic activation

  1. Epidemic keratoconjunctivitis and lacrimal excretory system obstruction.

    Science.gov (United States)

    Hyde, K J; Berger, S T

    1988-10-01

    Epiphora is a common symptom associated with the acute phase of epidemic keratoconjunctivitis (EKC). Reflex lacrimal secretion occurs secondary to conjunctival or corneal inflammation. Acquired obstruction of the lacrimal excretory system may account for persistence of tearing after resolution of the acute inflammatory phase of the viral infection. Three cases of lacrimal excretory system obstruction after EKC are reported. Multifocal obstruction of the canaliculi and nasolacrimal duct is characteristic. Dacryocystorhinostomy (DCR) was required to relieve obstruction in all cases. Probing and corticosteroid irrigation may avoid the need for silicone intubation or conjunctivodacryocystorhinostomy in the management of canalicular obstruction. Persistent epiphora after EKC should raise clinical suspicion of acquired dacryostenosis. Early recognition may allow for optimal management.

  2. Small Bowel Obstruction due to Intestinal Xanthomatosis

    Directory of Open Access Journals (Sweden)

    L. E. Barrera-Herrera

    2015-01-01

    Full Text Available Vast majority of bowel obstruction is due to postoperative adhesions, malignancy, intestinal inflammatory disease, and hernias; however, knowledge of other uncommon causes is critical to establish a prompt treatment and decrease mortality. Xanthomatosis is produced by accumulation of cholesterol-rich foamy macrophages. Intestinal xanthomatosis is an uncommon nonneoplastic lesion that may cause small bowel obstruction and several cases have been reported in the English literature as obstruction in the jejunum. We report a case of small intestinal xanthomatosis occurring in a 51-year-old female who presented with one day of copious vomiting and intermittent abdominal pain. Radiologic images revealed jejunal loop thickening and inflammatory changes suggestive of foreign body obstruction, diagnostic laparoscopy found two strictures at the jejunum, and a pathologic examination confirmed a segmental small bowel xanthomatosis. This case illustrates that obstruction even without predisposing factors such as hyperlipidemia or lymphoproliferative disorders.

  3. Gallstone ileus resulting in strong intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Israel Szajnbok

    Full Text Available Mechanic intestinal obstruction, caused by the passage of biliary calculus from vesicle to intestine, through fistulization, although not frequent, deserve study due to the morbi-mortality rates. Incidence in elder people explains the association with chronic degenerative diseases, increasing complexity in terms of therapy decision. Literature discusses the need and opportunity for the one or two-phase surgical attack of the cholecystenteric fistule, in front of the resolution on the obstructive urgency and makes reference to Gallstone Ileus as an exception for strong intestinal obstruction. The more frequent intestinal obstruction observed is when it occurs a Gallstone Ileus impacting in terms of ileocecal valve. The authors submit a Gallstone Ileus manifestation as causing strong intestinal obstruction, discussing aspects regarding diagnostic and treatment.

  4. Presynaptic spike broadening reduces junctional potential amplitude.

    Science.gov (United States)

    Spencer, A N; Przysiezniak, J; Acosta-Urquidi, J; Basarsky, T A

    1989-08-24

    Presynaptic modulation of action potential duration may regulate synaptic transmission in both vertebrates and invertebrates. Such synaptic plasticity is brought about by modifications to membrane currents at presynaptic release sites, which, in turn, lead to changes in the concentration of cytosolic calcium available for mediating transmitter release. The 'primitive' neuromuscular junction of the jellyfish Polyorchis penicillatus is a useful model of presynaptic modulation. In this study, we show that the durations of action potentials in the motor neurons of this jellyfish are negatively correlated with the amplitude of excitatory junctional potentials. We present data from in vitro voltage-clamp experiments showing that short duration voltage spikes, which elicit large excitatory junctional potentials in vivo, produce larger and briefer calcium currents than do long duration action potentials, which elicit small excitatory junctional potentials.

  5. Tight Junctions in Salivary Epithelium

    Directory of Open Access Journals (Sweden)

    Olga J. Baker

    2010-01-01

    Full Text Available Epithelial cell tight junctions (TJs consist of a narrow belt-like structure in the apical region of the lateral plasma membrane that circumferentially binds each cell to its neighbor. TJs are found in tissues that are involved in polarized secretions, absorption functions, and maintaining barriers between blood and interstitial fluids. The morphology, permeability, and ion selectivity of TJ vary among different types of tissues and species. TJs are very dynamic structures that assemble, grow, reorganize, and disassemble during physiological or pathological events. Several studies have indicated the active role of TJ in intestinal, renal, and airway epithelial function; however, the functional significance of TJ in salivary gland epithelium is poorly understood. Interactions between different combinations of the TJ family (each with their own unique regulatory proteins define tissue specificity and functions during physiopathological processes; however, these interaction patterns have not been studied in salivary glands. The purpose of this review is to analyze some of the current data regarding the regulatory components of the TJ that could potentially affect cellular functions of the salivary epithelium.

  6. Androgen-Dependent Sertoli Cell Tight Junction Remodeling Is Mediated by Multiple Tight Junction Components

    National Research Council Canada - National Science Library

    Chakraborty, Papia; William Buaas, F; Sharma, Manju; Smith, Benjamin E; Greenlee, Anne R; Eacker, Stephen M; Braun, Robert E

    2014-01-01

    Sertoli cell tight junctions (SCTJs) of the seminiferous epithelium create a specialized microenvironment in the testis to aid differentiation of spermatocytes and spermatids from spermatogonial stem cells...

  7. Junction Plasmon-Induced Molecular Reorientation

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, Patrick Z.; Hu, Dehong; Hess, Wayne P.

    2013-10-17

    Time and frequency dependent intensity variations in sequences of Raman spectra recorded at plasmonic junctions can be assigned to molecular reorientation. This is revealed through Raman trajectories recorded at a nanojunction formed between a silver AFM tip and a corrugated silver surface coated with biphenyl-4,4’-dithiol. Molecular motion is not observed when the tip is retracted and only surface enhancement is operative. In effect, junction plasmon induced molecular reorientation is tracked.

  8. [Clinical anatomy of the esophagogastric junction].

    Science.gov (United States)

    Tănase, M; Aldea, A S

    2012-01-01

    The esophagogastric junction is a controversial anatomical area, due to its sphincteric mechanism which does not show an obvious anatomical basis. The aim of this study is to investigate the anatomical components that endoscopically indicate the mucosal esophagogastric junction in hiatal hernia patients. The esophagogastric junction was investigated in 27 hiatal hernia patients undergoing surgery. Hiatal hernia is an extension of the stomach situated between the esophagogastric junction and the diaphragmatic indentation. The following types of hiatal hernia were found: sliding hiatal hernia (type I) in 4 patients (14.81%), rolling hiatal hernia (type II) in 2 (7.4%), mixed hiatal hernia (type III) in 12 (44.44%), type IV hiatal hernia in 4 (14.81%) and recurrent hiatal hernia in 5 (18.51%). Of the 27 hiatal hernia patients, 8 (29.6%) were operated using classical procedures: laparotomy--6 (75%) and laparoscopic surgery--2 (25%). The angle of His cannot be used for marking the mucosal esophagogastric junction due to the severe damage of the lower esophageal sphincter in hiatal hernia patients. The squamocolumnar junction is displaced in hiatal hernia patients and was not an option for the study group. The distal end of the esophageal longitudinal palisading vessels needs medication (proton pump inhibitors that reduce the gastric acid production), in order to enhance the visibility of these vessels. The proximal end of gastric longitudinal mucosal folds proved to be the most reliable site to identify endoscopically the mucosal esophagogastric junction. The anatomical structure of the esophagogastric junction differs in hiatal hernia patients and these peculiarities are very important in surgery.

  9. The Dissolution of Double Holliday Junctions

    DEFF Research Database (Denmark)

    Bizard, Anna H; Hickson, Ian D

    2014-01-01

    as "double Holliday junction dissolution." This reaction requires the cooperative action of a so-called "dissolvasome" comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding......) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions....

  10. Gap junction intercellular communication and benzene toxicity.

    Science.gov (United States)

    Rivedal, Edgar; Witz, Gisela; Leithe, Edward

    2010-03-19

    Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to several human diseases, including cancer and abnormal hematopoietic development. Benzene exposure has been shown to cause hematotoxicity and leukemia, but the underlying mechanisms involved remain unclear. We have observed that several metabolites of benzene have the ability to block gap junction intercellular communication. The ring-opened trans,trans-muconaldehyde (MUC) was found to be the most potent inhibitor of gap junction channels. MUC was found to induce cross-linking of the gap junction protein connexin43, which seemed to be responsible for the induced inhibition of GJIC. Glutaraldehyde, which has a similar molecular structure as MUC, was found to possess similar effects on gap junctions as MUC, while the mono-aldehyde formaldehyde shows lower potency, both as a connexin cross-linker, and as an inhibitor of GJIC. Both glutaraldehyde and formaldehyde have previously been associated with induction of leukemia and disturbance of hematopoiesis. Taken together, the data support a possible link between the effect of MUC on gap junctions, and the toxic effects of benzene. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  11. Gap junctions: structure and function (Review).

    Science.gov (United States)

    Evans, W Howard; Martin, Patricia E M

    2002-01-01

    Gap junctions are plasma membrane spatial microdomains constructed of assemblies of channel proteins called connexins in vertebrates and innexins in invertebrates. The channels provide direct intercellular communication pathways allowing rapid exchange of ions and metabolites up to approximately 1 kD in size. Approximately 20 connexins are identified in the human or mouse genome, and orthologues are increasingly characterized in other vertebrates. Most cell types express multiple connexin isoforms, making likely the construction of a spectrum of heteromeric hemichannels and heterotypic gap junctions that could provide a structural basis for the charge and size selectivity of these intercellular channels. The precise nature of the potential signalling information traversing junctions in physiologically defined situations remains elusive, but extensive progress has been made in elucidating how connexins are assembled into gap junctions. Also, participation of gap junction hemichannels in the propagation of calcium waves via an extracellular purinergic pathway is emerging. Connexin mutations have been identified in a number of genetically inherited channel communication-opathies. These are detected in connexin 32 in Charcot Marie Tooth-X linked disease, in connexins 26 and 30 in deafness and skin diseases, and in connexins 46 and 50 in hereditary cataracts. Biochemical approaches indicate that many of the mutated connexins are mistargeted to gap junctions and/or fail to oligomerize correctly into hemichannels. Genetic ablation approaches are helping to map out a connexin code and point to specific connexins being required for cell growth and differentiation as well as underwriting basic intercellular communication.

  12. Predictive modelling of ferroelectric tunnel junctions

    Science.gov (United States)

    Velev, Julian P.; Burton, John D.; Zhuravlev, Mikhail Ye; Tsymbal, Evgeny Y.

    2016-05-01

    Ferroelectric tunnel junctions combine the phenomena of quantum-mechanical tunnelling and switchable spontaneous polarisation of a nanometre-thick ferroelectric film into novel device functionality. Switching the ferroelectric barrier polarisation direction produces a sizable change in resistance of the junction—a phenomenon known as the tunnelling electroresistance effect. From a fundamental perspective, ferroelectric tunnel junctions and their version with ferromagnetic electrodes, i.e., multiferroic tunnel junctions, are testbeds for studying the underlying mechanisms of tunnelling electroresistance as well as the interplay between electric and magnetic degrees of freedom and their effect on transport. From a practical perspective, ferroelectric tunnel junctions hold promise for disruptive device applications. In a very short time, they have traversed the path from basic model predictions to prototypes for novel non-volatile ferroelectric random access memories with non-destructive readout. This remarkable progress is to a large extent driven by a productive cycle of predictive modelling and innovative experimental effort. In this review article, we outline the development of the ferroelectric tunnel junction concept and the role of theoretical modelling in guiding experimental work. We discuss a wide range of physical phenomena that control the functional properties of ferroelectric tunnel junctions and summarise the state-of-the-art achievements in the field.

  13. Cough in obstructive sleep apnoea.

    Science.gov (United States)

    Chan, Kevin; Ing, Alvin; Birring, Surinder S

    2015-12-01

    Obstructive Sleep Apnoea (OSA) has recently been reported to be a cause of chronic cough. It should be considered when cough remains unexplained following investigations and treatments for common causes. The presence of nocturnal cough, snoring and gastro-oesophageal reflux may be helpful in identifying patients who require further investigation. Daytime somnolence is often absent. Continuous positive airway pressure (CPAP) therapy has been reported to be effective in alleviating cough. Therapy for gastro-oesophageal reflux disease, if present, should be optimised. The mechanism of the association between OSA and cough is not clear, but airway inflammation, gastro-oesophageal reflux disease, increased cough reflex sensitivity and tracheobronchomalacia are possible explanations. Further studies should identify clinical predictors of OSA-cough, establish mechanisms and the optimal therapy.

  14. Chronic Obstructive Pulmonary Disease Biomarkers

    Directory of Open Access Journals (Sweden)

    Tatsiana Beiko

    2016-04-01

    Full Text Available Despite significant decreases in morbidity and mortality of cardiovascular diseases (CVD and cancers, morbidity and cost associated with chronic obstructive pulmonary disease (COPD continue to be increasing. Failure to improve disease outcomes has been related to the paucity of interventions improving survival. Insidious onset and slow progression halter research successes in developing disease-modifying therapies. In part, the difficulty in finding new therapies is because of the extreme heterogeneity within recognized COPD phenotypes. Novel biomarkers are necessary to help understand the natural history and pathogenesis of the different COPD subtypes. A more accurate phenotyping and the ability to assess the therapeutic response to new interventions and pharmaceutical agents may improve the statistical power of longitudinal clinical studies. In this study, we will review known candidate biomarkers for COPD, proposed pathways of pathogenesis, and future directions in the field.

  15. Charge transport in nanoscale junctions.

    Science.gov (United States)

    Albrecht, Tim; Kornyshev, Alexei; Bjørnholm, Thomas

    2008-09-03

    many particle excitations, new surface states in semiconductor electrodes, various mechanisms for single molecule rectification of the current, inelastic electron spectra and SERS spectroscopy. Three terminal architectures allowing (electrochemical) gating and transistor effects. Electrochemical nanojunctions and gating: intermolecular electron transfer in multi-redox metalloproteins, contact force modulation, characteristic current-noise patterns due to conformational fluctuations, resonance effects and electrocatalysis. Novel architectures: linear coupled quantum-dot-bridged junctions, electrochemical redox mediated transfer in two center systems leading to double maxima current-voltage plots and negative differential resistance, molecular-nanoparticle hybrid junctions and unexpected mesoscopic effects in polymeric wires. Device integration: techniques for creating stable metal/molecule/metal junctions using 'nano-alligator clips' and integration with 'traditional' silicon-based technology. The Guest Editors would like to thank all of the authors and referees of this special issue for their meticulous work in making each paper a valuable contribution to this research area, the early-bird authors for their patience, and Journal of Physics: Condensed Matter editorial staff in Bristol for their continuous support.

  16. Obstructive sleep apnea in ischemic stroke patients

    Directory of Open Access Journals (Sweden)

    Aliye Tosun

    2008-01-01

    Full Text Available OBJECTIVE: To investigate the prevalence of obstructive sleep apnea in patients with ischemic stroke and to evaluate the effectiveness of nasal continuous positive airway pressure treatment. METHODS: Overnight polysomnography was performed by a computerized system in 19 subjects with ischemic stroke. Patients with an apnea-hypopnea index > 5 were considered to have obstructive sleep apnea. The appropriate level of continuous positive airway pressure for each patient was determined during an all-night continuous positive airway pressure determination study. Attended continuous positive airway pressure titration was performed with a continuous positive airway pressure auto-titrating device. RESULTS: Obstructive sleep apnea prevalence among patients with ischemic stroke was 73.7%. The minimum SaO2 was significantly lower, and the percent of total sleep time in the wake stage and stage 1 sleep was significantly longer in patients with obstructive sleep apnea. In two patients with severe obstructive sleep apnea, we observed a decrease in the apnea-hypopnea index, an increase in mean wake time, mean SaO2, and minimum SaO2, and alterations in sleep structures with continuous positive airway pressure treatment. CONCLUSION: As the diagnosis and treatment of obstructive sleep apnea is of particular importance in secondary stroke prevention, we suggest that the clinical assessment of obstructive sleep apnea be part of the evaluation of stroke patients in rehabilitation units, and early treatment should be started.

  17. Acucise™ endopyelotomy in a porcine model: procedure standardization and analysis of safety and immediate efficacy

    Directory of Open Access Journals (Sweden)

    Andreoni Cássio

    2004-01-01

    Full Text Available PURPOSE: The study here presented was done to test the technical reliability and immediate efficacy of the Acucise device using a standardized technique. MATERIALS AND METHODS: 56 Acucise procedures were performed in pigs by a single surgeon who used a standardized technique: insert 5F angiographic catheter bilaterally up to the midureter, perform retrograde pyelogram, Amplatz super-stiff guidewire is advanced up to the level of the renal pelvis, angiographic catheters are removed, Acucise catheter balloon is advanced to the ureteropelvic junction (UPJ level, the super-stiff guide-wire is removed and the contrast medium in the renal pelvis is aspirated and replaced with distilled water, activate Acucise at 75 watts of pure cutting current, keep the balloon fully inflated for 10 minutes, perform retrograde ureteropyelogram to document extravasation, remove Acucise catheter and pass an ureteral stent and remove guide-wire. RESULTS: In no case did the Acucise device present malfunction. The electrocautery activation time was 2.2 seconds (ranging from 2 to 4 seconds. The extravasation of contrast medium, visible by fluoroscopy, occurred in 53 of the 56 cases (94.6%. In no case there was any evidence of intraoperative hemorrhage. CONCLUSIONS: This study revealed that performing Acucise endopyelotomy routinely in a standardized manner could largely preclude intraoperative device malfunction and eliminate complications while achieving a successful incision in the UPJ. With the guidelines that were used in this study, we believe that Acucise endopyelotomy can be completed successfully and safely in the majority of selected patients with UPJ obstruction.

  18. Evaluation of painful hydronephrosis in pregnancy: magnetic resonance urographic patterns in physiological dilatation versus calculous obstruction.

    Science.gov (United States)

    Spencer, J A; Chahal, R; Kelly, A; Taylor, K; Eardley, I; Lloyd, S N

    2004-01-01

    We evaluated magnetic resonance urography (MRU) appearances in symptomatic hydronephrosis in pregnancy and compared urographic patterns in physiological and calculous disease. A total of 24 consecutive pregnant women with symptomatic hydronephrosis underwent MRU, comprising an overview fast T2-weighted examination of the abdomen and pelvis, and thick slab, heavily T2-weighted MRU images, followed by focused, high resolution T2-weighted sequences obtained in an axial and coronal oblique plane through the level of ureteral caliber change. Of these 24 pregnant women 15 were found to have physiological hydronephrosis, 7 had calculous disease and 2 had preexisting urinary anomalies. MRU findings in physiological hydronephrosis cases were extrinsic compression of the middle third of the ureter, no filling defect and a collapsed ureter below it. Obstruction by ureteral calculi was seen at points of ureteral narrowing in the ureter, that is at the vesicoureteral junction in 2 cases, in the compressed mid ureter in 3 and at the pelviureteral junction in 1. Nonobstructive renal calculi were seen in another patient. Calculi presented throughout pregnancy but physiological hydronephrosis presented only in the late second and third trimesters. With distal calculi the MRU appearance was the double kink sign with constriction at the pelvic brim and the vesicoureteral junction with a standing column of urine in the pelvic ureter. There was renal edema and perirenal extravasation. Small calculi were only identified using high resolution T2-weighted magnetic resonance imaging. MRU is a valuable and well tolerated investigation for evaluating painful hydronephrosis in pregnancy. There are characteristic and differing urographic appearances in physiological and calculous obstruction.

  19. Experimental obstructive jaundice alters claudin-4 expression in intestinal mucosa: Effect of bombesin and neurotensin

    Institute of Scientific and Technical Information of China (English)

    Stelios F Assimakopoulos; Constantine E Vagianos; Aristides S Charonis; Ilias H Alexandris; Iris Spiliopoulou; Konstantinos C Thomopoulos; Vassiliki N Nikolopoulou; Chrisoula D Scopa

    2006-01-01

    AIM: To investigate the influence of experimental obstructive jaundice and exogenous bombesin (BBS) and neurotensin (NT) administration on the expression of the tight junction (TJ)-protein claudin-4 in intestinal epithelium of rats.METHODS: Forty male Wistar rats were randomly divided into five groups: Ⅰ = controls, Ⅱ = sham operated, Ⅲ = bile duct ligation (BDL), Ⅳ = BDL+BBS (30 μg/kg per d), V = BDL+NT (300 μg/kg per d). At the end of the experiment on d 10, endotoxin was measured in portal and aortic blood. Tissue sections of the terminal ileum were examined histologically and immunohistochemically for evaluation of claudin-4 expression in intestinal epithelium.RESULTS: Obstructive jaundice led to intestinal barrier failure demonstrated by significant portal and aortic endotoxemia. Claudin-4 expression was significantly increased in the upper third of the villi in jaundiced rats and an upregulation of its lateral distribution was noted.Administration of BBS or NT restored claudin-4 expression to the control state and significantly reduced portal and aortic endotoxemia.CONCLUSION: Experimental obstructive jaundice increases claudin-4 expression in intestinal epithelium,which may be a key factor contributing to the disruption of the mucosal barrier. Gut regulatory peptides BBS and NT can prevent this alteration and reduce portal and sysremic endotoxemia.

  20. Josephson tunnel junctions with ferromagnetic interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Weides, M.P.

    2006-07-01

    Superconductivity and ferromagnetism are well-known physical properties of solid states that have been widely studied and long thought about as antagonistic phenomena due to difference in spin ordering. It turns out that the combination of both superconductor and ferromagnet leads to a very rich and interesting physics. One particular example, the phase oscillations of the superconducting order parameter inside the ferromagnet, will play a major role for the devices discussed in this work. In this thesis, I present Josephson junctions with a thin Al{sub 2}O{sub 3} tunnel barrier and a ferromagnetic interlayer, i.e. superconductor-insulator-ferromagnet-superconductor (SIFS) stacks. The fabrication of junctions was optimized regarding the insulation of electrodes and the homogeneity of the current transport. The junctions were either in the 0 or {pi} coupled ground state, depending on the thickness of the ferromagnetic layer and on temperature. The influence of ferromagnetic layer thickness on the transport properties and the coupling (0, {pi}) of SIFS tunnel junctions was studied. Furthermore, using a stepped ferromagnetic layer with well-chosen thicknesses, I obtained the so-called 0-{pi} Josephson junction. At a certain temperature this 0-{pi} junction can be made perfectly symmetric. In this case the ground state corresponds to a vortex of supercurrent creating a magnetic flux which is a fraction of the magnetic flux quantum {phi}{sub 0}. Such structures allow to study the physics of fractional vortices and to build various electronic circuits based on them. The SIFS junctions presented here have an exponentially vanishing damping at T {yields} 0. The SIFS technology developed within the framework of this work may be used to construct classical and quantum devices such as oscillators, memory cells and qubits. (orig.)

  1. Model Building to Facilitate Understanding of Holliday Junction and Heteroduplex Formation, and Holliday Junction Resolution

    Science.gov (United States)

    Selvarajah, Geeta; Selvarajah, Susila

    2016-01-01

    Students frequently expressed difficulty in understanding the molecular mechanisms involved in chromosomal recombination. Therefore, we explored alternative methods for presenting the two concepts of the double-strand break model: Holliday junction and heteroduplex formation, and Holliday junction resolution. In addition to a lecture and…

  2. Increasing gap junctional coupling: a tool for dissecting the role of gap junctions

    DEFF Research Database (Denmark)

    Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin;

    2007-01-01

    . In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing......Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes...... the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs...

  3. Dislocation Multi-junctions and Strain Hardening

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, V; Hsiung, L; Tang, M; Arsenlis, A; Bartelt, M; Cai, W; Florando, J; Hiratani, M; Rhee, M; Hommes, G; Pierce, T; Diaz de la Rubia, T

    2006-06-20

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects--dislocations. First theorized in 1934 to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed only two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening: a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions tying dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed hereafter multi-junctions. The existence of multi-junctions is first predicted by Dislocation Dynamics (DD) and atomistic simulations and then confirmed by the transmission electron microscopy (TEM) experiments in single crystal molybdenum. In large-scale Dislocation Dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in BCC crystals.

  4. Within-breath respiratory impedance and airway obstruction in patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Karla Kristine Dames da Silva

    2015-07-01

    Full Text Available OBJECTIVE: Recent work has suggested that within-breath respiratory impedance measurements performed using the forced oscillation technique may help to noninvasively evaluate respiratory mechanics. We investigated the influence of airway obstruction on the within-breath forced oscillation technique in smokers and chronic obstructive pulmonary disease patients and evaluated the contribution of this analysis to the diagnosis of chronic obstructive pulmonary disease. METHODS: Twenty healthy individuals and 20 smokers were assessed. The study also included 74 patients with stable chronic obstructive pulmonary disease. We evaluated the mean respiratory impedance (Zm as well as values for the inspiration (Zi and expiration cycles (Ze at the beginning of inspiration (Zbi and expiration (Zbe, respectively. The peak-to-peak impedance (Zpp=Zbe-Zbi and the respiratory cycle dependence (ΔZrs=Ze-Zi were also analyzed. The diagnostic utility was evaluated by investigating the sensitivity, the specificity and the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01888705. RESULTS: Airway obstruction increased the within-breath respiratory impedance parameters that were significantly correlated with the spirometric indices of airway obstruction (R=−0.65, p90%. CONCLUSIONS: We conclude the following: (1 chronic obstructive pulmonary disease introduces higher respiratory cycle dependence, (2 this increase is proportional to airway obstruction, and (3 the within-breath forced oscillation technique may provide novel parameters that facilitate the diagnosis of respiratory abnormalities in chronic obstructive pulmonary disease.

  5. 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.

  6. An obstructing endobronchial lipoma simulating COPD

    DEFF Research Database (Denmark)

    Sivapalan, Pradeesh; Gottlieb, Magnus; Christensen, Merete

    2014-01-01

    Endobronchial lipomas are rare benign tumors of the respiratory tract. Bronchial occlusion may cause parenchymal damage and lead to a misdiagnosis of chronic obstructive pulmonary disease or malignancy. Therefore, both accurate diagnosis and radical treatment of endobronchial lipomas are essentia...

  7. [Obstructive anuria secondary to uterine prolapse].

    Science.gov (United States)

    Rodríguez Alonso, A; González Blanco, A; Cachay Ayala, M E; Bonelli Martín, C i; Porta Vila, A; Lorenzo Franco, J; Cuerpo Pérez, M A; Nieto García, J

    2002-10-01

    The prevalence of obstructive uropathy linked to uterine prolapse ranges between 4% and 80%, depending on the series, probably due to the varying degree of severity of the prolapses under consideration. Renal failure or anuria is an unusual complication. Several etiopathogenic theories regarding obstructive uropathy secondary to prolapse have been put forward: ureteral compression by the uterine vessels, severe urethral angulation, ureteral compression against levator ani muscles and the elongation and narrowing of the distal ureter. The major radiological exploration used in studying the urinary tract of these patients is intravenous urography in bipedestation. Emergency treatment for obstructive anuria resulting from a uterine prolapse consists of manually replacement of the prolapse. Surgery is considered to be the definitive ideal treatment, although in the case of surgical or anaesthetic high risk patients, inserting a permanent pessary may constitute a satisfactory solution. We present a case of obstructive anuria resulting from uterine prolapse, which was successfully treated with the insertion of a ring pessary.

  8. Childhood intestinal obstruction in Northwestern Nigeria

    African Journals Online (AJOL)

    sentation of childhood intestinal obstruction in this study agrees with those .... nal distension in 7(43.8%), and fever in another 7(43.8%). .... boys defaulted from definitive treatment after the initial ... rent abdominal pain and constipation.

  9. Obstructive sleep apnea: Awakening the hidden truth

    African Journals Online (AJOL)

    2014-01-16

    Jan 16, 2014 ... to OSA include reduced upper-airway dilator muscle activity during sleep, ..... three‑dimensionally analyzed with an advanced analysis technique ... Padma A, Ramakrishnan N, Narayanan V. Management of obstructive sleep.

  10. Obstructive Respiratory Disease Complicating Pneumonia in ...

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... clinical pattern of presentation may be relevant in the management of similar cases in the future. ... may become complicated with obstructive airway disease in children.

  11. Diagnostic strategies for chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Broekhuizen, B.D.L.

    2010-01-01

    Adequate detection of chronic obstructive pulmonary disease (COPD) in patients who present with persistent cough in general practice is highly warranted, because targeted interventions for COPD (notably smoking cessation programmes) improve the quality of life. Nevertheless, much is unknown about

  12. Effect of bilastine upon nasal obstruction.

    Science.gov (United States)

    Dávila, I; Sastre, J; Mullol, J; Montoro, J; Jáuregui, I; Ferrer, M; del Cuvillo, A; Bartra, J; Valero, A

    2011-01-01

    H1 antihistamines constitute one of the main references for the treatment of allergic rhinitis. Classically, these drugs have been considered effective in controlling sneezing, rhinorrhea and itching, though they have not been regarded as particularly effective in application to nasal obstruction. The most recent studies, involving second-generation H1 antihistamines (desloratadine, fexofenadine, levocetirizine, rupatadine), have shown these drugs to offer effects upon nasal obstruction significantly superior to those of placebo. The present review examines the effect of bilastine, a new, potent and highly specific H1 antihistamine without sedative effects or cardiac toxicity, upon nasal obstruction. The analysis of the data from the different clinical trials indicates that in patients with allergic rhinitis, the effect of bilastine upon nasal obstruction is superior to that of placebo and similar to that of other second-generation H1 antihistamines, manifesting within 24 hours after the start of treatment.

  13. CSF Obstruction and Malabsorption in Congenital Hydrocephalus

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-11-01

    Full Text Available The relative contribution of CSF malabsorption and obstruction in three different etiological groups of neonatal high-pressure hydrocephalus (HC was assessed in a study at University of Bonn, Germany, and University of Groningen, The Netherlands.

  14. What to do with an obstructed newborn.

    Science.gov (United States)

    Bravo Bravo, M C; García-Herrera Taillefer, P

    2016-05-01

    Bowel obstruction is the most common abdominal emergency in newborns. Managing bowel obstruction is a challenge for both clinicians and radiologists. The clinical presentation is nonspecific, and both the diagnosis and subsequent management are based on imaging studies. The traditional approach to studying obstructed newborns consists of plain-film abdominal X-rays and contrast-based studies of the gastrointestinal tract. Ultrasonography has proven useful in bowel obstruction, thus avoiding the use of ionizing radiation in certain cases, so diagnostic strategies should include it as a first-line technique. Using an appropriate combination of these techniques, it is possible to reach an accurate diagnosis quickly, orienting treatment and decreasing complications. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  15. Valiente Kroon's obstructions to smoothness at infinity

    Science.gov (United States)

    Grant, James; Tod, Paul

    2015-03-01

    We conjecture an interpretation in terms of multipole moments of the obstructions to smoothness at infinity found for time-symmetric, conformally-flat initial data by Kroon (Commun Math Phys 244(1):133-156, 2004).

  16. Obstructions to Clifford System Extensions of Algebras

    Indian Academy of Sciences (India)

    Antonio M Cegarra; Antonio R Garzón

    2001-05-01

    In this paper we do phrase the obstruction for realization of a generalized group character, and then we give a classification of Clifford systems in terms of suitable low-dimensional cohomology groups.

  17. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  18. Spiral CT venography in central venous obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Wook; Park, Jae Hyung; Im, Jung Gi; Han, Moon Hee; Kim, In One; Chang, Kee Hyun; Yeon, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Song, Chi Sung [Boramae Hospital, Seoul (Korea, Republic of)

    1998-11-01

    To determine the clinical usefulness of spiral computed tomographic (CT) venography for the evaluation of central venous obstruction. The authors prospectively performed a total of 29 spiral CT venography procedures in 25 consecutive patients with suspected central venous obstrucion. Diluted contrast media were directly injected into the peripheral veins of the hand or the foot. Scan parameters were 3mm X-ray beam collimation, table speed of 4-6cm/sec, scan time of 32-40sec, and injection delay of 20 sec. Axial images were reconstructed at 2-mm intervals, and using shaded surface display(SSD), maximum intensity projection(MIP), and multiplanar reformation(MPR), 3-D reconstruction was performed. In all cases, ascending venograp-hy(n=3D13) and/or direct catheter venography (n=3D21) was performed within 2 days of CT venography. With regard to site, extent, extent, severity, and cause of obstruction and collateral circulation, we compared the results of CT and contrast venography. In 24 patients, a total of 56 sites of central venous obstruction or stenosis (>50%) were demonstrated. The causes of obstruction were venous thrombosis(n=3D6), malignant tumors(n=3D4), arteriovenous fistula for hemodialysis(n=3D5), extrinsic compression(n=3D2), coincidence of extrinsic compression and arteriovenous fistula(n=3D1), pacemaker(n=3D1), mediastinal inflammatory pseudotumor(n=3D1), spinal tuberculosis(n=3D1), membranous obstruction of the hepatic inferior vena cava(n=3D1), Behcet's disease(n=3D1), or unknown cause(n=3D1). When compared with ascending venography(n=3D13), CT venography was superior for evaluation of the extent and cause of obstruction and collateral circulation in two, four and one case(s), respectively. For the evaluation of site and severity of obstruction, CT venography was equal to ascending venography. In two cases, direct catheter venography (n=3D21) was superior to CT venography for evaluating the obstruction site, but in three, five and one case

  19. Neonatal intestinal obstruction in Benin, Nigeria

    Directory of Open Access Journals (Sweden)

    Osifo Osarumwense

    2009-01-01

    Full Text Available Background: Intestinal obstruction is a life threatening condition in the newborn, with attendant high mortality rate especially in underserved subregion. This study reports the aetiology, presentation, and outcome of intestinal obstruction management in neonates. Materials and Methods: A prospective study of neonatal intestinal obstruction at the University of Benin Teaching Hospital, Benin, Nigeria, between January 2006-June 2008. Data were collated on a structured proforma and analysed for age, sex, weight, presentation, type/date of gestation/delivery, aetiology, clinical presentation, associated anomaly, treatment, and outcome. Results: There were 71 neonates, 52 were males and 19 were females (2.7:1. Their age range was between 12 hours and 28 days (mean, 7.9 ± 2.7 days and they weighed between 1.8 and 5.2 kg (average, 3.2 kg. The causes of intestinal obstruction were: Anorectal anomaly, 28 (39.4%; Hirschsprung′s disease, 8 (11.3%′ prematurity, 3 (4.2%; meconeum plug, 2 (2.8%; malrotation, 6 (8.5%; intestinal atresia, 8 (11.3%; necrotising enterocolitis (NEC, 4 (5.6%; obstructed hernia, 4 (5.6%; and spontaneous gut perforation, 3 (4.2%. Also, 27 (38% children had colostomy, 24 (33.8% had laparotomy, 9 (12.8% had anoplasty, while 11 (15.4% were managed nonoperatively. A total of 41 (57.7% neonates required incubator, 26 (36.6% needed total parenteral nutrition, while 15 (21.1% require d paediatric ventilator. Financial constraint, late presentation, presence of multiple anomalies, aspiration, sepsis, gut perforation, and bowel gangrene were the main contributors to death. Neonates with lower obstructions had a better outcome compared to those having upper intestinal obstruction ( P < 0.0001. Conclusion: Outcomes of intestinal obstruction are still poor in our setting; late presentation, financial constraints, poor parental motivation and lack of basic facilities were the major determinants of mortality.

  20. Computed tomography and obstructive biliary disease.

    Science.gov (United States)

    Havrilla, T R; Haaga, J R; Alfidi, R J; Reich, N E

    1977-05-01

    Forty-four patients with confirmed biliary diseases were studied to determine the value of computed tomography (CT) in the diagnosis of biliary pathology. The results indicate that CT is useful and highly accurate in differentiating between obstructive (surgical) and nonobstructive (medical) disease entities. Of the cases with proved obstruction, 88% were correctly identified. All of the nonobstructive cases had positive CT correlation. In addition, the underlying cause of the occlusion was determined in the majority of cases.

  1. Chronic obstructive pulmonary disease : a proteomics approach

    OpenAIRE

    Alexandre, Bruno Miguel Coelho, 1980-

    2011-01-01

    Tese de doutoramento, Biologia (Biologia Molecular), Universidade de Lisboa, Faculdade de Ciências, 2012 Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow limitation that is not fully reversible even under bronchodilators effect, caused by a mixture of small airway disease – obstructive bronchiolitis – and parenchymal destruction – emphysema. At the present time, COPD is the fourth leading cause of death and its prevalence and mortality are expected to contin...

  2. Radiological interventions in malignant biliary obstruction

    Institute of Scientific and Technical Information of China (English)

    Kumble Seetharama Madhusudhan; Shivanand Gamanagatti; Deep Narayan Srivastava; Arun Kumar Gupta

    2016-01-01

    Malignant biliary obstruction is commonly caused by gall bladder carcinoma, cholangiocarcinoma and metastatic nodes. Percutaneous interventions play an important role in managing these patients. Biliary drainage, which forms the major bulk of radiological interventions, can be pal iative in inoperable patients or pre-operative to improve liver function prior to surgery. Other interventions include cholecystostomy and radiofrequency ablation. We present here the indications, contraindications, technique and complications of the radiological interventions performed in patients with malignant biliary obstruction.

  3. Obstruction Theory and Coincidences in Positive Codimension

    Institute of Scientific and Technical Information of China (English)

    Daciberg GON(C)ALVES; Jerzy JEZIERSKI; Peter WONG

    2006-01-01

    Let f, g: X → Y be two maps between closed manifolds with dim X ≥ dim Y = n ≥ 3.We study the primary obstruction on(f,g) to deforming f and g to be coincidence free on the n-th skeleton of X. We give examples for which obstructions to deforming f and g to be coincidence free are detected by on (f, g).

  4. Created-by-current states in long Josephson junctions

    Science.gov (United States)

    Boyadjiev, T. L.; Andreeva, O. Yu.; Semerdjieva, E. G.; Shukrinov, Yu. M.

    2008-08-01

    Critical curves "critical current-external magnetic field" of long Josephson junctions with inhomogeneity and variable width are studied. We demonstrate the existence of regions of magnetic field where some fluxon states are stable only if the external current through the junction is different from zero. Position and size of such regions depend on the length of the junction, its geometry, parameters of inhomogeneity and form of the junction. The noncentral (left and right) pure fluxon states appear in the inhomogeneous Josephson junction with the increase in the junction length. We demonstrate new bifurcation points with change in width of the inhomogeneity and amplitude of the Josephson current through the inhomogeneity.

  5. Sulfadiazine-related obstructive urinary tract lithiasis: an unusual cause of acute renal failure after kidney transplantation.

    Science.gov (United States)

    Guitard, J; Kamar, N; Mouzin, M; Borde, J S; Tran-Van, T; Durand, D; Rostaing, L

    2005-05-01

    We report on the first case of acute renal failure related to obstructive urinary tract lithiasis involving sulfadiazine crystals in a kidney transplant recipient. This patient had disseminated toxoplasmosis which was treated by sulfadiazine (4 g/day) and pyrimethamine (50 mg/day). In the fourth week of anti-toxoplasmosis therapy, he presented with obstructive acute renal failure: the plasma creatinine level increased from 220 micromol/l to 547 micromol/l. Apercutaneous pyelography was conducted showing the presence of a lithiasis located at the junction between the graft ureter and the bladder. Six days later, he underwent surgery to retrieve an orange-colored, friable stone. Its spectrophotometric analysis confirmed that the stone consisted of N-acetyl sulfadiazine crystals.

  6. Thermionic refrigeration at CNT-CNT junctions

    Science.gov (United States)

    Li, C.; Pipe, K. P.

    2016-10-01

    Monte Carlo (MC) simulation is used to study carrier energy relaxation following thermionic emission at the junction of two van der Waals bonded single-walled carbon nanotubes (SWCNTs). An energy-dependent transmission probability gives rise to energy filtering at the junction, which is predicted to increase the average electron transport energy by as much as 0.115 eV, leading to an effective Seebeck coefficient of 386 μV/K. MC results predict a long energy relaxation length (˜8 μm) for hot electrons crossing the junction into the barrier SWCNT. For SWCNTs of optimal length, an analytical transport model is used to show that thermionic cooling can outweigh parasitic heat conduction due to high SWCNT thermal conductivity, leading to a significant cooling capacity (2.4 × 106 W/cm2).

  7. Silicon fiber with p-n junction

    Energy Technology Data Exchange (ETDEWEB)

    Homa, D.; Cito, A.; Pickrell, G.; Hill, C.; Scott, B. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, 312 Holden Hall, Blacksburg, Virginia 24060 (United States)

    2014-09-22

    In this study, we fabricated a p-n junction in a fiber with a phosphorous doped silicon core and fused silica cladding. The fibers were fabricated via a hybrid process of the core-suction and melt-draw techniques and maintained overall diameters ranging from 200 to 900 μm and core diameters of 20–800 μm. The p-n junction was formed by doping the fiber with boron and confirmed via the current-voltage characteristic. The demonstration of a p-n junction in a melt-drawn silicon core fiber paves the way for the seamless integration of optical and electronic devices in fibers.

  8. Vortex structures in exponentially shaped Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Semerdjieva, E. G.; Boyadjiev, T. L.

    2005-04-01

    We report the numerical calculations of the static vortex structure and critical curves in exponentially shaped long Josephson junctions for in-line and overlap geometries. Stability of the static solutions is investigated by checking the sign of the smallest eigenvalue of the associated Sturm-Liouville problem. The change in the junction width leads to the renormalization of the magnetic flux in comparison with the case of a linear one-dimensional model. We study the influence of the model's parameters, and particularly, the shape parameter on the stability of the states of the magnetic flux. We compare the vortex structure and critical curves for the in-line and overlap geometries. Our numerically constructed critical curve of the Josephson junction matches well with the experimental one.

  9. Holographic Josephson Junction from Massive Gravity

    CERN Document Server

    Hu, Ya-Peng; Zeng, Hua-Bi; Zhang, Hai-Qing

    2015-01-01

    We study the holographic superconductor-normal metal-superconductor (SNS) Josephon junction in the massive gravity. In the homogeneous case of the chemical potential, we find that the graviton mass will make the normal metal-superconductor phase transition harder to take place. In the holographic model of Josephson junction, it is found that the maximal tunneling current will decrease according to the graviton mass. Besides, the coherence length of the junction decreases as well with respect to the graviton mass. If one interprets the graviton mass as the effect of momentum dissipation in the boundary field theory, it indicates that the stronger the momentum dissipation is, the smaller the coherence length is.

  10. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...... on square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements...... as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment....

  11. Gap junction diseases of the skin.

    Science.gov (United States)

    van Steensel, M A M

    2004-11-15

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by mutations in one of the genes coding for the constituent proteins of gap junctions, known as connexins. In this review, the currently known connexin disorders that feature skin abnormalities are described: keratitis-ichthyosis deafness syndrome, erythrokeratoderma variabilis, Vohwinkel's syndrome, and a novel disorder called hypotrichosis-deafness syndrome. What is known about the pathogenesis of these disorders is discussed and related to gap junction physiology. (c) 2004 Wiley-Liss, Inc.

  12. Overdamped Josephson junctions for digital applications

    Energy Technology Data Exchange (ETDEWEB)

    Febvre, P., E-mail: Pascal.Febvre@univ-savoie.fr [University of Savoie, IMEP-LAHC – CNRS UMR5130, 73376 Le Bourget du Lac (France); De Leo, N.; Fretto, M.; Sosso, A. [I.N.Ri.M., Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino (Italy); Belogolovskii, M. [Donetsk Institute for Physics and Engineering, 72 R. Luxemburg str., 83114 Donetsk (Ukraine); Collot, R. [University of Savoie, IMEP-LAHC – CNRS UMR5130, 73376 Le Bourget du Lac (France); Lacquaniti, V. [I.N.Ri.M., Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Torino (Italy)

    2013-01-15

    Highlights: ► Properties of self-shunted sub-micron Nb/Al–AlO{sub x}/Nb SNIS junctions are studied. ► 1–100 kA/cm{sup 2} current densities and 0.1–0.7 mV critical voltages are obtained. ► The critical voltage-vs-temperature behavior of SNIS junctions is discussed. ► Numerical results showing an effect of the aluminum film thickness are presented. ► A Josephson balanced comparator is studied for different temperatures of operation. -- Abstract: An interesting feature of Superconductor–Normal metal–Superconductor Josephson junctions for digital applications is due to their non-hysteretic current–voltage characteristics in a broad temperature range below T{sub c}. This allows to design Single-Flux-Quantum (SFQ) cells without the need of external shunts. Two advantages can be drawn from this property: first the SFQ cells can be more compact which leads to a more integrated solution towards nano-devices and more complex circuits; second the absence of electrical parasitic elements associated with the wiring of resistors external to the Josephson junctions increases the performance of SFQ circuits, in particular regarding the ultimate speed of operation. For this purpose Superconductor–Normal metal–Insulator–Superconductor Nb/Al–AlO{sub x}/Nb Josephson junctions have been recently developed at INRiM with aluminum layer thicknesses between 30 and 100 nm. They exhibit non-hysteretic current–voltage characteristics with I{sub c}R{sub n} values higher than 0.5 mV in a broad temperature range and optimal Stewart McCumber parameters at 4.2 K for RSFQ applications. The main features of obtained SNIS junctions regarding digital applications are presented.

  13. Multiplication in Silicon p-n Junctions

    DEFF Research Database (Denmark)

    Moll, John L.

    1965-01-01

    Multiplication values were measured in the collector junctions of silicon p-n-p and n-p-n transistors before and after bombardment by 1016 neutrons/cm2. Within experimental error there was no change either in junction fields, as deduced from capacitance measurements, or in multiplication values...... in any of the transistors. The implication is that the electron and hole ionization rates did not change as a result of the addition of extra scattering centers. This result is in direct contradiction to observations of Lee et al. The most likely explanation for the discrepancy is erroneous determination...

  14. Fast transient response of novel Peltier junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hoyos, G.E.; Rao, K.R.; Jerger, D.

    1977-01-01

    The fast transient response of a thermoelectric (TE) cooler with novel geometry is discussed. This geometry involves conical semiconductor legs whose hot to cold junction cross-sectional area ratios can be varied. The novel TE junctions are fabricated such that the thermal capacitance and electrical conductance are decreased while simultaneously increasing the thermal resistance. The experimental apparatus which includes the vacuum system, power supplies, pulse and control circuitry, sensing and measuring instrumentation etc. is described. With narrow pulse width and large amplitudes, additional cooling of the order of 45/sup 0/C below the steady-state maximum with recovery times in the range of 1 to 3 sec is obtained.

  15. The Geometric Field at a Josephson Junction

    CERN Document Server

    Atanasov, Victor

    2016-01-01

    A geometric potential from the kinetic term of a constrained to a curved hyper-plane of space-time quantum superconducting condensate is derived. An energy conservation relation involving the geometric field at every material point in the superconductor is demonstrated. At a Josephson junction the energy conservation relation implies the possibility to transform electric energy into geometric field energy, that is curvature of space-time. Experimental procedures to verify that the Josephson junction can act as a voltage-to-curvature converter are discussed.

  16. Microscopic tunneling theory of long Josephson junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

    1992-01-01

    We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate that the detai......We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...

  17. Rectangular-to-circular groove waveguide junction

    Institute of Scientific and Technical Information of China (English)

    CUI; Licheng; (崔立成); YANG; Hongsheng; (杨鸿生)

    2003-01-01

    Mode matching method is used to analyze the scattering characteristics of the rectangular-to-circular groove waveguide junction. Firstly, the scattering matrix equation is obtained by matching the electromagnetic fields at the boundary of the junction. The scattering coefficients can be obtained from the equation. Secondly the scattering characteristics of the iris with rectangular window positioned in circular groove waveguide are briefly analyzed. Thirdly, the convergent problem is discussed and the numerical results are given. At last experiment is made and good agreement is found between the calculated results and the measured results.

  18. Electroplated Ni on the PN Junction Semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Joo; Uhm, Young Rang; Son, Kwang Jae; Kim, Jong Bum; Choi, Sang Moo; Park, Jong Han; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Nickel (Ni) electroplating was implemented by using a metal Ni powder in order to establish a Ni-63 plating condition on the PN junction semiconductor needed for production of betavoltaic battery. PN junction semiconductors with a Ni seed layer of 500 and 1000 A were coated with Ni at current density from 10 to 50 mA cm{sup 2}. The surface roughness and average grain size of Ni deposits were investigated by XRD and SEM techniques. The roughness of Ni deposit was increased as the current density was increased, and decreased as the thickness of Ni seed layer was increased.

  19. Rethinking chronic obstructive pulmonary disease.

    Science.gov (United States)

    Tonello, Antonella; Poli, Giovanni

    2011-03-01

    Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease characterized by an abnormal inflammatory response to smoke, and results in a progressive and debilitating condition with declining lung function. The reasons why some smokers get COPD are not known. We suggest that corticosteroid resistance, which derives from oxidative stress, might actually be the cause of COPD and represent the starting point of the pathology. The absence of response to corticosteroids would let the disease develop, impairing the organism capacity to suppress any kind of inflammatory process. Corticosteroid resistance may derive from smoke induced oxidative stress and plausibly impairs the organism capacity to suppress inflammation. Many factors may contribute to the development and persistence of corticosteroid resistance: inefficient antioxidant defences, a corticosteroid response less efficient or more sensitive to oxidative conditions, and also any other concomitant factor, environmental, genetic or intercurrent, which would contribute to amplify inflammation and hence oxidative stress. One or more of these factors might represent the variable component of the disease, which gives origin to COPD heterogeneity. This hypotheses may also explain why the disease persists after quitting smoking, as an inflammatory process severe enough to generate a strong oxidative stress may support itself by maintenance of corticosteroid resistance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Obstructive sleep apnea and inflammation.

    LENUS (Irish Health Repository)

    McNicholas, Walter T

    2012-02-01

    The pathogenesis of cardiovascular complications in obstructive sleep apnea syndrome (OSAS) is not fully understood but is likely multifactorial in origin. Inflammatory processes play an important role in the pathogenesis of atherosclerosis, and circulating levels of several markers of inflammation have been associated with future cardiovascular risk. These include cell adhesion molecules such as intercellular adhesion molecule-1 and selectins, cytokines such as tumour necrosis factor alpha and interleukin 6, chemokines such as interleukin 8, and C-reactive protein. There is also increasing evidence that inflammatory processes play an important role in the cardiovascular pathophysiology of OSAS and many of the inflammatory markers associated with cardiovascular risk have been reported as elevated in patients with OSAS. Furthermore, animal and cell culture studies have demonstrated preferential activation of inflammatory pathways by intermittent hypoxia, which is an integral feature of OSAS. The precise role of inflammation in the development of cardiovascular disease in OSAS requires further study, particularly the relationship with oxidative stress, metabolic dysfunction, and obesity.

  1. Self-expanding metal stents in malignant colonic obstruction: experiences from Sweden

    Directory of Open Access Journals (Sweden)

    Toth Ervin

    2011-07-01

    Full Text Available Background Acute surgery in the management of malignant colonic obstruction is associated with high morbidity and mortality. The use of self-expanding metal stents (SEMS is an alternative method of decompressing colonic obstruction. SEMS may allow time to optimize the patient and to perform preoperative staging, converting acute surgery into elective. SEMS is also proposed as palliative treatment in patients with contraindications to open surgery. Aim: To review our experience of SEMS focusing on clinical outcome and complications. The method used was a review of 75 consecutive trials at SEMS on 71 patients based on stent-protocols and patient charts. Findings SEMS was used for palliation in 64 (85% cases and as a bridge to surgery in 11 (15% cases. The majority of obstructions, 53 (71% cases, were located in the recto-sigmoid. Technical success was achieved in 65 (87% cases and clinical decompression was achieved in 60 (80% cases. Reasons for technical failure were inability to cannulate the stricture in 5 (7% cases and suboptimal SEMS placement in 3 (4% cases. Complications included 4 (5% procedure-related bowel perforations of which 2 (3% patients died in junction to post operative complications. Three cases of bleeding after SEMS occurred, none of which needed invasive treatment. Five of the SEMS occluded. Two cases of stent erosion were diagnosed at the time of surgery. Average survival after palliative SEMS treatment was 6 months. Conclusion Our results correspond well to previously published data and we conclude that SEMS is a relatively safe and effective method of treating malignant colonic obstruction although the risk of SEMS-related perforations has to be taken into account.

  2. Common features of a vortex structure in long exponentially shaped Josephson junctions and Josephson junctions with inhomogeneities

    Science.gov (United States)

    Boyadjiev, T. L.; Semerdjieva, E. G.; Shukrinov, Yu. M.

    2007-09-01

    We study the vortex structure in three different models of the long Josephson junction: the exponentially shaped Josephson junction and the Josephson junctions with the resistor and the shunt inhomogeneities in the barrier layer. For these three models the critical curves “critical current-magnetic field” are numerically constructed. We develop the idea of the equivalence of the exponentially shaped Josephson junction and the rectangular junction with the distributed inhomogeneity and demonstrate that at some parameters of the shunt and the resistor inhomogeneities in the ends of the junction the corresponding critical curves are very close to the exponentially shaped one.

  3. Common features of a vortex structure in long exponentially shaped Josephson junctions and Josephson junctions with inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Boyadjiev, T.L. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Semerdjieva, E.G. [Plovdiv University, 24 Tzar Asen Str., Plovdiv 4000 (Bulgaria); Shukrinov, Yu.M. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)], E-mail: shukrinv@theor.jinr.ru

    2007-09-01

    We study the vortex structure in three different models of the long Josephson junction: the exponentially shaped Josephson junction and the Josephson junctions with the resistor and the shunt inhomogeneities in the barrier layer. For these three models the critical curves 'critical current-magnetic field' are numerically constructed. We develop the idea of the equivalence of the exponentially shaped Josephson junction and the rectangular junction with the distributed inhomogeneity and demonstrate that at some parameters of the shunt and the resistor inhomogeneities in the ends of the junction the corresponding critical curves are very close to the exponentially shaped one.

  4. Association between airway obstruction and peripheral arterial stiffness in elderly patients with chronic obstructive pulmonary disease

    Institute of Scientific and Technical Information of China (English)

    付志方

    2014-01-01

    Objective To evaluate the relationship between se-verity of airway obstruction and peripheral arterial stiffness in patients with chronic obstructive pulmonary disease(COPD).Methods 81 COPD patients[aged(78.32±6.98)yrs,73 males,8 females]from Jan2008 to Oct 2012 were enrolled in Geriatric Department

  5. Transcriptional mechanisms coordinating tight junction assembly during epithelial differentiation.

    Science.gov (United States)

    Boivin, Felix J; Schmidt-Ott, Kai M

    2017-06-01

    Epithelial tissues form a selective barrier via direct cell-cell interactions to separate and establish concentration gradients between the different compartments of the body. Proper function and formation of this barrier rely on the establishment of distinct intercellular junction complexes. These complexes include tight junctions, adherens junctions, desmosomes, and gap junctions. The tight junction is by far the most diverse junctional complex in the epithelial barrier. Its composition varies greatly across different epithelial tissues to confer various barrier properties. Thus, epithelial cells rely on tightly regulated transcriptional mechanisms to ensure proper formation of the epithelial barrier and to achieve tight junction diversity. Here, we review different transcriptional mechanisms utilized during embryogenesis and disease development to promote tight junction assembly and maintenance of intercellular barrier integrity. We focus particularly on the Grainyhead-like transcription factors and ligand-activated nuclear hormone receptors, two central families of proteins in epithelialization. © 2017 New York Academy of Sciences.

  6. Ballistic transport in InSb Josephson junctions

    Science.gov (United States)

    Damasco, John Jeffrey; Gill, Stephen; Car, Diana; Bakkers, Erik; Mason, Nadya

    We present transport measurements on Josephson junctions consisting of InSb nanowires contacted by Al at various junction lengths. Junction behavior as a function of gate voltage, electric field, and magnetic field is discussed. We show that short junctions behave as 1D quantum wires, exhibiting quantized conductance steps. In addition, we show how Josephson behavior changes as transport evolves from ballistic to diffusive as a function of contact spacing.

  7. Dynamics near Resonance Junctions in Hamiltonian Systems

    CERN Document Server

    Goto, S; Goto, Shin-itiro; Nozaki, Kazuhiro

    1999-01-01

    An approximate Poincare map near equally strong multiple resonances is reduced by means the method of averaging. Near the resonance junction of three degrees of freedom, we find that some homoclinic orbits ``whiskers'' in single resonance lines survive and form nearly periodic orbits, each of which looks like a pair of homoclinic orbits.

  8. Cooling of suspended nanostructures with tunnel junctions

    OpenAIRE

    Koppinen, P. J.; Maasilta, I. J.

    2009-01-01

    We have investigated electronic cooling of suspended nanowires with SINIS tunnel junction coolers. The suspended samples consist of a free standing nanowire suspended by four narrow ($\\sim$ 200 nm) bridges. We have compared two different cooler designs for cooling the suspended nanowire. We demonstrate that cooling of the nanowire is possible with a proper SINIS cooler design.

  9. Polyphosphonium-based ion bipolar junction transistors.

    Science.gov (United States)

    Gabrielsson, Erik O; Tybrandt, Klas; Berggren, Magnus

    2014-11-01

    Advancements in the field of electronics during the past few decades have inspired the use of transistors in a diversity of research fields, including biology and medicine. However, signals in living organisms are not only carried by electrons but also through fluxes of ions and biomolecules. Thus, in order to implement the transistor functionality to control biological signals, devices that can modulate currents of ions and biomolecules, i.e., ionic transistors and diodes, are needed. One successful approach for modulation of ionic currents is to use oppositely charged ion-selective membranes to form so called ion bipolar junction transistors (IBJTs). Unfortunately, overall IBJT device performance has been hindered due to the typical low mobility of ions, large geometries of the ion bipolar junction materials, and the possibility of electric field enhanced (EFE) water dissociation in the junction. Here, we introduce a novel polyphosphonium-based anion-selective material into npn-type IBJTs. The new material does not show EFE water dissociation and therefore allows for a reduction of junction length down to 2 μm, which significantly improves the switching performance of the ion transistor to 2 s. The presented improvement in speed as well the simplified design will be useful for future development of advanced iontronic circuits employing IBJTs, for example, addressable drug-delivery devices.

  10. Flux interactions on stacked Josephson junctions

    DEFF Research Database (Denmark)

    Scott, Alwyn C.; A., Petraglia

    1996-01-01

    Perturbation methods are used to study the dynamics of locked fluxon modes on stacked Josephson junctions and single crystals of certain high-T-c, superconductors. Two limiting cases are considered: (i) The nonlinear diffusion regime in which fluxon dynamics are dominated by energy exchange betwe...

  11. Defect formation in long Josephson junctions

    DEFF Research Database (Denmark)

    Gordeeva, Anna; Pankratov, Andrey

    2010-01-01

    We study numerically a mechanism of vortex formation in a long Josephson junction within the framework of the one-dimensional sine-Gordon model. This mechanism is switched on below the critical temperature. It is shown that the number of fluxons versus velocity of cooling roughly scales according...

  12. Gap junction diseases of the skin.

    NARCIS (Netherlands)

    Steensel, M.A.M. van

    2004-01-01

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by muta

  13. Gap junctions-guards of excitability

    DEFF Research Database (Denmark)

    Stroemlund, Line Waring; Jensen, Christa Funch; Qvortrup, Klaus;

    2015-01-01

    Cardiomyocytes are connected by mechanical and electrical junctions located at the intercalated discs (IDs). Although these structures have long been known, it is becoming increasingly clear that their components interact. This review describes the involvement of the ID in electrical disturbances...

  14. Fluxon density waves in long Josephson junctions

    DEFF Research Database (Denmark)

    Olsen, O. H.; Ustinov, A. V.; Pedersen, Niels Falsig

    1993-01-01

    Numerical simulations of the multiple fluxon dynamics stimulated by an external oscillating force applied at a boundary of a long Josephson junction are presented. The calculated IV characteristics agree well with a recent experimental observation of rf-induced satellite flux-flow steps. The volt...... density waves....

  15. Transmembrane potentials of canine AV junctional tissues.

    Science.gov (United States)

    Tse, W W

    1986-06-01

    The atrioventricular (AV) junction comprises the AV node, His bundle (HB), and specialized tissues proximal to the node called paranodal fibers (PNF). In the present study, an in vitro, dissection-exposed canine right atrial (RA), transitional fiber (TF), AV junctional preparation was used. The TF and PNF formed a pathway running along the base of the septal cusp of the tricuspid valve (SCTV). In the first experiment, impulses elicited at the RA were monitored to propagate sequentially through the TF, PNF, AV node, and then the HB. This functional evidence supports the concept that a conduction pathway connecting the RA and the AV node exists along the base of the SCTV. This internodal pathway is referred to as the septal cusp pathway. In another experiment, transmembrane potentials and Vmax were determined on each of the AV junctional tissues. Results showed that PNF had the lowest Vmax (2.5 V/sec), followed by AV node (7.0 V/sec) and HB (33 V/sec). This finding showed that PNF, and not the AV node, has the lowest Vmax, suggesting that the PNF has the lowest conductivity among the AV junctional tissues, and this study advances our understanding on the mechanism of AV conduction delay in dog hearts.

  16. Lateral junction dynamics lead the way out.

    Science.gov (United States)

    Behrndt, Martin; Heisenberg, Carl-Philipp

    2014-02-01

    Epithelial cell layers need to be tightly regulated to maintain their integrity and correct function. Cell integration into epithelial sheets is now shown to depend on the N-WASP-regulated stabilization of cortical F-actin, which generates distinct patterns of apical-lateral contractility at E-cadherin-based cell-cell junctions.

  17. Soliton excitations in Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Lomdahl, P. S.; Sørensen, O. H.; Christiansen, Peter Leth

    1982-01-01

    on the Nth ZFS yields the frequency Nf1 Coexistence of two adjacent frequencies is found on the third ZFS of the longer junction (L / λJ=6) in a narrow range of bias current as also found in the experiments. Small asymmetries in the experimental environment, a weak magnetic field, e.g., is introduced via...

  18. Gap junction diseases of the skin.

    NARCIS (Netherlands)

    Steensel, M.A.M. van

    2004-01-01

    Gap junctions are intercellular channels that allow the passage of water, ions, and small molecules. They are involved in quick, short-range messaging between cells and are found in skin, nervous tissue, heart, and muscle. An increasing number of hereditary skin disorders appear to be caused by muta

  19. Fluxon Dynamics in Elliptic Annular Josephson Junctions

    DEFF Research Database (Denmark)

    Monaco, Roberto; Mygind, Jesper

    2016-01-01

    We analyze the dynamics of a magnetic flux quantum (current vortex) trapped in a current-biased long planar elliptic annular Josephson tunnel junction. The system is modeled by a perturbed sine-Gordon equation that determines the spatial and temporal behavior of the phase difference across the tu...

  20. Intercellular junctions in nerve-free hydra

    DEFF Research Database (Denmark)

    McDowall, A W; Grimmelikhuijzen, C J

    1980-01-01

    with particles in an "enplaque conformation appearing as a raised plateau on the E-face or as a depression on the P-face; (ii) structures morphologically similar to gap junctions in rat liver, containing particles on the P-face and corresponding pits on the E-face, both having hexagonal packing with a lattice...

  1. All-carbon molecular tunnel junctions.

    Science.gov (United States)

    Yan, Haijun; Bergren, Adam Johan; McCreery, Richard L

    2011-11-30

    This Article explores the idea of using nonmetallic contacts for molecular electronics. Metal-free, all-carbon molecular electronic junctions were fabricated by orienting a layer of organic molecules between two carbon conductors with high yield (>90%) and good reproducibility (rsd of current density at 0.5 V carbon devices exhibit current density-voltage (J-V) behavior similar to those with metallic Cu top contacts. However, the all-carbon devices display enhanced stability to bias extremes and greatly improved thermal stability. Completed carbon/nitroazobenzene(NAB)/carbon junctions can sustain temperatures up to 300 °C in vacuum for 30 min and can be scanned at ±1 V for at least 1.2 × 10(9) cycles in air at 100 °C without a significant change in J-V characteristics. Furthermore, these all-carbon devices can withstand much higher voltages and current densities than can Cu-containing junctions, which fail upon oxidation and/or electromigration of the copper. The advantages of carbon contacts stem mainly from the strong covalent bonding in the disordered carbon materials, which resists electromigration or penetration into the molecular layer, and provides enhanced stability. These results highlight the significance of nonmetallic contacts for molecular electronics and the potential for integration of all-carbon molecular junctions with conventional microelectronics.

  2. Mesh Currents and Josephson Junction Arrays

    OpenAIRE

    1995-01-01

    A simple but accurate mesh current analysis is performed on a XY model and on a SIMF model to derive the equations for a Josephson junction array. The equations obtained here turn out to be different from other equations already existing in the literature. Moreover, it is shown that the two models come from an unique hidden structure

  3. Asthma and Obstructive Sleep Apnea

    Institute of Scientific and Technical Information of China (English)

    Yi-Xian Qiao; Yi Xiao

    2015-01-01

    Objective:To get a comprehensive understanding about the relationship between obstructive sleep apnea (OSA) and asthma by reviewing the epidemiology,pathophysiology,and clinical manifestation and then summarizing the latest progress on diagnosis and treatment.Data Sources:Articles referred in this review were mainly collected from a comprehensive search of the PubMed published in English from 1990 to 2015 with the terms "OSA" and “asthma'" as the main keywords.Highly regarded older publications were also included.Study Selection:Information about the features of the two diseases in common,the pathophysiologic association between them and their current treatments from the literature search were identified,retrieved,and summarized.Results:Both OSA and asthma are very prevalent conditions.The incidences of them have kept on rising in recent years.Asthma is often accompanied by snoring and apnea,and OSA often combines with asthma,as well.They have many predisposing and aggravating factors in common.Possible shared direct mechanistic links between them include mechanical effects,intermittent hypoxia,nerve reflex,inflammation,leptin,etc.Indirect mechanistic links include medication,nose diseases,smoking,obesity,and gastroesophageal reflux disease.Since OSA presents many similar features with nocturnal asthma,some scholars termed them as a sole syndrome "alternative overlap syndrome,"and proved that asthma symptoms in those patients could be improved through the treatment of continuous positive airway pressure.Conclusions:OSA and asthma are closely associated in pathogenesis,symptoms,and therapies.With the growing awareness of the relationship between them,we should raise our vigilance on the coexistence of OSA in those difficult-to-control asthmatic patients.Further studies are still needed to guide the clinical works.

  4. Zero-voltage nondegenerate parametric mode in Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1976-01-01

    A new parametric mode in a Josephson tunnel junction biased in the zero-voltage mode is suggested. It is a nondegenerate parametric excitation where the junction plasma resonance represents the input circuit, and a junction geometrical resonance represents the idler circuit. This nondegenerate mo...... for such a coupling. Journal of Applied Physics is copyrighted by The American Institute of Physics....

  5. Systematic study of shallow junction formation on germanium substrates

    DEFF Research Database (Denmark)

    Hellings, Geert; Rosseel, Erik; Clarysse, Trudo

    2011-01-01

    Published results on Ge junctions are benchmarked systematically using RS–XJ plots. The electrical activation level required to meet the ITRS targets is calculated. Additionally, new results are presented on shallow furnace-annealed B junctions and shallow laser-annealed As junctions. Co-implanti...

  6. Long Josephson Junction Stack Coupled to a Cavity

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Pedersen, Niels Falsig; Groenbech-Jensen, N.

    2007-01-01

    A stack of inductively coupled long Josephson junctions are modeled as a system of coupled sine-Gordon equations. One boundary of the stack is coupled electrically to a resonant cavity. With one fluxon in each Josephson junction, the inter-junction fluxon forces are repulsive. We look at a possible...

  7. Structure Stability of Ⅰ-Type Carbon Nanotube Junctions

    Institute of Scientific and Technical Information of China (English)

    夏丹; 袁喆; 李家明

    2002-01-01

    Carbon nanotubes with junctions may play an important role in future ‘nanoelectronics' and future ‘nano devices'.In particular, junctions constructed with metal and semiconducting nanotubes have potential applications. Basedon the orthogonal tight-binding molecular dynamics method, we present our study of the structure stability ofI-type carbon nanotube junctions.

  8. Vacuum Tight Threaded Junctions (VTTJ): A new solution for reliable heterogeneous junctions in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Agostinetti, P., E-mail: piero.agostinetti@igi.cnr.it; Palma, M. Dalla; Agostini, F. Degli; Marcuzzi, D.; Rizzolo, A.; Rossetto, F.; Sonato, P.; Zaccaria, P.

    2015-10-15

    Highlights: • Heterogeneous junctions represent a critical issue in Nuclear Fusion experiments. • We have developed a new technique for heterogeneous junctions, called VTTJ, whose main advantages are low cost, high reliability and easiness of construction. • The VTTJ junctions have passed all the tests required by ITER for the heterogeneous junctions of the divertor. • Further tests have demonstrated wide margins for operation (up to 700 °C and 500 bar). - Abstract: A new technique, called Vacuum Tight Threaded Junction (VTTJ), has been developed and patented by Consorzio RFX, permitting to obtain low-cost and reliable non-welded junctions, able to maintain vacuum tightness also in heavy loading conditions (high temperature and high mechanical loads). The technique can be applied also if the materials to be joint are not weldable and for heterogeneous junctions (for example, between steel and copper) and has been tested up to 500 bar internal pressure and up to 700 °C, showing excellent leak tightness in vacuum conditions and high mechanical resistance. The main advantages with respect to existing technologies (for example, friction welding and electron beam welding) are an easy construction, a low cost, a precise positioning of the junction and a high repeatability of the process. Due to these advantages, the new technique has been adopted for several components of the SPIDER experiment and it is proposed for ITER, in particular for the ITER Heat and Current Drive Neutral Beam Injector and for its prototype, the MITICA experiment, to be tested at Consorzio RFX. This paper gives a detailed description of the VTTJ technique, of the samples manufactured and of the qualification tests that have been carried out so far.

  9. Graphene junction field-effect transistor

    Science.gov (United States)

    Ou, Tzu-Min; Borsa, Tomoko; van Zeghbroeck, Bart

    2014-03-01

    We have demonstrated for the first time a novel graphene transistor gated by a graphene/semiconductor junction rather than an insulating gate. The transistor operates much like a semiconductor junction Field Effect Transistor (jFET) where the depletion layer charge in the semiconductor modulates the mobile charge in the channel. The channel in our case is the graphene rather than another semiconductor layer. An increased reverse bias of the graphene/n-silicon junction increases the positive charge in the depletion region and thereby reduces the total charge in the graphene. We fabricated individual graphene/silicon junctions as well as graphene jFETs (GjFETs) on n-type (4.5x1015 cm-3) silicon with Cr/Au electrodes and 3 μm gate length. As a control device, we also fabricated back-gated graphene MOSFETs using a 90nm SiO2 on a p-type silicon substrate (1019 cm-3) . The graphene was grown by APCVD on copper foil and transferred with PMMA onto the silicon substrate. The GjFET exhibited an on-off ratio of 3.75, an intrinsic graphene doping of 1.75x1012 cm-2, compared to 1.17x1013 cm-2 in the MOSFET, and reached the Dirac point at 13.5V. Characteristics of the junctions and transistors were measured as a function of temperature and in response to light. Experimental data and a comparison with simulations will be presented.

  10. MR urography evaluation of obstructive uropathy

    Energy Technology Data Exchange (ETDEWEB)

    Grattan-Smith, J.D.; Jones, Richard A. [Emory University School of Medicine, Department of Radiology, Children' s Healthcare of Atlanta, Atlanta, GA (United States); Little, Stephen B. [Children' s Healthcare of Atlanta, Department of Radiology, Atlanta, GA (United States)

    2008-01-15

    Hydronephrosis and the evaluation of obstructive uropathy are the most common indications for MR urography in our practice. Typically our patients fall into one of two groups: infants with antenatal hydronephrosis and older children who present with abdominal pain, hematuria or urinary tract infection. Obstruction in children is usually chronic and partial. Intermittent episodes of increased pressure occur when the urine production exceeds the capacity for drainage. MR urography uses a fluid and diuretic challenge to assess the hydronephrotic kidney. High-quality anatomic images provide a morphologic assessment of the hydronephrotic system. Although it is relatively straightforward to determine if a system is not obstructed on the basis of the renal transit time (RTT), no single parameter is adequate to fully characterize obstruction. By evaluating the changes in signal intensity in the renal parenchyma following contrast administration, the hydronephrotic systems are classified as compensated or decompensated. Delayed RTT and the presence of urine-contrast levels indicate stasis. Calyceal transit time and the difference between the volumetric and the Patlak differential renal function (vDRF-pDRF) are measures of the physiologic changes within the kidney. Additionally, MR urography provides prognostic information by assessing the quality of the renal parenchyma and identifying uropathy preoperatively. MR urography combines both anatomic and functional information in a single test and is capable of providing a comprehensive evaluation of obstructive uropathy that could ultimately help select those patients most likely to benefit from surgical intervention. (orig.)

  11. Percutaneous transhepatic cholangiographic evaluation of obstructive jaundice

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hee Tae; Kim, Hong Soo; Kim, Jong Deok; Rhee, Hak Song [Presbyterian Medical Center, Jeonju (Korea, Republic of)

    1983-12-15

    PTC is the single most valuable diagnostic method available to evaluate the size, shape and site of the causes of obstructive jaundice among various radiological procedures. The authors reviewed and radiologically classified the PTC films of 203 cases of obstructive jaundice from July, 1977 to June, 1983 at Presbyterian Medical Center, Jeonju confirmed clinically, operatively and pathologically. The results are as follows; 1. The most common cause of obstructive jaundice was bile duct stone (64/203: 31.53%) and the other causes were bile duct cancer (43/203: 21.18%), pancreas cancer (41/203: 20.19%), biliary ascariasis and/or clonorchiasis (20/203: 9.8%), ampulla and duodenal cancer (7/203: 3.45%), fibrotic stenosis of sphincter of Oddi (6/203: 2.96%) etc. in the order. Of these primary involvement with cancer was more frequent (91/203: 44.33%) than stone. 3. The average maximal diameter of extrahepatic bile duct just proximal to the site of obstruction or stenosis by stones or by cancers was nearly equal (2.36 cm : 2.38 cm). 4. Cancers caused complete bile duct obstruction in about 75% (68/91) of cases and also were associated with intrahepatic duct dilatation about 92% (84/91) of cases. But in contrast biliary calculi showed good drainage of contrast medium in 75% (48/64) of cases and 92% (59/64) showed normal diameter.

  12. Pelviureteral inhibitory reflex and ureteropelvic excitatory reflex: role of the two reflexes in regulation of urine flow from the renal pelvis to the ureter.

    Science.gov (United States)

    Shafik, A

    1997-01-01

    The mechanism by which the ureteropelvic junction (UPJ) regulates the passage of urine from the renal pelvis to the ureter, and prevents urinary backflow from the the ureter to the renal pelvis, is not completely understood. The current communication studies this mechanism in 18 dogs. With the dogs under anesthesia, nephrostomy was done through which two catheters (one pressure and one balloon-tipped) were introduced into the UPJ and the renal pelvis, respectively. Renal pelvis distension with a balloon filled with 1 ml of saline effected a rise of renal pelvic pressure from a mean basal pressure of 4.8 +/- 1.2 cm H2O to 6.9 +/- 2.3 cm H2O (P pelvic balloon (P > 0.05). Renal pelvic distension with 2, 3, and 4 ml caused a significant rise of renal pelvic pressure to 8.4 +/- 2.7 (P 0.05). In contrast, the UPJ showed no significant pressure change upon distension of the locally anesthetized renal pelvis or ureter, respectively. Likewise, the locally anesthetized UPJ exhibited no significant pressure response to renal pelvic or ureteric distension. The study demonstrates that urine might have to accumulate in the renal pelvis up to a certain volume and pressure so as to effect UPJ opening, which occurs at its maximum irrespective of the distending volume. UPJ opening upon renal pelvic distension postulates a reflex relationship which we call "pelviureteral inhibitory reflex." This reflex is believed to regulate the passage of urine from the renal pelvis to the ureter. Ureteric distension closes the UPJ; we call this reflex action the "ureteropelvic excitatory reflex" as it seems to prevent reflux of urine through the UPJ and thus protects the kidney. The concept that the UPJ acts as a physiologic sphincter is put forward.

  13. Small intestinal obstruction in pregnancy and puerperium

    Directory of Open Access Journals (Sweden)

    Chiedozi Lawrence

    1999-01-01

    Full Text Available The problem of intestinal obstruction in pregnancy and puerperium is worsened by the risk it poses not just to the mother, but also to the fetus. In this review of 10 pregnant/puerperium patients the maternal mortality was 10% and fetal wastage 20%. In pregnancy and puerperium, intestinal obstruction carries a higher mortality, 10-33%, than in non-pregnant patients, 6-10%. The rarity of the problem, delay in diagnosis, anxiety over radiological examination in pregnant women, worry over laparotomy in pregnant women, all result in delay in instituting definite treatment and contribute to the morbidity. Application of established principles in the management of intestinal obstruction even when it occurs in pregnancy and puerperium might help to improve the results of management and reduce the current level of morbidity and mortality.

  14. Snoring Sounds Predict Obstruction Sites and Surgical Response in Patients with Obstructive Sleep Apnea Hypopnea Syndrome

    Science.gov (United States)

    Lee, Li-Ang; Lo, Yu-Lun; Yu, Jen-Fang; Lee, Gui-She; Ni, Yung-Lun; Chen, Ning-Hung; Fang, Tuan-Jen; Huang, Chung-Guei; Cheng, Wen-Nuan; Li, Hsueh-Yu

    2016-01-01

    Snoring sounds generated by different vibrators of the upper airway may be useful indicators of obstruction sites in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). This study aimed to investigate associations between snoring sounds, obstruction sites, and surgical responses (≥50% reduction in the apnea-hypopnea index [AHI] and DISE), and relocation pharyngoplasty. All patients received follow-up polysomnography after 6 months. Fifteen (42%) patients with at least two complete obstruction sites defined by DISE were significantly, positively associated with maximal snoring sound intensity (40–300 Hz; odds ratio [OR], 1.25, 95% confidence interval [CI] 1.05–1.49) and body mass index (OR, 1.48, 95% CI 1.02–2.15) after logistic regression analysis. Tonsil obstruction was significantly, inversely correlated with mean snoring sound intensity (301–850 Hz; OR, 0.84, 95% CI 0.74–0.96). Moreover, baseline tonsil obstruction detected by either DISE or mean snoring sound intensity (301–850 Hz), and AHI could significantly predict the surgical response. Our findings suggest that snoring sound detection may be helpful in determining obstruction sites and predict surgical responses. PMID:27471038

  15. Planar Josephson tunnel junctions in a transverse magnetic field

    DEFF Research Database (Denmark)

    Monacoa, R.; Aarøe, Morten; Mygind, Jesper

    2007-01-01

    Traditionally, since the discovery of the Josephson effect in 1962, the magnetic diffraction pattern of planar Josephson tunnel junctions has been recorded with the field applied in the plane of the junction. Here we discuss the static junction properties in a transverse magnetic field where...... demagnetization effects imposed by the tunnel barrier and electrodes geometry are important. Measurements of the junction critical current versus magnetic field in planar Nb-based high-quality junctions with different geometry, size, and critical current density show that it is advantageous to use a transverse...

  16. The computation of first order moments on junction trees

    CERN Document Server

    Djuric, Milos B; Stankovic, Miomir S

    2012-01-01

    We review some existing methods for the computation of first order moments on junction trees using Shafer-Shenoy algorithm. First, we consider the problem of first order moments computation as vertices problem in junction trees. In this way, the problem is solved using the memory space of an order of the junction tree edge-set cardinality. After that, we consider two algorithms, Lauritzen-Nilsson algorithm, and Mau\\'a et al. algorithm, which computes the first order moments as the normalization problem in junction tree, using the memory space of an order of the junction tree leaf-set cardinality.

  17. Feasibility of laparoscopy for small bowel obstruction

    Directory of Open Access Journals (Sweden)

    De Sol Angelo A

    2009-01-01

    Full Text Available Abstract Background Adherential pathology is the most common cause of small bowel obstruction. Laparoscopy in small bowel obstruction does not have a clear role yet; surely it doesn't always represent only a therapeutic act, but it is always a diagnostic act, which doesn't interfere with abdominal wall integrity. Methods We performed a review without any language restrictions considering international literature indexed from 1980 to 2007 in Medline, Embase and Cochrane Library. We analyzed the reference lists of the key manuscripts. We also added a review based on international non-indexed sources. Results The feasibility of diagnostic laparoscopy is high (60–100%, while that of therapeutic laparoscopy is low (40–88%. The frequency of laparotomic conversions is variable ranging from 0 to 52%, depending on patient selection and surgical skill. The first cause of laparotomic conversion is a difficult exposition and treatment of band adhesions. The incidence of laparotomic conversions is major in patients with anterior peritoneal band adhesions. Other main causes for laparotomic conversion are the presence of bowel necrosis and accidental enterotomies. The predictive factors for successful laparoscopic adhesiolysis are: number of previous laparotomies ≤ 2, non-median previous laparotomy, appendectomy as previous surgical treatment causing adherences, unique band adhesion as phatogenetic mechanism of small bowel obstruction, early laparoscopic management within 24 hours from the onset of symptoms, no signs of peritonitis on physical examination, experience of the surgeon. Conclusion Laparoscopic adhesiolysis in small bowel obstruction is feasible but can be convenient only if performed by skilled surgeons in selected patients. The laparoscopic adhesiolysis for small bowel obstruction is satisfactorily carried out when early indicated in patients with a low number of laparotomies resulting in a short hospital stay and a lower postoperative

  18. Office of Coast Survey's Automated Wreck and Obstruction Information System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Automated Wreck and Obstruction Information System (AWOIS) is an automated file that contains information on wrecks and obstructions, and other significant...

  19. Office of Coast Survey Wrecks and Obstructions Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of Coast Survey's Wrecks and Obstructions database contains information on the identified submerged wrecks and obstructions within the U.S. maritime...

  20. An unusual cause of obstructive jaundice

    Science.gov (United States)

    Abbara, Aula; Al-Hadithy, Huda; Khan, Shahid; Shorvon, Philip

    2009-01-01

    An 80-year-old Caucasian woman presented with a 3-week history of painless jaundice, pruritis, dark urine and weight loss. Blood analysis demonstrated an obstructive jaundice pattern. A CT scan demonstrated a gas-filled duodenal diverticulum arising from the second part of the duodenum. Once food material was cleared from the diverticulum endoscopically, there was clinical and biochemical improvement. This case demonstrates an unusual cause of obstructive jaundice that has seldom been reported in the literature; once impacted food material was removed from the diverticulum, there was radiological improvement of the patient’s condition. PMID:21686538

  1. Airway distensibility in Chronic Obstructive Airway Disease

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde Marie; Pedersen, Jesper Holst; Dirksen, Asger

    2013-01-01

    Rationale – Chronic Obstructive Pulmonary Disease (COPD) is a combination of chronic bronchitis and emphysema, which both may lead to airway obstruction. Under normal circumstances, airway dimensions vary as a function of inspiration level. We aim to study the influence of COPD and emphysema...... and emphysema, respectively. Conclusions – Airway distensibility decreases significantly with increasing severity of both GOLD status and emphysema, indicating that in COPD the dynamic change in airway calibre during respiration is compromised. Chronic bronchitis and emphysema appear to be interacting...

  2. Uterine rotation: a cause of intestinal obstruction.

    Science.gov (United States)

    González-Mesa, Ernesto; Narbona, Isidoro; Cohen, Isaac; Villegas, Emilia; Cuenca, Celia

    2013-01-01

    Intestinal obstruction is an uncommon surgical emergency during pregnancy that affects seriously the prognosis of gestation. The underlying cause can be identified in the majority of cases and usually consists of adhesions secondary to previous abdominal or pelvic surgery, followed in order of frequency by intestinal volvuli. In recent years there have been no reports in which the gravid uterus has been the cause of intestinal obstruction. We report the case of a woman in week 33 + 4 of pregnancy who developed extrinsic compression of the colon secondary to uterine rotation and pelvic impaction of the head of the fetus.

  3. Neonatal Duodenal Obstruction: A 15-Year Experience

    Directory of Open Access Journals (Sweden)

    Kamal Nain Rattan

    2016-04-01

    Full Text Available Background: Congenital duodenal obstruction is one of the commonest causes of neonatal intestinal obstruction. We are presenting our 15-year experience by analyzing clinical spectrum and outcome in neonates with duodenal obstruction admitted at our center. Material and Methods: The hospital records of all neonates admitted with duodenal obstruction from June 2000 to June 2015 were reviewed. The patient records were analyzed for antenatal diagnosis, age, sex, clinical presentation, diagnosis, associated anomalies, surgical procedures performed; postoperative morbidity and mortality. We excluded from our study malrotation of gut associated with congenital diaphragmatic hernia and abdominal wall defects. Results: A total of 81 patients were admitted, out of which 56 were males and 25 were females. Polyhydramnios was detected in 24 (30% pregnancies. Average birth weight was 2.1±1.0Kg and average gestational age was 38 (SD±1 weeks with 17 (21% preterm neonates. Presenting features were vomiting in 81(100% which was bilious in 81% and non bilious in 19%, epigastric fullness in 56 (69% and dehydration in 18 (22% and failure to thrive in 16 (19%. Most common cause of obstruction was duodenal atresia in 38 (46.9%, followed by malrotation of gut in 33 (40.7%, and annular pancreas in 4 cases. Depending upon site of location, infra-ampullary obstruction was the most common in 64 (79%, supra-ampullary in 9 (7.4% and ampullary 8 neonates. Both duodenal atresia and malrotation of gut was present in 4 cases. X-ray abdomen was most commonly used investigation to confirm the diagnosis. All cases were managed surgically by open laparotomy. Eleven (13.5% patients died due to sepsis and associated congenital anomalies. Conclusion: Congenital duodenal obstruction most commonly presents in early neonatal period with features of upper GIT obstruction like vomiting and epigastrium fullness as in our series. Early antenatal diagnosis and surgical interventions hold the

  4. Bronchial or Laryngeal Obstruction Induced by Exercise?

    Directory of Open Access Journals (Sweden)

    Ayoub Bey

    2017-06-01

    Full Text Available A child suspected of exercise-induced laryngeal obstruction and asthma is examined by laryngoscopy and respiratory resistance (Rrs after exercise challenge. Immediately at exercise cessation, the visualized adduction of the larynx in inspiration is reflected in a paroxystic increase in Rrs. While normal breathing has apparently resumed later on during recovery from exercise, the pattern of Rrs in inspiration is observed to reoccur following a deep breath or swallowing. The procedure may thus help diagnosing the site of exercise-induced obstruction when laryngoscopy is not available and identify re-inducers of laryngeal dysfunction.

  5. Bronchial or Laryngeal Obstruction Induced by Exercise?

    Science.gov (United States)

    Bey, Ayoub; Botti, Sophie; Coutier-Marie, Laurianne; Bonabel, Claude; Metche, Stéphanie; Demoulin-Alexikova, Silvia; Schweitzer, Cyril Etienne; Marchal, François; Coffinet, Laurent; Ioan, Iulia

    2017-01-01

    A child suspected of exercise-induced laryngeal obstruction and asthma is examined by laryngoscopy and respiratory resistance (Rrs) after exercise challenge. Immediately at exercise cessation, the visualized adduction of the larynx in inspiration is reflected in a paroxystic increase in Rrs. While normal breathing has apparently resumed later on during recovery from exercise, the pattern of Rrs in inspiration is observed to reoccur following a deep breath or swallowing. The procedure may thus help diagnosing the site of exercise-induced obstruction when laryngoscopy is not available and identify re-inducers of laryngeal dysfunction.

  6. Lung Compliance and Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    D. Papandrinopoulou

    2012-01-01

    Full Text Available Chronic obstructive pulmonary disease, namely, pulmonary emphysema and chronic bronchitis, is a chronic inflammatory response of the airways to noxious particles or gases, with resulting pathological and pathophysiological changes in the lung. The main pathophysiological aspects of the disease are airflow obstruction and hyperinflation. The mechanical properties of the respiratory system and its component parts are studied by determining the corresponding volume-pressure (P-V relationships. The consequences of the inflammatory response on the lung structure and function are depicted on the volume-pressure relationships.

  7. Endoscopic third ventriculostomy in obstructed hydrocephalus

    Directory of Open Access Journals (Sweden)

    Singh D

    2003-01-01

    Full Text Available Forty-three ETV were performed in 46 patients of obstructive hydrocephalus. Study was divided into two groups. Group 1 was with 29 children of less than two years age. Group 2 had seventeen patients of more than 2 years, adolescent and adults. Group 1 had 70% clinical and 63% radiological improvement whereas Group 2 showed 100% clinical and 73% radiological improvement. ETV failed in relieving the symptoms of hydrocephalus in eight patients. They were eventually benefited with VP Shunt. There was one postoperative death, which was not related to the procedure. ETV is an important alternative to VP Shunt in relieving hydrocephalus due to obstruction in CSF pathway.

  8. Bilateral Nasoalveolar Cyst Causing Nasal Obstruction

    Directory of Open Access Journals (Sweden)

    Uzeyir Yildizoglu

    2016-01-01

    Full Text Available Nasoalveolar cysts, which originate from epithelial remnants of nasolacrimal duct, are nonodontogenic soft tissue lesions of the upper jaw. These cysts are thought to be developmental and are presented with fullness in the upper lip and nose, swelling on the palate, and sometimes nasal obstruction. Because of cosmetic problems, they are often diagnosed at an early stage. These lesions are mostly revealed unilaterally but also can be seen on both sides. In this case report, a patient who complained of nasal obstruction and then diagnosed with bilateral nasoalveolar cysts and treated by sublabial excision is presented and clinical features and treatment approaches are discussed with the review of literature.

  9. Bilateral Nasoalveolar Cyst Causing Nasal Obstruction

    Science.gov (United States)

    Yildizoglu, Uzeyir; Polat, Bahtiyar; Durmaz, Abdullah

    2016-01-01

    Nasoalveolar cysts, which originate from epithelial remnants of nasolacrimal duct, are nonodontogenic soft tissue lesions of the upper jaw. These cysts are thought to be developmental and are presented with fullness in the upper lip and nose, swelling on the palate, and sometimes nasal obstruction. Because of cosmetic problems, they are often diagnosed at an early stage. These lesions are mostly revealed unilaterally but also can be seen on both sides. In this case report, a patient who complained of nasal obstruction and then diagnosed with bilateral nasoalveolar cysts and treated by sublabial excision is presented and clinical features and treatment approaches are discussed with the review of literature. PMID:27980871

  10. Medication bezoar: Intestinal obstruction by an Isocal bezoar

    Energy Technology Data Exchange (ETDEWEB)

    O' Malley, J.A.M.; Ferrucci, J.T. Jr.; Goodgame, J.T. Jr.

    1981-05-15

    Medications may occasionally obstruct the gastrointestinal tract by virtue of their physical mass. Obturative obstruction of the alimentary tract is reportedly caused by an increasing number of medications, including hydroscopic bulk laxatives, cholestyramine, nonabsorbable antacids, and vitamin C tablets. Inspissated Isocal tube feedings caused jejunal obstruction in a postoperative patient. Medication bezoars are a rare cause of intestinal obstruction that may result in significant patient morbidity, including bowel necrosis, perforation, and peritonitis. The radiographic appearance may mimic an abdominal abscess.

  11. Surgical Reconstruction for Severe Tracheal Obstruction in Morquio A Syndrome.

    Science.gov (United States)

    Pizarro, Christian; Davies, Ryan R; Theroux, Mary; Spurrier, Ellen A; Averill, Lauren W; Tomatsu, Shunji

    2016-10-01

    Progressive tracheal obstruction is commonly seen in Morquio A syndrome and can lead to life-threatening complications. Although tracheostomy can address severe upper airway obstruction, lower airway obstruction, commonly associated with a narrow thoracic inlet and vascular compression, requires an alternative approach. We describe the case of a 16-year-old patient with Morquio A syndrome whose near-fatal tracheal obstruction was relieved by timely surgical tracheal vascular reconstruction with dramatic resolution of his respiratory symptoms.

  12. [Nasal obstruction and mouth breathing: the ENT's point of view].

    Science.gov (United States)

    Leboulanger, Nicolas

    2013-06-01

    Obstructive diseases of children's upper airways are frequent, mostly caused by tonsils and adenoids hypertrophy. A nasal septum deviation or a lower turbinate hypertrophy may also cause a significant obstruction. Tonsillectomy and adenoidectomy must be performed in case of clinical obstruction, sometimes documented by a sleep study. A tonsils' hypertrophy without significant obstruction and clinical symptoms is not an indication of adenotonsillectomy, even in case of snoring or if an orthodontic treatment is planned.

  13. String networks with junctions in competition models

    Science.gov (United States)

    Avelino, P. P.; Bazeia, D.; Losano, L.; Menezes, J.; de Oliveira, B. F.

    2017-03-01

    In this work we give specific examples of competition models, with six and eight species, whose three-dimensional dynamics naturally leads to the formation of string networks with junctions, associated with regions that have a high concentration of enemy species. We study the two- and three-dimensional evolution of such networks, both using stochastic network and mean field theory simulations. If the predation, reproduction and mobility probabilities do not vary in space and time, we find that the networks attain scaling regimes with a characteristic length roughly proportional to t 1 / 2, where t is the physical time, thus showing that the presence of junctions, on its own, does not have a significant impact on their scaling properties.

  14. Vibrational Heat Transport in Molecular Junctions

    Science.gov (United States)

    Segal, Dvira; Agarwalla, Bijay Kumar

    2016-05-01

    We review studies of vibrational energy transfer in a molecular junction geometry, consisting of a molecule bridging two heat reservoirs, solids or large chemical compounds. This setup is of interest for applications in molecular electronics, thermoelectrics, and nanophononics, and for addressing basic questions in the theory of classical and quantum transport. Calculations show that system size, disorder, structure, dimensionality, internal anharmonicities, contact interaction, and quantum coherent effects are factors that combine to determine the predominant mechanism (ballistic/diffusive), effectiveness (poor/good), and functionality (linear/nonlinear) of thermal conduction at the nanoscale. We review recent experiments and relevant calculations of quantum heat transfer in molecular junctions. We recount the Landauer approach, appropriate for the study of elastic (harmonic) phononic transport, and outline techniques that incorporate molecular anharmonicities. Theoretical methods are described along with examples illustrating the challenge of reaching control over vibrational heat conduction in molecules.

  15. String networks with junctions in competition models

    CERN Document Server

    Avelino, P P; Losano, L; Menezes, J; de Oliveira, B F

    2016-01-01

    In this work we give specific examples of competition models, with six and eight species, whose three-dimensional dynamics naturally leads to the formation of string networks with junctions, associated with regions that have a high concentration of enemy species. We study the two- and three-dimensional evolution of such networks, both using stochastic network and mean field theory simulations. If the predation, reproduction and mobility probabilities do not vary in space and time, we find that the networks attain scaling regimes with a characteristic length roughly proportional to $t^{1/2}$, where $t$ is the physical time, thus showing that the presence of junctions, on its own, does not have a significant impact on their scaling properties.

  16. Junction between surfaces of two topological insulators

    Science.gov (United States)

    Sen, Diptiman; Deb, Oindrila

    2012-02-01

    We study scattering from a line junction which separates the surfaces of two three-dimensional topological insulators; some aspects of this problem were recently studied in Takahashi and Murakami, Phys. Rev. Lett. 107, 166805 (2011). The velocities of the Dirac electrons on the two surfaces may be unequal and may even have opposite signs; in the latter case, we find that the electrons must, in general, go into the two-dimensional interface separating the two topological insulators. We also study what happens if the two surfaces are at an angle φ with respect to each other. We find in this case that there are bound states which propagate along the line junction with a velocity and direction of spin which depend on the bending angle φ.

  17. Current distributions in stripe Majorana junctions

    Science.gov (United States)

    Osca, Javier; Llorenç, Serra

    2017-02-01

    We calculate current and density distributions in stripe (2D planar) junctions between normal and Majorana nanowires having a finite ( y) transverse length. In presence of a magnetic field with vertical and in-plane components, the y-symmetry of the charge current distribution in the normal lead changes strongly across the Majorana phase transition: from center-symmetric if a Majorana mode is present to laterally-shifted (as expected by the Hall effect) if the field is tilted such as to destroy the Majorana mode due to the projection rule. We compare quasi-particle and charge distributions of current and density, as well as spin magnetizations. The Majorana mode causes opposite spin accumulations on the transverse sides of the junction and the emergence of a spin current.

  18. Boson Josephson Junction with Trapped Atoms

    Science.gov (United States)

    Raghavan, S.; Smerzi, A.; Fantoni, S.; Shenoy, S. R.

    We consider coherent atomic tunneling between two weakly coupled Bose-Einstein condensates at T=0 in a double-well trap. The condensate dynamics of the macroscopic amplitudes in the two wells is modeled by two Gross-Pitaevskii equations (GPE) coupled by a tunneling matrix element. Analytic elliptic function solutions are obtained for the time evolution of the inter-well fractional population imbalance z(t) (related to the condensate phase difference) of the Boson Josephson junction (BJJ). Surprisingly, the neutral-atom BJJ shows (non-sinusoidal generalizations of) effects seen in charged-electron superconductor Josephson junctions (SJJ). The BJJ elliptic-function behavior has a singular dependence on a GPE parameter ratio Λ at a critical ratio Λ=Λc, beyond which a novel 'macroscopic quantum self-trapping' effect sets in with a non-zero time-averaged imbalance ≠0.

  19. Non-Lagrangian theories from brane junctions

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ling [Chalmers Univ. of Technology, Goeteborg (Sweden); Mitev, Vladimir [Humboldt Univ., Berlin (Germany). Inst. fuer Mathematik und Inst. fuer Physik; Pomoni, Elli [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany). Theory Group; Taki, Masato [RIKEN Nishina Center, Saitama (Japan). Mathematical Physics Lab.; Yagi, Futoshi [International School of Advanced Studies (SISSA), Trieste (Italy); INFN, Trieste (Italy); Korea Institute for Advanced Study (KIAS), Seoul (Korea, Republic of)

    2013-10-15

    In this article we use 5-brane junctions to study the 5D T{sub N} SCFTs corresponding to the 5D N=1 uplift of the 4D N=2 strongly coupled gauge theories, which are obtained by compactifying N M5 branes on a sphere with three full punctures. Even though these theories have no Lagrangian description, by using the 5-brane junctions proposed by Benini, Benvenuti and Tachikawa, we are able to derive their Seiberg-Witten curves and Nekrasov partition functions. We cross-check our results with the 5D superconformal index proposed by Kim, Kim and Lee. Through the AGTW correspondence, we discuss the relations between 5D superconformal indices and n-point functions of the q-deformed W{sub N} Toda theories.

  20. An Important Member of Tight Junctions: Claudins

    Directory of Open Access Journals (Sweden)

    Ozlem Demirpence

    2016-01-01

    Full Text Available The tight junction (TJs, the most apically located of the intercellular junctional complexes, inhibits solute and water flow through the paracellular space, termed the %u201Cbarrier%u201D function. TJs participate in signal transduction mechanisms that regulate epithelial cell proliferation, gene expression, differentiation and morphogenesis. The claudin family of transmembrane proteins localized to the TJ. Loss of expression of Claudin causes of suppression TJs function. Recent studies have shown that altered levels of the different claudins may be related to invasion and progression of carcinoma cells in several primary neoplasms. A better knowledge of the mechanisms underlying carcinogenesis will likely result in the development of novel approaches for the diagnosis and therapy.

  1. Electron transport in doped fullerene molecular junctions

    Science.gov (United States)

    Kaur, Milanpreet; Sawhney, Ravinder Singh; Engles, Derick

    The effect of doping on the electron transport of molecular junctions is analyzed in this paper. The doped fullerene molecules are stringed to two semi-infinite gold electrodes and analyzed at equilibrium and nonequilibrium conditions of these device configurations. The contemplation is done using nonequilibrium Green’s function (NEGF)-density functional theory (DFT) to evaluate its density of states (DOS), transmission coefficient, molecular orbitals, electron density, charge transfer, current, and conductance. We conclude from the elucidated results that Au-C16Li4-Au and Au-C16Ne4-Au devices behave as an ordinary p-n junction diode and a Zener diode, respectively. Moreover, these doped fullerene molecules do not lose their metallic nature when sandwiched between the pair of gold electrodes.

  2. Charge Transport Phenomena in Peptide Molecular Junctions

    Directory of Open Access Journals (Sweden)

    Alessandra Luchini

    2008-01-01

    Full Text Available Inelastic electron tunneling spectroscopy (IETS is a valuable in situ spectroscopic analysis technique that provides a direct portrait of the electron transport properties of a molecular species. In the past, IETS has been applied to small molecules. Using self-assembled nanoelectronic junctions, IETS was performed for the first time on a large polypeptide protein peptide in the phosphorylated and native form, yielding interpretable spectra. A reproducible 10-fold shift of the I/V characteristics of the peptide was observed upon phosphorylation. Phosphorylation can be utilized as a site-specific modification to alter peptide structure and thereby influence electron transport in peptide molecular junctions. It is envisioned that kinases and phosphatases may be used to create tunable systems for molecular electronics applications, such as biosensors and memory devices.

  3. Role of sleep endoscopy in obstructive sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Suzan Salama

    2013-07-01

    Conclusion: Sleep endoscopy is a useful tool for the assessment of level, degree and shape of the upper airway obstruction during sleep in OSAS and this could be helpful in preoperative evaluation. Presence of obstruction at hypopharyngeal level or tongue base obstruction is an indicator of OSAS severity.

  4. Gastroesophageal Reflux Symptoms in Patients with Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Zlatica Goseva

    2014-09-01

    CONCLUSION: GER symptoms are more prevalent in patients with severe airways obstruction when compared to less airways obstructed group and controls. We could suggest an association between the degree of airways obstruction in patients with COPD and the increased rate of GER symptoms.

  5. Peltier Junction heats and cools car seat

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, M.A.

    1994-10-10

    Electrically heated seats may soon become heated and cooled seats. The design called the CCS module exploits the heat-pump capability of a class of semiconductor thermoelectric devices (TEDs) known as Peltier Junction. Every CCS module contain two TEDs. Heating and cooling occurs through convection and conduction. The heart of the system is the thermoelectric heat pump. This is originally conceived as the sole heating/cooling options for a prototype electric vehicle.

  6. Josephson junction microwave modulators for qubit control

    Science.gov (United States)

    Naaman, O.; Strong, J. A.; Ferguson, D. G.; Egan, J.; Bailey, N.; Hinkey, R. T.

    2017-02-01

    We demonstrate Josephson junction based double-balanced mixer and phase shifter circuits operating at 6-10 GHz and integrate these components to implement both a monolithic amplitude/phase vector modulator and an I/Q quadrature mixer. The devices are actuated by flux signals, dissipate no power on chip, exhibit input saturation powers in excess of 1 nW, and provide cryogenic microwave modulation solutions for integrated control of superconducting qubits.

  7. Internal dynamics of long Josephson junction oscillators

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Lomdahl, P. S.; Scott, Alwyn C.;

    1981-01-01

    Numerical computations on a sine-Gordon model of the Josephson junction fluxon oscillator are compared with experimental measurements. Good agreement is found for the voltage current characteristic, oscillator power output, and range of current bias over which oscillation is observed. Our numeric...... results imply a ''bunched-fluxon'' mode of oscillation at larger values of bias current. Applied Physics Letters is copyrighted by The American Institute of Physics....

  8. Decreased Vision and Junctional Scotoma from Pituicytoma

    Directory of Open Access Journals (Sweden)

    Nancy Huynh

    2012-05-01

    Full Text Available Pituicytomas are rare neoplasms of the sellar region. We report a case of vision loss and a junctional scotoma in a 43-year-old woman caused by compression of the optic chiasm by a pituitary tumor. The morphological and immunohistochemical characteristics of the tumor were consistent with the diagnosis of pituicytoma. The tumor was debulked surgically, and the patient’s vision improved.

  9. Brownian refrigeration by hybrid tunnel junctions

    OpenAIRE

    Peltonen, J. T.; Helle, M.; Timofeev, A. V.; Solinas, P.; Hekking, F. W. J.; Pekola, Jukka P.

    2011-01-01

    Voltage fluctuations generated in a hot resistor can cause extraction of heat from a colder normal metal electrode of a hybrid tunnel junction between a normal metal and a superconductor. We extend the analysis presented in Phys. Rev. Lett. 98, 210604 (2007) of this heat rectifying system, bearing resemblance to a Maxwell’s demon. Explicit analytic calculations show that the entropy of the total system is always increasing. We then consider a single-electron transistor configuration with two ...

  10. RADIOLOGICAL EVALUATION OF CRANIOVERTEBRAL JUNCTION ANOMALIES

    Directory of Open Access Journals (Sweden)

    Joji Reddy

    2015-08-01

    Full Text Available INTRODUCTION: Detailed discussions of the CVJ are conspicuously absent in many standard textbooks and chapters addressing the skull or cervical spine, since it lies in between these regions . CVJ anomalies are common in India subcontinent. OBJECTIVES : To outline the normal anatomy and various abnormalities of craniovertebral junction. To evaluate the most common developmental and acquired craniovertebral junction abnormalities . CRANIOMETRY AND DIAGNOSIS: Radiological evaluation of CVJ requir es identification of only a few anatomic structures. Over the years multiple lines , planes and angles have been described for assessment of CVJ relationship , initially with radiography and later with polytomography. Two lines have remained particularly use ful for evaluation of CVJ relationship with virtually any imaging modality: the chamberlain`s line and weckenheim ’ s clivus base line . Two angles also continue to be useful: the welcher basal angle and atlanto occipital joint axis angle. PATIENTS AND METHOD S: The prospective study of craniovertebral junction anomalies was carried out at Kurnool medical college , Governament general hospital Kurnool from NOV 2012 to AUG 2014. The patients are subjected to clinical evaluation and radiological evaluation. OBSERV ATIONS AND RESULTS : In our study there is male predominance with male to female ratio of 2:1 . Majority of patients are in the age group of 11 - 40 (73.26%. The commonest symptom seen is weakness of extremities ( 70% with associated numbness (50%. On clinica l examination pyramidal tract involvement noticed in 70% of cases. Basilar invagination is the most common followed by Atlantoocoipital assimilation (40% and AAD (30% . CONCLUSION : Computed tomography and magnetic resonance imaging are invalvable adjuncts to the plain radiographs in the evaluation of the craniovertebral junction anomalies. Chamberlain’s line and McGregor line are the most commonly applied craniometric measurements

  11. Interfacial capacitance effects in magnetic tunneling junctions

    CERN Document Server

    Landry, G; Du, J; Xiao, J Q

    2001-01-01

    We have investigated the AC transport properties of magnetic tunnel junctions (MTJ) in order to characterize interfacial properties. One such property is interfacial charge accumulation, which leads to a voltage drop in the electrodes of the MTJ and the measured capacitance differing from the geometrical capacitance. Through measurement of capacitance spectra, we have extracted an interfacial capacitance of 16 mu F/cm sup 2 per interface and a screening length of 0.55 A for FeNi electrodes.

  12. Gap junction channels and cardiac impulse propagation.

    Science.gov (United States)

    Desplantez, Thomas; Dupont, Emmanuel; Severs, Nicholas J; Weingart, Robert

    2007-08-01

    The role of gap junction channels on cardiac impulse propagation is complex. This review focuses on the differential expression of connexins in the heart and the biophysical properties of gap junction channels under normal and disease conditions. Structural determinants of impulse propagation have been gained from biochemical and immunocytochemical studies performed on tissue extracts and intact cardiac tissue. These have defined the distinctive connexin coexpression patterns and relative levels in different cardiac tissues. Functional determinants of impulse propagation have emerged from electrophysiological experiments carried out on cell pairs. The static properties (channel number and conductance) limit the current flow between adjacent cardiomyocytes and thus set the basic conduction velocity. The dynamic properties (voltage-sensitive gating and kinetics of channels) are responsible for a modulation of the conduction velocity during propagated action potentials. The effect is moderate and depends on the type of Cx and channel. For homomeric-homotypic channels, the influence is small to medium; for homomeric-heterotypic channels, it is medium to strong. Since no data are currently available on heteromeric channels, their influence on impulse propagation is speculative. The modulation by gap junction channels is most prominent in tissues at the boundaries between cardiac tissues such as sinoatrial node-atrial muscle, atrioventricular node-His bundle, His bundle-bundle branch and Purkinje fibers-ventricular muscle. The data predict facilitation of orthodromic propagation.

  13. Gap Junctions: The Claymore for Cancerous Cells

    Directory of Open Access Journals (Sweden)

    Ailar Nakhlband

    2011-07-01

    Full Text Available Introduction: Gap junctions play an important role in the cell proliferation in mammalian cells as well as carcinogenesis. However, there are controversial issues about their role in cancer pathogenesis. This study was designed to evaluate genotoxicity and cytotoxicity of Carbenoxolone (CBX as a prototype of inter-cellular gap junction blocker in MCF7 and BT20 human breast cancer cells. Methods: The MCF7and BT20 human breast cancer cell lines were cultivated, and treated at designated confluency with different doses of CBX. Cellular cytotoxicity was examined using standard colorimetric assay associated with cell viability tests. Gene expression evaluation was carried out using real time polymerase chain reaction (PCR. Results: MCF7 and BT20 cells were significantly affected by CBX in a dose dependent manner in cell viability assays. Despite varying expression of genes, down regulation of pro- and anti-apoptotic genes was observed in these cells. Conclusion: Based upon this investigation, it can be concluded that CBX could affect both low and high proliferative types of breast cancer cell lines and disproportionate down regulation of both pre- and anti-apoptotic genes may be related to interacting biomolecules, perhaps via gap junctions.

  14. Molecular beam epitaxy growth of germanium junctions for multi-junction solar cell applications

    Science.gov (United States)

    Masuda, T.; Faucher, J.; Lee, M. L.

    2016-11-01

    We report on the molecular beam epitaxy (MBE) growth and device characteristics of Ge solar cells. Integrating a Ge bottom cell beneath a lattice-matched triple junction stack grown by MBE could enable ultra-high efficiencies without metamorphic growth or wafer bonding. However, a diffused junction cannot be readily formed in Ge by MBE due to the low sticking coefficient of group-V molecules on Ge surfaces. We therefore realized Ge junctions by growth of homo-epitaxial n-Ge on p-Ge wafers within a standard III-V MBE system. We then fabricated Ge solar cells, finding growth temperature and post-growth annealing to be key factors for achieving high efficiency. Open-circuit voltage and fill factor values of ~0.175 V and ~0.59 without a window layer were obtained, both of which are comparable to diffused Ge junctions formed by metal-organic vapor phase epitaxy. We also demonstrate growth of high-quality, single-domain GaAs on the Ge junction, as needed for subsequent growth of III-V subcells, and that the surface passivation afforded by the GaAs layer slightly improves the Ge cell performance.

  15. Natural histories of chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Rennard, Stephen I; Vestbo, Jørgen

    2008-01-01

    Concepts relating to the natural history of chronic obstructive pulmonary disease (COPD) arise most importantly from the classic study of Fletcher and colleagues (The Natural History of Chronic Bronchitis and Emphysema, Oxford University Press, New York, 1976). This study, which evaluated working...

  16. Intestinal obstruction by trichobezoars in five cats.

    Science.gov (United States)

    Barrs, V R; Beatty, J A; Tisdall, P L; Hunt, G B; Gunew, M; Nicoll, R G; Malik, R

    1999-12-01

    Between 1997 and 1999, five domestic crossbred cats (four long haired, one short haired) presented with a palpable abdominal mass and were shown to have small intestinal trichobezoars at laparotomy or necropsy. Hair balls were associated with partial or complete intestinal obstruction and were situated in the proximal jejunum to distal ileum. In four cats obstructions were simple, while the remaining cat had a strangulating obstruction. Three of the cats were 10 years or older, and two were less than 4 years. In the three older cats abdominal neoplasia was suspected and investigations were delayed or declined in two of these cats because of a perceived poor prognosis. Predisposing factors identified in this series of cats included a long-hair coat, flea allergy dermatitis, inflammatory bowel disease and ingestion of non-digestible plant material. This report shows that the ingestion of hair is not always innocuous and that intestinal trichobezoars should be considered in the differential diagnoses of intestinal obstruction and intra-abdominal mass lesions, particularly in long-haired cats.

  17. Chronic obstructive pulmonary disease and cancer risk

    DEFF Research Database (Denmark)

    Kornum, Jette Brommann; Sværke, Claus; Thomsen, Reimar Wernich

    2012-01-01

    Little is known about the risk of cancer in patients with chronic obstructive pulmonary disease (COPD), including which cancer sites are most affected. We examined the short- and long-term risk of lung and extrapulmonary cancer in a nationwide cohort of COPD patients....

  18. Intraoperative endoscopy in obstructive hypopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Predrag Pesko; Djordjije Saranovic; Vera Todorovic; Milos Bjelovic; Predrag Sabljak; Dejan Stojakov; Ebrahimi Keramatollah; Dejan Velickovic; Bratislav Spica; Branka Nenadic; Aleksandra Djuric-Stefanovic

    2006-01-01

    AIM: To demonstrate the necessity of intraoperative endoscopy in the diagnosis of secondary primary tumors of the upper digestive tract in patients with obstructive hypopharyngeal carcinoma.METHODS: Thirty-one patients with hypopharyngeal squamous cell carcinoma had been operated, with radical intent, at our Institution in the period between 1978 and 2004. Due to obstructive tumor mass, in 7(22.6%) patients, preoperative endoscopic evaluation of the esophagus and stomach could not be performed. In those patients, intraoperative endoscopy, made through an incision in the cervical esophagus, was standard diagnostic method for examination of the esophagus and stomach.RESULTS: We found synchronous foregut carcinomas in 3 patients (9.7%). In two patients, synchronous carcinomas had been detected during preoperative endoscopic evaluation, and in one (with obstructive carcinoma) using intraoperative endoscopy. In this case, preoperative barium swallow and CT scan did not reveal the existence of second primary tumor within esophagus, despite the fact that small, but T2 carcinoma, was present.CONCLUSION: It is reasonable to use intraoperative endoscopy as a selective screening test in patients with obstructive hypopharyngeal carcinoma.

  19. Bronchoscopic interventions for chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Mineshita, Masamichi; Slebos, Dirk-Jan

    2014-01-01

    Over the past decade, several non-surgical and minimally invasive bronchoscopic lung volume reduction (BLVR) techniques have been developed to treat patients with severe chronic obstructive pulmonary disease (COPD). BLVR can be significantly efficacious, suitable for a broad cohort of patients, and

  20. The bladder ran dry: bilateral ureteral obstruction.

    Science.gov (United States)

    Schattner, Ami; Drahy, Yosef; Dubin, Ina

    2017-08-07

    A relatively young healthy man (barring obesity and distant gouty arthritis) was admitted with severe acute kidney injury (serum creatinine, 15.9 mg/dL) following acute gastroenteritis and occasional use of diclofenac. Abdominal ultrasound revealed mild left hydronephrosis due to staghorn stone and normal right kidney. Soon after, complete anuria necessitating haemodialysis developed without pain or evidence of infection. CT imaging revealed stones obstructing the right ureter. Following urological surgery, postobstructive diuresis developed and the serum creatinine came down to near normal. The stones were identified as uric acid stones.Anuria has a relatively narrow differential and painless (partially non-dilated) bilateral ureteral obstruction is a distinctly unusual cause. A review of the literature to cover all reported causes of bilateral ureteral obstruction is presented. Only a minority of cases were not associated with an underlying malignant disease or its treatment. The multifactorial aetiology of the patient's acute kidney injury (volume depletion, diclofenac and obstructive uropathy) is presented and discussed. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Management of obstructive sleep apnea in Europe

    DEFF Research Database (Denmark)

    Fietze, I; Penzel, T; Alonderis, A;

    2011-01-01

    In Europe, the services provided for the investigation and management of obstructive sleep apnoea (OSA) varies from country to country. The aim of this questionnaire-based study was to investigate the current status of diagnostic pathways and therapeutic approaches applied in the treatment of OSA...... in Europe, qualification requirements of physicians involved in diagnosis and treatment of OSA, and reimbursement of these services....

  2. Endoscopic third ventriculostomy for obstructive hydrocephalus.

    NARCIS (Netherlands)

    Hellwig, D.; Grotenhuis, J.A.; Tirakotai, W.; Riegel, T.; Schulte, D.M.; Bauer, B.L.; Bertalanffy, H.

    2005-01-01

    The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive

  3. Mandibular advancement appliance for obstructive sleep apnoea

    DEFF Research Database (Denmark)

    Petri, Niels; Svanholt, Palle; Solow, Beni

    2008-01-01

    The aim of this trial was to evaluate the efficacy of a mandibular advancement appliance (MAA) for obstructive sleep apnoea (OSA). Ninety-three patients with OSA and a mean apnoea-hypopnoea index (AHI) of 34.7 were centrally randomised into three, parallel groups: (a) MAA; (b) mandibular non...

  4. 33 CFR 401.53 - Obstructing navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Obstructing navigation. 401.53 Section 401.53 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.53...

  5. 15.6.Nephrolithiasis and obstructive nephropathy

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920362 Vesicoureteral reflux and refluxnephropathy in adults.LI Youji (李幼姬),et al.Renal Instit,1st Hosp,Zhongshan Med Univ.ChinJ Nephrol 1991;7(6):341-344.Chronic recurent non-obstructive urinary tract

  6. Cognitive complaints in obstructive sleep apnea

    NARCIS (Netherlands)

    Vaessen, T.J.A.; Overeem, S.; Sitskoorn, M.M.

    2015-01-01

    Obstructive sleep apnea (OSA) is associated with impairments in cognitive functioning. Although cognitive complaints are related to quality of life, work productivity and health care expenditures, most research and all reviews have focused exclusively on objective cognitive functioning so far. In

  7. Unusual cause of neonatal intestinal obstruction | Zikavska ...

    African Journals Online (AJOL)

    Unusual cause of neonatal intestinal obstruction. ... In some cases, diagnosis can be made prenatally but in others manifestation occurs after birth. The aim of this article is to ... Stenosis may result from extrinsic or intrinsic factors. It arises from ...

  8. Biomarkers in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Sin, Don D; Vestbo, Jørgen

    2009-01-01

    Currently, with exception of lung function tests, there are no well validated biomarkers or surrogate endpoints that can be used to establish efficacy of novel drugs for chronic obstructive pulmonary disease (COPD). However, the lung function test is not an ideal surrogate for short-term drug...

  9. ROUNDED FLOWING STATES OF OBSTRUCTED BUOYANT JET

    Institute of Scientific and Technical Information of China (English)

    HUAI Wen-xin; FANG Shen-guang

    2006-01-01

    The mutual relationships of three effective factors, the diameter D/d (d is the diameter of exit) of obstructed plate, exit densimetric Froude number and the distance H/d of the plate from jet orifice for obstructed buoyant jet in static ambient, are analyzed to explain normal and abnormal rounded flowing (reverberated and bifurcated flowing).The critical Froude numbers for obstructed buoyant jets with H/d=2, 4, 6, 8 which distinguished normal and abnormal flowing pattern are obtained. Normal rounded flowing is found only for a plate under a special value of H/d. A fitted formula of critical Froude numbers with H/d and D/d is presented to distinguish rounded flowing types. The occurring of reverberated or bifurcated flowing in abnormal rounded flow is analyzed. Based on the results of obstructed buoyant jets with D/d=1, normal rounded flowing occurred only for all conditions and axial dilution behind the plate under different H/D is obtained.

  10. Pulmonary biomarkers in chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Barnes, Peter J.; Chowdhury, Badrul; Kharitonov, Sergei A.; Magnussen, Helgo; Page, Clive P.; Postma, Dirkje; Saetta, Marina

    2006-01-01

    There has been increasing interest in using pulmonary biomarkers to understand and monitor the inflammation in the respiratory tract of patients with chronic obstructive pulmonary disease (COPD). In this Pulmonary Perspective we discuss the merits of the various approaches by reviewing the current l

  11. Severe upper airway obstruction during sleep.

    Science.gov (United States)

    Bonekat, H William; Hardin, Kimberly A

    2003-10-01

    Few disorders may manifest with predominantly sleep-related obstructive breathing. Obstructive sleep apnea (OSA) is a common disorder, varies in severity and is associated with significant cardiovascular and neurocognitive morbidity. It is estimated that between 8 and 18 million people in the United States have at least mild OSA. Although the exact mechanism of OSA is not well-delineated, multiple factors contribute to the development of upper airway obstruction and include anatomic, mechanical, neurologic, and inflammatory changes in the pharynx. OSA may occur concomitantly with asthma. Approximately 74% of asthmatics experience nocturnal symptoms of airflow obstruction secondary to reactive airways disease. Similar cytokine, chemokine, and histologic changes are seen in both disorders. Sleep deprivation, chronic upper airway edema, and inflammation associated with OSA may further exacerbate nocturnal asthma symptoms. Allergic rhinitis may contribute to both OSA and asthma. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA. Treatment with CPAP therapy has also been shown to improve both daytime and nighttime peak expiratory flow rates in patients with concomitant OSA and asthma. It is important for allergists to be aware of how OSA may complicate diagnosis and treatment of asthma and allergic rhinitis. A thorough sleep history and high clinical suspicion for OSA is indicated, particularly in asthma patients who are refractory to standard medication treatments.

  12. Management of obstructive sleep apnea in Europe

    DEFF Research Database (Denmark)

    Fietze, I; Penzel, T; Alonderis, A

    2011-01-01

    In Europe, the services provided for the investigation and management of obstructive sleep apnoea (OSA) varies from country to country. The aim of this questionnaire-based study was to investigate the current status of diagnostic pathways and therapeutic approaches applied in the treatment of OSA...

  13. Obstruction of cerebral arteries in childhood stroke

    Energy Technology Data Exchange (ETDEWEB)

    Velkey, I.; Lombay, B. (County Teaching Hospital, Miskolc (Hungary). Child Health Center); Panczel, G. (Semmelweis Medical Univ., Budapest (Hungary). Dept. of Psychiatry)

    1992-09-01

    Middle cerebral artery obstruction in children is reviewed by our two cases. Ischemic childhood stroke was caused by moyamoya disease in the first, and by fibromuscular dysplasia in the second patient. In both cases transcranial Doppler sonography and cranial CT were performed, but the final diagnosis was made by angiography. The importance of angiography in childhood stroke is emphasized. (orig.).

  14. STUDY OF LARGE BOWEL OBSTRUCTION IN ADULTS

    Directory of Open Access Journals (Sweden)

    Atish

    2013-05-01

    Full Text Available ABSTRACT: AIM : To study the Incidence, Etiology, Clinical featur es, Investigations undertaken to arrive at Diagnosis, Treatment and Post-operative o utcomes of large bowel obstruction in adults. METHODS : This is a prospective observational study of larg e bowel obstruction in adults and was carried out from Nov 2010 to Oct 2012. RESULTS : A total of 211 cases of intestinal obstruction were diagnosed out of these 25(11.85% cases were o f large bowel obstruction. Maximum patients 8(32% cases belonged to age group 51-60yrs and 15( 60% cases were males. Obstipation seen in 25(100%, pain 22(88%, distension 21(84%, tendern ess 22(88% and increased bowel sounds 21(84%. X-ray and ultrasonography was useful in 21 (84% cases while CT scan was used in only 7 cases and proved 100% effective.13(52% cases were of sigmoid volvulus, 1(4% of caecal volvulus and 9(36% cases of malignancy.15(60% cases underw ent primary resection anastomosis and 10(40% cases had a decompressive colostomy.8(32% patients developed immediate wound complication, 3(12% cases had anastomotic leak, 1( 4% case developed burst abdomen and 6(24% cases had septicaemia. Mortality of the stud y was 6(24% cases. CONCLUSION : Patients with large bowel obstruction in adults form a small percentage of patients. Commonest causes are sigmoid volvulus and obstructing colorectal maligna ncies. X-ray abdomen, Ultrasound of abdomen and Computerized Tomography of abdomen are very hel pful in diagnosing. Single stage resectional procedure without colostomies can be done in patien ts even in emergency surgeries and Proximal diverting colostomies may be safely performed in pa tients with pre-existing sepsis, shock, gangrene of large bowel and excessively loaded colon with re versal of colostomies and a definitive procedure may be performed later, after stabilisation of pati ents. Post-operative complications are more because of late presentation associated with comorb idities and large bacterial load of

  15. Ischemic colitis due to obstruction of mesenteric and splenic veins: A case report

    Institute of Scientific and Technical Information of China (English)

    Seong-Su Hwang; Woo-Chul Chung; Kang-Moon Lee; Hyun-Jin Kim; Chang-Nyol Paik; Jin-Mo Yang

    2008-01-01

    Ischemic injury to the bowel is a well known disease entity that has a wide spectrum of pathological and clinical findings. A sudden drop in the colonic blood supply is essential to its development. We encountered a 41-year-old male patient, who presented with abdominal pain and bloody diarrhea. A colonoscopy showed markedly edematous mucosa with tortuous dilatation of the veins and a deep ulceration at the rectosigmoid junction. On an abdominal computed tomography (CT) scan and CT angiography, the mesenteric and splenic veins were absent with numerous venous collaterals for drainage. The patient gradually responded to oral aminosalicylate therapy, and was in remission after nine months. In most cases, non-occlusive ischemic injury is caused by idiopathic form and occlusive ischemia is caused by abnormalities of arteries and acute venous thrombosis. However, chronic venous insufficiency due to obstruction of macrovascular mesenteric vein rarely causes ischemia of the bowel. This report describes the first case of ischemic colitis caused by obstruction of the mesenteric and splenic veins.

  16. Association of chronic obstructive pulmonary disease and obstructive sleep apnea consequences

    Directory of Open Access Journals (Sweden)

    Carlos Zamarrón

    2009-01-01

    Full Text Available Carlos Zamarrón1, Vanesa García Paz1, Emilio Morete1, Felix del Campo Matías21Servicio de Neumología, Hospital Clínico Universitario de Santiago, Santiago, Spain; 2Servicio de Neumologia, Hospital Universitario Rio Ortega de Vallaclolid, Vallaclolid, SpainAbstract: Obstructive sleep apnea syndrome (OSAS and chronic obstructive pulmonary disease (COPD are two diseases that often coexist within an individual. This coexistence is known as overlap syndrome and is the result of chance rather than a pathophysiological link. Although there are claims of a very high incidence of OSAS in COPD patients, recent studies report that it is similar to the general population. Overlap patients present sleep-disordered breathing associated to upper and lower airway obstruction and a reduction in respiratory drive. These patients present unique characteristics, which set them apart from either COPD or OSAS patients. COPD and OSAS are independent risk factors for cardiovascular events and their coexistence in overlap syndrome probably increases this risk. The mechanisms underlying cardiovascular risk are still unclear, but may involve systemic inflammation, endothelial dysfunction, and tonic elevation of sympathetic neural activity. The treatment of choice for overlap syndrome in stable patients is CPAP with supplemental oxygen for correction of upper airway obstructive episodes and hypoxemia during sleep.Keywords: chronic obstructive pulmonary disease, obstructive sleep apnea syndrome, overlap syndrome, sleep, cardiovascular disease

  17. Therapeutic Bronchoscopy for Malignant Central Airway Obstruction

    Science.gov (United States)

    Ernst, Armin; Grosu, Horiana B.; Lei, Xiudong; Diaz-Mendoza, Javier; Slade, Mark; Gildea, Thomas R.; Machuzak, Michael S.; Jimenez, Carlos A.; Toth, Jennifer; Kovitz, Kevin L.; Ray, Cynthia; Greenhill, Sara; Casal, Roberto F.; Almeida, Francisco A.; Wahidi, Momen M.; Eapen, George A.; Feller-Kopman, David; Morice, Rodolfo C.; Benzaquen, Sadia; Tremblay, Alain; Simoff, Michael; Kovitz, Kevin; Greenhill, Sara; Gildea, Thomas R.; Machuzak, Michael; Almeida, Francisco A.; Cicenia, Joseph; Wahidi, Momen; Mahmood, Kamran; MacEachern, Paul; Tremblay, Alain; Simoff, Michael; Diaz-Mendoza, Javier; Ray, Cynthia; Feller-Kopman, David; Yarmus, Lonny; Estrada-Y-Martin, Rosa; Casal, Roberto F.; Toth, Jennifer; Karunakara, Raj; Slade, Mark; Ernst, Armin; Rafeq, Samaan; Ost, David; Eapen, George A.; Jimenez, Carlos A.; Morice, Rodolfo C.; Benzaquen, Sadia; Puchalski, Jonathan

    2015-01-01

    BACKGROUND: There is significant variation between physicians in terms of how they perform therapeutic bronchoscopy, but there are few data on whether these differences impact effectiveness. METHODS: This was a multicenter registry study of patients undergoing therapeutic bronchoscopy for malignant central airway obstruction. The primary outcome was technical success, defined as reopening the airway lumen to > 50% of normal. Secondary outcomes were dyspnea as measured by the Borg score and health-related quality of life (HRQOL) as measured by the SF-6D. RESULTS: Fifteen centers performed 1,115 procedures on 947 patients. Technical success was achieved in 93% of procedures. Center success rates ranged from 90% to 98% (P = .02). Endobronchial obstruction and stent placement were associated with success, whereas American Society of Anesthesiology (ASA) score > 3, renal failure, primary lung cancer, left mainstem disease, and tracheoesophageal fistula were associated with failure. Clinically significant improvements in dyspnea occurred in 90 of 187 patients measured (48%). Greater baseline dyspnea was associated with greater improvements in dyspnea, whereas smoking, having multiple cancers, and lobar obstruction were associated with smaller improvements. Clinically significant improvements in HRQOL occurred in 76 of 183 patients measured (42%). Greater baseline dyspnea was associated with greater improvements in HRQOL, and lobar obstruction was associated with smaller improvements. CONCLUSIONS: Technical success rates were high overall, with the highest success rates associated with stent placement and endobronchial obstruction. Therapeutic bronchoscopy should not be withheld from patients based solely on an assessment of risk, since patients with the most dyspnea and lowest functional status benefitted the most. PMID:25358019

  18. Iliocaval Confluence Stenting for Chronic Venous Obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Rick de, E-mail: r.de.graaf@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Wolf, Mark de, E-mail: markthewolf@gmail.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Sailer, Anna M., E-mail: anni.sailer@mumc.nl [Maastricht University Medical Centre (MUMC), Department of Radiology (Netherlands); Laanen, Jorinde van, E-mail: jorinde.van.laanen@mumc.nl; Wittens, Cees, E-mail: c.wittens@me.com [Maastricht University Medical Centre (MUMC), Department of Surgery (Netherlands); Jalaie, Houman, E-mail: hjalaie@ukaachen.de [University Hospital Aachen, Department of Surgery (Germany)

    2015-10-15

    PurposeDifferent techniques have been described for stenting of venous obstructions. We report our experience with two different confluence stenting techniques to treat chronic bi-iliocaval obstructions.Materials and MethodsBetween 11/2009 and 08/2014 we treated 40 patients for chronic total bi-iliocaval obstructions. Pre-operative magnetic resonance venography showed bilateral extensive post-thrombotic scarring in common and external iliac veins as well as obstruction of the inferior vena cava (IVC). Stenting of the IVC was performed with large self-expandable stents down to the level of the iliocaval confluence. To bridge the confluence, either self-expandable stents were placed inside the IVC stent (24 patients, SECS group) or high radial force balloon-expandable stents were placed at the same level (16 patients, BECS group). In both cases, bilateral iliac extensions were performed using nitinol stents.ResultsRecanalization was achieved for all patients. In 15 (38 %) patients, a hybrid procedure with endophlebectomy and arteriovenous fistula creation needed to be performed because of significant involvement of inflow vessels below the inguinal ligament. Mean follow-up was 443 ± 438 days (range 7–1683 days). For all patients, primary, assisted-primary, and secondary patency rate at 36 months were 70, 73, and 78 %, respectively. Twelve-month patency rates in the SECS group were 85, 85, and 95 % for primary, assisted-primary, and secondary patency. In the BECS group, primary patency was 100 % during a mean follow-up period of 134 ± 118 (range 29–337) days.ConclusionStenting of chronic bi-iliocaval obstruction shows relatively high patency rates at medium follow-up. Short-term patency seems to favor confluence stenting with balloon-expandable stents.

  19. [Obstructive sleep apnea features and occupational fitness of railway workers].

    Science.gov (United States)

    Buniatyan, M S; Belozerova, N V; At'kov, O Yu

    2016-01-01

    The article covers prevalence of obstructive sleep apnea syndrome, its role in health disorders of workers engaged into railway safety. The authors analyzed present standards of occupational fitness in workers performing critically important operating activities and methods of occupational selection with possible obstructive sleep apnea syndrome. I stage recommendations are suggested in diagnosis of obstructive sleep apnea syndrome in workers engaged into railway safety. Obstructive sleep apnea syndrome appeared to threaten operators' activity, to cause accidents, to early disablement due to life-threatening complications, to unsuitability for the occupation due to diseases connected with obstructive sleep apnea syndrome (arterial hypertension, diabetes mellitus, metabolic syndrome, cardiac rhythm and conductivity disorders, obesity).

  20. Influence of three-dimensional p-buried layer pattern on the performance of 4H-SiC floating junction Schottky barrier diode

    Science.gov (United States)

    Yang, Shuai; Zhang, Yuming; Song, Qingwen; Tang, Xiaoyan; Zhang, Yimen; Huo, Tianjia; Liu, Sicheng; Yuan, Hao

    2015-10-01

    4H-SiC floating junction Schottky barrier diodes (FJ-SBDs) are excellent SiC devices with high Baliga’s figure of merit (BFOM). However, the p-type buried layers in epilayers partially obstruct the current paths, and increase the on-resistance, while the buried layers of dot patterns can reduce the obstruction. In this paper, a three-dimensional (3D) simulation of 4H-SiC FJ-SBDs with dot patterns is reported for the first time. By comparing the results obtained from stripe, square, octagon, and circle patterns, dot patterns are proved to be good choices for buried layers in 4H-SiC FJ-SBDs, and the FJ-SBD with the circle pattern has the highest BFOM of 12.09 GW/cm2, which is 22.62% greater than that of the FJ-SBD with the stripe pattern.

  1. Estimation of airway obstruction using oximeter plethysmograph waveform data

    Directory of Open Access Journals (Sweden)

    Desmond Renee' A

    2005-06-01

    Full Text Available Abstract Background Validated measures to assess the severity of airway obstruction in patients with obstructive airway disease are limited. Changes in the pulse oximeter plethysmograph waveform represent fluctuations in arterial flow. Analysis of these fluctuations might be useful clinically if they represent physiologic perturbations resulting from airway obstruction. We tested the hypothesis that the severity of airway obstruction could be estimated using plethysmograph waveform data. Methods Using a closed airway circuit with adjustable inspiratory and expiratory pressure relief valves, airway obstruction was induced in a prospective convenience sample of 31 healthy adult subjects. Maximal change in airway pressure at the mouthpiece was used as a surrogate measure of the degree of obstruction applied. Plethysmograph waveform data and mouthpiece airway pressure were acquired for 60 seconds at increasing levels of inspiratory and expiratory obstruction. At each level of applied obstruction, mean values for maximal change in waveform area under the curve and height as well as maximal change in mouth pressure were calculated for sequential 7.5 second intervals. Correlations of these waveform variables with mouth pressure values were then performed to determine if the magnitude of changes in these variables indicates the severity of airway obstruction. Results There were significant relationships between maximal change in area under the curve (P Conclusion The findings suggest that mathematic interpretation of plethysmograph waveform data may estimate the severity of airway obstruction and be of clinical utility in objective assessment of patients with obstructive airway diseases.

  2. Electron Transport through Porphyrin Molecular Junctions

    Science.gov (United States)

    Zhou, Qi

    The goal of this work is to study the properties that would affect the electron transport through a porphyrin molecular junction. This work contributes to the field of electron transport in molecular junctions in the following 3 aspects. First of all, by carrying out experiments comparing the conductance of the iron (III) porphyrin (protected) and the free base porphyrin (protected), it is confirmed that the molecular energy level broadening and shifting occurs for porphyrin molecules when coupled with the metal electrodes, and this level broadening and shifting plays an important role in the electron transport through molecular junctions. Secondly, by carrying out an in-situ deprotection of the acetyl-protected free base porphyrin molecules, it is found out that the presence of acetyl groups reduces the conductance. Thirdly, by incorporating the Matrix-assisted laser desorption/ionization (MALDI) spectrum and the in-situ deprotection prior to formation of molecular junctions, it allows a more precise understanding of the molecules involved in the formation of molecular junctions, and therefore allows an accurate analysis of the conductance histogram. The molecules are prepared by self-assembly and the junctions are formed using a Scanning Tunneling Microscopy (STM) molecular break junction technique. The porphyrin molecules are characterized by MALDI in solution before self-assembly to a gold/mica substrate. The self-assembled monolayers (SAMs) of porphyrins on gold are characterized by Ultraviolet-visible (UV-Vis) reflection spectroscopy to confirm that the molecules are attached to the substrate. The SAMs are then characterized by Angle-Resolved X-ray photoelectron spectroscopy (ARXPS) to determine the thickness and the average molecular orientation of the molecular layer. The electron transport is measured by conductance-displacement (G-S) experiments under a given bias (-0.4V). The conductance value of a single molecule is identified by a statistical analysis

  3. Electron optics with p-n junctions in ballistic graphene

    Science.gov (United States)

    Chen, Shaowen; Han, Zheng; Elahi, Mirza M.; Habib, K. M. Masum; Wang, Lei; Wen, Bo; Gao, Yuanda; Taniguchi, Takashi; Watanabe, Kenji; Hone, James; Ghosh, Avik W.; Dean, Cory R.

    2016-09-01

    Electrons transmitted across a ballistic semiconductor junction are expected to undergo refraction, analogous to light rays across an optical boundary. In graphene, the linear dispersion and zero-gap band structure admit highly transparent p-n junctions by simple electrostatic gating. Here, we employ transverse magnetic focusing to probe the propagation of carriers across an electrostatically defined graphene junction. We find agreement with the predicted Snell’s law for electrons, including the observation of both positive and negative refraction. Resonant transmission across the p-n junction provides a direct measurement of the angle-dependent transmission coefficient. Comparing experimental data with simulations reveals the crucial role played by the effective junction width, providing guidance for future device design. Our results pave the way for realizing electron optics based on graphene p-n junctions.

  4. Single P-N junction tandem photovoltaic device

    Science.gov (United States)

    Walukiewicz, Wladyslaw; Ager, III, Joel W.; Yu, Kin Man

    2011-10-18

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  5. The critical power to maintain thermally stable molecular junctions

    Science.gov (United States)

    Wang, Yanlei; Xu, Zhiping

    2014-07-01

    With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 109 kW-1. Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

  6. Single P-N junction tandem photovoltaic device

    Science.gov (United States)

    Walukiewicz, Wladyslaw [Kensington, CA; Ager, III, Joel W.; Yu, Kin Man [Lafayette, CA

    2012-03-06

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  7. Structure, regulation and function of gap junctions in liver

    Science.gov (United States)

    Maes, Michaël; Decrock, Elke; Wang, Nan; Leybaert, Luc; da Silva, Tereza Cristina; Veloso Alves Pereira, Isabel; Jaeschke, Hartmut; Cogliati, Bruno; Vinken, Mathieu

    2016-01-01

    Gap junctions are a specialized group of cell-to-cell junctions that mediate direct intercellular communication between cells. They arise from the interaction of 2 hemichannels of adjacent cells, which in turn are composed of 6 connexin proteins. In liver, gap junctions are predominantly found in hepatocytes and play critical roles in virtually all phases of the hepatic life cycle, including cell growth, differentiation, liver-specific functionality and cell death. Liver gap junctions are directed through a broad variety of mechanisms ranging from epigenetic control of connexin expression to posttranslational regulation of gap junction activity. This paper reviews established and novel aspects regarding the architecture, control and functional relevance of liver gap junctions. PMID:27001459

  8. Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    Yu-Kun Zhou; Huan-Long Qin; Ming Zhang; Tong-Yi Shen; Hong-Qi Chen; Yan-Lei Ma; Zhao-Xin Chu

    2012-01-01

    AIM:To investigate the mechanisms of Lactobacillus plantarum (L.plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats.METHODS:Forty rats were randomly divided into groups of sham-operation,bile duct ligation (BDL),BDL + L.plantarum,BDL + internal biliary drainage (IBD),and BDL + IBD + L.plantarum.Ten days after L,plantarum administration,blood and ileal samples were collected from the rats for morphological examination,and intestinal barrier function,liver function,intestinal oxidative stress and protein kinase C (PKC) activity measurement.The distribution and expression of the PKC and tight junction (TJ) proteins,such as occludin,zonula occludens-1,claudin-1,claudin-4,junction adhesion molecule-A and F-actin,were examined by confocal laser scanning microscopy,immunohistochemistry,Western blotting,real-time fluorescent quantitative polymerase chain reaction assay.RESULTS:L.plantarum administration substantially restored gut barrier,decreased enterocyte apoptosis,improved intestinal oxidative stress,promoted the activity and expression of protein kinase (BDL vs BDL + L.plantarum,0.295 ± 0.007 vs 0.349 ± 0.003,P < 0.05;BDL + IBD vs BDL + IBD + L.plantarum,0.407 ± 0.046 vs 0.465 ± 0.135,P < 0.05),and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L.plantarum,0.266 ± 0.118 vs 0.326 ± 0.009,P < 0.05).The protective effect of L.plantarum was more prominent after internal biliary drainage (BDL + IBD vs BDL + IBD + L.plantarum,0.415 ± 0.105 vS 0.494 ± 0.145,P < 0.05).CONCLUSION:L.plantarum can decrease intestinal epithelial cell apoptosis,reduce oxidative stress,and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

  9. Geometrical theory of triple junctions of CSL boundaries.

    Science.gov (United States)

    Gertsman, V Y

    2001-07-01

    When three grain boundaries having misorientations generating coincidence site lattices (CSLs) meet at a triple junction, a common (triple-junction) CSL is formed. A theory is developed as a set of theorems establishing the relationships between the geometrical parameters of the grain-boundary and triple-junction CSLs. Application of the theory is demonstrated in detail for the case of the cubic crystal system. It is also shown how the theory can be extended to an arbitrary crystal lattice.

  10. Turbulence-induced magnetic flux asymmetry at nanoscale junctions

    OpenAIRE

    2007-01-01

    It was recently predicted [J. Phys.: Condens. Matter 18, 11059 (2006)] that turbulence of the electron flow may develop at nonadiabatic nanoscale junctions under appropriate conditions. Here we show that such an effect leads to an asymmetric current-induced magnetic field on the two sides of an otherwise symmetric junction. We propose that by measuring the fluxes ensuing from these fields across two surfaces placed at the two sides of the junction would provide direct and noninvasive evidence...

  11. Magnetic interaction between spatially extended superconducting tunnel junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    2002-01-01

    A general description of magnetic interactions between superconducting tunnel junctions is given. The description covers a wide range of possible experimental systems, and we explicitly explore two experimentally relevant limits of coupled junctions. One is the limit of junctions with tunneling...... been considered through arrays of superconducting weak links based on semiconductor quantum wells with superconducting electrodes. We use the model to make direct interpretations of the published experiments and thereby propose that long-range magnetic interactions are responsible for the reported...

  12. Endoplasmic reticulum-plasma membrane junctions: structure, function and dynamics.

    Science.gov (United States)

    Okeke, Emmanuel; Dingsdale, Hayley; Parker, Tony; Voronina, Svetlana; Tepikin, Alexei V

    2016-06-01

    Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are contact sites between the ER and the PM; the distance between the two organelles in the junctions is below 40 nm and the membranes are connected by protein tethers. A number of molecular tools and technical approaches have been recently developed to visualise, modify and characterise properties of ER-PM junctions. The junctions serve as the platforms for lipid exchange between the organelles and for cell signalling, notably Ca(2+) and cAMP signalling. Vice versa, signalling events regulate the development and properties of the junctions. Two Ca(2+) -dependent mechanisms of de novo formation of ER-PM junctions have been recently described and characterised. The junction-forming proteins and lipids are currently the focus of vigorous investigation. Junctions can be relatively short-lived and simple structures, forming and dissolving on the time scale of a few minutes. However, complex, sophisticated and multifunctional ER-PM junctions, capable of attracting numerous protein residents and other cellular organelles, have been described in some cell types. The road from simplicity to complexity, i.e. the transformation from simple 'nascent' ER-PM junctions to advanced stable multiorganellar complexes, is likely to become an attractive research avenue for current and future junctologists. Another area of considerable research interest is the downstream cellular processes that can be activated by specific local signalling events in the ER-PM junctions. Studies of the cell physiology and indeed pathophysiology of ER-PM junctions have already produced some surprising discoveries, likely to expand with advances in our understanding of these remarkable organellar contact sites. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  13. Engineering of Droplet Manipulation in Tertiary Junction Microfluidic Channels

    Science.gov (United States)

    2017-06-30

    in silico investigation of path selection by a single droplet inside a tertiary junction microchannel using oil-in-water as a model system. The...droplet was generated at a T-junction inside a microfluidic chip and its flow behaviour as a function of droplet size, streamline position, viscosity...investigation of path selection by a single droplet inside a tertiary- junction microchannel using oil-in-water as a model system. The droplet was generated at

  14. ACCIDENT PREDICTION MODELS FOR UNSIGNALISED URBAN JUNCTIONS IN GHANA

    OpenAIRE

    Mohammed SALIFU, MSc., PhD, MIHT, MGhIE

    2004-01-01

    The main objective of this study was to provide an improved method for safety appraisal in Ghana through the development and application of suitable accident prediction models for unsignalised urban junctions. A case study was designed comprising 91 junctions selected from the two most cosmopolitan cities in Ghana. A wide range of traffic and road data together with the corresponding accident data for each junction for the three-year period 1996-1998 was utilized in the model development p...

  15. Some chaotic features of intrinsically coupled Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Kolahchi, M.R., E-mail: kolahchi@iasbs.ac.ir [Institute for Advanced Studies in Basic Sciences, Zanjan 45195-1159 (Iran, Islamic Republic of); Shukrinov, Yu.M. [BLTP, JINR, Dubna, Moscow Region 141980 (Russian Federation); Max-Planck-Institute for the Physics of Complex Systems, 01187 Dresden (Germany); Hamdipour, M. [Institute for Advanced Studies in Basic Sciences, Zanjan 45195-1159 (Iran, Islamic Republic of); BLTP, JINR, Dubna, Moscow Region 141980 (Russian Federation); Botha, A.E. [Department of Physics, University of South Africa, P.O. Box 392, Pretoria 0003 (South Africa); Suzuki, M. [Photonics and Electronics Science and Engineering Center and Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510 (Japan)

    2013-08-15

    Highlights: ► Intrinsically coupled Josephson junctions model a high-T{sub c} superconductor. ► Intrinsically coupled Josephson junctions can act as a chaotic nonlinear system. ► Chaos could be due to resonance overlap. ► Avoiding parameters that lead to chaos is important for the design of resonators. -- Abstract: We look for chaos in an intrinsically coupled system of Josephson junctions. This study has direct applications for the high-T{sub c} resonators which require coherence amongst the junctions.

  16. Imaging snake orbits at graphene n -p junctions

    Science.gov (United States)

    Kolasiński, K.; Mreńca-Kolasińska, A.; Szafran, B.

    2017-01-01

    We consider conductance mapping of the snake orbits confined along the n -p junction defined in graphene by the electrostatic doping in the quantum Hall regime. We explain the periodicity of conductance oscillations at the magnetic field and the Fermi energy scales by the properties of the n -p junction as a conducting channel. We evaluate the conductance maps for a floating gate scanning the surface of the device. In the quantum Hall conditions the currents flow near the edges of the sample and along the n -p junction. The conductance mapping resolves only the n -p junction and not the edges. The conductance oscillations along the junction are found in the maps with periodicity related to the cyclotron orbits of the scattering current. Stronger probe potentials provide support to localized resonances at one of the sides of the junction with current loops that interfere with the n -p junction currents. The interference results in a series of narrow lines parallel to the junction with positions that strongly depend on the magnetic field through the Aharonov-Bohm effect. The consequences of a limited transparency of finite-width n -p junctions are also discussed.

  17. Assemble four-arm DNA junctions into nanoweb

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    DNA is of structural polymorphism, which is useful in nanoarchitecture; especially, four-arm DNA junc tions can be used to assemble nanowebs. The static four-arm DNA junctions were designed and synthesized. One-arm DNA and two-arm DNA came out simultaneously with the four-arm DNA junction's formation. A new method, termed the two-step method, was proposed and the productivity of four-arm DNA junctions was increased. A nanoweb was assembled successfully, but it showed irregularity itself. It was not the same as we expected. We consider that it is aresult from the flexibility of four-arm DNA junction.

  18. Terahertz Detection with Twin Superconductor-Insulator-Superconductor Tunnel Junctions

    Institute of Scientific and Technical Information of China (English)

    LI Jing; WANG Ming-Jye; SHI Sheng-Cai; Hiroshi Mat-suo

    2007-01-01

    Terahertz detection with twin superconductor-insulator-superconductor (SIS) tunnel junctions, which are connected in parallel via an inductive thin-film superconducting microstrip line, is mainly studied. Firstly, we investigate the direct-detection response of a superconducting twin-junction device by means of a Fourier transform spectrometer. Secondly, we construct a direct-detection model of twin SIS tunnel junctions. The superconducting twin-junction device is then simulated in terms of the constructed model. The simulation result is found to be in good agreement with the measured one. In addition, we observe that the direct-detection response of the device is consistent with the noise temperature behaviour.

  19. F-Theory Description of 3-String Junction

    Institute of Scientific and Technical Information of China (English)

    YANGFu-Zhong

    2003-01-01

    The geometrical description of BPS 3-string junction in the F-theory background is given by lifting a string junction in lib into F-theory and constructing a holomorphic curve in K3 with respect to a special complex structure of K3. The holomorphic curve is fibration of 1-cycles of the elliptic fiber over the geodesic string junction. The F-theory picture in this paper provides a unifying description of both string and string junction, and is advantageous over their M-theory picture.

  20. F-Theory Description of 3-String Junction

    Institute of Scientific and Technical Information of China (English)

    YANG Fu-Zhong

    2003-01-01

    The geometrical description of BPS 3-string junction in the F-theory background is given by lifting a string junction in IIB into F-theory and constructing a holomorphic curve in K3 with respect to a special complex structure of K3. The holomorphic curve is fibration of 1-cycles of the elliptic fiber over the geodesic string junction. The F-theory picture in this paper provides a unifying description of both string and string junction, and is advantageous over their M-theory picture.

  1. ‘Gap Junctions and Cancer: Communicating for 50 Years’

    Science.gov (United States)

    Aasen, Trond; Mesnil, Marc; Naus, Christian C.; Lampe, Paul D.; Laird, Dale W.

    2017-01-01

    Fifty years ago, tumour cells were found to lack electrical coupling, leading to the hypothesis that loss of direct intercellular communication is commonly associated with cancer onset and progression. Subsequent studies linked this phenomenon to gap junctions composed of connexin proteins. While many studies support the notion that connexins are tumour suppressors, recent evidence suggests that, in some tumour types, they may facilitate specific stages of tumour progression through both junctional and non-junctional signalling pathways. This Timeline article highlights the milestones connecting gap junctions to cancer, and underscores important unanswered questions, controversies and therapeutic opportunities in the field. PMID:27782134

  2. Superconducting Tunnel Junction Arrays for UV Photon Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An innovative method is described for the fabrication of superconducting tunnel junction (STJ) detector arrays offering true "three dimensional" imaging throughout...

  3. Improving transition voltage spectroscopy of molecular junctions

    DEFF Research Database (Denmark)

    Markussen, Troels; Chen, Jingzhe; Thygesen, Kristian Sommer

    2011-01-01

    Transition voltage spectroscopy (TVS) is a promising spectroscopic tool for molecular junctions. The principles in TVS is to find the minimum on a Fowler-Nordheim plot where ln(I/V2) is plotted against 1/V and relate the voltage at the minimum Vmin to the closest molecular level. Importantly, Vmin...... is approximately half the voltage required to see a peak in the dI/dV curve. Information about the molecular level position can thus be obtained at relatively low voltages. In this work we show that the molecular level position can be determined at even lower voltages, Vmin(α), by finding the minimum of ln...

  4. Anatomy and biomechanics of the craniovertebral junction.

    Science.gov (United States)

    Lopez, Alejandro J; Scheer, Justin K; Leibl, Kayla E; Smith, Zachary A; Dlouhy, Brian J; Dahdaleh, Nader S

    2015-04-01

    The craniovertebral junction (CVJ) has unique anatomical structures that separate it from the subaxial cervical spine. In addition to housing vital neural and vascular structures, the majority of cranial flexion, extension, and axial rotation is accomplished at the CVJ. A complex combination of osseous and ligamentous supports allow for stability despite a large degree of motion. An understanding of anatomy and biomechanics is essential to effectively evaluate and address the various pathological processes that may affect this region. Therefore, the authors present an up-to-date narrative review of CVJ anatomy, normal and pathological biomechanics, and fixation techniques.

  5. Magnetic resonance imaging in craniovertebral junction anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Shimpei; Hata, Yuichi; Miyamoto, Yukio

    1985-03-01

    Materials consisted of 6 cases with occipitalization of the atlas, (4 of them complicated by basilar impression), 7 with basilar impression, one with hypoplasia of the atlas and C2-3 fusion, and one with os odontoideum. Basal angles after Welcker were all more than 130 in contrast to 118-138 (127 an average) in control group. Basal angle more than 140 denoted platybasia. Syringomyelia was seen in 7 of all 15 cases and 4 of 5 cases with platybasia. Chiari malformation was seen in 9 of all 15 cases and 4 of 5 with platybasia. Basal angles were closely related to craniovertebral junction bone anomaly, syringomyelia, and Chiari malformation. (author).

  6. Magic-T Junction using Microstrip/Slotline Transitions

    Science.gov (United States)

    U-yen, Kongpop; Wollack, Edward J.; Doiron, Terence

    2008-01-01

    An improved broadband planar magic-T junction that incorporates microstrip/slotline transitions has been developed. In comparison with a prior broadband magic-T junction incorporating microstrip/slotline transitions, this junction offers superior broadband performance. In addition, because this junction is geometrically simpler and its performance is less affected by fabrication tolerances, the benefits of the improved design can be realized at lower fabrication cost. There are potential uses for junctions like this one in commercial microwave communication receivers, radar and polarimeter systems, and industrial microwave instrumentation. A magic-T junction is a four-port waveguide junction consisting of a combination of an H-type and an E-type junction. An E-type junction is so named because it includes a junction arm that extends from a main waveguide in the same direction as that of the electric (E) field in the waveguide. An H-type junction is so named because it includes a junction arm parallel to the magnetic (H) field in a main waveguide. A magic-T junction includes two input ports (here labeled 1 and 2, respectively) and two output ports (here labeled E and H, respectively). In an ideal case, (1) a magic-T junction is lossless, (2) the input signals add (that is, they combine in phase with each other) at port H, and (3) the input signals subtract (that is, they combine in opposite phase) at port E. The prior junction over which the present junction is an improvement affords in-phase-combining characterized by a broadband frequency response, and features a small slotline area to minimize in-band loss. However, with respect to isolation between ports 1 and 2 and return loss at port E, it exhibits narrowband frequency responses. In addition, its performance is sensitive to misalignment of microstrip and slotline components: this sensitivity is attributable to a limited number of quarter-wavelength (lambda/4) transmission-line sections for matching impedances

  7. Grades 1-8, Apache Junction Unified School District 43, Apache Junction, Arizona. PLATO Evaluation Series.

    Science.gov (United States)

    Quinn, David W.; Quinn, Nancy W.

    Apache Junction Unified School District, Arizona, has embarked on a 5-year program of instructional improvement using technology. PLATO Elementary reading and mathematics products were installed in the district's elementary and middle schools at the beginning of the 1999-2000 school year. This evaluation studied the use and preliminary student…

  8. Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers

    Science.gov (United States)

    Chang, Y. Austin; Yang, Jianhua Joshua

    2008-11-11

    This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

  9. Small bowel obstruction attributable to phytobezoar

    Science.gov (United States)

    Razavianzadeh, Nasrin; Foroutan, Behzad; Honarvar, Farhad; Forozeshfard, Mohammad

    2016-01-01

    Small bowel obstruction (SBO) is a common condition encountered in surgical practice. Literature shows divers and many different etiologies for intestinal obstruction. However, bezoars are rarely reported as an etiological factor. A bezoar happens most commonly in patients with impaired gastrointestinal motility. There are four types of bezoars: phytobezoars, trichobezoars, pharmacobezoars and lactobezoars. The most common type is phytobezoars, which are composed of undigested fiber from vegetables or fruits especially persimmons. They are mostly composed of cellulose, tannin and lignin. The commonest phytobezoar reported worldwide is related to the persimmon fruit ingestion. The most common symptom of bezoar-induced SBO is abdominal pain (96–100%). Other common symptoms include nausea and vomiting. Primary small bowel phytobezoars almost always present as SBO. We present an unusual case of SBO caused by a phytobezoar in a 35-year-old patient. Many types of bezoar can be removed endoscopically, but some will require operative intervention. PMID:28031856

  10. Obstructive jaundice induced by biliary ascariasis.

    Science.gov (United States)

    Keating, Aine; Quigley, James Aidan; Genterola, Al Frederick

    2012-12-13

    Ascaris lumbricoides is one of the most prevalent parasitic infections, especially in developing countries. Its presence can lead to a multitude of presentations, one of the rarer ones being obstructive jaundice due to migration of the worm in to the biliary tree. We describe a case of a man who presented as an emergency to the general surgeons complaining of abdominal pain, fever, jaundice and vomiting. Ultrasound was used and the diagnosis of biliary ascariasis was made. The patient underwent surgery consisting of a cholecystectomy, common bile duct exploration and T-tube choledochostomy. Our report highlights the varied aetiology of obstructive jaundice and the importance of including biliary ascariasis in the differential diagnosis of the jaundiced patient, especially from endemic areas.

  11. Complex networks analysis of obstructive nephropathy data

    Science.gov (United States)

    Zanin, M.; Boccaletti, S.

    2011-09-01

    Congenital obstructive nephropathy (ON) is one of the most frequent and complex diseases affecting children, characterized by an abnormal flux of the urine, due to a partial or complete obstruction of the urinary tract; as a consequence, urine may accumulate in the kidney and disturb the normal operation of the organ. Despite important advances, pathological mechanisms are not yet fully understood. In this contribution, the topology of complex networks, based on vectors of features of control and ON subjects, is related with the severity of the pathology. Nodes in these networks represent genetic and metabolic profiles, while connections between them indicate an abnormal relation between their expressions. Resulting topologies allow discriminating ON subjects and detecting which genetic or metabolic elements are responsible for the malfunction.

  12. Esophageal stent migration leads to intestinal obstruction

    Directory of Open Access Journals (Sweden)

    Oguzhan Karatepe

    2009-07-01

    Full Text Available Background: Self-expanding metallic stents are the devices of choice in the treatment of malign or benign strictures of esophagus. Stent migration is a well-known complication of this procedure. Aims: We report a case of intestinal obstruction caused by esophageal stent migration, in which surgical intervention was used. Methods: A 65-year-old woman, who had a medical history of gastric cancer operation and esophageal stent application admitted to our emergeny department with a 48-hour history of abdominal pain, nausea and vomiting. An emergeny laparotomy was performed and the migrated stent leading to intestinal obstruction was removed. Results: The patient recovered without incident and was discharged on postoperative day 3. Conclusion: This case illustrates that esophageal stent migration has to be considered as a potential life-threatening complication.

  13. Hepatic venous outflow obstruction: Three similar syndromes

    Institute of Scientific and Technical Information of China (English)

    Ulas Darda Bayraktar; Soley Seren; Yusuf Bayraktar

    2007-01-01

    Our goal is to provide a detailed review of venoocclusive disease (VOD), Budd-Chiari syndrome (BCS),and congestive hepatopathy (CH), all of which results in hepatic venous outflow obstruction. This is the first article in which all three syndromes have been reviewed,enabling the reader to compare the characteristics of these disorders. The histological findings in VOD, BCS,and CH are almost identical: sinusoidal congestion and cell necrosis mostly in perivenular areas of hepatic acini which eventually leads to bridging fibrosis between adjacent central veins. Tender hepatomegaly with jaundice and ascites is common to all three conditions.However, the clinical presentation depends mostly on the extent and rapidity of the outflow obstruction.Although the etiology and treatment are completely different in VOD, BCS, and CH; the similarities in clinical manifestations and liver histology may suggest a common mechanism of hepatic injury and adaptation in response to increased sinusoidal pressure.

  14. Pierre Robin sequence and obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Rubens Reimão

    1994-12-01

    Full Text Available The case of a 12-year-old female patient with Pierre Robin sequence is reported, in which reduction of the pharyngeal airway leads to obstructive sleep apnea syndrome (OSAS and excessive daytime sleepiness. Radiological evaluation, computerized tomography and magnetic resonance image showed bilateral temporomandibular ankylosis. Cephalometric data evidenced marked reduction of the posterior airway space. Three all-night polysomnographic evaluations detected severe OSAS with decrease in oxygen saturation. The Multiple Sleep Latency Test (MSLT perfomed on two separate days objectively quantified the excessive daytime sleepiness with short sleep latencies; stage REM was not present. Polysomnography, MSLT and thorough radiologic studies, in this case, made it possible to determine the severity of OSAS, the site of obstruction, and the associated malformations.

  15. Intestinal obstruction for biliary lithiasis: case report

    Directory of Open Access Journals (Sweden)

    Miguel Enrique Rodriguez Rodriguez

    2017-06-01

    Full Text Available The biliary ileum is an infrequent complication of cholelithiasis, that is manifested as an intestinal obstruction, is more prevalent in aged people. The clinical square of the biliary ileum is diffuse and the Triad of Rigler is observed in less than 30% of the patient one. The surgical treatment goes from enterotomía and litotricia to the colecistectomía with treatment of the water-pipe. The case of a female, 86-year-old patient is presented that after a week of symptoms and of medical treatment it was detected the presence of a mechanical intestinal obstruction for which the patient underwent emergency surgery. As the cause of occlusion it was found a thick gallstone in a jejunal loop.

  16. Partial upper airway obstruction in sleep after uvulopalatopharyngoplasty.

    Science.gov (United States)

    Polo, O; Brissaud, L; Fraga, J; Déjean, Y; Billiard, M

    1989-11-01

    Uvulopalatopharyngoplasty is the treatment of choice for selected patients with obstructive sleep apnea, although the response to surgery is variable. We measured, in addition to obstructive apnea, the frequency of sleep-related partial upper airway obstruction in 11 patients with the obstructive sleep apnea syndrome both before and after uvulopalatopharyngoplasty. Partial obstruction was detected indirectly by recording the secondary hemodynamic changes and respiratory stimulation with the static charge sensitive bed. The frequency of obstructive apnea episodes was reduced from 56.3% to 18.4% by the operation, while the episodes of increased respiratory resistance rose from 3.6% to 20.4%. The various breathing anomalies decreased significantly, although they were still present during 75.6% of the recording time. The results suggest that uvulopalatopharyngoplasty substantially reduces the frequency of obstructive apnea, some of which persists as partial obstruction. The persistent partial obstruction may be the key factor contributing to further pharyngeal narrowing and a recurrence of obstructive sleep apnea syndrome.

  17. Effect of bowel obstruction on stage IV colorectal cancer.

    Science.gov (United States)

    Chen, Wei; Tan, Xiao-Ping; Ye, Jun-Wen; Liu, Qin; Zeng, Qingli; Wang, Lei; Wang, Jian-Ping

    2014-03-01

    Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide, with a high mortality rate, particularly among patients with advanced-stage disease complicated by bowel obstruction. The present study aimed to investigate the value of different surgical procedures and potential predictors of survival for patients with stage IV CRC, with or without bowel obstruction. Between August, 1994 and December, 2005, a total of 2,950 CRC patients were diagnosed and treated at our hospital. Among these, 381 patients had stage IV disease and were divided into two groups according to the presence (n=295) or absence (n=86) of bowel obstruction. The clinical data of all the patients with stage IV CRC were retrospectively analyzed and all the patients were followed up. Our results demonstrated statistically significant differences in gender, radical resection, histological type, ascites, tumor location, peritoneal and liver metastases between the obstruction and non-obstruction groups. We also observed that hepatic metastases and radical resection were factors associated with prognosis according to the univariate and multivariate analyses. Furthermore, the mean/median survival time was 49.4/21.6 and 37.2/17.1 months in the non-obstruction and obstruction groups, respectively. In conclusion, obstruction was not found to be an independent indicator of survival for patients with stage IV CRC, with patients in the obstruction group exhibiting a worse overall survival compared to those in the non-obstruction group, whereas active radical surgery significantly improved the prognosis of patients with stage IV CRC.

  18. Lingua-epiglottis position predicts glossopharyngeal obstruction in patients with obstructive sleep apnea hypopnea syndrome.

    Science.gov (United States)

    Li, Shuhua; Wu, Dahai; Jie, Qin; Bao, Jimin; Shi, Hongjin

    2014-10-01

    The objective of the study was to investigate the relationship between lingua-epiglottis position and glossopharyngeal obstruction in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). One hundred and four patients with OSAHS diagnosed by polysomnography (PSG) were enrolled. Lingua-epiglottis position was visualized using endoscopy and classified into three types. Spiral CT imaging of the upper respiratory tract was performed to measure the cross-sectional area and inner diameter of the glossopharyngeal airway. The PSG was repeated after nasopharyngeal tube insertion (NPT-PSG). The NPT-PSG results, CT-measured data and incidence of stenosis were compared among the different lingua-epiglottis position groups. Obstructive sleep apnea hypopnea syndrome patients with different lingua-epiglottis positions had similar demographics. As lingua-epiglottis position type varied from type I to type III, cross-sectional area and inner diameter of the glossopharyngeal area decreased, glossopharyngeal airway stenosis rate increased, and apnea hypopnea index measured by NPT-PSG increased. The lowest oxygen saturation decreased. Lingua-epiglottis position was significantly related to glossopharyngeal obstruction. Lingua-epiglottis position should be used in clinical practice for the preliminary assessment of glossopharyngeal obstruction.

  19. Atrial fibrillation in obstructive sleep apnea

    OpenAIRE

    Goyal, Sandeep K; Sharma, Abhishek

    2013-01-01

    Atrial fibrillation (AF) is a common arrhythmia with rising incidence. Obstructive sleep apnea (OSA) is prevalent among patients with AF. This observation has prompted significant research in understanding the relationship between OSA and AF. Multiple studies support a role of OSA in the initiation and progression of AF. This association has been independent of obesity, body mass index and hypertension. Instability of autonomic tone and wide swings in intrathoracic pressure are seen in OSA. T...

  20. Gingival hyperplasia by upper airway obstruction

    OpenAIRE

    Díaz Soriano, Ana; Docente Departamento Académico de Estomatología Biosocial.; Lévano Torres, Víctor; Docente Departamento Académico Médico Quirúrgico.; Pastor Yataco, Shamila; Alumnos del 3er año de Odontología de la UNMSM.; Vallejos Pulido, Arturo; Alumnos del 3er año de Odontología de la UNMSM.; Huamanyauri Gonzales, Lizbeth; Alumnos del 3er año de Odontología de la UNMSM.

    2014-01-01

    The effects of mouth breathing are the introduction of cold air, dry and dusty in the mouth and pharynx, the lost functions of heating, humedificacion and filtering the air entering the nose increases the oral mucosa irritation and pharyngeal. A case of a female patient 15 years old who comes for consultation of Periodontology with increase in volume and gingival redness in the upper anterior sector of upper airway obstruction caused by deviated septum right turbinate hypertrophy and maxillar...

  1. Childhood Obesity and Obstructive Sleep Apnea

    OpenAIRE

    Indra Narang; Mathew, Joseph L

    2012-01-01

    The global epidemic of childhood and adolescent obesity and its immediate as well as long-term consequences for obese individuals and society as a whole cannot be overemphasized. Obesity in childhood and adolescence is associated with an increased risk of adult obesity and clinically significant consequences affecting the cardiovascular and metabolic systems. Importantly, obesity is additionally complicated by obstructive sleep apnea (OSA), occurring in up to 60% of obese children. OSA, which...

  2. Endocrinological disturbances in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Creutzberg, E C; Casaburi, R

    2003-11-01

    In this overview, the available literature on endocrinological disturbances in chronic obstructive pulmonary disease (COPD) is reviewed, with stress on growth hormone/insulin-like growth factor I (IGF-I), thyroid hormone and the anabolic steroids. In COPD, little is known about circulating growth hormone or IGF-I concentrations. Some authors find a decrease in growth hormone or IGF-I, others an increase. An increase of growth hormone might reflect a nonspecific response of the body to stress (for instance, hypoxaemia). Until now, only one controlled study on growth hormone supplementation has been published, which however did not reveal any functional benefits. Before growth hormone supplementation can be advised as part of the treatment in COPD, further controlled studies must be performed to investigate its functional efficacy. The prevalence of thyroid dysfunction in COPD and its role in pulmonary cachexia has not been extensively studied. So far, there is no evidence that thyroid function is consistently altered in COPD, except perhaps in a subgroup of patients with severe hypoxaemia. Further research is required to more extensively study the underlying mechanisms and consequences of disturbed thyroid function in this subgroup of COPD patients. A few studies have reported the results of anabolic steroid supplementation in chronic obstructive pulmonary disease. Although some studies have discerned that low circulating levels of testosterone are common in males with chronic obstructive pulmonary disease, little is known about the prevalence, the underlying causes or functional consequences of hypogonadism in these patients. The use of systemic glucocorticosteroids and an influence of the systemic inflammatory response have been suggested as contributing to low testosterone levels. It can be hypothesised that low anabolic hormones will reduce muscle mass and eventually result in a diminished muscle function. Further evidence is required before testosterone

  3. Chronic Idiopathic Intestinal Pseudo-obstruction.

    Science.gov (United States)

    Malagelada

    2000-08-01

    The definition of chronic idiopathic intestinal pseudo-obstruction (CIIP) is somewhat vague because it was based on clinical observations that preceded modern advances in the measurement of gut motility and neuromuscular integrity. Appropriate management of patients with CIIP requires an initial consideration, supported by pertinent diagnostic tests, of the tissue affected (muscle, nerves, both), extent and magnitude of gut propulsive failure, and extraintestinal disease.

  4. Obstructive lung disease models: what is valid?

    Science.gov (United States)

    Ferdinands, Jill M; Mannino, David M

    2008-12-01

    Use of disease simulation models has led to scrutiny of model methods and demand for evidence that models credibly simulate health outcomes. We sought to describe recent obstructive lung disease simulation models and their validation. Medline and EMBASE were used to identify obstructive lung disease simulation models published from January 2000 to June 2006. Publications were reviewed to assess model attributes and four types of validation: first-order (verification/debugging), second-order (comparison with studies used in model development), third-order (comparison with studies not used in model development), and predictive validity. Six asthma and seven chronic obstructive pulmonary disease models were identified. Seven (54%) models included second-order validation, typically by comparing observed outcomes to simulations of source study cohorts. Seven (54%) models included third-order validation, in which modeled outcomes were usually compared qualitatively for agreement with studies independent of the model. Validation endpoints included disease prevalence, exacerbation, and all-cause mortality. Validation was typically described as acceptable, despite near-universal absence of criteria for judging adequacy of validation. Although over half of recent obstructive lung disease simulation models report validation, inconsistencies in validation methods and lack of detailed reporting make assessing adequacy of validation difficult. For simulation modeling to be accepted as a tool for evaluating clinical and public health programs, models must be validated to credibly simulate health outcomes of interest. Defining the required level of validation and providing guidance for quantitative assessment and reporting of validation are important future steps in promoting simulation models as practical decision tools.

  5. Positional Right Ventricular Obstruction in Pectus Excavatum.

    Science.gov (United States)

    Underwood, Katherine; Vorsanger, Matthew; Saric, Muhamed; Skolnick, Adam H

    2017-01-25

    Pectus excavatum is one of the most common congenital chest wall deformities. The degree of sternal depression, which may result in compression of the right heart by the chest wall, is variable. While typically asymptomatic, there are various symptoms that can result from severe pectus excavatum. We report on a patient with severe pectus excavatum leading to dynamic obstruction of the right ventricular outflow tract in the seated position.

  6. Post-extubation airway obstruction. Literature review

    Directory of Open Access Journals (Sweden)

    Álvaro SÁNCHEZ-TABERNERO

    2017-03-01

    Full Text Available Introduction and objective: airway obstruction after extubation in any surgery is a critical event with low incidence, which may require reintubation or tracheostomy, which often otolaryngologist is required. Objective: To determine the prevalence of BVA and its causes through systematic literature review. Method: Literature review in PubMed, Scopus and Cochrane clinical trials, meta-analysis, reviews and case series and control over airway obstruction after extubation that requires reintubation in adults. Results: 6 studies and one clinical practice guidelines were selected. The most common cause of extubation failure is blocking the airway for various reasons (pharyngeal muscle weakness residual effect -often farmacologycal-, laryngospasm, vocal cord paralysis, edema of upper respiratory tract, cervical postoperative hematoma, foreign bodies or secretions. Most cases of re-intubation occurred within 2 hours after extubation. Conclusions: The most common cause of failure after general anesthesia extubation is blocking the airway generally caused by residual neuromuscular blocking effect. Airway obstruction risk increases in airway and head and neck surgery. Difficult intubation guidlines have improved performance and reduced adverse events and similar strategies must be implemented in extubation. The procedure extubation and reintubation should be documented. Working groups airway must be multidisciplinary and include specialists in otolaryngology.

  7. Models of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Chung K Fan

    2004-11-01

    Full Text Available Abstract Chronic obstructive pulmonary disease (COPD is a major global health problem and is predicted to become the third most common cause of death by 2020. Apart from the important preventive steps of smoking cessation, there are no other specific treatments for COPD that are as effective in reversing the condition, and therefore there is a need to understand the pathophysiological mechanisms that could lead to new therapeutic strategies. The development of experimental models will help to dissect these mechanisms at the cellular and molecular level. COPD is a disease characterized by progressive airflow obstruction of the peripheral airways, associated with lung inflammation, emphysema and mucus hypersecretion. Different approaches to mimic COPD have been developed but are limited in comparison to models of allergic asthma. COPD models usually do not mimic the major features of human COPD and are commonly based on the induction of COPD-like lesions in the lungs and airways using noxious inhalants such as tobacco smoke, nitrogen dioxide, or sulfur dioxide. Depending on the duration and intensity of exposure, these noxious stimuli induce signs of chronic inflammation and airway remodelling. Emphysema can be achieved by combining such exposure with instillation of tissue-degrading enzymes. Other approaches are based on genetically-targeted mice which develop COPD-like lesions with emphysema, and such mice provide deep insights into pathophysiological mechanisms. Future approaches should aim to mimic irreversible airflow obstruction, associated with cough and sputum production, with the possibility of inducing exacerbations.

  8. Clinical practice: Obstructive renal candidiasis in infancy.

    Science.gov (United States)

    Bisht, Veena; Voort, Judith VanDer

    2011-10-01

    Renal candidiasis is an increasingly common condition affecting predominantly premature infants receiving neonatal intensive care or term infants with urogenital tract anomalies. Multiple risk factors are usually present. Although rare, some infants develop an obstructive uropathy due to fungal balls, and this requires prompt detection and intervention to preserve kidney function. The management of obstructive renal bezoars is challenging and not well summarised in the past. This is mainly due to scarce literature confined to case reports or case series only. This review clarifies various definitions used in relation to renal candidiasis and identifies infants particularly at risk of obstruction. Clinical presentation, diagnosis and the role of imaging are discussed. A summary of the recent literature is provided to outline the range of existing treatment options available with published drug dosages and mode of delivery used. No single approach is successful in all cases and clinicians need to be aware of the different options available: apart from adequate urinary drainage and use of systemic +/- local antifungal agents, additional treatment with fibrinolytic agents and/or endoscopic or open surgical removal may be required. A new simplified algorithm for use in management is proposed. We hope this review will help clinicians in their management of patients presenting with this complex and challenging diagnosis.

  9. Gap junctions in the nervous system.

    Science.gov (United States)

    Rozental, R; Giaume, C; Spray, D C

    2000-04-01

    Synapses are classically defined as close connections between two nerve cells or between a neuronal cell and a muscle or gland cell across which a chemical signal (i.e., a neurotransmitter) and/or an electrical signal (i.e., current-carrying ions) can pass. The definition of synapse was developed by Charles Sherrington and by Ramon y Cajal at the beginning of this century and refined by John Eccles and Bernard Katz 50 years later; in this collection of papers, the definition of synapses is discussed further in the chapter by Mike Bennett. who provided the first functional demonstration of electrical transmission via gap junction channels between vertebrate neurons. As is evidenced by the range of topics covered in this issue, research dealing with gap junctions in the nervous system has expanded enormously in the past decade, major findings being that specific cell types in the brain expresses specific types of connexins and that expression patterns coincide with tissue compartmentalization and function and that these compartments change during development.

  10. Electrophysiological study in neuromuscular junction disorders

    Directory of Open Access Journals (Sweden)

    Ajith Cherian

    2013-01-01

    Full Text Available This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS, congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS. SFEMG requires skill and patience and its availability is limited to a few centers. For RNS supramaximal stimulation is essential and so is display of the whole waveform of each muscle response at maximum amplitude. The amplitudes of the negative phase of the first and fourth responses are measured from baseline to negative peak, and the percent change of the fourth response compared with the first represents the decrement or increment. A decrement greater than 10% is accepted as abnormal and smooth progression of response amplitude train and reproducibility form the crux. In suspected LEMS the effect of fast rates of stimulation should be determined after RNS response to slow rates of stimulation. Caution is required to avoid misinterpretation of potentiation and pseudofacilitation.

  11. Improving transition voltage spectroscopy of molecular junctions

    Science.gov (United States)

    Markussen, Troels; Chen, Jingzhe; Thygesen, Kristian S.

    2011-04-01

    Transition voltage spectroscopy (TVS) is a promising spectroscopic tool for molecular junctions. The principles in TVS is to find the minimum on a Fowler-Nordheim plot where ln(I/V2) is plotted against 1/V and relate the voltage at the minimum Vmin to the closest molecular level. Importantly, Vmin is approximately half the voltage required to see a peak in the dI/dV curve. Information about the molecular level position can thus be obtained at relatively low voltages. In this work we show that the molecular level position can be determined at even lower voltages, Vmin(α), by finding the minimum of ln(I/Vα) with α<2. On the basis of a simple Lorentzian transmission model we analyze theoretical ab initio as well as experimental I-V curves and show that the voltage required to determine the molecular levels can be reduced by ~30% as compared to conventional TVS. As for conventional TVS, the symmetry/asymmetry of the molecular junction needs to be taken into account in order to gain quantitative information. We show that the degree of asymmetry may be estimated from a plot of Vmin(α) vs α.

  12. Development of superconducting tunnel junction radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Katagiri, Masaki; Kishimoto, Maki; Ukibe, Masahiro; Nakamura, Tatsuya; Nakazawa, Masaharu [Japan Atomic Energy Research Inst., Tokyo (Japan); Kurakado, Masahiko; Ishibashi, Kenji; Maehata, Keisuke

    1998-07-01

    Study on development of high energy resolution X-ray detector using superconducting tunnel junction (STJ) for radiation detection was conducted for 5 years under cooperation of University of Tokyo group and Kyushu University group by Quantum measurement research group of Advanced fundamental research center of JAERI. As the energy resolution of STJ could be obtained better results than that of Si semiconductor detector told to be actually best at present, this study aimed to actualize an X-ray detector usable for the experimental field and to elucidate radiation detection mechanism due to STJ. The STJ element used for this study was the one developed by Kurakado group of Nippon Steel Corp. As a results, some technical problems were almost resolved, which made some trouble when using the STJ element to detection element of X-ray spectrometer. In order to make the X-ray detector better, it is essential to manufacture a STJ element and develop serial junction type STJ element on the base of optimization of the element structure and selection and single crystallization of new superconducting materials such as Ta and others, activating the research results. (G.K.)

  13. Junction like behavior in polycrystalline diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, Shivakumar, E-mail: sbhaskar@mail.uh.edu [Department of Electrical and Computer Engineering, Cullen College of Engineering, University of Houston, TX 77004 (United States); Charlson, Earl Joe; Litvinov, Dmitri [Department of Electrical and Computer Engineering, Cullen College of Engineering, University of Houston, TX 77004 (United States); Makarenko, Boris [Department of Chemistry, University of Houston, TX 77004 (United States)

    2012-01-25

    Highlights: Black-Right-Pointing-Pointer The result that we obtained are compared with single crystalline diamond devices. Black-Right-Pointing-Pointer The barrier height of 4.4 eV matches the ideal pn-junction barrier height of diamond thin film. - Abstract: We have successfully fabricated polycrystalline diamond rectifying junction devices on n-type (1 0 0) silicon substrates by Hot Filament Chemical Vapor Deposition (HFCVD) using methane/hydrogen process gas and trimethyl borate and trimethyl phosphite dissolved in acetone as p- and n-type dopants, respectively. Impedance spectroscopy and current-voltage analysis indicates that the conduction is vertical down the grains and facets and not due to surface effects. Electrical characteristics were analyzed with In and Ti/Au top metal contacts with Al as the substrate contact. Current-voltage characteristics as a function of temperature showed barrier potentials of 1.1 eV and 0.77 eV for the In and Ti/Au contacts, respectively. Barrier heights of 4.8 eV (In) and 4.4 eV (Ti/Au) were obtained from capacitance-voltage measurements.

  14. GAP junctional communication in brain secondary organizers.

    Science.gov (United States)

    Bosone, Camilla; Andreu, Abraham; Echevarria, Diego

    2016-06-01

    Gap junctions (GJs) are integral membrane proteins that enable the direct cytoplasmic exchange of ions and low molecular weight metabolites between adjacent cells. They are formed by the apposition of two connexons belonging to adjacent cells. Each connexon is formed by six proteins, named connexins (Cxs). Current evidence suggests that gap junctions play an important part in ensuring normal embryo development. Mutations in connexin genes have been linked to a variety of human diseases, although the precise role and the cell biological mechanisms of their action remain almost unknown. Among the big family of Cxs, several are expressed in nervous tissue but just a few are expressed in the anterior neural tube of vertebrates. Many efforts have been made to elucidate the molecular bases of Cxs cell biology and how they influence the morphogenetic signal activity produced by brain signaling centers. These centers, orchestrated by transcription factors and morphogenes determine the axial patterning of the mammalian brain during its specification and regionalization. The present review revisits the findings of GJ composed by Cx43 and Cx36 in neural tube patterning and discuss Cx43 putative enrollment in the control of Fgf8 signal activity coming from the well known secondary organizer, the isthmic organizer. © 2016 The Authors. Development, Growth & Differentiation published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Developmental Biologists.

  15. Annealing free magnetic tunnel junction sensors

    Science.gov (United States)

    Knudde, S.; Leitao, D. C.; Cardoso, S.; Freitas, P. P.

    2017-04-01

    Annealing is a major step in the fabrication of magnetic tunnel junctions (MTJs). It sets the exchange bias between the pinned and antiferromagnetic layers, and helps to increase the tunnel magnetoresistance (TMR) in both amorphous and crystalline junctions. Recent research on MTJs has focused on MgO-based structures due to their high TMR. However, the strict process control and mandatory annealing step can limit the scope of the application of these structures as sensors. In this paper, we present AlOx-based MTJs that are produced by ion beam sputtering and remote plasma oxidation and show optimum transport properties with no annealing. The microfabricated devices show TMR values of up to 35% and using NiFe/CoFeB free layers provides tunable linear ranges, leading to coercivity-free linear responses with sensitivities of up to 5.5%/mT. The top-pinned synthetic antiferromagnetic reference shows a stability of about 30 mT in the microfabricated devices. Sensors with linear ranges of up to 60 mT are demonstrated. This paves the way for the integration of MTJ sensors in heat-sensitive applications such as flexible substrates, or for the design of low-footprint on-chip multiaxial sensing devices.

  16. Virus interaction with the apical junctional complex.

    Science.gov (United States)

    Gonzalez-Mariscal, Lorenza; Garay, Erika; Lechuga, Susana

    2009-01-01

    In order to infect pathogens must breach the epithelial barriers that separate the organism from the external environment or that cover the internal cavities and ducts of the body. Epithelia seal the passage through the paracellular pathway with the apical junctional complex integrated by tight and adherens junctions. In this review we describe how viruses like coxsackie, swine vesicular disease virus, adenovirus, reovirus, feline calcivirus, herpes viruses 1 and 2, pseudorabies, bovine herpes virus 1, poliovirus and hepatitis C use as cellular receptors integral proteins present at the AJC of epithelial cells. Interaction with these proteins contributes in a significant manner in defining the particular tropism of each virus. Besides these proteins, viruses exhibit a wide range of cellular co-receptors among which proteins present in the basolateral cell surface like integrins are often found. Therefore targeting proteins of the AJC constitutes a strategy that might allow viruses to bypass the physical barrier that blocks their access to receptors expressed on the basolateral surface of epithelial cells.

  17. Switching and Rectification in Carbon-Nanotube Junctions

    Science.gov (United States)

    Srivastava, Deepak; Andriotis, Antonis N.; Menon, Madhu; Chernozatonskii, Leonid

    2003-01-01

    Multi-terminal carbon-nanotube junctions are under investigation as candidate components of nanoscale electronic devices and circuits. Three-terminal "Y" junctions of carbon nanotubes (see Figure 1) have proven to be especially interesting because (1) it is now possible to synthesize them in high yield in a controlled manner and (2) results of preliminary experimental and theoretical studies suggest that such junctions could exhibit switching and rectification properties. Following the preliminary studies, current-versus-voltage characteristics of a number of different "Y" junctions of single-wall carbon nanotubes connected to metal wires were computed. Both semiconducting and metallic nanotubes of various chiralities were considered. Most of the junctions considered were symmetric. These computations involved modeling of the quantum electrical conductivity of the carbon nanotubes and junctions, taking account of such complicating factors as the topological defects (pentagons, heptagons, and octagons) present in the hexagonal molecular structures at the junctions, and the effects of the nanotube/wire interfaces. A major component of the computational approach was the use of an efficient Green s function embedding scheme. The results of these computations showed that symmetric junctions could be expected to support both rectification and switching. The results also showed that rectification and switching properties of a junction could be expected to depend strongly on its symmetry and, to a lesser degree, on the chirality of the nanotubes. In particular, it was found that a zigzag nanotube branching at a symmetric "Y" junction could exhibit either perfect rectification or partial rectification (asymmetric current-versus-voltage characteristic, as in the example of Figure 2). It was also found that an asymmetric "Y" junction would not exhibit rectification.

  18. Acute small bowel obstruction as a result of a Meckel's diverticulum encircling the terminal ileum: A case report

    Directory of Open Access Journals (Sweden)

    Thakor Avnesh S

    2007-03-01

    Full Text Available Abstract Background In the developed world, small bowel obstruction accounts for 20% of all acute surgical admissions. The aetiology for majority of these cases includes postoperative adhesions and herniae. However, a relatively uncommon cause is a Meckel's diverticulum. Although this diagnosis is primarily reported in the adolescent population, it should also be considered in adults. Case Presentation In the present report, we present a rare case where a fit and healthy 74-year-old gentleman, with no previous history of abdominal surgery, presented with the cardinal symptoms and signs of small bowel obstruction as the result of a Meckel's diverticulum encircling his terminal ileum. Initial investigations included a supine abdominal x-ray showing dilated loops of small bowel and computerised tomographic imaging of the abdomen, which revealed a stricture in the terminal ileum of unknown aetiology. At laparotomy, multiple loops of distended small bowel were seen from the duodeno-jeujenal junction to the terminal ileum, which was encircled by a Meckel's diverticulum. The Meckel's diverticulum was then divided to release the obstruction, mobilised and subsequently removed. Finally, the small bowel contents were decompressed into the stomach and the nasogastric tube aspirated, before returning the loops of bowel into the abdomen in sequence. The patient made a good postoperative recovery and was discharged home 5 days later. Conclusion This report highlights the importance of considering a Meckel's diverticulum as a cause of small bowel obstruction in individuals from all age groups and especially in a person with no previous abdominal pathology or surgery.

  19. Neonatal Intestinal Obstruction-Four Year Experience

    Directory of Open Access Journals (Sweden)

    D. Rathore

    2015-06-01

    Full Text Available Aim of study: To study the aetiology and frequency, sex incidence, age of presentation, management and outcome of neonatal intestinal obstruction. Material and Methods: This prospective study of 316 neonates with intestinal obstruction was conducted over a period of 4 years from November 2009 to October 2013 at single institute. These cases were managed by various surgical procedures. Their epidemiology, day of presentation, associated anomalies and outcomes were studied. Results: A total of 316 neonates (277 males and 39 females were operated for intestinal obstruction. 268(84.81% neonates presented in the 1st week of life. Imperforate anus occurred in 206 (65.19%.Small bowel atresia accounted for23 (7.27% cases while duodenal atresia was seen in19 (6.01% patients. Infantile hypertrophic pyloric stenosis and Malrotation each occurred in 14 (4.43% patients; Hirschsprung’s disease in 18(5.69%, Necrotising Enterocolitis in 12(3.79%, Meconium disease of newborn in 9(2.85% while colonic atresia was seen in one (0.3% patient. Colostomy was performed in 145(45.88%, Pouchostomy in 15(4.74% and Cutback anoplasty in 56(17.72% patients. Ramsted’s Pyloromyotomy in 13(4.11%% neonates, Laparoscopic Pyloromyotomy in 1(0.3%,Kimura’s Duodenoduodenostomy in 19(6.01% ,End to Back anastomosis in 24(7.59% , End to End anastomosis in 7(2.21% , Multiple anastomosis in 2(0.6% , Enterotomy with irrigation in 7(2.21% , Ladd’s procedure in 14(4.43% , ,Single stage transanal pull through in 8(2.53% , Ileostomy in 2(0.6% , Single stage Abdominoperineal pull through in 2(0.6%, Levelling colostomy in 6(1.89% ,Peritoneal drain insertion under Local anaesthesia in 5(1.58% . Overall mortality was 13.60%. Conclusion: Intestinal Obstruction is the most common surgical emergency in neonatal period. Early and accurate diagnosis is paramount for proper patient management. The etiology, mode of presentation, morbidity and outcome of surgery of intestinal obstruction in

  20. Hormonal treatment of obstructed kidneys in patients with prostatic cancer

    DEFF Research Database (Denmark)

    Honnens de Lichtenberg, M; Miskowiak, J; Rolff, H

    1993-01-01

    A review of 1288 patients with previously untreated prostatic cancer revealed 209 patients (16%) with ureteric obstruction; the obstruction was bilateral in 36%. The effect of hormonal treatment was assessed in 88 patients with 120 obstructed kidneys: 77 patients had androgen deprivation or hormo......A review of 1288 patients with previously untreated prostatic cancer revealed 209 patients (16%) with ureteric obstruction; the obstruction was bilateral in 36%. The effect of hormonal treatment was assessed in 88 patients with 120 obstructed kidneys: 77 patients had androgen deprivation...... or hormonal medication alone and 11 patients needed percutaneous nephrostomy or ureteric catheters in addition. Drainage improved in 58% of the kidneys. The diverting catheter was withdrawn in 9 of the 11 patients after a median of 4 weeks. In all, 95% of patients were discharged. The patients with hormonal...

  1. Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study.

    Science.gov (United States)

    Yazıcı, Mehmet; Celebi, Suleyman; Kuzdan, Özgür; Koçan, Hüseyin; Ayyıldız, Halil Suat; Bayrak, İlkay Koray; Bilgici, Meltem Ceyhan; Yapıcı, Oktay; Kefeli, Mehmet; Arıtürk, Ender

    2015-07-01

    The aim of this study was to evaluate functional and prognostic benefits of Doppler ultrasonography (DU), diuretic renal scintigraphy (DRS), and magnetic resonance urography (MRU) during diagnosis and follow-up of ureteropelvic junction obstruction (UPJO) and to examine apoptosis rates caused by UPJO in an experimental rabbit model. Twenty-four rabbits were divided randomly into two groups. The left kidneys of 15 rabbits from the first group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJO-created side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a

  2. MgB2 tunnel junctions and SQUIDs

    NARCIS (Netherlands)

    Brinkman, A.; Rowell, J.M.

    2007-01-01

    Recent advances in the realization and understanding of MgB2 tunnel junctions and SQUIDs are surveyed. High quality MgB2 junctions with suitable tunnel barriers have been realized based on both oriented and epitaxial thin MgB2 films. Multiband transport properties, such as the existence of two energ

  3. Craniovertebral Junction Instability in the Setting of Chiari I Malformation.

    Science.gov (United States)

    Goldstein, Hannah E; Anderson, Richard C E

    2015-10-01

    This article addresses the key features, clinical presentation, and radiographic findings associated with craniovertebral junction instability in the setting of Chiari I malformation. It further discusses surgical technique for treating patients with Chiari I malformation with concomitant craniovertebral junction instability, focusing on modern posterior rigid instrumentation and fusion techniques.

  4. Parametric excitation of plasma oscillations in a Josephson tunnel junction

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl; Kofoed, Bent; Pedersen, Niels Falsig

    1975-01-01

    Experimental evidence for subharmonic parametric excitation of plasma oscillations in Josephson tunnel junctions is presented. The experiments described are performed by measuring the microwave power necessary to switch a Josephson−tunnel junction biased in the zero−voltage state to a finite−volt......−voltage state. Journal of Applied Physics is copyrighted by The American Institute of Physics....

  5. Shapiro and parametric resonances in coupled Josephson junctions

    Science.gov (United States)

    Gaafar, Ma A.; Shukrinov, Yu M.; Foda, A.

    2012-11-01

    The effect of microwave irradiation on the phase dynamics of intrinsic Josephson junctions in high temperature superconductors is investigated. We compare the current-voltage characteristics for a stack of coupled Josephson junctions under external irradiation calculated in the framework of CCJJ and CCJJ+DC models.

  6. Microwave phase locking of Josephson-junction fluxon oscillators

    DEFF Research Database (Denmark)

    Salerno, M.; Samuelsen, Mogens Rugholm; Filatrella, G.;

    1990-01-01

    -dimensional functional map. Phase-locked states correspond to fixed points of the map. For junctions of in-line geometry, the existence and stability of such fixed points can be studied analytically. Study of overlap-geometry junctions requires the numerical inversion of a functional equation, but the results...

  7. Josephson junctions in high-T/sub c/ superconductors

    Science.gov (United States)

    Falco, C.M.; Lee, T.W.

    1981-01-14

    The invention includes a high T/sub c/ Josephson sperconducting junction as well as the method and apparatus which provides the junction by application of a closely controlled and monitored electrical discharge to a microbridge region connecting two portions of a superconducting film.

  8. Junction leakage measurements with micro four-point probes

    DEFF Research Database (Denmark)

    Lin, Rong; Petersen, Dirch Hjorth; Wang, Fei

    2012-01-01

    We present a new, preparation-free method for measuring the leakage current density on ultra-shallow junctions. The junction leakage is found by making a series of four-point sheet resistance measurements on blanket wafers with variable electrode spacings. The leakage current density is calculate...

  9. How good are one-dimensional Josephson junction models?

    DEFF Research Database (Denmark)

    Lomdahl, P. S.; Olsen, O.H.; Eilbeck, J. C.

    1985-01-01

    A two-dimensional model of Josephson junctions of overlap type is presented and shown to reduce to the usual one-dimensional (1D) model in the limit of a very narrow junction. Comparisons between the stability limits for fluxon reflection obtained from the two models suggest that the many results...

  10. Relaxation towards phase-locked dynamics in long Josephson junctions

    DEFF Research Database (Denmark)

    Salerno, M.; Grønbech-Jensen, Niels; Samuelsen, Mogens Rugholm

    1995-01-01

    We study the relaxation phenomenon towards phase-locked dynamics in long Josephson junctions. In particular the dependence of the relaxation frequency for the equal time of flight solution on the junction parameters is derived. The analysis is based on a phase-locked map and is compared with dire...

  11. Processing of Superconductor-Normal-Superconductor Josephson Edge Junctions

    Science.gov (United States)

    Kleinsasser, A. W.; Barner, J. B.

    1997-01-01

    The electrical behavior of epitaxial superconductor-normal-superconductor (SNS) Josephson edge junctions is strongly affected by processing conditions. Ex-situ processes, utilizing photoresist and polyimide/photoresist mask layers, are employed for ion milling edges for junctions with Yttrium-Barium-Copper-Oxide (YBCO) electrodes and primarily Co-doped YBCO interlayers.

  12. 75 FR 76294 - Radio Broadcasting Services: Pacific Junction, IA

    Science.gov (United States)

    2010-12-08

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 Radio Broadcasting Services: Pacific Junction, IA AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: The staff deletes FM Channel 299C2 at Pacific Junction,...

  13. Shunted-Josephson-junction model. I. The autonomous case

    DEFF Research Database (Denmark)

    Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

    1977-01-01

    of the junction behavior in different regions of the parameter space. Approximate formulas are given for the parameter-space decomposition into regions of qualitatively different junction behavior corroborated by the associated-phase plane portraits and also approximate expressions for the corresponding dc...

  14. Gap junction protein connexin-43 interacts directly with microtubules

    NARCIS (Netherlands)

    Giepmans, B N; Verlaan, I; Hengeveld, T; Janssen, H; Calafat, J; Falk, M M; Moolenaar, W H

    2001-01-01

    Gap junctions are specialized cell-cell junctions that mediate intercellular communication. They are composed of connexin proteins, which form transmembrane channels for small molecules [1, 2]. The C-terminal tail of connexin-43 (Cx43), the most widely expressed connexin member, has been implicated

  15. Septal Junctions in Filamentous Heterocyst-Forming Cyanobacteria.

    Science.gov (United States)

    Flores, Enrique; Herrero, Antonia; Forchhammer, Karl; Maldener, Iris

    2016-02-01

    In the filaments of heterocyst-forming cyanobacteria, septal junctions that traverse the septal peptidoglycan join adjacent cells, allowing intercellular communication. Perforations in the septal peptidoglycan have been observed, and proteins involved in the formation of such perforations and putative protein components of the septal junctions have been identified, but their relationships are debated.

  16. Vortex dynamics in Josephson ladders with II-junctions

    DEFF Research Database (Denmark)

    Kornev, Victor K.; Klenov, N. V.; Oboznov, V.A.;

    2004-01-01

    Both experimental and numerical studies of a self-frustrated triangular array of pi-junctions are reported. The array of SFS Josephson junctions shows a transition to the pi-state and self-frustration with a decrease in temperature. This manifests itself in a half-period shift of the bias critica...

  17. Determination of Relaxation Time of a Josephson Tunnel Junction

    Institute of Scientific and Technical Information of China (English)

    WEN Xue-Da; YU Yang

    2008-01-01

    We propose a non-stationary method to measure the energy relaxation time of Josephson tunnel junctions from microwave enhanced escape phenomena.Compared with the previous methods,our method possesses simple and accurate features.Moreover,having determined the energy relaxation time,we can further obtain the coupling strength between the microwave source and the junction by changing the microwave power.

  18. Shunted-Josephson-junction model. II. The nonautonomous case

    DEFF Research Database (Denmark)

    Belykh, V. N.; Pedersen, Niels Falsig; Sørensen, O. H.

    1977-01-01

    The shunted-Josephson-junction model with a monochromatic ac current drive is discussed employing the qualitative methods of the theory of nonlinear oscillations. As in the preceding paper dealing with the autonomous junction, the model includes a phase-dependent conductance and a shunt capacitance...

  19. Conditions for synchronization in Josephson-junction arrays

    Energy Technology Data Exchange (ETDEWEB)

    Chernikov, A.A.; Schmidt, G. [Stevens Institute of Technology, Hoboken, NJ (United States)

    1995-12-31

    An effective perturbation theoretical method has been developed to study the dynamics of Josephson Junction series arrays. It is shown that the inclusion of Junction capacitances, often ignored, has a significant impact on synchronization. Comparison of analytic with computational results over a wide range of parameters shows excellent agreement.

  20. Hepatic expression of detoxification enzymes is decreased in human obstructive cholestasis due to gallstone biliary obstruction.

    Directory of Open Access Journals (Sweden)

    Jin Chai

    Full Text Available Levels of bile acid metabolic enzymes and membrane transporters have been reported to change in cholestasis. These alterations (e.g. CYP7A1 repression and MRP4 induction are thought to be adaptive responses that attenuate cholestatic liver injury. However, the molecular mechanisms of these adaptive responses in human obstructive cholestasis due to gallstone biliary obstruction remain unclear.We collected liver samples from cholestatic patients with biliary obstruction due to gallstones and from control patients without liver disease (n = 22 per group. The expression levels of bile acid synthetic and detoxification enzymes, membrane transporters, and the related nuclear receptors and transcriptional factors were measured.The levels of bile acid synthetic enzymes, CYP7B1 and CYP8B1, and the detoxification enzyme CYP2B6 were increased in cholestatic livers by 2.4-fold, 2.8-fold, and 1.9-fold, respectively (p<0.05. Conversely, the expression levels of liver detoxification enzymes, UGT2B4/7, SULT2A1, GSTA1-4, and GSTM1-4, were reduced by approximately 50% (p<0.05 in human obstructive cholestasis. The levels of membrane transporters, OSTβ and OCT1, were increased 10.4-fold and 1.8-fold, respectively, (p<0.05, whereas those of OSTα, ABCG2 and ABCG8 were all decreased by approximately 40%, (p<0.05 in human cholestatic livers. Hepatic nuclear receptors, VDR, HNF4α, RXRα and RARα, were induced (approximately 2.0-fold, (p<0.05 whereas FXR levels were markedly reduced to 44% of control, (p<0.05 in human obstructive cholestasis. There was a significantly positive correlation between the reduction in FXR mRNA and UGT2B4/7, SULT2A1, GSTA1, ABCG2/8 mRNA levels in livers of obstructive cholestatic patients (p<0.05.The levels of hepatic detoxification enzymes were significantly decreased in human obstructive cholestasis, and these decreases were positively associated with a marked reduction of FXR levels. These findings are consistent with impaired

  1. Hypertrophic cardiomyopathy with mid-ventricular obstruction and apical aneurysm

    Directory of Open Access Journals (Sweden)

    N.D. Oryshchyn

    2016-11-01

    Full Text Available A case report of apical left ventricular aneurysm in patient with hypertrophic cardiomyopathy with mid-ventricular obstruction (diagnosis and surgical treatment is presented. We revealed apical aneurysm and mid-ventricular obstruction during echocardiography and specified anatomical characteristics of aneurysm during computer tomography. There was no evidence of obstructive coronary artery disease during coronary angiography. Taking into consideration multiple cerebral infarcts, aneurysm resection and left ventricular plastics was performed. Electronic microscopy of myocardium confirmed the diagnosis of hypertrophic cardiomyopathy.

  2. Acute intestinal pseudo-obstruction (Ogilvie's syndrome: A case report

    Directory of Open Access Journals (Sweden)

    Navas Nadukkandiyil, MD

    2014-12-01

    Full Text Available Acute colonic pseudo-obstruction, also known as Ogilvie's syndrome, is an acute clinical condition with clinical and radiological features of an acute large bowel obstruction in the absence of any mechanical cause. Patients presenting with Ogilvie's syndrome usually have underlying medical and surgical conditions predisposing them to the syndrome. In this article, we describe an elderly patient who presented with acute colonic pseudo-obstruction without any apparent cause.

  3. Multiple giant diverticula of the foregut causing upper gastrointestinal obstruction

    Institute of Scientific and Technical Information of China (English)

    Genoveffa Balducci; Mario Dente; Giulia Cosenza; Paolo Mercantini; Pier Federico Salvi

    2008-01-01

    Small bowel diverticulosis represents an uncommon disorder (except for Meckel diverticulum) often misdiagnosed since it causes non-specific gastrointestinal symptoms.Most of times the diagnosis is carried out in case of related complications,such as diverticulitis,hemorrhage,perforation or obstruction.Intestinal obstruction can be caused by inflammatory stenosis due to repeated episodes of diverticulitis,volvulus,intussusception or jejunal stones.Herein we report a case of multiple jejunal diverticula causing chronic gastrointestinal obstruction.

  4. Fetal tracheolaryngeal airway obstruction: prenatal evaluation by sonography and MRI

    Science.gov (United States)

    Courtier, Jesse; Poder, Liina; Wang, Zhen J.; Westphalen, Antonio C.; Yeh, Benjamin M.

    2010-01-01

    We reviewed the sonographic and MRI findings of tracheolaryngeal obstruction in the fetus. Conditions that can cause tracheolaryngeal obstruction include extrinsic causes such as lymphatic malformation, cervical teratoma and vascular rings and intrinsic causes such as congenital high airway obstruction syndrome (CHAOS). Accurate distinction of these conditions by sonography or MRI can help facilitate parental counseling and management, including the decision to utilize the ex utero intrapartum treatment (EXIT) procedure. PMID:20737145

  5. Intestinal obstruction caused by Taenia taeniaeformis infection in a cat.

    Science.gov (United States)

    Wilcox, Rebbecca S; Bowman, Dwight D; Barr, Stephen C; Euclid, James M

    2009-01-01

    An adult domestic shorthair (DSH) cat was presented with acute vomiting, anorexia, lethargy, and dyspnea. The cat's clinical status worsened over 24 hours with conservative medical management. An exploratory celiotomy was performed. Acute intestinal obstruction resulting from infection with Taenia (T.) taeniaeformis was diagnosed. Surgical removal of the cestodes via multiple enterotomies resolved the obstruction. This paper reports, for the first time, small intestinal obstruction caused by T. taeniaeformis infection in a cat.

  6. Fetal tracheolaryngeal airway obstruction: prenatal evaluation by sonography and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Courtier, Jesse; Poder, Liina; Wang, Zhen J.; Westphalen, Antonio C.; Yeh, Benjamin M.; Coakley, Fergus V. [University of California San Francisco, Department of Radiology, San Francisco, CA (United States)

    2010-11-15

    We reviewed the sonographic and MRI findings of tracheolaryngeal obstruction in the fetus. Conditions that can cause tracheolaryngeal obstruction include extrinsic causes such as lymphatic malformation, cervical teratoma and vascular rings and intrinsic causes such as congenital high airway obstruction syndrome (CHAOS). Accurate distinction of these conditions by sonography or MRI can help facilitate parental counseling and management, including the decision to utilize the ex utero intrapartum treatment (EXIT) procedure. (orig.)

  7. Internal resonances in periodically modulated long Josephson junctions

    DEFF Research Database (Denmark)

    Larsen, Britt Hvolbæk; Mygind, Jesper; Ustinov, Alexey V.

    1995-01-01

    Current-voltage (I-V) characteristics of long Josephson junctions with a periodic lattice of localized inhomogeneities are studied. The interaction between the moving fluxons and the inhomogeneities causes resonant steps in the IV-curve. Some of these steps are due to a synchronization to resonan...... into account the interaction between the resonance in the sub-junction and the magnetic flux density waves excited in the whole junction is given....... Fiske modes in the sub-junctions formed between the inhomogeneities. The voltage positions of the resonant steps oscillate as function of the applied magnetic field with a period corresponding to the inclusion of one magnetic flux quantum, Φ0=h/2e, per sub-junction. A qualitative explanation that takes...

  8. Parametric resonance in the system of long Josephson junctions

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Irie, A.

    2014-08-01

    The phase dynamics of the system of long Josephson junctions whose length exceeds the Josephson penetration depth has been studied. The possibility of the appearance of a longitudinal plasma wave and parametric resonance has been demonstrated. Both inductive and capacitive couplings between Josephson junctions have been taken into account in the calculations. The current-voltage characteristics, as well as time evolution of the spatial distribution of the electric charge in superconducting layers and the magnetic field, have been calculated in all Josephson junctions of the system. The coexistence of the longitudinal plasma wave and fluxon states has been observed in the region of parametric resonance beginning with a certain length of the Josephson junction. This indicates the appearance of a new unique collective excitation in the system of coupled Josephson junctions, namely, a composite state of the Josephson current, electric field, and vortex magnetic field.

  9. Design of Steerable Wavelets to Detect Multifold Junctions.

    Science.gov (United States)

    Püspöki, Zsuzsanna; Uhlmann, Virginie; Vonesch, Cédric; Unser, Michael

    2016-02-01

    We propose a framework for the detection of junctions in images. Although the detection of edges and key points is a well examined and described area, the multiscale detection of junction centers, especially for odd orders, poses a challenge in pattern analysis. The goal of this paper is to build optimal junction detectors based on 2D steerable wavelets that are polar-separable in the Fourier domain. The approaches we develop are general and can be used for the detection of arbitrary symmetric and asymmetric junctions. The backbone of our construction is a multiscale pyramid with a radial wavelet function where the directional components are represented by circular harmonics and encoded in a shaping matrix. We are able to detect M -fold junctions in different scales and orientations. We provide experimental results on both simulated and real data to demonstrate the effectiveness of the algorithm.

  10. Observation of supercurrent in graphene-based Josephson junction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Libin; Li, Sen; Kang, Ning [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Xu, Chuan; Ren, Wencai [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2015-07-01

    Josephson junctions with a normal metal region sandwiched between two superconductors (S) are known as superconductor- normal-superconductor (SNS) structures. It has attracted significant attention especially when changing the normal metal with graphene, which allow for high tunability with the gate voltage and to study the proximity effect of the massless Dirac fermions. Here we report our work on graphene-based Josephson junction with a new two dimensional superconductor crystal, which grown directly on graphene, as superconducting electrodes. At low temperature, we observer proximity effect induced supercurrent flowing through the junction. The temperature and the magnetic field dependences of the critical current characteristics of the junction are also studied. The critical current exhibits a Fraunhofer-type diffraction pattern against magnetic field. Our experiments provided a new route of fabrication of graphene-based Josephson junction.

  11. Low conductance of nickel atomic junctions in hydrogen atmosphere

    Science.gov (United States)

    Li, Shuaishuai; Xie, Yi-Qun; Hu, Yibin

    2017-08-01

    The low conductance of nickel atomic junctions in the hydrogen environment is studied using the nonequilibrium Green's function theory combined with first-principles calculations. The Ni junction bridged by a H2 molecule has a conductance of approximately 0.7 G 0. This conductance is contributed by the anti-bonding state of the H2 molecule, which forms a bonding state with the 3 d orbitals of the nearby Ni atoms. In contrast, the Ni junction bridged by the two single H atoms has a conductance of approximately 1 G 0, which is weakly spin-polarized. The spin-up channels were found to contribute mostly to the conductance at a small junction gap, while the spin-down channels play a dominant role at a larger junction gap.

  12. Visualizing supercurrents in 0-{pi} ferromagnetic Josephson tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Goldobin, Edward; Guerlich, Christian; Gaber, Tobias; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena, Universitaet Tuebingen (Germany); Weides, Martin; Kohlstedt, Hermann [Institute of Solid State Physics, Reserch Center Juelich (Germany)

    2009-07-01

    So-called 0 and {pi} Josephson junctions can be treated as having positive and negative critical currents. This implies that the same phase shift applied to a Josephson junction causes counterflow of supercurrents in 0 and in {pi} junctions connected in parallel provided they are short in comparison with Josephson penetration depth {lambda}{sub J}. We have fabricated several 0, {pi}, 0-{pi}, 0-{pi}-0 and 20 x (0-{pi}-) planar superconductor-insulator-ferromagnet-superconductor Josephson junctions and studied the spatial supercurrent density distribution j{sub s}(x,y) across the junction area using low temperature scanning electron microscopy. At zero magnetic field we clearly see counterflow of the supercurrents in 0 and {pi} regions. The picture also changes consistently in the applied magnetic field.

  13. The current-phase relation in HTS Josephson junctions

    Science.gov (United States)

    Il'ichev, E.; Zakosarenko, V.; Ijsselsteijn, R. P. J.; Schultze, V.; Meyer, H.-G.; Hoenig, H. E.

    The current-phase relation of YBa2Cu3O7-x step-edge as well as 24° and 45° grain boundary Josephson junctions has been investigated experimentally. The junctions were incorporated into a washer-shaped superconducting ring with inductance L≈80-300 pH. The ring was inductively coupled to a tank circuit with a resonance frequency 9…40 MHz. The current-phase relation was obtained from the measurement of the impedance of the phase-biased junction. It is shown, that experimentally observed deviations from harmonic behavior of the apparent current-phase relation for step-edge and 24° grain boundary junctions can be explained by the influence of thermal noise. The current-phase relation of 45° grain boundary junctions was found to be extremely non-harmonic. The reasons of this unusual behavior are discussed.

  14. Glial connexins and gap junctions in CNS inflammation and disease.

    Science.gov (United States)

    Kielian, Tammy

    2008-08-01

    Gap junctions facilitate direct cytoplasmic communication between neighboring cells, facilitating the transfer of small molecular weight molecules involved in cell signaling and metabolism. Gap junction channels are formed by the joining of two hemichannels from adjacent cells, each composed of six oligomeric protein subunits called connexins. Of paramount importance to CNS homeostasis are astrocyte networks formed by gap junctions, which play a critical role in maintaining the homeostatic regulation of extracellular pH, K+, and glutamate levels. Inflammation is a hallmark of several diseases afflicting the CNS. Within the past several years, the number of publications reporting effects of cytokines and pathogenic stimuli on glial gap junction communication has increased dramatically. The purpose of this review is to discuss recent observations characterizing the consequences of inflammatory stimuli on homocellular gap junction coupling in astrocytes and microglia as well as changes in connexin expression during various CNS inflammatory conditions.

  15. Fixed-gap tunnel junction for reading DNA nucleotides.

    Science.gov (United States)

    Pang, Pei; Ashcroft, Brian Alan; Song, Weisi; Zhang, Peiming; Biswas, Sovan; Qing, Quan; Yang, Jialing; Nemanich, Robert J; Bai, Jingwei; Smith, Joshua T; Reuter, Kathleen; Balagurusamy, Venkat S K; Astier, Yann; Stolovitzky, Gustavo; Lindsay, Stuart

    2014-12-23

    Previous measurements of the electronic conductance of DNA nucleotides or amino acids have used tunnel junctions in which the gap is mechanically adjusted, such as scanning tunneling microscopes or mechanically controllable break junctions. Fixed-junction devices have, at best, detected the passage of whole DNA molecules without yielding chemical information. Here, we report on a layered tunnel junction in which the tunnel gap is defined by a dielectric layer, deposited by atomic layer deposition. Reactive ion etching is used to drill a hole through the layers so that the tunnel junction can be exposed to molecules in solution. When the metal electrodes are functionalized with recognition molecules that capture DNA nucleotides via hydrogen bonds, the identities of the individual nucleotides are revealed by characteristic features of the fluctuating tunnel current associated with single-molecule binding events.

  16. The results of 15 years of consistent strategy in treating antenatally suspected pelvi-ureteric junction obstruction

    DEFF Research Database (Denmark)

    Thorup, J; Jokela, R; Cortes, D

    2003-01-01

    in the hydronephrotic kidney, with 49 followed for 1-10 years with no change in kidney function and no symptoms. Twelve patients in this group had later surgery (at 0.7-8 years old) because of pyelonephritis (four), pain and/or renal functional impairment (eight, three of whom had normal function afterward). Thirty...

  17. Shear Modulus of the Partially Obstructed Rat Small Intestine

    DEFF Research Database (Denmark)

    Sun, Daming; Zhao, Jingbo; Liao, Donghua;

    2016-01-01

    A number of factors influence gastrointestinal tissue structure and mechanical properties such as the physical environment and diseases like partial obstruction. Hence multi-axial biomechanical properties are important for understanding the pathophysiology of the obstructed intestine. The aim......-cm intestinal segments were used for histological and mechanical analysis. The segments were obtained distal (S1), proximal (S2) and further proximal (S3) to the site of obstruction or suturing site. The tri-axial testing included simultaneous torsion, inflation and longitudinal stretching. The lumen...... and longitudinal direction where as it was softer in shear direction, especially in S2 (p intestinal obstruction site....

  18. A DEMOGRAPHIC, CLINICAL AND SURGICAL STUDY OF OBSTRUCTED INGUINAL HERNIA

    Directory of Open Access Journals (Sweden)

    Mohammed Imran Khaleel

    2016-11-01

    Full Text Available BACKGROUND An obstructed inguinal hernia means the inguinal hernia is associated with intestinal obstruction due to occlusion of lumen of bowel. A distinguishing feature of strangulated hernia is the bowel's blood supply is not compromised. Intestinal obstruction is absent in case of omentocele, Richter's hernia and Littre's hernia. In this study, a sincere effort has been made to study and understand an obstructed inguinal hernia. This study is intended to help the practicing surgeon to understand the complications and to take necessary actions. MATERIALS AND METHODS  Eighty cases of obstructed inguinal hernia were studied between June 2009 to September 2011.  This study has been conducted from the patients of Deccan College of Medical Sciences admitted during the above period.  Out of 80 cases for follow up after discharge, 25 cases were reviewed. RESULTS  The incidence of obstruction in inguinal hernia is 7.9% in this study.  Obstructed inguinal hernia is more common in age group 20-50 yrs. of age.  It is 80 times more common in males. Male-to-female ratio is 79:1.  There is right-sided preponderance. Obstruction occurs in ratio of 3:1 on right and left sides. CONCLUSION A study of common surgical emergency- obstructed inguinal hernia was presented. Anatomy, pathophysiology, aetiological factors, clinical features and complications were noted.

  19. Microscopic hematuria and calculus-related ureteral obstruction.

    Science.gov (United States)

    Stewart, D P; Kowalski, R; Wong, P; Krome, R

    1990-01-01

    The evaluation of patients with ureteral calculi in the emergency department has historically included urinalysis (UA) and intravenous pyelograms (IVP). This retrospective study was done to determine if a statistically significant relationship existed between the degree of calculus-related ureteral obstruction, proven by IVP, and the presence or absence of microscopic hematuria. Urine red blood cells were recorded as less than 3 rbc/hpf (negative) or greater than or equal to 3 rbc/hpf (positive). IVPs were recorded as nonsevere or severe. IVP criteria were based on the presence or absence of extravasation, greater than 2-hour ureteral filling times, and a numerical scoring system of 1 to 4 for ureteral or calyceal dilatation and nephrogenic effect. Eighty-nine men (72%) had non-severe obstructions and 34 (28%) had severe obstructions. Twenty-five women (68%) had nonsevere obstructions and 12 (32%) had severe obstructions. Of the 28 patients with normal UAs, 11 had severe ureteral obstructions and 17 had nonsevere ureteral obstructions. There were no statistically significant differences between the presence or absence of significant microscopic hematuria and the presence or absence of severe ureteral obstruction. Microscopic hematuria is neither sensitive nor specific in determining the degree of calculus-related ureteral obstruction.

  20. Obturator hernia: An uncommon cause of small bowel obstruction

    Directory of Open Access Journals (Sweden)

    S Shreshtha

    2016-01-01

    Full Text Available A 70 year old lady presented to surgery emergency with small bowel obstruction without any obvious etiology. On exploration she was found to have an obstructed obturator hernia, which is a rare pelvic hernia with an incidence of 0.07-1.4% of all intra-abdominal hernias. Diagnosis is often delayed until laparotomy for bowel obstruction. Strangulation is frequent and mortality remains high (25%. Early diagnosis and surgical treatment contributes greatly to reduce the mortality and morbidity rates. A variety of techniques have been described, however surgical repair has not been standardized. It is an important diagnosis to be considered in elderly patients with intestinal obstruction.

  1. High prevalence of obstructive sleep apnea in Marfan's syndrome

    Institute of Scientific and Technical Information of China (English)

    Mo Li; He Quanying; Wang Yinna; Dong Birong; He Jinhan

    2014-01-01

    Objective To review the current evidence about the prevalence of obstructive sleep apnea in patients with Marfan's syndrome,and discuss some proposed potential mechanisms for this relationship.Data sources The data in this review were mainly from Medline and PubMed articles published in English from 1990 to 2013.The search term was "Marfan's syndrome and sleep apnea".Study selection Clinical evidence about the epidemiology of obstructive sleep apnea in patients with Marfan's syndrome; the mechanism that causes obstructive sleep apnea; interventional therapy for patients with Marfan's syndrome,and coexisting obstructive sleep apnea.Results A high prevalence of obstructive sleep apnea exists in patients with Marfan's syndrome.The potential reasons are craniofacial abnormalities and lax upper airway muscles,which lead to high nasal airway resistance and upper airway collapse.Obstructive sleep apnea mechanically deteriorates aortic dilatation and accelerates progression of aortic aneurysms.The condition is reversible and rapid maxillary expansion and adequate continuous positive airway pressure therapy are possible effective therapies to delay the expansion of aortic diameter in patients with Marfan's syndrome.Conclusions Obstructive sleep apnea is strongly associated with Marfan's syndrome.Craniofacial abnormalities and lax upper airway are the main mechanisms.Untreated obstructive sleep apnea accelerates progression of aortic dissection and rupture.Effective therapies for obstructive sleep apnea could postpone the aortic dilatation in patients with Marfan's syndrome.

  2. Scintigraphic Demonstration of Urine Extravasation Secondary to Acute Ureteral Obstruction: A Case Report and Some Considerations about Acute Ureteral Obstruction

    Directory of Open Access Journals (Sweden)

    Federico M. Sarmiento

    2006-01-01

    Full Text Available Acute ureteral obstruction produces renal damage and complications that are proportional to the severity and length of the obstruction. Anatomic diagnosis of the obstruction may be insufficient to manage the patient. Intravenous urogram (IVU is the method usually advised by radiologists to obtain functional information, but requires iodinated contrast agents. IVU anatomic information is superior to anatomic information obtained with renal scintigraphy, but normally the physician already has the anatomic information (unenhanced CT or ultrasound. A renal scan offers better physiologic information than the IVU, has neither adverse effects nor complications, is accurate to confirm or discard significant ureteral obstruction, and depicts obstruction complications. This paper presents a patient with spontaneous urine extravasation secondary to acute renal obstruction who is diagnosed with renal scintigraphy. The authors describe the scintigraphic signs of extraperitoneal, diffuse perinephric, urine extravasation and emphasize the role of renal scintigraphy in diagnosis and follow-up of renal colic.

  3. Scattering form factors for self-assembled network junctions

    Science.gov (United States)

    Foster, T.; Safran, S. A.; Sottmann, T.; Strey, R.

    2007-11-01

    The equilibrium microstructures in microemulsions and other self-assembled systems show complex, connected shapes such as symmetric bicontinuous spongelike structures and asymmetric bicontinuous networks formed by cylinders interconnected at junctions. In microemulsions, these cylinder network microstructures may mediate the structural transition from a spherical or globular phase to the bicontinuous microstructure. To understand the structural and statistical properties of such cylinder network microstructures as measured by scattering experiments, models are needed to extract the real-space structure from the scattering data. In this paper, we calculate the scattering functions appropriate for cylinder network microstructures. We focus on such networks that contain a high density of network junctions that connect the cylindrical elements. In this limit, the network microstructure can be regarded as an assembly of randomly oriented, closed packed network junctions (i.e., the cylinder scattering contributions are neglected). Accordingly, the scattering spectrum of the network microstructure can be calculated as the product of the junction number density, the junction form factor, which describes the scattering from the surface of a single junction, and a structure factor, which describes the local correlations of different junctions due to junction interactions (including their excluded volume). This approach is applied to analyze the scattering data from a bicontinuous microemulsion with equal volumes of water and oil. In a second approach, we included the cylinder scattering contribution in the junction form factor by calculating the scattering intensity of Y junctions to which three rods with spherical cross section are attached. The respective theoretical predictions are compared with results of neutron scattering measurements on a water-in-oil microemulsion with a connected microstructure.

  4. Influence of Coupling between Junctions on Breakpoint Current in Intrinsic Josephson Junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Mahfouzi, F.

    2007-04-01

    We study theoretically the current-voltage characteristics of intrinsic Josephson junctions in high-Tc superconductors. An oscillation of the breakpoint current on the outermost branch as a function of coupling α and dissipation β parameters is found. We explain this oscillation as a result of the creation of longitudinal plasma waves at the breakpoint with different wave numbers. We demonstrate the commensurability effect and predict a group behavior of the current-voltage characteristics for the stacks with a different number of junctions. A method to determine the wave number of longitudinal plasma waves from α and β dependence of the breakpoint current is suggested. We model the α and β dependence of the breakpoint current and obtain good agreement with the results of the simulation.

  5. Ruptured venous aneurysm of cervicomedullary junction

    Directory of Open Access Journals (Sweden)

    Ashish Aggarwal

    2014-01-01

    Full Text Available Background: Ruptured venous aneurysm is often seen with arterio-venous malformation (AVM or developmental venous anomaly (DVA. However, isolated venous aneurysm is unusual. Case Description: We present a case of ruptured venous aneurysm that presented with subarachnoid hemorrhage (SAH and intraventricular hemorrhage (IVH. Digital substraction angiography (DSA revealed a saccular contrast filling pouch in the left lateral aspect of cervicomedullary junction (CMJ. Endovascular intervention was not a viable option. During surgery, a saccular pliable structure approx. 1.5 Χ 1 cm was found in the subarachnoid space that was clipped and excised. There were no arterial feeders, no evidence of surrounding AVM, and no dilated perimedullary vein. Conclusion: This is perhaps the first reported case of ruptured venous aneurysm (without associated AVM of CMJ, which was successfully managed surgically. The possible etiologies remain an unnoticed head trauma or a congenital vessel wall abnormality. Surgically clipping and excision remains the treatment of choice for such lesion.

  6. Nonlinear nonequilibrium quasiparticle relaxation in Josephson junctions.

    Science.gov (United States)

    Krasnov, V M

    2009-11-27

    I solve numerically a full set of nonlinear kinetic balance equations for stacked Josephson junctions, which allows analysis of strongly nonequilibrium phenomena. It is shown that nonlinearity becomes significant already at very small disequilibrium. The following new, nonlinear effects are obtained: (i) At even-gap voltages V = 2nDelta/e (n = 2, 3, ...) nonequilibrium bosonic bands overlap. This leads to enhanced emission of Omega = 2Delta bosons and to the appearance of dips in tunnel conductance. (ii) A new type of radiative solution is found at strong disequilibrium. It is characterized by the fast stimulated relaxation of quasiparticles. A stack in this state behaves as a light emitting diode and directly converts electric power to boson emission, without utilization of the ac-Josephson effect. The phenomenon can be used for realization of a new type of superconducting cascade laser in the THz frequency range.

  7. Fully magnetic manganite spin filter tunnel junctions

    Science.gov (United States)

    Prasad, Bhagwati; Blamire, Mark G.

    2016-09-01

    In this paper we demonstrate spintronic devices which combine magnetic tunnel junctions with a spin-filtering tunnel barrier. These consist of an ultrathin ferromagnetic insulating barrier, Sm0.75Sr0.25MnO3, sandwiched between two ferromagnetic half-metallic manganite electrodes, La0.7Sr0.3MnO3 and La0.7Ca0.3MnO3, in a nanopillar structure. Depending on the relative magnetic configurations of barrier and electrode layers, three resistance states are well defined, which therefore represent a potential three-state memory concept. These results open the way for the development of spintronic devices by exploiting the many degrees of freedom of perovskite manganite heterostructure systems.

  8. Electron and Phonon Transport in Molecular Junctions

    DEFF Research Database (Denmark)

    Li, Qian

    transmission at the Fermi energy. We propose and analyze a way of using π   stacking to design molecular junctions to control heat transport. We develop a simple model system to identify optimal parameter regimes and then use density functional theory (DFT) to extract model parameters for a number of specific....... The system we are interested in here are π-stacked molecules connected with two semi-infinite leads. π-stacked aromatic rings, connected via π-π electronic coupling, provides a rather soft mechanical bridge while maintaining high electronic conductivity. We investigate electron transport...... and the thermoelectric response of five representative π-stacked systems. We find that the transmission and power factor are both enhanced by increasing the conjugation length or adding substituent groups. The local transmission shows that several extra paths are added by cyano groups, which increases the total...

  9. Electronic transport properties of phenylacetylene molecular junctions

    Institute of Scientific and Technical Information of China (English)

    Liu Wen; Cheng Jie; Yah Cui-Xia; Li Hai-Hong; Wang Yong-Juan; Liu De-Sheng

    2011-01-01

    Electronic transport properties of a kind of phenylacetylene compound- (4-mercaptophenyl)-phenylacetylene are calculated by the first-principles method in the framework of density functional theory and the nonequilibrium Green's function formalism.The molecular junction shows an obvious rectifying behaviour at a bias voltage larger than 1.0 V.The rectification effect is attributed to the asymmetry of the interface contacts.Moreover,at a bias voltage larger than 2.0 V,which is not referred to in a relevant experiment [Fang L,Park J Y,Ma H,Jan A K Y and Salmeron M 2007 Langmuir 23 11522],we find a negative differential resistance phenomenon.The negative differential resistance effect may originate from the change of the delocalization degree of the molecular orbitais induced by the bias.

  10. Functional oesophago-gastric junction imaging

    Institute of Scientific and Technical Information of China (English)

    Barry P McMahon; Asbj(φ)rn M Drewes; Hans Gregersen

    2006-01-01

    Despite its role in disease there is still no definitive method to assess oesophago-gastric junction competence (OGJ). Traditionally the OGJ has been assessed using manometry with lower oesophageal sphincter pressure as the indicator. More recently this has been shown not to be a very reliable marker of sphincter function and competence against reflux.Disorders such as gastro-oesophageal reflux disease and to a lesser extend achalasia still effects a significant number of patients. This review looks at using a new technique known as impedance planimetry to profile the geometry and pressure in the OGJ during distension of a bag. The data gathered can be reconstructed into a dynamic representation of OGJ action. This has been shown to provide a useful representation of the OGJ and to show changes to the competence of the OGJ in terms of compliance and distensibility as a result of endoluminal therapy.

  11. Shot Noise in Ferromagnetic Superconductor Tunnel Junctions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, the superconducting order parameter and the energy spectrum of the Bogoliubov excitations are obtained from the Bogoliubov-de Gennes (BdG) equation for a ferromagnetic superconductor (FS). Taking into account the rough interface scattering effect, we calculate the shot noise and the differential conductance of the normal- metal insulator ferromagnetic superconductor junction. It is shown that the exchange energy Eh in FS can lead to splitting of the differential shot noise peaks and the conductance peaks. The energy difference between the two splitting peaks is equal to 2Eh. The rough interface scattering strength results in descent of conductance peaks and the shot noise-to-current ratio but increases the shot noise.

  12. Permanent junctional reciprocating tachycardia in a dog.

    Science.gov (United States)

    Santilli, Roberto A; Santos, Luis F N; Perego, Manuela

    2013-09-01

    A 5-year-old male English Bulldog was presented with a 1-year history of paroxysmal supraventricular tachycardia (SVT) partially responsive to amiodarone. At admission the surface ECG showed sustained runs of a narrow QRS complex tachycardia, with a ventricular cycle length (R-R interval) of 260 ms, alternating with periods of sinus rhythm. Endocardial mapping identified the electrogenic mechanism of the SVT as a circus movement tachycardia with retrograde and decremental conduction along a concealed postero-septal atrioventricular pathway (AP) and anterograde conduction along the atrioventricular node. These characteristics were indicative of a permanent junctional reciprocating tachycardia (PJRT). Radiofrequency catheter ablation of the AP successfully terminated the PJRT, with no recurrence of tachycardia on Holter monitoring at 12 months follow-up.

  13. Exotic Brane Junctions from F-theory

    CERN Document Server

    Kimura, Tetsuji

    2016-01-01

    Applying string dualities to F-theory, we obtain various $[p,q]$-branes whose constituents are standard branes of codimension two and exotic branes. We construct junctions of the exotic five-branes and their Hanany-Witten transitions associated with those in F-theory. In this procedure, we understand the monodromy of the single $5^2_2$-brane. We also find the objects which are sensitive to the branch cut of the $5^2_2$-brane. Considering the web of branes in the presence of multiple exotic five-branes analogous to the web of five-branes with multiple seven-branes, we obtain novel brane constructions for $SU(2)$ gauge theories with $n$ flavors and their superconformal limit with enhanced $E_{n+1}$ symmetry in five, four, and three dimensions. Hence, adapting the techniques of the seven-branes to the exotic branes, we will be able to construct F-theories in diverse dimensions.

  14. Operating modes of superconducting tunnel junction device

    Energy Technology Data Exchange (ETDEWEB)

    Maehata, Keisuke [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1998-07-01

    In the Electrotechnical Laboratory, an Nb type superconducting tunnel junction (STJ) device with 200 x 200 sq. micron in area and super high quality was manufactured. By using 55-fe source, response of this large area STJ to X-ray was measured. In this measurement, two action modes with different output wave height from front amplifier were observed. Then, in this study, current-voltage feature of the element in each action mode was analyzed to elucidate a mechanism to form such two action modes. The feature was analyzed by using first order approximate solution on cavity resonance mode of Sine-Gordon equation. From the analytical results, it could be supposed that direction and magnitude of effective magnetic field penetrating into jointed area changed by an induction current effect owing to impressing speed of the magnetic field, which brings two different current-voltage features to make possible to observe two action modes with different pulse wave height. (G.K.)

  15. Studies of silicon pn junction solar cells

    Science.gov (United States)

    Lindholm, F. A.; Neugroschel, A.

    1977-01-01

    Modifications of the basic Shockley equations that result from the random and nonrandom spatial variations of the chemical composition of a semiconductor were developed. These modifications underlie the existence of the extensive emitter recombination current that limits the voltage over the open circuit of solar cells. The measurement of parameters, series resistance and the base diffusion length is discussed. Two methods are presented for establishing the energy bandgap narrowing in the heavily-doped emitter region. Corrections that can be important in the application of one of these methods to small test cells are examined. Oxide-charge-induced high-low-junction emitter (OCI-HLE) test cells which exhibit considerably higher voltage over the open circuit than was previously seen in n-on-p solar cells are described.

  16. Tantalum oxide barrier in magnetic tunnel junctions

    Institute of Scientific and Technical Information of China (English)

    Guanghua Yu; Tingting Ren; Wei Ji; Jiao Teng; Fengwu Zhu

    2004-01-01

    Tantalum as an insulating barrier can take the place of Al in magnetic tunnel junctions (MTJs). Ta barriers in MTJs were fabricated by natural oxidation. X-ray photoelectron spectroscopy (XPS) was used to characterize the oxidation states of Ta barrier.The experimental results show that the chemical state of tantalum is pure Ta5+ and the thickness of the oxide is 1.3 nm. The unoxidized Ta in the barrier may chemically reacted with NiFe layer which is usually used in MTJs to form an intermetallic compound,NiTa2. A magnetic "dead layer" could be produced in the NiFe/Ta interface. The "dead layer" is likely to influence the spinning electron transport and the magnetoresistance effect.

  17. Controlling local currents in molecular junctions

    CERN Document Server

    Yadalam, Hari Kumar

    2016-01-01

    The effect of non-equilibrium constraints and dephasing on the circulating currents in molecular junctions are analyzed. Circulating currents are manifestations of quantum effects and can be induced either by externally applied bias or an external magnetic field through the molecular system. In symmetric Aharonov-Bohm ring, bond currents have two contributions, bias driven and magnetic field driven. We analyze the competition between these two contributions and show that, as a consequence, current through one of the branches can be completely suppressed. We then study the effect of asymmetry (as a result of chemical substitution) on the current pathways inside the molecule and study asymmetry induced circulating currents (without magnetic field) by tuning the coupling strength of the substituent (at finite bias).

  18. Tunable Magnetic Proximity Effects in Graphene Junctions

    Science.gov (United States)

    Lazic, Predrag; Belashchenko, Kirill; Zutic, Igor

    2015-03-01

    The characteristic length of the magnetic proximity effects exceed the thickness of a graphene layer leading to an important, but typically overlooked, modifications of equilibrium and transport properties, as well as the implications for graphene spintronics. Using the first-principles studies that integrate a real space density functional theory (GPAW) with the state-of-the art boundary elements electrostatic code based on the Robin Hood method, we explore tunable electronic structure and magnetic proximity effects in the ferromagnet/insulator/graphene junctions. We show that the inclusion of a finite-size gate electrodes and van der Walls interaction lead to nontrivial effects that could also be important in other two-dimensional materials beyond graphene. Work supported by US ONR, NSF-DMR and Nebraska NSF MRSEC.

  19. Computation of flow through the oesophagogastric junction

    Institute of Scientific and Technical Information of China (English)

    Barry P McMahon; Karl D Odie; Kenneth W Moloney; Hans Gregersen

    2007-01-01

    Whilst methods exist to indirectly measure the effects of increased flow or gastro-oesophageal refluxing,they cannot quantitatively measure the amount of acid travelling back up into the oesophagus during reflux, nor can they indicate the flow rate through the oesophagogastric junction (OGJ). Since OGJ dysfunction affects flow it seems most appropriate to describe the geometry of the OGJ and its effect on the flow.A device known as the functional lumen imaging probe (FLIP) has been shown to reliably measure the geometry of and pressure changes in the OGJ. FLIP cannot directly measure flow but the data gathered from the probe can be used to model flow through the junction by using computational flow dynamics (CFD).CFD uses a set of equations known as the Navier-Stokes equations to predict flow patterns and is a technique widely used in engineering. These equations are complex and require appropriate assumptions to provide simplifications before useful data can be obtained. With the assumption that the cross-sectional areas obtained via FLIP are circular, the radii of these circles can be obtained. A cubic interpolation scheme can then be applied to give a high-resolution geometry for the OGJ.In the case of modelling a reflux scenario, it can be seen that at the narrowest section a jet of fluid squirts into the oesophagus at a higher velocity than the fluid surrounding it. This jet has a maximum velocity of almost 2 ms-1 that occurs where the OGJ is at its narrowest. This simple prediction of acid 'squirting' into the oesophagus illustrates how the use of numerical methods can be used to develop a better understanding of the OGJ. This initial work using CFD shows some considerable promise for the future.

  20. Influence of coupling between junctions on breakpoint current in intrinsic Josephson junctions

    OpenAIRE

    Shukrinov, Yu M.; Mahfouzi, F.

    2006-01-01

    We study theoretically the current-voltage characteristics of intrinsic Josephson junctions in high-$T_c$ superconductors. An oscillation of the breakpoint current on the outermost branch as a function of coupling $\\alpha$ and dissipation $\\beta$ parameters is found. We explain this oscillation as a result of the creation of longitudinal plasma waves at the breakpoint with different wave numbers. We demonstrate the commensurability effect and predict a group behavior of the current-voltage ch...