Exploratory tests of two strut fuel injectors for supersonic combustion

NASA Technical Reports Server (NTRS)

Anderson, G. Y.; Gooderum, P. B.

1974-01-01

Results of supersonic mixing and combustion tests performed with two simple strut injector configurations, one with parallel injectors and one with perpendicular injectors, are presented and analyzed. Good agreement is obtained between static pressure measured on the duct wall downstream of the strut injectors and distributions obtained from one-dimensional calculations. Measured duct heat load agrees with results of the one-dimensional calculations for moderate amounts of reaction, but is underestimated when large separated regions occur near the injection location. For the parallel injection strut, good agreement is obtained between the shape of the injected fuel distribution inferred from gas sample measurements at the duct exit and the distribution calculated with a multiple-jet mixing theory. The overall fraction of injected fuel reacted in the multiple-jet calculation closely matches the amount of fuel reaction necessary to match static pressure with the one-dimensional calculation. Gas sample measurements with the perpendicular injection strut also give results consistent with the amount of fuel reaction in the one-dimensional calculation.

Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

2014-03-01

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques - manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the usemore » of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.« less

Botulinum neurotoxin A injection for the treatment of epiphora with patent lacrymal ducts.

PubMed

Girard, B; Piaton, J-M; Keller, P; Nguyen, T H

2018-04-01

Retrospective longitudinal study to evaluate the efficacy of botulinum neurotoxin A (BoNT/A) therapy for epiphora with patent lacrimal ducts. BoNT/A has been used since 2000 in axillary hyperhidrosis to reduce sweat secretion. Some isolated cases of hyperlacrimation or crocodile tear syndrome have been treated with BoNT/A on this basis. We report our experience in the treatment of tearing despite patent lacrimal ducts by BoNT/A injection into the lacrimal gland. We reviewed qualitative and quantitative criteria to evaluate the degree of improvement of epiphora after BoNT/A injections in the palpebral lobe of the lacrimal gland in patients referred for epiphora despite patent lacrimal ducts between 2009 and 2016. Epiphora was graded using a functional questionnaire, Munk score and Schirmer test performed before and after the injections. Side effects were recorded. Sixty-five palpebral lacrimal glands of forty-two patients with epiphora despite patent lacrimal ducts, of mean age 65 years, sex ratio 0.8, were treated with BoNT/A (IncobotulinumtoxinA, XEOMIN ® , MERZ Pharma France) from April 2009 to April 2016. The etiology of the epiphora was represented by 56 paroxysmal lacrimal hypersecretion, 2 crocodile tear syndrome and 7 facial palsies. No conventional medical or surgical treatment had been effective in these cases. The technique of injection, dilution and dosage of BoNT/A were specific. We re-injected 33/65 cases a second time upon patient request due to recurrence of epiphora, 16/65 cases three times, 8/65 cases four times, 6/65 cases five times and 3/65 six times. The Schirmer's test measured a decrease of lacrimal secretion in 51/65 glands (78%) after the first botulinum neurotoxin injection. Side effects were limited to ptosis in 2 cases (3%) and six patients (9%) with rapidly regressing diplopia. Two patients experienced immediate lacrimal gland hematoma (3%) with no sequelae. The authors describe the injection techniques, the dosage, the volume and concentration of BoNT/A. Patients with intractable epiphora despite patent lacrimal ducts can be effectively treated with BoNT/A (IncobotulinumtoxinA) injection into the palpebral lobe of the lacrimal gland. Most of the patients (80%) were very satisfied with few side effects (hematoma, ptosis or mild diplopia lasting from 3 days to 3 weeks). More studies are needed to delineate which types of epiphora can be treated with BoNT A. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Burner Rig with an Unattached Duct for Evaluating the Erosion Resistance of Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria A.; Zhu, Dongming

2011-01-01

Extensive computational fluid dynamics (CFD) modeling backed by experimental observation has demonstrated the feasibility of using an unattached duct to increase the velocity and spatial spread of erodent particles exiting from a burner rig. It was shown that gas velocity and temperature are mostly retained if the inner diameter of the unattached duct equaled the exit diameter of the burner rig nozzle. For particles having a mean diameter of 550 millimeters, the modeled velocity attained at a distance 2.0 in. (50.8 millimeters) beyond the exit of a 12 in. (305 millimeters) long duct was approximately twice as large as the velocity the same distance from the nozzle when the duct was not present. For finer particles, the relative enhancement was somewhat less approximately 1.5 times greater. CFD modeling was also used to guide the construction of a device for slowing down the velocity of the particles being injected into the burner rig. This device used a simple 45 degree fitting to slow the particle velocity in the feed line from 20 meters per second, which is in the range needed to convey the particles, to about 3 meters per second just as they are injected into the burner. This lower injection velocity would lessen the severity of the collision of large particles with the wall of the burner liner opposite the injection port, thereby reducing potential damage to the burner liner by high-velocity particles.

Diagnosis of mild chronic pancreatitis (Cambridge classification): comparative study using secretin injection-magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography.

PubMed

Sai, Jin-Kan; Suyama, Masafumi; Kubokawa, Yoshihiro; Watanabe, Sumio

2008-02-28

To investigate the usefulness of secretin injection-MRCP for the diagnosis of mild chronic pancreatitis. Sixteen patients having mild chronic pancreatitis according to the Cambridge classification and 12 control subjects with no abnormal findings on the pancreatogram were examined for the diagnostic accuracy of secretin injection-MRCP regarding abnormal branch pancreatic ducts associated with mild chronic pancreatitis (Cambridge Classification), using endoscopic retrograde cholangiopancreatography (ERCP) for comparison. The sensitivity and specificity for abnormal branch pancreatic ducts determined by two reviewers were respectively 55%-63% and 75%-83% in the head, 57%-64% and 82%-83% in the body, and 44%-44% and 72%-76% in the tail of the pancreas. The sensitivity and specificity for mild chronic pancreatitis were 56%-63% and 92%-92%, respectively. Interobserver agreement (kappa statistics) concerning the diagnosis of an abnormal branch pancreatic duct and of mild chronic pancreatitis was good to excellent. Secretin injection-MRCP might be useful for the diagnosis of mild chronic pancreatitis.

Postoperative Biliary Leak Treated with Chemical Bile Duct Ablation Using Absolute Ethanol: A Report of Two Cases.

PubMed

Sasaki, Maho; Hori, Tomohide; Furuyama, Hiroaki; Machimoto, Takafumi; Hata, Toshiyuki; Kadokawa, Yoshio; Ito, Tatsuo; Kato, Shigeru; Yasukawa, Daiki; Aisu, Yuki; Kimura, Yusuke; Takamatsu, Yuichi; Kitano, Taku; Yoshimura, Tsunehiro

2017-08-08

BACKGROUND Postoperative bile duct leak following hepatobiliary and pancreatic surgery can be intractable, and the postoperative course can be prolonged. However, if the site of the leak is in the distal bile duct in the main biliary tract, the therapeutic options may be limited. Injection of absolute ethanol into the bile duct requires correct identification of the bile duct, and balloon occlusion is useful to avoid damage to the surrounding tissues, even in cases with non-communicating biliary fistula and bile leak. CASE REPORT Two cases of non-communicating biliary fistula and bile leak are presented; one case following pancreaticoduodenectomy (Whipple's procedure), and one case following laparoscopic cholecystectomy. Both cases were successfully managed by chemical bile duct ablation with absolute ethanol. In the first case, the biliary leak occurred from a fistula of the right posterior biliary tract following pancreaticoduodenectomy. Cannulation of the leaking bile duct and balloon occlusion were achieved via a percutaneous route, and seven ablation sessions using absolute ethanol were required. In the second case, perforation of the bile duct branch draining hepatic segment V occurred following laparoscopic cholecystectomy. Cannulation of the bile duct and balloon occlusion were achieved via a transhepatic route, and seven ablation sessions using absolute ethanol were required. CONCLUSIONS Chemical ablation of the bile duct using absolute ethanol is an effective treatment for biliary leak following hepatobiliary and pancreatic surgery, even in cases with non-communicating biliary fistula. Identification of the bile duct leak is required before ethanol injection to avoid damage to the surrounding tissues.

A histochemical study of rat salivary gland acid phosphatase.

PubMed

Isacsson, G

1986-01-01

Male Sprague-Dawley rats received 4 mg pilocarpine/100 g body wt intraperitoneally or physiological saline as control and were killed at various intervals. Acid phosphatase was reacted on frozen sections from soft palate, parotid and submandibular glands using sodium-alpha-naphthyl acid phosphate as substrate. Various inhibitors were added to the incubation medium. The strongest acid phosphatase activity was in the parotid gland acinar and proximal secretory duct cells; the mucous minor glands of the palate were completely negative. Activity was found in the acinar cells, proximal secretory duct cells, granular and striated duct and excretory duct cells. Pilocarpine injection slightly reduced the activity up to 6 h after injection. Cupric chloride added to the incubation medium lowered the overall activity. Fluoride and molybdate inhibited the acid phosphatase reaction in all structures. Tartrate inhibited the reaction in all structures except the submandibular striated duct cells. The tartrate-resistant activity may be a Na+K+-dependent ATPase involved in re-absorbing water and electrolytes from the primary saliva.

Advanced in-duct sorbent injection for SO{sub 2} control. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stouffer, M.R.; Withium, J.A.; Rosenhoover, W.A.

1994-12-01

The objective of this research project was to develop a second generation duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research and development work was focused on the Advanced Coolside process, which showed the potential for exceeding the original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. Process development was conducted in a 1000 acfm pilot plant. The pilot plant testing showed that the Advanced Coolside process can achieve 90% SO{sub 2} removal at sorbent utilizations up to 75%. The testing also showed that the process has the potentialmore » to achieve very high removal efficiency (90 to >99%). By conducting conceptual process design and economic evaluations periodically during the project, development work was focused on process design improvements which substantially lowered process capital and operating costs, A final process economic study projects capital costs less than one half of those for limestone forced oxidation wet FGD. Projected total SO{sub 2} control cost is about 25% lower than wet FGD for a 260 MWe plant burning a 2.5% sulfur coal. A waste management study showed the acceptability of landfill disposal; it also identified a potential avenue for by-product utilization which should be further investigated. Based on the pilot plant performance and on the above economic projections, future work to scale up the Advanced Coolside process is recommended.« less

Can bile duct injuries be prevented? "A new technique in laparoscopic cholecystectomy"

PubMed Central

Sari, Yavuz Selim; Tunali, Vahit; Tomaoglu, Kamer; Karagöz, Binnur; Güneyİ, Ayhan; KaragöZ, İbrahim

2005-01-01

Background Over the last decade, laparoscopic cholecystectomy has gained worldwide acceptance and considered to be as "gold standard" in the surgical management of symptomatic cholecystolithiasis. However, the incidence of bile duct injury in laparoscopic cholecystectomy is still two times greater compared to classic open surgery. The development of bile duct injury may result in biliary cirrhosis and increase in mortality rates. The mostly blamed causitive factor is the misidentification of the anatomy, especially by a surgeon who is at the beginning of his learning curve. Biliary tree injuries may be decreased by direct coloration of the cystic duct, ductus choledochus and even the gall bladder. Methods gall bladder fundus was punctured by Veress needle and all the bile was aspirated. The same amount of fifty percent methylene blue diluted by saline solution was injected into the gall bladder for coloration of biliary tree. The dissection of Calot triangle was much more safely performed after obtention of coloration of the gall bladder, cystic duct and choledocus. Results Between October 2003 and December 2004, overall 46 patients (of which 9 males) with a mean age of 47 (between 24 and 74) underwent laparoscopic cholecystectomy with methylene blue injection technique. The diagnosis of chronic cholecystitis (the thickness of the gall bladder wall was normal) confirmed by pre-operative abdominal ultrasonography in all patients. The diameters of the stones were greater than 1 centimeter in 32 patients and calcula of various sizes being smaller than 1 cm. were documented in 13 cases. One patient was operated for gall bladder polyp (our first case). Successful coloration of the gall bladder, cystic duct and ductus choledochus was possible in 43 patients, whereas only the gall bladder and proximal cystic duct were visualised in 3 cases. In these cases, ductus choledochus visibility was not possible. None of the patients developed bile duct injury. Conclusion The number of bile duct injuries related to anatomic misidentification can be decreased and even vanished by using intraoperative methylene blue injection technique into the gall bladder fundus intraoperatively. PMID:15963227

Measurements and PHITS Monte Carlo Estimations of Residual Activities Induced by the 181 MeV Proton Beam in the Injection Area at J-PARC RCS Ring

NASA Astrophysics Data System (ADS)

Yamakawa, Emi; Yoshimoto, Masahiro; Kinsho, Michikazu

At the injection area of the RCS ring in the J-PARC, residual gamma dose at the rectangular ceramic ducts, especially immediately downstream of the charge-exchanged foil, has increased with the output beam power. In order to investigate the cause of high residual activities, residual gamma dose and radioactive sources produced at the exterior surface of the ducts have been measured by a GM survey meter and a handy type of Germanium (Ge) semiconductor detector in the case of 181 MeV injected proton beam energy. With these measurements, it is revealed that the radioactive sources produced by nuclear reactions cause the high activities at the injection area. For a better understanding of phenomena in the injection area, various simulations have been done with the PHITS Monte Carlo code. The distribution of radioactive sources and residual gamma dose rate obtained by the calculations are consistent with the measurement results. With this consistency, secondary neutrons and protons derived from nuclear reactions at the charge-exchanged foil are the dominant cause to high residual gamma dose at the ceramic ducts in the injection area. These measurements and calculations are unique approaches to reveal the cause of high residual dose around the foil. This study is essential for the future of high-intensity proton accelerators using a stripping foil.

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are given on the mixing of a single row of jets with an isothermal mainstream in a straight duct, to include flow and geometric variations typical of combustion chambers in gas turbine engines. The principal conclusions reached from these experiments were: at constant momentum ratio, variations in density ratio have only a second-order effect on the profiles; a first-order approximation to the mixing of jets with a variable temperature mainstream can be obtained by superimposing the jets-in-an isothermal-crossflow and mainstream profiles; flow area convergence, especially injection-wall convergence, significantly improves the mixing; for opposed rows of jets, with the orifice centerlines in-line, the optimum ratio of orifice spacing to duct height is one half of the optimum value for single side injection at the same momentum ratio; and for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single side injection at the same momentum ratio.

Air Distribution Retrofit Strategies for Affordable Housing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dentz, Jordan; Conlin, Francis; Holloway, Parker

2014-03-01

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques -- manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the usemore » of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.« less

Air Distribution Retrofit Strategies for Affordable Housing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dentz, J.; Conlin, F.; Holloway, Parker

2014-03-01

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques, manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multiunit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder are two story. Results show that duct leakage to the outside was reduced by an average of 59% through themore » use of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.« less

Detonation duct gas generator demonstration program

NASA Technical Reports Server (NTRS)

Wortman, Andrew; Brinlee, Gayl A.; Othmer, Peter; Whelan, Michael A.

1991-01-01

The feasibility of the generation of detonation waves moving periodically across high speed channel flow is experimentally demonstrated. Such waves are essential to the concept of compressing requirements and increasing the engine pressure compressor with the objective of reducing conventional compressor requirements and increasing the engine thermodynamic efficiency through isochoric energy addition. By generating transient transverse waves, rather than standing waves, shock wave losses are reduced by an order of magnitude. The ultimate objective is to use such detonation ducts downstream of a low pressure gas turbine compressor to produce a high overall pressure ratio thermodynamic cycle. A 4 foot long, 1 inch x 12 inch cross-section, detonation duct was operated in a blow-down mode using compressed air reservoirs. Liquid or vapor propane was injected through injectors or solenoid valves located in the plenum or the duct itself. Detonation waves were generated when the mixture was ignited by a row of spark plugs in the duct wall. Problems with fuel injection and mixing limited the air speeds to about Mach 0.5, frequencies to below 10 Hz, and measured pressure ratios of about 5 to 6. The feasibility of the gas dynamic compression was demonstrated and the critical problem areas were identified.

Three Dimensional Compressible Turbulent Flow Computations for a Diffusing S-Duct With/Without Vortex Generators

NASA Technical Reports Server (NTRS)

Cho, Soo-Yong; Greber, Isaac

1994-01-01

Numerical investigations on a diffusing S-duct with/without vortex generators and a straight duct with vortex generators are presented. The investigation consists of solving the full three-dimensional unsteady compressible mass averaged Navier-Stokes equations. An implicit finite volume lower-upper time marching code (RPLUS3D) has been employed and modified. A three-dimensional Baldwin-Lomax turbulence model has been modified in conjunction with the flow physics. A model for the analysis of vortex generators in a fully viscous subsonic internal flow is evaluated. A vortical structure for modeling the shed vortex is used as a source term in the computation domain. The injected vortex paths in the straight duct are compared with the analysis by two kinds of prediction models. The flow structure by the vortex generators are investigated along the duct. Computed results of the flow in a circular diffusing S-duct provide an understanding of the flow structure within a typical engine inlet system. These are compared with the experimental wall static-pressure, static- and total-pressure field, and secondary velocity profiles. Additionally, boundary layer thickness, skin friction values, and velocity profiles in wall coordinates are presented. In order to investigate the effect of vortex generators, various vortex strengths are examined in this study. The total-pressure recovery and distortion coefficients are obtained at the exit of the S-duct. The numerical results clearly depict the interaction between the low velocity flow by the flow separation and the injected vortices.

Demonstration of An Integrated Approach to Mercury Control at Lee Station

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitali Lissianski; Pete Maly

2007-12-31

General Electric (GE) has developed an approach whereby native mercury reduction on fly ash can be improved by optimizing the combustion system. This approach eliminates carbon-rich areas in the combustion zone, making the combustion process more uniform, and allows increasing carbon content in fly ash without significant increase in CO emissions. Since boiler excess O{sub 2} can be also reduced as a result of optimized combustion, this process reduces NO{sub x} emissions. Because combustion optimization improves native mercury reduction on fly ash, it can reduce requirements for activated carbon injection (ACI) when integrated with sorbent injection for more efficient mercurymore » control. The approach can be tailored to specific unit configurations and coal types for optimal performance. This report describes results of a U.S. DOE sponsored project designed to evaluate the effect of combustion conditions on 'native' mercury capture on fly ash and integrate combustion optimization for improved mercury and NO{sub x} reduction with ACI. The technology evaluation took place in Lee Station Unit 3 located in Goldsboro, NC and operated by Progress Energy. Unit 3 burns a low-sulfur Eastern bituminous coal and is a 250 MW opposed-wall fired unit equipped with an ESP with a specific collection area of 249 ft{sup 2}/kacfm. Unit 3 is equipped with SO{sub 3} injection for ESP conditioning. The technical goal of the project was to evaluate the technology's ability to achieve 70% mercury reduction below the baseline emission value of 2.9 lb/TBtu, which was equivalent to 80% mercury reduction relative to the mercury concentration in the coal. The strategy to achieve the 70% incremental improvement in mercury removal in Unit 3 was (1) to enhance 'naturally' occurring fly ash mercury capture by optimizing the combustion process and using duct humidification to reduce flue gas temperatures at the ESP inlet, and (2) to use ACI in front of the ESP to further reduce mercury emissions. The program was comprised of field and pilot-scale tests, engineering studies and consisted of eight tasks. As part of the program, GE conducted pilot-scale evaluation of sorbent effect on mercury reduction, supplied and installed adjustable riffle boxes to assist in combustion optimization, performed combustion optimization, supplied mobile sorbent injection and flue gas humidification systems, conducted CFD modeling of sorbent injection and flue gas humidification, and performed mercury testing including a continuous 30-day sorbent injection trial. Combustion optimization was the first step in reduction of mercury emissions. Goals of combustion optimization activities were to improve 'native' mercury capture on fly ash and reduce NO{sub x}. Combustion optimization included balancing of coal flow through individual burners to eliminate zones of carbon-rich combustion, air flow balancing, and burner adjustments. As part of the project, the original riffle boxes were replaced with Foster-Wheeler's adjustable riffle boxes to allow for biasing the coal flow between the coal pipes. A 10-point CO/O{sub 2}/NO{sub x} grid was installed in the primary superheater region of the back pass to assist in these activities. Testing of mercury emissions before and after combustion optimization demonstrated that mercury emissions were reduced from 2.9 lb/TBtu to 1.8 lb/TBtu due to boiler operation differences in conjunction with combustion optimization, a 38% improvement in 'native' mercury capture on fly ash. Native mercury reduction from coal was {approx}42% at baseline conditions and 64% at optimized combustion conditions. As a result of combustion optimization NO{sub x} emissions were reduced by 18%. A three-dimensional CFD model was developed to study the flow distribution and sorbent injection in the post air heater duct in Lee Station Unit 3. Modeling of the flow pattern exiting the air pre-heater demonstrated that because of the duct transition from a circular opening at the exit of air-pre-heater to a rectangular ESP inlet duct, flow separation occurred at the corners after the transition. Modeling also demonstrated that the flow was severely biased from the South side to the North side due to the bend of the duct. Results of CFD modeling were used to design lances for better sorbent distribution across the ESP inlet duct. Modeling of water injection demonstrated that because of flue gas temperature biasing, the droplet evaporation rate was slower on the North side than that on the South side of the duct. Modeling suggested that an improvement of water droplet evaporation could be achieved by closing the lance on the North side where flue gas temperatures were lower. Preliminary evaluation of the effect of carbon-based sorbents on mercury reduction took place in a 1 MBtu/hr (300 kW) Boiler Simulator Facility using the same coal as fired at Lee Station.« less

Positive predictive value of cholescintigraphy in common bile duct obstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lecklitner, M.L.; Austin, A.R.; Benedetto, A.R.

1986-09-01

Technetium-99m DISIDA imaging was employed in 400 patients to differentiate obstruction of the common bile duct from medical and other surgical causes of hyperbilirubinemia. Sequential anterior images demonstrated variable degrees of liver uptake, yet there was no evidence of intrabiliary or extrabiliary radioactivity for at least 4 hr after injection in 25 patients. Twenty-three patients were surgically documented to have complete obstruction of the common bile duct. One patient had hepatitis, and another had sickle cell crisis without bile duct obstruction. The remaining patients had either partial or no obstruction of the common bile duct. We conclude that the presencemore » of liver uptake without evident biliary excretion by 4 hr on cholescintigraphy is highly sensitive and predictive of total obstruction of the common bile duct.« less

Tracer airflow measurement system (TRAMS)

DOEpatents

Wang, Duo [Albany, CA

2007-04-24

A method and apparatus for measuring fluid flow in a duct is disclosed. The invention uses a novel high velocity tracer injector system, an optional insertable folding mixing fan for homogenizing the tracer within the duct bulk fluid flow, and a perforated hose sampling system. A preferred embodiment uses CO.sub.2 as a tracer gas for measuring air flow in commercial and/or residential ducts. In extant commercial buildings, ducts not readily accessible by hanging ceilings may be drilled with readily plugged small diameter holes to allow for injection, optional mixing where desired using a novel insertable foldable mixing fan, and sampling hose.

Humanization of the mouse mammary gland by replacement of the luminal layer with genetically engineered preneoplastic human cells.

PubMed

Verbeke, Stephanie; Richard, Elodie; Monceau, Elodie; Schmidt, Xenia; Rousseau, Benoit; Velasco, Valerie; Bernard, David; Bonnefoi, Herve; MacGrogan, Gaetan; Iggo, Richard D

2014-12-20

The cell of origin for estrogen receptor α-positive (ERα+) breast cancer is probably a luminal stem cell in the terminal duct lobular units. To model these cells, we have used the murine myoepithelial layer in the mouse mammary ducts as a scaffold upon which to build a human luminal layer. To prevent squamous metaplasia, a common artifact in genetically-engineered breast cancer models, we sought to limit activation of the epidermal growth factor receptor (EGFR) during in vitro cell culture before grafting the cells. Human reduction mammoplasty cells were grown in vitro in WIT medium. Epidermal growth factor in the medium was replaced with amphiregulin and neuregulin to decrease activation of EGFR and increase activation of EGFR homologs 3 and 4 (ERBB3 and ERBB4). Lentiviral vectors were used to express oncogenic transgenes and fluorescent proteins. Human mammary epithelial cells were mixed with irradiated mouse fibroblasts and Matrigel, then injected through the nipple into the mammary ducts of immunodeficient mice. Engrafted cells were visualized by stereomicroscopy for fluorescent proteins and characterized by histology and immunohistochemistry. Growth of normal mammary epithelial cells in conditions favoring ERBB3/4 signaling prevented squamous metaplasia in vitro. Normal human cells were quickly lost after intraductal injection, but cells infected with lentiviruses expressing CCND1, MYC, TERT, BMI1 and a short-hairpin RNA targeting TP53 were able to engraft and progressively replace the luminal layer in the mouse mammary ducts, resulting in the formation of an extensive network of humanized ducts. Despite expressing multiple oncogenes, the human cells formed a morphologically normal luminal layer. Expression of a single additional oncogene, PIK3CA-H1047R, converted the cells into invasive cancer cells. The resulting tumors were ERα+, Ki67+ luminal B adenocarcinomas that were resistant to treatment with fulvestrant. Injection of preneoplastic human mammary epithelial cells into the mammary ducts of immunodeficient mice leads to replacement of the murine luminal layer with morphologically normal human cells. Genetic manipulation of the injected cells makes it possible to study defined steps in the transformation of human mammary epithelial cells in a more physiological environment than has hitherto been possible.

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are presented on the mixing of a single row of jets with an isothermal mainstream in a straight duct, with flow and geometric variations typical of combustion chambers in gas turbine engines included. It is found that at a constant momentum ratio, variations in the density ratio have only a second-order effect on the profiles. A first-order approximation to the mixing of jets with a variable temperature mainstream can, it is found, be obtained by superimposing the jets-in-an-isothermal-crossflow and mainstream profiles. Another finding is that the flow area convergence, especially injection-wall convergence, significantly improves the mixing. For opposed rows of jets with the orifice cone centerlines in-line, the optimum ratio of orifice spacing to duct height is determined to be 1/2 of the optimum value for single injection at the same momentum ratio. For opposed rows of jets with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is found to be twice the optimum value for single side injection at the same momentum ratio.

An experimental trace gas investigation of fluid transport and mixing in a circular-to-rectangular transition duct

NASA Technical Reports Server (NTRS)

Reichert, B. A.; Hingst, W. R.; Okiishi, T. H.

1991-01-01

An ethylene trace gas technique was used to map out fluid transport and mixing within a circular to rectangular transition duct. Ethylene gas was injected at several points in a cross stream plane upstream of the transition duct. Ethylene concentration contours were determined at several cross stream measurement planes spaced axially within the duct. The flow involved a uniform inlet flow at a Mach number level of 0.5. Statistical analyses were used to quantitatively interpret the trace gas results. Also, trace gas data were considered along with aerodynamic and surface flow visualization results to ascertain transition duct flow phenomena. Convection of wall boundary layer fluid by vortices produced regions of high total pressure loss in the duct. The physical extent of these high loss regions is governed by turbulent diffusion.

Subsonic Flows through S-Ducts with Flow Control

NASA Astrophysics Data System (ADS)

Chen, Yi

An inlet duct of an aircraft connects the air intake mounted on the fuselage to the engine within the aircraft body. The ideal outflow quality of the duct is steady, uniform and of high total pressure. Recently compact S-shaped inlet ducts are drawing more attention in the design of UAVs with short propulsion system. Compact ducts usually involve strong streamwise adverse pressure gradient and transverse secondary flow, leading to large-scale harmful vortical structures in the outflow. To improve the outflow quality modern flow control techniques have to be applied. Before designing successful flow control methods a solid understanding of the baseline flow field with the duct is crucial. In this work the fundamental mechanism of how the three dimensional flow topology evolves when the relevant parameters such as the duct geometry and boundary layer thickness are varied, is studied carefully. Two distinct secondary-flow patterns are identified. For the first time the sensitivity of the flow topology to the inflow boundary layer thickness in long ducts is clearly addressed. The interaction between the transverse motion induced by the transverse pressure gradient and the streamwise separation is revealed as the crucial reason for the various flow patterns existing in short ducts. A non-symmetric flow pattern is identified for the first time in both experiments and simulations in short ducts in which the intensity of the streamwise separation and the transverse invasion are in the same order of magnitude. A theory of energy accumulation and solution bifurcation is used to give a reasonable explanation for this non-symmetry. After gaining the knowledge of where and how the harmful vortical structures are generated several flow control techniques are tested to achieve a better outflow quality. The analysis of the flow control cases also provides a deeper insight into the behavior of the three-dimensional flow within the ducts. The conventional separation control method of Coanda injection is proved to be less effective in short ducts dominated by strong three-dimensional effects. Besides, the injection enhances the energy accumulation in duct with the asymmetric pattern and leads to the amplification of the asymmetry. Vortex generator jets are applied to generate spanwise near-wall motions opposing the transverse invasion and to break the strong interaction between the invasion and the separation. Symmetry is regained successfully.

Filling defects in the pancreatic duct on endoscopic retrograde pancreatography.

PubMed

Taylor, A J; Carmody, T J; Schmalz, M J; Wiedmeyer, D A; Stewart, E T

1992-12-01

Filling defects in the pancreatic duct are a frequent finding during endoscopic retrograde pancreatography (ERP) and have a variety of causes. Some filling defects may be artifactual or related to technical factors and, once their origin is recognized, can be disregarded. Others may be due to acute changes of pancreatitis and should prompt more careful injection of contrast material into the duct. Intraluminal masses may represent calculi or a neoplasm, either of which may require surgery or endoscopic intervention. The exact nature of these filling defects may not be apparent on radiographs, and other studies may be needed. This article reviews our approach to the evaluation of filling defects in the pancreatic duct.

Glass melter off-gas system

DOEpatents

Jantzen, Carol M.

1997-01-01

Apparatus and method for melting glass in a glass melter in such a way as to reduce deposition of particulates in the off-gas duct. Deposit accumulation is reduced by achieving an off-gas velocity above approximately 15 meters/second and an off-gas temperature as close as possible to, but not higher than, the glass softening point. Because the deposits are largely water-soluble, those that do form on the interior surface of the duct can be readily removed by injecting water or steam directly into the off-gas duct from its entrance or exit.

Experimental investigation of crossflow jet mixing in a rectangular duct

NASA Technical Reports Server (NTRS)

Liscinsky, D. S.; True, B.; Holdeman, J. D.

1993-01-01

An experimental investigation of the mixing of nonreacting opposed rows of jets injected normal to a confined rectangular crossflow has been conducted. Planar Mie-scattering was used to measure the time-average concentration distribution of the jet fluid in planes perpendicular to the duct axis. The mixing effectiveness of round orifice injectors was measured as a function of orifice spacing and orifice diameter. Mixing effectiveness was determined using a spatial unmixedness parameter based on the variance of mean jet concentration distributions. Optimum mixing was obtained when the spacing-to-duct height ratio was inversely proportional to the square root of the jet-to-mainstream momentum-flux ratio. For opposed rows of round holes with centerlines inline, mixing was similar for blockages up to 75 percent. Lower levels of unmixedness were obtained as a function of downstream location when axial injection length was minimized. Mixing may be enhanced if orifice centerlines of opposed rows are staggered, but note that blockage must be less than 50 percent for this configuration.

CFD Mixing Analysis of Jets Injected from Straight and Slanted Slots into Confined Crossflow in Rectangular Ducts

NASA Technical Reports Server (NTRS)

Bain, D. B.; Smith, C. E.; Holdeman, J. D.

1992-01-01

A CFD study was performed to analyze the mixing potential of opposed rows of staggered jets injected into confined crossflow in a rectangular duct. Three jet configurations were numerically tested: (1) straight (0 deg) slots; (2) perpendicular slanted (45 deg) slots angled in opposite directions on top and bottom walls; and (3) parallel slanted (45 deg) slots angled in the same direction on top and bottom walls. All three configurations were tested at slot spacing-to-duct height ratios (S/H) of 0.5, 0.75, and 1.0; a jet-to-mainstream momentum flux ratio (J) of 100; and a jet-to-mainstream mass flow ratio of 0.383. Each configuration had its best mixing performance at S/H of 0.75. Asymmetric flow patterns were expected and predicted for all slanted slot configurations. The parallel slanted slot configuration was the best overall configuration at x/H of 1.0 for S/H of 0.75.

Ducted fuel injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, Charles J.

Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be locatedmore » proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.« less

Factors associated with post-ERCP pancreatitis and the effect of pancreatic duct stenting in a pediatric population.

PubMed

Troendle, David M; Abraham, Omana; Huang, Rong; Barth, Bradley A

2015-01-01

Risk factors for the development of post-ERCP pancreatitis (PEP) have not been identified in the pediatric population. It remains unclear what constitutes appropriate prophylaxis in this patient population. To assess the prevalence and severity of PEP in the pediatric population and identify factors associated with developing PEP and to evaluate the effect of prophylactic pancreatic duct stenting in high-risk patients. Retrospective analysis of an ERCP database at a single large pediatric center. Academic center. A total of 432 ERCPs performed on 313 patients younger than 19 years of age from January 2004 to October 2013. ERCP for any indication. Rates and severity of PEP, preprocedural and procedural risk factors for the development of PEP, and the effect of pancreatic stents on preventing PEP in high-risk patients. PEP occurred after 47 procedures (prevalence, 10.9%). Thirty-four cases were mild, 9 were moderate, and 4 were severe. There was no mortality. On multiple logistic analysis, pancreatic duct injection (P<.0001; odds ratio 30.8; 95% confidence interval [CI], 9.1-103.9) and pancreatic sphincterotomy (P<.01; OR 3.8; 95% CI, 1.6-9.8) were positively associated with PEP. A history of chronic pancreatitis was negatively associated with PEP (P<.05; OR 0.37; 95% CI, 0.15-0.93). On subset analysis, placing a prophylactic pancreatic stent was associated with significantly increased rates of PEP in patients with pancreatic duct injection compared with those who had no attempt at stent placement (P<.01). Two patients with severe pancreatitis had prophylactic pancreatic stents in place. Retrospective investigation. In the pediatric population, pancreatic duct injection and pancreatic sphincterotomy are associated with significantly increased rates of PEP, whereas a history of chronic pancreatitis is negatively associated. Prophylactic pancreatic stenting is associated with higher rates of PEP in high-risk patients and does not eliminate severe PEP. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Multiple jet study

NASA Technical Reports Server (NTRS)

Walker, R. E.; Kors, D. L.

1973-01-01

Test data is presented which allows determination of jet penetration and mixing of multiple cold air jets into a ducted subsonic heated mainstream flow. Jet-to-mainstream momentum flux ratios ranged from 6 to 60. Temperature profile data is presented at various duct locations up to 24 orifice diameters downstream of the plane of jet injection. Except for two configurations, all geometries investigated had a single row of constant diameter orifices located transverse to the main flow direction. Orifice size and spacing between orifices were varied. Both of these were found to have a significant effect on jet penetration and mixing. The best mixing of the hot and cold streams was achieved with duct height.

Argon/UF6 plasma exhaust gas reconstitution experiments using preheated fluorine and on-line diagnostics. [fissioning uranium plasma core reactor design

NASA Technical Reports Server (NTRS)

Roman, W. C.

1979-01-01

The feasibility of employing a flowing, high-temperature, pure fluorine/UF6 regeneration system to efficiently convert a large fraction of the effluent plasma exhaust back to pure UF6 was demonstrated. The custom built T.O.F. mass spectrometer sampling system permitted on-line measurements of the UF6 concentration at different locations in the exhaust system. Negligible amounts ( 100 ppm) of UF6 were detected in the axial bypass exhaust duct and the exhaust ducts downstream of the cryogenic trap system used to collect the UF6, thus verifying the overall system efficiency over a range of operating conditions. Use of a porous Monel duct as part of the exhaust duct system, including provision for injection of pure fluorine, provided a viable technique to eliminate uranium compound residue on the inside surface of the exhaust ducts. Typical uranium compound mass deposition per unit area of duct was 2 micron g/sq cm. This porous duct technique is directly applicable to future uranium compound transfer exhaust systems. Throughout these experiments, additional basic data on the corrosion aspects of hot, pressurized UF6/fluorine were also accumulated.

Pilot scale-SO{sub 2} control by dry sodium bicarbonate injection and an electrostatic precipitator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pliat, M.J.; Wilder, J.M.

2007-10-15

A 500 actual cubic feet gas per minute (acfm) pilot-scale SO{sub 2} control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400{sup o}F (204.5{sup o}C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO{sub 2}. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO{sub 2} concentrations weremore » measured upstream of the reagent injection, 25-ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO{sub 2} collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in-duct SO{sub 2} removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide-sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature.« less

Vitamin K1 attenuates bile duct ligation-induced liver fibrosis in rats.

PubMed

Jiao, Kun; Sun, Quan; Chen, Baian; Li, Shengli; Lu, Jing

2014-06-01

Vitamin K1 is used as a liver protection drug for cholestasis-induced liver fibrosis in China, but the mechanism of vitamin K1's action in liver fibrosis is unclear. In this study, a model of liver fibrosis was achieved via bile duct ligation in rats. The rats were then injected with vitamin K1, and the levels of serum aspartate aminotransferase, alanine transaminase, total bilirubin and the fibrotic grade score, collagen content, the expressions of α-smooth muscle actin (SMA) and cytokeratin 19 (CK19) were measured on day 28 after ligation. The levels of the biochemical parameters, fibrotic score and collagen content were significantly reduced by treatment with vitamin K1 in bile duct-ligated rats. In addition, α-SMA and CK19 expression was significantly reduced by vitamin K1 treatment in bile duct-ligated rats. These results suggested that vitamin K1 may attenuate liver fibrosis by inhibiting hepatic stellate cell activation in bile duct-ligated rats.

Improving patient and user safety during endoscopic investigation of the pancreatic and biliary ducts

NASA Astrophysics Data System (ADS)

Chandler, John E.; Melville, C. David; Lee, Cameron M.; Saunders, Michael D.; Burkhardt, Matthew R.; Seibel, Eric J.

2011-03-01

Endoscopic investigation of the main pancreatic duct and biliary ducts is called endoscopic retrograde cholangiopancreatography (ERCP), and carries a risk of pancreatitis for the patient. During ERCP, a metal guidewire is inserted into the pancreatobiliary duct from a side-viewing large endoscope within the duodenum. To verify correct placement of the ERCP guidewire, an injection of radiopaque dye is required for fluoroscopic imaging, which exposes the patient and clinical team to x-ray radiation. A safer and more effective means to access the pancreatobiliary system can use direct optical imaging, although the endoscope diameter and stiffness will be significantly larger than a guidewire's. To quantify this invasiveness before human testing, a synthetic force-sensing pancreas was fabricated and attached to an ERCP training model. The invasiveness of a new, 1.7-mm diameter, steerable scanning fiber endoscope (SFE) was compared to the standard ERCP guidewire of 0.89-mm (0.035") diameter that is not steerable. Although twice as large and significantly stiffer than the ERCP guidewire, the SFE generated lower or significantly less average force during insertion at all 4 sensor locations (P<0.05) within the main pancreatic duct. Therefore, the addition of steering and forward visualization at the tip of the endoscope reduced the invasiveness of the in vitro ERCP procedure. Since fluoroscopy is not required, risks associated with dye injection and x-ray exposure can be eliminated when using direct optical visualization. Finally, the SFE provides wide-field high resolution imaging for image-guided interventions, laser-based fluorescence biomarker imaging, and spot spectral analysis for future optical biopsy.

Autoignition in a premixing-prevaporizing fuel duct using 3 different fuel injection systems at inlet air temperatures to 1250 K

NASA Technical Reports Server (NTRS)

Tacina, R. R.

1983-01-01

Conditions were determined in a continuous-flow, premixing-prevaporizing duct at which autoignition occurred. Test conditions were representative of an advanced, regenerative-cycle, automotive gas turbine. The test conditions inlet air temperatures from 600 to 1250 K (a vitiated preheater was used), pressures from 170 to 600 kPa, air velocities of 10 to 30 m/sec, equivalence ratios from 0.3 to 1.0, mixing lengths from 10 to 60 cm, and residence times of 2 to 100 ms. The fuel was diesel number 2. The duct was insulated and had an inside diameter of 12 cm. Three different fuel injection systems were used: One was a single simplex pressure atomizer, and the other two were multiple-source injectors. The data obtained with the simplex and one of the multiple-source injectors agreed satisfactorily with the references and correlated with an Arrenhius expression. The data obtained with the other multiple source injector, which used multiple cones to improve the fuel-air distribution, did not correlate well with residence time.

In vivo biocompatibility of the PLGA microparticles in parotid gland

PubMed Central

Cantín, Mario; Miranda, Patricio; Suazo Galdames, Iván; Zavando, Daniela; Arenas, Patricia; Velásquez, Luis; Vilos, Cristian

2013-01-01

Poly(lactic-co-glycolic acid) (PLGA) microparticles are used in various disorders for the controlled or sustained release of drugs, with the management of salivary gland pathologies possible using this technology. There is no record of the response to such microparticles in the glandular parenchyma. The purpose of this study was to assess the morphological changes in the parotid gland when injected with a single dose of PLGA microparticles. We used 12 adult female Sprague Dawley rats (Rattus norvegicus) that were injected into their right parotid gland with sterile vehicle solution (G1, n=4), 0.5 mg PLGA microparticles (G2, n=4), and 0.75 mg PLGA microparticles (G3, n=4); the microparticles were dissolved in a sterile vehicle solution. The intercalar and striated ducts lumen, the thickness of the acini and the histology aspect in terms of the parenchyma organization, cell morphology of acini and duct system, the presence of polymeric residues, and inflammatory response were determined at 14 days post-injection. The administration of the compound in a single dose modified some of the morphometric parameters of parenchyma (intercalar duct lumen and thickness of the glandular acini) but did not induce tissue inflammatory response, despite the visible presence of polymer waste. This suggests that PLGA microparticles are biocompatible with the parotid tissue, making it possible to use intraglandular controlled drug administration. PMID:24228103

Experimental investigation on the effect of liquid injection by multiple orifices in the formation of droplets in a Venturi scrubber.

PubMed

Guerra, V G; Gonçalves, J A S; Coury, J R

2009-01-15

Venturi scrubbers are widely utilized in gas cleaning. The cleansing elements in these scrubbers are droplets formed from the atomization of a liquid into a dust-laden gas. In industrial scrubbers, this liquid is injected through several orifices so that the cloud of droplets can be evenly distributed throughout the duct. The interaction between droplets when injected through many orifices, where opposite clouds of atomized liquid can reach each other, is to be expected. This work presents experimental measurements of droplet size measured in situ and the evidence of cloud interaction within a Venturi scrubber operating with multi-orifice jet injection. The influence of gas velocity, liquid flow rate and droplet size variation in the axial position after the point of the injection of the liquid were also evaluated for the different injection configurations. The experimental results showed that an increase in the liquid flow rate generated greater interaction between jets. The number of orifices had a significant influence on droplet size. In general, the increase in the velocity of the liquid jet and in the gas velocity favored the atomization process by reducing the size of the droplets.

System and method for treatment of a medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Surinder Prabhjot; Acharya, Harish Radhakrishna; Perry, Robert James

2017-05-23

A system and method for treatment of a medium is disclosed. The system includes a plurality of separator zones and a plurality of heat transfer zones. Each of the separator zone and the heat transfer zone among the plurality of separator zones and heat transfer zones respectively, are disposed alternatively in a flow duct. Further, each separator zone includes an injector device for injecting a sorbent into the corresponding separator zone. Within the corresponding separator zone, the injected sorbent is reacted with a gaseous medium flowing in the flow duct, so as to generate a reacted gaseous medium and amore » reacted sorbent. Further, each heat transfer zone exchanges heat between the reacted gaseous medium fed from the corresponding separator zone and a heat transfer medium.« less

Characterization of flow in a scroll duct

NASA Technical Reports Server (NTRS)

Begg, E. K.; Bennett, J. C.

1985-01-01

A quantitative, flow visualization study was made of a partially elliptic cross section, inward curving duct (scroll duct), with an axial outflow through a vaneless annular cutlet. The working fluid was water, with a Re(d) of 40,000 at the inlet to the scroll duct, this Reynolds number being representative of the conditions in an actual gas turbine scroll. Both still and high speed moving pictures of fluorescein dye injected into the flow and illuminated by an argon ion laser were used to document the flow. Strong secondary flow, similar to the secondary flow in a pipe bend, was found in the bottom half of the scroll within the first 180 degs of turning. The pressure field set up by the turning duct was strong enough to affect the inlet flow condition. At 90 degs downstream, the large scale secondary flow was found to be oscillatory in nature. The exit flow was nonuniform in the annular exit. By 270 degs downstream, the flow appeared unorganized with no distinctive secondary flow pattern. Large scale structures from the upstream core region appeared by 90 degs and continued through the duct to reenter at the inlet section.

Effects of saliva from chronically reserpinized rat on Na and K transport in perfused main excretory duct of submandibular gland of normal rat.

PubMed

Jirakulsomchok, D; Schneyer, C A

1987-09-01

Reserpine (RES) (0.5 mg/kg body wt, ip) was administered to rats for 7 days. On Day 8 saliva was evoked from these animals by intraperitoneal injection of pilocarpine nitrate (10 mg/kg body wt) and saliva from submandibular and parotid glands was collected separately. These collected salivas were used to perfuse through the main ducts of the submandibular glands of normal rats. After a control period of perfusion of the main duct with bicarbonate saline solution, parotid saliva from RES rats was perfused through the duct followed by regular perfusion. There was inhibition of Na absorption (22%) and K secretion (23%). Moreover, when submandibular saliva from treated rat was perfused through the main duct prior to regular perfusion, there was a decrease in Na absorption (31%) and K secretion (28%). In contrast, perfusion of the main duct with either parotid or submandibular saliva from normal rats caused no significant changes in Na and K transport. The present experiments confirm previous studies that there is some Na-inhibitory factor(s) present in saliva of the chronically RES-treated rat.

Antipollution system to remove nitrogen dioxide gas

NASA Technical Reports Server (NTRS)

Metzler, A. J.; Slough, J. W.

1971-01-01

Gas phase reaction system using anhydrous ammonia removes nitrogen dioxide. System consists of ammonia injection and mixing section, reaction section /reactor/, and scrubber section. All sections are contained in system ducting.

Simultaneous desulfurization and denitrification of flue gas by ·OH radicals produced from O2+ and water vapor in a duct.

PubMed

Bai, Mindi; Zhang, Zhitao; Bai, Mindong

2012-09-18

In the present study, simultaneous flue gas desulfurization and denitrification are achieved with ·OH radicals generated from O(2)(+) reacting with water vapor in a duct. The O(2)(+) ions are generated by a strong ionization dielectric barrier discharge and then injected into the duct. Compared with conventional gas discharge treatment, the present method does not need a plasma reaction reactor, additional catalysts, reductants, or oxidants. The main recovered products are the liquids H(2)SO(4) and HNO(3), which can be used in many processes. Removal rates of 97% for NO and 82% for SO(2) are obtained under the following optimal experimental conditions: molar ratio of reactive oxygen species (O(2)(+), O(3)) to SO(2) and NO, 5; inlet flue gas temperature, 65 °C; reaction time, 0.94 s; and H(2)O volume fraction, 8%. Production of O(2)(+) and the plasma reaction mechanisms are discussed, and the recovered acid is characterized. The experimental results show that the present method performs better for denitrification than for desulfurization. Compared with conventional air discharge flue gas treatments, the present method has lower initial investment and operating costs, and the equipment is more compact.

MINIMIZING DECOMPOSITION OF VAPORIZED HYDROGEN PEROXIDE IN CLEAN GALVANIZED STEEL DUCTING: IMPLICATIONS FOR BIOLOGICAL DECONTAMINATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verce, M F; Jayaraman, B; Ford, T D

2007-09-07

This work examined the behavior of vaporous hydrogen peroxide (VHP) in clean, room-scale galvanized steel (GS) and polyvinylchloride-coated steel air ducts, to understand how it might be used to decontaminate larger ventilation systems. VHP injected into the GS duct decreased in concentration along the length of the duct, whereas VHP concentrations in the polyvinylchloride coated duct remained essentially constant, suggesting that VHP decomposed at the GS surface. However, decomposition was reduced at lower temperatures ({approx} 22 C) and higher flow rates ({approx} 80 actual cubic meter per hour). A computational fluid dynamics model incorporating reactive transport was used to estimatemore » surface VHP concentrations where contamination is likely to reside, and also showed how bends encourage VHP decomposition. Use of G. stearothermophilus indicators, in conjunction with model estimates, indicated that a concentration-contact time of {approx} 100 mg/L H{sub 2}O{sub 2}(g){center_dot}min was required to achieve a 6 log reduction of indicator spores in clean GS duct, at 30 C. When VHP is selected for building decontamination, this work suggests the most efficacious strategy may be to decontaminate GS ducting separately from the rest of the building, as opposed to a single decontamination event in which the ventilation system is used to distribute VHP throughout the entire building.« less

Lymphatic route of transport and pharmacokinetics of Micrurus fulvius (coral snake) venom in sheep.

PubMed

Paniagua, D; Jiménez, L; Romero, C; Vergara, I; Calderón, A; Benard, M; Bernas, M J; Rilo, H; de Roodt, A; D' Suze, G; Witte, M H; Boyer, L; Alagón, A

2012-12-01

The contribution of the lymphatic system to the absorption and systemic bioavailability of Micrurus fulvius venom after subcutaneous (SC) administration was assessed using a central lymph-cannulated sheep model. Micrurus fulvius venom was administered either by intravenous bolus (IV) or subcutaneous injection (SC) in 12 sheep with and without thoracic duct cannulation and drainage. Venom concentration in serum and lymph was determined by a sandwich enzyme-linked immunosorbent assay (ELISA) in samples collected over a 6-hour period and in tissues harvested at the end of the experiment. Pharmacokinetic parameters were determined by a non-compartmental analysis. In the lymphatic cannulated group, over the 6 hours after the venom was administered, 69% of administered dose was accounted for in blood (45%) and lymph (25%). Negligible levels of venom were detected in organs and urine implying that the steady state observed after SC administration is maintained by a slow absorption process. Comparison of kinetics of the thoracic duct cannulated and non-cannulated groups showed that lymphatic absorption contributed in an important way to maintenance of this steady state. These results show that the limiting process in the pharmacokinetics of Micrurus fulvius venom following SC administration is absorption, and that the lymphatic system plays a key role in this process.

Numerical and experimental analysis of a ducted propeller designed by a fully automated optimization process under open water condition

NASA Astrophysics Data System (ADS)

Yu, Long; Druckenbrod, Markus; Greve, Martin; Wang, Ke-qi; Abdel-Maksoud, Moustafa

2015-10-01

A fully automated optimization process is provided for the design of ducted propellers under open water conditions, including 3D geometry modeling, meshing, optimization algorithm and CFD analysis techniques. The developed process allows the direct integration of a RANSE solver in the design stage. A practical ducted propeller design case study is carried out for validation. Numerical simulations and open water tests are fulfilled and proved that the optimum ducted propeller improves hydrodynamic performance as predicted.

Potential application of in vivo imaging of impaired lymphatic duct to evaluate the severity of pressure ulcer in mouse model

NASA Astrophysics Data System (ADS)

Kasuya, Akira; Sakabe, Jun-Ichi; Tokura, Yoshiki

2014-02-01

Ischemia-reperfusion (IR) injury is a cause of pressure ulcer. However, a mechanism underlying the IR injury-induced lymphatic vessel damage remains unclear. We investigated the alterations of structure and function of lymphatic ducts in a mouse cutaneous IR model. And we suggested a new method for evaluating the severity of pressure ulcer. Immunohistochemistry showed that lymphatic ducts were totally vanished by IR injury, while blood vessels were relatively preserved. The production of harmful reactive oxygen species (ROS) was increased in injured tissue. In vitro study showed a high vulnerability of lymphatic endothelial cells to ROS. Then we evaluated the impaired lymphatic drainage using an in vivo imaging system for intradermally injected indocyanine green (ICG). The dysfunction of ICG drainage positively correlated with the severity of subsequent cutaneous changes. Quantification of the lymphatic duct dysfunction by this imaging system could be a useful strategy to estimate the severity of pressure ulcer.

Electrohydrodynamic convective heat transfer in a square duct.

PubMed

Grassi, Walter; Testi, Daniele

2009-04-01

Laminar to weakly turbulent forced convection in a square duct heated from the bottom is strengthened by ion injection from an array of high-voltage points opposite the heated strip. Both positive and negative ion injection are activated within the working liquid HFE-7100 (C(4)F(9)OCH(3)), with transiting electrical currents on the order of 0.1 mA. Local temperatures on the heated wall are measured by liquid crystal thermography. The tests are conducted in a Reynolds number range from 510 to 12,100. In any case, heat transfer is dramatically augmented, almost independently from the flow rate. The pressure drop increase caused by the electrohydrodynamically induced flow is also measured. A profitable implementation of the technique in the design of heat sinks and heat exchangers is foreseen; possible benefits are pumping power reduction, size reduction, and heat exchange capability augmentation.

Ducted combustion chamber for direct injection engines and method

DOEpatents

Mueller, Charles

2015-03-03

An internal combustion engine includes an engine block having a cylinder bore and a cylinder head having a flame deck surface disposed at one end of the cylinder bore. A piston connected to a rotatable crankshaft and configured to reciprocate within the cylinder bore has a piston crown portion facing the flame deck surface such that a combustion chamber is defined within the cylinder bore and between the piston crown and the flame deck surface. A fuel injector having a nozzle tip disposed in fluid communication with the combustion chamber has at least one nozzle opening configured to inject a fuel jet into the combustion chamber along a fuel jet centerline. At least one duct defined in the combustion chamber between the piston crown and the flame deck surface has a generally rectangular cross section and extends in a radial direction relative to the cylinder bore substantially along the fuel jet centerline.

Active noise control: A tutorial for HVAC designers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelin, L.J.

1997-08-01

This article will identify the capabilities and limitations of ANC in its application to HVAC noise control. ANC can be used in ducted HVAC systems to cancel ductborne, low-frequency fan noise by injecting sound waves of equal amplitude and opposite phase into an air duct, as close as possible to the source of the unwanted noise. Destructive interference of the fan noise and injected noise results in sound cancellation. The noise problems that it solves are typically described as rumble, roar or throb, all of which are difficult to address using traditional noise control methods. This article will also contrastmore » the use of active against passive noise control techniques. The main differences between the two noise control measures are acoustic performance, energy consumption, and design flexibility. The article will first present the fundamentals and basic physics of ANC. The application to real HVAC systems will follow.« less

Post-Tensioning Duct Air Pressure Testing Effects on Web Cracking

DOT National Transportation Integrated Search

2015-01-01

Nevada Department of Transportation (NDOT) post-tensioned concrete bridges have experienced web cracking near the post-tensioning ducts during the construction process. The ducts were air pressure tested to ensure the duct can successfully be grouted...

Design and Testing of Non-Toxic RCS Thrusters for Second Generation Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Calvignac, Jacky; Dang, Lisa; Tramel, Terri; Paseur, Lila; Champion, Robert (Technical Monitor)

2003-01-01

Under NASA sponsorship, Northrop Grumman Space Technology (NGST) designed, built and tested two non-toxic, reaction control engines, one using liquid oxygen (LOX) and liquid hydrogen (LH2) and the other using liquid oxygen and ethanol. This paper presents the design and testing of the LOX/LH2 thruster. The two key enabling technologies are the coaxial liquid-on-liquid pintle injector and the fuelcooling duct. The workhorse thruster was hotfire tested at the NASA Marshall Space Flight Center Test Stand 500 in March and April of 2002. All tests were performed at sea-level conditions. During the test program, 7 configurations were tested, including 2 combustion chambers, 3 LOX injector pintle tips, and 4 LHp injector settings. The operating conditions surveyed were 70 to 100% thrust levels, mixture ratios from 3.27 to 4.29, and LH2 duct cooling from 18.0 to 25.5% fuel flow. The copper heat sink chamber was used for 16 burns, each burn lasting from 0.4 to 10 seconds, totaling 51.4 seconds, followed by Haynes chamber testing ranging from 0.9 to 120 seconds, totaling 300.9 seconds. The performance of the engine reached 95% C* efficiency. The temperature on the Haynes chamber remained well below established material limits, with the exception of one localized hot spot. These results demonstrate that both the coaxial liquid-on-liquid pintle injector design and fuel duct concepts are viable for the intended application. The thruster headend design maintained cryogenic injection temperatures while firing, which validates the selected injector design approach for minimal heat soak-back. Also, off -nominal operation without adversely impacting the thermal response of the engine showed the robustness of the duct design, a key design feature for this application. By injecting fuel into the duct, the throat temperatures are manageable, yet the split of fuel through the cooling duct does not compromise the overall combstion efficiency, which indicates that, provided proper design refinement, such a concept could be applied to a high-performance version of the thruster.

Investigation of ramp injectors for supersonic mixing enhancement

NASA Technical Reports Server (NTRS)

Haimovitch, Y.; Gartenberg, E.; Roberts, A. S., Jr.

1994-01-01

A comparative study of wall mounted swept ramp injectors fitted with injector nozzles of different shape has been conducted in a constant area duct to explore mixing enhancement techniques for scramjet combustors. Six different injector nozzle inserts, all having equal exit and throat areas, were tested to explore the interaction between the preconditioned fuel jet and the vortical flowfield produced by the ramp: circular nozzle (baseline), nozzle with three downstream facing steps, nozzle with four vortex generators, elliptical nozzle, tapered-slot nozzle, and trapezoidal nozzle. The main flow was air at Mach 2, and the fuel was simulated by air injected at Mach 1.63 or by helium injected at Mach 1.7. Pressure and temperature surveys, combined with Mie and Rayleigh scattering visualization, were used to investigate the flow field. The experiments were compared with three dimensional Navier-Stokes computations. The results indicate that the mixing process is dominated by the streamwise vorticity generated by the ramp, the injectors' inner geometry having a minor effect. It was also found that the injectant/air mixing in the far-field is nearly independent of the injector geometry, molecular weight of the injectant, and the initial convective Mach number.

Shock Tunnel Studies of Scramjet Phenomena

NASA Technical Reports Server (NTRS)

Stalker, R. J.

1996-01-01

Work focussed on a large number of preliminary studies of supersonic combustion in a simple combustion duct - thrust nozzle combination, investigating effects of Mach number, equivalence ratio, combustor divergence, fuel injecting angle and other parameters with an influence on the combustion process. This phase lasted for some three or four years, during which strongest emphasis was placed on responding to the request for preliminary experimental information on high enthalpy effects, to support the technology maturation activities of the NASP program. As the need for preliminary data became less urgent, it was possible to conduct more systematic studies of high enthalpy combustion phenomena, and to initiate other projects aimed at improving the facilities and instrumentation used for studying scramjet phenomena at high enthalpies. The combustion studies were particularly directed towards hypersonic combustion, and to the effects of injecting fuel along the combustion chamber wall. A substantial effort was directed towards a study of the effect of scale on the supersonic combustion process. The influence of wave phenomena (both compression waves and expansion waves) on the realization of thrust from a supersonic combustion process was also investigated. The effect of chemical kinetics was looked into, particularly as it affected the composition of the test flow provided by a ground facility. The effect of injection of the fuel through wall orifices was compared with injection from a strut spanning the stream, and the effect of heating the fuel prior to injection was investigated. Studies of fuel-air mixing by shock impingement were also done, as well as mass spectrometer surveys of a combustion wake. The use of hypersonic nozzles with an expansion tube was investigated. A new method was developed for measuring the forces acting of a model in less than one millisecond. Also included in this report are listings of published journal papers and conference presentations.

Biliopancreatic duct injection of ethanol as an experimental model of acute and chronic pancreatitis in rats

PubMed Central

Unal, Ethem; Atalay, Suleyman; Tolan, Huseyin Kerem; Yuksekdag, Sema; Yucel, Metin; Acar, Aylin; Basak, Fatih; Gunes, Pembegul; Bas, Gurhan

2015-01-01

In the present study, we described an easily reproducable experimental pancreatits model induced by biliopancreatic duct injection of ethyl alcohol. Seventy Wistar albino rats were divided equally into seven groups randomly: the control group (group 1), acute pancreatitis groups; induced by 20% ethanol (group 2), 48% ethanol (group 3), 80% ethanol (group 4), chronic pancreatitis groups; induced by 20% ethanol (group 5), 48% ethanol (group 6) and by 80% ethanol (group 7). Acute pancreatitis groups were sacrified on postoperative day 3, while the control group and chronic pancreatitis groups were killed on postoperative day 7. Histopathologic evaluation was done, and P < 0.05 was accepted as statistically significant. All rats in group 3 developed acute pancreatitis (100%). Inflammatory infiltration of neutrophils and mononuclear cells, interstitial edema, and focal necrotic areas were seen in the pancreatic tissues. Similarly, all rats in group 6 developed chronic pancreatitis (100%). Interstitial fibrosis, lymphotic infiltration, ductal dilatation, acinar cell atrophy, periductal hyperplasia were seen in the pancreatic tissues. Mortality was seen only in group 7. The biliopancreatic ductal injection of 48% ethanol induced acute and chronic pancreatitis has 100% success rate. PMID:25785001

Supersonic Pulsed Injection

NASA Technical Reports Server (NTRS)

Cutler, A. D.; Harding, G. C.; Diskin, G. S.

2001-01-01

An injector has been developed to provide high-speed high-frequency (order 10 kHz) pulsed a supersonic crossflow. The injector nozzle is formed between the fixed internal surface of the nozzle and a freely rotating three- or four-sided wheel embedded within the device. Flow-induced rotation of the wheel causes the nozzle throat to open and close at a frequency proportional to the speed of sound of the injected gas. Measurements of frequency and mass flow rate as a function of supply pressure are discussed for various injector designs. Preliminary results are presented for wall-normal injection of helium into a Mach-2 ducted airflow. The data include schlieren images in the injectant plume in a plane normal to the flow, downstream of injection.

A laser-induced-fluorescence visualization study of transverse, sonic fuel injection in a nonreacting supersonic combustor

NASA Technical Reports Server (NTRS)

Mcdaniel, J. C.; Graves, J., Jr.

1986-01-01

The present paper reports work which has been conducted in the first phase of a research program which is to provide a data base of spatially-resolved measurements in nonreacting supersonic combustors. In the measurements, a nonintrusive diagnostic technique based on the utilization of laser-induced fluorescence (LIF) is employed. The reported work had the objective to conduct LIF visualization studies of the injection of a simulated fuel into a Mach 2.07 airstream for comparison with corresponding numerical calculations. Attention is given to injection from a single orifice into a constant-area duct, injection from a single orifice behind a rearward-facing step, and injection from staged orifices behind a rearward-facing step.

Identification of AQP5 in lipid rafts and its translocation to apical membranes by activation of M3 mAChRs in interlobular ducts of rat parotid gland.

PubMed

Ishikawa, Yasuko; Yuan, Zhenfang; Inoue, Noriko; Skowronski, Mariusz T; Nakae, Yoshiko; Shono, Masayuki; Cho, Gota; Yasui, Masato; Agre, Peter; Nielsen, Søren

2005-11-01

Aquaporin-5 (AQP5), an apical plasma membrane (APM) water channel in salivary glands, lacrimal glands, and airway epithelium, has an important role in fluid secretion. M(3) muscarinic acetylcholine receptor (mAChR)-induced changes in AQP5 localization in rat parotid glands were investigated with immunofluorescence or immunoelectron microscopy, detergent solubility, and gradient density floatation assays. Confocal microscopy revealed AQP5 localization in intracellular vesicles of interlobular duct cells in rat parotid glands and AQP5 trafficking to the APM 10 min after injection of the mAChR agonist cevimeline. Conversely, 60 min after injection, there was a diffuse pattern of AQP5 staining in the cell cytoplasm. The calcium ionophore A-23187 mimicked the effects of cevimeline. Immunoelectron microscopic studies confirmed that cevimeline induced AQP5 trafficking from intracellular structures to APMs in the interlobular duct cells of rat parotid glands. Lipid raft markers flotillin-2 and GM1 colocalized with AQP5 and moved with AQP5 in response to cevimeline. Under control conditions, the majority of AQP5 localized in the Triton X-100-insoluble fraction and floated to the light-density fraction on discontinuous density gradients. After 10-min incubation of parotid tissue slices with cevimeline or A-23187, AQP5 levels decreased in the Triton X-100-insoluble fraction and increased in the Triton X-100-soluble fraction. Thus AQP5 localizes in the intracellular lipid rafts, and M(3) mAChR activation induces AQP5 trafficking to the APM with lipid rafts via intracellular Ca(2+) signaling and induces AQP5 dissociation from lipid rafts to nonrafts on the APM in the interlobular duct cells of rat parotid glands.

Computer analysis of three-dimensional morphological characteristics of the bile duct

NASA Astrophysics Data System (ADS)

Ma, Jinyuan; Chen, Houjin; Peng, Yahui; Shang, Hua

2017-01-01

In this paper, a computer image-processing algorithm for analyzing the morphological characteristics of bile ducts in Magnetic Resonance Cholangiopancreatography (MRCP) images was proposed. The algorithm consisted of mathematical morphology methods including erosion, closing and skeletonization, and a spline curve fitting method to obtain the length and curvature of the center line of the bile duct. Of 10 cases, the average length of the bile duct was 14.56 cm. The maximum curvature was in the range of 0.111 2.339. These experimental results show that using the computer image-processing algorithm to assess the morphological characteristics of the bile duct is feasible and further research is needed to evaluate its potential clinical values.

Suppository naproxen reduces incidence and severity of post-endoscopic retrograde cholangiopancreatography pancreatitis: Randomized controlled trial.

PubMed

Mansour-Ghanaei, Fariborz; Joukar, Farahnaz; Taherzadeh, Zahra; Sokhanvar, Homayoon; Hasandokht, Tolou

2016-06-07

To determine the efficacy of rectally administered naproxen for the prevention of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). This double-blind randomized control trial conducted from January 2013 to April 2014 at the Gastrointestinal and Liver Diseases Research Center in Rasht, Iran. A total of 324 patients were selected from candidates for diagnostic or therapeutic ERCP by using the simple sampling method. Patients received a single dose of Naproxen (500 mg; n = 162) or a placebo (n = 162) per rectum immediately before ERCP. The overall incidence of PEP, incidence of mild to severe PEP, serum amylase levels and adverse effects were measured. The primary outcome measure was the development of pancreatitis onset of pain in the upper abdomen and elevation of the serum amylase level to > 3 × the upper normal limit (60-100 IU/L) within 24 h after ERCP. The severity of PEP was classified according to the duration of therapeutic intervention for PEP: mild, 2-3 d; moderate 4-10 d; and severe, > 10 d and/or necessitated surgical or intensive treatment, or contributed to death. PEP occurred in 12% (40/324) of participants, and was significantly more frequent in the placebo group compared to the naproxen group (P < 0.01). Of the participants, 25.9% (84/324) developed hyperamylasemia within 2 h of procedure completion, among whom only 35 cases belonged to the naproxen group (P < 0.01). The incidence of PEP was significantly higher in female sex, in patients receiving pancreatic duct injection, more than 3 times pancreatic duct cannulations, and ERCP duration more than 40 min (Ps < 0.01). There were no statistically significant differences between the groups regarding the procedures or factors that might increase the risk of PEP, sphincterotomy, precut requirement, biliary duct injection and number of pancreatic duct cannulations. In the subgroup of patients with pancreatic duct injection, the rate of pancreatitis in the naproxen group was significantly lower than that in the placebo (6 patients vs 23 patients, P < 0.01, RRR = 12%, AR = 0.3, 95%CI: 0.2-0.6). Naproxen reduced the PEP in patients with ≥ 3 pancreatic cannulations (P < 0.01, RRR = 25%, AR = 0.1, 95%CI: 0.1-0.4) and an ERCP duration > 40 min (P < 0.01, RRR = 20%, AR = 0.9, 95%CI: 0.4-1.2). Single dose of suppository naproxen administered immediately before ERCP reduces the incidence of PEP.

Acoustic propagation in curved ducts with extended reacting wall treatment

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1989-01-01

A finite-element Galerkin formulation was employed to study the attenuation of acoustic waves propagating in two-dimensional S-curved ducts with absorbing walls without a mean flow. The reflection and transmission at the entrance and the exit of a curved duct were determined by coupling the finite-element solutions in the curved duct to the eigenfunctions of an infinite, uniform, hard wall duct. In the frequency range where the duct height and acoustic wave length are nearly equal, the effects of duct length, curvature (duct offset) and absorber thickness were examined. For a given offset in the curved duct, the length of the S-duct was found to significantly affect both the absorptive and reflective characteristics of the duct. A means of reducing the number of elements in the absorber region was also presented. In addition, for a curved duct, power attenuation contours were examined to determine conditions for maximum acoustic power absorption. Again, wall curvature was found to significantly effect the optimization process.

Transition mixing study empirical model report

NASA Technical Reports Server (NTRS)

Srinivasan, R.; White, C.

1988-01-01

The empirical model developed in the NASA Dilution Jet Mixing Program has been extended to include the curvature effects of transition liners. This extension is based on the results of a 3-D numerical model generated under this contract. The empirical model results agree well with the numerical model results for all tests cases evaluated. The empirical model shows faster mixing rates compared to the numerical model. Both models show drift of jets toward the inner wall of a turning duct. The structure of the jets from the inner wall does not exhibit the familiar kidney-shaped structures observed for the outer wall jets or for jets injected in rectangular ducts.

Exact solution for flow in a porous pipe with unsteady wall suction and/or injection

NASA Astrophysics Data System (ADS)

Tsangaris, S.; Kondaxakis, D.; Vlachakis, N. W.

2007-10-01

This paper presents an extension of the exact solution of the steady laminar axisymmetric flow in a straight pipe of circular cross section with porous wall, given by R.M. Terrill, to the case of unsteady wall injection and/or suction. The cases of the pulsating parabolic profile and of the developed pulsating flow are investigated as examples. The pulsating flow in porous ducts has many applications in biomedical engineering and in other engineering areas.

XAS AND XPS CHARACTERIZATION OF MERCURY BINDING ON BROMINATED ACTIVATED CARBON

EPA Science Inventory

Brominated powdered activated carbon sorbents have been shown to e quite effective for mercury capture when injected into the flue gas duct at coal-fired power plants and are especially useful when buring Western low-chlorine subbituminous coals. X-ray absorption spectroscopy (X...

Melatonin attenuates oxidative stress, liver damage and hepatocyte apoptosis after bile-duct ligation in rats.

PubMed

Aktas, Cevat; Kanter, Mehmet; Erboga, Mustafa; Mete, Rafet; Oran, Mustafa

2014-10-01

The goal of this study was to evaluate the possible protective effects of melatonin against cholestatic oxidative stress, liver damage and hepatocyte apoptosis in the common rats with bile duct ligation (BDL). A total of 24 male Wistar albino rats were divided into three groups: control, BDL and BDL + received melatonin; each group contains eight animals. Melatonin-treated BDL rats received daily melatonin 100 mg/kg/day via intraperitoneal injection. The application of BDL clearly increased the malondialdehyde (MDA) levels and decreased the superoxide dismutase (SOD) and glutathione (GSH) activities. Melatonin treatment significantly decreased the elevated tissue MDA levels and increased the reduced SOD and GSH enzyme levels in the tissues. The changes demonstrate that the bile duct proliferation and fibrosis in expanded portal tracts include the extension of proliferated bile ducts into lobules, mononuclear cells and neutrophil infiltration into the widened portal areas as observed in the BDL group. The data indicate that melatonin attenuates BDL-induced cholestatic liver injury, bile duct proliferation and fibrosis. The α-smooth muscle actin (α-SMA) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in the BDL were observed to be reduced with the melatonin treatment. These results suggest that administration of melatonin is a potentially beneficial agent to reduce liver damage in BDL by decreasing oxidative stress. © The Author(s) 2012.

Identification of Noise Sources During Rocket Engine Test Firings and a Rocket Launch Using a Microphone Phased-Array

NASA Technical Reports Server (NTRS)

Panda, Jayanta; Mosher, Robert N.; Porter, Barry J.

2013-01-01

A 70 microphone, 10-foot by 10-foot, microphone phased array was built for use in the harsh environment of rocket launches. The array was setup at NASA Wallops launch pad 0A during a static test firing of Orbital Sciences' Antares engines, and again during the first launch of the Antares vehicle. It was placed 400 feet away from the pad, and was hoisted on a scissor lift 40 feet above ground. The data sets provided unprecedented insight into rocket noise sources. The duct exit was found to be the primary source during the static test firing; the large amount of water injected beneath the nozzle exit and inside the plume duct quenched all other sources. The maps of the noise sources during launch were found to be time-dependent. As the engines came to full power and became louder, the primary source switched from the duct inlet to the duct exit. Further elevation of the vehicle caused spilling of the hot plume, resulting in a distributed noise map covering most of the pad. As the entire plume emerged from the duct, and the ondeck water system came to full power, the plume itself became the loudest noise source. These maps of the noise sources provide vital insight for optimization of sound suppression systems for future Antares launches.

Pure 3D laparoscopic living donor right hemihepatectomy in a donor with separate right posterior and right anterior hepatic ducts and portal veins.

PubMed

Hong, Suk Kyun; Suh, Kyung-Suk; Kim, Hyo-Sin; Yoon, Kyung Chul; Ahn, Sung-Woo; Oh, Dongkyu; Kim, Hyeyoung; Yi, Nam-Joon; Lee, Kwang-Woong

2017-11-01

Despite increases in the performance of pure laparoscopic living donor hepatectomy, variations in the bile duct or portal vein have been regarded as relative contraindications to this technique [1-3]. This report describes a donor with separate right posterior and right anterior hepatic ducts and portal veins who underwent pure laparoscopic living donor right hemihepatectomy, integrated with 3D laparoscopy and indocyanine green (ICG) near-infrared fluorescence cholangiography [1, 4, 5]. A 50-year-old man offered to donate part of his liver to his older brother, who required a transplant for hepatitis B-associated liver cirrhosis and hepatocellular carcinoma. Donor height was 178.0 cm, body weight was 82.7 kg, and body mass index was 26.1 kg/m 2 . Preoperative computed tomography and magnetic resonance cholangiopancreatography showed that the donor had separate right posterior and right anterior hepatic ducts and portal veins. The entire procedure was performed under 3D laparoscopic view. Following intravenous injections of 0.05 mg/kg ICG, ICG near-infrared fluorescence camera was used to demarcate the exact transection line and determine the optimal bile duct division point. The total operation time was 443 min; the donor required no transfusions and experienced no intraoperative complications. The graft weighed 1146 g with a graft-to-recipient weight ratio of 1.88%. The optimal bile duct division point was identified using ICG fluorescence cholangiography, and the bile duct was divided with good patency without any stricture. The right anterior and posterior portal veins were transected with endostaplers without any torsion. The patient was discharged on postoperative day 8, with no complications. Using a 3D view and ICG fluorescence cholangiography, pure 3D laparoscopic living donor right hemihepatectomy is feasible in a donor with separate right posterior and right anterior hepatic ducts and portal veins.

Obstructive parotitis secondary to an acute masseteric bend.

PubMed

Reddy, Ryan; White, David R; Gillespie, M Boyd

2012-01-01

To investigate 3 cases of chronic parotitis secondary to an acute bend in Stensen's duct caused by an enlargement of the masseteric space. Three female patients presented with symptoms consistent with obstructive parotitis including glandular swelling and tenderness during meals. A 10-year-old patient had unilateral facial swelling with enlargement of the masseter muscle and mandible later diagnosed as fibrous dysplasia. Salivary endoscopy showed an acute bend in Stensen's duct secondary to a mass effect. The patient's parotid swelling resolved following debulking of the mandibular mass and sialendoscopy with irrigation. Two adult patients with bilateral parotid involvement presented with bilateral masseteric hypertrophy and dental wear facets consistent with bruxism. Salivary endoscopy revealed bilateral kinking of Stensen's duct with jaw closure. Both patients improved symptomatically following nightly bite guard use and ultrasound-guided Botox injections of the masseter muscle and parotid. Obstructive parotitis is rarely caused by an acute masseteric bend. Diagnosis of a kinking Stensen's duct is aided with salivary endoscopy and imaging to determine the precipitating pathology. In the case of masseteric hypertrophy, symptomatic improvement can be achieved with Botox-induced atrophy of masseteric hypertrophy or with surgical reduction for associated fibrous dysplasia. Copyright © 2011 S. Karger AG, Basel.

[Iatrogenic bile duct injuries during the process of laparoscopic cholecystectomy].

PubMed

Qian, G; Wu, M; Zhang, Y

1995-11-01

Twelve patients with iatrogenic bile duct injuries occurred during laparoscopic cholecystectomy (LC) were treated from June 1992 to May 1994. All the patients underwent re-operation and were cured. The causes and characteristics of the injuries were: (1) perforation of the common hepatic or common bile duct caused by dissecting hook (3 cases); (2) necrosis and perforation of the common hepatic duct due to diathermic injury (1 case); (3) clamping of the common hepatic duct by Ti clip (1 case); (4) secondary high bile duct stricture following a failed end-to-end anastomosis or hepatico-cholangio-jejunostomy of the amputated common hepatic duct (5 cases); (5) delayed high bile duct stricture (2 cases). It is emphasized that the severity of bile duct injuries by LC be should not overlooked, and more experience in this field be accumulated to avoid this serious complication.

[Expression of calponin and P63 in human submandibular glands].

PubMed

Lu, Yu-he; Gao, Yan

2007-02-01

To observe the expression of new myoepithelial cell markers calponin and P63 in human submandibular glands. Calponin and P63 antigen in routinely processed human submandibular gland tissues were immunohistochemically demonstrated by monoclonal antibodies to calponin and P63. Calponin expressed around all acinus and intercalated ducts as linear or punctuate pattern. Positive staining was also noted in peripheral area of some thin striated ducts that connect to intercalated ducts. Subulate or trigonal calponin expression was sometimes seen between the duct dells of striated ducts. P63 expressed mainly in the nucleus of the basal cells of excretory duct. Calponin is an ideal gland. P63 labels mainly the basal cells of excretory duct. marker for myoepithelial cells of human submandibular

Coupled parametric design of flow control and duct shape

NASA Technical Reports Server (NTRS)

Florea, Razvan (Inventor); Bertuccioli, Luca (Inventor)

2009-01-01

A method for designing gas turbine engine components using a coupled parametric analysis of part geometry and flow control is disclosed. Included are the steps of parametrically defining the geometry of the duct wall shape, parametrically defining one or more flow control actuators in the duct wall, measuring a plurality of performance parameters or metrics (e.g., flow characteristics) of the duct and comparing the results of the measurement with desired or target parameters, and selecting the optimal duct geometry and flow control for at least a portion of the duct, the selection process including evaluating the plurality of performance metrics in a pareto analysis. The use of this method in the design of inter-turbine transition ducts, serpentine ducts, inlets, diffusers, and similar components provides a design which reduces pressure losses and flow profile distortions.

Experiments and modeling of dilution jet flow fields

NASA Technical Reports Server (NTRS)

Holdeman, James D.

1986-01-01

Experimental and analytical results of the mixing of single, double, and opposed rows of jets with an isothermal or variable-temperature main stream in a straight duct are presented. This study was performed to investigate flow and geometric variations typical of the complex, three-dimensional flow field in the dilution zone of gas-turbine-engine combustion chambers. The principal results, shown experimentally and analytically, were the following: (1) variations in orifice size and spacing can have a significant effect on the temperature profiles; (2) similar distributions can be obtained, independent of orifice diameter, if momentum-flux ratio and orifice spacing are coupled; (3) a first-order approximation of the mixing of jets with a variable-temperature main stream can be obtained by superimposing the main-stream and jets-in-an-isothermal-crossflow profiles; (4) the penetration of jets issuing mixing is slower and is asymmetric with respect to the jet centerplanes, which shift laterally with increasing downstream distance; (5) double rows of jets give temperature distributions similar to those from a single row of equally spaced, equal-area circular holes; (6) for opposed rows of jets, with the orifice centerlines in line, the optimum ratio of orifice spacing to duct height is one-half the optimum value for single-side injection at the same momentum-flux ratiol and (7) for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single-side injection at the same momentum-flux ratio.

Comparison of Mixing Characteristics for Several Fuel Injectors on an Open Plate and in a Ducted Flowpath Configuration at Hypervelocity Flow Conditions

NASA Technical Reports Server (NTRS)

Drozda, Tomasz G.; Shenoy, Rajiv R.; Passe, Bradley J.; Baurle, Robert A.; Drummond, J. Philip

2017-01-01

In order to reduce the cost and complexity associated with fuel injection and mixing experiments for high-speed flows, and to further enable optical access to the test section for nonintrusive diagnostics, the Enhanced Injection and Mixing Project (EIMP) utilizes an open flat plate configuration to characterize inert mixing properties of various fuel injectors for hypervelocity applications. The experiments also utilize reduced total temperature conditions to alleviate the need for hardware cooling. The use of "cold" flows and non-reacting mixtures for mixing experiments is not new, and has been extensively utilized as a screening technique for scramjet fuel injectors. The impact of reduced facility-air total temperature, and the use of inert fuel simulants, such as helium, on the mixing character of the flow has been assessed in previous numerical studies by the authors. Mixing performance was characterized for three different injectors: a strut, a ramp, and a flushwall. The present study focuses on the impact of using an open plate to approximate mixing in the duct. Toward this end, Reynolds-averaged simulations (RAS) were performed for the three fuel injectors in an open plate configuration and in a duct. The mixing parameters of interest, such as mixing efficiency and total pressure recovery, are then computed and compared for the two configurations. In addition to mixing efficiency and total pressure recovery, the combustion efficiency and thrust potential are also computed for the reacting simulations.

Hepatic immunohistochemical localization of the tight junction protein ZO-1 in rat models of cholestasis.

PubMed Central

Anderson, J. M.; Glade, J. L.; Stevenson, B. R.; Boyer, J. L.; Mooseker, M. S.

1989-01-01

Structural alterations in hepatocyte tight junctions accompanying cholestasis were investigated using immunolocalization of ZO-1, the first known protein component of the tight junction. Disruption in the paracellular barrier function of the tight junction has been proposed to allow reflux of bile into the blood. Cholestasis was induced in 210 to 235 g male Sprague-Dawley rats either by five consecutive daily subcutaneous injections of 17-alpha-ethinyl estradiol (0.5 mg/kg/d in propylene glycol) or ligation of the common bile duct for 72 hours. The structural organization of the tight junction was assessed in each model by indirect immunofluorescent and immunoperoxidase staining for ZO-1 on frozen sections of liver and compared with controls. In control, sham-operated, and estradiol-injected animals, ZO-1 localizes in a uniform continuous manner along the margins of the canaliculi. In contrast, bile duct ligation results in the appearance of numerous discontinuities in ZO-1 staining accompanied by dilation or collapse of the lumenal space. Tissue content of the ZO-1 protein, as determined by quantitative immunoblotting, was unaffected in either cholestatic model compared with controls. These findings indicate that the molecular organization of the tight junction can be assessed from immunostaining patterns of ZO-1 in frozen sections of cholestatic livers. Under these experimental conditions, the organization of the tight junction at the level of the ZO-1 protein is altered by bile duct obstruction but not by ethinyl estradiol. Images Figure 1 Figure 2 PMID:2719075

An Overview of Research Activity at the Launch Systems Testbed

NASA Technical Reports Server (NTRS)

Vu, Bruce; Kandula, Max

2003-01-01

This paper summarizes the acoustic testing and analysis activities at the Launch System Testbed (LST) of Kennedy Space Center (KSC). A major goal is to develop passive methods of mitigation of sound from rocket exhaust jets with ducted systems devoid of traditional water injection. Current testing efforts are concerned with the launch-induced vibroacoustic behavior of scaled exhaust jets. Numerical simulations are also developed to study the sound propagation from supersonic jets in free air and through enclosed ducts. Scaling laws accounting for the effects of important parameters such as jet Mach number, jet velocity, and jet temperature on the far-field noise are investigated in order to deduce full-scale environment from small-scale tests.

Monitoring of Grouting Compactness in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers

PubMed Central

Jiang, Tianyong; Kong, Qingzhao; Wang, Wenxi; Huo, Linsheng; Song, Gangbing

2016-01-01

A post-tensioning tendon duct filled with grout can effectively prevent corrosion of the reinforcement, maintain bonding behavior between the reinforcement and concrete, and enhance the load bearing capacity of concrete structures. In practice, grouting of the post-tensioning tendon ducts always causes quality problems, which may reduce structural integrity and service life, and even cause accidents. However, monitoring of the grouting compactness is still a challenge due to the invisibility of the grout in the duct during the grouting process. This paper presents a stress wave-based active sensing approach using piezoceramic transducers to monitor the grouting compactness in real time. A segment of a commercial tendon duct was used as research object in this study. One lead zirconate titanate (PZT) piezoceramic transducer with marble protection, called a smart aggregate (SA), was bonded on the tendon and installed in the tendon duct. Two PZT patch sensors were mounted on the top outside surface of the duct, and one PZT patch sensor was bonded on the bottom outside surface of the tendon duct. In the active sensing approach, the SA was used as an actuator to generate a stress wave and the PZT sensors were utilized to detect the wave response. Cement or grout in the duct functions as a wave conduit, which can propagate the stress wave. If the cement or grout is not fully filled in the tendon duct, the top PZT sensors cannot receive much stress wave energy. The experimental procedures simulated four stages during the grout pouring process, which includes empty status, half grouting, 90% grouting, and full grouting of the duct. Experimental results show that the bottom PZT sensor can detect the signal when the grout level increases towards 50%, when a conduit between the SA and PZT sensor is formed. The top PZT sensors cannot receive any signal until the grout process is completely finished. The wavelet packet-based energy analysis was adopted in this research to compute the total signal energy received by PZT sensors. Experimental results show that the energy levels of the PZT sensors can reflect the degree of grouting compactness in the duct. The proposed method has the potential to be implemented to monitor the tendon duct grouting compactness of the reinforced concrete structures with post tensioning. PMID:27556470

Evaluation of the White Test for the Intraoperative Detection of Bile Leakage

PubMed Central

Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-ad

2012-01-01

We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was compared between the conventional method and the White test. A bile leak was demonstrated in 8 patients (26.7%) by the conventional method and in 19 patients (63.3%) by the White test. In addition, the White test detected a significantly higher number of bile leakage sites compared with the conventional method (Wilcoxon signed-rank test; P < 0.001). The White test is better than the conventional test for the intraoperative detection of bile leakage. Based on our study, we recommend that surgeons investigating bile leakage sites during liver resections should use the White test instead of the conventional bile leakage test. PMID:22547901

Evaluation of the white test for the intraoperative detection of bile leakage.

PubMed

Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-Ad

2012-01-01

We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was compared between the conventional method and the White test. A bile leak was demonstrated in 8 patients (26.7%) by the conventional method and in 19 patients (63.3%) by the White test. In addition, the White test detected a significantly higher number of bile leakage sites compared with the conventional method (Wilcoxon signed-rank test; P < 0.001). The White test is better than the conventional test for the intraoperative detection of bile leakage. Based on our study, we recommend that surgeons investigating bile leakage sites during liver resections should use the White test instead of the conventional bile leakage test.

Lightweight Forms for Epoxy/Aramid Ducts

NASA Technical Reports Server (NTRS)

Mix, E. W.; Anderson, A. N.; Bedford, Donald L., Sr.

1986-01-01

Aluminum mandrels easy to remove. Lightweight aluminum mandrel for shaping epoxy/aramid ducts simplifies and speeds production. In new process, glass-reinforced epoxy/aramid cloth wrapped on aluminum mandrel. Stainless-steel flanges and other hardware fitted on duct and held by simple tooling. Entire assembly placed in oven to cure epoxy. After curing, assembly placed in alkaline bath dissolves aluminum mandrel in about 4 hours. Epoxy/aramid shell ready for use as duct. Aluminum mandrel used to make ducts of various inside diameters up to 6 in. Standard aluminum forms used. Conventional tube-bending equipment produces requisite curves in mandrels.

Design and evaluation of a low nitrogen oxides natural gas-fired conical wire-mesh duct burner for a micro-cogeneration unit

NASA Astrophysics Data System (ADS)

Ramadan, Omar Barka Ab

A novel low NOx conical wire-mesh duct burner was designed, built and tested in the present research. This thesis documents the design process and the in-depth evaluation of this novel duct burner for the development of a more efficient micro-cogeneration unit. This duct burner provides the thermal energy necessary to raise the microturbine exhaust gases temperature to increase the heat recovery capability. The duct burner implements both lean-premixed and surface combustion techniques to achieve low NOx and CO emissions. The design of the duct burner was supported by a qualitative flow visualization study for the duct burner premixer to provide insight into the premixer flow field (mixing process). Different premixer geometries were used to control the homogeneity of the fuel-oxidant mixture at the exit of the duct burner premixer. Laser sheet illumination (LSI) technique was used to capture images of the mixing process, for each configuration studied. A quasi-quantitative analysis technique was developed to rank the different premixer geometries in terms of mixing effectiveness. The premixer geometries that provided better mixing were selected and used for the combustion tests. The full-scale gas-fired duct burner was installed in the exhaust duct of a micro-cogeneration unit for the evaluation. Three wire-mesh burners with different pressure drops were used. Each burner has a conical shape made from FeCrAL alloy mat and was designed based on a heat release per unit area of 2500 kW/m2 and a total heat release of 240kW at 100 percent excess air. The local momentum of the gaseous mixture introduced through the wire-mesh was adjusted so that the flame stabilized outside the burner mesh (surface combustion). Cold flow tests (i.e., the duct burner was off, but the microturbine was running) were conducted to measure the effect of different duct burner geometrical parameters on flow split between the combustion zone and the bypass channel, and on pressure drop across the duct burner. A considerable amount of detailed parametric experimental data was collected to investigate the performance characteristics of the duct burner. The variables studied (firing rate, mass flow ratio, conical burner pressure drop, blockage ratio, conical burner shield length, premixer geometry and inlet conditions) were all found to play an important role on emissions (NOx and CO), overall duct burner pressure drop and flame stability. The range of firing rates at which surface combustion was maintained for the duct burner was defined by direct observation of the burner surface and monitoring of the temperature in the combustion zone. Flame images were captured for qualitative assessment. The combustion tests results presented in this thesis proved that the design procedures that were implemented to design this novel microturbine conical wire-mesh duct burner were successful. During the course of the combustion tests, the duct burner displayed stable, low emissions operation throughout the surface firing rate range of 148 kW to 328 kW (1574 kW/m 2 to 3489 kW/m2). Emissions of less than 5 ppm (corrected to 15 percent 02) for NOx and CO emissions were recorded, while the duct burner successfully raised the microturbine exhaust gases temperature from about 227°C to as high as 700°C. The overall duct burner pressure drop throughout was consistently below the design limit of 249 Pa.

[Notch signaling pathway participates in the differentiation of hepatic progenitor cells into bile duct epithelial cells and progression of hepatic fibrosis in cholestatic liver fibrosis rat].

PubMed

Mu, Y P; Zhang, X; Xu, Y; Fan, W W; Li, X W; Chen, J M; Chen, G F; Liu, P

2017-06-08

Objective: To investigate differentiation direction of hepatic progenitor cells (HPCs) in cholestatic liver fibrosis (CLF), and the role of Notch signaling pathway in the differentiation of HPCs. Methods: A CLF rat model was established by bile duct ligation (BDL) followed by monitoring changes of Notch signal pathway and the cellular origin of proliferating cholangiocytes. After intraperitoneal injection of DAPT (a Notch signaling inhibitor) after bile duct ligation, the progress of liver fibrosis and the proliferation of cholangiocytes after inhibition of the Notch pathway were analyzed. Results: Data showed that bile duct proliferation gradually increased along with inflammatory cell infiltration and proliferating bile duct cells surrounded by abundant collagen in the BDL group. Immunostaining confirmed markedly increased expression of CK19, OV6, Sox9 and EpCAM. In addition, RT-PCR results showed that Notch signaling pathway was activated significantly. Once the Notch signaling pathway was inhibited by DAPT, bile duct proliferation markedly suppressed along with significantly decreased the mRNA expression of CK19, OV6, Sox9 and EpCAM, compared with BDL group [(10.2±0.7) vs . (22.3±0.8), (7.6±1.5) vs . (18.1±3.7), (1.4±0.4) vs . (4.1±1.1), (1.3±0.3) vs . (5.0±1.4), respectively, P <0.01]. Moreover, liver fibrosis was also reduced significantly. Conclusion: Notch signaling activation is required for HPCs differentiation into cholangiocytes in CLF and inhibition of the Notch signaling pathway may offer a therapeutic option for treating CLF.

Development and Testing of a High Level Axial Array Duct Sound Source for the NASA Flow Impedance Test Facility

NASA Technical Reports Server (NTRS)

Johnson, Marty E.; Fuller, Chris R.; Jones, Michael G. (Technical Monitor)

2000-01-01

In this report both a frequency domain method for creating high level harmonic excitation and a time domain inverse method for creating large pulses in a duct are developed. To create controllable, high level sound an axial array of six JBL-2485 compression drivers was used. The pressure downstream is considered as input voltages to the sources filtered by the natural dynamics of the sources and the duct. It is shown that this dynamic behavior can be compensated for by filtering the inputs such that both time delays and phase changes are taken into account. The methods developed maximize the sound output while (i) keeping within the power constraints of the sources and (ii) maintaining a suitable level of reproduction accuracy. Harmonic excitation pressure levels of over 155dB were created experimentally over a wide frequency range (1000-4000Hz). For pulse excitation there is a tradeoff between accuracy of reproduction and sound level achieved. However, the accurate reproduction of a pulse with a maximum pressure level over 6500Pa was achieved experimentally. It was also shown that the throat connecting the driver to the duct makes it difficult to inject sound just below the cut-on of each acoustic mode (pre cut-on loading effect).

Studies of the effects of curvature on dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Srinivasan, Ram; Reynolds, Robert S.; White, Craig D.

1992-01-01

An analytical program was conducted using both three-dimensional numerical and empirical models to investigate the effects of transition liner curvature on the mixing of jets injected into a confined crossflow. The numerical code is of the TEACH type with hybrid numerics; it uses the power-law and SIMPLER algorithms, an orthogonal curvilinear coordinate system, and an algebraic Reynolds stress turbulence model. From the results of the numerical calculations, an existing empirical model for the temperature field downstream of single and multiple rows of jets injected into a straight rectangular duct was extended to model the effects of curvature. Temperature distributions, calculated with both the numerical and empirical models, are presented to show the effects of radius of curvature and inner and outer wall injection for single and opposed rows of cool dilution jets injected into a hot mainstream flow.

Duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma.

PubMed

Wu, Wen-Guang; Gu, Jun; Dong, Ping; Lu, Jian-Hua; Li, Mao-Lan; Wu, Xiang-Song; Yang, Jia-Hua; Zhang, Lin; Ding, Qi-Chen; Weng, Hao; Ding, Qian; Liu, Ying-Bin

2013-04-21

At present, radical resection remains the only effective treatment for patients with hilar cholangiocarcinoma. The surgical approach for R0 resection of hilar cholangiocarcinoma is complex and diverse, but for the biliary reconstruction after resection, almost all surgeons use Roux-en-Y hepaticojejunostomy. A viable alternative to Roux-en-Y reconstruction after radical resection of hilar cholangiocarcinoma has not yet been proposed. We report a case of performing duct-to-duct biliary reconstruction after radical resection of Bismuth IIIa hilar cholangiocarcinoma. End-to-end anastomosis between the left hepatic duct and the distal common bile duct was used for the biliary reconstruction, and a single-layer continuous suture was performed along the bile duct using 5-0 prolene. The patient was discharged favorably without biliary fistula 2 wk later. Evidence for tumor recurrence was not found after an 18 mo follow-up. Performing bile duct end-to-end anastomosis in hilar cholangiocarcinoma can simplify the complex digestive tract reconstruction process.

Radio Frequency Propagation and Performance Assessment Suite (RFPPAS)

DTIC Science & Technology

2016-11-15

Intelligence, Surveillance, and Reconnaissance Clutter-to-Noise Ratio Central Processing Unit Evaporation Duct Climatology Engineer’s Refractive Effects...and maximum trapped wavelength (right) PCS display ...23 12. AREPS surface layer (evaporation duct) climatology regions...evaporation duct profiles computed from surface layer climatological statistics. The impetus for building such a database is to provide a means for instant

5 Percent Ares I Scale Model Acoustic Test: Overpressure Characterization and Analysis

NASA Technical Reports Server (NTRS)

Alvord, David; Casiano, Matthew; McDaniels, Dave

2011-01-01

During the ignition of a ducted solid rocket motor (SRM), rapid expansion of injected hot gases from the motor into a confined volume causes the development of a steep fronted wave. This low frequency transient wave propagates outward from the exhaust duct, impinging the vehicle and ground structures. An unsuppressed overpressure wave can potentially cause modal excitation in the structures and vehicle, subsequently leading to damage. This presentation details the ignition transient f indings from the 5% Ares I Scale Model Acoustic Test (ASMAT). The primary events of the ignition transient environment induced by the SRM are the ignition overpressure (IOP), duct overpressure (DOP), and source overpressure (SOP). The resulting observations include successful knockdown of the IOP environment through use of a Space Shuttle derived IOP suppression system, a potential load applied to the vehicle stemming from instantaneous asymmetrical IOP and DOP wave impingement, and launch complex geometric influences on the environment. The results are scaled to a full-scale Ares I equivalent and compared with heritage data including Ares I-X and both suppressed and unsuppressed Space Shuttle IOP environments.

Indocyanine-green-loaded microballoons for biliary imaging in cholecystectomy

NASA Astrophysics Data System (ADS)

Mitra, Kinshuk; Melvin, James; Chang, Shufang; Park, Kyoungjin; Yilmaz, Alper; Melvin, Scott; Xu, Ronald X.

2012-11-01

We encapsulate indocyanine green (ICG) in poly[(D,L-lactide-co-glycolide)-co-PEG] diblock (PLGA-PEG) microballoons for real-time fluorescence and hyperspectral imaging of biliary anatomy. ICG-loaded microballoons show superior fluorescence characteristics and slower degradation in comparison with pure ICG. The use of ICG-loaded microballoons in biliary imaging is demonstrated in both biliary-simulating phantoms and an ex vivo tissue model. The biliary-simulating phantoms are prepared by embedding ICG-loaded microballoons in agar gel and imaged by a fluorescence imaging module in a Da Vinci surgical robot. The ex vivo model consists of liver, gallbladder, common bile duct, and part of the duodenum freshly dissected from a domestic swine. After ICG-loaded microballoons are injected into the gallbladder, the biliary structure is imaged by both hyperspectral and fluorescence imaging modalities. Advanced spectral analysis and image processing algorithms are developed to classify the tissue types and identify the biliary anatomy. While fluorescence imaging provides dynamic information of movement and flow in the surgical region of interest, data from hyperspectral imaging allow for rapid identification of the bile duct and safe exclusion of any contaminant fluorescence from tissue not part of the biliary anatomy. Our experiments demonstrate the technical feasibility of using ICG-loaded microballoons for biliary imaging in cholecystectomy.

Double-duct liquid metal magnetohydrodynamic engine

DOEpatents

Haaland, Carsten M.

1995-01-01

An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

Double-duct liquid metal magnetohydrodynamic engine

DOEpatents

Haaland, Carsten M.

1997-01-01

An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

SOXAL combined SO{sub x}/NO{sub x} flue gas control demonstration. Quarterly report, April--June 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

AQUATECH Systems, a business unit of Allied-Signal Inc., proposes to demonstrate the technical viability and cost effectiveness of the SOXAL process a combined SO{sub x}/NO{sub x} control process on a 3 MW equivalent flue gas slip stream from Niagara Mohawk Power Corporation, Dunkirk Steam Station Boiler No. 4, a coal fired boiler. The SOXAL process combines 90+% sulfur dioxide removal from the flue gas using a sodium based scrubbing solution and regeneration of the spent scrubbing liquor using AQUATECH Systems` proprietary bipolar membrane technology. This regeneration step recovers a stream of sulfur dioxide suitable for subsequent processing to salable sulfurmore » or sulfuric acid. Additionally 90+% control of NO{sub x} gases can be achieved in combination with conventional urea/methanol injection of NO{sub 2} gas into the duct. The SOXAL process is applicable to both utility and industrial scale boilers using either high or low sulfur coal. The SOXAL demonstration Program began September 10, 1991 and is approximately 22 months in duration.« less

SOXAL combined SO{sub x}/NO{sub x} flue gas control demonstration. Quarterly report, October--December 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

AQUATECH Systems a business unit of Allied-Signal Inc., proposes to demonstrate the technical viability and cost effectiveness of the SOXAL process a combined SO{sub x}/NO{sub x} control process on a 2--3 MW equivalent flue gas slip stream from Niagara Mohawk Power Corporation, Dunkirk Steam Station Boiler {number_sign}4, a coal fired boiler. The SOXAL process combines 90+% sulfur dioxide removal from the flue gas using a sodium based scrubbing solution and regeneration of the spent scrubbing liquor using AQUATECH Systems` proprietary bipolar membrane technology. This regeneration step recovers a stream of sulfur dioxide suitable for subsequent processing to salable sulfur ormore » sulfuric acid. Additionally 90+% control of NO{sub x} gases can be achieved in combination with conventional urea/methanol injection of NO{sub 2} gas into the duct. The SOXAL process is applicable to both utility and industrial scale boilers using either high or low sulfur coal. The SOXAL Demonstration Program began September 10, 1991 and is approximately 22 months in duration.« less

Use of Computational Fluid Dynamics for improving freeze-dryers design and process understanding. Part 2: Condenser duct and valve modelling.

PubMed

Marchisio, Daniele L; Galan, Miquel; Barresi, Antonello A

2018-05-05

This manuscript shows how computational models, mainly based on Computational Fluid Dynamics (CFD), can be used to simulate different parts of an industrial freeze-drying equipment and to properly design them; in particular in this part the duct connecting the chamber with the condenser, with its valves, is considered, while the chamber design and its effect on drying kinetics have been investigated in Part 1. Such an approach allows a much deeper process understanding and assessment of the critical aspects of lyophilisation. This methodology will be demonstrated on freeze-drying equipment of different sizes, investigating influence of valve type (butterfly and mushroom) and shape on duct conductance and critical flow conditions. The role of the inlet and boundary conditions considered has been assessed, also by modelling the whole apparatus including chamber and condenser, and the influence of the duct diameter has been discussed; the results show a little dependence of the relationship between critical mass flux and chamber pressure on the duct size. Results concerning the fluid dynamics of a simple disk valve, a profiled butterfly valve and a mushroom valve installed in a medium size horizontal condenser are presented. Also in these cases the maximum allowable flow when sonic flow conditions are reached can be described by a correlation similar to that found valid for empty ducts; for the mushroom valve the parameters are dependent on the valve opening length. The possibility to use the equivalent length concept, and to extend the validity of the results obtained for empty ducts will be also discussed. Finally the presence of the inert gas modifies the conductance of the duct, reducing the maximum flow rate of water that can be removed through it before the flow is choked; this also requires a proper over-sizing of the duct (or duct-butterfly valve system). Copyright © 2018. Published by Elsevier B.V.

Structure and function of the major ampullate spinning duct of the golden orb weaver, Nephila edulis.

PubMed

Davies, G J G; Knight, D P; Vollrath, F

2013-10-01

Silks are fibres produced by spiders, some insects and even a crustacean, and are formed from protein solution by a pulltrusion process that is not well understood. Here we describe three aspects of the functional anatomy of the spinning apparatus in a spider: (i) changes in the diameter of the duct of the silk gland along its length for individuals at different stages of development, (ii) the correlation between the morphology of the duct and size and (iii) changes in the thickness of the wall of the duct. We conclude that in the distal part of the duct both the lumen's geometry and change in diameter with distance remains remarkably constant as the duct increases in length from moult to moult as the spider grows. This suggests constancy in the region where the nascent silk filament is drawn down within the lumen of the duct, which is likely to be fundamental for forming strong and tough fibres. Copyright © 2013 Elsevier Ltd. All rights reserved.

Dendritic Cells Regulate Treg-Th17 Axis in Obstructive Phase of Bile Duct Injury in Murine Biliary Atresia

PubMed Central

Tang, Shao-tao; Wang, Xin-xing; Cao, Guo-qing; Li, Shuai; Lei, Hai-yan; Zhang, Xi

2015-01-01

Several cell types are considered to be effector cells in bile duct injury in rhesus rotavirus (RRV)-induced experimental biliary atresia (BA). Here, we identified an increased T helper 17 (Th17) cell population in a BA mode. By depleting the Th17 cells, the BA symptoms (onset of jaundice, acholic stools and retarded growth) were attenuated and the survival rate was improved. Furthermore, we found that in mice with BA, the percentage of CD4+CD25highFoxp3+ T regulatory (Treg) cells decreased along with the increased percentage of Th17 cells. However, the absolute numbers of Treg and Th17 cells were both increased in liver of RRV-injected mice compared to saline-injected mice. The proportion of Th17 cells at 7 days post-infection was decreased if Treg cells isolated from normal adult mice, but not Treg cells from the livers of mice with BA, were intraperitoneally transferred on day 5 of life. In vitro experiments also showed that Treg cells from mice with BA had a diminished suppressive effect on Th17 cell generation. To determine the mechanisms, we investigated the production of cytokines in the liver. The level of IL-6, which has been shown to be abundantly secreted by activated dendritic cells (DCs), was remarkably elevated. Importantly, in a Treg/Th17 cell suppression assay, IL-6 was demonstrated to paralyze the Treg cells’ suppressive effect on Th17 cells and eventually the unrestrained increase of Th17 cells contributed to bile duct injury. In conclusion, the DC-regulated Treg-Th17 axis, probably in conjunction with other effector T cells, aggravates progressive inflammatory injury at the time of ductal obstruction. PMID:26325187

First observations of elevated ducts associated with intermittent turbulence in the stable boundary layer over Bosten Lake, China

NASA Astrophysics Data System (ADS)

Sun, Zheng; Ning, Hui; Song, Shihui; Yan, Dongmei

2016-10-01

Nocturnal radiative cooling is a main driver for atmospheric duct formation. Within this atmospheric process, the impacts of intermittent turbulence on ducting have seldom been studied. In this paper, we reported two confusing ducting events observed in the early morning in August 2014 over Bosten Lake, China, when a stable boundary layer (SBL) still survived, by using tethered high-resolution GPS radiosondes. Elevated ducts with strong humidity inversions were observed during the balloon ascents but were absent during observations made upon the balloon descents several minutes later. This phenomenon was initially hypothesized to be attributable to turbulence motions in the SBL, and the connection between the turbulence event and the radar duct was examined by the statistical Thorpe method. Turbulence patches were detected from the ascent profiles but not from the descent profiles. The possible reasons for the duct formation and elimination were discussed in detail. The turbulent transport of moisture in the SBL and the advection due to airflows coming from the lake are the most probable reasons for duct formation. In one case, the downward transport of moisture by turbulence mixing within a Kelvin-Helmholtz billow at the top of the low-level jet resulted in duct elimination. In another case, the passage of density currents originating from the lake may have caused the elimination of the duct. Few studies have attempted to associate intermittent turbulence with radar ducts; thus, this work represents a pioneering study into the connection between turbulent events and atmospheric ducts in a SBL.

Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beal, D.; McIlvaine , J.; Fonorow, K.

2011-11-01

This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition tomore » enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.« less

Spin coating apparatus

DOEpatents

Torczynski, John R.

2000-01-01

A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

Effect of L-cysteine on remote organ injury in rats with severe acute pancreatitis induced by bile-pancreatic duct obstruction.

PubMed

Yang, Li-Juan; Wan, Rong; Shen, Jia-Qing; Shen, Jie; Wang, Xing-Peng

2013-08-01

Remote organ failure occurs in cases of acute pancreatitis (AP); however, the reports on AP induced by pancreatic duct obstruction are rare. In this study we determined the effect of L-cysteine on pancreaticobiliary inflammation and remote organ damage in rats after pancreaticobiliary duct ligation (PBDL). AP was induced by PBDL in rats with 5/0 silk. Sixty rats were randomly divided into 4 groups. Groups A and B were sham-operated groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). Groups C and D were PBDL groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). The tissue samples of the pancreas and remote organs such as the lung, liver, intestine and kidney were subsequently examined for pathological changes under a light microscope. The samples were also stored for the determination of malondialdehyde and glutathione levels. Blood urea nitrogen (BUN), plasma amylase, ALT and AST levels were determined spectrophotometrically using an automated analyzer. Also, we evaluated the effect of L-cysteine on remote organ injury in rats with AP induced by retrograde infusion of 3.5% sodium taurocholate (NaTc) into the bile-pancreatic duct. Varying degrees of injury in the pancreas, lung, liver, intestine and kidney were observed in the rats 24 hours after PBDL. The severity of injury to the lung, liver and intestine was attenuated, while injury status was not changed significantly in the pancreas and kidney after L-cysteine treatment. Oxidative stress was also affected by L-cysteine in PBDL-treated rats. The concentration of tissue malondialdehyde decreased in the pancreas and remote organs of PBDL and L-cysteine administrated rats, and the concentration of glutathione increased more significantly than that of the model control group. However, L-cysteine administration reduced the severity of injury in remote organs but not in the pancreas in rats with NaTc-induced AP. L-cysteine treatment attenuated multiple organ damage at an early stage of AP in rats and modulated the oxidant/antioxidant imbalance.

[The microcirculatory bed of the human epididymis].

PubMed

Aleksieiev, O M

1998-08-01

Based on the material of 24 human epididymides at ages 18 to 54, hemomicrocirculatory bed was studied of epididymis in man with the aid of a complex of morphologic techniques (injection of 20% Chinese ink-gelatine suspension, injection of a weak solution of caustic silver, transmission electron microscopy). It has been ascertained that architectonics and ultrastructural features of various links of the hemomicrocirculatory bed have signs of regional specificity for the subcapsular vascular network, small seminal ducts of caput epididymidis, ductus epididymidis of the head, body and tail of the organ. Reasons are discussed why specific hemomicrocirculatory bed should be caused to develop in different parts of the organ.

Numerical study on the impacts of the bogus data assimilation and sea spray parameterization on typhoon ducts

NASA Astrophysics Data System (ADS)

Fei, Jianfang; Ding, Juli; Huang, Xiaogang; Cheng, Xiaoping; Hu, Xiaohua

2013-06-01

The Weather Research and Forecasting model version 3.2 (WRF v3.2) was used with the bogus data assimilation (BDA) scheme and sea spray parameterization (SSP), and experiments were conducted to assess the impacts of the BDA and SSP on prediction of the typhoon ducting process induced by Typhoon Mindule (2004). The global positioning system (GPS) dropsonde observations were used for comparison. The results show that typhoon ducts are likely to form in every direction around the typhoon center, with the main type of ducts being elevated duct. With the BDA scheme included in the model initialization, the model has a better performance in predicting the existence, distribution, and strength of typhoon ducts. This improvement is attributed to the positive effect of the BDA scheme on the typhoon's ambient boundary layer structure. Sea spray affects typhoon ducts mainly by changing the latent heat (LH) flux at the air-sea interface beyond 270 km from the typhoon center. The strength of the typhoon duct is enhanced when the boundary layer under this duct is cooled and moistened by the sea spray; otherwise, the typhoon duct is weakened. The sea spray induced changes in the air-sea sensible heat (SH) flux and LH flux are concentrated in the maximum wind speed area near the typhoon center, and the changes are significantly weakened with the increase of the radial range.

Premixed Supersonic Combustion (Rev)

DTIC Science & Technology

2015-02-20

the effects of equivalence ratio and inflow gas temperature on flame ignition, propagation, and flameout. This study was performed in collaboration...6 combustor. CFD analysis indicates this feature promotes flame holding in the combustor. The cavity spans the width of the duct and has an...Fig. 1). Figure 2 shows results from a RANS CFD study of several potential strategies based on fuel injection at the upstream end of the isolator

Technical report: gadoxetate-disodium-enhanced 2D R2* mapping: a novel approach for assessing bile ducts in living donors.

PubMed

Fazeli Dehkordy, Soudabeh; Fowler, Kathryn J; Wolfson, Tanya; Igarashi, Saya; Lamas Constantino, Carolina P; Hooker, Jonathan C; Hong, Cheng W; Mamidipalli, Adrija; Gamst, Anthony C; Hemming, Alan; Sirlin, Claude B

2017-10-31

Gadoxetate-disodium (Gd-EOB-DTPA)-enhanced 3D T1- weighted (T1w) MR cholangiography (MRC) is an efficient method to evaluate biliary anatomy due to T1 shortening of excreted contrast in the bile. A method that exploits both T1 shortening and T2* effects may produce even greater bile duct conspicuity. The aim of our study is to determine feasibility and compare the diagnostic performance of two-dimensional (2D) T1w multi-echo (ME) spoiled gradient-recalled-echo (SPGR) derived R2* maps against T1w MRC for bile duct visualization in living liver donor candidates. Ten potential living liver donor candidates underwent pretransplant 3T MRI and were included in our study. Following injection of Gd-EOBDTPA and a 20-min delay, 3D T1w MRC and 2D T1w ME SPGR images were acquired. 2D R2* maps were generated inline by the scanner assuming exponential decay. The 3D T1w MRC and 2D R2* maps were retrospectively and independently reviewed in two separate sessions by three radiologists. Visualization of eight bile duct segments was scored using a 4-point ordinal scale. The scores were compared using mixed effects regression model. Imaging was tolerated by all donors and R2* maps were successfully generated in all cases. Visualization scores of 2D R2* maps were significantly higher than 3D T1w MRC for right anterior (p = 0.003) and posterior (p = 0.0001), segment 2 (p < 0.0001), segment 3 (p = 0.0001), and segment 4 (p < 0.0001) ducts. Gd-EOB-DTPA-enhanced 2D R2* mapping is a feasible method for evaluating the bile ducts in living donors and may be a valuable addition to the living liver donor MR protocol for delineating intrahepatic biliary anatomy.

Novel laparoscopic narrow band imaging for real-time detection of bile leak during hepatectomy: proof of the concept in a porcine model.

PubMed

Diana, Michele; Usmaan, Hameed; Legnèr, Andras; Yu-Yin, Liu; D'Urso, Antonio; Halvax, Peter; Nagao, Yoshihiro; Pessaux, Patrick; Marescaux, Jacques

2016-07-01

Bile leakage is a serious complication occurring in up to 10 % of hepatic resections. Intraoperative detection of bile leakage is challenging, and concomitant blood oozing can mask the presence of bile. Intraductal dye injection [methylene blue or indocyanine green (ICG)] is a validated technique to detect bile leakage. However, this method is time-consuming, particularly in the laparoscopic setting. A novel narrow band imaging (NBI) modality (SPECTRA-A; Karl Storz, Tuttlingen, Germany) allows easy discrimination of the presence of bile, which appears in clear orange, by image processing. The aim of this experimental study was to evaluate SPECTRA-A ability to detect bile leakage. Twelve laparoscopic partial hepatectomies were performed in seven pigs. The common bile duct was clipped distally and dissected, and a catheter was inserted and secured with a suture or a clip. Liver dissection was achieved with an ultrasonic cutting device. Dissection surfaces were checked by frequently switching on the SPECTRA filter to identify the presence of bile leakage. Intraductal ICG injection through the catheter was performed to confirm SPECTRA findings. Three active bile leakages were obtained out of 12 hepatectomies and successfully detected intraoperatively by the SPECTRA. There was complete concordance between NBI and ICG fluorescence detection. No active leaks were found in the remaining cases with both techniques. The leaking area identified was sutured, and SPECTRA was used to assess the success of the repair. The SPECTRA laparoscopic image processing system allows for rapid detection of bile leaks following hepatectomy without any contrast injection.

CARS Temperature Measurements in a Hypersonic Propulsion Test Facility

NASA Technical Reports Server (NTRS)

Jarrett, Olin, Jr.; Smith, M. W.; Antcliff, R. R.; Northam, G. Burt; Cutler, A. D.; Capriotti, D. P.; Taylor, D. J.

1990-01-01

Nonintrusive diagnostic measurements were performed in the supersonic reacting flow of the Hypersonic Propulsion Test Cell 2 at NASA-Langley. A Coherent Anti-stokes Raman Spectroscopy (CARS) system was assembled specifically for the test cell environment. System design considerations were: (1) test cell noise and vibration; (2) contamination from flow field or atmospheric borne dust; (3) unwanted laser or electrically induced combustion (inside or outside the duct); (4) efficient signal collection; (5) signal splitting to span the wide dynamic range present throughout the flow field; (6) movement of the sampling volume in the flow; and (7) modification of the scramjet model duct to permit optical access to the reacting flow with the CARS system. The flow in the duct was a nominal Mach 2 flow with static pressure near one atmosphere. A single perpendicular injector introduced hydrogen into the flow behind a rearward facing step. CARS data was obtained in three planes downstream of the injection region. At least 20 CARS data points were collected at each of the regularly spaced sampling locations in each data plane. Contour plots of scramjet combustor static temperature in a reacting flow region are presented.

Thermal Characteristics and Structure of Fully-Modulated, Turbulent Diffusion Flames in Microgravity

NASA Technical Reports Server (NTRS)

Hermanson, J. C.; Johari, H.; Stocker, D. P.; Hegde, U. G.

2003-01-01

Turbulent jet diffusion flames are studied in microgravity and normal gravity under fully-modulated conditions for a range of injection times and a 50% duty cycle. Diluted ethylene was injected through a 2-mm nozzle at a Reynolds number of 5,000 into an open duct, with a slow oxidizer co-flow. Microgravity tests are conducted in NASA's 2.2 Second Drop Tower. Flames with short injection times and high duty cycle exhibit a marked increase in the ensemble-averaged flame length due to the removal of buoyancy. The cycle-averaged centerline temperature profile reveals higher temperatures in the microgravity flames, especially at the flame tip where the difference is about 200 K. In addition, the cycle-averaged measurements of flame radiation were about 30% to 60% greater in microgravity than in normal gravity.

Experimental studies on islets isolation, purification and function in rats

PubMed Central

Pang, Xinlu; Xue, Wujun; Feng, Xinshun; Tian, Xiaohui; Teng, Yan; Ding, Xiaoming; Pan, Xiaoming; Guo, Qi; He, Xiaoli

2015-01-01

To develop a simple and effective method of islet isolation and purification in rats. Collagenase P was injected into pancreatic duct followed by incubation in water bath to digest the pancreas and isolate islet, then discontinuous gravity gradient purification was used to purify the islet. The purified islets were identified by dithizone staining. The viability of islets was assessed by fluorescence staining of acridine orange (AO) and propidium iodide (PI). The function of purified islets was determined by glucose-stimulated insulin release test and transplantation of rat with streptozocin-induced diabetes. 738±193 islets were recovered after purification. The average purity was 77±13%, the viability of islets was more than 95%. When inspected by glucose stimulation, the secreted insulin concentration was 24.31±5.47 mIU/L when stimulated by low concentration glucose and 37.62±4.29 mIU/L by high concentration glucose. There was significant difference between the two phases (P<0.05). The blood sugar concentration recovered to normal level after two days in the animals with islet transplantation. In conclusion, islets can be procured with good function and shape by using the method of injecting collagenase into pancreatic duct followed by incubation in water bath and purification using discontinuous gravity gradient. PMID:26885021

THE ROLE OF LYMPHOCYTES IN THE SENSITIZATION OF RATS TO RENAL HOMOGRAFTS

PubMed Central

Strober, S.; Gowans, J. L.

1965-01-01

In order to study the role of blood-borne small lymphocytes in the sensitization of rats to renal homografts 2 techniques for the perfusion of isolated rat kidneys were employed: (a) the in vitro perfusion of kidneys with thoracic duct cells suspended in either an artificial medium or in blood; the perfusates were then injected into rats syngeneic with the lymphocyte donors; (b) the in vivo perfusion of kidneys with blood issuing from the femoral artery and returning to the femoral vein of living rats. The degree of sensitization conferred on the recipients by the perfusates was assessed by applying a skin homograft from the kidney donor and scoring the epithelial necrosis at 6 days. The in vitro experiments indicated that parental strain thoracic duct cells, which had passed through an F1 hybrid kidney could confer upon a parental rat sensitivity to an F1 skin graft. Several perfusions with radioactively labelled lymphocytes showed that the injected cells migrated to the lymph nodes and spleen of the recipients Labelled large pyroninophilic cells were occasionally seen in the spleen and lymph nodes of recipients, and it was suggested that these had arisen from the injected cells. Although the in vitro perfusions with blood indicated that renal homografts might sensitize their hosts within 1 hour, the in vivo perfusions suggested that about 5 to 12 hours were required. The more rapid sensitization in vitro was possibly due to the more frequent opportunity for contact between lymphocytes and kidney vascular endothelium which was afforded by the conditions in vitro. PMID:14316949

Generation of Higher Order Modes in a Rectangular Duct

NASA Technical Reports Server (NTRS)

Gerhold, Carl H.; Cabell, Randolph H.; Brown, Donald E.

2004-01-01

Advanced noise control methodologies to reduce sound emission from aircraft engines take advantage of the modal structure of the noise in the duct. This noise is caused by the interaction of rotor wakes with downstream obstructions such as exit guide vanes. Mode synthesis has been accomplished in circular ducts and current active noise control work has made use of this capability to cancel fan noise. The goal of the current effort is to examine the fundamental process of higher order mode propagation through an acoustically treated, curved duct. The duct cross-section is rectangular to permit greater flexibility in representation of a range of duct curvatures. The work presented is the development of a feedforward control system to generate a user-specified modal pattern in the duct. The multiple-error, filtered-x LMS algorithm is used to determine the magnitude and phase of signal input to the loudspeakers to produce a desired modal pattern at a set of error microphones. Implementation issues, including loudspeaker placement and error microphone placement, are discussed. Preliminary results from a 9-3/8 inch by 21 inch duct, using 12 loudspeakers and 24 microphones, are presented. These results demonstrate the ability of the control system to generate a user-specified mode while suppressing undesired modes.

Testicular Busulfan Injection in Mice to Prepare Recipients for Spermatogonial Stem Cell Transplantation Is Safe and Non-Toxic.

PubMed

Qin, YuSheng; Liu, Ling; He, YaNan; Wang, Chen; Liang, MingYuan; Chen, XiaoLi; Hao, HaiSheng; Qin, Tong; Zhao, XueMing; Wang, Dong

2016-01-01

Current methods of administering busulfan to remove the endogenous germ cells cause hematopoietic toxicity, require special instruments and a narrow transplantation time. We use a direct testicular injection of busulfan method for preparing recipients for SSC transplantation. Male ICR mice (recipients) were divided into four groups, and two experimental groups were treated with a bilateral testicular injection of 4 or 6 mg/kg/side busulfan (n = 60 per concentration group). Mice received an intraperitoneal injection (i.p.) of 40 mg/kg busulfan (n = 60, positive control) and bilateral testicular injections of 50% DMSO (n = 60, negative control). Donor SSCs from RFP-transgenic C57BL/6J mice were introduced into the seminiferous tubules of each recipient testis via efferent duct injection on day 16-17 after busulfan treatment. Recipient mice mated with mature female ICR mice and the number of progeny was recorded. The index detected at day 14, 21, 28, 35 and 70 after busulfan treatment. Blood analysis shows that the toxicity of busulfan treated groups was much lower than i.p. injection groups. Fertility was restored in mice treated with busulfan and donor-derived offspring were obtained after SSC transplantation. Our study indicated that intratesticular injection busulfan for the preparation of recipients in mice is safe and feasible.

PMR Graphite Engine Duct Development

NASA Technical Reports Server (NTRS)

Stotler, C. L.; Yokel, S. A.

1989-01-01

The objective was to demonstrate the cost and weight advantages that could be obtained by utilizing the graphite/PMR15 material system to replace titanium in selected turbofan engine applications. The first component to be selected as a basis for evaluation was the outer bypass duct of the General Electric F404 engine. The operating environment of this duct was defined and then an extensive mechanical and physical property test program was conducted using material made by processing techniques which were also established by this program. Based on these properties, design concepts to fabricate a composite version of the duct were established and two complete ducts fabricated. One of these ducts was proof pressure tested and then run successfully on a factory test engine for over 1900 hours. The second duct was static tested to 210 percent design limit load without failure. An improved design was then developed which utilized integral composite end flanges. A complete duct was fabricated and successfully proof pressure tested. The net results of this effort showed that a composite version of the outer duct would be 14 percent lighter and 30 percent less expensive that the titanium duct. The other type of structure chosen for investigation was the F404 fan stator assembly, including the fan stator vanes. It was concluded that it was feasible to utilize composite materials for this type structure but that the requirements imposed by replacing an existing metal design resulted in an inefficient composite design. It was concluded that if composites were to be effectively used in this type structure, the design must be tailored for composite application from the outset.

A simple method for long-term biliary access in large animals.

PubMed

Andrews, J C; Knutsen, C; Smith, P; Prieskorn, D; Crudip, J; Klevering, J; Ensminger, W D

1988-07-01

A simple method to obtain long-term access to the biliary tree in dogs and pigs is presented. In ten dogs and four pigs, a cholecystectomy was performed, the cystic duct isolated, and a catheter inserted into the cut end of the cystic duct. The catheter was connected to a subcutaneous infusion port, producing a closed, internal system to allow long-term access. The catheter placement was successful in three of the pigs and all of the dogs. Thirty-five cholangiograms were obtained in the 13 subjects by accessing the port with a 20 gauge Huber needle and injecting small amounts (4-10 mL) of contrast under fluoroscopic control. Cholangiograms were obtained up to four months after catheter placement without evidence for catheter failure or surgically induced changes in the biliary tree. This model provides a simple, reliable means to obtain serial cholangiograms in a research setting.

Normal injection of helium from swept struts into ducted supersonic flow

NASA Technical Reports Server (NTRS)

Mcclinton, C. R.; Torrence, M. G.

1975-01-01

Recent design studies have shown that airframe-integrated scramjets should include instream mounted, swept-back strut fuel injectors to obtain short combustors. Because there was no data in the literature on mixing characteristics of swept strut fuel injectors, the present investigation was undertaken to provide such data. This investigation was made with two swept struts in a closed duct at Mach number of 4.4 and nominal jet-to-air mass flow ratio of 0.029 with helium used to simulate hydrogen fuel. The data is compared with flat plate mounted normal injector data to obtain the effect of swept struts on mixing. Three injector patterns were evaluated representing the range of hole spacing and jet-to-freestream dynamic pressure ratio of interest. Measured helium concentration, pitot pressure, and static pressure in the downstream mixing region are used to generate contour plots necessary to define the mixing region flow field and the mixing parameters.

Truss-Integrated Thermoformed Ductwork Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steven Winter; Dianne Griffiths; Ravi Gorthala

2007-08-30

This report summarizes a multi-year research effort to develop a leak-free duct system that can be readily installed within the thermal envelope. There are numerous efforts underway to improve duct system efficiency. Most of these involve modifications to current technology such as air sealing techniques like mastic and aeroseal, snap together duct connections, and greater levels of insulation. This project sought to make a more significant stride forward by introducing a duct system of a material that can be more readily sealed and can exhibit lower friction losses. The research focused on the use of smooth internal surface, low frictionmore » plastic ducts that could be easily installed with very low air leakage. The initial system concept that was proposed and researched in Phase I focused on the use of thermoformed plastic ducts installed in a recessed roof truss underneath the attic insulation. A bench top thermoformed system was developed and tested during Phase I of the project. In Phase II, a first generation duct system utilizing a resin impregnated fiberglass duct product was designed and specified. The system was installed and tested in an Atlanta area home. Following this installation research and correspondence with code officials was undertaken to alleviate the continued concern over the code acceptance of plastic ducts in above ground applications. A Committee Interpretation response was received from the International Code Council (ICC) stating that plastic ducts were allowed, but must be manufactured from materials complying with Class 0 or Class 1 rating. With assurance of code acceptance, a plastic duct system using rotomolded high density polyethylene ducts that had passed the material test requirements by impregnating the material with a fire retardant during the molding process was installed in the basement of a new ranch-style home in Madison, WI. A series of measurements to evaluate the performance benefits relative to a similar control house with a standard sheet metal installation were made.« less

Mathematical modeling of flow in the working part of an acousto-convective drying system

NASA Astrophysics Data System (ADS)

Kravchenko, A. S.; Zhilin, A. A.; Fedorova, N. N.

2018-03-01

The objective of this study was to numerically simulate the nonstationary processes occurring in the acoustic-convective dryer (ACD) channel. In the present work, the problem was solved numerically in a three-dimensional formulation taking into account all features of the ACD duct in real geometry. The processes occurring in the ACD duct were simulated using the ANSYS Fluent 18.0 software. The numerical experiments provided an aggregate picture of the working gas flow in the ACD duct with the features near the subsonic nozzle and the cavity. The results of the numerical calculations were compared with experimental data. The best agreement with the experimental data was obtained for the viscosity model neglecting turbulent effects.

Closeup view of the top of Space Shuttle Main Engine ...

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

Close-up view of the top of Space Shuttle Main Engine (SSME) 2057 mounted in a SSME Engine Handler in the Vertical Processing area of the SSME Processing Facility at Kennedy Space Center. The most prominent components in this view is the large Low-Pressure Oxidizer Turbopump (LPOTP) Discharge Duct wrapping itself around the right side of the engine assembly. The smaller tube to the left of LPOTP Discharge Duct is the High-Pressure Oxidizer Duct used to supply the turbine of the LPOTP. The other major feature in this view is the Low-Pressure Fuel Turbopump at the top of the engine assembly. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Analyses of Injection-Coupled Combustion Instability from J-2X Gas Generator Development

NASA Technical Reports Server (NTRS)

Hulka, James R.; Kenny, R. Jeremy; Protz, Chris; Casiano, Matthew

2011-01-01

During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, combustion instabilities were observed near the frequency of the first longitudinal acoustic mode of the hot gas combustion chamber duct. These instabilities were similar to intermediate-frequency or buzz-type instabilities as described in historical programs, except for several aspects: 1) the frequencies were low, in the realm of chug; 2) at times the instability oscillation amplitudes were quite large, with peak-to-peak amplitudes exceeding 50% of the mean chamber pressure along with the appearance of harmonics; 3) the chamber excitation was related to but not exactly at the first longitudinal combustion chamber acoustic mode; and 4) the injector provided mass flow rate oscillations induced by capacitance and inertance effects in the injector rather than by organ pipe resonances of the coaxial oxidizer posts. This type of combustion instability is referred to as "injection coupling" because one critical driving source of the instability is mass flow rate oscillations from the injector. However, the type of injection coupling observed here is different than observed in previous instances of buzz instability with coaxial injectors, because of the lower frequencies and lack of influence from the oxidizer post organ pipe resonances. Test data and preliminary analyses of the initial combustion instabilities were presented in several papers at the 5th Liquid Propulsion Subcommittee meeting. Since that time, additional hot-fire tests with several new hardware configurations have been conducted, and additional analyses have been completed. The analytical models described in previous papers have been updated to include the influences of new geometrical configurations, including a different oxidizer injector manifold configuration and a branch pipe in the hot gas duct that supplies gaseous helium during the start transient to pre-spin the turbine. In addition, the analysis methodology has been revisited to evaluate the potential influence of a combustion response as well as an injection response.

The effect of cleanliness control during installation work on the amount of accumulated dust in ducts of new HVAC installations.

PubMed

Holopainen, R; Tuomainen, M; Asikainen, V; Pasanen, P; Säteri, J; Seppänen, O

2002-09-01

The aim of this study was to evaluate the amount of dust in supply air ducts in recently installed ventilation systems. The samples for the determination of dust accumulation were collected from supply air ducts in 18 new buildings that have been constructed according to two different cleanliness control levels classified as category P1 (low oil residues and protected against contaminations) and category P2, as defined in the Classification of Indoor Climate, Construction and Building Materials. In the ducts installed according to the requirements of cleanliness category P1 the mean amount of accumulated dust was 0.9 g/m2 (0.4-2.9 g/m2), and in the ducts installed according to the cleanliness category P2 it was 2.3 g/m2 (1.2-4.9 g/m2). A significant difference was found in the mean amounts of dust between ducts of categories P1 and P2 (P < 0.008). The cleanliness control procedure in category P1 proved to be a useful and effective tool for preventing dust accumulation in new air ducts during the construction process. Additionally, the ducts without residual oil had lower amounts of accumulated dust indicating that the demand for oil free components in the cleanliness classification is reasonable.

Meibomian gland studies: histologic and ultrastructural investigations.

PubMed

Jester, J V; Nicolaides, N; Smith, R E

1981-04-01

Heightened interest in meibomian gland dysfunction has prompted us to evaluate the normal morphological and ultrastructural characteristics of the meibomian gland. Histologic analysis of human, primate, steer, and rabbit glands revealed evidence of keratinized epithelium extending throughout the meibomian gland duct. Characteristic ultrastructural features of keratinized epithelium identified in primate and rabbit glands included tonofilaments, keratohyaline granules, lamellar bodies, and keratinized squamous cells. Comparison of the meibomian gland duct to the pilosebaceous canal and the sebaceous duct brought out certain dissimilarities such as (1) the lack of a well-developed stratum granulosum and (2) the absence of lipid inclusions within transitional cells from duct to acini. We postulate that abnormalities of the keratinizing process may be responsible for meibomian gland dysfunction states.

Turbofan Duct Propagation Model

NASA Technical Reports Server (NTRS)

Lan, Justin H.; Posey, Joe W. (Technical Monitor)

2001-01-01

The CDUCT code utilizes a parabolic approximation to the convected Helmholtz equation in order to efficiently model acoustic propagation in acoustically treated, complex shaped ducts. The parabolic approximation solves one-way wave propagation with a marching method which neglects backwards reflected waves. The derivation of the parabolic approximation is presented. Several code validation cases are given. An acoustic lining design process for an example aft fan duct is discussed. It is noted that the method can efficiently model realistic three-dimension effects, acoustic lining, and flow within the computational capabilities of a typical computer workstation.

Intraductal delivery of adenoviruses targets pancreatic tumors in transgenic Ela-myc mice and orthotopic xenografts.

PubMed

José, Anabel; Sobrevals, Luciano; Miguel Camacho-Sánchez, Juan; Huch, Meritxell; Andreu, Núria; Ayuso, Eduard; Navarro, Pilar; Alemany, Ramon; Fillat, Cristina

2013-01-01

Gene-based anticancer therapies delivered by adenoviruses are limited by the poor viral distribution into the tumor. In the current work we have explored the feasibility of targeting pancreatic tumors through a loco-regional route. We have taken advantage of the ductal network in the pancreas to retrogradelly inject adenoviruses through the common bile duct in two different mouse models of pancreatic carcinogenesis: The transgenic Ela-myc mice that develop mixed neoplasms displaying both acinar-like and duct-like neoplastic cells affecting the whole pancreas; and mice bearing PANC-1 and BxPC-3 orthotopic xenografts that constitute a model of localized human neoplastic tumors. We studied tumor targeting and the anticancer effects of newly thymidine kinase-engineered adenoviruses both in vitro and in vivo, and conducted comparative studies between intraductal or intravenous administration. Our data indicate that the intraductal delivery of adenovirus efficiently targets pancreatic tumors in the two mouse models. The in vivo application of AduPARTKT plus ganciclovir (GCV) treatment induced tumor regression in Ela-myc mice. Moreover, the intraductal injection of ICOVIR15-TKT oncolytic adenoviruses significantly improved mean survival of mice bearing PANC-1 and BxPC-3 pancreatic xenografts from 30 to 52 days and from 20 to 68 days respectively (p less than 0.0001) when combined with GCV. Of notice, both AduPARTKT and ICOVIR15-TKT antitumoral responses were stronger by ductal viral application than intravenously, in line with the 38-fold increase in pancreas transduction observed upon ductal administration. In summary our data show that cytotoxic adenoviruses retrogradelly injected to the pancreas can be a feasible approach to treat localized pancreatic tumors.

Impact of recombinant globular adiponectin on early warm ischemia-reperfusion injury in rat bile duct after liver transplantation.

PubMed

Xia, Yang; Gong, Jian-Ping

2014-09-19

Adiponectin (APN) is an adipocyte protein with anti-diabetic properties, which has been recently revealed to have anti-inflammatory activity in organ ischemia- reperfusion injury (IRI). However, little is known about its function in bile duct IRI after liver transplantation. Therefore, we investigated whether APN affects early warm IRI in rat bile duct using a liver autologous transplantation model. In our study, rats were randomly divided into three experimental groups: a sham group, a IRI group, and a APN group. The serum enzyme levels and BDISS scores of bile duct histology associated with bile duct injury, decreased after administration of APN. Subsequently, the expression of proinflammatory cytokines, such as tumor necrosis factor(TNF-α),.interleukin-6(IL-6) and myeloperoxidase (MPO) decreased. Furthermore, pretreatment with APN suppressed the activation of nuclear factor-kappa B (NF-κB) (p65), a transcription factor involved in inflammatory reactions, compared to other two groups. Administration of APN also downregulated the expression of Fas protein and attenuated caspase-3 activity to decrease bile duct apoptosis. Our results illustrate that APN protects the rat bile duct against early warm IRI by suppressing the inflammatory response and hepatocyte apoptosis, and NF-κB (p65) plays an important role in this process.

Development of resistance to serotonin-induced itch in bile duct ligated mice.

PubMed

Ostadhadi, Sattar; Haddadi, Nazgol-Sadat; Foroutan, Arash; Azimi, Ehsan; Elmariah, Sarina; Dehpour, Ahmad-Reza

2017-06-01

Cholestatic itch can be severe and significantly impair the quality of life of patients. The serotonin system is implicated in cholestatic itch; however, the pruritogenic properties of serotonin have not been evaluated in cholestatic mice. Here, we investigated the serotonin-induced itch in cholestatic mice which was induced by bile duct ligation (BDL). Serotonin, sertraline or saline were administered intradermally to the rostral back area in BDL and sham operated (SHAM) mice, and the scratching behaviour was videotaped for 1 hour. Bile duct ligated mice had significantly increased scratching responses to saline injection on the seventh day after surgery. Additionally, serotonin or sertraline significantly induced scratching behaviour in BDL mice compared to saline at day 7 after surgery, while it did not induce itch at day 5. The scratching behaviour induced by serotonin or sertraline was significantly less in BDL mice compared to SHAM mice. Likewise, the locomotor activity of BDL or SHAM mice was not significantly different from unoperated (UNOP) mice on the fifth and seventh day, suggesting that the scratching behaviour was not affected by motor dysfunctions. Our data suggest that despite the potentiation of evoked itch, a resistance to serotonin-induced itch is developed in cholestatic mice. © 2017 John Wiley & Sons Australia, Ltd.

Multi-fidelity numerical simulations of shock/turbulent-boundary layer interaction with uncertainty quantification

NASA Astrophysics Data System (ADS)

Bermejo-Moreno, Ivan; Campo, Laura; Larsson, Johan; Emory, Mike; Bodart, Julien; Palacios, Francisco; Iaccarino, Gianluca; Eaton, John

2013-11-01

We study the interaction between an oblique shock wave and the turbulent boundary layers inside a nearly-square duct by combining wall-modeled LES, 2D and 3D RANS simulations, targeting the experiment of Campo, Helmer & Eaton, 2012 (nominal conditions: M = 2 . 05 , Reθ = 6 , 500). A primary objective is to quantify the effect of aleatory and epistemic uncertainties on the STBLI. Aleatory uncertainties considered include the inflow conditions (Mach number of the incoming air stream and thickness of the boundary layers) and perturbations of the duct geometry upstream of the interaction. The epistemic uncertainty under consideration focuses on the RANS turbulence model form by injecting perturbations in the Reynolds stress anisotropy in regions of the flow where the model assumptions (in particular, the Boussinesq eddy-viscosity hypothesis) may be invalid. These perturbations are then propagated through the flow solver into the solution. The uncertainty quantification (UQ) analysis is done through 2D and 3D RANS simulations, assessing the importance of the three-dimensional effects imposed by the nearly-square duct geometry. Wall-modeled LES are used to verify elements of the UQ methodology and to explore the flow features and physics of the STBLI for multiple shock strengths. Financial support from the United States Department of Energy under the PSAAP program is gratefully acknowledged.

THE EFFECT OF PILOCARPINE ON THE OUTPUT OF LYMPHOCYTES THROUGH THE THORACIC DUCT.

PubMed

Rous, F P

1908-05-01

The intravenous injection of pilocarpine nitrate causes in the dog a rapid and considerable increase in the output of lymphocytes through the thoracic duct. The corresponding lymphocytosis induced by the drug in the blood of this animal is not profound, and increased cell-output with the lymph will explain a large part if not all of it. Quickened lymph-flow and dyspnoeic breathing are accessory in the production of the large cell-output with the lymph, but it is mainly dependent on some undetermined element. The evidence points to the mechanical nature of this element. It is probably to be sought in direct pressure from contraction of smooth muscle, as suggested by Harvey, but his observation that atropine prevents the appearance of a lymphocytosis after pilocarpine cannot be quoted in proof because atropine much slows the lymph-flow, and thus decreases cell-output. These findings are in accord with the theory that makes mechanical factors responsible for rapidly appearing lymphocytosis. They show that there are more such factors than has been supposed. Especially do they indicate that the contribution of cells through the thoracic duct may be important in the production of lymphocytosis, and is not, as is often asserted, subsidiary to direct migration into the blood of cells from spleen, bone-marrow and the lymph-glands.

Scramjet mixing establishment times for a pulse facility

NASA Technical Reports Server (NTRS)

Rogers, R. Clayton; Weidner, Elizabeth H.

1991-01-01

A numerical simulation of the temporally developing flow through a generic scramjet combustor duct is presented for stagnation conditions typical of flight at Mach 13 as produced by a shock tunnel pulse facility. The particular focus is to examine the start up transients and to determine the time required for certain flow parameters to become established. The calculations were made with a Navier-Stokes solver SPARK with temporally relaxing inflow conditions derived from operation of the T4 shock tunnel at the University of Queensland in Australia. Calculations at nominal steady inflow conditions were made for comparison. The generic combustor geometry includes the injection of hydrogen fuel from the base of a centrally located strut. In both cases, the flow was assumed laminar and fuel combustion was not included. The establishment process is presented for viscous parameters in the boundary layer and for parameters related to the fuel mixing.

Mixing and NO(x) Emission Calculations of Confined Reacting Jet Flows in a Cylindrical Duct

NASA Technical Reports Server (NTRS)

Holdeman, James D. (Technical Monitor); Oechsle, Victor L.

2003-01-01

Rapid mixing of cold lateral jets with hot cross-stream flows in confined configurations is of practical interest in gas turbine combustors as it strongly affects combustor exit temperature quality, and gaseous emissions in for example rich-lean combustion. It is therefore important to further improve our fundamental understanding of the important processes of dilution jet mixing especially when the injected jet mass flow rate exceeds that of the cross-stream. The results reported in this report describe some of the main flow characteristics which develop in the mixing process in a cylindrical duct. A 3-dimensional tool has been used to predict the mixing flow field characteristics and NOx emission in a quench section of an RQL combustor, Eighteen configurations have been analyzed in a circular geometry in a fully reacting environment simulating the operating condition of an actual RQL gas turbine combustion liner. The evaluation matrix was constructed by varying three parameters: 1) jet-to-mainstream momentum-flux ratio (J), 2) orifice shape or orifice aspect ratio, and 3) slot slant angle. The results indicate that the mixing flow field significantly varies with the value of the jet penetration and subsequently, slanting elongated slots generally improve the mixing uniformity at high J conditions. Round orifices produce more uniform mixing and low NO(x) emissions at low J due to the strong and adequate jet penetration. No significant correlation was found between the NO(x) production rates and the mixing deviation parameters, however, strong correlation was found between NO(x) formation and jet penetration. In the computational results, most of the NO(x) formation occurred behind the orifice starting at the orifice wake region. Additional NO(x) is formed upstream of the orifice in certain configurations with high J conditions due to the upstream recirculation.

The Effect of Botulinum Toxin on an Iatrogenic Sialo-Cutaneous Fistula

PubMed Central

Hong, Seung Eun; Kwon, Jung Woo; Kang, So Ra

2016-01-01

A sialo-cutaneous fistula is a communication between the skin and a salivary gland or duct discharging saliva. Trauma and iatrogenic complications are the most common causes of this condition. Treatments include aspiration, compression, and the administration of systemic anticholinergics; however, their effects are transient and unsatisfactory in most cases. We had a case of a patient who developed an iatrogenic sialo-cutaneous fistula after wide excision of squamous cell carcinoma in the parotid region that was not treated with conventional management, but instead completely resolved with the injection of botulinum toxin. Based on our experience, we recommend the injection of botulinum toxin into the salivary glands, especially the parotid gland, as a conservative treatment option for sialo-cutaneous fistula. PMID:28913292

Albumin to ascites: demonstration of a direct pathway bypassing the systemic circulation

PubMed Central

Zimmon, D. S.; Oratz, M.; Kessler, R.; Schreiber, S. S.; Rothschild, M. A.

1969-01-01

The transport of plasma albumin and newly made albumin into ascitic fluid was studied in eight patients with cirrhosis and ascites. The thoracic duct was cannulated in two patients and lymph collected over a period of 2 hr. Simultaneously albumin-131I and carbonate-14C were injected intravenously. The albumin-131I measured the transfer of plasma albumin into ascites and into thoracic duct lymph. The carbonate-14C, by labeling newly formed albumin, permitted the estimation of the transfer of newly formed albumin into plasma, ascites, and lymph. If the newly synthesized albumin entering ascites and thoracic duct lymph is delivered initially into the plasma, then the ratios of the albumin-14C and -131I in ascites and lymph compared with the content of albumin-14C and -131I in plasma would be identical. However, if some newly formed albumin is delivered directly into ascites or lymph, the ratio for albumin-14C would be higher than that for albumin-131I in lymph or ascites. The ratios of both labeled albumins found in ascites or lymph are expressed as per cent of the total plasma pool. In the eight patients studied 4.2-11.7% of the albumin-14C in plasma was found in ascites in 2 hr whereas only 0.4-2.2% of plasma albumin-131I entered in this same period. In the two patients studied during thoracic duct lymph drainage 6.1 and 13.5% of newly made albumin-14C appeared in lymph in 2 hr whereas only 2.8 and 3.8% of plasma albumin-131I was found in the lymph. In cirrhosis with ascites some newly formed albumin entered ascites and thoracic duct lymph by a direct pathway from the liver bypassing the systemic circulation. PMID:5824072

Systematic use of an intraoperative air leak test at the time of major liver resection reduces the rate of postoperative biliary complications

PubMed Central

Zimmitti, Giuseppe; Vauthey, Jean-Nicolas; Shindoh, Junichi; Tzeng, Ching-Wei D.; Roses, Robert E.; Ribero, Dario; Capussotti, Lorenzo; Giuliante, Felice; Nuzzo, Gennaro; Aloia, Thomas A.

2013-01-01

Objective After hepatectomy, bile leaks remain a major cause of morbidity, cost, and disability. This study was designed to determine if a novel intraoperative Air Leak Test (ALT) would reduce the incidence of post-hepatectomy biliary complications. Study design Rates of postoperative biliary complications were compared between 103 patients who underwent ALT and 120 matched patients operated on before ALT was utilized. All study patients underwent major hepatectomy without bile duct resection at 3 high-volume hepatobiliary centers between 2008 and 2012. ALT was performed by placement of a trans-cystic cholangiogram catheter to inject air into the biliary tree while the upper abdomen was filled with saline and the distal common bile duct was manually occluded. Uncontrolled bile ducts were identified by localization of air bubbles at the transection surface and were directly repaired. Results The 2 groups were similar in diagnosis, chemotherapy use, tumor number and size, resection extent, surgery duration, and blood loss (all p>0.05). Single or multiple uncontrolled bile ducts were intraoperatively detected and repaired in 62.1% of ALT vs. 8.3% of non-ALT patients (p<0.001). This resulted in a lower rate of postoperative bile leaks in ALT (1.9%) vs. non-ALT patients (10.8%, p=0.008). Independent risk factors for postoperative bile leaks included extended hepatectomy (p=0.031), caudate resection (p=0.02), and not performing ALT (p=0.002) [odds ratio (95% Confidence Interval): 3.8 (1.3–11.8), 4.0 (1.1–14.3), and 11.8 (2.4–58.8), respectively]. Conclusion ALT is an easily reproducible test that is highly effective for intraoperative detection and repair of open bile ducts, reducing the rate of postoperative bile leaks. PMID:24246619

Systematic use of an intraoperative air leak test at the time of major liver resection reduces the rate of postoperative biliary complications.

PubMed

Zimmitti, Giuseppe; Vauthey, Jean-Nicolas; Shindoh, Junichi; Tzeng, Ching-Wei D; Roses, Robert E; Ribero, Dario; Capussotti, Lorenzo; Giuliante, Felice; Nuzzo, Gennaro; Aloia, Thomas A

2013-12-01

After hepatectomy, bile leaks remain a major cause of morbidity, cost, and disability. This study was designed to determine if a novel intraoperative air leak test (ALT) would reduce the incidence of post-hepatectomy biliary complications. Rates of postoperative biliary complications were compared among 103 patients who underwent ALT and 120 matched patients operated on before ALT was used. All study patients underwent major hepatectomy without bile duct resection at 3 high-volume hepatobiliary centers between 2008 and 2012. The ALT was performed by placement of a transcystic cholangiogram catheter to inject air into the biliary tree, the upper abdomen was filled with saline, and the distal common bile duct was manually occluded. Uncontrolled bile ducts were identified by localization of air bubbles at the transection surface and were directly repaired. The 2 groups were similar in diagnosis, chemotherapy use, tumor number and size, resection extent, surgery duration, and blood loss (all, p > 0.05). Single or multiple uncontrolled bile ducts were intraoperatively detected and repaired in 62.1% of ALT vs 8.3% of non-ALT patients (p < 0.001). This resulted in a lower rate of postoperative bile leaks in ALT (1.9%) vs non-ALT patients (10.8%; p = 0.008). Independent risk factors for postoperative bile leaks included extended hepatectomy (p = 0.031), caudate resection (p = 0.02), and not performing ALT (p = 0.002) (odds ratio = 3.8; 95% CI, 1.3-11.8; odds ratio = 4.0; 95% CI, 1.1-14.3; and odds ratio = 11.8; 95% CI, 2.4-58.8, respectively). The ALT is an easily reproducible test that is highly effective for intraoperative detection and repair of open bile ducts, reducing the rate of postoperative bile leaks. Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Testicular Busulfan Injection in Mice to Prepare Recipients for Spermatogonial Stem Cell Transplantation Is Safe and Non-Toxic

PubMed Central

Qin, YuSheng; Liu, Ling; He, YaNan; Wang, Chen; Liang, MingYuan; Chen, XiaoLi; Hao, HaiSheng; Qin, Tong; Zhao, XueMing; Wang, Dong

2016-01-01

Current methods of administering busulfan to remove the endogenous germ cells cause hematopoietic toxicity, require special instruments and a narrow transplantation time. We use a direct testicular injection of busulfan method for preparing recipients for SSC transplantation. Male ICR mice (recipients) were divided into four groups, and two experimental groups were treated with a bilateral testicular injection of 4 or 6 mg/kg/side busulfan (n = 60 per concentration group). Mice received an intraperitoneal injection (i.p.) of 40 mg/kg busulfan (n = 60, positive control) and bilateral testicular injections of 50% DMSO (n = 60, negative control). Donor SSCs from RFP-transgenic C57BL/6J mice were introduced into the seminiferous tubules of each recipient testis via efferent duct injection on day 16–17 after busulfan treatment. Recipient mice mated with mature female ICR mice and the number of progeny was recorded. The index detected at day 14, 21, 28, 35 and 70 after busulfan treatment. Blood analysis shows that the toxicity of busulfan treated groups was much lower than i.p. injection groups. Fertility was restored in mice treated with busulfan and donor-derived offspring were obtained after SSC transplantation. Our study indicated that intratesticular injection busulfan for the preparation of recipients in mice is safe and feasible. PMID:26871566

Design and Testing of Non-Toxic RCS Thrusters for Second Generation Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Calvignac, Jacky; Tramel, Terri

2003-01-01

The current NASA Space Shuttle auxiliary propulsion system utilizes nitrogen tetroxide (NTO) and monomethylhydrazine (MMH), hypergolic propellants. This use of these propellants has resulted in high levels of maintenance and precautions that contribute to costly launch operations. By employing alternate propellant combinations, those less toxic to humans, the hazards and time required between missions can be significantly reduced. Use of alternate propellants can thereby increase the efficiency and lower the cost in launch operations. In support of NASA's Space Launch Initiative (SLI), TRW proposed a three-phase project structured to significantly increase the technology readiness of a high-performance reaction control subsystem (RCS) thruster using non-toxic propellant for an operationally efficient and reusable auxiliary propulsion system (APS). The project enables the development of an integrated primary/vernier thruster capable of providing dual-thrust levels of both 1000-lbf class thrust and 25-lbf thrust. The intent of the project is to reduce the risk associated with the development of an improved RCS flight design that meets the primary NASA objectives of improved safety and reliability while reducing systems operations and maintenance costs. TRW proposed two non-toxic auxiliary propulsion engine designs, one using liquid oxygen and liquid hydrogen and the other using liquid oxygen and liquid ethanol, as candidates to meet the goals of reliability and affordability at the RCS level. Both of these propellant combinations offer the advantage of a safe environment for maintenance, while at the same time providing adequate to excellent performance for a conventional liquid propulsion systems. The key enabling technology incorporated in both TRW thrusters is the coaxial liquid on liquid pintle injector. This paper will concentrate on only the design and testing of one of the thrusters, the liquid oxygen (LOX) and liquid hydrogen (LH2) thruster. The LOX/LH2 thruster design includes a LOX-centered pintle injector, consisting of two rows of slots that create a radial spoke spray pattern in the combustion chamber. The main fuel injector creates a continuous sheet of LH2 originating upstream of the LOX pintle injector. The two propellants impinge at the pintle slots, where the resulting momentum ratio and spray pattern determines the combustion efficiency and thermal effects on the hardware. Another enabling technology used in the design of this thruster is fuel film cooling through a duct, lining the inner wall of the combustion chamber barrel section. The duct is also acts as a secondary fuel injection point. The variation in the amount of LH2 used for the duct allows for adjustments in the cooling capacity for the thruster. The Non-Toxic LOX-LH2 RCS Workhorse Thruster was tested at the NASA Marshall Space Flight Center's Test Stand 500. Hot-fire tests were conducted between March 08, 2002 and April 05, 2002. All testing during the program base period were performed at sea-level conditions. During the test program, 7 configurations were tested, including 2 combustion chambers, 3 LOX injector pintle tips, and 4 LH2 injector stroke settings. The operating conditions that were surveyed varied thrust levels, mixture ratio and LH2 duct cooling flow. The copper heat sink chamber was used for 16 burns, each burn lasting from 0.4 to 10 seconds, totaling 51.4 seconds, followed by Haynes chamber testing ranging from 0.9 to 120 seconds, totaling 300.9 seconds. The total accumulated burn time for the test program is 352.3 seconds. C* efficiency was calculated and found to be within expectable limits for most operating conditions. The temperature on the Haynes combustion chamber remained below established material limits, with the exception of one localized hot spot. The test results demonstrate that both the coaxial liquid-on-liquid pintle injector design and fuel duct concepts are viable for the intended application. The thruster head-e design maintained cryogenic injection temperatures while firing, which validates the concept for minimal heat soak back. By injecting fuel into the duct, the throat temperatures were manageable, yet the split of fuel through the cooling duct does not compromise the overall combustion efficiency, which indicates that, provided proper design refinement, such a concept can be applied to a high-performance version of the thruster. These hot fire tests demonstrate the robustness of the duct design concept and good capability to withstand off-nominal operating conditions without adversely impacting the thermal response of the engine, a key design feature for a cryogenic thruster.

Conservation of pancreatic tissue by combined gastric, biliary, and pancreatic duct drainage for pain from chronic pancreatitis.

PubMed

Warshaw, A L

1985-04-01

In patients with chronic pancreatitis, the sclerosing process of the pancreas may constrict not only the pancreatic duct for also the bile duct and duodenum. This study analyzes the prevalence of these obstructive lesions in 58 consecutive patients with chronic pancreatitis requiring surgery for either pain (57 patients) or for painless jaundice (1 patient). There was significant biliary obstruction in 21, 4 of whom also had symptomatic duodenal obstruction. All 21 patients with biliary and duodenal obstruction were among the 38 with a dilated pancreatic duct suitable for pancreaticojejunostomy (modified Puestow procedure). None of the 20 patients with small duct pancreatitis had biliary or duodenal obstruction. Pseudocysts were distributed evenly between the two groups (9 of 38 patients with a dilated duct versus 4 of 20 patients with small duct pancreatitis). Pancreaticojejunostomy combined with choledochoenterostomy and gastrojejunostomy in appropriately selected patients provided good to excellent long-term (mean 3.6 years) relief of pain in 30 of 36 patients (83 percent). There was no correlation between successful relief of pain and development of pancreatic exocrine or endocrine insufficiency or calcification. Stenosis of the bile duct developed some years subsequent to pancreaticojejunostomy in four patients and required a second operation for choledochoenterostomy in three. Three other patients required secondary pancreatic resections due to failure of the pancreaticojejunostomy to relieve pain. It is often possible to effect excellent relief of symptoms with maximal conservation of remaining pancreatic functions despite sclerotic obstruction of multiple organ systems.

Ballooning of the papilla during contrast injection: the semaphore of a choledochocele.

PubMed

Kim, M H; Myung, S J; Lee, S K; Yoo, B M; Seo, D W; Lee, M H; Jung, S A; Kim, Y S; Min, Y I

1998-09-01

Choledochocele is a rare abnormality involving the intramural segment of the common bile duct. ERCP is essential to demonstrate a choledochocele. The aim of this study was to investigate the duodenoscopic and cholangiographic findings during ERCP. Over a 4-year period, 17 symptomatic patients (8 men, 9 women; age range 45 to 83 years) were identified as having choledochoceles. The diagnosis of choledochocele was made by both duodenoscopic and cholangiographic findings. As a characteristic duodenoscopic finding, the enlarged bulging papilla was noted in 8 patients (47%), whereas a normal-appearing papilla was noted in 9 patients (53%) before the injection of contrast media. However, in all 17 patients progressive enlargement or ballooning of the papilla was noted during contrast injection. The maximum diameter of the choledochocele, determined by cholangiography, was significantly larger (19 +/-4 mm) in patients with initially bulging papilla than in those with normal-appearing papilla (9+/-3 mm) (p < 0.05). Ballooning of the papilla during contrast injection may be a specific duodenoscopic finding for choledochocele. To avoid missing the diagnosis of a choledochocele, especially when it is small, it is important to watch the papilla carefully during contrast injection.

Female mating receptivity after injection of male-derived extracts in Callosobruchus maculatus.

PubMed

Yamane, Takashi; Miyatake, Takahisa; Kimura, Yoshinobu

2008-12-01

The effects of male-derived extracts on female receptivity were investigated in Callosobruchus maculatus (Coleoptera: Bruchidae). Injection of aqueous extracts of the male reproductive tract into the abdomen of females reduced receptivity. Aqueous extracts of male reproductive tracts were divided to three molecular weight (MW) fractions by ultrafiltration: Fractions: (I) MW<3 kDa, (II) 3-14 kDa, and (III)>14 kDa. Fraction II reduced female receptivity from 3h after injection, and Fraction III reduced female receptivity from 2 days after injection. On the other hand, no effect on receptivity was found for Fraction I. Furthermore, male reproductive tract organs were divided into accessory gland, testis, and seminal vesicle including the ejaculatory duct. Aqueous extracts of the seminal vesicle reduced receptivity of females immediately following injection, while aqueous extracts of the accessory gland reduced receptivity at the second day. The results suggest that the components of Fraction II existed in the seminal vesicle, and those of Fraction III in the accessory gland. The results of the present and the previous studies in Callosobruchus chinensis, a species closely related to C. maculatus, were compared and are discussed from the viewpoint of the significance of ejaculation in the two species.

Tamoxifen decreases the myofibroblast count in the healing bile duct tissue of pigs

PubMed Central

Siqueira, Orlando Hiroshi Kiono; Filho, Benedito Herani; de Paula, Rafael Erthal; Áscoli, Fábio Otero; da Nóbrega, Antonio Cláudio Lucas; Carvalho, Angela Cristina Gouvêa; Pires, Andréa Rodrigues Cordovil; Gaglionone, Nicolle Cavalcante; Cunha, Karin Soares Gonçalves; Granjeiro, José Mauro

2013-01-01

OBJECTIVE: The aim of this study was to evaluate the effect of oral tamoxifen treatment on the number of myofibroblasts present during the healing process after experimental bile duct injury. METHODS: The sample consisted of 16 pigs that were divided into two groups (the control and study groups). Incisions and suturing of the bile ducts were performed in the two groups. Tamoxifen (20 mg/day) was administered only to the study group. The animals were sacrificed after 30 days. Quantification of myofibroblasts in the biliary ducts was made through immunohistochemistry analysis using anti-alpha smooth muscle actin of the smooth muscle antibody. Immunohistochemical quantification was performed using a digital image system. RESULTS: In the animals treated with tamoxifen (20 mg/day), there was a significant reduction in immunostaining for alpha smooth muscle actin compared with the control group (0.1155 vs. 0.2021, p = 0.046). CONCLUSION: Tamoxifen reduced the expression of alpha smooth muscle actin in the healing tissue after bile duct injury, suggesting a decrease in myofibroblasts in the scarred area of the pig biliary tract. These data suggest that tamoxifen could be used in the prevention of biliary tract stenosis after bile duct surgeries. PMID:23420165

Algorithm of dynamic regulation of a system of duct, for a high accuracy climatic system

NASA Astrophysics Data System (ADS)

Arbatskiy, A. A.; Afonina, G. N.; Glazov, V. S.

2017-11-01

Currently, major part of climatic system, are stationary in projected mode only. At the same time, many modern industrial sites, require constant or periodical changes in technological process. That is 80% of the time, the industrial site is not require ventilation system in projected mode and high precision of climatic parameters must maintain. While that not constantly is in use for climatic systems, which use in parallel for different rooms, we will be have a problem for balance of duct system. For this problem, was created the algorithm for quantity regulation, with minimal changes. Dynamic duct system: Developed of parallel control system of air balance, with high precision of climatic parameters. The Algorithm provide a permanent pressure in main duct, in different a flow of air. Therefore, the ending devises air flow have only one parameter for regulation - flaps open area. Precision of regulation increase and the climatic system provide high precision for temperature and humidity (0,5C for temperature, 5% for relative humidity). Result: The research has been made in CFD-system - PHOENICS. Results for velocity of air in duct, for pressure of air in duct for different operation mode, has been obtained. Equation for air valves positions, with different parameters for climate in room’s, has been obtained. Energy saving potential for dynamic duct system, for different types of a rooms, has been calculated.

Observationally constrained modeling of sound in curved ocean internal waves: examination of deep ducting and surface ducting at short range.

PubMed

Duda, Timothy F; Lin, Ying-Tsong; Reeder, D Benjamin

2011-09-01

A study of 400 Hz sound focusing and ducting effects in a packet of curved nonlinear internal waves in shallow water is presented. Sound propagation roughly along the crests of the waves is simulated with a three-dimensional parabolic equation computational code, and the results are compared to measured propagation along fixed 3 and 6 km source/receiver paths. The measurements were made on the shelf of the South China Sea northeast of Tung-Sha Island. Construction of the time-varying three-dimensional sound-speed fields used in the modeling simulations was guided by environmental data collected concurrently with the acoustic data. Computed three-dimensional propagation results compare well with field observations. The simulations allow identification of time-dependent sound forward scattering and ducting processes within the curved internal gravity waves. Strong acoustic intensity enhancement was observed during passage of high-amplitude nonlinear waves over the source/receiver paths, and is replicated in the model. The waves were typical of the region (35 m vertical displacement). Two types of ducting are found in the model, which occur asynchronously. One type is three-dimensional modal trapping in deep ducts within the wave crests (shallow thermocline zones). The second type is surface ducting within the wave troughs (deep thermocline zones). © 2011 Acoustical Society of America

Partial Müllerian Duct Retention in Smad4 Conditional Mutant Male Mice.

PubMed

Petit, Fabrice G; Deng, Chuxia; Jamin, Soazik P

2016-01-01

Müllerian duct regression is a complex process which involves the AMH signalling pathway. We have previously demonstrated that besides AMH and its specific type II receptor (AMHRII), BMPR-IA and Smad5 are two essential factors implicated in this mechanism. Mothers against decapentaplegic homolog 4 (Smad4) is a transcription factor and the common Smad (co-Smad) involved in transforming growth factor beta (TGF-β) signalling pathway superfamily. Since Smad4 null mutants die early during gastrulation, we have inactivated Smad4 in the Müllerian duct mesenchyme. Specific inactivation of Smad4 in the urogenital ridge leads to the partial persistence of the Müllerian duct in adult male mice. Careful examination of the urogenital tract reveals that the Müllerian duct retention is randomly distributed either on one side or both sides. Histological analysis shows a uterus-like structure, which is confirmed by the expression of estrogen receptor α. As previously described in a β-catenin conditional mutant mouse model, β-catenin contributes to Müllerian duct regression. In our mutant male embryos, it appears that β-catenin expression is locally reduced along the urogenital ridge as compared to control mice. Moreover, the expression pattern is similar to those observed in control female mice. This study shows that reduced Smad4 expression disrupts the Wnt/β-catenin signalling leading to the partial persistence of Müllerian duct.

Response of Propellant Combustion to Unsteady Turbulent Flows.

DTIC Science & Technology

1991-06-01

Proj- ect Manager was Gary L. Vogt. This report has been reviewed and is approved for release and distribution in accor- dance with the distribution...AS RPT 0" DTIC EUSERS UNCLASSIFIED 22a NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (include Area Code) 22c OFFICE SYMBOL Gary Vogt 10-7-2 RFT DO...437. 5. Beddini, R. A. "Injection-Induced Flows in Porous Walled Ducts", AIAA Journal, Vol. 24, Nov. 1986, pp. 1766-1773. 6. Flandro , G. A., "Non-linear

Early development of the zebrafish pronephros and analysis of mutations affecting pronephric function.

PubMed

Drummond, I A; Majumdar, A; Hentschel, H; Elger, M; Solnica-Krezel, L; Schier, A F; Neuhauss, S C; Stemple, D L; Zwartkruis, F; Rangini, Z; Driever, W; Fishman, M C

1998-12-01

The zebrafish pronephric kidney provides a simplified model of nephron development and epithelial cell differentiation which is amenable to genetic analysis. The pronephros consists of two nephrons with fused glomeruli and paired pronephric tubules and ducts. Nephron formation occurs after the differentiation of the pronephric duct with both the glomeruli and tubules being derived from a nephron primordium. Fluorescent dextran injection experiments demonstrate that vascularization of the zebrafish pronephros and the onset of glomerular filtration occurs between 40 and 48 hpf. We isolated fifteen recessive mutations that affect development of the pronephros. All have visible cysts in place of the pronephric tubule at 2-2.5 days of development. Mutants were grouped in three classes: (1) a group of twelve mutants with defects in body axis curvature and manifesting the most rapid and severe cyst formation involving the glomerulus, tubule and duct, (2) the fleer mutation with distended glomerular capillary loops and cystic tubules, and (3) the mutation pao pao tang with a normal glomerulus and cysts limited to the pronephric tubules. double bubble was analyzed as a representative of mutations that perturb the entire length of the pronephros and body axis curvature. Cyst formation begins in the glomerulus at 40 hpf at the time when glomerular filtration is established suggesting a defect associated with the onset of pronephric function. Basolateral membrane protein targeting in the pronephric duct epithelial cells is also severely affected, suggesting a failure in terminal epithelial cell differentiation and alterations in electrolyte transport. These studies reveal the similarity of normal pronephric development to kidney organogenesis in all vertebrates and allow for a genetic dissection of genes needed to establish the earliest renal function.

Aliskiren increases aquaporin-2 expression and attenuates lithium-induced nephrogenic diabetes insipidus.

PubMed

Lin, Yu; Zhang, Tiezheng; Feng, Pinning; Qiu, Miaojuan; Liu, Qiaojuan; Li, Suchun; Zheng, Peili; Kong, Yonglun; Levi, Moshe; Li, Chunling; Wang, Weidong

2017-10-01

The direct renin inhibitor aliskiren has been shown to be retained and persist in medullary collecting ducts even after treatment is discontinued, suggesting a new mechanism of action for this drug. The purpose of the present study was to investigate whether aliskiren regulates renal aquaporin expression in the collecting ducts and improves urinary concentrating defect induced by lithium in mice. The mice were fed with either normal chow or LiCl diet (40 mmol·kg dry food -1 ·day -1 for 4 days and 20 mmol·kg dry food -1 ·day -1 for the last 3 days) for 7 days. Some mice were intraperitoneally injected with aliskiren (50 mg·kg body wt -1 ·day -1 in saline). Aliskiren significantly increased protein abundance of aquaporin-2 (AQP2) in the kidney inner medulla in mice. In inner medulla collecting duct cell suspension, aliskiren markedly increased AQP2 and phosphorylated AQP2 at serine 256 (pS256-AQP2) protein abundance, which was significantly inhibited both by adenylyl cyclase inhibitor MDL-12330A and by PKA inhibitor H89, indicating an involvement of the cAMP-PKA signaling pathway in aliskiren-induced increased AQP2 expression. Aliskiren treatment improved urinary concentrating defect in lithium-treated mice and partially prevented the decrease of AQP2 and pS256-AQP2 protein abundance in the inner medulla of the kidney. In conclusion, the direct renin inhibitor aliskiren upregulates AQP2 protein expression in inner medullary collecting duct principal cells and prevents lithium-induced nephrogenic diabetes insipidus likely via cAMP-PKA pathways. Copyright © 2017 the American Physiological Society.

A tandem mirror plasma source for a hybrid plume plasma propulsion concept

NASA Technical Reports Server (NTRS)

Yang, T. F.; Miller, R. H.; Wenzel, K. W.; Krueger, W. A.; Chang, F. R.

1985-01-01

This paper describes a tandem mirror magnetic plasma confinement device to be considered as a hot plasma source for the hybrid plume rocket concept. The hot plasma from this device is injected into an exhaust duct, which will interact with an annular layer of hypersonic neutral gas. Such a device can be used to study the dynamics of the hybrid plume and to experimentally verify the numerical predictions obtained with computer codes. The basic system design is also geared toward being lightweight and compact, as well as having high power density (i.e., several kW/sq cm) at the exhaust. This feature is aimed toward the feasibility of 'space testing'. The plasma is heated by microwaves. A 50 percent heating efficiency can be obtained by using two half-circle antennas. The preliminary Monte Carlo modeling of test particles result reported here indicates that interaction does take place in the exhaust duct. Neutrals gain energy from the ion, which confirms the hybrid plume concept.

Jet mixing into a heated cross flow in a cylindrical duct: Influence of geometry and flow variations

NASA Technical Reports Server (NTRS)

Hatch, M. S.; Sowa, W. A.; Samuelsen, G. S.; Holdeman, J. D.

1992-01-01

To examine the mixing characteristics of jets in an axi-symmetric can geometry, temperature measurements were obtained downstream of a row of cold jets injected into a heated cross stream. Parametric, non-reacting experiments were conducted to determine the influence of geometry and flow variations on mixing patterns in a cylindrical configuration. Results show that jet to mainstream momentum flux ratio and orifice geometry significantly impact the mixing characteristics of jets in a can geometry. For a fixed number of orifices, the coupling between momentum flux ratio and injector determines (1) the degree of jet penetration at the injection plane, and (2) the extent of circumferential mixing downstream of the injection plane. The results also show that, at a fixed momentum flux ratio, jet penetration decreases with (1) an increase in slanted slot aspect ratio, and (2) an increase in the angle of the slots with respect to the mainstream direction.

MIGRATION OF INTRADERMALLY INJECTED QUANTUM DOTS TO SENTINEL ORGANS IN MICE

PubMed Central

Gopee, Neera V.; Roberts, Dean W.; Webb, Peggy; Cozart, Christy R.; Siitonen, Paul H.; Warbritton, Alan R.; Yu, William W.; Colvin, Vicki L.; Walker, Nigel J.; Howard, Paul C.

2012-01-01

Topical exposure to nanoscale materials is likely from a variety of sources including sunscreens and cosmetics. Because the in vivo disposition of nanoscale materials is not well understood, we have evaluated the distribution of quantum dots (QD) following intradermal injection into female SKH-1 hairless mice as a model system for determining tissue localization following intradermal infiltration. The QD [CdSe core, CdS capped, poly(ethylene glycol) (PEG) coated, 37 nm diameter, 621 nm fluorescence emission] were injected intradermally on the right dorsal flank. Within minutes following intradermal injection, the highly UV fluorescent QD could be observed moving from the injection sites apparently through the lymphatic duct system to regional lymph nodes. Residual fluorescent QD remained at the site of injection until necropsy at 24 hours. Quantification of cadmium and selenium levels after 0, 4, 8, 12 or 24 hours in multiple tissues, using inductively coupled plasma mass spectrometry (ICP-MS) showed a time-dependent loss of cadmium from the injection site, and accumulation in the liver, regional draining lymph nodes, kidney, spleen, and hepatic lymph node. Fluorescence microscopy corroborated the ICP-MS results regarding the tissue distribution of QD. The results indicated that (a) intradermally injected nanoscale QD remained as a deposit in skin and penetrated the surrounding viable subcutis, (b) QD were distributed to draining lymph nodes through the subcutaneous lymphatics and to the liver and other organs, and (c) sentinel organs are effective locations for monitoring transdermal penetration of nanoscale materials into animals. PMID:17404394

Single-Operator Peroral Cholangioscopy for Extraction of Cystic Duct Stones in Postcholecystectomy Mirizzi Syndrome.

PubMed

Jones, Jason Deforest; Pawa, Rishi

2017-01-01

Mirizzi syndrome is an exceptionally rare diagnosis with an annual incidence of less than 1% in developed countries. In this disease process, stone burden in the cystic duct or gallbladder neck leads to common hepatic duct obstruction, either by mechanical compression or secondary inflammation. Mirizzi syndrome is classified into one of four types based on the presence and severity of cholecystobiliary fistulization. Treatment is primarily surgical in nature and largely dictated by the type of Mirizzi syndrome encountered. It is typically diagnosed in the preoperative or operative setting of cholecystectomy; however, there have been rare occurrences of postcholecystectomy diagnosis. Factors thought to predispose to postcholecystectomy disease include low insertion of the cystic duct and long remnant duct length. Few case reports exist describing this phenomenon and its management, which is made exceptionally difficult due to the presence of inflammation and surgical adhesion. We present the case of a young female with postcholecystectomy Mirizzi syndrome who underwent successful endoscopic management using peroral cholangioscopy and electrohydraulic lithotripsy. We also provide a brief overview of both Mirizzi syndrome and peroral cholangioscopy.

The generation of sound by vorticity waves in swirling duct flows

NASA Technical Reports Server (NTRS)

Howe, M. S.; Liu, J. T. C.

1977-01-01

Swirling flow in an axisymmetric duct can support vorticity waves propagating parallel to the axis of the duct. When the cross-sectional area of the duct changes a portion of the wave energy is scattered into secondary vorticity and sound waves. Thus the swirling flow in the jet pipe of an aeroengine provides a mechanism whereby disturbances produced by unsteady combustion or turbine blading can be propagated along the pipe and subsequently scattered into aerodynamic sound. In this paper a linearized model of this process is examined for low Mach number swirling flow in a duct of infinite extent. It is shown that the amplitude of the scattered acoustic pressure waves is proportional to the product of the characteristic swirl velocity and the perturbation velocity of the vorticity wave. The sound produced in this way may therefore be of more significance than that generated by vorticity fluctuations in the absence of swirl, for which the acoustic pressure is proportional to the square of the perturbation velocity. The results of the analysis are discussed in relation to the problem of excess jet noise.

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beach, R.; Burdick, A.

2014-03-01

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Boxmore » Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.« less

Coherent flow structures and heat transfer in a duct with electromagnetic forcing

NASA Astrophysics Data System (ADS)

Himo, Rawad; Habchi, Charbel

2018-04-01

Coherent vortices are generated electromagnetically in a square duct flow. The vortices are induced by a Lorentz force applied in a small section near the entrance of the duct. The flow structure complexity increases with the electromagnetic forcing since the primary vortices propagating along the duct detach to generate secondary smaller streamwise vortices and hairpin-like structures. The Reynolds number based on the mean flow velocity and hydraulic diameter is 500, and five cases were studied by varying the electromagnetic forcing. Even though this Reynolds number is relatively low, a periodic sequence of hairpin-like structure flow was observed for the high forcing cases. This mechanism enhances the mixing process between the different flow regions resulting in an increase in the thermal performances which reaches 66% relative to the duct flow without forcing. In addition to the flow complexity, lower forcing cases remained steady, unlike high Lorentz forces that induced periodic instabilities with a Strouhal number around 0.59 for the transient eddies. The effect of the flow structure on the heat transfer is analyzed qualitatively and quantitatively using numerical simulations based on the finite volume method. Moreover, proper orthogonal decomposition (POD) analysis was performed on the flow structures to evaluate the most energetic modes contributing in the flow. It is found from the POD analysis that the primary streamwise vortices and hairpin legs are the flow structures that are the most contributing to the heat transfer process.

Effect of glandular kallikrein on distal nephron HCO3- secretion in rats and on HCO3- secretion in MDCK cells.

PubMed

Vallés, P; Ebner, S; Manucha, W; Gutierrez, L; Marin-Grez, M

1997-11-01

Renal kallikrein is localized in the connecting tubule cells and secreted into the tubular fluid at late distal nephron segments. The present experiments were performed to further test the hypothesis that renal kallikrein reduces bicarbonate secretion of cortical collecting duct (CCD). The effect of orthograde injections of pig pancreatic kallikrein (1 or 3 micrograms/ml) into the renal tubular system was investigated. Urine fractions (Fr) were collected after a 2-min stop flow. Changes in the urine fraction with respect to those in free-flow urine samples (Ff) were related to the respective polyfructosan (Inutest) ratio. Renal kallikrein activity (Fr:Ff kallikrein/ Fr:Ff polyfructosan) increased significantly in the first two urine fractions collected after glandular kallikrein administration (kallikrein, 1 microgram/ml, P < 0.05; kallikrein, 3 micrograms/ml, P < 0.01). HCO3- secretion of collecting ducts was significantly reduced dose dependently by orthograde and also reduced by retrograde pig pancreatic kallikrein administration. Release of kinins into the fractions was not affected by the retrograde kallikrein injection, even though the kallikrein activity increased considerably (2.26 +/- 0.2 vs. 1.55 +/- 0.2, P < 0.05). Adequacy of retrograde injections for delivering substances to the CCD was demonstrated by injecting colloidal mercury and detecting the appearance of this mercury in the renal cortex by transmission electron microscopy. The integrity of the renal tissue after a retrograde ureteral injection was confirmed by scanning electron microscopy. These results confirm and extend previous data (M. Marin-Grez and P. Vallés. Renal Physiol. Biochem. 17: 301-306, 1994; and M. Marin-Grez, P. Vallés, and P. Odigie. J. Physiol. 488: 163-170, 1995) showing that renal kallikrein reduces bicarbonate secretion at the CCD, probably by inhibiting HCO3- transported by a mechanism unrelated to its kininogenase activity. Support for this assessment was obtained in experiments testing the effect of kallikrein on the luminal bicarbonate secretion of a subpopulation of Madin-Darby canine kidney cells capable of extruding the anion. Kallikrein inhibited HCO3-/Cl- exchange, and the degree of inhibition was dose dependent. This inhibition occurred in the absence of kininogen in the bathing solution.

The effect of activated protein C on experimental acute necrotizing pancreatitis

PubMed Central

Yamenel, Levent; Mas, Mehmet Refik; Comert, Bilgin; Isik, Ahmet Turan; Aydin, Sezai; Mas, Nuket; Deveci, Salih; Ozyurt, Mustafa; Tasci, Ilker; Unal, Tahir

2005-01-01

Introduction Acute pancreatitis is a local inflammatory process that leads to a systemic inflammatory response in the majority of cases. Bacterial contamination has been estimated to occur in 30–40% of patients with necrotizing pancreatitis. Development of pancreatic necrosis depends mainly on the degree of inflammation and on the microvascular circulation of the pancreatic tissue. Activated protein C (APC) is known to inhibit coagulation and inflammation, and to promote fibrinolysis in patients with severe sepsis. We investigated the effects of APC on histopathology, bacterial translocation, and systemic inflammation in experimental acute necrotizing pancreatitis. Materials and method Forty-five male Sprague-Dawley rats were studied. Rats were randomly allocated to three groups. Acute pancreatitis was induced in group II (positive control; n = 15) and group III (treatment; n = 15) rats by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (sham; n = 15) received an injection of normal saline into the common biliopancreatic duct to mimic a pressure effect. Group III rats were treated with intravenous APC 6 hours after induction of pancreatitis. Pancreatic tissue and blood samples were obtained from all animals for histopathological examination and assessment of amylase, tumor necrosis factor-α, and IL-6 levels in serum. Bacterial translocation to pancreas and mesenteric lymph nodes was measured. Results Acute pancreatitis developed in all groups apart from group I (sham), as indicated by microscopic parenchymal necrosis, fat necrosis and abundant turbid peritoneal fluid. Histopathological pancreatitis scores in the APC-treated group were lower than in positive controls (10.31 ± 0.47 versus 14.00 ± 0.52; P < 0.001). Bacterial translocation to mesenteric lymph nodes and to pancreas in the APC-treated group was significantly decreased compared with controls (P < 0.02 and P < 0.007, respectively). Serum amylase, tumor necrosis factor--α, and IL-6 levels were also significantly decreased in comparison with positive controls (P < 0.001, P < 0.04 and P < 0.001, respectively). Conclusion APC improved the severity of pancreatic tissue histology, superinfection rates and serum markers of inflammation during the course of acute necrotizing pancreatitis. PMID:15987389

Research on cylinder processes of gasoline homogenous charge compression ignition (HCCI) engine

NASA Astrophysics Data System (ADS)

Cofaru, Corneliu

2017-10-01

This paper is designed to develop a HCCI engine starting from a spark ignition engine platform. The engine test was a single cylinder, four strokes provided with carburetor. The results of experimental research on this version were used as a baseline for the next phase of the work. After that, the engine was modified for a HCCI configuration, the carburetor was replaced by a direct fuel injection system in order to control precisely the fuel mass per cycle taking into account the measured intake air-mass. To ensure that the air - fuel mixture auto ignite, the compression ratio was increased from 9.7 to 11.5. The combustion process in HCCI regime is governed by chemical kinetics of mixture of air-fuel, rein ducted or trapped exhaust gases and fresh charge. To modify the quantities of trapped burnt gases, the exchange gas system was changed from fixed timing to variable valve timing. To analyze the processes taking place in the HCCI engine and synthesizing a control system, a model of the system which takes into account the engine configuration and operational parameters are needed. The cylinder processes were simulated on virtual model. The experimental research works were focused on determining the parameters which control the combustion timing of HCCI engine to obtain the best energetic and ecologic parameters.

Numerical investigation of the air injection effect on the cavitating flow in Francis hydro turbine

NASA Astrophysics Data System (ADS)

Chirkov, D. V.; Shcherbakov, P. K.; Cherny, S. G.; Skorospelov, V. A.; Turuk, P. A.

2017-09-01

At full and over load operating points, some Francis turbines experience strong self-excited pressure and power oscillations. These oscillations are occuring due to the hydrodynamic instability of the cavitating fluid flow. In many cases, the amplitude of such pulsations may be reduced substantially during the turbine operation by the air injection/ admission below the runner. Such an effect is investigated numerically in the present work. To this end, the hybrid one-three-dimensional model of the flow of the mixture "liquid-vapor" in the duct of a hydroelectric power station, which was proposed previously by the present authors, is augmented by the second gaseous component — the noncondensable air. The boundary conditions and the numerical method for solving the equations of the model are described. To check the accuracy of computing the interface "liquid-gas", the numerical method was applied at first for solving the dam break problem. The algorithm was then used for modeling the flow in a hydraulic turbine with air injection below the runner. It is shown that with increasing flow rate of the injected air, the amplitude of pressure pulsations decreases. The mechanism of the flow structure alteration in the draft tube cone has been elucidated, which leads to flow stabilization at air injection.

Experimental Investigation of a Multiplex Fuel Injector Module With Discrete Jet Swirlers for Low Emission Combustors

NASA Technical Reports Server (NTRS)

Tacina, Robert; Mao, Chien-Pei; Wey, Changlie

2004-01-01

A low-NOx emissions combustor concept has been demonstrated in flame-tube tests. A lean-direct injection (LDI) concept was used where the fuel is injected directly into the flame zone and the overall equivalence ratio of the mixture is lean. The LDI concept described in this report is a multiplex fuel injector module containing multipoint fuel injection tips and multi-burning zones. The injector module comprises 25 equally spaced injection tips within a 76 by 76 mm area that fits into the flame-tube duct. The air swirlers were made from a concave plate on the axis of the fuel injector using drilled holes at an angle to the axis of the fuel injector. The NOx levels were quite low and are greater than 70 percent lower than the 1996 ICAO standard. At an inlet temperature of 810 K, inlet pressure of 2760 kPa, pressure drop of 4 percent and a flame temperature of 1900 K with JP8 fuel, the NOx emission index was 9. The 25-point injector module exhibited the most uniform radial distribution of fuel-air mixture and NOx emissions in the flame tube when compared to other multipoint injection devices. A correlation is developed relating the NOx emissions to inlet temperature, inlet pressure, equivalence ratio and pressure drop.

On-Chip Pressure Generation for Driving Liquid Phase Separations in Nanochannels.

PubMed

Xia, Ling; Choi, Chiwoong; Kothekar, Shrinivas C; Dutta, Debashis

2016-01-05

In this Article, we describe the generation of pressure gradients on-chip for driving liquid phase separations in submicrometer deep channels. The reported pressure-generation capability was realized by applying an electrical voltage across the interface of two glass channel segments with different depths. A mismatch in the electroosmotic flow rate at this junction led to the generation of pressure-driven flow in our device, a fraction of which was then directed to an analysis channel to carry out the desired separation. Experiments showed the reported strategy to be particularly conducive for miniaturization of pressure-driven separations yielding flow velocities in the separation channel that were nearly unaffected upon scaling down the depth of the entire fluidic network. Moreover, the small dead volume in our system allowed for high dynamic control over this pressure gradient, which otherwise was challenging to accomplish during the sample injection process using external pumps. Pressure-driven velocities up to 3.1 mm/s were realized in separation ducts as shallow as 300 nm using our current design for a maximum applied voltage of 3 kV. The functionality of this integrated device was demonstrated by implementing a pressure-driven ion chromatographic analysis that relied on analyte interaction with the nanochannel surface charges to yield a nonuniform solute concentration across the channel depth. Upon coupling such analyte distribution to the parabolic pressure-driven flow profile in the separation duct, a mixture of amino acids could be resolved. The reported assay yielded a higher separation resolution compared to its electrically driven counterpart in which sample migration was realized using electroosmosis/electrophoresis.

[Male pseudohermaphroditism].

PubMed

Fukutani, K

1997-11-01

Male pseudohermaphroditism is a condition of sex differentiation disorders in which the gonads are tests, but the genital ducts and/or external genitalia are incompletely masculinized. This syndrome is caused by a failure of the sequential process in embryonal development of the testis. In the presence of functioning testis the Müllerian ducts regress, while the mesonephric ducts and urogenital sinus differentiate into the internal and external male genitalia. Male pseudohermaphroditism is classified to subtypes according to etiological factors: (1) testicular unresponsiveness to hCG and LH; (2) defect in testosterone biosynthesis; (3) end-organ resistance to androgen; (4) defects in the intracellular metabolism of testosterone; (5) aberrations in testicular organogenesis; (6) defects in anti-Müllerian hormone.

Enhanced absorption of cyclosporin A by complexation with dimethyl-beta-cyclodextrin in bile duct-cannulated and -noncannulated rats.

PubMed

Miyake, K; Arima, H; Irie, T; Hirayama, F; Uekama, K

1999-01-01

The enhancing effects of dimethyl-beta-cyclodextrin (DM-beta-CyD) on the absorption of cyclosporin A (CsA) after oral administration to rats under bile duct-cannulated and -noncannulated conditions were investigated. The dissolution rate of CsA was markedly augmented by complexation with DM-beta-CyD. In a closed loop in situ study, DM-beta-CyD considerably increased the cumulative amounts of CsA in the mesenteric venous blood after injection of the aqueous CsA suspension into the small intestinal sac of rats. In addition, the cumulative amount ratio of M1, the dominant metabolite of CsA in rats, to CsA in the mesenteric venous blood for up to 40 min after the injection of the CsA-DM-beta-CyD suspension into the sac was lower than that of the CsA suspension alone. DM-beta-CyD inhibited the bioconversion of CsA in the small intestinal microsomes of rats. These results indicate that the bioconversion of CsA was abated by complexation with DM-beta-CyD. An in vivo study revealed that DM-beta-CyD increased the transfer of CsA to blood, not lymph, with low variability in the absorption after oral administration of the CsA suspension to rats. The variability of bioavailability of DM-beta-CyD complex was lower than that of Sandimmune, although the extent of bioavailability of DM-beta-CyD was only a little higher than that of Sandimmune. The bioavailability of CsA or its DM-beta-CyD complex was appreciably decreased by the cannulation of the bile duct of rats, and the extent of the lowering in the bioavailability in the presence of DM-beta-CyD was much less serious than that of CsA alone. The present results suggest that DM-beta-CyD is particularly useful in designing oral preparations of CsA with an enhanced bioavailability and a reduced variability in absorption.

Investigation of Counter-Flow in a Heat Pipe-Thermoelectric Generator (HPTEG)

NASA Astrophysics Data System (ADS)

Remeli, Muhammad Fairuz; Singh, Baljit; Affandi, Nor Dalila Nor; Ding, Lai Chet; Date, Abhijit; Akbarzadeh, Aliakbar

2017-05-01

This study explores a method of generating electricity while recovering waste heat through the integration of heat pipes and thermoelectric generators (i.e. HPTEG system). The simultaneous waste heat recovery and power generation processes are achieved without the use of any moving parts. The HPTEG system consists of bismuth telluride thermoelectric generators (TEG), which are sandwiched between two finned pipes to achieve a temperature gradient across the TEG for electricity generation. A counter-flow heat exchanger was built using two separate air ducts. The air ducts were thermally coupled using the HPTEG modules. The evaporator section of the heat pipe absorbed the waste heat in a hot air duct. The heat was then transferred across the TEG surfaces. The condenser section of the HPTEG collected the excess heat from the TEG cold side before releasing it to the cold air duct. A 2-kW electrical heater was installed in the hot air duct to simulate the exhaust gas. An air blower was installed at the inlet of each duct to direct the flow of air into the ducts. A theoretical model was developed for predicting the performance of the HPTEG system using the effectiveness-number of transfer units method. The developed model was able to predict the thermal and electrical output of the HPTEG, along with the rate of heat transfer. The results showed that by increasing the cold air velocity, the effectiveness of the heat exchanger was able to be increased from approximately 52% to 58%. As a consequence of the improved heat transfer, maximum power output of 4.3 W was obtained.

Acid-base interactions during exocrine pancreatic secretion. Primary role for ductal bicarbonate in acinar lumen function.

PubMed

Freedman, S D; Scheele, G A

1994-03-23

The role of acid-base interactions during coordinated acinar and duct cell secretion in the exocrine pancreas is described. The sequence of acid-base events may be summarized as follows: (1) Sorting of secretory proteins and membrane components into the regulated secretory pathway of pancreatic acinar cells is triggered by acid- and calcium-induced aggregation and association mechanisms located in the trans-Golgi network. (2) Cholecystokinin-stimulated exocytosis in acinar cells releases the acidic contents of secretory granules into the acinar lumen. (3) Secretin-stimulated bicarbonate secretion from duct and duct-like cells neutralizes the acidic pH of exocytic contents, which leads to dissociation of protein aggregates and solubilization of (pro)enzymes within the acinar lumen. (4) Stimulated fluid secretion transports solubilized enzymes through the ductal system. (5) Further alkalinization of acinar lumen pH accelerates the enzymatic cleavage of the glycosyl phosphatidyl-inositol anchor associated with GP2 and thus releases the GP2/proteoglycan matrix from lumenal membranes, a process that appears to be required for vesicular retrieval of granule membranes from the apical plasma membrane and their reuse in the secretory process. We conclude that the central function of bicarbonate secretion by centroacinar and duct cells in the pancreas is to neutralize and then alkalinize the pH of the acinar lumen, sequential process that are required for (a) solubilization of secreted proteins and (b) cellular retrieval of granule membranes, respectively.

Pressure gradient induced generation of microbubbles

NASA Astrophysics Data System (ADS)

Evangelio, Alvaro; Campo-Cortes, Francisco; Gordillo, Jose Manuel

2015-11-01

It is well known that the controlled production of monodisperse bubbles possesses uncountable applications in medicine, pharmacy and industry. Here we provide with a detailed physical description of the bubble formation processes taking place in a type of flow where the liquid pressure gradient can be straightforwardly controlled. In our experiments, a gas flow rate discharges through a cylindrical needle into a pressurized chamber. The pressure gradient created from the exit of the injection needle towards the entrance of a extraction duct promotes the stretching of the gas ligament downstream. In our analysis, which is supported by an exhaustive experimental study in which the liquid viscosity is varied by three orders of magnitude, different regimes can be distinguished depending mainly on the Reynolds number. Through our physical modeling, we provide closed expressions for both the bubbling frequencies and for the bubble diameters as well as the conditions under which a monodisperse generation is obtained in all regimes found. The excellent agreement between our expressions and the experimental data fully validates our physical modeling.

A computer simulation of the turbocharged turbo compounded diesel engine system: A description of the thermodynamic and heat transfer models

NASA Technical Reports Server (NTRS)

Assanis, D. N.; Ekchian, J. E.; Frank, R. M.; Heywood, J. B.

1985-01-01

A computer simulation of the turbocharged turbocompounded direct-injection diesel engine system was developed in order to study the performance characteristics of the total system as major design parameters and materials are varied. Quasi-steady flow models of the compressor, turbines, manifolds, intercooler, and ducting are coupled with a multicylinder reciprocator diesel model, where each cylinder undergoes the same thermodynamic cycle. The master cylinder model describes the reciprocator intake, compression, combustion and exhaust processes in sufficient detail to define the mass and energy transfers in each subsystem of the total engine system. Appropriate thermal loading models relate the heat flow through critical system components to material properties and design details. From this information, the simulation predicts the performance gains, and assesses the system design trade-offs which would result from the introduction of selected heat transfer reduction materials in key system components, over a range of operating conditions.

Ignition of lean fuel-air mixtures in a premixing-prevaporizing duct at temperatures up to 1000 K

NASA Technical Reports Server (NTRS)

Tacina, R. R.

1980-01-01

Conditions were determined in a premixing prevaporizing fuel preparation duct at which ignition occurred. An air blast type fuel injector with nineteen fuel injection points was used to provide a uniform spatial fuel air mixture. The range of inlet conditions where ignition occurred were: inlet air temperatures of 600 to 1000 K air pressures of 180 to 660 kPa, equivalence ratios (fuel air ratio divided by stoichiometric fuel air ratio) from 0.12 to 1.05, and velocities from 3.5 to 30 m/s. The duct was insulated and the diameter was 12 cm. Mixing lengths were varied from 16.5 to 47.6 and residence times ranged from 4.6 to 107 ms. The fuel was no. 2 diesel. Results show a strong effect of equivalence ratio, pressure and temperature on the conditions where ignition occurred. The data did not fit the most commonly used model of auto-ignition. A correlation of the conditions where ignition would occur which apply to this test apparatus over the conditions tested is (p/V) phi to the 1.3 power = 0.62 e to the 2804/T power where p is the pressure in kPa, V is the velocity in m/e, phi is the equivalence ratio, and T is the temperature in K. The data scatter was considerable, varying by a maximum value of 5 at a given temperature and equivalence ratio. There was wide spread in the autoignition data contained in the references.

Combination of secretin and fluvastatin ameliorates the polyuria associated with X-linked nephrogenic diabetes insipidus in mice.

PubMed

Procino, Giuseppe; Milano, Serena; Carmosino, Monica; Barbieri, Claudia; Nicoletti, Maria C; Li, Jian H; Wess, Jürgen; Svelto, Maria

2014-07-01

X-linked nephrogenic diabetes insipidus (X-NDI) is a disease caused by inactivating mutations of the vasopressin (AVP) type 2 receptor (V2R) gene. Loss of V2R function prevents plasma membrane expression of the AQP2 water channel in the kidney collecting duct cells and impairs the kidney concentration ability. In an attempt to develop strategies to bypass V2R signaling in X-NDI, we evaluated the effects of secretin and fluvastatin, either alone or in combination, on kidney function in a mouse model of X-NDI. The secretin receptor was found to be functionally expressed in the kidney collecting duct cells. Based on this, X-NDI mice were infused with secretin for 14 days but urinary parameters were not altered by the infusion. Interestingly, secretin significantly increased AQP2 levels in the collecting duct but the protein primarily accumulated in the cytosol. Since we previously reported that fluvastatin treatment increased AQP2 plasma membrane expression in wild-type mice, secretin-infused X-NDI mice received a single injection of fluvastatin. Interestingly, urine production by X-NDI mice treated with secretin plus fluvastatin was reduced by nearly 90% and the urine osmolality was doubled. Immunostaining showed that secretin increased intracellular stores of AQP2 and the addition of fluvastatin promoted AQP2 trafficking to the plasma membrane. Taken together, these findings open new perspectives for the pharmacological treatment of X-NDI.

Combination of secretin and fluvastatin ameliorates the polyuria associated with X-linked nephrogenic diabetes insipidus in mice

PubMed Central

Procino, Giuseppe; Milano, Serena; Carmosino, Monica; Barbieri, Claudia; Nicoletti, Maria C; H. Li, Jian; Wess, Jürgen; Svelto, Maria

2014-01-01

X-linked nephrogenic diabetes insipidus (X-NDI) is a disease caused by inactivating mutations of the vasopressin (AVP) type 2 receptor (V2R) gene. Loss of V2R function prevents plasma membrane expression of the AQP2 water channel in the kidney collecting duct cells and impairs the kidney concentration ability. In an attempt to develop strategies to bypass V2R signaling in X-NDI, we evaluated the effects of secretin and fluvastatin, either alone or in combination, on kidney function in a mouse model of X-NDI. The secretin receptor was found to be functionally expressed in the kidney collecting duct cells. Based on this, X-NDI mice were infused with secretin for 14 days but urinary parameters were not altered by the infusion. Interestingly, secretin significantly increased AQP2 levels in the collecting duct but the protein primarily accumulated in the cytosol. Since we previously reported that fluvastatin treatment increased AQP2 plasma membrane expression in wild-type mice, secretin-infused X-NDI mice received a single injection of fluvastatin. Interestingly, urine production by X-NDI mice treated with secretin plus fluvastatin was reduced by nearly 90% and the urine osmolality was doubled. Immunostaining showed that secretin increased intracellular stores of AQP2 and the addition of fluvastatin promoted AQP2 trafficking to the plasma membrane. Taken together, these findings open new perspectives for the pharmacological treatment of X-NDI. PMID:24522493

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beach, R.; Burdick, A.

2014-03-01

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance. IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations. These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with fourmore » outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.« less

Effectiveness of HVAC duct cleaning procedures in improving indoor air quality.

PubMed

Ahmad, I; Tansel, B; Mitrani, J D

2001-12-01

Indoor air quality has become one of the most serious environmental concerns as an average person spends about 22 hr indoors on a daily basis. The study reported in this article, was conducted to determine the effectiveness of three commercial HVAC (Heating Ventilation Air Conditioning) duct cleaning processes in reducing the level of airborne particulate matter and viable bioaerosols. The three HVAC sanitation processes were: (1) Contact method (use of conventional vacuum cleaning of interior duct surfaces); (2) Air sweep method (use of compressed air to dislodging dirt and debris); (3) Rotary brush method (insertion of a rotary brush into the ductwork to agitate and dislodge the debris). Effectiveness of these sanitation processes was evaluated in terms of airborne particulate and viable bioaerosol concentrations in residential homes. Eight identical homes were selected in the same neighborhood. Two homes were cleaned using each procedure and two were used as controls. It was found that both particle count readings and bioaerosol concentrations were higher when cleaning was being performed than before or after cleaning, which suggests that dirt, debris and other pollutants may become airborne as a result of disturbances caused by the cleaning processes. Particle count readings at 0.3 micron size were found to have increased due to cigarette smoking. Particle counts at 1.0 micron size were reduced due to HVAC duct cleaning. Post-level bioaerosol concentrations, taken two days after cleaning, were found to be lower than the pre-level concentrations suggesting that the cleaning procedures were effective to some extent. Homes cleaned with the Air Sweep procedure showed the highest degree of reduction in bioaerosol concentration among the three procedures investigated.

Decreased collagen types I and IV, laminin, CK-19 and α-SMA expression after bone marrow cell transplantation in rats with liver fibrosis.

PubMed

Carvalho, S N; Lira, D C; Oliveira, G P; Thole, A A; Stumbo, A C; Caetano, C E; Marques, R G; Carvalho, L

2010-11-01

Bone marrow cells have frequently been tested in animal models of liver fibrosis to assess their role in hepatic regeneration. The mononuclear fraction of bone marrow cells is of particular interest, as many studies show that these cells may be beneficial to treat hepatic fibrosis. In this study, we used the bile duct ligation model to induce hepatic fibrosis in an irreversible manner, and rats were treated with bone marrow mononuclear (BMMN) cells after fibrosis was established. Analysis of collagen types I and IV, laminin and α-SMA showed a decreased expression of these proteins in fibrotic livers after 7 days of BMMN cell injection. Moreover, cytokeratin-19 analysis showed a reduction in bile ducts in the BMMN cell-treated group. These results were accompanied by ameliorated levels of hepatic enzymes GPT (Glutamic-pyruvic transaminase), GOT (glutamic-oxaloacetic transaminase) and alkaline phosphatase (AP). Therefore, we showed that BMMN cells decrease hepatic fibrosis by significantly reducing myofibroblast numbers and through reduction of the collagen and laminin-rich extracellular matrix of fibrotic septa and hepatic sinusoids.

Magnetic booster fast ignition macron accelerator

NASA Astrophysics Data System (ADS)

Winterberg, F.

2006-11-01

A new fast ignition scheme was recently proposed where the ignition is done by the impact of a small solid projectile accelerated to velocities in excess of 108cm/s, with the acceleration done in two steps: first, by laser ablation of a flyer plate, and second by injecting the flyer plate into a conical duct. The two principal difficulties of this scheme are as follows: first, the required large mass ratio for the laser ablation rocket propelled flyer plate, and second, the Rayleigh-Taylor instability of the flyer plate during its implosive compression in the conical duct. To overcome these difficulties, it is suggested to accelerate a projectile by a magnetic fusion booster stage, made up of a dense, wall-confined magnetized plasma brought to thermonuclear temperatures. After ignition, this plasma undergoes a thermonuclear excursion greatly increasing its pressure, resulting in the explosion of a weakened segment of the wall, with the segment becoming a fast moving projectile. The maximum velocity this projectile can reach is the velocity of sound of the booster stage plasma, which at a temperature of 108K is of the order 108cm/s.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klingensmith, W.C.; Spitzer, W.M.; Fritzberg, A.R.

Diisopropyl-IDA TC 99m imaging studies were performed in 11 normal subjects in both the fasting and postprandial states. In 5- to 60-minute analog images obtained in both fasting and postprandial studies, the cardiac blood pool was almost never seen, renal pelvic radioactivity was commonly seen, the extrahepatic biliary tract was always seen, and the left hepatic duct was always more prominent than the right hepatic duct. The billiary tract was visualized by ten minutes in nine of 11 fasting studies and 10 of 11 postprandial studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandialmore » studies (p<0.05). The zero- to sixty-minute digital data indicated a greater hepatocyte clearance, an earlier time of peak parenchymal radioactivity, and a faster parenchymal washout in the postprandial studies compared with fasting studies (p<0.05). Approximately nine percent of the injected dose was recovered in the urine during the first three hours in fasting and postprandial studies. The normal diisopropyl-IDA Tc 99m study in the fasting and postprandial states is defined; significant differences exist between the two states.« less

[Bushen Huoxue Fang promotes the apoptosis of epithelial cells in the prostatic ductal system of rats with benign prostatic hyperplasia].

PubMed

Sun, Jie; Li, Qiu-Fen; Tian, Dai-Zhi; Jiang, Shao-Bo; Wu, Xian-De; Qiu, Shun-An; Ren, Xiao-Gang; Li, Yu-Bing

2014-09-01

To investigate the effects of Bushen Huoxue Fang (BSHX) on the apoptosis of epithelial cells in the prostatic ductal system of rats with benign prostatic hyperplasia (BPH) and its possible action mechanism. One hundred 3- month-old male Wistar rats were randomly divided into four groups of equal number (control, castrated, BPH model, and BSHX). BPH models were made by subcutaneous injection of testosterone following castration; the rats in the BSHX group were treated intragastrically with BSHX at 2.34 g/ml after modeling, while those in the other two groups with equal volume of saline, all for 37 days. On the 38th day, all the rats were sacrificed and their prostates harvested for detection of the distribution of TGF-beta1 and alpha-actin and the count of positive cells in the prostatic ductal system by immunohistochemical staining. The apoptosis rate of epithelial cells in the prostatic ductal system was determined by TUNEL assay. The expression of TGF-beta1 was significantly increased in the rats of the BSHX group as compared with the BPH models in both the proximal prostatic duct ([15.28 +/- 4.30]% vs [36.42 +/- 8.10]%, P < 0.01) and the distal prostatic duct ([4.42 +/- 2.07]% vs [8.71 +/- 2.28 ]%, P < 0.05), while the expression of alpha-actin in the proximal duct was remarkably higher in the BSHX-treated rats than in the models ([28.14 +/- 7.43]% vs [18.28 +/- 4.07]%, P < 0.01), but lower than in the control animals ([33.57 +/- 6.85]%, P < 0.05). Compared with the control group, the BPH models and BSHX-treated rats both exhibited markedly decreased apoptosis of epithelial cells in the proximal prostatic duct ([39.42 +/- 9.20]% vs [3.86 +/- 1.34]%, P < 0.01, and [31.14 +/- 5.64]%, P < 0.01) and distal prostatic duct ([17.60 +/- 4.86]% vs [3.07 +/- 1.14]%, P < 0.01, and [12.37 +/- 2.25]%, P < 0.05). The apoptosis rate of epithelial cells in the prostatic ductal system was significantly higher in the BSHX-treated rats than in the BPH models (P < 0.01). By upregulating the expression of TGF-beta, BSHX can suppress the reduction of smooth muscle cells in the proximal prostatic duct, promote the apoptosis of prostatic epithelial cells, and thus effectively inhibit benign prostatic hyperplasia.

SLC26 anion exchangers of guinea pig pancreatic duct: molecular cloning and functional characterization

PubMed Central

Stewart, Andrew K.; Shmukler, Boris E.; Vandorpe, David H.; Reimold, Fabian; Heneghan, John F.; Nakakuki, M.; Akhavein, Arash; Ko, Shigeru; Ishiguro, Hiroshi

2011-01-01

The secretin-stimulated human pancreatic duct secretes HCO3−-rich fluid essential for normal digestion. Optimal stimulation of pancreatic HCO3− secretion likely requires coupled activities of the cystic fibrosis transmembrane regulator (CFTR) anion channel and apical SLC26 Cl−/HCO3− exchangers. However, whereas stimulated human and guinea pig pancreatic ducts secrete ∼140 mM HCO3− or more, mouse and rat ducts secrete ∼40–70 mM HCO3−. Moreover, the axial distribution and physiological roles of SLC26 anion exchangers in pancreatic duct secretory processes remain controversial and may vary among mammalian species. Thus the property of high HCO3− secretion shared by human and guinea pig pancreatic ducts prompted us to clone from guinea pig pancreatic duct cDNAs encoding Slc26a3, Slc26a6, and Slc26a11 polypeptides. We then functionally characterized these anion transporters in Xenopus oocytes and human embryonic kidney (HEK) 293 cells. In Xenopus oocytes, gpSlc26a3 mediated only Cl−/Cl− exchange and electroneutral Cl−/HCO3− exchange. gpSlc26a6 in Xenopus oocytes mediated Cl−/Cl− exchange and bidirectional exchange of Cl− for oxalate and sulfate, but Cl−/HCO3− exchange was detected only in HEK 293 cells. gpSlc26a11 in Xenopus oocytes exhibited pH-dependent Cl−, oxalate, and sulfate transport but no detectable Cl−/HCO3− exchange. The three gpSlc26 anion transporters exhibited distinct pharmacological profiles of 36Cl− influx, including partial sensitivity to CFTR inhibitors Inh-172 and GlyH101, but only Slc26a11 was inhibited by PPQ-102. This first molecular and functional assessment of recombinant SLC26 anion transporters from guinea pig pancreatic duct enhances our understanding of pancreatic HCO3− secretion in species that share a high HCO3− secretory output. PMID:21593449

Detonation wave compression in gas turbines

NASA Technical Reports Server (NTRS)

Wortman, A.

1986-01-01

A study was made of the concept of augmenting the performance of low pressure ratio gas turbines by detonation wave compression of part of the flow. The concept exploits the constant volume heat release of detonation waves to increase the efficiency of the Brayton cycle. In the models studied, a fraction of the compressor output was channeled into detonation ducts where it was processed by transient transverse detonation waves. Gas dynamic studies determined the maximum cycling frequency of detonation ducts, proved that upstream propagation of pressure pulses represented no problems and determined the variations of detonation duct output with time. Mixing and wave compression were used to recombine the combustor and detonation duct flows and a concept for a spiral collector to further smooth the pressure and temperature pulses was presented as an optional component. The best performance was obtained with a single firing of the ducts so that the flow could be re-established before the next detonation was initiated. At the optimum conditions of maximum frequency of the detonation ducts, the gas turbine efficiency was found to be 45 percent while that of a corresponding pressure ratio 5 conventional gas turbine was only 26%. Comparable improvements in specific fuel consumption data were found for gas turbines operating as jet engines, turbofans, and shaft output machines. Direct use of the detonation duct output for jet propulsion proved unsatisfactory. Careful analysis of the models of the fluid flow phenomena led to the conclusion that even more elaborate calculations would not diminish the uncertainties in the analysis of the system. Feasibility of the concept to work as an engine now requires validation in an engineering laboratory experiment.

Expression and localization of sterile alpha motif domain containing 5 is associated with cell type and malignancy of biliary tree

PubMed Central

Harada, Kenichi; Inagaki, Fuyuki F.; Saijou, Eiko; Miura, Yasushi; Nakanuma, Yasuni; Miyajima, Atsushi

2017-01-01

Cholangiocarcinoma (CC) is a type of relatively rare neoplasm in adenocarcinoma. The characteristics of CCs as well as biliary epithelial cells are heterogeneous at the different portion of the biliary tree. There are two candidate stem/progenitor cells of the biliary tree, i.e., biliary tree stem/progenitor cell (BTSC) at the peribiliary gland (PBG) of large bile ducts and liver stem/progenitor cell (LPC) at the canals of Hering of peripheral small bile duct. Although previous reports suggest that intrahepatic CC (ICC) can arise from such stem/progenitor cells, the characteristic difference between BTSC and LPC in pathological process needs further investigation, and the etiology of CC remains poorly understood. Here we show that Sterile alpha motif domain containing 5 (SAMD5) is exclusively expressed in PBGs of large bile ducts in normal mice. Using a mouse model of cholestatic liver disease, we demonstrated that SAMD5 expression was upregulated in the large bile duct at the hepatic hilum, the extrahepatic bile duct and PBGs, but not in proliferating intrahepatic ductules, suggesting that SAMD5 is expressed in BTSC but not LPC. Intriguingly, human ICCs and extrahepatic CCs exhibited striking nuclear localization of SAMD5 while the normal hilar large bile duct displayed slight-to-moderate expression in cytoplasm. In vitro experiments using siRNA for SAMD5 revealed that SAMD5 expression was associated with the cell cycle regulation of CC cell lines. Conclusion: SAMD5 is a novel marker for PBG but not LPC in mice. In humans, the expression and location of SAMD5 could become a promising diagnostic marker for the cell type as well as malignancy of bile ducts and CCs. PMID:28388653

The pelvic kidney of male Ambystoma maculatum (Amphibia, urodela, ambystomatidae) with special reference to the sexual collecting ducts.

PubMed

Siegel, Dustin S; Sever, David M; Aldridge, Robert D

2010-12-01

This study details the gross and microscopic anatomy of the pelvic kidney in male Ambystoma maculatum. The nephron of male Ambystoma maculatum is divided into six distinct regions leading sequentially away from a renal corpuscle: (1) neck segment, which communicates with the coelomic cavity via a ventrally positioned pleuroperitoneal funnel, (2) proximal tubule, (3) intermediate segment, (4) distal tubule, (5) collecting tubule, and (6) collecting duct. The proximal tubule is divided into a vacuolated proximal region and a distal lysosomic region. The basal plasma membrane is modified into intertwining microvillus lamellae. The epithelium of the distal tubule varies little along its length and is demarcated by columns of mitochondria with their long axes oriented perpendicular to the basal lamina. The distal tubule possesses highly interdigitating microvillus lamellae from the lateral membranes and pronounced foot processes of the basal membrane that are not intertwined, but perpendicular to the basal lamina. The collecting tubule is lined by an epithelium with dark and light cells. Light cells are similar to those observed in the distal tuble except with less mitochondria and microvillus lamellae of the lateral and basal plasma membrane. Dark cells possess dark euchromatic nuclei and are filled with numerous small mitochondria. The epithelium of the neck segment, pleuroperitoneal funnel, and intermediate segment is composed entirely of ciliated cells with cilia protruding from only the central portion of the apical plasma membrane. The collecting duct is lined by a highly secretory epithelium that produces numerous membrane bound granules that stain positively for neutral carbohydrates and proteins. Apically positioned ciliated cells are intercalated between secretory cells. The collecting ducts anastomose caudally and unite with the Wolffian duct via a common collecting duct. The Wolffian duct is secretory, but not to the extent of the collecting duct, synthesizes neutral carbohydrates and proteins, and is also lined by apical ciliated cells intercalated between secretory cells. Although functional aspects associated with the morphological variation along the length of the proximal portions of the nephron have been investigated, the role of a highly secretory collecting duct has not. Historical data that implicated secretory activity concordant with mating activity, and similarity of structure and chemistry to sexual segments of the kidneys in other vertebrates, lead us to believe that the collecting duct functions as a secondary sexual organ in Ambystoma maculatum. © 2010 Wiley-Liss, Inc.

Congenital or torsion-induced absence of Fallopian tubes. Two case reports.

PubMed

Paternoster, D M; Costantini, W; Uglietti, A; Vasile, C; Bocconi, L

1998-05-01

Unilateral absence of a uterine tube is an extremely rare finding, for which there are two possible etiopathogenic causes: in some cases it is due to haemorrhage filling of the cavity and its reabsorption as a result of asymptomatic torsion of the uterine tube during adult life, in pediatric age or even during intrauterine life; alternatively, the absence may be congenital, associated with developmental alterations of the mesonephric and paramesonephric ducts. The article presents two cases of fallopian tube absence: a congenital monolateral absence and a tubal torsion during pregnancy. The symptomatology of the torsion of the fallopian tube in pregnancy can be milder than in the classic description with peritoneal reaction and severe clinical alteration. The main risk factors for tubal torsion are: adhesions and inflammatory processes, ovarian cysts, usually of dermoid type, menstrual period, pregnancy, abnormal long mesosalpinx and/or mesovarium, pelvic congestion induced by constipation and disturbed venous blood flow from the adnexa. A congenital defect of the mesonephric duct is followed by a homolateral defect of the paramesonephric duct. The resulting anomaly is characterized by the absence of the uterine tube, uterus-tube angle, kidney and ureter. Partial or total unilateral defects of a paramesonephric duct are more common than aplasia of both ducts. Some authors have suggested that an inadequate blood supply during the descent into the pelvis of the caudal part of the paramesonephric duct might feasibly lead to incomplete tube development.

Automated Breast Ultrasound for Ductal Pattern Reconstruction: Ground Truth File Generation and CADe Evaluation

NASA Astrophysics Data System (ADS)

Manousaki, D.; Panagiotopoulou, A.; Bizimi, V.; Haynes, M. S.; Love, S.; Kallergi, M.

2017-11-01

The purpose of this study was the generation of ground truth files (GTFs) of the breast ducts from 3D images of the Invenia™ Automated Breast Ultrasound System (ABUS) system (GE Healthcare, Little Chalfont, UK) and the application of these GTFs for the optimization of the imaging protocol and the evaluation of a computer aided detection (CADe) algorithm developed for automated duct detection. Six lactating, nursing volunteers were scanned with the ABUS before and right after breastfeeding their infants. An expert in breast ultrasound generated rough outlines of the milk-filled ducts in the transaxial slices of all image volumes and the final GTFs were created by using thresholding and smoothing tools in ImageJ. In addition, a CADe algorithm automatically segmented duct like areas and its results were compared to the expert’s GTFs by estimating true positive fraction (TPF) or % overlap. The CADe output differed significantly from the expert’s but both detected a smaller than expected volume of the ducts due to insufficient contrast (ducts were partially filled with milk), discontinuities, and artifacts. GTFs were used to modify the imaging protocol and improve the CADe method. In conclusion, electronic GTFs provide a valuable tool in the optimization of a tomographic imaging system, the imaging protocol, and the CADe algorithms. Their generation, however, is an extremely time consuming, strenuous process, particularly for multi-slice examinations, and alternatives based on phantoms or simulations are highly desirable.

Multiple jet study data correlations. [data correlation for jet mixing flow of air jets

NASA Technical Reports Server (NTRS)

Walker, R. E.; Eberhardt, R. G.

1975-01-01

Correlations are presented which allow determination of penetration and mixing of multiple cold air jets injected normal to a ducted subsonic heated primary air stream. Correlations were obtained over jet-to-primary stream momentum flux ratios of 6 to 60 for locations from 1 to 30 jet diameters downstream of the injection plane. The range of geometric and operating variables makes the correlations relevant to gas turbine combustors. Correlations were obtained for the mixing efficiency between jets and primary stream using an energy exchange parameter. Also jet centerplane velocity and temperature trajectories were correlated and centerplane dimensionless temperature distributions defined. An assumption of a Gaussian vertical temperature distribution at all stations is shown to result in a reasonable temperature field model. Data are presented which allow comparison of predicted and measured values over the range of conditions specified above.

[Common intralobular microcirculatory module peculliarities in cholestasis in white rats].

PubMed

Sulaberidze, G D; Kardzvia, D Dzh; Kikalishvili, L A; Khomeriki, Ts T

2006-03-01

The dynamics of intralobular microcirculatory module transformation in cholestasis was investigated. The liver tissues of 54 white Wistar rats were studied by Histology, TEM, TEM after injection of 1% Pb(NO(3))(3), vie common bile duct (CBD), SEM of corrosion casts prepared after methylmethacrylate injection vie CBD. It is demonstrated that liver is the basis of microcirculation of 4 different liquids: blood, bile, connective tissue liquid and lymph. Accordingly, in normal condition 4 different well formed compartments bordered from each-others by different types of cells exist. In the yearly stages of cholestasis (3-6 days) the function of bile drainage is partially overtaken by lymph pathways. This is accompanied by the beginning of the destruction of structures bordering above-mentioned microcirculatory beds. In the later stages of cholestasis (12-18 days) the final disorganization of microcirculatory compartments with mixture of all liquids is observed. It is accompanied by increased dystrophy of liver cells population.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aceves, Salvador M.; Ledesma-Orozco, Elias Rigoberto; Espinosa-Loza, Francisco

A pressure vessel apparatus for cryogenic capable storage of hydrogen or other cryogenic gases at high pressure includes an insert with a parallel inlet duct, a perpendicular inlet duct connected to the parallel inlet. The perpendicular inlet duct and the parallel inlet duct connect the interior cavity with the external components. The insert also includes a parallel outlet duct and a perpendicular outlet duct connected to the parallel outlet duct. The perpendicular outlet duct and the parallel outlet duct connect the interior cavity with the external components.

Expression of nestin and chromogranin in regeneration zones of rat pancreas.

PubMed

Ege, Bahadir; Dinc, Tolga; Kayilioglu, Selami Ilgaz; Tezel, Ekmel; Ersoy, Emin

2017-01-01

The particular signals that start and orchestrate the regeneration process in pancreas are not well understood yet. We aimed to investigate the expression of nestin and chromogranin A in pancreatic regeneration zones and a secondary objective, we assessed the efficiency of pancreatic duct ligation method in creation of a pancreatic regeneration model in rats. Partial (90%) pancreatectomy and pancreatic duct ligation were performed in Wistar rats, in order to create pancreatic regeneration models. Pancreatic tissues were examined histologically. Expression profiles were investigated by immunohistochemistry for nestin and chromogranin A. Nestin and chromogranin A expressions were observed in regeneration zones. Pancreatic regenerations zones were seen in pancreatic duct ligation group samples as well as partial pancreatectomy group. Nestin was expressed prominently in acinoductular metaplasia cells in regeneration zones. This was best demonstrated in the samples of pancreatic duct ligation group. In the subsequent sections of nestin positive sites, cytoplasmic positivity with chromogranin A was observed. This study confirms that nestin and chromogranin A can be detected in neogenesis-evoked pancreatic tissue, particularly in the acinoductular epithelium. Nestin and chromogranin A may be important markers to identify pancreatic stem cells. Pancreatic duct ligation can be used for creating pancreatic regeneration model in rats. Chromogranin A, Nestin, Pancreas, Regeneration, Stem cells.

Development of Experimental and Computational Aeroacoustic Tools for Advanced Liner Evaluation

NASA Technical Reports Server (NTRS)

Jones, Michael G.; Watson, Willie R.; Nark, Douglas N.; Parrott, Tony L.; Gerhold, Carl H.; Brown, Martha C.

2006-01-01

Acoustic liners in aircraft engine nacelles suppress radiated noise. Therefore, as air travel increases, increasingly sophisticated tools are needed to maximize noise suppression. During the last 30 years, NASA has invested significant effort in development of experimental and computational acoustic liner evaluation tools. The Curved Duct Test Rig is a 152-mm by 381- mm curved duct that supports liner evaluation at Mach numbers up to 0.3 and source SPLs up to 140 dB, in the presence of user-selected modes. The Grazing Flow Impedance Tube is a 51- mm by 63-mm duct currently being fabricated to operate at Mach numbers up to 0.6 with source SPLs up to at least 140 dB, and will replace the existing 51-mm by 51-mm duct. Together, these test rigs allow evaluation of advanced acoustic liners over a range of conditions representative of those observed in aircraft engine nacelles. Data acquired with these test ducts are processed using three aeroacoustic propagation codes. Two are based on finite element solutions to convected Helmholtz and linearized Euler equations. The third is based on a parabolic approximation to the convected Helmholtz equation. The current status of these computational tools and their associated usage with the Langley test rigs is provided.

Patent ductus arteriosus: patho-physiology, hemodynamic effects and clinical complications.

PubMed

Capozzi, Giovanbattista; Santoro, Giuseppe

2011-10-01

During fetal life, patent arterial duct diverts placental oxygenated blood from the pulmonary artery into the aorta by-passing lungs. After birth, decrease of prostacyclins and prostaglandins concentration usually causes arterial duct closure. This process may be delayed, or may even completely fail in preterm infants with arterial duct still remaining patent. If that happens, blood flow by-pass of the systemic circulation through the arterial duct results in pulmonary overflow and systemic hypoperfusion. When pulmonary flow is 50% higher than systemic flow, a hemodynamic "paradox" results, with an increase of left ventricular output without a subsequent increase of systemic output. Cardiac overload support neuro-humoral effects (activation of sympathetic nervous system and renin-angiotensin system) that finally promote heart failure. Moreover, increased pulmonary blood flow can cause vascular congestion and pulmonary edema. However, the most dangerous effect is cerebral under-perfusion due to diastolic reverse-flow and resulting in cerebral hypoxia. At last, blood flow decreases through the abdominal aorta, reducing perfusion of liver, gut and kidneys and may cause hepatic failure, renal insufficiency and necrotizing enterocolitis. Conclusions Large patent arterial duct may cause life-threatening multi-organ effects. In pre-term infant early diagnosis and timely effective treatment are cornerstones in the prevention of cerebral damage and long-term multi-organ failure.

Relaminarization of fluid flows

NASA Technical Reports Server (NTRS)

Narasimha, R.; Sreenivasan, K. R.

1979-01-01

The mechanisms of the relaminarization of turbulent flows are investigated with a view to establishing any general principles that might govern them. Three basic archetypes of reverting flows are considered: the dissipative type, the absorptive type, and the Richardson type exemplified by a turbulent boundary layer subjected to severe acceleration. A number of other different reverting flows are then considered in the light of the analysis of these archetypes, including radial Poiseuille flow, convex boundary layers, flows reverting by rotation, injection, and suction, as well as heated horizontal and vertical gas flows. Magnetohydrodynamic duct flows are also examined. Applications of flow reversion for turbulence control are discussed.

Feasibility Study of a Pressure-fed Engine for a Water Recoverable Space Shuttle Booster

NASA Technical Reports Server (NTRS)

Gerstl, E.

1972-01-01

Detailed mass properties are presented for a gimbaled, fixed thrust, regeneratively cooled engine having a coaxial pintle injector. The baseline design parameters for this engine are tabulated. Mass properties are also summarized for several other engine configurations i.e., a hinge nozzle using a Techroll seal, a gimbaled duct cooled engine and a regeneratively cooled engine using liquid injection thrust vector control (LITVC). Detailed engine analysis and design trade studies leading to the selection of a regeneratively cooled gimbaled engine and pertaining to the selection of the baseline design configuration are also given.

In vivo multiphoton imaging of bile duct ligation

NASA Astrophysics Data System (ADS)

Liu, Yuan; Li, Feng-Chieh; Chen, Hsiao-Chin; Chang, Po-shou; Yang, Shu-Mei; Lee, Hsuan-Shu; Dong, Chen-Yuan

2008-02-01

Bile is the exocrine secretion of liver and synthesized by hepatocytes. It is drained into duodenum for the function of digestion or drained into gallbladder for of storage. Bile duct obstruction is a blockage in the tubes that carry bile to the gallbladder and small intestine. However, Bile duct ligation results in the changes of bile acids in serum, liver, urine, and feces1, 2. In this work, we demonstrate a novel technique to image this pathological condition by using a newly developed in vivo imaging system, which includes multiphoton microscopy and intravital hepatic imaging chamber. The images we acquired demonstrate the uptake, processing of 6-CFDA in hepatocytes and excretion of CF in the bile canaliculi. In addition to imaging, we can also measure kinetics of the green fluorescence intensity.

Numerical simulations of an impinging liquid spray in a cross-flow

NASA Astrophysics Data System (ADS)

Gomatam, Sreekar; Vengadesan, S.; Chakravarthy, S. R.

2017-11-01

The characteristics of a liquid spray in a uniform cross-flow field are numerically simulated in this study. A hollow cone liquid spray is injected perpendicular to the air stream flowing through a rectangular duct under room temperature and pressure. An Eulerian-Lagrangian framework is adopted to simulate the spray in cross-flow phenomenon. The cross-flow velocity is varied from 6-12 m/s while the liquid injection pressure is varied from 0.3-0.6 MPa. The liquid droplets from the injected spray undergo breakup and/or coalescence further in the cross-flow. Moreover, the spray injected into the cross-flow impinges on the opposite wall resulting in the formation of a liquid film. This liquid film disintegrates further into discrete droplets because of the impingement of the droplets from the spray and the shear from the cross-flow. The overall distribution of the droplets in the cross-flow for varying conditions is studied in detail. The evolution of the liquid film with space and time for varying conditions is also investigated. Suitable sub-models are used to numerically model the droplet break-up, coalescence, liquid film formation and disintegration, splashing of the droplets on the film and subsequent formation of daughter droplets. Department of Applied Mechanics, Indian Inst of Tech-Madras.

Performance of a multiple venturi fuel-air preparation system. [fuel injection for gas turbines

NASA Technical Reports Server (NTRS)

Tacina, R. R.

1979-01-01

Spatial fuel-air distributions, degree of vaporization, and pressure drop were measured 16.5 cm downstream of the fuel injection plane of a multiple Venturi tube fuel injector. Tests were performed in a 12 cm tubular duct. Test conditions were: a pressure of 0.3 MPa, inlet air temperature from 400 to 800K, air velocities of 10 and 20 m/s, and fuel-air ratios of 0.010 and 0.020. The fuel was Diesel #2. Spatial fuel-air distributions were within + or - 20 percent of the mean at inlet air temperatures above 450K. At an inlet air temperature of 400K, the fuel-air distribution was measured when a 50 percent blockage plate was placed 9.2 cm upstream of the fuel injection plane to distort the inlet air velocity fuel injection plane to distort the inlet air velocity profile. Vaporization of the fuel was 50 percent complete at an inlet air temperature of 400K and the percentage increased linearly with temperature to complete vaporization at 600K. The pressure drop was 3 percent at the design point which was three times greater than the designed value and the single tube experiment value. No autoignition or flashback was observed at the conditions tested.

Active noise control: a review of the field.

PubMed

Gordon, R T; Vining, W D

1992-11-01

Active noise control (ANC) is the application of the principle of the superposition of waves to noise attenuation problems. Much progress has been made toward applying ANC to narrow-band, low-frequency noise in confined spaces. During this same period, the application of ANC to broad-band noise or noise in three-dimensional spaces has seen little progress because of the recent quantification of serious physical limitations, most importantly, noncausality, stability, spatial mismatch, and the infinite gain controller requirement. ANC employs superposition to induce destructive interference to affect the attenuation of noise. ANC was believed to utilize the mechanism of phase cancellation to achieve the desired attenuation. However, current literature points to other mechanisms that may be operating in ANC. Categories of ANC are one-dimensional field and duct noise, enclosed spaces and interior noise, noise in three-dimensional spaces, and personal hearing protection. Development of active noise control stems from potential advantages in cost, size, and effectiveness. There are two approaches to ANC. In the first, the original sound is processed and injected back into the sound field in antiphase. The second approach is to synthesize a cancelling waveform. ANC of turbulent flow in pipes and ducts is the largest area in the field. Much work into the actual mechanism involved and the causal versus noncausal aspects of system controllers has been done. Fan and propeller noise can be divided into two categories: noise generated directly as the blade passing tones and noise generated as a result of blade tip turbulence inducing vibration in structures. Three-dimensional spaces present a noise environment where physical limitations are magnified and the infinite gain controller requirement is confronted. Personal hearing protection has been shown to be best suited to the control of periodic, low-frequency noise.

Diagnostic value of Gd-EOB-DTPA-enhanced MR cholangiography in non-invasive detection of postoperative bile leakage.

PubMed

Kul, Melahat; Erden, Ayşe; Düşünceli Atman, Ebru

2017-04-01

To assess the diagnostic value of dynamic T 1 weighted (T1w) gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced MR cholangiography (MRC) for the detection of active bile leaks. A total of 28 patients with suspected biliary leakage who underwent routine T 2 weighted (T2w) MRC and T1w GD-EOB-DTPA-enhanced MRC at our institution from February 2013 to June 2016 were included in this study. The image sets were retrospectively analyzed in consensus by three radiologists. T1w Gd-EOB-DTPA-enhanced MRC findings were correlated with clinical data, follow-up examinations and findings of invasive/surgical procedures. Patients with positive bile leak findings in Gd-EOB-DTPA-enhanced MRC were divided into hepatobiliary phase (HBP) (20-30 min) and delayed phase (DP) (60-390 min) group according to elapsed time between Gd-EOB-DTPA injection and initial bile leak findings in MRC images. These groups were compared in terms of laboratory test results (total bilirubin, liver enzymes) and the presence of bile duct dilatation in T2w MRC images. In each patient, visualization of bile ducts was sufficient in the HBP. The accuracy, sensitivity and specificity of dynamic Gd-EOB-DTPA-enhanced T1w MRC in the detection of biliary leaks were 92.9%, 90.5% and 100%, respectively (p < 0.001). 19 of 28 patients had bile leak findings in T1w Gd-EOB-DTPA-enhanced MRC [HBP group: N = 7 (36.8%), DP group: N = 12 (63.2%)]. There was no statistically significant difference in terms of laboratory test results and the presence of bile duct dilatation between HBP and DP group (p > 0.05). Three patients, each of them in DP group, showed normal laboratory test results and bile duct diameters. Dynamic T1w Gd-EOB-DTPA-enhanced MRC is a useful non-invasive diagnostic tool to detect bile leak. Advances in knowledge: Prolonged DP imaging may be required for bile leak detection even if visualization of biliary tree is sufficient in HBP and liver function tests, total bilirubin levels and bile duct diameters are normal.

Inlets, ducts, and nozzles

NASA Technical Reports Server (NTRS)

Abbott, John M.; Anderson, Bernhard H.; Rice, Edward J.

1990-01-01

The internal fluid mechanics research program in inlets, ducts, and nozzles consists of a balanced effort between the development of computational tools (both parabolized Navier-Stokes and full Navier-Stokes) and the conduct of experimental research. The experiments are designed to better understand the fluid flow physics, to develop new or improved flow models, and to provide benchmark quality data sets for validation of the computational methods. The inlet, duct, and nozzle research program is described according to three major classifications of flow phenomena: (1) highly 3-D flow fields; (2) shock-boundary-layer interactions; and (3) shear layer control. Specific examples of current and future elements of the research program are described for each of these phenomenon. In particular, the highly 3-D flow field phenomenon is highlighted by describing the computational and experimental research program in transition ducts having a round-to-rectangular area variation. In the case of shock-boundary-layer interactions, the specific details of research for normal shock-boundary-layer interactions are described. For shear layer control, research in vortex generators and the use of aerodynamic excitation for enhancement of the jet mixing process are described.

Recurrence of inflammatory pseudotumor in the distal bile duct: Lessons learned from a single case and reported cases

PubMed Central

Fernández, EM López-Tomassetti; Luis, H Díaz; Malagón, A Martín; González, I Arteaga; Pallarés, A Carrillo

2006-01-01

Inflammatory myofibroblastic tumors (IMTs) or inflammatory pseudotumors (IPs) have been extensively discussed in the literature. They are usually found in the lung and upper respiratory tract. However, reporting of cases involving the biliopancreatic region has increased over recent years. Immunohistochemical study of these lesions limited to the pancreatic head or distal bile duct seems to be compatible with those observed in a new entity called autoimmune pancreatitis, but usually intense fibrotic reaction (zonation) predominates producing a mass. When this condition is limited to the pancreatic head, the common bile duct might be involved by the inflammatory process and jaundice may occur often resembling adenocarcinoma of the pancreas. We have previously reported a case of IMT arising from the bile duct associated with autoimmune pancreatitis which is an extremely rare entity. Four years after Kaush-Whipple resection, radiological examination on routine follow-up revealed a tumor mass, suggesting local recurrence. Ultrasound-guided FNA confirmed our suspicious diagnosis. This present case, as others, suggests that persistent follow-up is necessary in order to prevent irreversible liver damage at this specific location. PMID:16804988

Concurrent identification of aero-acoustic scattering and noise sources at a flow duct singularity in low Mach number flow

NASA Astrophysics Data System (ADS)

Sovardi, Carlo; Jaensch, Stefan; Polifke, Wolfgang

2016-09-01

A numerical method to concurrently characterize both aeroacoustic scattering and noise sources at a duct singularity is presented. This approach combines Large Eddy Simulation (LES) with techniques of System Identification (SI): In a first step, a highly resolved LES with external broadband acoustic excitation is carried out. Subsequently, time series data extracted from the LES are post-processed by means of SI to model both acoustic propagation and noise generation. The present work studies the aero-acoustic characteristics of an orifice placed in a duct at low flow Mach numbers with the "LES-SI" method. Parametric SI based on the Box-Jenkins mathematical structure is employed, with a prediction error approach that utilizes correlation analysis of the output residuals to avoid overfitting. Uncertainties of model parameters due to the finite length of times series are quantified in terms of confidence intervals. Numerical results for acoustic scattering matrices and power spectral densities of broad-band noise are validated against experimental measurements over a wide range of frequencies below the cut-off frequency of the duct.

Changes in laboratory test results and diagnostic imaging presentation before the detection of occupational cholangiocarcinoma.

PubMed

Kubo, Shoji; Takemura, Shigekazu; Sakata, Chikaharu; Urata, Yorihisa; Nishioka, Takayoshi; Nozawa, Akinori; Kinoshita, Masahiko; Hamano, Genya; Nakanuma, Yasuni; Endo, Ginji

2014-01-01

A cholangiocarcinoma outbreak among workers of an offset color proof-printing department in a printing company was recently reported. It is important to understand the clinical course leading to occupational cholangiocarcinoma development for investigation of the carcinogenesis process and for surveillance and early detection. We evaluated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma. We investigated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma in 2 patients because the data were available. Results The clinical courses observed in the 2 participating patients showed persistent elevation of serum γ-glutamyl transpeptidase levels with or without elevated serum levels of alanine aminotransferase and/or aspartate aminotransferase before cholangiocarcinoma detection. Dilatation of the bile ducts without tumor-induced stenosis was observed several years before cholangiocarcinoma detection and progressed gradually in both patients. The serum concentration of carbohydrate 19-9 also increased prior to cholangiocarcinoma detection in both patients. Eventually, observation of stenosis of the bile duct and a space-occupying lesion strongly suggested cholangiocarcinoma. Pathological examination of the resected specimens showed chronic bile duct injury and neoplastic lesions, such as "biliary intraepithelial neoplasia" and "intraductal papillary neoplasm of the bile duct" in various sites of the bile ducts, particularly in the dilated bile ducts. The changes in laboratory test results and diagnostic imaging might be related to the development of cholangiocarcinoma. It is important to monitor diagnostic imaging presentation and laboratory test results in workers with extended exposure to organic solvents.

Plasticity in Major Ampullate Silk Production in Relation to Spider Phylogeny and Ecology

PubMed Central

Boutry, Cecilia; Řezáč, Milan; Blackledge, Todd Alan

2011-01-01

Spider major ampullate silk is a high-performance biomaterial that has received much attention. However, most studies ignore plasticity in silk properties. A better understanding of silk plasticity could clarify the relative importance of chemical composition versus processing of silk dope for silk properties. It could also provide insight into how control of silk properties relates to spider ecology and silk uses. We compared silk plasticity (defined as variation in the properties of silk spun by a spider under different conditions) between three spider clades in relation to their anatomy and silk biochemistry. We found that silk plasticity exists in RTA clade and orbicularian spiders, two clades that differ in their silk biochemistry. Orbiculariae seem less dependent on external spinning conditions. They probably use a valve in their spinning duct to control friction forces and speed during spinning. Our results suggest that plasticity results from different processing of the silk dope in the spinning duct. Orbicularian spiders seem to display better control of silk properties, perhaps in relation to their more complex spinning duct valve. PMID:21818328

Finding Infrastructure with Non-Destructive Imaging Technologies (FINDIT)

NASA Astrophysics Data System (ADS)

Tuckwell, G.; Usher, C.; Stringfellow, M.; Chapman, D.; Metje, N.; Roberts, D.

2017-12-01

Novel uses for existing technologies and new post-processing techniques have been developed to generate a level and detail of information that will make a step-change to standard practice in mapping and assessing the condition of buried infrastructure. The most appropriate sensing technologies for buried telecommunications ducts have been identified as Ground Penetrating Radar and Acoustic reflectometry. Dielectric permittivity changes in the near-surface can manifest themselves in different ways within GPR data. Numerical modelling work has been undertaken by applying a Kuepper signal and an exploding source, and using various different frequencies to determine minute changes (e.g. cracks in pipes) in an object or feature within the near surface. This modelling demonstrated that there is a clear difference between an empty duct, a duct partially filled with cables and a damaged duct. This was confirmed in a laboratory test on dry sand to determine the detectability of a hole in a plastic pipe. This has formed the foundation new data processing algorithms to detect the presence of such defects in real and synthetic data sets. Future work will focus on the development of a test site and field trials to assess the detectability of defects under realistic field conditions. This ongoing programme of work will be validated and iteratively improved by field trials under controlled and live commercial conditions. Finally the cost/benefit of the new workflows develop evaluated through the development of business models for the application of such techniques in telecoms, water and energy supply sectors. In the UK, the majority of the communication network is buried in ducts which are often several decades old. They have often collapsed or become blocked so that spare capacity cannot be used. There is currently no surface detection technology which can accurately locate the position of these defects (or even accurately locate the ducts in all circumstances), so time consuming and costly manual rodding is performed which cannot detect subsequent blockages, resulting in inadequate and inefficient repair planning, increasing the costs and causing disruption to road users.

Electromagnetic propagation in PEC and absorbing curved S-ducts

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1988-01-01

A finite-element Galerkin formulation has been developed to study transverse magnetic (TM) wave propagation in 2-D S-curved ducts with both perfectly conducting and absorbing walls. The reflection and transmission at the entrances and the exits of the curved ducts are determined by coupling the finite-element solutions in the curved ducts to the eigenfunctions of an infinite, uniform, perfectly conducting duct. Example solutions are presented for a double mitred and S-ducts of various lengths. The length of the S-duct is found to significantly effect the reflective characteristics of the duct. Also, the effect of curvature on an absorbing duct is illustrated.

Transition duct assembly with modified trailing edge in turbine system

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMahan, Kevin Weston; Schott, Carl Gerard; Ingram, Clint Luigie

2016-10-04

Transition duct assemblies for turbine systems and turbomachines are provided. In one embodiment, a transition duct assembly includes a plurality of transition ducts disposed in a generally annular array and comprising a first transition duct and a second transition duct. Each of the plurality of transition ducts includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of each transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct assembly further includes anmore » aerodynamic structure defined by the passages of the first transition duct and the second transition duct. The aerodynamic structure includes a pressure side, a suction side, and a trailing edge, the trailing edge having a modified aerodynamic contour.« less

Abnormal subcellular localization of AQP5 and downregulated AQP5 protein in parotid glands of streptozotocin-induced diabetic rats.

PubMed

Wang, Di; Yuan, Zhenfang; Inoue, Noriko; Cho, Gota; Shono, Masayuki; Ishikawa, Yasuko

2011-05-01

The mechanisms underlying diabetic xerostomia have not been clarified in relation with aquaporin-5 (AQP5) subcellular localization in salivary glands. Western blotting, real-time PCR, and immunocytochemistry were used to analyse AQP5 protein levels and mRNA expression. AQP5 protein levels were measured in the apical plasma membrane (APM) and detergent-insoluble fraction prepared from streptozotocin-diabetic rat parotid glands. Despite an increase in AQP5 mRNA, AQP5 protein levels were decreased in diabetic parotid glands compared with controls. Immunohistochemical studies indicated that AQP5, under unstimulated conditions, colocalised with flotillin-2 and GM1 with a diffuse pattern in the apical cytoplasm of acinar and duct cells in both control and diabetic rats. Ten minutes after intravenous injection of muscarinic agonist cevimeline, AQP5 was dramatically increased together with flotillin-2 and GM1 in the APM of parotid acinar and duct cells of control but not diabetic rats. Sixty minutes after injection, AQP5 was located in a diffuse pattern in the apical cytoplasm in both rats. Treatment of the parotid tissues with cevimeline for 10min increased the Triton X-100 solubility of AQP5 in control but not diabetic rats. Administration of insulin to diabetic rats tended to restore the cevimeline-induced translocation of AQP5. Lack of AQP5 translocation in the salivary gland in response to a muscarinic agonist and downregulation of AQP5 protein might lead to diabetic xerostomia. Cevimeline is useful to cure diabetic xerostomia under insulin administration. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

The Effects of Air Preheat and Number of Orifices on Flow and Emissions in an RQL Mixing Section

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Chang, Clarence T.

2007-01-01

This study was motivated by a goal to understand the mixing and emissions in the rich-burn/quick-mix/lean-burn (RQL) combustor scheme that has been proposed to minimize the formation of oxides of nitrogen (NOx) in gas turbine combustors. The study reported in this paper was a reacting jet-in-crossflow experiment at atmospheric pressure in a cylindrical duct. The jets were injected from the perimeter of the duct through round-hole orifices into a fuel-rich mainstream flow. The number of orifices investigated in this study gave over- to optimum to underpenetrating jets at a jet-to-mainstream momentum-flux ratio of 57. The size of individual orifices was decreased as their number increased to maintain a constant total area. The jet-to-mainstream mass-flow ratio was held constant at 2.5. The experiments focused on the effects of the number of orifices and inlet air preheat and were conducted in a facility that provided the capability for independent variation of jet and main inlet air preheat temperature. The number of orifices was found to have a significant effect on mixing and the distributions of species, but very little effect on overall NOx emissions, suggesting that an aerodynamically optimum mixer may not minimize NOx emissions. Air preheat was found to have very little effect on mixing and the distributions of major species, but preheat did increase NOx emissions significantly. Although the air jets injected in the quick-mix section of a RQL combustor may comprise over 70% of the total air flow, the overall NOx emission levels were found to be more sensitive to mainstream air preheat than to jet stream air preheat.

Hsp90 and hepatobiliary transformation during sea lamprey metamorphosis.

PubMed

Chung-Davidson, Yu-Wen; Yeh, Chu-Yin; Bussy, Ugo; Li, Ke; Davidson, Peter J; Nanlohy, Kaben G; Brown, C Titus; Whyard, Steven; Li, Weiming

2015-12-01

Biliary atresia (BA) is a human infant disease with inflammatory fibrous obstructions in the bile ducts and is the most common cause for pediatric liver transplantation. In contrast, the sea lamprey undergoes developmental BA with transient cholestasis and fibrosis during metamorphosis, but emerges as a fecund adult. Therefore, sea lamprey liver metamorphosis may serve as an etiological model for human BA and provide pivotal information for hepatobiliary transformation and possible therapeutics. We hypothesized that liver metamorphosis in sea lamprey is due to transcriptional reprogramming that dictates cellular remodeling during metamorphosis. We determined global gene expressions in liver at several metamorphic landmark stages by integrating mRNA-Seq and gene ontology analyses, and validated the results with real-time quantitative PCR, histological and immunohistochemical staining. These analyses revealed that gene expressions of protein folding chaperones, membrane transporters and extracellular matrices were altered and shifted during liver metamorphosis. HSP90, important in protein folding and invertebrate metamorphosis, was identified as a candidate key factor during liver metamorphosis in sea lamprey. Blocking HSP90 with geldanamycin facilitated liver metamorphosis and decreased the gene expressions of the rate limiting enzyme for cholesterol biosynthesis, HMGCoA reductase (hmgcr), and bile acid biosynthesis, cyp7a1. Injection of hsp90 siRNA for 4 days altered gene expressions of met, hmgcr, cyp27a1, and slc10a1. Bile acid concentrations were increased while bile duct and gall bladder degeneration was facilitated and synchronized after hsp90 siRNA injection. HSP90 appears to play crucial roles in hepatobiliary transformation during sea lamprey metamorphosis. Sea lamprey is a useful animal model to study postembryonic development and mechanisms for hsp90-induced hepatobiliary transformation.

Development of an experimental model of cholestasis induced by hypoxic/ischemic damage to the bile duct and liver tissues in infantile rats.

PubMed

Toki, Fumiaki; Takahashi, Atsushi; Suzuki, Makoto; Ootake, Sayaka; Hirato, Junko; Kuwano, Hiroyuki

2011-05-01

We aimed to develop experimental models of hypoxia/ischemia-induced cholestasis using neonatal and infantile rats. Hypoxia/ischemia was induced in the bile duct (BD) by injecting prostaglandin (PG) at birth and/or by coagulation of the hepatic artery (CHA) at about 3 weeks after birth. The rats were divided into 6 groups: control; PG-injected; sham-operated with or without PG; CHA; and CHA + PG. CHA was also performed in adult rats. Liver specimens and blood samples were obtained at 5 weeks after birth, and immunohistochemical and biochemical examinations were performed. (1) BD proliferation with fibrosis (BDPF) was found in the intrahepatic portal tract in the CHA and CHA + PG groups. Low-grade BDPF was observed in the PG group. (2) Cyst formation in the extrahepatic BD (EBD) was observed in the porta hepatis of some rats in the CHA and CHA + PG groups. In these groups, the number of peribiliary vascular plexuses (PVPs) decreased. BD proliferation and infiltration of inflammatory cells were observed in the EBD wall in the CHA + PG group. (3) Ki-67 was expressed in BD and EBD cells in the CHA + PG group. (4) BDPF was not detected in adult rats with CHA. (5) Serum liver function tests indicated obstructive changes in the EBD in the CHA and CHA + PG groups. Reduced blood flow in the EBD during infancy induced BDPF and obstructive changes in the EBD, which may, along with immature PVP and inflammatory changes in the EBD, contribute to hypoxia/ischemia of the EBD.

Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

NASA Astrophysics Data System (ADS)

Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

2017-05-01

How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of intensive fuel burnout and generation of nitrogen oxides do not coincide over the flame length, and the ambient temperature has a significant impact on the combustion stability at low values and on the concentration of nitrogen oxides in the combustion products at high values.

Effects of Diabetes on Post-Menopausal Rat Submandibular Glands: A Histopathological and Stereological Examination

PubMed Central

Buyuk, Basak; Parlak, Secil Nazife; Keles, Osman Nuri; Can, Ismail; Yetim, Zeliha; Toktay, Erdem; Selli, Jale; Unal, Bunyami

2015-01-01

Objective: The menopause in elderly women is a physiological process where ovarian and uterine cycles end. Diabetes means higher blood glucose level that is a metabolic disease and has an increased incidence. The aim of the study was to examine the single or combined effects of menopause and diabetes that causes pathophysiological processes on submandibular gland on ovariectomy and diabetes induced rat models. Materials and Methods: Sprague Dawley twelve weeks old female (n=24) rats were divided randomly into four groups; Healthy control group (n=6), diabetic group (DM, n=6), ovariectomized group (OVX, n=6), post ovariectomy diabetes induced group (DM+OVX, n=6) individually. Histopathological, histochemical and stereological analyses were done in these groups. Results: Significant neutrophil cell infiltrations and myoepithelial cell proliferations, granular duct and seromucous acini damages and changes in the content of especially seromucous acini secretion in DM and/or OVX groups and distinctive interstitial and striated duct damages in post ovariectomy diabetes induced group were detected. Alterations ingranular ducts hypertrophic and in seromucous acini atrophic were determined in DM and/or OVX groups. Conclusion: The results revealed the pathophysiological processes that lead to morphological and functional alterations on the cellular level in submandibular glands. The molecular mechanisms related with pathogenesis of diabetes and menopause need further investigation. PMID:26644770

Turbofan aft duct suppressor study program listing and user's guide

NASA Technical Reports Server (NTRS)

Joshi, M. C.; Kraft, R. E.

1983-01-01

A description of the structure of the Annular Flow Duct Program (AFDP) for the calculation of acoustic suppression due to treatment in a finite length annular duct carrying sheared flow is presented. Although most appropriate for engine exhaust ducts, this program can be used to study sound propagation in any duct that maintains annular geometry over a considerable length of the duct. The program is based on the modal analysis of sound propagation in ducts with axial segments of different wall impedances. For specified duct geometry, wall impedance, flow and acoustic conditions in the duct (including mode amplitude distribution of the source) and duct termination reflection characteristics, the program calculates the suppression due to the treatment in the duct. The presence of forward and backward traveling modes in the duct due to the reflection and redistribution of modes at segment interfaces and duct end terminations are taken into account in the calculations. The effects of thin wall boundary layers (with a linear or mean flow velocity profile) on the acoustic propagation are also included in the program. A functional description of the major subroutines is included and a sample run is provided with an explanation of the output.

Data integration in physiology using Bayes’ rule and minimum Bayes’ factors: deubiquitylating enzymes in the renal collecting duct

PubMed Central

Xue, Zhe; Chen, Jia-Xu; Zhao, Yue; Medvar, Barbara

2017-01-01

A major challenge in physiology is to exploit the many large-scale data sets available from “-omic” studies to seek answers to key physiological questions. In previous studies, Bayes’ theorem has been used for this purpose. This approach requires a means to map continuously distributed experimental data to probabilities (likelihood values) to derive posterior probabilities from the combination of prior probabilities and new data. Here, we introduce the use of minimum Bayes’ factors for this purpose and illustrate the approach by addressing a physiological question, “Which deubiquitylating enzymes (DUBs) encoded by mammalian genomes are most likely to regulate plasma membrane transport processes in renal cortical collecting duct principal cells?” To do this, we have created a comprehensive online database of 110 DUBs present in the mammalian genome (https://hpcwebapps.cit.nih.gov/ESBL/Database/DUBs/). We used Bayes’ theorem to integrate available information from large-scale data sets derived from proteomic and transcriptomic studies of renal collecting duct cells to rank the 110 known DUBs with regard to likelihood of interacting with and regulating transport processes. The top-ranked DUBs were OTUB1, USP14, PSMD7, PSMD14, USP7, USP9X, OTUD4, USP10, and UCHL5. Among these USP7, USP9X, OTUD4, and USP10 are known to be involved in endosomal trafficking and have potential roles in endosomal recycling of plasma membrane proteins in the mammalian cortical collecting duct. PMID:28039431

Data integration in physiology using Bayes' rule and minimum Bayes' factors: deubiquitylating enzymes in the renal collecting duct.

PubMed

Xue, Zhe; Chen, Jia-Xu; Zhao, Yue; Medvar, Barbara; Knepper, Mark A

2017-03-01

A major challenge in physiology is to exploit the many large-scale data sets available from "-omic" studies to seek answers to key physiological questions. In previous studies, Bayes' theorem has been used for this purpose. This approach requires a means to map continuously distributed experimental data to probabilities (likelihood values) to derive posterior probabilities from the combination of prior probabilities and new data. Here, we introduce the use of minimum Bayes' factors for this purpose and illustrate the approach by addressing a physiological question, "Which deubiquitylating enzymes (DUBs) encoded by mammalian genomes are most likely to regulate plasma membrane transport processes in renal cortical collecting duct principal cells?" To do this, we have created a comprehensive online database of 110 DUBs present in the mammalian genome (https://hpcwebapps.cit.nih.gov/ESBL/Database/DUBs/). We used Bayes' theorem to integrate available information from large-scale data sets derived from proteomic and transcriptomic studies of renal collecting duct cells to rank the 110 known DUBs with regard to likelihood of interacting with and regulating transport processes. The top-ranked DUBs were OTUB1, USP14, PSMD7, PSMD14, USP7, USP9X, OTUD4, USP10, and UCHL5. Among these USP7, USP9X, OTUD4, and USP10 are known to be involved in endosomal trafficking and have potential roles in endosomal recycling of plasma membrane proteins in the mammalian cortical collecting duct. Copyright © 2017 the American Physiological Society.

SOXAL combined SO{sub x}/NO{sub x} flue gas control demonstration. Quarterly report, January--March 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

AQUATECH Systems a business unit of Allied-Signal Inc., proposes to demonstrate the technical viability and cost effectiveness of the SOXAL process a combined SO{sub x}/NO{sub x} control process on a 3 MW equivalent flue gas slip stream from Niagara Mohawk Power Corporation, Dunkirk Steam Station Boiler No. 4, a coal fired boiler. The SOXAL process combines 90+% sulfur dioxide removal from the flue gas using a sodium based scrubbing solution and regeneration of the spent scrubbing liquor using AQUATECH Systems` proprietary bipolar membrane technology. This regeneration step recovers a stream of sulfur dioxide suitable for subsequent processing to salable sulfurmore » or sulfuric acid. Additionally 90+% control of NO{sub x} gases can be achieved in combination with conventional urea/methanol injection of NO{sub 2} gas into the duct. The SOXAL process is applicable to both utility and industrial scale boilers using either high or low sulfur coal. The SOXAL demonstration Program began September 10, 1991 and is approximately 22 months in duration. During the 6 months of scheduled operations period, expected to begin January 1992, data will be collected from the SOXAL system to define: SO{sub 2} and NO{sub x} control efficiencies; Current efficiency for the regeneration unit; Sulfate oxidation in the absorber; Make-up reagent rates; Product quality including concentrations and compositions; System integration and control philosophy; and Membrane stability and performance with respect to foulants.« less

Airbreathing Propulsion System Analysis Using Multithreaded Parallel Processing

NASA Technical Reports Server (NTRS)

Schunk, Richard Gregory; Chung, T. J.; Rodriguez, Pete (Technical Monitor)

2000-01-01

In this paper, parallel processing is used to analyze the mixing, and combustion behavior of hypersonic flow. Preliminary work for a sonic transverse hydrogen jet injected from a slot into a Mach 4 airstream in a two-dimensional duct combustor has been completed [Moon and Chung, 1996]. Our aim is to extend this work to three-dimensional domain using multithreaded domain decomposition parallel processing based on the flowfield-dependent variation theory. Numerical simulations of chemically reacting flows are difficult because of the strong interactions between the turbulent hydrodynamic and chemical processes. The algorithm must provide an accurate representation of the flowfield, since unphysical flowfield calculations will lead to the faulty loss or creation of species mass fraction, or even premature ignition, which in turn alters the flowfield information. Another difficulty arises from the disparity in time scales between the flowfield and chemical reactions, which may require the use of finite rate chemistry. The situations are more complex when there is a disparity in length scales involved in turbulence. In order to cope with these complicated physical phenomena, it is our plan to utilize the flowfield-dependent variation theory mentioned above, facilitated by large eddy simulation. Undoubtedly, the proposed computation requires the most sophisticated computational strategies. The multithreaded domain decomposition parallel processing will be necessary in order to reduce both computational time and storage. Without special treatments involved in computer engineering, our attempt to analyze the airbreathing combustion appears to be difficult, if not impossible.

Effects of Jet Swirl on Mixing of a Light Gas Jet in a Supersonic Airstream

NASA Technical Reports Server (NTRS)

Doerner, Steven E.; Cutler, Andrew D.

1999-01-01

A non reacting experiment was performed to investigate the effects of jet swirl on mixing of a light gas jet in a supersonic airstream. The experiment consisted of two parts. The first part was an investigation of the effects of jet swirl and skew on the mixing and penetration of a 25 deg. supersonic jet injected from a flat surface (flush wall injection) into a supersonic ducted airflow. Specifically, the objective was to determine whether the jet would mix more rapidly if the jet were swirling, and whether swirl, with and without skew, causes the injectant-air plume to have a net circulation (i.e., a single or dominant vortex). The second part was a preliminary study of the mixing of swirling jets injected from the base of a skewed ramp. The hypothesis was that favorable interactions between vorticity generated by the swirling jet and vortices generated by the ramp could produce mixing enhancements. Both parts of the experiment were conducted at equal injectant mass flow rate and total pressure. The results for the flush wall injection cases indicate that, except relatively close to the injection point, swirl, with or without skew, does not enhance the mixing of the jet, and can in fact reduce penetration. In addition, a plume with significant net circulation is not generated, as had previously been believed. The results for the ramp cases indicated no improvements in mixing in comparison with the baseline (swept ramp injector) case. However, it was not possible to determine the vorticity mechanisms underlying the poor performance, since no measurements of vorticity were made. Thus, since many geometric parameters were chosen arbitrarily, the results are inconclusive for this class of injector.

Comparative morphology and ultrastructure of the prosomal salivary glands in the unfed larvae Leptotrombidium orientale (Acariformes, Trombiculidae), a possible vector of tsutsugamushi disease agent.

PubMed

Shatrov, Andrew B

2015-07-01

The prosomal salivary glands of the unfed larvae Leptotrombidium orientale (Schluger) were investigated using transmission electron microscopy. In total, four pairs of the prosomal glands were identified--three pairs, the lateral, the medial and the anterior, belong to the podocephalic system, and one pair, the posterior, is separate having an own excretory duct. All glands are simple alveolar/acinous with prismatic cells arranged around a relatively small intra-alveolar lumen with the duct base. The cells of all glands besides the lateral ones contain practically mature electron-dense secretory granules ready to be discharged from the cells. The secretory granules in the lateral glands undergo formation and maturation due to the Golgi body activity. The cells of all gland types contain a large basally located nucleus and variously expressed rough endoplasmic reticulum. Specialized duct-forming cells filled with numerous freely scattered microtubules are situated in the middle zone of each gland's acinus and form the intra-alveolar lumen and the duct base. Both the acinar (secretory) and the duct-forming cells contact each other via gap junctions and septate desmosomes. Axons of nerve cells come close to the basal extensions of the duct-forming cells where they form the bulb-shaped synaptic terminations. The process of secretion is under the control of the nerve system that provides contraction of the duct-forming cells and discharge of secretion from the secretory cells into the intra-alveolar lumen and further to the exterior. Unfed larvae of L. orientale, the potential vector of tsutsugamushi disease agents, contain the most simply organized salivary secretory granules among known trombiculid larvae, and this secretion, besides the lateral glands, does not undergo significant additional maturation. Thus, the larvae are apparently ready to feed on the appropriate host just nearly after hatching.

14 CFR 29.1103 - Induction systems ducts and air duct systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction systems ducts and air duct systems. 29.1103 Section 29.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Induction System § 29.1103 Induction systems ducts and air duct...

14 CFR 25.1103 - Induction system ducts and air duct systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system ducts and air duct systems. 25.1103 Section 25.1103 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Induction System § 25.1103 Induction system ducts and air duct...

Duct Joining System

DOEpatents

Proctor, John P.

2001-02-27

A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

Duct joining system

DOEpatents

Proctor, John P.; deKieffer, Robert C.

2001-01-01

A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

Parametric study of electromagnetic waves propagating in absorbing curved S ducts

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1989-01-01

A finite-element Galerkin formulation has been developed to study attenuation of transverse magnetic (TM) waves propagating in two-dimensional S-curved ducts with absorbing walls. In the frequency range where the duct diameter and electromagnetic wave length are nearly equal, the effect of duct length, curvature (duct offset), and absorber wall thickness was examined. For a given offset in the curved duct, the length of the S-duct was found to significantly affect both the absorptive and reflective characteristics of the duct. For a straight and a curved duct with perfect electric conductor terminations, power attenuation contours were examined to determine electromagnetic wall properties associated with maximum input signal absorption. Offset of the S-duct was found to significantly affect the value of the wall permittivity associated with the optimal attenuation of the incident electromagnetic wave.

Clinical application of indocyanine green-fluorescence imaging during hepatectomy

PubMed Central

Ishizawa, Takeaki; Saiura, Akio

2016-01-01

In hepatobiliary surgery, the fluorescence and bile excretion of indocyanine green (ICG) can be used for real-time visualization of biological structure. Fluorescence cholangiography is used to obtain fluorescence images of the bile ducts following intrabiliary injection of 0.025−0.5 mg/mL ICG or intravenous injection of 2.5 mg ICG. Recently, the latter technique has been used in laparoscopic/robotic cholecystectomy. Intraoperative fluorescence imaging can be used to identify subcapsular hepatic tumors. Primary and secondary hepatic malignancy can be identified by intraoperative fluorescence imaging using preoperative intravenous injection of ICG through biliary excretion disorders that exist in cancerous tissues of hepatocellular carcinoma (HCC) and in non-cancerous hepatic parenchyma around adenocarcinoma foci. Intraoperative fluorescence imaging may help detect tumors to be removed, especially during laparoscopic hepatectomy, in which visual inspection and palpation are limited, compared with open surgery. Fluorescence imaging can also be used to identify hepatic segments. Boundaries of hepatic segments can be visualized following injection of 0.25−2.5 mg/mL ICG into the portal veins or by intravenous injection of 2.5 mg ICG following closure of the proximal portal pedicle toward hepatic regions to be removed. These techniques enable identification of hepatic segments before hepatectomy and during parenchymal transection for anatomic resection. Advances in imaging systems will increase the use of fluorescence imaging as an intraoperative navigation tool that can enhance the safety and accuracy of open and laparoscopic/robotic hepatobiliary surgery. PMID:27500144

Photoneutron radiation field of ducts in barrier of 15 MV medical electron accelerators

NASA Astrophysics Data System (ADS)

Deng, Lei; Zhou, Ning; Chen, Yi-shui; Tu, Yu

2017-11-01

Shielding body of the high-energy medical electron accelerators is always penetrated by ducts, which would influence the shielding capability of local barrier. In order to quantitatively analyze the duct's impact on shielding of the photoneutron from 15 MV accelerators, the ambient dose equivalent rate and energy spectrum at the center of a typical duct and the external mouth of duct were calculated based on MCNP program for the first time. The results demonstrate that leakage neutrons at the external mouth of duct are mainly thermal neutron, and its dose rate is decreased with the increase of the intersection angle between duct and wall as well as the reduction of duct diameter. When a duct in a diameter no more than 30 cm penetrates the wall unidirectionally and the inclined Angle (θ) is 60°, neutron dose rate at the external mouth of duct could meet the requirements of protection. At last, according to the calculation results, some suggestions are proposed for the shielding design of ducts in walls.

Anomalous pancreatico-biliary ductal union with cystic dilatation of the bile duct.

PubMed

Richer, J P; Faure, J P; Morichau-Beauchant, M; Dugue, T; Maillot, N; Kamina, P; Carretier, M

1998-01-01

We report, in an adult, an asymptomatic association between cystic dilation of the bile duct (type IV A in Todani's classification) and anomalous pancreatico-biliary ductal union (APBD) with stones in a long common channel. In APBD, the connection between the common bile duct and the main pancreatic duct is located outside the duodenal wall andis therefore not under the influence of the sphincter of Boyden. An abnormally long common channel is in excess of 15 mm. Two types of convergence anomalies are defined according to whether the bile duct opens into the main pancreatic duct (BP) or the main pancreatic duct into the bile duct (PB). In APBD, there is probably a reverse pressure gradient between the bile and pancreatic ducts, with regurgitation of pancreatic juice into the bile duct, repeated attacks of cholangitis, stenosis and cystic dilatation. A long common channel is associated with a higher incidence of carcinoma of the gall bladder of the bile duct.

Hypoglycemic effects of date seed extract. Possible mechanism of action, and potential therapeutic implications.

PubMed

El Fouhil, Ahmed F; Ahmed, Aly M; Atteya, Muhammad; Mohamed, Raeesa A; Moustafa, Amr S; Al-Roalle, Ali H; Darwish, Hasem H

2013-11-01

To investigate the possible mechanism, by which an extract from date seeds exert its hypoglycemic effect. This study was performed at the Anatomy Department, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia from May to December 2012. Eighty rats were divided into 4 groups. Group 1 received no treatment. Group 2 received daily ingestions of 10 ml of date seed extract for 8 weeks. Animals of groups 3 and 4 were made diabetic by streptozotocin injection, and were given daily subcutaneous injections of 3 IU/day of insulin for 8 weeks. Group 4 received, in addition, daily ingestions of 10 ml of seed extracts. Rats were sacrificed, and the sera were separated for estimation of serum C-peptide levels. Pancreatic tissues were processed for histological study of the islet cells, immunohistochemical study for insulin secretion and image analysis for insulin quantification. Mean serum C-peptide level was significantly higher in group 4 compared to group 3. Pancreatic islets from rats of group 3 showed weak immunoreactivity for insulin, while those of group 4 showed strong immunoreactivity in some hypertrophied beta cells. Immunopositive cells were detected in the wall of interlobular ducts and in centroacinar cells of pancreas only in group 4. Quantification of insulin immunoreactivity showed a marked reduction in islet size and extent of insulin immunoreactivity in diabetic compared to control groups. Date seed extracts may stimulate endogenous insulin secretion through extra-islet sources.

Lightweight Valve Closes Duct Quickly

NASA Technical Reports Server (NTRS)

Fournier, Walter L.; Burgy, N. Frank

1991-01-01

Expanding balloon serves as lightweight emergency valve to close wide duct. Uninflated balloon stored in housing of duct. Pad resting on burst diaphragm protects balloon from hot gases in duct. Once control system triggers valve, balloon inflates rapidly to block duct. Weighs much less than does conventional butterfly, hot-gas, or poppet valve capable of closing duct of equal diameter.

Jet Mixing in a Reacting Cylindrical Crossflow

NASA Technical Reports Server (NTRS)

Leong, M. Y.; Samuelsen, G. S.; Holdeman, J. D.

1995-01-01

This paper addresses the mixing of air jets into the hot, fuel-rich products of a gas turbine primary zone. The mixing, as a result, occurs in a reacting environment with chemical conversion and substantial heat release. The geometry is a crossflow confined in a cylindrical duct with side-wall injection of jets issuing from round orifices. A specially designed reactor, operating on propane, presents a uniform mixture without swirl to mixing modules consisting of 8, 9, 10, and 12 holes at a momentum-flux ratio of 57 and a jet-to-mainstream mass-flow ratio of 2.5. Concentrations of O2, CO2, CO, and HC are obtained upstream, downstream, and within the orifice plane. O2 profiles indicate jet penetration while CO2, CO, and HC profiles depict the extent of reaction. Jet penetration is observed to be a function of the number of orifices and is found to affect the mixing in the reacting system. The results demonstrate that one module (the 12-hole) produces near-optimal penetration defined here as a jet penetration closest to the module half-radius, and hence the best uniform mixture at a plane one duct radius from the orifice leading edge.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klingensmith, W.C.; Spitzer, V.M.; Fritzberg, A.R.

Diisopropyl-IDA Tc 99m imaging studies were performed in 11 normal subjects in both the fasting and postprandial states. In 5- to 60-minute analog images obtained in both fasting and postprandial studies, the cardiac blood pool was almost never seen, renal pelvic radioactivity was commonly seen, the extrahepatic biliary tract was always seen, and the left hepatic duct was always more prominent than the right hepatic duct. The biliary tract was visualized by ten minutes in nine of 11 fasting studies and 10 of 11 postprandial studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandialmore » studies. The gallbladder was visualized in all eleven fasting studies, but in only four postprandial studies (p less than 0.05). The zero- to sixty-minute digital data indicated a greater hepatocyte clearance, an earlier time of peak parenchymal radioactivity, and a faster parenchymal washout in the postprandial studies compared with fasting studies (p less than 0.05). Approximately nine percent of the injected dose was recovered in the urine during the first three hours in fasting and postprandial studies. The normal diisopropyl-IDA Tc 99m study in the fasting and postprandial states is defined; significant differences exist between the two states.« less

Thief process for the removal of mercury from flue gas

DOEpatents

Pennline, Henry W.; Granite, Evan J.; Freeman, Mark C.; Hargis, Richard A.; O'Dowd, William J.

2003-02-18

A system and method for removing mercury from the flue gas of a coal-fired power plant is described. Mercury removal is by adsorption onto a thermally activated sorbent produced in-situ at the power plant. To obtain the thermally activated sorbent, a lance (thief) is inserted into a location within the combustion zone of the combustion chamber and extracts a mixture of semi-combusted coal and gas. The semi-combusted coal has adsorptive properties suitable for the removal of elemental and oxidized mercury. The mixture of semi-combusted coal and gas is separated into a stream of gas and semi-combusted coal that has been converted to a stream of thermally activated sorbent. The separated stream of gas is recycled to the combustion chamber. The thermally activated sorbent is injected into the duct work of the power plant at a location downstream from the exit port of the combustion chamber. Mercury within the flue gas contacts and adsorbs onto the thermally activated sorbent. The sorbent-mercury combination is removed from the plant by a particulate collection system.

Persistent Mullerian Duct Syndrome: an interesting case report.

PubMed

Farag, S; Sutton, P; Leow, K S; Kosai, N R; Razman, J; Hanafiah, H; Das, S

2013-01-01

Transverse testicular ectopia is an uncommon disorder of testicular ectopia. Nearly thirty percent of the cases is associated with Persistent mullerian duct syndrome which is characterized by karyotypically normal males with retained mullerian derivatives. Understanding the natural process of the condition and the association with malignant potential will allow for a better understanding of the optimal surgical approach. This is a case report of young male presented a left sided inguinal hernia in which the sac contained both testes and uterus. The literature review of the syndrome will be discussed.

Secondary sclerosing cholangitis in critically ill patients.

PubMed

Peña-Pérez, Carlos Alberto; Ponce-Medrano, Juan Alberto Díaz

2018-01-01

Primary sclerosing cholangitis (PSC) is a rare idiopathic condition with immunopathogenic mechanisms where there is chronic progressive destruction of the biliary tree. Secondary sclerosing cholangitis (SSC) is clinically comparable to PSC, but is caused by specific processes which directly damage the biliary tree; examples include recurrent pancreatitis, bile duct malignancy, congenital bile duct abnormalities. A new cause of SSC has been described during or following significant critical illness associated with severe respiratory insufficiency, vasopressor requirement, shock and sepsis. This condition rapidly progresses to cirrhosis, frequently requiring liver transplantation for definitive management. Copyright: © 2018 Permanyer.

Apparatus for supplying conditioned air at a substantially constant temperature and humidity

NASA Technical Reports Server (NTRS)

Obler, H. D. (Inventor)

1980-01-01

The apparatus includes a supply duct coupled to a source of supply air for carrying the supply air therethrough. A return duct is coupled to the supply duct for carrying return conditioned air therethrough. A temperature reducing device is coupled to the supply duct for decreasing the temperature of the supply and return conditioned air. A by-pass duct is coupled to the supply duct for selectively directing portions of the supply and return conditioned air around the temperature reducing device. Another by-pass duct is coupled to the return duct for selectively directing portions of the return conditioned air around the supply duct and the temperature reduction device. Controller devices selectively control the flow and amount of mixing of the supply and return conditioned air.

Correlations for heat transfer coefficient and friction factor for turbulent flow of air through square and hexagonal ducts with twisted tape insert

NASA Astrophysics Data System (ADS)

Yadav, Rupesh J.; Kore, Sandeep S.; Joshi, Prathamesh S.

2018-05-01

The experimental and numerical Nusselt number and friction factor investigation for turbulent flow through a non-circular duct with twisted-tape inserts have been presented. The non-circular ducts include square, hexagonal duct. The results of non-circular ducts are compared with circular duct. All the ducts have same equivalent diameter. The twist ratios used for the experiment are Y = 3.5, 4.5, 5.5 and 6.5. Experiments were carried out on square duct, hexagonal duct and circular duct. The Reynolds number lied between 10,000 and 1, 05,000. The present study is restricted to the flow of air at Pr = 0.7 only and within a narrow temperature range of 40 to 75 ΟC, within which the compressible nature of air can be neglected. The results reveal that, both Nusselt number and friction factor increases as the side of non-circular duct increases. Maximum Nusselt number and friction factor is obtained in case of circular duct with twisted tape. Further the correlations of Nu and f are given for different non circular duct with twisted tape insert for engineering applications for the turbulent regime. Since the thermal performance factor (η) is observed to be within the range of 0.8 to 1.13 for both circular and noncircular ducts, the overall benefit of using twisted tape in the flow field shall nevertheless be marginal.

40 CFR Table 8 to Subpart Sssss of... - Continuous Compliance with Operating Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... recent performance test; andii. Conducting annually an inspection of all duct work, vents, and capture... process operating parameters within the limits established during the most recent performance test i... processing rate at or below the maximum organic HAP processing rate established during the most recent...

40 CFR Table 8 to Subpart Sssss of... - Continuous Compliance with Operating Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

... recent performance test; andii. Conducting annually an inspection of all duct work, vents, and capture... process operating parameters within the limits established during the most recent performance test i... processing rate at or below the maximum organic HAP processing rate established during the most recent...

40 CFR Table 8 to Subpart Sssss of... - Continuous Compliance with Operating Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

... recent performance test; andii. Conducting annually an inspection of all duct work, vents, and capture... process operating parameters within the limits established during the most recent performance test i... processing rate at or below the maximum organic HAP processing rate established during the most recent...

Bile Duct Exploration

MedlinePlus

... Patients & Visitors Health Library Institutes & Departments Home / Health Library / Diagnostics & Testing / Bile Duct Exploration Advertising Policy Bile Duct Exploration Common bile duct exploration is ...

Trypsin level in gallbladder bile and ductitis and width of the cystic duct.

PubMed

Vracko, J; Wiechel, K L

2000-01-01

The change from laparotomy to laparoscopy for cholecystectomy has raised the question of how to manage concomitant bile duct stones. The present-day interest--and controversy--has focused on a transcystic approach reported to be feasible in 66-96% of cases, but without explaining the necessary prerequisite: the widening of the cystic duct. The cystic duct, wide mainly in patients with bile duct stones, has been reported to be highly variable: from strictured to very wide. The present study aims at comparing the trypsin level in the gallbladder bile and the cystic duct morphology and width in patients with and without bile duct stones. A prospective series of 63 gallstone patients, 30 with and 33 without bile duct stones (controls), underwent cholecystectomy and bile duct clearance. The study includes the trypsin level in the gallbladder bile, the width and morphology of the cystic duct, and the size of the gallstones. The patients with bile duct stones had, in contrast to the controls, higher trypsin levels in the gallbladder bile (P < 0.001) and wider cystic ducts (P < 0.001) with more pronounced signs of chronic ductitis. The obtained results strongly suggest that the increased trypsin level, a sign of reflux of pancreatic juice, caused changes in the cystic duct that facilitate gallstone migration, which also ought to render a transcystic stone extraction feasible.

Examination of Duct Physiology in the Human Mammary Gland

PubMed Central

Mills, Dixie; Gomberawalla, Ameer; Gordon, Eva J.; Tondre, Julie; Nejad, Mitra; Nguyen, Tinh; Pogoda, Janice M.; Rao, Jianyu; Chatterton, Robert; Henning, Susanne; Love, Susan M.

2016-01-01

Background The human breast comprise several ductal systems, or lobes, which contain a small amount of fluid containing cells, hormones, proteins and metabolites. The complex physiology of these ducts is likely a contributing factor to the development of breast cancer, especially given that the vast majority of breast cancers begin in a single lobular unit. Methods We examined the levels of total protein, progesterone, estradiol, estrone sulfate, dehydroepiandrosterone sulfate, and macrophages in ductal fluid samples obtained from 3 ducts each in 78 women, sampled twice over a 6 month period. Samples were processed for both cytological and molecular analysis. Intraclass correlation coefficients and mixed models were utilized to identify significant data. Results We found that the levels of these ductal fluid components were generally uncorrelated among ducts within a single breast and over time, suggesting that each lobe within the breast has a distinct physiology. However, we also found that estradiol was more correlated in women who were nulliparous or produced nipple aspirate fluid. Conclusions Our results provide evidence that the microenvironment of any given lobular unit is unique to that individual unit, findings that may provide clues about the initiation and development of ductal carcinomas. PMID:27073976

The renal TRPV4 channel is essential for adaptation to increased dietary potassium

PubMed Central

Mamenko, Mykola; Boukelmoune, Nabila; Tomilin, Viktor; Zaika, Oleg; Jensen, V. Behrana; O’Neil, Roger G.; Pochynyuk, Oleh

2016-01-01

To maintain potassium homeostasis, kidneys exert flow-dependent potassium secretion to facilitate kaliuresis in response to elevated dietary potassium intake. This process involves stimulation of calcium-activated large conductance maxi-K (BK) channels in the distal nephron, namely the connecting tubule and the collecting duct. Recent evidence suggests that the TRPV4 channel is a critical determinant of flow-dependent intracellular calcium elevations in these segments of the renal tubule. Here, we demonstrate that elevated dietary potassium intake (five percent potassium) increases renal TRPV4 mRNA and protein levels in an aldosterone-dependent manner and causes redistribution of the channel to the apical plasma membrane in native collecting duct cells. This, in turn, leads to augmented TRPV4-mediated flow-dependent calcium ion responses in freshly isolated split-opened collecting ducts from mice fed the high potassium diet. Genetic TRPV4 ablation greatly diminished BK channel activity in collecting duct cells pointing to a reduced capacity to excrete potassium. Consistently, elevated potassium intake induced hyperkalemia in TRPV4 knockout mice due to deficient renal potassium excretion. Thus, regulation of TRPV4 activity in the distal nephron by dietary potassium is an indispensable component of whole body potassium balance. PMID:28187982

BRAF V600E mutational status in bile duct adenomas and hamartomas.

PubMed

Pujals, Anaïs; Bioulac-Sage, Paulette; Castain, Claire; Charpy, Cécile; Zafrani, Elie Serge; Calderaro, Julien

2015-10-01

Bile duct adenomas (BDA) and bile duct hamartomas (BDH) are benign bile duct lesions considered neoplastic or secondary to ductal plate malformation, respectively. We have reported previously a high prevalence of BRAF V600E mutations detected by allele-specific polymerase chain reaction assay in BDA, and suggested that BDA may be precursors to a subset of intrahepatic cholangiocarcinomas harbouring V600E mutations. The aim of the present study was to assess the existence of BRAF V600E mutations, using immunohistochemical methods, in additional BDA as well as in BDH. Fifteen BDA and 35 BDH were retrieved from the archives of the pathology departments of two French university hospitals. All cases were reviewed by two pathologists specialized in liver diseases. BRAF V600E mutational status was investigated by immunohistochemistry. Mutated BRAF mutant protein was detected in 53% of the BDA and in none of the cases of BDH. Our findings suggest that BDA and BDH are different processes, and that BDA represent true benign neoplasms. They also support the hypothesis that mutated BDA might precede the development of the subset of intrahepatic cholangiocarcinomas harbouring BRAF V600E mutations. © 2015 John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Severini, Aldo; Mantero, Sara; Tanzi, Maria Cristina

Purpose: Prototypes of Gianturco-Rosch Z-stents coated with polycarbonate urethane (PCU) were placed in the biliary tree of pigs, in order to test their biomechanical behavior, stability, and biocompatibility. Methods: The stents were surgically implanted in the common bile duct of three pairs of pigs, which were killed after 1, 3, and 6 months respectively. Explanted livers from pigs of the same race, age, and size were used to provide comparative data. The bile ducts were radiologically and histopathologically examined; the stents were processed and examined by scanning electron microscopy. Results: No complications occurred and the animals showed a normal weightmore » gain. The main bile duct appeared radiologically and macroscopically dilated, but the stents proved to be in place. Histologically, the bile duct epithelium was destroyed, but neither hyperplastic nor inflammatory fibrotic reactions of the wall were evident. Both the metallic structure and the polymeric coating of the stents were intact. A layer of organic material with a maximum thickness of approximately 3 {mu}m was evident on the inner surface of the stents. Conclusion: The present in vivo study demonstrates the biocompatibility, efficacy, and stability of PCU-coated Gianturco-Rosch stents in the biliary environment.« less

CT differentiation of mucin-producing cystic neoplasms of the liver from solitary bile duct cysts.

PubMed

Kim, Hyoung Jung; Yu, Eun Sil; Byun, Jae Ho; Hong, Seung-Mo; Kim, Kyoung Won; Lee, Jong Seok; Kim, So Yeon

2014-01-01

The purpose of this study was to identify the CT features required for differentiating mucin-producing cystic neoplasms of the liver (mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct) from solitary bile duct cysts. CT images of pathologically confirmed mucinous cystic neoplasms (n = 15), cyst-forming intraductal papillary neoplasms of the bile duct (n = 16), and solitary bile duct cysts (n = 31) were reviewed. Analysis of the CT findings included shape, presence of septa, location of septa (peripheral vs central), thickness of septa (thin vs thick), mosaic pattern, mural nodules, intracystic debris, calcification, upstream bile duct dilatation, downstream bile duct dilatation, and communication between a cystic lesion and the bile duct. The maximum size of a cystic lesion and the maximum size of the largest mural nodule were measured. The presence of septa, central septa, mural nodules, upstream bile duct dilatation, and downstream bile duct dilatation were found to be significant CT findings for differentiating mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct from solitary bile duct cysts (p < 0.05 for each finding). When two of these five criteria were used in combination, the sensitivity and specificity for diagnosing mucin-producing cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct were 87% (27 of 31) and 87% (27 of 31), respectively. When two of these five criteria were used in combination, the sensitivity and specificity for diagnosing mucinous cystic neoplasms and cyst-forming intraductal papillary neoplasms of the bile duct were 87% (27 of 31) and 87% (27 of 31), respectively [corrected]. With the use of specific CT criteria, mucin-producing cystic neoplasms of the liver can be differentiated from solitary bile duct cysts with a high degree of accuracy.

Method and apparatus for duct sealing using a clog-resistant insertable injector

DOEpatents

Wang, Duo; Modera, Mark P.

2010-12-14

A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

User's Manual for DuctE3D: A Program for 3D Euler Unsteady Aerodynamic and Aeroelastic Analysis of Ducted Fans

NASA Technical Reports Server (NTRS)

Srivastava, R.; Reddy, T. S. R.

1997-01-01

The program DuctE3D is used for steady or unsteady aerodynamic and aeroelastic analysis of ducted fans. This guide describes the input data required and the output files generated, in using DuctE3D. The analysis solves three dimensional unsteady, compressible Euler equations to obtain the aerodynamic forces. A normal mode structural analysis is used to obtain the aeroelastic equations, which are solved using either the time domain or the frequency domain solution method. Sample input and output files are included in this guide for steady aerodynamic analysis and aeroelastic analysis of an isolated fan row.

Characteristics of a trapped-vortex (TV) combustor

NASA Technical Reports Server (NTRS)

Hsu, K.-Y.; Gross, L. P.; Trump, D. D.; Roquemore, W. M.

1994-01-01

The characteristics of a Trapped-Vortex (TV) combustor are presented. A vortex is trapped in the cavity established between two disks mounted in tandem. Fuel and air are injected directly into the cavity in such a way as to increase the vortex strength. Some air from the annular flow is also entrained into the recirculation zone of the vortex. Lean blow-out limits of the combustor are determined for a wide range of annular air flow rates. These data indicate that the lean blow-out limits are considerably lower for the TV combustor than for flames stabilized using swirl or bluff-bodies. The pressure loss through the annular duct is also low, being less than 2% for the flow conditions in this study. The instantaneous shape of the recirculation zone of the trapped vortex is measured using a two-color PIV technique. Temperature profiles obtained with CARS indicate a well mixed recirculation zone and demonstrate the impact of primary air injection on the local equivalence ratio.

Development of automated extraction method of biliary tract from abdominal CT volumes based on local intensity structure analysis

NASA Astrophysics Data System (ADS)

Koga, Kusuto; Hayashi, Yuichiro; Hirose, Tomoaki; Oda, Masahiro; Kitasaka, Takayuki; Igami, Tsuyoshi; Nagino, Masato; Mori, Kensaku

2014-03-01

In this paper, we propose an automated biliary tract extraction method from abdominal CT volumes. The biliary tract is the path by which bile is transported from liver to the duodenum. No extraction method have been reported for the automated extraction of the biliary tract from common contrast CT volumes. Our method consists of three steps including: (1) extraction of extrahepatic bile duct (EHBD) candidate regions, (2) extraction of intrahepatic bile duct (IHBD) candidate regions, and (3) combination of these candidate regions. The IHBD has linear structures and intensities of the IHBD are low in CT volumes. We use a dark linear structure enhancement (DLSE) filter based on a local intensity structure analysis method using the eigenvalues of the Hessian matrix for the IHBD candidate region extraction. The EHBD region is extracted using a thresholding process and a connected component analysis. In the combination process, we connect the IHBD candidate regions to each EHBD candidate region and select a bile duct region from the connected candidate regions. We applied the proposed method to 22 cases of CT volumes. An average Dice coefficient of extraction result was 66.7%.

Trauma pancreaticoduodenectomy for complex pancreaticoduodenal injury. Delayed reconstruction.

PubMed

Gupta, Vikas; Wig, Jai Dev; Garg, Harsh

2008-09-02

To assess the feasibility and safety of the delayed reconstruction approach in patients with complex pancreaticoduodenal injuries. Tertiary care center in Northern India. Five patients with complex pancreaticoduodenal injuries, three following blunt and two following penetrating injury. All patients underwent a pancreaticoduodenectomy. T-tube drainage of the common bile duct and external tube drainage of the pancreatic duct were established. A wide bore tube drain was left in the right upper abdomen. The postoperative course was uneventful in four patients. One patient died from coagulopathy on the 4th postoperative day. Delayed reconstruction was carried out in four patients. In one patient, a pancreaticojejunal anastomosis could not be performed. The postoperative period was uneventful and no patient had a biliary or a pancreatic leak. All four patients are well on follow-up. Delayed reconstruction in complex pancreaticoduodenal injuries is a feasible and viable option as was demonstrated by this study. Controlled external tube drainage of the bile and pancreatic ducts facilitates postoperative care and prevents on-going contamination of the peritoneal cavity with bile and pancreatic juice. Leaving behind the uncinate process shortens the operating time with less blood loss. Planned reconstruction is carried out once the inflammatory process has settled.

Building America Case Study: Compact Buried Ducts in a Hot-Humid Climate House, Lady's Island, South Carolina

DOE Office of Scientific and Technical Information (OSTI.GOV)

2016-02-01

A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely onmore » encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences, 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs, and 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.« less

Compact Buried Ducts in a Hot-Humid Climate House

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mallay, Dave

2016-01-07

"9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely onmore » encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.« less

[Vascular relationships of the right great splanchnic nerve in the thorax].

PubMed

Ndoye, J-M; Hamel, O; Hamel, A; Ploteau, S; Armstrong, O; Le Borgne, J; Rogez, J-M; Robert, R

2015-12-01

The surgical assumption of responsibility of the pancreatic pain requires either a truncular coelioscopic or radicular neurectomy of greater splanchnic nerves (gsn). The goal of our work is to describe the way and relations of the right gsn which are variable and rarely described. This constitutes an undeniable peroperational hemorrhagic risk during splanchnicectomy. After a double side thoracotomy and a bilateral sterno-clavicular desarticulation on 15 adult cadaveric subjects preserved by method of Winckler we removed the sterno-costal drill plate as well as the ventral rib arch and proceeded to a mediastinal evisceration of the thorax. Then we respected only the thoracic aorta and the oesophagus, the azygos venous system, the thoracic duct and the thoracic sympathetic chain. In some of the subjects, the azygos vein was injected (after catheterization of its stick) using gelatine coloured with blue paint. We studied the way and vascular relations of the right gsn. We measured the transverse distances between the origin of the gsn on one hand and the longitudinal axes of the azygos vein and the thoracic duct on the other hand. The relations of the right gsn trunk during its way related to the azygos vein in particular its constitutive origin and its affluents: ascending lumbar vein and twelfth intercostal vein. Sometimes the thoracic duct even a lymphatic node was near the gsn in the posterior infra-mediastinal space. A classification of the way and vascular relations of the right gsn in the thorax identified 3 anatomical types. The average distances separating the right gsn on one hand from the azygos vein and the thoracic duct on the other hand were respectively 5.7 mm and 11.2 mm. The vascular relations of the right gsn are very variable from one subject to another but primarily venous, sometimes lymphatic. They concerned the great thoracic vessels whose respect is essential in particular at the time of mini-invasive access procedure for a cœlioscopic splanchnicectomy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Bone marrow-derived mesenchymal stem cells effectively regenerate fibrotic liver in bile duct ligation rat model

PubMed Central

Elswefy, Sahar E; Rashed, Laila A; Younis, Nahla N; Shaheen, Mohamed A; Ghanim, Amal MH

2016-01-01

Mesenchymal stem cells (MSCs) have attracted lots of attention for the treatment of acute liver failure and end-stage liver diseases. This study aimed at investigating the fundamental mechanism by which bone marrow-derived MSCs (BM-MSCs) induce liver regeneration of fibrotic liver in rats. Rats underwent bile duct ligation (BDL) surgery and four weeks later they were treated with either BM-MSCs (3 × 106 cells /rat, once, tail vein injection) or silymarin (100 mg/kg, daily, orally) for four weeks. Liver function tests and hepatic oxidative stress were determined. Hepatic injury and fibrosis were assessed by H and E, Sirus red staining and immunohistochemical expression of α-smooth muscle actin (α-SMA). Hepatocyte growth factor (HGF) and the gene expression of cytokeratin-19 (CK-19) and matrix metalloproteinase-2 (MMP-2) in liver tissue were determined. BDL induced cholestatic liver injury characterized by elevated ALT and AST activities, bilirubin and decreased albumin. The architecture damage was staged as Metavir score: F3, A3. Fibrosis increased around proliferating bile duct as indicated by sirus red staining and α-SMA immunostaining. Fibrogenesis was favored over fibrolysis and confirmed by decreased HGF with increased expression of CK-19, but decreased MMP-2 expression. BM-MSCs treatment restored deteriorated liver functions and restored the histological changes, resolved fibrosis by improving liver regenerative capabilities (P < 0.001), increases in HGF and MMP-2 mRNA and downregulating CK-19 mRNA. Sliymarin, however, induced similar but less prominent effects compared to BM-MSCs. In conclusion, liver regenerative capabilities can be stimulated by BM-MSCs via augmentation of HGF that subsequently up-regulate MMP-2 mRNA while downregulating CK-19 mRNA. PMID:26811102

Ultrahigh-field imaging of the biliary tract at 7 T: initial results of gadoxetic acid-enhanced magnetic resonance cholangiography.

PubMed

Fischer, Anja; Kraff, Oliver; Orzada, Stephan; Nensa, Felix; Schäfer, Lena C; Ladd, Mark E; Umutlu, Lale; Lauenstein, Thomas C

2014-05-01

The objectives of this study were to assess the feasibility of magnetic resonance cholangiography (MRC) using biliary-secreted gadoxetic acid at 7 T and to compare it with T2-weighted (w) MRC at 3 T. Ten healthy volunteers were examined on a 7-T whole-body magnetic resonance system. T2-weighted turbo-spin-echo sequence, T1-w volume-interpolated breath-hold examination (VIBE), and fast low-angle shot (FLASH) with inversion recovery (IR) were acquired in coronal orientation. For dynamic imaging, gadoxetic acid was administrated and data were collected for a period of 5 to 40 minutes after injection. The volunteers underwent subsequent T2-w respiratory-gated MRC at 3 T. For qualitative analysis, a 5-point scale was used. Contrast ratios (CRs) were calculated for quantitative assessment. Contrast-enhanced T1-w MRC at 7 T showed a homogeneous depiction of the intrahepatic and extrahepatic biliary tract with a maximum enhancement of 20 minutes after contrast. Volume-interpolated breath-hold examination and FLASH IR provided a good image quality for the intrahepatic (VIBE, 3.60; FLASH IR, 3.67) and extrahepatic bile ducts (VIBE, 3.50; FLASH IR, 3.72). The quantitative analysis revealed high CR values for FLASH IR (intrahepatic CR, 0.41; extrahepatic CR, 0.45) because of an effective suppression of hepatic tissue and vessels. The T2-w TSE at 7 T showed only a poor image quality without diagnostic potential (intrahepatic, 2.22; extrahepatic, 1.93). Seven-tesla VIBE and FLASH revealed superiority in the depiction of the intrahepatic bile ducts, whereas 3-T MRC was superior in the delineation of the extrahepatic biliary tract. Our results demonstrate the feasibility of contrast-enhanced imaging of the biliary ducts at 7 T.

Bone marrow-derived mesenchymal stem cells effectively regenerate fibrotic liver in bile duct ligation rat model.

PubMed

Mohamed, Hoda E; Elswefy, Sahar E; Rashed, Laila A; Younis, Nahla N; Shaheen, Mohamed A; Ghanim, Amal M H

2016-03-01

Mesenchymal stem cells (MSCs) have attracted lots of attention for the treatment of acute liver failure and end-stage liver diseases. This study aimed at investigating the fundamental mechanism by which bone marrow-derived MSCs (BM-MSCs) induce liver regeneration of fibrotic liver in rats. Rats underwent bile duct ligation (BDL) surgery and four weeks later they were treated with either BM-MSCs (3 × 10(6) cells /rat, once, tail vein injection) or silymarin (100 mg/kg, daily, orally) for four weeks. Liver function tests and hepatic oxidative stress were determined. Hepatic injury and fibrosis were assessed by H and E, Sirus red staining and immunohistochemical expression of α-smooth muscle actin (α-SMA). Hepatocyte growth factor (HGF) and the gene expression of cytokeratin-19 (CK-19) and matrix metalloproteinase-2 (MMP-2) in liver tissue were determined. BDL induced cholestatic liver injury characterized by elevated ALT and AST activities, bilirubin and decreased albumin. The architecture damage was staged as Metavir score: F3, A3. Fibrosis increased around proliferating bile duct as indicated by sirus red staining and α-SMA immunostaining. Fibrogenesis was favored over fibrolysis and confirmed by decreased HGF with increased expression of CK-19, but decreased MMP-2 expression. BM-MSCs treatment restored deteriorated liver functions and restored the histological changes, resolved fibrosis by improving liver regenerative capabilities (P < 0.001), increases in HGF and MMP-2 mRNA and downregulating CK-19 mRNA. Sliymarin, however, induced similar but less prominent effects compared to BM-MSCs. In conclusion, liver regenerative capabilities can be stimulated by BM-MSCs via augmentation of HGF that subsequently up-regulate MMP-2 mRNA while downregulating CK-19 mRNA. © 2016 by the Society for Experimental Biology and Medicine.

Effect of heme oxygenase-1 on the protection of ischemia reperfusion injury of bile duct in rats after liver transplantation.

PubMed

Zhan, Xi; Zhang, Zhiqing; Huang, Hanfei; Zhang, Yujun; Zeng, Zhong

2018-06-01

To investigate the effect of heme oxygenase-1 (HO-1) on the ischemic reperfusion injury (IRI) of bile duct in rat models after liver transplantation. 320 SD rats were equally and randomly divided into 5 groups, which were group A receiving injection of 3×10 8 /pfu/ml adenovirus (adv), group B with donor receiving Adv-HO-1 and recipient receiving Adv-HO-1-siRNA, group C with donor and recipient both receiving Adv-HO-1, group D with donor receiving Adv-HO-1-siRNA and recipient receiving Adv-HO-1, and group E with donor and recipient both receiving Adv-HO-1-siRNA at 24h before liver transplantation. Donor liver was stored in UW liquid at 4°C followed by measuring HO-1 level by western blot before transplantation. On d1, d3, d7 and d14, serum and liver was isolated for analysis of liver function, inflammatory cell infiltration by H&E staining, ultrastructure of liver by transmission electron microscopy as well as the expression of HO-1, Bsep, Mrp2 and Ntcp by western blot. Compared with group D and E, group B and C displayed improved liver function as demonstrated by lower level of ALT, AST, LDH, TBIL, ALP and GGT, increased secretion of TBA and PL as well as expression of transporter proteins (Bsep, Mrp2 and Ntcp), reduced inflammatory cells infiltration and liver injury. Our study demonstrated that overexpression of HO-1 in donor liver can ameliorate the damage to bile duct and liver, and improved liver function, suggesting HO-1 might be a new therapeutic target in the treatment of IRI after liver transplantation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Using Innovative Technologies for Manufacturing Rocket Engine Hardware

NASA Technical Reports Server (NTRS)

Betts, E. M.; Eddleman, D. E.; Reynolds, D. C.; Hardin, N. A.

2011-01-01

Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As the United States enters into the next space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, rapid manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on NASA s Space Launch System (SLS) upper stage engine, J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator (GG) discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using a workhorse gas generator (WHGG) test fixture at MSFC's East Test Area, the duct was subjected to extreme J-2X hot gas environments during 7 tests for a total of 537 seconds of hot-fire time. The duct underwent extensive post-test evaluation and showed no signs of degradation. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

Using Innovative Techniques for Manufacturing Rocket Engine Hardware

NASA Technical Reports Server (NTRS)

Betts, Erin M.; Reynolds, David C.; Eddleman, David E.; Hardin, Andy

2011-01-01

Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using the Workhorse Gas Generator (WHGG) test setup at MSFC?s East Test Area test stand 116, the duct was subject to extreme J-2X gas generator environments and endured a total of 538 seconds of hot-fire time. The duct survived the testing and was inspected after the test. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

Rocket Propellant Ducts (Cryogenic Fuel Lines): First Cut Approximations and Design Guidance

NASA Technical Reports Server (NTRS)

Brewer, William V.

1998-01-01

The design team has to set parameters before analysis can take place. Analysis is customarily a thorough and time consuming process which can take weeks or even months. Only when analysis is complete can the designer obtain feedback. If margins are negative, the process must be repeated to a greater or lesser degree until satisfactory results are achieved. Reduction of the number of iterations thru this loop would beneficially conserve time and resources. The task was to develop relatively simple, easy to use, guidelines and analytic tools that allow the designer to evaluate what effect various alternatives may have on performance as the design progresses. "Easy to use" is taken to mean closed form approximations and the use of graphic methods. "Simple" implies that 2-d and quasi 3-d approximations be exploited to whatever degree is useful before more resource intensive methods are applied. The objective is to avoid the grosser violation of performance margins at the outset. Initial efforts are focused on thermal expansion/contraction and rigid body kinematics as they relate to propellant duct displacements in the gimbal plane loop (GPL). The purpose of the loop is to place two flexible joints on the same two orthogonal intersecting axes as those of the rocket motor gimbals. This supposes the ducting will flex predictably with independent rotations corresponding to those of the motor gimbal actions. It can be shown that if GPL joint axes do not coincide with motor gimbal axes, displacement incompatibilities result in less predictable movement of the ducts.

FUNDAMENTAL PROCESSES INVOLVED IN SO2 CAPTURE BY CALCIUM-BASED ADSORBENTS

EPA Science Inventory

The paper discusses the fundamental processes in sulfur dioxide (SO2) capture by calcium-based adsorbents for upper furnace, duct, and electrostatic precipitator (ESP) reaction sites. It examines the reactions in light of controlling mechanisms, effect of sorbent physical propert...

Bile Duct Cancer (Cholangiocarcinoma) Treatment (PDQ®)—Health Professional Version

Cancer.gov

Bile duct cancer (also called cholangiocarcinoma) can occur in the bile ducts in the liver (intrahepatic) or outside the liver (perihilar or distal extrahepatic). Learn about the types of bile duct cancer, risk factors, clinical features, staging, and treatment for bile duct cancer in this expert-reviewed summary.

Ducted turbine theory with right angled ducts

NASA Astrophysics Data System (ADS)

McLaren-Gow, S.; Jamieson, P.; Graham, J. M. R.

2014-06-01

This paper describes the use of an inviscid approach to model a ducted turbine - also known as a diffuser augmented turbine - and a comparison of results with a particular one-dimensional theory. The aim of the investigation was to gain a better understanding of the relationship between a real duct and the ideal diffuser, which is a concept that is developed in the theory. A range of right angled ducts, which have a rim for a 90° exit angle, were modelled. As a result, the performance of right angled ducts has been characterised in inviscid flow. It was concluded that right angled ducts cannot match the performance of their associated ideal diffuser and that the optimum rotor loading for these turbines varies with the duct dimensions.

Air conditioning system and component therefore distributing air flow from opposite directions

NASA Technical Reports Server (NTRS)

Obler, H. D.; Bauer, H. B. (Inventor)

1974-01-01

The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

Bile duct hamartomas (von Mayenburg complexes) mimicking liver metastases from bile duct cancer: MRC findings

PubMed Central

Nagano, Yasuhiko; Matsuo, Kenichi; Gorai, Katsuya; Sugimori, Kazuya; Kunisaki, Chikara; Ike, Hideyuki; Tanaka, Katsuaki; Imada, Toshio; Shimada, Hiroshi

2006-01-01

We present a case of a 72-year-old man with a common bile duct cancer, who was initially believed to have multiple liver metastases based on computed tomography findings, and in whom magnetic resonance cholangiography (MRC) revealed a diagnosis of bile duct hamartomas. At exploration for pancreaticoduodenectomy, liver palpation revealed disseminated nodules at the surface of the liver. These nodules showed gray-white nodular lesions of about 0.5 cm in diameter scattered on the surface of both liver lobes, which were looked like multiple liver metastases from bile duct cancer. Frozen section of the liver biopsy disclosed multiple bile ducts with slightly dilated lumens embedded in the collagenous stroma characteristics of multiple bile duct hamartomas (BDHs). Only two reports have described the MRC features of bile duct hamartomas. Of all imaging procedures, MRC provides the most relevant features for the imaging diagnosis of bile duct hamartomas. PMID:16534895

Risk Factors for Bile Duct Injury After Percutaneous Thermal Ablation of Malignant Liver Tumors: A Retrospective Case-Control Study.

PubMed

Lin, Man-Xia; Ye, Jie-Yi; Tian, Wen-Shuo; Xu, Ming; Zhuang, Bo-Wen; Lu, Ming-De; Xie, Xiao-Yan; Kuang, Ming

2017-04-01

Bile duct injury after ablation of malignant liver tumors (MLTs) was not unusual and should be avoided. However, few studies have focused on evaluating the risk factors for intrahepatic bile duct injury. To evaluate the risk factors for intrahepatic bile duct injury after ablation of MLTs and to evaluate the minimum safe distance for ablating tumors abutting bile ducts. Sixty-five patients with intrahepatic bile duct injury after ablation of MLTs, and 65 controls were recruited. Risk factors for intrahepatic bile duct injury were analyzed. Tumor location was recorded as ≤5 mm (group A), 5-10 mm (group B), and >10 mm (group C) from the right/left main duct or segmental bile duct. Ascites history (P < 0.001), TACE treatment history (P = 0.025), intrahepatic bile duct dilatation before ablation (P < 0.001), and tumor location (P = 0.000) were identified as significant risk factors for intrahepatic bile duct injury. Significant differences in the risk of intrahepatic bile duct injury were found between groups B and C (P = 0.000), but not between groups A and B (P = 0.751). Ascites history (P = 0.002) and tumor location (P < 0.001) were independent predictors with the OR (95 % confidence interval) of 39.31(3.95-391.69) and 16.56 (5.87-46.71), respectively. Bile duct injury after ablation of MLTs was the result of local treatment-related factors combined with the patients' general condition. The minimum safe distance for ablation of tumor abutting a bile duct was 10 mm.

Assessment of Chronological Effects of Irreversible Electroporation on Hilar Bile Ducts in a Porcine Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Jae Woong, E-mail: cooljay@korea.ac.kr; Lu, David S. K., E-mail: dlu@mednet.ucla.edu; Osuagwu, Ferdnand, E-mail: fosuagwu@mednet.ucla.edu

2013-11-07

PurposeTo evaluate the chronological effects of irreversible electroporation (IRE) on large hilar bile ducts in an in vivo porcine model correlated with computed tomography (CT) cholangiography and histopathology.Materials and MethodsTwelve IRE zones were made along hilar bile ducts intraoperatively under ultrasound (US)-guidance in 11 pigs. Paired electrodes were placed either on opposing sides of the bile duct (straddle [STR]) or both on one side of the bile duct (one-sided [OSD]). The shortest electrode-to-duct distance was classified as periductal (≤2 mm) or nonperiductal (>2 mm). CT cholangiography and laboratory tests were performed before IRE and again at 2 days, 4 weeks, and 8 weeks after IRE.more » Degree of bile duct injury were graded as follows: grade 0 = no narrowing; grade 1 = ≤50 % duct narrowing; grade 2 = >50 % narrowing without proximal duct dilatation; grade 3 = grade 2 with proximal duct dilatation; and grade 4 = grade 3 with enzyme elevation. Pigs were selected for killing and histopathology at 2 days, 4, and 8 weeks.ResultsNonperiductal electrode placement produced no long-term strictures in 5 of 5 ducts. Periductal electrode placement produced mild narrowing in 6 of 7 ducts: 5 grade 1 and 1 grade 2. None showed increased enzymes. There was no significant difference between STR versus OSD electrode placement. Histopathology showed minor but relatively greater ductal mural changes in narrowed ducts.ConclusionIn the larger hilar ducts, long-term patency and mural integrity appear resistant to IRE damage with the energy deposition used, especially if the electrode is not immediately periductal in position.« less

Pathology, Organ Distribution, and Immune Response after Single and Repeated Intravenous Injection of Rats with Clinical-Grade Parvovirus H1

PubMed Central

Geletneky, Karsten; Leoni, Anne-Laure; Pohlmeyer-Esch, Gabriele; Loebhard, Stephanie; Baetz, Andrea; Leuchs, Barbara; Roscher, Mandy; Hoefer, Constance; Jochims, Karin; Dahm, Michael; Huber, Bernard; Rommelaere, Jean; Krebs, Ottheinz; Hajda, Jacek

2015-01-01

Parvovirus H1 (H1PV) is an autonomous parvovirus that is transmitted in rodent populations. Its natural host is rats. H1PV infection is nonpathogenic except in rat and hamster fetuses and newborns. H1PV infection of human cancer cells caused strong oncolytic effects in preclinical models. For a clinical trial of H1PV in patients with brain tumors, clinical-grade H1PV was produced according to Good Manufacturing Practices. This report focuses on results obtained after a single high-dose intravenous injection of highly purified H1PV in 30 rats and multiple (n = 17) intravenous injections at 3 dose levels in 223 rats. In both studies, no virus-related mortality or macroscopic organ changes related to H1PV occurred. Histopathology after multiple virus injections revealed minimal diffuse bile duct hyperplasia in livers of animals of the highest dose group and germinal center development in spleens of animals from the high-dose group. Liver changes were reversible within a 2-wk recovery period after the last injection. Hematology, blood chemistry, and coagulation analyses did not reveal significant toxicologic changes due to H1PV. Virus injection stimulated the production of IgG antibodies but did not alter mononuclear cell function or induce cytokine release. PCR analysis showed dose-dependent levels of viral genomes in all organs tested. The virus was excreted primarily through feces. These data provide important information regarding H1PV infection in its natural host. Due to the confirmation of the favorable safety profile of H1PV in a permissive animal model, a phase I/IIa clinical trial of H1PV in brain tumor patients could be initiated. PMID:25730754

Biliary complications after right lobe living donor liver transplantation: a single-centre experience

PubMed Central

Yaprak, Onur; Dayangac, Murat; Akyildiz, Murat; Demirbas, Tolga; Guler, Necdet; Bulutcu, Fisun; Bassullu, Nuray; Akun, Elif; Yuzer, Yildiray; Tokat, Yaman

2012-01-01

Background Biliary complications that developed after right lobe liver transplantation from living donors were studied in a single centre. Methods From 2004 to 2010, 200 consecutive living donor right lobe liver transplantations were performed. The database was evaluated retrospectively. Biliary complications were diagnosed according to clinical, biochemical and radiological tests. The number of biliary ducts in the transplanted graft, the surgical techniques used for anastomosis, biliary strictures and bile leakage rates were analysed. Results Of a total of 200 grafts, 117 invloved a single bile duct, 77 had two bile ducts and in six grafts there were three bile ducts. In 166 transplants, the anastomosis was performed as a single duct to duct, in 21 transplants double duct to ducts, in one transplant, three duct to ducts and in 12 transplants as a Roux-en-Y reconstruction. In all, 40 bile leakages (20%) and 17 biliary strictures (8.5%) were observed in 49 patients resulting in a total of 57 biliary complications (28.5%). Seventeen patients were re-operated (12 as a result of bile leakages and five owing to biliary strictures). Conclusion Identification of more than one biliary orifice in the graft resulted in an increase in the complication rates. In grafts containing multiple orifices, performing multiple duct-to-duct (DD) or Roux-en-Y anastomoses led to a lower number of complications. PMID:22151451

Traumatic resin ducts as indicators of bark beetle outbreaks

Treesearch

R. Justin DeRose; Matthew F. Bekker; James N. Long

2017-01-01

The formation of traumatic resin ducts (TRDs) represents an important induced defense in woody plants that enhances oleoresin production and flow in response to environmental perturbations. In some genera (Pinus), resin ducts are copious and conspicuous; however, in others (Picea), resin ducts are relatively rare. The occurrence and strength of resin ducts, in...

Bile Duct Cancer (Cholangiocarcinoma) Symptoms, Tests, Prognosis, and Stages (PDQ®)—Patient Version

Cancer.gov

Bile duct cancer, or cholangiocarcinoma, is rare. Bile ducts are tubes that carry bile between the liver, gallbladder, and small intestine. Bile duct cancer can occur in the intrahepatic, perihilar (Klatskin tumor), or distal extrahepatic area. Learn about tests to diagnose and the stages of bile duct cancer.

CPI-613 in Treating Patients With Advanced or Metastatic Bile Duct Cancer That Cannot Be Removed By Surgery

ClinicalTrials.gov

2018-05-22

Adult Primary Cholangiocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Localized Unresectable Adult Primary Liver Cancer; Metastatic Extrahepatic Bile Duct Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Unresectable Extrahepatic Bile Duct Cancer

Numerical and experimental investigation of conventional and un-conventional preswirl duct for VLCC

NASA Astrophysics Data System (ADS)

Shin, Hyun-Joon; Lee, Jong-Seung; Lee, Kang-Hoon; Han, Myung-Ryun; Hur, Eui-Beom; Shin, Sung-Chul

2013-09-01

This paper shows the study of preswirl duct as an effective energy saving devices that have been devised and reviewed to support the propeller performance, especially for the ship of VLCC with large block coefficients. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The 2 kinds of pre-swirl duct, Unconventional half circular duct and Conventional circular pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction. The optimum self propulsion tests with various angle configurations were carried out and the best configuration was decided. Accordingly, cavitation test was carried out with best configuration of unconventional half circular duct. The blade surface and tip vortex cavitation behaved smoother when the duct was mounted. The hull pressure amplitudes reflected this difference, so the hull pressure amplitude with duct was smaller than that of without duct.

Carbachol-induced fluid movement through methazolamide-sensitive bicarbonate production in rat parotid intralobular ducts: quantitative analysis of fluorescence images using fluorescent dye sulforhodamine under a confocal laser scanning microscope.

PubMed

Nakamoto, Tetsuji; Shiba, Yoshiki; Hirono, Chikara; Sugita, Makoto; Takemoto, Kazuhisa; Iwasa, Yoshiko; Akagawa, Yasumasa

2002-09-01

Fluid secretion is observed at the openings of ducts in the exocrine gland. It remains unclear whether the ducts are involved in fluid secretion in the salivary glands. In the present study, we investigated the exclusion of fluorescent dye from the duct lumen by carbachol (CCh) in isolated parotid intralobular duct segments to clarify the ability of the ducts for the fluid secretion. When the membrane-impermeable fluorescent dye, sulforhodamine, was added to the superfused extracellular solution, quantitative fluorescence images of the duct lumen were obtained under the optical sectioning at the level of the duct lumen using a confocal laser scanning microscope. CCh decreased the fluorescent intensity in the duct lumen during the superfusion of the fluorescent dye, and CCh flushed out small viscous substances stained with the fluorescent dye from isolated duct lumen, suggesting that CCh might induce fluid secretion in the duct, leading to the clearance of the dye and small stained clumps from the duct lumen. CCh-induced clearance of the fluorescent dye was divided into two phases by the sensitivity to external Ca2+ and methazolamide, an inhibitor for carbonic anhydrase. The initial phase was insensitive to these, and the subsequent late phase was sensitive to these. A major portion in the late phase was inhibited by removal of bicarbonate in the superfusion solution and DPC, but not low concentration of external Cl-, bumetanide or DIDS, suggesting that methazolamide-sensitive production of HCO3-, but not the Cl- uptake mechanism, might contribute to the CCh-induced clearance of the dye from the duct lumen. These results represent the first measurements of fluid movement in isolated duct segments, and suggest that carbachol might evoke fluid secretion possibly through Ca2+-activated, DPC-sensitive anion channels with HCO3- secretion in the rat parotid intralobular ducts.

Mixing and NOx Emission Calculations of Confined Reacting Jet Flows in Cylindrical and Annular Ducts

NASA Technical Reports Server (NTRS)

Oechsle, Victor L.; Connor, Christopher H.; Holdeman, James D. (Technical Monitor)

2000-01-01

Rapid mixing of cold lateral jets with hot cross-stream flows in confined configurations is of practical interest in gas turbine combustors as it strongly affects combustor exit temperature quality, and gaseous emissions in for example rich-lean combustion. It is therefore important to further improve our fundamental understanding of the important processes of dilution jet mixing especially when the injected jet mass flow rate exceeds that of the cross-stream. The results reported in this report describe some of the main flow characteristics which develop in the mixing process in a cylindrical duct. A three-dimensional computational fluid dynamics (CFD) code has been used to predict the mixing flow field characteristics and NOx emission in a quench section of a rich-burn/quick-mix/lean-burn (RQL) combustor. Sixty configurations have been analyzed in both circular and annular geometries in a fully reacting environment simulating the operating condition of an actual RQL gas turbine combustion liner. The evaluation matrix was constructed by varying the number of orifices per row and orifice shape. Other parameters such as J (momentum-flux ratio), MR (mass flowrate ratio), DR (density ratio), and mixer sector orifice ACd (effective orifice area) were maintained constant throughout the entire study. The results indicate that the mixing flow field can be correlated with the NOx production if they are referenced with the stoichiometric equivalence ratio value and not the equilibrium value. The mixing flowfields in both circular and annular mixers are different. The penetration of equal jets in both annular and circular geometries is vastly different which significantly affects the performance of the mixing section. In the computational results with the circular mixer, most of the NOx formation occurred behind the orifice starting at the orifice wake region. General trends have been observed in the NOx production as the number of orifices is changed and this appears to be common for all hole configurations and mixer types (circular or annular). The performance of any orifice shape (in producing minimum NOx) appears to be acceptable if the number of orifices can be freely varied in order to attain the optimum jet penetration.

Carcinoids of the common bile duct: a case report and literature review

PubMed Central

Ross, Alison C.; Hurley, James B.; Hay, W. Bruce; Rusnak, Conrad H.; Petrunia, Denis M.

1999-01-01

Carcinoids of the extrahepatic bile ducts and particularly the common bile duct are extremely rare. A 65-year-old woman presented with obstructive jaundice. Laboratory and imaging studies gave results that were consistent with an obstructing lesion in the common bile duct. In this case, a stent was inserted initially to decompress the bile ducts. Subsequently a laparotomy and pancreaticoduodenectomy were performed and a tissue diagnosis of carcinoid of the common bile duct was made. The patient was well with no evidence of recurrence 17 months postoperatively. The authors believe this is the 19th reported case of an extrahepatic bile duct carcinoid. PMID:10071590

Hollow lensing duct

DOEpatents

Beach, Raymond J.; Honea, Eric C.; Bibeau, Camille; Mitchell, Scott; Lang, John; Maderas, Dennis; Speth, Joel; Payne, Stephen A.

2000-01-01

A hollow lensing duct to condense (intensify) light using a combination of focusing using a spherical or cylindrical lens followed by reflective waveguiding. The hollow duct tapers down from a wide input side to a narrow output side, with the input side consisting of a lens that may be coated with an antireflective coating for more efficient transmission into the duct. The inside surfaces of the hollow lens duct are appropriately coated to be reflective, preventing light from escaping by reflection as it travels along the duct (reflective waveguiding). The hollow duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials.

Convolution seal for transition duct in turbine system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston

2015-05-26

A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface feature for interfacing with an adjacent transition duct. The turbine system further includes a convolution seal contacting the interface feature to provide a seal between the interface feature andmore » the adjacent transition duct.« less

Mammary Duct Ectasia

MedlinePlus

... tenderness or inflammation of the clogged duct (periductal mastitis). Mammary duct ectasia most often occurs in women ... that's turned inward (inverted) A bacterial infection called mastitis also may develop in the affected milk duct, ...

Acoustic radiation from lined, unflanged ducts: Acoustic source distribution program

NASA Technical Reports Server (NTRS)

Beckemeyer, R. J.; Sawdy, D. T.

1971-01-01

An acoustic radiation analysis was developed to predict the far-field characteristics of fan noise radiated from an acoustically lined unflanged duct. This analysis is comprised of three modular digital computer programs which together provide a capability of accounting for the impedance mismatch at the duct exit plane. Admissible duct configurations include circular or annular, with or without an extended centerbody. This variation in duct configurations provides a capability of modeling inlet and fan duct noise radiation. The computer programs are described in detail.

Dynamic Observation of the Morphological Changes in Paraurethral Ducts Infected with Gonococci in Men before and after Ceftriaxone Therapy Using High-Frequency Ultrasound.

PubMed

Fan, Wenge; Zhang, Qingsong; Ye, Xun; Fan, Zhijiang

2018-01-01

To observe the morphological changes in paraurethral ducts infected with gonococci in men before and after the administration of the ceftriaxone therapy using high-frequency ultrasound and determine its clinical significance. Thirty-two male patients with gonococcal paraurethral duct infection were enrolled. Their lesions were examined using an ACUSON X300 ultrasound system before and after they were subjected to ceftriaxone therapy. The paraurethral duct was completely closed 3-4 days after ceftriaxone treatment in 30 patients. Paraurethral duct closure began from the blind end and proceeded gradually towards its orifice; during closure, the paraurethral duct diameter showed no apparent change. These 30 patients whose paraurethral ducts closed were considered cured. In the remaining 2 patients, the length and diameter of the paraurethral ducts showed no change before and after ceftriaxone treatment; one patient was unresponsive to ceftriaxone treatment, and the other had secondary dilatation of the paraurethral duct. These 2 patients were cured after surgery. High-frequency ultrasound enables dynamic observation of the morphological changes in paraurethral ducts infected with gonococci before and after ceftriaxone therapy. High-frequency ultrasound can provide valuable information for incision, drainage, and wedge resection of paraurethral ducts. © 2017 S. Karger AG, Basel.

Heat Transfer Computations of Internal Duct Flows With Combined Hydraulic and Thermal Developing Length

NASA Technical Reports Server (NTRS)

Wang, C. R.; Towne, C. E.; Hippensteele, S. A.; Poinsatte, P. E.

1997-01-01

This study investigated the Navier-Stokes computations of the surface heat transfer coefficients of a transition duct flow. A transition duct from an axisymmetric cross section to a non-axisymmetric cross section, is usually used to connect the turbine exit to the nozzle. As the gas turbine inlet temperature increases, the transition duct is subjected to the high temperature at the gas turbine exit. The transition duct flow has combined development of hydraulic and thermal entry length. The design of the transition duct required accurate surface heat transfer coefficients. The Navier-Stokes computational method could be used to predict the surface heat transfer coefficients of a transition duct flow. The Proteus three-dimensional Navier-Stokes numerical computational code was used in this study. The code was first studied for the computations of the turbulent developing flow properties within a circular duct and a square duct. The code was then used to compute the turbulent flow properties of a transition duct flow. The computational results of the surface pressure, the skin friction factor, and the surface heat transfer coefficient were described and compared with their values obtained from theoretical analyses or experiments. The comparison showed that the Navier-Stokes computation could predict approximately the surface heat transfer coefficients of a transition duct flow.

Advanced Duct Sealing Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherman, Max H.; Walker, Iain S.

Duct leakage has been identified as a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums or branches in the duct system. At each of these connections a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with naturalmore » rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of five UL 181B-FX listed duct tapes (three cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The first test involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars, and sheet metal ''collar-to-plenum joints'' pressurized with 200 F (93 C) air. The second test consisted of baking duct tape specimens in a constant 212 F (100 C) oven following the UL 181B-FX ''Temperature Test'' requirements. Additional tests were also performed on only two tapes using sheet metal collar-to-plenum joints. Since an unsealed flexible duct joint can have a variable leakage depending on the positioning of the flexible duct core, the durability of the flexible duct joints could not be based on the 10% of unsealed leakage criteria. Nevertheless, the leakage of the sealed specimens prior to testing could be considered as a basis for a failure criteria. Visual inspection was also documented throughout the tests. The flexible duct core-to-collar joints were inspected monthly, while the sheet metal collar-to-plenum joints were inspected weekly. The baking test specimens were visually inspected weekly, and the durability was judged by the observed deterioration in terms of brittleness, cracking, flaking and blistering (the terminology used in the UL 181B-FX test procedure).« less

[Stenon or Stensen duct. How sholud we call the secretory duct of the parotid gland? Brief biography of its discoverer].

PubMed

Morais Pérez, D

2004-01-01

The duct of the parotid gland had been indiscriminately named Stenon's duct or Stensen's duct. In order to establish its origin we carried out a biographic search and a brief revision of the life of the great anatomist, geologist, palaeontologist, bishop and finally Saint Nicolaus Stensen.

Experimental and Numerical Study on Performance of Ducted Hydrokinetic Turbines with Pre-Swirl Stator Blades.

NASA Astrophysics Data System (ADS)

Gish, Andrew

2015-11-01

Ducts (also called shrouds) have been shown to improve performance of hydrokinetic turbines in some situations, bringing the power coefficient (Cp) closer to the Betz limit. Here we investigate optimization of the duct design as well as the addition of stator blades upstream of the turbine rotor to introduce pre-swirl in the flow. A small scale three-bladed turbine was tested in a towing tank. Three cases (bare turbine, with duct, and with duct and stators) were tested over a range of flow speeds. Important parameters include duct cross-sectional shape, blade-duct gap, stator cross-sectional shape, and stator angle. For each test, Cp was evaluated as a function of tip speed ratio (TSR). Experimental results were compared with numerical simulations. Results indicate that ducts and stators can improve performance at slower flow speeds and lower the stall speed compared to a bare turbine, but may degrade performance at higher speeds. Ongoing efforts to optimize duct and stator configurations will be discussed.

Investigation of the tone-burst tube for duct lining attenuation measurement

NASA Technical Reports Server (NTRS)

Soffel, A. R.; Morrow, P. F.

1972-01-01

The tone burst technique makes practical the laboratory evaluation of potential inlet and discharge duct treatments. Tone burst apparatus requires only simple machined parts and standard components. Small, simply made, lining samples are quickly and easily installed in the system. Two small electromagnetric loudspeaker drivers produce peak sound pressure level of over 166 db in the 3-square-inch sample duct. Air pump available in most laboratories can produce air flows of over plus and minus Mach 0.3 in the sample duct. The technique uses short shaped pulses of sound propagated down a progressive wave tube containing the sample duct. The peak pressure level output of the treated duct is compared with the peak pressure level output of a substituted reference duct. The difference between the levels is the attenuation or insertion loss of the treated duct. Evaluations of resonant absorber linings by the tone burst technique check attenuation values predicted by empirical formulas based on full scale ducts.

Application of "papillary-like main pancreatic duct invaginated" pancreaticojejunostomy for normal soft pancreas cases.

PubMed

Zhang, Bo; Xu, Jin; Liu, Chen; Long, Jiang; Liu, Liang; Xu, Yongfeng; Wu, Chuntao; Luo, Guopei; Ni, Quanxing; Li, Min; Yu, Xianjun

2013-01-01

Pancreaticojejunostomy is the key procedure of pancreaticoduodenectomy. Our study introduced a new pancreaticojejunal (PJ) anastomosis named "papillary-like main pancreatic duct invaginated" pancreaticojejunostomy. Nighty-two patients underwent pancreaticojejunostomy with either conventional duct-to-mucosa pancreaticojejunostomy or the new "papillary-like main pancreatic duct invaginated" techniques were analyzed retrospectively from January 2010 to September 2012. The incidence of pancreatic fistula was 15.7% (8/51) for the "papillary-like main pancreatic duct invaginated" group and 19.5% (8/41) for the duct-to-mucosa fashion respectively. It is noteworthy that the rate of grade B/C postoperative pancreatic fistula (POPF) in the "papillary-like main pancreatic duct invaginated" group was significantly lower than that of the duct-to-mucosa group (P = 0.039). There were no differences in the incidence of postoperative morbidity and mortality such as postoperative hemorrhage, delayed gastric emptying or remnant pancreatitis. The "papillary-like main pancreatic duct invaginated" pancreaticojejunostomy could provide a feasible option to pancreatic surgeons for patients with normal soft pancreas.

An estimate of the noise shielding on the fuselage resulting from installing a short duct around an advanced propeller

NASA Technical Reports Server (NTRS)

Dittmar, James H.

1988-01-01

A simple barrier shielding model was used to estimate the amount of noise shielding on the fuselage that could result from installing a short duct around a wing-mounted advanced propeller. With the propeller located one-third of the duct length from the inlet, estimates for the maximum blade passing tone attenuation varied from 7 dB for a duct 0.25 propeller diameter long to 16.75 dB for a duct 1 diameter long. Attenuations for the higher harmonics would be even larger because of their shorter wavelengths relative to the duct length. These estimates show that the fuselage noise reduction potential of a ducted compared with an unducted propeller is significant. Even more reduction might occur if acoustic attenuation material were installed in the duct.

Design integration and noise studies for jet STOL aircraft. Task 7C: Augmentor wing cruise blowing valveless system. Volume 2: Small-scale development testing of augmentor wing critical ducting components

NASA Technical Reports Server (NTRS)

Runnels, J. N.; Gupfa, A.

1973-01-01

Augmentor wing ducting system studies conducted on a valveless system configuration that provides cruise thrust from the augmentor nozzles have shown that most of the duct system pressure loss would occur in the strut-wing duct y-junction and the wing duct-augmentor lobe nozzles. These components were selected for development testing over a range of duct Mach numbers and pressure ratios to provide a technical basis for predicting installed wing thrust loading and for evaluating design wing loading of a particular wing aspect ratios. The flow characteristics of ducting components with relatively high pressure loss coefficients were investigated. The turbulent pressure fluctuations associated with flows at high Mach numbers were analyzed to evaluate potential duct fatigue problems.

Pancreatic-duct-lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

PubMed

Sai, Jin Kan; Suyama, Masafumi; Kubokawa, Yoshihiro; Watanabe, Sumio; Maehara, Tadayuki

2009-03-01

The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results. To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines. Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter. Single-center retrospective study. Academic medical center. The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs. More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively. Single-center and small number of patients. Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

Voluntary and involuntary ligature of the bile duct in iatrogenic injuries: a nonadvisable approach.

PubMed

Mercado, Miguel Angel; Chan, Carlos; Jacinto, Juan Carlos; Sanchez, Norberto; Barajas, Alexandra

2008-06-01

Bile duct injuries related to laparoscopic and/or open cholecystectomy are a frequent finding and require surgical treatment. Complete obstruction is due to either intentionally or unintentionally placed ligatures or clips. The intentional application is usually performed to "facilitate identification of the duct by bile duct dilation." Considering that we are a national referral center for such injuries, we decided to analyze our cases of voluntary and involuntary duct ligation after iatrogenic bile duct injury. We reviewed the files of patients with voluntary or involuntary bile duct ligation. Results of preoperative evaluation of the ducts, operative treatment, and postoperative results were analyzed. A total of 413 patients were included. Forty-five patients presented with complete obstruction. In 15 cases, the ligature was intentional, and in 30 cases, occlusion was involuntary. Bile duct dilation (>10 mm) was demonstrated in one case of voluntary (6%) and three cases of involuntary ligations (10%). The remaining cases in both groups had no duct dilation and developed necrosis at the blinded duct and leakage proximal to the ligature, with different degrees of bilioperitoneum and/or biloma. In all cases, a Roux-en-Y hepatojejunostomy was performed. Bile duct ligature produces dilation in a very small number of patients (less than 10%) and usually produces necrosis of the blinded stump with subsequent bile leakage. Placement of a subhepatic drain and transference of the patient to a qualified center for reconstruction is the best approach if the primary surgeon is not able to do the repair.

Decline of the performance of a portable axial-flow fan due to the friction and duct bending loss of a connected flexible duct.

PubMed

Ojima, Jun

2017-03-28

In a job site, a portable fan is often used to ventilate a confined space. When a portable fan is applied to such a space, the actual ventilation flow rate must be accurately estimated in advance because the safety level of contaminant and oxygen concentrations in the space will determine the ventilation requirements. When a portable fan is used with a flexible duct, the actual flow rate of the fan decreases due to the friction and duct bending loss of the duct. Intending to show the decline of a fan performance, the author conducted laboratory experiments and reported the quantitative effect of the friction and duct bending loss of a flexible duct to the flow rate of a portable fan. Four commercial portable fans of different specifications were procured for the experiments, and the decline of the performance of each portable fan due to the friction loss etc. of a connected flexible duct was investigated by measuring actual flow rate. The flow rate showed an obvious decrease from the rated flow rate when a flexible duct was connected. Connection of a straight polyester flexible duct and a straight aluminum flexible duct reduced the flow rates to 81.2 - 52.9% and less than 50%, respectively. The flow rate decreased with an increase of the bend angle of the flexible duct. It is recommended that flow rate check of a portable fan should be diligently carried out in every job site.

Eversion Bile Duct Anastomosis: A Safe Alternative for Bile Duct Size Discrepancy in Deceased Donor Liver Transplantation.

PubMed

Leal-Leyte, Pilar; McKenna, Greg J; Ruiz, Richard M; Anthony, Tiffany L; Saracino, Giovanna; Giuliano, Testa; Klintmalm, Goran B; Kim, Peter Tw

2018-04-10

Introduction Bile duct size discrepancy in liver transplantation may increase the risk of biliary complications. The aim of this study was to evaluate the safety and outcomes of the eversion bile duct anastomosis technique in deceased donor liver transplantation (DDLT) with duct to duct anastomosis. Methods A total of 210 patients who received a DDLT with duct to duct anastomosis from 2012 to 2017 were divided into two groups: those who had eversion bile duct anastomosis (N=70) and standard bile duct anastomosis (N=140). Biliary complications rates were compared between the two groups. Results There was no difference in the cumulative incidence of biliary strictures (P=0.20) and leaks (P=0.17) between the two groups. The biliary complication rate in the eversion group was 14.3% and 11.4% in the standard anastomosis group. All the biliary complications in the eversion group were managed with endoscopic stenting. A severe size mismatch (≥3:1 ratio) was associated with a significantly higher incidence of biliary strictures (44.4%) compared to 2:1 ratio (8.2%), (P=0.002). Conclusion The use of the eversion technique is a safe alternative for bile duct discrepancy in deceased donor liver transplantation; however, severe bile duct size mismatch may be a risk factor for biliary strictures with such technique. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sweet, M. L.; Francisco, A.; Roberts, S. G.

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk ofmore » condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.« less

SOXAL combined SO{sub x}/NO{sub x} flue gas control demonstration. Quarterly report, July--September 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

AQUATECH Systems, a business unit of Allied-Signal Inc., proposes to demonstrate the technical viability and cost effectiveness of the SOXAL process a combined SO{sub x}/NO{sub x} control process on a 3 MW equivalent flue gas slip stream from Niagara Mohawk Power Corporation Dunkirk Steam Station Boiler No. 4, a coal fired boiler. The SOXAL process combines 90+% sulfur dioxide removal from the flue gas using a sodium based scrubbing solution and regeneration of the spent scrubbing liquor using AQUATECH Systems` proprietary bipolar membrane technology. This regeneration step recovers a stream of sulfur dioxide suitable for subsequent processing to salable sulfurmore » or sulfuric acid. Additionally 90+% control of NO{sub x} gases can be achieved in combination with conventional urea/methanol injection of NO{sub 2} gas into the duct. The SOXAL process is applicable to both utility and industrial scale boilers using either high or lower sulfur coal. The SOXAL demonstration Program began September 10, 1991 and is approximately 26 months in duration. During the 6 months of scheduled operations, between January and July of 1993, data was collected from the SOXAL system to define: SO{sub 2} and NO{sub x} control efficiencies; Current efficiency for the regeneration unit; Sulfate oxidation in the absorber; Make-up reagent rates; Product quality including concentrations and compositions; System integration and control philosophy; and Membrane stability and performance with respect to foulants. The program is expected to be concluded in November 1993.« less

A case of annular pancreas with Wirsung's duct encircling the duodenum: embryological hypothesis based on cholangiopancreatographic and immunohistochemical findings.

PubMed

Fukai, Manami; Kamisawa, Terumi; Horiguchi, Shin-Ichirou; Hishima, Tsunekazu; Kuruma, Sawako; Chiba, Kazuro; Koizumi, Satomi; Tabata, Taku; Nagao, Sayaka; Kikuyama, Masataka; Honda, Goro; Kurata, Masanao

2017-06-01

We present a resected case of annular pancreas in which Wirsung's duct encircled the duodenum and continued directly to the main pancreatic duct in the body and tail. Furthermore, Wirsung's duct coursed along the right side of the lower bile duct near the major duodenal papilla. Histologically, the islets of Langerhans in the annular pancreas were irregular in shape and were characterized by a striking abundance of pancreatic polypeptide (PP)-positive cells. The PP-rich area that encircled the duodenum was fused with the PP-poor area in the head of the pancreas. The following embryological hypothesis is proposed. The tip of the ventral pancreatic anlage adhered to the duodenal wall and stretched to form a ring during clockwise rotation. The rotation was incomplete, and the pancreatic duct did not cross over the lower bile duct. Since there was adequate ventral anlage in the lower part of the head of the pancreas, fusion between the ducts of the ventral and dorsal anlagen did not occur. The tip of the ventral anlage overgrew and adhered to the dorsal anlage, and the annular duct fused with the main duct of the dorsal anlage.

Reciprocity principle in duct acoustics

NASA Technical Reports Server (NTRS)

Cho, Y.-C.

1979-01-01

Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

On Computations of Duct Acoustics with Near Cut-Off Frequency

NASA Technical Reports Server (NTRS)

Dong, Thomas Z.; Povinelli, Louis A.

1997-01-01

The cut-off is a unique feature associated with duct acoustics due to the presence of duct walls. A study of this cut-off effect on the computations of duct acoustics is performed in the present work. The results show that the computation of duct acoustic modes near cut-off requires higher numerical resolutions than others to avoid being numerically cut off. Duct acoustic problems in Category 2 are solved by the DRP finite difference scheme with the selective artificial damping method and results are presented and compared to reference solutions.

Spatial and temporal dynamics of the colonization of Pinus radiata by Fusarium circinatum, of conidiophora development in the pith and of traumatic resin duct formation.

PubMed

Martín-Rodrigues, Noemí; Espinel, Santiago; Sanchez-Zabala, Joseba; Ortíz, Amaia; González-Murua, Carmen; Duñabeitia, Miren K

2013-06-01

· Fusarium circinatum causes pitch canker disease in a wide range of pine trees, including Pinus radiata, with devastating economic consequences. · To assess the spatial and temporal dynamics of growth of this pathogen in radiata pine, we examined the process of infection using both real-time PCR to quantify fungal biomass inside the plant host, and confocal microscopy using a green fluorescent protein (GFP)-tagged strain of F. circinatum. · Pathogen growth exhibited three distinct phases: an initial exponential increase in fungal biomass, concomitant with pathogen colonization of the cortex and phloem; a slowdown in fungal growth coincident with sporulating hyphae deep within the host; and stabilization of the fungal biomass when the first wilting symptoms appeared. The number of resin ducts in the xylem was found to increase in response to infection and the fungus grew inside both constitutive and traumatic resin ducts. · These results indicate that conidiation may contribute to the spatial or temporal dissemination of the pathogen. Moreover, the present findings raise the intriguing possibility that the generation of traumatic resin ducts may be of more benefit to the fungus than to the plant. © 2013 The Authors New Phytologist © 2013 New Phytologist Trust.

The renal TRPV4 channel is essential for adaptation to increased dietary potassium.

PubMed

Mamenko, Mykola V; Boukelmoune, Nabila; Tomilin, Viktor N; Zaika, Oleg L; Jensen, V Behrana; O'Neil, Roger G; Pochynyuk, Oleh M

2017-06-01

To maintain potassium homeostasis, kidneys exert flow-dependent potassium secretion to facilitate kaliuresis in response to elevated dietary potassium intake. This process involves stimulation of calcium-activated large conductance maxi-K (BK) channels in the distal nephron, namely the connecting tubule and the collecting duct. Recent evidence suggests that the TRPV4 channel is a critical determinant of flow-dependent intracellular calcium elevations in these segments of the renal tubule. Here, we demonstrate that elevated dietary potassium intake (five percent potassium) increases renal TRPV4 mRNA and protein levels in an aldosterone-dependent manner and causes redistribution of the channel to the apical plasma membrane in native collecting duct cells. This, in turn, leads to augmented TRPV4-mediated flow-dependent calcium ion responses in freshly isolated split-opened collecting ducts from mice fed the high potassium diet. Genetic TRPV4 ablation greatly diminished BK channel activity in collecting duct cells pointing to a reduced capacity to excrete potassium. Consistently, elevated potassium intake induced hyperkalemia in TRPV4 knockout mice due to deficient renal potassium excretion. Thus, regulation of TRPV4 activity in the distal nephron by dietary potassium is an indispensable component of whole body potassium balance. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Sound Radiation from a Supersonic Jet Passing Through a Partially Open Exhaust Duct

NASA Technical Reports Server (NTRS)

Kandula, Max

2011-01-01

The radiation of sound from a perfectly expanded Mach 2.5 cold supersonic jet of 25.4 mm exit diameter flowing through a partially open rigid-walled duct with an upstream i-deflector has been studied experimentally. In the experiments, the nozzle is mounted vertically, with the nozzle exit plane at a height of 73 jet diameters above ground level. Relative to the nozzle exit plane (NEP), the location of the duct inlet is varied at 10, 5, and -1 jet diameters. Far-field sound pressure levels were obtained at 54 jet diameters above ground with the aid of acoustic sensors equally spaced around a circular arc of radius equal to 80 jet diameters from the jet axis. Data on the jet acoustic field for the partially open duct were obtained and compared with those with a free jet and with a closed duct. The results suggest that for the partially open duct the overall sound pressure level (OASPL) decreases as the distance between the NEP and the duct inlet plane decreases, while the opposite trend is observed for the closed duct. It is also concluded that the observed peak frequency in the partially open duct increases above the free jet value as the angle from the duct axis is increased, and as the duct inlet plane becomes closer to the NEP.

Investigation in the 7-by-10 Foot Wind Tunnel of Ducts for Cooling Radiators within an Airplane Wing

NASA Technical Reports Server (NTRS)

Harris, Thomas A; Recant, Isidore G

1942-01-01

Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a large-chord wing model with a duct to house a simulated radiator suitable for a liquid-cooled engine. The duct was expanded to reduce the radiator losses, and the installation of the duct and radiator was made entirely within the wing to reduce form and interference drag. The tests were made using a two-dimensional-flow setup with a full-span duct and radiator. Section aerodynamic characteristics of the basic airfoil are given and also curves showing the characteristics of the various duct-radiator combinations. An expression for efficiency, the primary criterion of merit of any duct, and the effect of the several design parameters of the duct-radiator arrangement are discussed. The problem of throttling is considered and a discussion of the power required for cooling is included.

Van Allen Probes observations of structured whistler mode activity and coincident electron Landau acceleration inside a remnant plasmaspheric plume

NASA Astrophysics Data System (ADS)

Woodroffe, J. R.; Jordanova, V. K.; Funsten, H. O.; Streltsov, A. V.; Bengtson, M. T.; Kletzing, C. A.; Wygant, J. R.; Thaller, S. A.; Breneman, A. W.

2017-03-01

We present observations from the Van Allen Probes spacecraft that identify a region of intense whistler mode activity within a large density enhancement outside of the plasmasphere. We speculate that this density enhancement is part of a remnant plasmaspheric plume, with the observed wave being driven by a weakly anisotropic electron injection that drifted into the plume and became nonlinearly unstable to whistler emission. Particle measurements indicate that a significant fraction of thermal (<100 eV) electrons within the plume were subject to Landau acceleration by these waves, an effect that is naturally explained by whistler emission within a gradient and high-density ducting inside a density enhancement.

Building America Case Study: Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4, LaFayette, Georgia (CZ4), and Savannah, Georgia (CZ2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

V. Kochkin, M. Sweet

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk ofmore » condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.« less

Building America Case Study: Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4, LaFayette, Georgia (CZ4), and Savannah, Georgia (CZ2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-02-01

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk ofmore » condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.« less

Ultrasound imaging of the mouse pancreatic duct using lipid microbubbles

NASA Astrophysics Data System (ADS)

Banerjee, B.; McKeown, K. R.; Skovan, B.; Ogram, E.; Ingram, P.; Ignatenko, N.; Paine-Murrieta, G.; Witte, R.; Matsunaga, T. O.

2012-03-01

Research requiring the murine pancreatic duct to be imaged is often challenging due to the difficulty in selectively cannulating the pancreatic duct. We have successfully catheterized the pancreatic duct through the common bile duct in severe combined immune deficient (SCID) mice and imaged the pancreatic duct with gas filled lipid microbubbles that increase ultrasound imaging sensitivity due to exquisite scattering at the gas/liquid interface. A SCID mouse was euthanized by CO2, a midline abdominal incision made, the common bile duct cut at its midpoint, a 2 cm, 32 gauge tip catheter was inserted about 1 mm into the duct and tied with suture. The duodenum and pancreas were excised, removed in toto, embedded in agar and an infusion pump was used to instill normal saline or lipid-coated microbubbles (10 million / ml) into the duct. B-mode images before and after infusion of the duct with microbubbles imaged the entire pancreatic duct (~ 1 cm) with high contrast. The microbubbles were cavitated by high mechanical index (HMI) ultrasound for imaging to be repeated. Our technique of catheterization and using lipid microbubbles as a contrast agent may provide an effective, affordable technique of imaging the murine pancreatic duct; cavitation with HMI ultrasound would enable repeated imaging to be performed and clustering of targeted microbubbles to receptors on ductal cells would allow pathology to be localized accurately. This research was supported by the Experimental Mouse Shared Service of the AZ Cancer Center (Grant Number P30CA023074, NIH/NCI and the GI SPORE (NIH/NCI P50 CA95060).

IL-33 overexpression reflects less aggressive tumour features in large-duct type cholangiocarcinomas.

PubMed

Sawada, Ryuichiro; Ku, Yuna; Akita, Masayuki; Otani, Kyoko; Fujikura, Kohei; Itoh, Tomoo; Ajiki, Tetsuo; Fukumoto, Takumi; Kakeji, Yoshihiro; Zen, Yoh

2018-04-19

The present study aimed to elucidate the clinicopathological significance of IL-6 and IL-33 expression in intrahepatic cholangiocarcinomas (iCCAs) and perihilar cholangiocarcinomas (pCCAs). IL-6 and IL-33 mRNA expression was examined in iCCAs (n=55) and pCCAs (n=32) using quantitative real-time PCR and a highly sensitive in situ hybridization protocol (RNAscope ® ), and expression values were correlated with clinicopathological features. According to a recently proposed classification scheme, iCCAs were separated into small- (n=33) and large-duct types (n=22). IL-6 and IL-33 expression levels were higher in large-duct iCCAs and pCCAs than in small-duct iCCAs, with a positive correlation between the values of these cytokines. In double in situ hybridization/immunostaining, IL-6 mRNA was expressed in actin-positive (myo)fibroblasts, while IL-33 was mainly produced by CD31-positive endothelial cells. Based on the average expression value as a cut-off point, cases were classified as IL-6 high and IL-6 low or IL-33 high and IL-33 low . In the combined cohort of large-duct iCCAs and pCCAs, IL-6 high and IL-6 low cholangiocarcinomas shared many features, while IL-33 high cases had less aggressive characteristics than IL-33 low cases as evidenced by lower tumour marker concentrations, smaller tumour sizes, less common vascular invasion, lower pT stages, and higher lymphocyte-to-monocyte ratios in blood. KRAS mutations were slightly less common in IL-33 high cases than in IL-33 low cancers (9% vs 29%; p=0.061). The strong expression of IL-33 in tissue appeared to be an independent favourable prognostic factor. IL-33 high cholangiocarcinomas may represent a unique, less aggressive carcinogenetic process of the large bile ducts. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Validation of a spectrophotometer-based method for estimating daily sperm production and deferent duct transit.

PubMed

Froman, D P; Rhoads, D D

2012-10-01

The objectives of the present work were 3-fold. First, a new method for estimating daily sperm production was validated. This method, in turn, was used to evaluate testis output as well as deferent duct throughput. Next, this analytical approach was evaluated in 2 experiments. The first experiment compared left and right reproductive tracts within roosters. The second experiment compared reproductive tract throughput in roosters from low and high sperm mobility lines. Standard curves were constructed from which unknown concentrations of sperm cells and sperm nuclei could be predicted from observed absorbance. In each case, the independent variable was based upon hemacytometer counts, and absorbance was a linear function of concentration. Reproductive tracts were excised, semen recovered from each duct, and the extragonadal sperm reserve determined by multiplying volume by sperm cell concentration. Testicular sperm nuclei were procured by homogenization of a whole testis, overlaying a 20-mL volume of homogenate upon 15% (wt/vol) Accudenz (Accurate Chemical and Scientific Corporation, Westbury, NY), and then washing nuclei by centrifugation through the Accudenz layer. Daily sperm production was determined by dividing the predicted number of sperm nuclei within the homogenate by 4.5 d (i.e., the time sperm with elongated nuclei spend within the testis). Sperm transit through the deferent duct was estimated by dividing the extragonadal reserve by daily sperm production. Neither the efficiency of sperm production (sperm per gram of testicular parenchyma per day) nor deferent duct transit differed between left and right reproductive tracts (P > 0.05). Whereas efficiency of sperm production did not differ (P > 0.05) between low and high sperm mobility lines, deferent duct transit differed between lines (P < 0.001). On average, this process required 2.2 and 1.0 d for low and high lines, respectively. In summary, we developed and then tested a method for quantifying male reproductive tract throughput. This method makes the study of semen production amenable to systems biology.

Total rupture of hydatid cyst of liver in to common bile duct: a case report.

PubMed

Robleh, Hassan; Yassine, Fahmi; Driss, Khaiz; Khalid, Elhattabi; Fatima-Zahra, Bensardi; Saad, Berrada; Rachid, Lefriyekh; Abdalaziz, Fadil; Najib, Zerouali Ouariti

2014-01-01

Rupture of hydatid liver cyst into biliary tree is frequent complications that involve the common hepatic duct, lobar biliary branches, the small intrahepatic bile ducts,but rarely rupture into common bile duct. The rupture of hydatid cyst is serious life threating event. The authors are reporting a case of total rupture of hydatid cyst of liver into common bile duct. A 50-year-old male patient who presented with acute cholangitis was diagnosed as a case of totally rupture of hydatid cyst on Abdominal CT Scan. Rupture of hydatid cyst of liver into common bile duct and the gallbladder was confirmed on surgery. Treated by cholecystectomy and T-tube drainage of Common bile duct.

[Rare bile duct anatomy variant - Right bile duct intraparenchymal junction into the left bile duct].

PubMed

Gál, Adrián Róbert; Kalmár-Nagy, Károly; Fincsur, András; Horváth, Örs Péter; Vereczkei, András

2018-03-01

The authors present a case of a 67-year-old male patient, who previously had been diagnosed with a malignant liver tumor localized in segment II. He underwent bisegmentectomy (II and III) and partial IV segmentectomy. After the primary surgery jaundice developed, the level of bilirubin increased and after several imaging modalities reoperation was indicated. During the surgery a rare bile duct anatomy variant was found. The right hepatic duct joined the left duct in the parenchyma of the left lobe, and was ligated at the resection. As the liver hilum was not explored, the absence of the right duct was not discovered. Reconstruction of the biliary system was accomplished by a Roux-en-Y loop.

Preliminary Investigation of Curved Liner Sample in the NASA LaRC Curved Duct Test Rig

NASA Technical Reports Server (NTRS)

Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.

2007-01-01

This viewgraph presentation reviews the preliminary investigation of the curved liner sample in the NASA LaRC Curved Duct Test Rig (CDTR). It reviews the purpose of the Curved Duct Test Rig. Its purpose is to develop capability to investigate acoustic and aerodynamic properties in ducts. It has several features to accomplish that purpose: (1) Large scale (2) Flow rate to M = 0.275 (3) Higher order mode control (4) Curved flow path (5) Adaptable test section (6) Flexible test configurations. The liner has minimal effect on turbulence or boundary layer growth in duct. The curved duct sample attenuation is affected by mode scattering. In conclusion, the CDTR is valid tool for aerodynamic and acoustic evaluation of duct treatment

Cholangiocarcinoma in a middle-aged patient working at a printing plant.

PubMed

Tanaka, Shogo; Fukumoto, Nobusuke; Ohno, Kohichi; Tanaka, Sayaka; Ohsawa, Masahiko; Yamamoto, Takatsugu; Nakanuma, Yasuni; Kuboo, Shoji

2014-06-01

A 39-year-old male with elevated serum transferases consulted our hospital in September 2010. Since 1999, he had worked at a printing company using organic solvents. Cholangiography revealed stenosis of the left hepatic duct with peripheral dilation, stricture of the right hepatic duct, and irregularity of the extrahepatic bile duct. As a preoperative diagnosis of sclerosing cholangitis and cholangiocarcinoma was made, extended left hepatectomy with resection of the extrahepatic bile duct and anastomosis of the anterior and posterior branches of the bile duct and the jejunum (Roux-en Y reconstruction) were performed. A histological examination showed papillary carcinoma of the medial hepatic bile duct with intraductal growth, and biliary intraepithelial neoplasia-2/3 lesions from the medial hepatic bile duct to the right hepatic and the common bile ducts. Chronic cholangitis was shown around the tumors. Postoperatively, the patient was treated with adjuvant chemo-radiation, and he is doing well 30 months after the operation, without recurrence. Unknown causes, including exposure to organic solvents, might have induced chronic bile duct injury and contributed to the development of cholangiocarcinoma.

Combined Endoscopic and Laparoscopic Management of Postcholecystectomy Mirizzi Syndrome from a Remnant Cystic Duct Stone: Case Report and Review of the Literature

PubMed Central

Amin, Arpit; Zhurov, Yuriy; Ibrahim, George; Maffei, Anthony; Giannone, Jonathan; Cerabona, Thomas; Kaul, Ashutosh

2016-01-01

Mirizzi syndrome has been defined in the literature as common bile duct obstruction resulting from calculi within Hartmann's pouch or cystic duct. We present a case of a 78-year-old female, who developed postcholecystectomy Mirizzi syndrome from a remnant cystic duct stone. Diagnosis of postcholecystectomy Mirizzi syndrome was made on endoscopic retrograde cholangiography (ERCP) performed postoperatively. The patient was treated with a novel strategy by combining advanced endoscopic and laparoscopic techniques in three stages as follows: Stage 1 (initial presentation): endoscopic sphincterotomy with common bile duct stent placement; Stage 2 (6 weeks after Stage 1): laparoscopic ultrasonography to locate the remnant cystic duct calculi followed by laparoscopic retrieval of the calculi and intracorporeal closure of cystic duct stump; Stage 3 (6 weeks after Stage 2): endoscopic removal of common bile duct stent along with performance of completion endoscopic retrograde cholangiogram. In addition, we have performed an extensive review of the various endoscopic and laparoscopic management techniques described in the literature for the treatment of postcholecystectomy syndrome occurring from retained cystic duct stones. PMID:27047698

Application of “Papillary-Like Main Pancreatic Duct Invaginated” Pancreaticojejunostomy for Normal Soft Pancreas Cases

PubMed Central

Zhang, Bo; Xu, Jin; Liu, Chen; Long, Jiang; Liu, Liang; Xu, Yongfeng; Wu, Chuntao; Luo, Guopei; Ni, Quanxing; Li, Min; Yu, Xianjun

2013-01-01

Pancreaticojejunostomy is the key procedure of pancreaticoduodenectomy. Our study introduced a new pancreaticojejunal (PJ) anastomosis named “papillary-like main pancreatic duct invaginated” pancreaticojejunostomy. Nighty-two patients underwent pancreaticojejunostomy with either conventional duct-to-mucosa pancreaticojejunostomy or the new “papillary-like main pancreatic duct invaginated” techniques were analyzed retrospectively from January 2010 to September 2012. The incidence of pancreatic fistula was 15.7% (8/51) for the “papillary-like main pancreatic duct invaginated” group and 19.5% (8/41) for the duct-to-mucosa fashion respectively. It is noteworthy that the rate of grade B/C postoperative pancreatic fistula (POPF) in the “papillary-like main pancreatic duct invaginated” group was significantly lower than that of the duct-to-mucosa group (P = 0.039). There were no differences in the incidence of postoperative morbidity and mortality such as postoperative hemorrhage, delayed gastric emptying or remnant pancreatitis. The “papillary-like main pancreatic duct invaginated” pancreaticojejunostomy could provide a feasible option to pancreatic surgeons for patients with normal soft pancreas. PMID:23797701

Combined Endoscopic and Laparoscopic Management of Postcholecystectomy Mirizzi Syndrome from a Remnant Cystic Duct Stone: Case Report and Review of the Literature.

PubMed

Amin, Arpit; Zhurov, Yuriy; Ibrahim, George; Maffei, Anthony; Giannone, Jonathan; Cerabona, Thomas; Kaul, Ashutosh

2016-01-01

Mirizzi syndrome has been defined in the literature as common bile duct obstruction resulting from calculi within Hartmann's pouch or cystic duct. We present a case of a 78-year-old female, who developed postcholecystectomy Mirizzi syndrome from a remnant cystic duct stone. Diagnosis of postcholecystectomy Mirizzi syndrome was made on endoscopic retrograde cholangiography (ERCP) performed postoperatively. The patient was treated with a novel strategy by combining advanced endoscopic and laparoscopic techniques in three stages as follows: Stage 1 (initial presentation): endoscopic sphincterotomy with common bile duct stent placement; Stage 2 (6 weeks after Stage 1): laparoscopic ultrasonography to locate the remnant cystic duct calculi followed by laparoscopic retrieval of the calculi and intracorporeal closure of cystic duct stump; Stage 3 (6 weeks after Stage 2): endoscopic removal of common bile duct stent along with performance of completion endoscopic retrograde cholangiogram. In addition, we have performed an extensive review of the various endoscopic and laparoscopic management techniques described in the literature for the treatment of postcholecystectomy syndrome occurring from retained cystic duct stones.

Xenopus Bicaudal-C Is Required for the Differentiation of the Amphibian Pronephros

PubMed Central

Tran, Uyen; Mary Pickney, L.; Duygu Özpolat, B.; Wessely, Oliver

2007-01-01

The RNA-binding molecule Bicaudal-C regulates embryonic development in Drosophila and Xenopus. Interestingly, mouse mutants of Bicaudal-C do not show early patterning defects, but instead develop polycystic kidney disease (PKD). To further investigate the molecular mechanism of Bicaudal-C in kidney development, we analyzed its function in the developing amphibian pronephros. Bicaudal-C mRNA was present in the epithelial structures of the Xenopus pronephros, the tubules and the duct, but not the glomus. Inhibition of the translation of endogenous Bicaudal-C with antisense morpholino oligomers (xBic-C-MO) led to a PKD-like phenotype in Xenopus. Embryos lacking Bicaudal-C developed generalized edemas and dilated pronephric tubules and ducts. This phenotype was caused by impaired differentiation of the pronephros. Molecular markers specifically expressed in the late distal tubule were absent in xBic-C-MO-injected embryos. Furthermore, Bicaudal-C was not required for primary cilia formation, an important organelle affected in PKD. These data support the idea that Bicaudal-C functions downstream or parallel of a cilia-regulated signaling pathway. This pathway is required for terminal differentiation of the late distal tubule of the Xenopus pronephros and regulates renal epithelial cell differentiation, which - when disrupted - results in PKD. PMID:17521625

Laparoscopic Transcystic Treatment Biliary Calculi by Laser Lithotripsy

PubMed Central

Jin, Lan; Zhang, Zhongtao

2016-01-01

Background and Objectives: Laparoscopic transcystic common bile duct exploration (LTCBDE) is a complex procedure requiring expertise in laparoscopic and choledochoscopic skills. The purpose of this study was to investigate the safety and feasibility of treating biliary calculi through laparoscopic transcystic exploration of the CBD via an ultrathin choledochoscope combined with dual-frequency laser lithotripsy. Methods: From August 2011 through September 2014, 89 patients at our hospital were treated for cholecystolithiasis with biliary calculi. Patients underwent laparoscopic cholecystectomy and exploration of the CBD via the cystic duct and the choledochoscope instrument channel. A dual-band, dual-pulse laser lithotripsy system was used to destroy the calculi. Two intermittent laser emissions (intensity, 0.12 J; pulse width 1.2 μs; and pulse frequency, 10 Hz) were applied during each contact with the calculi. The stones were washed out by water injection or removed by a stone-retrieval basket. Results: Biliary calculi were removed in 1 treatment in all 89 patients. No biliary tract injury or bile leakage was observed. Follow-up examination with type-B ultrasonography or magnetic resonance cholangiopancreatography 3 months after surgery revealed no instances of retained-calculi–related biliary tract stenosis. Conclusion: The combined use of laparoscopic transcystic CBD exploration by ultrathin choledochoscopy and dual-frequency laser lithotripsy offers an accurate, convenient, safe, effective method of treating biliary calculi. PMID:27904308

Genes and Proteins Differentially Expressed during In Vitro Malignant Transformation of Bovine Pancreatic Duct Cells1

PubMed Central

Jesnowski, R; Zubakov, Dmitri; Faissner, Ralf; Ringel, Jörg; Hoheisel, Jörg D; Lösel, Ralf; Schnölzer, Martina; Löhr, Matthias

2007-01-01

Abstract Pancreatic carcinoma has an extremely bad prognosis due to lack of early diagnostic markers and lack of effective therapeutic strategies. Recently, we have established an in vitro model recapitulating the first steps in the carcinogenesis of the pancreas. SV40 large T antigen-immortalized bovine pancreatic duct cells formed intrapancreatic adenocarcinoma tumors on k-rasmut transfection after orthotopic injection in the nude mouse pancreas. Here we identified genes and proteins differentially expressed in the course of malignant transformation using reciprocal suppression subtractive hybridization and 2D gel electrophoresis and mass spectrometry, respectively. We identified 34 differentially expressed genes, expressed sequence tags, and 15 unique proteins. Differential expression was verified for some of the genes or proteins in samples from pancreatic carcinoma. Among these genes and proteins, the majority had already been described either to be influenced by a mutated ras or to be differentially expressed in pancreatic adenocarcinoma, thus proving the feasibility of our model. Other genes and proteins (e.g., BBC1, GLTSCR2, and rhoGDIα), up to now, have not been implicated in pancreatic tumor development. Thus, we were able to establish an in vitro model of pancreatic carcinogenesis, which enabled us to identify genes and proteins differentially expressed during the early steps of malignant transformation. PMID:17356710

Effect of bromoethylamine hydrobromide on systemic acid-base balance.

PubMed

Nakamura, Y; Sasaki, S; Shigai, T; Marumo, F

1988-09-01

Intravenous administration of bromoethylamine hydrobromide (BEA) has been shown to induce papillary necrosis of the kidney. We used this model to clarify the role of the medullary structure in acid-base homeostasis. BEA (25 mg) or vehicle was injected to male Sprague-Dawley rats. Blood specimens and 24 hr urine were collected once a week totaling 4 weeks. Blood bicarbonate significantly decreased in BEA treated rats with no change in plasma creatinine or creatinine clearance at 3 and 4 weeks, we noted that these parameters did not change in control rats. Administration of 1 M NH4Cl solution (1 ml/100 g) into the peritoneal space resulted in a significant reduction in urine pH by 0.41 +/- 0.05 in control rats, whereas it did not induce any change in BEA treated rats. Ammonia excretion rates were significantly lower in BEA treated rats than in control rats. Histological examination showed that in BEA treated rats there was necrosis of epithelial cells of papillary collecting ducts at 1 week. Observation showed they recovered at 4 weeks with only mild interstitial edema and slight dilatation of collecting ducts. The present results suggested that tissue damages in the papillary structure caused metabolic acidosis due to a decreased renal acidification.

Pathophysiology of chronic pancreatitis.

PubMed

Brock, Christina; Nielsen, Lecia Møller; Lelic, Dina; Drewes, Asbjørn Mohr

2013-11-14

Chronic pancreatitis (CP) is an inflammatory disease of the pancreas characterized by progressive fibrotic destruction of the pancreatic secretory parenchyma. Despite the heterogeneity in pathogenesis and involved risk factors, processes such as necrosis/apoptosis, inflammation or duct obstruction are involved. This fibrosing process ultimately leads to progressive loss of the lobular morphology and structure of the pancreas, deformation of the large ducts and severe changes in the arrangement and composition of the islets. These conditions lead to irreversible morphological and structural changes resulting in impairment of both exocrine and endocrine functions. The prevalence of the disease is largely dependent on culture and geography. The etiological risk-factors associated with CP are multiple and involve both genetic and environmental factors. Throughout this review the M-ANNHEIM classification system will be used, comprising a detailed description of risk factors such as: alcohol-consumption, nicotine-consumption, nutritional factors, hereditary factors, efferent duct factors, immunological factors and miscellaneous and rare metabolic factors. Increased knowledge of the different etiological factors may encourage the use of further advanced diagnostic tools, which potentially will help clinicians to diagnose CP at an earlier stage. However, in view of the multi factorial disease and the complex clinical picture, it is not surprising that treatment of patients with CP is challenging and often unsuccessful.

Acidic Residues Control the Dimerization of the N-terminal Domain of Black Widow Spiders’ Major Ampullate Spidroin 1

NASA Astrophysics Data System (ADS)

Bauer, Joschka; Schaal, Daniel; Eisoldt, Lukas; Schweimer, Kristian; Schwarzinger, Stephan; Scheibel, Thomas

2016-09-01

Dragline silk is the most prominent amongst spider silks and comprises two types of major ampullate spidroins (MaSp) differing in their proline content. In the natural spinning process, the conversion of soluble MaSp into a tough fiber is, amongst other factors, triggered by dimerization and conformational switching of their helical amino-terminal domains (NRN). Both processes are induced by protonation of acidic residues upon acidification along the spinning duct. Here, the structure and monomer-dimer-equilibrium of the domain NRN1 of Latrodectus hesperus MaSp1 and variants thereof have been investigated, and the key residues for both could be identified. Changes in ionic composition and strength within the spinning duct enable electrostatic interactions between the acidic and basic pole of two monomers which prearrange into an antiparallel dimer. Upon naturally occurring acidification this dimer is stabilized by protonation of residue E114. A conformational change is independently triggered by protonation of clustered acidic residues (D39, E76, E81). Such step-by-step mechanism allows a controlled spidroin assembly in a pH- and salt sensitive manner, preventing premature aggregation of spider silk proteins in the gland and at the same time ensuring fast and efficient dimer formation and stabilization on demand in the spinning duct.

Pathophysiology of chronic pancreatitis

PubMed Central

Brock, Christina; Nielsen, Lecia Møller; Lelic, Dina; Drewes, Asbjørn Mohr

2013-01-01

Chronic pancreatitis (CP) is an inflammatory disease of the pancreas characterized by progressive fibrotic destruction of the pancreatic secretory parenchyma. Despite the heterogeneity in pathogenesis and involved risk factors, processes such as necrosis/apoptosis, inflammation or duct obstruction are involved. This fibrosing process ultimately leads to progressive loss of the lobular morphology and structure of the pancreas, deformation of the large ducts and severe changes in the arrangement and composition of the islets. These conditions lead to irreversible morphological and structural changes resulting in impairment of both exocrine and endocrine functions. The prevalence of the disease is largely dependent on culture and geography. The etiological risk-factors associated with CP are multiple and involve both genetic and environmental factors. Throughout this review the M-ANNHEIM classification system will be used, comprising a detailed description of risk factors such as: alcohol-consumption, nicotine-consumption, nutritional factors, hereditary factors, efferent duct factors, immunological factors and miscellaneous and rare metabolic factors. Increased knowledge of the different etiological factors may encourage the use of further advanced diagnostic tools, which potentially will help clinicians to diagnose CP at an earlier stage. However, in view of the multi factorial disease and the complex clinical picture, it is not surprising that treatment of patients with CP is challenging and often unsuccessful. PMID:24259953

Physics of Acoustic Radiation from Jet Engine Inlets

NASA Technical Reports Server (NTRS)

Tam, Christopher K. W.; Parrish, Sarah A.; Envia, Edmane; Chien, Eugene W.

2012-01-01

Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test (SDT) is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic wave to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of sound waves by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number and duct mode frequency, azimuthal mode number, and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition and in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

Ducting Conditions for Electromagnetic Wave Propagation in Tropical Disturbances from GPS Dropsonde Data

DTIC Science & Technology

2013-12-01

depression, tropical storm , hurricane, extratropical cyclone, subtropical depression, subtropical storm , a low of no category, tropical wave, disturbance or...surface-based ducts, and elevated ducts. We further separate the duct occurrence based on the location relative to their respective storms . Based...on the number of soundings in different types of tropical disturbances, we chose to further analyze duct conditions in hurricanes and tropical storms

Mucocele of the cystic duct remnant after orthotopic liver transplant: a problem revisited.

PubMed

Chatterjee, Suvadip; Das, Debasish; Hudson, Mark; Bassendine, Margaret Fiona; Scott, John; Oppong, Kofi Ernest; Sen, Gourab; French, Jeremy J

2011-06-01

Mucocele of the cystic duct remnant is an uncommon hepatobiliary complication of a liver transplant. Current practice usually involves either excising the cystic duct, or incorporating the distal end of the transected cystic duct into the suture line of the biliary anastomosis to ensure drainage. We report a patient who developed cystic duct remnant mucocele after the latter approach was adopted. We believe that this is likely related to delayed anastomotic stricturing, which prevented draining from the remnant cystic duct. We also discuss the incidence, pathology, investigations, and treatment of this condition.

Lensing duct

DOEpatents

Beach, R.J.; Benett, W.J.

1994-04-26

A lensing duct to condense (intensify) light using a combination of front surface lensing and reflective waveguiding is described. The duct tapers down from a wide input side to a narrow output side, with the input side being lens-shaped and coated with an antireflective coating for more efficient transmission into the duct. The four side surfaces are uncoated, preventing light from escaping by total internal reflection as it travels along the duct (reflective waveguiding). The duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials, and can be fabricated from inexpensive glass and plastic. 3 figures.

Simple resection of the lesion bile duct branch for treatment of regional hepatic bile duct stones

PubMed Central

Enliang, Li; Rongshou, Wu; Shidai, Shi; Jingling, Zhang; Qian, Feng; Wenjun, Liao; Linquan, Wu

2017-01-01

Abstract To evaluate the effectiveness and safety of simple resections of bile duct branch lesions for the treatment of regional hepatic bile duct stones. A retrospective analysis of the clinical data from patients in our hospital from November 2008 to November 2015, who only underwent a simple resection of the lesion bile duct branch. The patients’ clinical characteristics, surgical features, postoperative complications, stone clear rate, residual stone rate, and recurrence stone rate were analyzed. This study of 32 patients included 13 males and 19 females with intrahepatic bile duct stones confined to the right hepatic bile duct branch. The intraoperative blood loss, operation time, and postoperative hospital stay were 478.0 ± 86.5, 210.7 ± 6.6, and 10.8 ± 3.5, respectively. Postoperative complications occurred in 6 patients (18.8%), all of whom recovered with conservative management. There were no deaths during hospitalization. The intraoperative stone clearance rate was 95.8%. Three patients had a recurrence of stones at a mean of 22 months of follow-up (range, 4–36 months). Simple resection of bile duct branch lesions is safe and feasible for patients who have regional hepatic bile duct stones limited to the right hepatic bile duct branches. PMID:28682899

Reference values of MRI measurements of the common bile duct and pancreatic duct in children.

PubMed

Gwal, Kriti; Bedoya, Maria A; Patel, Neal; Rambhatla, Siri J; Darge, Kassa; Sreedharan, Ram R; Anupindi, Sudha A

2015-07-01

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial measurement was 2.0 mm; the mean coronal measurement of the pancreatic duct was 0.9 mm and the axial measurement was 0.8 mm. Our study provides normative measurements for the common bile duct and pancreatic duct for children up to age 10 years. The upper limits of the CBD and pancreatic duct increase with age, and the values range 1.1-4.0 mm for the CBD and 0.6-1.9 mm for the pancreatic duct.

Modeling the compliance of polyurethane nanofiber tubes for artificial common bile duct

NASA Astrophysics Data System (ADS)

Moazeni, Najmeh; Vadood, Morteza; Semnani, Dariush; Hasani, Hossein

2018-02-01

The common bile duct is one of the body’s most sensitive organs and a polyurethane nanofiber tube can be used as a prosthetic of the common bile duct. The compliance is one of the most important properties of prosthetic which should be adequately compliant as long as possible to keep the behavioral integrity of prosthetic. In the present paper, the prosthetic compliance was measured and modeled using regression method and artificial neural network (ANN) based on the electrospinning process parameters such as polymer concentration, voltage, tip-to-collector distance and flow rate. Whereas, the ANN model contains different parameters affecting on the prediction accuracy directly, the genetic algorithm (GA) was used to optimize the ANN parameters. Finally, it was observed that the optimized ANN model by GA can predict the compliance with high accuracy (mean absolute percentage error = 8.57%). Moreover, the contribution of variables on the compliance was investigated through relative importance analysis and the optimum values of parameters for ideal compliance were determined.

Nonlinear effects on sound propagation through high subsonic Mach number flows in variable area ducts

NASA Technical Reports Server (NTRS)

Callegari, A. J.

1979-01-01

A nonlinear theory for sound propagation in variable area ducts carrying a nearly sonic flow is presented. Linear acoustic theory is shown to be singular and the detailed nature of the singularity is used to develop the correct nonlinear theory. The theory is based on a quasi-one dimensional model. It is derived by the method of matched asymptotic expansions. In a nearly chocked flow, the theory indicates the following processes to be acting: a transonic trapping of upstream propagating sound causing an intensification of this sound in the throat region of the duct; generation of superharmonics and an acoustic streaming effect; development of shocks in the acoustic quantities near the throat. Several specific problems are solved analytically and numerical parameter studies are carried out. Results indicate that appreciable acoustic power is shifted to higher harmonics as shocked conditions are approached. The effect of the throat Mach number on the attenuation of upstream propagating sound excited by a fixed source is also determined.

Technology Solutions Case Study: High-Performance Ducts in Hot-Dry Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. Hoeschele, A. German, E. Weitzel, R. Chitwood

2015-08-01

Ducts in conditioned space (DCS) represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. Various strategies exist for incorporating ducts within the conditioned thermal envelope. To support this activity, in 2013 the Pacific Gas & Electric Company initiated a project with Davis Energy Group (lead for the Building America team, Alliance for Residential Building Innovation) to solicit builder involvement in California to participate in field demonstrations of various DCS strategies. Builders were given incentives and design support in exchange for providing site access for construction observation, diagnostic testing, andmore » builder survey feedback. Information from the project was designed to feed into California's 2016 Title 24 process, but also to serve as an initial mechanism to engage builders in more high performance construction strategies. This Building America project complemented information collected in the California project with BEopt simulations of DCS performance in hot/dry climate regions.« less

Integrated dry NO{sub x}/SO{sub 2} emissions control system performance summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunt, T.; Muzio, L.J.; Smith, R.

1997-12-31

The Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System was installed at Public Service Company of Colorado`s Arapahoe 4 generating station in 1992 in cooperation with the US Department of Energy (DOE) and the Electric Power Research Institute (EPRI). This full-scale 100 MWe demonstration combines low-NO{sub x} burners, overfire, air, and selective non-catalytic reduction (SNCR) for NO{sub x} control and dry sorbent injection (DSI) with or without humidification for SO{sub 2} control. Operation and testing of the Integrated Dry NO{sub x}/SO{sub 2} Emissions Control System began in August 1992 and will continue through 1996. Results of the NO{sub x} controlmore » technologies show that the original system goal of 70% NO{sub x} removal has been easily met and the combustion and SNCR systems can achieve NO{sub x} removals of up to 80% at full load. Duct injection of commercial calcium hydroxide has achieved a maximum SO{sub 2} removal of nearly 40% while humidifying the flue gas to a 20 F approach to saturation. Sodium-based dry sorbent injection has provided SO{sub 2} removal of over 70% without the occurrence of a visible NO{sub 2} plume. Recent test work has improved SNCR performance at low loads and has demonstrated that combined dry sodium injection and SNCR yields both lower NO{sub 2} levels and NH{sub 3} slip than either technology alone.« less

Anatomical variations in lymphatic drainage of the right lung: applications in lung cancer surgery.

PubMed

Ndiaye, Assane; Di-Marino, V; Ba, P S; Ndiaye, Aï; Gaye, M; Nazarian, S

2016-12-01

To specify the topography and variations in lymphatic drainage of the right lung to the mediastinum and their therapeutic implications in non-small cell lung cancers (NSCLC). We injected a dye into the subpleural lymphatic vessels in 65 right lung segments, followed by dissection in 22 subjects. At the upper lobe, we had injected 32 segments. We noted extrasegmental overflow in one case; extrasegmental and extralobar drainage in two cases; drainage to the lymph nodes of another lobe in one case. Fifty-six percent of the segments drained directly (skipping intrapulmonary and hilar lymph nodes) into the right paratracheal lymph nodes, and one dorsal segment drained into the thoracic duct. A ventral segment drained into the inferior tracheobronchial lymph nodes. A contralateral drainage to the recurrent chain was observed in two cases. Sixteen segments of the middle lobe were injected and mainly drained into the inferior tracheobronchial lymph nodes with six direct paths; one medial segment drained into the right anterior mediastinal chain. We noted three contralateral drainages and eight downward abdominal drainages. Out of the 17 segments of the lower lobe injected, 6 segments drained into the lymph nodes of another lobe, 5 segments showed a direct route to the lower quadrant chains. We noted one time a drainage into the paraesophageal lymph nodes. The variations in lymphatic drainage of the right lung require to carry out systematically a radical mediastinal lymphadenectomy during the removal of non-small cell lung cancers and to associate an adjuvant treatment.

Renal development: a complex process dependent on inductive interaction.

PubMed

Upadhyay, Kiran K; Silverstein, Douglas M

2014-01-01

Renal development begins in-utero and continues throughout childhood. Almost one-third of all developmental anomalies include structural or functional abnormalities of the urinary tract. There are three main phases of in-utero renal development: Pronephros, Mesonephros and Metanephros. Within three weeks of gestation, paired pronephri appear. A series of tubules called nephrotomes fuse with the pronephric duct. The pronephros elongates and induces the nearby mesoderm, forming the mesonephric (Woffian) duct. The metanephros is the precursor of the mature kidney that originates from the ureteric bud and the metanephric mesoderm (blastema) by 5 weeks of gestation. The interaction between these two components is a reciprocal process, resulting in the formation of a mature kidney. The ureteric bud forms the major and minor calyces, and the collecting tubules while the metanephrogenic blastema develops into the renal tubules and glomeruli. In humans, all of the nephrons are formed by 32 to 36 weeks of gestation. Simultaneously, the lower urinary tract develops from the vesico urethral canal, ureteric bud and mesonephric duct. In utero, ureters deliver urine from the kidney to the bladder, thereby creating amniotic fluid. Transcription factors, extracellular matrix glycoproteins, signaling molecules and receptors are the key players in normal renal development. Many medications (e.g., aminoglycosides, cyclooxygenase inhibitors, substances that affect the renin-angiotensin aldosterone system) also impact renal development by altering the expression of growth factors, matrix regulators or receptors. Thus, tight regulation and coordinated processes are crucial for normal renal development.

A Plug-and-Play Duct System Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beach, Robert; Dickson, Bruce; Grisolia, Anthony

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit inmore » the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.« less

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

PubMed Central

Choi, Jin Woo; Kim, Kyoung Won; Kim, Ah Young; Kim, Pyo Nyun; Ha, Hyun Kwon; Lee, Moon-Gyu

2003-01-01

Objective To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. Materials and Methods The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. Results The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). Conclusion The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%). PMID:12845303

Anatomy of the lactating human breast redefined with ultrasound imaging

PubMed Central

Ramsay, DT; Kent, JC; Hartmann, RA; Hartman, PE

2005-01-01

The aim of this study was to use ultrasound imaging to re-investigate the anatomy of the lactating breast. The breasts of 21 fully lactating women (1–6 months post partum) were scanned using an ACUSON XP10 (5–10 MHz linear array probe). The number of main ducts was measured, ductal morphology was determined, and the distribution of glandular and adipose tissue was recorded. Milk ducts appeared as hypoechoic tubular structures with echogenic walls that often contained echoes. Ducts were easily compressed and did not display typical sinuses. All ducts branched within the areolar radius, the first branch occurring 8.0 ± 5.5 mm from the nipple. Duct diameter was 1.9 ± 0.6 mm, 2.0 ± 90.7 mm and the number of main ducts was 9.6 ± 2.9, 9.2 ± 2.9, for left and right breast, respectively. Milk ducts are superficial, easily compressible and echoes within the duct represent fat globules in breastmilk. The low number and size of the ducts, the rapid branching under the areola and the absence of sinuses suggest that ducts transport breastmilk, rather than store it. The distribution of adipose and glandular tissue showed wide variation between women but not between breasts within women. The proportion of glandular and fat tissue and the number and size of ducts were not related to milk production. This study highlights inconsistencies in anatomical literature that impact on breast physiology, breastfeeding management and ultrasound assessment. PMID:15960763

On modeling the sound propagation through a lined duct with a modified Ingard-Myers boundary condition

NASA Astrophysics Data System (ADS)

Yang, Cheng; Fang, Yi; Zhao, Chao; Zhang, Xin

2018-06-01

A duct acoustics model is an essential component of an impedance eduction technique and its computation cost determines the impedance measurement efficiency. In this paper, a model is developed for the sound propagation through a lined duct carrying a uniform mean flow. In contrast to many existing models, the interface between the liner and the duct field is defined with a modified Ingard-Myers boundary condition that takes account of the effect of the boundary layer above the liner. A mode-matching method is used to couple the unlined and lined duct segments for the model development. For the lined duct segment, the eigenvalue problem resulted from the modified boundary condition is solved by an integration scheme which, on the one hand, allows the lined duct modes to be computed in an efficient manner, and on the other hand, orders the modes automatically. The duct acoustics model developed from the solved lined duct modes is shown to converge more rapidly than the one developed from the rigid-walled duct modes. Validation against the experiment data in the literature shows that the proposed model is able to predict more accurately the liner performance measured by the two-source method. This, however, cannot be made by a duct acoustics model associated with the conventional Ingard-Myers boundary condition. The proposed model has the potential to be integrated into an impedance eduction technique for more reliable liner measurement.

Reconstruction of Bile Duct Injury and Defect with the Round Ligament.

PubMed

Dokmak, Safi; Aussilhou, Béatrice; Ragot, Emilia; Tantardini, Camille; Cauchy, François; Ponsot, Philippe; Belghiti, Jacques; Sauvanet, Alain; Soubrane, Olivier

2017-09-01

Lateral injury of the bile duct can occur after cholecystectomy, bile duct dissection, or exploration. If direct repair is not possible, conversion to bilioenteric anastomosis can be needed with the risk of long-term bile duct infections and associated complications. We developed a new surgical technique which consist of reconstructing the bile duct with the round ligament. The vascularized round ligament is completely mobilized until its origin and used for lateral reconstruction of the bile duct to cover the defect. T tube was inserted and removed after few months. Patency of the bile duct was assessed by cholangiography, the liver function test and magnetic resonance imaging (MRI). Two patients aged 33 and 59 years old underwent lateral reconstruction of the bile duct for defects secondary to choledocotomy for stone extraction or during dissection for Mirizzi syndrome. The defects measured 2 and 3 cm and occupied half of the bile duct circumference. The postoperative course was marked by low output biliary fistula resolved spontaneously. In one patient, the T tube was removed at 3 months after surgery and MRI at 9 months showed strictly normal aspect of the bile duct with normal liver function test. The second patient is going very well 2 months after surgery and the T tube is closed. Lateral reconstruction of the bile duct can be safely achieved with the vascularized round ligament. We will extend our indications to tubular reconstruction.

Synchronous double primary cancers of the extrahepatic bile duct: A case report and literature review.

PubMed

Nishi, Takeshi; Sato, Yoshitoshi; Hanaoka, Takuya; Takahashi, Takuya; Miura, Hiroshi; Takubo, Kenji

2018-01-01

Double cancers of the biliary tract system are rare. Most of these cancers are synchronous double cancers of the gall bladder and bile duct, associated with pancreaticobiliary maljunction (PBM). Synchronous double cancers of the extrahepatic bile duct without PBM are especially rare, and only 4 cases have been reported. A 78-year-old woman was admitted to our hospital for examination of hyperbilirubinemia and liver dysfunction. Contrast-enhanced abdominal computed tomography, Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed 2 stenotic regions in the common bile duct: at its junction with the cystic duct and in the distal bile duct. No findings suggested PBM, such as a markedly long common channel. The diagnosis based on endoscopic brush cytology from both stricture portions was adenocarcinoma. The patient had a pylorus-preserving pancreaticoduodenectomy with regional lymph node resection. Macroscopically, there were 2 stenotic regions at the cystic duct junction and in the distal bile duct. Microscopically, the tumor at the junction of the cystic duct was a well-to-moderately differentiated adenocarcinoma. On the other hand, the tumor of the distal bile duct was a poorly differentiated adenocarcinoma. There was no evidence of communication between these 2 cancers. Double cancers of the extrahepatic bile duct without PBM are very rare. Therefore, an accurate diagnosis prior to surgery is necessary. Furthermore, this rare condition seems to be associated with a poor prognosis. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Relationship Between Bile Duct Reconstruction and Complications in Living Donor Liver Transplantation.

PubMed

Miyagi, S; Kawagishi, N; Kashiwadate, T; Fujio, A; Tokodai, K; Hara, Y; Nakanishi, C; Kamei, T; Ohuchi, N; Satomi, S

2016-05-01

In living donor liver transplantation (LDLT), the recipient bile duct is thin and short. Bile duct complications often occur in LDLT, with persistent long-term adverse effects. Recently, we began to perform microsurgical reconstruction of the bile duct. The purpose of this study was to investigate the relationship between bile duct reconstruction methods and complications in LDLT. From 1991 to 2014, we performed 161 LDLTs (pediatric:adult = 90:71; left lobe:right lobe = 95:66). In this study, we retrospectively investigated the initial bile duct complications in LDLT and performed univariate and multivariate analyses to identify the independent risk factors for complications. The most frequent complication was biliary stricture (9.9%), followed by biliary leakage (6.8%). On univariate and multiple logistic regression analysis, the independent risk factors for biliary stricture were bile leakage (P = .0103) and recurrent cholangitis (P = .0077). However, there were no risk factors for biliary leakage on univariate analysis in our study. The reconstruction methods (hepaticojejunostomy or duct-to-duct anastomosis) and reconstruction technique (with or without microsurgery) were not risk factors for biliary stricture and leakage. In this study, the most frequent complication of LDLT was biliary stricture. The independent risk factors for biliary stricture were biliary leakage and recurrent cholangitis. Duct-to-duct anastomosis and microsurgical reconstruction of the bile duct were not risk factors for biliary stricture and leakage. Copyright © 2016 Elsevier Inc. All rights reserved.

A Plug-and-Play Duct System Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beach, R.; Dickson, B.; Grisolia, A.

2017-07-01

This report describes an air distribution system composed of a series of uniformly-sized ducts that terminate in rooms throughout the home and return to a central manifold, similar in fashion to a “home-run” cross-linked polyethylene plumbing system. With a well-designed manifold, each duct receives an equal static pressure potential for airflow from the air handling unit, and the number of needed ducts for each room are simply attached to fittings located on the manifold; in this sense, the system is plug-and-play (PnP). As indicated, all ducts in the PnP system are identical in size and small enough to fit inmore » the ceiling and wall cavities of a house (i.e., less than 3.5-in. outer diameter). These ducts are also more appropriately sized for the lower airflow requirements of modern, energy-efficient homes; therefore, the velocity of the air moving through the duct is between that of conventional duct systems (approximately 700 ft/min) and high-velocity systems (more than 1,500 ft/min) on the market today. The PnP duct system uses semi-rigid plastic pipes, which have a smooth inner wall and are straightforward to install correctly, resulting in a system that has minimal air leakage. However, plastic ducts are currently not accepted by code for use in residential buildings; therefore, the project team considered other duct materials for the system that are currently accepted by code, such as small-diameter, wirehelix, flexible ductwork.« less

Mockup Small-Diameter Air Distribution System

DOE Office of Scientific and Technical Information (OSTI.GOV)

A. Poerschke and A. Rudd

2016-05-01

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to be brought easily within conditioned space via interior partition walls. Centrally locating the air hander unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives an equal amount of airflow, regardless of the duct position on the box. Furthermore, within a reasonable set of length restrictions, each duct continues to receive similar airflow. The design method uses anmore » additive approach to reach the total needed zonal airflow. Once the cubic feet per minute needed to satisfy the thermal load of a zone has been determined, the total number of duct runs to a zone can be calculated by dividing the required airflow by the standard airflow from each duct. The additive approach greatly simplifies the design effort and reduces the potential for duct design mistakes to be made. Measured results indicate that this plenum design can satisfy the heating load. However, the total airflow falls short of satisfying the cooling load in a hypothetical building. Static pressure inside the plenum box of 51.5 Pa limited the total airflow of the attached mini-split heat pump blower, thus limiting the total thermal capacity. Fan energy consumption is kept to 0.16 to 0.22 watt/CFM by using short duct runs and smooth duct material.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to be brought easily within conditioned space via interior partition walls. Centrally locating the air hander unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives an equal amount of airflow, regardless of the duct position on the box. Furthermore, within a reasonable set of length restrictions, each duct continues to receive similar airflow. The design method uses anmore » additive approach to reach the total needed zonal airflow. Once the cubic feet per minute needed to satisfy the thermal load of a zone has been determined, the total number of duct runs to a zone can be calculated by dividing the required airflow by the standard airflow from each duct. The additive approach greatly simplifies the design effort and reduces the potential for duct design mistakes to be made. Measured results indicate that this plenum design can satisfy the heating load. However, the total airflow falls short of satisfying the cooling load in a hypothetical building. Static pressure inside the plenum box of 51.5 Pa limited the total airflow of the attached mini-split heat pump blower, thus limiting the total thermal capacity. Fan energy consumption is kept to 0.16 to 0.22 watt/CFM by using short duct runs and smooth duct material.« less

Anatomic variations in intrahepatic bile ducts in a north Indian population.

PubMed

Sharma, Vijay; Saraswat, Vivek Anand; Baijal, Sanjay Saran; Choudhuri, Gourdas

2008-07-01

In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India. The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct. Anatomy of the IHD was typical in 52.9% of cases (n = 134), showing triple confluence in 11.46% (n = 29), anomalous drainage of the RPSD into the LHD in 18.2% (n = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% (n = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% (n = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% (n = 12), individual drainage of the LHD into the RHD or CHD in 2.4% (n = 6), and unclassified or complex variations in 2.7% (n = 7). None had anomalous drainage of RPSD into the cystic duct. The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).

Improved Merge Valve

NASA Technical Reports Server (NTRS)

George-Falvy, Dez

1992-01-01

Circumferential design combines compactness and efficiency. In remotely controlled valve, flow in tributary duct along circumference of primary duct merged with flow in primary duct. Flow in tributary duct regulated by variable throat nuzzle driven by worm gear. Design leak-proof, and most components easily fabricated on lathe.

Cholestasis‐induced adaptive remodeling of interlobular bile ducts

PubMed Central

Damle‐Vartak, Amruta; Richter, Beate; Dirsch, Olaf; Dahmen, Uta; Hammad, Seddik

2016-01-01

Cholestasis is a common complication in liver diseases that triggers a proliferative response of the biliary tree. Bile duct ligation (BDL) is a frequently used model of cholestasis in rodents. To determine which changes occur in the three‐dimensional (3D) architecture of the interlobular bile duct during cholestasis, we used 3D confocal imaging, surface reconstructions, and automated image quantification covering a period up to 28 days after BDL. We show a highly reproducible sequence of interlobular duct remodeling, where cholangiocyte proliferation initially causes corrugation of the luminal duct surface, leading to an approximately five‐fold increase in surface area. This is analogous to the function of villi in the intestine or sulci in the brain, where an expansion of area is achieved within a restricted volume. The increase in surface area is further enhanced by duct branching, branch elongation, and loop formation through self‐joining, whereby an initially relatively sparse mesh surrounding the portal vein becomes five‐fold denser through elongation, corrugation, and ramification. The number of connections between the bile duct and the lobular bile canalicular network by the canals of Hering decreases proportionally to the increase in bile duct length, suggesting that no novel connections are established. The diameter of the interlobular bile duct remains constant after BDL, a response that is qualitatively distinct from that of large bile ducts, which tend to enlarge their diameters. Therefore, volume enhancement is only due to net elongation of the ducts. Because curvature and tortuosity of the bile duct are unaltered, this enlargement of the biliary tree is caused by branching and not by convolution. Conclusion: BDL causes adaptive remodeling that aims at optimizing the intraluminal surface area by way of corrugation and branching. (Hepatology 2016;63:951–964) PMID:26610202

Effects of partial portal vein arterialization on the hilar bile duct in a rat model.

PubMed

Guo, Shao-Hua; Li, Chong-Hui; Chen, Yong-Liang; Song, Jian-Ning; Zhang, Ai-Qun; Zhou, Cheng

2011-10-01

Liver revascularization is frequently required during the enlarged radical operation for hilar cholangiocarcinoma involving the hepatic artery. Researchers have carried out a number of experiments applying partial portal vein arterialization (PVA) in clinical practice. In this study we aimed to establish a theoretical basis for clinical application of partial PVA and to investigate the effects of partial PVA on rat hilar bile duct and hepatic functions. Thirty rats were randomly and equally assigned into 3 groups: control (group A), hepatic artery ligation+bile duct recanalization (group B), and partial PVA+bile duct recanalization (group C). Proliferation and apoptosis of rat hilar bile duct epithelial cells, arteriolar counts of the peribiliary plexus (PBP) of the bile duct wall, changes in serum biochemistry, and pathologic changes in the bile duct were assessed 1 month after operation. The proliferation of hilar bile duct epithelial cells in group B was greater than in groups A and C (P<0.01). No apoptotic hilar bile duct epithelial cells were detected in any of the groups. The PBP arteriolar counts of the hilar bile duct wall were similar in groups A and C (P>0.05), but the count was lower in group B than in group A (P<0.01). No statistically significant differences in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and albumin were found in the 3 groups. The gamma-glutamyltransferase value was higher in group B than in groups A and C (P<0.01). The hepatic tissues of groups A and C showed no significant abnormality. Chronic inflammatory changes in the hilar bile duct walls were observed only in group B. Partial PVA can restore the arterial blood supply of the hilar bile duct and significantly extenuate the injury to hilar bile duct epithelial cells resulting from hepatic artery ligation.

Da Vinci robot-assisted anatomic left hemihepatectomy and biliary reconstruction.

PubMed

Wang, Zhifei; Liu, Quanda; Chen, Junzhou; Duan, Weihong; Zhou, Ningxin

2013-06-01

Since the introduction of Da Vinci robotic surgery, more and more complicated surgeries can now be performed robotically, yet there have been very few on robotic hepatectomy, especially when billiary reconstruction is involved. The video shows our initial experience with an anatomic hepatectomy using Da Vinci surgical robot. In this case, we also conducted billiary reconstruction due to the anatomic abnormality of bile duct, while applying the choledochoscopy. The preoperative diagnosis is primary liver carcinoma, tumor thrombi in bile duct, and hepatitis B. First, the gallbladder was resected, and cystic artery and duct were identified. After opening of the common bile duct above the junction, the choledochoscopy was performed. Tumor thrombi were found in common bile duct and left hepatic duct, and they were all removed. Left branches hepatic artery and portal vein were dissected, ligated, and divided. Thrombi in the left hepatic duct were removed also. After marking the cutting line along the ischemic boarder, liver parenchyma was transected using robotic harmonic scalpel. Branches of ducts were encountered and managed by either direct coagulating or dividing after clipping. The left hepatic vein was visualized, exposed, and divided during hepatectomy. Two T tubes were placed into common hepatic duct and the proximal cutting end of right anterior bile duct which was found to join the left hepatic duct, respectively. The operation went on successfully. The operation time was 410 minutes, the blood loss was 200 mL. The pathologic diagnosis was introductal papillary adenocarcinoma of left hepatic duct. The patient went on well postoperatively and was followed up for 22 months till now. Postoperative computed tomography examination showed no recurrence. Da Vinci-assisted robotic hepatectomy can be performed safely in the hands of experienced hepatobilliary surgeons, and choledochoscopy can be combined for bile duct exploration. With the advantages of Da Vinci robot system, complicated billiary reconstruction can be performed (http://links.lww.com/SLE/A74).

A novel technique of percutaneous stone extraction in choledocholithiasis after cholecystostomy.

PubMed

Lim, Kyoung Hoon; Kim, Yong Joo

2013-05-01

To evaluate the technical feasibility and clinical efficacy of percutaneous common bile duct stone extraction via cystic duct after percutaneous cholecystostomy. Twenty-five consecutive patients with choledocholithiasis underwent percutaneous stone extraction under conscious sedation. The stones were extracted through the 12-Fr sheath using Wittich nitinol stone basket under fluoroscopic guidance via cystic duct after percutaneous trnas-hepatic cholecystostomy. Common bile duct stones were successfully removed in 22 of the 25 patients (88%) by this new technique. The causes of failure in three patients were bile leakage, hematoma of the gallbladder and failure of cystic duct cannulation. Cystic duct injury during this procedure did not occur and there was no post-procedure mortality. The mean period of indwelling catheter was 8.7±4.6 days and the mean duration of hospitalization was 13.4±5.9 days. Percutaneous commmon bile duct stone extraction via the cystic duct through percutaneous cholecystostomy route is effective and feasible for treating choledocholithiasis.

Study of Gas Solid Flow Characteristics in Cyclone Inlet Ducts of A300Mwe CFB Boiler

NASA Astrophysics Data System (ADS)

Tang, J. Y.; Lu, X. F.; Lai, J.; Liu, H. Z.

Gas solid flow characteristics in cyclone's inlet duct of a 300MW CFB boiler were studied in a cold circulating fluidized bed (CFB) experimental setup according to a 410t/h CFB boiler with a scale of 10∶1. Tracer particles were adopted in the experiment and their motion trajectories in the two kinds of cyclone's inlet ducts were photographed by a high-speed camera. By analyzing the motion trajectories of tracer particles, acceleration performance of particle phases in the two inlet ducts was obtained. Results indicate that the acceleration performance of particles in the long inlet duct is better than that in the short inlet duct, but the pressure drop of the long inlet duct is higher. Meanwhile, under the same operating conditions, both the separation efficiency and the pressure drop of the cyclone are higher when the cyclone is connected with the long inlet duct. Figs 11, Tabs 4 and refs 10.

Synchronous papillary carcinoma in thyroglossal duct cyst and thyroid gland: case report and review of literature.

PubMed

Cherian, Mathew Pynumootil; Nair, Balakrishnan; Thomas, Shaji; Somanathan, Thara; Sebastian, Paul

2009-10-01

We report a rare case of synchronous occurrence of thyroglossal duct cyst carcinoma and thyroid carcinoma and discuss its management in detail. A 59-year-old woman was clinically diagnosed to have a thyroglossal duct cyst and a solitary nodule. Fine-needle aspiration cytology revealed a papillary carcinoma in the thyroglossal duct cyst and a colloid in the thyroid nodule. Sistrunk's procedure along with a total thyroidectomy was performed followed by postoperative radioiodine ablation. Histopathologic examination revealed thyroglossal duct cyst carcinoma and bilateral foci of papillary carcinoma in the thyroid gland. She has remained free of disease on follow-up. Most cancers arising in thyroglossal duct cysts are of low risk, and Sistrunk's procedure is an adequate treatment for such cancers. However, for synchronously occurring cancers of the thyroglossal duct cyst and thyroid gland, or high-risk thyroglossal duct cyst cancers, more aggressive treatment comprising total thyroidectomy, Sistrunk's procedure, and radioiodine therapy is indicated. (c) 2009 Wiley Periodicals, Inc.

[Clinicopathologic features of drug-induced vanishing bile duct syndrome].

PubMed

Ye, L H; Wang, C K; Zhang, H C; Liu, Z Q; Zheng, H W

2017-04-20

Vanishing bile duct syndrome (VBDS) manifests as progressive destruction and disappearance of the intrahepatic bile duct caused by various factors and cholestasis. VBDS associated with drug-induced liver injury (D-VBDS) is an important etiology of VBDS, and immune disorder or immune imbalance may be the main pathogenesis. According to its clinical symptoms, serological markers, and course of the disease, D-VBDS is classified into major form and minor form, and its clinical features are based on various pathomorphological findings. Its prognosis is associated various factors including regeneration of bile duct cells, number of bile duct injuries, level and range of bile duct injury, bile duct proliferation, and compensatory shunt of bile duct branches. This disease has various clinical outcomes; most patients have good prognosis after drug withdrawal, and some patients may experience cholestatic cirrhosis, liver failure, and even death. Due to the clinical manifestation and biochemical changes are similar to the primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), it need to identify by clinical physician.

Cystic Duct Closure by Sealing With Bipolar Electrocoagulation

PubMed Central

Damgaard, B.; Jorgensen, L. N.; Larsen, S. S.; Kristiansen, V. B.

2010-01-01

Background: Cystic duct leakage after cholecystectomy is not uncommon and is a potentially serious complication. The aim of this study was to assess a bipolar sealing system (LigaSure®) for closure of the cystic duct. Methods: The records from consecutive laparoscopic cholecystectomies performed in 2 hospitals with closure of the cystic duct with LigaSure after informed consent were recorded and complications and morbidity registered. The records were compared with those of patients undergoing laparoscopic cholecystectomy with closure of the cystic duct with clips during the same period. Results: During the study period, 218 laparoscopic cholecystectomies were performed; 102 of these were performed with the LigaSure. One patient was excluded due to violation of the protocol. We experienced no cases of cystic duct leakage, but in one patient, bile leakage from the gallbladder bed was observed probably due to a small aberrant duct. Conclusion: The LigaSure system was safe and effective for closure and division of the cystic duct in laparoscopic cholecystectomy. PMID:20412641

Sealing ducts to save energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siuru, B.

1996-07-01

Large amounts of energy are wasted when heat leaks through ductwork located in uninsulated spaces. The Electric Power Research INstitute recently did a study that accurately measured these losses, then substantially reduced them by sealing the leaky ductwork. Six homes in the Pacific Northwest with significant duct leakage to the outside were selected for the study. The homes had electric resistance or heat pump, forced-air heating systems with a major portion of the supply and return ductwork in crawl spaces, attics, garages, etc. Measurements of duct leakage and heating system efficiency were done on all the homes before starting themore » duct sealing. Retrofitting included finding holes, gaps, cracks and disconnected joints in supply and return ducts as well as in plenums. When necessary, plenums were cut open for repairs. Leaks were sealed with Latex mastic and fiberglass tape. Outside ducts were covered or wrapped with insulation. Unducted returns were sealed with duct board. In some cases, leakage was corrected by merely reconnecting ducts and boots.« less

Transient liquid-crystal technique used to produce high-resolution convective heat-transfer-coefficient maps

NASA Technical Reports Server (NTRS)

Hippensteele, Steven A.; Poinsatte, Philip E.

1993-01-01

In this transient technique the preheated isothermal model wall simulates the classic one-dimensional, semi-infinite wall heat transfer conduction problem. By knowing the temperature of the air flowing through the model, the initial temperature of the model wall, and the surface cooling rate measured at any location with time (using the fast-response liquid-crystal patterns recorded on video tape), the heat transfer coefficient can be calculated for the color isothermal pattern produced. Although the test was run transiently, the heat transfer coefficients are for the steady-state case. The upstream thermal boundary condition was considered to be isothermal. This transient liquid-crystal heat-transfer technique was used in a transient air tunnel in which a square-inlet, 3-to-1 exit transition duct was placed. The duct was preheated prior to allowing room temperature air to be suddenly drawn through it. The resulting isothermal contours on the duct surfaces were revealed using a surface coating of thermochromic liquid crystals that display distinctive colors at particular temperatures. A video record was made of the temperature and time data for all points on the duct surfaces during each test. The duct surfaces were uniformly heated using two heating systems: the first was an automatic temperature-controlled heater blanket completely surrounding the test duct like an oven, and the second was an internal hot-air loop through the inside of the test duct. The hot-air loop path was confined inside the test duct by insulated heat dams located at the inlet and exit ends of the test duct. A recirculating fan moved hot air into the duct inlet, through the duct, out of the duct exit, through the oven, and back to the duct inlet. The temperature nonuniformity of the test duct model wall was held very small. Test results are reported for two inlet Reynolds numbers of 200,000 and 1,150,000 (based on the square-inlet hydraulic diameter) and two free-stream turbulence intensities of about 1 percent, which is typical of wind tunnels, and up to 20 percent (using a grid), which is typical of real engine conditions.

Design of power-plant installations pressure-loss characteristics of duct components

NASA Technical Reports Server (NTRS)

Henry, John R

1944-01-01

A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging bends; vaned bends; diffusers; branch ducts; internal inlets; and an angular placement of heat exchangers. Examples are included to illustrate methods of applying these data in analyzing duct systems. (author)

Transition duct with divided upstream and downstream portions

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Maldonado, Jaime Javier

2015-07-14

Turbine systems are provided. In one embodiment, a turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion extending from the inlet and a downstream portion extending from the outlet. The turbine system further includes a rib extending from an outer surface of the duct passage, the rib dividing themore » upstream portion and the downstream portion.« less

Importance of resin ducts in reducing ponderosa pine mortality from bark beetle attack.

PubMed

Kane, Jeffrey M; Kolb, Thomas E

2010-11-01

The relative importance of growth and defense to tree mortality during drought and bark beetle attacks is poorly understood. We addressed this issue by comparing growth and defense characteristics between 25 pairs of ponderosa pine (Pinus ponderosa) trees that survived and trees that died from drought-associated bark beetle attacks in forests of northern Arizona, USA. The three major findings of our research were: (1) xylem resin ducts in live trees were >10% larger (diameter), >25% denser (no. of resin ducts mm(-2)), and composed >50% more area per unit ring growth than dead trees; (2) measures of defense, such as resin duct production (no. of resin ducts year(-1)) and the proportion of xylem ring area to resin ducts, not growth, were the best model parameters of ponderosa pine mortality; and (3) most correlations between annual variation in growth and resin duct characteristics were positive suggesting that conditions conducive to growth also increase resin duct production. Our results suggest that trees that survive drought and subsequent bark beetle attacks invest more carbon in resin defense than trees that die, and that carbon allocation to resin ducts is a more important determinant of tree mortality than allocation to radial growth.

Balloon catheter dilation and nasolacrimal duct intubation for treatment of nasolacrimal duct obstruction after failed probing.

PubMed

Repka, Michael X; Chandler, Danielle L; Holmes, Jonathan M; Hoover, Darren L; Morse, Christine L; Schloff, Susan; Silbert, David I; Tien, D Robbins

2009-05-01

To compare the outcomes of balloon catheter dilation and nasolacrimal intubation as treatment for congenital nasolacrimal duct obstruction after failed probing in children younger than 4 years. We conducted a prospective, nonrandomized, multicenter study that enrolled 159 children aged 6 months to younger than 48 months who had a history of a single failed nasolacrimal duct probing and at least 1 of the following clinical signs of nasolacrimal duct obstruction: epiphora, mucous discharge, or increased tear lake. One hundred ninety-nine eyes underwent either balloon catheter nasolacrimal duct dilation or nasolacrimal duct intubation. Treatment success was defined as absence of epiphora, mucous discharge, or increased tear lake at the outcome visit 6 months after surgery. Treatment success was reported in 65 of 84 eyes (77%; 95% confidence interval, 65%-85%) in the balloon catheter dilation group compared with 72 of 88 eyes (84% after adjustment for intereye correlation; 74%-91%) in the nasolacrimal intubation group (risk ratio for success for intubation vs balloon dilation, 1.08; 0.95-1.22). Both balloon catheter dilation and nasolacrimal duct intubation alleviate the clinical signs of persistent nasolacrimal duct obstruction in a similar percentage of patients.

Acute carbon tetrachloride feeding induces damage of large but not small cholangiocytes from BDL rat liver.

PubMed

LeSage, G D; Glaser, S S; Marucci, L; Benedetti, A; Phinizy, J L; Rodgers, R; Caligiuri, A; Papa, E; Tretjak, Z; Jezequel, A M; Holcomb, L A; Alpini, G

1999-05-01

Bile duct damage and/or loss is limited to a range of duct sizes in cholangiopathies. We tested the hypothesis that CCl4 damages only large ducts. CCl4 or mineral oil was given to bile duct-ligated (BDL) rats, and 1, 2, and 7 days later small and large cholangiocytes were purified and evaluated for apoptosis, proliferation, and secretion. In situ, we measured apoptosis by morphometric and TUNEL analysis and the number of small and large ducts by morphometry. Two days after CCl4 administration, we found an increased number of small ducts and reduced number of large ducts. In vitro apoptosis was observed only in large cholangiocytes, and this was accompanied by loss of proliferation and secretion in large cholangiocytes and loss of choleretic effect of secretin. Small cholangiocytes de novo express the secretin receptor gene and secretin-induced cAMP response. Consistent with damage of large ducts, we detected cytochrome P-4502E1 (which CCl4 converts to its radicals) only in large cholangiocytes. CCl4 induces selective apoptosis of large ducts associated with loss of large cholangiocyte proliferation and secretion.

Solar coal gasification reactor with pyrolysis gas recycle

DOEpatents

Aiman, William R.; Gregg, David W.

1983-01-01

Coal (or other carbonaceous matter, such as biomass) is converted into a duct gas that is substantially free from hydrocarbons. The coal is fed into a solar reactor (10), and solar energy (20) is directed into the reactor onto coal char, creating a gasification front (16) and a pyrolysis front (12). A gasification zone (32) is produced well above the coal level within the reactor. A pyrolysis zone (34) is produced immediately above the coal level. Steam (18), injected into the reactor adjacent to the gasification zone (32), reacts with char to generate product gases. Solar energy supplies the energy for the endothermic steam-char reaction. The hot product gases (38) flow from the gasification zone (32) to the pyrolysis zone (34) to generate hot char. Gases (38) are withdrawn from the pyrolysis zone (34) and reinjected into the region of the reactor adjacent the gasification zone (32). This eliminates hydrocarbons in the gas by steam reformation on the hot char. The product gas (14) is withdrawn from a region of the reactor between the gasification zone (32) and the pyrolysis zone (34). The product gas will be free of tar and other hydrocarbons, and thus be suitable for use in many processes.

Inhibitory effect of dietary capsaicin on liver fibrosis in mice.

PubMed

Bitencourt, Shanna; Stradiot, Leslie; Verhulst, Stefaan; Thoen, Lien; Mannaerts, Inge; van Grunsven, Leo A

2015-06-01

Virtually all chronic liver injuries result in the activation of hepatic stellate cells (HSCs). In their activated state, these cells are the main collagen-producing cells implicated in liver fibrosis. Capsaicin (CPS), the active compound of chili peppers, can modulate the activation and migration of HSCs in vitro. Here, we evaluated the potential protective and prophylactic effects of CPS related to cholestatic and hepatotoxic-induced liver fibrosis and its possible underlying mechanism of action. Male Balb/c mice received dietary CPS after 3 days of bile duct ligation (BDL) or before and during carbon tetrachloride (CCl4 ) injections. Mice receiving dietary CPS after BDL had a significant improvement of liver fibrosis accompanied by a decrease in collagen deposition and downregulation of activation markers in isolated HSCs. In the CCl4 model, dietary CPS inhibited the upregulation of profibrogenic markers. However, CPS could not attenuate the CCl4 -induced fibrosis when it was already established. Furthermore, in vitro CPS treatment inhibited the autophagic process during HSC activation. Dietary CPS has potential benefits in the therapy of cholestatic liver fibrosis and in the prophylaxis of hepatotoxic-induced liver injury. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mixing of multiple jets with a confined subsonic crossflow. Summary of NASA-supported experiments and modeling

NASA Technical Reports Server (NTRS)

Holdeman, James D.

1991-01-01

Experimental and computational results on the mixing of single, double, and opposed rows of jets with an isothermal or variable temperature mainstream in a confined subsonic crossflow are summarized. The studies were performed to investigate flow and geometric variations typical of the complex 3-D flowfield in the dilution zone of combustion chambers in gas turbine engines. The principal observations from the experiments were that the momentum-flux ratio was the most significant flow variable, and that temperature distributions were similar (independent of orifice diameter) when the orifice spacing and the square-root of the momentum-flux ratio were inversely proportional. The experiments and empirical model for the mixing of a single row of jets from round holes were extended to include several variations typical of gas turbine combustors. Combinations of flow and geometry that gave optimum mixing were identified from the experimental results. Based on results of calculations made with a 3-D numerical model, the empirical model was further extended to model the effects of curvature and convergence. The principle conclusions from this study were that the orifice spacing and momentum-flux relationships were the same as observed previously in a straight duct, but the jet structure was significantly different for jets injected from the inner wall wall of a turn than for those injected from the outer wall. Also, curvature in the axial direction caused a drift of the jet trajectories toward the inner wall, but the mixing in a turning and converging channel did not seem to be inhibited by the convergence, independent of whether the convergence was radial or circumferential. The calculated jet penetration and mixing in an annulus were similar to those in a rectangular duct when the orifice spacing was specified at the radius dividing the annulus into equal areas.

Risk Factors for Immediate and Delayed-Onset Fever After Percutaneous Transhepatic Biliary Drainage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucatelli, Pierleone, E-mail: pierleone.lucatelli@gmail.com; Corradini, Stefano Ginanni, E-mail: stefano.corradini@uniroma1.it; Corona, Mario, E-mail: mario.corona@uniroma1.it

ObjectivesTo prospectively investigate the pre and intra-procedural risk factors for immediate (IF) and delayed-onset (DOF) fever development after percutaneous transhepatic biliary drainage (PTBD).MethodsInstitutional review board approval and informed patient consent were obtained. Between February 2013 and February 2014, 97 afebrile patients (77 at the Sapienza University of Rome, Italy and 20 at the Sun Yat-sen University of Guangzhou, China) with benign (n = 31) and malignant (n = 66) indications for a first PTBD were prospectively enrolled. Thirty pre- and intra-procedural clinical/radiological characteristics, including the amount of contrast media injected prior to PTBD placement, were collected in relation to the development of IF (withinmore » 24 h) or DOF (after 24 h). Fever was defined as ≥37.5 °C. Binary logistic regression analysis was used to assess independent associations with IF and DOF.ResultsFourteen (14.4 %) patients developed IF and 17 (17.5 %) developed DOF. At multivariable analysis, IF was associated with pre-procedural absence of intrahepatic bile duct dilatation (OR 63.359; 95 % CI 2.658–1510.055; P = 0.010) and low INR (OR 4.7 × 10{sup −4}; 95 % CI 0.000–0.376; P = 0.025), while DOF was associated with unsatisfactory biliary drainage at the end of PTBD (OR 4.571; 95 % CI 1.161–17.992; P = 0.030).ConclusionsThe amount of contrast injected is not associated with post-PTBD fever development. Unsatisfactory biliary drainage at the end of PTBD is associated with DOF, suggesting that complete biliary tree decompression should be pursued within the first PTBD. Patients with unsatisfactory drainage and those with the absence of pre-procedural intrahepatic bile duct dilatation, which is associated with IF, require tailored post-PTBD management.« less

Effects of interstage diffuser flow distortion on the performance of a 15.41-centimeter tip diameter axial power turbine

NASA Technical Reports Server (NTRS)

Mclallin, K. L.; Kofskey, M. G.; Civinskas, K. C.

1983-01-01

The performance of a variable-area stator, axial flow power turbine was determined in a cold-air component research rig for two inlet duct configurations. The two ducts were an interstage diffuser duct and an accelerated-flow inlet duct which produced stator inlet boundary layer flow blockages of 11 percent and 3 percent, respectively. Turbine blade total efficiency at design point was measured to be 5.3 percent greater with the accelerated-flow inlet duct installed due to the reduction in inlet blockage. Blade component measurements show that of this performance improvement, 35 percent occurred in the stator and 65 percent occurred in the rotor. Analysis of inlet duct internal flow using an Axisymmetric Diffuser Duct Code (ADD Code) were in substantial agreement with the test data.

Endoscopic therapy of posttransplant biliary stenoses after right-sided adult living donor liver transplantation.

PubMed

Zoepf, Thomas; Maldonado-Lopez, Evelyn J; Hilgard, Philip; Schlaak, Joerg; Malago, Massimo; Broelsch, Christoph E; Treichel, Ulrich; Gerken, Guido

2005-11-01

Endoscopic treatment of biliary strictures after liver transplantation is a therapeutic challenge. In particular, outcomes of endoscopic therapy of biliary complications in the case of duct-to-duct anastomosis after living related liver transplantation are limited. The aim of this study was to evaluate the feasibility and success of an endoscopic treatment approach to posttransplant biliary strictures (PTBS) after right-sided living donor liver transplantation (RLDLT) with duct-to-duct anastomosis. Ninety patients who received adult-to-adult RLDLT in our center were screened retrospectively with respect to endoscopic treatment of PTBS. Therapy was judged as successful when cholestasis parameters returned to normal and bile duct narrowing was reduced significantly after the completion of therapy. Forty of 90 RLDLT patients received duct-to-duct anastomosis, 12 (30%) showed PTBS. Seven of 12 patients were treated successfully by endoscopy; the remaining 5 patients were treated primarily by surgery. Most patients were treated by balloon dilatation followed by insertion of endoprostheses. A median of 2.5 dilatation sessions were necessary and the median treatment duration was 8 months. One patient developed endoscopy-treatable recurrent stenosis, no surgical intervention was necessary. Mild pancreatitis occurred in 7.9% and cholangitis in 5.3% of the procedures. One minor bleeding episode occurred during sphincterotomy. Bleeding was managed endoscopically. Endoscopic therapy of adult-to-adult right living related liver transplantation with duct-to-duct anastomosis is feasible and frequently is successful. The duct-to-duct anastomosis offers the possibility of endoscopic treatment. Endoscopic treatment of posttransplant biliary strictures is safe, with a low specific complication rate.

Albumin expression distinguishes bile duct adenomas from metastatic adenocarcinoma.

PubMed

Moy, Andrea P; Arora, Kshitij; Deshpande, Vikram

2016-09-01

Bile duct adenomas may be difficult to distinguish from metastatic carcinomas, particularly well-differentiated pancreatic ductal adenocarcinoma. Prior studies have evaluated the utility of various immunohistochemical markers, although these markers are notable for low sensitivity and/or specificity. The aim of this study was to investigate the utility of albumin and BRAFV600E expression in distinguishing between metastatic pancreatic adenocarcinoma and bile duct adenoma. We studied 26 bile duct adenomas, three bile duct hamartomas, and 158 pancreatic ductal adenocarcinomas. Branched-chain in-situ hybridization (bISH) for albumin was performed; bISH is based on the branched DNA technology, wherein signal amplification is achieved via a series of sequential steps. Additionally, BRAFV600E immunohistochemistry (IHC) was performed on a subset of cases. Twenty-three of 25 (92%) bile duct adenomas were positive for albumin; 18 (72%) showed diffuse staining, and five showed focal staining (20%), including two challenging examples. Two bile duct hamartomas also stained positively. All pancreatic adenocarcinomas were negative for albumin. Seven of 16 (44%) bile duct adenomas and five of 106 (5%) pancreatic ductal adenocarcinomas were positive for BRAFV600E by IHC. The sensitivity and specificity of expression of albumin, as detected by bISH, for distinguishing bile duct adenomas from metastatic pancreatic adenocarcinomas were 92% and 100%, respectively; the sensitivity and specificity of BRAFV600E IHC for distinguishing bile duct adenomas from metastatic pancreatic adenocarcinomas were 43.8% and 95.3%, respectively. Diagnostically challenging examples of bile duct adenoma may be distinguished from metastatic pancreatic adenocarcinoma by the use of albumin bISH. © 2016 John Wiley & Sons Ltd.

Biliary and pancreatic ductal dilation in patients on methadone maintenance therapy.

PubMed

Bates, David D B; Tamayo-Murillo, Dorathy; Kussman, Steven; Luce, Adam; LeBedis, Christina A; Soto, Jorge A; Anderson, Stephan W

2017-03-01

To determine whether the diameter of intrahepatic and extrahepatic bile ducts and pancreatic ducts in patients on methadone maintenance therapy is increased when compared with control subjects. Between January 1, 2000 and March 15, 2013, a total of 97 patients (mean age 49.9, range 22-79, 65 male, 32 female) were identified who were receiving chronic methadone maintenance therapy (MMT) when they underwent imaging with abdominal MRI or a contrast-enhanced abdominopelvic CT. A group of 97 consecutive non-MMT control patients (mean age 51.4, range 21-86, 45 male, 52 female) who underwent imaging with abdominal MRI or contrast-enhanced abdominopelvic CT were identified. Patients with known pancreaticobiliary pathology that may confound biliary ductal measurements were excluded. Blinded interpretation was performed, documenting the diameters of the intrahepatic and extrahepatic bile ducts and pancreatic ducts. Descriptive statistics were performed. Patients on MMT demonstrated increased bile duct diameter, with an average increase in duct diameter of 2.39 mm for the common bile duct (p < 0.001; 95% CI 1.88-2.90 mm), 1.43 mm for the intrahepatic bile ducts (p < 0.001; 95% CI 1.12-1.74 mm), and 0.90 mm for the pancreatic duct (p < 0.001; 95% CI 0.64-1.16 mm). No statistically significant correlation was found between ductal diameters and the daily dose of methadone. Patients on methadone maintenance therapy demonstrate significantly increased intra- and extrahepatic bile duct and pancreatic duct diameter when compared with controls. There was no correlation between the dose of methadone and ductal diameter.

Performance Analysis of a Modular Small-Diamter Air Distribution System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poerschke, Andrew; Rudd, Armin

2016-03-01

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to be brought easily within conditioned space via interior partition walls. Centrally locating the air handler unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives an equal amount of airflow, regardless of the duct position on the box. Furthermore, within a reasonable set of length restrictions, each duct continues to receive similar airflow. The design method uses anmore » additive approach to reach the total needed zonal airflow. Once the cubic feet per minute needed to satisfy the thermal load of a zone has been determined, the total number of duct runs to a zone can be calculated by dividing the required airflow by the standard airflow from each duct. The additive approach greatly simplifies the design effort and reduces the potential for duct design mistakes to be made. Measured results indicate that this plenum design can satisfy the heating load. However, the total airflow falls short of satisfying the cooling load in a hypothetical building. Static pressure inside the plenum box of 51.5 Pa limited the total airflow of the attached mini-split heat pump blower, thus limiting the total thermal capacity. Fan energy consumption is kept to 0.16 to 0.22 watt/CFM by using short duct runs and smooth duct material.« less

[Spontaneous perforation of the hepatic duct during biliary lithiasis complicated by acute pancreatitis].

PubMed

Assadourian, R; Chometowski, S; Bourde, J; Poitout, D; Lamy, J

1975-10-01

The association of perforation of the common bile duct, cholecystitis and acute pancreatitis, should be emphasized. Physiopathology of perforation of the bile duct may be compared with that of pancreatitis. Repair of the bile duct may be delicate requiring hepatico-jejunostomy on an isolated loop.

Magnetic Nozzle Simulation Studies for Electric Propulsion

NASA Astrophysics Data System (ADS)

Tarditi, Alfonso

2010-11-01

Electric Propulsion has recently re-gained interest as one of the key technologies to enable NASA's long-range space missions. Options are being considered also in the field of aneutronic fusion propulsion for high-power electric thrusters. To support these goals the study of the exhaust jet in a plasma thruster acquires a critical importance because the need of high-efficiency generation of thrust. A model of the plasma exhaust has been developed with the 3D magneto-fluid NIMROD code [1] to study the physics of the plasma detachment in correlation with experimentally relevant configurations. The simulations show the role of the plasma diamagnetism and of the magnetic reconnection process in the formation of a detached plasma. Furthermore, in direct fusion-propulsion concepts high-energy (MeV range) fusion products have to be efficiently converted into a slower and denser plasma jet (with specific impulse down to few 1000's seconds, for realistic missions in the Solar System). For this purpose, a two-stage conversion process is being modeled where high-energy ions are non-adiabatically injected and confined into a magnetic duct leading to the magnetic nozzle, transferring most of their energy into their gyro-motion and drifting at slower speed along with the plasma propellant. The propellant acquires then thermal energy that gets converted into the direction of thrust by the magnetic nozzle. [1] C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004).

Molecular Mechanism of Pancreatic and Salivary Glands Fluid and HCO3− Secretion

PubMed Central

Lee, Min Goo; Ohana, Ehud; Park, Hyun Woo; Yang, Dongki; Muallem, Shmuel

2013-01-01

Fluid and HCO3− secretion is a vital function of all epithelia and is required for the survival of the tissue. Aberrant fluid and HCO3− secretion is associated with many epithelial diseases, such as cystic fibrosis, pancreatitis, Sjögren’s syndrome and other epithelial inflammatory and autoimmune diseases. Significant progress has been made over the last 20 years in our understanding of epithelial fluid and HCO3− secretion, in particular by secretory glands. Fluid and HCO3− secretion by secretory glands is a two step process. Acinar cells secrete isotonic fluid in which the major salt is NaCl. Subsequently, the duct modifies the volume and electrolyte composition of the fluid to absorb the Cl− and secrete HCO3−. The relative volume secreted by acinar and duct cells and modification of electrolyte composition of the secreted fluids varies among secretory glands to meet their physiological functions. In the pancreas, acinar cells secrete small amount of NaCl-rich fluid, while the duct absorbs the Cl− and secretes HCO3− and the bulk of the fluid in the pancreatic juice. Fluid secretion appears to be driven by active HCO3− secretion. In the salivary glands, acinar cells secrete the bulk of the fluid in the saliva that contains high concentrations of Na+ and Cl− and fluid secretion is mediated by active Cl− secretion. The salivary glands duct absorbs both the Na+ and Cl− and secretes K+ and HCO3−. In this review, we focus on the molecular mechanism of fluid and HCO3− secretion by the pancreas and salivary glands, to highlight the similarities of the fundamental mechanisms of acinar and duct cell functions, and point the differences to meet glands specific secretions. PMID:22298651

Complement Component 5 Mediates Development of Fibrosis, via Activation of Stellate Cells, in 2 Mouse Models of Chronic Pancreatitis

PubMed Central

Sendler, Matthias; Beyer, Georg; Mahajan, Ujjwal M.; Kauschke, Vivien; Maertin, Sandrina; Schurmann, Claudia; Homuth, Georg; Völker, Uwe; Völzke, Henry; Halangk, Walter; Wartmann, Thomas; Weiss, Frank-Ulrich; Hegyi, Peter; Lerch, Markus M.; Mayerle, Julia

2015-01-01

Background & Aims Little is known about the pathogenic mechanisms of chronic pancreatitis. We investigated the roles of complement component 5 (C5) in pancreatic fibrogenesis in mice and patients. Methods Chronic pancreatitis was induced by ligation of the midpancreatic duct, followed by a single supramaximal intraperitoneal injection of cerulein, in C57Bl6 (control) and C5-deficient mice. Some mice were given injections of 2 different antagonists of the receptor for C5a over 21 days. In a separate model, mice were given injections of cerulein for 10 weeks to induce chronic pancreatitis. Direct effects of C5 were studied in cultured primary cells. We performed genotype analysis for the single-nucleotide polymorphisms rs 17611 and rs 2300929 in C5 in patients with pancreatitis and healthy individuals (controls). Blood cells from 976 subjects were analyzed by transcriptional profiling. Results During the initial phase of pancreatitis, levels of pancreatic damage were similar between C5-deficient and control mice. During later stages of pancreatitis, C5-deficient mice and mice given injections of C5a-receptor antagonists developed significantly less pancreatic fibrosis than control mice. Primary pancreatic stellate cells were activated in vitro by C5a. There were no differences in the rs 2300929 SNP between subjects with or without pancreatitis, but the minor allele rs17611 was associated with a significant increase in levels of C5 in whole blood. Conclusions In mice, loss of C5 or injection of a C5a-receptor antagonist significantly reduced the level of fibrosis of chronic pancreatitis, but this was not a consequence of milder disease in early stages of pancreatitis. C5 might be a therapeutic target for chronic pancreatitis. PMID:26001927

Intraductal collagenase delivery into the human pancreas using syringe loading or controlled perfusion.

PubMed

Lakey, J R; Warnock, G L; Shapiro, A M; Korbutt, G S; Ao, Z; Kneteman, N M; Rajotte, R V

1999-01-01

Effective intraductal delivery of the enzyme collagenase into the pancreas is crucial to the subsequent ability to isolate viable islets. Most clinical islet transplant centers load the enzyme into the pancreas by retrograde injection using a syringe following cannulation of the pancreatic duct. An alternative approach is to perfuse the pancreas via the pancreatic duct with collagenase solution using a recirculating perfusion device system. This provides control over perfusion pressures and collagenase temperature. This study reports on our evaluation of the delivery of Liberase-HI into the pancreas of 14 consecutive adult multiorgan cadaveric donors. Alternate glands were procured and processed using an identical protocol with the exception of collagenase delivery. The first group of pancreases was loaded using the perfusion technique where cold (4 degrees C) Liberase-HI was perfused at 80 mmHg for 5 min after which the pressure was increased to 180 mmHg. The collagenase solution was then slowly warmed to 35 degrees C, transferred to the dissociation chamber and mechanically dissociated, and then purified using discontinuous gradients of Ficoll. Pancreases in the second group were loaded with collagenase (28-32 degrees C) using the syringe technique before mechanical dissociation and purification. There were no significant differences in pancreas cold ischemia, donor age, body mass index, maximum blood glucose, or serum amylase of the donors between the two groups. Mean collagenase digestion time in the digestion chamber was not different between the two groups; however, the amount of undigested tissue remaining after dissociation was significantly higher in the syringe-loaded group (15.3 +/- 2.6 g vs. 4.6 +/- 2.1 g, mean +/- SEM, p < 0.05). Postdigestion recovery of islets was 471 +/- 83 x 10(3) IE in the perfusion group compared with 391 +/- 57 x 10(3) IE for the syringe-loaded group. Postpurification recovery was higher in the perfused group (379 +/- 45 vs. 251 +/- 28 x 10(3) IE, p < 0.05, two-tailed paired t-test). No difference in in vitro islet viability was observed between the two groups following glucose perifusion with the calculated stimulation index of 4.6 +/- 0.6 for the perfusion group and 4.2 +/- 0.7 for the syringe-loaded group. Controlled perfusion via the pancreatic duct allows the effective delivery of the enzyme achieving maximal distension to all regions of the pancreas leading to an increased recovery of the islets with no detrimental effect on subsequent in vitro islet function.

Tetramethylammonium for in vivo marking of the cross-sectional area of the scala media in the guinea pig cochlea.

PubMed

Salt, A N; DeMott, J

1992-01-01

A physiologic technique was developed to measure endolymphatic cross-sectional area in vivo using tetramethylammonium (TMA) as a volume marker. The technique was evaluated in guinea pigs as an animal model. In the method, the cochlea was exposed surgically and TMA was injected into endolymph of the second turn at a constant rate by iontophoresis. The concentration of TMA was monitored during and after the injection using ion-selective electrodes. Cross-section estimates derived from the TMA concentration measurements were compared in normal animals and animals in which endolymphatic hydrops had been induced by ablation of the endolymphatic duct and sac 8 weeks earlier. The method demonstrated a mean increase in cross-sectional area of 258% in the hydropic group. Individually measured area values were compared with action potential threshold shifts and the magnitude of the endocochlear potential (EP). Hydropic animals typically showed an increase in threshold to 2 kHz stimuli and a decrease in EP. However, the degree of threshold shift or EP decrease did not correlate well with the degree of hydrops present.

Effects of PPAR-γ agonist treatment on LPS-induced mastitis in rats.

PubMed

Mingfeng, Ding; Xiaodong, Ming; Yue, Liu; Taikui, Piao; Lei, Xiao; Ming, Liu

2014-12-01

PPAR-γ, a member of the nuclear receptor superfamily, plays an important role in lipid metabolism and inflammation. The aim of this study was to investigate the preventive effects of synthetic PPAR-γ agonist rosiglitazone on lipopolysaccharide (LPS)-induced mastitis in rats. The mouse model of mastitis was induced by the injection of LPS through the duct of the mammary gland. Rosiglitazone was injected 1 h before the induction of LPS intraperitoneally. The results showed that rosiglitazone attenuated the infiltration of inflammatory cells, the activity of myeloperoxidase (MPO), and the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in a dose-dependent manner. Additionally, Western blotting showed that rosiglitazone inhibited the phosphorylation of IκB-α and NF-κB p65. These results indicated that rosiglitazone has a protective effect on mastitis, and the anti-inflammatory mechanism of rosiglitazone on LPS-induced mastitis in rats may be due to its ability to inhibit NF-κB signaling pathways. PPAR-γ may be a potential therapeutic target against mastitis.

The Potential Benefits of Advanced Casing Treatment for Noise Attenuation in Utra-High Bypass Ratio Turbofan Engines

NASA Technical Reports Server (NTRS)

Elliott, David

2007-01-01

In order to increase stall margin in a high-bypass ratio turbofan engine, an advanced casing treatment was developed that extracted a small amount of flow from the casing behind the fan and injected it back in front of the fan. Several different configurations of this casing treatment were designed by varying the distance of the extraction and injection points, as well as varying the amount of flow. These casing treatments were tested on a 55.9 cm (22 in.) scale model of the Pratt & Whitney Advanced Ducted Propulsor in the NASA Glenn 9 by 15 Low Speed Wind Tunnel. While all of the casing treatment configurations showed the expected increase in stall margin, a few of the designs showed a potential noise benefit for certain engine speeds. This paper will show the casing treatments and the results of the testing as well as propose further research in this area. With better prediction and design techniques, future casing treatment configurations could be developed that may result in an optimized casing treatment that could conceivably reduce the noise further.

Evaluation of a ducted-fan power plant designed for high output and good cruise fuel economy

NASA Technical Reports Server (NTRS)

Behun, M; Rom, F E; Hensley, R V

1950-01-01

Theoretical analysis of performance of a ducted-fan power plant designed both for high-output, high-altitude operation at low supersonic Mach numbers and for good fuel economy at lower fight speeds is presented. Performance of ducted fan is compared with performance (with and without tail-pipe burner) of two hypothetical turbojet engines. At maximum power, the ducted fan has propulsive thrust per unit of frontal area between thrusts obtained by turbojet engines with and without tail-pipe burners. At cruise, the ducted fan obtains lowest thrust specific fuel consumption. For equal maximum thrusts, the ducted fan obtains cruising flight duration and range appreciably greater than turbojet engines.

Carcinosarcoma of the Extrahepatic Bile Duct Presenting with Stone-like Radiological Findings.

PubMed

Kumei, Shinsuke; Onishi, Yutaka; Ogura, Takeshi; Kusumoto, Chosei; Matsuno, Yasuko; Nishigami, Takashi; Maeda, Mitsuo; Harada, Masaru

2015-01-01

A 73-year-old woman was referred to our hospital due to epigastralgia and jaundice. The radiological findings showed a stone-like tumor in the extrahepatic bile duct. The patient was initially thought to have adenocarcinoma of the bile duct based on the findings of a pathological examination of the bile duct biopsy specimen and underwent pancreaticoduodenectomy; the final diagnosis of the lesion was so-called carcinosarcoma of the extrahepatic bile duct. She died of liver metastasis six months after the surgery. This case suggests that surgical resection is not adequate for achieving a radical cure, and the optimal treatment for extrahepatic bile duct carcinosarcoma should be established immediately.

Laser velocimeter and total pressure measurements in circular-to-rectangular transition ducts

NASA Technical Reports Server (NTRS)

Patrick, William P.; Mccormick, Duane C.

1988-01-01

A comprehensive set of total pressure and three-component laser velocimetry (LV) data were obtained within two circular-to-rectangular transition ducts at low subsonic speeds. This set of reference data was acquired for use in identifying secondary flow mechanisms and for assessing the accuracy of computational procedures for calculating such flows. Data were obtained at the inlet and exit planes of an aspect ratio three duct having a length-to-diameter ratio of one (AR310) and an aspect ratio six duct having a length-to-diameter ratio of three (AR630). Each duct was unseparated throughout its transition section. It is therefore concluded that secondary flows can play an important part in the fluid dynamics of transition ducts and needs to be addressed in computational analysis. The strength of the secondary flows depends on both the aspect ratio and relative axial duct length.

Apoptosis in Early Salivary Gland Duct Morphogenesis and Lumen Formation.

PubMed

Teshima, T H N; Wells, K L; Lourenço, S V; Tucker, A S

2016-03-01

Salivary glands are essential for the maintenance of oral health by providing lubrication and antimicrobial protection to the mucosal and tooth surfaces. Saliva is modified and delivered to the oral cavity by a complex multifunctional ductal system. During development, these ducts form as solid tubes, which undergo cavitation to create lumens. Apoptosis has been suggested to play a role in this cavitation process along with changes in cell polarity. Here, we show that apoptosis occurs from the very earliest stages of mouse salivary gland development, much earlier than previously reported. Apoptotic cells were observed in the center of the first epithelial stalk at early-stage embryonic day 12.5 (E12.5) according to both TUNEL staining and cleaved caspase 3 immunofluorescence. The presumptive lumen space was highlighted by the colocalization of a predictive lumen marker, cytokeratin 7. At E14.5, as lumens start to form throughout the glands, apoptotic expression decreased while cytokeratin 7 remained positive. In vitro inhibition of all caspases in E12.5 and E13.5 salivary glands resulted in wider ducts, as compared with the controls, and a defect in lumen formation. In contrast, no such defect in lumen formation was observed at E14.5. Our data indicate that apoptosis is involved during early stages of gland formation (E12.5 onward) and appears important for shaping the forming ducts. © International & American Associations for Dental Research 2015.

Bortezomib in Treating Patients With Unresectable Locally Advanced or Metastatic Adenocarcinoma of the Bile Duct or Gallbladder

ClinicalTrials.gov

2017-06-13

Adenocarcinoma of the Extrahepatic Bile Duct; Adenocarcinoma of the Gallbladder; Advanced Adult Primary Liver Cancer; Gastrointestinal Cancer; Localized Unresectable Adult Primary Liver Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

Erlotinib in Treating Patients With Unresectable Liver, Bile Duct, or Gallbladder Cancer

ClinicalTrials.gov

2013-06-03

Adult Primary Cholangiocellular Carcinoma; Adult Primary Hepatocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Localized Unresectable Adult Primary Liver Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

Agenesis of the gallbladder with hypoplastic cystic duct diagnosed at laparoscopy.

PubMed

Kwon, A-Hon; Yanagimoto, Hiroaki; Matsui, Yoichi; Imamura, Atsushi

2006-08-01

An 86-year-old man was admitted to our department with complaints of intermittent upper abdominal pain. Ultrasonography of the abdomen showed dilated extrahepatic bile ducts containing stones; however, the gallbladder was not clearly identified. Magnetic resonance cholangiopancreatography showed dilated extrahepatic ducts and choledocholithiasis without gallbladder visualization. The stone extraction was performed with endoscopic sphincterotomy. Three-dimensional images using spiral-computed tomography after intravenous-infusion cholangiography clearly demonstrated an obstruction of the cystic duct. The patient was scheduled for laparoscopic cholecystectomy. At laparoscopy, the gallbladder fossa was not identified on the undersurface of the liver. Despite a thorough examination of the intrahepatic (left-sided within the lesser omentum), retroperitoneal, retrohepatic (within the falciform ligament), retroduodenal, and retropancreatic areas using laparoscopic ultrasonography, the gallbladder was not found. After careful dissection of the hepatoduodenal ligament, the dilated extrahepatic bile duct and a 1-cm length of hypoplastic cystic duct were found. Gallbladder agenesis is usually accompanied by the lack of the cystic duct. The present case is the third report of gallbladder agenesis with a patent or hypoplastic cystic duct.

Iatrogenic salivary duct injury in head and neck cancer patients: Report of four cases and review of the literature

PubMed Central

Kulyapina, Alena; Ochandiano-Caicoya, Santiago; Navarro-Cuellar, Carlos; Navarro-Vila, Carlos

2014-01-01

Introduction: The lesions of the salivary ducts may be idiopathic, post- traumatic, or iatrogenic and lead to sialocele formation with persistent painful facial swelling or cutaneous fistula formation. No consensus on treatment of this condition exists: the options of treatment include needle aspiration, pressure dressings, antisialogogue therapy, radiotherapy, botulinum toxin and surgical approaches as duct repair, diversion, ligation, different drainage systems and even parotidectomy/submaxilectomy. The management and special features of iatrogenic salivary duct injury in patients with oral cancer who underwent head and neck reconstructive surgery has not been described yet. Material and Methods: We present four cases of iatrogenic lesions of salivary ducts and its management in patients with oral cancer. Conclusions: The iatrogenic lesions of salivary ducts are to be taken into account in patients with oral cancer as the distal ends of salivary ducts could be involved in the margins of surgical resection. Different options of treatment of this complication are described. Key words:Sialocele, oral cancer, salivary duct. PMID:25136433

Developing flow in S-shaped ducts. 2: Circular cross-section duct

NASA Technical Reports Server (NTRS)

Taylor, A. M. K. P.; Whitelaw, J. H.; Yianneskis, M.

1984-01-01

Laser-Doppler velocimetry measured the laminar and turbulent streamwise flow in a S-duct. The wall pressure distribution and one component of cross-stream velocity were also obtained for the turbulent flow case. Boundary layers near the duct inlet were about 25 percent of the hydraulic diameter in the laminar flow and varied around the periphery of the pipe between 10 percent and 20 percent in turbulent flow. Pressure-driven secondary flows develop in the first half of the S-duct and are attenuated and reversed in the second half. For both Reynolds numbers there is a region near the outer wall of the second half of the duct where the sign of the radial vorticity results in an enforcement of the secondary flow which was established in the first half of the S-duct. The core flow migrates, for both Reynolds numbers, to the outside wall of the first half and lies towards the inside wall of the second half of the S-duct at the outlet. The thinner inlet boundary layers in the turbulent flow give rise to weaker secondary motion.

Duct Diameter and Size of Stones Predict Successful Extracorporeal Shock Wave Lithotripsy and Endoscopic Clearance in Patients With Chronic Pancreatitis and Pancreaticolithiasis.

PubMed

Lapp, Robert T; Wolf, J Stuart; Faerber, Gary J; Roberts, William W; McCarthy, Sean T; Anderson, Michelle A; Wamsteker, Erik-Jan; Elta, Grace H; Scheiman, James M; Kwon, Richard S

2016-09-01

The need for endoscopic therapy before extracorporeal shock wave lithotripsy (SWL) to facilitate pancreatic duct stone removal is unclear. Predictive factors associated with successful fragmentation and subsequent complete duct clearance are variable. We hypothesize pancreatic duct strictures and large stones, but not pre-SWL endotherapy, correlate with successful fragmentation and complete duct clearance. A retrospective cohort study of patients with pancreaticolithiasis who underwent SWL and endoscopic retrograde cholangiopancreatography between January 2009 and June 2014 was evaluated. Thirty-seven patients were treated. Technical success (TS) of fragmentation was achieved in 22 patients (60%). Technical success was associated with fewer stones and SWL sessions and smaller stone and duct size. By multivariate logistic regression, only duct dilation was associated with TS. Endoscopic success of complete duct clearance was achieved in 29 patients (80%). Endoscopic success was more frequent with stones 12 mm or less and with successful TS. By multivariate logistic regression, stones greater than 12 mm were associated with endoscopic failure. Pre-SWL endotherapy does not affect stone fragmentation. Patients with a dilated duct (>8 mm) and pancreatic stones 12 mm or greater were associated with unsuccessful TS and endoscopic success, respectively, and may benefit from early referral for surgical decompression.

Bile duct anastomotic stricture after pediatric living donor liver transplantation.

PubMed

Chok, Kenneth S H; Chan, See Ching; Chan, Kwong Leung; Sharr, William W; Tam, Paul K H; Fan, Sheung Tat; Lo, Chung Mau

2012-07-01

Hepaticojejunostomy is a well-accepted method, whereas duct-to-duct anastomosis is gaining popularity for bile duct reconstruction in pediatric living donor liver transplantation (LDLT). Biliary complications, especially biliary anastomotic stricture (BAS), are not clearly defined. The aim of the present study is to determine the rate of BAS and its associated risk factors. The study included 78 pediatric patients (<18 years old) who underwent LDLT during the period from end of September 1993 to end of November 2010. The diagnosis of BAS was based on clinical, biochemical, histologic, and radiologic results. All patients received left-side grafts. Thirteen patients (16.7%) developed BAS after LDLT. Among them, 3 patients (23.1%) had duct-to-duct anastomosis during LDLT. The median follow-up period for the BAS group and the non-BAS group was 57.8 and 79.5 months, respectively (P = .683). Ten of the patients with BAS required percutaneous transhepatic biliary drainage with or without dilatation for treating the stricture. Multivariable analysis showed that hepatic artery thrombosis and duct-to-duct anastomosis were 2 risk factors associated with BAS. In pediatric LDLT, hepaticojejunostomy is the preferred method for bile duct reconstruction, but more large-scale research needs to be done to reconfirm this result. Copyright © 2012 Elsevier Inc. All rights reserved.

Common Bile Duct Stricture After Laparoscopic Cholecystectomy: Case Report

PubMed

Zoričić, Ivan; Soldo, Ivo; Simović, Ivan; Sever, Marko; Bakula, Branko; Grbavac, Martin; Marušić, Marinko; Soldo, Anamaria

2017-03-01

Despite progress in laparoscopic surgery and increasing surgical experience, the incidence of bile duct injury during laparoscopic cholecystectomy fails to fall below 0.3%-0.6% and it is still higher than those recorded in the era of open cholecystectomy. Bile duct injuries belong to the most serious complications of abdominal surgery in general and often end up with liver transplantation as the only hope for cure. We present a case of a 78-year-old jaundiced male patient who sustained common hepatic duct injury during laparoscopic cholecystectomy eight months earlier. Exploratory laparotomy, ERCP and MRCP revealed a metal clip placed just below hepatic duct confluence and causing stricture of bile duct with dilatation of bile ducts proximal to the level of stenosis (Strasberg classification type E3 injury). Repair of the injury was performed by creating termino-lateral hepaticojejunostomy between the right and left hepatic ducts and retrocolic Roux en-Y jejunal limb. By presenting this case, we wish to emphasize the importance of timely conversion and execution of intraoperative cholangiography in all cases when identification of the structures of Calot’s triangle is not clear enough. Successful treatment of bile duct injury is only possible with joint approach of radiologist, gastroenterologist and experienced hepatobiliary surgeon.

Investigation of the interference effects of mixed flow long duct nacelles on a DC-10 wing

NASA Technical Reports Server (NTRS)

Patel, S. P.; Donelson, J. E.

1982-01-01

Wind tunnel test results utilizing a 4.7 percent scale semispan model in the 11 foot transonic wind tunnel are presented. A low drag long duct nacelle installation for the DC-10 jet transport was developed. A long duct nacelle representative of a CF6-50 mixed flow configuration was investigated on the DC-10-30. The results showed that the long duct nacelle installation located in the same position as the current short duct nacelle and with the current production symmetrical pylon is a relatively low risk installation for the DC-10 aircraft. Tuft observations and analytical boundary layer analysis confirmed that the flow on the nacelle afterbody was attached. A small pylon fairing was evaluated and found to reduce channel peak suction pressures, which resulted in a small drag improvement. The test also confirmed that the optimum nacelle incidence angle is the same as for the short duct nacelle, thus the same engine mount as for the production short duct nacelle can be used for the long duct nacelle installation. Comparison of the inboard wing pylon nacelle channel pressure distributions, with flow through and powered long duct nacelles showed that the power effects did not change the flow mechanism; hence, power effects can be considered negligible.

Long duct nacelle aerodynamic development for DC-10 derivatives

NASA Technical Reports Server (NTRS)

Patel, S. P.; Donelson, J. E.

1980-01-01

The results are presented of a wind tunnel test utilizing a 4.7-percent-scale semispan model of the DC-10 in the Calspan 8-foot transonic wind tunnel. The effect of a revised long-duct nacelle shape on the channel velocities, the incremental drag relative to the baseline long-duct nacelle, and channel velocities for the baseline long-duct nacelle were determined and compared with data obtained at Ames. The baseline and the revised long-duct nacelles are representative of a CF6-50 mixed-flow configuration and were evaluated on a model of a proposed DC-10 stretched-fuselage configuration. The results showed that the revised long-duct nacelle has an appreciable effect on the inboard channel velocities, resulting in an increased channel Mach number. However, the pressure recovery on the nacelle afterbody was about the same for both nacelles. The lift curves for both long-duct nacelle configurations were the same. The channel pressures measured at Calspan were in good agreement with those measured at Ames for the baseline long-duct nacelle. The incremental drag for the revised nacelle was measured as two to four counts (three counts is approximately equal to one percent of the airplane drag) higher than that of the baseline long-duct nacelle.

Viscous flow computations for elliptical two-duct version of the SSME hot gas manifold

NASA Technical Reports Server (NTRS)

Roger, R. P.

1986-01-01

The objective of the effort was to numerically simulate viscous subsonic flow in a proposed elliptical two-duct version of the fuel side Hot Gas Manifold (HGM) for the Space Shuttle Main Engine (SSME). The numerical results were to complement both water flow and air flow experiments in the two-duct geometry performed at NASA-MSFC and Rocketdyne. The three-dimensional character of the HGM consists of two essentially different geometries. The first part of the construction is a concentric shell duct structure which channels the gases from a turbine exit into the second part comprised of two cylindrically shaped transfer ducts. The initial concentric shell portion can be further subdivided into a turnaround section and a bowl section. The turnaround duct (TAD) changes the direction of the mean flow by 180 degress from a smaller radius to a larger radius duct which discharges into the bowl. The cylindrical transfer ducts are attached to the bowl on one side thus providing a plane of symmetry midway between the two. Centerline flow distance from the TAD inlet to the transfer duct exit is approximately two feet. Details of the approach used to numerically simulate laminar or turbulent flow in the HGM geometry are presented. Computational results are presented and discussed.

Characterization of the biliary tract by virtual ultrasonography constructed by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.

PubMed

Koizumi, Yohei; Hirooka, Masashi; Ochi, Hironori; Tokumoto, Yoshio; Takechi, Megumi; Hiraoka, Atsushi; Ikeda, Yoshio; Kumagi, Teru; Matsuura, Bunzo; Abe, Masanori; Hiasa, Yoichi

2015-04-01

This study aimed at prospectively evaluating bile duct anatomy on ultrasonography and evaluating the safety and utility of radiofrequency ablation (RFA) assisted by virtual ultrasonography from gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI). The institutional review board approved this study, and patients provided written informed consent prior to entry into the study. Bile duct anatomy was assessed in 201 patients who underwent Gd-EOB-DTPA-enhanced MRI for the evaluation of hepatic tumor. Eighty-one of these patients subsequently underwent RFA assisted by ultrasound imaging. In 23 patients, the tumor was located within 5 mm of the central bile duct, as demonstrated by MRI. Virtual ultrasonography constructed by Gd-EOB-enhanced MRI was able to visualize the common bile duct, left hepatic duct, and right hepatic duct in 96.5, 94.0, and 89.6 % of cases, respectively. The target hepatic tumor nodule and biliary duct could be detected with virtual ultrasonography in all patients, and no severe complications occurred. The running pattern of the bile ducts could be recognized on conventional ultrasound by referencing virtual ultrasonography constructed by Gd-EOB-DTPA-enhanced MRI. RFA assisted by this imaging strategy did not result in bile duct injury.

The statistical evaluation of duct tape end match as physical evidence

NASA Astrophysics Data System (ADS)

Chan, Ka Lok

Duct tapes are often submitted to crime laboratories as evidence associated with abductions, homicides, or construction of explosive devices. As a result, trace evidence examiners are often asked to analyze and compare commercial duct tapes so that they can establish possible evidentiary links. Duct tape end matches are believed to be the strongest association between exemplar and question samples because they are considered as evidence with unique individual characteristics. While end match analysis and comparison have long been undertaken by trace evidence examiners, there is a significant lack of scientific research for associating two or more segments of duct tapes. This study is designed to obtain statistical inferences on the uniqueness of duct tape tears. Three experiments were devised to compile the basis for a statistical assessment of the probability of duct tape end matches along with a proposed error rate. In one experiment, we conducted the equivalent of 10,000 end match examinations with an error rate of 0%. In the second experiment, we performed 2,704 end match examinations having 0% error rate. In the third experiment, using duct tape by an Elmendorf Tear tester, we conducted 576 end match examinations with an error rate of 0% and having all samples correctly associated. The results of this study indicate that end matches are distinguishable among a single roll of duct tape and between two different rolls of duct tape having very similar surface features and weave pattern.

The Preliminary Study on Procurement Biliary Convergence from Donors with Complicated Bile Duct Variant in Emergency Right Lobe Living Donor Liver Transplantation.

PubMed

Ye, Sheng; Dong, Jia-Hong; Duan, Wei-Dong; Ji, Wen-Bing; Liang, Yu-Rong

2017-03-01

The incidence of biliary complications after living donor adult liver transplantation (LDALT) is still high due to the bile duct variation and necessity reconstruction of multiple small bile ducts. The current surgical management of the biliary variants is unsatisfactory. We evaluated the role of a new surgical approach in a complicated hilar bile duct variant (Nakamura type IV and Nakamura type II) under emergent right lobe LDALT for high model for end-stage liver disease score patients. The common hepatic duct (CHD) and the left hepatic duct (LHD) of the donor were transected in a right-graft including short common trunks with right posterior and anterior bile ducts, whereas the LHD of the donor was anastomosed to the CHD and the common trunks of a right-graft bile duct and the recipient CHD was end-to-end anastomosed. Ten of 13 grafts (Nakamura types II, III, and IV) had two or more biliary orifices after right graft lobectomy; seven patients had biliary complications (53.8%). Later, the surgical innovation was carried out in five donors with variant bile duct (four Nakamura type IV and one type II), and, consequently, no biliary or other complications were observed in donors and recipients during 47-53 months of follow-up; significant differences ( P  < 0.05) were found when two stages were compared. Our initial experience suggests that, in the urgent condition of LDALT when an alternative live donor was unavailable, a surgical innovation of cutting part of the CHD trunks including variant right hepatic ducts in a complicated donor bile duct variant may facilitate biliary reconstruction and reduce long-term biliary complications.

Clinical Presentations and Outcomes of Bile Duct Loss caused by Drugs and Herbal and Dietary Supplements

PubMed Central

Bonkovsky, Herbert L.; Kleiner, David E.; Gu, Jiezhun; Odin, Joseph A.; Russo, Mark W.; Navarro, Victor M.; Fontana, Robert J.; Ghabril, Marwan S.; Barnhart, Huiman; Hoofnagle, Jay H.

2016-01-01

Bile duct loss during the course of drug induced liver injury is uncommon but can be an indication of vanishing bile duct syndrome. In this work we assess the frequency, causes, clinical features and outcomes of cases of drug induced liver injury with histologically proven bile duct loss. All cases of drug induced liver injury enrolled into a prospective database over a ten year period that had undergone liver biopsies (n=363) were scored for the presence of bile duct loss and assessed for clinical and laboratory features, causes and outcomes. 26 of the 363 patients (7%) with drug, herbal or dietary supplement associated liver injury had bile duct loss on liver biopsy which was moderate to severe (<50% of portal areas with bile ducts) in 14 and mild (50–75%) in 12. The presenting clinical features of the 26 cases varied, but the most common clinical pattern was a severe cholestatic hepatitis. The implicated agents included amoxicillin/clavulanate (n=3), temozolomide (n=3), various herbal products (n=3), azithromycin (n=2) and 15 other medications or dietary supplements. Compared to those without, those with bile duct loss were more likely to develop chronic liver injury (94% vs 47%), which was usually cholestatic and sometimes severe. Five patients died and two others underwent liver transplantation for progressive cholestasis despite treatment with corticosteroids and ursodiol. The most predictive factor of poor outcome was the degree of bile duct loss on liver biopsy. Conclusions Bile duct loss during acute cholestatic hepatitis is an ominous early indicator of possible vanishing bile duct syndrome, for which at present there are no known means of prevention or therapy. PMID:27981596

Surgical treatment of chronic pancreatitis with pancreatic main duct dilatation: Long term results after head resection and duct drainage

PubMed Central

Schwarz, A.; Beger, H. G.

2005-01-01

Tissue and duct hypertension is considered as a major factor in the etiology of pain in patients with chronic pancreatitis (CP). Duct dilatation is a consequence of duct obstruction due to scars or duct stones. Nevertheless, the procedure of choice, drainage or resection, is still under discussion. We present long-term results of patients operated with duodenum-preserving pancreatic head resection (DPPHR) combined with a Partington-Rochelle duct drainage in cases of chronic pancreatitis with multiple stenosis and dilatation of the side ducts. Methods and patients. From April 1982 to September 2001, in 55 out of 538 patients with chronic pancreatitis, a DPPHR with additionally Partington-Rochelle duct drainage was performed (44 male, 11 female, mean age 45.8 years). Ninety-two percent of the patients suffered from alcoholic pancreatitis. Medical respective pain treatment for chronic pancreatitis was in median 64.5 months prior to surgery. The indications for surgery were in 87% pain, 59% of the patients had an inflammatory mass in the head of the pancreas, 36% a common bile duct stenosis and 5% a severe stenosis of the duodenum. The endocrine function (OGGT) was impaired in 79% of the patients preoperatively. Results. Hospital mortality was 0%, postoperative complications occurred in 11 patients. Follow-up: All except 2 patients were followed up in the outpatient clinic with the mean follow-up time of 69.7 months (8–105 months), the late mortality was 9%. Sixty-eight percent of the patients were completely free of pain, 29% had occasional pain, 3% suffered from a further attack of pancreatitis. Body weight increased in 79%, 58% were professionally rehabilitated. Late postoperative endocrine function was unchanged in 85% (improved in 5%, deteriorated in 10%). Conclusion. The pain control in patients with multiple duct stenosis after duodenum-preserving pancreatic head resection with duct drainage leads to long-standing absence of pain and low recurrence rate of attacks of pancreatitis. PMID:18333173

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

PubMed

Nagalakshmi, Vidya K; Yu, Jing

2015-03-01

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

Endolymphatic Thoracic Duct Stent-Graft Reconstruction for Chylothorax: Approach, Technical Success, Safety, and Short-term Outcomes.

PubMed

Srinivasa, Rajiv N; Chick, Jeffrey Forris Beecham; Hage, Anthony N; Gemmete, Joseph J; Murrey, Douglas C; Srinivasa, Ravi N

2018-04-01

To report approach, technical success, safety, and short-term outcomes of thoracic duct stent-graft reconstruction for the treatment of chylothorax. Two patients, 1 (50%) male and 1 (50%) female, with mean age of 38 years (range: 16-59 years) underwent endolymphatic thoracic duct stent-graft reconstruction between September 2016 and July 2017. Patients had radiographic left-sided chylothoraces (n = 2) from idiopathic causes (n = 1) and heart transplantation (n = 1). In both (100%) patients, antegrade lymphatic access was used to opacify the thoracic duct after which retrograde access was used for thoracic duct stent-graft placement. Pelvic lymphangiography technical success, antegrade cisterna chyli cannulation technical success, thoracic duct opacification technical success, retrograde thoracic duct access technical success, thoracic duct stent-graft reconstruction technical success, ethiodized oil volume, contrast volume, estimated blood loss, procedure time, fluoroscopy time, radiation dose, clinical success, complications, deaths, and follow-up were recorded. Pelvic lymphangiography, antegrade cisterna chyli cannulation, thoracic duct opacification, retrograde thoracic duct access, and thoracic duct stent-graft reconstruction were technically successful in both (100%) patients. Mean ethiodized oil volume was 8 mL (range: 5-10 mL). Mean contrast volume was 13 mL (range: 5-20 mL). Mean estimated blood loss was 13 mL (range: 10-15 mL). Mean fluoroscopy time was 50.4 min (range: 31.2-69.7 min). Mean dose area product and reference air kerma were 954.4 μGmy 2 (range: 701-1,208 μGmy 2 ) and 83.5 mGy (range: 59-108 mGy), respectively. Chylothorax resolved in both (100%) patients. There were no minor or major complications directly related to the procedure. Thoracic duct stent-graft reconstruction may be a technically successful and safe alternative to thoracic duct embolization, disruption, and surgical ligation for the treatment of chylothorax. Additional studies are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

Laparoscopic bile duct injury: understanding the psychology and heuristics of the error.

PubMed

Dekker, Sidney W A; Hugh, Thomas B

2008-12-01

Bile duct injury is an important unsolved problem of laparoscopic cholecystectomy, occurring with unacceptable frequency even in the hands of experienced surgeons. This suggests that a systemic predisposition to the injury is intrinsic to cholecystectomy and indicates that an analysis of the psychology and heuristics of surgical decision-making in relation to duct identification may be a guide to prevention. Review of published reports on laparoscopic bile duct injury from 1997 to 2007 was carried out. An analysis was also carried out of the circumstances of the injuries in 49 patients who had transection of an extrahepatic bile duct and who were referred for reconstruction or were assessed in a medicolegal context. Special emphasis was placed on identifying the possible psychological aspects of duct misidentification. Review of published work showed an emphasis on the technical aspects of correct identification of the cystic duct, with few papers addressing the heuristics and psychology of surgical decision-making during cholecystectomy. Duct misidentification was the cause of injury in 42 out of the 49 reviewed patients (86%). The injury was not recognized at operation in 70% and delay in recognition persisted into the postoperative period in 57%. Underestimation of risk, cue ambiguity and visual misperception ('seeing what you believe') were important factors in misidentification. Delay in recognition of the injury is a feature consistent with cognitive fixation and plan continuation, which help construct and sustain the duct misidentification during the operation and beyond. Changing the 'culture' of cholecystectomy is probably the most effective strategy for preventing laparoscopic bile duct injury, especially if combined with new technical approaches and an understanding of the heuristics and psychology of the duct misidentification error. Training of surgeons for laparoscopic cholecystectomy should emphasize the need to be alert for cues that the incorrect duct is being dissected or that a bile duct injury might have occurred. Surgeons may also be trained to accept the need for plan modification, to seek cues that refute a given hypothesis and to apply 'stopping rules' for modifying or converting the operation.

Observations of Strong Surface Radar Ducts over the Persian Gulf.

NASA Astrophysics Data System (ADS)

Brooks, Ian M.; Goroch, Andreas K.; Rogers, David P.

1999-09-01

Ducting of microwave radiation is a common phenomenon over the oceans. The height and strength of the duct are controlling factors for radar propagation and must be determined accurately to assess propagation ranges. A surface evaporation duct commonly forms due to the large gradient in specific humidity just above the sea surface; a deeper surface-based or elevated duct frequently is associated with the sudden change in temperature and humidity across the boundary layer inversion.In April 1996 the U.K. Meteorological Office C-130 Hercules research aircraft took part in the U.S. Navy Ship Antisubmarine Warfare Readiness/Effectiveness Measuring exercise (SHAREM-115) in the Persian Gulf by providing meteorological support and making measurements for the study of electromagnetic and electro-optical propagation. The boundary layer structure over the Gulf is influenced strongly by the surrounding desert landmass. Warm dry air flows from the desert over the cooler waters of the Gulf. Heat loss to the surface results in the formation of a stable internal boundary layer. The layer evolves continuously along wind, eventually forming a new marine atmospheric boundary layer. The stable stratification suppresses vertical mixing, trapping moisture within the layer and leading to an increase in refractive index and the formation of a strong boundary layer duct. A surface evaporation duct coexists with the boundary layer duct.In this paper the authors present aircraft- and ship-based observations of both the surface evaporation and boundary layer ducts. A series of sawtooth aircraft profiles map the boundary layer structure and provide spatially distributed estimates of the duct depth. The boundary layer duct is found to have considerable spatial variability in both depth and strength, and to evolve along wind over distances significant to naval operations (100 km). The depth of the evaporation duct is derived from a bulk parameterization based on Monin-Obukhov similarity theory using near-surface data taken by the C-130 during low-level (30 m) flight legs and by ship-based instrumentation. Good agreement is found between the two datasets. The estimated evaporation ducts are found to be generally uniform in depth; however, localized regions of greatly increased depth are observed on one day, and a marked change in boundary layer structure resulting in merging of the surface evaporation duct with the deeper boundary layer duct was observed on another. Both of these cases occurred within exceptionally shallow boundary layers (100 m), where the mean evaporation duct depths were estimated to be between 12 and 17 m. On the remaining three days the boundary layer depth was between 200 and 300 m, and evaporation duct depths were estimated to be between 20 and 35 m, varying by just a few meters over ranges of up to 200 km.The one-way radar propagation factor is modeled for a case with a pronounced change in duct depth. The case is modeled first with a series of measured profiles to define as accurately as possible the refractivity structure of the boundary layer, then with a single profile collocated with the radar antenna and assuming homogeneity. The results reveal large errors in the propagation factor when derived from a single profile.

The Energy Implications of Air-Side Fouling in Constant Air Volume HVAC Systems

NASA Astrophysics Data System (ADS)

Wilson, Eric J. H.

2011-12-01

This thesis examines the effect of air-side fouling on the energy consumption of constant air volume (CAV) heating, ventilating, and air conditioning (HVAC) systems in residential and small commercial buildings. There is a particular focus on evaluating the potential energy savings that may result from the remediation of such fouling from coils, filters, and other air system components. A computer model was constructed to simulate the behavior of a building and its duct system under various levels of fouling. The model was verified through laboratory and field testing and then used to run parametric simulations to examine the range of energy impacts for various climates and duct system characteristics. A sensitivity analysis was conducted to determine the impact of parameters like duct insulation, duct leakage, duct location, and duct design on savings potential. Duct system pressures, temperatures, and energy consumption for two houses were monitored for one month. The houses' duct systems, which were both in conditioned space, were given a full cleaning, and were then monitored for another month. The flow rates at the houses improved by 10% and 6%. The improvements were primarily due to installing a new filter, as both houses had only light coil fouling. The results indicate that there was negligible change in heating energy efficiency due to the system cleaning. The parametric simulation results are in agreement with the field experiment: for systems in all eight climates, with flowrates degraded by 20% or less, if ducts are located within the thermal zone, HVAC source energy savings from cleaning are negligible or even slightly negative. However, if ducts are outside the thermal zone, savings are in the 1 to 5% range. For systems with flowrates degraded by 40%, if ducts are within the thermal zone, savings from cleaning occurs only for air conditioning energy, up to 8% in climates like Miami, FL. If ducts are outside the thermal zone, savings occurs with both heating and cooling energy, and ranges from 7% in Los Angeles, CA to 13% in Fairbanks, AK. These results assume a leaky and uninsulated duct system. The potential for savings from cleaning decreases if duct insulation is in place or sealing has been performed. The potential for energy savings is directly related to the distribution system's thermal efficiency, with air conditioner performance also playing a minor role. Results for small commercial buildings with constant air volume HVAC systems and leaky and uninsulated duct systems span a wider range: from -12% in Miami, FL to 30% in Minneapolis, MN. However, for improved ducts or ducts in the conditioned space, small commercial HVAC source energy savings is always negative (down to -17%) for flowrates degradation in the 0--40% range. The sensitivity of these results to duct characteristics (location, leakage, and insulation) and the after-cleaning flowrate, as it varies from an ideal flowrate, was also evaluated. Energy savings can reach up to 80% for some scenarios where clean airflow is severely restricted down to 20% of ideal by poor duct layout or other obstructions not removable by cleaning. In addition, a simplified spreadsheet tool was developed for technicians to use in the field to estimate potential savings resulting from a system cleaning. Measuring the temperature rise across the furnace was found to give less uncertainty than measuring the pressure rise and assuming a fan curve. Despite the uncertainty, the tool can give a general idea of the range of savings possible under various conditions.

Gemcitabine, Oxaliplatin, Tarceva &/or Cisplatin in HCC & Biliary Tree Cancers

ClinicalTrials.gov

2018-06-27

Hepatocellular Carcinoma; Cholangiocellular Carcinoma; Cholangiocarcinoma of the Extrahepatic Bile Duct; Bile Duct Cancer; Periampullary Adenocarcinoma; Gallbladder Cancer; Extrahepatic Bile Duct Cancer

Design and performance of duct acoustic treatment

NASA Technical Reports Server (NTRS)

Motsinger, R. E.; Kraft, R. E.

1991-01-01

The procedure for designing acoustic treatment panels used to line the walls of aircraft engine ducts and for estimating the resulting suppression of turbofan engine duct noise is discussed. This procedure is intended to be used for estimating noise suppression of existing designs or for designing new acoustic treatment panels and duct configurations to achieve desired suppression levels.

Influence of Resin Duct Size and Number on Oleoresin Flow in the Southern Pines

Treesearch

John D. Hodges; William W. Elam; Donald R. Bluhm

1981-01-01

The number of radial resin ducts was significantly higher in slash pines than in loblolly, longleaf, or shortleaf. Average width of resin ducts was less in shortleaf than in the other three species. Flow rate of oleoresin was not correlated with size or number of resin ducts for any of the four species.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Are duct burners and waste heat... Stationary Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam...

[Syncrhonous carcinosarcoma of the extrahepatic bile duct and gallbladder.

PubMed

Páramo, Ana Alberca; Valverde, David Padilla; Campos, Pedro Villarejo; Santos, Esther Pilar Garcia; Puche, Jose Luis Bertelli; Guerrero, Paloma Núńez; Delgado, Margarita; Fernindez, Jesus Martin

2016-03-01

Carcinosarcoma is a malignant neoplasm characterized for intermingled epithelial and mesenchymal components. A preoperative suspected diagnosis will allow a radical therapy avoiding a very bad prognosis. We report on a male patient who was operated in our Service with diagnosis of synchronous carcinosarcoma of gallbladder and extrahepatic bile duct and a review of the Medical Literature. A gallblader carcinosarcoma showing extension into common bile duct is very rare, a carcinosarcoma of the bile duct is exceptional, and a synchronous carcinosarcoma ofthe bile duct and gallbladder has not been reported previously.

Chitin in the Silk Gland Ducts of the Spider Nephila edulis and the Silkworm Bombyx mori

PubMed Central

Davies, Gwilym J. G.; Knight, David P.; Vollrath, Fritz

2013-01-01

Here we report the detection and localisation of chitin in the cuticle of the spinning ducts of both the spider Nephila edulis and the silkworm Bombyx mori. Our observations demonstrate that the duct walls of both animals contain chitin notwithstanding totally independent evolutionary pathways of the systems. We conclude that chitin may well be an essential component for the construction of spinning ducts; we further conclude that in both species chitin may indicate the evolutionary origin of the spinning ducts. PMID:24015298

Selumetinib and Akt Inhibitor MK-2206 in Treating Patients With Refractory or Advanced Gallbladder or Bile Duct Cancer That Cannot Be Removed By Surgery

ClinicalTrials.gov

2014-09-08

Adenocarcinoma of the Gallbladder; Adenocarcinoma With Squamous Metaplasia of the Gallbladder; Adult Primary Cholangiocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Localized Unresectable Adult Primary Liver Cancer; Metastatic Extrahepatic Bile Duct Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Stage II Gallbladder Cancer; Stage IIIA Gallbladder Cancer; Stage IIIB Gallbladder Cancer; Stage IVA Gallbladder Cancer; Stage IVB Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer

Using the surface panel method to predict the steady performance of ducted propellers

NASA Astrophysics Data System (ADS)

Cai, Hao-Peng; Su, Yu-Min; Li, Xin; Shen, Hai-Long

2009-12-01

A new numerical method was developed for predicting the steady hydrodynamic performance of ducted propellers. A potential based surface panel method was applied both to the duct and the propeller, and the interaction between them was solved by an induced velocity potential iterative method. Compared with the induced velocity iterative method, the method presented can save programming and calculating time. Numerical results for a JD simplified ducted propeller series showed that the method presented is effective for predicting the steady hydrodynamic performance of ducted propellers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poerschke, Andrew; Rudd, Armin

This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space-conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to easily be brought within conditioned space via interior partition walls. Centrally locating the air handling unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives a similar amount of airflow—regardless of its position on the box. Furthermore, within a reasonable set of length restrictions each duct continues to receive similar airflow.

VALVE

DOEpatents

Arkelyan, A.M.; Rickard, C.L.

1962-04-17

A gate valve for controlling the flow of fluid in separate concentric ducts or channels by means of a single valve is described. In one position, the valve sealing discs engage opposed sets of concentric ducts leading to the concentric pipes defining the flow channels to block flow therethrough. In another position, the discs are withdrawn from engagement with the opposed ducts and at the same time a bridging section is interposed therebetween to define concentric paths coextensive with and connecting the opposed ducts to facilitate flow therebetween. A wedge block arrangement is employed with each sealing disc to enable it to engage the ducts. The wedge block arrangement also facilitates unobstructcd withdrawal of the discs out of the intervening space between the sets of ducts. (AEC)

Common bile duct stricture as a late complication of upper abdominal radiotherapy.

PubMed

Cherqui, D; Palazzo, L; Piedbois, P; Charlotte, F; Duvoux, C; Duron, J J; Fagniez, P L; Valla, D

1994-06-01

We report the cases of two patients who developed symptomatic common bile duct stricture 10 years after upper abdominal radiotherapy for malignant lymphoma. Both patients were in complete remission and presented with marked obstructive jaundice. Endosonography was useful in both cases and showed segmental thickening of the bile duct wall narrowing in the lumen. Both patients underwent surgical exploration, confirming biliary obstruction due to intrinsic wall thickening, and had successful biliary drainage by Roux-en-Y hepatico-jejunostomy. Histological examination of the resected bile duct, in one case, and of a bile duct biopsy, in the other, was consistent with late irradiation injury. We conclude that stricture may be a delayed consequence of radiotherapy applied to normal bile ducts.

A radiopharmaceutical for pancreatic exocrine functional diagnosis: 62Zn-EDDA metabolism in pancreas.

PubMed

Fujibayashi, Y; Saji, H; Kawai, K; Unuma, Y; Miyata, S; Okuno, T; Hosotani, R; Inoue, K; Adachi, H; Horiuchi, K

1986-01-01

The metabolic pathway of radioactive 62Zn-EDDA (ethylenediamine-N,N'-diacetic acid), in the exocrine pancreas was studied with respect to that of endogenous Zn. In pancreatic duct cannulated dog, the secretion of intravenously injected exogenous 62Zn into pancreatic juice increased under the stimulation of CCK-PZ (pancreatic protein secretion stimulating hormone), which closely correlated to endogenous Zn. Moreover, in pancreatic juice, 62Zn as well as endogenous Zn was selectively bound to Zn-metalloenzymes, carboxypeptidase A and B. These results demonstrated the close correlation between the endogenous and the exogenously-administered Zn (62Zn-EDDA), as well as the high availability of 62Zn-EDDA as a marker of pancreatic function for the follow up of carboxypeptidase metabolism.

General view of a Space Shuttle Main Engine (SSME) mounted ...

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

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping diagonally across the top of the assembly and connecting to the High-Pressure Fuel Turbopump, the Low-Pressure Oxidizer Turbopump (LPOTP) located center right of the assembly and the LPOTP Discharge Duct looping around from the pump to the underside of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

GPON FTTH trial: lessons learned

NASA Astrophysics Data System (ADS)

Weis, Erik; Hölzl, Rainer; Breuer, Dirk; Lange, Christoph

2009-11-01

This paper reports on a FTTH field trial with GPON (Gigabit-capable passive optical network) technology in the network of Deutsche Telekom in the region of the cities of Berlin and Potsdam. Focus of this trial was to gain practical experience regarding GPON technology, fibre installation in existing ducts with micro duct technology, fibre cabling in customer buildings and impact on operational processes. Furthermore it is reported on an initial Deutsche Telekom FTTB deployment based on GPON technology in the city of Dresden with the main targets to obtain practical deployment and operation experiences with fibre-based access networks and to provide broadband access to a part of the city formerly not servable by DSL (digital subscriber line) technology.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct andmore » leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.« less

Lesions of the segmental and lobar hepatic ducts.

PubMed Central

Longmire, W P; Tompkins, R K

1975-01-01

Despite reports to the contrary, unobstructed drainage of 50% of an otherwise normal liver through either the right or left uninfected hepatic duct is adequate to restore normal liver function, even if the obstructed lobe remains in place. An undrained liver lobe, if present, may require no further treatment. As long as it is completely obstructed and uninfected, it will undergo a progressive asymptomatic atrophy. Cholangitis invariably develops behind a partial lobar ductal obstruction, producing jaundice, pruritis, and fever. Unless unobstructed, uninfected biliary flow can be achieved through a segmental or lobar duct, it is better that the duct be completely obstructed and the affected liver parenchyma allowed to atrophy, provided there is normal biliary flow from the residual 50% of liver. This concept is important in the management of injured anomalous segmental or lobar hepatic duct and in the palliative treatment of bile duct carcinoma. Localized intrahepatic infections communicating with abnormal biliary ducts will require hepatic resection of the infected parenchyma and ducts for cure. The abnormality may be saccular dilatation of the intrahepatic ductal system with abscess formation or intrahepatic abscess associated with stenosis of the ductal system from trauma to the duct, to the duct and liver, or to retained intrahepatic stones. Diffusely situated intrahepatic abscesses secondary to ductal abnormalities can be treated with systemic antibiotics, local drainage of a dmoninant abscess, and efforts to improve biliary drainage. Images Fig. 4. Fig. 5. Fig. 6. Fig. 8. Fig. 9. Fig. 10. Figs. 11A and B Figs. 12A and B. Fig. 13. Fig. 14. Fig. 15. Fig. 16. Fig. 17. PMID:1180585

Biliary tract enhancement in gadoxetic acid-enhanced MRI correlates with liver function biomarkers.

PubMed

Noda, Yoshifumi; Goshima, Satoshi; Kajita, Kimihiro; Kawada, Hiroshi; Kawai, Nobuyuki; Koyasu, Hiromi; Matsuo, Masayuki; Bae, Kyongtae T

2016-11-01

To evaluate the association between gadoxetic-acid-enhanced magnetic resonance (MR) imaging measurements and laboratory and clinical biomarkers of liver function and fibrosis. One hundred thirty nine consecutive patients with suspected liver disease or liver tumor underwent gadoxetic-acid-enhanced MR imaging. MR imaging measurements during the hepatobiliary phase included biliary tract structure-to-muscle signal intensity ratio (SIR). These measurements were compared with Child-Pugh classification, end-stage liver disease (MELD) score, and aspartate aminotransferase-to-platelet ratio index (APRI). The SIRs of cystic duct and common bile duct were significantly correlated with Child-Pugh classification (P=0.012 for cystic duct and P<0.0001 for common bile duct), MELD score (P=0.0016 and P=0.0033), and APRI (P=0.0022 and P=0.0015). The sensitivity, specificity, and area under the receiver-operating-characteristic curve were: (74%, 88%, 0.86) with the SIR of common bile duct for the detection of patients with Child-Pugh class B or C; (100%, 87%, 0.94) with the SIR of cystic duct for MELD score (>10); (65%, 76%, 0.70) with the SIR of common bile duct for APRI (>1.5). Gadoxetic-acid contrast enhancement of cystic duct and common bile duct could be used as biomarkers to assess liver function. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Are duct burners and waste heat... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units...

Results and comparison of Hall and DW duct experiments

NASA Technical Reports Server (NTRS)

Smith, J. M.; Morgan, J. L.

1982-01-01

Experimental data from recent tests of a 45 deg diagonal wall duct are presented and compared with the results of a similar Hall duct. It is shown that while the peak power density of the two devices is approximately equal that the diagonal wall duct produces greater total power output due to its ability to better utilize the available magnetic field.

Bile duct epithelial tight junctions and barrier function

PubMed Central

Rao, R.K.; Samak, G.

2013-01-01

Bile ducts play a crucial role in the formation and secretion of bile as well as excretion of circulating xenobiotic substances. In addition to its secretory and excretory functions, bile duct epithelium plays an important role in the formation of a barrier to the diffusion of toxic substances from bile into the hepatic interstitial tissue. Disruption of barrier function and toxic injury to liver cells appear to be involved in the pathogenesis of a variety of liver diseases such as primary sclerosing cholangitis, primary biliary cirrhosis and cholangiocarcinoma. Although the investigations into understanding the structure and regulation of tight junctions in gut, renal and endothelial tissues have expanded rapidly, very little is known about the structure and regulation of tight junctions in the bile duct epithelium. In this article we summarize the current understanding of physiology and pathophysiology of bile duct epithelium, the structure and regulation of tight junctions in canaliculi and bile duct epithelia and different mechanisms involved in the regulation of disruption and protection of bile duct epithelial tight junctions. This article will make a case for the need of future investigations toward our understanding of molecular organization and regulation of canalicular and bile duct epithelial tight junctions. PMID:24665411

Modified duval procedure for small-duct chronic pancreatitis without head dominance.

PubMed

Oida, Takatsugu; Aramaki, Osamu; Kano, Hisao; Mimatsu, Kenji; Kawasaki, Atsushi; Kuboi, Youichi; Fukino, Nobutada; Kida, Kazutoshi; Amano, Sadao

2011-01-01

In the case of small-duct chronic pancreatitis, surgery for pain relief is broadly divided into resection and drainage procedures. These procedures should be selected according to the location of dominant lesion, diameter of the pancreatic duct and extent of the disease. The appropriate procedure for the treatment of small-duct chronic pancreatitis, especially small-duct chronic pancreatitis without head dominance, remains controversial. We developed the modified Duval procedure for the treatment of small-duct chronic pancreatitis without head dominance and determined the efficacy of this procedure. We retrospectively studied 14 patients who underwent surgical drainage with or without pancreatic resection for chronic pancreatitis with small pancreatic duct (<7mm) without head dominance. These patients were divided into 2 groups; the modified Puestow procedure group and the modified Duval procedure group. No complications occurred in the modified Duval group. In the modified Puestow procedure group, complete and partial pain relief were observed in 62.5%, and 37.5% of patients respectively. In contrast, complete pain relief was observed in all the patients in the modified Duval procedure group. Our modified Duval procedure is useful and should be considered the appropriate surgical technique for the treatment of small-duct chronic pancreatitis without head dominance.

Acoustics flow analysis in circular duct using sound intensity and dynamic mode decomposition

NASA Astrophysics Data System (ADS)

Weyna, S.

2014-08-01

Sound intensity generation in hard-walled duct with acoustic flow (no mean-flow) is treated experimentally and shown graphically. In paper, numerous methods of visualization illustrating the vortex flow (2D, 3D) can graphically explain diffraction and scattering phenomena occurring inside the duct and around open end area. Sound intensity investigation in annular duct gives a physical picture of sound waves in any duct mode. In the paper, modal energy analysis are discussed with particular reference to acoustics acoustic orthogonal decomposition (AOD). The image of sound intensity fields before and above "cut-off" frequency region are found to compare acoustic modes which might resonate in duct. The experimental results show also the effects of axial and swirling flow. However acoustic field is extremely complicated, because pressures in non-propagating (cut-off) modes cooperate with the particle velocities in propagating modes, and vice versa. Measurement in cylindrical duct demonstrates also the cut-off phenomenon and the effect of reflection from open end. The aim of experimental study was to obtain information on low Mach number flows in ducts in order to improve physical understanding and validate theoretical CFD and CAA models that still may be improved.

Biliary tract variations of the left liver with special reference to the left medial sectional bile duct in 500 patients.

PubMed

Furusawa, Norihiko; Kobayashi, Akira; Yokoyama, Takahide; Shimizu, Akira; Motoyama, Hiroaki; Kanai, Keita; Arakura, Norikazu; Yamada, Akira; Kitou, Yoshihiro; Miyagawa, Shin-Ichi

2015-08-01

Among the intrahepatic bile ducts, the biliary system of the left medial sectional bile duct (B4) is known to have relatively complex patterns. The records of 500 patients who had been diagnosed as having hepato-pancreatico-biliary disease were retrospectively studied for anatomical biliary variations of the left liver with special reference to the drainage system of B4 using magnetic resonance images. The left hepatic duct was present in 494 patients (98.8%), whereas it was lacking in 6 patients (1.2%), and these patients exhibited the following B4 confluence patterns: B4 drained into the common hepatic duct in 2 patients (.4%), the right anterior sectional bile duct in 3 patients (.6%), and the right posterior sectional bile duct in 1 patient (.2%). The left hepatic duct was absent more frequently in patients with portal venous variations than in patients with a common branching pattern (8.2% vs .4%, P = .0011). The presently reported data are useful for obtaining a better understanding of the surgical anatomy of the biliary system of the left liver. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of sound propagation in ducts using the wave envelope concept

NASA Technical Reports Server (NTRS)

Baumeister, K. J.

1974-01-01

A finite difference formulation is presented for sound propagation in a rectangular two-dimensional duct without steady flow for plane wave input. Before the difference equations are formulated, the governing Helmholtz equation is first transformed to a form whose solution does not oscillate along the length of the duct. This transformation reduces the required number of grid points by an order of magnitude, and the number of grid points becomes independent of the sound frequency. Physically, the transformed pressure represents the amplitude of the conventional sound wave. Example solutions are presented for sound propagation in a one-dimensional straight hard-wall duct and in a two-dimensional straight soft-wall duct without steady flow. The numerical solutions show evidence of the existence along the duct wall of a developing acoustic pressure diffusion boundary layer which is similar in nature to the conventional viscous flow boundary layer. In order to better illustrate this concept, the wave equation and boundary conditions are written such that the frequency no longer appears explicitly in them. The frequency effects in duct propagation can be visualized solely as an expansion and stretching of the suppressor duct.

CFD analysis of gas explosions vented through relief pipes.

PubMed

Ferrara, G; Di Benedetto, A; Salzano, E; Russo, G

2006-09-21

Vent devices for gas and dust explosions are often ducted to safe locations by means of relief pipes. However, the presence of the duct increases the severity of explosion if compared to simply vented vessels (i.e. compared to cases where no duct is present). Besides, the identification of the key phenomena controlling the violence of explosion has not yet been gained. Multidimensional models coupling, mass, momentum and energy conservation equations can be valuable tools for the analysis of such complex explosion phenomena. In this work, gas explosions vented through ducts have been modelled by a two-dimensional (2D) axi-symmetric computational fluid dynamic (CFD) model based on the unsteady Reynolds Averaged Navier Stokes (RANS) approach in which the laminar, flamelet and distributed combustion models have been implemented. Numerical test have been carried out by varying ignition position, duct diameter and length. Results have evidenced that the severity of ducted explosions is mainly driven by the vigorous secondary explosion occurring in the duct (burn-up) rather than by the duct flow resistance or acoustic enhancement. Moreover, it has been found out that the burn-up affects explosion severity due to the reduction of venting rate rather than to the burning rate enhancement through turbulization.

Observed characteristics of atmospheric ducts over the South China Sea in autumn

NASA Astrophysics Data System (ADS)

Cheng, Yinhe; Zhou, Shengqi; Wang, Dongxiao; Lu, Yuanzheng; Huang, Ke; Yao, Jinglong; You, Xiaobao

2016-05-01

The observed characteristics of lower atmospheric ducts over the South China Sea (SCS) were analyzed based on Global Position Systerm (GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012. Duct occurrence, thickness, and strength over the SCS were about 40%, 150-m thick, and 8 M units, respectively, which were larger than during the summer monsoon period. Most ducts occurred at heights <1 500 m and these ducts easily trap electromagnetic wave clusters with wavelengths <2 m. Diurnal variation of the SCS ducts appeared evident. They occurred more often at midnight at higher altitudes (about 1 100 m), with a thickest layer of about 145 m and less frequently during the evening at lower altitudes (about 800 m), with a thinnest layer of about 125 m. Moreover, ducts during the daytime at a mean height of about 900 m, with the greatest strength of about 10 M units. Furthermore, all duct variables observed over the SCS in autumn decreased from north to south. These findings are useful not only in the design of radar and communication systems, but also for evaluating possible effects of anomalous propagation on meteorological radar and military applications.

Experimental Measurements of Two-dimensional Planar Propagating Edge Flames

NASA Technical Reports Server (NTRS)

Villa-Gonzalez, Marcos; Marchese, Anthony J.; Easton, John W.; Miller, Fletcher J.

2007-01-01

The study of edge flames has received increased attention in recent years. This work reports the results of a recent study into two-dimensional, planar, propagating edge flames that are remote from solid surfaces (called here, free-layer flames, as opposed to layered flames along floors or ceilings). They represent an ideal case of a flame propagating down a flammable plume, or through a flammable layer in microgravity. The results were generated using a new apparatus in which a thin stream of gaseous fuel is injected into a low-speed laminar wind tunnel thereby forming a flammable layer along the centerline. An airfoil-shaped fuel dispenser downstream of the duct inlet issues ethane from a slot in the trailing edge. The air and ethane mix due to mass diffusion while flowing up towards the duct exit, forming a flammable layer with a steep lateral fuel concentration gradient and smaller axial fuel concentration gradient. We characterized the flow and fuel concentration fields in the duct using hot wire anemometer scans, flow visualization using smoke traces, and non-reacting, numerical modeling using COSMOSFloWorks. In the experiment, a hot wire near the exit ignites the ethane air layer, with the flame propagating downwards towards the fuel source. Reported here are tests with the air inlet velocity of 25 cm/s and ethane flows of 967-1299 sccm, which gave conditions ranging from lean to rich along the centerline. In these conditions the flame spreads at a constant rate faster than the laminar burning rate for a premixed ethane air mixture. The flame spread rate increases with increasing transverse fuel gradient (obtained by increasing the fuel flow rate), but appears to reach a maximum. The flow field shows little effect due to the flame approach near the igniter, but shows significant effect, including flow reversal, well ahead of the flame as it approaches the airfoil fuel source.

Biliary tract instillation of a SMAC mimetic induces TRAIL-dependent acute sclerosing cholangitis-like injury in mice

PubMed Central

Guicciardi, Maria Eugenia; Krishnan, Anuradha; Bronk, Steven F; Hirsova, Petra; Griffith, Thomas S; Gores, Gregory J

2017-01-01

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiopathogenesis characterized by fibrous cholangiopathy of large and small bile ducts. Systemic administration of a murine TNF-related apoptosis-inducing ligand (TRAIL) receptor agonist induces a sclerosing cholangitis injury in C57BL/6 mice, suggesting endogenous TRAIL may contribute to sclerosing cholangitis syndromes. Cellular inhibitor of apoptosis proteins (cIAP-1 and cIAP-2) are negative regulators of inflammation and TRAIL receptor signaling. We hypothesized that if endogenous TRAIL promotes sclerosing cholangitis, then cIAP depletion should also induce this biliary tract injury. Herein, we show that cIAP protein levels are reduced in the interlobular bile ducts of human PSC livers. Downregulation of cIAPs in normal human cholangiocytes in vitro by use of a SMAC mimetic (SM) induces moderate, ripoptosome-mediated apoptosis and RIP1-independent upregulation of proinflammatory cytokines and chemokines. Cytokine and chemokine expression was mediated by the non-canonical activation of NF-κB. To investigate whether downregulation of cIAPs is linked to generation of a PSC-like phenotype, an SM was directly instilled into the mouse biliary tree. Twelve hours after biliary instillation, TUNEL-positive cholangiocytes were identified; 5 days later, PSC-like changes were observed in the SM-treated mice, including a fibrous cholangiopathy of the interlobular bile ducts, portal inflammation, significant elevation of serum markers of cholestasis and cholangiographic evidence of intrahepatic biliary tract injury. In contrast, TRAIL and TRAIL-receptor deficient mice showed no sign of cholangiopathy following SM intrabiliary injection. We conclude that in vivo antagonism of cIAPs in mouse biliary epithelial cells is sufficient to trigger cholangiocytes apoptosis and a proinflammatory response resulting in a fibrous cholangiopathy resembling human sclerosing cholangitis. Therefore, downregulation of cIAPs in PSC cholangiocytes may contribute to the development of the disease. Our results also indicate that inhibition of TRAIL signaling pathways may be beneficial in the treatment of PSC. PMID:28055006

Effect of microscopic modeling of skin in electrical and thermal analysis of transcranial direct current stimulation

NASA Astrophysics Data System (ADS)

Gomez-Tames, Jose; Sugiyama, Yukiya; Laakso, Ilkka; Tanaka, Satoshi; Koyama, Soichiro; Sadato, Norihiro; Hirata, Akimasa

2016-12-01

Transcranial direct current stimulation (tDCS) is a neuromodulation scheme where a small current is delivered to the brain via two electrodes attached to the scalp. The electrode design is an important topic, not only as regards efficacy, but also from a safety perspective, as tDCS may be related to skin lesions that are sometimes observed after stimulation. Previous computational models of tDCS have omitted the effects of microscopic structures in the skin, and the different soak conditions of the electrodes, and model validation has been limited. In this study, multiphysics and multiscale analysis are proposed to demonstrate the importance of microscopic modeling of the skin, in order to clarify the effects of the internal electric field, and to examine temperature elevation around the electrodes. This novel microscopic model of the skin layer took into consideration the effect of saline/water penetration in hair follicles and sweat ducts on the field distribution around the electrodes. The temperature elevation in the skin was then computed by solving the bioheat equation. Also, a multiscale model was introduced to account for macroscopic and microscopic tissues of the head and skin, which was validated by measurement of the head resistance during tDCS. As a result, the electric field in the microscopic model of the skin was less localized when the follicles/ducts were filled with saline instead of hair or tap water. Temperature elevation was also lessened with saline, in comparison with other substances. Saline, which may penetrate the hair follicles and sweat ducts, suppressed the field concentration around the electrodes. For conventional magnitudes of current injection, and a head resistance of less than 10 kΩ, the temperature elevation in the skin when using saline-soaked electrodes was low, less than 0.1 °C, and unlikely to cause adverse thermal effects.

[A photo-optical observation of gallbladder motility in dogs (author's transl)].

PubMed

Kudo, N

1976-03-01

A photo-optical observation on gallbladder motility was made with the 16 mm cine-cholangiography. The subjects studied were thirty two mongrel dogs. The gallbladder was exposed by a short upper midline abdominal incision under pentothal anesthesia. Gallbladder bile was aspirated and contrast medium was given into the bladder, through a transhepatic route. The cine-cholangiography was done by an image intensifier at a speed of one frame every 2 to 4 seconds. The cinefilms taken were observed repeatedly by the screen projection at various speeds. The drawings were made by tracing the outline of the image of the gallbladder on each frame and were overlapped. Moreover, a contraction curve was made by the cholecystometry using of film motion analyzer in every case. At the same time bile flow into the duodenum was recorded to study a relationship between the gallbladder contraction and motility of the terminal common bile duct. The results obtained are as follows: 1. In a resting state any contraction of the gallbladder was not seen during 30 minutes, and a peristalsis-like movements of the neck portion was observed. However, there was not a relationship between the contraction curve of the gallbladder and the bile flow into the duodenum. 2. Immediately after giving Caerulein, the contrast medium injected into the gallbladder was rapidly discharged into the common bile duct by a peristalsis-like movement of the neck. The size of the gallbladder was markedly decreased into three fifths of the initial state three minutes after administration. At the same time contrast medium was continuously discharged into the duodenum. 3. After giving pilocarpine a marked contraction with forceful movement of the neck and body was observed, and the size of the gallbladder was decreased into three quarters ot the initial state. Bile discharge into the duodenum was markedly increased with an active open- and closing movement of the terminal common bile duct.

Sound propagation in and radiation from acoustically lined flow ducts: A comparison of experiment and theory

NASA Technical Reports Server (NTRS)

Plumblee, H. E., Jr.; Dean, P. D.; Wynne, G. A.; Burrin, R. H.

1973-01-01

The results of an experimental and theoretical study of many of the fundamental details of sound propagation in hard wall and soft wall annular flow ducts are reported. The theory of sound propagation along such ducts and the theory for determining the complex radiation impedance of higher order modes of an annulus are outlined, and methods for generating acoustic duct modes are developed. The results of a detailed measurement program on propagation in rigid wall annular ducts with and without airflow through the duct are presented. Techniques are described for measuring cut-on frequencies, modal phase speed, and radial and annular mode shapes. The effects of flow velocity on cut-on frequencies and phase speed are measured. Comparisons are made with theoretical predictions for all of the effects studies. The two microphone method of impedance is used to measure the effects of flow on acoustic liners. A numerical study of sound propagation in annular ducts with one or both walls acoustically lined is presented.

Energy efficient engine: Turbine transition duct model technology report

NASA Technical Reports Server (NTRS)

Leach, K.; Thurlin, R.

1982-01-01

The Low-Pressure Turbine Transition Duct Model Technology Program was directed toward substantiating the aerodynamic definition of a turbine transition duct for the Energy Efficient Engine. This effort was successful in demonstrating an aerodynamically viable compact duct geometry and the performance benefits associated with a low camber low-pressure turbine inlet guide vane. The transition duct design for the flight propulsion system was tested and the pressure loss goal of 0.7 percent was verified. Also, strut fairing pressure distributions, as well as wall pressure coefficients, were in close agreement with analytical predictions. Duct modifications for the integrated core/low spool were also evaluated. The total pressure loss was 1.59 percent. Although the increase in exit area in this design produced higher wall loadings, reflecting a more aggressive aerodynamic design, pressure profiles showed no evidence of flow separation. Overall, the results acquired have provided pertinent design and diagnostic information for the design of a turbine transition duct for both the flight propulsion system and the integrated core/low spool.

Sound radiation from a flanged inclined duct.

PubMed

McAlpine, Alan; Daymond-King, Alex P; Kempton, Andrew J

2012-12-01

A simple method to calculate sound radiation from a flanged inclined duct is presented. An inclined annular duct is terminated by a rigid vertical plane. The duct termination is representative of a scarfed exit. The concept of a scarfed duct has been examined in turbofan aero-engines as a means to, potentially, shield a portion of the radiated sound from being transmitted directly to the ground. The sound field inside the annular duct is expressed in terms of spinning modes. Exterior to the duct, the radiated sound field owing to each mode can be expressed in terms of its directivity pattern, which is found by evaluating an appropriate form of Rayleigh's integral. The asymmetry is shown to affect the amplitude of the principal lobe of the directivity pattern, and to alter the proportion of the sound power radiated up or down. The methodology detailed in this article provides a simple engineering approach to investigate the sound radiation for a three-dimensional problem.

Turbofan aft duct suppressor study

NASA Technical Reports Server (NTRS)

Syed, A. A.; Motsinger, R. E.; Fiske, G. H.; Joshi, M. C.; Kraft, R. E.

1983-01-01

Suppressions due to acoustic treatment in the annular exhaust duct of a model fan were theoretically predicted and compared with measured suppressions. The predictions are based on the modal analysis of sound propagation in a straight annular flow duct with segmented treatment. Modal distributions of the fan noise source (fan-stator interaction only) were measured using in-duct modal probes. The flow profiles were also measured in the vicinity of the modal probes. The acoustic impedance of the single degree of freedom treatment was measured in the presence of grazing flow. The measured values of mode distribution of the fan noise source, the flow velocity profile and the acoustic impedance of the treatment in the duct were used as input to the prediction program. The predicted suppressions, under the assumption of uniform flow in the duct, compared well with the suppressions measured in the duct for all test conditions. The interaction modes generated by the rotor-stator interaction spanned a cut-off ratio range from nearly 1 to 7.

Noise radiation directivity from a wind-tunnel inlet with inlet vanes and duct wall linings

NASA Technical Reports Server (NTRS)

Soderman, P. T.; Phillips, J. D.

1986-01-01

The acoustic radiation patterns from a 1/15th scale model of the Ames 80- by 120-Ft Wind Tunnel test section and inlet have been measured with a noise source installed in the test section. Data were acquired without airflow in the duct. Sound-absorbent inlet vanes oriented parallel to each other, or splayed with a variable incidence relative to the duct long axis, were evaluated along with duct wall linings. Results show that splayed vans tend to spread the sound to greater angles than those measured with the open inlet. Parallel vanes narrowed the high-frequency radiation pattern. Duct wall linings had a strong effect on acoustic directivity by attenuating wall reflections. Vane insertion loss was measured. Directivity results are compared with existing data from square ducts. Two prediction methods for duct radiation directivity are described: one is an empirical method based on the test data, and the other is a analytical method based on ray acoustics.

A non-local computational boundary condition for duct acoustics

NASA Technical Reports Server (NTRS)

Zorumski, William E.; Watson, Willie R.; Hodge, Steve L.

1994-01-01

A non-local boundary condition is formulated for acoustic waves in ducts without flow. The ducts are two dimensional with constant area, but with variable impedance wall lining. Extension of the formulation to three dimensional and variable area ducts is straightforward in principle, but requires significantly more computation. The boundary condition simulates a nonreflecting wave field in an infinite duct. It is implemented by a constant matrix operator which is applied at the boundary of the computational domain. An efficient computational solution scheme is developed which allows calculations for high frequencies and long duct lengths. This computational solution utilizes the boundary condition to limit the computational space while preserving the radiation boundary condition. The boundary condition is tested for several sources. It is demonstrated that the boundary condition can be applied close to the sound sources, rendering the computational domain small. Computational solutions with the new non-local boundary condition are shown to be consistent with the known solutions for nonreflecting wavefields in an infinite uniform duct.

Pressures in the sphincter of Oddi in patients with gallstones, common duct stones, and recurrent pancreatitis.

PubMed

Guelrud, M; Mendoza, S; Vicent, S; Gomez, M; Villalta, B

1983-02-01

To determine the significance of manometric pressure, measurements of the sphincter of Oddi in a control group and in patients with cholelithiasis with common duct stones with and without recurrent pancreatitis were studied. Sphincter of Oddi pressure was recorded continuously and by station pull-through by a triple lumen catheter. The basal sphincter of Oddi pressure, the mean pressure gradient between common duct and duodenum, and the sphincter of Oddi wave amplitude were measured. There was no significant difference between control subjects and patients with gallstones and common duct stones. In patients with common duct stones and recurrent pancreatitis the basal sphincter of Oddi pressure, the pressure gradient between common duct and duodenum, and the wave amplitude were significantly increased over control patients. These studies suggest that abnormalities in the sphincter of Oddi motor function are more common in patients with common duct stones with recurrent pancreatitis than in similar patients without pancreatitis.

Building America Case Study: Duct in Conditioned Space in a Dropped Ceiling or Fur-down, Gainesville, Florida (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2014-09-01

Forced air distribution systems (duct systems) typically are installed out of sight for aesthetic reasons, most often in unconditioned areas such as an attic or crawlspace. Any leakage of air to or from the duct system (duct leakage) in unconditioned space not only loses energy, but impacts home and equipment durability and indoor air quality. An obvious solution to this problem is to bring the duct system into the interior of the house, either by sealing the area where the ducts are installed (sealed attic or crawlspace) or by building an interior cavity or chase above the ceiling plane (raisedmore » ceiling or fur-up chase) or below the ceiling plane (dropped ceiling or fur-down) for the duct system. This case study examines one Building America builder partner's implementation of an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase.« less

Acoustic theory of axisymmetric multisectioned ducts. [reduction of turbofan engine noise

NASA Technical Reports Server (NTRS)

Zorumski, W. E.

1974-01-01

Equations are developed for the acoustic field in a duct system which is made up of a number of connected circular and annular ducts. These equations are suitable for finding the acoustic field inside of and radiated from an aircraft turbofan engine. Acoustic modes are used as generalized coordinates in order to develop a set of matrix equations for the acoustic field. Equations for these modes are given for circular and annular ducts with uniform flow. Modal source equations are derived for point acoustic sources. General equations for mode transmission and reflection are developed and detailed equations are derived for ducts with multiple sections of acoustic treatment and for ducts with circumferential splitter rings. The general theory is applied to the special case of a uniform area circular duct with multisection liners and it is shown that the mode reflection effects are proportional to differences of the acoustic admittances of adjacent liners. A numerical example is given which shows that multisection liners may provide greater noise suppression than uniform liners.

Experimental methodology for turbocompressor in-duct noise evaluation based on beamforming wave decomposition

NASA Astrophysics Data System (ADS)

Torregrosa, A. J.; Broatch, A.; Margot, X.; García-Tíscar, J.

2016-08-01

An experimental methodology is proposed to assess the noise emission of centrifugal turbocompressors like those of automotive turbochargers. A step-by-step procedure is detailed, starting from the theoretical considerations of sound measurement in flow ducts and examining specific experimental setup guidelines and signal processing routines. Special care is taken regarding some limiting factors that adversely affect the measuring of sound intensity in ducts, namely calibration, sensor placement and frequency ranges and restrictions. In order to provide illustrative examples of the proposed techniques and results, the methodology has been applied to the acoustic evaluation of a small automotive turbocharger in a flow bench. Samples of raw pressure spectra, decomposed pressure waves, calibration results, accurate surge characterization and final compressor noise maps and estimated spectrograms are provided. The analysis of selected frequency bands successfully shows how different, known noise phenomena of particular interest such as mid-frequency "whoosh noise" and low-frequency surge onset are correlated with operating conditions of the turbocharger. Comparison against external inlet orifice intensity measurements shows good correlation and improvement with respect to alternative wave decomposition techniques.

Characterization of synthesis and storage of TGF-alpha in rat parotid acinar and intercalated duct cells.

PubMed

Login, G R; Yang, J; Bryan, K P; Digenis, E C; McBride, J; Elovic, A; Quissell, D O; Dvorak, A M; Wong, D T

1997-03-01

Although the expression and biological role of transforming growth factor-alpha (TGF-alpha) have been explored in a variety of normal cells in mammalian species, little is known about the storage of TGF-alpha in secretory cells of exocrine organs. Parotid glands from four rats were homogenized for RNA isolation followed by reverse transcription-polymerase chain reaction to determine the presence of TGF-alpha message. In situ hybridization using a hamster-specific TGF-alpha riboprobe was done on paraffin sections. Parotid gland and isolated acinar cells were processed for transmission electron microscopy (TEM) and postembedding immunogold labeled for TGF-alpha. Gold particles were counted on approximately 200 granules in 10 acinar cells and in 10 intercalated duct cells. Labeling density was calculated as the number of gold particles per square micrometer +/- SD. Statistical significance was calculated using one-way analysis of variance. Using multiple technologies, we have established that rat parotid acinar and intercalated duct cells synthesize TGF-alpha and store the precursor form of this cytokine in their secretory granules.

Pitot tube calculations with a TI-59

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, K.

Industrial plant and stack analysis dictates that flow measurements in ducts be accurate. This is usually accomplished by running a traverse with a pitot tube across the duct or flue. A traverse is a series of measurements taken at predetermined points across the duct. The values of these measurements are calculated into point flow rates and averaged. A program for the Texas Instruments TI-59 programmable calculator follows. The program will perform calculations for an infinite number of test points, both with the standard (combined impact type) pitot tube and the S-type (combined reverse type). The type of tube is selectedmore » by inputting an indicating valve that triggers a flag in the program. To use the standard pitot tube, a 1 is input into key E. When the S-type is used, a zero is input into key E. The program output will note if the S-type had been used. Since most process systems are not at standard conditions (32/sup 0/F, 1 atm) the program will take this into account.« less

Simplified pancreatoduodenectomy for complex blunt pancreaticoduodenal injury.

PubMed

Feng, Xin-Fu; Fan, Wei; Shi, Cheng-Xian; Li, Jun-Hua; Liu, Jun; Liu, Zhen-Hua

2013-01-01

A 34-year-old man admitted to our department with complex blunt pancreaticoduodenal injury after a car accident. The wall of the first, second, and third portions of the duodenum was extensively lacerated, and the pancreas was longitudinally transected along the superior mesenteric vein-portal vein trunk. The pancreatic head and the uncinate process were devitalized and the distal common bile duct and the proximal main pancreatic duct were completely detached from the Vater ampulla. The length of the stump of distal common bile located at the cut surface of remnant pancreas was approximately 0.6 cm. A simplified Kausch-Whipple's procedure was performed after debridement of the devitalized pancreatic head and resection of the damaged duodenum in which the stump of distal common bile duct and the pancreatic remnant were embedded into the jejunal loop. Postoperative wound abscess appeared that eventually recovered by conservative treatment. During 16 months follow-up the patient has been stable and healthy. A simplified pancreaticoduodenectomy is a safe alternative for the Whipple procedure in managing complex pancreaticoduodenal injury in a hemodynamically stable patient.

Canalicular laceration repair using a viscoelastic injection to locate and dilate the proximal torn edge.

PubMed

Örge, Faruk H; Dar, Suhail A

2015-06-01

Canalicular lacerations are common complications of eyelid trauma in the pediatric population. Irrigating air, water, and colored or viscous agents through the intact canaliculus have been suggested to identify the torn proximal edge. We report our experience in repairing canalicular lacerations using a novel viscoelastic injection technique with a Monoka monocanalicular stent. The medical records of patients <18 years of age who underwent repair of a canalicular laceration with a monocanalicular stent using superficial viscoelastic deployment to locate the torn canaliculus were retrospectively reviewed. Demographics, cause of eyelid injury, surgical management using our novel viscoelastic injection technique, and outcome were analyzed. A total of 38 children with lid lacerations were identified, of whom the 17 with canalicular involvement were included (mean age, 6.27 years). Canalicular injury in these 17 was due to dog bite (9 patients) and shearing trauma (8 patients). In 11 patients, the injury was located in the lower lid; in 4, the upper lid; and in 2, combined upper and lower lids. All patients had good anatomic repair and on follow-up had negative dye disappearance tests and were free of tearing. Deploying viscoelastic superficially near, and injecting into the injured canaliculus can improve visualization of the operative field by retracting the surrounding tissue and tamponading any bleeding, which aids in location and dilation of the torn canaliculus initially and in subsequent steps, eases intubation into the lubricated torn canaliculus and nasolacrimal duct, and avoids iatrogenic injury to an uninjured canaliculus. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Double Gallbladder Originating from Left Hepatic Duct: A Case Report and Review of Literature

PubMed Central

Gorecki, Piotr J.; Andrei, Valeriu E; Musacchio, Tito

1998-01-01

Background: Double gallbladder is a rare anomaly of the biliary tract. Double gallbladder arising from the left hepatic duct was previously reported only once in the literature. Case Report: A case of symptomatic cholelithiasis in a double gallbladder, diagnosed on preoperative ultrasound, computed tomography (CT) and endoscopic retrograde cholangiopancreatogram (ERCP) is reported. At laparoscopic cholangiography via the accessory gallbladder no accessory cystic duct was visualized. After conversion to open cholecystectomy, the duplicated gallbladder was found to arise directly from the left hepatic duct; it was resected and the duct repaired. Conclusions: We emphasize that a careful intraoperative cholangiographic evaluation of the accessory gallbladder is mandatory in order to prevent inadvertent injury to bile ducts, since a large variety of ductal abnormality may exist. PMID:10036124

Analyses of radiation impedances of finite cylindrical ducts

NASA Astrophysics Data System (ADS)

Shao, W.; Mechefske, C. K.

2005-08-01

To aid in understanding the characteristics of acoustic radiation from finite cylindrical ducts with infinite flanges, mathematical expressions of generalized radiation impedances at the open ends have been developed. Newton's method is used to find the complex wavenumbers of radial modes for the absorption boundary condition. The self-radiation impedances and mutual impedances for some acoustic modes are calculated for the ducts with rigid and absorption walls. The results show that the acoustical conditions of the duct walls have a significant influence on the radiation impedance. The acoustical interaction between the two open ends of the ducts cannot be neglected, especially for plane waves. To increase the wall admittance will reduce this interference effect. This study creates the possibility for simulating the sound field inside finite ducts in future work.

Propagation and radiation of sound from flanged circular ducts with circumferentially varying wall admittances. I Semi-infinite ducts. II - Finite ducts with sources

NASA Technical Reports Server (NTRS)

Fuller, C. R.

1984-01-01

Sound propagation in infinite, semiinfinite, and finite circular ducts with circumferentially varying wall admittances is investigated analytically. The infinite case is considered, and an example demonstrates the effects of wall-admittance distribution on dispersion characteristics and mode shapes. An exact solution is obtained for the semiinfinite case, a circular duct with a flanged opening: sidelobe suppression and circumferential-mode energy scattering leading to radiated-field asymmetry are found. A finite duct system with specified hard-walled pressure sources is examined in detail, evaluating reflection coefficients, transmission losses, and radiated-field directivity. Graphs and diagrams are provided, and the implications of the results obtained for the design of aircraft-turbofan inlet liners are discussed.

Longitudinal flow of endolymph measured by distribution of tetraethylammonium and choline in scala media.

PubMed

Syková, E; Syka, J; Johnstone, B M; Yates, G K

1987-01-01

Longitudinal endolymph flow rate in the guinea pig cochlea was measured by determining the rate of migration of extrinsic ions, tetraethylammonium chloride (TEA) or choline, with a potassium sensitive ion-selective microelectrode (ISM). Low concentrations of iontophoretically injected TEA were detected with the ISM at various distances from the injection electrode. The results were variable when the ISM was used to record spread of TEA from turn II to turn I and vice versa. However, consistent data were obtained when the TEA spread was measured at different electrode separations (0.2, 0.5, 0.7 mm) within turn II. Electrode locations were systematically exchanged without changing their distance, i.e. the ISM electrode was placed basally or apically with respect to the TEA electrode. Comparison of data with a model, which combines the bulk diffusion of TEA and the flow of endolymph, is consistent with a rate of endolymph flow in turn II of about 0.2 mm/min, apex to base. A similar value was also obtained with the iontophoretic injection of choline. The endolymph flow rate may be different in turn I as indicated by measurements of compound action potential (CAP) changes. However, the results of experiments when TEA spread is measured at large distances must be interpreted cautiously because TEA may enter cellular walls of the cochlear duct and alternative routes of transport may be involved.

Active chimney effect using heated porous layers: optimum heat transfer

NASA Astrophysics Data System (ADS)

Mehiris, Abdelhak; Ameziani, Djamel-Edine; Rahli, Omar; Bouhadef, Khadija; Bennacer, Rachid

2017-05-01

The purpose of the present work is to treat numerically the problem of the steady mixed convection that occurs in a vertical cylinder, opened at both ends and filled with a succession of three fluid saturated porous elements, namely a partially porous duct. The flow conditions fit with the classical Darcy-Brinkman model allowing analysing the flow structure on the overall domain. The induced heat transfer, in terms of local and average Nusselt numbers, is discussed for various controlling parameters as the porous medium permeability, Rayleigh and Reynolds numbers. The efficiency of the considered system is improved by the injection/suction on the porous matrices frontier. The undertaken numerical exploration particularly highlighted two possible types of flows, with and without fluid recirculation, which principally depend on the mixed convection regime. Thus, it is especially shown that recirculation zones appear in some domain areas under specific conditions, obvious by a negative central velocity and a prevalence of the natural convection effects, i.e., turnoff flow swirls. These latter are more accentuated in the areas close to the porous obstacles and for weak permeability. Furthermore, when fluid injection or suction is considered, the heat transfer increases under suction and reduces under injection. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

Leaf seal for transition duct in turbine system

DOEpatents

Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

2013-06-11

A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a leaf seal contacting the interface member to provide a seal between the interface member and the turbine section.

Choleperitoneum due to intrahepatic bile duct rupture - case report.

PubMed

Simion, L; Straja, Dn; Prunoiu, Vm; Alecu, M; Brătucu, E

2014-01-01

Non-traumatic perforations of the bile ducts are unfrequently encountered entities, all the more when they affect the intrahepatic bile ducts, exteriorizing their biliary content in the great peritoneal cavity. Reporting such a case has determined the authors to perform a careful overview of the cases present in the literature. An observation that can be made based on these is that the obstruction of the main bile duct due to lithiasis determines, by pressure increase, the dilation of the bile system branches, all on the background of an unknown malformation of the intrahepatic bile ducts. Celsius.

Preliminary Full-Scale Wind-Tunnel Investigation of Wing Ducts for Radiators, Special Report

NASA Technical Reports Server (NTRS)

Silverstein, Abe; Nickle, F. R.

1938-01-01

Wing ducts for liquid-cooled engine radiators have been investigated in the N.A.C.A. full-scale wind tunnel on a large model airplane. Th e tests were made to determine the relative merits of several types of duct and radiator installations for an airplane of a particular des ign. In the test program the principal duct dimensions were system atically varied, and the results are therefore somewhat applicable to the general problems of wing duct design, although they should be co nsidered as preliminary and only indicative of the inherent possibil ities.

Understanding the Mechanical forces of Self-Expandable Metal Stents in the Biliary Ducts.

PubMed

Isayama, Hiroyuki; Nakai, Yousuke; Hamada, Tsuyoshi; Matsubara, Saburo; Kogure, Hirofumi; Koike, Kazuhiko

2016-12-01

Self-expandable metallic stent (SEMS) was an effective biliary endoprosthesis. Mechanical properties of SEMS, radial and axial force (RF, AF), may play important roles in the bile duct after placement. RF was well known dilation force and influenced on the occurrence of migration. AF, newly proposed by this author, was defined as the recovery force when the SEMS vended. AF was related with the cause of bile duct kinking, pancreatitis, and cholecystitis due to the compression of the bile duct, orifice of the cystic duct, and pancreatic orifice. Ideal SEMS may show high RF and low AF.

Choledochoscopic Holmium Laser Lithotripsy for Difficult Bile Duct Stones.

PubMed

Lv, Shangdong; Fang, Zheping; Wang, Aidong; Yang, Jian; Zhang, Wenlong

2017-01-01

The aim of this study was to evaluate the feasibility and efficacy of choledochoscopic holmium laser lithotripsy as a means of removing resistant extrahepatic and intrahepatic bile duct stones. Clinical data on 28 patients who had undergone choledochoscopic holmium laser lithotripsy were analyzed. Complete stone clearance was obtained in 24 patients; small numbers of residual stones in the left or right hepatic duct were found in 4 patients. No severe complications such as hemobilia and bile duct injuries occurred. Choledochoscopic holmium laser lithotripsy is a simple, safe, and effective treatment method for patients with resistant bile duct stones.

Generator stator core vent duct spacer posts

DOEpatents

Griffith, John Wesley; Tong, Wei

2003-06-24

Generator stator cores are constructed by stacking many layers of magnetic laminations. Ventilation ducts may be inserted between these layers by inserting spacers into the core stack. The ventilation ducts allow for the passage of cooling gas through the core during operation. The spacers or spacer posts are positioned between groups of the magnetic laminations to define the ventilation ducts. The spacer posts are secured with longitudinal axes thereof substantially parallel to the core axis. With this structure, core tightness can be assured while maximizing ventilation duct cross section for gas flow and minimizing magnetic loss in the spacers.

On the Induced Flow of an Electrically Conducting Liquid in a Rectangular Duct by Electric and Magnetic Fields of Finite Extent

NASA Technical Reports Server (NTRS)

Rossow, Vernon J.; Jones, William Prichard; Huerta, Robert H.

1961-01-01

Reported here are the results of a systematic study of a model of the direct-current electromagnetic pump. Of particular interest is the motion imparted to the electrically conducting fluid in the rectangular duct by the body forces that result from applied electric and magnetic fields. The purpose of the investigation is to associate the observed fluid motion with the characteristics of the electric and magnetic fields which cause them. The experiments were carried out with electromagnetic fields that moved a stream of copper sulphate solution through a clear plastic channel. Ink filaments injected into the stream ahead of the region where the fields were applied identify the motion of the fluid elements as they passed through the test channel. Several magnetic field configurations were employed with a two-dimensional electric current distribution in order to study and identify the magnitude of some of the effects on the fluid motion brought about by nonuniformities in the electromagnetic fields. A theoretical analysis was used to guide and evaluate the identification of the several fluid motions observed. The agreement of the experimental data with the theoretical predictions is satisfactory. It is found that sizable variations in the velocity profile and pressure head of the output stream are produced by the shape of the electric and magnetic fields.

Carcinoma gallbladder.

PubMed

Biswas, P K

2010-07-01

Carcinoma gallbladder (CaGb) is a rare disease. The aetiology of CaGb is yet not known. However the risk of CaGb is increased in anomalous pancreaticobiliary duct junction (APBDJ), gall stones, xanthogranulomatus cholecystitis, calcified or porcelain gallbladder, cholelithiasis with typhoid carriers, gallbladder adenoma, red meat consumption and tobacco uses. There are protective effects of vegetables on CaGb. Most of the cases present with advanced disease. In early carcinoma of a gallbladder sign and symptoms mimic benign disease. The diagnosis is established by ultrasonography, computerized tomography and guided fine needle aspiration cytology (FNAC). Biochemical tests are of very little value in making a diagnosis. The treatment depends on the clinical stage at presentation. Surgery offers the best chance of cure. In stage T1a, laparoscopic or open cholecystectomy alone is curative, and in T1b, cholecystectomy with hepatoduodenal lymph node dissection without combined resection of an adjacent organ is required. Segment S4a+5 hepatectomy combined with extrahepatic bile duct resection (BDR) and D2 lymph node dissection is a highly recommended operation for the treatment of T2 and T3 CaGb. The dye injection method is useful in determining the appropriate extent of hepatic resection for advanced CaGb. Resurgery is required only in those cases where tumour has invaded the serosa and/ or adjacent structures when diagnosed postoperatively. Biliary bypass is required for palliation. Prognosis depends on early diagnosis and appropriate surgical excision.

Morphological study of the TK cholangiocarcinoma cell line with three-dimensional cell culture.

PubMed

Akiyoshi, Kohei; Kamada, Minori; Akiyama, Nobutake; Suzuki, Masafumi; Watanabe, Michiko; Fujioka, Kouki; Ikeda, Keiichi; Mizuno, Shuichi; Manome, Yoshinobu

2014-04-01

Cholangiocarcinoma is an intractable carcinoma originating from the bile duct epithelium. To gain an understanding of the cell biology of cholangiocarcinoma, in vitro cell culture is valuable. However, well‑characterized cell lines are limited. In the present study, the morphology of the TK cholangiocarcinoma cell line was analyzed by three‑dimensional culture. Dispersed TK cells were injected into a gelatin mesh scaffold and cultivated for 3‑20 days. The morphology of the TK cells was investigated by phase‑contrast microscopy, optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TK cells were observed to proliferate three-dimensionally in the scaffold. The cells exhibited a globoid structure and attached to the scaffold. The SEM observation demonstrated typical microvilli and plicae on the surface of the structure. Light microscopy and TEM confirmed intercellular and cell‑to‑scaffold attachment in the three‑dimensional mesh. The culture also exhibited the formation of a duct-like structure covered by structured microvilli. In conclusion, three‑dimensional culture of TK cells demonstrated the morphological characteristics of cholangiocarcinoma in vitro. Production of high levels of carbohydrate antigen (CA)19‑9, CA50 and carcinoembryonic antigen was previously confirmed in the TK cell line. As a characteristic morphology was demonstrated in the present study, the TK cholangiocarcinoma cell line may be useful as an experimental model for further study of cholangiocarcinoma.

Carbachol improves the secretion of transplanted submandibular glands during the latent period after microvascular autologous transplantation for severe keratoconjunctivitis sicca.

PubMed

Liu, X-J; Li, M; Su, J-Z; Wang, Z; Xie, Z; Yu, G-Y

2016-10-01

Poor secretion of transplanted submandibular glands (SMGs) during the latent period may cause duct obstruction and affects the surgical outcome. The objective of this study was to investigate the efficacy and systemic side effects of carbachol on transplanted SMG secretion. Twenty-seven patients who underwent SMG transplantation for severe keratoconjunctivitis sicca were treated with subcutaneous injections of 0.2mg/2ml carbachol at 10 days, 1 month, and/or 3 months after surgery. The effect on secretion was evaluated by Schirmer test and technetium 99m ((99m)Tc) scintigraphy. Systemic side effects were evaluated subjectively using a questionnaire. The results showed that the time to onset varied from 4 to 9min and the duration of action from 50 to 110min after carbachol administration. The secretion at each time point after drug administration was significantly higher than the pre-administration value (all P<0.01). (99m)Tc scintigraphy showed a decline in the dynamic time-activity curve in 26 patients, demonstrating a stimulatory effect on the secretion of carbachol. No serious systemic side effects were experienced. In conclusion, the intermittent administration of carbachol could be an effective and safe strategy to promote secretion from transplanted SMGs in the latent period to prevent duct obstruction. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The Immunological and Migratory Properties of the Lymphocytes Recirculating Through the Rat Spleen

PubMed Central

Ford, W. L.

1969-01-01

The great majority of the cells released by the isolated, perfused rat spleen were lymphocytes of which about 95 per cent were small lymphocytes. The rate of release of small lymphocytes from the spleen was independent of the prevailing concentration in the perfusate. The cells released by the spleen were immunologically competent in respect of a graft-versus-host reaction and a primary antibody response. They could also transfer secondary responsiveness to a viral antigen. Several spleen donors were given a continuous intravenous infusion of tritiated thymidine prior to spleen perfusion and the proportion of labelled small lymphocytes among the population released by the spleen was compared to the proportion in populations of small lymphocytes from other sources. The small lymphocytes released by the spleen recirculated from the blood to thoracic duct lymph after injection into a syngeneic recipient. Conversely the perfused spleen released thoracic duct small lymphocytes which had been given to the spleen donor 24 hr previously. It is therefore probable that a single population of recirculating small lymphocytes exists which migrates from the blood into both lymph-nodes and spleen. The release of small lymphocytes from the spleen was mostly at the expense of the lymphocyte content of the periarteriolar lymphoid sheaths. ImagesFigs. 8-9Figs. 4-5Fig. 10Figs. 6-7 PMID:5792901

Navier-Stokes analysis and experimental data comparison of compressible flow within ducts

NASA Technical Reports Server (NTRS)

Harloff, G. J.; Reichert, B. A.; Sirbaugh, J. R.; Wellborn, S. R.

1992-01-01

Many aircraft employ ducts with centerline curvature or changing cross-sectional shape to join the engine with inlet and exhaust components. S-ducts convey air to the engine compressor from the intake and often decelerate the flow to achieve an acceptable Mach number at the engine compressor by increasing the cross-sectional area downstream. Circular-to-rectangular transition ducts are used on aircraft with rectangular exhaust nozzles to connect the engine and nozzle. To achieve maximum engine performance, the ducts should minimize flow total pressure loss and total pressure distortion at the duct exit. Changes in the curvature of the duct centerline or the duct cross-sectional shape give rise to streamline curvature which causes cross stream pressure gradients. Secondary flows can be caused by deflection of the transverse vorticity component of the boundary layer. This vortex tilting results in counter-rotating vortices. Additionally, the adverse streamwise pressure gradient caused by increasing cross-sectional area can lead to flow separation. Vortex pairs have been observed in the exit planes of both duct types. These vortices are due to secondary flows induced by pressure gradients resulting from streamline curvature. Regions of low total pressure are produced when the vortices convect boundary layer fluid into the main flow. The purpose of the present study is to predict the measured flow field in a diffusing S-duct and a circular-to-rectangular transition duct with a full Navier-Stokes computer program, PARC3D, and to compare the numerical predictions with new detailed experimental measurements. The work was undertaken to extend previous studies and to provide additional CFD validation data needed to help model flows with strong secondary flow and boundary layer separation. The S-duct computation extends the study of Smith et al, and Harloff et al, which concluded that the computation might be improved by using a finer grid and more advanced turbulence models. The present study compares results for both the Baldwin-Lomas and k-epsilon turbulence models and is conducted with a refined grid. For the transition duct, two inlet conditions were considered, the first with straight flow and the second with swirling flow. The first case permits examination of the effects of the geometric transition on the flow field, while the second case includes the rotational flow effect characteristic of a gas turbine engine.

Resin duct characteristics in the wood of fire-scarred North American conifers

Treesearch

Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

2013-01-01

Traumatic resin ducts form in xylem and phloem tissue of conifers in response to abiotic wounding, fungal invasion, and insect attack. Little is known about resin duct characteristics in the wood of fire-scarred trees. The aim of this study is to quantify changes in traits of both axial and radial resin ducts, along with those of associated epithelial cells and...

HVAC; Heating, Ventilation, Air Conditioning - Aerosol Duct Sealant

DTIC Science & Technology

2016-09-01

material was applied. Annual energy and cost savings were predicted based on a typical weather year for each site. The installation of the duct...Balance reports; Visible dust streaks on duct work, ceilings near supply diffusers, or electrical boxes; Comfort complaints Specific Leakage...energy consumption , depending on the HVAC system type and the location of the ducts that were sealed. The cost effectiveness of the technology is

A possible approach to optimization of parameters of sound-absorbing structures for multimode waveguides

NASA Astrophysics Data System (ADS)

Mironov, M. A.

2011-11-01

A method of allowing for the spatial sound field structure in designing the sound-absorbing structures for turbojet aircraft engine ducts is proposed. The acoustic impedance of a duct should be chosen so as to prevent the reflection of the primary sound field, which is generated by the sound source in the absence of the duct, from the duct walls.

BMS-247550 in Treating Patients With Liver or Gallbladder Cancer

ClinicalTrials.gov

2014-05-13

Adult Primary Cholangiocellular Carcinoma; Adult Primary Hepatocellular Carcinoma; Advanced Adult Primary Liver Cancer; Cholangiocarcinoma of the Extrahepatic Bile Duct; Cholangiocarcinoma of the Gallbladder; Localized Extrahepatic Bile Duct Cancer; Localized Gallbladder Cancer; Localized Resectable Adult Primary Liver Cancer; Localized Unresectable Adult Primary Liver Cancer; Recurrent Adult Primary Liver Cancer; Recurrent Extrahepatic Bile Duct Cancer; Recurrent Gallbladder Cancer; Unresectable Extrahepatic Bile Duct Cancer; Unresectable Gallbladder Cancer

Cooling air recycling for gas turbine transition duct end frame and related method

DOEpatents

Cromer, Robert Harold; Bechtel, William Theodore; Sutcu, Maz

2002-01-01

A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

Ponderosa pine resin defenses and growth: metrics matter.

PubMed

Hood, Sharon; Sala, Anna

2015-11-01

Bark beetles (Coleoptera: Curculionidae, Scolytinae) cause widespread tree mortality in coniferous forests worldwide. Constitutive and induced host defenses are important factors in an individual tree's ability to survive an attack and in bottom-up regulation of bark beetle population dynamics, yet quantifying defense levels is often difficult. For example, in Pinus spp., resin flow is important for resistance to bark beetles but is extremely variable among individuals and within a season. While resin is produced and stored in resin ducts, the specific resin duct metrics that best correlate with resin flow remain unclear. The ability and timing of some pine species to produce induced resin is also not well understood. We investigated (i) the relationships between ponderosa pine (Pinus ponderosa Lawson & C. Lawson) resin flow and axial resin duct characteristics, tree growth and physiological variables, and (ii) if mechanical wounding induces ponderosa pine resin flow and resin ducts in the absence of bark beetles. Resin flow increased later in the growing season under moderate water stress and was highest in faster growing trees. The best predictors of resin flow were nonstandardized measures of resin ducts, resin duct size and total resin duct area, both of which increased with tree growth. However, while faster growing trees tended to produce more resin, models of resin flow using only tree growth were not statistically significant. Further, the standardized measures of resin ducts, density and duct area relative to xylem area, decreased with tree growth rate, indicating that slower growing trees invested more in resin duct defenses per unit area of radial growth, despite a tendency to produce less resin overall. We also found that mechanical wounding induced ponderosa pine defenses, but this response was slow. Resin flow increased after 28 days, and resin duct production did not increase until the following year. These slow induced responses may allow unsuccessfully attacked or wounded trees to resist future bark beetle attacks. Forest management that encourages healthy, vigorously growing trees will also favor larger resin ducts, thereby conferring increased constitutive resistance to bark beetle attacks. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular characteristics and alterations during early development of the human vagina

PubMed Central

Fritsch, Helga; Richter, Elisabeth; Adam, Nadia

2012-01-01

Unresolved questions remain concerning the derivation of the vagina with respect to the relative contributions from the Müllerian ducts, the urogenital sinus, and the Wolffian ducts. Recent molecular and cellular studies in rodents have opened up a large gap between the level of understanding of vaginal development in mice and understanding of human vaginal development, which is based on histology. To compare the findings in mice with human vaginal development and to address this gap, we analysed molecular characteristics of the urogenital sinus, Wolffian ducts, and Müllerian ducts in 8–14-week-old human specimens using immunohistochemical methods. The monoclonal antibodies used were directed against cytokeratin (CK) 14, CK19, vimentin, laminin, p63, E-cadherin, caspase-3, Ki67, HOX A13, and BMP-4. The immunohistochemical analysis revealed that, during weeks 8–9, the epithelium of the Müllerian ducts became positive for p63 as p63-positive cells that originated from the sinus epithelium reached the caudal tip of the fused Müllerian ducts via the Wolffian ducts. The lumen of the fused Müllerian ducts was closed by an epithelial plug that contained both vimentin-positive and vimentin-negative cells. Subsequently, the resulting epithelial tube enlarged by proliferation of basal p63-positive cells. The first signs of squamous differentiation were detected during week 14, with the appearance of CK14-positive cells. According to our results, all three components, namely, the urogenital sinus, Wolffian ducts, and Müllerian ducts, interacted during the formation of the human vagina. The sinus epithelium provided p63-positive cells, the Wollfian ducts acted as a ‘transporter’, and the Müllerian ducts contributed the guiding structure for the vaginal anlagen. Epithelial differentiation began at the end of the period studied and extended in a caudo-cranial direction. The present study is one of the first to provide up-to-date molecular correlates for human vaginal development that can be compared with the results of cell biological studies in rodents. PMID:22256858

Passive noise control by enhancing aeroacoustic interference due to structural discontinuities in close proximity

NASA Astrophysics Data System (ADS)

Leung, R. C. K.; So, R. M. C.; Tang, S. K.; Wang, X. Q.

2011-07-01

In-duct devices are commonly installed in flow ducts for various flow management purposes. The structural construction of these devices indispensably creates disruption to smooth flow through duct passages so they exist as structural discontinuities in duct flow. The presence of these discontinuities provides additional possibility of noise generation. In real practice, in-duct devices do not exist alone in any duct system. Even though each in-duct device would generate its own noise, it might be possible that these devices could be properly arranged so as to strengthen the interference between individual noise; thus giving rise to an overall reduction of noise radiation in the in-duct far field. This concept of passive noise control is investigated by considering different configurations of two structural discontinuities of simple form (i.e., a cavity) in tandem in an unconfined flow and in opposing setting within a flow duct. It is known that noise generated by a cavity in unconfined domain (unconfined cavity) is strongly dependent on flow-resonant behavior within the cavity so the interference it produces is merely aeroacoustic. The objective of the present study is to verify the concept of passive noise reduction through enhancement of aeroacoustic interference due to two cavities by considering laminar flow only. A two-dimensional approach is adopted for the direct aeroacoustic calculations using a direct numerical simulation (DNS) technique. The position and geometries of the cavities and the Mach number are varied; the resultant aeroacoustic behavior and acoustic power are calculated. The numerical results are compared with a single cavity case to highlight the effect of introducing additional cavities to the aeroacoustic problem. Resonant flow oscillations occur when two unconfined cavities are very close and the associated acoustic field is very intense with no noise reduction possible. However, for duct aeroacoustics, it is found that a 7.9 db reduction of acoustic power in the downstream side of the duct or a total reduction of ˜6 db is possible with opposing cavities having an offset of half a cavity length. In addition, the reduction is shown to be free from lock-on with trapped modes of the ducts with cavities.

Development of an Experimental Rig for Investigation of Higher Order Modes in Ducts

NASA Technical Reports Server (NTRS)

Gerhold, Carl H.; Cabell, Randolph H.; Brown, Martha C.

2006-01-01

Continued progress to reduce fan noise emission from high bypass ratio engine ducts in aircraft increasingly relies on accurate description of the sound propagation in the duct. A project has been undertaken at NASA Langley Research Center to investigate the propagation of higher order modes in ducts with flow. This is a two-pronged approach, including development of analytic models (the subject of a separate paper) and installation of a laboratory-quality test rig. The purposes of the rig are to validate the analytical models and to evaluate novel duct acoustic liner concepts, both passive and active. The dimensions of the experimental rig test section scale to between 25% and 50% of the aft bypass ducts of most modern engines. The duct is of rectangular cross section so as to provide flexibility to design and fabricate test duct liner samples. The test section can accommodate flow paths that are straight through or offset from inlet to discharge, the latter design allowing investigation of the effect of curvature on sound propagation and duct liner performance. The maximum air flow rate through the duct is Mach 0.3. Sound in the duct is generated by an array of 16 high-intensity acoustic drivers. The signals to the loudspeaker array are generated by a multi-input/multi-output feedforward control system that has been developed for this project. The sound is sampled by arrays of flush-mounted microphones and a modal decomposition is performed at the frequency of sound generation. The data acquisition system consists of two arrays of flush-mounted microphones, one upstream of the test section and one downstream. The data are used to determine parameters such as the overall insertion loss of the test section treatment as well as the effect of the treatment on a modal basis such as mode scattering. The methodology used for modal decomposition is described, as is a description of the mode generation control system. Data are presented which demonstrate the performance of the controller to generate the desired mode while suppressing all other cut on modes in the duct.

Flow in out-of-plane double S-bonds

NASA Technical Reports Server (NTRS)

Schmidt, M. C.; Whitelaw, J. H.; Yianneskis, M.

1986-01-01

Developing flows in two out-of-plane double S-bend configurations have been measured by laser-Doppler anemometry. The first duct had a rectangular cross-section 40mmx40mm at the inlet and consisted of a uniform area 22.5 deg. - 22.5 deg. S-duct upstream with a 22.5 deg.- 22.5 deg. S- diffuser downstream. The second duct had a circular cross-section and consisted of a 45 deg. - 45 deg. uniform area S-duct upstream with a 22.5 deg. -22.5 deg. S-diffuser downstream. In both configurations the ratio of the mean radius of curvature to the inlet hydraulic diameter was 7.0, the exit-to-inlet area ratio of the diffusers was 1.5 and the ducts were connected so that the centerline of the S-duct lay in a plane normal to that of the S-diffuser. Streamwise and cross-stream velocity components were measured in laminar flow for the rectangular duct and in turbulent flow for both configurations; measurements of the turbulence levels, cross-correlations and wall static pressures were also made in the turbulent flow cases. Secondary flows of the first kind are present in the first S-duct and they are complemented or counteracted by the secondary flows generated by the area expansion and by the curvature of the S-diffusers downstream. Cross-stream velocities with magnitudes up to 0.19 and 0.11 of the bulk velocity were measured in the laminar and turbulent flows respectively in the rectangular duct and six cross-flow vortices were evident at the exit of the duct in both flow cases. The turbulent flow in the circular duct was qualitatively similar to that in the rectangular configuration, but the cross-stream velocities measured at the exit plane were smaller in the circular geometry. The results are presented in sufficient detail and accuracy for the assessment of numerical calculation methods and are listed in tabular form for this purpose.

[Analysis of clinical prognosis and the correlation between bile duct injury after transcatheter arterial chemoembolization and the level of hepatic arterial embolization in patients with hepatocellular carcinoma].

PubMed

Xu, H Y; Yu, X P; Feng, R; Hu, H J; Xiao, W W

2017-05-23

Objective: To evaluate the correlation between bile duct injury after transcatheter arterial chemoembolization and the level of hepatic arterial embolization, and to analyze the clinical prognosis of hepatocellular carcinoma patients. Methods: From January18, 2012 to December18, 2014, 21 patients underwent TACE for HCC were retrospectively reviewed, including patients' clinical and pathological data. The clinical outcome and relevant factors for bile duct injury were analyzed. Results: A total of 21 patients were identified with bile duct injury at our single institution. All patients received 48 TACE treatments, including proper hepatic artery (14), left hepatic artery (3), the right hepatic artery (10), left and right hepatic artery (9) and tumor artery branches (12). Thirty-five bile duct injury occurred in 21 patients: 7 cases was close to the tumor, 2 distant to the tumor, 7 at right liver, 2 left liver, 11 both lobes of liver and 6 hepatic hilar. After medical conservative treatment and biliary tract inside and outside drainage, liver function of 10 cases were improved. In four patients with hepatic bile duct stricture and biloma, the effect of drainage was not obvious, which subsequently caused biliary complications such as infection, gallbladder and common bile duct stones. Three patients with liver cirrhosis at decompensation stage developed complications, and one of them died of hepatic encephalopathy. Four patients experienced tumor recurrence during the follow-up period. Conclusions: The location of bile duct injury after transcatheter arterial chemoembolization is quite consistent with the level of hepatic arterial embolization. There may be some blood vessels mainly involved in blood supply of biliary duct. Complete embolism of these vessels may lead to bile duct injuries. Biliary drainage is ineffective in patients with hilar bile duct stricture, and can lead to complications of biliary tract later on.

Effect of Right Posterior Bile Duct Anatomy on Biliary Complications in Patients Undergoing Right Lobe Living Donor Liver Transplant.

PubMed

Tezcaner, Tugan; Dinç, Nadire; Y Karakayalı, Feza; Kırnap, Mahir; Coşkun, Mehmet; Moray, Gökhan; Haberal, Mehmet

2017-01-27

Our aim was to evaluate the influence of the localization of right posterior bile duct anatomy relative to portal vein of the donors on posttransplant bile duct complications. We retrospectively investigated 141 patients who had undergone living donor liver transplant using right hemiliver grafts. The patients were classified based on the pattern of the right posterior bile duct and divided into infraportal and supraportal types. Clinical donor and recipient risk factors and surgical outcomes were compared for their relationship with biliary complications using logistic regression analyses. The 2 groups were similar according to demographic and clinical features. The biliary complication rate was 23.7% (9/38) in the infraportal group and 47.4% (37/78) in the supraportal group (P = .014). An analysis of risk factors for the development of anastomotic bile leak using logistic regression showed that a supraportal right posterior bile duct anatomy was a statistically significant positive predictor, with odds ratio of 18.905 (P = .012; confidence interval, 1.922-185.967). The distance of the right posterior bile duct from confluence was significantly lower in patients with biliary complications than in those without (mean of 7.66 vs 0.40 mm; P = .044). According to receiver operating characteristic analyses, the cut-off point for the length of right bile duct to right posterior bile duct from the hepatic confluence was 9.5 mm regarding presence of complications. Factors influencing bile duct anastomosis leakage were supraportal-type donor bile duct anatomy and length of the right main bile duct from biliary confluence. Hepatic arterial complications were similarly a risk factor for biliary strictures. Because of the multiple factors leading to complications in living donor liver transplant, it is challenging to group these patients by operative risk; however, establishing risk models may facilitate the prediction of complications.

Silver zeolite antimicrobial activity in aluminium heating, ventilation and air conditioning system ducts.

PubMed

Rizzetto, R; Mansi, A; Panatto, D; Rizzitelli, E; Tinteri, C; Sasso, T; Gasparini, R; Crovari, P

2008-03-01

Air pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of air-conditioning systems in many public and private buildings aggravates this health risk, especially when these systems are not correctly installed or regularly serviced. The aim of our study was to verify the capacity of Ag+ ions to stop the growth of bacteria and moulds inside the ducts of Heating, Ventilation and Air Conditioning system ducts (HVAC) systems when these ducts were lined with active Ag+ ions zeolite-coated panels. A Y-shaped HVAC model with two branches was used; one branch was made of traditional galvanized iron, as was the whole system, while the other was lined with active Ag+ zeolite-coated polyurethane panels. During the test, samples of dust present inside both ducts were collected and seeded in liquid and solid media to detect bacteria and moulds. The presence of bacteria was also sought in the air emerging from the outlets of both ducts. Tests made on samples of particulate collected from the two different ducts revealed a lower total bacterial load in the samples collected from the Ag+ zeolite-coated duct than in the samples from the traditional Zn galvanized duct. In addition, the values of bacterial load found in the air emerging from the Ag+ ions zeolite-lined duct were 5 times lower than those found in the air from the traditional galvanized iron duct. The utilization of Ag+ zeolite-coated panels in air-conditioning systems could improve the quality of the emerging air in comparison with traditional installations in galvanized iron. This innovation could prove particularly advantageous in the event of accidents during the installation of air-conditioning systems or of contaminated aerosols coming from outside.

Biopsy - biliary tract

MedlinePlus

... be due to: Cancer of the bile ducts ( cholangiocarcinoma ) Cysts in the liver Liver cancer Pancreatic cancer ... and the A.D.A.M. Editorial team. Bile Duct Cancer Read more Bile Duct Diseases Read more Biopsy ...

Waves in Space Plasmas (WISP)

NASA Technical Reports Server (NTRS)

Calvert, Wynne

1994-01-01

Activities under this project have included participation in the Waves in Space Plasmas (WISP) program, a study of the data processing requirements for WISP, and theoretical studies of radio sounding, ducting, and magnetoionic theory. An analysis of radio sounding in the magnetosphere was prepared.

Pyramidal lobe of the thyroid gland and the thyroglossal duct remnant: a study using human fetal sections.

PubMed

Takanashi, Yoshitaka; Honkura, Yohei; Rodriguez-Vazquez, Jose Francisco; Murakami, Gen; Kawase, Tetsuaki; Katori, Yukio

2015-01-01

To investigate developmental changes in the thyroglossal duct, we observed serial sagittal sections of eight embryos (crown-rump length (CRL) 6-12 mm; approximately 5-6 weeks of gestation) as well as serial horizontal or cross-sections of 70 embryos and fetuses (CRL 15-110 mm; 6-15 weeks). In the sagittal sections, the thyroglossal duct was identified as a small sheet or mass of relatively large cells with vacuolization anterior, superior or inferior to the fourth pharyngeal arch artery. However, we found no continuous duct-like structure that reached the thyroid gland. Thus, previous classical schemes might have overestimated the continuity of the duct. Among cross-sections of 70 specimens, we found the thyroglossal duct remnant in only two specimens (CRL 15 mm and 100 mm), in contrast to the pyramidal lobe, which was seen in one-third of the specimens. The duct remnant ran downward along the lateral edge of the hyoid body to reach the anterior aspect of the thyroid cartilage. However, the connection between the pyramidal lobe and the duct remnant was interrupted by the anterior cervical muscles. Therefore, it was unlikely that the thyroglossal duct remnant would more frequently be evident in fetuses than in adults. The highly tortuous course of the duct along the lingual aspect of the hyoid body, which has been reported previously, appeared to become established near term. Descent of the thyroid gland was not evident after the CRL 20 mm stage (6 weeks): the gland appeared to retain its position at the level of the third-sixth cervical vertebrae. Copyright © 2014 Elsevier GmbH. All rights reserved.

Clinical presentations and outcomes of bile duct loss caused by drugs and herbal and dietary supplements.

PubMed

Bonkovsky, Herbert L; Kleiner, David E; Gu, Jiezhun; Odin, Joseph A; Russo, Mark W; Navarro, Victor M; Fontana, Robert J; Ghabril, Marwan S; Barnhart, Huiman; Hoofnagle, Jay H

2017-04-01

Bile duct loss during the course of drug-induced liver injury is uncommon, but can be an indication of vanishing bile duct syndrome (VBDS). In this work, we assess the frequency, causes, clinical features, and outcomes of cases of drug-induced liver injury with histologically proven bile duct loss. All cases of drug-induced liver injury enrolled into a prospective database over a 10-year period that had undergone liver biopsies (n = 363) were scored for the presence of bile duct loss and assessed for clinical and laboratory features, causes, and outcomes. Twenty-six of the 363 patients (7%) with drug-, herbal-, or dietary-supplement-associated liver injury had bile duct loss on liver biopsy, which was moderate to severe (<50% of portal areas with bile ducts) in 14 and mild (50%-75%) in 12. The presenting clinical features of the 26 cases varied, but the most common clinical pattern was a severe cholestatic hepatitis. The implicated agents included amoxicillin/clavulanate (n = 3), temozolomide (n = 3), various herbal products (n = 3), azithromycin (n = 2), and 15 other medications or dietary supplements. Compared to those without, those with bile duct loss were more likely to develop chronic liver injury (94% vs. 47%), which was usually cholestatic and sometimes severe. Five patients died and 2 others underwent liver transplantation for progressive cholestasis despite treatment with corticosteroids and ursodiol. The most predictive factor of poor outcome was the degree of bile duct loss on liver biopsy. Bile duct loss during acute cholestatic hepatitis is an ominous early indicator of possible VBDS, for which at present there are no known means of prevention or therapy. (Hepatology 2017;65:1267-1277). © 2016 by the American Association for the Study of Liver Diseases.

T-EUS for Gastrointestinal Disorders: A Multicenter Registry

ClinicalTrials.gov

2017-02-16

Cholangiocarcinoma; Pancreatic Cancer; Bile Duct Cancer; Biliary Stricture; Biliary Obstruction; Stent Obstruction; Proximal Duct Stricture; Distal Duct Stricture; Ampullary Cancer; Biliary Sphincter Stenosis; Impacted Stones; Chronic Pancreatitis; Peri-ampullary Diverticula; Altered Anatomy

Bile Duct Cancer

MedlinePlus

... the liver get rid of toxins and wastes. Bile duct cancer is rare. It can happen in the parts ... Itchy skin Fever Abdominal pain Tests to diagnose bile duct cancer may include a physical exam, imaging tests of ...

Heat Transfer in Conical Corner and Short Superelliptical Transition Ducts

NASA Technical Reports Server (NTRS)

Poinsatte, Philip; Thurman, Douglas; Hippensteele, Steven

2008-01-01

Local surface heat transfer measurements were experimentally mapped using a transient liquid-crystal heat-transfer technique on the surface of two circular-to-rectangular transition ducts. One has a transition cross section defined by conical corners (Duct 1) and the other by an elliptical equation with changing coefficients (Duct 2). Duct 1 has a length-to-diameter ratio of 0.75 and an exit plane aspect ratio of 1.5. Duct 2 has a length-to-diameter ratio of 1.0 and an exit plane aspect ratio of 2.9. Test results are reported for various inlet-diameter-based Reynolds numbers ranging from 0.45 106 to 2.39 106 and two freestream turbulence intensities of about 1 percent, which is typical of wind tunnels, and up to 16 percent, which may be more typical of real engine conditions.

Evaluation of several non-reflecting computational boundary conditions for duct acoustics

NASA Technical Reports Server (NTRS)

Watson, Willie R.; Zorumski, William E.; Hodge, Steve L.

1994-01-01

Several non-reflecting computational boundary conditions that meet certain criteria and have potential applications to duct acoustics are evaluated for their effectiveness. The same interior solution scheme, grid, and order of approximation are used to evaluate each condition. Sparse matrix solution techniques are applied to solve the matrix equation resulting from the discretization. Modal series solutions for the sound attenuation in an infinite duct are used to evaluate the accuracy of each non-reflecting boundary conditions. The evaluations are performed for sound propagation in a softwall duct, for several sources, sound frequencies, and duct lengths. It is shown that a recently developed nonlocal boundary condition leads to sound attenuation predictions considerably more accurate for short ducts. This leads to a substantial reduction in the number of grid points when compared to other non-reflecting conditions.

Accuracy of percutaneous transhepatic cholangiography in predicting the location and nature of major bile duct injuries.

PubMed

Fidelman, Nicholas; Kerlan, Robert K; Laberge, Jeanne M; Gordon, Roy L

2011-06-01

To determine the ability of percutaneous transhepatic cholangiography (PTC) to predict accurately the anatomic location and nature of major bile duct injuries, to examine the contribution of endoscopic retrograde cholangiopancreatography (ERCP) and PTC to the diagnosis of injuries to the low-inserting right posterior segmental ducts, and to compare the ability of radiologists and gastroenterologists to detect injuries to the low-inserting right posterior segmental duct. PTC images and operative reports of 78 consecutive patients who underwent surgical repair of major bile duct injuries at the authors' institution were retrospectively reviewed. The location of injury was assessed according to the Bismuth classification. Images were also evaluated for the presence of a biliary stricture, biliary leak, or both. Imaging observations were compared with findings obtained during surgical biliary reconstruction. PTC correctly predicted the anatomic location of injuries in 85% of patients. Incorrect Bismuth type was assigned in 12 patients. Seven of the errors (58%) originated from the inability to distinguish injuries at the confluence of the lobar ducts from injuries involving the cephalad 2 cm of the common hepatic duct. Injuries to the right posterior segmental duct were detected more often on ERCP images by gastroenterologists than by diagnostic radiologists. In four patients (5%), biliary strictures were masked on PTC by the presence of a concomitant leak. PTC accurately depicts the location and nature of major bile duct injuries in most patients. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

Use of a vessel sealant device for cystic duct ligation in the dog.

PubMed

Marvel, Sarah; Monnet, Eric

2014-11-01

To compare a vessel sealant device to hemostatic clips for cystic duct ligation in a canine cadaveric model. Experimental. Hepatobiliary systems were collected from normal dogs. A microtip pressure transducer was inserted into the common bile duct and a 20-24 g intravenous catheter was placed in a hepatic duct. The cystic duct was ligated with 1 of 3 techniques: vessel sealant device (VSD), 10 mm medium Endoclips™, or 10 mm large Endoclips™ with 6 specimens in each group. Methylene blue was infused until failure, which was recorded as seal/clip failure or retrograde movement of methylene blue into the liver. Mean failure pressure of the medium endoclip group was significantly lower than the large endoclip group (P = .014). There was no difference between the failure pressure of the VSD group and the medium and large endoclip groups (P = .097, P = .34, respectively). Failure by leakage at the cut surface of the cystic duct occurred in 2 specimens in the medium endoclip group while all others failed by retrograde flow of the methylene blue through the hepatic ducts. The vessel sealant device appears comparable to large endoclips for closure of the cystic duct in an acute cadaveric model, while medium endoclips may not fully compress or span the diameter of a cystic duct in large breed dogs and leak at lower pressures. © Copyright 2014 by The American College of Veterinary Surgeons.