Roll-Out and Turn-Off Display Software for Integrated Display System

NASA Technical Reports Server (NTRS)

Johnson, Edward J., Jr.; Hyer, Paul V.

1999-01-01

This report describes the software products, system architectures and operational procedures developed by Lockheed-Martin in support of the Roll-Out and Turn-Off (ROTO) sub-element of the Low Visibility Landing and Surface Operations (LVLASO) program at the NASA Langley Research Center. The ROTO portion of this program focuses on developing technologies that aid pilots in the task of managing the deceleration of an aircraft to a pre-selected exit taxiway. This report focuses on software that produces a system of redundant deceleration cues for a pilot during the landing roll-out, and presents these cues on a head up display (HUD). The software also produces symbology for aircraft operational phases involving cruise flight, approach, takeoff, and go-around. The algorithms and data sources used to compute the deceleration guidance and generate the displays are discussed. Examples of the display formats and symbology options are presented. Logic diagrams describing the design of the ROTO software module are also given.

[Surgical treatment of intraoperative injuries and cicatricial strictures of extrahepatic bile ducts].

PubMed

Tret'iakov, A A; Slepykh, N I; Kornilov, A K; Karimov, Z Kh

1998-01-01

The analysis of 70 cases of surgical treatment for intraoperative injuries and cicatricial strictures of extrahepatic bile ducts was carried out. In 25 patients surgical procedure was restorative and in 45--reconstructiver. Most common causes of corrective operations were: iatrogenic injuries of extrahepatic bile ducts (14) and cicatricial strictures of hepaticocholedochal duct due to intraoperative trauma (31). The problems of operative technique in performing biliobilio-, hepato-hepatico and hepatico-jejuno-anastomoses are considered. There were three deaths in the early postoperative period: 2 patients died of hepatic failure, pyogenic cholangiogenic intoxication caused by cholangioectasies and intrahepatic abscesses, and 1-due to generalyzed peritonitis caused by acute gastric ulcer perforation. Special attention is paid to the choice of the method of prolonged drainage used in reconstructive as well as in restorative operations.

["Cholethorax" revealing injury to the common bile duct after celioscopic cholecystectomy].

PubMed

Lehur, P A; Guiberteau-Canfrère, V; Bury, A; Cloarec, D; Le Borgne, J

1992-01-01

The case-report describes the unusual formation of a bilious pleural effusion or "cholethorax" revealing a common bile duct injury secondary to laparoscopic cholecystectomy. Pleural drainage led to a diagnostic ERCP. Subsequently a Roux en Y hepatico-jejunostomy allowed a satisfactory outcome.

[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.

[Reconstructive surgery in iatrogenic bile duct injuries].

PubMed

Krawczyk, M; Kania, M; Zieniewicz, K; Nyckowski, P; Patkowski, W; Karwowski, A

1997-01-01

The paper presents the results of surgical treatment performed in 54 patients with iatrogenic injury of biliary tract. All cases of injury were made during open and laparoscopic cholecystectomy. We concluded that Roux-en-Y hepatico-jejunostomy should be recommended. There were no deaths after surgery. This technic was successful therapeutic management more than 95% of cases.

Asymptomatic T-tube remnant in common bile duct.

PubMed

Rozario, A; Thomas, P G; Pais, A; Ravindra, K V; Rao, V

1999-01-01

A 46-year-old lady presented with itching, five years after a primary common bile duct repair following cholecystectomy. Prior to this she underwent an interno-external biliary drainage. At laparotomy the horizontal limb of a T-tube was found in the common hepatic duct. Eleven months after a Roux loop hepatico-jejunostomy she is asymptomatic.

Inadvertent choledochotomy during Frey's procedure: management options.

PubMed

D'Cruz, Kenneth; Angamuthu, Natarajan; Anand, J

2003-01-01

We report the occurrence of inadvertent injury to the intra-pancreatic common bile duct in 3 of 9 patients undergoing Frey's procedure for chronic pancreatitis with inflammatory mass in the head. In one case, the choledochotomy was extended and anastomosed to the cored-out parenchyma. In the other two, after lateral pancreatico-jejunostomy, hepatico-jejunostomy was performed using the same Roux loop.

Broken Bones (For Parents)

MedlinePlus

... Safe Videos for Educators Search English Español Broken Bones KidsHealth / For Parents / Broken Bones Print en español Huesos rotos What Is a Broken Bone? A broken bone, also called a fracture, is ...

Excluded segmental duct bile leakage: the case for bilio-enteric anastomosis.

PubMed

Patrono, Damiano; Tandoi, Francesco; Romagnoli, Renato; Salizzoni, Mauro

2014-06-01

Excluded segmental duct bile leak is the rarest type of post-hepatectomy bile leak and presents unique diagnostic and management features. Classical management strategies invariably entail a significant loss of functioning hepatic parenchyma. The aim of this study is to report a new liver-sparing technique to handle excluded segmental duct bile leakage. Two cases of excluded segmental duct bile leak occurring after major hepatic resection were managed by a Roux-en-Y hepatico-jejunostomy on the excluded segmental duct, avoiding the sacrifice of the liver parenchyma origin of the fistula. In both cases, classical management strategies would have led to the functional loss of roughly 50 % of the liver remnant. Diagnostic and management implications are thoroughly discussed. Both cases had an uneventful postoperative course. The timing of repair was associated with a different outcome: the patient who underwent surgical repair in the acute phase developed no long-term complications, whereas the patient who underwent delayed repair developed a late stenosis requiring percutaneous dilatation. Roux-en-Y hepatico-jejunostomy on the excluded bile duct is a valuable technique in selected cases of excluded segmental duct bile leakage.

Arterialised hepatic nodules in the Fontan circulation: hepatico-cardiac interactions.

PubMed

Bryant, Timothy; Ahmad, Zaheer; Millward-Sadler, Harry; Burney, Kashif; Stedman, Brian; Kendall, Tim; Vettukattil, Joseph; Haw, Marcus; Salmon, Anthony P; Cope, Richard; Hacking, Nigel; Breen, David; Sheron, Nick; Veldtman, Gruschen R

2011-09-15

Hypervascular nodules occur commonly when there is hepatic venous outlet obstruction. Their nature and determinants in the Fontan circulation is poorly understood. We reviewed the records of 27 consecutive Fontan patients who had computerized tomography scan (CT) over a 4 year period for arterialised nodules and alterations in hepatic flow patterns during contrast enhanced CT scans and related these findings to cardiac characteristics. Mean patient age was 24 ± 5.8 years, (range 16.7-39.8) and mean Fontan duration was 16.8 ± 4.8 years (range 7.3-28.7). Twenty-two patients demonstrated a reticular pattern of enhancement, 4 a zonal pattern and only 1 demonstrated normal enhancement pattern. Seven (26%) patients had a median of 4 (range 1-22) arterialised nodules, mean size 1.8 cm (range 0.5 to 3.2 cm). All nodules were located in the liver periphery, their outer aspect lying within 2 cm of the liver margin. Patients with nodules had higher mean RA pressures (18 mmHg ± 5.6 vs. 13 mmHg ± 4, p=0.025), whereas their mixed venous saturation and aortic saturation was not significantly different (70% ± 11 vs. 67% ± 9 and 92% ± 10 vs. 94% ± 4, p>0.05). Post-mortem histology suggests focal nodular hyperplasia is the underlying pathology. ConclusionsAbnormalities of hepatic blood flow and the presence of arterialised nodules are common in the failing Fontan circulation. They occur especially when central venous pressures are high, and very likely indicate arterialisation of hepatic blood flow and reciprocal portal venous deprivation. The underlying pathology is most likely focal nodular hyperplasia. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

On the roto-translatory internal motions of a three layer non-isobarycentric Earth model: a Lagrangian system approach

NASA Astrophysics Data System (ADS)

Escapa, Alberto; Fukushima, Toshio

2010-05-01

of this relative motion, three characteristic proper modes appear: one in the direction of the figure axis (polar mode) and two orthogonal to it (equatorial modes). These modes are usually referred as Slichter triplet. In the case of the polar mode, Busse (1974) determined analytically its expression in an implicit way; later other authors have obtained by numerical methods the values of all the modes (e.g Rieutord 2002). These expressions differ substantially from the single degenerate mode existing for a non-rotating model, the differences arising from the roto-traslatory coupling of the system. To construct an analytical description of the motion of this non-isobarycentric Earth model we have approximated it by a Lagrangian system, inspired in the successful of this variational approach to tackle the rotational dynamics of isobarycentric Earth models (e.g. Moritz 1982, Getino and Ferrándiz 2001). In this way, the fluid flow is represented as the sum of a rigid motion part plus a potential motion part. In this way, the resulting dynamical system is described by means of nine generalized co-ordinates. Once constructed the kinetic energy of each layer of the Earth model and the potential energy due to the gravitational interaction of the spherical rigid inner core with the fluid, we form the Euler-Lagrange equations of the system which turn out to be non-linear. By assuming a small departure with respect to the steady rotation configuration we linearice the differential equations of the motion, deriving from them the analytical expressions of the Slichter triplet. These expressions are compared with the existing numerical ones, appearing some discrepancies between both approaches. They might be caused by neglecting the non-linear terms in the resolution of the equations or by an incomplete description of the fluid flow. However, the numerical values of the modes derived with this treatment show a great improvement with respect to the values obtained from performing

[The surgical correction of iatrogenic damage to and cicatricial stricture of the extrahepatic bile ducts].

PubMed

Vecherko, V N; Konoplia, P P; Shatalov, V F; Khatsko, V V; Shatalov, A D

1993-01-01

In treatment of 86 patients with a iatrogenic injury, or cicatricial stricture of the extrahepatic bile ducts, the Prader-Smith, Saypole-Kurian transhepatic drainage of hepatico-digestive anastomosis and that with the use of the method suggested by the authors have been used. The technique for performance of the operations is described, the special instruments are offered. After the operation, only one female patient has developed a subphrenic abscess.

POLYETHYLENE ENCAPSULATES FOR HAZARDOUS WASTE DRUMS

EPA Science Inventory

This capsule report summarizes studies of the use of polyethylene (P.E.) for encapsulating drums of hazardous wastes. Flat PE sheet is welded to roto moded PE containers which forms the encapsulates. Plastic pipe welding art was used, but the prototype welding apparatus required ...

Something of Value: How Franchise Sellers Make Training Pay

ERIC Educational Resources Information Center

Berger, Gladys

1975-01-01

Training can be the most important benefit included in the purchase of a franchise. Several of these training programs used by franchise sellers (Castro Convertibles, Roto-Rooter, H and R Block, Dunhill Personnel Systems Inc., Carvel, Holiday Inns, Sheraton Inns Inc., McDonald's) are discussed. (Author/BP)

Collective Properties of Neural Systems and Their Relation to Other Physical Models

DTIC Science & Technology

1988-08-05

been computed explicitly. This has been achieved algorithmically by utilizing methods introduced earlier. It should be emphasized that in addition to...Research Institute for Mathematical Sciences. K’oto Universin. K roto 606. .apan and E. BAROUCH Department of Mathematics and Computer Sciene. Clarkon...Mathematics and Computer Science, Clarkson University, where this work was collaborated. References I. IBabu, S. V. and Barouch E., An exact soIlution for the

Novel portable press for synchrotron time-resolved 3-D micro-imagining under extreme conditions

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

Philippe, J.; Le Godec, Y., E-mail: yann.legodec@impmc.upmc.fr; Bergame, F.

Here we present the instrumental development to extend the synchrotron X-ray microtomography techniques to in situ studies under static compression (HP) or shear stress or the both conditions at high temperatures (HT). To achieve this, a new rotating tomography Paris-Edinburgh cell (rotoPEc) has been developed. This ultra-compact portable device, easily and successfully adapted to various multi-modal synchrotron experimental set-up at ESRF, SOLEIL and DIAMOND is explained in detail.

The Effectiveness of Power Tool Cleaning as an Alternative to Abrasive Blasting

DTIC Science & Technology

1995-06-01

Lamar Avenue Houston, TX 77251 3M Building Service and Cleaning Products Division Building 223-65-03 St. Paul, MN 55144-1000 Marindus Company P. O...Mill Scale Removal with 3M Brand Heavy Duty RotoPeen Flap Wheel”;”Scotch-Brite” Surface Conditioning Products, 3M Building Service and Cleaning ... Products Division. 18. “The Dilemma of Removing Lead-Based Paint,” January 1988, p. 34-35. Specifications: ASTM TEST METHODS: B1 17, Salt Spray (Fog

Speed Profiles for Deceleration Guidance During Rollout and Turnoff (ROTO)

NASA Technical Reports Server (NTRS)

Barker, L. Keith; Hankins, Walter W., III; Hueschen, Richard M.

1999-01-01

Two NASA goals are to enhance airport safety and to improve capacity in all weather conditions. This paper contributes to these goals by examining speed guidance profiles to aid a pilot in decelerating along the runway to an exit. A speed profile essentially tells the pilot what the airplane's speed should be as a function of where the airplane is on the runway. While it is important to get off the runway as soon as possible (when striving to minimize runway occupancy time), the deceleration along a speed profile should be constrained by passenger comfort. Several speed profiles are examined with respect to their maximum decelerations and times to reach exit speed. One profile varies speed linearly with distance; another has constant deceleration; and two related nonlinear profiles delay maximum deceleration (braking) to reduce time spent on the runway.

Ischemic mass effect from biliary surgical clips.

PubMed

Mateo, Rod; Tsai, Steven; Stapfer, Maria V; Sher, Linda S; Selby, Rick; Genyk, Yuri S

2008-02-01

Migrating surgical clips in the hepatic hilum are known causes of biliary stricture or obstruction, most often due to direct intraluminal obstruction or secondary stone formation. Two cases are reported on patients with previous cholecystectomies presenting with delayed symptoms of biliary tract stricture. Both patients were successfully treated with a resection of the strictured area and a Roux-en-Y hepatico-jejunostomy. Resected specimens grossly demonstrated surgical clips adjacent to the stricture, but not directly within the lumen, suggestive of an ischemic mass effect, which was supported by histology. In addition to the direct intraluminal obstruction and lithogenic effects of migratory surgical clips, "clipomas" due to an ischemic mass effect can also lead to biliary tract strictures.

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.

[Pathology of crush syndrome].

PubMed

Zimina, L N; Zvedina, M V; Musselius, S G; Vacina, T A

1995-01-01

Clinico-anatomical analysis of surgical material (32 cases) and 86 autopsy cases of myorenal syndrome (crush syndrome) is presented. Clinically in all cases there were symptoms of acute renal (hepatico-renal) failure which was a cause of death during the first 2 weeks. Septic complications were a cause of death at later periods. Grave alterations of traumatic, metabolic and septic origin were found in many organs in all cases. The sources of sepsis were decompressing longitudinal cuts and fasciotomies, shunts, lacerated wounds, catheters. Combined local treatment of wounds with sorbents, antibiotics, proteolytic enzymes, quantum therapy facilitated the destruction of bacteria and loss of their activity, wound purification and thus allowed coping with septic complications.

An Evaluation of the United States Coast Guard’s Enlisted Dining Facility Accounting and Reporting System.

DTIC Science & Technology

1980-09-01

GUAR COMPTROLLER MAMUIAL.o roto t m46 DEPAUT2UKr Of TiMANOUIATMN ZAIHM12M V. &. COMT CNARD lONM43AD UNITfO? jAM 60P.4 ... Mm@*tIJ 94k ~fpd~ K=(waui~m...its monetary allowance, the EDE receives income from the sale of meals . Meals are sold to enlisted personnel to whom the CO has granted a cash amount...in lieu of rations- in kind. For example, this permission would be granted if a married enlisted person at a shore station ate most meals at home and

[Drainage variants in reconstructive and restorative operations for high strictures and injuries of the biliary tract].

PubMed

Toskin, K D; Starosek, V N; Grinchesku, A E

1990-10-01

The article deals with the author's views on certain aspects of the problem of reconstructive and restorative surgery of the biliary tract. Original methods are suggested for external drainage (through the inferior surface of the right hepatic lobe in the region of the gallbladder seat and through the round ligament of the liver) in formation of ++hepato-hepatico- and hepaticojejunoanastomoses. Problems of operative techniques in formation of the anastomoses are discussed. Thirty-nine operations have been carried out in the clinic in the recent decade in high strictures and traumas of the biliary tract, 25 were reconstructive and 14 restorative. Postoperative mortality was 28.2% (11 patients). Intoxication and hepatargia associated with cholangiolytic abscesses of the liver were the main causes of death.

Preliminary Investigation of Spoiler Lateral Control on a 42 deg Sweptback Wing at Transonic Speeds

DTIC Science & Technology

1947-08-12

4,03 DIA . -1 ~-hue,t-buc.Figure 4.- LYaumg u/rig. S =0/65s , ft;uspect rot[o =40; 8Tuper rUtIO = 0. 3 . Al/ @/men s/ ens m Inches unless otberwse mdica ted...from approximately O.~ t~ 1.25 at 3 ° angle of attack, and for a small angle-of-attack range at a constant’Mach number of 0,98. The testing technique...1947, p, 10,) . . NACA !34No. L7F19 3 . v~ iocal air-stream velocity, feet per ., : ‘, Ml local air-stream Mach number . ,. second H free-stream total

"Sideways": results of repair of biliary injuries using a policy of side-to-side hepatico-jejunostomy.

PubMed

Winslow, Emily R; Fialkowski, Elizabeth A; Linehan, David C; Hawkins, William G; Picus, Daniel D; Strasberg, Steven M

2009-03-01

The Hepp-Couinaud technique describes side-to-side HJ to the main left hepatic duct but a side-to-side approach is not consistently used when repairing other ducts. Compared with end-to-side repairs, side-to-side anastomoses require less dissection, theoretically preserving blood supply to the bile ducts, and usually permit wider anastomoses. We report the treatment results of 113 consecutive biliary injuries, with intention to perform side-to side anastomosis in all. 113 biliary injuries, 109 associated with cholecystectomy, were treated from 1992-2006. Injury types were B (7 patients, 6%); C (11 patients, 10%); E1 (8 patients, 7%); E2 (37 patients, 33%); E3 (20 patients, 18%); E4 (24 patients, 21%); E5 (6 patients, 5%). 19% of repairs were early (within 1 week after cholecystectomy), 58% were delayed (at least 6 weeks after cholecystectomy), and 22% were reoperations for recurrent strictures. In 92% of cases, side-to-side repair was accomplished. 23/113 (20%) developed postoperative complications, with one postoperative death. Mean follow-up was 4.9 years. Excellent anastomotic function was achieved in 107/112 (95%). "Poor" anastomotic results occurred in 5 patients: 2 patients with E4 injuries had postoperative anastomotic stenting >3 months, and 3 developed strictures requiring percutaneous dilation. There have been no reoperations for biliary strictures. HJ using side-to-side anastomosis has theoretical advantages and is usually possible. In some high right-sided injuries it could not be achieved. 95% excellent anastomotic function without intervention attests to the benefit of the method, especially as postoperative stenting >3 months was considered to be a "poor" result.

[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.

Spectroscopic and thermodynamic properties of molecular hydrogen dissolved in water at pressures up to 200 MPa

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

Borysow, Jacek, E-mail: jborysow@mtu.edu; Rosso, Leonardo del; Celli, Milva

2014-04-28

We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines weremore » narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.« less

Spectroscopic and thermodynamic properties of molecular hydrogen dissolved in water at pressures up to 200 MPa.

PubMed

Borysow, Jacek; del Rosso, Leonardo; Celli, Milva; Moraldi, Massimo; Ulivi, Lorenzo

2014-04-28

We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines were narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.

Spectroscopic and thermodynamic properties of molecular hydrogen dissolved in water at pressures up to 200 MPa

NASA Astrophysics Data System (ADS)

Borysow, Jacek; del Rosso, Leonardo; Celli, Milva; Moraldi, Massimo; Ulivi, Lorenzo

2014-04-01

We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines were narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.

Double line groups: structure, irreducible representations and spin splitting of the bands

NASA Astrophysics Data System (ADS)

Lazić, N.; Milivojević, M.; Vuković, T.; Damnjanović, M.

2018-06-01

Double line groups are derived, structurally examined and classified within 13 infinite families. Their irreducible representations, found and tabulated, single out the complete set of conserved quantum numbers in fermionic quasi-one-dimensional systems possessing either translational periodicity or incommensurate helical symmetry. Spin–orbit interaction is analyzed: the induced orbital band splitting and the consequent removal of the spin degeneracy are completely explained. Being incompatible with vertical mirror symmetry, as well as with simultaneous invariance under time-reversal and horizontal (roto)reflections, spin splitting and spin polarized currents may occur only in the systems with the first and the fifth family double line group symmetry. The effects are illustrated on carbon nanotubes.

Iatrogenic bile duct strictures: a review of 22 cases.

PubMed

Ersumo, Tessema

2003-10-01

The incidence of iatrogenic bile duct strictures in Ethiopia appears to be increasing. Of 27 patients that sustained bile duct injuries at open cholecystectomy, admitted during May 1996 to December 2002, 22 cases of bile duct strictures are presented to evaluate outcome of treatment. The mean age was 40 years, 15 females. Twenty-one were referrals. The usual presenting features were biliary peritonitis and jaundice. The average time lapse between the original surgery and admission to hospital was eight months. About 73% had Bismuth grade III-IV strictures and all patients underwent Roux-en-Y hepatico-jejunostomy. Postoperatively, biliary-cutaneous fistula, recurrent ascending cholangitis and wound infection were observed frequently. The overall mortality rate was 13.6%. Bile duct injuries and strictures occur in young productive age groups. Prevention of the occurrence of bile duct injury and its progression to a devastating stricture reduces morbidity and mortality.

A case of recurrent cholangitis after bile duct injury during laparoscopic cholecystectomy: value of scintigraphy with Tc-99m GSA and hepatobiliary scintigraphy for indication of lobectomy.

PubMed

Nishiguchi, S; Shiomi, S; Sasaki, N; Iwata, Y; Tanaka, H; Kubo, S; Hirohashi, K; Ochi, H

2000-10-01

A 39-year-old woman with acute cholecystitis and gallstones underwent laparoscopic cholecystectomy. She suffered from recurrent episodes of cholangitis due to injury of the major bile ducts during laparoscopic cholecystectomy. Hepatobiliary scintigraphy with Tc-99m Sn-N-pyridoxyl-5-methyltryptophan was performed. Although normal bile excretion was found from the left hepatic duct to the percutaneous transhepatic biliary drainage (PTBD) tube, excretion from the right hepatic lobe was prolonged. Scintigraphy with Tc-99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin demonstrated atrophy of the right hepatic lobe and enlargement of the left hepatic lobe. Cholangiography via the PTBD tube revealed complete obstruction of the left hepatico-jejunal anastomosis and could not enhance the right intrahepatic bile duct. A right hepatic lobectomy was performed because of the atrophy, glissonitis and the absence of an appropriate bile duct for reconstruction. Postoperatively she was active and exhibited no evidence of recurrent cholangitis.

Bile duct injury during cholecystectomy.

PubMed

Kapoor, V K

2015-08-01

Laparoscopic cholecystectomy (LC) is the treatment of choice for gallstones, but is associated with increased risk of bile duct injury (BDI bile duct injury). If the BDI is detected during LC can be addressed immediately, if available hepatobiliary surgeon, but the easiest and safest procedure for the general surgeon is placing drains into subhepatic region and the transfer of acute BDI to controlled external biliary fistula (external Biliary fistula EBF). Most BDI is diagnosed when the postoperative period, when there is biliary leak. Therapy is a percutaneous catheter drainage and endoscopic stenting in the bile duct; early repair is not recommended. Repair in the form hepatico-jejunostomy (HJ) should be performed hepatobiliary surgeon at intervals of 46 weeks after it closes EBF. BDI is a frequent cause medico-legal actions and a substantial burden on health care costs. Most BDI can be avoided by adherence to the principles of safe cholecystectomy.

[Post-traumatic pseudoaneurysm of an anomalous right hepatic artery with arteriobiliary fistula and hemobilia].

PubMed

Bober, J; Vrzgula, A; Samek, P; Mach, P

1999-09-01

The authors describe a rare case of posttraumatic pseudoaneurysm of an anomaly arising right hepatic artery accompanied with arteriobiliary fistula. Treacherousness of this case was given by anomaly origin of the affected vessel. Thirty-four year old female has been treated at the author's department after sustained knife abdominal injury. Before our treatment, she was twice operated at the other hospital for haemoperitoneum and subhepatic abscess with haemobilia. The patient was transferred to the 1st department of surgery in Kosice because of septic shock, right-lobe hepatic abscess and repeated haemobilia. Selective hepatico-mesentericography revealed the cause of haemobilia. At the operation a double ligation of anomaly right hepatic artery was carried out together with closure of arteriobiliary fistula via choledochotomy. Haemobilia was not seen after surgery and the patient was discharged without any signs of liver disfunction. Repeated angiography showed closure of anomaly arising vessel.

Biliary stricture due to neuroma after an innocent blunt abdominal trauma.

PubMed

Katsinelos, P; Dimiropoulos, S; Galanis, I; Tsolkas, P; Paroutoglu, G; Arvaniti, M; Katsiba, D; Baltaglannis, S; Pilpilidis, I; Papagiannis, A; Vaslliadis, I

2002-10-01

A traumatic neuroma of the biliary tract is rarely associated with biliary obstruction. However, when it arises in the common bile duct (CBD) and is associated with obstructive jaundice, it is difficult to distinguish it from bile duct cancer. We describe a patient who developed obstructive jaundice and itching, due to CBD stricture, 8 years after innocent blunt abdominal trauma. The stricture was resected and hepatico-jejunal anastomosis was performed. Histological examination revealed a traumatic neuroma and a fibrous scar around the common bile duct. Symptoms disappeared following surgical removal of the lesion. Blunt abdominal injury may cause the late onset of a fibrous scar and traumatic neuroma in the common bile duct. To our knowledge, a traumatic neuroma of the biliary tract after blunt abdominal trauma has not been reported previously. We review the clinical picture of this relatively rare problem, along with its diagnosis, pathogenesis and treatment.

Cystic Dilation of Extrahepatic Bile Ducts in Adulthood: Diagnosis, Surgical Treatment and Long. Term Results

PubMed Central

Rotondano, G.; D'Agostino, A.; Iannelli, A.; Marano, I.; Santangelo, M. L.

1998-01-01

To evaluate the long-term results of surgery for choledohal cyst in adulthood, a series of 13 patients over the age of 16 operated on for choledochal cyst during a period of six years and followed-up for a minimum of 3 years was analyzed. Patients with type I and IVa cysts underwent extrahepatic cyst resection and Roux-en-Y hepatico-jejunostomy. Choledochoceles (type III) were managed endoscopically. No operative mortality or morbidity occurred. Type I and III cysts showed almost ideal follow-up with no sign of stricture on HIDA scan. One type IVa cyst patients developed recurrent cholangitis due to anastomotic stricture, managed percutaneously. Whenever possible, complete cyst resection and Roux-en-Y reconstruction is the treatment of choice for all extrahepatic biliary cysts. Intra- and extrahepatic dilatations are adequately treated by extrahepatic resection and careful endoscopic or radiologic surveillance. Small choledochoceles can be safely managed by endoscopic sphincterotomy. PMID:9515236

Pose estimation and tracking of non-cooperative rocket bodies using Time-of-Flight cameras

NASA Astrophysics Data System (ADS)

Gómez Martínez, Harvey; Giorgi, Gabriele; Eissfeller, Bernd

2017-10-01

This paper presents a methodology for estimating the position and orientation of a rocket body in orbit - the target - undergoing a roto-translational motion, with respect to a chaser spacecraft, whose task is to match the target dynamics for a safe rendezvous. During the rendezvous maneuver the chaser employs a Time-of-Flight camera that acquires a point cloud of 3D coordinates mapping the sensed target surface. Once the system identifies the target, it initializes the chaser-to-target relative position and orientation. After initialization, a tracking procedure enables the system to sense the evolution of the target's pose between frames. The proposed algorithm is evaluated using simulated point clouds, generated with a CAD model of the Cosmos-3M upper stage and the PMD CamCube 3.0 camera specifications.

[Injuries of the extrahepatic bile ducts in laparoscopic cholecystectomy].

PubMed

Pătraşcu, Tr; Burcoş, Tr; Doran, H; Cristian, D; Brezean, I; Voiculescu, St; Catrina, E; Vereanu, I

2006-01-01

Laparoscopic cholecystectomy has become the "gold standard" for cholelithiasis. In laparoscopic technique, the incidence and the severity of injuries of the extrahepatic bile ducts are significantly higher (0-2,7%) than in open surgery (0,2-0,5%). The authors present a series of 18 patients with such lesions, operated between 1996 and 2005 in the surgical departments of 2 Clinical Hospitals: "Dr.I.Cantacuzino" and Coltea, from Bucharest. The injuries were: 2--of type A, 10--of type D and 6--of type E, according to Soper-Strasberg classification. There are analysed the causes and the circumstances in which these injuries have occurred, the clinical signs and imagistic findings and, most of all, their treatment. In complete transections of the common bile duct, a hepatico-jejuno-anastomosis using a Roux en Y-loop appears to be the best solution. It is emphasized the fact that an accurate diagnosis and surgical technique are essential for a favourable evolution. That's why these operations must be accomplished by experimented surgeons, from highly specialized departments.

[Iatrogenic biliary lesions and stenosis].

PubMed

Latteri, S; Vecchio, R; Angilello, A

1997-01-01

Pathogenetic, diagnostic and therapeutic aspects of postoperative bile duct injuries are reviewed. Treatment options are discussed in relation to the time of diagnosis. Lesions detected during the same operation must be immediately repaired through an end-to-end biliary anastomosis or a bilioenteric anastomosis. In limited lesions of the bile duct a T-tube placement should be sufficient. Bile duct lesions recognized postoperatively can be managed through a multimodal surgical, endoscopic, and radiologic approach. In the early postoperative period, surgery is indicated when a complete section of the biliary tract or a severe peritonitis is recognized, or when endoscopic and radiologic treatment has failed. Surgery is also the treatment of choice in the late complete stenosis of the bile duct. Roux-en-Y hepatico-jejunostomy is the most common surgical procedure for the treatment of bile duct lesions and strictures. However, in high bile duct lesions, especially if the risk of anastomotic dehiscence is increased the Authors emphasize the Rodney-Smith technique for the reconstruction of the biliary tract.

Post-traumatic arteriovenous fistula of the hepatic pedicle.

PubMed

Ibn Majdoub Hassani, K; Mohsine, R; Belkouchi, A; Bensaid, Y

2010-10-01

Hepatico-portal fistula (HPF) is a rare condition, most often of post-traumatic or iatrogenic origin and occasionally secondary to a ruptured aneurysm of the hepatic artery into the portal vein. HPF in extrahepatic locations often results in portal hypertension (PHT). While Doppler ultrasound, CT angiography, and magnetic resonance angiography are usually demonstrative, arteriography remains indispensable to clarify the exact anatomical configuration. In the treatment of these arteriovenous (AV) fistulas, open surgical approaches have increasingly given way to radiological embolization techniques, especially in intrahepatic locations, but surgery remains indicated for AV fistulas of the hepatic pedicle where maintenance of hepatic arterial flow is a priority of treatment. We report a patient who had an AV fistula of the hepatic pedicle with resultant PHT presenting 5 years after open abdominal trauma. Treatment was surgical; the immediate and long-term postoperative course was uneventful with regression of PHT. Through analysis of this case and a review of the literature, we discuss the clinical, paraclinical, therapeutic, and prognostic features of this lesion. Copyright © 2010. Published by Elsevier Masson SAS.

[Bile duct lesions in laparoscopic cholecystectomy].

PubMed

Siewert, J R; Ungeheuer, A; Feussner, H

1994-09-01

Laparoscopic cholecystectomy is both resulting in a slightly higher incidence of biliary lesions and a change of prevalence of the type of lesions. Damage to the biliary system occurs in 4 different types: The most severe case is the lesion with a structural defect of the hepatic or common bile duct with (IVa) or without (IVb) vascular injury. Tangential lesions without structural loss of the duct should be denominated as type III (IIIa with additional lesion to the vessels, type IIIb without). Type II comprehends late strictures without obvious intraoperative trauma to the duct. Type I includes immediate biliary fistulae of usually good prognosis. The increasing prevalence of structural defects of the bile ducts appears to be a peculiarity of laparoscopic cholecystectomy necessitating highly demanding operative repair. In the majority of cases, hepatico-jejunostomy or even intraparenchymatous anastomoses are required. Adaptation of well proven principles of open surgery is the best prevention of biliary lesions in laparoscopic cholecystectomy as well as the readiness to convert early to the open procedure.

Biliary complications of cholecystectomy.

PubMed

Joshi, Rajeev M; Shetty, Tilakdas S; Singh, Rajinder; Adhikari, Devbrata R; Patil, Bhushan P; Bhange, Snehal A

2008-01-01

Biliary complications occur because of causes such as obscure or variant anatomy, predisposing conditions such as fibrosis or severe inflammation, equipment failure, and surgeon factors. The aim of this study was to review the optimal surgical treatment. Analysis of 81 patients with bile duct injuries treated in a single referral unit over an 8.5-year period was done. Time of detection of biliary injury and its presentation were ascertained as well as the level of injury (Strasburg's). In 8 patients, injury was detected intraoperatively, and 41 were detected in the early postoperative period with bile leak (n = 25) or obstructive jaundice (n = 10). Those diagnosed in the delayed postoperative period (n = 32) presented with recurrent cholangitis (n = 9), obstructive jaundice (n = 16), and a cholestatic enzymatic profile (n = 1). Roux-en-Y hepatico-jejunostomy was the preferred option (n = 64). One patient died because of biliary peritonitis. Improper treatment is associated with disastrous results, but early recognition and correct management can lead to a successful outcome and good prognosis.

Credit PSR. The northwest and southwest facades appear as seen ...

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

Credit PSR. The northwest and southwest facades appear as seen when looking northeast (460). Doors have been opened to show the interiors of the oxidizer dust receiver room at left; the building equipment room (air conditioning) is on the right. The dust receiver is a Roto-Clone Type N hydrostatic precipitator, which uses a 5 horsepower vacuum motor. Refrigeration units are mounted on pads immediately to the right of the building in this view. The grinder room is at the far end of the building; access to it is gained via double doors on the left where a hoist beam projects out from the top of the door opening. Building 4284/E85 (Oxidizer Dryer Blender) appears in the left background; 4283/E-84 (Oxidizer Grinder) appears in the right background - Jet Propulsion Laboratory Edwards Facility, Oxidizer Grinder Building, Edwards Air Force Base, Boron, Kern County, CA

Selectivity in the inelastic rotational scattering of D2 and HD molecules from graphite: Similarities and differences respect to the H2 case

NASA Astrophysics Data System (ADS)

Rutigliano, Maria; Pirani, Fernando

2018-03-01

The inelastic scattering of D2 and HD molecules impinging on a graphite surface in well-defined initial roto-vibrational states has been studied by using the computational setup recently developed to characterize important selectivities in the molecular dynamics occurring at the gas-surface interface. In order to make an immediate comparison of determined elastic and inelastic scattering probabilities, we considered for D2 and HD molecules the same initial states, as well as the same collision energy range, previously selected for the investigation of H2 behaviour. The analysis of the back-scattered molecules shows that, while low-lying initial vibrational states are preserved, the medium-high initial ones give rise to final states covering the complete ladder of vibrational levels, although with different probability for the various cases investigated. Moreover, propensities in the formation of the final rotational states are found to depend strongly on the initial ones, on the collision energy, and on the isotopologue species.

Measured Aerodynamic Interaction of Two Tiltrotors

NASA Technical Reports Server (NTRS)

Yamauchi, Gloria K.; Wadcock, Alan J.; Derby, Michael R.

2003-01-01

The aerodynamic interaction of two model tilrotors in helicopter-mode formation flight is investigated. Three cenarios representing tandem level flight, tandem operations near the ground, and a single tiltrotor operating above thc ground for varying winds are examined. The effect of aircraft separation distance on the thrust and rolling moment of the trailing aircraft with and without the presence of a ground plane are quantified. Without a ground plane, the downwind aircraft experiences a peak rolling moment when the right (left) roto- of the upwind aircraft is laterally aligned with the left (right) rotor of the downwind aircraft. The presence of the ground plane causes the peak rolling moment on the downwind aircraft to occur when the upwind aircraft is further outboard of the downwind aircraft. Ground plane surface flow visualization images obtained using rufts and oil are used to understand mutual interaction between the two aircraft. These data provide guidance in determining tiltrotor flight formations which minimize disturbance to the trailing aircraft.

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

Gabuda, S. P.; Kozlova, S. G.; Novosibirsk State University, 2, Pirogova Str., Novosibirsk 630090

We report an abnormal difference of low-temperature mobility of left-twisted and right-twisted conformations of roto symmetric molecules C{sub 6}H{sub 12}N{sub 2} (dabco) located in the same positions in crystal Zn{sub 2}(C{sub 8}H{sub 4}O{sub 4}){sub 2}⋅C{sub 6}H{sub 12}N{sub 2}. The difference between {sup 1}H NMR (Nuclear Magnetic Resonance) spin-relaxation data for left-twisted and right-twisted molecules reaches ∼3 × 10{sup 3} times at 8 K and tends to grow at lower temperatures. We argue that taking into account four-component relativistic Dirac wave functions in the vicinity of the nodal plane of dabco molecules and vacuum fluctuations due to virtual particle-antiparticle pairs canmore » explain the changes which C{sub 6}H{sub 12}N{sub 2} conformations undergo at low temperatures.« less

Hazard and outcome of retreated choledochal cyst patients.

PubMed

Chijiiwa, K

1993-01-01

Thirty-nine patients initially treated for choledochal cyst (25: cyst-enterostomy for 15 type I and 10 type IV A, 13: cyst excision for 8 type I and 5 type IV A, 1: sphincterotomy for type III) have been completely followed up for a mean period of 17 years to examine the effect of surgical management on their lives. Eighteen of 25 cases with cyst-enterostomy (72%) needed retreatment due to the complications but one could not be retreated because of the presence of advanced bile duct carcinoma. Fourteen of 17 cases were retreated with cyst excision, of whom 12 showed an excellent outcome but other two were suffering from cholangitis and hepatolithiasis. The remaining 3 patients retreated with PTCS or cyst-enterostomy showed a poor outcome. Of 13 patients who had undergone cyst excision with hepatico-jejunostomy as the first choice, 12 showed a good outcome but one needed retreatment due to the anastomotic stenosis and hepatolithiasis. Thus, excision of cyst should be the surgical management for choledochal cyst. However, it should be noted that three of 27 patients treated initially or secondarily with cyst excision showed unsatisfactory results mainly due to the anastomotic stenosis. The results demonstrate that hepaticojejunostomy with a wide opening stoma is necessary to prevent postoperative morbidity.

[Spontaneous bile duct perforation: a rare cause of acute abdominal pain during childhood].

PubMed

Ozdemir, Tunç; Akgül, Ahsen Karagözlü; Arpaz, Yağmur; Arikan, Ahmet

2008-07-01

Spontaneous perforation of the bile duct (SPBD) is a rare cause of acute abdominal pain during childhood. Pancreatico-biliary malfunction has been postulated to contribute to its etiology. Factors related to diagnosis and treatment and difference from the other common causes of acute abdominal pain are emphasized. Five patients (3 boys, 2 girls, mean age 4.6) were admitted with peritonitis and operated with initial diagnosis of perforated appendicitis. During laparotomy, SPBD was detected. Presentation, laboratory findings and operative technique of the patients were evaluated retrospectively. Common complaints were abdominal pain and bilious vomiting. Abdominal distention was present in all patients. Leukocytosis and mild hyperbilirubinemia were detected in 5, elevated serum transaminase levels in 4, hyperglycemia in 1 and constipation in 1 patient(s). Abdominal ultrasonography showed a large amount of free fluid. During laparotomy, sterile bile peritonitis was detected initially. After exploration, SPBD was seen. T-tube drainage of the bile duct was carried out. Patients were discharged after removal of the T-tubes. Pancreatico-biliary malfunction was detected in 4 of 5 patients. In patients with generalized peritonitis, elevated transaminase levels and hyperbilirubinemia, SPBD must be considered. Even though the T-tube drainage is the treatment of choice, Roux-en-Y hepatico-portoenterostomy may be mandatory in certain patients.

Results of Heineke-Mikulicz type choledochoplasty in benign biliary strictures.

PubMed

Csendes, A; Burdiles, P; Diaz, J C; Maluenda, F

1993-10-01

During a 20-year period from 1970 to 1991, a total of 30,800 patients underwent biliary tract surgery at the Department of Surgery, University of Chile Clinical Hospital. Of these, seven female adults with a mean age of 39.7 years (range 29 to 54) were considered for analysis in this study. The results of the Heineke-Mikulicz type choledochoplasty repair in patients with short localized strictures of the biliary tract were analyzed in these patients. In six cases, the repair was performed at a mean time of 20 months after cholecystectomy and accidental injury of the common bile duct; in one case it was carried out during cholecystectomy and repair of a Mirizzi type II cholecysto-hepatic fistula. This patient remained asymptomatic during a follow-up of 120 months. Of the six cases on whom choledochoplasty was performed as treatment of short strictures, five patients (83%) developed a new stricture at a mean time of 14 months after surgery; a hepatico-jejunostomy was performed in all. After this procedure, only one patient was re-operated again, and all remained asymptomatic long after surgery. We believe that this Heineke-Mikulicz type choledochoplasty, which has been recommended in short distal strictures, is not advisable as a definitive surgical repair for this kind of stricture.

Bile duct injury repair: when? what? who?

PubMed

Kapoor, Vinay K

2007-01-01

Laparoscopic cholecystectomy is associated with a two-to-four times higher risk of bile duct injury (BDI) than open cholecystectomy. BDI can lead to significant morbidity and even mortality. The first priority in BDI is to control peritoneal and biliary sepsis and to convert an acute BDI to a controlled external biliary fistula (EBF) - this can be achieved by endoscopic and/ or radiological intervention in most cases. This should be followed by assessment of the extent of injury - both biliary and vascular. Immediate management of BDI recognized during cholecystectomy depends on the type of injury, the condition of the patient, and the experience of the surgeon. For BDI recognized after cholecystectomy, early repair is not recommended, as the results are poor. The EBF may evolve into a benign biliary stricture (BBS), which should be electively repaired by a Roux-en-Y hepatico-jejunostomy. The use of an endoscopic stent as definitive management of BDI is not recommended. Long-term follow-up is essential after the repair of a BBS, as recurrence can occur several years after repair. Recurrent BBS is best treated with endoscopic balloon dilatation. Excellent early and long-term results can be obtained in specialized units at tertiary care referral centers.

Towards Forming a Primordial Protostar in a Cosmological AMR Simulation

NASA Astrophysics Data System (ADS)

Turk, Matthew J.; Abel, Tom; O'Shea, Brian W.

2008-03-01

Modeling the formation of the first stars in the universe is a well-posed problem and ideally suited for computational investigation.We have conducted high-resolution numerical studies of the formation of primordial stars. Beginning with primordial initial conditions appropriate for a ΛCDM model, we used the Eulerian adaptive mesh refinement code (Enzo) to achieve unprecedented numerical resolution, resolving cosmological scales as well as sub-stellar scales simultaneously. Building on the work of Abel, Bryan and Norman (2002), we followed the evolution of the first collapsing cloud until molecular hydrogen is optically thick to cooling radiation. In addition, the calculations account for the process of collision-induced emission (CIE) and add approximations to the optical depth in both molecular hydrogen roto-vibrational cooling and CIE. Also considered are the effects of chemical heating/cooling from the formation/destruction of molecular hydrogen. We present the results of these simulations, showing the formation of a 10 Jupiter-mass protostellar core bounded by a strongly aspherical accretion shock. Accretion rates are found to be as high as one solar mass per year.

New insights into the 2012 Emilia (Italy) seismic sequence through advanced numerical modeling of ground deformation InSAR measurements

NASA Astrophysics Data System (ADS)

Tizzani, P.; Castaldo, R.; Solaro, G.; Pepe, S.; Bonano, M.; Casu, F.; Manunta, M.; Manzo, M.; Pepe, A.; Samsonov, S.; Lanari, R.; Sansosti, E.

2013-05-01

We provide new insights into the two main seismic events that occurred in 2012 in the Emilia region, Italy. We extend the results from previous studies based on analytical inversion modeling of GPS and RADARSAT-1 InSAR measurements by exploiting RADARSAT-2 data. Moreover, we benefit from the available large amount of geological and geophysical information through finite element method (FEM) modeling implemented in a structural-mechanical context to investigate the impact of known buried structures on the modulation of the ground deformation field. We find that the displacement pattern associated with the 20 May event is consistent with the activation of a single fault segment of the inner Ferrara thrust, in good agreement with the analytical solution. In contrast, the interpretation of the 29 May episode requires the activation of three different fault segments and a block roto-translation of the Mirandola anticline. The proposed FEM-based methodology is applicable to other seismic areas where the complexity of buried structures is known and plays a fundamental role in the modulation of the associated surface deformation pattern.

Effect of Intrinsic Twist on Length of Crystalline and Disordered Regions in Cellulose Microfibrils

NASA Astrophysics Data System (ADS)

Nili, Abdolmadjid; Shklyaev, Oleg; Zhao, Zhen; Zhong, Linghao; Crespi, Vincent

2013-03-01

Cellulose is the most abundant biological material in the world. It provides mechanical reinforcement for plant cell wall, and could potentially serve as renewable energy source for biofuel. Native cellulose forms a non-centrosymmetric chiral crystal due to lack of roto-inversion symmetry of constituent glucose chains. Chirality of cellulose crystal could result in an overall twist. Competition between unwinding torsional/extensional and twisting energy terms leads to twist induced frustration along fibril's axis. The accumulated frustration could be the origin of periodic disordered regions observed in cellulose microfibrils. These regions could play significant role in properties of cellulose bundles and ribbons as well as biological implications on plant cell walls. We propose a mechanical model based on Frenkel-Kontorova mechanism to investigate effects of radius dependent twist on crystalline size in cellulose microfibrils. Parameters of the model are adjusted according to all-atom molecular simulations. This work is supported by the US Department of Energy, Office of Basic Energy Sciences as part of The Center for LignoCellulose Structure and Formation, an Energy Frontier Research Center

Bile duct injury: management options during and after gallbladder surgery.

PubMed

Vecchio, R; MacFadyen, B V; Ricardo, A E

1998-06-01

Proper management of iatrogenic bile duct injuries is mandatory to avoid immediate or late life threatening sequelae. Results of surgery depend mainly on the type of injury, the detection of the injury, and the timing of the surgery. Lesions detected during cholecystectomy should be repaired immediately, preferably with an end-to-side biliary anastomosis, a Roux-en-Y bilio-enteric anastomosis, or by the insertion of a T-tube. Bile duct injuries detected in the postoperative phase require a multidisciplinary approach and an algorithm for treatment of each type of lesion is proposed. In bile peritonitis with biliary obstruction and/or transection and in tight long strictures, which develop several months after cholecystectomy, a Roux-en-Y hepatico-jejunostomy is the most commonly performed operation. Other surgical techniques include a "mucosal graft" procedure and intrahepatic biliary enteric anastomoses, which may be required in difficult high-biliary lesions. Endoscopy and/or interventional radiology offer the best treatment options in bile duct leaks and in short ductal strictures that involve less than 50% of the bile duct lumen. In these injuries, surgical management should be performed only in the failure of nonsurgical methods. Because these lesions involve complicated biliary surgery, therapeutic endoscopy, and interventional radiology, treatment should be performed where there is expertise in all three areas. Copyright 1998 W.B. Saunders Company.

Value of MRI in three patients with major vascular injuries after laparoscopic cholecystectomy.

PubMed

Ragozzino, Alfonso; Lassandro, Francesco; De Ritis, Rosaria; Imbriaco, Massimo

2007-11-01

The aim of this study was to describe three cases of major vascular injuries after laparoscopic cholecystectomy depicted on magnetic resonance (MR) examination. Three female patients (mean age, 32 years; range, 22-39 years) were studied with clinical suspicion of bilio-vascular injuries after laparoscopic cholecystectomy. All MR examinations were performed within 24 h after the laparoscopic procedure. MR imaging was evaluated for major vascular injuries involving the arterial and portal venous system, for bile duct discontinuity, presence or absence of biliary dilation, stricture, excision injury, free fluid and collections. In the first patient, a type-IV Bismuth injury with associated intrahepatic bile ducts dilation was observed. Contrast-enhanced MR revealed lack of enhancement in the right hepatic lobe due to occlusion of the right hepatic artery and the right portal branch. This patient underwent right hepatectomy with hepatico-jejunostomy. In the other two cases, no visualization of the right hepatic artery and the right portal branch was observed on MR angiography. In the first case, the patient underwent right hepatectomy; in the second case, because of stable liver condition, the patient was managed conservatively. MR imaging combined with MR angiography and MR cholangiography can be performed emergently in patients with suspicion of bilio-vascular injury after laparoscopic cholecystectomy allowing the simultaneous evaluation of the biliary tree and the hepatic vascular supply that is essential for adequate treatment planning.

Repair of a mal-repaired biliary injury: a case report.

PubMed

Aldumour, Awad; Aseni, Paolo; Alkofahi, Mohmmad; Lamperti, Luca; Aldumour, Elias; Girotti, Paolo; De Carlis, Luciano-Gregorio

2009-05-14

Iatrogenic bile-duct injury post-laparoscopic cholecystectomy remains a major serious complication with unpredictable long-term results. We present a patient who underwent laparoscopic cholecystectomy for gallstones, in which the biliary injury was recognized intraoperatively. The surgical procedure was converted to an open one. The first surgeon repaired the injury over a T-tube without recognizing the anatomy and type of the biliary lesion, which led to an unusual biliary mal-repair. Immediately postoperatively, the abdominal drain brought a large amount of bile. A T-tube cholangiogram was performed. Despite the contrast medium leaking through the abdominal drain, the mal-repair was unrecognized. The patient was referred to our hospital for biliary leak. Ultrasound and cholangiography was repeated, which showed an unanatomical repair (right to left hepatic duct anastomosis over the T-tube), with evidence of contrast medium coming out through the abdominal drain. Eventually the patient was subjected to a definitive surgical treatment. The biliary continuity was re-established by a Roux-en-Y hepatico-jejunostomy, over transanastomotic external biliary stents. The patient is now doing well 4 years after the second surgical procedure. In reviewing the literature, we found a similar type of injury but we did not find a similar surgical mal-repair. We propose an algorithm for the treatment of early and late biliary injuries.

Repair of a mal-repaired biliary injury: A case report

PubMed Central

Aldumour, Awad; Aseni, Paolo; Alkofahi, Mohmmad; Lamperti, Luca; Aldumour, Elias; Girotti, Paolo; Carlis, Luciano Gregorio De

2009-01-01

Iatrogenic bile-duct injury post-laparoscopic cholecystectomy remains a major serious complication with unpredictable long-term results. We present a patient who underwent laparoscopic cholecystectomy for gallstones, in which the biliary injury was recognized intraoperatively. The surgical procedure was converted to an open one. The first surgeon repaired the injury over a T-tube without recognizing the anatomy and type of the biliary lesion, which led to an unusual biliary mal-repair. Immediately postoperatively, the abdominal drain brought a large amount of bile. A T-tube cholangiogram was performed. Despite the contrast medium leaking through the abdominal drain, the mal-repair was unrecognized. The patient was referred to our hospital for biliary leak. Ultrasound and cholangiography was repeated, which showed an unanatomical repair (right to left hepatic duct anastomosis over the T-tube), with evidence of contrast medium coming out through the abdominal drain. Eventually the patient was subjected to a definitive surgical treatment. The biliary continuity was re-established by a Roux-en-Y hepatico-jejunostomy, over transanastomotic external biliary stents. The patient is now doing well 4 years after the second surgical procedure. In reviewing the literature, we found a similar type of injury but we did not find a similar surgical mal-repair. We propose an algorithm for the treatment of early and late biliary injuries. PMID:19437572

Collective dynamics and transport in extremely magnetized dusty plasmas

NASA Astrophysics Data System (ADS)

Hartmann, Peter

2016-09-01

We have built an experimental setup to realize and observe rotating dusty plasmas in a co-rotating frame. Based on the Larmor theorem, the ``RotoDust'' setup is able to create effective magnetizations, mimicked by the Coriolis inertial force, in strongly coupled dusty plasmas that are impossible to approach with superconducting magnets. At the highest rotation speed, we have achieved effective magnetic fields of 3200 T. The effective magnetization β =ωc /ωp (ratio of cyclotron to plasma frequency) reaches 0.76 which is typical for many strongly magnetized and strongly correlated plasmas in compact astrophysical objects. The analysis of the wave spectra as observed in the rotating frame clearly shows the equivalence of the rotating dust cloud and a magnetized plasma. Further, the analysis of the mean square displacement (MSD) and the velocity autocorrelation function (VAC) revealed the transport parameters diffusion and viscosity, which are in reasonable agreement with numerical predictions for magnetized 2D Yukawa systems. Small degree of super-diffusion is observed. This research was supported by grant NKFIH K-115805 and the Janos Bolyai Research Scholarship of the HAS.

Retroportal proper hepatic artery with malrotated gut.

PubMed

Wadhwa, Surbhi; Khorwal, Gitanjali; Tigga, Sarika Rachel

2013-09-01

he celiac trunk is the artery supplying the upper abdominal organs, mainly the lower part of esophagus, stomach, parts of duodenum, liver, gallbladder, spleen and pancreas. It normally trifurcates into the left gastric artery (LGA), the common hepatic artery (CHA) and the splenic artery (SA) at the superior border of the pancreas. This ‘normal variant’ of the vessel has been observed in 89.8 % cadaveric dissections in the Japanese population by Chen et al. (2009). Prakash et al. (2012) reported a normally trifurcating celiac trunk in 86 % of the south Indian population. The CHA branches from the celiac trunk, forms the gastroduodenal artery (GDA) and a proper hepatic artery (PHA), which further divides distally into right and left hepatic arteries. This normal origin and branching of CHA has been observed in 52–80 % of individuals (Michels 1966; Nelson et al. 1988; Hiatt et al. 1994; Koops et al. 2004; Chen et al. 2009). In a large series of 604 selective celiac and superior mesenteric angiographies, aberrant or anomalous vasculature was reported in 20.9 % of individuals by Koops et al. (2004). This knowledge and recognition of anomalous/aberrant or accessory vasculature in the upper abdomen, occurring in about one-fifth of the population is of vital importance to the hepatico-biliary-pancreatic surgeon to avoid iatrogenic injuries and complications, as well as to the interventional radiologist performing trans-arterial chemo-ablative procedures.

[Surgical treatment of iatrogenic bile duct injuries following laparoscopic cholecystectomy: analysis of long-term results. Retrospective clinical study in 51 patients operated in the Campania region from 1991 to 2003].

PubMed

Conzo, Giovanni; Amato, Giuseppe; Angrisani, Luigi; Bardi, Ugo; Barone, Giovanni; Belli, Giulio; Brancaccio, Umberto; Calise, Fulvio; Caliendo, Angelo; Celsi, Salvatore; Corcione, Francesco; Cuccurullo, Diego; De Falco, Giuseppe; Delrio, Paolo; De Werra, Carlo; De Sena, Guido; Docimo, Giovanni; Esposito, Maria Grazia; Fantini, Corrado; Giardiello, Cristiano; Musella, Mario; Molino, Carlo; Muto, Crescenzo; Pennetti, Lucio; Puziello, Alessandro; Porcelli, Alberto; Rea, Roberto; Rendano, Franco; Palazzo, Antonietta; Santangelo, Michele; Santaniello, Walter; Santini, Luigi; Sperlongano, Pasquale; Stanzione, Francesco; Tartaglia, Alberto; Tricarico, Annunziato; Vincenti, Rodolfo; Lorenzo, Michele

2005-01-01

An higher incidence rate of iatrogenic bile duct injuries is reported in cholecystectomy performed with the laparoscopy than with the laparotomy approach. The aim of this study was to provide a multicentre report on surgical treatment and the outcome of biliary complications during and following laparoscopic cholecystectomy. A questionnaire was mailed to all surgeons with experience in laparoscopic cholecystectomy in the Campania region. Data were collected from January 1991 to December 2003. Each patient was requested to indicate age, gender, associated diseases, site and type of lesion, surgical experience, diagnosis, treatment and complications. Twenty-six surgeons answered the questionnaire. Fifty-one patients (36 F/15 M; mean age: 42.5 +/- 11.9, range 13-91 years) with bile duct injuries following laparoscopic cholecystectomy were reported. The most frequent lesions were main bile duct partial or total transection. The intraoperative mortality rate was 1/51 (1.9%) due to a complex biliary and vascular injury. The postoperative mortality rate of revision surgery was 5/50 (10%). T-tube positioning (n = 20) and Roux-en-Y hepato-jejunostomy (n = 20) were the procedures most frequently performed. The complication rate in patients treated with the T-tube was significantly higher than in those treated with hepatico-jejunostomy. Surgical treatment of biliary injuries following laparoscopic cholecystectomy was characterized by unusually high mortality and morbidity for a non-neoplastic disease. Roux-en-Y hepato-jejunostomy remains the procedure of choice for these injuries.

Uso de curativo a vácuo como terapia adjuvante na cicatrização de sítio cirúrgico infectado

PubMed Central

de Camargo, Paula Angeleli Bueno; Bertanha, Matheus; Moura, Regina; Jaldin, Rodrigo Gibin; Yoshida, Ricardo de Alvarenga; Pimenta, Rafael Elias Farres; Mariúba, Jamil Victor de Oliveira; Sobreira, Marcone Lima

2016-01-01

Resumo Infecções de sítios cirúrgicos com envolvimento de próteses sintéticas constituem grande desafio para tratamento. Apresentamos o caso de uma paciente com múltiplas comorbidades, histórico de enxerto aortobifemoral há 6 anos e reabordagem das anastomoses femorais por reestenoses há 5 anos. Apresentou dor inguinal esquerda e abaulamento súbitos com diagnóstico de pseudoaneurisma femoral roto e instabilidade hemodinâmica. Foi submetida a correção emergencial com interposição de prótese de dácron recoberta por prata e correção de grande hérnia incisional abdominal com tela sintética ao mesmo tempo. No pós-operatório, manteve-se por longo período sob terapia intensiva com dificuldade de extubação. Nesse ínterim, apresentou deiscência das suturas e fístula purulenta inguinal esquerda em contato com a prótese vascular. Optou-se pelo tratamento conservador, com desbridamento das feridas e aplicação de curativo a vácuo. A paciente evoluiu com melhora e cicatrização das feridas. Essa pode se constituir em ferramenta importante em casos similares.

Fragment approach to constrained density functional theory calculations using Daubechies wavelets

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

Ratcliff, Laura E.; Genovese, Luigi; Mohr, Stephan

2015-06-21

In a recent paper, we presented a linear scaling Kohn-Sham density functional theory (DFT) code based on Daubechies wavelets, where a minimal set of localized support functions are optimized in situ and therefore adapted to the chemical properties of the molecular system. Thanks to the systematically controllable accuracy of the underlying basis set, this approach is able to provide an optimal contracted basis for a given system: accuracies for ground state energies and atomic forces are of the same quality as an uncontracted, cubic scaling approach. This basis set offers, by construction, a natural subset where the density matrix ofmore » the system can be projected. In this paper, we demonstrate the flexibility of this minimal basis formalism in providing a basis set that can be reused as-is, i.e., without reoptimization, for charge-constrained DFT calculations within a fragment approach. Support functions, represented in the underlying wavelet grid, of the template fragments are roto-translated with high numerical precision to the required positions and used as projectors for the charge weight function. We demonstrate the interest of this approach to express highly precise and efficient calculations for preparing diabatic states and for the computational setup of systems in complex environments.« less

Jejunal varices after choledochojejunostomy treated with laparotomic transcatheter variceal embolization.

PubMed

Waguri, Nobuo; Azumi, Rie; Sugimura, Kazuhito; Arao, Yoshihisa; Ikarashi, Shunzo; Sakai, Norihiro; Ogawa, Masahiro; Osaki, Akihiko; Sato, Munehiro; Aiba, Tsuneo; Yoneyama, Osamu; Furukawa, Koichi; Igarashi, Kentarou

2016-01-01

Portal hypertension induces collateral shunt formation between the portal and systemic circulation, decompressing the elevated portal pressure. Ectopic varices outside of the gastroesophageal region, such as jejunal varices, are rare conditions. This report describes the successful embolization of ruptured jejunal varices resulting from an extrahepatic portal obstruction. A 62-year-old man was admitted to our hospital with recurrent massive gastrointestinal bleeding. Fourteen months earlier, he had undergone a choledochojejunostomy and pancreatic cystojejunostomy for bile duct stenosis with an enlarged pancreatic pseudocyst due to severe chronic pancreatitis. Contrast-enhanced computed tomography showed jejunal intramural dilated vessels close to the choledochojejunal anastomosis, but extravasation was not observed. Due to the lack of a rapid definitive diagnosis, the patient required massive blood transfusions. Hemorrhagic scintigraphy using 99m Tc-HSAD finally identified the site of the hemorrhage. Angiography and double-balloon endoscopy revealed the anastomotic jejunal varices to be the result of an extrahepatic portal obstruction. Laparotomic transcatheter variceal embolization with microcoils was successful in halting the refractory gastrointestinal bleeding. This surgery preserved hepatopetal portal venous flow by another route, and no complications were observed. At present, 4 years post-surgery, there has been no recurrence of gastrointestinal hemorrhage. The development of jejunal varices is often associated with postoperative adhesions. Some patients with a history of hepatico- or choledochojejunostomy may experience portal hypertension resulting from extrahepatic portal obstruction, leading to the formation of jejunal varices as hepatopetal portal collaterals. The choice of therapy in each patient should be based on the individual hemodynamics of the ectopic varices.

Emergency right hepatectomy after laparoscopic tru-cut liver biopsy

PubMed Central

Quezada, Nicolás; León, Felipe; Martínez, Jorge; Jarufe, Nicolás; Guerra, Juan Francisco

2015-01-01

Background Liver biopsy is a common procedure usually required for final pathologic diagnosis of different liver diseases. Morbidity following tru-cut biopsy is uncommon, with bleeding complications generally self-limited. Few cases of major hemorrhage after liver biopsies have been reported, but to our knowledge, no cases of emergency hepatectomy following a tru-cut liver biopsy have been reported previously. Presentation of case We report the case of a 38 years-old woman who presented with an intrahepatic arterial bleeding after a tru-cut liver biopsy under direct laparoscopic visualization, initially controlled by ligation of the right hepatic artery and temporary liver packing. On tenth postoperative day, she developed a pseudo-aneurysm of the anterior branch of the right hepatic artery, evolving with massive bleeding that was not amenable to control by endovascular therapy. Therefore, an emergency right hepatectomy had to be performed in order to stop the bleeding. The patient achieved hemodynamic stabilization, but developed a biliary fistula from the liver surface, refractory to non-operative treatment. In consequence, a Roux-Y hepatico-jejunostomy was performed at third month, with no further complications. Discussion Bleeding following tru-cut biopsy is a rare event. To our knowledge, this is the first report of an emergency hepatectomy due to hemorrhage following liver biopsy. Risks and complications of liver biopsy are revised. Conclusion Care must be taken when performing this kind of procedures and a high level of suspicion regarding this complication should be taken in count when clinical/hemodynamic deterioration occurs after these procedures. PMID:25618399

Biliary bypass surgery - Analysis of indications & outcome of different procedures.

PubMed

Hussain Talpur, K Altaf; Mahmood Malik, Arshad; Iqbal Memon, Amir; Naeem Qureshi, Jawed; Khan Sangrasi, Ahmed; Laghari, Abdul Aziz

2013-05-01

This study reports the indications and outcome of various biliary bypass surgical procedures from a single centre over a period of 10 years. This is a prospective observational study conducted over a period of 10 years (January 2001-december 2010). A total of 1500 patients were included, who underwent pancreatico-biliary surgery due to common bile duct (CBD) stones, congenital anomalies of biliary tree, unoperable pancreatico-biliary malignancies, CBD strictures and cases who developed iatrogenic biliary injuries during cholecystectomy (both open & laproscopic) during this period of time. The patients who required biliary bypass surgery were further analysed for indications and outcome. Out of 1500 patients 83(5.53%) required biliary bypass surgical procedures. The CBD stones were observed as the most common indication (25.3%), followed by CBD injuries after open(10.84%) or laproscopic-cholecystectomy (14.46%), carcinoma head of pancreas (12.05%) and CBD obstruction(14.46%) either due to CBD strictures or unknown distal obstruction. Roux-en-Y-hepatico-jejunostomy (26.51%) was the most frequently performed procedure, followed by choledochoduodenostomy and Roux-en-Y choledocho-jejunostomy (i.e. 25.3% and 12.05% respectively). Roux-en-Y biliary bypass procedure was observed to be associated with better outcome in terms of rate of complications as well duration of hospital stay. Biliary bypass surgical procedures are the better options to restore the continuity of biliary system in patients with iatrogenic biliary tree injuries and un-operable pancreatico-biliary malignancy. Roux-en-Y biliary bypass procedure is safe and problem solving method in these cases.

Biliary bypass surgery – Analysis of indications & outcome of different procedures

PubMed Central

Hussain Talpur, K.Altaf; Mahmood Malik, Arshad; Iqbal Memon, Amir; Naeem Qureshi, Jawed; Khan Sangrasi, Ahmed; Laghari, Abdul Aziz

2013-01-01

Objectives: This study reports the indications and outcome of various biliary bypass surgical procedures from a single centre over a period of 10 years. Methods: This is a prospective observational study conducted over a period of 10 years (January 2001-december 2010). A total of 1500 patients were included, who underwent pancreatico-biliary surgery due to common bile duct (CBD) stones, congenital anomalies of biliary tree, unoperable pancreatico-biliary malignancies, CBD strictures and cases who developed iatrogenic biliary injuries during cholecystectomy (both open & laproscopic) during this period of time. The patients who required biliary bypass surgery were further analysed for indications and outcome. Results: Out of 1500 patients 83(5.53%) required biliary bypass surgical procedures. The CBD stones were observed as the most common indication (25.3%), followed by CBD injuries after open(10.84%) or laproscopic-cholecystectomy (14.46%), carcinoma head of pancreas (12.05%) and CBD obstruction(14.46%) either due to CBD strictures or unknown distal obstruction. Roux-en-Y-hepatico-jejunostomy (26.51%) was the most frequently performed procedure, followed by choledochoduodenostomy and Roux-en-Y choledocho-jejunostomy (i.e. 25.3% and 12.05% respectively). Roux-en-Y biliary bypass procedure was observed to be associated with better outcome in terms of rate of complications as well duration of hospital stay. Conclusion: Biliary bypass surgical procedures are the better options to restore the continuity of biliary system in patients with iatrogenic biliary tree injuries and un-operable pancreatico-biliary malignancy. Roux-en-Y biliary bypass procedure is safe and problem solving method in these cases. PMID:24353631

Determination of Ensemble-Average Pairwise Root Mean-Square Deviation from Experimental B-Factors

PubMed Central

Kuzmanic, Antonija; Zagrovic, Bojan

2010-01-01

Abstract Root mean-square deviation (RMSD) after roto-translational least-squares fitting is a measure of global structural similarity of macromolecules used commonly. On the other hand, experimental x-ray B-factors are used frequently to study local structural heterogeneity and dynamics in macromolecules by providing direct information about root mean-square fluctuations (RMSF) that can also be calculated from molecular dynamics simulations. We provide a mathematical derivation showing that, given a set of conservative assumptions, a root mean-square ensemble-average of an all-against-all distribution of pairwise RMSD for a single molecular species, 1/2, is directly related to average B-factors () and 1/2. We show this relationship and explore its limits of validity on a heterogeneous ensemble of structures taken from molecular dynamics simulations of villin headpiece generated using distributed-computing techniques and the Folding@Home cluster. Our results provide a basis for quantifying global structural diversity of macromolecules in crystals directly from x-ray experiments, and we show this on a large set of structures taken from the Protein Data Bank. In particular, we show that the ensemble-average pairwise backbone RMSD for a microscopic ensemble underlying a typical protein x-ray structure is ∼1.1 Å, under the assumption that the principal contribution to experimental B-factors is conformational variability. PMID:20197040