Science.gov

Sample records for aortic caged ball-valve

  1. Echocardiographic features of aortic ball valve prosthesis malfunction.

    PubMed

    Weisburst, M R; Singh, A K; Riley, R S

    1982-11-01

    A case of aortic ball valve prosthesis malfunction is described in which the poppet became alternately stuck in the open and closed position. The patient experienced chest pain followed by pulmonary edema and cardiac arrest. Malfunction of prosthetic valve was diagnosed on echocardiogram and cardiopulmonary resuscitation was carried out until a Bjork-Shiley valve could be inserted in place of the faulty prosthesis. At the time of the operation, poppet migration had occurred and the poppet could not be found. Subsequent Bjork-Shiley aortic valve prosthesis dysfunction was suggested by variation in the intensity of the aortic opening sound and in the duration of the systolic ejection period. Fluoroscopy revealed the missing poppet in the left ventricle. Following surgical removal of the poppet, "normal" Bjork-Shiley valve function was restored.

  2. Ball valve extractor

    DOEpatents

    Herndon, Charles; Brown, Roger A.

    2002-01-01

    An apparatus and process for removing a ball valve is provided. The ball valve removal tool provides a handle sliding along the length of a shaft. One end of the shaft is secured within an interior cavity of a ball valve while the opposite end of the shaft defines a stop member. By providing a manual sliding force to the handle, the handle impacts the stop member and transmits the force to the ball valve. The direction of the force is along the shaft of the removal tool and disengages the ball valve from the ball valve housing.

  3. Stemless ball valve

    NASA Technical Reports Server (NTRS)

    Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

    2011-01-01

    A stemless ball valve comprising two flanges and a ball with a channel, two axis pins and two travel pins. One end of each axis and travel pin is fixedly attached to the ball, and the other end of each axis pin is lodged into a notch in the first or second flange such that the axis pin is allowed to rotate in the notch. The guide sleeve comprises two channels, and one end of each travel pin is situated within one of the two channels in the guide sleeve. An outer magnetic cartridge causes the inner magnetic cartridge and guide sleeve to rotate, and when the guide sleeve rotates, the travel pins move up and down within the channels in the guide sleeve. The movement of the travel pins within the channels in the guide sleeve causes the ball to rotate, thereby opening and closing the ball valve.

  4. Stemless Ball Valve

    NASA Technical Reports Server (NTRS)

    Burgess, Robert K.; Yakos, David; Walthall, Bryan

    2012-01-01

    This invention utilizes a new method of opening and closing a ball valve. Instead of rotating the ball with a perpendicular stem (as is the case with standard ball valves), the ball is rotated around a fixed axis by two guide pins. This innovation eliminates the leak point that is present in all standard ball valves due to the penetration of an actuation stem through the valve body. The VOST (Venturi Off-Set-Technology) valve has been developed for commercial applications. The standard version of the valve consists of an off-set venturi flow path through the valve. This path is split at the narrowest portion of the venturi, allowing the section upstream from the venturi to be rotated. As this rotation takes place, the venturi becomes restricted as one face rotates with respect to the other, eventually closing off the flow path. A spring-loaded seal made of resilient material is embedded in the upstream face of the valve, making a leak-proof seal between the faces; thus a valve is formed. The spring-loaded lip seal is the only seal that can provide a class six, or bubble-tight, seal against the opposite face of the valve. Tearing action of the seal by high-velocity gas on this early design required relocation of the seal to the downstream face of the valve. In the stemless embodiment of this valve, inner and outer magnetic cartridges are employed to transfer mechanical torque from the outside of the valve to the inside without the use of a stem. This eliminates the leak path caused by the valve stems in standard valves because the stems penetrate through the bodies of these valves.

  5. Quartz ball valve

    NASA Technical Reports Server (NTRS)

    Goetz, C.; Ingle, W. M. (Inventor)

    1980-01-01

    A ball valve particularly suited for use in the handling of highly corrosive fluids is described. It is characterized by a valve housing formed of communicating segments of quartz tubing, a pair of communicating sockets disposed in coaxial alignment with selected segments of tubing for establishing a pair of inlet ports communicating with a common outlet port, a ball formed of quartz material supported for displacement between the sockets and configured to be received alternately thereby, and a valve actuator including a rod attached to the ball for selectively displacing the ball relative to each of the sockets for controlling fluid flow through the inlet ports.

  6. Ball valve safety screen

    SciTech Connect

    Bolding, B.H.

    1981-09-01

    A device for preventing unwanted objects from entering the ball assembly of a float collar or float shoe and otherwise damaging or plugging the valve mechanism therein is disclosed. The device comprises a screen constructed of expanded metal and rigidly affixed to the interior of the float collar or float shoe above the ball valve assembly. The screen portion is either mounted to the interior surface of the float collar sleeve by an annular structural member or mounted to a structural band which is partially embedded in the concrete portion of the float collar or casing guide shoe.

  7. Stemless ball valve

    NASA Technical Reports Server (NTRS)

    Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

    2012-01-01

    A stemless ball valve comprising: a right flange; left flange; ball with an axis pin and two travel pins; ball seal on either side of the ball; guide sleeve with inner walls comprising two channels; cartridge guide holder; inner magnetic cartridge; and outer magnetic cartridge. The ball is situated inside of the guide sleeve, and a travel pin is located in each of the two channels. The guide sleeve is situated inside of the cartridge guide holder, which is located adjacent to and outside of the inner magnetic cartridge and secured to the inner magnetic cartridge such that when the inner magnetic cartridge rotates, the cartridge guide holder also rotates. The cartridge guide holder is secured to the guide sleeve such that when the cartridge guide holder rotates, the travel pins move within the channels in the inner walls of the guide sleeve, thereby causing the ball to rotate.

  8. The unnatural history of valvular heart disease: late results with silastic ball valve prostheses.

    PubMed

    Freimanis, I; Starr, A

    1984-01-01

    The development of prosthetic heart valves successfully arrested the dismal natural history of valvular heart disease for thousands of patients. The experiences of numerous investigators provided a setting wherein the design and implantation of the silastic ball valves led to improved survival with both aortic and mitral valve replacement. Refinement of the caged-ball design was based on clinical and laboratory findings. In the mitral position, valve related thromboembolism was reduced from 38% to 3%. With the aortic prostheses the problem of ball variance was overcome by reducing trauma to the poppet and altering its heat curing process. In 1967 a completely cloth covered valve was introduced to reduce further the thromboembolic rate. Significant improvement in the embolus-free rate was ultimately found to be dependent on the year of operation with introduction of the time-frame concept. The current mitral silastic ball valve, Model 6120, yields an actuarial survival of 72 (+/- 3%), 54 (+/- 5%), and 37 (+/- 5%) for five, ten and fifteen years respectively. For aortic valve replacement, current Model 1260, the actuarial survival is 71 (+/- 2%), 58 (+/- 3%) and 48 (+/- 4%) for five, ten and fifteen years respectively. Late results are compared to other valvular prostheses.

  9. 16. DETAIL SHOWING LIQUID OXYGEN TANK FOURTEENINCH BALL VALVE. Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. DETAIL SHOWING LIQUID OXYGEN TANK FOURTEEN-INCH BALL VALVE. Looking southwest. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  10. 17. DETAIL, FOURTEENINCH LIQUID OXYGEN BALL VALVE. Looking south southeast. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. DETAIL, FOURTEEN-INCH LIQUID OXYGEN BALL VALVE. Looking south southeast. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  11. Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

    NASA Technical Reports Server (NTRS)

    Lueders, Kathy; Buntain, Nick; Fries, Joseph (Technical Monitor)

    1999-01-01

    Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

  12. Acute tricuspid valve obstruction following the use of tricuspid ball valve prosthesis

    PubMed Central

    Samaan, H. A.; Murali, R.

    1970-01-01

    A case is presented in which the mitral and tricuspid valves were replaced by a ball-valve prosthesis. The patient was admitted as an emergency 18 months later with the clinical picture of acute venous inflow obstruction to the heart due to tricuspid ball-valve prosthesis obstruction. Successful replacement under emergency open heart surgery, using assisted circulation, is described. Images PMID:5452288

  13. Ball valve design for solid withdrawal service in coal liquefaction

    NASA Astrophysics Data System (ADS)

    Patton, Alexander J.

    1981-02-01

    Valves used for drawdown of the solids produced in the coal liquefaction process must be designed to operate at high temperatures and must prevent the buildup of solids within the valve internals to insure operability. Consideration must also be given to materials used for seating surfaces in terms of being able to withstand abrasion. Research into the design and materials for this application results in a new ball valve design with a special inlet port liner and O-ring seal. A prototype valve was built and put in service in a small scale, experimental coal liquefaction plant. For comparative purposes a standard design valve was also used, with both valves being subjected to over 1000 open/close cycles, after which both valves were removed, tested, and disassembled for inspection. The results of this experimental program will be presented, including process parameters, service conditions, and material evaluation. Particular emphasis will be placed on wear of seating surfaces and the effects of process material on the physical properties of seal and packing materials.

  14. Failure analyses of two ball valves used for coal-gasification applications

    SciTech Connect

    Van Den Avyle, J.A.; Pope, L.E.

    1982-07-01

    Two ball valves which had failed by developing excess leakage were supplied for analyses. The 2'' (51 mm) valve had experienced 5000 cycles during 20 hrs usage in an unknown chemical environment. Wear on the ball and seats was a multi-stage process starting with breakdown of a hard chrome plating on the stainless steel ball. This eventually led to adhesive weld transfer of the stainless steel to the seat made of Stellite 6 alloy. The 6'' (152 mm) ball valve had experienced a cycling test sequence using compressed air up to 300 psig (2.07 MPa) at 850/sup 0/F (727/sup 0/K). Damage was characterized as abrasive wear caused either by particles deposited by the compressed air or by carbide particles present in the Stellite 6 alloy ball and seat hardfacing. The decrease in this alloy's compressive yield strength at the elevated test temperature contributed to increased wear rates.

  15. Whitey Swagelok SCHe Ball Valves Provide Isolation between SCHe Purge Lines C and D and the Process Vent

    SciTech Connect

    VAN KATWIJK, C.

    2000-06-21

    These valves are 1/4 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They provide an isolation function between SCHe Purge Line C, (PV-V-*079), and Purge Line D, (PV-V-*080), and the Process Vent.

  16. Transfemoral implantation of CoreValve Evolut-R aortic prosthesis in patient with prior ball-cage mechanical mitral valve prosthesis.

    PubMed

    Maluenda, Gabriel; Caorsi, Carlos; Baeza, Cristian

    2016-06-01

    Transcatheter aortic valve replacement remains challenge in patients with ball-cage-type mechanical valve in mitral position. Potential under-expansion of the percutaneous valve and interaction between the mitral ball-cage mechanical valve tilted towards the left ventricular outflow tract and the percutaneous valve adds risk during and after implantation. We report a successful implantation of the novel CoreValve Evolut-R self-expanding in a patient with severe aortic stenosis and a mitral Starr-Edwards mechanical valve implanted 28years ago.

  17. Understanding how brass ball valves passing certification testing can cause elevated lead in water when installed.

    PubMed

    Triantafyllidou, Simoni; Raetz, Meredith; Parks, Jeffrey; Edwards, Marc

    2012-06-15

    The lead leaching potential of new brass plumbing devices has come under scrutiny as a significant source of lead in drinking water (>300 μg/L) of new buildings around the world. Experiments were conducted using ball valves that were sold as certified and known to have caused problems in practice, in order to better understand how installed products could create such problems, even if they passed "leaching tests" such as National Sanitation Foundation (NSF) Standard 61 Section 8. Diffusion of lead from within the device into water when installed can increase lead leaching by orders of magnitude relative to results of NSF testing, which once only required exposure of very small volumes of water within the device. "Normalization" of the lead-in-water result tended to produce estimates of lead concentration that were much lower than actual lead measured at the tap. Finally, the presence of flux could also dramatically increase lead leaching, whereas high water velocity had relatively little effect.

  18. Aortic angiography

    MedlinePlus

    ... to: Abdominal aortic aneurysm Aortic dissection Aortic regurgitation Aortic stenosis Congenital (present from birth) problems Double aortic arch ... Aortic aneurysm repair - endovascular Aortic dissection Aortic insufficiency Aortic stenosis Magnetic resonance ... Patient Instructions Abdominal ...

  19. [Ball variance and fracture of a Smeloff-Cutter prosthesis 24 years after aortic valve replacement].

    PubMed

    Hust, M H; Klinkmüller, A; Keim, M; Momper, R; Nothwang, G

    1997-07-01

    This report documents a case of ball variance in a Smeloff-Cutter aortic prosthesis occurring 24 years after implantation. After episodes of embolic complications the patient died in acute shock. The silicone rubber ball showed several alterations including discoloration, grooving, cracking, swelling and subtotal fracture of the poppet. Terminal valvular malfunction was caused by complete thrombosis of the prosthesis. In most patients ball variance occurred during the first years after valve replacement; thus, the observed case is a very rare late complication of a ball-valve prosthesis.

  20. The performance of the Braunwald-Cutter aortic prosthetic valve.

    PubMed

    Blackstone, E H; Kirklin, J W; Pluth, J R; Turner, M E; Parr, G V

    1977-04-01

    Four hundred seventy-five patients underwent aortic valve replacement with the Braunwald-Cutter ball-valve prosthesis at two institutions. The early (30-day) hospital mortality was 4.7% for those with isolated aortic valve replacement and 6.9% for the entire group. For the former, 5-year actuarial survival of the hospital survivors was 72 +/- 5.7%; for the latter group it was 71 +/- 4.4%. Eleven patients (5 since the date of follow-up inquiry) have suffered poppet escape, 9 of whom died. The actuarial incidence of known poppet escape is 4 +/- 2.6% at 47 months; when the 5 patients suffering poppet escape since the date of follow-up inquiry are included, with certain assumptions, the incidence is 3.7 +/- 1.14%. The projected probability of poppet escape using all 11 patients is 12.2% at 5 years; the 70% confidence bands of projected probability of poppet escape separate from those of the risk of re-replacement at 61 months. This and other analyses indicate that in general, patients with the Braunwald-Cutter aortic prosthesis should have it replaced 4 1/2 to 5 years after its insertion.

  1. Ten year clinical evaluation of Starr-Edwards 2400 and 1260 aortic valve prostheses.

    PubMed Central

    Hackett, D; Fessatidis, I; Sapsford, R; Oakley, C

    1987-01-01

    The long term performance characteristics of the 2400 and 1260 series of Starr-Edwards aortic prostheses were investigated by a follow up study of clinical outcome of 327 patients discharged from hospital with isolated aortic valve replacement. Follow up lasted for up to 10 years and was based on 1616 patient-years. The 2400 series cloth covered tracked valve was implanted in 182 patients from 1974 to 1980 and the 1260 series bare strut silastic ball valve was inserted in 145 patients from 1979 to 1983. Total 10 year mortality and valve related morbidity were low and no cases of mechanical valve failure were recorded. There were no significant actuarial differences in mortality or valve related morbidity between the 2400 and 1260 valves. Starr-Edwards models 2400 and 1260 aortic valve prostheses showed excellent durability without any mechanical failures over a 10 year period. The long term outcome of isolated aortic valve replacement with these models is associated with a low frequency of valve related complications. PMID:3580223

  2. Aortic Valve Disease

    MedlinePlus

    ... Ventricle Normal Heart Select Disease To Learn More Aortic Stenosis Aortic Insufficiency Aorta The aorta is the main ... the rest of your body. Aortic Valve In aortic stenosis, the aortic valve becomes narrowed and does not ...

  3. Flow Cage Assemblies

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Bar-Cohen, Yoseph (Inventor)

    2017-01-01

    Apparatus, systems and methods for implementing flow cages and flow cage assemblies in association with high pressure fluid flows and fluid valves are provided. Flow cages and flow assemblies are provided to dissipate the energy of a fluid flow, such as by reducing fluid flow pressure and/or fluid flow velocity. In some embodiments the dissipation of the fluid flow energy is adapted to reduce erosion, such as from high-pressure jet flows, to reduce cavitation, such as by controllably increasing the flow area, and/or to reduce valve noise associated with pressure surge.

  4. Aortic Aneurysm

    MedlinePlus

    ... these occur in the part of the aorta running through the chest Abdominal aortic aneurysms (AAA) - these occur in the part of the aorta running through the abdomen Most aneurysms are found during ...

  5. Aortic Valve Stenosis

    MedlinePlus

    ... By Mayo Clinic Staff Aortic valve stenosis — or aortic stenosis — occurs when the heart's aortic valve narrows. This ... pressure may prevent or slow the development of aortic stenosis. Ask your doctor if you need to lower ...

  6. Three-dimensional visualization of axial velocity profiles downstream of six different mechanical aortic valve prostheses, measured with a hot-film anemometer in a steady state flow model.

    PubMed

    Hasenkam, J M; Westphal, D; Reul, H; Gormsen, J; Giersiepen, M; Stodkilde-Jorgensen, H; Paulsen, P K

    1987-01-01

    Hot-film anemometry was used for in vitro steady-state measurements downstream of six mechanical aortic valve prostheses at flow rates 10, 20 and 30 l.min-1. Three-dimensional visualizations of velocity profiles at two downstream levels were made with the valves rotated 0 and 60 degrees in relation to the sinuses of valsalvae. The velocity fields downstream of the disc valves were generally skew with increasing velocity gradients and laminar shear stresses with increasing flow rates. Furthermore, increased skewness of the velocity profiles was noticed when the major orifices of the disc valves were towards the commissure than when approaching a sinus of valsalvae. The velocity profiles downstream of the ball valve were generally flat but with considerably more disturbed flow, consistent with the findings in turbulent flow.

  7. [Aortic dissection].

    PubMed

    Ogino, Hitoshi

    2011-07-01

    Acute aortic dissection suddenly occurrs and results in a variety of catastrophic sequelae including cardiac tamponade, rupture, and organ malperfusion. In acute stage (< 2 weeks), according to the classifications on the region of aortic dissection, the condition of the false channel and the onset, appropriate medical, surgical, or endovascular treatments including endovascular aneurysm repair followed by the rapid and accurate diagnosis of aortic dissection using computed tomography and ultrasound should be performed without delay. In the chronic stage (> 2 weeks), the behavior of the chronic dissection or residual distal dissection after the initial treatment should be followed-up carefully with best medical treatment at the regular intervals. If necessary, appropriate surgical and endovascular treatment should be carried out in the proper timing before rupture.

  8. Bicuspid Aortic Valve

    DTIC Science & Technology

    2006-08-01

    severe aortic stenosis . Figure 1F. Oblique axial cine bright blood imaging through the valve plane of the aorta, demonstrates the aortic valve to...the ascending aorta. This moderate to large jet is consistent with moderate to severe aortic stenosis . No diastolic jet to suggest aortic ...conditions. Functional impairment of the aortic valve—namely aortic stenosis and aortic regurgitation—is the most common complication (in up to 68-85% of

  9. John Cage Discusses Fluxus.

    ERIC Educational Resources Information Center

    Snyder, Ellsworth

    1992-01-01

    Presents an informal discussion with composer John Cage which includes his response to George Maciunas' work, his recollections of Marcel Duchamp, the complex relationship between inelegant material and revealing works of art, neo-Dada and neo-Fluxus, Wittgenstein and the artist's ultimate responsibility to initiate a change in the viewer or…

  10. Acute Aortic Syndromes and Thoracic Aortic Aneurysm

    PubMed Central

    Ramanath, Vijay S.; Oh, Jae K.; Sundt, Thoralf M.; Eagle, Kim A.

    2009-01-01

    Acute and chronic aortic diseases have been diagnosed and studied by physicians for centuries. Both the diagnosis and treatment of aortic diseases have been steadily improving over time, largely because of increased physician awareness and improvements in diagnostic modalities. This comprehensive review discusses the pathophysiology and risk factors, classification schemes, epidemiology, clinical presentations, diagnostic modalities, management options, and outcomes of various aortic conditions, including acute aortic dissection (and its variants intramural hematoma and penetrating aortic ulcers) and thoracic aortic aneurysms. Literature searches of the PubMed database were conducted using the following keywords: aortic dissection, intramural hematoma, aortic ulcer, and thoracic aortic aneurysm. Retrospective and prospective studies performed within the past 20 years were included in the review; however, most data are from the past 15 years. PMID:19411444

  11. Thoracic aortic aneurysm

    MedlinePlus

    ... common cause of a thoracic aortic aneurysm is hardening of the arteries . This condition is more common ... aortic aneurysm repair - open Aortic aneurysm repair - endovascular Hardening of the arteries High blood pressure Marfan syndrome ...

  12. Aortic Valve Regurgitation

    MedlinePlus

    ... valve. Also, a narrowing of the aortic valve (aortic stenosis) can be associated with leaking. High blood pressure (hypertension). High blood pressure may stretch the root of the aorta where the aortic valve sits. The valve flaps ( ...

  13. Aortic Stenosis.

    PubMed

    Bakaeen, Faisal G; Rosengart, Todd K; Carabello, Blase A

    2017-01-03

    This issue provides a clinical overview of aortic stenosis, focusing on screening, diagnosis, treatment, and practice improvement. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  14. Percutaneous Transcatheter Aortic Disc Valve Prosthesis Implantation: A Feasibility Study

    SciTech Connect

    Sochman, Jan

    2000-09-15

    Purpose: Over the past 30 years there have been experimental efforts at catheter-based management of aortic valve regurgitation with the idea of extending treatment to nonsurgical candidates. A new catheter-based aortic valve design is described.Methods: The new catheter-delivered valve consists of a stent-based valve cage with locking mechanism and a prosthetic flexible tilting valve disc. The valve cage is delivered first followed by deployment and locking of the disc. In acute experiments, valve implantation was done in four dogs.Results: Valve implantation was successful in all four animals. The implanted valve functioned well for the duration of the experiments (up to 3 hr).Conclusion: The study showed the implantation feasibility and short-term function of the tested catheter-based aortic disc valve. Further experimental studies are warranted.

  15. CAGE — EDRN Public Portal

    Cancer.gov

    Promoter hypermethylation of the CAGE1 gene is related to plays a crucial role during the phenotypical morphogenesis of several types of cancer. CAGE1 shows testis-specific expression in normal tissues, but wide expression among cancer tissues and cell lines.

  16. Faraday Cage Protects Against Lightning

    NASA Technical Reports Server (NTRS)

    Jafferis, W.; Hasbrouck, R. T.; Johnson, J. P.

    1992-01-01

    Faraday cage protects electronic and electronically actuated equipment from lightning. Follows standard lightning-protection principles. Whether lightning strikes cage or cables running to equipment, current canceled or minimized in equipment and discharged into ground. Applicable to protection of scientific instruments, computers, radio transmitters and receivers, and power-switching equipment.

  17. Building a better Faraday cage

    NASA Astrophysics Data System (ADS)

    MartinAlfven; Wright, David; skocpol; Rounce, Graham; Richfield, Jon; W, Nick; wheelsonfire

    2015-11-01

    In reply to the physicsworld.com news article “Are Faraday cages less effective than previously thought?” (15 September, http://ow.ly/SfklO), about a study that indicated, based on mathematical modelling, that conducting wire-mesh cages may not be as good at excluding electromagnetic radiation as is commonly assumed.

  18. Late ball variance with the Model 1000 Starr-Edwards aortic valve prosthesis. Risk analysis and strategy of operative management.

    PubMed

    Grunkemeier, G L; Starr, A

    1986-06-01

    The first generation of aortic ball-valve prostheses, used until 1965, was associated with poppet damage owing to fatty infiltration of the silicone rubber ball, a phenomenon termed ball variance. For the Model 1000 Starr-Edwards valves, almost all cases were discovered before 8 years. However, a review of our patients still at risk with the original valve and poppet, prompted by other recent reports of late ball variance, has shown that severe variance can exist up to 20 years after implantation. There is a relationship between the year of valve implantation and the timing and severity of ball variance for the overall series of patients surviving operation, but for the subgroup currently at risk the sample sizes are too small to detect any difference, if one still exists. Only three of 12 patients in the current subset were found to have severe variance. Simple ball change has been the operation of choice. Prophylactic reoperation is not indicated in the current subset, but patients require careful follow-up and should be considered for reoperation should symptoms develop.

  19. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis or plaque buildup causes the ... weak and bulge outward like a balloon. An AAA develops slowly over time and has few noticeable ...

  20. Abdominal aortic aneurysm

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000162.htm Abdominal aortic aneurysm To use the sharing features on this page, ... blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs when an area of the aorta becomes ...

  1. Transcatheter aortic valve replacement

    MedlinePlus

    ... fully will restrict blood flow. This is called aortic stenosis. If there is also a leak, it is ... TAVR is used for people with severe aortic stenosis who aren't ... valve . In adults, aortic stenosis usually occurs due to calcium ...

  2. Supravalvular aortic stenosis in adult with anomalies of aortic arch vessels and aortic regurgitation

    PubMed Central

    Valente, Acrisio Sales; Alencar, Polyanna; Santos, Alana Neiva; Lobo, Roberto Augusto de Mesquita; de Mesquita, Fernando Antônio; Guimarães, Aloyra Guedis

    2013-01-01

    The supravalvular aortic stenosis is a rare congenital heart defect being very uncommon in adults. We present a case of supravalvular aortic stenosis in adult associated with anomalies of the aortic arch vessels and aortic regurgitation, which was submitted to aortic valve replacement and arterioplasty of the ascending aorta with a good postoperative course. PMID:24598962

  3. Furnished Cage System and Hen Well-Being: Comparative Effects of Furnished Cages and Battery Cages on Behavioral Exhibitions in White Leghorn Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The battery cage system is being banned in the European Union before or by 2012; and the furnished cage system will be the only cage system allowed after 2012. This study was conducted to examine the different effects of caging systems, furnished cages vs. battery cages, on bird behaviors. One hundr...

  4. Spectral moments of fullerene cages

    NASA Astrophysics Data System (ADS)

    Zhang, Hongxing; Balasubramanian, K.

    Based on the symmetric method, analytical expression or recursive relations for the spectral moments of the C20, C24, C26, C28, C30, C32, C36, C38, C40, C42, C44, C50 and C60 fullerene cage clusters are obtained by factoring the original graphs and the corresponding characteristic polynomials into their smaller subgraphs and subpolynomials. We also give numerical results for the spectral moments. It is demonstrated that the symmetric method is feasible in enumerating the moments as well as factoring the characteristic polynomials for fullerene cages.

  5. Aortic valve surgery - minimally invasive

    MedlinePlus

    ... of the heart is reduced. This is called aortic stenosis. The aortic valve can be replaced using: Minimally ... RN, Wang A. Percutaneous heart valve replacement for aortic stenosis: state of the evidence. Ann Intern Med . 2010; ...

  6. System for remotely servicing a top loading captive ball valve

    DOEpatents

    Berry, Stephen M.; Porter, Matthew L.

    1996-01-01

    An attachment for facilitating servicing of a valve, the valve including: an assembly composed of a valve seat defining a flow path, a flow control member movable relative to the valve seat for blocking or unblocking the valve seat, and a control device including a stem coupled to the flow control member and operable for moving the flow control member relative to the valve seat; a housing for receiving the assembly, the housing having an opening via which the assembly can be removed from, and installed in, the housing, and the housing having a plurality of threaded studs which surround the opening and project away from the housing; a valve housing cover for closing and sealing the opening in the housing, the cover having a first bore for passage of the stem of the control device when the assembly is installed in the housing and a plurality of second bores each located for passage of a respective stud when the cover closes the opening in the housing. A plurality of threaded nuts are engageable with the studs for securing the cover to the housing when the cover closes the opening in the housing, wherein the attachment comprises: a plurality of nut guide devices removable from the housing and each operatively associated with a respective stud for retaining a respective nut and guiding the respective nut into alignment with the respective stud to enable the respective nut to be rotated into engagement with the respective stud; and aligning the nut guide devices with the studs.

  7. System for remotely servicing a top loading captive ball valve

    DOEpatents

    Berry, S.M.; Porter, M.L.

    1996-06-25

    An attachment for facilitating servicing of a valve is disclosed including: an assembly composed of a valve seat defining a flow path, a flow control member movable relative to the valve seat for blocking or unblocking the valve seat, and a control device including a stem coupled to the flow control member and operable for moving the flow control member relative to the valve seat; a housing for receiving the assembly, the housing having an opening via which the assembly can be removed from, and installed in, the housing, and the housing having a plurality of threaded studs which surround the opening and project away from the housing; a valve housing cover for closing and sealing the opening in the housing, the cover having a first bore for passage of the stem of the control device when the assembly is installed in the housing and a plurality of second bores each located for passage of a respective stud when the cover closes the opening in the housing. A plurality of threaded nuts are engageable with the studs for securing the cover to the housing when the cover closes the opening in the housing, wherein the attachment comprises: a plurality of nut guide devices removable from the housing and each operatively associated with a respective stud for retaining a respective nut and guiding the respective nut into alignment with the respective stud to enable the respective nut to be rotated into engagement with the respective stud; and aligning the nut guide devices with the studs. 7 figs.

  8. A Mobile Phone Faraday Cage

    ERIC Educational Resources Information Center

    French, M. M. J.

    2011-01-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

  9. Be a Cage-Buster

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2013-01-01

    "A cage-buster can't settle for ambiguity, banalities, or imprecision," writes well-known educator and author Rick Hess. "These things provide dark corners where all manners of ineptitude and excuse-making can hide." Hess suggests that leaders need to clearly define the problems they're trying to solve and open…

  10. 50 CFR 648.75 - Cage identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Clam and Ocean Quahog Fisheries § 648.75 Cage identification. Except as provided in § 648.76, the... clams and ocean quahogs: (a) Tagging. Before offloading, all cages that contain surfclams or ocean...)(2). (h) Presumptions. Surf clams and ocean quahogs found in cages without a valid state tag...

  11. Novel RDX-Based Cage and Cage-Like Nitramines

    NASA Astrophysics Data System (ADS)

    Türker, Lemi; Çelik Bayar, Çağlar; Turhan, Hamza

    2013-10-01

    1,3,5-Trinitroperhydro-1,3,5-triazine (RDX)-based cage and cage-like nitramines in which two RDX molecules are linked to each other via three and two carbon atoms, respectively, have been investigated computationally using density functional theory (DFT) at a B3LYP/6-31G(d,p) theoretical level. The study focused on finding out how the quantum chemical and detonation properties of RDX change if two RDX molecules come together and form these structures. Both considered nitramines exhibited higher heats of formation (calculated via both PM3 and isodesmic methods) and Kamlet-Jacobs detonation performances and were found to be more sensitive than the reference compounds RDX and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX).

  12. Bovine aortic arch with supravalvular aortic stenosis.

    PubMed

    Idhrees, Mohammed; Cherian, Vijay Thomas; Menon, Sabarinath; Mathew, Thomas; Dharan, Baiju S; Jayakumar, K

    2016-09-01

    A 5-year-old boy was diagnosed to have supravalvular aortic stenosis (SVAS). On evaluation of CT angiogram, there was associated bovine aortic arch (BAA). Association of BAA with SVAS has not been previously reported in literature, and to best of our knowledge, this is the first case report of SVAS with BAA. Recent studies show BAA as a marker for aortopathy. SVAS is also an arteriopathy. In light of this, SVAS can also possibly be a manifestation of aortopathy associated with BAA.

  13. A mobile phone Faraday cage

    NASA Astrophysics Data System (ADS)

    French, M. M. J.

    2011-05-01

    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is described in some detail, and this is followed by a explanation of some demonstrations and experiments which I have used.

  14. Sutureless aortic valve replacement

    PubMed Central

    Phan, Kevin

    2015-01-01

    The increasing incidence of aortic stenosis and greater co-morbidities and risk profiles of the contemporary patient population has driven the development of minimally invasive aortic valve surgery and percutaneous transcatheter aortic valve implantation (TAVI) techniques to reduce surgical trauma. Recent technological developments have led to an alternative minimally invasive option which avoids the placement and tying of sutures, known as “sutureless” or rapid deployment aortic valves. Potential advantages for sutureless aortic prostheses include reducing cross-clamp and cardiopulmonary bypass (CPB) duration, facilitating minimally invasive surgery and complex cardiac interventions, whilst maintaining satisfactory hemodynamic outcomes and low paravalvular leak rates. However, given its recent developments, the majority of evidence regarding sutureless aortic valve replacement (SU-AVR) is limited to observational studies and there is a paucity of adequately-powered randomized studies. Recently, the International Valvular Surgery Study Group (IVSSG) has formulated to conduct the Sutureless Projects, set to be the largest international collaborative group to investigate this technology. This keynote lecture will overview the use, the potential advantages, the caveats, and current evidence of sutureless and rapid deployment aortic valve replacement (AVR). PMID:25870807

  15. Asymptomatic Strut Fracture in DeBakey-Surgitool Aortic Valves

    PubMed Central

    Von Der Emde, Jürgen; Eberlein, Ulrich; Breme, Jürgen

    1990-01-01

    From August 1971 through November 1972, we implanted 62 Model 2 DeBakey-Surgitool aortic valve prostheses in 62 patients, 4 of whom later had clinically asymptomatic strut fractures. In 1 case, the patient died suddenly, and autopsy revealed detachment of the ball-cage; in each of the other 3 cases, fractures of 2 struts close to the base of the prosthesis were diagnosed fluoroscopically, and the patients underwent successful reoperation. The interval between implantation and reoperation ranged from 11 months to 16 years, 9 months. In 1 patient, retrospective study of chest radiographs revealed that the fracture had been present for 2½ years. Larger valves (≥ A6) were affected significantly more often than smaller ones. We performed metallurgic analysis of 1 prosthesis: results revealed strut wear from fatigue cracking and secondary abrasion. Strut fracture was also promoted by suspension of the cage at right angles to the prosthetic ring and by use of a pyrolytic carbon ball in a titanium cage (i.e., an occluder harder than its holder). Patients with DeBakey-Surgitool aortic valve prostheses should undergo annual radiologic examinations to enable early detection of strut fractures. Prophylactic valve replacement is not indicated. (Texas Heart Institute Journal 1990;17:223-7) Images PMID:15227175

  16. Polymers containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E; Eastwood, Eric A

    2013-04-23

    Polymers comprising residues of cage compound monomers having at least one polyalkoxy silyl substituent are provided. The cage compound monomers are selected from borane cage compound monomers comprising at least 7 cage atoms and/or carborane cage compound monomers comprising 7 to 11 cage compound monomers. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Articles of manufacture comprising such polymers are also disclosed.

  17. Aortic Aneurysm Statistics

    MedlinePlus

    ... this? Submit What's this? Submit Button Related CDC Web Sites Heart Disease Stroke High Blood Pressure Salt ... to Prevent and Control Chronic Diseases Million Hearts® Web Sites with More Information About Aortic Aneurysm For ...

  18. Bicuspid aortic valve

    MedlinePlus

    ... stiff and not open up. This is called aortic stenosis , which causes the heart to pump harder than usual to get blood through the valve. The aorta may become enlarged with this condition. BAV is ...

  19. Phototriggerable 2′,7-Caged Paclitaxel

    PubMed Central

    Gropeanu, Radu A.; Baumann, Hella; Ritz, Sandra; Mailänder, Volker; Surrey, Thomas; del Campo, Aránzazu

    2012-01-01

    Three different variants of photoactivatable caged paclitaxel (PTX) have been synthesized and their bioactivity was characterized in in vitro assays and in living cells. The caged PTXs contain the photoremovable chromophore 4,5-dimethoxy-2-nitrobenzyloxycarbonyl (Nvoc) attached to position C7, C2' and to both of these positions via a carbonate bond. Single caged PTXs remained biologically active even at low dosages. Double caging was necessary in order to fully inhibit its activity and to obtain a phototriggerable PTX that can be applied successfully at commonly used concentrations. Irradiation of solutions containing the double caged PTX allowed dose-dependent delivery of functional PTX. Light-triggered stabilization of microtubule assemblies in vitro and in vivo by controlled light exposure of tubulin solutions or cell cultures containing caged PTX was demonstrated. Short light exposure under a fluorescence microscope allowed controlled delivery of free PTX during imaging. PMID:22970137

  20. Excessive strut wear allowing ball-poppet embolization in a DeBakey-Surgitool aortic valve prosthesis.

    PubMed

    Sutherland, R D; Guynes, W A; Nichols, C T; Martinez, H E

    1982-01-01

    Excessive cage strut wear allowing ball-poppet embolization caused the sudden death of a 47 year old lady in whom a DeBakey-Surgitool aortic prosthesis had been implanted nine years earlier. Patients with this type of prosthesis should have periodic valvular cine fluoroscopy with image intensification to allow visualization of significant strut wear or fracture, and appropriate prosthetic valve replacement.

  1. Cleaning Animals' Cages With Little Water

    NASA Technical Reports Server (NTRS)

    Harman, Benjamin J.

    1989-01-01

    Proposed freeze/thaw method for cleaning animals' cages requires little extra weight and consumes little power and water. Cleaning concept developed for maintaining experimental rat cages on extended space missions. Adaptable as well to similar use on Earth. Reduces cleaning time. Makes use of already available facilities such as refrigerator, glove box, and autoclave. Rat waste adheres to steel-wire-mesh floor of cage. Feces removed by loosening action of freezing-and-thawing process, followed by blast of air.

  2. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Ziaja, K; Sedlak, L; Urbanek, T; Kostyra, J; Ludyga, T

    2000-01-01

    The reported incidence of inflammatory abdominal aortic aneurysm (IAAA) is from 2% to 14% of patients with abdominal aortic aneurysm and the etiology of this disease is still discussed--according to the literature several pathogenic theories have been proposed. From 1992 to 1997 32 patients with IAAA were operated on. The patients were mostly symptomatic--abdominal pain was present in 68.75% cases, back pain in 31.25%, fever in 12.5% and weight loss in 6.25% of the operated patients. In all the patients ultrasound examination was performed, in 4 patients CT and in 3 cases urography. All the patients were operated on and characteristic signs of inflammatory abdominal aortic aneurysm like: thickened aortic wall, perianeurysmal infiltration or retroperitoneal fibrosis with involvement of retroperitoneal structures were found. In all cases surgery was performed using transperitoneal approach; in three cases intraoperatively contiguous abdominal organs were injured, which was connected with their involvement into periaortic inflammation. In 4 cases clamping of the aorta was done at the level of the diaphragmatic hiatus. 3 patients (9.37%) died (one patient with ruptured abdominal aortic aneurysm). Authors present diagnostic procedures and the differences in the surgical tactic, emphasizing the necessity of the surgical therapy in patients with inflammatory abdominal aortic aneurysm.

  3. Are Aortic Stent Grafts Safe in Pregnancy?

    PubMed Central

    Khandanpour, Nader; Mehta, Tapan A.; Adiseshiah, M.; Meyer, Felicity J.

    2015-01-01

    Aortic stent grafts are increasingly used to treat aortic aneurysms and also other aortic pathologies. The safety of aortic stent grafts in pregnancy has never been studied or reported. We report on two cases of aortic stent grafts in pregnant women and discuss the effect of pregnancy on these aortic stent grafts. PMID:26229702

  4. Successful transfemoral aortic valve implantation through aortic stent graft after endovascular repair of abdominal aortic aneurysm.

    PubMed

    Kawashima, Hideyuki; Watanabe, Yusuke; Kozuma, Ken

    2017-04-01

    The patient was a 91-year-old woman presenting with severe aortic valve stenosis. Pre-procedural computed tomography scan revealed a 45-mm abdominal aortic aneurysm (AAA). Transfemoral transcatheter aortic valve implantation (TF-TAVI) was performed after endovascular aortic repair (EVAR) of the AAA. The 23-mm Edwards Sapien XT system passed through the aortic stent graft smoothly. This is the first case report showing that successful TF-TAVI can be performed through a prior abdominal aortic stent graft. TF-TAVI after EVAR of AAA is a feasible option for patients with extremely poor access.

  5. Clinical and morphologic observations after simultaneous replacement of the tricuspid, mitral and aortic valves.

    PubMed

    Sullivan, M F; Roberts, W C

    1986-10-01

    Clinical and morphologic observations are described in 12 patients who underwent simultaneous replacement of the tricuspid, mitral and aortic valves. All 12 patients had mitral stenosis, 10 aortic valve stenosis and 2 pure aortic valve regurgitation; 5 had tricuspid valve stenosis and 7 pure tricuspid valve regurgitation. Of the 10 patients who died within 60 days of triple valve replacement, 7 had the low cardiac output syndrome, which in 4, and possibly 5, of the 7 was attributed to prosthetic aortic valve stenosis. In none of the 12 patients was the ascending aorta dilated, and in the 4 (possibly 5) patients with low cardiac output, the space between the surface of the caged poppet (4 patients) or margins of the tilting disc (1 patient) in the aortic valve position and the aortic endothelium appeared inadequate to allow unobstructed flow despite small-sized prostheses in all but 1 patient. Thus, aortic valve replacement in the setting of triple valve dysfunction is hazardous or potentially so. The relative small sizes of the hearts in these patients also make valve replacement more difficult (and hazardous) compared to hearts with larger ventricles and aortas.

  6. Aortic aneurysm repair - endovascular- discharge

    MedlinePlus

    ... MRI scan Aortic aneurysm repair - endovascular Aortic angiography Hardening of ... Center-Shreveport, Shreveport, LA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla ...

  7. Particle cage dynamics in flowing colloidal dispersions

    NASA Astrophysics Data System (ADS)

    Marenne, Stephanie; Morris, Jeffrey F.

    2016-11-01

    The idea of the particle in a suspension at rest being trapped in a cage formed by its neighbors, widely used to understand glassy suspensions, has been applied to freely flowing suspensions. Stokesian Dynamics, a discrete particle simulation, is used to simulate the flow of monodisperse colloidal hard sphere suspensions. The cage analogy is useful to study the nonlinear stress in the material during start-up of shear flow, where the neighbor cage deforms and breaks, and during oscillatory shear flow where, depending on the amplitude of oscillation, the particle is trapped inside the cage or escapes during the oscillation cycle. A precise statistical definition of the cage in terms of the nearest neighbor ring in the pair distribution function is developed. We examine the dependence of the cage dynamics on the volume fraction of particles and the Peclet number Pe , the ratio between shear and Brownian forces. Under flow, the cage is found to break at quite definite positions, and the structural distortion is found to be clearly related to the shear and normal stress response. The shear strain needed to break the neighbor cage depends on Pe as Brownian motion enhances the total deformation. A simple model captures the strain at the stress overshoot for start-up of steady shear.

  8. COATING ALTERNATIVES GUIDE (CAGE) USER'S GUIDE

    EPA Science Inventory

    The guide provides instructions for using the Coating Alternatives GuidE (CAGE) software program, version 1.0. It assumes that the user is familiar with the fundamentals of operating an IBM-compatible personal computer (PC) under the Microsoft disk operating system (MS-DOS). CAGE...

  9. [Congenital aortic stenosis].

    PubMed

    Yamaguchi, M

    2001-08-01

    Recent advances in and controversies concerning the management of children with congenital valvular aortic stenosis are discussed. In neonates with critical aortic stenosis, improved survival has recently been reported after surgical open valvotomy and balloon valvuloplasty, although it is difficult at this point to compare the results of the two procedures and determine their differential indications. Good results have also been achieved after extended aortic valvuloplasty for recurrent aortic stenosis and/or insufficiency, but the length of follow-up in these patients is still short. The technique first reported in 1991 for bilateral enlargement fo a small annulus permits the insertion of an aortic valve 3-4 sizes larger than the native annulus. It entails no risk of distorting the mitral valve, damaging the conduction system or important branches of the coronary arteries, or resulting in left ventricular dysfunction. The Ross procedure is now widely applied in the West, with reports of early mortality rates of less than 5% and event-free survival rates of 80-90% during follow-up of 4-8 years. Longer follow-up and continued careful evaluation are required to resolve the issue of possible dilatation and subsequent neoaortic valve dysfunction and pulmonary stenosis due to allograft degeneration after pulmonary autograft root replacement in children.

  10. Molecular shape sorting using molecular organic cages.

    PubMed

    Mitra, Tamoghna; Jelfs, Kim E; Schmidtmann, Marc; Ahmed, Adham; Chong, Samantha Y; Adams, Dave J; Cooper, Andrew I

    2013-04-01

    The energy-efficient separation of chemical feedstocks is a major sustainability challenge. Porous extended frameworks such as zeolites or metal-organic frameworks are one potential solution to this problem. Here, we show that organic molecules, rather than frameworks, can separate other organic molecules by size and shape. A molecular organic cage is shown to separate a common aromatic feedstock (mesitylene) from its structural isomer (4-ethyltoluene) with an unprecedented perfect specificity for the latter. This specificity stems from the structure of the intrinsically porous cage molecule, which is itself synthesized from a derivative of mesitylene. In other words, crystalline organic molecules are used to separate other organic molecules. The specificity is defined by the cage structure alone, so this solid-state 'shape sorting' is, uniquely, mirrored for cage molecules in solution. The behaviour can be understood from a combination of atomistic simulations for individual cage molecules and solid-state molecular dynamics simulations.

  11. Geomechanics of fracture caging in wellbores

    NASA Astrophysics Data System (ADS)

    Weijermars, Ruud; Zhang, Xi; Schultz-Ela, Dan

    2013-06-01

    This study highlights the occurrence of so-called `fracture cages' around underbalanced wellbores, where fractures cannot propagate outwards due to unfavourable principal stress orientations. The existence of such cages is demonstrated here by independent analytical and numerical methods. We explain the fracture caging mechanism and pinpoint the physical parameters and conditions for its control. This new insight has great practical relevance for the effectiveness and safety of drilling operations in general, and hydraulic fracturing in particular. Fracture caging runaway poses a hazard for drilling operations in overpressured formations. Recognition of the fracture caging mechanism also opens up new opportunities for controlled engineering of its effects by the manipulation of the Frac number in wells in order to bring more precision in the fracking process of tight formations.

  12. Holographic photolysis of caged neurotransmitters

    PubMed Central

    Lutz, Christoph; Otis, Thomas S.; DeSars, Vincent; Charpak, Serge; DiGregorio, David A.; Emiliani, Valentina

    2009-01-01

    Stimulation of light-sensitive chemical probes has become a powerful tool for the study of dynamic signaling processes in living tissue. Classically, this approach has been constrained by limitations of lens–based and point-scanning illumination systems. Here we describe a novel microscope configuration that incorporates a nematic liquid crystal spatial light modulator (LC-SLM) to generate holographic patterns of illumination. This microscope can produce illumination spots of variable size and number and patterns shaped to precisely match user-defined elements in a specimen. Using holographic illumination to photolyse caged glutamate in brain slices, we demonstrate that shaped excitation on segments of neuronal dendrites and simultaneous, multi-spot excitation of different dendrites enables precise spatial and rapid temporal control of glutamate receptor activation. By allowing the excitation volume shape to be tailored precisely, the holographic microscope provides an extremely flexible method for activation of various photosensitive proteins and small molecules. PMID:19160517

  13. Theory of nanotube faraday cage

    NASA Astrophysics Data System (ADS)

    Roxana Margine, Elena; Nisoli, Cristiano; Kolmogorov, Aleksey; Crespi, Vincent H.

    2003-03-01

    Charge transfer between dopants and double-wall carbon nanotubes is examined theoretically. We model the system as a triple cylindrical capacitor with the dopants forming a shell around the outer wall of the nanotube. The total energy of the system contains three terms: the band structure energies of the inner and outer tube, calculated in a tight-binding model with rigid bands, and the electrostatic energy of the tri-layer distribution. Even for metallic inner and outer tube walls, wherein the diameter dependence of the bandgap does not favor the outer wall, nearly all of the dopant charge resides on the outer layer, a nanometer-scale Faraday cage. The calculated charge distribution is in agreement with recent experimental measurements.

  14. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Mikami, Y; Kyogoku, M

    1994-08-01

    Inflammatory abdominal aortic aneurysm (IAAA) is a distinct clinicopathological entity, characterized by: (1) clinical presentation, such as back pain, weight loss, and increased ESR, (2) patchy and/or diffuse lymphoplasmacytic infiltration, and (3) marked periaortic fibrosis resulting in thickening of the aneurysmal wall and occasional retroperitoneal fibrosis. Its pathogenesis is unknown, but some authors support the theory that IAAA is a subtype of atherosclerotic abdominal aortic aneurysm because of close relationship between IAAA and atherosclerotic change. In this article, we describe clinical and histological features of IAAA on the basis of the literature and our review of 6 cases of IAAA, emphasizing the similarity and difference between IAAA and atherosclerotic abdominal aortic aneurysm. Our review supports that marked lamellar fibrosis completely replacing the media and adventitia, patchy lymphocytic infiltration (mostly B cells) and endarteritis obliterans are characteristic features of IAAA.

  15. Robotic aortic surgery.

    PubMed

    Duran, Cassidy; Kashef, Elika; El-Sayed, Hosam F; Bismuth, Jean

    2011-01-01

    Surgical robotics was first utilized to facilitate neurosurgical biopsies in 1985, and it has since found application in orthopedics, urology, gynecology, and cardiothoracic, general, and vascular surgery. Surgical assistance systems provide intelligent, versatile tools that augment the physician's ability to treat patients by eliminating hand tremor and enabling dexterous operation inside the patient's body. Surgical robotics systems have enabled surgeons to treat otherwise untreatable conditions while also reducing morbidity and error rates, shortening operative times, reducing radiation exposure, and improving overall workflow. These capabilities have begun to be realized in two important realms of aortic vascular surgery, namely, flexible robotics for exclusion of complex aortic aneurysms using branched endografts, and robot-assisted laparoscopic aortic surgery for occlusive and aneurysmal disease.

  16. Chronic Type A Aortic Dissection and Giant Aortic Root Aneurysm After Aortic Valve Replacement

    PubMed Central

    Puga, Andrés Enríquez; Rodríguez, Sara Castaño; Pañero, Blanca Mateos; Moreira, Beatriz Castaño; López Almodóvar, Luis Fernando

    2016-01-01

    We describe the case of a 61-year-old male with a giant aortic root aneurysm associated with chronic aortic Type A dissection. The patient had been operated on 16 years before due to aortic annuloectasia with mechanical valve replacement. The patient underwent revision aortic surgery with a Bentall-De Bono operation with Svensson modification, using a #21 On-X Valsalva mechanical valve conduit. The postoperative course was uneventful. PMID:28097190

  17. Inflammatory abdominal aortic aneurysm.

    PubMed

    Savarese, R P; Rosenfeld, J C; DeLaurentis, D A

    1986-05-01

    Between January 1976 and December 1982, 181 patients with abdominal aortic aneurysms were treated surgically, and in 13 patients the aneurysms were found to be inflammatory. Inflammatory aneurysms of the abdominal aorta (IAAA) share important characteristics with typical atherosclerotic abdominal aortic aneurysms. Diagnosis and surgical management of IAAA are distinctive which suggests that IAAA should be considered separately, as a varient of typical abdominal aortic aneurysms. IAAA occur predominantly in males. The presenting symptoms are often idiosyncratic and include severe abdominal or back pain, or both, and ureteral obstruction; the diagnosis of IAAA should be considered when these symptoms are present. Although grossly and microscopically, the perianeurysmal fibrosis resembles idiopathic retroperitoneal fibrosis, the two conditions can be differentiated. At the present time, ultrasonography and computed tomography appear to offer reliable means for diagnosing IAAA. The presence of IAAA, whether established preoperatively or discovered unexpectedly at operation, necessitate certain modifications in the surgical approach, in order to avoid injuring the duodenum and the venous structures. Most patients can be successfully treated by resection and graft replacement. Rupture of the aneurysm in IAAA appears to be less frequent than in typical atherosclerotic abdominal aortic aneurysm.

  18. Maintenance of a Drosophila melanogaster Population Cage.

    PubMed

    Caravaca, Juan Manuel; Lei, Elissa P

    2016-03-15

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

  19. Maintenance of a Drosophila melanogaster Population Cage

    PubMed Central

    Caravaca, Juan Manuel; Lei, Elissa P.

    2016-01-01

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle. PMID:27023790

  20. Cage allocation designs for rodent carcinogenicity experiments

    PubMed Central

    Herzberg, Agnes M.; Lagakos, Stephen W.

    1991-01-01

    Cage allocation designs for rodent carcinogenicity experiments are discussed and presented with the goal of avoiding dosage group biases related to cage location. Considerations in selecting a cage design are first discussed in general terms. Specific designs are presented for use in experiments involving three, four, and five dose groups and with one, four, and five rodents per cage. Priorities for balancing treatment groups include horizontal position on shelf and shelf of rack, nearest neighbor balance, and male–female balance. It is proposed that these balance criteria be considered together with practical issues, such as the ability to accurately conform to a design and to determine a sensible and efficient design for each experiment. PMID:17539183

  1. Cage allocation designs for rodent carcinogenicity experiments.

    PubMed Central

    Herzberg, A M; Lagakos, S W

    1992-01-01

    Cage allocation designs for rodent carcinogenicity experiments are discussed and presented with the goal of avoiding dosage group biases related to cage location. Considerations in selecting a cage design are first discussed in general terms. Specific designs are presented for use in experiments involving three, four, and five dose groups and with one, four, and five rodents per cage. Priorities for balancing treatment groups include horizontal position on shelf and shelf of rack, nearest neighbor balance, and male-female balance. It is proposed that these balance criteria be considered together with practical issues, such as the ability to accurately conform to a design and to determine a sensible and efficient design for each experiment. PMID:1295494

  2. Compositions containing borane or carborane cage compounds and related applications

    SciTech Connect

    Bowen, III, Daniel E.; Eastwood, Eric A.

    2015-09-15

    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  3. Compositions containing borane or carborane cage compounds and related applications

    SciTech Connect

    Bowen, III, Daniel E; Eastwood, Eric A

    2014-11-11

    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  4. NMR Evidence of Cage-to-Cage Diffusion of H2 in H2-Clathrates

    NASA Astrophysics Data System (ADS)

    Senadheera, Lasitha; Conradi, Mark

    2008-03-01

    H2 and heavy-ice at P>1 kbar and T ˜250 K form H2-D2O clathrate; four and one H2 may occupy each large (L) and small (S) cage, respectively. In H2-THF-H2O clathrate, H2 occupies singly and only S cages. Previous electronic-structure calculations estimate the barriers for H2 passage though hexagonal and pentagonal faces of cages as ˜6 and ˜25 kcal/mol, respectively. Our H2 NMR linewidth data reflect random crystal fields from frozen cage-wall D2O orientations. We find dramatic reductions in linewidth starting at 120 K (175 K) for H2-D2O (H2-TDF-D2O) indicating time-averaging of the crystal fields. Assuming Arrhenius behavior, our data imply energies for escape from L (S) cages of about ˜4 (˜6) kcal/mol. For L cages, the agreement with the calculated (cages were treated as rigid) barrier is reasonable. For H2 in S cages, in H2-TDF-D2O, the extreme disagreement with theory points to another mechanism of time-averaging, reorientations of the cage-wall D2O molecules, as suggested by previous work in TDH-H2O clathrate. Our limited NMR spectra at high T ˜145 K in H2-D2O show evidence of distinct resonances from diffusionally mobile and immobile H2 molecules, as expected.

  5. Cage change intervals for opossums (Monodelphis domestica) in individually ventilated cages.

    PubMed

    Allison, Sarah O; Criley, Jennifer M; Kim, Ji Young; Goodly, Lyndon J

    2011-09-01

    The opossum Monodelphis domestica is the most commonly used marsupial in biomedical research. At our institution, these opossums are housed in polycarbonate (35.6 cm × 25.4 cm × 17.8 cm) individually ventilated cages. Previous studies of the cage microenvironment of rodents housed in individually ventilated cages have demonstrated that the cage-change frequency could be extended from 7 to 14 d, without detriment to the animals' wellbeing. We sought to determine whether the cage change frequency for opossums housed in individually ventilated cages could be extended to 14 d. Opossums were placed into 3 experimental groups: singly housed males, singly housed females, and females housed with litters. The 14-d testing period was repeated twice, with temperature, relative humidity, and ammonia levels tested on days 0, 7, and 14. Acceptable ranges for the cage microenvironment were based on standards followed by our institution for housing rodents: temperature between 22 to 26 °C, relative humidity between 30% to 70%, and ammonia less than 25 ppm. Throughout both 14-d testing periods, temperature, relative humidity, and ammonia levels for singly housed male and singly housed female opossums were within acceptable ranges. However, ammonia levels exceeded the recommended 25 ppm on day 7 of both testing periods for female opossums housed with litters. In summary, the cage-change frequency for a singly housed opossum in an individually ventilated cage can be extended to 14 d.

  6. Magnetic Fluid Gyro Bearing and Caging Mechanism.

    DTIC Science & Technology

    In accordance wtih this invention, a gyro is provided which has a bearing means between the rotor and stator provided by magnetic fluid and a caging...means which also includes a magnetic fluid provided between the rotor and caging plate. The gyro of this invention includes a stator with motor...and mounted about the circumference of the rotor with magnetic fluid between the rotor and stator spherical surfaces and being held by the permanent

  7. Aortic coarctation with persistent fifth left aortic arch.

    PubMed

    Santoro, Giuseppe; Caianiello, Giuseppe; Palladino, Maria Teresa; Iacono, Carola; Russo, Maria Giovanna; Calabrò, Raffaele

    2009-08-14

    A neonate with severe aortic coarctation showed a double lumen transverse aorta (persistent fifth aortic arch) with both channels joining at the isthmus where the obstruction was confirmed by echocardiography and cardiac catheterization. Surgical repair was performed with a pantaloon-shaped patch. Persistent fifth aortic arch does not result in a vascular ring and, per se, is not hemodynamically significant unless associated with other cardiac malformations.

  8. Genetics Home Reference: supravalvular aortic stenosis

    MedlinePlus

    ... Genetics Home Health Conditions supravalvular aortic stenosis supravalvular aortic stenosis Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Supravalvular aortic stenosis (SVAS) is a heart defect that develops before ...

  9. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection.

  10. Microclimatic variation within sleeve cages used in ecological studies.

    PubMed

    Nelson, Lori A; Rieske, Lynne K

    2014-01-01

    Sleeve cages for enclosing or excluding arthropods are essential components of field studies evaluating trophic interactions. Microclimatic variation in sleeve cages was evaluated to characterize its potential effects on subsequent long-term experiments. Two sleeve cage materials, polyester and nylon, and two cage sizes, 400 and 6000 cm(2), were tested on eastern hemlock, Tsuga canadensis (L.) Carrière. Temperature and relative humidity inside and outside cages, and the cost and durability of the cage materials, were compared. Long-term effects of the sleeve cages were observed by measuring new growth on T. canadensis branches. The ultimate goal was to identify a material that minimizes bag-induced microclimatic variation. Bagged branches whose microclimates mimic those of surrounding unbagged branches should have minimal effects on plant growth and may prove ideal venues for assessing herbivore and predator behavior under natural conditions. No differences were found in temperature or humidity between caging materials. Small cages had higher average temperatures than large cages, especially in the winter, but this difference was confounded by the fact that small cages were positioned higher in trees than large cages. Differences in plant growth were detected. Eastern hemlock branches enclosed within polyester cages produced fewer new growth tips than uncaged controls. Both polyester and nylon cages reduced the length of new shoot growth relative to uncaged branches. In spite of higher costs, nylon cages were superior to polyester with respect to durability and ease of handling.

  11. Ruptured abdominal aortic aneurysm.

    PubMed

    Sachs, T; Schermerhorn, M

    2010-06-01

    Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management.

  12. Aortic dimensions in Turner syndrome.

    PubMed

    Quezada, Emilio; Lapidus, Jodi; Shaughnessy, Robin; Chen, Zunqiu; Silberbach, Michael

    2015-11-01

    In Turner syndrome, linear growth is less than the general population. Consequently, to assess stature in Turner syndrome, condition-specific comparators have been employed. Similar reference curves for cardiac structures in Turner syndrome are currently unavailable. Accurate assessment of the aorta is particularly critical in Turner syndrome because aortic dissection and rupture occur more frequently than in the general population. Furthermore, comparisons to references calculated from the taller general population with the shorter Turner syndrome population can lead to over-estimation of aortic size causing stigmatization, medicalization, and potentially over-treatment. We used echocardiography to measure aortic diameters at eight levels of the thoracic aorta in 481 healthy girls and women with Turner syndrome who ranged in age from two to seventy years. Univariate and multivariate linear regression analyses were performed to assess the influence of karyotype, age, body mass index, bicuspid aortic valve, blood pressure, history of renal disease, thyroid disease, or growth hormone therapy. Because only bicuspid aortic valve was found to independently affect aortic size, subjects with bicuspid aortic valve were excluded from the analysis. Regression equations for aortic diameters were calculated and Z-scores corresponding to 1, 2, and 3 standard deviations from the mean were plotted against body surface area. The information presented here will allow clinicians and other caregivers to calculate aortic Z-scores using a Turner-based reference population. © 2015 Wiley Periodicals, Inc.

  13. Development of net cage acoustic alarm system

    NASA Astrophysics Data System (ADS)

    Hong, Shih-Wei; Wei, Ruey-Chang

    2001-05-01

    In recent years, the fishery production has been drastically decreased in Taiwan, mainly due to overfishing and coast pollution; therefore, fishermen and corporations are encouraged by government to invest in ocean net cage aquaculture. However, the high-price fishes in the net cage are often coveted, so incidences of fish stealing and net cage breaking were found occasionally, which cause great economical loss. Security guards or a visual monitoring system has limited effect, especially in the night when these intrusions occur. This study is based on acoustic measure to build a net cage alarm system, which includes the sonobuoy and monitor station on land. The sonobuoy is a passive sonar that collects the sounds near the net cage and transmits the suspected signal to the monitor station. The signals are analyzed by the control program on the personal computer in the monitor station, and the alarms at different stages could be activated by the sound levels and durations of the analyzed data. To insure long hours of surveillance, a solar panel is applied to charge the battery, and a photodetector is used to activate the system.

  14. Management of Acute Aortic Syndrome and Chronic Aortic Dissection

    SciTech Connect

    Nordon, Ian M. Hinchliffe, Robert J.; Loftus, Ian M.; Morgan, Robert A.; Thompson, Matt M.

    2011-10-15

    Acute aortic syndrome (AAS) describes several life-threatening aortic pathologies. These include intramural hematoma, penetrating aortic ulcer, and acute aortic dissection (AAD). Advances in both imaging and endovascular treatment have led to an increase in diagnosis and improved management of these often catastrophic pathologies. Patients, who were previously consigned to medical management or high-risk open surgical repair, can now be offered minimally invasive solutions with reduced morbidity and mortality. Information from the International Registry of Acute Aortic Dissection (IRAD) database demonstrates how in selected patients with complicated AAD the 30-day mortality from open surgery is 17% and endovascular stenting is 6%. Despite these improvements in perioperative deaths, the risks of stroke and paraplegia remain with endovascular treatment (combined outcome risk 4%). The pathophysiology of each aspect of AAS is described. The best imaging techniques and the evolving role of endovascular techniques in the definitive management of AAS are discussed incorporating strategies to reduce perioperative morbidity.

  15. Uranium pyrophosphate / methylenediphosphonate polyoxometalate cage clusters

    SciTech Connect

    Ling, Jie; Qiu, Jie; Sigmon, Ginger E.; Ward, Matt; Szymanowski, Jennifer E.S.; Burns, Peter C

    2010-09-29

    Despite potential applications in advanced nuclear energy systems, nanoscale control of uranium materials is in its infancy. In its hexavalent state, U occurs as (UO{sub 2}){sup 2+} uranyl ions that are coordinated by various ligands to give square, pentagonal, or hexagonal bipyramids. Creation and design of nanostructured uranyl materials requires interruption of the tendency of uranyl bipyramids to share equatorial edges to form infinite sheets that occur in extended structures. Where a bidentate peroxide group bridges uranyl bipyramids, the configuration is inherently bent, fostering formation of cage clusters. Here the bent configurations of four- and five-membered rings of uranyl peroxide hexagonal bipyramids are bridged by pyrophosphate or methylenediphosphonate, creating eight chemically complex cage clusters with specific topologies. Chemical complexity in such clusters provides opportunities for the tuning of cage sizes, pore sizes, and properties such as aqueous solubility. Several of these are topological derivatives of simpler clusters that contain only uranyl bipyramids, whereas others exhibit new topologies.

  16. Temperature dependence of polyhedral cage volumes in clathrate hydrates

    USGS Publications Warehouse

    Chakoumakos, B.C.; Rawn, C.J.; Rondinone, A.J.; Stern, L.A.; Circone, S.; Kirby, S.H.; Ishii, Y.; Jones, C.Y.; Toby, B.H.

    2003-01-01

    The polyhedral cage volumes of structure I (sI) (carbon dioxide, methane, trimethylene oxide) and structure II (sII) (methane-ethane, propane, tetrahydrofuran, trimethylene oxide) hydrates are computed from atomic positions determined from neutron powder-diffraction data. The ideal structural formulas for sI and sII are, respectively, S2L6 ?? 46H2O and S16L???8 ?? 136H2O, where S denotes a polyhedral cage with 20 vertices, L a 24-cage, and L??? a 28-cage. The space-filling polyhedral cages are defined by the oxygen atoms of the hydrogen-bonded network of water molecules. Collectively, the mean cage volume ratio is 1.91 : 1.43 : 1 for the 28-cage : 24-cage : 20-cage, which correspond to equivalent sphere radii of 4.18, 3.79, and 3.37 A??, respectively. At 100 K, mean polyhedral volumes are 303.8, 227.8, and 158.8 A??3 for the 28-cage, 24-cage, and 20-cage, respectively. In general, the 20-cage volume for a sII is larger than that of a sI, although trimethylene oxide is an exception. The temperature dependence of the cage volumes reveals differences between apparently similar cages with similar occupants. In the case of trimethylene oxide hydrate, which forms both sI and sII, the 20-cages common to both structures contract quite differently. From 220 K, the sII 20-cage exhibits a smooth monotonic reduction in size, whereas the sI 20-cage initially expands upon cooling to 160 K, then contracts more rapidly to 10 K, and overall the sI 20-cage is larger than the sII 20-cage. The volumes of the large cages in both structures contract monotonically with decreasing temperature. These differences reflect reoriented motion of the trimethyelene oxide molecule in the 24-cage of sI, consistent with previous spectroscopic and calorimetric studies. For the 20-cages in methane hydrate (sI) and a mixed methane-ethane hydrate (sII), both containing methane as the guest molecule, the temperature dependence of the 20-cage volume in sII is much less than that in sI, but sII is overall

  17. Pentacuspid aortic valve diagnosed by transoesophageal echocardiography

    PubMed Central

    Cemri, M; Cengel, A; Timurkaynak, T

    2000-01-01

    Congenital aortic valve anomalies are quite a rare finding in echocardiographic examinations. A case of a 19 year old man with a pentacuspid aortic valve without aortic stenosis and regurgitation, detected by transoesophageal echocardiography, is presented.


Keywords: pentacuspid aortic valve; echocardiography PMID:10995427

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

    PubMed

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

    2006-04-01

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

  19. Aortic biomechanics in hypertrophic cardiomyopathy

    PubMed Central

    Badran, Hala Mahfouz; Soltan, Ghada; Faheem, Nagla; Elnoamany, Mohamed Fahmy; Tawfik, Mohamed; Yacoub, Magdi

    2015-01-01

    Background: Ventricular-vascular coupling is an important phenomenon in many cardiovascular diseases. The association between aortic mechanical dysfunction and left ventricular (LV) dysfunction is well characterized in many disease entities, but no data are available on how these changes are related in hypertrophic cardiomyopathy (HCM). Aim of the work: This study examined whether HCM alone is associated with an impaired aortic mechanical function in patients without cardiovascular risk factors and the relation of these changes, if any, to LV deformation and cardiac phenotype. Methods: 141 patients with HCM were recruited and compared to 66 age- and sex-matched healthy subjects as control group. Pulse pressure, aortic strain, stiffness and distensibility were calculated from the aortic diameters measured by M-mode echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic and diastolic velocities were measured using pulsed wave Doppler tissue imaging (DTI). Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) and mechanical dyssynchrony. Results: The pulsatile change in the aortic diameter, distensibility and aortic wall systolic velocity (AWS') were significantly decreased and aortic stiffness index was increased in HCM compared to control (P < .001) In HCM AWS' was inversely correlated to age(r = − .32, P < .0001), MWT (r = − .22, P < .008), LVMI (r = − .20, P < .02), E/Ea (r = − .16, P < .03) LVOT gradient (r = − 19, P < .02) and severity of mitral regurg (r = − .18, P < .03) but not to the concealed LV deformation abnormalities or mechanical dyssynchrony. On multivariate analysis, the key determinant of aortic stiffness was LV mass index and LVOT obstruction while the role LV dysfunction in aortic stiffness is not evident in this population. Conclusion: HCM is associated with abnormal aortic mechanical properties. The severity of cardiac

  20. Prosthesis-preserving aortic root repair after aortic valve replacement.

    PubMed

    Hamamoto, Masaki; Kobayashi, Taira; Kodama, Hiroshi

    2015-07-01

    We describe a new technique of prosthesis-preserving aortic root replacement for patients who have previously undergone aortic valve replacement. With preservation of the mechanical prosthesis, we implant a Gelweave Valsalva graft using double suture lines. The first suture line is made between the sewing cuff of the mechanical valve and the graft, with mattress sutures of 2/0 braided polyester with pledgets. After the first sutures are tied, the second suture line is created between the graft collar and the aortic root remnant with continuous 4/0 polypropylene sutures.

  1. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Siebenmann, R; Schneider, K; von Segesser, L; Turina, M

    1988-06-11

    348 cases of abdominal aortic aneurysm were reviewed for typical features of inflammatory aneurysm (IAAA) (marked thickening of aneurysm wall, retroperitoneal fibrosis and rigid adherence of adjacent structures). IAAA was present in 15 cases (14 male, 1 female). When compared with patients who had ordinary aneurysms, significantly more patients complained of back or abdominal pain (p less than 0.01). Erythrocyte sedimentation rate was highly elevated. Diagnosis was established in 7 of 10 computed tomographies. 2 patients underwent emergency repair for ruptured aneurysm. Unilateral ureteral obstruction was present in 4 cases and bilateral in 1. Repair of IAAA was performed by a modified technique. Histological examination revealed thickening of the aortic wall, mainly of the adventitial layer, infiltrated by plasma cells and lymphocytes. One 71-year-old patient operated on for rupture of IAAA died early, and another 78-year-old patient after 5 1/2 months. Control computed tomographies revealed spontaneous regression of inflammatory infiltration after repair. Equally, hydronephrosis due to ureteral obstruction could be shown to disappear or at least to decrease. IAAA can be diagnosed by computed tomography with high sensitivity. Repair involves low risk, but modification of technique is necessary. The etiology of IAAA remains unclear.

  2. The excluder aortic endograft.

    PubMed

    Alterman, Daniel M; Stevens, Scott L

    2008-06-01

    Since its introduction, more than 59000 patients have been treated with Gore Excluder endoprosthesis (GORE) for abdominal aortic aneurysm (AAA) in the past 11 years. It has become clearer that differences in device delivery and design provide certain advantages that may favor one anatomical milieu over another. Behavior of the aneurysm sac also seems to be graft dependent as more long-term data become available. The currently available low-permeability GORE seems to have addressed the problem of endotension noted with previous designs. Cumulative data are reviewed, and the data demonstrate very low perioperative morbidity and mortality and excellent protection from aneurysm-related complications with the GORE device. Superior ease of use, excellent trackability, and rare failures requiring acute open conversion characterize the GORE device. By addressing clinical demands of aortic endografting, Gore has eclipsed other endografts in the industry to now dominate the US market. The aim of this review is to describe the history, experience, advantages, and future goals with the GORE for the treatment of AAA.

  3. CO chemisorption on the surfaces of the golden cages

    SciTech Connect

    Huang, Wei; Bulusu, Satya; Pal, R; Zeng, Xiao Cheng; Wang, Lai S

    2009-12-18

    We report a joint experimental and theoretical study of CO chemisorption on the golden cages. We find that the Au17- cage is highly robust and retains its cage structure in Au17-CO-. On the other hand, the Au16 - cage is transformed to a structure similar to Au17- upon the adsorption of CO. Au18 - is known to consist of two nearly degenerate structures, i.e., a cage and a pyramidal isomer, which coexist in the cluster beam. However, upon CO chemisorption only the cage isomer is observed while the pyramidal isomer no longer exists due to its less favorable interaction with CO, compared to the cage isomer. We find that inclusion of the spin-orbit effects is critical in yielding simulated spectra in quantitative agreement with the experimental data and providing unequivocal structural information and molecular insights into the chemical interactions between CO and the golden cages.

  4. Design and modeling of Faraday cages for substrate noise isolation

    NASA Astrophysics Data System (ADS)

    Wu, Joyce H.; del Alamo, Jesús A.

    2013-07-01

    A Faraday cage structure using through-substrate vias is an effective strategy to suppress substrate crosstalk, particularly at high frequencies. Faraday cages can reduce substrate noise by 32 dB at 10 GHz, and 26 dB at 50 GHz. We have developed lumped-element, equivalent circuit models of the Faraday cages and test structures to better understand the performance of the Faraday cages. These models compare well to measured results and show that the vias of the Faraday cage act as an RLC shunt to ground that draws substrate current. Designing a Faraday cage to achieve optimum isolation requires low via impedance and mitigation of via sidewall capacitance. The Faraday cage inductance is correlated to the number of vias and via spacing of the cage and can be optimized for the frequency of operation.

  5. Busting out of the Teacher Cage

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2015-01-01

    The author lays out guidelines and suggestions for how teachers can actually become policy leaders, taken from his book, "The Cage-Busting Teacher" (Harvard Education Press, 2015). Teachers serious about leadership can get the ear of policy makers by leveraging their positional and moral authority--though they may need to be persistent…

  6. Cage-Busting Leadership. Educational Innovations Series

    ERIC Educational Resources Information Center

    Hess, Frederick M.

    2013-01-01

    A practical and entertaining volume, "Cage-Busting Leadership" will be of profound interest and value to school and district leaders--and to everyone with a stake in school improvement. Rick Hess aptly describes his aims at the start of this provocative book: "I believe that two things are true. It is true, as would-be reformers…

  7. 50 CFR 648.75 - Cage identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Atlantic Surf Clam and Ocean Quahog Fisheries § 648.75 Cage identification. Link to an amendment published... requirements apply to all vessels issued a Federal fishing permit for surf clams and ocean quahogs: (a) Tagging... from the Regional Administrator. (g) Transfer. See § 648.70(b)(2). (h) Presumptions. Surf clams...

  8. An Easy Synthesis of Two Cage Hydrocarbons.

    ERIC Educational Resources Information Center

    Dong, Dao Cong

    1982-01-01

    Describes a simple, three-step synthesis of two cage molecules, birdcage hydrocarbon (VIII) and its homologue, the homobirdcage hydrocarbon IX. Indicates that all products are easily purified and formed in high yields in this activity suitable for advanced undergraduate laboratory courses. (Author/JN)

  9. Minimally invasive aortic valve surgery

    PubMed Central

    Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil

    2016-01-01

    Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease. PMID:27582764

  10. Porous Organic Cage Thin Films and Molecular-Sieving Membranes.

    PubMed

    Song, Qilei; Jiang, Shan; Hasell, Tom; Liu, Ming; Sun, Shijing; Cheetham, Anthony K; Sivaniah, Easan; Cooper, Andrew I

    2016-04-06

    Porous organic cage molecules are fabricated into thin films and molecular-sieving membranes. Cage molecules are solution cast on various substrates to form amorphous thin films, with the structures tuned by tailoring the cage chemistry and processing conditions. For the first time, uniform and pinhole-free microporous cage thin films are formed and demonstrated as molecular-sieving membranes for selective gas separation.

  11. Novel Metal Encapsulated Silicon Cage Clusters

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshiyuki

    2002-03-01

    The discovery of novel nano-forms of carbon such as fullerenes and nanotubes created much interest in the search for similar novel structures of silicon for applications in nano-devices. However, these cage structures are not stable for silicon. Small silicon clusters having upto about 20 atoms are found to have prolate structures in which a 10-atom unit plays an important role. Here we report results of new findings(Vijay Kumar and Yoshiyuki Kawazoe, ``Metal-Encapsulated Fullerenelike and Cubic Caged Clusters of Silicon", Phys. Rev. Lett., 87[4] (2001), 045503-1-045503-4.) on a rich variety of caged silicon clusters that are realized by encapsulating a metal atom. The shape and size of these new clusters depend upon the metal atom which also determines their properties. As silicon is the most important material for devices, these findings offer new opportunities to design novel nano-silicon based devices. The results have been obtained by performing computer experiments using ab initio calculations in an effort to stabilize a silicon cage of 20 atoms. We have tried several metal atoms and used a cage shrinking approach. These led to the findings of fullerene and cubic type stable symmetric clusters in the range of 14 to 16 silicon atoms, depending on the encapsulated metal atom. A Frank-Kasper polyhedron, M@Si16 is found to be of lowest energy for M = Ti and Hf with exceptionally large gaps of about 2.35 eV that lie in the optical region. Further studies have been done to stabilize the smallest fullerene shape of 20 silicon atoms and to develop assemblies of clusters to form more interesting nano-scale structures like wires, which might be useful industrially to realize conducting atomic lines covered by semiconductor tubes.

  12. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false CAGE codes. 204.7202-1..., DEPARTMENT OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-1 CAGE codes. (a) DLIS assigns or records and maintains CAGE codes to identify commercial and Government entities....

  13. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closing cage doors or gates. 56.19070 Section 56.19070 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be...

  14. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Closing cage doors or gates. 57.19070 Section 57.19070 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be...

  15. 30 CFR 56.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Closing cage doors or gates. 56.19070 Section 56.19070 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 56.19070 Closing cage doors or gates. Cage doors or gates shall be...

  16. 30 CFR 57.19070 - Closing cage doors or gates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Closing cage doors or gates. 57.19070 Section 57.19070 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoisting Procedures § 57.19070 Closing cage doors or gates. Cage doors or gates shall be...

  17. Screening for Abdominal Aortic Aneurysm

    MedlinePlus

    ... signs or symptoms of an abdominal aortic aneurysm (AAA). The final recommendation statement summarizes what the Task ... the potential benefits and harms of screening for AAA: (1) Men ages 65 to 75 who smoke ...

  18. Biomechanical study of a hat type cervical intervertebral fusion cage.

    PubMed

    Gu, Yu-Tong; Jia, Lian-Shun; Chen, Tong-Yi

    2007-02-01

    The purpose of this study was to evaluate the biomechanical effect of a hat type cervical intervertebral fusion cage (HCIFC). In this in vitro biomechanical study, 48 goat cervical spines (C2-5) were tested in flexion, extension, axial rotation, and lateral bending with a nondestructive stiffness method using a nonconstrained testing apparatus, and three-dimensional displacement was measured. Autologous iliac bone and cervical spine intervertebral fusion cage were implanted according to manufacturers' information after complete discectomy (C3-4). Eight spines in each of the following groups were tested: intact, autologous iliac bone graft, Harms cage, SynCage C, carbon cage, and HCIFC. The mean apparent stiffness values were calculated from the corresponding load-displacement curves. Additionally, cage volume and volume-related stiffness were determined. The stiffness of the SynCage C was statistically greatest in all directions. After implantation of the HCIFC, flexion stiffness increased compared with that of the intact motion segment. There was no significant difference in stiffness between the HCIFC and carbon cage. The stiffness of the HCIFC was statistically higher than that of the Harms cage in axial rotation and significantly lower in flexion, extension, and lateral bending. Volume-related stiffness of all cages was higher than that of iliac bone graft. The Harms cage was highest in volume-related stiffness in all directions. The HCIFC can provide enough primary stability for cervical intervertebral fusion.

  19. Comparison between Two Different Cervical Interbody Fusion Cages in One Level Stand-alone ACDF: Carbon Fiber Composite Frame Cage Versus Polyetheretherketone Cage

    PubMed Central

    Yoo, Minwook; Kim, Wook-Ha; Hyun, Seung-Jae; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2014-01-01

    Objective The authors conducted a retrospective study to compare the implantation of carbon fiber composite frame cages (CFCFCs) to the implantation of polyetheretherketone (PEEK) cages after anterior cervical discectomy for cervical degenerative disc disease. In addition, the predictive factors that influenced fusion or subsidence were investigated. Methods A total of 58 patients with single-level degenerative disc disease were treated with anterior cervical discectomy and implantation of stand-alone cages; CFCFCs were used in 35 patients, and PEEK cages were used in 23 patients. Preoperative and postoperative radiological and clinical assessments were performed. Results During the mean follow-up period of 41 months, fusion occurred in 43 patients (74.1%), and subsidence developed in 18 patients (31.0%). Pain decreased in all patients, and the patients' satisfaction rate was 75.9%. Neither fusion nor subsidence was related to the clinical outcome. There were no significant differences in the clinical and radiological outcomes between the CFCFC and the PEEK cage groups. Smoking history (p=0.023) was significantly associated with pseudarthrosis, and cage height (≥7mm) (p=0.037) were significantly associated with subsidence. Conclusion The clinical and radiological results were similar between the CFCFC and the PEEK cage groups. Fusion or subsidence did not affect the clinical outcomes. Smoking history and cage height (≥7mm) were predictive factors for pseudarthrosis or subsidence in anterior cervical discectomy and fusion with stand-alone cages. PMID:25346758

  20. [New aspects in aortic valve disease].

    PubMed

    Tornos, P

    2001-01-01

    Renewed interest for aortic valve disease has evolved in recent years. Aortic valve replacement has become the second most frequent cause of cardiac surgery, following coronary bypass surgery. In addition, the etiologic and physiopathologic knowledge of this disorder has improved. In the present paper we analyze three aspects of the disease which are, at present, the subject of study and controversy: first, we discuss the possible relationship between degenerative aortic stenosis and atherosclerosis; second, the involvement of the aortic root in cases of bicuspid aortic valve; and third, the surgical indications in asymptomatic patients with either aortic stenosis or regurgitation.

  1. Porous Organic Cages for Sulfur Hexafluoride Separation

    PubMed Central

    2016-01-01

    A series of porous organic cages is examined for the selective adsorption of sulfur hexafluoride (SF6) over nitrogen. Despite lacking any metal sites, a porous cage, CC3, shows the highest SF6/N2 selectivity reported for any material at ambient temperature and pressure, which translates to real separations in a gas breakthrough column. The SF6 uptake of these materials is considerably higher than would be expected from the static pore structures. The location of SF6 within these materials is elucidated by X-ray crystallography, and it is shown that cooperative diffusion and structural rearrangements in these molecular crystals can rationalize their superior SF6/N2 selectivity. PMID:26757885

  2. Rotational and constitutional dynamics of caged supramolecules

    PubMed Central

    Kühne, Dirk; Klappenberger, Florian; Krenner, Wolfgang; Klyatskaya, Svetlana; Ruben, Mario; Barth, Johannes V.

    2010-01-01

    The confinement of molecular species in nanoscale environments leads to intriguing dynamic phenomena. Notably, the organization and rotational motions of individual molecules were controlled by carefully designed, fully supramolecular host architectures. Here we use an open 2D coordination network on a smooth metal surface to steer the self-assembly of discrete trimeric guest units, identified as noncovalently bound dynamers. Each caged chiral supramolecule performs concerted, chirality-preserving rotary motions within the template honeycomb pore, which are visualized and quantitatively analyzed using temperature-controlled scanning tunneling microscopy. Furthermore, with higher thermal energies, a constitutional system dynamics appears, which is revealed by monitoring repetitive switching events of the confined supramolecules’ chirality signature, reflecting decay and reassembly of the caged units. PMID:21098303

  3. Biology's built-in Faraday cages

    NASA Astrophysics Data System (ADS)

    Klee, Maurice M.

    2014-05-01

    Biological fluids are water-based, ionic conductors. As such, they have both high relative dielectric constants and substantial conductivities, meaning they are lossy dielectrics. These fluids contain charged molecules (free charges), whose movements play roles in essentially all cellular processes from metabolism to communication with other cells. Using the problem of a point source in air above a biological fluid of semi-infinite extent, the bound charges in the fluid are shown to perform the function of a fast-acting Faraday cage, which protects the interior of the fluid from external electric fields. Free charges replace bound charges in accordance with the fluid's relaxation time, thereby providing a smooth transition between the initial protection provided by the bound charges and the steady state protection provided by the free charges. The electric fields within the biological fluid are thus small for all times just as they would be inside a classical Faraday cage.

  4. Rare or unusual causes of chronic, isolated, pure aortic regurgitation

    SciTech Connect

    Waller, B.F.; Taliercio, C.P.; Dickos, D.K.; Howard, J.; Adlam, J.H.; Jolly, W. )

    1990-08-01

    Six patients undergoing aortic valve replacement had rare or unusual causes of isolated, pure aortic regurgitation. Two patients had congenitally bicuspid aortic valves with a false commissure (raphe) displaced to the aortic wall (tethered bicuspid aortic valve), two had floppy aortic valves, one had a congenital quadricuspid valve, and one had radiation-induced valve damage.

  5. The Beta Cage: Screening Low Radioactive Backgrounds

    NASA Astrophysics Data System (ADS)

    Poinar, K.; Akerib, D.; Grant, D.; Schnee, R.; Shutt, T.; Golwala, S.; Ahmed, Z.

    2006-10-01

    The beta cage is a proposed multi-wire proportional chamber that will be the most sensitive device available to screen low-energy (200 keV) betas emitted at rates as low as 10-5 counts keV^1 cm-2 day-1 (of order 10-4 Bq/m^2). The expected sensitivity and details of the construction and commissioning of its prototype chamber are presented. The prototype beta cage is a 50x50x25 cm frame gridded by stacked wire planes contained in a chamber of gas. To reduce background, the chamber contains only enough mass to stop betas of interest. Samples are placed beneath the grid; the wires multiply the betas and collect their electron avalanche. Readouts allow discrimination of its events from background and determination of the beta (or alpha) source. The beta cage has potential use in carbon or tritium dating, with ^3H/^1H sensitivity of 10-20 and ^ 14C/ ^12C sensitivity of 10-18. Its design was motivated by CDMS, whose sensitivity to the dark matter candidate WIMPs is currently limited by low-energy beta contamination.

  6. Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

    PubMed Central

    Banghart, Matthew R.; Shah, Ruchir C.; Lavis, Luke D.

    2013-01-01

    The spatiotemporal dynamics of opioid signaling in the brain remain poorly defined. Photoactivatable opioid ligands provide a means to quantitatively measure these dynamics and their underlying mechanisms in brain tissue. Although activation kinetics can be assessed using caged agonists, deactivation kinetics are obscured by slow clearance of agonist in tissue. To reveal deactivation kinetics of opioid signaling we developed a caged competitive antagonist that can be quickly photoreleased in sufficient concentrations to render agonist dissociation effectively irreversible. Carboxynitroveratryl-naloxone (CNV-NLX), a caged analog of the competitive opioid antagonist NLX, was readily synthesized from commercially available NLX in good yield and found to be devoid of antagonist activity at heterologously expressed opioid receptors. Photolysis in slices of rat locus coeruleus produced a rapid inhibition of the ionic currents evoked by multiple agonists of the μ-opioid receptor (MOR), but not of α-adrenergic receptors, which activate the same pool of ion channels. Using the high-affinity peptide agonist dermorphin, we established conditions under which light-driven deactivation rates are independent of agonist concentration and thus intrinsic to the agonist-receptor complex. Under these conditions, some MOR agonists yielded deactivation rates that are limited by G protein signaling, whereas others appeared limited by agonist dissociation. Therefore, the choice of agonist determines which feature of receptor signaling is unmasked by CNV-NLX photolysis. PMID:23960100

  7. Insidious strut fractures in a DeBakey-Surgitool aortic valve prosthesis.

    PubMed

    Scott, S M; Sethi, G K; Paulson, D M; Takaro, T

    1978-04-01

    Recent reports of cage wear occurring in DeBakey-Surgitool aortic valve prostheses prompted us to examine with image intensification all our patients who have had this type of prosthesis implanted. One patient, who was asymptomatic, was discovered to have a prosthesis with two fractured struts. This patient's prosthetic valve was replaced successfully with a stented porcine heterograft prosthesis. Including the valve removed from this patient, 8 DeBakey-Surgitool aortic valves with structural defects have been reported to the manufacturer. In the absence of a catastrophic event, patients with valves having fractured or worn struts may be totally asymptomatic, and routine periodic roentgenographic examination may be the only way of detecting strut wear or fracture.

  8. Coronary Flow Impacts Aortic Leaflet Mechanics and Aortic Sinus Hemodynamics.

    PubMed

    Moore, Brandon L; Dasi, Lakshmi Prasad

    2015-09-01

    Mechanical stresses on aortic valve leaflets are well-known mediators for initiating processes leading to calcific aortic valve disease. Given that non-coronary leaflets calcify first, it may be hypothesized that coronary flow originating from the ostia significantly influences aortic leaflet mechanics and sinus hemodynamics. High resolution time-resolved particle image velocimetry (PIV) measurements were conducted to map the spatiotemporal characteristics of aortic sinus blood flow and leaflet motion with and without physiological coronary flow in a well-controlled in vitro setup. The in vitro setup consists of a porcine aortic valve mounted in a physiological aorta sinus chamber with dynamically controlled coronary resistance to emulate physiological coronary flow. Results were analyzed using qualitative streak plots illustrating the spatiotemporal complexity of blood flow patterns, and quantitative velocity vector and shear stress contour plots to show differences in the mechanical environments between the coronary and non-coronary sinuses. It is shown that the presence of coronary flow pulls the classical sinus vorticity deeper into the sinus and increases flow velocity near the leaflet base. This creates a beneficial increase in shear stress and washout near the leaflet that is not seen in the non-coronary sinus. Further, leaflet opens approximately 10% farther into the sinus with coronary flow case indicating superior valve opening area. The presence of coronary flow significantly improves leaflet mechanics and sinus hemodynamics in a manner that would reduce low wall shear stress conditions while improving washout at the base of the leaflet.

  9. Aortic root replacement with a valve-sparing technique for quadricuspid aortic valve.

    PubMed

    Yamanaka, Katsuhiro; Okada, Kenji; Okita, Yutaka

    2015-04-01

    A 67-year old man with ascending aortic aneurysm was referred because of a quadricuspid aortic valve. He underwent aortic root replacement with a valve-sparing technique. Under deep hypothermic circulatory arrest, replacement of the ascending aorta was successfully performed. The postoperative course was uneventful without recurrence of aortic regurgitation.

  10. Aortic Arch Interruption and Persistent Fifth Aortic Arch in Phace Syndrome: Prenatal Diagnosis and Postnatal Course.

    PubMed

    Chiappa, Enrico; Greco, Antonella; Fainardi, Valentina; Passantino, Silvia; Serranti, Daniele; Favilli, Silvia

    2015-09-01

    PHACE is a rare congenital neurocutaneous syndrome where posterior fossa malformations, hemangiomas, cerebrovascular anomalies, aortic arch anomalies, cardiac defects, and eye abnormalities are variably associated. We describe the prenatal detection and the postnatal course of a child with PHACE syndrome with a unique type of aortic arch anomaly consisting of proximal interruption of the aortic arch and persistence of the fifth aortic arch. The fifth aortic arch represented in this case a vital systemic-to-systemic connection between the ascending aorta and the transverse portion of the aortic arch allowing adequate forward flow through the aortic arch without surgical treatment.

  11. Abdominal aortic aneurysm repair - open - discharge

    MedlinePlus

    ... aortic aneurysm repair - open Aortic angiography Chest MRI Hardening of the ... Center-Shreveport, Shreveport, LA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla ...

  12. Management of bicuspid aortic valve with or without involvement of ascending aorta and aortic root.

    PubMed

    Neragi-Miandoab, S

    2014-06-01

    Patients with a bicuspid aortic valve (BAV) constitute a heterogeneous population with variable clinical presentation and complications. More than 50% of the patients who require aortic valve replacement have a BAV, a condition that may be associated with dilation of ascending aorta and aortic insufficiency caused by cusp disease or aortic root pathology. Of the potential BAV-related complications, dilation of the aortic root and ascending aorta are among the most serious. The dilation of ascending aorta and aortic root have been the subject of controversy. Whereas some surgeons believe that the dilation of the aorta is caused by the hemodynamic properties of the BAV, others believe that the dilation of the aortic root is secondary to genetic defects associated with the BAV. Management of a BAV should be tailored to each patient's clinical condition. The surgical approach varies from aortic valve replacement to combined aortic valve and root replacement to aortic-valve-sparing root replacement.

  13. Abdominal aortic feminism.

    PubMed

    Mortimer, Alice Emily

    2014-11-14

    A 79-year-old woman presented to a private medical practice 2 years previously for an elective ultrasound screening scan. This imaging provided the evidence for a diagnosis of an abdominal aortic aneurysm (AAA) to be made. Despite having a number of recognised risk factors for an AAA, her general practitioner at the time did not follow the guidance set out by the private medical professional, that is, to refer the patient to a vascular specialist to be entered into a surveillance programme and surgically evaluated. The patient became symptomatic with her AAA, was admitted to hospital and found to have a tender, symptomatic, 6 cm leaking AAA. She consented for an emergency open AAA repair within a few hours of being admitted to hospital, despite the 50% perioperative mortality risk. The patient spent 4 days in intensive care where she recovered well. She was discharged after a 12 day hospital stay but unfortunately passed away shortly after her discharge from a previously undiagnosed gastric cancer.

  14. Thoracic Aortic Aneurysm from Chronic Antiestrogen Therapy.

    PubMed

    Tripathi, Rishi; Sainathan, Sandeep; Ziganshin, Bulat A; Elefteriades, John A

    2017-03-01

    Aortic aneurysms are a common but often undetected pathology prevalent in the population. They are often detected as incidental findings on imaging studies performed for unrelated pathologies. Estrogens have been shown to exert a protective influence on aortic tissue. Pharmacological agents blocking the actions of estrogens may thus be implicated in causing aortic pathologies. We present the case of an elderly woman with breast carcinoma treated for 18 years with antiestrogen therapy who subsequently developed acute thoracic aortic deterioration (enlargement and wall disruption).

  15. Surgical Repair of Retrograde Type A Aortic Dissection after Thoracic Endovascular Aortic Repair

    PubMed Central

    Kim, Chang-Young; Kim, Yeon Soo; Ryoo, Ji Yoon

    2014-01-01

    It is expected that the stent graft will become an alternative method for treating aortic diseases or reducing the extent of surgery; therefore, thoracic endovascular aortic repair has widened its indications. However, it can have rare but serious complications such as paraplegia and retrograde type A aortic dissection. Here, we report a surgical repair of retrograde type A aortic dissection that was performed after thoracic endovascular aortic repair. PMID:24570865

  16. Aortic or Mitral Valve Replacement With the Biocor and Biocor Supra

    ClinicalTrials.gov

    2016-03-09

    Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence

  17. Balloon aortic valvuloplasty as a bridge to aortic valve replacement in a patient with severe calcific aortic stenosis

    PubMed Central

    Swinkels, B.M.; Jaarsma, W.; Wely, L. Relik-van; van Swieten, H.A.; Ernst, J.M.P.G.; Plokker, H.W.M.

    2003-01-01

    This case report describes a patient with severe calcific aortic stenosis who was initially considered inoperable because of a very poor left ventricular function and severe pulmonary hypertension. After balloon aortic valvuloplasty, the clinical and haemodynamic status of the patient improved to such an extent that subsequent aortic valve replacement was considered possible and eventually proved to be successful. Balloon aortic valvuloplasty has value as a potential bridge to aortic valve replacement when the risks for surgery are considered to be too high. ImagesFigure 1 PMID:25696195

  18. [MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT].

    PubMed

    Tabata, Minoru

    2016-03-01

    Minimally invasive aortic valve replacement (MIAVR) is defined as aortic valve replacement avoiding full sternotomy. Common approaches include a partial sternotomy right thoracotomy, and a parasternal approach. MIAVR has been shown to have advantages over conventional AVR such as shorter length of stay and smaller amount of blood transfusion and better cosmesis. However, it is also known to have disadvantages such as longer cardiopulmonary bypass and aortic cross-clamp times and potential complications related to peripheral cannulation. Appropriate patient selection is very important. Since the procedure is more complex than conventional AVR, more intensive teamwork in the operating room is essential. Additionally, a team approach during postoperative management is critical to maximize the benefits of MIAVR.

  19. Pseudoaneurysm of the aortic arch

    PubMed Central

    Lu, Yuan-Qiang; Yao, Feng; Shang, An-Dong; Pan, Jian

    2016-01-01

    Abstract Background: Pseudoaneurysm of the aortic arch is uncommonly associated with cancer, and is extremely rare in pulmonary cancer. Here, we report an unusual and successfully treated case of aortic arch pseudoaneurysm in a male patient with lung squamous cell carcinoma. Methods: A 64-year-old male patient was admitted to the Emergency Department, presenting with massive hemoptysis (>500 mL blood during the 12 hours prior to treatment). The diagnosis of aortic arch pseudoaneurysm was confirmed after inspection of computed tomographic angiography and three-dimensional reconstruction. We processed the immediate endovascular stent-grafting for this patient. Results: This patient recovered with no filling or enlargement of the pseudoaneurysm, no episodes of hemoptysis, and no neurological complications during the 4-week follow-up period. Conclusion: Herein, we compare our case with other cancer-related pseudoaneurysms in the medical literature and summarize the clinical features and treatment of this unusual case. PMID:27495079

  20. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, J.S.

    1999-03-23

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced. 12 figs.

  1. Extended cage adjustable speed electric motors and drive packages

    DOEpatents

    Hsu, John S.

    1999-01-01

    The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

  2. Application of bicyclic and cage compounds

    NASA Technical Reports Server (NTRS)

    Clark, R. D.; Archuleta, B. S.

    1976-01-01

    The results of a literature survey of the field of bicyclic and cage compounds were presented, with the objective of identifying those types of compounds with unusual physical and chemical stability, and determining what practical applications have been found for these compounds. Major applications have been as polymers, polymer additives, medicinals, and pesticides. Lesser applications have included fuels, fuel additives, lubricants, lubricant additives, and perfumes. Several areas where further work might be useful were also outlined; these are primarily in the areas of polymers, polymer additives, medicinals, and synthetic lubricants.

  3. C60 as a Faraday cage

    NASA Astrophysics Data System (ADS)

    Delaney, P.; Greer, J. C.

    2004-01-01

    Endohedral fullerenes have been proposed for a number of technological uses, for example, as a nanoscale switch, memory bit and as qubits for quantum computation. For these technology applications, it is important to know the ease with which the endohedral atom can be manipulated using an applied electric field. We find that the Buckminsterfullerene (C60) acts effectively as a small Faraday cage, with only 25% of the field penetrating the interior of the molecule. Thus influencing the atom is difficult, but as a qubit the endohedral atom should be well shielded from environmental electrical noise. We also predict how the field penetration should increase with the fullerene radius.

  4. Severe aortic stenosis: forgotten associations.

    PubMed

    Godinho, Ana Rita; Amorim, Sandra; Campelo, Manuel; Martins, Elisabete; Lopez Rodriguez, Elisa; Coelho, Rosa; Macedo, Guilherme; Maciel, Maria Júlia

    2014-09-01

    The authors present the case of a 68-year-old man with predominantly right heart failure in the context of severe aortic stenosis associated with pulmonary hypertension. Anemia was diagnosed which, after endoscopic study, was considered to be secondary to angiodysplasia and a diagnosis of Heyde syndrome was made. After valve replacement surgery the patient's heart failure improved and hemoglobin levels stabilized. We present this case to show the need to recognize less common associations of severe aortic stenosis, in order to provide immediate and appropriate treatment.

  5. Genetic encoding of caged cysteine and caged homocysteine in bacterial and mammalian cells.

    PubMed

    Uprety, Rajendra; Luo, Ji; Liu, Jihe; Naro, Yuta; Samanta, Subhas; Deiters, Alexander

    2014-08-18

    We report the genetic incorporation of caged cysteine and caged homocysteine into proteins in bacterial and mammalian cells. The genetic code of these cells was expanded with an engineered pyrrolysine tRNA/tRNA synthetase pair that accepts both light-activatable amino acids as substrates. Incorporation was validated by reporter assays, western blots, and mass spectrometry, and differences in incorporation efficiency were explained by molecular modeling of synthetase-amino acid interactions. As a proof-of-principle application, the genetic replacement of an active-site cysteine residue with a caged cysteine residue in Renilla luciferase led to a complete loss of enzyme activity; however, upon brief exposure to UV light, a >150-fold increase in enzymatic activity was observed, thus showcasing the applicability of the caged cysteine in live human cells. A simultaneously conducted genetic replacement with homocysteine yielded an enzyme with greatly reduced activity, thereby demonstrating the precise probing of a protein active site. These discoveries provide a new tool for the optochemical control of protein function in mammalian cells and expand the set of genetically encoded unnatural amino acids.

  6. Cage-to-cage migration rates of Xe atoms in zeolite NaA from magnetization transfer experiments and simulations

    NASA Astrophysics Data System (ADS)

    Jameson, A. Keith; Jameson, Cynthia J.; Gerald, Rex E., II

    1994-08-01

    Xenon trapped in the alpha cages of zeolite NaA exhibits distinct NMR signals for clusters Xe1, Xe2, Xe3,..., up to Xe8. Using multisite magnetization transfer experiments, we have measured the rate constants kmn for the elementary processes that are involved in the cage-to-cage transfer of Xe atoms in the zeolite NaA, that is, for a single Xe atom leaving a cage containing Xen to appear in a neighboring cage containing Xem-1, thereby forming Xem. In a random walk simulation, these rate constants reproduce over a hundred magnetization decay/recovery curves that we have measured in four samples of Xe in zeolite NaA at room temperature, in selective inversion, and complementary experiments for all the significantly populated clusters. The simulations also lead to the correct experimental equilibrium distributions, that is, the fractions of the alpha cages containing Xe1,Xe2,...,Xe8.

  7. Acute aortic dissection at two extreme ages.

    PubMed

    Ramzisham, A R M; Arief, H; Ngoo, K S; Zamrin, D M; Joanna, O S M

    2011-01-01

    Acute aortic dissection is a life-threatening condition, warranting prompt diagnosis and treatment. Management of which incorporates multidisciplinary expertise from the medical, surgical and intensive care. If left untreated, the mortality rate of acute aortic disease exceeds 50% within 48 hours and 80% within two weeks, with a 5-year survival rate of 19%. The most common cause of death in untreated acute aortic dissection, regardless of aetiology, is aortic rupture. We would like to share our successful experience of cases at the two extreme ages of acute aortic dissection. Literature review with their pathogenesis are discussed.

  8. MMP-2 Isoforms in Aortic Tissue and Serum of Patients with Ascending Aortic Aneurysms and Aortic Root Aneurysms

    PubMed Central

    Tscheuschler, Anke; Meffert, Philipp; Beyersdorf, Friedhelm; Heilmann, Claudia; Kocher, Nadja; Uffelmann, Xenia; Discher, Philipp; Siepe, Matthias; Kari, Fabian A.

    2016-01-01

    Objective The need for biological markers of aortic wall stress and risk of rupture or dissection of ascending aortic aneurysms is obvious. To date, wall stress cannot be related to a certain biological marker. We analyzed aortic tissue and serum for the presence of different MMP-2 isoforms to find a connection between serum and tissue MMP-2 and to evaluate the potential of different MMP-2 isoforms as markers of high wall stress. Methods Serum and aortic tissue from n = 24 patients and serum from n = 19 healthy controls was analyzed by ELISA and gelatin zymography. 24 patients had ascending aortic aneurysms, 10 of them also had aortic root aneurysms. Three patients had normally functioning valves, 12 had regurgitation alone, eight had regurgitation and stenosis and one had only stenosis. Patients had bicuspid and tricuspid aortic valves (9/15). Serum samples were taken preoperatively, and the aortic wall specimen collected during surgical aortic repair. Results Pro-MMP-2 was identified in all serum and tissue samples. Pro-MMP-2 was detected in all tissue and serum samples from patients with ascending aortic/aortic root aneurysms, irrespective of valve morphology or other clinical parameters and in serum from healthy controls. We also identified active MMP-2 in all tissue samples from patients with ascending aortic/aortic root aneurysms. None of the analyzed serum samples revealed signals relatable to active MMP-2. No correlation between aortic tissue total MMP-2 or tissue pro-MMP-2 or tissue active MMP-2 and serum MMP-2 was found and tissue MMP-2/pro-MMP-2/active MMP-2 did not correlate with aortic diameter. This evidence shows that pro-MMP-2 is the predominant MMP-2 species in serum of patients and healthy individuals and in aneurysmatic aortic tissue, irrespective of aortic valve configuration. Active MMP-2 species are either not released into systemic circulation or not detectable in serum. There is no reliable connection between aortic tissue—and serum MMP-2

  9. Notch-dependent EMT is attenuated in patients with aortic aneurysm and bicuspid aortic valve.

    PubMed

    Kostina, Aleksandra S; Uspensky, Vladimir Е; Irtyuga, Olga B; Ignatieva, Elena V; Freylikhman, Olga; Gavriliuk, Natalia D; Moiseeva, Olga M; Zhuk, Sergey; Tomilin, Alexey; Kostareva, Аnna А; Malashicheva, Anna B

    2016-04-01

    Bicuspid aortic valve is the most common congenital heart malformation and the reasons for the aortopathies associated with bicuspid aortic valve remain unclear. NOTCH1 mutations are associated with bicuspid aortic valve and have been found in individuals with various left ventricular outflow tract abnormalities. Notch is a key signaling during cardiac valve formation that promotes the endothelial-to-mesenchymal transition. We address the role of Notch signaling in human aortic endothelial cells from patients with bicuspid aortic valve and aortic aneurysm. Aortic endothelial cells were isolated from tissue fragments of bicuspid aortic valve-associated thoracic aortic aneurysm patients and from healthy donors. Endothelial-to-mesenchymal transition was induced by activation of Notch signaling. Effectiveness of the transition was estimated by loss of endothelial and gain of mesenchymal markers by immunocytochemistry and qPCR. We show that aortic endothelial cells from the patients with aortic aneurysm and bicuspid aortic valve have down regulated Notch signaling and fail to activate Notch-dependent endothelial-to-mesenchymal transition in response to its stimulation by different Notch ligands. Our findings support the idea that bicuspid aortic valve and associated aortic aneurysm is associated with dysregulation of the entire Notch signaling pathway independently on the specific gene mutation.

  10. Aortic Root Enlargement or Sutureless Valve Implantation?

    PubMed Central

    Baikoussis, Nikolaos G.; Dedeilias, Panagiotis; Argiriou, Michalis

    2016-01-01

    Aortic valve replacement (AVR) in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM) post aortic valve replacement (AVR) is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR) and the transcatheter valve implantation (TAVI). PMID:28028424

  11. Genetic and Epigenetic Regulation of Aortic Aneurysms

    PubMed Central

    Kim, Ha Won

    2017-01-01

    Aneurysms are characterized by structural deterioration of the vascular wall leading to progressive dilatation and, potentially, rupture of the aorta. While aortic aneurysms often remain clinically silent, the morbidity and mortality associated with aneurysm expansion and rupture are considerable. Over 13,000 deaths annually in the United States are attributable to aortic aneurysm rupture with less than 1 in 3 persons with aortic aneurysm rupture surviving to surgical intervention. Environmental and epidemiologic risk factors including smoking, male gender, hypertension, older age, dyslipidemia, atherosclerosis, and family history are highly associated with abdominal aortic aneurysms, while heritable genetic mutations are commonly associated with aneurysms of the thoracic aorta. Similar to other forms of cardiovascular disease, family history, genetic variation, and heritable mutations modify the risk of aortic aneurysm formation and provide mechanistic insight into the pathogenesis of human aortic aneurysms. This review will examine the relationship between heritable genetic and epigenetic influences on thoracic and abdominal aortic aneurysm formation and rupture. PMID:28116311

  12. Aortic Wall Injury Related to Endovascular Therapy for Aortic Coarctation.

    PubMed

    Tretter, Justin T; Jones, Thomas K; McElhinney, Doff B

    2015-09-01

    Aortic wall complications can occur in unrepaired aortic coarctation (CoA) and after surgical repair or endovascular treatment. This review summarizes the available literature and current understanding of aortic wall injury (AWI) surrounding the management of CoA, focusing specifically on acute and follow-up AWI after endovascular treatment. There have been 23 reported cases of aortic rupture after endovascular treatment for CoA, including angioplasty alone, bare metal stenting, and primary covered stent therapy. Even if these published cases represent only a minority of ruptures that have actually occurred, the incidence is substantially <1%. The incidence of acute aneurysm formation was 0% to 13% after angioplasty, 0% to 5% after bare metal stent placement, and <1% after covered stent placement. The reported incidence and natural history of both acute and new AWI during follow-up after endovascular therapy for CoA varies considerably, likely secondary to ascertainment and reporting biases and inconsistent definitions. Although important AWI after endovascular treatment of CoA seems to be declining in frequency with increasing experience and improving technology, it remains one of the most important potential adverse outcomes. Long-term surveillance for new AWI and monitoring of existing AWI is mandatory, with institution of appropriate treatment when necessary. A central research focus in this population should be determination of the appropriate treatment for both native and recurrent CoA across various ages with regard to limiting recurrent CoA and preventing associated aortic wall complications, in addition to determining the appropriate treatment of various AWI. Consistent definitions and reporting are necessary to truly understand the incidence of, risk factors for, and measures protective against AWI after angioplasty or stent implantation for CoA.

  13. Hybrid uranyl-carboxyphosphonate cage clusters.

    PubMed

    Adelani, Pius O; Ozga, Michael; Wallace, Christine M; Qiu, Jie; Szymanowski, Jennifer E S; Sigmon, Ginger E; Burns, Peter C

    2013-07-01

    Two new hybrid uranyl-carboxyphosphonate cage clusters built from uranyl peroxide units were crystallized from aqueous solution under ambient conditions in approximately two months. The clusters are built from uranyl hexagonal bipyramids and are connected by employing a secondary metal linker, the 2-carboxyphenylphosphonate ligand. The structure of cluster A is composed of a ten-membered uranyl polyhedral belt that is capped on either end of an elongated cage by five-membered rings of uranyl polyhedra. The structure of cluster B consists of 24 uranyl cations that are arranged into 6 four-membered rings of uranyl polyhedra. Four of the corresponding topological squares are fused together to form a sixteen-membered double uranyl pseudobelt that is capped on either end by 2 topological squares. Cluster A crystallizes over a wide pH range of 4.6-6.8, while cluster B was isolated under narrower pH range of 6.9-7.8. Studies of their fate in aqueous solution upon dissolution of crystals by electrospray ionization mass spectrometry (ESI-MS) and small-angle X-ray scattering (SAXS) provide evidence for their persistence in solution. The well-established characteristic fingerprint from the absorption spectra of the uranium(VI) cations disappears and becomes a nearly featureless peak; nonetheless, the two compounds fluoresce at room temperature.

  14. 1/f Noise Inside a Faraday Cage

    SciTech Connect

    Handel, Peter H.; George, Thomas F.

    2009-04-23

    We show that quantum 1/f noise does not have a lower frequency limit given by the lowest free electromagnetic field mode in a Faraday cage, even in an ideal cage. Indeed, quantum 1/f noise comes from the infrared-divergent coupling of the field with the charges, in their joint nonlinear system, where the charges cause the field that reacts back on the charges, and so on. This low-frequency limitation is thus not applicable for the nonlinear system of matter and field in interaction. Indeed, this nonlinear system is governed by Newton's laws, Maxwell's equations, in general also by the diffusion equations for particles and heat, or reaction kinetics given by quantum matrix elements. Nevertheless, all the other quantities can be eliminated in principle, resulting in highly nonlinear integro-differential equations for the electromagnetic field only, which no longer yield a fundamental frequency. Alternatively, we may describe this through the presence of an infinite system of subharmonics. We show how this was proven early in the classical and quantum domains, adding new insight.

  15. 1/f Noise Inside a Faraday Cage

    NASA Astrophysics Data System (ADS)

    Handel, Peter H.; George, Thomas F.

    2009-04-01

    We show that quantum 1/f noise does not have a lower frequency limit given by the lowest free electromagnetic field mode in a Faraday cage, even in an ideal cage. Indeed, quantum 1/f noise comes from the infrared-divergent coupling of the field with the charges, in their joint nonlinear system, where the charges cause the field that reacts back on the charges, and so on. This low-frequency limitation is thus not applicable for the nonlinear system of matter and field in interaction. Indeed, this nonlinear system is governed by Newton's laws, Maxwell's equations, in general also by the diffusion equations for particles and heat, or reaction kinetics given by quantum matrix elements. Nevertheless, all the other quantities can be eliminated in principle, resulting in highly nonlinear integro-differential equations for the electromagnetic field only, which no longer yield a fundamental frequency. Alternatively, we may describe this through the presence of an infinite system of subharmonics. We show how this was proven early in the classical and quantum domains, adding new insight.

  16. Preliminary in vivo study of an intra-aortic impeller pump driven by an extracorporeal whirling magnet.

    PubMed

    Li, Guorong; Zhao, Hong; Zhu, Xiaodong; Ren, Bing

    2002-10-01

    To achieve the aim of long-term heart-assist with a simple implantable device, we have been trying to develop a minimal intra-aortic impeller blood pump driven by an extracorporeal magnetic device. The purpose of the current study was to evaluate its feasibility by acute in vivo animal tests. The minimal intra-aortic pump was a cage-supported rotor-impeller, 17 mm in diameter with a total length of 30 mm. The driving magnet, mounted extracorporeally, was 55 mm in diameter and 50 mm in length. Seventeen dogs weighing from 28-34 kg were used in the study. After thoracic incision, heparin (50 U/kg) was infused. The impeller pump was inserted into the aortic chamber via a prosthetic vessel and fastened. Thin tubes were inserted into the left ventricular apex and the femoral artery to monitor the left ventricular (LV) and the aortic pressure. After closing the thoracic cavity, the extracorporeal whirling magnet, turned by an electric motor, was placed tightly against the thoracic wall parallel to the intra-aortic pump. The experiments, each lasting for about 40 min, were successful in 7 animals; the other 10 animals died of bleeding during pump implantation and were excluded from the experiment. The peak systolic pressure of the left ventricle could be considerably decreased by the pump and was reduced to as low as 28 mm Hg at a rotational speed of 9,000 rpm, showing that the simple intra-aortic impeller was effective in unloading the natural heart. The novel left ventricular assist device (LVAD) concept of an intra-aortic impeller pump, driven by an extracorporeal magnetic device, is feasible.

  17. Visceral Infarction Following Aortic Surgery

    PubMed Central

    Johnson, Willard C.; Nabseth, Donald C.

    1974-01-01

    An experience with aortic surgery is reported which reveals that visceral ischemia is more frequent than expected and significantly contributes to operative mortality. Two of five deaths among 84 patients who had aorto-iliac occlusive disease and four of 40 deaths among 103 aneurysmectomies (both ruptured and elective) were related to visceral ischemia. A review of the literature reveals 99 cases of colonic ischemia in more than 6,100 cases of aortic surgery, an incidence of 1.5%. Only 10 cases of small bowel ischemia were recorded. The present experience with 9 cases of colon ischemia and one of small bowel ischemia is presented particularly with reference to pathophysiology and prevention. It is concluded that patients should be identified by appropriate angiography if considered a risk for visceral infarction, and, if present, visceral arterial reconstruction should be performed in addition to aortic reconstructive surgery. Colon infarction following aortic aneurysmal surgery is directly related to ligation of a patent IMA. Thus re-implantation of the patent IMA should be considered. ImagesFig. 1a. PMID:4277757

  18. Critical aortic stenosis and acute ascending aortic penetrating ulcer managed utilizing transapical TAVR and TEVAR.

    PubMed

    Allen, Keith B; Davis, J Russell; Cohen, David J

    2015-10-01

    Thoracic endovascular aortic repair (TEVAR) of acute ascending aortic pathology is feasible; however, the unique features of this aortic segment in addition to access challenges restricts its use to a select, high-risk subset of patients. With the advent of TAVR, large device delivery using transapical access has become a well-defined technique. We report a patient with critical aortic stenosis and an acute ascending aortic penetrating ulcer with tamponade managed successfully utilizing transapical TAVR and TEVAR. To our knowledge, this is the first reported case of a hybrid single-stage TAVR and ascending aortic TEVAR using transapical access.

  19. Teaching in the Institutional Cage: Metaphor and Collateral Oppression

    ERIC Educational Resources Information Center

    Noël Smith, Becky L.

    2014-01-01

    This analysis is a philosophical exploration of Marilyn Frye's metaphor of the cage and Patricia Hill Collins' theory of intersecting oppressions. It argues that social structures and forms of oppressive knowledge make up the individual wires on each person's cage and that these work to confine individuals, particularly those in the…

  20. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... System for Award Management (SAM) database (see FAR subpart 4.11) and does not have a CAGE code, DLA... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false CAGE codes. 204.7202-1 Section 204.7202-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...

  1. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... System for Award Management (SAM) database (see FAR subpart 4.11) and does not have a CAGE code, DLA... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false CAGE codes. 204.7202-1 Section 204.7202-1 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...

  2. Structural analysis of aquaculture net cages in current

    NASA Astrophysics Data System (ADS)

    Moe, H.; Fredheim, A.; Hopperstad, O. S.

    2010-04-01

    A method for structural analysis of aquaculture net cages has been developed and verified for a netting solidity of 0.23, water current velocities from 0.1 to 0.5 m/s and relatively large deformations (volume reduction up to 70%) by comparing the numerical results to tests in a flume tank. Strength analysis was performed using commercial explicit finite element software to calculate distribution of loads in the net cage due to current, weights and gravity. The net cage was modelled using truss elements that represented several parallel twines. Sub-elements allowed the trusses to buckle in compression, and only negligible compressive forces were seen in the numerical results. Resulting drag loads and cage volume were shown to be dependent on the net cage size and weight system. Drag loads increased almost proportional to the current velocity for velocities in the range of 0.2-0.5 m/s, while the cage volume was reduced proportional to the current velocity. The calculated forces in ropes and netting of full-size net cages were well below the design capacity for current velocities up to 0.5 m/s. However, netting seams in the bottom panel of the net cage were identified as a potential problem area as the forces could reach the design capacity.

  3. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... electronic equivalent, to— DLA Logistics Information Service, DLIS-SBB, Federal Center, 74 Washington Avenue... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes...) Additional guidance for maintaining CAGE codes is in Volume 7 of DoD 4100.39-M, Federal Logistics...

  4. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... electronic equivalent, to— DLA Logistics Information Service, DLIS-SBB, Federal Center, 74 Washington Avenue... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes...) Additional guidance for maintaining CAGE codes is in Volume 7 of DoD 4100.39-M, Federal Logistics...

  5. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... electronic equivalent, to— DLA Logistics Information Service, DLIS-SBB, Federal Center, 74 Washington Avenue... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes...) Additional guidance for maintaining CAGE codes is in Volume 7 of DoD 4100.39-M, Federal Logistics...

  6. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... electronic equivalent, to— DLA Logistics Information Service, DLIS-SBB, Federal Center, 74 Washington Avenue... Maintenance of the CAGE file. (a) DLA Logistics Information Service will accept written requests for changes...) Additional guidance for maintaining CAGE codes is in Volume 7 of DoD 4100.39-M, Federal Logistics...

  7. Abnormal Behavior in Relation to Cage Size in Rhesus Monkeys

    ERIC Educational Resources Information Center

    Paulk, H. H.; And Others

    1977-01-01

    Examines the effects of cage size on stereotyped and normal locomotion and on other abnormal behaviors in singly caged animals, whether observed abnormal behaviors tend to co-occur, and if the development of an abnormal behavior repertoire leads to reduction in the number of normal behavior categories. (Author/RK)

  8. Caging Mechanism for a drag-free satellite position sensor

    NASA Technical Reports Server (NTRS)

    Hacker, R.; Mathiesen, J.; Debra, D. B.

    1976-01-01

    A disturbance compensation system for satellites based on the drag-free concept was mechanized and flown, using a spherical proof mass and a cam-guided caging mechanism. The caging mechanism controls the location of the proof mass for testing and constrains it during launch. Design requirements, design details, and hardware are described.

  9. Caged molecular beacons: controlling nucleic acid hybridization with light.

    PubMed

    Wang, Chunming; Zhu, Zhi; Song, Yanling; Lin, Hui; Yang, Chaoyong James; Tan, Weihong

    2011-05-28

    We have constructed a novel class of light-activatable caged molecular beacons (cMBs) that are caged by locking two stems with a photo-labile biomolecular interaction or covalent bond. With the cMBs, the nucleic acid hybridization process can be easily controlled with light, which offers the possibility for a high spatiotemporal resolution study of intracellular mRNAs.

  10. Polymers containing borane or carborane cage compounds and related applications

    DOEpatents

    Bowen, III, Daniel E.; Eastwood, Eric A [Raymore, MO

    2012-06-05

    Polymers comprising residues of borane and/or carborane cage compound monomers having at least one polyalkoxy silyl substituent. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Methods of making and applications for using such polymers are also disclosed.

  11. Bio-Inspired Nanomaterials: Protein Cage Nano-Architectures

    DTIC Science & Technology

    2008-04-01

    competitive binding reduced the density of STIV cages on the surface. We expect to improve the density by using high purity protein cages (i.e. tobacco ...monoxide ligands and a bridging carbon monoxide, terminal lamine.1 Direct experimental evidence concerning the composi- cyanide ligands, and a unique

  12. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... available at http://www.dlis.dla.mil/Forms/Form_AC135.asp. (2) If registration in the CCR database is not... (D) The Internet to access the CAGE Lookup Server at http://www.dlis.dla.mil/cage_welcome.asp....

  13. 48 CFR 204.7202-1 - CAGE codes.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... available at http://www.dlis.dla.mil/Forms/Form_AC135.asp. (2) If registration in the CCR database is not... (D) The Internet to access the CAGE Lookup Server at http://www.dlis.dla.mil/cage_welcome.asp....

  14. A Locust Cage and Hatchery from Plastic Aquarium Tanks

    ERIC Educational Resources Information Center

    Stoneman, C. F.; And Others

    1973-01-01

    Describes how to construct a locust cage from two plastic aquaria and four coffee jars with plastic lids. Its advantages over a conventional locust cage include the inexpensive cost, lack of breakable glass, ease of cleaning, and visibility from all angles. (JR)

  15. Ammonia Levels and Urine-Spot Characteristics as Cage-Change Indicators for High-Density Individually Ventilated Mouse Cages

    PubMed Central

    Washington, Ida M; Payton, Mark E

    2016-01-01

    Mouse cage and bedding changes are potentially stressful to mice and are also labor- and resource-intensive. These changes are often performed on a calendar-based schedule to maintain a clean microenvironment and limit the concentrations of ammonia to which mice and workers are exposed. The current study sought to establish a performance-based approach to mouse cage-changing that uses urine spot characteristics as visual indicators of intracage ammonia levels. Colorimetric ammonia indicators were used to measure ammonia levels in individually-ventilated cages (IVC) housing male or female mice (n =5 per cage) of various strains at 1 to 16 d after cage change. Urine spot characteristics were correlated with ammonia levels to create a visual indicator of the cage-change criterion of 25 ppm ammonia. Results demonstrated a consistent increase in ammonia levels with days since cage change, with cages reaching the cage-change criterion at approximately 10 d for IVC containing male mice and 16 d for those with female mice. Ammonia levels were higher for male than female mice but were not correlated with mouse age. However, urine spot diameter, color, and edge characteristics were strongly correlated with ammonia levels. Husbandry practices based on using urine spot characteristics as indicators of ammonia levels led to fewer weekly cage changes and concomitant savings in labor and resources. Therefore, urine spot characteristics can be used as visual indicators of intracage ammonia levels for use of a performance (urine spot)-based approach to cage-changing frequency that maintains animal health and wellbeing. PMID:27177558

  16. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors.

    PubMed

    Pinchuk, Boris; Horbert, Rebecca; Döbber, Alexander; Kuhl, Lydia; Peifer, Christian

    2016-04-29

    In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG) to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV) irradiation of the prodrugs original inhibitory activity was completely restored and even distinctly reinforced, as was the case for the prodrug 4. The presented results are a further evidence for caging technique being an interesting approach in the protein kinase field. It could enable spatial and temporal control for the inhibition of VEGFR-2. The described photoactivatable prodrugs might be highly useful as biological probes for studying the VEGFR-2 signal transduction.

  17. In-situ bioassays using caged bivalves

    SciTech Connect

    Salazar, M.H.; Salazar, S.M.

    1995-12-31

    It is important to make the distinction between chemical measurements to assess bioaccumulation potential versus biological measurements to assess potential bioeffects because bioaccumulation is not a bioeffect. Caging provides a unique opportunity to make synoptic measurements of each and facilitates making these measurements over space and time. Measuring bioaccumulation in resident and transplanted bivalves has probably been the most frequently used form of an in-situ bioassay because bivalves concentrate chemicals in their tissues. They are also easy to collect, cage, and measure. The authors have refined bivalve bioassay methods by minimizing the size range of test animals, making repetitive measurements of the same individuals, and standardizing test protocols for a variety of applications. They are now attempting to standardize criteria for accepting and interpreting data in the same way that laboratory bioassays have been standardized. Growth measurements can serve two purposes in this assessment strategy: (1) An integrated biological response endpoint that is easily quantifiable and with significance to the population, and (2) A means of calibrating bioaccumulation by assessing the relative health and physiological state of tissues that have accumulated the chemicals. In general, the authors have found the highest bioconcentration factors associated with the highest growth rates, the highest concentrations ({micro}g/g) of chemicals in juvenile mussels, and the highest chemical content ({micro}g/animal) in adult mussels. Without accounting for possible dilution of chemical concentrations by tissue growth or magnification through degrowth, contaminant concentrations can be misleading. Examples are provided for the Sudbury River in Massachusetts (Elliptio complanata), San Diego Bay (Mytilus galloprovincialis), and the Harbor Island Superfund Site in Puget Sound (Mytilus trossulus).

  18. A novel vented microisolation container for caging animals: microenvironmental comfort in a closed-system filter cage.

    PubMed

    Rivard, G F; Neff, D E; Cullen, J F; Welch, S W

    2000-01-01

    We designed a closed-system cage with vent ports that would allow continuous airflow in the occupied cage to ensure adequate ventilation and gas exchange. In this system, the metabolic heat loads of mice generate upward thermal air currents. Heat exits via the exhaust port, and room air enters via the intake port, providing adequate ventilation. Simulations based on computational fluid dynamics (CFD) helped us to optimize the cage's design. CFD simulations and smoke visualizations with a feeder-trough assembly illustrated the one-pass air circulation pattern and the lack of air recirculation, turbulence, and dead air space in our system. We used hot-film anemometry and smoke-test methodologies to show that adequate ventilation was provided. In a room with still air (0 air changes per hour [ACH]), a cage fitted with double wire-cloth filters (40 mesh size) and occupied by five mice has at least 12 ACH, whereas the same cage occupied by one mouse has 6 ACH. After five mice had occupied the cage for a week, its average temperature was 0.58C, relative humidity was 34%, and ammonia concentration was 3 ppm higher than that of the room. Our novel vented microisolation cage provides adequate intracage ACH, isolates mice from environmental contaminants, and contains allergenic particles within the cage in an environment appropriate for the species.

  19. Hypertensive Emergency in Aortic Dissection and Thoracic Aortic Aneurysm—A Review of Management

    PubMed Central

    Gupta, Prateek K.; Gupta, Himani; Khoynezhad, Ali

    2009-01-01

    Over the last few decades, treatment for aortic dissection and thoracic aortic aneurysms has evolved significantly with improvement in outcomes. Treatment paradigms include medical, endovascular and surgical options. As aortic dissection presents as a hypertensive emergency, diligent control of BP is of utmost importance in order to reduce the progression of dissection with possible aortic branch malperfusion. Treatment should begin on arrival to the emergency department and continues in the intensive care unit, endovascular suite or the operating room. Novel antihypertensive medications with improved pharmacological profile and improved surgical techniques, have improved the prognosis of patients with aortic aneurysm and/or aortic dissection. Nevertheless, morbidity and mortality remain high and hypertensive emergency poses a significant challenge in aortic dissection and thoracic aortic aneurysms. PMID:27713224

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

    PubMed

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

    2006-04-01

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

  1. Social discrimination of cage-mates and non-cage-mates by rats.

    PubMed

    Jones, Samantha; Burman, Oliver; Mendl, Michael

    2014-07-01

    The ability to discriminate between group-mates and non-group-mates likely underpins the occurrence of affiliative and aggressive behaviour towards 'in-group' and 'out-group' individuals. Here we present two experiments aimed at testing the ability of rats (Rattus norvegicus) to discriminate between cage-mate (CM: animals residing in the subject's home cage) and non-cage-mate (NCM) conspecifics. In experiment 1, rats were trained to discriminate between different exemplars of CM and NCM using a lever pressing task employing symmetrical reinforcement. Subjects did not reach performance criterion, but they did show some evidence of discrimination between the two types of stimuli. In experiment 2, we employed a digging task to determine if rats can discriminate between odour cues from CM and NCM presented simultaneously on two sand-filled bowls. Subjects reached performance criterion on the first pair of odours, and on three more different pairs of CM and NCM odours. The results of a reversal task, using a fifth pair of odours, indicate that the rats were using a common factor to discriminate between social cues from CM and NCM conspecifics, rather than learning each pair independently. Possible candidates include a group-specific odour cue, or the development of a CM/NCM category concept.

  2. The Relationship between Tension and Length of the Aortic Adventitia Resected from the Aortic Wall of Acute Aortic Dissection

    PubMed Central

    Kitano, Mitsuru; Teranishi, Hiroo; Kudo, Masahumi; Matsuura, Makoto

    2014-01-01

    Objective: To our knowledge, no previous study has described the measurement of the tensile strength of the human aortic adventitia. In the present study, we examined the relationship between the tension and length of the aortic adventitia resected from the aortic wall of patients with acute aortic dissection. Methods: We obtained rectangular specimens from the aortic adventitia that was resected in patients with acute aortic dissection during surgery. The specimens were placed on a tension meter (Digital Force Gauge FGS-10, SHIMPO, Kyoto, Japan) within 15 min after resection and stretched until they were pulled apart, and the tension and length were recorded. Results: We obtained 18 specimens during surgery from 11 cases of acute aortic dissection. When the specimen was being pulled apart, the mean tension recorded was 10.2 ± 4.9 N/cm specimen width, whereas the mean elongated length recorded was 4.2 ± 1.1 mm/cm specimen length. Discussion: We determined that the aortic adventitia is elastic and expandable up to 140% of its original length. This indicates that dilation of the aorta to >4.2 cm in diameter may result in a rupture if the original aortic diameter prior to dissection was 3 cm. (*English translation of J Jpn Coll Angiol 2013; 53: 77-81) PMID:25298826

  3. Severe Aortic Stenosis Associated with Unicommissural Unicuspid Aortic Valve in a Middle Aged Male

    PubMed Central

    Kwon, Hee-Jin; Kim, Song Soo; Sun, Byung Joo; Jin, Sun Ah; Kim, Jun-Hyung; Lee, Jae-Hwan; Choi, Siwan; Jeong, Jin-Ok; Seong, In-Whan

    2016-01-01

    Unicuspid aortic valve (UAV) is an extremely rare form of congenital aortic valvular abnormality. Although UAV shows similar clinical characteristics to bicuspid aortic valve, the clinical symptoms develop at earlier age and progress at a faster pace in UAV. In this report, we are presenting a 42-year-old male with severe aortic stenosis associated with unicommissural UAV. The patients underwent a successful Bentall operation. PMID:27721957

  4. Aortic Stenosis: Pathophysiology, Diagnosis, and Therapy.

    PubMed

    Joseph, Jessica; Naqvi, Syed Yaseen; Giri, Jay; Goldberg, Sheldon

    2017-03-01

    The incidence of aortic stenosis increases with age, affecting up to 10% of the population by the eighth decade. Once symptoms develop, aortic stenosis is rapidly fatal. Proper management requires an understanding of the physiology and criteria used to define disease severity. There is no effective pharmacologic treatment. Surgical aortic valve replacement has been the gold standard treatment for decades. However, over the last 10 years transcatheter aortic valve replacement has emerged as an attractive, less-invasive option for appropriately selected patients. Refinements in valve design and delivery systems have led to widespread use of this breakthrough technology in selected patients. We review the pathophysiology, criteria for valve replacement, and the results of the trials comparing transcatheter aortic valve replacement with surgical aortic valve replacement.

  5. Transcatheter aortic valve replacement for bicuspid aortic stenosis 13years post heart transplant.

    PubMed

    Julien, Maureen B; Desai, Nimesh; Brozena, Susan; Herrmann, Howard C

    2016-12-16

    Despite the widespread use of transcatheter aortic valve replacement (TAVR) for moderate and high-risk patients with severe aortic stenosis, it is utilized less frequently in patients with bicuspid aortic valves (BAV). Orthotopic heart transplant (OHT) donors tend to be younger and may have undiagnosed BAV. We present a case of successful TAVR in a patient with BAV thirteen years after OHT.

  6. Traumatic aortic incompetence following road traffic accident

    PubMed Central

    Irving, J. B.

    1974-01-01

    This case report describes the presentation and treatment of a case of aortic incompetence, resulting from a road traffic accident. The relevant literature is briefly reviewed. Aortic incompetence due to trauma has been described following non-penetrating chest injuries, such as kicks from horses (Barie, 1881), falls from heights and crushing accidents (Kissane, Koons and Clark, 1948; Levine, Roberts and Morrow, 1962). Despite the frequency of road traffic accidents, there have been no recent reports of traumatic aortic valve damage. PMID:4467876

  7. Low-gradient aortic stenosis.

    PubMed

    Clavel, Marie-Annick; Magne, Julien; Pibarot, Philippe

    2016-09-07

    An important proportion of patients with aortic stenosis (AS) have a 'low-gradient' AS, i.e. a small aortic valve area (AVA <1.0 cm(2)) consistent with severe AS but a low mean transvalvular gradient (<40 mmHg) consistent with non-severe AS. The management of this subset of patients is particularly challenging because the AVA-gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication for aortic valve replacement (AVR) if the patient has symptoms and/or left ventricular (LV) systolic dysfunction. The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced left ventricular ejection fraction (LVEF), i.e. classical low-flow, low-gradient (LF-LG), or preserved LVEF, i.e. paradoxical LF-LG. Furthermore, a substantial proportion of patients with AS may have a normal-flow, low-gradient (NF-LG) AS: i.e. a small AVA-low-gradient combination but with a normal flow. One of the most important clinical challenges in these three categories of patients with LG AS (classical LF-LG, paradoxical LF-LG, and NF-LG) is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS that should be managed conservatively. A low-dose dobutamine stress echocardiography may be used for this purpose in patients with classical LF-LG AS, whereas aortic valve calcium scoring by multi-detector computed tomography is the preferred modality in those with paradoxical LF-LG or NF-LG AS. Although patients with LF-LG severe AS have worse outcomes than those with high-gradient AS following AVR, they nonetheless display an important survival benefit with this intervention. Some studies suggest that transcatheter AVR may be superior to surgical AVR in patients with LF-LG AS.

  8. Cocking of a poppet-disc prosthesis in the aortic position. A cause of intermittent aortic regurgitation.

    PubMed

    Hammer, W J; Hearne, M J; Roberts, W C

    1976-02-01

    Intermittent aortic regurgitation due to cocking is described for the first time after replacement of the aortic valve with a poppet-disc prosthesis. A combination of disc grooving and strut thrombus produced the cocking with resultant aortic regurgitation.

  9. Bacillus licheniformis prosthetic aortic valve endocarditis.

    PubMed Central

    Santini, F; Borghetti, V; Amalfitano, G; Mazzucco, A

    1995-01-01

    A 73-year old man developed an acute prosthetic aortic valve dehiscence for which emergent operation was undertaken. The intraoperative evidence of an aortic annular disruption and of a subannular abscess led to the hypothesis that an endocarditis process was involved. The aortic valve was replaced with a stentless porcine bioprosthesis. Cultures taken intraoperatively from the aortic area had a pure growth of aerobic, spore-forming, gram-positive bacilli identified as Bacillus licheniformis. The patient responded to specific antibiotic therapy with no relapse at a 20-month follow-up. The potentiality of B. licheniformis as a pathogen should be reconsidered. PMID:8576381

  10. Aortic Aneurysm: Etiopathogenesis and Clinicopathologic Correlations

    PubMed Central

    2016-01-01

    Aortic aneurysm (AA) is one of the life-threatening aortic diseases, leading to aortic rupture of any cause including atherosclerotic and non-atherosclerotic diseases. AA is diagnosed in a variable proportion of patients with dilated aorta by imaging modality. The etiopathogenesis of AA remains unclear in many aortic diseases. Furthermore, although it may be difficult to explain all phenotypes of patients even if genetic mutation could be identified in some proteins such as smooth muscle cell α-actin (ACTA2), myosin heavy chain 11 (MYH11) or SMAD3, individualized consideration of these factors in each patient is essential on the basis of clinicopathological characteristics. PMID:27375798

  11. Hypoplasia of the aortic root 1

    PubMed Central

    Nicks, Rowan; Cartmill, T.; Bernstein, L.

    1970-01-01

    We report a technique for the enlargement of a hypoplastic aortic root by an operation whereby the hypoplastic aortic root has been so enlarged by the insertion of a Dacron fabric gusset that it will accommodate a size 9A or larger Starr-Edwards prosthesis. Our experience in five patients is described. No matter what type of valve is used for replacement of a diseased aortic valve, and no matter what improved designs of valvular prosthesis are ultimately developed, it will be necessary (in the particular group described) to enlarge the aortic ring to accommodate a size which will function correctly without causing left ventricular outflow obstruction. Images PMID:5452289

  12. Aortic dilatation in children with systemic hypertension.

    PubMed

    Gupta-Malhotra, Monesha; Devereux, Richard B; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana

    2014-04-01

    The aim of the study was to determine the presence of aortic dilatation in hypertensive children, the prevalence of which is 4% to 10% in hypertensive adults. Prospectively enrolled multiethnic children, untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at three levels: the sinus of Valsalva, supra-tubular junction, and the ascending aorta. Aortic dilatation was determined by z-score >2 at any one of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Among 142 consecutive hypertensive children (median age, 14 years; 45% females) aortic dilatation was detected in 2.8% (95% confidence interval, 1%-7%; median age, 16 years; 100% females). Children with aortic dilatation, when compared with those without, had significantly more aortic valve insufficiency (P = .005) and left ventricular hypertrophy (P = .018). Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation.

  13. Aortic Dilatation in Children with Systemic Hypertension

    PubMed Central

    Gupta-Malhotra, Monesha; Devereux, Richard B.; Dave, Archana; Bell, Cynthia; Portman, Ronald; Milewicz, Diana

    2014-01-01

    Background The aim of the study was to determine presence of aortic dilatation in hypertensive children, the prevalence of which is 4–10% in hypertensive adults. Methods Prospectively enrolled multiethnic children untreated for their hypertension, underwent an echocardiogram to exclude congenital heart disease and evaluate for end-organ damage and aortic size. The aorta was measured in the parasternal long-axis view at 3 levels: the sinus of Valsalva, supra-tubular junction and the ascending aorta. Aortic dilatation was determined by z-score > 2 at any 1 of the levels measured. Hypertension was defined as blood pressure above the 95th percentile based on the Fourth Working Group criteria confirmed by 24-hour ambulatory blood pressure monitoring. Results Among 142 consecutive hypertensive children (median age 14 years, 45% females) aortic dilatation was detected in 2.8% (95% CI 1% to 7%, median age 16 years, 100% females). Children with aortic dilatation, when compared to those without, had significantly more aortic valve insufficiency (p = 0.005) and left ventricular hypertrophy (p = 0.018). Conclusions Prevalence of aortic dilatation was 2.8% and was associated with significantly more aortic insufficiency and left ventricular hypertrophy in comparison to those without aortic dilatation. PMID:24507486

  14. Aortic Stenosis: Changing Disease Concepts

    PubMed Central

    Rashedi, Nina

    2015-01-01

    Aortic stenosis (AS) occurs in almost 10% of adults over age 80 years with a mortality about 50% at 2 years unless outflow obstruction is relieved by aortic valve replacement (AVR). Development of AS is associated with anatomic, clinical and genetic risk factors including a bicuspid valve in 50%; clinical factors that include older age, hypertension, smoking, diabetes and elevated serum lipoprotein(a) [Lp(a)] levels; and genetic factors such as a polymorphism in the Lp(a) locus. Early stages of AS are characterized by focal areas of leaflet thickening and calcification. The rate of hemodynamic progression is variable but eventual severe AS is inevitable once even mild valve obstruction is present. There is no specific medical therapy to prevent leaflet calcification. Basic principles of medical therapy for asymptomatic AS are patient education, periodic echocardiographic and clinical monitoring, standard cardiac risk factor evaluation and modification and treatment of hypertension or other comorbid conditions. When severe AS is present, a careful evaluation for symptoms is needed, often with an exercise test to document symptom status and cardiac reserve. In symptomatic patients with severe AS, AVR improves survival and relieves symptoms. In asymptomatic patients with severe AS, AVR also is appropriate if ejection fraction is < 50%, disease progression is rapid or AS is very severe (aortic velocity > 5 m/s). The choice of surgical or transcatheter AVR depends on the estimated surgical risk plus other factors such as frailty, other organ system disease and procedural specific impediments. PMID:26140146

  15. Aortic and mitral valve replacement with cloth-covered Braunwald-Cutter prosthesis. A three-year follow-up.

    PubMed

    Pluth, J R; Broadbent, J C; Barnhorst, D A; Danielson, G K

    1975-09-01

    From February, 1971, through February, 1974, heart valves of 510 patients were replaced with cloth-covered Braunwald-Cutter prostheses. The data indicate that cloth encapsulation of the prosthetic cage is associated with a reduction in thromboembolic complications, particularly for mitral valves. Cloth wear on the distal strut, however, is not prevented by use of a Silastic poppet and appears to be a typical finding in aortic valves recovered or inspected after 3 months. Excessive poppet wear has also been noted in the aortic position; poppet embolization has occurred on 2 occasions, and a third patient was found, at the time of reoperation for periprosthetic leak, to have opppet wear sufficient to permit embolization. Although there have been no reports of clinical malfunction of the mitral prosthesis at the time of this writing, further long-term observation of these patients appears warranted.

  16. Migration of hydrogen radicals through clathrate hydrate cages

    NASA Astrophysics Data System (ADS)

    Alavi, Saman; Ripmeester, John A.

    2009-09-01

    Electronic structure calculations are used to determine energy barriers to hydrogen radical migration in structure II clathrate small and large cages. Migration of H-radicals through pentagonal and hexagonal faces of small and large cages are considered and energies barriers calculated at the MP2 level with the 6-311++G( d, p) basis set are 61 and 17 kJ mol -1, respectively. Energy barriers (with tunneling corrections) are used to estimate escape rates from the cages and to explain results of recent experiments on the transformation of n-propyl radical in the propane hydrate and the behavior of hydrogen radicals in tetrahydrofuran/H 2 hydrates.

  17. Metabolic Cage for a Space Flight Model in the Rat

    NASA Technical Reports Server (NTRS)

    Harper, Jennifer S.; Mulenburg, Gerald M.; Evans, Juli; Navidi, Meena; Wolinsky, Ira; Arnaud, Sara B.

    1994-01-01

    The new cage facilitates the collection of 24-h specimens of separated urine and feces apparently uncontaminated by food, as required for precise nutritional and metabolic studies, while maintaining the large floor area and suspension method of Holton's design (3). Although the cage was evaluated, using 6-month-old rats weighing 408 to 488 g, it can be easily adjusted for smaller rats. It also was successfully used to collect post-flight urine after the recent Spacelab Life Sciences-2 space shuttle flight. With its flexibility and ease of use, this new cage design adds a new tool to study the physiologic effects of simulated space flight and other disuse conditions.

  18. Isolation and metabolism cage system for newborn pigs.

    PubMed

    Songer, J R; Mathis, R G; Skartvedt, S M

    1976-03-01

    An isolation system was designed and constructed for isolating normal and infected newborn pigs. The system consisted of an outer cage fitted with a biological diffusion filter and a dunk bath entry system and an inner metabolism cage to contain the pig. When tested with S-13 bacteriophage, the isolation and metabolism cage system was at least 99% efficient in preventing the entry or escape of microorganism. A total of 267 Escherichia coli-infected newborn pigs have been isolated in these units, with no cross contaminations.

  19. Beam-induced graphitic carbon cage transformation from sumanene aggregates

    SciTech Connect

    Fujita, Jun-ichi Tachi, Masashi; Murakami, Katsuhisa; Sakurai, Hidehiro; Morita, Yuki; Higashibayashi, Shuhei; Takeguchi, Masaki

    2014-01-27

    We found that electron-beam irradiation of sumanene aggregates strongly enhanced their transformation into a graphitic carbon cage, having a diameter of about 20 nm. The threshold electron dose was about 32 mC/cm{sup 2} at 200 keV, but the transformation is still induced at 20 keV. The transformation sequence suggested that the cage was constructed accompanied by the dynamical movement of the transiently linked sumanene molecules in order to pile up inside the shell. Thus, bond excitation in the sumanene molecules rather than a knock-on of carbon atoms seems to be the main cause of the cage transformation.

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

    PubMed

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

    2001-12-01

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

  1. Aortic Stiffness, Cerebrovascular Dysfunction, and Memory

    PubMed Central

    Cooper, Leroy L.; Mitchell, Gary F.

    2016-01-01

    Background Aortic stiffness is associated with cardiovascular and cerebrovascular events and cognitive decline. This mini-review focuses on relations of aortic stiffness with microvascular dysfunction and discusses the contribution of abnormal pulsatile hemodynamics to cerebrovascular damage and cognitive decline. We also provide a rationale for considering aortic stiffness as a putative and important contributor to memory impairment in older individuals. Summary Aging is associated with stiffening of the aorta but not the muscular arteries, which reduces wave reflection and increases the transmission of pulsatility into the periphery. Aortic stiffening thereby impairs a protective mechanism that shields the peripheral microcirculation from excessive pulsatility within downstream target organs. Beyond midlife, aortic stiffness increases rapidly and exposes the cerebral microcirculation to abnormal pulsatile mechanical forces that are associated with microvascular damage and remodeling in the brain. Aortic stiffening and high-flow pulsatility are associated with alterations in the microvasculature of the brain; however, a mechanistic link between aortic stiffness and memory has not been established. We showed that in a community-based sample of older individuals, cerebrovascular resistance and white matter hyperintensities - markers of cerebrovascular remodeling and damage - mediated the relation between higher aortic stiffness and lower performance on memory function tests. These data suggest that microvascular and white matter damage associated with excessive aortic stiffness contribute to impaired memory function with advancing age. Key Messages Increasing evidence suggests that vascular etiologies - including aortic stiffness and microvascular damage - contribute to memory impairment and the pathogenesis of dementia, including Alzheimer's disease. Interventions that reduce aortic stiffness may delay memory decline among older individuals. PMID:27752478

  2. Opportunity Studies Bait in Shark's Cage

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In its 49th sol on Mars, NASA's Opportunity had nearly concluded its scientific examination of the extreme southwestern end of the outcrop in Meridiani Planum. In the 'Shark's Cage' area of the neighborhood called 'Shoemaker's Patio,' featured in this image from the front hazard avoidance camera, Opportunity deployed its arm to study the features called 'Shark's Tooth,' 'Shark Pellets,' and 'Lamination.' 'Shark's Tooth' is a piece of the unusual red rind that appears to fill cracks in the outcrop. This rind may be some kind of chemical alteration of the rocks. 'Shark Pellets' is an area of soil that was under investigation as part of the crater soil survey. 'Lamination' is a target with very thin layers that resemble uniform pages in a book, an indication of how the sediments were deposited. A final experiment in this area will be attempted on sol 51. Opportunity's front left wheel will 'scuff' the rock called 'Carousel.' 'Scuffing' involves scraping the rock with one wheel while holding all the others still. This experiment essentially turns the rover wheels into tools, to try and determine the hardness of the target rock.

  3. Linear diffusion into a Faraday cage.

    SciTech Connect

    Warne, Larry Kevin; Lin, Yau Tang; Merewether, Kimball O.; Chen, Kenneth C.

    2011-11-01

    Linear lightning diffusion into a Faraday cage is studied. An early-time integral valid for large ratios of enclosure size to enclosure thickness and small relative permeability ({mu}/{mu}{sub 0} {le} 10) is used for this study. Existing solutions for nearby lightning impulse responses of electrically thick-wall enclosures are refined and extended to calculate the nearby lightning magnetic field (H) and time-derivative magnetic field (HDOT) inside enclosures of varying thickness caused by a decaying exponential excitation. For a direct strike scenario, the early-time integral for a worst-case line source outside the enclosure caused by an impulse is simplified and numerically integrated to give the interior H and HDOT at the location closest to the source as well as a function of distance from the source. H and HDOT enclosure response functions for decaying exponentials are considered for an enclosure wall of any thickness. Simple formulas are derived to provide a description of enclosure interior H and HDOT as well. Direct strike voltage and current bounds for a single-turn optimally-coupled loop for all three waveforms are also given.

  4. [Unicuspid Aortic Valve Stenosis Combined with Aortic Coarctation;Report of a Case].

    PubMed

    Kubota, Takehiro; Wakasa, Satoru; Shingu, Yasushige; Matsui, Yoshiro

    2016-06-01

    Unicuspid aortic valve in an adult is extremely rare. In addition, 90% of the patients with aortic coarctation are reported to die before the age 50. A 60-year-old woman was admitted to our hospital for further examination of exertional dyspnea which had begun one year before. She had been under medical treatment for hypertension since early thirties, and had been also diagnosed with moderate aortic stenosis at 50 years of age. She was at 1st diagnosed with aortic coarctation combined with bicuspid aortic valve stenosis. The aortic valve was then found unicuspid and was replaced under cardiopulmonary bypass with perfusion to both the ascending aorta and the femoral artery. Repair of aortic coarctation was performed 3 months later through left thoracotomy without extracorporeal circulation due to the rich collateral circulation. She had no postoperative complications, and hypertension as well as ankle-brachial index improved to the normal levels.

  5. Aortic annuloplasty with aortic root reconstruction to prevent patient-prosthesis mismatch.

    PubMed

    Hopkins, Richard A

    2006-07-01

    Part of the ongoing argument concerning patient-prosthesis mismatch (PPM) following aortic valve replacement (AVR) is due to the perception that aortic annulus enlargement procedures increase the risk and technical difficulty of aortic valve surgery. Here, an aortic root reconstruction that involves enlargement of the annulus and tailoring of the aortic root to accommodate larger stented prostheses is presented that has been personally performed in 196 patients with no technique-related surgical deaths or complications, and thus can be carried out without additional risk. This aortic root enlargement aortoplasty and annuloplasty method can be calibrated to all AVRs involving stented manufactured prostheses when these are deemed the prosthesis of choice for the patient with a relatively small annulus and/or aortic root, severe left ventricular hypertrophy, compromised LV function or a very active lifestyle, to achieve predicted EOA values > or = 1.00 cm2/m2.

  6. Mitral and aortic regurgitation following transcatheter aortic valve replacement

    PubMed Central

    Szymański, Piotr; Hryniewiecki, Tomasz; Dąbrowski, Maciej; Sorysz, Danuta; Kochman, Janusz; Jastrzębski, Jan; Kukulski, Tomasz; Zembala, Marian

    2016-01-01

    Objective To analyse the impact of postprocedural mitral regurgitation (MR), in an interaction with aortic regurgitation (AR), on mortality following transcatheter aortic valve implantation (TAVI). Methods To assess the interaction between MR and AR, we compared the survival rate of patients (i) without both significant MR and AR versus (ii) those with either significant MR or significant AR versus (iii) with significant MR and AR, all postprocedure. 381 participants of the Polish Transcatheter Aortic Valve Implantation Registry (166 males (43.6%) and 215 females (56.4%), age 78.8±7.4 years) were analysed. Follow-up was 94.1±96.5 days. Results Inhospital and midterm mortality were 6.6% and 10.2%, respectively. Significant MR and AR were present in 16% and 8.1% patients, including 3.1% patients with both significant MR and AR. Patients with significant versus insignificant AR differed with respect to mortality (log rank p=0.009). This difference was not apparent in a subgroup of patients without significant MR (log rank p=0.80). In a subgroup of patients without significant AR, there were no significant differences in mortality between individuals with versus without significant MR (log rank p=0.44). Significant MR and AR had a significant impact on mortality only when associated with each other (log rank p<0.0001). At multivariate Cox regression modelling concomitant significant MR and AR were independently associated with mortality (OR 3.2, 95% CI 1.54 to 5.71, p=0.002). Conclusions Significant MR or AR postprocedure, when isolated, had no impact on survival. Combined MR and AR had a significant impact on a patient's prognosis. PMID:26908096

  7. Metal dimer and trimer within spherical carbon cage

    NASA Astrophysics Data System (ADS)

    Kato, Tatsuhisa

    2007-07-01

    C 80 fulleren cage can be used to realize confinement with the highest possible icosahedral ( Ih) symmetry. As examples, La 2@C 80 and Sc 3C 2@C 80 are molecules in which metal dimer and trimer are encapsulated within the C 80 cage. They are recently purified in the substantial amount by using a high performance liquid chromatograph (HPLC), and studied by spectroscopy and X-ray diffraction. The confinement of the metal cluster with the high symmetry ( Ih) cage is reflected in their specific potential of the intra-molecular rotation for the cluster. The result of electron spin resonance (ESR) measurements indicates that the intra-molecular potential is modified by the chemical modification of the C 80 cage as well as by the injection of an excess electron.

  8. 30. LOCKER CAGE, CHANGE AREA, TOILETS ABOVE ROOF PANEL STORAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. LOCKER CAGE, CHANGE AREA, TOILETS ABOVE ROOF PANEL STORAGE AREA. VIEW TO SOUTH. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  9. 4. VIEW OF WATER TOWER FROM ELECTRICAL TRANSFORMER CAGE AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF WATER TOWER FROM ELECTRICAL TRANSFORMER CAGE AT NORTH END OF SECOND FLOOR WAREHOUSE. VIEW TO WEST-NORTHWEST. - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  10. Inorganic cage molecules encapsulating Kr: A computational study

    NASA Astrophysics Data System (ADS)

    Chang, Ch.; Patzer, A. B. C.; Sedlmayr, E.; Sülzle, D.

    2005-12-01

    Structural and energetic properties of a series of neutral and charged inorganic cage molecules Kr@Y12@Z20q ( Y=Ni,Pd ; Z=As,Sb,Bi ; q=0,-1,-3 ) where a central krypton atom is encapsulated by two outer cages Y12 and Z20 have been investigated by theoretical density functional techniques (DFT) employing the Becke-Perdew-86 (BP86) gradient corrected exchange correlation functional. The structures are closed shell species representing highly stable local minima of icosahedral point group symmetry Ih . We report energies, equilibrium geometric parameters, selected harmonic vibrational frequencies, and discuss static electric dipole polarizabilities. The overall charge q of these cages seems to be controllable by the nature of the central atom leading to stable configurations when Kr is replaced by Br or As. In this context, we report a stable system where a krypton atom is enclosed by a fullerenelike inorganic double cage.

  11. Multiexpandable cage for minimally invasive posterior lumbar interbody fusion

    PubMed Central

    Coe, Jeffrey D; Zucherman, James F; Kucharzyk, Donald W; Poelstra, Kornelis A; Miller, Larry E; Kunwar, Sandeep

    2016-01-01

    The increasing adoption of minimally invasive techniques for spine surgery in recent years has led to significant advancements in instrumentation for lumbar interbody fusion. Percutaneous pedicle screw fixation is now a mature technology, but the role of expandable cages is still evolving. The capability to deliver a multiexpandable interbody cage with a large footprint through a narrow surgical cannula represents a significant advancement in spinal surgery technology. The purpose of this report is to describe a multiexpandable lumbar interbody fusion cage, including implant characteristics, intended use, surgical technique, preclinical testing, and early clinical experience. Results to date suggest that the multiexpandable cage allows a less invasive approach to posterior/transforaminal lumbar interbody fusion surgery by minimizing iatrogenic risks associated with static or vertically expanding interbody prostheses while providing immediate vertebral height restoration, restoration of anatomic alignment, and excellent early-term clinical results. PMID:27729817

  12. Recent advances in aortic valve replacement for aortic stenosis

    PubMed Central

    Al-Adhami, Ahmed; Al-Attar, Nawwar

    2016-01-01

    Aortic valve replacement is no longer an operation that is approached solely through a median sternotomy. Recent advances in the fields of transcatheter valves have expanded the proportion of patients eligible for intervention. Comparisons between transcatheter valves and conventional surgery have shown non-inferiority of transcatheter valve implants in patients with a high or intermediate pre-operative predictive risk. With advances in our understanding of sutureless valves and their applicability to minimally invasive surgery, the invasiveness and trauma of surgery can be reduced with potential improvements in outcome. The strategy of care has radically changed over the last decade. PMID:27803800

  13. Biomechanical characterization of ascending aortic aneurysm with concomitant bicuspid aortic valve and bovine aortic arch.

    PubMed

    Pham, T; Martin, C; Elefteriades, J; Sun, W

    2013-08-01

    Studies have shown that patients harboring bicuspid aortic valve (BAV) or bovine aortic arch (BAA) are more likely than the general population to develop ascending aortic aneurysm (AsAA). A thorough quantification of the AsAA tissue properties for these patient groups may offer insights into the underlying mechanisms of AsAA development. Thus, the objective of this study was to investigate and compare the mechanical and microstructural properties of aortic tissues from AsAA patients with and without concomitant BAV or BAA. AsAA (n=20), BAV (n=20) and BAA (n=15) human tissues were obtained from patients who underwent elective AsAA surgery. Planar biaxial and uniaxial failure tests were used to characterize the mechanical and failure properties of the tissues, respectively. Histological analysis was performed to detect medial degenerative characteristics of aortic aneurysm. Individual layer thickness and composition were quantified for each patient group. The circumferential stress-strain response of the BAV samples was stiffer than both AsAA (p=0.473) and BAA (p=0.152) tissues at a low load. The BAV samples were nearly isotropic, while AsAA and BAA samples were anisotropic. The areal strain of BAV samples was significantly less than that of AsAA (p=0.041) and BAA (p=0.004) samples at a low load. The BAA samples were similar to the AsAA samples in both mechanical and failure properties. On the microstructural level, all samples displayed moderate medial degeneration, characterized by elastin fragmentation, cell loss, mucoid accumulation and fibrosis. The ultimate tensile strength of BAV and BAA sampleswere also found to decrease with age. Overall, the BAV samples were stiffer than both AsAA and BAA samples, and the BAA samples were similar to the AsAA samples. The BAV samples were thinnest, with less elastin than AsAA and BAA samples, which may be attributed to the loss of extensibility of these tissues at a low load. No apparent difference in failure mechanics among

  14. Improved mouse cage provides versatility and ease in handling laboratory mice

    NASA Technical Reports Server (NTRS)

    Jones, N. D.

    1969-01-01

    Mouse cage system provides versatility and ease in handling laboratory mice, cleaning their cages, and collecting uncontaminated metabolic test specimens. The cage, compact and free standing, contains a screened bottom and funnel channel to collect waste. The feed is in the cage top and thereby separates the food and waste.

  15. A DFT study of dodecahedral beryllium silicide cage clusters

    NASA Astrophysics Data System (ADS)

    Fioressi, Silvina; Bacelo, Daniel E.; Binning, R. C.

    2012-06-01

    Density functional theory calculations have been conducted on 20- and 32-atom dodecahedral and face-capped dodecahedral cage clusters of beryllium and silicon. Stable Be24Si8, Be12Si8 and Be12Si20 cages are described, as is a stuffed cluster consisting of dodecahedral Si20 with an endohedral icosahedral Be12. Especial stability is associated with clusters in which faces are capped by silicon atoms, acting as electron donors to beryllium atoms.

  16. Correction of Spray Concentration and Bioassay Cage Penetration Data

    DTIC Science & Technology

    2012-01-01

    analysis were deployed. Mosquito mortality was monitored using Townzen type bioassay cages (Townzen and Natvig 1973) (16 cm diam 3 4 cm depth; with T-310...into holding cups and mortality counts were made 24 h after treatment. Mosquitoes were considered dead if unresponsive to gentle prodding. Overall insect...Bioassay Cage Penetration Data Author(s): Bradley K. Fritz , W. Clint Hoffmann , Keith Haas , and Jane Bonds Source: Journal of the American Mosquito

  17. Aortic Valve Calcification in Mild Primary Hyperparathyroidism

    PubMed Central

    Iwata, Shinichi; Walker, Marcella Donovan; Di Tullio, Marco R.; Hyodo, Eiichi; Jin, Zhezhen; Liu, Rui; Sacco, Ralph L.; Homma, Shunichi

    2012-01-01

    Context: It is unclear whether cardiovascular disease is present in primary hyperparathyroidism (PHPT). Objective: Aortic valve structure and function were compared in PHPT patients and population-based controls. Design: This is a case-control study. Setting: The study was conducted in a university hospital metabolic bone disease unit. Participants: We studied 51 patients with PHPT and 49 controls. Outcome Measures: We measured the aortic valve calcification area and the transaortic pressure gradient. Results: Aortic valve calcification area was significantly higher in PHPT (0.24 ± 0.02 vs. 0.17 ± 0.02 cm2, p<0.01), although there was no difference in the peak transaortic pressure gradient, a functional measure of valvular calcification (5.6 ± 0.3 vs. 6.0 ± 0.3 mm Hg, P = 0.39). Aortic valve calcification area was positively associated with PTH (r = 0.34; P < 0.05) but not with serum calcium, phosphorus, or 25-hydroxyvitamin D levels or with calcium-phosphate product. Serum PTH level remained an independent predictor of aortic valve calcification area after adjustment for age, sex, body mass index, smoking status, history of hypercholesterolemia and hypertension, and estimated glomerular filtration rate. Conclusions: Mild PHPT is associated with subclinical aortic valve calcification. PTH, but not serum calcium concentration, predicted aortic valve calcification. PTH was a more important predictor of aortic valve calcification than well-accepted cardiovascular risk factors. PMID:22031523

  18. Endovascular approach to acute aortic trauma

    PubMed Central

    Karmy-Jones, Riyad; Teso, Desarom; Jackson, Nicole; Ferigno, Lisa; Bloch, Robert

    2009-01-01

    Traumatic thoracic aortic injury remains a major cause of death following motor vehicle accidents. Endovascular approaches have begun to supersede open repair, offering the hope of reduced morbidity and mortality. The available endovascular technology is associated with specific anatomic considerations and complications. This paper will review the current status of endovascular management of traumatic thoracic aortic injuries. PMID:21160721

  19. Homogenized boundary conditions and resonance effects in Faraday cages

    PubMed Central

    Hewitt, I. J.

    2016-01-01

    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called ‘Faraday cage effect’). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells. PMID:27279775

  20. Homogenized boundary conditions and resonance effects in Faraday cages.

    PubMed

    Hewett, D P; Hewitt, I J

    2016-05-01

    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called 'Faraday cage effect'). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells.

  1. Folding Dynamics and Pathways of the Trp-Cage Miniproteins

    PubMed Central

    2015-01-01

    Using alternate measures of fold stability for a wide variety of Trp-cage mutants has raised the possibility that prior dynamics T-jump measures may not be reporting on complete cage formation for some species. NMR relaxation studies using probes that only achieve large chemical shift difference from unfolded values on complete cage formation indicate slower folding in some but not all cases. Fourteen species have been examined, with cage formation time constants (1/kF) ranging from 0.9–7.5 μs at 300 K. The present study does not change the status of the Trp-cage as a fast folding, essentially two-state system, although it does alter the stage at which this description applies. A diversity of prestructuring events, depending on the specific analogue examined, may appear in the folding scenario, but in all cases, formation of the N-terminal helix is complete either at or before the cage-formation transition state. In contrast, the fold-stabilizing H-bonding interactions of the buried Ser14 side chain and the Arg/Asp salt bridge are post-transition state features on the folding pathway. The study has also found instances in which a [P12W] mutation is fold destabilizing but still serves to accelerate the folding process. PMID:25184759

  2. Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein Prenylation

    PubMed Central

    DeGraw, Amanda J.; Hast, Michael A.; Xu, Juhua; Mullen, Daniel; Beese, Lorena S.; Barany, George

    2009-01-01

    Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in pre-clinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease, and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and x-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate, and their photolysis products are benign. These properties highlight the utility of those analogues towards a variety of in vitro and in vivo applications. PMID:18844669

  3. Electrostatic assembly of binary nanoparticle superlattices using protein cages

    NASA Astrophysics Data System (ADS)

    Kostiainen, Mauri A.; Hiekkataipale, Panu; Laiho, Ari; Lemieux, Vincent; Seitsonen, Jani; Ruokolainen, Janne; Ceci, Pierpaolo

    2013-01-01

    Binary nanoparticle superlattices are periodic nanostructures with lattice constants much shorter than the wavelength of light and could be used to prepare multifunctional metamaterials. Such superlattices are typically made from synthetic nanoparticles, and although biohybrid structures have been developed, incorporating biological building blocks into binary nanoparticle superlattices remains challenging. Protein-based nanocages provide a complex yet monodisperse and geometrically well-defined hollow cage that can be used to encapsulate different materials. Such protein cages have been used to program the self-assembly of encapsulated materials to form free-standing crystals and superlattices at interfaces or in solution. Here, we show that electrostatically patchy protein cages--cowpea chlorotic mottle virus and ferritin cages--can be used to direct the self-assembly of three-dimensional binary superlattices. The negatively charged cages can encapsulate RNA or superparamagnetic iron oxide nanoparticles, and the superlattices are formed through tunable electrostatic interactions with positively charged gold nanoparticles. Gold nanoparticles and viruses form an AB8fcc crystal structure that is not isostructural with any known atomic or molecular crystal structure and has previously been observed only with large colloidal polymer particles. Gold nanoparticles and empty or nanoparticle-loaded ferritin cages form an interpenetrating simple cubic AB structure (isostructural with CsCl). We also show that these magnetic assemblies provide contrast enhancement in magnetic resonance imaging.

  4. Homogenized boundary conditions and resonance effects in Faraday cages

    NASA Astrophysics Data System (ADS)

    Hewett, D. P.; Hewitt, I. J.

    2016-05-01

    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called `Faraday cage effect'). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells.

  5. Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein Prenylation

    SciTech Connect

    DeGraw, Amanda J.; Hast, Michael A.; Xu, Juhua; Mullen, Daniel; Beese, Lorena S.; Barany, George; Distefano, Mark D.

    2010-11-15

    Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications.

  6. Electrostatic assembly of binary nanoparticle superlattices using protein cages.

    PubMed

    Kostiainen, Mauri A; Hiekkataipale, Panu; Laiho, Ari; Lemieux, Vincent; Seitsonen, Jani; Ruokolainen, Janne; Ceci, Pierpaolo

    2013-01-01

    Binary nanoparticle superlattices are periodic nanostructures with lattice constants much shorter than the wavelength of light and could be used to prepare multifunctional metamaterials. Such superlattices are typically made from synthetic nanoparticles, and although biohybrid structures have been developed, incorporating biological building blocks into binary nanoparticle superlattices remains challenging. Protein-based nanocages provide a complex yet monodisperse and geometrically well-defined hollow cage that can be used to encapsulate different materials. Such protein cages have been used to program the self-assembly of encapsulated materials to form free-standing crystals and superlattices at interfaces or in solution. Here, we show that electrostatically patchy protein cages--cowpea chlorotic mottle virus and ferritin cages--can be used to direct the self-assembly of three-dimensional binary superlattices. The negatively charged cages can encapsulate RNA or superparamagnetic iron oxide nanoparticles, and the superlattices are formed through tunable electrostatic interactions with positively charged gold nanoparticles. Gold nanoparticles and viruses form an AB(8)(fcc) crystal structure that is not isostructural with any known atomic or molecular crystal structure and has previously been observed only with large colloidal polymer particles. Gold nanoparticles and empty or nanoparticle-loaded ferritin cages form an interpenetrating simple cubic AB structure (isostructural with CsCl). We also show that these magnetic assemblies provide contrast enhancement in magnetic resonance imaging.

  7. [Acute aortic syndromes and sleep apnea].

    PubMed

    Baguet, Jean-Philippe

    2016-10-01

    Obstructive sleep apnea (OSA) is a common disease, often present in "cardiovascular or metabolic patients". OSA favours the occurrence of arterial lesions, all the more if severe. There is a strong relationship between OSA and acute aortic syndromes (AAS). This relationship is in part explained by aortic dilatation linked to OSA. The presence of repeated episodes of sudden variation of transmural pressure applied on aortic wall seems to play a major role in this dilatation. All OSA patients should have a search of aortic dilatation by ultrasound (at a thoracic and abdominal level). Also, screening of OSA should be systematically performed in patients with aortic disease. The effect of continuous positive airway pressure in apneic patients with AAS has not been studied.

  8. Valvular and aortic diseases in osteogenesis imperfecta.

    PubMed

    Lamanna, Arvin; Fayers, Trevor; Clarke, Sophie; Parsonage, William

    2013-10-01

    Osteogenesis imperfecta (OI) is an inheritable connective tissue disorder caused by defective collagen synthesis with the principal manifestations of bone fragility. OI has been associated with left sided valvular regurgitation and aortic dilation. Valve and aortic surgery are technically feasible in patients with OI but are inherently high risk due to the underlying connective tissue defect. This report reviews the valvular and aortic pathology associated with OI and their management. We describe two cases of patients with OI who have significant aortic and mitral valve regurgitation, one of whom has been managed conservatively and the other who has undergone successful mitral valve repair and aortic valve replacement. The latter case represents the fifth case of mitral valve repair in a patient with OI reported in the medical literature.

  9. [Modern aortic surgery in Marfan syndrome--2011].

    PubMed

    Kallenbach, K; Schwill, S; Karck, M

    2011-09-01

    Marfan syndrome is a hereditary disease with a prevalence of 2-3 in 10,000 births, leading to a fibrillin connective tissue disorder with manifestations in the skeleton, eye, skin, dura mater and in particular the cardiovascular system. Since other syndromes demonstrate similar vascular manifestations, but therapy may differ significantly, diagnosis should be established using the revised Ghent nosology in combination with genotypic analysis in specialized Marfan centres. The formation of aortic root aneurysms with the subsequent risk of acute aortic dissection type A (AADA) or aortic rupture limits life expectancy in patients with Marfan syndrome. Therefore, prophylactic replacement of the aortic root needs to be performed before the catastrophic event of AADA can occur. The goal of surgery is the complete resection of pathological aortic tissue. This can be achieved with excellent results by using a (mechanically) valved conduit that replaces both the aortic valve and the aortic root (Bentall operation). However, the need for lifelong anticoagulation with Coumadin can be avoided using the aortic valve sparing reimplantation technique according to David. The long-term durability of the reconstructed valve is favourable, and further technical improvements may improve longevity. Although results of prospective randomised long-term studies comparing surgical techniques are lacking, the David operation has become the surgical method of choice for aortic root aneurysms, not only at the Heidelberg Marfan Centre. Replacement of the aneurysmal dilated aortic arch is performed under moderate hypothermic circulatory arrest combined with antegrade cerebral perfusion using a heart-lung machine, which we also use in thoracic or thoracoabdominal aneurysms. Close post-operative follow-up in a Marfan centre is pivotal for the early detection of pathological changes on the diseased aorta.

  10. Diagnostic imaging for aortic dissection.

    PubMed

    Kapustin, Andrew J; Litt, Harold I

    2005-01-01

    Diagnostic imaging for aortic dissection has dramatically changed in recent years. Previously, imaging consisted of conventional X-ray radiography, followed by invasive catheter angiography. Now imaging of dissection is performed primarily with multidetector CT, and to a lesser extent, with ultrasound and MRI. Catheter angiography is used primarily as a means of treating complications. Which modality to choose depends on patient factors, physician preference, and differences in availability of state-of-the-art equipment. All three modalities are highly accurate in experienced hands and have revolutionized the detection and evaluation of this condition.

  11. Abdominal Aortic Surgery: Anesthetic Implications

    PubMed Central

    Cunningham, Anthony J.

    1991-01-01

    The objectives of the review are to highlight the clinical characteristics of the patient population; to assess multivariate risk factor analysis and the invasive/non-invasive techniques available for risk factor identification and management in this high-risk surgical population; to assess the major hemodynamic, metabolic, and regional blood flow changes associated with aortic cross-clamping/unclamping procedures and techniques for their modification or attenuation; and to assess the influence of perioperative anesthetic techniques and management on patient outcome. PMID:1814052

  12. Multicomponent Protein Cage Architectures for Photocatalysis

    SciTech Connect

    Gupta, Arunava; Prevelige, Peter E

    2016-01-04

    The primary goal of the project was to develop protein-templated approaches for the synthesis and directed assembly of semiconductor nanomaterials that are efficient for visible light absorption and hydrogen production. In general, visible-light-driven photocatalysis reactions exhibit low quantum efficiency for solar energy conversion primarily because of materials-related issues and limitations, such as the control of the band gap, band structure, photochemical stability, and available reactive surface area of the photocatalyst. Synthesis of multicomponent hierarchical nano-architectures, consisting of semiconductor nanoparticles (NPs) with desired optical properties fabricated to maximize spatial proximity for optimum electron and energy transfer represents an attractive route for addressing the problem. Virus capsids are highly symmetrical, self-assembling protein cage nanoparticles that exist in a range of sizes and symmetries. Selective deposition of inorganic, by design, at specific locations on virus capsids affords precise control over the size, spacing, and assembly of nanomaterials, resulting in uniform and reproducible nano-architectures. We utilized the self-assembling capabilities of the 420 subunit, 60 nm icosahedral, P22 virus capsid to direct the nucleation, growth, and proximity of a range of component materials. Controlled fabrication on the exterior of the temperature stable shell was achieved by genetically encoding specific binding peptides into an externally exposed loop which is displayed on each of the 420 coat protein subunits. Localization of complimentary materials to the interior of the particle was achieved through the use “scaffolding-fusion proteins. The scaffolding domain drives coat protein polymerization resulting in a coat protein shell surrounding a core of approximately 300 scaffolding/fusion molecules. The fusion domain comprises a peptide which specifically binds the semiconductor material of interest.

  13. Role of Cardiac CT Before Transcatheter Aortic Valve Implantation (TAVI).

    PubMed

    Marwan, Mohamed; Achenbach, Stephan

    2016-02-01

    Catheter-based aortic valve implantation is increasingly being performed in high-risk patients with symptomatic aortic valve stenosis. For successful planning of the procedure, CT has been shown to provide crucial information concerning the aortic root as well as the peripheral access vessels. This article illustrates the increasing role of CT before transcatheter aortic valve implantation.

  14. Improved technique of transapical aortic valve implantation: "the Berlin addition".

    PubMed

    Pasic, Miralem; Dreysse, Stephan; Drews, Thorsten; Buz, Semih; Unbehaun, Axel; Kukucka, Marian; Mladenow, Alexandar; Hetzer, Roland

    2010-06-01

    Transapical aortic valve implantation carries some degree of uncertainty regarding the definitive valve position. We added angiographic visualization of the aortic root while the prosthetic valve is being slowly deployed. It enables easy correction of the position of the valve so that perfect alignment can be achieved of the relationships between the prosthetic valve, aortic valve annulus, aortic cusps, and the coronary arteries.

  15. Nontraumatic avulsion of aortic valve commissure as a cause of acute aortic valve regurgitation

    PubMed Central

    Chang, Rei-Yeuh; Chen, Chien-Chang; Hsu, Wei-Pang; Hsiao, Pei-Ching; Tsai, Han-Lin; Hsiao, Ping-Gune; Wu, Jiann-Der; Guo, How-Ran

    2016-01-01

    Abstract Background: Avulsion of the aortic valve commissure as a cause of acute aortic valve regurgitation is mostly due to trauma, infective endocarditis, or ascending aortic dissection. Nontraumatic avulsion of the aortic valve commissure is very rare. We reviewed the literature and analyzed potential risk factors of nontraumatic avulsion. Case presentation: An 80-year-old male with hypertension was seen in the emergency department with acute onset dyspnea. Echocardiogram revealed left ventricular hypertrophy with adequate systolic function, prolapse of the noncoronary cusp, and incomplete coaptation of the right coronary and noncoronary cusps with severe aortic valve regurgitation. Surgery revealed an avulsion between the left coronary and noncoronary cusps. Histopathology examination of the aortic valve showed myxoid degeneration, fibrosis, and calcification. Examination of the ascending aorta revealed myxoid degeneration and fragmentation of elastic fibers. Aortic valve replacement was performed, and the patient was alive and well 4 years after surgery. A review of the literature showed that more than three-fourths of the similar cases occurred in males, and about half in patients with hypertension and those 60 years of age or older. Conclusions: In the case of acute aortic regurgitation without a history of trauma, infection, or valvotomy, when 2 prolapsed aortic cusps are observed by echocardiography in the absence of an intimal tear of the ascending aorta, an avulsion of the aortic commissure should be suspected, especially in males with hypertension who are 60 years of age or older. PMID:27749570

  16. Automated home cage observations as a tool to measure the effects of wheel running on cage floor locomotion.

    PubMed

    de Visser, Leonie; van den Bos, Ruud; Spruijt, Berry M

    2005-05-28

    This paper introduces automated observations in a modular home cage system as a tool to measure the effects of wheel running on the time distribution and daily organization of cage floor locomotor activity in female C57BL/6 mice. Mice (n = 16) were placed in the home cage system for 6 consecutive days. Fifty percent of the subjects had free access to a running wheel that was integrated in the home cage. Overall activity levels in terms of duration of movement were increased by wheel running, while time spent inside a sheltering box was decreased. Wheel running affected the hourly pattern of movement during the animals' active period of the day. Mice without a running wheel, in contrast to mice with a running wheel, showed a clear differentiation between novelty-induced and baseline levels of locomotion as reflected by a decrease after the first day of introduction to the home cage. The results are discussed in the light of the use of running wheels as a tool to measure general activity and as an object for environmental enrichment. Furthermore, the possibilities of using automated home cage observations for e.g. behavioural phenotyping are discussed.

  17. Outcomes of contemporary use of rectangular titanium stand-alone cages in anterior cervical discectomy and fusion: cage subsidence and cervical alignment.

    PubMed

    Yamagata, Toru; Takami, Toshihiro; Uda, Takehiro; Ikeda, Hidetoshi; Nagata, Takashi; Sakamoto, Shinichi; Tsuyuguchi, Naohiro; Ohata, Kenji

    2012-12-01

    Cervical intervertebral disc replacement using a rectangular titanium stand-alone cage has become a standard procedure for anterior cervical discectomy and fusion (ACDF). We examined outcomes resulting from the contemporary use of rectangular titanium stand-alone cages for ACDF, particularly focusing on cage subsidence and subsequent kyphotic malalignment. Patient data were collected prospectively, and a total of 47 consecutive patients who underwent periodic follow-up of at least 1 year's duration after ACDF were studied retrospectively. Sixty-three rectangular titanium cages were implanted during 31 1-level and 16 2-level procedures. None of the patients developed surgery-related complications (including cage displacement or extrusion). Mean Neurosurgical Cervical Spine Scale scores were significantly improved at 1 year after surgery. Twelve of the 63 inserted cages (19.0%) were found to have cage subsidence, occurring in 11 of 47 patients (23.4%). There was no significant difference in functional recovery between patients with and without cage subsidence. Logistic regression analysis indicated that fusion level, cage size and cage position were significantly related to cage subsidence. The distraction ratio among patients with cage subsidence was significantly higher than that among patients without cage subsidence. Cage subsidence resulted in early deterioration of local angle and total alignment of the cervical spine. Although a longer follow-up is warranted, a good surgical outcome with negligible complications appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF. Excessive distraction at the fusion level should be avoided, and cage position should be adjusted to the anterior vertical line.

  18. Severe Aortic Coarctation in a 75-Year-Old Woman: Total Simultaneous Repair of Aortic Coarctation and Severe Aortic Stenosis

    PubMed Central

    Park, Ju Hyun; Song, Sung Gook; Kim, Jeong Su; Park, Yong Hyun; Kim, Jun; Choo, Ki Seuk; Kim, June Hong; Lee, Sang Kwon

    2012-01-01

    Aortic coarctation is usually diagnosed and repaired in childhood and early adulthood. Survival of a patient with an uncorrected coarctation to more than 70 years of age is extremely unusual, and management strategies for these cases remain controversial. We present a case of a 75-year-old woman who was first diagnosed with aortic coarctation and severe aortic valve stenosis 5 years ago and who underwent a successful one-stage repair involving valve replacement and insertion of an extra-anatomical bypass graft from the ascending to the descending aorta. PMID:22363387

  19. Repair for acquired aortic valve disease.

    PubMed

    Antunes, M J

    1996-10-01

    The favorable results of mitral valvuloplasty when compared with valve replacement have renewed the interest of many surgeons in aortic valve repair. However, these efforts have, for the most part, been unsuccessful. Also, the results of aortic valve replacement are usually better than those of mitral valve replacement. Yet, some patients appear to derive benefit from a conservative aortic valve procedure. The best examples are mild or moderate aortic valve disease associated with mitral valve or coronary artery disease, which constitute the primary indication for operation, where "prophylactic" aortic valve replacement does not appear justifiable. Other possible indications for aortic valvuloplasty includes patient's lack of compliance or contraindication to anticoagulation in young patients. Senile aortic stenosis, in very old patients with a small annulus, preserved leaflet morphology and nonsignificant commissural fusion should be considered for repair. However, since the procedure is not easily reproducible and the results not uniformly predictable, it cannot be recommended for generalized use. Nonetheless, experienced surgeons should be encouraged to continue these efforts.

  20. Synthesis and Characterization of Polyfunctional Polyhedral Silsesquioxane Cages

    NASA Astrophysics Data System (ADS)

    Sulaiman, Santy

    Recent studies on octameric polyhedral silsesquioxanes, (RSiO1.5 )8, indicate that the silsesquioxane cage is not just a passive component but appears to be involved in electron delocalization with conjugated organic tethers in the excited state. This dissertation presents the synthesis and characterization of (RSiO1.5)8 molecules with unique photophysical properties that provide support for the existence of conjugation that involves the (RSiO1.5)8 cage. The dissertation first discusses the elaboration of octavinylsilsesquioxane via cross-metathesis to form styrenyl-functionalized octasilsesquioxane molecules. Subsequent Heck coupling reactions of p-bromostyrenyl derivative provides vinylstilbene-functionalized octasilsesquioxane. The amino derivative, NH2VinylStilbeneOS, show highly red-shifted emission spectrum (100 nm from the simple organic analog p-vinylstilbene) and high two-photon absorption (TPA) cross-section value (100 GM/moiety), indicating charge-transfer processes involving the silsesquioxane cage as the electron acceptor. The unique photophysical properties of polyfunctional luminescent cubic silsesquioxanes synthesized from ortho-8-, (2,5)-16-, and 24-brominated octaphenylsilsesquioxane (OPS) via Heck coupling show how the steric interactions of the organic tethers at the silsesquioxane cage corner affect conjugation with the silsesquioxane cage. Furthermore, the high TPA cross-section (10 GM/moiety) and photoluminescence quantum yield (20%) of OPS functionalized with 24 acetoxystyrenyl groups suggest that the existence excited states in these molecules with similar energies and decay rates: normal radiative pi- pi* transition and charge transfer involving the silsesquioxane cage. The fluoride ion-catalyzed rearrangement reactions of cage and polymeric silsesquioxanes provide a convenient route to a mixture of deca- and dodecameric silsesquioxane molecules in high yields, giving us the opportunity to investigate the effect of silsesquioxane cage

  1. Metabolic Cages for a Space Flight Model in the Rat

    NASA Technical Reports Server (NTRS)

    Harper, Jennifer S.; Mulenburg, Gerald M.; Evans, Juli; Navidi, Meena; Wolinsky, Ira; Arnaud, Sara B.

    1994-01-01

    A variety of space flight models are available to mimic the physiologic changes seen in the rat during weightlessness. The model reported by Wronski and Morey-Holton has been widely used by many investigators, in musculoskeletal physiologic studies especially, resulting in accumulation of an extensive database that enables scientists to mimic space flight effects in the 1-g environment of Earth. However, information on nutrition or gastrointestinal and renal function in this space flight model is limited by the difficulty in acquiring uncontaminated metabolic specimens for analysis. In the Holton system, a traction tape harness is applied to the tail, and the rat's hindquarters are elevated by attaching the harness to a pulley system. Weight-bearing hind limbs are unloaded, and there is a headward fluid shift. The tail-suspended rats are able to move freely about their cages on their forelimbs and tolerate this procedure with minimal signs of stress. The cage used in Holton's model is basically a clear acrylic box set on a plastic grid floor with the pulley and tail harness system attached to the open top of the cage. Food is available from a square food cup recessed into a corner of the floor. In this system, urine, feces, and spilled food fall through the grid floor onto absorbent paper beneath the cage and cannot be separated and recovered quantitatively for analysis in metabolic balance studies. Commercially available metabolic cages are generally cylindrical and have been used with a centrally located suspension apparatus in other space flight models. The large living area, three times as large as most metabolic cages, and the free range of motion unique to Holton's model, essential for musculoskeletal investigations, were sacrificed. Holton's cages can accommodate animals ranging in weight from 70 to 600 g. Although an alternative construction of Holton's cage has been reported, it does not permit collection of separate urine and fecal samples. We describe

  2. Endohedral metal atoms in pristine and functionalized fullerene cages.

    PubMed

    Yamada, Michio; Akasaka, Takeshi; Nagase, Shigeru

    2010-01-19

    Fullerene, an allotropic form of carbon made up of spherical molecules formed from pentagonal and hexagonal rings, was first discovered in 1985. Because fullerenes have spacious inner cavities, atoms and clusters can be encapsulated inside the fullerene cages to form endohedral fullerenes. In particular, the unique structural and electronic properties of endohedral metallofullerenes (EMFs), where metal atoms are encapsulated within the fullerene, have attracted wide interest from physicists and chemists as well as materials scientists and biologists. The remarkable characteristics of these molecules originate in the electron transfer from the encapsulated metal atoms to the carbon cage. The positions and movements of the encapsulated metal atoms are important determinants of the chemical and physical properties of EMFs. In this Account, we specifically describe the positions and dynamic behavior of the metal atoms encapsulated in pristine and functionalized fullerene cages. First, we examined whether the metal atoms are attached rigidly to cage carbons or move around. Our systematic investigations of EMFs, including M@C(2v)-C(82), M(2)@D(2)(10611)-C(72), M(2)@D(3h)(5)-C(78), M(2)@I(h)-C(80), and M(2)@D(5h)-C(80), revealed that the metal positions and movements vary widely with different cage structures and numbers of metal atoms. Second, we wanted to understand whether we could control the positions and movements of the untouchable metal atoms in EMFs. One possible way to modulate this behavior was through attachment of a molecule to the outer surface of the cage. We developed synthetic methods to modify EMFs and have examined the metal positions and movements in the functionalized carbon cages. Remarkably, we could alter the dynamic behavior of the encaged metal atoms in M(2)@I(h)-C(80) drastically through chemical modification of the outer cage. We anticipate that the control of metal atom structures and dynamics within a cage could be valuable for designing

  3. Acute Type B Aortic Dissection in a Patient with Previous Endovascular Abdominal Aortic Aneurysm Repair

    PubMed Central

    Park, Sung Hun; Rha, Seung-Woon

    2017-01-01

    Endovascular aortic repair (EVAR) was relatively safe, and became a widely performed procedure. If aortic dissection (AD) occurred in patient with previous EVAR, it could cause fatal complications like endograft collapse. Surgical treatment was limited in this situation for comorbidities and complex anatomies. Here we report a rare case of acute type B AD developed following trans-radial coronary intervention in a patient with previous EVAR of abdominal aortic aneurysm, which was treated with thoracic EVAR. PMID:28377913

  4. Aortic root abscess presenting as alternating bundle branch block: Infective endocarditis of bicuspid aortic valve

    PubMed Central

    Jain, Rakesh; Kader, Muneer; Sajeev, C.G.; Krishnan, M.N.

    2015-01-01

    Bicuspid aortic valve is the most common congenital cardiac malformation, affecting 1%–2% of the population. Among various complications, incidence of infective endocarditis (IE) in the bicuspid aortic valve population is high with higher rate of periannular extension resulting in conduction disturbances. Here we are reporting a rare case of infective endocarditis of bicuspid aortic valve presented with alternating bundle branch block. PMID:26138186

  5. Simulations of Transcatheter Aortic Valve Implantation – Implications for Aortic Root Rupture

    PubMed Central

    Wang, Qian; Kodali, Susheel; Primiano, Charles; Sun, Wei

    2014-01-01

    Objectives Aortic root rupture is one of the most severe complications of transcatheter aortic valve implantation (TAVI). The mechanism of this adverse event remains mostly unknown. The purpose of this study was to obtain a better understanding of the biomechanical interaction between the tissue and stent for patients with a high risk of aortic rupture. Methods We simulated the stent deployment process of three TAVI patients with high aortic rupture risk using finite element method. The first case was a retrospective analysis of an aortic rupture case, while the other two cases were prospective studies, which ended with one cancelled procedure and one successful TAVI. Simulation results were evaluated for the risk of aortic root rupture, as well as coronary artery occlusion, and paravalvular leak. Results For Case 1, the simulated aortic rupture location was the same as clinical observations. From the simulation results, it can be seen that the large calcified spot on the interior of the left coronary sinus between coronary ostium and the aortic annulus was pushed by the stent, causing the aortic rupture. For Case 2 and Case 3, predicated results from the simulations were presented to the clinicians at pre-procedure meetings; and they were in agreement with clinician’s observations and decisions. Conclusions Our results indicated that the engineering analysis could provide additional information to help clinicians evaluate complicated, high risk aortic rupture cases. Since a systematic study of a large patient cohort of aortic rupture is currently not available (due to the low occurrence rate) to clearly understand underlying rupture mechanisms, case by case engineering analysis is recommended for evaluating patient-specific aortic rupture risk. PMID:24736808

  6. Bacillus cereus endocarditis in native aortic valve.

    PubMed

    Ngow, H A; Wan Khairina, W M N

    2013-02-01

    Bacillus cereus endocarditis is rare. It has been implicated in immunocompromised individuals, especially in intravenous drug users as well as in those with a cardiac prosthesis. The patient was a 31-year-old ex-intravenous drug addict with a past history of staphylococcal pulmonary valve endocarditis, who presented with symptoms of decompensated cardiac failure. Echocardiography showed severe aortic regurgitation with an oscillating vegetation seen on the right coronary cusp of the aortic valve. The blood cultures grew Bacillus cereus. We report this as a rare case of Bacillus cereus endocarditis affecting a native aortic valve.

  7. Stent graft implantation in an aortic pseudoaneurysm associated with a fractured Cheatham-Platinum stent in aortic coarctation.

    PubMed

    Kuhelj, Dimitrij; Berden, Pavel; Podnar, Tomaž

    2016-03-01

    We report a case of aortic pseudoaneurysm associated with a fractured bare Cheatham-Platinum stent following stenting for aortic coarctation. These complications were recognised 6 years after the implantation procedure and were successfully managed by percutaneous stent graft implantation. Staged approach for stent dilatation might prevent development of aortic pseudoaneurysms. In addition, careful follow-up is warranted after stenting for aortic coarctation, particularly in patients with recognised aortic wall injury.

  8. Comparison of 2 Rat Breeding Schemes Using Conventional Caging

    PubMed Central

    Allen, Kenneth P; Dwinell, Melinda R; Zappa, Allison; Temple, Anne; Thulin, Joseph

    2013-01-01

    Compared with earlier editions, the eighth edition of the Guide for the Care and Use of Laboratory Animals recommends more cage floor space for female rats with litters. As such, conventional rat cages often do not supply the recommended floor space to maintain 2 adult rats and a litter in the same cage. We evaluated 2 breeding schemes using traditional cages that afford 140 in.2 (903 cm2) of floor space: (1) monogamous pairs housed continuously and (2) monogamous pairs cohoused intermittently with removal of the male rat after parturition. The results did not demonstrate a significant difference between breeding schemes in generation time, number of litters per breeding pair, percentage of litters weaned, number of pups born per breeding pair, and number of pups weaned per breeding pair. However, the average weaning weight of pups was significantly higher with scheme 1 compared with scheme 2. Collectively, these results indicate continuous housing of monogamous breeding pairs may be preferable to intermittent housing when conventional cages are used. PMID:23562096

  9. High levitation pressures with cage-cooled superconductors

    NASA Astrophysics Data System (ADS)

    Hull, John R.; Komori, Mochimitsu

    2002-05-01

    We present an analysis of and experimental results from a levitational system comprising a stationary, bulk high-temperature superconductor (HTS) and a levitated component (rotor) that consists of a cylindrical permanent magnet surrounded by an annular HTS. The rotor is cooled below the critical temperature of the HTS while surrounded by a ferromagnetic cage. When the ferromagnetic cage is removed, the flux from the permanent magnet is essentially excluded from the interior of the HTS. When brought into proximity with the HTS stator, the cage-cooled rotor experiences a levitational force. The levitational force may be calculated by applying magnetic circuit theory. Such calculations indicate that for a sufficiently high critical current density, the levitational pressure may exceed that between the permanent magnet and its mirror image. We constructed a rotor from an NdFeB permanent magnet and YBCO bulk HTS with a critical current density of ≈5 kA cm-2. A soft ferromagnetic steel cage was constructed in segments. The critical current density of the stator HTS was also ≈5 kA cm-2. Experimental results obtained with the cage-cooled rotor and stationary HTS show a significant increase in force over that of an equivalent PM rotor and stationary HTS.

  10. Application of Taguchi method in optimization of cervical ring cage.

    PubMed

    Yang, Kai; Teo, Ee-Chon; Fuss, Franz Konstantin

    2007-01-01

    The Taguchi method is a statistical approach to overcome the limitation of the factorial and fractional factorial experiments by simplifying and standardizing the fractional factorial design. The objective of the current study is to illustrate the procedures and strengths of the Taguchi method in biomechanical analysis by using a case study of a cervical ring cage optimization. A three-dimensional finite element (FE) model of C(5)-C(6) with a generic cervical ring cage inserted was modelled. Taguchi method was applied in the optimization of the cervical ring cage in material property and dimensions for producing the lowest stress on the endplate to reduce the risk of cage subsidence, as in the following steps: (1) establishment of objective function; (2) determination of controllable factors and their levels; (3) identification of uncontrollable factors and test conditions; (4) design of Taguchi crossed array layout; (5) execution of experiments according to trial conditions; (6) analysis of results; (7) determination of optimal run; (8) confirmation of optimum run. The results showed that a cage with larger width, depth and wall thickness can produce the lower von Mises stress under various conditions. The contribution of implant materials is found trivial. The current case study illustrates that the strengths of the Taguchi method lie in (1) consistency in experimental design and analysis; (2) reduction of time and cost of experiments; (3) robustness of performance with removing the noise factors. The Taguchi method will have a great potential application in biomechanical field when factors of the issues are at discrete level.

  11. Anterior extrusion of fusion cage in posttraumatic cervical disk disease.

    PubMed

    Amelot, Aymeric; Bouazza, Schahrazed; George, Bernard; Orabi, Mikael; Bresson, Damien

    2015-03-01

    Anterior interbody fusion of the cervical spine (ACDF) with bone grafts or cages has become the gold standard for treating cervical disk disease. Several technical modifications have been developed, but currently no consensus exists regarding the optimal technique. In addition, there is also evidence that complications are frequently associated with this procedure. A frequent cause for implant failure in monosegmental ACDF is cage migration into the vertebral end plates or the spinal canal. We report a patient admitted for sudden quadriparesis with complete motor deficit caused by posttraumatic cervical disk protrusion at C4-C5, resulting in spinal compression. ACDF using a titanium stand-alone cage was performed and cured the patient. At the 1-year follow-up visit, imaging showed asymptomatic anterior complete extrusion of the cage out of the disk space. To our knowledge, such an anterior cage migration without trauma has not been reported in the literature to date, and we tried to find technical reasons to explain this complication.

  12. Pseudopeptidic cages as receptors for N-protected dipeptides.

    PubMed

    Faggi, Enrico; Moure, Alejandra; Bolte, Michael; Vicent, Cristian; Luis, Santiago V; Alfonso, Ignacio

    2014-05-16

    The molecular recognition of short peptides is a challenge in supramolecular chemistry, and the use of peptide-like cage receptors represents a promising approach. Here we report the synthesis and characterization of a diverse family of pseudopeptidic macrobicycles, as well as their binding abilities toward N-protected dipeptides using a combination of different techniques (NMR, ESI-MS, and fluorescence spectroscopy). The cage hosts were assayed for dipeptide binding using competition ESI-MS experiments as high-throughput screening to obtain general trends for the recognition phenomena. Selected hosts were additionally studied by NMR spectroscopy ((1)H NMR titration and diffusion-ordered spectroscopy experiments) in different solvents. The results unambiguously demonstrated the formation of the [cage·dipeptide] supramolecular complexes and rendered quantitative information about the strength of the interaction (K(ass)). The structural variables within the pseudopeptidic cage framework that produced a stronger and more selective recognition were thus identified. The cages showed a remarkable selectivity for N-protected dipeptides with an aromatic amino acid at the carboxylic terminus, which prompted us to propose a mode of binding based on polar and nonpolar noncovalent interactions. Accordingly, we faced the molecular recognition of a target dipeptide (Ac-EY-OH) mimicking a biologically relevant sequence by NMR and fluorescence spectroscopy in highly competitive media.

  13. A metabolic cage for the hindlimb suspended rat

    NASA Technical Reports Server (NTRS)

    Evans, J.; Mulenburg, G. M.; Harper, J. S.; Skundberg, T. L.; Navidi, M.; Arnaud, S. B.

    1994-01-01

    Hindlimb suspension has been successfully used to simulate the effects of microgravity in rats. The cage and suspension system developed by E. R. Holton is designed to produce a headward shift of fluid and unload the hindlimbs in rodents, causing changes in bone and muscle similar to those in animals and humans exposed to spaceflight. While the Holton suspension system simulates many of the conditions observed in the spaceflight animal, it does not provide for the collection of urine and feces needed to monitor some metabolic activities. As a result, only limited information has been gathered on the nutritional status, and the gastrointestinal and renal function of animals using that model. Although commercial metabolic cages are available, they are usually cylindrical and require a centrally located suspension system and thus, do not readily permit movement of the rats. The limited floor space of commercial cages may affect comparisons with studies using the Holton model which has more than twice the living space of most commercially available cages. To take advantage of the extra living space and extensive data base that has been developed with the Holton model, Holton's cage was modified to make urine and fecal collections possible.

  14. Heparin-Induced-Thrombocytopenia Causing Massive Aortic Thrombosis after Ascending Aortic Replacement for Type A Acute Aortic Dissection

    PubMed Central

    Imoto, Kiyotaka; Uchida, Keiji; Isoda, Susumu; Karube, Norihisa; Yasuda, Shota; Masuda, Munetaka

    2016-01-01

    A 77-year-old woman underwent emergency ascending aortic replacement for type A acute aortic dissection. Fifteen days after the operation, she had motor and sensory disturbances in the lower limbs. Computed tomography revealed multiple aortic thrombi and disrupted blood flow in the right external iliac and left common iliac arteries. She underwent an emergency thrombectomy for acute limb ischemia. Because heparin- induced-thrombocytopenia (HIT) was suspected to have caused the multiple aortic thrombi, we postoperatively changed the anticoagulant therapy from heparin to argatroban. Seventeen days after the first operation, gastrointestinal bleeding developed, and the patient died of mesenteric ischemia caused by HIT. Arterial embolization caused by HIT after cardiovascular surgery is a rare, but fatal event. To avoid fatal complications, early diagnosis and early treatment are essential. Use of a scoring system would probably facilitate early diagnosis. PMID:26780951

  15. Patient-prosthesis mismatch: surgical aortic valve replacement versus transcatheter aortic valve replacement in high risk patients with aortic stenosis

    PubMed Central

    Kron, Irving L.

    2016-01-01

    Patient prosthesis mismatch (PPM) can occur when a prosthetic aortic valve has an effective orifice area (EOA) less than that of a native valve. A recent study by Zorn and colleagues evaluated the incidence and significance of PPM in high risk patients with severe aortic stenosis who were randomized to transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). TAVR is associated with decreased incidence of severe PPM compared to traditional SAVR valves. Severe PPM increases risk for death at 1 year postoperatively in high risk patients. The increased incidence of PPM is largely due to differences in valve design and should encourage development of newer SAVR valves to reduce risk for PPM. In addition more vigorous approaches to root enlargement in small annulus should be performed with SAVR to prevent PPM. PMID:27867654

  16. Patient-prosthesis mismatch: surgical aortic valve replacement versus transcatheter aortic valve replacement in high risk patients with aortic stenosis.

    PubMed

    Ghanta, Ravi K; Kron, Irving L

    2016-10-01

    Patient prosthesis mismatch (PPM) can occur when a prosthetic aortic valve has an effective orifice area (EOA) less than that of a native valve. A recent study by Zorn and colleagues evaluated the incidence and significance of PPM in high risk patients with severe aortic stenosis who were randomized to transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). TAVR is associated with decreased incidence of severe PPM compared to traditional SAVR valves. Severe PPM increases risk for death at 1 year postoperatively in high risk patients. The increased incidence of PPM is largely due to differences in valve design and should encourage development of newer SAVR valves to reduce risk for PPM. In addition more vigorous approaches to root enlargement in small annulus should be performed with SAVR to prevent PPM.

  17. Liverpool Aortic Surgery Symposium V: New Frontiers in Aortic Disease and Surgery

    PubMed Central

    Bashir, Mohamad; Fok, Matthew; Shaw, Matthew; Field, Mark; Kuduvalli, Manoj; Desmond, Michael; Harrington, Deborah; Rashid, Abbas; Oo, Aung

    2014-01-01

    Aortic aneurysm disease is a complex condition that requires a multidisciplinary approach in management. The innovation and collaboration among vascular surgery, cardiothoracic surgery, interventional radiology, and other related specialties is essential for progress in the management of aortic aneurysms. The Fifth Liverpool Aortic Surgery Symposium that was held in May 2013 aimed at bringing national and international experts from across the United Kingdom and the globe to deliver their thoughts, applications, and advances in aortic and vascular surgery. In this report, we present a selected short synopsis of the key topics presented at this symposium. PMID:26798724

  18. Management of concomitant large aortic aneurysm and severe stenosis of aortic arc.

    PubMed

    Ren, Shiyan; Sun, Guang; Yang, Yuguang; Liu, Peng

    2014-01-01

    Primary large saccular aortic aneurysm with high grade stenosis of aortic arc is rare, and no standard therapy is available. We have encountered one case and successfully treated using a hybrid interventional approach. A 59-year-old woman with a 7-day history of headache, dizziness and chest pain, and a 5-year history of hypertension admitted and was diagnosed with transverse aortic aneurysm with sever aortic stenosis, the huge saccular aneurysm was located behind the transverse aortic arc. During surgery, a bypass with graft from ascending aorta to left external iliac artery was made initially in order to ensure the blood supply to the left leg, afterward, a 40 mm × 160 mm covered stent was implanted to cover the orifice of aneurysm and was used as a supporting anchorage in the descending aorta, a second covered stent (20 mm × 100 mm) was implanted to expand the stenosis of aortic arc. Follow-up at 1.5-year after surgery, the patient has been doing well without any surgical complication. A collateral pathway between internal mammary artery and inferior epigastric artery via the superior epigastric artery was found on3-dimensional reconstruction before surgery. Interruption of the compensatory arterial collateral pathway in the patient with severe stenosis of aortic arc should be prevented if possible in order to ensure the satisfactory perfusion of the lower limbs of the body.In conclusion, a patient with transverse aortic aneurysm accompanied with severe aortic stenosis can be treated by hybrid surgery.

  19. Anterior cervical corpectomy: review and comparison of results using titanium mesh cages and carbon fibre reinforced polymer cages.

    PubMed

    Kabir, Syed M R; Alabi, J; Rezajooi, Kia; Casey, Adrian T H

    2010-10-01

    Different types of cages have recently become available for reconstruction following anterior cervical corpectomy. We review the results using titanium mesh cages (TMC) and stackable CFRP (carbon fibre reinforced polymer) cages. Forty-two patients who underwent anterior cervical corpectomy between November 2001 and September 2008 were retrospectively reviewed. Pathologies included cervical spondylotic myelopathy (CSM), cervical radiculopathy, OPLL (ossified posterior longitudinal ligament), metastasis/primary bone tumour, rheumatoid arthritis and deformity correction. All patients were evaluated clinically and radiologically. Outcome was assessed on the basis of the Odom's criteria, neck disability index (NDI) and myelopathy disability index (MDI). Mean age was 60 years and mean follow-up was 1½ years. Majority of the patients had single-level corpectomy. Twenty-three patients had TMC cages while 19 patients had CFRP cages. The mean subsidence noted with TMC cage was 1.91 mm, while with the stackable CFRP cage it was 0.5 mm. This difference was statistically significant (p < 0.05). However, there was no statistically significant correlation noted between subsidence and clinical outcome (p > 0.05) or between subsidence and post-operative sagittal alignment (p > 0.05) in either of the groups. Three patients had significant subsidence (> 3 mm), one of whom was symptomatic. There were no hardware-related complications. On the basis of the Odom's criterion, 9 patients (21.4%) had an excellent outcome, 14 patients (33.3%) had a good outcome, 9 patients (21.4%) had a fair outcome and 5 patients (11.9%) had a poor outcome, i.e. symptoms and signs unchanged or exacerbated. Mean post-operative NDI was 26.27% and mean post-operative MDI was 19.31%. Fusion was noted in all 42 cases. Both TMC and stackable CFRP cages provide solid anterior column reconstruction with good outcome following anterior cervical corpectomy. However, more subsidence is noted with TMC cages though

  20. The cage effect in systems of hard spheres

    NASA Astrophysics Data System (ADS)

    van Megen, W.; Schöpe, H. J.

    2017-03-01

    The cage effect is generally invoked when discussing the delay in the decay of time correlation functions of dense fluids. In an attempt to examine the role of caging more closely, we consider the spread of the displacement distributions of Brownian particles. These distributions are necessarily biased by the presence of neighbouring particles. Accommodation of this bias by those neighbours conserves the displacement distribution locally and presents a collective mechanism for exploring configuration space that is more efficient than the intrinsic Brownian motion. Caging of some particles incurs, through the impost of global conservation of the displacement distribution, a delayed, non-local collective process. This non-locality compromises the efficiency with which configuration space is explored. Both collective mechanisms incur delay or stretching of time correlation functions, in particular the particle number and flux densities. This paper identifies and distinguishes these mechanisms in existing data from experiments and computer simulations on systems of particles with hard sphere interactions.

  1. Encapsulation of cobalt nanoparticles in cross-linked-polymer cages

    NASA Astrophysics Data System (ADS)

    Hatamie, Shadie; Dhole, S. D.; Ding, J.; Kale, S. N.

    2009-07-01

    Nanoparticles embedded in polymeric cages give rise to interesting applications ranging from nanocatalysis to drug-delivery systems. In this context, we report on synthesis of cobalt (Co) nanoparticles trapped in polyvinyl alcohol (PVA) matrix to yield self-supporting magnetic films in PVA slime. A 20 nm, Co formed in FCC geometry encapsulated with a weak citrate coat when caged in PVA matrix exhibited persistence of magnetism and good radio-frequency response. Cross-linking of PVA chains to form cage-like structures to arrest Co nanoparticles therein, is believed to be the reason for oxide-free nature of Co, promising applications in biomedicine as well as in radio-frequency shielding.

  2. Abdominal aortic aneurysms in women

    PubMed Central

    Lo, Ruby C.; Schermerhorn, Marc L.

    2015-01-01

    Abdominal aortic aneurysm (AAA) has long been recognized as a condition predominantly afflicting males, with sex-associated differences described for almost every aspect of the disease from pathophysiology and epidemiology to morbidity and mortality. Women are generally spared from AAA formation by the immunomodulating effects of estrogen but once they develop, the natural history of AAAs in women appears to be more aggressive, with more rapid expansion, a higher tendency to rupture at smaller diameters, and higher mortality following rupture. However, simply repairing AAA at smaller diameters in women is a debatable solution, as even elective endovascular AAA repair (EVAR) is fraught with higher morbidity and mortality in women compared to men. The goal of this review is to summarize what is currently known about the effect of gender on AAA presentation, treatment, and outcomes. Additionally, we aim to review current controversies over screening recommendations and threshold for repair in women. PMID:26747679

  3. Understanding the pathogenesis of abdominal aortic aneurysms

    PubMed Central

    Kuivaniemi, Helena; Ryer, Evan J.; Elmore, James R.; Tromp, Gerard

    2016-01-01

    Summary An aortic aneurysm is a dilatation in which the aortic diameter is ≥ 3.0 cm. If left untreated, the aortic wall continues to weaken and becomes unable to withstand the forces of the luminal blood pressure resulting in progressive dilatation and rupture, a catastrophic event associated with a mortality of 50 – 80%. Smoking and positive family history are important risk factors for the development of abdominal aortic aneurysms (AAA). Several genetic risk factors have also been identified. On the histological level, visible hallmarks of AAA pathogenesis include inflammation, smooth muscle cell apoptosis, extracellular matrix degradation, and oxidative stress. We expect that large genetic, genomic, epigenetic, proteomic and metabolomic studies will be undertaken by international consortia to identify additional risk factors and biomarkers, and to enhance our understanding of the pathobiology of AAA. Collaboration between different research groups will be important in overcoming the challenges to develop pharmacological treatments for AAA. PMID:26308600

  4. Valve selection in aortic valve endocarditis

    PubMed Central

    Zubrytska, Yana

    2016-01-01

    Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis. PMID:27785132

  5. Computational analysis of an aortic valve jet

    NASA Astrophysics Data System (ADS)

    Shadden, Shawn C.; Astorino, Matteo; Gerbeau, Jean-Frédéric

    2009-11-01

    In this work we employ a coupled FSI scheme using an immersed boundary method to simulate flow through a realistic deformable, 3D aortic valve model. This data was used to compute Lagrangian coherent structures, which revealed flow separation from the valve leaflets during systole, and correspondingly, the boundary between the jet of ejected fluid and the regions of separated, recirculating flow. Advantages of computing LCS in multi-dimensional FSI models of the aortic valve are twofold. For one, the quality and effectiveness of existing clinical indices used to measure aortic jet size can be tested by taking advantage of the accurate measure of the jet area derived from LCS. Secondly, as an ultimate goal, a reliable computational framework for the assessment of the aortic valve stenosis could be developed.

  6. Aortic coarctation repair in the adult.

    PubMed

    Cardoso, Goncalo; Abecasis, Miguel; Anjos, Rui; Marques, Marta; Koukoulis, Giovanna; Aguiar, Carlos; Neves, José Pedro

    2014-07-01

    Aortic coarctation can be repaired surgically or percutaneously. The decision should be made according to the anatomy and location of the coarctation, age of the patient, presence of other cardiac lesions, and other anatomic determinants (extensive collaterals or aortic calcification). This article reviews the different therapeutic options available, explaining the differences between children and adults, describing different approaches to the same disease, exemplified by three cases of nonclassic surgical approach and one percutaneous treatment.

  7. Regional aortic distensibility and its relationship with age and aortic stenosis: a computed tomography study.

    PubMed

    Wong, Dennis T L; Narayan, Om; Leong, Darryl P; Bertaso, Angela G; Maia, Murilo G; Ko, Brian S H; Baillie, Timothy; Seneviratne, Sujith K; Worthley, Matthew I; Meredith, Ian T; Cameron, James D

    2015-06-01

    Aortic distensibility (AD) decreases with age and increased aortic stiffness is independently associated with adverse cardiovascular outcomes. The association of severe aortic stenosis (AS) with AD in different aortic regions has not been evaluated. Elderly subjects with severe AS and a cohort of patients without AS of similar age were studied. Proximal aortic cross-sectional-area changes during the cardiac cycle were determined using retrospective-ECG-gating on 128-detector row computed-tomography. Using oscillometric-brachial-blood-pressure measurements, the AD at the ascending-aorta (AA), proximal-descending-aorta (PDA) and distal-descending-aorta (DDA) was determined. Linear mixed effects modelling was used to determine the association of age and aortic stenosis on regional AD. 102 patients were evaluated: 36 AS patients (70-85 years), 24 AS patients (>85 years) and 42 patients without AS (9 patients <50 years, 20 patients between 51-70 years and 13 patients 70-85 years). When comparing patients 70-85 years, AA distensibility was significantly lower in those with AS compared to those without AS (0.9 ± 0.9 vs. 1.4 ± 1.1, P = 0.03) while there was no difference in the PDA (1.0 ± 1.1 vs. 1.0 ± 1.2, P = 0.26) and DDA (1.1 ± 1.2 vs. 1.2 ± 0.8, P = 0.97). In patients without AS, AD decreased with age in all aortic regions (P < 0.001). The AA in patients <50 years were the most distensible compared to other aortic regions. There is regional variation in aortic distensibility with aging. Patients with aortic stenosis demonstrated regional differences in aortic distensibility with lower distensibility demonstrated in the proximal ascending aorta compared to an age-matched cohort.

  8. Equivalence Between Squirrel Cage and Sheet Rotor Induction Motor

    NASA Astrophysics Data System (ADS)

    Dwivedi, Ankita; Singh, S. K.; Srivastava, R. K.

    2016-06-01

    Due to topological changes in dual stator induction motor and high cost of its fabrication, it is convenient to replace the squirrel cage rotor with a composite sheet rotor. For an experimental machine, the inner and outer stator stampings are normally available whereas the procurement of rotor stampings is quite cumbersome and is not always cost effective. In this paper, the equivalence between sheet/solid rotor induction motor and squirrel cage induction motor has been investigated using layer theory of electrical machines, so as to enable one to utilize sheet/solid rotor in dual port experimental machines.

  9. Late entrapment of ball and cage valve in mitral position.

    PubMed

    Akbari, Jayesh G; Varma, Praveen K; Gadhinglajkar, Shrinivas V; Neelakandhan, Kurur S

    2006-02-01

    A 32-year-old female underwent mitral valve replacement with total chordal preservation (Miki's technique) using 26 mm (1M) Starr-Edward prosthesis (SEP) in 1988. The patient was in NYHA class-I until 2001. She progressed to NYHA class-III with paroxysmal nocturnal dyspnoea. Transthoracic echocardiogram showed increased prosthetic valve gradient, and cardiac catheterization confirmed the findings. Intraoperatively, the poppet movement in the cage was found to be restricted due to the preserved subvalvular apparatus entrapping the poppet inside the prosthetic valve cage.

  10. A Post-Functionalizable Iso-Polyoxotitanate Cage Cluster.

    PubMed

    Hou, Jie; Hu, Junyi; Sun, Qing; Zhang, Guanyun; Tung, Chen-Ho; Wang, Yifeng

    2016-07-18

    During solvothermal alcoholysis of a mixture of TiI4 and Ti(O(i)Pr)4, a {I@Ti22} cage cluster encapsulating an OH and iodide guests is crystallized. The {I@Ti22} host-guest cluster surface is postfunctionalizable with catecholate and carboxylate ligands. The synthetic details, structural characterization, spectroscopic properties of the obtained cages clusters are provided. The present study provides candidates for modeling ligand exchange and electron-hole transfer at the titanate nanoparticle surface, and meanwhile offers new opportunities for understanding the TiO2 nanocrystalline formation in solvothermal processes.

  11. Gender Differences in Abdominal Aortic Aneurysms

    PubMed Central

    Hannawa, Kevin K.; Eliason, Jonathan L.; Upchurch, Gilbert R.

    2010-01-01

    Abdominal aortic aneurysms (AAAs) comprise the 10th leading cause of death in Caucasian males 65–74 years of age, and accounted for nearly 16,000 deaths overall in the year 2000. Therefore, understanding the pathophysiology of AAAs is an important undertaking. Clinically, multiple risk factors are associated with the development of AAAs, including increasing age, positive smoking history, and hypertension. Male gender is also a well-established risk factor for the development of an AAA with a 4:1 male to female ratio. The reason for this gender disparity is unknown. The pathogenesis of AAAs formation is complex and multifactorial. Histologically, AAAs are characterized by early chemokine driven leukocyte infiltration into the aortic wall. Subsequent destruction of elastin and collagen in the media and adventitia ensues due to excessive local production of matrix degrading enzymes, and is accompanied by smooth muscle cell loss and thinning of the aortic wall. At present, there are no medical therapies available to treat patients with aortic aneurysms, using only the crude measurement of aortic diameter as a threshold for which patients must undergo life-threatening and costly surgery. Defining the early mechanisms underlying gender-related differences in AAA formation are critical, as understanding differences in disease patterns based on gender may allow us to develop new translational approaches to the prevention and treatment of patients with aortic aneurysms. PMID:19426607

  12. Quantification of abdominal aortic deformation after EVAR

    NASA Astrophysics Data System (ADS)

    Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

    2009-02-01

    Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

  13. Reproductive performance of mice in disposable and standard individually ventilated cages.

    PubMed

    Ferguson, Danielle R; Bailey, Michele M

    2013-01-01

    This study assessed the reproductive performance of mice housed in 2 types of individually ventilated caging systems. Breeding pairs from 48 female and 24 male mice of 3 established transgenic mouse breeding colonies were placed in either a standard or disposable ventilated caging system. For 3 breeding cycles, the number of pups born, pup survival rate to weaning, time interval between litters, and pup weights were monitored for each breeding pair. Disposable and standard cages were maintained in the same location during breeding. Environmental parameters included intracage temperature, humidity, and ammonia and carbon dioxide levels and room light intensity and sound. Overall, 776 offspring were produced. Breeding performance did not differ significantly between the 2 cage types. By 11 wk of age, the weights of pups from both cage types were equivalent. The intracage temperature was 1.1 °F warmer and light intensity at the site of the nest was 34 lx dimmer in disposable cages than in standard caging. The difference in lighting likely was due to nest location; the nests in the disposable cages were at the back of the cages and away from the anterior air supply, whereas in standard caging, nests were at the front of the cages, with the air supply at the rear. Under these husbandry conditions, mice housed in disposable caging systems have comparable breeding performance to those housed in standard individually ventilated cages.

  14. Analysis of hydrodynamic losses for various types of aortic valves

    NASA Astrophysics Data System (ADS)

    Starobin, I. M.; Lupachev, S. P.; Dolgopolov, R. V.; Zaiko, V. M.; Kas'yanov, V. A.; Mungalov, D. D.; Morov, G. V.

    1985-05-01

    The creation of an automated computer-controlled hydraulic stand made it possible to measure the main hydrodynamic parameters of the flow through the investigated HVP and to determine the coefficients of Eq. (2) of fluid flow in the test chamber of the stand. The coefficients found can serve as a criterion of a comparative assessment of the hydrodynamics of HVPs. An analysis of the coefficients showed that the main contribution to pressure losses across ball and disc valves is made by viscous and convective effects. An analysis of inertial losses confirmed the presence of oscillations of the ball closing elements of the AKCh-3-06 valve around the props of the stroke limiters and made it possible to assess them quantitatively. For leaflet valves the contribution of inertial losses to the total pressure losses is more considerable than in the case of disc and ball valves both in the regime of an increase of power of the output and in the regime of a constant power. The mechanical properties of the material of leaflet valves have an effect on the hydrodynamic characteristics. The advantage of the investigated leaflet valves consists not only in that they have smaller total hydraulic losses compared with the other valves, but also in that they provide a high amplitude of pulsations of the blood stream in the case of insufficient contractility of the heart.

  15. Valve sparing: aortic root replacement with the reimplantation technique.

    PubMed

    Mastrobuoni, Stefano; Tamer, Sadallah; de Kerchove, Laurent; El Khoury, Gebrine

    2015-01-01

    Aortic valve-sparing procedures are alternative options to aortic valve replacement in patients with aortic root aneurysm and/or severe aortic regurgitation reducing the risk of prosthesis-related complications, such as thromboembolism, and have no need for long-term oral anticoagulation. However, these techniques are technically demanding and long-term results are highly dependent on perfect intraoperative restoration of valve function. We describe a systematic approach to aortic valve-sparing aortic root replacement with the reimplantation technique the way it is currently performed in our institution.

  16. Early aortic valve cusp rupture in relapsing polychondritis.

    PubMed Central

    Marshall, D A; Jackson, R; Rae, A P; Capell, H A

    1992-01-01

    Aortic regurgitation associated with relapsing polychondritis usually occurs late in the disease as a result of aortic root dilatation. A case where aortic regurgitation occurred early and was due to cusp rupture with a normal aortic root is reported. The patient required urgent aortic valve replacement within six weeks of developing a murmur despite apparent control of inflammation with immunosuppressive treatment. The possibility of cusp rupture with sudden haemodynamic deterioration should be considered in patients with relapsing polychondritis who develop aortic regurgitation. Images PMID:1575597

  17. Cage Compounds as Potential Energetic Oxidizers: A Theoretical Study of a Cage Isomer of N2O3

    DTIC Science & Technology

    2014-07-01

    Oxidizers: A Theoretical Study of a Cage Isomer of N2O3 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Robert J...of a Cage Isomer of N2O3 Robert J. Buszek[a] and Jerry A. Boatz*[b] Abstract: Ab initio electronic structure calculations are employed to investigate...Q. Z. Qin, Photoisomerization of N2O3 in an Ar matrix, J. Photochem. Photobio. A 1999, 122, 1-5. [15] a) A. Stirling , I. Papai, J. Mink, D. R

  18. Aortic Dissection in Patients With Bicuspid Aortic Valve–Associated Aneurysms

    PubMed Central

    Wojnarski, Charles M.; Svensson, Lars G.; Roselli, Eric E.; Idrees, Jay J.; Lowry, Ashley M.; Ehrlinger, John; Pettersson, Gösta B.; Gillinov, A. Marc; Johnston, Douglas R.; Soltesz, Edward G.; Navia, Jose L.; Hammer, Donald F.; Griffin, Brian; Thamilarasan, Maran; Kalahasti, Vidyasagar; Sabik, Joseph F.; Blackstone, Eugene H.; Lytle, Bruce W.

    2016-01-01

    Background Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging. Methods From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention. Results Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm—from 4.1% to 13% at 7.2 cm—and then increased steeply at an ascending aortic diameter of 5.3 cm—from 3.8% to 35% at 8.4 cm—corresponding to a cross-sectional area to height ratio of 10 cm2/m for sinuses of Valsalva and 13 cm2/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73). Conclusions Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm2/m. PMID:26209494

  19. Aortobronchial Fistula after Thoracic Endovascular Aortic Repair (TEVAR) for Descending Thoracic Aortic Aneurysm.

    PubMed

    Melvan, John Nicholas; DeLaRosa, Jacob; Vasquez, Julio C

    2017-03-07

    Continued enlargement of the aneurysm sac after thoracic endovascular aortic repair (TEVAR) is a known risk after endovascular treatment of thoracic aortic aneurysms. For this reason, periodic outpatient follow-up is required to identify situations that require repair. Here, we describe an aortobronchial fistula (ABF) in a patient lost to follow-up, that presented 3 years after an elective TEVAR done for a primary, descending thoracic aortic aneurysm. Our patient arrived in extremis and suffered massive hemoptysis leading to her demise. Computed tomography (CT) angiogram near the time of her death demonstrated a bleeding ABF immediately distal to her previous TEVAR repair. Aortic aneurysmal disease remains life threatening even after repair. Improved endovascular techniques and devices have resulted in decreased need for reintervention. However, this case demonstrates the risk of thoracic aortic disease progression and highlights the importance of establishing consistent, long-term follow-up after TEVAR.

  20. Percutaneous balloon aortic valvuloplasty in the era of transcatheter aortic valve implantation: a narrative review

    PubMed Central

    Keeble, Thomas R; Khokhar, Arif; Akhtar, Mohammed Majid; Mathur, Anthony; Weerackody, Roshan; Kennon, Simon

    2016-01-01

    The role of percutaneous balloon aortic valvuloplasty (BAV) in the management of severe symptomatic aortic stenosis has come under the spotlight following the development of the transcatheter aortic valve implantation (TAVI) technique. Previous indications for BAV were limited to symptom palliation and as a bridge to definitive therapy for patients undergoing conventional surgical aortic valve replacement (AVR). In the TAVI era, BAV may also be undertaken to assess the ‘therapeutic response’ of a reduction in aortic gradient in borderline patients often with multiple comorbidities, to assess symptomatic improvement prior to consideration of definitive TAVI intervention. This narrative review aims to update the reader on the current indications and practical techniques involved in undertaking a BAV procedure. In addition, a summary of the haemodynamic and clinical outcomes, as well as the frequently encountered procedural complications is presented for BAV procedures conducted during both the pre-TAVI and post-TAVI era. PMID:28008354

  1. The effects of cage enrichment on agonistic behaviour and dominance in male laboratory rats (Rattus norvegicus).

    PubMed

    Abou-Ismail, Usama A

    2011-04-01

    This experiment was carried out to investigate the effects of enriching laboratory cages on agonistic interaction and dominance of rats. In a series of three replicates, 48 rats were housed in groups of four in either 'standard' or 'enriched' cages for 6 weeks. Successful aggressive and defensive behaviour that ended up in a clear winner and loser were sampled in the first hour of the dark phase of the light/dark cycle every other week. Rats in the 'complex' cages showed lower levels of both successful aggressive and successful defensive bouts compared to rats in the 'standard' cages. Enriching cages of laboratory rat did not change the social order of the animals in the cage. Thus, enhancing the complexity of cages of laboratory rats by the particular cage modification regimen implemented in this experiment could be considered enrichment and could therefore result in an improvement of welfare in these animals.

  2. Patch annulo-aortoplasty in an adult patient with congenital supravalvular aortic stenosis and a small aortic annulus.

    PubMed

    Morimoto, Naoto; Morimoto, Keisuke; Morimoto, Yoshihisa; Tanaka, Akiko; Sakamoto, Toshihito; Okada, Kenji; Okita, Yutaka

    2011-08-01

    A 39-year-old woman with familial homozygous hypercholesterolemia had supravalvular and valvular aortic stenosis. Modified Nick's procedure and aortic valve replacement was performed to relieve both the supravalvular and annular stenoses. At surgery, the ascending aorta was found to be narrowing at the level of the sinotubular junction, which was compatible with congenital supravalvular aortic stenosis. Histological examination of the aortic cusps showed sclerotic change due to hypercholesterolemia. These findings indicated that familial homozygous hypercholesterolemia caused valvular aortic stenosis and exacerbated congenital supravalvular aortic stenosis.

  3. Aortic Disease Presentation and Outcome Associated with ACTA2 mutations

    PubMed Central

    Regalado, Ellen S.; Guo, Dongchuan; Prakash, Siddharth; Bensend, Tracy A.; Flynn, Kelly; Estrera, Anthony; Safi, Hazim; Liang, David; Hyland, James; Child, Anne; Arno, Gavin; Boileau, Catherine; Jondeau, Guillaume; Braverman, Alan; Moran, Rocio; Morisaki, Takayuki; Morisaki, Hiroko; Consortium, Montalcino Aortic; Pyeritz, Reed; Coselli, Joseph; LeMaire, Scott; Milewicz, Dianna M.

    2015-01-01

    Background ACTA2 mutations are the major cause of familial thoracic aortic aneurysms and dissections. We sought to characterize these aortic diseases in a large case series of individuals with ACTA2 mutations. Methods and Results Aortic disease, management, and outcome associated with the first aortic event (aortic dissection or aneurysm repair) were abstracted from the medical records of 277 individuals with 41 various ACTA2 mutations. Aortic events occurred in 48% of these individuals, with the vast majority presenting with thoracic aortic dissections (88%) associated with 25% mortality. Type A dissections were more common than type B dissections (54% versus 21%), but the median age of onset of type B dissections was significantly younger than type A dissections (27 years, IQR 18–41 versus 36 years, IQR 26–45). Only 12% of aortic events were repair of ascending aortic aneurysms, which variably involved the aortic root, ascending aorta and aortic arch. Overall cumulative risk of an aortic event at age 85 years was 0.76 (95% CI 0.64, 0.86). After adjustment for intra-familial correlation, gender and race, mutations disrupting p.R179 and p.R258 were associated with significantly increased risk for aortic events, whereas p.R185Q and p.R118Q mutations showed significantly lower risk of aortic events compared to other mutations. Conclusions ACTA2 mutations are associated with high risk of presentation with an acute aortic dissection. The lifetime risk for an aortic event is only 76%, suggesting that additional environmental or genetic factors play a role in expression of aortic disease in individuals with ACTA2 mutations. PMID:25759435

  4. Caged polyprenylated xanthones from the resin of Garcinia hanburyi.

    PubMed

    Chen, Yu; He, Shiwen; Tang, Chu; Li, Jun; Yang, Guangzhong

    2016-03-01

    Five new caged polyprenylated xanthones (1a, 2a, 3, 10a and 10b), and 12 known related compounds were isolated from the resin of Garcinia hanburyi. Their structures were elucidated by detailed spectroscopic analyses and their α-glucosidase inhibitory activities were investigated in vitro. Most of xanthones showed modest inhibitory activity against α-glucosidase.

  5. EFFECTS OF CAGING DENSITY ON PITUITARY AND TESTICLE RELATED RESPONSES

    EPA Science Inventory

    Effects of caging density on pituitary and testicle related responses

    A significant negative correlation between the incidence of testicular interstitial cell tumors (ICT) and of pituitary tumors (PT) in control male F344 rats is reported associated with the number of ani...

  6. Pathogen Prevalence From Traditional Cage and Free Range Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Overview: A study was conducted to determine if differences in pathogen prevalence occurred between a sister flock of conventional cage and free range laying hens. Both environmental and egg microbiology was monitored throughout 20 – 79 weeks of age. Salmonella, Campylobacter, and Listeria preval...

  7. Xen clusters in the alpha cages of zeolite KA

    NASA Astrophysics Data System (ADS)

    Jameson, Cynthia J.; Jameson, A. Keith; Gerald, Rex E., II; Lim, Hyung-Mi

    1995-11-01

    We have observed the individual signals of the Xen clusters (n=1-5) trapped in the alpha cages of zeolite KA. The 129Xe NMR chemical shift of each cluster in zeolite KA is larger than that of the corresponding Xen cluster in zeolite NaA. The temperature dependence of the chemical shifts of the clusters vary systematically with cluster size as they do in NaA, but the change of the temperature coefficients with n is somewhat more pronounced for Xen in the cages of KA than in NaA. The Xen chemical shifts and their variation with temperature are reproduced by the grand canonical Monte Carlo (GCMC) simulations. GCMC simulations of the distribution of the Xe atoms among the alpha cages in KA provide the fractions of cages containing n Xe atoms which agree reasonably well with the observed equilibrium distributions. The characteristics of Xe distribution and chemical shifts in KA are compared with that in NaA.

  8. CO cage recombination in hemoglobin : Picosecond photolysis and nanosecond observation

    NASA Astrophysics Data System (ADS)

    Pin, S.; Valat, P.; Tourbez, H.; Alpert, B.

    1986-07-01

    Carboxy hemoglobin in aqueous solution was photodissociated by laser pulses of 30 ps at 532 nm. Kinetic studies show that only upon complete photodissociation can the pure CO geminate binding process be revealed. The protein region of the iron cage, where the geminate ligand diffuses before reaching the heme, is smaller than a single subunit and larger than the heme pocket.

  9. Synthesis of a photo-caged aminooxy alkane thiol.

    PubMed

    Mancini, Rock J; Li, Ronald C; Tolstyka, Zachary P; Maynard, Heather D

    2009-12-07

    A photo-caged aminooxy alkane thiol synthesized in 7 steps and 15% overall yield was used to form a self-assembled monolayer (SAM). Photo-deprotection on the surface was confirmed by FT-IR spectroscopy and contact angle goniometry. Conjugation of a small molecule ketone, ethyl levulinate, further confirmed the presence of aminooxy groups on the surface.

  10. Assessment of density in enriched colony cages: Egg quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enriched colony cage production systems are becoming more prevalent in the US. A study was undertaken to determine the impact of housing density on hen health, well-being, egg production and quality. Six densities were examined with 8 housing replicates per density. Egg quality was assessed at hen a...

  11. Three-dimensional protonic conductivity in porous organic cage solids

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y.; Little, Marc A.; Hasell, Tom; Aldous, Iain M.; Brown, Craig M.; Smith, Martin W.; Morrison, Carole A.; Hardwick, Laurence J.; Cooper, Andrew I.

    2016-09-01

    Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10-3 S cm-1 at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores.

  12. 48 CFR 204.7204 - Maintenance of the CAGE file.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Submit requests for changes to CAGE files on DD Form 2051, or electronic equivalent, to—Defense Logistics Information Service, DLIS-SBB, Federal Center, 74 Washington Avenue, North, Battle Creek, MI 49017-3084... codes is in Volume 7 of DoD 4100.39-M, Federal Logistics Information System (FLIS) Procedures Manual....

  13. Flexible, symmetry-directed approach to assembling protein cages

    PubMed Central

    Sciore, Aaron; Su, Min; Koldewey, Philipp; Eschweiler, Joseph D.; Diffley, Kelsey A.; Linhares, Brian M.; Ruotolo, Brandon T.; Bardwell, James C. A.; Skiniotis, Georgios; Marsh, E. Neil G.

    2016-01-01

    The assembly of individual protein subunits into large-scale symmetrical structures is widespread in nature and confers new biological properties. Engineered protein assemblies have potential applications in nanotechnology and medicine; however, a major challenge in engineering assemblies de novo has been to design interactions between the protein subunits so that they specifically assemble into the desired structure. Here we demonstrate a simple, generalizable approach to assemble proteins into cage-like structures that uses short de novo designed coiled-coil domains to mediate assembly. We assembled eight copies of a C3-symmetric trimeric esterase into a well-defined octahedral protein cage by appending a C4-symmetric coiled-coil domain to the protein through a short, flexible linker sequence, with the approximate length of the linker sequence determined by computational modeling. The structure of the cage was verified using a combination of analytical ultracentrifugation, native electrospray mass spectrometry, and negative stain and cryoelectron microscopy. For the protein cage to assemble correctly, it was necessary to optimize the length of the linker sequence. This observation suggests that flexibility between the two protein domains is important to allow the protein subunits sufficient freedom to assemble into the geometry specified by the combination of C4 and C3 symmetry elements. Because this approach is inherently modular and places minimal requirements on the structural features of the protein building blocks, it could be extended to assemble a wide variety of proteins into structures with different symmetries. PMID:27432965

  14. Flexible, symmetry-directed approach to assembling protein cages.

    PubMed

    Sciore, Aaron; Su, Min; Koldewey, Philipp; Eschweiler, Joseph D; Diffley, Kelsey A; Linhares, Brian M; Ruotolo, Brandon T; Bardwell, James C A; Skiniotis, Georgios; Marsh, E Neil G

    2016-08-02

    The assembly of individual protein subunits into large-scale symmetrical structures is widespread in nature and confers new biological properties. Engineered protein assemblies have potential applications in nanotechnology and medicine; however, a major challenge in engineering assemblies de novo has been to design interactions between the protein subunits so that they specifically assemble into the desired structure. Here we demonstrate a simple, generalizable approach to assemble proteins into cage-like structures that uses short de novo designed coiled-coil domains to mediate assembly. We assembled eight copies of a C3-symmetric trimeric esterase into a well-defined octahedral protein cage by appending a C4-symmetric coiled-coil domain to the protein through a short, flexible linker sequence, with the approximate length of the linker sequence determined by computational modeling. The structure of the cage was verified using a combination of analytical ultracentrifugation, native electrospray mass spectrometry, and negative stain and cryoelectron microscopy. For the protein cage to assemble correctly, it was necessary to optimize the length of the linker sequence. This observation suggests that flexibility between the two protein domains is important to allow the protein subunits sufficient freedom to assemble into the geometry specified by the combination of C4 and C3 symmetry elements. Because this approach is inherently modular and places minimal requirements on the structural features of the protein building blocks, it could be extended to assemble a wide variety of proteins into structures with different symmetries.

  15. A novel method of anterior lumbosacral cage reconstruction.

    PubMed

    Mathios, Dimitrios; Kaloostian, Paul Edward; Bydon, Ali; Sciubba, Daniel M; Wolinsky, Jean Paul; Gokaslan, Ziya L; Witham, Timothy F

    2014-02-01

    Reconstruction of the lumbosacral junction is a considerable challenge for spinal surgeons due to the unique anatomical constraints of this region as well as the vectors of force that are applied focally in this area. The standard cages, both expandable and nonexpendable, often fail to reconstitute the appropriate anatomical alignment of the lumbosacral junction. This inadequate reconstruction may predispose the patient to continued back pain and neurological symptoms as well as possible pseudarthrosis and instrumentation failure. The authors describe their preoperative planning and the technical characteristics of their novel reconstruction technique at the lumbosacral junction using a cage with adjustable caps. Based precisely on preoperative measurements that maintain the appropriate Cobb angle, they performed reconstruction of the lumbosacral junction in a series of 3 patients. All 3 patients had excellent installation of the cages used for reconstruction. Postoperative CT scans were used to radiographically confirm the appropriate reconstruction of the lumbosacral junction. All patients had a significant reduction in pain, had neurological improvement, and experienced no instrumentation failure at the time of latest follow-up. Taking into account the inherent morphology of the lumbosacral junction and carefully planning the technical characteristics of the cage installation preoperatively and intraoperatively, the authors achieved favorable clinical and radiographic outcomes in all 3 cases. Based on this small case series, this technique for reconstruction of the lumbosacral junction appears to be a safe and appropriate method of reconstruction of the anterior spinal column in this technically challenging region of the spine.

  16. Three-dimensional protonic conductivity in porous organic cage solids

    PubMed Central

    Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y.; Little, Marc A.; Hasell, Tom; Aldous, Iain M.; Brown, Craig M.; Smith, Martin W.; Morrison, Carole A.; Hardwick, Laurence J.; Cooper, Andrew I.

    2016-01-01

    Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10−3 S cm−1 at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores. PMID:27619230

  17. Dynamic Folding Pathway Models of the Trp-Cage Protein

    PubMed Central

    Kim, Seung-Yeon

    2013-01-01

    Using action-derived molecular dynamics (ADMD), we study the dynamic folding pathway models of the Trp-cage protein by providing its sequential conformational changes from its initial disordered structure to the final native structure at atomic details. We find that the numbers of native contacts and native hydrogen bonds are highly correlated, implying that the native structure of Trp-cage is achieved through the concurrent formations of native contacts and native hydrogen bonds. In early stage, an unfolded state appears with partially formed native contacts (~40%) and native hydrogen bonds (~30%). Afterward, the folding is initiated by the contact of the side chain of Tyr3 with that of Trp6, together with the formation of the N-terminal α-helix. Then, the C-terminal polyproline structure docks onto the Trp6 and Tyr3 rings, resulting in the formations of the hydrophobic core of Trp-cage and its near-native state. Finally, the slow adjustment processes of the near-native states into the native structure are dominant in later stage. The ADMD results are in agreement with those of the experimental folding studies on Trp-cage and consistent with most of other computational studies. PMID:23865078

  18. Three-dimensional protonic conductivity in porous organic cage solids.

    PubMed

    Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y; Little, Marc A; Hasell, Tom; Aldous, Iain M; Brown, Craig M; Smith, Martin W; Morrison, Carole A; Hardwick, Laurence J; Cooper, Andrew I

    2016-09-13

    Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10(-3) S cm(-1) at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores.

  19. 3. SHOP AREA. Looking west into storage cage from near ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SHOP AREA. Looking west into storage cage from near northeast corner of room. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A Terminal Room, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  20. Genotoxicity monitoring of freshwater environments using caged crayfish (Astacus leptodactylus).

    PubMed

    Klobučar, Göran I V; Malev, Olga; Šrut, Maja; Štambuk, Anamaria; Lorenzon, Simonetta; Cvetković, Želimira; Ferrero, Enrico A; Maguire, Ivana

    2012-03-01

    Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mrežnica) and exposed in cages for 1 week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.

  1. Aortic Valve Calcification is Mediated by a Differential Response of Aortic Valve Interstitial Cells to Inflammation

    PubMed Central

    Venardos, Neil; Nadlonek, Nicole A.; Zhan, Qiong; Weyant, Michael J.; Reece, T. Brett; Meng, Xianzhong; Fullerton, David A.

    2014-01-01

    Background While calcific aortic stenosis is common, calcification of the other three heart valves is not. The aortic valve interstitial cell (VIC) has been implicated in the pathogenesis of aortic stenosis. Pro-inflammatory stimulation of aortic VICs induces an osteogenic and inflammatory phenotypic change. We hypothesized that the VICs of the other heart valves do not undergo these changes. Using isolated human VICs from normal aortic, mitral, pulmonary and tricuspid valves, our purpose was to compare the osteogenic response to pro-inflammatory stimulation via TLR-4. Materials And Methods Aortic, pulmonic, mitral, and tricuspid (n=4 for each valve type) VICs were isolated from hearts valves explanted from patients undergoing cardiac transplantation. Cells were cultured and grown to confluence in passage 2-6 before treatment with LPS (100-200ng/mL) for 24 or 48 hours. Cells were characterized by immunofluorescent staining. TLR-4 expression was analyzed (immunoblotting, flow cytometry). BMP-2 and intercellular adhesion molecule-1 (ICAM-1) production were determined (immunoblotting). Monocyte chemoattractant protein-1 (MCP-1) levels were determined by ELISA. Statistics were by Mann-Whitney U test. Results TLR-4 stimulation induced BMP-2 production only in aortic VICs (p<0.05). ICAM-1 production and MCP-1 secretion increased in a similar fashion among TLR4-stimulated VICs from all four valves. Conclusions Pro-inflammatory stimulation induces an osteogenic phenotype in aortic VICs but not mitral, pulmonic, or tricuspid VICs. We conclude that this differential osteogenic response of aortic VICs contributes to the pathogenesis of calcific aortic stenosis. PMID:24746950

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

    PubMed

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

    2012-12-01

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

  3. Cage Versus Noncage Laying-Hen Housings: Worker Respiratory Health.

    PubMed

    Mitchell, Diane; Arteaga, Veronica; Armitage, Tracey; Mitloehner, Frank; Tancredi, Daniel; Kenyon, Nicholas; Schenker, Marc

    2015-01-01

    The objective of this study was to compare respiratory health of poultry workers in conventional cage, enriched cage and aviary layer housing on a single commercial facility, motivated by changing requirements for humane housing of hens. Three workers were randomly assigned daily, one to each of conventional cage, enriched cage, and aviary housing in a crossover repeated-measures design for three observation periods (for a total of 123 worker-days, eight different workers). Workers' exposure to particles were assessed (Arteaga et al. J Agromedicine. 2015;20:this issue) and spirometry, exhaled nitric oxide, respiratory symptoms, and questionnaires were conducted pre- and post-shift. Personal exposures to particles and endotoxin were significantly higher in the aviary than the other housings (Arteaga et al., 2015). The use of respiratory protection was high; the median usage was 70% of the shift. Mixed-effects multivariate regression models of respiratory cross-shift changes were marginally significant, but the aviary system consistently posted the highest decrements for forced expiratory volume in 1 and 6 seconds (FEV1 and FEV6) compared with the enriched or conventional housing. The adjusted mean difference in FEV1 aviary - enriched cage housing was -47 mL/s, 95% confidence interval (CI): (-99 to 4.9), P = .07. Similarly, for FEV6, aviary - conventional housing adjusted mean difference was -52.9 mL/6 s, 95% CI: (-108 to 2.4), P = .06. Workers adopting greater than median use of respiratory protection were less likely to exhibit negative cross-shift pulmonary function changes. Although aviary housing exposed workers to significantly higher respiratory exposures, cross-shift pulmonary function changes did not differ significantly between houses. Higher levels of mask use were protective; poultry workers should wear respiratory protection as appropriate to avoid health decrements.

  4. A cell attracting composite of lumbar fusion cage.

    PubMed

    Gunay, Busra; Hasirci, Nesrin; Hasirci, Vasif

    2017-06-01

    Lumbar fusion cages are devices used in spinal fusion procedures for disorders such as spondylosis and degenerative disc diseases that may occur due to age, trauma or genetic reasons. These devices are most frequently made of metals and polymers. The mechanical properties of such devices should be comparable to the bone to avoid stress shielding. Besides, cages should interact with the cells to prevent extrusion and achieve satisfactory fusion. In this study, poly(methylmethacrylate) (PMMA) and hydroxyapatite (HAp) were compounded to create products with HAp contents up to 40% (w/w), processed by hot melt extrusion and injection molded to produce composites with maximum polymer-mineral interaction. The morphology, interaction with the plates and rate of proliferation of human osteoblast-like (HOB) cells were studied in vitro. We learned that cells interact more with HAp when the HAp content is higher than 20%. Tensile and compressive properties of PMMA were significantly increased with increasing HAp content; from an elastic modulus (E) of 2.08 to 3.92 GPa in tension, and from 349 to 562 MPa in compression. High HAp content of the samples increased the roughness from 0.69 μm for pure PMMA to 1.35 μm for 40% (w/w) HAp loaded PMMA, increased cell proliferation and as a result the cells presented filopodia indicating a satisfactory level of interaction with the cage surface. Based on mechanical and in vitro studies, a HAp content of around 30% (w/w) was found to be appropriate for good cell adhesion and satisfactory mechanical properties for use in the construction of a fusion cage. It was concluded that when PMMA and HAp were compounded at an optimal value, a cage material with adequate mechanical properties and increased cell attachment can be obtained for use in spinal fusion applications.

  5. Corpectomy cage subsidence with rectangular versus round endcaps.

    PubMed

    Deukmedjian, Armen R; Manwaring, Jotham; Le, Tien V; Turner, Alexander W L; Uribe, Juan S

    2014-09-01

    Corpectomy cages with rectangular endcaps utilize the stronger peripheral part of the endplate, potentially decreasing subsidence risk. The authors evaluated cage subsidence during cyclic biomechanical testing, comparing rectangular versus round endcaps. Fourteen cadaveric spinal segments (T12-L2) were dissected and potted at T12 and L2, then assigned to a rectangular (n=7) or round (n=7) endcap group. An L1 corpectomy was performed and under uniform conditions a cage/plate construct was cyclically tested in a servo-hydraulic frame with increasing load magnitude. Testing was terminated if the test machine actuator displacement exceeded 6mm, or the specimen completed cyclic loading at 2400 N. Number of cycles, compressive force and force-cycles product at test completion were all greater in the rectangular endcap group compared with the round endcap group (cycles: 3027 versus 2092 cycles; force: 1943 N versus 1533 N; force-cycles product: 6162kN·cycles versus 3973 kN·cycles), however these differences were not statistically significant (p ⩾ 0.076). After normalizing for individual specimen bone mineral density, the same measures increased to a greater extent with the rectangular endcaps (cycles: 3014 versus 1855 cycles; force: 1944 N versus 1444 N; force-cycles product: 6040 kN·cycles versus 2980 kN·cycles), and all differences were significant (p⩽0.030). The rectangular endcap expandable corpectomy cage displayed increased resistance to subsidence over the round endcap cage under cyclic loading as demonstrated by the larger number of cycles, maximum load and force-cycles product at test completion. This suggests rectangular endcaps will be less susceptible to subsidence than the round endcap design.

  6. 48 CFR 252.204-7001 - Commercial and Government Entity (CAGE) code reporting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Entity (CAGE) code reporting. 252.204-7001 Section 252.204-7001 Federal Acquisition Regulations System... Entity (CAGE) Code Reporting (AUG 1999) (a) The offeror is requested to enter its CAGE code on its offer... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.204-7001 Commercial and Government...

  7. MicroRNAs, fibrotic remodeling, and aortic aneurysms

    PubMed Central

    Milewicz, Dianna M.

    2012-01-01

    Aortic aneurysms are a common clinical condition that can cause death due to aortic dissection or rupture. The association between aortic aneurysm pathogenesis and altered TGF-β signaling has been the subject of numerous investigations. Recently, a TGF-β–responsive microRNA (miR), miR-29, has been identified to play a role in cellular phenotypic modulation during aortic development and aging. In this issue of JCI, Maegdefessel and colleagues demonstrate that decreasing the levels of miR-29b in the aortic wall can attenuate aortic aneurysm progression in two different mouse models of abdominal aortic aneurysms. This study highlights the relevance of miR-29b in aortic disease but also raises questions about its specific role. PMID:22269322

  8. Acute thoracic aortic dissection: how to defuse a time bomb.

    PubMed

    McClarren-Curry, C; Shaughnessy, K

    1999-01-01

    Acute thoracic aortic dissection is frequently misdiagnosed, and even with surgical intervention, the mortality rate is 50%. This article focuses on assessment, interventions, and postoperative care of patients with aortic dissection.

  9. Talk to Your Doctor about Abdominal Aortic Aneurysm

    MedlinePlus

    ... español Talk to Your Doctor about Abdominal Aortic Aneurysm Browse Sections The Basics Overview What is AAA? ... doctor about getting screened (tested) for abdominal aortic aneurysm (AAA). If AAA isn't found and treated ...

  10. Intra-cage dynamics of molecular hydrogen confined in cages of two different dimensions of clathrate hydrates

    PubMed Central

    Russina, Margarita; Kemner, Ewout; Mezei, Ferenc

    2016-01-01

    In porous materials the molecular confinement is often realized by means of weak Van der Waals interactions between the molecule and the pore surface. The understanding of the mechanism of such interactions is important for a number of applications. In order to establish the role of the confinement size we have studied the microscopic dynamics of molecular hydrogen stored in the nanocages of clathrate hydrates of two different dimensions. We have found that by varying the size of the pore the diffusive mobility of confined hydrogen can be modified in both directions, i.e. reduced or enhanced compared to that in the bulk solid at the same temperatures. In the small cages with a mean crystallographic radius of 3.95 Å the confinement reduces diffusive mobility by orders of magnitude. In contrast, in large cages with a mean radius of 4.75 Å hydrogen molecules displays diffusive jump motion between different equilibrium sites inside the cages, visible at temperatures where bulk H2 is solid. The localization of H2 molecules observed in small cages can promote improved functional properties valuable for hydrogen storage applications. PMID:27270444

  11. Multiplexed Analysis of Cage and Cage Free Chicken Egg Fatty Acids Using Stable Isotope Labeling and Mass Spectrometry

    PubMed Central

    Torde, Richard G.; Therrien, Andrew J.; Shortreed, Michael R.; Smith, Lloyd M.; Lamos, Shane M.

    2014-01-01

    Binary stable isotope labeling couple with LC-ESI-MS has been used as a powerful non-targeted approach for the relative quantification of lipids, amino acids, and many other important metabolite classes. A multiplexed approach using three or more isotopic labeling reagents greatly reduces analytical run-time while maintaining excellent sensitivity and reproducibility. Three isotopic cholamine labeling reagents have been developed to take advantage of the pre-ionized character of cholamine, for ESI, and the ease by which stable isotopes can be incorporated into the cholamine structure. These three cholamine labeling reagents have been used to relatively quantify three fatty acid samples simultaneously. The quantification resulted in the observation of 12 fatty acids that had an average absolute error of 0.9% and an average coefficient of variation of 6.1%. Caged versus cage-free isotope labeling experiments showed that cage-free eggs have an increased level of omega-3 fatty acids as compared to caged eggs. This multiplexed fatty acid analysis provides an inexpensive and expedited tool for broad-based lipid profiling that will further aid discoveries in the mechanisms of fatty acid action in cells. PMID:24317525

  12. Flow in an Aortic Coarctation

    NASA Astrophysics Data System (ADS)

    Loma, Luis; Miller, Paul; Hertzberg, Jean

    2009-11-01

    Coarctation of the aorta is a congenital cardiovascular defect that causes a constriction in the descending thoracic aorta. To gain a better understanding of the cause of post-surgical problems, a rigid glass and a compliant in vitro model of the aortic arch and descending aorta with a coarctation were constructed. Near-physiologic compliance was obtained using a silicone elastomer. Stereoscopic PIV was used to obtain 3D velocity maps. Results show a high speed turbulent jet formed at the exit of the coarctation. Flow in the rigid model was significantly different from in the compliant model. In the rigid model, the jet was symmetric, creating a toroidal recirculation area. In the compliant model, the jet was directed towards the medial wall, inducing flow reversal only at the lateral wall. Peak velocities and turbulence intensities were higher in the rigid model, however shear rate values in the compliant model were significantly above both the rigid model and normal in vivo values at the medial wall. In both models the reattachment region fluctuated, creating oscillatory shear.

  13. Intra-aortic balloon pumps.

    PubMed

    1997-05-01

    Intra-aortic balloon pumps (IABPs) are circulatory assist devices used to treat a number of cardiovascular conditions. IABPs provide temporary circulatory support by reducing the resistance to blood flow out of the heart during systole and by providing added pressure to aid in perfusing the heart during diastole. In this Evaluation, we tested three IABPs from three suppliers. We examined the units' technical performance, safety and monitoring, human factors design, transport operation, and supplier support. Rather than test all the triggering (activation) modes available, we focused our testing on the modes most commonly used on each unit. We also provide information on an IABP currently available only in Japan; although we did not test this unit, we do provide a preliminary judgment based on the information provided to us by the supplier. In the Technology Overview also included in the Evaluation, we describe the basic operation and use of an IABP, as well as review the state of the art of this technology. And in the Selection, Purchasing, and Use Guide at the conclusion of the Evaluation, we discuss such topics as balloon costs and sizing, interfacing IABPs with patient monitors, and the use of IABPs in community hospitals.

  14. Rapid prototyping in aortic surgery.

    PubMed

    Bangeas, Petros; Voulalas, Grigorios; Ktenidis, Kiriakos

    2016-04-01

    3D printing provides the sequential addition of material layers and, thus, the opportunity to print parts and components made of different materials with variable mechanical and physical properties. It helps us create 3D anatomical models for the better planning of surgical procedures when needed, since it can reveal any complex anatomical feature. Images of abdominal aortic aneurysms received by computed tomographic angiography were converted into 3D images using a Google SketchUp free software and saved in stereolithography format. Using a 3D printer (Makerbot), a model made of polylactic acid material (thermoplastic filament) was printed. A 3D model of an abdominal aorta aneurysm was created in 138 min, while the model was a precise copy of the aorta visualized in the computed tomographic images. The total cost (including the initial cost of the printer) reached 1303.00 euros. 3D imaging and modelling using different materials can be very useful in cases when anatomical difficulties are recognized through the computed tomographic images and a tactile approach is demanded preoperatively. In this way, major complications during abdominal aorta aneurysm management can be predicted and prevented. Furthermore, the model can be used as a mould; the development of new, more biocompatible, less antigenic and individualized can become a challenge in the future.

  15. [Invention of an air forced ventilated micro-isolation cage and rack system--environment within the cages: ventilation, air flow].

    PubMed

    Kurosawa, T; Yoshida, K; Okamoto, M; Tajima, M

    1993-10-01

    A forced air ventilation system for small laboratory animals was developed. The system consists of an air handling unit with air supply and exhaust fans, a rack, hard cage covers with a large diameter air inlet and an outlet, and shoe box cages. Air flow from the supply duct, to the exhaust duct and within the cage were observed. Variations in air flow among cages was minimal. The optimal air exchange rate of the cages in this system was determined to be 60 times per hour based on the results obtained in the present study. At this air exchange rate, air flow at the base of the cages had a velocity of less than 0.09m/sec, which was within the range of recommended values for humans. The observed results show that the system developed is capable of sustaining a laboratory animal microenvironment well in terms of air flow, without too much energy cost.

  16. Research of Customized Aortic Stent Graft Manufacture

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Chen, Xin; Liu, Muhan

    2017-03-01

    Thoracic descending aorta diseases include aortic dissection and aortic aneurysm, of which the natural mortality rate is extremely high. At present, endovascular aneurysm repair (EVAR) has been widely used as an effective means for the treatment of descending aortic disease. Most of the existing coating stents are standard design, which are unable to meet the size or structure of different patients. As a result, failure of treatment would be caused by dimensional discrepancy between stent and vessels, which could lead to internal leakage or rupture of blood vessels. Therefore, based on rapid prototyping sacrificial core – coating forming (RPSC-CF), a customized aortic stent graft manufactured technique has been proposed in this study. The aortic stent graft consists of film and metallic stent, so polyether polyurethane (PU) and nickel-titanium (NiTi) shape memory alloy with good biocompatibility were chosen. To minimum film thickness without degrading performance, effect of different dip coating conditions on the thickness of film were studied. To make the NiTi alloy exhibit super-elasticity at body temperature (37°C), influence of different heat treatment conditions on austenite transformation temperature (Af) and mechanical properties were studied. The results show that the customized stent grafts could meet the demand of personalized therapy, and have good performance in blasting pressure and radial support force, laying the foundation for further animal experiment and clinical experiment.

  17. Phonocardiographic diagnosis of aortic ball variance.

    PubMed

    Hylen, J C; Kloster, F E; Herr, R H; Hull, P Q; Ames, A W; Starr, A; Griswold, H E

    1968-07-01

    Fatty infiltration causing changes in the silastic poppet of the Model 1000 series Starr-Edwards aortic valve prostheses (ball variance) has been detected with increasing frequency and can result in sudden death. Phonocardiograms were recorded on 12 patients with ball variance confirmed by operation and of 31 controls. Ten of the 12 patients with ball variance were distinguished from the controls by an aortic opening sound (AO) less than half as intense as the aortic closure sound (AC) at the second right intercostal space (AO/AC ratio less than 0.5). Both AO and AC were decreased in two patients with ball variance, with the loss of the characteristic high frequency and amplitude of these sounds. The only patient having a diminished AO/AC ratio (0.42) without ball variance at reoperation had a clot extending over the aortic valve struts. The phonocardiographic findings have been the most reliable objective evidence of ball variance in patients with Starr-Edwards aortic prosthesis of the Model 1000 series.

  18. Advances in Transcatheter Aortic Valve Replacement

    PubMed Central

    Kleiman, Neal S.; Reardon, Michael J.

    2016-01-01

    Transcatheter aortic valve replacement (TAVR) is becoming widely used for the treatment of symptomatic severe aortic stenosis in patients with high surgical risk. Data from The PARTNER Trial (Placement of AoRtic TraNscathetER Valves) and the Medtronic CoreValve® U.S. Pivotal Investigational Device Exemption trial indicate that survival for extreme-risk patients is superior to best medical therapy and equivalent or superior to surgical aortic valve replacement (SAVR), although long-term durability remains unknown. Paravalvular leak remains higher in TAVR than SAVR, as does permanent pacemaker implantation in self-expanding valves. New-generation valves are addressing these issues, especially for paravalvular leak. There is strong evidence that TAVR is appropriate for both extreme-risk and high-risk patients with symptomatic severe aortic stenosis, and the continued development of new valves are making implantation more reliable. This review discusses the studies supporting the use of TAVR and explores current advances in the field. PMID:27127560

  19. Tracheal replacement with an aortic autograft.

    PubMed

    Azorin, Jacques F; Bertin, Francois; Martinod, Emmanuel; Laskar, Marc

    2006-02-01

    Tracheal replacement after extensive resection remains a challenge for the thoracic surgeon. We propose an innovative solution: the use of an aortic autograft. After an experimental work on animals with aortic autografts and allografts [Martinod E, Seguin A, Pfeuty K, Fornes P, Kambouchner M, Azorin JF, Carpentier AF. Long-term evaluation of the replacement of the trachea with an autologous aortic graft. Ann Thorac Surg 2003;75(5):1572-8; Martinod E, Seguin A, Holder-Espinasse M, Kambouchner M, Duterque-Coquillaud M, Azorin JF, Carpentier AF. Tracheal regeneration following tracheal replacement with an allogenic aorta. Ann Thorac Surg 2005;79(3):942-8], we present the first human case of long tracheal replacement with an aortic autograft. In this case we replaced 7 cm of a tumoral trachea using an aortic infra-renal autograft supported by a silicone stent. The early postoperative course was uneventful. The stent was removed at three months. The patient died at six months from an acute pulmonary infection without any sign of anastomosis leakage or graft rupture. A new field of clinical study has to be investigated.

  20. Primary Stenting in Infrarenal Aortic Occlusive Disease

    SciTech Connect

    Nyman, Ulf; Uher, Petr; Lindh, Mats; Lindblad, Bengt; Ivancev, Krasnodar

    2000-03-15

    Purpose: To evaluate the results of primary stenting in aortic occlusive disease.Methods: Thirty patients underwent primary stenting of focal concentric (n = 2) and complex aortic stenoses (n = 19), and aortic or aorto-iliac occlusions (n = 9). Sixteen patients underwent endovascular outflow procedures, three of whom also had distal open surgical reconstructions. Median follow-up was 16 months (range 1-60 months).Results: Guidewire crossing of two aorto-biiliac occlusions failed, resulting in a 93% (28/30) technical success. Major complications included one access hematoma, one myocardial infarction, one death (recurrent thromboembolism) in a patient with widespread malignancy, and one fatal hemorrhage during thrombolysis of distal emboli from a recanalized occluded iliac artery. One patient did not improve his symptoms, resulting in a 1-month clinical success of 83% (25/30). Following restenting the 26 stented survivors changed their clinical limb status to +3 (n = 17) and +2 (n = 9). During follow-up one symptomatic aortic restenosis occurred and was successfully restented.Conclusions: Primary stenting of complex aortic stenoses and short occlusions is an attractive alternative to conventional surgery. Larger studies with longer follow-up and stratification of lesion morphology are warranted to define its role relative to balloon angioplasty. Stenting of aorto-biiliac occlusions is feasible but its role relative to bypass grafting remains to be defined.

  1. Transcatheter aortic valve implantation: status and challenges.

    PubMed

    Fishbein, Gregory A; Schoen, Frederick J; Fishbein, Michael C

    2014-01-01

    Calcific aortic valve disease of the elderly is the most prevalent hemodynamically-significant valvular disease, and the most common lesion requiring valve replacement in industrialized countries. Transcatheter aortic valve implantation is a less invasive alternative to classical aortic valve replacement that can provide a therapeutic option for high-risk or inoperable patients with aortic stenosis. These devices must be biocompatible, have excellent hemodynamic performance, be easy to insert, be securely anchored without sutures, and be durable, without increased risk of thrombosis or infection. To date, complications are related to the site of entry for insertion, the site of implantation (aorta, coronary ostia, base of left ventricle), and to the structure and design of the inserted device. However, as with any novel technology unanticipated complications will develop. Goals for future development will be to make the devices more effective, more durable, safer, and easier to implant, so as to further improve outcome for patients with severe aortic stenosis. The pathologist participating in research and development, and examination of excised devices will have a critical role in improving outcome for these patients.

  2. Acute aortic syndromes: pathophysiology and management.

    PubMed

    Alli, Oluseun; Jacobs, Larry; Amanullah, Aman M

    2008-01-01

    The acute aortic syndromes carry significant morbidity and mortality, especially when detected late. Symptoms may mimic myocardial ischemia, and physical findings may be absent or, if present, can be suggestive of a diverse range of other conditions. Maintaining a high clinical index of suspicion is crucial in establishing the diagnosis. All patients with suspected aortic disease and evidence of acute ischemia on electrocardiogram should undergo diagnostic imaging studies before thrombolytics are administered. The demonstration of an intimal flap separating 2 lumina is the basis for diagnosis. Tear detection and localization are very important because any therapeutic intervention aims to occlude the entry tear. The goals of medical therapy are to reduce the force of left ventricular contractions, decrease the steepness of the rise of the aortic pulse wave, and reduce the systemic arterial pressure to as low a level as possible without compromising perfusion of vital organs. Surgical therapy still remains the gold standard of care for type A aortic dissection, whereas in type B dissection, percutaneous aortic stenting and fenestration techniques have been developed and are sometimes used in conjunction with medical therapy in certain situations.

  3. Bicuspid aortic valve and severe aortic stenosis in a newborn exposed to carbamazapine during pregnancy

    PubMed Central

    Karataş, Zehra; Karataş, Ahmet; Özlü, Tülay; Goksugur, Sevil B.; Varan, Birgül

    2014-01-01

    The use of antiepileptic drugs increases the risk of major congenital malformations during pregnancy. Here, we report an infant who had a history of in-utero carbamazepine exposure and who was born with a cardiac malformation. The infant was born at 39 weeks of gestation vaginally to an epileptic mother who had been treated with carbamazepine throughout her pregnancy. He was referred due to cardiac murmur in the second week of his life. The mother had not received folic acid supplementation. Transthoracic echocardiography revealed bicuspid aortic valve, mild aortic stenosis, patent ductus arteriosus, patent foramen ovale and the renal ultrasound revealed mild left hydronephrosis. Follow-up echocardiography performed 14 weeks later showed increased severity of aortic stenosis and percutaneous balloon aortic valvuloplasty was performed. To our knowledge, there is only one case report in the literature mentioning the association of a bicuspid aortic valve and aortic stenosis with oxcarbazepine exposure, which is a structural derivative of carbamazepine. However, there are no reports for association with carbamazepine itself. Bicuspid aorta and aortic stenosis may be among the cardiac malformations that result from the teratogenic effect of carbamazepine. PMID:25584038

  4. Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages.

    PubMed

    Hoffmann, W Clint; Fritz, Bradley K; Farooq, Muhammad; Cooperband, Miriam F

    2008-09-01

    Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.

  5. Local repair of distal thoracal aortic dissections (Locus minoris resistencia).

    PubMed

    Belov, Iu V; Komarov, R N; Stepanenko, A B; Gens, A P; Charchian, E R

    2007-01-01

    The paper presents the method of local repair of distal aortic dissections. Local aortic grafting for surgical correction of type B dissecting aortic aneurysms helped to decrease hospital mortality up to 15.4%, the rate of paraparesis and multiorgan failure - up to 11.5%.

  6. Aortic Calcification: An Early Sign of Heart Valve Problems?

    MedlinePlus

    ... Rekha Mankad, M.D. References AskMayoExpert. Valvular disease – aortic stenosis. Rochester, Minn.: Mayo Foundation for Medical Education and ... Original article: http://www.mayoclinic.org/diseases-conditions/aortic-stenosis/expert-answers/aortic-valve-calcification/FAQ-20058525 . Mayo ...

  7. Complete cage migration/subsidence into the adjacent vertebral body after posterior lumbar interbody fusion.

    PubMed

    Corniola, Marco V; Jägersberg, Max; Stienen, Martin N; Gautschi, Oliver P

    2015-03-01

    A variety of implant-related short and long-term complications after lumbar fusion surgery are recognized. Mid to long-term complications due to cage migration and/or cage subsidence are less frequently reported. Here, we report a patient with a complete cage migration into the superior adjacent vertebral body almost 20 years after the initial posterior lumbar interbody fusion procedure. In this patient, the cage migration/subsidence was clinically silent, but a selective decompression for adjacent segment degenerative lumbar spinal stenosis was performed. We discuss the risk factors for cage migration/subsidence in view of the current literature.

  8. Heritable retinoblastoma and accelerated aortic valve disease

    PubMed Central

    Abeyratne, L R; Kingston, J E; Onadim, Z; Dubrey, S W

    2013-01-01

    Heritable retinoblastoma is associated with a germline mutation in the tumour suppressor gene RBI. The Rb protein (pRb) arises from the RB1 gene, which was the first demonstrated cancer susceptibility gene in humans. 1 Second primary malignancies are recognised complications of retinoblastoma. Furthermore, pRb is implicated in valve remodelling in calcific aortic valve disease. 2 3 We report a family with hereditary retinoblastoma and associated secondary primary malignancies. There are two interesting aspects to this family. The first is the concept of ‘cancer susceptibility genes’; the RBI gene being the first reported in humans. A further feature of note is that two family members also have bicuspid aortic valves. We discuss a potential association between the gene defect responsible for retinoblastoma (with its associated propensity for further malignancies) and accelerated deterioration of the bicuspid aortic valve in the proband carrying this gene defect. PMID:23595191

  9. Ventricular Septal Defect from Aortic Regurgitation Jet Lesion in Aortic Valve Infective Endocarditis.

    PubMed

    Darabant, Sergiu; Oberton, Shelby B; Roldan, Luis P; Roldan, Carlos A

    2016-03-01

    Aortic valve infective endocarditis (IE) can be complicated with severe aortic regurgitation (AR) jet-related lesions such as vegetations, pseudoaneurysms, aneurysms or perforations on the anterior mitral leaflet. Herein is reported the case of a 69-year-old male with culture-negative aortic valve endocarditis complicated with aortic valve perforations resulting in severe and eccentric AR and an AR jet-related ventricular septal defect (VSD). Neither transthoracic echocardiography (TTE) nor two-dimensional transesophageal echocardiography (2D-TEE) were unable to clearly discriminate an aorto-right ventricular fistula from a VSD. By contrast, three-dimensional TEE (3D-TEE) demonstrated multiple aortic valve vegetations, aortic valve perforations, severe AR, and an AR jet-related VSD. The 3D-TEE findings were confirmed at surgery, the aortic valve was replaced with a bioprosthetic valve, and the VSD was repaired with a pericardial patch. To the authors' knowledge, this is the first case of a VSD resulting from an AR jet lesion to be detected and characterized using 3D-TEE. The accurate preoperative diagnosis and characterization of the VSD with 3D-TEE contributed to successful surgery and the patient's short- and long-term survival. Video 1A: This four-chamber transthoracic echocardiography (TTE) view with color Doppler shows a color-Doppler jet traversing the basal interventricular septum (IVS) into the right ventricle, predominantly during systole. However, the origin of the jet resulting from an aortic-right ventricular fistula cannot be determined. A mild to moderate degree of tricuspid regurgitation is also noted. Video 1B: Close-up view of the basal IVS demonstrates a color Doppler jet traversing the IVS, predominantly during systole and apparently originating in the left ventricular outflow tract side, as illustrated by a color Doppler acceleration zone. However, and as in Fig. 1A, the origin of the jet resulting from an aortic-right ventricular fistula cannot

  10. Aortic Input Impedance during Nitroprusside Infusion

    PubMed Central

    Pepine, Carl J.; Nichols, W. W.; Curry, R. C.; Conti, C. Richard

    1979-01-01

    Beneficial effects of nitroprusside infusion in heart failure are purportedly a result of decreased afterload through “impedance” reduction. To study the effect of nitroprusside on vascular factors that determine the total load opposing left ventricular ejection, the total aortic input impedance spectrum was examined in 12 patients with heart failure (cardiac index <2.0 liters/min per m2 and left ventricular end diastolic pressure >20 mm Hg). This input impedance spectrum expresses both mean flow (resistance) and pulsatile flow (compliance and wave reflections) components of vascular load. Aortic root blood flow velocity and pressure were recorded continuously with a catheter-tip electromagnetic velocity probe in addition to left ventricular pressure. Small doses of nitroprusside (9-19 μg/min) altered the total aortic input impedance spectrum as significant (P < 0.05) reductions in both mean and pulsatile components were observed within 60-90 s. With these acute changes in vascular load, left ventricular end diastolic pressure declined (44%) and stroke volume increased (20%, both P < 0.05). Larger nitroprusside doses (20-38 μg/min) caused additional alteration in the aortic input impedance spectrum with further reduction in left ventricular end diastolic pressure and increase in stroke volume but no additional changes in the impedance spectrum or stroke volume occurred with 39-77 μg/min. Improved ventricular function persisted when aortic pressure was restored to control values with simultaneous phenylephrine infusion in three patients. These data indicate that nitroprusside acutely alters both the mean and pulsatile components of vascular load to effect improvement in ventricular function in patients with heart failure. The evidence presented suggests that it may be possible to reduce vascular load and improve ventricular function independent of aortic pressure reduction. PMID:457874

  11. Aortic injuries in newer vehicles.

    PubMed

    Ryb, Gabriel E; Dischinger, Patricia C; Kleinberger, Michael; McGwin, Gerald; Griffin, Russell L

    2013-10-01

    The occurrence of AI was studied in relation to vehicle model year (MY) among front seat vehicular occupants, age≥16 in vehicles MY≥1994, entered in the National Automotive Sampling System Crashworthiness Data System between 1997 and 2010 to determine whether newer vehicles, due to their crashworthiness improvements, are linked to a lower risk of aortic injuries (AI). MY was categorized as 1994-1997, 1998-2004, or 2005-2010 reflecting the introduction of newer occupant protection technology. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals for the association between AI and MY independent of possible confounders. Analysis was repeated, stratified by frontal and near lateral impacts. AI occurred in 19,187 (0.06%) of the 31,221,007 (weighted) cases, and contributed to 11% of all deaths. AIs were associated with advanced age, male gender, high BMI, near-side impact, rollover, ejection, collision against a fixed object, high ΔV, vehicle mismatch, unrestrained status, and forward track position. Among frontal crashes, MY 98-04 and MY 05-10 showed increased adjusted odds of AI when compared to MY 94-97 [OR 1.84 (1.02-3.32) and 1.99 (0.93-4.26), respectively]. In contrast, among near-side impact crashes, MY 98-04 and MY 05-10 showed decreased adjusted odds of AI [OR 0.50 (0.25-0.99) and 0.27 (0.06-1.31), respectively]. While occupants of newer vehicles experience lower odds of AI in near side impact crashes, a higher AI risk is present in frontal crashes.

  12. Environmental impacts of cage culture in Lake Victoria: the case of Shirati Bay-Sota, Tanzania.

    PubMed

    Kashindye, Benedicto Boniphace; Nsinda, P; Kayanda, R; Ngupula, G W; Mashafi, C A; Ezekiel, C N

    2015-01-01

    The experimental cage culture was conducted at Shirati bay, Lake Victoria from February to August 2013, to investigate the impacts of the small scale cage culture on the environment. Three locations along the cages, at the intermediate and one in the offshore (control) were sampled for water quality parameters, phytoplankton and macro invertebrates. A notable increase in nutrient concentration was observed after the set of cages among the stations. However DO, pH, and water transparency showed no major changes and was within the recommended ranges. Cyanophytes an indicator of inorganic pollution dominated before and after the set of cages, an increase in phytoplankton numerical abundance was observed after stocking of fish in cages. In addition there was an increase in the invertebrate community especially bivalves and gastropods. In conclusion we found no consistent environmental change caused by cage culture, and therefore it can be allowed in Lake Victoria, Tanzania part, with close monitoring of its impacts.

  13. A bovine aortic arch in humans

    PubMed Central

    Arnáiz-García, María Elena; González-Santos, Jose María; López-Rodriguez, Javier; Dalmau-Sorli, María José; Bueno-Codoñer, María; Arévalo-Abascal, Adolfo; Fdez García-Hierro, Jose Ma; Arnáiz-García, Ana María; Arnáiz, Javier

    2014-01-01

    We describe a curious congenital variation of human aortic arch (AA) branching pattern termed the “bovine aortic arch”. Rather than arising directly from the AA as a separate branch as occurs in the most common AA branching pattern, the left common carotid artery moves to the right and merges from the brachiocephalic trunk. It is the normal AA branching pattern presented in a number of animals (canines, felines or Macaque monkeys) but it has nothing to do with anatomy of AA in ruminant animals, including cattle and buffalo. That is why it is one of the most widely misnomers used in medical literature whose origin is nowadays unknown. PMID:24973853

  14. A bovine aortic arch in humans.

    PubMed

    Arnáiz-García, María Elena; González-Santos, Jose María; López-Rodriguez, Javier; Dalmau-Sorli, María José; Bueno-Codoñer, María; Arévalo-Abascal, Adolfo; Fdez García-Hierro, Jose Ma; Arnáiz-García, Ana María; Arnáiz, Javier

    2014-01-01

    We describe a curious congenital variation of human aortic arch (AA) branching pattern termed the "bovine aortic arch". Rather than arising directly from the AA as a separate branch as occurs in the most common AA branching pattern, the left common carotid artery moves to the right and merges from the brachiocephalic trunk. It is the normal AA branching pattern presented in a number of animals (canines, felines or Macaque monkeys) but it has nothing to do with anatomy of AA in ruminant animals, including cattle and buffalo. That is why it is one of the most widely misnomers used in medical literature whose origin is nowadays unknown.

  15. Supravalvular aortic stenosis after arterial switch operation.

    PubMed

    Maeda, Takuya; Koide, Masaaki; Kunii, Yoshifumi; Watanabe, Kazumasa; Kanzaki, Tomohito; Ohashi, Yuko

    2016-07-01

    Supravalvular aortic stenosis as a late complication of transposition of the great arteries is very rare, and only a few cases have been reported. We describe the case of a 14-year-old girl who developed supravalvular aortic stenosis as a late complication of the arterial switch operation for transposition of the great arteries. The narrowed ascending aorta was replaced with a graft. The right pulmonary artery was transected to approach the ascending aorta which adhered severely to the main pulmonary trunk, and we obtained a good operative field.

  16. Idiopathic thoracic aortic aneurysm at pediatric age.

    PubMed

    Marín-Manzano, E; González-de-Olano, D; Haurie-Girelli, J; Herráiz-Sarachaga, J I; Bermúdez-Cañete, R; Tamariz-Martel, A; Cuesta-Gimeno, C; Pérez-de-León, J

    2009-03-01

    A 6-year-old-boy presented with epigastric pain and vomiting over 1 year. Chest X-ray and esophagogastric transit showed a mediastinal mass. A chest computerized tomography angiogram demonstrated a descending thoracic aortic aneurysm. Analytical determinations carried out were all negative. The aneurysm was surgically repaired using a Dacron patch. The anatomopathological study described atherosclerotic lesions with calcifications, compatible with an atherosclerotic aneurysm wall. Aneurysms are uncommon in the pediatric population. Usually, no pathogenesis can be determined, and thus, such cases are grouped as idiopathic. Direct repair with or without patch is a therapeutic alternative in pediatric aneurysms and can allow the growth of the aortic circumference.

  17. Rotational Brownian dynamics simulations of clathrin cage formation.

    PubMed

    Ilie, Ioana M; den Otter, Wouter K; Briels, Wim J

    2014-08-14

    The self-assembly of nearly rigid proteins into ordered aggregates is well suited for modeling by the patchy particle approach. Patchy particles are traditionally simulated using Monte Carlo methods, to study the phase diagram, while Brownian Dynamics simulations would reveal insights into the assembly dynamics. However, Brownian Dynamics of rotating anisotropic particles gives rise to a number of complications not encountered in translational Brownian Dynamics. We thoroughly test the Rotational Brownian Dynamics scheme proposed by Naess and Elsgaeter [Macromol. Theory Simul. 13, 419 (2004); Naess and Elsgaeter Macromol. Theory Simul. 14, 300 (2005)], confirming its validity. We then apply the algorithm to simulate a patchy particle model of clathrin, a three-legged protein involved in vesicle production from lipid membranes during endocytosis. Using this algorithm we recover time scales for cage assembly comparable to those from experiments. We also briefly discuss the undulatory dynamics of the polyhedral cage.

  18. Rotational Brownian Dynamics simulations of clathrin cage formation

    SciTech Connect

    Ilie, Ioana M.; Briels, Wim J.; Otter, Wouter K. den

    2014-08-14

    The self-assembly of nearly rigid proteins into ordered aggregates is well suited for modeling by the patchy particle approach. Patchy particles are traditionally simulated using Monte Carlo methods, to study the phase diagram, while Brownian Dynamics simulations would reveal insights into the assembly dynamics. However, Brownian Dynamics of rotating anisotropic particles gives rise to a number of complications not encountered in translational Brownian Dynamics. We thoroughly test the Rotational Brownian Dynamics scheme proposed by Naess and Elsgaeter [Macromol. Theory Simul. 13, 419 (2004); Naess and Elsgaeter Macromol. Theory Simul. 14, 300 (2005)], confirming its validity. We then apply the algorithm to simulate a patchy particle model of clathrin, a three-legged protein involved in vesicle production from lipid membranes during endocytosis. Using this algorithm we recover time scales for cage assembly comparable to those from experiments. We also briefly discuss the undulatory dynamics of the polyhedral cage.

  19. Spatiotemporal Control of Embryonic Gene Expression Using Caged Morpholinos

    PubMed Central

    Shestopalov, Ilya A.; Chen, James K.

    2015-01-01

    Embryonic development depends on spatial and temporal control of gene function, and deciphering the molecular mechanisms that underlie pattern formation requires methods for perturbing gene expression with similar precision. Emerging chemical technologies can enable such perturbations, as exemplified by the use of caged morpholino (cMO) oligonucleotides to photo-inactivate genes in zebrafish embryos with spatiotemporal control. This chapter describes general principles for cMO design and methods for cMO assembly in three steps from commercially available reagents. Experimental techniques for the microinjection and photoactivation of these reagents are described in detail, as well as the preparation and application of caged fluorescein dextran (cFD) for labeling irradiated cells. Using these protocols, cMOs can be effective tools for functional genomic studies in zebrafish and other model organisms. PMID:21924162

  20. Macromolecularly "Caged" Carbon Nanoparticles for Intracellular Trafficking via Switchable Photoluminescence.

    PubMed

    Misra, Santosh K; Srivastava, Indrajit; Tripathi, Indu; Daza, Enrique; Ostadhossein, Fatemeh; Pan, Dipanjan

    2017-02-08

    Reversible switching of photoluminescence (PL) of carbon nanoparticles (CNP) can be achieved with counterionic macromolecular caging and decaging at the nanoscale. A negatively charged uncoated, "bare" CNP with high luminescence loses its PL when positively charged macromolecules are wrapped around its surface. Prepared caged carbons could regain their emission only through interaction with anionic surfactant molecules, representing anionic amphiphiles of endocytic membranes. This process could be verified by gel electrophoresis, spectroscopically and in vitro confocal imaging studies. Results indicated for the first time that luminescence switchable CNPs can be synthesized for efficient intracellular tracking. This study further supports the origin of photoluminescence in CNP as a surface phenomenon correlated a function of characteristic charged macromolecules.

  1. Battery with modular air cathode and anode cage

    DOEpatents

    Niksa, Marilyn J.; Pohto, Gerald R.; Lakatos, Leslie K.; Wheeler, Douglas J.; Niksa, Andrew J.; Schue, Thomas J.; Turk, Thomas R.

    1988-01-01

    A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom.

  2. Battery with modular air cathode and anode cage

    DOEpatents

    Niksa, Marilyn J.; Pohto, Gerald R.; Lakatos, Leslie K.; Wheeler, Douglas J.; Niksa, Andrew J.; Schue, Thomas J.

    1987-01-01

    A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom.

  3. Optical triggered seizures using a caged 4-Aminopyridine

    PubMed Central

    Zhao, Mingrui; McGarry, Laura M.; Ma, Hongtao; Harris, Samuel; Berwick, Jason; Yuste, Rafael; Schwartz, Theodore H.

    2015-01-01

    Animal models of epilepsy are critical not only for understanding the fundamental mechanism of epilepsy but also for testing the efficacy of new antiepileptic drugs and novel therapeutic interventions. Photorelease of caged molecules is widely used in biological research to control pharmacologic events with high spatio-temporal resolution. We developed a technique for in vivo optical triggering of neocortical seizures using a novel caged compound based on ruthenium photochemistry (RuBi-4AP). Epileptiform events in mouse cortex were induced with blue light in both whole brain and focal illumination. Multi-electrode array recording and optical techniques were used to characterize the propagation of these epileptic events, including interictal spikes, polyspikes, and ictal discharges. These results demonstrate a novel optically-triggered seizure model, with high spatio-temporal control, that could have widespread application in the investigation of ictal onset, propagation and to develop novel light-based therapeutic interventions. PMID:25698919

  4. Supramolecular Archimedean cages assembled with 72 hydrogen bonds.

    PubMed

    Liu, Yuzhou; Hu, Chunhua; Comotti, Angiolina; Ward, Michael D

    2011-07-22

    Self-assembly of multiple components into well-defined and predictable structures remains one of the foremost challenges in chemistry. Here, we report on the rational design of a supramolecular cage assembled from 20 ions of three distinct species through 72 hydrogen bonds. The cage is constructed from two kinds of hexagonal molecular tiles, a tris(guanidinium)nitrate cluster and a hexa(4-sulfonatophenyl)benzene, joined at their edges through complementary and metrically matched N-H···O-S hydrogen bonds to form a truncated octahedron, one of the Archimedean polyhedra. The truncated octahedron, with an interior volume of 2200 cubic angstroms, serves as the composite building unit of a body-centered cubic zeolite-like framework, which exhibits an ability to encapsulate a wide range of differently charged species, including organic molecules, transition metal complexes, and "ship-in-a-bottle" nanoclusters not observed otherwise.

  5. Supramolecular Archimedean Cages Assembled with 72 Hydrogen Bonds

    SciTech Connect

    Liu, Yuzhou; Hu, Chunhua; Comotti, Angiolina; Ward, Michael D.

    2011-12-09

    Self-assembly of multiple components into well-defined and predictable structures remains one of the foremost challenges in chemistry. Here, we report on the rational design of a supramolecular cage assembled from 20 ions of three distinct species through 72 hydrogen bonds. The cage is constructed from two kinds of hexagonal molecular tiles, a tris(guanidinium)nitrate cluster and a hexa(4-sulfonatophenyl)benzene, joined at their edges through complementary and metrically matched N-H {hor_ellipsis} O-S hydrogen bonds to form a truncated octahedron, one of the Archimedean polyhedra. The truncated octahedron, with an interior volume of 2200 cubic angstroms, serves as the composite building unit of a body-centered cubic zeolite-like framework, which exhibits an ability to encapsulate a wide range of differently charged species, including organic molecules, transition metal complexes, and 'ship-in-a-bottle' nanoclusters not observed otherwise.

  6. Modelling of current loads on aquaculture net cages

    NASA Astrophysics Data System (ADS)

    Kristiansen, Trygve; Faltinsen, Odd M.

    2012-10-01

    In this paper we propose and discuss a screen type of force model for the viscous hydrodynamic load on nets. The screen model assumes that the net is divided into a number of flat net panels, or screens. It may thus be applied to any kind of net geometry. In this paper we focus on circular net cages for fish farms. The net structure itself is modelled by an existing truss model. The net shape is solved for in a time-stepping procedure that involves solving a linear system of equations for the unknown tensions at each time step. We present comparisons to experiments with circular net cages in steady current, and discuss the sensitivity of the numerical results to a set of chosen parameters. Satisfactory agreement between experimental and numerical prediction of drag and lift as function of the solidity ratio of the net and the current velocity is documented.

  7. Endovascular treatment for traumatic thoracic aortic pseudoaneurysm: a case report

    PubMed Central

    2013-01-01

    Cases of an endovascular treatment for traumatic aortic injury are extremely rare. A prompt diagnosis of traumatic thoracic aortic pseudoaneurysm through a 3-dimensional computed tomographic angiography of aorta and emergency repair are mandatory to rescue the life-threatening condition. An endovascular treatment is a trend for traumatic aortic injury because of lower invasivity, morbidity and mortality. We reported a rare case of traumatic aortic injury with thoracic aortic pseudoaneurysm definitively diagnosed by the reconstructional computed tomographic angiography of aorta and successfully treated with endovascular stent-graft. PMID:23452982

  8. Portico Sheathless Transcatheter Aortic Valve Implantation via Distal Axillary Artery.

    PubMed

    Bruschi, Giuseppe; Colombo, Paola; Botta, Luca; Nava, Stefano; Merlanti, Bruno; Belli, Oriana; Musca, Francesco; Soriano, Francesco; Russo, Claudio F; Oliva, Fabrizio

    2017-02-01

    Transcatheter aortic valve implantation has been designed to treat older patients affected by severe aortic stenosis who are considered high-risk surgical candidates because of multiple comorbidities. The least invasive approach for transcatheter aortic valves implantation should be considered the transfemoral retrograde route, because it is minimally invasive and is feasible with local anesthesia and mild sedation. Despite significant technical improvements in recent years, the transfemoral approach is contraindicated in cases of severe peripheral artery disease. We describe the first case of a Portico transcatheter aortic valve implantation system (St. Jude Medical, Minneapolis, MN) made through the distal axillary artery in a 90-year-old patient affected by severe aortic stenosis.

  9. First reported case of fetal aortic valvuloplasty in Asia

    PubMed Central

    Yoon, Sun-Young; Lee, Mi-Young; Cho, Min Kyong; Jung, Euiseok; Kim, Ki-Soo; Kim, Young-Hwue

    2017-01-01

    Prenatal intervention of severe fetal aortic valve stenosis by ultrasound-guided percutaneous balloon valvuloplasty has been performed to prevent the progression to hypoplastic left heart syndrome, and achieve biventricular circulation in neonates. Here we report a case of fetal aortic valvuloplasty prenatally diagnosed with aortic stenosis at 24 weeks of gestation and showed worsening features on a follow-up echocardiography. Prenatal aortic valvuloplasty was performed at 29 weeks of gestation, and was a technical success. However, fetal bradycardia sustained, and an emergency cesarean delivery was performed. To the best of our knowledge, this is the first reported case of fetal aortic valvuloplasty which was performed in Asia. PMID:28217680

  10. Proposed modification for valve-sparing aortic root replacement.

    PubMed

    Mahesh, Balakrishnan; Deville, Claude; Nashef, Samer

    2014-05-01

    Valve-sparing aortic root replacement (ARR) is the procedure of choice in young patients with aortic root aneurysm and preserved aortic valve leaflets; however, coronary ostial anastomoses remain an issue. Troublesome bleeding sometimes occurs during surgery, and in the long term, there is a risk of aneurysmal formation in the residual aortic wall of the ostial "button." We describe a technique of valve-sparing ARR wherein each coronary button along with its flange of aortic tissue is implanted within the prosthetic graft used for ARR, thereby eliminating the risk of both immediate surgical bleeding and late coronary button aneurysms.

  11. Animal Welfare and Food Safety Aspects of Confining Broiler Chickens to Cages

    PubMed Central

    Shields, Sara; Greger, Michael

    2013-01-01

    Simple Summary In commercial chicken meat production, broiler chickens are usually kept on the floor in ware-house like buildings, but the use of cages is becoming more common. Confining chickens to cages is a welfare problem, as has been thoroughly demonstrated for laying hens used for egg production. Caged broiler chickens may suffer from poor bone strength due to lack of exercise, feather loss, and restriction of natural behavior. There are also potential food safety concerns associated with the use of cages. While cages may provide an economic advantage in some geographical regions of the world, the severe, inherent disadvantages should also be considered before cages are more widely adopted in the global broiler chicken industry. Abstract In most areas of the world, broiler chickens are raised in floor systems, but cage confinement is becoming more common. The welfare of broiler chickens in cages is affected by movement restriction, poor bone strength due to lack of exercise, and prevention of key behavioral patterns such as dustbathing and ground scratching. Cages for broiler chickens also have a long history of causing skin and leg conditions that could further compromise welfare, but a lack of controlled studies makes it difficult to draw conclusions about newer cage designs. Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds. Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms. Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval. PMID:26487409

  12. Flow Tagging Velocimetry Using Caged Dye Photo-Activated Fluorophores

    DTIC Science & Technology

    2000-01-01

    Meas. Sci. Technol. 11 (2000) 1251–1258. Printed in the UK PII: S0957-0233(00)10968-3 Flow tagging velocimetry using caged dye photo-activated...followed by laser induced electronic fluo- rescence, has been applied both to low speed turbulent air jets (Noullez et al 1997) and to supersonic flow...measurements in electrohydrodynamic flows with mean velocities of order 2–4 µm s−1. There are, however, some significant disadvantages associated with

  13. Home cage testing of delay discounting in rats.

    PubMed

    Koot, S; Adriani, W; Saso, L; van den Bos, R; Laviola, G

    2009-11-01

    Testing rodents in their home cages has become increasingly popular. Since human intervention, handling, and transport are minimized, behavior can be recorded undisturbed and continuously. Currently existing home cage systems are too complex if only relatively simple operant-learning tests are to be carried out in rats. For that purpose, a new low-cost computer-controlled operant panel was designed, which can be placed inside the home cage. A pilot study was carried out, using an intolerance-to-delay protocol, classically developed for testing behavioral impulsivity. Male adult rats were tested in their home cages, containing the operant panel provided with nose-poking holes. Nose poking in one hole resulted in the immediate delivery of one food pellet (small-soon, SS), whereas nose poking in the other hole delivered five food pellets after a delay (large-late), which was increased progressively each day (0-150 sec). The two daily sessions, spaced 8 h apart, lasted 1 h each, and the time-out after food delivery was 90 sec. A clear-cut shift toward preference for SS, which is considered a classical index of cognitive impulsivity, was shown at the longest delay. It is noteworthy that rats shifted when the delay interval was longer than the mean intertrial interval-that is, when they experienced more than one delay-equivalent odds against discounting (see Adriani & Laviola, 2006). The shortened training (2 days) and testing (5 days) phases, as allowed by prolonged and multiple daily sessions, can be advantageous in testing rodents during selected short phases of development. Current research is focusing on further validation of this and similar protocols.

  14. Caging the Dragon: The Containment of Underground Nuclear Explosions

    DTIC Science & Technology

    1995-06-01

    Washington Headquarters Services Directorate for informatton Operations and Reports, 1215 Jefferson 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3...REPORT TYPE AND DATES COVERED Technical 881001-951231 4. TITLE AND SUBTITLE Caging the Dragon The Containment of Underground Explosions 5. FUNDING... mathematics , the charts and graphs that make up the structure of the scientific and engineering practice of the containment of under- ground nuclear

  15. Endovascular Management of Chronic Type B Dissecting Aortic Aneurysm Utilizing Aortic and Renal Stents

    SciTech Connect

    Taylor, J. D. Dunckley, M.; Thompson, M.; Morgan, R. A.

    2008-07-15

    Over the last 10 years endovascular stent-graft placement has been increasingly used to treat complicated acute Type B thoracic aortic dissections. While studies have demonstrated the use of additional aortic stent-grafts to treat continued false lumen perfusion and case reports have detailed the use of renal artery stents to treat renal ischemia related to aortic dissection, to our knowledge the adjuvant use of renal artery stents to reduce false lumen perfusion has not been reported. We present the case of a 72-year-old male who had previously undergone endovascular repair of a complicated Type B thoracic aortic dissection and presented with an expanding false lumen in the peridiaphragmatic aorta despite coverage of the entire thoracic aorta. This was treated by closure of a right renal fenestration using a renal stent.

  16. Aortic Valvular Replacement: Clinical Experience With 13 Cases

    PubMed Central

    Grondin, Pierre; Lepage, Gilles; Castonguay, Yves

    1964-01-01

    Acquired aortic disease is now currently corrected by total prosthetic replacement of the aortic valve. Aortic valve replacement was performed in 13 cases at the Montreal Heart Institute in 1963. In the first four cases, Bahnson aortic leaflets were used; in the remaining nine, the Starr-Edwards semirigid aortic valve prosthesis. The surgical technique employed is described. There were two operative deaths and two late deaths. The results have been excellent in all of the survivors but one. They have returned to full-time activities and four of them to strenuous physical work. It is the contention of the authors that aortic valve replacement is a surgical procedure with acceptable risks, offering hope for a near-normal life to patients crippled by severe aortic valvular lesions. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7 PMID:14179061

  17. Aortic insufficiency. A result of intermittent migration of aortic valve prosthesis poppet.

    PubMed

    Kunstadt, D; Adeyemo, A; Clauss, R H

    1976-06-28

    A bizarre mechanism of aortic valve incompetence was observed when the occluder of a Braunwald-Cutter aortic valve prosthesis decreased in diameter, volume, and weight, and from time to time fell into the left ventricle. The patient's symptoms were palpitation, coughing, chocking sensations, and fright. An operation disclosed a small, smooth ball with disrupted cloth on all the struts. The residual torn mesh was removed, and the ball was replaced.

  18. Aortic Remodeling Following Transverse Aortic Constriction in Mice is Attenuated with AT1 Receptor Blockade

    PubMed Central

    Kuang, Shao-Qing; Geng, Liang; Prakash, Siddharth K.; Cao, Jiu-Mei; Guo, Steven; Villamizar, Carlos; Kwartler, Callie S.; Ju, Xiaoxi; Brasier, Allan R.; Milewicz, Dianna M.

    2016-01-01

    Objective Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of Ang II type 1 (AT1) receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model. Approach and Results Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation, aortic wall thickening and medial hypertrophy. Significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density due to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC induced adventitial hyperplasia, collagen accumulation and ascending aortic dilatation. Increased Tgfb2 expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas was effectively blocked with losartan. In contrast, the increased Tgfb1 expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked Erk activation and ROS production in the TAC ascending aorta. Conclusions Inhibition of the AT1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased TGF- β1 expression, adventitial Smad2 signaling and collagen accumulation. These results help to delineate the aortic TGF-β signaling that is dependent and independent of the AT1 receptor after TAC. PMID:23868934

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

    PubMed

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

    2006-04-01

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

  20. Computed tomography evaluation for transcatheter aortic valve implantation (TAVI): imaging of the aortic root and iliac arteries.

    PubMed

    Schoenhagen, Paul; Kapadia, Samir R; Halliburton, Sandra S; Svensson, Lars G; Tuzcu, E Murat

    2011-01-01

    For patients with severe aortic stenosis, open-heart surgical valve replacement remains the current clinical standard with documented, excellent long-term outcome. Over the past few years, transcatheter aortic valve implantation (TAVI) has developed into a treatment alternative for high-risk patients with severe aortic stenosis. Because transcatheter valvular procedures are characterized by lack of exposure of the operative field, image guidance is critical. This Pictorial Essay describes the role of 3-dimensional imaging with multidetector row computed tomography for detailed reconstructions of the aortic valve, aortic root, and iliac arteries in the context of TAVI.

  1. Aortic root aneurysm in an adult patient with aortic coarctation: a single-stage approach.

    PubMed

    Ananiadou, Olga G; Koutsogiannidis, Charilaos; Ampatzidou, Fotini; Drossos, George E

    2012-09-01

    Coarctation of the aorta is a common congenital defect that may be undiagnosed until adulthood. Moreover, coarctation is associated with congenital and acquired cardiac pathology that may require surgical intervention. The management of an adult patient with aortic coarctation and an associated cardiac defect poses a great technical challenge since there are no standard guidelines for the therapy of such a complex pathology. Several extra-anatomic bypass grafting techniques have been described, including methods in which distal anastomosis is performed on the descending thoracic aorta, allowing simultaneous intracardiac repair. We report here a 37-year old man who was diagnosed with an aortic root aneurysm and aortic coarctation. The patient was treated electively with a single-stage approach through a median sternotomy that consisted of valve-sparing replacement of the aortic root and ascending-to-descending extra-anatomic aortic bypass, using a 18-mm Dacron graft. Firstly, the aortic root was replaced with the Yacoub remodelling procedure, and then the distal anastomosis was performed to the descending aorta, behind the heart, with the posterior pericardial approach. The extra-anatomic bypass graft was brought laterally from the right atrium and implanted in the ascending graft. Postoperative recovery was uneventful and a control computed tomographic angiogram 1 month after complete repair showed good results.

  2. Aortic valve replacement with sutureless and rapid deployment aortic valve prostheses

    PubMed Central

    Berretta, Paolo; Di Eusanio, Marco

    2016-01-01

    Aortic valve stenosis is the most common valve disease in the western world. Over the past few years the number of aortic valve replacement (AVR) interventions has increased with outcomes that have been improved despite increasing age of patients and increasing burden of comorbidities. However, despite such excellent results and its well-established position, conventional AVR has undergone great development over the previous two decades. Such progress, by way of less invasive incisions and use of new technologies, including transcatheter aortic valve implantation and sutureless valve prostheses, is intended to reduce the traumatic impact of the surgical procedure, thus fulfilling lower risk patients' expectations on the one hand, and extending the operability toward increasingly high-risk patients on the other. Sutureless and rapid deployment aortic valves are biological, pericardial prostheses that anchor within the aortic annulus with no more than three sutures. The sutureless prostheses, by avoiding the passage and the tying of the sutures, significantly reduce operative times and may improve outcomes. However, there is still a paucity of robust, evidence-based data on the role and performance of sutureless AVR. Therefore, strongest long-term data, randomized studies and registry data are required to adequately assess the durability and long-term outcomes of sutureless aortic valve replacement. PMID:27582765

  3. Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

    NASA Astrophysics Data System (ADS)

    Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

    2004-05-01

    Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

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

    PubMed

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

    2014-02-01

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

  5. Aortic Valve Leaflet Replacement with Bovine Pericardium to Preserve Native Dynamic Capabilities of the Aortic Annulus

    PubMed Central

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

    2014-01-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations. PMID:24512414

  6. Aortic root aneurysm in an adult patient with aortic coarctation: a single-stage approach

    PubMed Central

    Ananiadou, Olga G.; Koutsogiannidis, Charilaos; Ampatzidou, Fotini; Drossos, George E.

    2012-01-01

    Coarctation of the aorta is a common congenital defect that may be undiagnosed until adulthood. Moreover, coarctation is associated with congenital and acquired cardiac pathology that may require surgical intervention. The management of an adult patient with aortic coarctation and an associated cardiac defect poses a great technical challenge since there are no standard guidelines for the therapy of such a complex pathology. Several extra-anatomic bypass grafting techniques have been described, including methods in which distal anastomosis is performed on the descending thoracic aorta, allowing simultaneous intracardiac repair. We report here a 37-year old man who was diagnosed with an aortic root aneurysm and aortic coarctation. The patient was treated electively with a single-stage approach through a median sternotomy that consisted of valve-sparing replacement of the aortic root and ascending-to-descending extra-anatomic aortic bypass, using a 18-mm Dacron graft. Firstly, the aortic root was replaced with the Yacoub remodelling procedure, and then the distal anastomosis was performed to the descending aorta, behind the heart, with the posterior pericardial approach. The extra-anatomic bypass graft was brought laterally from the right atrium and implanted in the ascending graft. Postoperative recovery was uneventful and a control computed tomographic angiogram 1 month after complete repair showed good results. PMID:22647969

  7. Current Indications for Surgical Repair in Patients with Bicuspid Aortic Valve and Ascending Aortic Ectasia

    PubMed Central

    Etz, Christian D.; Misfeld, Martin; Borger, Michael A.; Luehr, Maximilian; Strotdrees, Elfriede; Mohr, Friedrich-Wilhelm

    2012-01-01

    Preventive surgical repair of the moderately dilated ascending aorta/aortic root in patients with bicuspid aortic valve (BAV) is controversial. Most international reference centers are currently proposing a proactive approach for BAV patients with a maximum ascending aortic/root diameter of 45 mm since the risk of dissection/rupture raises significantly with an aneurysm diameter >50 mm. Current guidelines of the European Society of Cardiology (ESC) and the joint guidelines of the American College of Cardiology (ACC)/American Heart Association (AHA) recommend elective repair in symptomatic patients with dysfunctional BAV (aortic diameter ≥45 mm). In asymptomatic patients with a well-functioning BAV, elective repair is recommended for diameters ≥50 mm, or if the aneurysm is rapidly progressing (rate of 5 mm/year), or in case of a strong family history of dissection/rupture/sudden death, or with planned pregnancy. As diameter is likely not the most reliable predictor of rupture and dissection and the majority of BAV patients may never experience an aortic catastrophe at small diameters, an overly aggressive approach almost certainly will put some patients with BAV unnecessarily at risk of operative and early mortality. This paper discusses the indications for preventive, elective repair of the aortic root, and ascending aorta in patients with a BAV and a moderately dilated—or ectatic—ascending aorta. PMID:23050195

  8. Improved synthesis of the two-photon caging group 3-nitro-2-ethyldibenzofuran and its application to a caged thymidine phosphoramidite

    PubMed Central

    Lusic, Hrvoje; Uprety, Rajendra; Deiters, Alexander

    2010-01-01

    A new and efficient route to the recently reported 3-nitro-2-ethyldibenzofuran caging group was developed. Furthermore, its installation on a thymidine phosphoramidite is described. This caging group is efficiently removed through light-irradiation at 365 nm. PMID:20112966

  9. Furnished Cage System and Hen Well-Being: Comparative Effects of Furnished and Battery Cages on Egg Production and Physiological Parameters of White Leghorn Hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory animal well-being can be improved by housing the animals in a species-special “natural” or “near to natural” environment. This study was to examine if housing environment, furnished cages vs. battery cages, causes a similar impact on well-being in laying hens. One hundred seventy-two, on...

  10. Painless aortic dissection presenting as paraplegia.

    PubMed

    Colak, Necmettin; Nazli, Yunus; Alpay, Mehmet Fatih; Akkaya, Ismail Olgun; Cakir, Omer

    2012-01-01

    Acute dissection of the aorta can be life-threatening. As a presenting manifestation of aortic dissection, neurologic complications such as paraplegia are rare. Herein, we report the case of a 51-year-old man who presented with sudden-onset paraplegia and ischemia of the legs, with no chest or back pain. His medical history included coronary artery bypass grafting. Physical examination revealed pulseless lower extremities, and computed tomography showed aortic dissection from the ascending aorta to the common iliac arteries bilaterally. A lumbar catheter was inserted for cerebrospinal fluid drainage, and axillary arterial cannulation was established. With the use of cardiopulmonary bypass, the aortic dissection was corrected, and the previous coronary artery grafts were reattached. The surgery restored spinal and lower-extremity perfusion, and the patient walked unaided from the hospital upon his discharge 5 days later. Although acute aortic dissection presenting as paraplegia is rare, it should be considered in patients who have pulseless femoral arteries bilaterally and sudden-onset paraplegia, despite no pain in the chest or back. Prompt diagnosis and intervention can prevent morbidity and death.

  11. Complication of Behcet's disease: spontaneous aortic pseudoaneurysm.

    PubMed

    Ugurlucan, Murat; Sayin, Omer Ali; Surmen, Benguhan; Kafali, Eylul; Basaran, Murat; Alpagut, Ufuk; Dayioglu, Enver; Onursal, Ertan

    2006-01-01

    Behcet's disease is an autoimmune multisystemic disorder based on vasculitis. In this disease, the most important predictor of morbidity and mortality is the vascular complications. Appropriate surgical interventions are critical and must be planned strategically. Here, we will describe a very rare complication of the disease; spontaneous aortic pseudoaneurysm in a 33-year-old patient.

  12. [Albert Einstein and his abdominal aortic aneurysm].

    PubMed

    Cervantes Castro, Jorge

    2011-01-01

    The interesting case of Albert Einstein's abdominal aortic aneurysm is presented. He was operated on at age 69 and, finding that the large aneurysm could not be removed, the surgeon elected to wrap it with cellophane to prevent its growth. However, seven years later the aneurysm ruptured and caused the death of the famous scientist.

  13. Middle aortic syndrome in a teenager.

    PubMed

    Eyileten, Zeynep; Taşar, Mehmet; Yazıcıoğlu, Levent; Kaya, Bülent; Fitöz, Suat; Uysalel, Adnan

    2014-01-01

    Middle aortic syndrome (MAS) is a rare pathology that involves diffuse/segmental narrowing of the distal thoracic or abdominal aorta. The most common clinical manifestation is severe hypertension, which requires multiple antihypertensive medications and/or surgical repair. We report the surgical repair of MAS in a 14-year-old male.

  14. [Ascending-descending Aortic Bypass and Aortic Valve Replacement for Aortic Coarctation with Bicuspid Aortic Valve and an Aberrant Right Subclavian Artery;Report of a Case].

    PubMed

    Asano, Ryota; Nakano, Kiyoharu; Kodera, Kojiro; Sato, Atsuhiko; Kataoka, Go; Tatsuishi, Wataru; Kubota, Sayaka; Namiki, Shigetaka; Suzuki, Seiya

    2015-08-01

    A 53-year-old woman was developed congestive heart failure. She was diagnosed as having aortic coarctation, incompetent bicuspid aortic valve and an aberrant right subclavian artery by using echocardiography and enhanced computed tomography. Ankle brachial pressure index(ABI)in the right was 0.71 and 0.69 in the left. Blood pressure of the right arm was 60 mmHg lower than that of the left arm. To avoid perioperative adverse cardiac events due to a 2-staged operation, we performed ascending-descending aortic bypass and aortic valve replacement simultaneously through a median sternotomy. The heart was retracted cranially, and a vascular prosthesis was anastomosed to the descending aorta just above the diaphragm in an end-to-side manner. Then the graft was placed curvilinearly around the right atrium and was anastomosed to the ascending aorta. After the operation, the right and left ABI increased to 0.90 and 0.98 respectively. There was no pressure difference between the arms. The postoperative course was uneventful.

  15. Aortic mismatch in heart transplantation: readaptation.

    PubMed

    Miralles, A

    1997-10-01

    Great vessel mismatch between donor and recipient is very usual in heart transplantation. Different procedures have been used to manage this situation. A tailoring aortoplasty is described, as a technical alternative, in cases of considerable size incongruence between donor and recipient aortic diameters.

  16. Aortic aneurysm mimicking a right atrial mass.

    PubMed

    Mohamed, Ahmed; Elsayed, Mahmoud; Kalra, Rajat; Bulur, Serkan; Nanda, Navin C

    2016-10-01

    We present a case of a 54-year-old female who was initially thought to have a cystic mass in the right atrium on two-dimensional transthoracic echocardiography. Careful transducer angulation and off-axis imaging showed this mass-like effect was produced by an aortic root aneurysm impinging on the right atrium.

  17. Lipid Interventions in Aortic Valvular Disease.

    PubMed

    Choi, Kwang Jin; Tsomidou, Christiana; Lerakis, Stamatios; Madanieh, Raef; Vittorio, Timothy J; Kosmas, Constantine E

    2015-10-01

    Aortic valve stenosis is the most common valvular disease in the elderly population. Presently, there is increasing evidence that aortic stenosis (AS) is an active process of lipid deposition, inflammation, fibrosis and calcium deposition. The pathogenesis of AS shares many similarities to that of atherosclerosis; therefore, it was hypothesized that certain lipid interventions could prevent or slow the progression of aortic valve stenosis. Despite the early enthusiasm that statins may slow the progression of AS, recent large clinical trials did not consistently demonstrate a decrease in the progression of AS. However, some researchers believe that statins may have a benefit early on in the disease process, where inflammation (and not calcification) is the predominant process, in contrast to severe or advanced AS, where calcification (and not inflammation) predominates. Positron emission tomography using 18F-fluorodeoxyglucose and 18F-sodium fluoride can demonstrate the relative contributions of valvular calcification and inflammation in AS, and thus this method might potentially be useful in providing the answer as to whether lipid interventions at the earlier stages of AS would be more effective in slowing the progression of the disease. Currently, there is a strong interest in recombinant apolipoprotein A-1 Milano and in the development of new pharmacological agents, targeting reduction of lipoprotein (a) levels and possibly reduction of the expression of lipoprotein-associated phospholipase A2, as potential means to slow the progression of aortic valvular stenosis.

  18. Winged scapula after aortic valve replacement.

    PubMed

    Schmitz, Christoph; Sodian, Ralf; Witt, Thomas N; Juchem, Gerd; Lang, Nora; Bruegger, Christian; Kowalski, Christian; Reichart, Bruno

    2009-04-01

    Iatrogenic nerve lesions affecting the long thoracic nerve are very rare after a median sternotomy. Here we report on a patient who developed clinical signs of a so-called "winged scapula" after an uneventful aortic valve replacement for infective endocarditis.

  19. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    NASA Technical Reports Server (NTRS)

    Meyer, Michael (Technical Monitor); Smith, Davey; Metzgar, David; Wills, Christopher; Fierer, Joshua

    2002-01-01

    Saccharomyces cerevisiae is a yeast commonly used in baking and a frequent colonizer of human mucosal surfaces. It is considered relatively nonpathogenic in immunocompetent adults. We present a case of S. cerevisiae fungemia and aortic graft infection in an immunocompetent adult. This is the first reported case of S. cerevisiue fungemia where the identity of the pathogen was confirmed by rRNA sequencing.

  20. Surgical management of a hypoplastic distal aortic arch and coarctation of aorta in a patient with Klippel-Feil syndrome, ascending aortic aneurysm and bicuspid aortic valve.

    PubMed

    Sabol, Frantisek; Kolesar, Adrián; Toporcer, Tomás; Bajmoczi, Milan

    2014-10-01

    Klippel-Feil syndrome has been associated with cardiovascular malformations, but only 3 cases have been reported to be associated with aortic coarctation and surgical management is not defined. A 51-year old woman with Klippel-Feil syndrome associated with an aneurysm of the ascending aorta, hypoplastic aortic arch and aortic coarctation at the level of the left subclavian artery presented with shortness of breath 2 years after diagnosis. Imaging identified interim development of a 7.2-cm aneurysm at the level of the aortic coarctation. She underwent surgical repair with a Dacron interposition graft under hypothermic circulatory arrest. She continues to do well 18 months following repair.

  1. Structure and energetic characteristics of methane hydrates. From single cage to triple cage: A DFT-D study

    NASA Astrophysics Data System (ADS)

    Giricheva, N. I.; Ischenko, A. A.; Yusupov, V. I.; Bagratashvili, V. N.; Girichev, G. V.

    2017-03-01

    Electronic, geometrical, vibrational and energetic characteristics of the ice I TDT fragment consisted of dodecahedron H2O[512] (D) fused with two tetrakaidecahedrons H2O[51262] (T) and of the TDT cluster with three encapsulated CH4 molecules (3CH4·TDT) were calculated using a DFT/B97-D/6-311++G(2d,2p) approach. Binding energies, hydrogen bonding energies, energies of encapsulation of methane molecules into small D- and large T-cages of the TDT fragment, energies of frontier orbitals, the translational and librational frequencies, as well as the intramolecular vibrations of methane within the cages of different sizes were studied. Similar characteristics of isolated D- and T-cages and clathrates CH4·D and CH4·T were studied as function of compression/expansion of their oxygen skeletons using DFT/B97-D, LC-B3LYP, B3LYP-D2 methods.

  2. Preserving a Well-Functioning 33-Year-Old Starr-Edwards Aortic Prosthesis in Repeat Aortic Root Aneurysm Repair

    PubMed Central

    Alimov, Victor K.; Rousou, John A.; Pluchino, Fabrizio I.

    2016-01-01

    We report the case of a 61-year-old obese male patient in whom we found a well-functioning 33-year-old Starr-Edwards aortic prosthesis during repeat aortic surgery. Rather than explant the prosthesis, we remodeled the aortic root, almost completely removing the aortic sinuses and leaving only a pillar of aortic tissue around the coronary ostia. The proximal end of a Hemashield tube-graft was then scalloped to accommodate the remaining aortic tissue. The patient's heart function was excellent after his weaning from cardiopulmonary bypass. Simplifying the repeat aortic root repair, by preserving a well-functioning Starr-Edwards valve, might lead to a better outcome in similar cases. We also discuss other instances of this valve's durability. PMID:28100977

  3. Solute diffusion through fibrotic tissue formed around protective cage system for implantable devices.

    PubMed

    Prihandana, Gunawan Setia; Ito, Hikaru; Tanimura, Kohei; Yagi, Hiroshi; Hori, Yuki; Soykan, Orhan; Sudo, Ryo; Miki, Norihisa

    2015-08-01

    This article presents the concept of an implantable cage system that can house and protect implanted biomedical sensing and therapeutic devices in the body. Cylinder-shaped cages made of porous polyvinyl alcohol (PVA) sheets with an 80-µm pore size and/or stainless steel meshes with 0.54-mm openings were implanted subcutaneously in the dorsal region of rats for 5 weeks. Analysis of the explanted cages showed the formation of fibrosis tissue around the cages. PVA cages had fibrotic tissue growing mostly along the outer surface of cages, while stainless steel cages had fibrotic tissue growing into the inside surface of the cage structure, due to the larger porosity of the stainless steel meshes. As the detection of target molecules with short time lags for biosensors and mass transport with low diffusion resistance into and out of certain therapeutic devices are critical for the success of such devices, we examined whether the fibrous tissue formed around the cages were permeable to molecules of our interest. For that purpose, bath diffusion and microfluidic chamber diffusion experiments using solutions containing the target molecules were performed. Diffusion of sodium, potassium and urea through the fibrosis tissue was confirmed, thus suggesting the potential of these cylindrical cages surrounded by fibrosis tissue to successfully encase implantable sensors and therapeutic apparatus.

  4. Coronary Ostial Stenosis after Aortic Valve Replacement

    PubMed Central

    Ziakas, Antonios G.; Economou, Fotios I.; Charokopos, Nicholas A.; Pitsis, Antonios A.; Parharidou, Despina G.; Papadopoulos, Thomas I.; Parharidis, Georgios E.

    2010-01-01

    Coronary ostial stenosis is a rare but potentially serious sequela after aortic valve replacement. It occurs in the left main or right coronary artery after 1% to 5% of aortic valve replacement procedures. The clinical symptoms are usually severe and may appear from 1 to 6 months postoperatively. Although the typical treatment is coronary artery bypass grafting, patients have been successfully treated by means of percutaneous coronary intervention. Herein, we present the cases of 2 patients in whom coronary ostial stenosis developed after aortic valve replacement. In the 1st case, a 72-year-old man underwent aortic valve replacement and bypass grafting of the saphenous vein to the left anterior descending coronary artery. Six months later, he experienced a non-ST-segment-elevation myocardial infarction. Coronary angiography revealed a critical stenosis of the right coronary artery ostium. In the 2nd case, a 78-year-old woman underwent aortic valve replacement and grafting of the saphenous vein to an occluded right coronary artery. Four months later, she experienced unstable angina. Coronary angiography showed a critical left main coronary artery ostial stenosis and occlusion of the right coronary artery venous graft. In each patient, we performed percutaneous coronary intervention and deployed a drug-eluting stent. Both patients were asymptomatic on 6-to 12-month follow-up. We attribute the coronary ostial stenosis to the selective ostial administration of cardioplegic solution during surgery. We conclude that retrograde administration of cardioplegic solution through the coronary sinus may reduce the incidence of postoperative coronary ostial stenosis, and that stenting may be an efficient treatment option. PMID:20844624

  5. Effects of cage size and enrichment on reproductive performance and behavior in C57BL/6Tac mice.

    PubMed

    Whitaker, Julia; Moy, Sheryl S; Godfrey, Virginia; Nielsen, Judith; Bellinger, Dwight; Bradfield, John

    2009-01-01

    The authors examined the effects of cage size and enrichment on mouse breeding performance and behavior. Breeding trios of C57BL/6Tac mice were housed in cages of two different sizes ('standard' and 'large' cages with 82 in(2) and 124 in(2) floor space, respectively). Half of the cages of each size contained four enrichment items (Nestlet, plastic tunnel, nylon rings and running wheel), whereas the remaining cages had no enrichment. The authors measured the following reproductive parameters: litter size, number of pups that survived to weaning age, average pup weights at 21 d after birth and number of days between births of litters. A subset of weaned male and female pups from each cage size and enrichment condition completed a suite of behavioral tests. Pups raised in large cages weighed less than those raised in standard cages. Enrichment and cage size had certain behavioral effects, which were dependent on gender and behavioral measure. Male pups born in enriched cages showed more anxiety-like behavior and less exploration than did males born in non-enriched cages. Though being raised in enriched or large cages did not clearly improve pups' performance in behavioral tests, enrichment (regardless of cage size) did significantly benefit reproductive performance; pups from non-enriched cages weighed less than pups from enriched cages, and fewer survived to weaning age.

  6. Aortic hemodynamics and white matter hyperintensities in normotensive postmenopausal women.

    PubMed

    Barnes, Jill N; Harvey, Ronée E; Zuk, Samantha M; Lundt, Emily S; Lesnick, Timothy G; Gunter, Jeffrey L; Senjem, Matthew L; Shuster, Lynne T; Miller, Virginia M; Jack, Clifford R; Joyner, Michael J; Kantarci, Kejal

    2017-04-07

    Hypertension is associated with development of white matter hyperintensities (WMH) in the brain, which are risk factors for mild cognitive impairment. Hormonal shifts at menopause alter vascular function putting women at risk for both hypertension and WMH. Elevations in aortic hemodynamics precede the appearance of clinically defined hypertension but the relationship of aortic hemodynamics to development of WMH in women is not known. Therefore, this study aimed to characterize aortic hemodynamics in relationship to WMH in postmenopausal women. Aortic systolic and diastolic blood pressure (BP), aortic augmentation index (Alx) and aortic round trip travel time (Aortic T R) by tonometry were examined in 53 postmenopausal women (age 60 ± 2 years). WMH was calculated from fluid-attenuated inversion recovery MRI using a semi-automated segmentation algorithm. WMH as a fraction of total white matter volume positively associated with aortic systolic BP (regression coefficient = 0.018; p = 0.04) after adjusting for age. In addition, WMH fraction was positively associated with AIx (0.025; p = 0.04), and inversely associated with Aortic T R (-0.015; p = 0.04) after adjusting for age. Our results suggest that assessing aortic hemodynamics may identify individuals at risk for accelerated development of WMH and guide early treatment to reduce WMH burden and cognitive impairment in the future.

  7. Computer-aided design of the human aortic root.

    PubMed

    Ovcharenko, E A; Klyshnikov, K U; Vlad, A R; Sizova, I N; Kokov, A N; Nushtaev, D V; Yuzhalin, A E; Zhuravleva, I U

    2014-11-01

    The development of computer-based 3D models of the aortic root is one of the most important problems in constructing the prostheses for transcatheter aortic valve implantation. In the current study, we analyzed data from 117 patients with and without aortic valve disease and computed tomography data from 20 patients without aortic valvular diseases in order to estimate the average values of the diameter of the aortic annulus and other aortic root parameters. Based on these data, we developed a 3D model of human aortic root with unique geometry. Furthermore, in this study we show that by applying different material properties to the aortic annulus zone in our model, we can significantly improve the quality of the results of finite element analysis. To summarize, here we present four 3D models of human aortic root with unique geometry based on computational analysis of ECHO and CT data. We suggest that our models can be utilized for the development of better prostheses for transcatheter aortic valve implantation.

  8. Inhibitory role of Notch1 in calcific aortic valve disease.

    PubMed

    Acharya, Asha; Hans, Chetan P; Koenig, Sara N; Nichols, Haley A; Galindo, Cristi L; Garner, Harold R; Merrill, Walter H; Hinton, Robert B; Garg, Vidu

    2011-01-01

    Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD) are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs). We found significant downregulation of Sox9 along with several cartilage-specific genes that were direct targets of the transcription factor, Sox9. Loss of Sox9 expression has been published to be associated with aortic valve calcification. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, the addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. In conclusion, loss of Notch signaling contributes to aortic valve calcification via a Sox9-dependent mechanism.

  9. Synthesis and photochemical properties of PEGylated coumarin-caged ceramides for cell studies

    PubMed Central

    Kim, Young Ah; Day, Jenna; Lirette, Carol Ann; Costain, Willard J.; Johnston, Linda J.; Bittman, Robert

    2015-01-01

    Caged ceramide analogues (C6-, C16-, C18-, C22- and C24-Cer) have been prepared by introducing a hydrophilic coumarin-based cage bearing a short polyethylene glycol (PEG) chain. (6-Bromo-7-mTEGylated-coumarin-4-yl)methyl (Btc) caged ceramide showed efficient photo-uncaging to release the parent ceramide upon direct exposure to 350 nm UV light; in contrast (7-mTEGylated-coumarin-4-yl) methyl (Tc) caged ceramide was photolysed more slowly. In preliminary experiments, Btc-caged ceramides were taken up by cells and their photolysis led to decreases in cell viability, but not to activation of caspase enzymes, suggesting that either reactive oxygen species or an alternate caspase-independent pathway may be responsible for the decreases in cell viability caused by photolysis of caged ceramides. PMID:26200920

  10. Smallest fullerene-like silicon cage stabilized by a V{sub 2} unit

    SciTech Connect

    Xu, Hong-Guang E-mail: zhengwj@iccas.ac.cn; Kong, Xiang-Yu; Deng, Xiao-Jiao; Zhang, Zeng-Guang; Zheng, Wei-Jun E-mail: zhengwj@iccas.ac.cn

    2014-01-14

    We conducted a combined anion photoelectron spectroscopy and density functional theory study on V{sub 2}Si{sub 20} cluster. Our results show that the V{sub 2}Si{sub 20} cluster has an elongated dodecahedron cage structure with a V{sub 2} unit encapsulated inside the cage. It is the smallest fullerene-like silicon cage and can be used as building block to make cluster-assembled materials, such as pearl-chain style nanowires.

  11. Smallest fullerene-like silicon cage stabilized by a V2 unit

    NASA Astrophysics Data System (ADS)

    Xu, Hong-Guang; Kong, Xiang-Yu; Deng, Xiao-Jiao; Zhang, Zeng-Guang; Zheng, Wei-Jun

    2014-01-01

    We conducted a combined anion photoelectron spectroscopy and density functional theory study on V2Si20 cluster. Our results show that the V2Si20 cluster has an elongated dodecahedron cage structure with a V2 unit encapsulated inside the cage. It is the smallest fullerene-like silicon cage and can be used as building block to make cluster-assembled materials, such as pearl-chain style nanowires.

  12. Effect of steerable cage placement during minimally invasive transforaminal lumbar interbody fusion on lumbar lordosis.

    PubMed

    Lindley, Timothy E; Viljoen, Stephanus V; Dahdaleh, Nader S

    2014-03-01

    Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is commonly used for the treatment of a variety of degenerative spine disorders. Recently, steerable interbody cages have been developed which potentially allow for greater restoration of lumbar lordosis. Here we describe a technique and radiographic results following minimally invasive placement of steerable cages through a bilateral approach. A retrospective review was conducted of the charts and radiographs of 15 consecutive patients who underwent 19 levels of bilateral MIS-TLIF with the placement of steerable cages. These were compared to 10 patients who underwent 16 levels of unilateral MIS-TLIF with the placement of bullet cages. The average age, body mass index, distribution of the levels operated and follow-up were similar in both groups. The average height of the steerable cage placed was 10.9 mm compared to 8.5mm for bullet cages. The preoperative focal Cobb's angle per level was similar between both groups with a mean of -5.3 degrees for the steerable cage group and -4.8 degrees for the bullet cage group. There was a significant improvement in postoperative Cobb's angle after placement of a steerable cage with a mean of -13.7 (p<0.01) and this persisted at the last follow-up with -13 degrees (p<0.01). There was no significant change in Cobb's angle after bullet cage placement with -5.7 degrees postoperatively and a return to the baseline preoperative Cobb's angle of -4.8 at the last follow-up. Steerable cage placement for MIS-TLIF improves focal lordosis compared to bullet cage placement.

  13. Recovery of Campylobacter from broiler feces during extended storage of transport cages.

    PubMed

    Berrang, M E; Northcutt, J K; Cason, J A

    2004-07-01

    Feces deposited in transport cages by a Campylobacter-positive flock can cause the spread of Campylobacter to subsequent flocks placed in the same cages. This experiment was designed to determine the effect of extended cage storage on the viability of Campylobacter in feces deposited on the cage floor during commercial transport and holding. After 4 h of feed (but not water) withdrawal, Campylobacter-positive broilers were caught by commercial catching crews, placed into 3 new commercial cages and transported with the rest of the flock to the holding area at a commercial processing facility. Broilers were allowed to remain in the cages for 8 h before being unloaded by facility personnel. After removal of the broilers, empty cages were held under a shed and sampled at 7 intervals for the presence of viable Campylobacter. Cages were sampled by removing all the feces out of a different randomly assigned compartment in each cage at 0.5, 2, 4, 6, 8, 24, and 48 h after unloading. No decrease in Campylobacter numbers was noted through 8 h of storage. After 24 h in both replications, Campylobacter was detected in 2 of 3 compartments by direct plating and detected in the third by enrichment only. After 48 h, Campylobacter was detected in one replication by enrichment only, and was not detected in the second replication at all. Storing soiled transport cages for 48 h between uses results in lower numbers of Campylobacter in feces, but may not eliminate Campylobacter entirely. Due to cage cost and space requirements, routine cage storage between uses would not be practical.

  14. Thoracic aortic aneurysm: reading the enemy's playbook.

    PubMed

    Elefteriades, John A

    2008-05-01

    The vast database of the Yale Center for Thoracic Aortic Disease--which includes information on 3000 patients with thoracic aortic aneurysm or dissection, with 9000 catalogued images and 9000 patient-years of follow-up--has, over the last decade, permitted multiple glimpses into the "playbook" of this virulent disease. Understanding the precise behavioral features of thoracic aortic aneurysm and dissection permits us more effectively to combat this disease. In this monograph, we will first review certain fundamentals--in terms of anatomy, nomenclature, imaging, diagnosis, medical, surgical, and stent treatment. After reviewing these fundamentals, we will proceed with a detailed exploration of lessons learned by peering into the operational playbook of thoracic aortic aneurysm and dissection. Among the glimpses afforded in the behavioral playbook of this disease are the following: 1 Thoracic aortic aneurysm, while lethal, is indolent. Mortality usually does not occur until after years of growth. 2 The aneurysmal ascending thoracic aorta grows slowly: about 0.1 cm per year (the descending aorta grows somewhat faster). 3 Over a patient's lifetime, "hinge points" at which the likelihood of rupture or dissection skyrockets are seen at 5.5 cm for the ascending and 6.5 cm for the descending aorta. Intervening at 5 cm diameter for the ascending and 6 cm for the descending prevents most adverse events. 4 Symptomatic aneurysms require resection regardless of size. 5 The yearly rate of rupture, dissection, or death is 14.1% for a patient with a thoracic aorta of 6 cm diameter. 6 The mechanical properties of the aorta deteriorate markedly at 6 cm diameter (distensibility falls, and wall stress rises)--a finding that "dovetails" perfectly with observations of the clinical behavior of the thoracic aorta. 7 Thoracic aortic aneurysm and dissection are largely inherited diseases, with a predominantly autosomal-dominant pattern. The specific genetics are being elucidated at the

  15. Aortic Blood Flow Reversal Determines Renal Function: Potential Explanation for Renal Dysfunction Caused by Aortic Stiffening in Hypertension.

    PubMed

    Hashimoto, Junichiro; Ito, Sadayoshi

    2015-07-01

    Aortic stiffness determines the glomerular filtration rate (GFR) and predicts the progressive decline of the GFR. However, the underlying pathophysiological mechanism remains obscure. Recent evidence has shown a close link between aortic stiffness and the bidirectional (systolic forward and early diastolic reverse) flow characteristics. We hypothesized that the aortic stiffening-induced renal dysfunction is attributable to altered central flow dynamics. In 222 patients with hypertension, Doppler velocity waveforms were recorded at the proximal descending aorta to calculate the reverse/forward flow ratio. Tonometric waveforms were recorded to measure the carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocities, to estimate the aortic pressure from the radial waveforms, and to compute the aortic characteristic impedance. In addition, renal hemodynamics was evaluated by duplex ultrasound. The estimated GFR was inversely correlated with the aortic pulse wave velocity, reverse/forward flow ratio, pulse pressure, and characteristic impedance, whereas it was not correlated with the peripheral pulse wave velocity or mean arterial pressure. The association between aortic pulse wave velocity and estimated GFR was independent of age, diabetes mellitus, hypercholesterolemia, and antihypertensive medication. However, further adjustment for the aortic reverse/forward flow ratio and pulse pressure substantially weakened this association, and instead, the reverse/forward flow ratio emerged as the strongest determinant of estimated GFR (P=0.001). A higher aortic reverse/forward flow ratio was also associated with lower intrarenal forward flow velocities. These results suggest that an increase in aortic flow reversal (ie, retrograde flow from the descending thoracic aorta toward the aortic arch), caused by aortic stiffening and impedance mismatch, reduces antegrade flow into the kidney and thereby deteriorates renal function.

  16. Screen-Cage Ion Plating Of Silver On Polycrystalline Alumina

    NASA Technical Reports Server (NTRS)

    Spalvins, Talivaldis; Sliney, Harold E.; Deadmore, Daniel L.

    1995-01-01

    Screen-cage ion plating (SCIP) cost-effective technique offering high throwing power for deposition of adherent metal films on ceramic substrates. Applies silver films to complexly shaped substrates of polycrystalline alumina. Silver adheres tenaciously and reduces friction. SCIP holds promise for applying lubricating soft metallic films to high-temperature ceramic components of advanced combustion engines. Other potential uses include coating substrates with metal for protection against corrosion, depositing electrical conductors on dielectric substrates, making optically reflective or electrically or thermally conductive surface layers, and applying decorative metal coats to ceramic trophies or sculptures.

  17. Bambusurils as effective ion caging agents: Does desolvation guide conformation?

    NASA Astrophysics Data System (ADS)

    Cova, Tânia F. G. G.; Nunes, Sandra C. C.; Pinho e Melo, Teresa M. V. D.; Pais, Alberto A. C. C.

    2017-03-01

    Water soluble bambusurils can bind and isolate inorganic anions in the center of the hydrophobic cavity, with high affinity and selectivity. This makes them appealing anion carriers and ion transporters for a wide range of biomedical applications, including in ion-channel diseases of the muscles, bones and brain. For understanding the bambusuril ion caging ability in aqueous media, molecular dynamics simulations, including free energy calculations are used. It is seen that the ion is hermetically sealed inside the cavity, as a result of a concerted action involving conformation and desolvation of both ion and bambusuril cavity.

  18. DFT Optimization of Symmetric Be2Si Cage Clusters

    NASA Astrophysics Data System (ADS)

    Binning, Robert; Bacelo, Daniel

    2009-05-01

    Density functional theory calculations have been performed on several beryllium silicide cage clusters in which the atoms occupy the vertices of classic Archimedean solids. The BPW91 functionals with numerical basis sets were employed in the optimizations. The calculations were carried out to confirm the hypothesis that stable Be2Si clusters may be obtained by substituting Si for Be atoms in stable pure beryllium clusters. Stable beryllium clusters are obtained from symmetrical Ben polyhedra in which sides are triangular or capped pentagonal, and the Archimedean clusters composed of these elements with Si substitutions are indeed found to produce stable beryllium silicides.

  19. Greenhouse Gas Emissions from Three Cage Layer Housing Systems

    PubMed Central

    Fournel, Sébastien; Pelletier, Frédéric; Godbout, Stéphane; Lagacé, Robert; Feddes, John

    2011-01-01

    Simple Summary Greenhouse gas (GHG) emissions were measured from three different cage layer housing systems. A comparative study was conducted to identify the housing system with the least impact on the environment. The results showed that liquid manure from deep-pit housing systems produces greater emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) than natural and forced dried manure from belt housing systems. The influencing factors appeared to be the manure removal frequency and the dry matter content of the manure. Abstract Agriculture accounts for 10 to 12% of the World’s total greenhouse gas (GHG) emissions. Manure management alone is responsible for 13% of GHG emissions from the agricultural sector. During the last decade, Québec’s egg production systems have shifted from deep-pit housing systems to manure belt housing systems. The objective of this study was to measure and compare carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions from three different cage layer housing systems: a deep liquid manure pit and a manure belt with natural or forced air drying. Deep liquid manure pit housing systems consist of “A” frame layer cages located over a closed pit containing the hens’ droppings to which water is added to facilitate removal by pumping. Manure belt techniques imply that manure drops on a belt beneath each row of battery cages where it is either dried naturally or by forced air until it is removed. The experiment was replicated with 360 hens reared into twelve independent bench-scale rooms during eight weeks (19–27 weeks of age). The natural and forced air manure belt systems reduced CO2 (28.2 and 28.7 kg yr−1 hen−1, respectively), CH4 (25.3 and 27.7 g yr−1 hen−1, respectively) and N2O (2.60 and 2.48 g yr−1 hen−1, respectively) emissions by about 21, 16 and 9% in comparison with the deep-pit technique (36.0 kg CO2 yr−1 hen−1, 31.6 g CH4 yr−1 hen−1 and 2.78 g N2O yr−1 hen−1). The

  20. Stereoselective synthesis of heterocyclic cage compounds by domino conjugate additions.

    PubMed

    Carreño, M Carmen; Luzón, Carmen García; Ribagorda, María

    2002-01-04

    Heterocyclic cage compounds have been stereoselectively synthesized from enantiopure [(S)R]-[(p-tolylsulfinyl)methyl]-p-quinols or their amine analogues and 2-(trimethylsilyloxy)furan in the presence of Bu4NF. The method is particularly valuable not only because of the stereochemical control but also because the reactions occur in an experimentally simple one-pot procedure through a domino sequence of three consecutive conjugate additions. The intermediate 1,4-adducts could be isolated when the reaction was carried out in the presence of BF3 x OEt2.

  1. A calibration model for screen-caged Peltier thermocouple psychrometers

    NASA Astrophysics Data System (ADS)

    Brown, R. W.; Bartos, D. L.

    1982-07-01

    A calibration model for screen-caged Peltier thermocouple psychrometers was developed that applies to a water potential range of 0 to 80 bars, over a temperature range of 0 to 40 C, and for cooling times of 15 to 60 seconds. In addition, the model corrects for the effects of temperature gradients over zero-offsets from -60 to +60 microvolts. Complete details of model development are discussed, together with the theory of thermocouple psychrometers, and techniques of calibration and cleaning. Also, information for computer programing and tabular summaries of model characteristics are provided.

  2. Concerning the Optimal Salt Bridge for Trp-cage Stabilization†

    PubMed Central

    Williams, D. Victoria; Byrne, Aimee; Stewart, James; Andersen, Niels H.

    2011-01-01

    Gai and co-workers (Bunagan, M. R. (2006) J. Phys. Chem. B 110, 3759-3763) reported computational design studies suggesting that a D9E mutation would stabilize the Trp-cage. Experimental studies for this mutation were reported in 2008 (Hudaky, P. (2008) Biochemistry 47, 1007-1016); the authors suggested that [D9E]-TC5b presented a more compact, and melting resistant structure due to the “optimal distance between the two sides of the molecule”. Nonetheless, the authors reported essentially the same CD melting temperature, 38±0.3 °C, for TC5b and its [D9E] mutant. In this study, a more stable Trp-cage, DAYAQ WLKDG GPSSG RPPPS, was examined by NMR and CD with the following mutations: [D9E], [D9R,R16E], [R16Orn], [D9E,R16Orn], [R16K], and [D9E,R16K]. Of these, the [D9E]-mutant displayed the smallest acidification induced change in the apparent Tm. In analogy to the prior study, the CD melts of TC10b and its [D9E] mutant were, however, very similar; all of the other mutations were significantly fold destabilizing by all measures. A detailed analysis indicates that the original D9/R16 salt bridge is optimal with regard to fold cooperativity and fold stabilization. Evidence for salt-bridging is also provided for a swapped pair, the [D9R,R16E]-mutant. Model systems reveal that an ionized aspartate at the C-terminus of a helix significantly decreases intrinsic helicity, a requirement for Trp-cage fold stability. The CD evidence which was cited as supporting increased fold stability for the [D9E]-TC5b at higher temperatures appears to be a reflection of increased helix stability in both the folded and unfolded state rather than a more favorable salt bridge. The present study also provides evidence for other Trp-cage stabilizing roles of the R16 sidechain. PMID:21222485

  3. SAMURAI-TPC: Field Cage Design and Prototyping

    NASA Astrophysics Data System (ADS)

    Lu, F.; Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Estee, J.; Gilbert, J.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yenello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    The SAMURAI-TPC is a time-projection chamber to be used in conjunction with the SAMURAI spectrometer being built at the Radioactive Isotope Beam Facility at RIKEN, Japan. It will be used to measure charged pions, protons and light ions. The pi+/pi- ratios from heavy-ion collisions should provide constraints on the asymmetry term in the nuclear equation of state at densities about twice saturation density. In this talk, the design and operation of the field cage, an essential part of the detector, will be discussed, along with the results of prototype testing. This work is supported by the Department of Energy under Grant DE-SC0004835.

  4. Encapsulation of Semiconducting Polymers in Vault Protein Cages

    SciTech Connect

    Ng, B.C.; Yu, M.; Gopal, A.; Rome, L.H.; Monbouquette, H.G.; Tolbert, S.H.

    2009-05-22

    We demonstrate that a semiconducting polymer [poly(2-methoxy-5-propyloxy sulfonate phenylene vinylene), MPS-PPV] can be encapsulated inside recombinant, self-assembling protein nanocapsules called 'vaults'. Polymer incorporation into these nanosized protein cages, found naturally at {approx}10,000 copies per human cell, was confirmed by fluorescence spectroscopy and small-angle X-ray scattering. Although vault cellular functions and gating mechanisms remain unknown, their large internal volume and natural prevalence within the human body suggests they could be used as carriers for therapeutics and medical imaging reagents. This study provides the groundwork for the use of vaults in encapsulation and delivery applications.

  5. The COPII cage: unifying principles of vesicle coat assembly.

    PubMed

    Gürkan, Cemal; Stagg, Scott M; Lapointe, Paul; Balch, William E

    2006-10-01

    Communication between compartments of the exocytic and endocytic pathways in eukaryotic cells involves transport carriers - vesicles and tubules - that mediate the vectorial movement of cargo. Recent studies of transport-carrier formation in the early secretory pathway have provided new insights into the mechanisms of cargo selection by coat protein complex-II (COPII) adaptor proteins, the construction of cage-protein scaffolds and fission. These studies are beginning to produce a unifying molecular and structural model of coat function in the formation and fission of vesicles and tubules in endomembrane traffic.

  6. Evaluation of cage micro-environment of mice housed on various types of bedding materials

    USGS Publications Warehouse

    Smith, E.; Stockwell, J.D.; Schweitzer, I.; Langley, S.H.; Smith, A.L.

    2004-01-01

    A variety of environmental factors can affect the outcomes of studies using laboratory rodents. One such factor is bedding. Several new bedding materials and processing methods have been introduced to the market in recent years, but there are few reports of their performance. In the studies reported here, we have assessed the cage micro-environment (in-cage ammonia levels, temperature, and humidity) of mice housed on various kinds of bedding and their combinations. We also compared results for bedding supplied as Nestpaks versus loose bedding. We studied C57BL/6J mice (commonly used) and NOD/LtJ mice (heavy soilers) that were maintained, except in one study, in static duplex cages. In general, we observed little effect of bedding type on in-cage temperature or humidity; however, there was considerable variation in ammonia concentrations. The lowest ammonia concentrations occurred in cages housing mice on hardwood bedding or a mixture of corncob and alpha cellulose. In one experiment comparing the micro-environments of NOD/LtJ male mice housed on woodpulp fiber bedding in static versus ventilated caging, we showed a statistically significant decrease in ammonia concentrations in ventilated cages. Therefore, our data show that bedding type affects the micro-environment in static cages and that effects may differ for ventilated cages, which are being used in vivaria with increasing frequency.

  7. Development and application of fluorescent, green light-activatable caged compound

    NASA Astrophysics Data System (ADS)

    Umeda, Nobuhiro; Urano, Yasuteru; Nagano, Tetsuo

    2011-03-01

    Caged compound is one of the most powerful tools for spatiotemporal control of biomolecules in cells, which can be activated by irradiation of light. However, ultra violet light, which is required for activation of caged compounds, can damage cells and has poor permeability into tissues. In addition, invisibility of caged compounds makes it difficult to tell distribution of released small molecules. At the conference, we will describe the development of novel caging group and new caged compounds which are fluorescently visible and efficiently activatable with green light. We have found that boron dipyrromethene (BODIPY), known as a widely used fluorophore, is a potential caging group for phenol, carboxyl acid and amine, which can be photolized with irradiation of green light at around 500 nm wavelength. Based on the novel photo-reaction of 4-phenoxy BODIPY derivatives, we have developed caged histamine and applied it to HeLa cells. Photo-irradiation to cells in the presence of caged histamine induced transient increase of calcium ion in cytosol, which was specifically inhibited with pyrilamine, a H1 blocker. Also, we showed that BODIPY-caged compound can be utilized in vivo with tissue-permeable 500 nm green light.

  8. Rearing Laying Hens in Aviaries Reduces Fearfulness following Transfer to Furnished Cages

    PubMed Central

    Brantsæter, Margrethe; Tahamtani, Fernanda M.; Moe, Randi O.; Hansen, Tone B.; Orritt, Rachel; Nicol, Christine; Janczak, Andrew M.

    2016-01-01

    Appropriate rearing is essential for ensuring the welfare and productivity of laying hens. Early experience has the potential to affect the development of fearfulness. This study tested whether rearing in aviaries, as opposed to cages, reduces the fearfulness of laying hens after transfer to furnished cages. Fear responses were recorded as avoidance of a novel object in the home cage. Lohmann Selected Leghorns were reared in an aviary system or conventional rearing cages and then transported to furnished cages at 16 weeks, before the onset of lay. Observations of a selection of birds were conducted at 19 (N = 50 independent cages) and 21 (N = 48 independent cages) weeks of age. At 19 and 21 weeks, cage-reared birds showed higher levels of fearfulness indicated by spending more time away from the novel object compared to aviary-reared birds. These results suggest that rearing in an enriched aviary environment reduces fearfulness up to the fifth week after transfer to a new housing system, compared to rearing in cages. PMID:26955634

  9. 25 CFR 542.14 - What are the minimum internal control standards for the cage?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the cage? (a) Computer applications. For any computer applications utilized, alternate documentation... shall comply with procedures for the receipt, inventory, storage, and destruction of gaming chips...

  10. Sensitivity of BN nano-cages to caffeine and nicotine molecules

    NASA Astrophysics Data System (ADS)

    Soltani, Alireza; Baei, Mohammad T.; Tazikeh Lemeski, E.; Shahini, Malihe

    2014-12-01

    Adsorption of caffeine and nicotine molecules over B12N12 and B16N16 nano-cages were investigated by using first-principles calculations to define whether BN nano-cages are applicable for filtering or sensing caffeine and nicotine molecules. The chemisorption energy of nicotine molecule on BN nano-cages is very stronger than caffeine molecule. Upon the adsorption of caffeine and nicotine molecules, the electronic properties of the BN nano-cages can be significantly changed, being too much sensitized on the caffeine and nicotine adsorptions.

  11. High pressure oxygen turbopump bearing cage stability analyses. [space shuttle main engine

    NASA Technical Reports Server (NTRS)

    Merriman, T. L.; Kannel, J. W.

    1984-01-01

    The low service life of the high pressure oxygen turbopump (HPOTP) bearings used in the space shuttle main engine was examined by use of the Battelle "BASDAP' bearing computer stability model. The dynamic instability of the bearing cage resulted in excessive wear and eventual failure of the unit. By maintaining a cage/race clearance of no more than 0.25 millimeters (0.010 inches), ball/pocket clearance of no less than 0.54 millimeters (0.025 inches), dynamic balancing of the cages, and maintaining adequate lubricant films between the balls and races, cage instability and subsequent bearing degradation can be reduced.

  12. Effects of Nominal Differences in Cage Height and Floor Space on the Wellbeing of Rabbits.

    PubMed

    Stewart, Kay L; Suckow, Mark A

    2016-03-01

    The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720 in(2) of floor space) or 18 in. of interior height (784 in(2) of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits.

  13. Effects of Nominal Differences in Cage Height and Floor Space on the Wellbeing of Rabbits

    PubMed Central

    Stewart, Kay L; Suckow, Mark A

    2016-01-01

    The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720 in2 of floor space) or 18 in. of interior height (784 in2 of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits. PMID:27025808

  14. Biocentrifuge system capable of exchanging specimen cages while in operational mode

    NASA Technical Reports Server (NTRS)

    Belew, R. R. (Inventor)

    1981-01-01

    The centrifuge comprises a generally circular, rotatably mounted frame carrying a plurality of removable and replaceable cages for the animal specimens. Pairs of opposing cages may be removed from the frame while it is rotating by means of a cage exchanger which rotates concentrically within the centrifuge and the speed of which is controlled independently of the frame speed. An image rotator is provided for selective observation of the rotating animals. The system further includes a waste conveyor system, a food supply system, and a water supply system for each cage for creating a life sustaining environment so that the animals can live in the rotating centrifuge for extended periods.

  15. Photo-dependent protein biosynthesis using a caged aminoacyl-tRNA.

    PubMed

    Akahoshi, Akiya; Doi, Yoshio; Sisido, Masahiko; Watanabe, Kazunori; Ohtsuki, Takashi

    2014-12-01

    Translation systems with four-base codons provide a powerful strategy for protein engineering and protein studies because they enable site-specific incorporation of non-natural amino acids into proteins. In this study, a caged aminoacyl-tRNA with a four-base anticodon was synthesized. The caged aminoacyl-tRNA contains a photocleavable nitroveratryloxycarbonyl (NVOC) group. This study showed that the caged aminoacyl-tRNA was not deacylated, did not bind to EF-Tu, and was activated by light. Photo-dependent translation of an mRNA containing the four-base codon was demonstrated using the caged aminoacyl-tRNA.

  16. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage.

    PubMed

    Yang, Z; Chen, H; Yu, T; Li, B

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  17. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Chen, H.; Yu, T.; Li, B.

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  18. Transcatheter aortic valve replacement: transapical resection of the aortic valve in vivo.

    PubMed

    Bombien Quaden, René; Leester-Schaedel, Monika; Lozonschi, Lucian; Lutter, Georg

    2012-09-01

    The resection of pulmonary valves has already been demonstrated in an experimental beating-heart model. The aim of this study was to analyse the transapical laser-assisted resection of aortic valves in an in vivo porcine model in a non-beating heart. The resection was performed in a porcine model (n = 10) using a Thullium:YAG laser. After establishing a standard extracorporeal circulatory support, the aortic valve isolation chamber (AVIC) system was inserted transapically. The resection of the aortic leaflets was carried out step-by-step in the arrested heart. The AVIC implantation, the resection process, and the gross anatomy of intracardiac lesions were analysed. The procedure for installing the AVIC took 5.8 ± 1.5 min. A sealed chamber was achieved in 9/10 cases. The resection of the valves was performed in 8/10 and completed in 7/10 cases. The resection took, on average, 7.4 ± 2.7 min/cusp. In 9/10 cases, the sealing was sufficient. Gross anatomy and histological analysis demonstrated only superficial damage to the surrounding tissue. In this study, the in vivo on-pump isolation of the left ventricular outflow tract and the laser resection of the native aortic valve could be demonstrated successfully. Nevertheless, this model is the next step towards a beating-heart resection of the aortic valve using the isolation chamber.

  19. Aortic replacement in the setting of bicuspid aortic valve: how big? How much?

    PubMed

    Sundt, Thoralf M

    2015-02-01

    Despite more than a decade of intense investigation, controversy persists regarding appropriate triggers for aortic replacement in the setting of bicuspid aortic valve. The difficulty is that the data are inescapably imperfect. Although we can count individuals with bicuspid valve who suffer dissection, we have an insufficient understanding of the true denominator of individuals at risk to calculate the probability of dissection for an individual patient. In addition, our own decision-making process is subject to "denominator neglect" or focus on the fact of the occurrence of the event rather than on the risk of the occurrence. Furthermore, the data are inherently incomplete given the asymmetric nature of outcomes information. Specifically, although we can see those who did or did not dissect among the patients not undergoing surgery, the converse is not true; the tragedy of prophylactic surgery is that one cannot distinguish those who have benefited through prevention of dissection from those who paid the price of surgery but in whom dissection would never have occurred. Finally, we have data for only some of the critical determinants of dissection. Structural failure occurs when stresses exceed strengths. Aortic diameter gives us some insight into stress but we have little information on the material strength of the aorta. Early indications that patients undergoing aortic valve replacement for bicuspid valve had a significant risk of aortic dissection were followed by laboratory data showing histologic, biochemical, and mechanical abnormalities supporting an aggressive approach to resection; however, more recent clinical studies call this into question.

  20. Endovascular Treatment of Late Thoracic Aortic Aneurysms after Surgical Repair of Congenital Aortic Coarctation in Childhood

    PubMed Central

    Juszkat, Robert; Perek, Bartlomiej; Zabicki, Bartosz; Trojnarska, Olga; Jemielity, Marek; Staniszewski, Ryszard; Smoczyk, Wiesław; Pukacki, Fryderyk

    2013-01-01

    Background In some patients, local surgery-related complications are diagnosed many years after surgery for aortic coarctation. The purposes of this study were: (1) to systematically evaluate asymptomatic adults after Dacron patch repair in childhood, (2) to estimate the formation rate of secondary thoracic aortic aneurysms (TAAs) and (3) to assess outcomes after intravascular treatment for TAAs. Methods This study involved 37 asymptomatic patients (26 female and 11 male) who underwent surgical repair of aortic coarctation in the childhood. After they had reached adolescence, patients with secondary TAAs were referred to endovascular repair. Results Follow-up studies revealed TAA in seven cases (19%) (including six with the gothic type of the aortic arch) and mild recoarctation in other six (16%). Six of the TAA patients were treated with stentgrafts, but one refused to undergo an endovascular procedure. In three cases, stengrafts covered the left subclavian artery (LSA), in another the graft was implanted distally to the LSA. In two individuals, elective hybrid procedures were performed with surgical bypass to the supraaortic arteries followed by stengraft implantation. All subjects survived the secondary procedures. One patient developed type Ia endoleak after stentgraft implantation that was eventually treated with a debranching procedure. Conclusions The long-term course of clinically asymptomatic patients after coarctation patch repair is not uncommonly complicated by formation of TAAs (particularly in individuals with the gothic pattern of the aortic arch) that can be treated effectively with stentgrafts. However, in some patients hybrid procedures may be necessary. PMID:24386233

  1. A stepwise aortic clamp procedure to treat porcelain aorta associated with aortic valve stenosis and hemodialysis.

    PubMed

    Isoda, Susumu; Osako, Motohiko; Kimura, Tamizo; Nishimura, Kenji; Yamanaka, Nozomu; Nakamura, Shingo; Maehara, Tadaaki

    2014-01-01

    A 62-year-old man was referred for an aortic-valve surgery because of severe aortic stenosis. Thirty years ago, he had undergone a mitral valve commissurotomy and after 9 years, the valve had been replaced by a mechanical valve. He had been undergoing hemodialysis for the past 8 years. A computed tomographic (CT) scan of the chest and abdomen showed a dense circumferential calcification in the wall of the entire thoracic and abdominal aorta, pulmonary artery, and left and right atrium. A conventional aortic-valve replacement was performed. To avoid an embolic event, a "stepwise aortic clamp" procedure was attempted and involved the following: (1) brief circulatory arrest and aortotomy during moderate hypothermia; (2) balloon occlusion at the ascending aorta during low-flow cardiopulmonary bypass (CPB); (3) endoarterectomy by using an ultrasonic surgical aspirator to enable aortic cross-clamping; and (4) a cross-clamp reinforced with felt and full-flow CPB. The patient recovered without any thromboembolic events. Using this procedure to treat a porcelain aorta seemed to reduce the time limit and reduced the risk of brain injury during cardiac surgery.

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

    PubMed

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

    2014-01-01

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

  3. Experimental fluid dynamics of transventricular apical aortic cannulation.

    PubMed

    Fukuda, Ikuo; Yanaoka, Hideki; Inamura, Takao; Minakawa, Masahito; Daitoku, Kazuyuki; Suzuki, Yasuyuki

    2010-03-01

    To clarify the flow pattern from a transventricular apical aortic cannula, hydrodynamic analysis of transventricular apical aortic cannulation (apical cannulation) was performed using particle-image velocimetry in a glass aortic model. Simulated apical cannulation using a 7-mm Sarns Soft-Flow cannula and the newly developed 7-mm apical aortic cannula was compared with standard aortic cannulation. The flow-velocity, streamline, and distribution of magnitude of the strain rate tensor (function of shear stress) were analyzed. Streamline analysis revealed a steady and organized flow profile in apical cannulation as compared with that in standard aortic cannulation. The magnitude of the strain rate tensor decreased within a few centimeters from the exit of the apical cannula.

  4. Implantation of the CoreValve percutaneous aortic valve.

    PubMed

    Lamarche, Yoan; Cartier, Raymond; Denault, André Y; Basmadjian, Arsène; Berry, Colin; Laborde, Jean-Claude; Bonan, Raoul

    2007-01-01

    Surgical aortic valve replacement is the only recommended treatment for significant aortic valve stenosis. Percutaneous aortic valve replacement appears to be a novel option for high-risk patients. We report the implantation of the ReValving system (CoreValve, Paris, France) in a 64-year-old woman who was refused aortic valve replacement surgery for critical aortic stenosis and left ventricular dysfunction because of severe pulmonary fibrosis. After anesthesia, the patient was put on femorofemoral cardiopulmonary bypass, and underwent a balloon valvuloplasty with subsequent retrograde aortic valve replacement by the ReValving system. Transesophageal echocardiographic monitoring of the patient's hemodynamics showed immediate improvements of the valvular area and left ventricular ejection fraction and only traces of paravalvular leaks. The patient was easily weaned from ventilation and resumed activity soon after the surgery. A multidisciplinary approach is presently necessary to offer a reliable and safe procedure.

  5. Exertional dyspnea as a symptom of infrarenal aortic occlusive disease.

    PubMed

    Schott, Stacey L; Carreiro, Fernanda Porto; Harkness, James R; Malas, Mahmoud B; Sozio, Stephen M; Zakaria, Sammy

    2014-06-01

    Advanced atherosclerosis of the aorta can cause severe ischemia in the kidneys, refractory hypertension, and claudication. However, no previous reports have clearly associated infrarenal aortic stenosis with shortness of breath. A 77-year-old woman with hypertension and hyperlipidemia presented with exertional dyspnea. Despite extensive testing and observation, no apparent cause for this patient's dyspnea was found. Images revealed severe infrarenal aortic stenosis. After the patient underwent stenting of the aortic occlusion, she had immediate symptomatic improvement and complete resolution of her dyspnea within one month. Twelve months after vascular intervention, the patient remained asymptomatic. In view of the distinct and lasting elimination of dyspnea after angioplasty and stenting of a nearly occluded infrarenal aortic lesion, we hypothesize that infrarenal aortic stenosis might be a treatable cause of exertional dyspnea. Clinicians should consider infrarenal aortic stenosis as a possible cause of dyspnea. Treatment of the stenosis might relieve symptoms.

  6. Aortic valve replacement in familial hypercholesterolemia: not an ordinary procedure.

    PubMed

    Muretti, Mirko; Massi, Francesco; Coradduzza, Enrico; Portoghese, Michele

    2015-04-28

    Familial hypercholesterolemia is an inherited disorder with incidences of approximately 1:500 and 1:1,000,000 in heterozygous and homozygous form respectively. Affected patients usually show early coronary artery disease and severe aortic root calcification, despite optimization of therapy. We report a case of a 64-year-old woman affected by heterozygous familial hypercholesterolemia which presented dyspnea and anginal symptoms due to a severely calcified aortic root causing valve stenosis and narrowed sinotubular junction. Aortic valve replacement and aortic root enlargement were performed using the Manougian procedure. Even for experiences surgeons, this surgery could prove challenging for this group of patients due to aggressive degenerative tissue calcification of the aortic root, which often presents an extremely calcified aortic valve with a small annulus associated to a narrowed sinotubular junction.

  7. Transcatheter aortic valve replacement: techniques, complications, and bailout strategies.

    PubMed

    Singh, Vikas; Macon, Conrad J; Scot Shaw, Eric; Londoño, Juan C; Martinez, Claudia A

    2013-09-01

    Transcatheter aortic valve replacement has emerged as an alternative option for inoperable or very high-risk patients with severe aortic stenosis-however, there are serious complications associated with the procedure, such as patient mortality, stroke, conduction disturbances, paravalvular regurgitation, and vascular concerns. Our review focuses on the most common complications related to transcatheter aortic valve replacement procedures and potential bailout strategies and techniques.

  8. CT and MRI in the Evaluation of Thoracic Aortic Diseases

    PubMed Central

    2013-01-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are the most commonly used imaging examinations to evaluate thoracic aortic diseases because of their high spatial and temporal resolutions, large fields of view, and multiplanar imaging reconstruction capabilities. CT and MRI play an important role not only in the diagnosis of thoracic aortic disease but also in the preoperative assessment and followup after treatment. In this review, the CT and MRI appearances of various acquired thoracic aortic conditions are described and illustrated. PMID:24396601

  9. Absent Aortic Valve in DiGeorge Syndrome.

    PubMed

    Bertsch, Elizabeth C; Minturn, Lucy; Gotteiner, Nina L; Ernst, Linda M

    2016-01-01

    A 20-week-old fetus with the 22q11.2 deletion characteristic of DiGeorge syndrome is described with vertebral segmentation abnormalities and complex cardiovascular anomalies including an absent aortic valve. This is only the second known case of absent aortic valve in association with DiGeorge syndrome. We discuss the association of absent aortic valve with other conotruncal defects and the utility of fetal echocardiography in the diagnosis of DiGeorge syndrome.

  10. Apicoaortic conduit for severe hemolytic anemia after aortic valve replacement.

    PubMed

    Hatori, Kyohei; Ohki, Satoshi; Obayashi, Tamiyuki; Koyano, Tetsuya; Yasuhara, Kiyomitsu; Hirai, Hanako

    2015-06-01

    We describe the case of an 82-year-old woman who had undergone aortic mechanical valve replacement for aortic stenosis with a small annulus, and coronary artery bypass grafting. Four years after the operation, she began to experience hemolysis. Prosthetic valve obstruction was observed but there was no paravalvular leakage or aortic regurgitation through the mechanical valve. We elected to perform apicoaortic bypass in this patient with severe hemolytic anemia secondary to a mechanical valve malfunction.

  11. Acute aortic and mitral valve regurgitation following blunt chest trauma.

    PubMed

    Bernabeu, Eduardo; Mestres, Carlos A; Loma-Osorio, Pablo; Josa, Miguel

    2004-03-01

    Traumatic rupture of intracardiac structures is an uncommon phenomenon although there are a number of reports with regards to rupture of the tricuspid, mitral and aortic valves. We report the case of a 25-year-old patient who presented with acute aortic and mitral valve regurgitation of traumatic origin. Both lesions were seen separated by 2 weeks. Pathophysiology is reviewed. The combination of both aortic and mitral lesions following blunt chest trauma is almost exceptional.

  12. The para-aortic ridge plays a key role in the formation of the renal, adrenal and gonadal vascular systems

    PubMed Central

    Isogai, Sumio; Horiguchi, Mayuko; Hitomi, Jiro

    2010-01-01

    Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that ‘All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries’ has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava. PMID:20579173

  13. Glucose Suppresses Biological Ferroelectricity in Aortic Elastin

    NASA Astrophysics Data System (ADS)

    Liu, Yuanming; Wang, Yunjie; Chow, Ming-Jay; Chen, Nataly Q.; Ma, Feiyue; Zhang, Yanhang; Li, Jiangyu

    2013-04-01

    Elastin is an intriguing extracellular matrix protein present in all connective tissues of vertebrates, rendering essential elasticity to connective tissues subjected to repeated physiological stresses. Using piezoresponse force microscopy, we show that the polarity of aortic elastin is switchable by an electrical field, which may be associated with the recently discovered biological ferroelectricity in the aorta. More interestingly, it is discovered that the switching in aortic elastin is largely suppressed by glucose treatment, which appears to freeze the internal asymmetric polar structures of elastin, making it much harder to switch, or suppressing the switching completely. Such loss of ferroelectricity could have important physiological and pathological implications from aging to arteriosclerosis that are closely related to glycation of elastin.

  14. Single Coronary Artery with Aortic Regurgitation

    SciTech Connect

    Katsetos, Manny C. Toce, Dale T.

    2003-11-15

    An isolated single coronary artery can be associated with normal life expectancy; however, patients are at an increased risk of sudden death. A case is reported of a 54-year-old man with several months of chest pressure with activity. On exercise Sestamibi stress testing, the patient developed a hypotensive response with no symptoms and minimal electrocardiographic changes. Nuclear scanning demonstrated reversible septal and lateral perfusion defects consistent with severe ischemia. Coronary angiography revealed a single coronary artery with the right coronary artery arising from the left main. There were high-grade stenotic lesions in the left anterior descending and circumflex arteries with only moderate atherosclerotic disease in the right coronary artery. An aortogram showed 2-3+ aortic regurgitation, with an ejection fraction of 45% on ventriculography. The patient underwent four-vessel revascularization and aortic valve replacement and did well postoperatively.

  15. Basic mechanisms of calcific aortic valve disease.

    PubMed

    Mathieu, Patrick; Boulanger, Marie-Chloé

    2014-09-01

    Calcific aortic valve disease (CAVD) is the most common heart valve disorder. There is no medical treatment to prevent and/or promote the regression of CAVD. Hence, it is of foremost importance to delineate and understand the key basic underlying mechanisms involved in CAVD. In the past decade our comprehension of the underpinning processes leading to CAVD has expanded at a fast pace. Hence, our understanding of the basic pathobiological processes implicated in CAVD might lead eventually to the development of novel pharmaceutical therapies for CAVD. In this review, we discuss molecular processes that are implicated in fibrosis and mineralization of the aortic valve. Specifically, we address the role of lipid retention, inflammation, phosphate signalling and osteogenic transition in the development of CAVD. Interplays between these different processes and the key regulation pathways are discussed along with their clinical relevance.

  16. The pathophysiology of aortic cross-clamping.

    PubMed

    Zammert, Martin; Gelman, Simon

    2016-09-01

    During open aortic surgery, interrupting the blood flow through the aorta by applying a cross-clamp is often a key step to allow for surgical repair. As a consequence, ischemia is induced in parts of the body distal to the clamp site. This significant alteration in the blood flow is almost always associated with hemodynamic changes. Upon release of the cross-clamp, the blood flow is restored, triggering an ischemia-reperfusion response, leading to many pathophysiological processes such as inflammation, humoral changes, and metabolite circulation that could lead to injury in many organ systems and may significantly influence the postoperative outcome. It is therefore important to understand these processes and how they can be treated in order to allow for safe surgical aortic repairs while ensuring the best possible outcomes.

  17. Geometry of aortic heart valves. [prosthetic design

    NASA Technical Reports Server (NTRS)

    Karara, H. M.

    1975-01-01

    Photogrammetric measurements of the surface topography of the aortic valves obtained from silicon rubber molds of freshly excised human aortic valves are presented. The data are part of an investigation into the design of a new prosthetic valve which will be a central-flow device, like the real valve and unlike previous central-occluding prostheses. Since the maximum stress on the heart valve is induced when the valve is closed and subject to diastolic back-pressure, it was decided to determine the valve geometry during diastole. That is, the molds were formed by pouring the rubber down the excised aortas, causing the valves to close. The molds were made under different pressures (20-120 torr); photogrammetry served as a vehicle for the assessment of the mold topography through the following outputs: digital models, surface profiles, and contour maps.

  18. Optimal Design of Aortic Leaflet Prosthesis

    NASA Technical Reports Server (NTRS)

    Ghista, Dhanjoo N.; Reul, Helmut; Ray, Gautam; Chandran, K. B.

    1978-01-01

    The design criteria for an optimum prosthetic-aortic leaflet valve are a smooth washout in the valve cusps, minimal leaflet stress, minimal transmembrane pressure for the valve to open, an adequate lifetime (for a given blood-compatible leaflet material's fatigue data). A rigorous design analysis is presented to obtain the prosthetic tri-leaflet aortic valve leaflet's optimum design parameters. Four alternative optimum leaflet geometries are obtained to satisfy the criteria of a smooth washout and minimal leaflet stress. The leaflet thicknesses of these four optimum designs are determined by satisfying the two remaining design criteria for minimal transmembrane opening pressure and adequate fatigue lifetime, which are formulated in terms of the elastic and fatigue properties of the selected leaflet material - Avcothane-51 (of the Avco-Everett Co. of Massachusetts). Prosthetic valves are fabricated on the basis of the optimum analysis and the resulting detailed engineering drawings of the designs are also presented in the paper.

  19. Familial aortic aneurysm in Leonberg dogs.

    PubMed

    Chetboul, Valérie; Tessier, Dominique; Borenstein, Nicolas; Delisle, Françoise; Zilberstein, Luca; Payen, Guillaume; Leglaive, Eric; Franc, Brigitte; Derumeaux, Geneviève; Pouchelon, Jean-Louis

    2003-10-15

    A thoracic aortic aneurysm was diagnosed in a 6-month-old male Leonberg dog by use of radiography, transthoracic and transesophageal echocardiography, and magnetic resonance imaging. The aneurysm was associated with a twisted ascending aorta and dilatation of several other thoracic arteries (pulmonary trunk, brachiocephalic trunk, and left subclavian artery). Histologic examination of the aorta revealed cystic medial necrosis, with disruption of the elastic network, collagen fibers, and the muscle glycoprotein fibrillin-1. The dam and sire of the dog and 8 littermates were examined by use of transthoracic echocardiography. The sire and 1 male littermate also had an aneurysm of the ascending aorta. To the authors' knowledge, this is the first report of familial aortic aneurysm in dogs.

  20. Total Percutaneous Aortic Repair: Midterm Outcomes

    SciTech Connect

    Bent, Clare L. Fotiadis, Nikolas; Renfrew, Ian; Walsh, Michael; Brohi, Karim; Kyriakides, Constantinos; Matson, Matthew

    2009-05-15

    The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 {+-} 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 {+-} 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

  1. [Single coronary artery and right aortic arch].

    PubMed

    Martínez-Quintana, Efrén; Rodríguez-González, Fayna

    2015-01-01

    Coronary anomalies are mostly asymptomatic and diagnosed incidentally during coronary angiography or echocardiography. However, they must be taken into account in the differential diagnosis of angina, dyspnea, syncope, acute myocardial infarction or sudden death in young patients. The case is presented of two rare anomalies, single coronary artery originating from right sinus of Valsalva and right aortic arch, in a 65 year-old patient with atherosclerotic coronary artery disease treated percutaneously.

  2. Helical (spiral) CT in the evaluation of emergent thoracic aortic syndromes. Traumatic aortic rupture, aortic aneurysm, aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer.

    PubMed

    Ledbetter, S; Stuk, J L; Kaufman, J A

    1999-05-01

    For the near future, CT will play the critical and dominant role in the evaluation of patients presenting with emergent aortic syndromes. Its convenience, accuracy, and utility in the rapid evaluation of not just the aorta, but the entire thorax, make it ideally suited for use in emergency settings. Further benefits are likely to be realized in speed and resolution with multislice CT, although it is as yet not widely available.

  3. Transcatheter Aortic Valve Replacement: Comprehensive Review and Present Status

    PubMed Central

    Misenheimer, Jacob A.; Ramaraj, Radhakrishnan

    2017-01-01

    Aortic stenosis is the most common valvular heart disease in the developed world. About 7% of the population over age 65 years suffers from degenerative aortic stenosis. The prognosis of patients with symptomatic severe aortic stenosis is dismal without valve replacement. Even though the American College of Cardiology recommends aortic valve replacement to treat this condition as a class I recommendation, approximately one third of these patients over the age of 75 years are not referred for surgery. Typically, this is from concern about prohibitive surgical risk associated with patient frailty, comorbidities, age, and severe left ventricular dysfunction. The advent in France of transcatheter aortic valve replacement has raised the hope in the United States for an alternative, less invasive treatment for aortic stenosis. Two recent trials—the Placement of AoRTic TraNscathetER Valve Trial Edwards SAPIEN Transcatheter Heart Valve (Partner) and the CoreValve US Pivotal—have established transcatheter aortic valve replacement as the preferred approach in patients who are at high or prohibitive surgical risk. The more recently published Partner 2 trial has shown the feasibility of transcatheter aortic valve replacement in intermediate-surgical-risk patients as well. With a profile that promises easier use and better valve performance and delivery, newer-generation valves have shown their potential for further improvement in safety profile and overall outcomes. We review the history and status of this topic. PMID:28265210

  4. Surgery for supravalvular aortic stenosis - the three-patch technique.

    PubMed

    Arnáiz, Elena; Koolbergen, Dave; Adsuar, Alejandro; Hazekamp, Mark G

    2008-01-01

    The objective of this paper is to describe the three-patch technique for repair of supravalvular aortic stenosis (SVAS). Supravalvular aortic stenosis is a rare malformation as a result of an abnormal thickening of the aortic wall. SVAS may present in two forms: a localized form (affecting only the aortic sinotubular junction) and a diffuse form, where the aortic arch and its side branches are also affected. Since 1960, multiple surgical techniques have been described with the aim of relieving the aortic narrowing and restoring the aortic root. We present the three-patch technique as originally developed by Brom. After transection of the aorta at the sinotubular junction, three longitudinal incisions are made into the three sinuses. The aortic root geometry is then restored by placement of three separate patches of autologous pericardium in the opened sinuses. Brom's technique provides a complete and symmetric restoration of the aortic anatomy. The technique is illustrated by angiographies, surgical drawings, videos and a review of the literature. The results of the three-patch technique are good and our long-term experience will be described.

  5. Chronic Thoracic Aortic Aneurysm Presenting 29 Years following Trauma

    PubMed Central

    Miller, Sarah; Kumar, Prashant; Van den Bosch, Rene; Khanafer, Adib

    2015-01-01

    Blunt, nonpenetrating injuries of the thoracic aorta are uncommon and associated with a high mortality rate within the first hour. Aortic injury is missed in 1-2% of patients that survive to hospital, and a chronic thoracic aortic aneurysm may subsequently form. We present a case in which a chronic thoracic aortic aneurysm was diagnosed 29 years following a significant motor vehicle accident. We discuss the epidemiology, presentation, and management of this uncommon consequence of blunt, nonpenetrating aortic injury. Our case illustrates an important clinical lesson; a past medical history of trauma should not be overlooked at any patient assessment. PMID:26351610

  6. Aortic root abscess resulting from endocarditis: spectrum of angiographic findings

    SciTech Connect

    Miller, S.W.; Dinsmore, R.E.

    1984-11-01

    Abscesses in the aortic root are a serious complication of infective endocarditis and require accurate diagnosis for antibiotic and surgical management. Nineteen cases of endocarditis of a native valve or prosthetic valve and adjacent abscess cavities were identified with angiography. Of 6 patients with endocarditis of a native valve, 5 had bicuspid aortic valves and all had severe aortic regurgitation. Of 13 patients with endocarditis of a prosthetic aortic valve, all had paravalvular regurgitation. Fistulas were detected into the mitral anulus in 8 patients, and into the right ventricle in 3 patients. No complications from the catheterization were recorded during the 48-hour follow-up.

  7. Major dehiscence of a prosthetic aortic valve: detection by echocardiography.

    PubMed

    Salem, B I; Pechacek, L W; Leachman, R D

    1979-04-01

    A 21-year-old man had acute aortic insufficiency three months after insertion of an aortic valve prosthesis. Chest roentgenography demonstrated abnormal orientation of the prosthesis. M-mode echocardiography showed dense, linear echoes from the prosthetic valve between the interventricular septum and the mitral valve, along with loss of normal poppet motion within the aortic root. At surgery, the prosthesis was found to be extensively disrupted, resulting in prolapse into the left ventricular outflow tract. Another valve replacement was performed with patient survival. Echocardiography appears to be a useful adjunct to established roentgenographic procedures in the diagnosis of major dehiscence of prosthetic aortic valves.

  8. Early-onset Streptomyces endocarditis in a prosthetic aortic valve.

    PubMed

    Shehatha, Jaffar S; Taha, Abdulsalam Y

    2017-02-01

    A 66-year-old Australian man underwent elective replacement of a severely stenotic aortic valve with a 22-mm Medtronic-Hall valve. Six weeks later, he was readmitted with worsening dyspnea, fever, and mild anemia. Investigations confirmed pulmonary edema and moderate periprosthetic aortic regurgitation. The pulmonary edema was managed conservatively, and a second 22-mm Medtronic-Hall valve was implanted. Infective endocarditis was suspected in the aortic annulus below the orifice of the right coronary artery. A bacteriological study revealed a rare bacteria of Streptomyces species. The patient received intensive antibiotic therapy over a 6-week period of hospitalization, and the aortic regurgitation disappeared one week postoperatively.

  9. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections.

    PubMed

    Kuang, Shao-Qing; Medina-Martinez, Olga; Guo, Dong-Chuan; Gong, Limin; Regalado, Ellen S; Reynolds, Corey L; Boileau, Catherine; Jondeau, Guillaume; Prakash, Siddharth K; Kwartler, Callie S; Zhu, Lawrence Yang; Peters, Andrew M; Duan, Xue-Yan; Bamshad, Michael J; Shendure, Jay; Nickerson, Debbie A; Santos-Cortez, Regie L; Dong, Xiurong; Leal, Suzanne M; Majesky, Mark W; Swindell, Eric C; Jamrich, Milan; Milewicz, Dianna M

    2016-03-01

    The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3-/- mice with p53-/- mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease.

  10. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections

    PubMed Central

    Kuang, Shao-Qing; Medina-Martinez, Olga; Guo, Dong-chuan; Gong, Limin; Regalado, Ellen S.; Reynolds, Corey L.; Boileau, Catherine; Jondeau, Guillaume; Prakash, Siddharth K.; Kwartler, Callie S.; Zhu, Lawrence Yang; Peters, Andrew M.; Duan, Xue-Yan; Bamshad, Michael J.; Shendure, Jay; Nickerson, Debbie A.; Santos-Cortez, Regie L.; Dong, Xiurong; Leal, Suzanne M.; Majesky, Mark W.; Swindell, Eric C.; Jamrich, Milan; Milewicz, Dianna M.

    2016-01-01

    The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3–/– mice with p53–/– mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease. PMID:26854927

  11. Interrupted aortic arch: A misdiagnosed cause of hypertension.

    PubMed

    Ponte, Marta; Dias, Adelaide; Dias Ferreira, Nuno; Fonseca, Conceição; Mota, João Carlos; Gama, Vasco

    2014-06-01

    We present the case of a 47-year-old man with hypertension for over 20 years, referred to our hospital due to mild aortic dilatation detected on a transthoracic echocardiogram. On physical examination weak lower limb pulses and a blood pressure differential of >50 mmHg between arms and legs were detected. Complete interruption of the aortic arch below the left subclavian artery was diagnosed by computed tomography angiography. With this case we aim to draw attention to aortic coarctation and interrupted aortic arch as potential causes of hypertension and to highlight the importance of the physical examination in the diagnosis of secondary causes of hypertension.

  12. Cocaine induces apoptosis in primary cultured rat aortic vascular smooth muscle cells: possible relationship to aortic dissection, atherosclerosis, and hypertension.

    PubMed

    Su, Jialin; Li, Jianfeng; Li, Wenyan; Altura, Bella; Altura, Burton

    2004-01-01

    Cocaine abuse is known to induce many adverse cardiovascular effects, including hypertension, atherosclerosis, and aortic dissection. A major physiological event leading to these pathophysiological actions of cocaine could be apoptosis. This study was designed to investigate if primary cultured rat aortic vascular smooth muscle cells (VSMCs) can undergo apoptosis when treated with cocaine. After treatment with cocaine (10(-6) to 10(-4) M), morphological analysis of aortic VSMCs using confocal fluoresence microscopy showed that the percentage of apoptotic aortic VSMCs increased after cocaine (10(-6) to 10(-4) M) treatment for 12, 24, and 48 h. These results demonstrate that aortic VSMCs can undergo rapid apoptosis in response to cocaine in a concentration-dependent manner. Cocaine-induced apoptosis may thus play a major role in cocaine abuse-induced aortic dissection, atherosclerosis, and hypertension.

  13. Therapeutics Targeting Drivers of Thoracic Aortic Aneurysms and Acute Aortic Dissections: Insights from Predisposing Genes and Mouse Models.

    PubMed

    Milewicz, Dianna M; Prakash, Siddharth K; Ramirez, Francesco

    2017-01-14

    Thoracic aortic diseases, including aneurysms and dissections of the thoracic aorta, are a major cause of morbidity and mortality. Risk factors for thoracic aortic disease include increased hemodynamic forces on the ascending aorta, typically due to poorly controlled hypertension, and heritable genetic variants. The altered genes predisposing to thoracic aortic disease either disrupt smooth muscle cell (SMC) contraction or adherence to an impaired extracellular matrix, or decrease canonical transforming growth factor beta (TGF-β) signaling. Paradoxically, TGF-β hyperactivity has been postulated to be the primary driver for the disease. More recently, it has been proposed that the response of aortic SMCs to the hemodynamic load on a structurally defective aorta is the primary driver of thoracic aortic disease, and that TGF-β overactivity in diseased aortas is a secondary, unproductive response to restore tissue function. The engineering of mouse models of inherited aortopathies has identified potential therapeutic agents to prevent thoracic aortic disease.

  14. Endovascular Stent Grafting for Aortic Arch Aneurysm in Aortoiliac Occlusive Disease following Aortic Arch Debranching and Aortobifemoral Reconstruction

    PubMed Central

    Canbay, Cagla; Onal, Yilmaz; Beyaz, Metin Onur; Sayin, Omer Ali; Barburoglu, Mehmet; Yornuk, Mesut; Acunas, Bulent; Alpagut, Ufuk; Dayioglu, Enver

    2017-01-01

    Treatment of thoracic aortic aneurysms constitutes high mortality and morbidity rates despite improvements in surgery, anesthesia, and technology. Endovascular stent grafting may be an alternative therapy with lower risks when compared with conventional techniques. However, sometimes the branches of the aortic arch may require transport to the proximal segments prior to successful thoracic aortic endovascular stent grafting. Atherosclerosis is accounted among the etiology of both aneurysms and occlusive diseases that can coexist in the same patient. In these situations stent grafting may even be more complicated. In this report, we present the treatment of a 92-year-old patient with aortic arch aneurysm and proximal descending aortic aneurysm. For successful thoracic endovascular stent grafting, the patient needed an alternative route other than the native femoral and iliac arteries for the deployment of the stent graft. In addition, debranching of left carotid and subclavian arteries from the aortic arch was also required for successful exclusion of the thoracic aneurysm.

  15. Aortic Disease in the Young: Genetic Aneurysm Syndromes, Connective Tissue Disorders, and Familial Aortic Aneurysms and Dissections

    PubMed Central

    Cury, Marcelo; Zeidan, Fernanda; Lobato, Armando C.

    2013-01-01

    There are many genetic syndromes associated with the aortic aneurysmal disease which include Marfan syndrome (MFS), Ehlers-Danlos syndrome (EDS), Loeys-Dietz syndrome (LDS), familial thoracic aortic aneurysms and dissections (TAAD), bicuspid aortic valve disease (BAV), and autosomal dominant polycystic kidney disease (ADPKD). In the absence of familial history and other clinical findings, the proportion of thoracic and abdominal aortic aneurysms and dissections resulting from a genetic predisposition is still unknown. In this study, we propose the review of the current genetic knowledge in the aortic disease, observing, in the results that the causative genes and molecular pathways involved in the pathophysiology of aortic aneurysm disease remain undiscovered and continue to be an area of intensive research. PMID:23401778

  16. Cage experiments in an East African mangrove forest: a synthesis

    NASA Astrophysics Data System (ADS)

    Schrijvers, J.; Vincx, M.

    1997-12-01

    The impact of epibenthos on endobenthos has frequently been investigated for temperate saltmarsh regions by using cage exclusion experiments. Although the insight into the function of the endobenthos of mangrove forests is crucial for their management, very few cage experiments have so far been carried out in such areas. The present paper summaries the results of such experiments in a typical East African mangrove forest at Gazi Bay about 60 km south of Mombasa, Kenya. Epibenthic animals were excluded for one year in two mangrove zones which differed in forest morphology and intertidal position ( Ceriops tagal and Avicennia marina). Environmental factors and meiobenthic and macrobenthic densities were followed in a randomised block design, and procedural and exclusion effects were statistically detected. In confronting the separate responses of all faunal groups in the two mangrove zones, this synthesis gives a better insight into the tropho-dynamical interactions than the earlier separate reports on the same experiment. The ecosystem of the mangrove zones and the competitive interactions within this system provided an ideal opportunity to discover the existence of two food systems. This confirmed a strong involvement of the majority of the endobenthos in an isolated decompositional pathway in the mangrove sediment. It became clear that this exploitative competition was more important than the epibenthic predation in structuring and regulating the global endobenthic community. This synthesis therefore both demonstrates the decisive role of the endobenthos as regenators of mangrove material, and suggests that endobenthos plays a minor role as prey for the demersal or pelagic carnivores.

  17. Automated Operant Conditioning in the Mouse Home Cage

    PubMed Central

    Francis, Nikolas A.; Kanold, Patrick O.

    2017-01-01

    Recent advances in neuroimaging and genetics have made mice an advantageous animal model for studying the neurophysiology of sensation, cognition, and locomotion. A key benefit of mice is that they provide a large population of test subjects for behavioral screening. Reflex-based assays of hearing in mice, such as the widely used acoustic startle response, are less accurate than operant conditioning in measuring auditory processing. To date, however, there are few cost-effective options for scalable operant conditioning systems. Here, we describe a new system for automated operant conditioning, the Psibox. It is assembled from low cost parts, designed to fit within typical commercial wire-top cages, and allows large numbers of mice to train independently in their home cages on positive reinforcement tasks. We found that groups of mice trained together learned to accurately detect sounds within 2 weeks of training. In addition, individual mice isolated from groups also showed good task performance. The Psibox facilitates high-throughput testing of sensory, motor, and cognitive skills in mice, and provides a readily available animal population for studies ranging from experience-dependent neural plasticity to rodent models of mental disorders. PMID:28298887

  18. Protection characteristics of a Faraday cage compromised by lightning burnthrough.

    SciTech Connect

    Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt; Montoya, Sandra L.; Merewether, Kimball O.; Coats, Rebecca Sue; Martinez, Leonard E.; Jojola, John M.

    2012-01-01

    A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).

  19. Phototriggered release of tetrapeptide AAPV from coumarinyl and pyrenyl cages.

    PubMed

    Santos, Filipa C; Soares, Ana M S; Gonçalves, M Sameiro T; Costa, Susana P G

    2017-03-10

    Ala-Ala-Pro-Val (AAPV) is a bioactive tetrapeptide that inhibits human neutrophil elastase, an enzyme involved in skin chronic inflammatory diseases like psoriasis. Caged derivatives of this peptide were prepared by proper N- and C-terminal derivatisation through a carbamate or ester linkage, respectively, with two photoactive moieties, namely 7-methoxycoumarin-2-ylmethyl and pyren-2-ylmethyl groups. These groups were chosen to assess the influence of the photosensitive group and the type of linkage in the controlled photo release of the active molecule. The caged peptides were irradiated at selected wavelengths of irradiation (254, 300, and 350 nm), and the photolytic process was monitored by HPLC-UV. The results established the applicability of the tested photoactive groups for the release of AAPV, especially for the derivative bearing the carbamate-linked pyrenylmethyl group, which displayed the shortest irradiation times for the release at the various wavelengths of irradiation (ca. 4 min at 254 nm, 8 min at 300 nm and 46 min at 350 nm).

  20. Electromechanical interaction in rotordynamics of cage induction motors

    NASA Astrophysics Data System (ADS)

    Holopainen, Timo P.; Tenhunen, Asmo; Arkkio, Antero

    2005-06-01

    Eccentric rotor motion induces an unbalanced magnetic pull between the rotor and stator of cage induction motors. Recently, a linear parametric model of this eccentricity force due to the arbitrary rotor motion was presented. The purpose of this study is to combine this electromagnetic force model with a simple mechanical rotor model, and further, to demonstrate the rotordynamic response induced by this electromechanical interaction. An electromechanical rotor model is derived on the basis of the Jeffcott rotor with two additional variables for the harmonic currents of the rotor cage. Applying this model, the rotordynamic effects of electromechanical interaction were studied. Three induction motors were used in the numerical examples. The electromechanical parameters of these motors were estimated from the numerical simulations carried out separately. The results obtained show that the electromechanical interaction may decrease the natural frequencies of the rotor, induce additional damping or cause rotordynamic instability. These interaction effects are most significant in motors operating at or near the first bending critical speed. Excluding the potential rotordynamic instability, the numerical results indicate that the electromechanical interaction reduces effectively the unbalance response close to the first bending critical speed.

  1. Cage Dynamics in a Uniformly Heated Granular Fluid

    NASA Astrophysics Data System (ADS)

    Reis, Pedro

    2005-11-01

    We report a novel experimental investigation of the dynamics of a uniformly heated, horizontal and quasi-2D granular fluid. Our study is done as a function of filling fraction, φ, in the region prior to crystallization which we observe at φs=0.719±0.007. We perform a statistical analysis based on two quantities that are typically employed in colloidal/molecular systems: the Mean Square Displacement (MSD) and the Self Intermediate Scattering Function (SISF). These are calculated from the trajectories obtained by tracking all particles inside a representative imaging window of the full system. At low φ the classic diffusive behavior of a disordered fluid is observed. As the filling fraction is increased towards φs, the MSD (or SISF) develops a two-step increase (or decrease) analogous to what is commonly observed in glassy systems. This plateau at intermediate timescales is a signature of the slowing down of the motion of particles due to temporary trapping inside the cages formed by their neighbors. This caging is increasingly more pronounced as φs is approached from below. For φ>φs, each particle becomes fully arrested by its six neighbors, for the whole time accessible experimentally. Moreover, the relaxation time extracted from the SISF, as a function of φ, is well described by the Vogel-Fulcher's law. Our results are an important step in strengthening the analogy between colloidal/molecular glassy systems and dense granular materials under uniform thermalization.

  2. Caging mechanisms for the Mars Exploration Rover instrument deployment device

    NASA Astrophysics Data System (ADS)

    Billing, Rius

    2003-09-01

    The Mars Exploration Rover (MER) program will land two rovers on the Martian surface in January 2004. Each will be equipped with a 5 degree-of-freedom, 1-meter long robotic arm known as the Instrument Deployment Device (IDD). The IDD will position instruments mounted to its end effector with greater precision than any previous Martian arm. Two dual-use caging mechanisms were designed for the IDD. The mechanisms are very small in size, and act as launch restraints as well as passive cradling (re-stowing) features during rover excursions on the Martian surface. The caging mechanisms are designed to use existing structural elements of the IDD to minimize mass and volume. The design also uses the IDD actuators to deploy and re-stow subsequent to the arm's release from the launch locks. Unique design elements are employed because typical release interfaces, such as those using shear-pins in engagement with spherical bearings, could not be utilized due to volume constraints. The final designs, however, do not sacrifice release performance. A cable-cutter and pin-puller, both with standard NSI pyrotechnic initiators, are used to unlatch the IDD after landing. The cable-cutter is used at the end effector in the area of the IDD instruments, which have the highest susceptibility to pyrotechnic shock. This paper discusses design tradeoffs and considerations for the two mechanisms, reasons for choosing each pyrotechnic device, lubrication methodology, thermal-vacuum system testing, and lessons learned.

  3. Large-scale clustering of CAGE tag expression data

    PubMed Central

    Shimokawa, Kazuro; Okamura-Oho, Yuko; Kurita, Takio; Frith, Martin C; Kawai, Jun; Carninci, Piero; Hayashizaki, Yoshihide

    2007-01-01

    Background Recent analyses have suggested that many genes possess multiple transcription start sites (TSSs) that are differentially utilized in different tissues and cell lines. We have identified a huge number of TSSs mapped onto the mouse genome using the cap analysis of gene expression (CAGE) method. The standard hierarchical clustering algorithm, which gives us easily understandable graphical tree images, has difficulties in processing such huge amounts of TSS data and a better method to calculate and display the results is needed. Results We use a combination of hierarchical and non-hierarchical clustering to cluster expression profiles of TSSs based on a large amount of CAGE data to profit from the best of both methods. We processed the genome-wide expression data, including 159,075 TSSs derived from 127 RNA samples of various organs of mouse, and succeeded in categorizing them into 70–100 clusters. The clusters exhibited intriguing biological features: a cluster supergroup with a ubiquitous expression profile, tissue-specific patterns, a distinct distribution of non-coding RNA and functional TSS groups. Conclusion Our approach succeeded in greatly reducing the calculation cost, and is an appropriate solution for analyzing large-scale TSS usage data. PMID:17517134

  4. Effects of environmental pollution in caged mussels (Mytilus galloprovincialis).

    PubMed

    Cappello, Tiziana; Maisano, Maria; D'Agata, Alessia; Natalotto, Antonino; Mauceri, Angela; Fasulo, Salvatore

    2013-10-01

    Biological effects of environmental pollution, mainly related to presence of PAHs, were assessed in mussels Mytilus galloprovincialis caged in Priolo, an anthropogenically-impacted area, and Vendicari, a reference site, both located along the eastern coastline of Sicily (Italy). PAHs concentration and histopathological changes were measured in digestive gland tissues. Expression of cytochrome P4504Y1 (CYP4Y1) and glutathione S-transferase (GST), indicative of xenobiotic detoxification, and activity of catalase (CAT) as oxidative stress index, were evaluated. The results show a direct correlation between the high concentrations of PAHs in digestive glands of mussels from Priolo and the significantly altered activity of phase I (P < 0.001) and phase II (P < 0.0001) biotransformation enzymes, along with increased levels of CAT activity (P < 0.05). These findings show the enhancement of the detoxification and antioxidant defense systems. The mussel caging approach and selected biomarkers demonstrated to be reliable for the assessment of environmental pollution effects on aquatic organisms.

  5. Do all Critical Aortic Stenosis with Chest Pain Need Aortic Valve Replacement? A Case Report

    PubMed Central

    Sharma, Munish; Mascarenhas, Daniel A.N.

    2016-01-01

    Aortic valve replacement (AVR) remains the cornerstone of treatment for symptomatic critical aortic stenosis (AS). It is a Class I indication that symptomatic patients with critical AS undergo either surgical or transcatheter aortic valve replacement (TAVR). We present a patient with critical AS and new angina that was managed successfully with percutaneous coronary intervention (PCI) of the Right coronary artery. Physicians should consider that not all patients with critical AS and angina necessarily require AVR. Concomitant pathology leading to the symptoms should be carefully ruled out. This leads to a less invasive, cost effective care plan especially in patients with advanced age and comorbidities for which any type of surgical valvular intervention may pose high risk. PMID:27994841

  6. Transcaval Aortic Access for Percutaneous Thoracic Aortic Aneurysm Repair: Initial Human Experience

    PubMed Central

    Uflacker, Andre; Lim, Scott; Ragosta, Michael; Haskal, Ziv J; Lederman, Robert J.; Kern, John; Upchurch, Gilbert; Huber, Timothy; Angle, John F.; Ailawadi, Gorav

    2015-01-01

    Transcaval aortic access has been used for deployment of transcatheter aortic valves in patients in whom conventional arterial approaches are not feasible. The present report describes its use for thoracic endovascular aortic repair (TEVAR) in a 61-year-old man with a descending thoracic aneurysm. Transcaval access was performed in lieu of a surgical iliac conduit in view of small atherosclerotic pelvic arteries. TEVAR was successfully performed, followed by intervascular tract occlusion with the use of a ventricular septal occluder. Computed tomography 2 d later demonstrated no extravasation. At 1 mo, the aneurysm was free of endoleaks, the aortocaval tract had healed, and the patient had returned to baseline functional status. PMID:26408210

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

    PubMed

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

    2000-06-01

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

  8. Momentary and wide aortic regurgitation as an indicator of aortic dissection.

    PubMed

    Inokuchi, Takafumi; Sasaki, Osamu; Nishioka, Toshihiko; Ito, Hiroyuki; Yoshimoto, Nobuo; Yamabi, Hideaki; Imanaka, Kazuhito; Sasaki, Hideki

    2017-03-01

    A 55-year-old female with a history of hypertension was admitted for dyspnea, epigastralgia and nausea. A chest X-ray showed pulmonary congestion. Transthoracic echocardiography (TTE) revealed severe left ventricular dysfunction with akinesis of the infero-posterior wall and Doppler color-flow mode showed mild aortic regurgitation (AR). Noninvasive positive pressure ventilation, intravenous heparin and diuretics were administered. Follow-up TTE revealed a dissection flap as well as momentary and wide AR only during isovolumetric relaxation. Contrast-enhanced computed tomography of the chest revealed Stanford type A aortic dissection. A momentary and wide AR in echocardiograms might serve as an important and useful indicator of aortic dissection in patients with acute myocardial infarction and congestive heart failure.

  9. Monocytes and macrophages in abdominal aortic aneurysm.

    PubMed

    Raffort, Juliette; Lareyre, Fabien; Clément, Marc; Hassen-Khodja, Réda; Chinetti, Giulia; Mallat, Ziad

    2017-04-13

    Abdominal aortic aneurysm (AAA) is a life-threatening disease associated with high morbidity, and high mortality in the event of aortic rupture. Major advances in open surgical and endovascular repair of AAA have been achieved during the past 2 decades. However, drug-based therapies are still lacking, highlighting a real need for better understanding of the molecular and cellular mechanisms involved in AAA formation and progression. The main pathological features of AAA include extracellular matrix remodelling associated with degeneration and loss of vascular smooth muscle cells and accumulation and activation of inflammatory cells. The inflammatory process has a crucial role in AAA and substantially influences many determinants of aortic wall remodelling. In this Review, we focus specifically on the involvement of monocytes and macrophages, summarizing current knowledge on the roles, origin, and functions of these cells in AAA development and its complications. Furthermore, we show and propose that distinct monocyte and macrophage subsets have critical and differential roles in initiation, progression, and healing of the aneurysmal process. On the basis of experimental and clinical studies, we review potential translational applications to detect, assess, and image macrophage subsets in AAA, and discuss the relevance of these applications for clinical practice.

  10. Techniques for aortic arch endovascular repair.

    PubMed

    Hongku, Kiattisak; Dias, Nuno; Sonesson, Bjorn; Resch, Timothy

    2016-06-01

    This article reviews endovascular strategies for aortic arch repair. Open repair remains the gold standard particularly for good risk patients. Endovascular treatment potentially offers a less invasive repair. Principles, technical considerations, devices and outcomes of each technique are discussed and summarized. Hybrid repair combines less invasive revascularization options, instead of arch replacement while extending stent-graft into the arch. Outcomes vary with regard to extent of repair and aortic arch pathologies treated. Results of arch chimney and other parallel graft techniques perhaps make it a less preferable choice for elective cases. However, they are very appealing options for urgent or bailout situations. Fenestrated stent-grafting is subjected to many technical challenges in aortic arch due to difficulties in stent-graft orientation and fenestration positioning. In situ fenestration techniques emerge to avoid these problems, but durability of stent-grafts after fenestration and ischemic consequences of temporary carotid arteries coverage raises some concern total arch repair using this technique. Arch branched graft is a new technology. Early outcomes did not meet the expectation; however the results have been improving after its learning curve period. Refining stent-graft technologies and implantation techniques positively impact outcomes of endovascular approaches.

  11. [Transcatheter aortic valve implantation (TAVI): Current perspectives].

    PubMed

    Gaede, Luise; Möllmann, Helge

    2015-08-01

    Transcatheter aortic valve implantation (TAVI) has evolved as the treatment modality of choice for elderly patients with symptomatic severe aortic stenosis who are at high risk for surgery. More than 10,000 TAVI procedures were undertaken in Germany during 2014.A mortality benefit has been shown for TAVI compared with conservative treatment in patients deemed inoperable, and the procedure was proven to be at least non-inferior to surgical aortic valve replacement in high-risk patients. Through improvements in preprocedural imaging and in valve technology as well as increasing operator and surgical team experience, TAVI has developed rapidly in the past few years. Complication rates declinded considerably and the latest study results even suggest a superiority of TAVI to surgical valve replacement in patients at intermediate operative risk. Nevertheless, the challenge to avoid procedure-specific complications influencing the outcome still remains. Therefore, making an individual decision about the approach and the valve prosthesis in an interdisciplinary heart team consisting of a cardiologist and a cardiac surgeon is indispensable for guaranteeing the best therapy for the patient.Considering the rapid developments and procedural improvements in this field, randomized trials are required to assess whether the indication for TAVI may be extended to patients at lower perioperative risk in the future.

  12. Trans-Aortic Counterpulsation: A Viable Alternative?

    PubMed Central

    Datt, Bharat; Hutchison, Lisa; Peniston, Charles

    2007-01-01

    Abstract: Transthoracic intra-aortic balloon pump (IABP) insertion has been a relatively rare and uncommon procedure. However, it is an established beneficial option in patients with severe peripheral vascular disease (PVD) accompanied with bi-lateral femoral arterial occlusion. There are several viable alternatives to trans-aortic IABP insertion, including trans-axillary or in abdominal aorta (requiring a laparotomy). Cardiac surgery has the advantage of an open sternum, facilitating effortless direct intraaortic balloon (IAB) insertion into the aorta. The IAB can be inserted either through a 9-mm graft or directly into the ascending aorta. During cardiac surgery, direct insertion into the ascending aorta with the balloon tip lying distally in the abdominal aorta is facilitated with an open sternum. The base of the balloon lies ∼2 cm below the left subclavian and can be confirmed through a trans-esophageal echocardiogram (TEE). Elimination of a graft insertion saves the team from time-consuming maneuvers and additional hemorrhagic complications. In our experience, postoperative vasoplegic syndrome coupled with myocardial edema contributed to patent instability and was treated with vasopressin and transthoracic IAB insertion. The CS 100 (Datascope Corp., Mahwah, NJ) console allowed the ability to time the balloon accurately. This case report details our experience with one such patient and establishes trans-aortic counter-pulsation as a safe and viable option in patients with severe PVD, where percutaneous insertion is precluded or has failed. PMID:17672190

  13. Aortic arch dissection: a controversy of classification.

    PubMed

    Lempel, Jason K; Frazier, Aletta Ann; Jeudy, Jean; Kligerman, Seth J; Schultz, Randall; Ninalowo, Hammed A; Gozansky, Elliott K; Griffith, Bartley; White, Charles S

    2014-06-01

    Aortic dissections originating in the ascending aorta and descending aorta have been classified as type A and type B dissections, respectively. However, dissections with intimal flap extension into the aortic arch between the innominate and left subclavian arteries are not accounted for adequately in the widely used Stanford classification. This gap has been the subject of controversy in the medical and surgical literature, and there is a tendency among many radiologists to categorize such arch dissections as type A lesions, thus making them an indication for surgery. However, the radiologic perspective is not supported by either standard dissection classification or current clinical management. In this special report, the origin of dissection classification and its evolution into current radiologic interpretation and surgical practice are reviewed. The cause for the widespread misconception about classification and treatment algorithms is identified. Institutional review board approval and waiver of informed consent were obtained as part of this HIPAA-compliant retrospective study to assess all aortic dissection studies performed at the University of Maryland Medical Center, Baltimore between 2010 and 2012 to determine the prevalence of arch dissections. Finally, a unified classification system that reconciles imaging interpretation and management implementation is proposed.

  14. Fluid dynamics of aortic valve stenosis

    NASA Astrophysics Data System (ADS)

    Keshavarz-Motamed, Zahra; Maftoon, Nima

    2009-11-01

    Aortic valve stenosis, which causes considerable constriction of the flow passage, is one of the most frequent cardiovascular diseases and is the most common cause of the valvular replacements which take place for around 100,000 per year in North America. Furthermore, it is considered as the most frequent cardiac disease after arterial hypertension and coronary artery disease. The objective of this study is to develop an analytical model considering the coupling effect between fluid flow and elastic deformation with reasonable boundary conditions to describe the effect of AS on the left ventricle and the aorta. The pulsatile and Newtonian blood flow through aortic stenosis with vascular wall deformability is analyzed and its effects are discussed in terms of flow parameters such as velocity, resistance to flow, shear stress distribution and pressure loss. Meanwhile we developed analytical expressions to improve the comprehension of the transvalvular hemodynamics and the aortic stenosis hemodynamics which is of great interest because of one main reason. To medical scientists, an accurate knowledge of the mechanical properties of whole blood flow in the aorta can suggest a new diagnostic tool.

  15. Aortic arch geometry and exercise-induced hypertension in aortic coarctation.

    PubMed

    De Caro, Enrico; Trocchio, Gianluca; Smeraldi, Attilio; Calevo, Maria Grazia; Pongiglione, Giacomo

    2007-05-01

    Hypertension at rest or during effort is not uncommon in patients with aortic coarctation (CoA), even those with a successful repair or mild degree of obstruction. Anatomic factors and functional abnormalities have been proposed as causes of this finding. Recently, aortic arch geometry was reported in association with hypertension at rest in patients with successful CoA repair. Forty-one patients (age 15.7 +/- 4.6 years) without significant obstruction at rest (mean systolic Doppler gradient at rest < or =25 mm Hg) were selected for the study. All patients underwent a maximal cardiopulmonary exercise test and magnetic resonance imaging of the aorta. Aortic arch shape was defined on global geometry as normal, gothic, and crenel. Percentage of anatomic narrowing (AN) was also calculated. Twenty-four patients (58%) showed exercise-induced hypertension (EIH). Regarding the shape of the aortic arch, normal geometry was present in 17 patients (41%), 9 (21%) had gothic geometry, and 15 (36%) had crenel geometry. There were no differences among the 3 geometries in regard to the incidence of EIH (70.6% in normal, 55.6% in gothic, and 46.7% in crenel) or AN (36.9% in normal, 33.5% in gothic, and 36.6% in crenel). In conclusion, our results fail to show a correlation between a specific aortic arch shape and the incidence of EIH and significant AN in patients with native or residual CoA or repeat CoA. Therefore, at present, the role of aortic arch geometry in identifying patients at risk of EIH is still uncertain.

  16. Planimetry of aortic valve area using multiplane transoesophageal echocardiography is not a reliable method for assessing severity of aortic stenosis.

    PubMed Central

    Bernard, Y.; Meneveau, N.; Vuillemenot, A.; Magnin, D.; Anguenot, T.; Schiele, F.; Bassand, J. P.

    1997-01-01

    OBJECTIVE: To assess the reliability of aortic valve area planimetry by multiplane transoesophageal echocardiography (TOE) in aortic stenosis. DESIGN: Study of the diagnostic value of aortic valve area planimetry using multiplane TOE, compared with catheterisation and the continuity equation, both being considered as criterion standards. SETTING: University hospital. PATIENTS: 49 consecutive patients (29 male, 20 female, aged 44 to 82 years, average 66.6 (SD 8.5)), referred for haemodynamic evaluation of an aortic stenosis, were enrolled in a prospective study. From this sample, 37 patients were eligible for the final analysis. METHODS: Transthoracic and multiplane transoesophageal echocardiograms were performed within 24 hours before catheterisation. At transthoracic echo, aortic valve area was calculated by the continuity equation. At TOE, the image of the aortic valve opening was obtained with a 30-65 degrees rotation of the transducer. Numerical dynamic images were stored on optical discs for off-line analysis and were reviewed by two blinded observers. Catheterisation was performed in all cases and aortic valve area was calculated by the Gorlin formula. RESULTS: Feasibility of the method was 92% (48/52). The agreement between aortic valve area measured at TOE (mean 0.88 (SD 0.35) cm2) and at catheterisation (0.79 (0.24) cm2) was very poor. The same discrepancies were found between TOE and the continuity equation (0.72 (0.26) cm2). TOE planimetry overestimated aortic valve area determined by the two other methods. Predictive positive and negative values of planimetry to detect aortic valve area < 0.75 cm2 were 62% (10/16) and 43% (9/21) respectively. CONCLUSIONS: Planimetry of aortic valve area by TOE is difficult and less accurate than the continuity equation for assessing the severity of aortic stenosis. Images PMID:9290405

  17. Bisphenol A is released from used polycarbonate animal cages into water at room temperature

    USGS Publications Warehouse

    Howdeshell, Kembra L.; Peterman, Paul H.; Judy, Barbara M.; Taylor, Julia A.; Orazio, Carl E.; Ruhlen, Rachel L.; vom Saal, Frederick S.; Welshons, Wade V.

    2003-01-01

    Bisphenol A (BPA) is a monomer with estrogenic activity that is used in the production of food packaging, dental sealants, polycarbonate plastic, and many other products. The monomer has previously been reported to hydrolyze and leach from these products under high heat and alkaline conditions, and the amount of leaching increases as a function of use. We examined whether new and used polycarbonate animal cages passively release bioactive levels of BPA into water at room temperature and neutral pH. Purified water was incubated at room temperature in new polycarbonate and polysulfone cages and used (discolored) polycarbonate cages, as well as control (glass and used polypropylene) containers. The resulting water samples were characterized with gas chromatography/mass spectrometry (GC/MS) and tested for estrogenic activity using an MCF-7 human breast cancer cell proliferation assay. Significant estrogenic activity, identifiable as BPA by GC/MS (up to 310 micro g/L), was released from used polycarbonate animal cages. Detectable levels of BPA were released from new polycarbonate cages (up to 0.3 micro g/L) as well as new polysulfone cages (1.5 micro g/L), whereas no BPA was detected in water incubated in glass and used polypropylene cages. Finally, BPA exposure as a result of being housed in used polycarbonate cages produced a 16% increase in uterine weight in prepubertal female mice relative to females housed in used polypropylene cages, although the difference was not statistically significant. Our findings suggest that laboratory animals maintained in polycarbonate and polysulfone cages are exposed to BPA via leaching, with exposure reaching the highest levels in old cages.

  18. Anterior cervical discectomy and fusion: Comparison of titanium and polyetheretherketone cages

    PubMed Central

    2012-01-01

    Background Titanium (TTN) cages have a higher modulus of elasticity when compared with polyetheretherketone (PEEK) cages. This suggests that TTN-cages could show more frequent cage subsidence after anterior cervical discectomy and fusion (ACDF) and therefore might lead to a higher loss of correction. We compared the long term results of stand-alone PEEK- and TTN-cages in a comparable patient collective that was operated under identical operative settings. Methods From 2002 to 2007 154 patients underwent single-level ACDF for degenerative disc disease (DDD). Clinical and radiological outcome were assessed in 86 eligible patients after a mean of 28.4 months. 44 patients received a TTN- and 42 patients a PEEK-cage. Results Solid arthrodesis was found in 93.2% of the TTN-group and 88.1% of the PEEK-group. Cage subsidence was observed in 20.5% of the TTN- and 14.3% of the PEEK-group. A significant segmental lordotic correction was achieved by both cage-types. Even though a loss of correction was found at the last follow-up in both groups, it did not reach the level of statistical significance. Statistical analysis of these results revealed no differences between the TTN- and PEEK-group. When assessed with the neck disability index (NDI), the visual analogue scale (VAS) of neck and arm pain and Odom’s criteria the clinical data showed no significant differences between the groups. Conclusions Clinical and radiological outcomes of ACDF with TTN- or PEEK-cages do not appear to be influenced by the chosen synthetic graft. The modulus of elasticity represents only one of many physical properties of a cage. Design, shape, size, surface architecture of a cage as well as bone density, endplate preparation and applied distraction during surgery need to be considered as further important factors. PMID:22978810

  19. Design and construction of cage environments for air ion and electric field research

    NASA Astrophysics Data System (ADS)

    Yost, M. G.; Kellogg, E. W.

    1987-06-01

    This report describes the design and construction of cage environments suitable for chronic exposures of large groups of mice to air ions and electric fields. These environments provide defined and reproducible ion densities, ion flux, DC electric fields, sound levels, air temperature and air quality. When used during a 2 year study, these cage environments served as a durable and reliable continuous exposure system. Three environmental chambers (cubicles) housed a total of 12 cages and provided control of air temperature, air purity and lighting. Exposure cages had grounded metal exterior walls, a plexiglass door and interior walls lined with formica. An internal isolated field plate supplemented with guard wires, energized with ca 1000 VDC, created about a 2 kV/m electric field at the grounded cage floor. Air ions resulted from the beta emission of sealed tritium foils mounted on the field plate. Cages provided high ion (1.3×105 ions/cc), low ion (1.6×103 ions/cc) and field only (ion depleted < 50 ions/cc) conditions for both polarities with similar electric fields in ionized and field only cages. Detailed mapping of the floor level ion flux using 100 cm2 flat probes gave average fluxes of 880 fA cm-2 in high ion cages and 10 fA cm-2 in low ion cages. Whole body currents measured using live anesthethized mice in high ion cages averaged 104±63 pA. Both ion flux and whole body currents remained constant over time, indicating no charge accumulation on body fur or cage wall surfaces in this exposure system.

  20. Subsidence after single-level anterior cervical fusion with a stand-alone cage.

    PubMed

    Park, Jae-Young; Choi, Ki-Young; Moon, Bong Ju; Hur, Hyuk; Jang, Jae-Won; Lee, Jung-Kil

    2016-11-01

    To investigate the risk factors for subsidence in patients treated with stand-alone anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages for single-level degenerative cervical disease. Seventy-seven consecutive patients who underwent single-level stand-alone ACDF with a PEEK cage between 2005 and 2012 were included. Subsidence was defined as a decrease in the interbody height of more than 3mm on radiographs at the 1-year follow-up compared with that in the immediate post-operative image. Patients were divided into the subsidence and non-subsidence groups. The following factors were investigated in relation to the occurrence of subsidence: age, pre-operative overall cervical sagittal angle, segmental angle of the operated level, interbody height, cage height, cage devices and cage location (distance between anterior margin of the body endplate and that of the cage). The clinical outcomes were assessed with visual analog scale, modified Japanese Orthopedic Association score and neck disability index. Twenty-six out of the 77 (33.8%) patients had radiological signs of cage subsidence. Solid fusion was achieved in 25 out of the 26 patients (96.2%) in the subsidence group and in 47 out of the 51 patients (92.2%) in the non-subsidence group. More than 3mm distance between anterior margin of the vertebral body and that of the cage was significantly associated with subsidence (p<0.05). However, subsidence did not correlate with fusion rate or clinical outcomes. Cage location was the only significant risk factor. Therefore, cage location should be taken into consideration during stand-alone ACDF using PEEK cages.

  1. Effects of Cage-Change Frequency and Bedding Volume on Mice and Their Microenvironment

    PubMed Central

    Rosenbaum, Matthew D; VandeWoude, Susan; Johnson, Thomas E

    2009-01-01

    The frequency at which mouse cages are changed has important implications for the animals, animal care personnel, and facility managers. The objective of this study was to determine how bedding volume and the interval between changes affect microenvironmental conditions, health, and behavior of mice housed in individually ventilated cages (IVC). A total of 15 cages (n = 5 cages per bedding volume) housing ICR female mice (n = 5 animals per cage) were monitored for 17 d. Parameters monitored included clinical evaluation of each animal, appearance of the cage, fecal corticosterone levels, bedding weight, and mouse mass. Atmospheric analysis was performed daily to determine intracage ammonia cage humidity and temperature on a daily basis. Mice were videotaped for 10 min on days 1, 8, and 15, and videos were analyzed for abnormal behaviors. On day 17, 1 mouse from each cage was euthanized, and bronchoalveolar lavage was performed. Statistical differences in parameters were most often noted between low- and high-volume bedding groups. Correlation between visual appearance and actual intracage environmental conditions and mouse health and behavior at specific time points indicated cages that appear dirty to most observers did not have measurably adverse effects on the animals for any of the many parameters evaluated in this study. This study demonstrated that a 2-wk interval between cage changes for ICR female mice housed in IVC caging (with approximately 90 air changes per hour) and aspen chip bedding did not significantly affect measures of animal well-being in this study. This lack of effect occurred despite the appearance of excessive soiling by the 2-wk time point. PMID:19930825

  2. Laser photolysis of caged compounds at 405 nm: photochemical advantages, localisation, phototoxicity and methods for calibration.

    PubMed

    Trigo, Federico F; Corrie, John E T; Ogden, David

    2009-05-30

    Rapid, localised photolytic release of neurotransmitters from caged precursors at synaptic regions in the extracellular space is greatly hampered at irradiation wavelengths in the near-UV, close to the wavelength of maximum absorption of the caged precursor, because of inner-filtering by strong absorption of light in the cage solution between the objective and cell. For this reason two-photon excitation is commonly used for photolysis, particularly at multiple points distributed over large fields; or, with near-UV, if combined with local perfusion of the cage. These methods each have problems: the small cross-sections of common cages with two-photon excitation require high cage concentrations and light intensities near the phototoxic limit, while local perfusion gives non-uniform cage concentrations over the field of view. Single-photon photolysis at 405 nm, although less efficient than at 330-350 nm, with present cages is more efficient than two-photon photolysis. The reduced light absorption in the bulk cage solution permits efficient wide-field uncaging at non-toxic intensities with uniform cage concentration. Full photolysis of MNI-glutamate with 100 micros pulses required intensities of 2 mW microm(-2) at the preparation, shown to be non-toxic with repeated exposures. Light scattering at 405 nm was estimated as 50% at 18 microm depth in 21-day rat cerebellum. Methods are described for: (1) varying the laser spot size; (2) photolysis calibration in the microscope with the caged fluorophore NPE-HPTS over the wavelength range 347-405 nm; and (3) determining the point-spread function of excitation. Furthermore, DM-Nitrophen photolysis at 405 nm was efficient for intracellular investigations of Ca2+-dependent processes.

  3. Transcatheter aortic valve replacement for aortic bioprosthetic valve failure with cardiogenic shock.

    PubMed

    Fudim, Marat; Markley, Roshanak R; Robbins, Mark A

    2013-11-01

    Acutely failing bioprosthetic valves represent a clinical emergency and are exceedingly challenging given the paucity of therapeutic options. Oftentimes, these patients are not re-operative candidates due to clinical instability. We present 2 cases of acute degenerative aortic bioprosthetic valve failure with cardiogenic shock treated with transcatheter aortic valve replacement (TAVR). These cases were characterized by hemodynamic instability with vasopressor dependence and (multiple) organ failure. These 2 cases demonstrate that TAVR should be considered as a treatment option for unstable patients with bioprosthetic failure.

  4. Development of the Aortic Baroreflex in Microgravity

    NASA Technical Reports Server (NTRS)

    Shimizu, Tsuyoshi; Yamasaki, Masao; Waki, Hidefumi; Katsuda, Shin-ichiro; Oishi, Hirotaka; Katahira, Kiyoaki; Nagayama, Tadanori; Miyake, Masao; Miyamoto, Yukako

    2003-01-01

    Baroreceptors sense pressure in blood vessels and send this information to the brain. The primary baroreceptors are located in the main blood vessel leaving the heart (the aorta) and in the arteries in the neck (the carotid arteries). The brain uses information from the baroreceptors to determine whether blood pressure should be raised or lowered. These reflex responses are called baroreflexes. Changing position within a gravity field (i.e., moving from lying to sitting or standing) powerfully stimulates the baroreflexes. In weightlessness, the amount of stimuli that the baroreflexes receive is dramatically reduced. If this reduction occurs when the pathways that control the baroreflexes are being formed, it is possible that either the structure or function of the baroreceptors may be permanently changed. To study the effect of microgravity on structural and functional development of the aortic baroreflex system, we studied young rats (eight days old at launch) that flew on the Space Shuttle Columbia for 16 days. Six rats were studied on landing day; another six were studied after re-adapting to Earth's gravity for 30 days. On both landing day and 30 days after landing, we tested the sensitivity of the rats' baroreflex response. While the rats were anaesthetized, we recorded their arterial pressure, heart rate, and aortic nerve activity. After the tissues were preserved with perfusion fixation, we also examined the baroreflex structures. On landing day, we found that, compared to the controls, the flight rats had: fewer unmyelinated nerve fibers in their aortic nerves lower baroreflex sensitivity significantly lower contraction ability and wall tension of the aorta a reduced number of smooth muscle cells in the aorta. In the 30-day recovery group, the sensitivity of the baroreflex showed no difference between the flight rats and the control groups, although the unmyelinated fibers of the aortic nerve remained reduced in the flight rats. The results show that

  5. Transcatheter aortic valve repair for management of aortic insufficiency in patients supported with left ventricular assist devices.

    PubMed

    Pal, Jay D; McCabe, James M; Dardas, Todd; Aldea, Gabriel S; Mokadam, Nahush A

    2016-10-01

    The development of new aortic insufficiency after a period of support with a left ventricular assist device can result in progressive heart failure symptoms. Transcatheter aortic valve repair can be an effective treatment in selected patients, but the lack of aortic valve calcification can result in unstable prostheses or paravalvular leak. We describe a technique of deploying a self-expanding CoreValve (Medtronic, Minneapolis, MN, USA) into the aortic annulus, followed by a balloon-expandable SAPIEN-3 (Edwards, Irvine, CA, USA).

  6. Transcatheter aortic valve implantation with Core Valve: First Indian experience of three high surgical risk patients with severe aortic stenosis

    PubMed Central

    Seth, Ashok; Rastogi, Vishal; Kumar, Vijay; Maqbool, Syed; Mustaqueem, Arif; Sekar, V. Ravi

    2013-01-01

    The prevalence of aortic stenosis is increasing with aging population. However with multiple co-morbidities and prior procedures in this aging population, more and more patients are being declared unfit for the ‘Gold Standard’ treatment i.e. surgical aortic valve replacement (AVR). Among the patients who are unfit or high risk for aortic valve replacement (AVR) by open heart surgery, transcatheter aortic valve implantation (TAVI) has been proven to be a valuable alternative improving survival and quality of life. We report first Indian experience of Core Valve (Medtronic Inc.) implantation in three high surgical risk patients performed on 22nd and 23rd February 2012. PMID:23993000

  7. Cage Change Influences Serum Corticosterone and Anxiety-Like Behaviors in the Mouse

    PubMed Central

    Rasmussen, Skye; Miller, Melinda M.; Filipski, Sarah B.; Tolwani, Ravi J.

    2011-01-01

    Environmental variables and husbandry practices can influence physiology and alter behavior in mice. Our study evaluated the effects of cage change on serum corticosterone levels and anxiety-like behaviors in C57BL/6 male mice. We examined the effects of 3 different methods of performing cage transfer and of transferring mice to a clean or a dirty familiar cage microenvironment. The 3 different handling methods were forceps transfer, gentle transfer with gloved hands, and a passive transfer technique that did not involve active handling. Active handling methods and transfer to both clean and dirty cage microenvironments significantly increased serum corticosterone 15 min after cage change; however, at 60 min after cage change, levels were comparable to those of unmanipulated mice. Although the effects were transient, cage change altered anxiety-like behaviors in the open field when behavioral testing was performed on the same day. These results demonstrate that the timing of cage change can influence behavioral results, an effect that is an important consideration for rodent behavioral studies. PMID:21838975

  8. Mercury accumulation in caged Corbicula: rate of uptake and seasonal variation.

    PubMed

    Neufeld, Douglas S G

    2010-09-01

    The uptake and seasonal fluctuations of total mercury were followed in caged and uncaged Asiatic clams, Corbicula fluminea, over a 1-year period in South River, Virginia. Mercury was rapidly accumulated in clams transplanted from a nominally uncontaminated site into cages on the contaminated South River, reaching 0.99 microg g(-1) dry mass within the first month. Resident clams moved to cages had higher mercury contents after the first month (2.04 microg g(-1) dry mass) and at all subsequent times in the study. Large monthly fluctuations in mercury were noted for both resident caged and transplant caged clams with a notable peak occurring in early spring (4.31 microg g(-1) dry mass in resident caged clams). Tissue mass of caged clams steadily increased through the winter and early spring. Adjustment of mercury concentrations for tissue mass changes indicated that the changes in mercury contents were primarily due to uptake/release rather than changes in tissue mass (concentration/dilution). The present study demonstrates the utility of using caged Corbicula as mercury biomonitors and illustrates the importance of accounting for large, short-term changes of mercury content in Corbicula when designing long-term biomonitoring studies.

  9. The biological effect of cage design corrected for reductions in spray penetration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In-field measures of physical spray concentration do not tend to correlate well with caged insect mortality data. It is postulated that filtration of the spray due to the structure of the cage is one of the causes of this inconsistency. Wind tunnel studies were conducted to investigate the accuracy...

  10. Roller to separator contact forces and cage to shaft speed ratios in roller bearings

    NASA Technical Reports Server (NTRS)

    Nypan, L. J.

    1978-01-01

    Cage to roller force measurements, cage to shaft speed ratios are reported for 115- and 118-mm bore roller bearings operating at speeds of 4000, 8000, and 12,000 rpm under loads ranging from 360 to 6670 N (80 to 1500 lb).

  11. A generic strategy for pharmacological caging of growth factors for tissue engineering.

    PubMed

    Karlsson, Maria; Lienemann, Philipp S; Sprossmann, Natallia; Heilmann, Katharina; Brummer, Tilman; Lutolf, Matthias P; Ehrbar, Martin; Weber, Wilfried

    2013-07-07

    The caging of small molecules has revolutionized biological research by providing a means to regulate a wide range of processes. Here we report on a generic pharmacological method to cage proteins in a similar fashion. The present approach is of value in both fundamental and applied research, e.g. in tissue engineering.

  12. International standardization of cage designs and feeding regimes for honey bee in vitro experiments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to improve and standardize cage systems for maintaining adult honey bee workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Preve...

  13. Development of an integrated CAD-FEA system for patient-specific design of spinal cages.

    PubMed

    Zhang, Mingzheng; Pu, Fang; Xu, Liqiang; Zhang, Linlin; Liang, Hang; Li, Deyu; Wang, Yu; Fan, Yubo

    2017-03-01

    Spinal cages are used to create a suitable mechanical environment for interbody fusion in cases of degenerative spinal instability. Due to individual variations in bone structures and pathological conditions, patient-specific cages can provide optimal biomechanical conditions for fusion, strengthening patient recovery. Finite element analysis (FEA) is a valuable tool in the biomechanical evaluation of patient-specific cage designs, but the time- and labor-intensive process of modeling limits its clinical application. In an effort to facilitate the design and analysis of patient-specific spinal cages, an integrated CAD-FEA system (CASCaDeS, comprehensive analytical spinal cage design system) was developed. This system produces a biomechanical-based patient-specific design of spinal cages and is capable of rapid implementation of finite element modeling. By comparison with commercial software, this system was validated and proven to be both accurate and efficient. CASCaDeS can be used to design patient-specific cages with a superior biomechanical performance to commercial spinal cages.

  14. Self-Assembly, Guest Capture, and NMR Spectroscopy of a Metal-Organic Cage in Water

    ERIC Educational Resources Information Center

    Go, Eun Bin; Srisuknimit, Veerasak; Cheng, Stephanie L.; Vosburg, David A.

    2016-01-01

    A green organic-inorganic laboratory experiment has been developed in which students prepare a self-assembling iron cage in D[subscript 2]O at room temperature. The tetrahedral cage captures a small, neutral molecule such as cyclohexane or tetrahydrofuran. [Superscript 1]H NMR analysis distinguishes captured and free guests through diagnostic…

  15. Dissection of Ascending Aorta After Aortic Valve Replacement and Reduction Aortoplasty.

    PubMed

    Hashmi, Maria; Dar, Mudasser Iqbal; Khan, Asad Ullah; Khan, Farhan; Khan, Abdul Bari

    2015-12-01

    A case of Debakey type-II (Stanford type-A) dissecting aortic aneurysm, after aortic valve replacement and reduction aortoplasty, is reported. The patient was 35 years male who was diagnosed of severe aortic regurgitation along with aortic root dilatation of 7 cm. He underwent aortic valve replacement with 27-ASt Jude's mechanical aortic valve along with reduction aortoplasty. Nine months later, he was admitted to our hospital with complaint of severe sudden anterior chest pain. Computed tomography with aortic enhancement showed dilatation and dissection of ascending aorta. Successful operation of aortic root replacement with composite graft was performed and patient was discharged without any postoperative complication. The aortic diameter at the time of aortic valve replacement is an independent risk factor for the late aortic dissection.

  16. Comparison of echocardiography and angiography in determining the cause of severe aortic regurgitation.

    PubMed

    DePace, N L; Nestico, P F; Kotler, M N; Mintz, G S; Kimbiris, D; Goel, I P; Glazier-Laskey, E E; Ross, J

    1984-01-01

    To assess the accuracy of echocardiography in determining the cause of aortic regurgitation M mode and cross sectional echocardiography were compared with angiography in 43 patients with predominant aortic regurgitation. Each patient had all three investigations performed during the same admission to hospital. In each instance, the cause of aortic regurgitation was confirmed at surgery or necropsy. Seventeen patients had rheumatic aortic valve disease, 13 bacterial endocarditis with a perforated or partially destroyed cusp, five a bicuspid aortic valve (four with a history of endocarditis), and eight aortic regurgitation secondary to aortic root dilatation or aneurysm. Overall sensitivity of echocardiography and aortography was 84% in determining the cause of aortic regurgitation. Thus, rheumatic valve disease and endocarditis appear to be the most common causes of severe aortic regurgitation in this hospital based population. Furthermore, echocardiography is a sensitive non-invasive technique for determining the cause of aortic regurgitation and allows differentiation of valvular from root causes of aortic regurgitation.

  17. Comparison of echocardiography and angiography in determining the cause of severe aortic regurgitation.

    PubMed Central

    DePace, N L; Nestico, P F; Kotler, M N; Mintz, G S; Kimbiris, D; Goel, I P; Glazier-Laskey, E E; Ross, J

    1984-01-01

    To assess the accuracy of echocardiography in determining the cause of aortic regurgitation M mode and cross sectional echocardiography were compared with angiography in 43 patients with predominant aortic regurgitation. Each patient had all three investigations performed during the same admission to hospital. In each instance, the cause of aortic regurgitation was confirmed at surgery or necropsy. Seventeen patients had rheumatic aortic valve disease, 13 bacterial endocarditis with a perforated or partially destroyed cusp, five a bicuspid aortic valve (four with a history of endocarditis), and eight aortic regurgitation secondary to aortic root dilatation or aneurysm. Overall sensitivity of echocardiography and aortography was 84% in determining the cause of aortic regurgitation. Thus, rheumatic valve disease and endocarditis appear to be the most common causes of severe aortic regurgitation in this hospital based population. Furthermore, echocardiography is a sensitive non-invasive technique for determining the cause of aortic regurgitation and allows differentiation of valvular from root causes of aortic regurgitation. Images PMID:6689919

  18. Environmental Enrichment Reduces Signs of Boredom in Caged Mink

    PubMed Central

    Meagher, Rebecca K.; Mason, Georgia J.

    2012-01-01

    Animals housed in impoverished cages are often labelled ‘bored’. They have also been called ‘apathetic’ or ‘depressed’, particularly when profoundly inactive. However, these terms are rarely operationally defined and validated. As a negative state caused by under-stimulation, boredom should increase interest in stimuli of all kinds. Apathy (lack of interest), by contrast, should manifest as decreased interest in all stimuli, while anhedonia (loss of pleasure, a depressive symptom) should specifically decrease interest in normally rewarding stimuli. We tested the hypotheses that mink, a model carnivore, experience more boredom, depression-like apathy, or anhedonia in non-enriched (NE) cages than in complex, enriched (E) cages. We exposed 29 subjects (13 E, 16 NE) to ten stimuli categorized a priori as aversive (e.g. air puffs), rewarding (e.g. evoking chasing) or ambiguous/neutral (e.g. candles). Interest in stimuli was assessed via latencies to contact, contact durations, and durations oriented to stimuli. NE mink contacted all stimuli faster (P = 0.003) than E mink, and spent longer oriented to/in contact with them, albeit only significantly so for ambiguous ones (treatment*type P<0.013). With stimulus category removed from statistical models, interest in all stimuli was consistently higher among NE mink (P<0.0001 for all measures). NE mink also consumed more food rewards (P = 0.037). Finally, we investigated whether lying down while awake and stereotypic behaviour (both increased by NE housing) predicted these responses. Lying awake positively co-varied with certain measures of increased exploration. In contrast, stereotypic ‘scrabbling’ or locomotion (e.g. pacing) did not. Overall, NE mink showed no evidence of apathy or depression, but instead a heightened investigation of diverse stimuli consistent with boredom. This state was potentially indicated by spending much time lying still but awake (although this result requires replication

  19. Acute aortic syndromes: definition, prognosis and treatment options.

    PubMed

    Carpenter, S W; Kodolitsch, Y V; Debus, E S; Wipper, S; Tsilimparis, N; Larena-Avellaneda, A; Diener, H; Kölbel, T

    2014-04-01

    Acute aortic syndromes (AAS) are life-threatening vascular conditions of the thoracic aorta presenting with acute pain as the leading symptom in most cases. The incidence is approximately 3-5/100,000 in western countries with increase during the past decades. Clinical suspicion for AAS requires immediate confirmation with advanced imaging modalities. Initial management of AAS addresses avoidance of progression by immediate medical therapy to reduce aortic shear stress. Proximal symptomatic lesions with involvement of the ascending aorta are surgically treated in the acute setting, whereas acute uncomplicated distal dissection should be treated by medical therapy in the acute period, followed by surveillance and repeated imaging studies. Acute complicated distal dissection requires urgent invasive treatment and thoracic endovascular aortic repair has become the treatment modality of choice because of favorable outcomes compared to open surgical repair. Intramural hematoma, penetrating aortic ulcers, and traumatic aortic injuries of the descending aorta harbor specific challenges compared to aortic dissection and treatment strategies are not as uniformly defined as in aortic dissection. Moreover these lesions have a different prognosis. Once the acute period of aortic syndrome has been survived, a lifelong medical treatment and close surveillance with repeated imaging studies is essential to detect impending complications which might need invasive treatment within the short-, mid- or long-term.

  20. Aortic Endograft Infection by Pasteurella multocida: A Rare Case.

    PubMed

    Jayakrishnan, Thejus T; Keyashian, Brian; Amene, Juliet; Malinowski, Michael

    2016-08-01

    Infection of an aortic endograft is a rare complication following endovascular aneurysm repair. These patients have been treated with explantation of the graft to obtain source control followed by an extra-anatomic bypass to restore circulation. The present case study describes an interesting case of Pasteurella infection involving an aortic endograft managed nonoperatively by percutaneous drainage and graft preservation.