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Sample records for active site flap

  1. Reduction of urease activity by interaction with the flap covering the active site.

    PubMed

    Macomber, Lee; Minkara, Mona S; Hausinger, Robert P; Merz, Kenneth M

    2015-02-23

    With the increasing appreciation for the human microbiome coupled with the global rise of antibiotic resistant organisms, it is imperative that new methods be developed to specifically target pathogens. To that end, a novel computational approach was devised to identify compounds that reduce the activity of urease, a medically important enzyme of Helicobacter pylori, Proteus mirabilis, and many other microorganisms. Urease contains a flexible loop that covers its active site; Glide was used to identify small molecules predicted to lock this loop in an open conformation. These compounds were screened against the model urease from Klebsiella aerogenes, and the natural products epigallocatechin and quercetin were shown to inhibit at low and high micromolar concentrations, respectively. These molecules exhibit a strong time-dependent inactivation of urease that was not due to their oxygen sensitivity. Rather, these compounds appear to inactivate urease by reacting with a specific Cys residue located on the flexible loop. Substitution of this cysteine by alanine in the C319A variant increased the urease resistance to both epigallocatechin and quercetin, as predicted by the computational studies. Protein dynamics are integral to the function of many enzymes; thus, identification of compounds that lock an enzyme into a single conformation presents a useful approach to define potential inhibitors. PMID:25594724

  2. Reduction of Urease Activity by Interaction with the Flap Covering the Active Site

    PubMed Central

    Macomber, Lee; Minkara, Mona S.; Hausinger, Robert P.; Merz, Kenneth M.

    2015-01-01

    With the increasing appreciation for the human microbiome coupled with the global rise of antibiotic resistant organisms, it is imperative that new methods be developed to specifically target pathogens. To that end, a novel computational approach was devised to identify compounds that reduce the activity of urease, a medically important enzyme of Helicobacter pylori, Proteus mirabilis, and many other microorganisms. Urease contains a flexible loop that covers its active site; Glide was used to identify small molecules predicted to lock this loop in an open conformation. These compounds were screened against the model urease from Klebsiella aerogenes and the natural products epigallocatechin and quercetin were shown to inhibit at low and high micromolar concentrations, respectively. These molecules exhibit a strong time-dependent inactivation of urease that was not due to their oxygen sensitivity. Rather, these compounds appear to inactivate urease by reacting with a specific Cys residue located on the flexible loop. Substitution of this cysteine by alanine in the C319A variant increased the urease resistance to both epigallocatechin and quercetin, as predicted by the computational studies. Protein dynamics are integral to the function of many enzymes; thus, identification of compounds that lock an enzyme into a single conformation presents a useful approach to define potential inhibitors. PMID:25594724

  3. Correlation of Smart Active Flap Rotor Loads

    NASA Technical Reports Server (NTRS)

    Kottapalli, Sesi; Straub, Friedrich

    2009-01-01

    The ability to predict SMART active trailing edge flap rotor loads is explored in this study. Full-scale wind tunnel data recently acquired in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with analytical results from CAMRAD II. For the 5-bladed rotor, two high-speed forward flight cases are considered, namely, a 0 deg flap deflection case and a 5P, 2 deg flap deflection case. Overall, the correlation is reasonable, with the following exceptions: the torsion moment frequency and the chordwise bending moment are under predicted. In general, the effect of the 5P, 2 deg flap motion is captured by the analysis, though there is over prediction in the neighborhood of the 105 deg and 120 deg azimuthal locations. Changes to the flexbeam torsion stiffness are also briefly considered in this study, as this stiffness will be updated in the future. Finally, the indication is that compressibility effects are important, and this suggests that computational fluid dynamics might improve the current correlation.

  4. Global optimization of actively morphing flapping wings

    NASA Astrophysics Data System (ADS)

    Ghommem, Mehdi; Hajj, Muhammad R.; Mook, Dean T.; Stanford, Bret K.; Beran, Philip S.; Snyder, Richard D.; Watson, Layne T.

    2012-08-01

    We consider active shape morphing to optimize the flight performance of flapping wings. To this end, we combine a three-dimensional version of the unsteady vortex lattice method (UVLM) with a deterministic global optimization algorithm to identify the optimal kinematics that maximize the propulsive efficiency under lift and thrust constraints. The UVLM applies only to incompressible, inviscid flows where the separation lines are known a priori. Two types of morphing parameterization are investigated here—trigonometric and spline-based. The results show that the spline-based morphing, which requires specification of more design variables, yields a significant improvement in terms of propulsive efficiency. Furthermore, we remark that the average value of the lift coefficient in the optimized kinematics remained equal to the value in the baseline case (without morphing). This indicates that morphing is most efficiently used to generate thrust and not to increase lift beyond the basic value obtained by flapping only. Besides, our study gives comparable optimal efficiencies to those obtained from previous studies based on gradient-based optimization, but completely different design points (especially for the spline-based morphing), which would indicate that the design space associated with the flapping kinematics is very complex.

  5. Active Flap Control of the SMART Rotor for Vibration Reduction

    NASA Technical Reports Server (NTRS)

    Hall, Steven R.; Anand, R. Vaidyanathan; Straub, Friedrich K.; Lau, Benton H.

    2009-01-01

    Active control methodologies were applied to a full-scale active flap rotor obtained during a joint Boeing/ DARPA/NASA/Army test in the Air Force National Full-Scale Aerodynamic Complex 40- by 80-foot anechoic wind tunnel. The active flap rotor is a full-scale MD 900 helicopter main rotor with each of its five blades modified to include an on-blade piezoelectric actuator-driven flap with a span of 18% of radius, 25% of chord, and located at 83% radius. Vibration control demonstrated the potential of active flaps for effective control of vibratory loads, especially normal force loads. Active control of normal force vibratory loads using active flaps and a continuous-time higher harmonic control algorithm was very effective, reducing harmonic (1-5P) normal force vibratory loads by 95% in both cruise and approach conditions. Control of vibratory roll and pitch moments was also demonstrated, although moment control was less effective than normal force control. Finally, active control was used to precisely control blade flap position for correlation with pretest predictions of rotor aeroacoustics. Flap displacements were commanded to follow specific harmonic profiles of 2 deg or more in amplitude, and the flap deflection errors obtained were less than 0.2 deg r.m.s.

  6. Rotor Flapping Response to Active Control

    NASA Technical Reports Server (NTRS)

    Nguyen, Khanh; Johnson, Wayne

    2004-01-01

    Rotor active control using higher harmonic blade pitch has been proposed as a means to reduce both rotor radiated noise and airframe vibration and to enhance rotor performance. The higher harmonic input, however, can affect rotor thrust and cyclic flapping - the basic trim characteristics of the rotor. Some of the trim changes can negate the active control benefits. For example, wind tunnel test results of a full scale BO-105 rotor with individual-blade control indicate some rotor performance improvements, accompanied with changes in rotor trim, using two-per-rev blade pitch input. The observed performance benefits could therefore be a simple manifestation of the trim change rather than an efficient redistribution of the rotor airloads. More recently, the flight test of the BO-105 helicopter equip,ped with individual-blade-control actuators also reported trim changes whenever the two-per-rev blade pitch for noise reduction was activated. The pilot had to adjust the trim control to maintain the aircraft under a constant flight path. These two cases highlight the, importance of trim considerations in the application of active control to rotorcraft.

  7. What Is the Ideal Free Flap for Soft Tissue Reconstruction? A Ten-Year Experience of Microsurgical Reconstruction Using 334 Latissimus Dorsi Flaps From a Universal Donor Site.

    PubMed

    Kim, Jeong Tae; Kim, Sang Wha; Youn, Seungki; Kim, Youn Hwan

    2015-07-01

    Microsurgical free tissue transfer is regarded as the best available method of tissue reconstruction for intractable defects. The ideal soft tissue flap is thought to be the anterolateral thigh flap. On the basis of 334 procedures involving the latissimus dorsi (LD) flap, we discuss the advantages of the LD flap over the current universal option, and we aimed to establish whether the LD could also gain universal status in all reconstructive fields.Three hundred thirty-four reconstructive procedures using the LD flap were performed in 322 patients between September 2002 and July 2012. In accordance with defect characteristics, we performed 334 procedures using flaps, which included the LD muscle flap with skin graft, the myocutaneous flap, the muscle-sparing flap, the perforator flap, the chimeric flap, and the 2-flap technique using the serratus anterior branch.Flap-related complications occurred in 21 patients (6.3%), including total and partial flap failure. In 253 cases, the donor site was closed primarily, and in the remaining cases, we used split-thickness skin grafts. Donor-site complications occurred in 20 cases (6%). In 11 of the 182 cases, no suitable perforators were identified during surgery.The advantages of the LD as a donor site include the possibility of various harvesting positions without position change, versatility of components, availability of muscle to fill extensive defects, and presence of thick fascia to enable full abdominal reconstruction. On the basis of our experience, we concluded that this flap has the potential to be used as widely as, or in preference to, the anterolateral thigh flap in most reconstructive areas. PMID:25785382

  8. Wind Tunnel Test of the SMART Active Flap Rotor

    NASA Technical Reports Server (NTRS)

    Straub, Friedrich K.; Anand, Vaidyanthan R.; Birchette, Terrence S.; Lau, Benton H.

    2009-01-01

    Boeing and a team from Air Force, NASA, Army, DARPA, MIT, UCLA, and U. of Maryland have successfully completed a wind-tunnel test of the smart material actuated rotor technology (SMART) rotor in the 40- by 80-foot wind-tunnel of the National Full-Scale Aerodynamic Complex at NASA Ames Research Center. The Boeing SMART rotor is a full-scale, five-bladed bearingless MD 900 helicopter rotor modified with a piezoelectric-actuated trailing edge flap on each blade. The eleven-week test program evaluated the forward flight characteristics of the active-flap rotor at speeds up to 155 knots, gathered data to validate state-of-the-art codes for rotor aero-acoustic analysis, and quantified the effects of open and closed loop active flap control on rotor loads, noise, and performance. The test demonstrated on-blade smart material control of flaps on a full-scale rotor for the first time in a wind tunnel. The effectiveness of the active flap control on noise and vibration was conclusively demonstrated. Results showed significant reductions up to 6dB in blade-vortex-interaction and in-plane noise, as well as reductions in vibratory hub loads up to 80%. Trailing-edge flap deflections were controlled within 0.1 degrees of the commanded value. The impact of the active flap on control power, rotor smoothing, and performance was also demonstrated. Finally, the reliability of the flap actuation system was successfully proven in more than 60 hours of wind-tunnel testing.

  9. Stabilizing Morbidity and Predicting the Aesthetic Results of Radial Forearm Free Flap Donor Sites

    PubMed Central

    Yun, Tae Kyoung; Ahn, Duck Sun; Park, Seung Ha; Lee, Byung Il; Kim, Hyon Surk; You, Hi Jin

    2015-01-01

    Background The radial forearm flap is a versatile, widely used flap. However, the possibility of donor site complications has led to concern over its use. Some surgeons prefer using other flaps whose donor sites can be closed primarily with less morbidity, including avoiding unpleasant scarring. However, in our experience, donor site stability of the radial forearm flap can be reliably achieved by using well-implemented specific procedures. Here, we present a collection of donor site cases of the radial forearm flap and investigate factors that affect the aesthetic results as the basis for a reference for selecting a radial forearm flap. Methods In this retrospective study, we reviewed 171 cases in which a radial forearm flap was used for free tissue transfer after resecting head and neck cancer. We focused on donor site morbidity rates. Each operation involved a detailed procedure designed to minimize donor site morbidity. Moreover, statistical investigations were conducted for 22 cases to determine factors affecting the scar appearance. Results Only one case developed total skin graft necrosis as a major complication. Scar-related aesthetic results were acceptable, and the body-mass index, body weight, diabetes, and cardiac problems were significant factors related to the appearance of scars. Conclusions Performing the radial forearm flap using a well-implemented detailed technique helps achieve acceptable donor site morbidity results. The aesthetic results were more promising for patients without excess body weight, diabetes, or cardiac problems. Therefore, anxiety about donor site morbidity should not be a reason to avoid selecting the radial forearm flap in suitable patients. PMID:26618126

  10. Crystal structure of type I 3-dehydroquinate dehydratase of Aquifex aeolicus suggests closing of active site flap is not essential for enzyme action.

    PubMed

    Devi, Aribam Swarmistha; Ebihara, Akio; Kuramitsu, Seiki; Yokoyama, Shigeyuki; Kumarevel, Thirumananseri; Ponnuraj, Karthe

    2013-03-01

    Structural analyses of enzymes involved in biosynthetic pathways that are present in micro-organisms, but absent from mammals (for example Shikimate pathway) are important in developing anti-microbial drugs. Crystal structure of the Shikimate pathway enzyme, type I 3-dehydroquinate dehydratase (3-DHQase) from the hyperthermophilic bacterium Aquifex aeolicus was solved both as an apo form and in complex with a ligand. The complex structure revealed an interesting structural difference when compared to other ligand-bound type I 3-DHQases suggesting that closure of the active site loop is not essential for catalysis. This provides new insights into the catalytic mechanism of type I 3-DHQases. PMID:23396056

  11. Tracheoesophageal puncture site closure with sternocleidomastoid musculocutaneous transposition flap

    PubMed Central

    Jaiswal, Dushyant; Yadav, Prabha; Shankhdhar, Vinay Kant; Gujjalanavar, Rajendra Suresh; Puranik, Prashant

    2015-01-01

    Introduction: Tracheoesophageal voice prosthesis is highly effective in providing speech after total laryngectomy. Although it is a safe method, in certain cases dilatation or leakage occurs around the prosthesis that needs closure of tracheoesophageal fistula. Both non-surgical and surgical methods for closure have been described. Surgical methods are used when non-surgical methods fail. We present the use of the sternocleidomastoid musculocutaneous (SCMMC) transposition flap for the closure of tracheoesophageal fistula. Materials and Methods: An incision is made at the mucocutaneous junction circumferentially around the tracheostoma. Tracheoesophageal space is dissected down to and beyond the fistula. The tracheoesophageal tract is divided. The oesophageal mucosa is closed with simple sutures. Then SCMMC transposition flap is raised and transposed to cover sutured oesophagus and the defect between the oesophagus and the trachea. Results: This study was done prospectively over a period of 1 year from June 2012 to May 2013. This technique was used in patients with pliable neck skin. In nine patients, this procedure was done (inferior based flap in nine cases) and it was successful in eight patients. In one case, there was dehiscence at the leading edge of flap with oesophageal dehiscence, which required a second procedure. In two cases, there was marginal necrosis of flap, which healed without any intervention. Nine patients in this series were post-radiation. Conclusion: This method of closure is simple and effective for patients with pliable neck skin, who require permanent closure of the tracheoesophageal fistula. PMID:26933281

  12. Prospective biomechanical evaluation of donor site morbidity after radial forearm free flap.

    PubMed

    Riecke, Björn; Kohlmeier, Carsten; Assaf, Alexandre T; Wikner, Johannes; Drabik, Anna; Catalá-Lehnen, Philip; Heiland, Max; Rendenbach, Carsten

    2016-02-01

    Although the radial forearm free flap (RFF) is a commonly-used microvascular flap for orofacial reconstruction, we are aware of few prospective biomechanical studies of the donor site. We have therefore evaluated the donor site morbidity biomechanically of 30 consecutive RFF for orofacial reconstruction preoperatively and three months postoperatively. This included the Mayo wrist score, the Disabilities of the Arm, Shoulder and Hand (DASH) score, grip strength, followed by tip pinch, key pinch, palmar pinch, and range of movement of the wrist. Primary defects were all closed with local full-thickness skin grafts from the donor site forearm, thereby circumventing the need for a second defect. Postoperative functional results showed that there was a reduction in hand strength measured by (grip strength: -24.1%, in tip pinch: -23.3%, in key pinch: -16.5, and in palmar pinch: -19.3%); and wrist movement measured by extension (active=14.3% / passive= -11.5%) and flexion = -14.8% / -8.9%), and radial (-9.8% / -9.8%) and ulnar (-11.0% / -9.3%) abduction. The Mayo wrist score was reduced by 9.4 points (-12.9%) and the DASH score increased by 16.1 points (+35.5%) compared with the same forearm preoperatively. The local skin graft resulted in a robust wound cover with a good functional result. Our results show that the reduction in hand strength and wrist movement after harvest of a RFF is objectively evaluable, and did not reflect the subjectively noticed extent and restrictions in activities of daily living. Use of a local skin graft avoids a second donor site and the disadvantages of a split-thickness skin graft. PMID:26708799

  13. Localized, Non-Harmonic Active Flap Motions for Low Frequency In-Plane Rotor Noise Reduction

    NASA Technical Reports Server (NTRS)

    Sim, Ben W.; Potsdam, Mark; Kitaplioglu, Cahit; LeMasurier, Philip; Lorber, Peter; Andrews, Joseph

    2012-01-01

    A first-of-its-kind demonstration of the use of localized, non-harmonic active flap motions, for suppressing low frequency, in-plane rotor noise, is reported in this paper. Operational feasibility is verified via testing of the full-scale AATD/Sikorsky/UTRC active flap demonstration rotor in the NFAC's 40- by 80-Foot anechoic wind tunnel. Effectiveness of using localized, non-harmonic active flap motions are compared to conventional four-per-rev harmonic flap motions, and also active flap motions derived from closed-loop acoustics implementations. All three approaches resulted in approximately the same noise reductions over an in-plane three-by-three microphone array installed forward and near in-plane of the rotor in the nearfield. It is also reported that using an active flap in this localized, non-harmonic manner, resulted in no more that 2% rotor performance penalty, but had the tendency to incur higher hub vibration levels.

  14. A Biodegradable Polyurethane Dermal Matrix in Reconstruction of Free Flap Donor Sites: A Pilot Study

    PubMed Central

    Wagstaff, Marcus J.D.; Schmitt, Bradley J.; Coghlan, Patrick; Finkemeyer, James P.; Caplash, Yugesh

    2015-01-01

    We have developed a biodegradable temporizing matrix (BTM) capable of supporting secondary split-skin graft-take in animal studies. We report its first long-term implantation and use as a dermal scaffold in humans. This preliminary study assesses its ability to integrate, its ease of delamination, its ability to sustain split-skin graft in complex wounds, the degree of wound contraction, and ultimately the quality of the scar at 1 year postimplantation. Ten patients were recruited, each requiring elective free flap reconstruction. Free flap donor sites created were anterolateral thigh flaps, fibular osseocutaneous flaps, or radial/ulnar forearm (RF/UF) flaps. The BTM was implanted when the flap was detached from its donor site. Dressing changes were performed twice weekly. The time elapsed between implantation and delamination depended on the type of flap and thus the wound bed left. Once integrated, the BTMs were delaminated in theatre, and the surface of the “neodermis” was refreshed by dermabrasion, prior to application of a split-skin graft. The BTM integration occurred in all patients (100% in 6 patients, with 90%, 84%, 76%, and 60% integration in the remainder). Integrated BTM sustained successful graft-take in all patients. Complete take was marred in 2 patients, over areas of BTM that had not integrated and graft application was performed too early. The BTM can be applied into wounds in humans and can integrate, persist in the presence of infection, and sustain split-skin overgrafting, despite the trial group presenting with significant comorbidities. PMID:25987938

  15. A biodegradable polyurethane dermal matrix in reconstruction of free flap donor sites: a pilot study.

    PubMed

    Wagstaff, Marcus J D; Schmitt, Bradley J; Coghlan, Patrick; Finkemeyer, James P; Caplash, Yugesh; Greenwood, John E

    2015-01-01

    We have developed a biodegradable temporizing matrix (BTM) capable of supporting secondary split-skin graft-take in animal studies. We report its first long-term implantation and use as a dermal scaffold in humans. This preliminary study assesses its ability to integrate, its ease of delamination, its ability to sustain split-skin graft in complex wounds, the degree of wound contraction, and ultimately the quality of the scar at 1 year postimplantation. Ten patients were recruited, each requiring elective free flap reconstruction. Free flap donor sites created were anterolateral thigh flaps, fibular osseocutaneous flaps, or radial/ulnar forearm (RF/UF) flaps. The BTM was implanted when the flap was detached from its donor site. Dressing changes were performed twice weekly. The time elapsed between implantation and delamination depended on the type of flap and thus the wound bed left. Once integrated, the BTMs were delaminated in theatre, and the surface of the "neodermis" was refreshed by dermabrasion, prior to application of a split-skin graft. The BTM integration occurred in all patients (100% in 6 patients, with 90%, 84%, 76%, and 60% integration in the remainder). Integrated BTM sustained successful graft-take in all patients. Complete take was marred in 2 patients, over areas of BTM that had not integrated and graft application was performed too early. The BTM can be applied into wounds in humans and can integrate, persist in the presence of infection, and sustain split-skin overgrafting, despite the trial group presenting with significant comorbidities. PMID:25987938

  16. A Single Amino Acid Difference between Mouse and Human 5-Lipoxygenase Activating Protein (FLAP) Explains the Speciation and Differential Pharmacology of Novel FLAP Inhibitors.

    PubMed

    Blevitt, Jonathan M; Hack, Michael D; Herman, Krystal; Chang, Leon; Keith, John M; Mirzadegan, Tara; Rao, Navin L; Lebsack, Alec D; Milla, Marcos E

    2016-06-10

    5-Lipoxygenase activating protein (FLAP) plays a critical role in the metabolism of arachidonic acid to leukotriene A4, the precursor to the potent pro-inflammatory mediators leukotriene B4 and leukotriene C4 Studies with small molecule inhibitors of FLAP have led to the discovery of a drug binding pocket on the protein surface, and several pharmaceutical companies have developed compounds and performed clinical trials. Crystallographic studies and mutational analyses have contributed to a general understanding of compound binding modes. During our own efforts, we identified two unique chemical series. One series demonstrated strong inhibition of human FLAP but differential pharmacology across species and was completely inactive in assays with mouse or rat FLAP. The other series was active across rodent FLAP, as well as human and dog FLAP. Comparison of rodent and human FLAP amino acid sequences together with an analysis of a published crystal structure led to the identification of amino acid residue 24 in the floor of the putative binding pocket as a likely candidate for the observed speciation. On that basis, we tested compounds for binding to human G24A and mouse A24G FLAP mutant variants and compared the data to that generated for wild type human and mouse FLAP. These studies confirmed that a single amino acid mutation was sufficient to reverse the speciation observed in wild type FLAP. In addition, a PK/PD method was established in canines to enable preclinical profiling of mouse-inactive compounds. PMID:27129215

  17. Enhanced Correlation of SMART Active Flap Rotor Loads

    NASA Technical Reports Server (NTRS)

    Kottapalli, Sesi

    2011-01-01

    This is a follow-on study to a 2010 correlation effort. Measured data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. As background, during the wind tunnel test, unexpectedly high inboard loads were encountered, and it was hypothesized at that time that due to changes in the flexbeams over the years, the flexbeam properties used in the analysis needed updating. Boeing Mesa, recently updated these properties. This correlation study uses the updated flexbeam properties. Compared to earlier studies, the following two enhancements are implemented: i) the inboard loads (pitchcase and flexbeam loads) correlation is included for the first time (reliable prediction of the inboard loads is a prerequisite for any future anticipated flight-testing); ii) the number of blade modes is increased to better capture the flap dynamics and the pitchcase-flexbeam dynamics. Also, aerodynamically, both the rolled-up wake model and the more complex, multiple trailer wake model are used, with the latter slightly improving the blade chordwise moment correlation. This sensitivity to the wake model indicates that CFD is needed. Three high-speed experimental cases, one uncontrolled free flap case and two commanded flap cases, are considered. The two commanded flap cases include a 2o flap deflection at 5P case and a 0o flap deflection case. For the free flap case, selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the commanded 2o flap case, the experimental flap variation is approximately matched by increasing the analytical flap hinge stiffness. This increased flap hinge stiffness is retained for the commanded 0o flap case also, which is treated as a free flap case, but with larger flap hinge stiffness. The change in the mid-span and outboard loads correlation due to the updating of the flexbeam properties is not significant. Increasing the number of blade modes results in an

  18. Metabolic adaptations in delayed skin flaps. Glucose utilization and hexokinase activity.

    PubMed

    Im, M J; Su, C T; Hoopes, J E

    1979-08-01

    The distribution of glucose and hexokinase activity was determined in the epithelial tissue of delayed bipedicled skin flaps in guinea pigs. The periods of "delay" were 1, 3, 7, 14, or 21 days. The flap survival was maximal (100% of the flap) when the flap elevation was performed either 7 or 14 days following the "delay" procedure. When the flap elevation was performed 1, 3, or 21 days following the "delay" procedure, the result was partial necrosis. A differential distribution of epithelial glucose was found within the bipedicled flaps. The lowest glucose level (30% of normal) was at a distance of 2 to 3.5 cm from the end of the caudal pedicle during the first day after the "delay" procedure. This decreased glucose content recovered toward normal levels during the later part of the "delay" period. The bipedicled flaps exhibited increased hexokinase activity during the 3-week period of the "delay," and the responses of hexokinase activity and tissue glucose levels to the "delay" procedure were reciprocal in the caudal half of the flaps. PMID:377341

  19. Active Control of Separation From the Flap of a Supercritical Airfoil

    NASA Technical Reports Server (NTRS)

    Melton, La Tunia Pack; Yao, Chung-Sheng; Seifert, Avi

    2003-01-01

    Active flow control in the form of periodic zero-mass-flux excitation was applied at several regions on the leading edge and trailing edge flaps of a simplified high-lift system t o delay flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control at several locations on the deflected trailing edge flap. High frequency (F(+) approx.= 10) and low frequency amplitude modulation (F(+)AM approx.= 1) of the high frequency excitation were used for control. Preliminary efforts to combine leading and trailing edge flap excitations are also reported.

  20. Free Flap Donor Site Reconstruction: A Prospective Case Series Using an Optimized Polyurethane Biodegradable Temporizing Matrix

    PubMed Central

    Wagstaff, Marcus J. D.; Schmitt, Bradley J.; Caplash, Yugesh

    2015-01-01

    Introduction: We recently published a 10-patient case series where free flap donor site reconstruction was performed as a 2-stage procedure using an integrating biodegradable polyurethane matrix (to form a neodermis), followed by definitive closure with an autologous split-skin graft. Two issues were revealed by this pilot study that led to further modification of the biodegradable temporizing matrix. This involved alterations to the seal thickness and bonding to the foam matrix and the introduction of fenestrations to the seal. Objective: This article documents a second cohort of patients requiring free flap (fibular and radial forearm) donor site reconstruction with this optimized material. Methods: The biodegradable temporizing matrix was implanted when the free flap was detached from its donor site. Subsequent integration was monitored closely. Five weeks was the usual time of integration before delamination (seal removal), dermabrasion, and definitive closure with autograft. Results: Integration was complete and uncomplicated in every case, delamination occurred in 1 piece in 1 action, and subsequent graft take was 100% for every patient. Long-term scar outcomes improved compared with the pilot group. Degradation is complete by 12 months, other than occasional microscopic remnants undergoing phagocytosis. Conclusion: This study has reiterated that the biodegradable temporizing matrix can be implanted into humans, followed by neovascularization and integration. No infection was observed, and split-skin overgrafting was successful and uncomplicated. PMID:26171099

  1. Reduction of Donor Site Morbidity of Free Radial Forearm Flaps: What Level of Evidence Is Available?

    PubMed Central

    Loeffelbein, Denys J.; Al-Benna, Sammy; Steinsträßer, Lars; Satanovskij, Robin M.; Rohleder, Nils H.; Mücke, Thomas; Wolff, Klaus-Dietrich; Kesting, Marco R.

    2012-01-01

    Background: The radial forearm free flap (RFFF) is the most commonly used free flap in head and neck reconstructive surgery. However, despite excellent results with respect to the site of reconstruction, donor site morbidity cannot be neglected. This review summarizes the current state of knowledge and analyzes the level of evidence with regard to perioperative management of the reduction of RFFF donor site morbidity. Methods: The medical Internet source PubMed was screened for relevant articles. All relevant articles were tabulated according to the levels of scientific evidence, and the available methods for reduction of donor site morbidity are discussed. Results: Classification into levels of evidence reveals 3 publications (1.5%) with level I (randomized controlled trials), 29 (14.0%) with level II (experimental studies with no randomization, cohort studies, or outcome research), 3 (1.5%) with level III (systematic review of case-control studies or individual case-control studies), 121 (58.7%) with level IV (nonexperimental studies, such as cross-sectional trials, case series, case reports), and 15 (7.3%) with level V (narrative review or expert opinion without explicit critical appraisal). Thirty-five (17.0%) articles could not be classified, because they focused on a topic other than donor site morbidity of the RFFF. Conclusions: Although great interest has been expressed with regard to reducing the donor site morbidity of the workhorse flap in microvascular reconstruction procedures, most publications fail to provide the hard facts and solid evidence characteristic of high-quality research. PMID:22331991

  2. Technical refinements of composite thoracodorsal system free flaps for 1-stage lower extremity reconstruction resulting in reduced donor-site morbidity.

    PubMed

    Bannasch, Holger; Strohm, Peter C; Al Awadi, Khalid; Stark, G Björn; Momeni, Arash

    2008-04-01

    A multitude of local flaps has been suggested for lower extremity reconstruction. However, the gold standard for defect coverage remains free tissue transfer. In this regard, the scapular vascular axis is a well-established source of expendable skin, fascia, muscle, and bone for use in free flap reconstruction of defects requiring bone and soft tissue in complex 3-dimensional relationships. Composite bone and soft-tissue flaps derived from the subscapular vascular axis include the osteocutaneous scapular flap, the "latissimus/bone flap," and the thoracodorsal artery perforator-scapular osteocutaneous flap.Patient outcome following reconstruction of lower extremity defects with composite free flaps from the thoracodorsal system were analyzed. Here, we demonstrate the execution of technical refinements on free composite flap transfers based on the thoracodorsal vascular axis, thus resulting in a stepwise reduction of donor-site morbidity. PMID:18362565

  3. The Effect of the Active Ingredient Thymoquinone on Flap Viability in Random Pattern Flaps in Rats.

    PubMed

    Kocak, Omer Faruk; Bozan, Nazim; Oksuz, Mustafa; Yuce, Serdar; Demir, Canser Yılmaz; Bulut, Gulay; Ragbetli, Murat Cetin

    2016-08-01

    Thymoquinone (TQ) is a plant extract that has been shown to have antioxidant, anti-inflammatory, angiogenic, antimicrobial, and anticarcinogenic effects. The aim of this study is to research how the use of TQ affects flap viability. 42 rats were placed into 6 groups, with 7 rats in each. A 3 × 10 cm McFarlane flap model was used on the test animals. The sham group had used neither surgical nor TQ treatment. The control group had surgery but no treatment afterwards. The preoperative TQ group was given oral doses of 2 mg/kg. TQ for 10 days preoperatively with no treatment after the surgical procedure. The postoperative TQ group received oral doses of 2 mg/kg TQ for 10 days after the surgical process. The preoperative + postoperative (pre + postoperative) TQ group was given oral doses of 2 mg/kg TQ for 10 days both preoperatively and postoperatively. Finally, the dimethylsulfoxide group received 10 mg/kg dimethylsulfoxide (DMSO) for 10 days both preoperatively and postoperatively. Ten days after surgery the findings were evaluated. The average rates of necrosis were found to be 29.7 % in the control group, 19.18 % in the preoperative TQ group, 13.05 % in the postoperative TQ group, 8.42 % in the pre + postoperative TQ group, and 29.03 % in the DMSO group. The experimental groups had better area measurement, histopathological, and electron microscopic results than the control group (All; p < 0.05). We believe that, because of its antioxidant, anti-inflammatory, and angiogenic properties, thymoquinone is an agent that can prevent ischemia-reperfusion damage and, therefore, prevent necrosis. PMID:27072137

  4. Human exonuclease 1 (EXO1) activity characterization and its function on flap structures

    PubMed Central

    Keijzers, Guido; Bohr, Vilhelm A.; Rasmussen, Lene Juel

    2015-01-01

    Human exonuclease 1 (EXO1) is involved in multiple DNA metabolism processes, including DNA repair and replication. Most of the fundamental roles of EXO1 have been described in yeast. Here, we report a biochemical characterization of human full-length EXO1. Prior to assay EXO1 on different DNA flap structures, we determined factors essential for the thermodynamic stability of EXO1. We show that enzymatic activity and stability of EXO1 on DNA is modulated by temperature. By characterization of EXO1 flap activity using various DNA flap substrates, we show that EXO1 has a strong capacity for degrading double stranded DNA and has a modest endonuclease or 5′ flap activity. Furthermore, we report novel mechanistic insights into the processing of flap structures, showing that EXO1 preferentially cleaves one nucleotide inwards in a double stranded region of a forked and nicked DNA flap substrates, suggesting a possible role of EXO1 in strand displacement. PMID:26182368

  5. Active Management of Flap-Edge Trailing Vortices

    NASA Technical Reports Server (NTRS)

    Greenblatt, David; Yao, Chung-Sheng; Vey, Stefan; Paschereit, Oliver C.; Meyer, Robert

    2008-01-01

    The vortex hazard produced by large airliners and increasingly larger airliners entering service, combined with projected rapid increases in the demand for air transportation, is expected to act as a major impediment to increased air traffic capacity. Significant reduction in the vortex hazard is possible, however, by employing active vortex alleviation techniques that reduce the wake severity by dynamically modifying its vortex characteristics, providing that the techniques do not degrade performance or compromise safety and ride quality. With this as background, a series of experiments were performed, initially at NASA Langley Research Center and subsequently at the Berlin University of Technology in collaboration with the German Aerospace Center. The investigations demonstrated the basic mechanism for managing trailing vortices using retrofitted devices that are decoupled from conventional control surfaces. The basic premise for managing vortices advanced here is rooted in the erstwhile forgotten hypothesis of Albert Betz, as extended and verified ingeniously by Coleman duPont Donaldson and his collaborators. Using these devices, vortices may be perturbed at arbitrarily long wavelengths down to wavelengths less than a typical airliner wingspan and the oscillatory loads on the wings, and hence the vehicle, are small. Significant flexibility in the specific device has been demonstrated using local passive and active separation control as well as local circulation control via Gurney flaps. The method is now in a position to be tested in a wind tunnel with a longer test section on a scaled airliner configuration. Alternatively, the method can be tested directly in a towing tank, on a model aircraft, a light aircraft or a full-scale airliner. The authors believed that this method will have significant appeal from an industry perspective due to its retrofit potential with little to no impact on cruise (devices tucked away in the cove or retracted); low operating power

  6. No-drain DIEP Flap Donor-site Closure Using Barbed Progressive Tension Sutures

    PubMed Central

    Nagarkar, Purushottam; Lakhiani, Chrisovalantis; Cheng, Angela; Lee, Michael; Teotia, Sumeet

    2016-01-01

    Background: The use of progressive tension sutures has been shown to be comparable to the use of abdominal drains in abdominoplasty. However, the use of barbed progressive tension sutures (B-PTSs) in deep inferior epigastric artery perforator (DIEP) flap donor-site closure has not been investigated. Methods: A retrospective chart review was performed on patients with DIEP flap reconstruction in a 3-year period at 2 institutions by 2 surgeons. Patients were compared by method of DIEP donor-site closure. Group 1 had barbed running progressive tension sutures without drain placement. Group 2 had interrupted progressive tension closure with abdominal drain placement (PTS-AD). Group 3 had closure with only abdominal drain placement (AD). Data collected included demographics, perioperative data, and postoperative outcomes. Results: Seventy-five patients underwent DIEP reconstruction (25 B-PTS, 25 PTS-AD, and 25 AD). Patient characteristics—age, body mass index, comorbidities, smoking status, and chemotherapy—were not significantly different between groups. Rate of seroma was 1.3% (B-PTS = 0%, PTS-AD = 4%, AD = 0%), wound dehiscence 16% (B-PTS = 8%, PTS-AD = 16%, AD = 24%), and umbilical necrosis 5.3% (B-PTS = 0%, PTS-AD = 0%, AD = 16%). No hematomas were observed in any patients. No statistically significant difference was found between complication rates across groups. Conclusions: Use of B-PTSs for abdominal closure after DIEP flap harvest can obviate the need for abdominal drains. Complication rates following this technique are not significantly different from closure using progressive tension suture and abdominal drain placement. This practice can prevent the use of abdominal drains, which can promote patient mobility, increase independence upon discharge, and contribute to patient satisfaction. PMID:27200234

  7. Development and whirl tower test of the SMART active flap rotor

    NASA Astrophysics Data System (ADS)

    Straub, Friedrich K.; Kennedy, Dennis K.; Stemple, Alan D.; Anand, V. R.; Birchette, Terry S.

    2004-07-01

    A full scale Smart Material Actuated Rotor Technology (SMART) system with piezoelectric actuated blade flaps was developed and whirl tower tested. The development effort included design, fabrication, and component testing of rotor blades, trailing edge flaps, piezoelectric actuators, switching power amplifiers, and the data/power system. Simulations and model scale wind tunnel tests have shown that this system can provide 80% vibration reduction, 10dB noise reduction for a helicopter passing overhead, and substantial aerodynamic performance gains. Whirl tower testing of the 34-foot diameter rotor demonstrated the functionality, robustness, and required authority of the active flap system. The program involved extensive development work and risk reduction tests which resulted in a robust, high performance actuator and a tightly integrated actuator, flap, and blade system. The actuator demonstrated excellent performance during bench testing and has accumulated over 60 million cycles under a spectrum of loading conditions. The flight worthy active flap rotor blades were based on a modified design of the FAA certified MD900 Explorer production rotor blade. Whirl tower testing was conducted with full rotor instrumentation and a 5-component balance. The rotor was tested for 13 hours under a range of conditions, including 7 hours of flap operation. Flap inputs included open loop static and dynamic commands. The flaps showed excellent authority with oscillatory thrust greater than 10% of the steady baseline thrust. Various flap actuation frequency sweeps were run to investigate the dynamics of the rotor and the flap system. Limited closed loop tests used hub accelerations and hub loads for feedback. Proving the integration, robust operation, and authority of the flap system were the key objectives met by the whirl tower test. This success depended on tailoring the piezoelectric materials and actuator to the application and meeting actuator/blade integration requirements

  8. Design and development of an active Gurney flap for rotorcraft

    NASA Astrophysics Data System (ADS)

    Freire Gómez, Jon; Booker, Julian D.; Mellor, Phil H.

    2013-03-01

    The EU's Green Rotorcraft programme will develop an Active Gurney Flap (AGF) for a full-scale helicopter main rotor blade as part of its `smart adaptive rotor blade' technology demonstrators. AGFs can be utilized to provide a localized and variable lift enhancement on the rotor, enabling a redistribution of loading on the rotor blade around the rotor azimuth. Further advantages include the possibility of using AGFs to allow a rotor speed reduction, which subsequently provides acoustic benefits. Designed to be integrable into a commercial helicopter blade, and thereby capable of withstanding real in-flight centrifugal loading, blade vibrations and aerodynamic loads, the demonstrator is expected to achieve a high technology readiness level (TRL). The AGF will be validated initially by a constant blade section 2D wind tunnel test and latterly by full blade 3D whirl tower testing. This paper presents the methodology adopted for the AGF concept topology selection, based on a series of both qualitative and quantitative performance criteria. Two different AGF candidate mechanisms are compared, both powered by a small commercial electromagnetic actuator. In both topologies, the link between the actuator and the control surface consists of two rotating torque bars, pivoting on flexure bearings. This provides the required reliability and precision, while making the design virtually frictionless. The engineering analysis presented suggests that both candidates would perform satisfactorily in a 2D wind tunnel test, but that equally, both have design constraints which limit their potential to be further taken into a whirl tower test under full scale centrifugal and inertial loads.

  9. Functional and esthetic assessment of radial forearm flap donor site repaired with split thickness skin graft.

    PubMed

    Lee, Jong-Ho; Alrashdan, Mohammad S; Kim, Su-Gon; Rim, Jae-Seok; Jabaiti, Samir; Kim, Myung-Jin; Kim, Soung-Min

    2011-01-01

    The purpose of this study was to evaluate the long-term functional and esthetic outcomes of radial forearm flap (RFF) donor site repaired with split thickness skin graft (STSG). Nineteen patients underwent surgical reconstruction of oro-facial defects by the use of RFF and their donor sites were reconstructed with STSG. The patients were followed up at least for 12 months postoperatively and the left hand was the non-dominant hand in all of them. Objective methods including pinch strength, grip strength, range of motion, current perception threshold (CPT) and two-point discrimination, and subjective methods including patients interview, visual analogue score (VAS) about function, sensitivity, pain and color match, were collectively employed for donor site assessment. Our data revealed some degree of reduction in motor function and sensation compared to the non-donor hand. The difference of pinch strength means was 9.81% and of the grip strength was 12.6%. The difference of wrist flexion means was 17.6% and of wrist extension was 13.4%. However, none of the patients had functional defects of forearm supination and pronation, wrist ulnar deviation or wrist radial deviation. Subjective evaluation showed that the donor site repaired with STSG was well accepted by the patients particularly from a functional point of view. These results demonstrate that STSG represents a favorable choice for RFF donor site repair. PMID:20589506

  10. Role of induced vortex interaction in a semi-active flapping foil based energy harvester

    NASA Astrophysics Data System (ADS)

    Wu, J.; Chen, Y. L.; Zhao, N.

    2015-09-01

    The role of induced vortex interaction in a semi-active flapping foil based energy harvester is numerically examined in this work. A NACA0015 airfoil, which acts as an energy harvester, is placed in a two-dimensional laminar flow. It performs an imposed pitching motion that subsequently leads to a plunging motion. Two auxiliary smaller foils, which rotate about their centers, are arranged above and below the flapping foil, respectively. As a consequence, the vortex interaction between the flapping foil and the rotating foil is induced. At a Reynolds number of 1100 and the position of the pitching axis at one-third chord, the effects of the distance between two auxiliary foils, the phase difference between the rotating motion and the pitching motion as well as the frequency of pitching motion on the power extraction performance are systematically investigated. It is found that compared to the single flapping foil, the efficiency improvement of overall power extraction for the flapping foil with two auxiliary foils can be achieved. Based on the numerical analysis, it is indicated that the enhanced power extraction, which is caused by the increased lift force, thanks to the induced vortex interaction, directly benefits the efficiency enhancement.

  11. Structural integrity design for an active helicopter rotor blade with piezoelectric flap actuators

    NASA Astrophysics Data System (ADS)

    Lee, Jaehwan; Shin, SangJoon

    2011-04-01

    Helicopter uses a rotor system to generate lift, thrust and forces, and its aerodynamic environment is generally complex. Unsteady aerodynamic environment arises such as blade vortex interaction. This unsteady aerodynamic environment induces vibratory aerodynamic loads and high aeroacoustic noise. The aerodynamic load and aeroacoustic noise is at N times the rotor blade revolutions (N/rev). But conventional rotor control system composed of pitch links and swash plate is not capable of adjusting such vibratory loads because its control is restricted to 1/rev. Many active control methodologies have been examined to alleviate the problem. The blade using active control device manipulates the blade pitch angle with N/rev. In this paper, Active Trailing-edge Flap blade, which is one of the active control methods, is designed to reduce the unsteady aerodynamic loads. Active Trailing-edge Flap blade uses a trailing edge flap manipulated by an actuator to change camber line of the airfoil. Piezoelectric actuators are installed inside the blade to manipulate the trailing edge flap.

  12. Pivoting output unit control systems activated by jacks. [for controlling aircraft flaps

    NASA Technical Reports Server (NTRS)

    Belliere, P.

    1978-01-01

    An invention to be used for controlling aircraft flaps is described. It is applicable to control systems with two coaxial output units which pivot simultaneously with respect to two fixed units and which are activated by two opposed, straight coaxial jacks.

  13. Application of Sequential Quadratic Programming to Minimize Smart Active Flap Rotor Hub Loads

    NASA Technical Reports Server (NTRS)

    Kottapalli, Sesi; Leyland, Jane

    2014-01-01

    In an analytical study, SMART active flap rotor hub loads have been minimized using nonlinear programming constrained optimization methodology. The recently developed NLPQLP system (Schittkowski, 2010) that employs Sequential Quadratic Programming (SQP) as its core algorithm was embedded into a driver code (NLP10x10) specifically designed to minimize active flap rotor hub loads (Leyland, 2014). Three types of practical constraints on the flap deflections have been considered. To validate the current application, two other optimization methods have been used: i) the standard, linear unconstrained method, and ii) the nonlinear Generalized Reduced Gradient (GRG) method with constraints. The new software code NLP10x10 has been systematically checked out. It has been verified that NLP10x10 is functioning as desired. The following are briefly covered in this paper: relevant optimization theory; implementation of the capability of minimizing a metric of all, or a subset, of the hub loads as well as the capability of using all, or a subset, of the flap harmonics; and finally, solutions for the SMART rotor. The eventual goal is to implement NLP10x10 in a real-time wind tunnel environment.

  14. Tanshinone IIA Pretreatment Renders Free Flaps against Hypoxic Injury through Activating Wnt Signaling and Upregulating Stem Cell-Related Biomarkers

    PubMed Central

    Xu, Zihan; Zhang, Zhenxin; Wu, Lijun; Sun, Yaowen; Guo, Yadong; Qin, Gaoping; Mu, Shengzhi; Fan, Ronghui; Wang, Benfeng; Gao, Wenjie

    2014-01-01

    Partial or total flap necrosis after flap transplantation is sometimes clinically encountered in reconstructive surgery, often as a result of a period of hypoxia that exceeds the tolerance of the flap tissue. In this study, we determine whether tanshinone IIA (TSA) pretreatment can protect flap tissue against hypoxic injury and improve its viability. Primary epithelial cells isolated from the dorsal skin of mice were pretreated with TSA for two weeks. Cell counting kit-8 and Trypan Blue assays were carried out to examine the proliferation of TSA-pretreated cells after exposure to cobalt chloride. Then, Polymerase chain reaction and Western blot analysis were used to determine the expression of β-catenin, GSK-3β, SOX2, and OCT4 in TSA-treated cells. In vivo, after mice were pretreated with TSA for two weeks, a reproducible ischemic flap model was implemented, and the area of surviving tissue in the transplanted flaps was measured. Immunohistochemistry was also conducted to examine the related biomarkers mentioned above. Results show that epidermal cells, pretreated with TSA, showed enhanced resistance to hypoxia. Activation of the Wnt signaling pathway in TSA-pretreated cells was characterized by the upregulation of β-catenin and the downregulation of GSK-3β. The expression of SOX2 and OCT4 controlled by Wnt signaling were also found higher in TSA pretreated epithelial cells. In the reproducible ischaemic flap model, pretreatment with TSA enhanced resistance to hypoxia and increased the area of surviving tissue in transplanted flaps. The expression of Wnt signaling pathway components, stem-cell related biomarkers, and CD34, which are involved in the regeneration of blood vessels, was also upregulated in TSA-pretreated flap tissue. The results show that TSA pretreatment protects free flaps against hypoxic injury and increases the area of surviving tissue by activating Wnt signaling and upregulating stem cell-related biomarkers. PMID:25302618

  15. Reduced In-Plane, Low Frequency Helicopter Noise of an Active Flap Rotor

    NASA Technical Reports Server (NTRS)

    Sim, Ben W.; Janakiram, Ram D.; Barbely, Natasha L.; Solis, Eduardo

    2009-01-01

    Results from a recent joint DARPA/Boeing/NASA/Army wind tunnel test demonstrated the ability to reduce in-plane, low frequency noise of the full-scale Boeing-SMART rotor using active flaps. Test data reported in this paper illustrated that acoustic energy in the first six blade-passing harmonics could be reduced by up to 6 decibels at a moderate airspeed, level flight condition corresponding to advance ratio of 0.30. Reduced noise levels were attributed to selective active flap schedules that modified in-plane blade airloads on the advancing side of the rotor, in a manner, which generated counteracting acoustic pulses that partially offset the negative pressure peaks associated with in-plane, steady thickness noise. These favorable reduced-noise operating states are a strong function of the active flap actuation amplitude, frequency and phase. The associated noise reductions resulted in reduced aural detection distance by up to 18%, but incurred significant vibratory load penalties due to increased hub shear forces. Small reductions in rotor lift-to-drag ratios, of no more than 3%, were also measured

  16. Risk factors of recipient site infection in head and neck cancer patients undergoing pectoralis major myocutaneous flap reconstruction.

    PubMed

    Wang, Chao-Hsien; Wong, Yong-Kie; Wang, Ching-Ping; Wang, Chen-Chi; Jiang, Rong-San; Lai, Chih-Sheng; Liu, Shih-An

    2015-11-01

    The aim of this study was to investigate the factors associated with infection at the recipient site of pectoralis major myocutaneous flap (PMMF) of head and neck cancer patients. We retrospectively reviewed head and neck cancer patients who underwent PMMF reconstruction and identified those with recipient site infection. Variables of patients with and without infection were compared and associated factors were investigated by logistic regression model. A total of 478 patients were included in the final analysis and 183 patients (38.3%) developed recipient site infection. Lower margin of skin island, concurrent tracheotomy, diabetes mellitus, mandibular plate reconstruction, prior radiation, and peri-operative blood transfusion were independent factors associated with recipient site infection of PMMF. Skin island of PMMF beyond the eighth intercostal space markedly increased the risk of recipient site infection after major head and neck cancer surgery. Recognition of relevant factors associated with infection may help surgeons to identify those at risk. PMID:25359197

  17. Active Control of Separation From the Flap of a Supercritical Airfoil

    NASA Technical Reports Server (NTRS)

    Melton, LaTunia Pack; Yao, Chung-Sheng; Seifert, Avi

    2006-01-01

    Zero-mass-flux periodic excitation was applied at several regions on a simplified high-lift system to delay the occurrence of flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge flap and a 25% chord simply hinged trailing edge flap. Detailed flow features were measured in an attempt to identify optimal actuator placement. The measurements included steady and unsteady model and tunnel wall pressures, wake surveys, arrays of surface hot-films, flow visualization, and particle image velocimetry (PIV). The current paper describes the application of active separation control at several locations on the deflected trailing edge flap. High frequency (F(+) approximately equal to 10) and low frequency amplitude modulation (F(+) sub AM approximately equal to 1) of the high frequency excitation were used for control. It was noted that the same performance gains were obtained with amplitude modulation and required only 30% of the momentum input required by pure sine excitation.

  18. Pitching-motion-activated flapping foil near solid walls for power extraction: A numerical investigation

    NASA Astrophysics Data System (ADS)

    Wu, J.; Qiu, Y. L.; Shu, C.; Zhao, N.

    2014-08-01

    A numerical investigation on the power extraction of a pitching-motion-activated flapping foil near solid walls is performed by using an immersed boundary-lattice Boltzmann method in this study. The flapping motions of the foil include a forced pitching component and an induced plunging component. The foil is placed either near a solid wall or between two parallel plane walls. Compared to previous work on the flapping foil for power extraction, the effect of the walls is first considered in this work. At a Reynolds number of 1100 and with the position of the foil pitching axis at third chord, the influences of the mechanical parameters (such as damping coefficient and spring constant) of the foil, the amplitude and frequency of the pitching motion and the clearance between the foil pitching axis and the wall on the power extraction performance of the flapping foil are systematically evaluated. Compared to the situation of free stream, the power extraction performance of the foil near the wall is improved. For given amplitude and frequency, as the clearance decreases the net power extraction efficiency improves. Moreover, as the foil is placed near one wall, there is a transverse shift to the plunging motion that consequently weakens the improvement of net power extraction efficiency. In contrast, the shift can be significantly eliminated as the foil is placed between two walls, which can further improve the net power extraction efficiency. In addition, it is found that the efficiency improvement is essentially from the increased power extraction, which is due to the generation of high lift force.

  19. Active interrogation of helicopter main rotor faults using trailing edge flap actuation

    NASA Astrophysics Data System (ADS)

    Stevens, Patricia Lynn

    Over the past decade, the helicopter community has become increasingly interested in health monitoring. The rotor system, however, is not sufficiently covered in the current Health and Usage Monitoring Systems (HUMS). This dissertation describes the development and evaluation of a new approach for detecting helicopter rotor faults in which active trailing edge flaps are used to interrogate the system. This work is based on the presumption that trailing edge flaps would be installed for the primary purpose of vibration and/or noise control; health monitoring is a secondary use. Using this approach, the blade is excited by an interrogation signal, which is a low amplitude oscillation at a few discrete frequencies. The blade response is measured and the health of the system is determined using a frequency domain damage identification algorithm. Damage detection and location are achieved via the residual force vector. The residual force vector, coupled with an understanding of the system physics, also provides nature characterization. Quantification of damage extent is achieved via a frequency domain adaptation of the Asymmetric Minimum Rank Perturbation Theory. The active interrogation system is evaluated using an aeroelastic finite element model of the rotor system in hover, including an advanced unsteady aerodynamic model to predict the trailing edge flap loads. Realistic damage models, including distributed bending stiffness damage, torsional stiffness damage, control system stiffness damage, cracks and ballistic damage, are seeded in the rotor system model. Results demonstrate detection, location and quantification of extent of all of the faults tested. The effects of noise and modeling errors are discussed and mitigation techniques are developed. Additionally, a measurability study is included. Benefits of this work include both improved health monitoring for rotorcraft as well as insights into the application of structural damage detection algorithms to a

  20. The fat-fascia paddle only with a composite fibula flap: marked reduction in donor site morbidity.

    PubMed

    Mohindra, A; Parmar, S; Praveen, P; Martin, T

    2016-08-01

    Fibula free flaps are used widely in head and neck reconstruction, primarily for their versatility and contribution to aesthetic and functional outcomes. The literature suggests that early complications such as wound dehiscence and skin graft loss can occur in up to a third of patients. The healing of these donor sites can be prolonged, and in certain cases may require an operative intervention. A method to overcome this problem is described herein. In raising the skin paddle, a standard lateral approach to the fibula harvest is used. The skin paddle is not isolated and the posterior margin of the paddle is maintained. The skin paddle epithelium is separated with a small cuff of adipose tissue from the underlying fat-fascia layer. This fat-fascia paddle is then raised with the fibula as normal and tacked to the margins of the recipient soft tissue defect. The fat-fascia paddle heals, resulting in a thin mucosal covering for prosthetic dental rehabilitation. This technique can reduce the incidence of donor site wound complications when raising a composite fibula flap. PMID:27061479

  1. Long-term donor-site morbidity after vascularized free fibula flap harvesting: Clinical and gait analysis.

    PubMed

    Feuvrier, Damien; Sagawa, Yoshimasa; Béliard, Samuel; Pauchot, Julien; Decavel, Pierre

    2016-02-01

    The aim of this study was to determine the clinical morbidity and changes in gait temporal spatial parameters after harvesting of a vascularized free fibula flap. This study included 11 patients (mean age: 52 ± 17 years) and 11 healthy controls (mean age: 50 ± 14 years). The patients were assessed between 5 and 104 months post surgery. The study consisted of a subjective functional evaluation with two validated clinical scores (Kitaoka Score and Point Evaluation System (PES) score), clinical and neurological examination of the legs, and evaluation of gait temporal spatial parameters while walking at a comfortable speed. The mean functional Kitaoka score was 78/100, and the mean PES score of 12.18 was considered average. At the time of the review, five patients had sensory disorders, two had toe deformities, and eight had pain at the donor site. The gait analysis showed that the patient's comfortable walking speed was significantly lower in comparison to that of the controls, and that stride length and cadence were reduced. In addition, most of the gait-specific parameters were significantly different. The donor leg displayed greater variability during walking. To reduce the risk of falling, this study revealed that the patients' gait pattern had changed as they took a more cautious approach during walking. Early rehabilitation is expected to help improve and/or restore the physical abilities of patients after harvesting of the vascularized free fibula flap. PMID:26602741

  2. Use of active control systems to improve bending and rotor flapping response of a tilt rotor VTOL airplane

    NASA Technical Reports Server (NTRS)

    Whitaker, H. P.; Cheng, Y.

    1975-01-01

    The results are summarized of an analytical study of the use of active control systems for the purpose of reducing the root mean square response of wing vertical bending and rotor flapping to atmospheric turbulence for a tilt-rotor VTOL airplane. Only the wing/rotor assembly was considered so that results of a wind tunnel test program would be applicable in a subsequent phase of the research. The capabilities and limitations of simple single feedback configurations were identified, and the most promising multiloop feedback configurations were then investigated. Design parameters were selected so as to minimize either wing bending or rotor flapping response. Within the constraints imposed by practical levels of feedback gains and complexity and by considerations of safety, reduction in response due to turbulence of the order of 30 to 50 percent is predicted using the rotor longitudinal cyclic and a trailing edge wing flap as control effectors.

  3. Modified osteomyocutaneous iliac crest flaps transplantation.

    PubMed

    Liu, Jun; Song, Dajiang; Li, Jinsong; Xu, Jian; Lv, Hongbin

    2015-04-01

    The paper aims to improve the operative technique of osteomyocutaneous iliac crest flap harvesting, further minimise morbidity of donor site, and improve the effect of recipient site reconstruction. From March 2005 to March 2011, 55 cases of osteomyocutaneous iliac crest flap harvested by different methods were performed to reconstruct the defects of the extremities. Twenty-nine cases were reconstructed with a traditional deep circumflex iliac artery osteomusculocutaneous flap. Twenty-six cases were repaired with modified osteomyocutaneous iliac crest flaps. In 29 cases with a traditional DCIA osteomusculocutaneous flap, two cases showed the injured lateral femoral cutaneous nerve. Flapnecrosis was significant in two cases. Arterial compromise occurred in one case 5 days after operation completion and led to flap failure. Three flaps developed postoperative venous congestion, but only one flap received re-exploration. In the other two cases, some stitches were removed for decompression. All three flaps survived. In two cases, marginal flap necrosis occurred, but no secondary skin grafting was required. In 26 cases with modified flap transplantation, one case showed the injured lateral femoral cutaneous nerve. All flaps survived totally. Osseous integration was achieved in all 55 cases in 3 ∼ 9 months after operation. The modified osteomyocutaneous iliac crest flap technique enhances flap safety, provides the additional advantages of reducing donor-site morbidity, and improves the recipient-site contour. PMID:25001367

  4. The Deltopectoral Flap Revisited: The Internal Mammary Artery Perforator Flap.

    PubMed

    Ibrahim, Amir; Atiyeh, Bishara; Karami, Reem; Adelman, David M; Papazian, Nazareth J

    2016-03-01

    Pharyngo-esophageal and tracheostomal defects pose a challenge in head and neck reconstruction whenever microanastomosis is extremely difficult in hostile neck that is previously dissected and irradiated. The deltopectoral (DP) flap was initially described as a pedicled flap for such reconstruction with acceptable postoperative results. A major drawback is still that the DP flap is based on 3 perforator vessels leading to a decreased arc of rotation. The DP flap also left contour deformities in the donor site. The internal mammary artery perforator flap was described as a refinement of the deltopectoral flap. It is a pedicled fasciocutaneous flap based on a single perforator, with comparable and reliable blood supply compared with the DP flap, giving it the benefit of having a wide arc of rotation. It is both thin and pliable, with good skin color match and texture. The donor site can be closed primarily with no esthetic deformity and minimal morbidity. The procedure is relatively simple and does not require microvascular expertise. In this report, the authors describe a patient in whom bilateral internal mammary artery perforator flaps were used for subtotal pharyngo-esophageal reconstruction and neck resurfacing. The flaps healed uneventfully bilaterally with no postoperative complications. PMID:26854779

  5. Long-term vascular, motor, and sensory donor site outcomes after ulnar forearm flap harvest.

    PubMed

    Brown, Emile N; Chaudhry, Arif; Mithani, Suhail K; Bluebond-Langner, Rachel O; Feiner, Jeffrey M; Shaffer, Cynthia K; Call, Diana; Rodriguez, Eduardo D

    2014-02-01

    Use of the ulnar forearm flap (UFF) is limited by concerns for ulnar nerve injury and impaired perfusion in the donor extremity. Twenty UFFs were performed over a 6-year period. All patients underwent postoperative bilateral upper extremity arterial duplex studies. A subset of postoperative patients (n = 10) also had bilateral upper extremity sensory and motor evaluations, and functional evaluation via the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH). Motor function was tested by digital and key grip dynamometry. Ulnar nerve sensation was tested by evaluation of one- and two-point perceived pressure thresholds and two-point discrimination using the Pressure-Specified Sensory Device (Sensory Management Services, LLC, Baltimore, MD). All UFFs were viable postoperatively. Mean follow-up was 28.8 months for vascular studies and 45.3 months for motor, sensory, and QuickDASH evaluations. Although mid and distal radial artery flow velocities were significantly higher in donor versus control extremities evaluated at less than 1 year postoperatively, there was no significant difference in extremities evaluated at later time points. Digital pressures, grip strength, key pinch strength, and ulnar sensation were equivalent between donor and control extremities. The mean QuickDASH score was 17.4 ± 23.8. The UFF can be harvested reliably and long-term follow-up shows no evidence of impaired vascular, motor, or sensory function in the donor extremity. PMID:24163222

  6. Knee and Ankle Reconstruction With Reverse Anterolateral Thigh and Free Anterolateral Thigh Flap From One Donor Site.

    PubMed

    Choi, KyeongBeom; Cho, JaeHo; Park, MyongChul; Park, Dong Ha; Lee, Il Jae

    2016-09-01

    Traditionally, the anterolateral thigh (ALT) free flap is used in distal lower extremity reconstruction. Reverse ALT flap has become one of the most popular choices for knee joint soft tissue defects. A 53-year-old man sustained a degloving injury in the right lateral side of the lower extremity from the lateral malleolar area to the knee joint area. The contamination was severe, necessitating serial debridement and negative pressure wound therapy. After 4 weeks, no more soft tissue necrosis was evident. No more microorganism growth was confirmed by swab culture. ALT free flap using proximal perforator was planned for lateral malleolar area reconstruction and reverse ALT flap using distal perforator was planned to cover knee joint after confirming the pedicle length was sufficient for simultaneous knee and lateral malleolar area reconstruction. PMID:27317019

  7. 2D CFD Analysis of an Airfoil with Active Continuous Trailing Edge Flap

    NASA Astrophysics Data System (ADS)

    Jaksich, Dylan; Shen, Jinwei

    2014-11-01

    Efficient and quieter helicopter rotors can be achieved through on-blade control devices, such as active Continuous Trailing-Edge Flaps driven by embedded piezoelectric material. This project aims to develop a CFD simulation tool to predict the aerodynamic characteristics of an airfoil with CTEF using open source code: OpenFOAM. Airfoil meshes used by OpenFOAM are obtained with MATLAB scripts. Once created it is possible to rotate the airfoil to various angles of attack. When the airfoil is properly set up various OpenFOAM properties, such as kinematic viscosity and flow velocity, are altered to achieve the desired testing conditions. Upon completion of a simulation, the program gives the lift, drag, and moment coefficients as well as the pressure and velocity around the airfoil. The simulation is then repeated across multiple angles of attack to give full lift and drag curves. The results are then compared to previous test data and other CFD predictions. This research will lead to further work involving quasi-steady 2D simulations incorporating NASTRAN to model aeroelastic deformation and eventually to 3D aeroelastic simulations. NSF ECE Grant #1358991 supported the first author as an REU student.

  8. Control of Flap Vortices

    NASA Technical Reports Server (NTRS)

    Greenblatt, David

    2005-01-01

    A wind tunnel investigation was carried out on a semi-span wing model to assess the feasibility of controlling vortices emanating from outboard flaps and tip-flaps by actively varying the degree of boundary layer separation. Separation was varied by means of perturbations produced from segmented zero-efflux oscillatory blowing slots, while estimates of span loadings and vortex sheet strengths were obtained by integrating wing surface pressures. These estimates were used as input to inviscid rollup relations as a means of predicting changes to the vortex characteristics resulting from the perturbations. Surveys of flow in the wake of the outboard and tip-flaps were made using a seven-hole probe, from which the vortex characteristics were directly deduced. Varying the degree of separation had a marked effect on vortex location, strength, tangential velocity, axial velocity and size for both outboard and tip-flaps. Qualitative changes in vortex characteristics were well predicted by the inviscid rollup relations, while the failure to account for viscosity was presumed to be the main reason for observed discrepancies. Introducing perturbations near the outboard flap-edges or on the tip-flap exerted significant control over vortices while producing negligible lift excursions.

  9. Vibration reduction in helicopter rotors using an actively controlled partial span trailing edge flap located on the blade

    NASA Technical Reports Server (NTRS)

    Millott, T. A.; Friedmann, P. P.

    1994-01-01

    This report describes an analytical study of vibration reduction in a four-bladed helicopter rotor using an actively controlled, partial span, trailing edge flap located on the blade. The vibration reduction produced by the actively controlled flap (ACF) is compared with that obtained using individual blade control (IBC), in which the entire blade is oscillated in pitch. For both cases a deterministic feedback controller is implemented to reduce the 4/rev hub loads. For all cases considered, the ACF produced vibration reduction comparable with that obtained using IBC, but consumed only 10-30% of the power required to implement IBC. A careful parametric study is conducted to determine the influence of blade torsional stiffness, spanwise location of the control flap, and hinge moment correction on the vibration reduction characteristics of the ACF. The results clearly demonstrate the feasibility of this new approach to vibration reduction. It should be emphasized than the ACF, used together with a conventional swashplate, is completely decoupled from the primary flight control system and thus it has no influence on the airworthiness of the helicopter. This attribute is potentially a significant advantage when compared to IBC.

  10. Low Speed and High Speed Correlation of SMART Active Flap Rotor Loads

    NASA Technical Reports Server (NTRS)

    Kottapalli, Sesi B. R.

    2010-01-01

    Measured, open loop and closed loop data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. One open loop high-speed case and four closed loop cases are considered. The closed loop cases include three high-speed cases and one low-speed case. Two of these high-speed cases include a 2 deg flap deflection at 5P case and a test maximum-airspeed case. This study follows a recent, open loop correlation effort that used a simple correction factor for the airfoil pitching moment Mach number. Compared to the earlier effort, the current open loop study considers more fundamental corrections based on advancing blade aerodynamic conditions. The airfoil tables themselves have been studied. Selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the closed loop condition, the effect of the flap actuator is modeled by increased flap hinge stiffness. Overall, the open loop correlation is reasonable, thus confirming the basic correctness of the current semi-empirical modifications; the closed loop correlation is also reasonable considering that the current flap model is a first generation model. Detailed correlation results are given in the paper.

  11. Simultaneous BVI noise and vibration reduction in rotorcraft using actively-controlled flaps and including performance considerations

    NASA Astrophysics Data System (ADS)

    Patt, Daniel A.

    This work presents the development and application of an active control approach for reduction of both vibration and noise induced by helicopter rotor blade vortex interaction (BVI). Control is implemented through single or dual actively controlled flaps (ACFs) on each blade. Low-speed helicopter flight is prone to severe BVI, resulting in elevated vibration and noise levels. Existing research has suggested that when some form of active control is used to reduce vibration, noise will increase and vice versa. The present research achieves simultaneous reduction of noise and vibration, and also investigates the physical sources of the observed reduction. The initial portion of this work focused on developing a tool for simulating helicopter noise and vibrations in the BVI flight regime. A method for predicting compressible unsteady blade surface pressure distribution on rotor blades was developed and combined with an enhanced free-wake model and an acoustic prediction tool with provisions for blade flexibility. These elements were incorporated within an aeroelastic analysis featuring fully coupled flap-lag-torsional blade dynamics. Subsequently, control algorithms were developed that were effective for reducing noise and vibration even in the nonlinear BVI flight regime; saturation limits were incorporated constraining flap deflections to specified limits. The resulting simulation was also validated with a wide range of experimental data, achieving excellent correlation. Finally, a number of active control studies were performed. Multi-component vibration reductions of 40--80% could be achieved, while incurring a small noise penalty. Noise was reduced using an onboard feedback microphone; reductions of 4--10 dB on the advancing side were observed on a plane beneath the rotor when using dual flaps. Finally, simultaneous noise and vibration reduction was studied. A reduction of about 5 dB in noise on the advancing side combined with a 60% reduction in vibration was

  12. Four-flap Breast Reconstruction: Bilateral Stacked DIEP and PAP Flaps

    PubMed Central

    Mayo, James L.; Allen, Robert J.

    2015-01-01

    Background: In cases of bilateral breast reconstruction when the deep inferior epigastric perforator (DIEP) free flap alone does not provide sufficient volume for body-specific reconstruction, stacking each DIEP flap with a second free flap will deliver added volume and maintain a purely autologous reconstruction. Stacking the profunda artery perforator (PAP) flap with the DIEP flap offers favorable aesthetics and ideal operative efficiency. We present the indications, technique, and outcomes of our experience with 4-flap breast reconstruction using stacked DIEP/PAP flaps. Methods: The authors performed 4-flap DIEP/PAP breast reconstruction in 20 patients who required bilateral reconstruction without adequate single donor flap volume. The timing of reconstruction, average mastectomy/flap weights, and operative time are reported. Complications reviewed include fat necrosis, dehiscence, hematoma, seroma, mastectomy flap necrosis, and flap loss. Results: Twenty patients underwent 4-flap DIEP/PAP breast reconstruction. Surgical time averaged 7 hours and 20 minutes. The primary recipient vessels were the antegrade and retrograde internal mammary vessels. No flap losses occurred. Complications included 1 hematoma, 1 incidence of arterial and venous thrombosis successfully treated with anastomotic revision, 1 incidence of thigh donor site dehiscence, and 3 episodes of minor mastectomy skin flap necrosis. Conclusions: Four-flap breast reconstruction is a favorable autologous reconstructive option for patients requiring bilateral reconstruction without adequate single donor flap volume. Stacking DIEP/PAP flaps as described is both safe and efficient. Furthermore, this combination provides superior aesthetics mirroring the natural geometry of the breast. Bilateral stacked DIEP/PAP flaps represent our first choice for breast reconstruction in this patient population. PMID:26090273

  13. Stress optimization of leaf-spring crossed flexure pivots for an active Gurney flap mechanism

    NASA Astrophysics Data System (ADS)

    Freire Gómez, Jon; Booker, Julian D.; Mellor, Phil H.

    2015-04-01

    The EU's Green Rotorcraft programme is pursuing the development of a functional and airworthy Active Gurney Flap (AGF) for a full-scale helicopter rotor blade. Interest in the development of this `smart adaptive rotor blade' technology lies in its potential to provide a number of aerodynamic benefits, which would in turn translate into a reduction in fuel consumption and noise levels. The AGF mechanism selected employs leaf-spring crossed flexure pivots. These provide important advantages over bearings as they are not susceptible to seizing and do not require maintenance (i.e. lubrication or cleaning). A baseline design of this mechanism was successfully tested both in a fatigue rig and in a 2D wind tunnel environment at flight-representative deployment schedules. For full validation, a flight test would also be required. However, the severity of the in-flight loading conditions would likely compromise the mechanical integrity of the pivots' leaf-springs in their current form. This paper investigates the scope for stress reduction through three-dimensional shape optimization of the leaf-springs of a generic crossed flexure pivot. To this end, a procedure combining a linear strain energy formulation, a parametric leaf-spring profile definition and a series of optimization algorithms is employed. The resulting optimized leaf-springs are proven to be not only independent of the angular rotation at which the pivot operates, but also linearly scalable to leaf-springs of any length, minimum thickness and width. Validated using non-linear finite element analysis, the results show very significant stress reductions relative to pivots with constant cross section leaf-springs, of up to as much as 30% for the specific pivot configuration employed in the AGF mechanism. It is concluded that shape optimization offers great potential for reducing stress in crossed flexure pivots and, consequently, for extending their fatigue life and/or rotational range.

  14. Axial flow effects on robustness of vortical structures about actively deflected wings in flapping flight

    NASA Astrophysics Data System (ADS)

    Medina, Albert; Kweon, Jihoon; Choi, Haecheon; Eldredge, Jeff D.

    2012-11-01

    Flapping wing flight has garnered much attention in the past decade driven by our desire to understand capabilities observed in nature and to develop agile small-scale aerial vehicles. Nature has demonstrated the breadth of maneuverability achievable by flapping wing flight. However, despite recent advances the role of wing flexibility remains poorly understood. In an effort to develop a deeper understanding of wing deflection effects and to explore novel approaches to increasing leading-edge vortex robustness, this three-dimensional computational study explores the aerodynamics of low aspect ratio plates, in hovering kinematics, with isolated flexion lines undergoing prescribed deflection. Major flexion lines, recognized as the primary avenue for deflection in biological fliers, are isolated here in two distinct configurations, resulting in deflection about the wing root and the wing tip, respectively. Of interest is the interaction between axial flow along the span and the vortical structures about the wing. It is proposed that the modes of deflection explored may provide a means of axial flow control for favorably promoting LEV robustness over a broad range of flapping conditions, and provide insight into the nature of flexibility in flapping wing flight. National Science Foundation, National Research Foundation of Korea.

  15. Flap Conformations in HIV-1 Protease are Altered by Mutations

    NASA Astrophysics Data System (ADS)

    Fanucci, Gail; Blackburn, Mandy; Veloro, Angelo; Galiano, Luis; Fangu, Ding; Simmerling, Carlos

    2009-03-01

    HIV-1 protease (PR) is an enzyme that is a major drug target in the treatment of AIDS. Although the structure and function of HIV-1 PR have been studied for over 20 years, questions remain regarding the conformations and dynamics of the β-hairpin turns (flaps) that cover the active site cavity. Distance measurements with pulsed EPR spectroscopy of spin labeled constructs of HIV-1 PR have been used to characterize the flap conformations in the apo and inhibitor bound states. From the most probably distances and the breadth of the distance distribution profiles from analysis of the EPR data, insights regarding the flap conformations and flexibility are gained. The EPR results clearly show how drug pressure selected mutations alter the average conformation of the flaps and the degree of opening of the flaps. Molecular dynamics simulations successfully regenerate the experimentally determined distance distribution profiles, and more importantly, provide structural models for full interpretation of the EPR results. By combining experiment and theory to understand the role that altered flap flexibility/conformations play in the mechanism of drug resistance, key insights are gained toward the rational development of new inhibitors of this important enzyme.

  16. Flap Dynamics in Aspartic Proteases: A Computational Perspective.

    PubMed

    Mahanti, Mukul; Bhakat, Soumendranath; Nilsson, Ulf J; Söderhjelm, Pär

    2016-08-01

    Recent advances in biochemistry and drug design have placed proteases as one of the critical target groups for developing novel small-molecule inhibitors. Among all proteases, aspartic proteases have gained significant attention due to their role in HIV/AIDS, malaria, Alzheimer's disease, etc. The binding cleft is covered by one or two β-hairpins (flaps) which need to be opened before a ligand can bind. After binding, the flaps close to retain the ligand in the active site. Development of computational tools has improved our understanding of flap dynamics and its role in ligand recognition. In the past decade, several computational approaches, for example molecular dynamics (MD) simulations, coarse-grained simulations, replica-exchange molecular dynamics (REMD) and metadynamics, have been used to understand flap dynamics and conformational motions associated with flap movements. This review is intended to summarize the computational progress towards understanding the flap dynamics of proteases and to be a reference for future studies in this field. PMID:26872937

  17. The axillary versus internal mammary recipient vessel sites for breast reconstruction with diep flaps: a retrospective study of 256 consecutive cases.

    PubMed

    Santanelli Di Pompeo, Fabio; Longo, Benedetto; Sorotos, Michail; Pagnoni, Marco; Laporta, Rosaria

    2015-01-01

    The aim of this study is to present our experience on the use of various recipient sites for deep inferior epigastric perforator (DIEP) flap breast reconstruction and compare them by means of objective data. Two hundred fifty six DIEP flap breast reconstructions, performed between March 2004 and May 2011, were retrospectively analyzed. Only unilateral reconstructions were included in the study and divided into three groups depending on the recipient site choice: internal mammary vessels (IMV) (n = 52), thoracodorsal vessels (TDV) (n = 109), and circumflex scapular vessels (CSV) (n = 95). Clinical records of each patient were reviewed to acquire relevant data such as operative time, postoperative complications, and use of a second vein anastomosis. CSV group showed a statistically significant lower operative time (4.92 ± 0.54 hours) compared to TDV (5.67 ± 1.01 hours) and IMV groups (6.75 ± 1.09 hours) (P < 0.001). Second vein anastomosis was performed in 84 cases (88.1%) of CSV, in 85 cases (77.9%) of TDV, and in 18 cases (35.1%) of IMV groups (P < 0.001). No significant differences were observed among groups regarding risk factors and complications (P > 0.05). The axillary vessels seem to be the ideal recipient site because of reduced operative time and increased possibility to perform a second vein anastomosis. Among them, CSV can be safely used due to following advantages: easy dissection, larger vessel caliber, and optimal flap insetting. Moreover, their location does not expose them completely to radiotherapy consequences. PMID:24782202

  18. DNA and Protein Requirements for Substrate Conformational Changes Necessary for Human Flap Endonuclease-1-catalyzed Reaction*

    PubMed Central

    Algasaier, Sana I.; Exell, Jack C.; Bennet, Ian A.; Thompson, Mark J.; Gotham, Victoria J. B.; Shaw, Steven J.; Craggs, Timothy D.; Finger, L. David; Grasby, Jane A.

    2016-01-01

    Human flap endonuclease-1 (hFEN1) catalyzes the essential removal of single-stranded flaps arising at DNA junctions during replication and repair processes. hFEN1 biological function must be precisely controlled, and consequently, the protein relies on a combination of protein and substrate conformational changes as a prerequisite for reaction. These include substrate bending at the duplex-duplex junction and transfer of unpaired reacting duplex end into the active site. When present, 5′-flaps are thought to thread under the helical cap, limiting reaction to flaps with free 5′-termini in vivo. Here we monitored DNA bending by FRET and DNA unpairing using 2-aminopurine exciton pair CD to determine the DNA and protein requirements for these substrate conformational changes. Binding of DNA to hFEN1 in a bent conformation occurred independently of 5′-flap accommodation and did not require active site metal ions or the presence of conserved active site residues. More stringent requirements exist for transfer of the substrate to the active site. Placement of the scissile phosphate diester in the active site required the presence of divalent metal ions, a free 5′-flap (if present), a Watson-Crick base pair at the terminus of the reacting duplex, and the intact secondary structure of the enzyme helical cap. Optimal positioning of the scissile phosphate additionally required active site conserved residues Tyr40, Asp181, and Arg100 and a reacting duplex 5′-phosphate. These studies suggest a FEN1 reaction mechanism where junctions are bound and 5′-flaps are threaded (when present), and finally the substrate is transferred onto active site metals initiating cleavage. PMID:26884332

  19. HIGH EFFICIENCY STRUCTURAL FLOWTHROUGH ROTOR WITH ACTIVE FLAP CONTROL: VOLUME ONE: PRELIMINARY DESIGN REPORT

    SciTech Connect

    Zuteck, Michael D.; Jackson, Kevin L.; Santos, Richard A.; Chow, Ray; Nordenholz, Thomas R.; Wamble, John Lee

    2015-05-16

    The Zimitar one-piece rotor primary structure is integrated, so balanced thrust and gravity loads flow through the hub region without transferring out of its composite material. Large inner rotor geometry is used since there is no need to neck down to a blade root region and pitch bearing. Rotor control is provided by a highly redundant, five flap system on each blade, sized so that easily handled standard electric linear actuators are sufficient.

  20. HIGH EFFICIENCY STRUCTURAL FLOWTHROUGH ROTOR WITH ACTIVE FLAP CONTROL: VOLUME THREE: MARKET & TEAM

    SciTech Connect

    Zuteck, Michael D.; Jackson, Kevin L.; Santos, Richard A.

    2015-05-16

    The Zimitar one-piece rotor primary structure is integrated, so balanced thrust and gravity loads flow through the hub region without transferring out of its composite material. Large inner rotor geometry is used since there is no need to neck down to a blade root region and pitch bearing. Rotor control is provided by a highly redundant, five flap system on each blade, sized so that easily handled standard electric linear actuators are sufficient.

  1. HIGH EFFICIENCY STRUCTURAL FLOWTHROUGH ROTOR WITH ACTIVE FLAP CONTROL: VOLUME ZERO: OVERVIEW AND COMMERCIAL PATH

    SciTech Connect

    Zuteck, Michael D.; Jackson, Kevin L.; Santos, Richard A.

    2015-05-16

    The Zimitar one-piece rotor primary structure is integrated, so balanced thrust and gravity loads flow through the hub region without transferring out of its composite material. Large inner rotor geometry is used since there is no need to neck down to a blade root region and pitch bearing. Rotor control is provided by a highly redundant, five flap system on each blade, sized so that easily handled standard electric linear actuators are sufficient.

  2. HIGH EFFICIENCY STRUCTURAL FLOWTHROUGH ROTOR WITH ACTIVE FLAP CONTROL: VOLUME TWO: INNOVATION & COST OF ENERGY

    SciTech Connect

    Zuteck, Michael D.; Jackson, Kevin L.; Santos, Richard A.

    2015-05-16

    The Zimitar one-piece rotor primary structure is integrated, so balanced thrust and gravity loads flow through the hub region without transferring out of its composite material. Large inner rotor geometry is used since there is no need to neck down to a blade root region and pitch bearing. Rotor control is provided by a highly redundant, five flap system on each blade, sized so that easily handled standard electric linear actuators are sufficient.

  3. Active control system for a rotor blade trailing-edge flap

    NASA Astrophysics Data System (ADS)

    Duvernier, Marc; Reithler, Livier; Guerrero, Jean Y.; Rossi, Rinaldo A.

    2000-06-01

    Reducing the external noise is becoming a major issue for helicopter manufacturers. The idea beyond this goal is to reduce or even avoid the blade vortex interaction (BVI), especially during descent and flights over inhabited areas. This can be achieved by changing locally the lift of the blade. Several strategies to reach this goal are under investigation at EUROCOPTER such as the control of the local incidence of the blade by a direct lift flap. AEROSPATIALE MATRA Corporate Research Centre and AEROSPATIALE MATRA MISSILES proposed an actuator system able to answer EUROCOPTER's needs for moving a direct lift flap. The present paper describes the definition, manufacturing and testing of this new actuator system. This actuator is based on an electromagnetic patented actuation system developed by AEROSPATIALE MATRA MISSILES for missile and aeronautic applications. The particularity of this actuator is its ability to produce the desired force on its whole range of stroke. The flap is designed to be fitted on a DAUPHIN type blade produced by EUROCOPTER and the actuator system was designed to fit the room available within the blade and to produce the right amount of stroke and force within the required frequency range. Other constraints such as centrifugal loading were also taken into account. This paper describes briefly the specifications and the major characteristics of the actuating system and presents some results of its behavior on a representative composite test-bed manufactured by EUROCOPTER when subjected to realistic mechanical loads.

  4. The novel benzimidazole derivative BRP-7 inhibits leukotriene biosynthesis in vitro and in vivo by targeting 5-lipoxygenase-activating protein (FLAP)

    PubMed Central

    Pergola, C; Gerstmeier, J; Mönch, B; Çalışkan, B; Luderer, S; Weinigel, C; Barz, D; Maczewsky, J; Pace, S; Rossi, A; Sautebin, L; Banoglu, E; Werz, O

    2014-01-01

    BACKGROUND AND PURPOSE Leukotrienes (LTs) are inflammatory mediators produced via the 5-lipoxygenase (5-LOX) pathway and are linked to diverse disorders, including asthma, allergic rhinitis and cardiovascular diseases. We recently identified the benzimidazole derivative BRP-7 as chemotype for anti-LT agents by virtual screening targeting 5-LOX-activating protein (FLAP). Here, we aimed to reveal the in vitro and in vivo pharmacology of BRP-7 as an inhibitor of LT biosynthesis. EXPERIMENTAL APPROACH We analysed LT formation and performed mechanistic studies in human neutrophils and monocytes, in human whole blood (HWB) and in cell-free assays. The effectiveness of BRP-7 in vivo was evaluated in rat carrageenan-induced pleurisy and mouse zymosan-induced peritonitis. KEY RESULTS BRP-7 potently suppressed LT formation in neutrophils and monocytes and this was accompanied by impaired 5-LOX co-localization with FLAP. Neither the cellular viability nor the activity of 5-LOX in cell-free assays was affected by BRP-7, indicating that a functional FLAP is needed for BRP-7 to inhibit LTs, and FLAP bound to BRP-7 linked to a solid matrix. Compared with the FLAP inhibitor MK-886, BRP-7 did not significantly inhibit COX-1 or microsomal prostaglandin E2 synthase-1, implying the selectivity of BRP-7 for FLAP. Finally, BRP-7 was effective in HWB and impaired inflammation in vivo, in rat pleurisy and mouse peritonitis, along with reducing LT levels. CONCLUSIONS AND IMPLICATIONS BRP-7 potently suppresses LT biosynthesis by interacting with FLAP and exhibits anti-inflammatory effectiveness in vivo, with promising potential for further development. PMID:24641614

  5. Salt site performance assessment activities

    SciTech Connect

    Kircher, J.F.; Gupta, S.K.

    1983-01-01

    During this year the first selection of the tools (codes) for performance assessments of potential salt sites have been tentatively selected and documented; the emphasis has shifted from code development to applications. During this period prior to detailed characterization of a salt site, the focus is on bounding calculations, sensitivity and with the data available. The development and application of improved methods for sensitivity and uncertainty analysis is a focus for the coming years activities and the subject of a following paper in these proceedings. Although the assessments to date are preliminary and based on admittedly scant data, the results indicate that suitable salt sites can be identified and repository subsystems designed which will meet the established criteria for protecting the health and safety of the public. 36 references, 5 figures, 2 tables.

  6. 4,5-Diarylisoxazol-3-carboxylic acids: A new class of leukotriene biosynthesis inhibitors potentially targeting 5-lipoxygenase-activating protein (FLAP).

    PubMed

    Banoglu, Erden; Çelikoğlu, Erşan; Völker, Susanna; Olgaç, Abdurrahman; Gerstmeier, Jana; Garscha, Ulrike; Çalışkan, Burcu; Schubert, Ulrich S; Carotti, Andrea; Macchiarulo, Antonio; Werz, Oliver

    2016-05-01

    In this article, we report novel leukotriene (LT) biosynthesis inhibitors that may target 5-lipoxygenase-activating protein (FLAP) based on the previously identified isoxazole derivative (8). The design and synthesis was directed towards a subset of 4,5-diaryl-isoxazole-3-carboxylic acid derivatives as LT biosynthesis inhibitors. Biological evaluation disclosed a new skeleton of potential anti-inflammatory agents, exemplified by 39 and 40, which potently inhibit cellular 5-LO product synthesis (IC50 = 0.24 μM, each) seemingly by targeting FLAP with weak inhibition on 5-LO (IC50 ≥ 8 μM). Docking studies and molecular dynamic simulations with 5-LO and FLAP provide valuable insights into potential binding modes of the inhibitors. Together, these diaryl-isoxazol-3-carboxylic acids may possess potential as leads for development of effective anti-inflammatory drugs through inhibition of LT biosynthesis. PMID:26922224

  7. Davis flap: the glory still present

    PubMed Central

    El-Sabbagh, Ahmed Hassan

    2016-01-01

    Background: Upper third defects of the ear are too large to be closed primarily without distorting the auricle. Full thickness defects can be reconstructed with local flaps. In this article, Davis flap was used to fill the upper third defects of the ear with some modifications. Patients and methods: Eight patients underwent reconstruction of full thickness auricular defects with Davis flaps from July 2012 to December 2014. The posterior surface of the flap and the raw area of conchal area were covered by full thickness graft taken from posterior surface of ear. Results: All flaps survived. No congestion was noted. The donor sites and skin grafts healed uneventfully. Conclusion: Davis flap is a simple and reproducible tool for reconstruction of upper third of ear. PMID:27274439

  8. An Active Flow Circulation Controlled Flap Concept for General Aviation Aircraft Applications

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Viken, Sally A.; Washburn, Anthony E.; Jenkins, Luther N.; Cagle, C. Mark

    2002-01-01

    A recent focus on revolutionary aerodynamic concepts has highlighted the technology needs of general aviation and personal aircraft. New and stringent restrictions on these types of aircraft have placed high demands on aerodynamic performance, noise, and environmental issues. Improved high lift performance of these aircraft can lead to slower takeoff and landing speeds that can be related to reduced noise and crash survivability issues. Circulation Control technologies have been around for 65 years, yet have been avoided due to trade offs of mass flow, pitching moment, perceived noise etc. The need to improve the circulation control technology for general aviation and personal air-vehicle applications is the focus of this paper. This report will describe the development of a 2-D General Aviation Circulation Control (GACC) wing concept that utilizes a pulsed pneumatic flap.

  9. Unraveling HIV protease flaps dynamics by Constant pH Molecular Dynamics simulations.

    PubMed

    Soares, Rosemberg O; Torres, Pedro H M; da Silva, Manuela L; Pascutti, Pedro G

    2016-08-01

    The active site of HIV protease (HIV-PR) is covered by two flaps. These flaps are known to be essential for the catalytic activity of the HIV-PR, but their exact conformations at the different stages of the enzymatic pathway remain subject to debate. Understanding the correct functional dynamics of the flaps might aid the development of new HIV-PR inhibitors. It is known that, the HIV-PR catalytic efficiency is pH-dependent, likely due to the influence of processes such as charge transfer and protonation/deprotonation of ionizable residues. Several Molecular Dynamics (MD) simulations have reported information about the HIV-PR flaps. However, in MD simulations the protonation of a residue is fixed and thus it is not possible to study the correlation between conformation and protonation state. To address this shortcoming, this work attempts to capture, through Constant pH Molecular Dynamics (CpHMD), the conformations of the apo, substrate-bound and inhibitor-bound HIV-PR, which differ drastically in their flap arrangements. The results show that the HIV-PR flaps conformations are defined by the protonation of the catalytic residues Asp25/Asp25' and that these residues are sensitive to pH changes. This study suggests that the catalytic aspartates can modulate the opening of the active site and substrate binding. PMID:27291071

  10. Segmented vortex flaps

    NASA Technical Reports Server (NTRS)

    Rao, D. M.

    1983-01-01

    Segmented vortex flaps were suggested as a means of delaying the vortex spill-over causing thrust loss over the outboard region of single-panel flaps. Also proposed was hinge-line setback for exploiting leading-edge suction in conjunction with vortex flaps to improve the overall thrust per unit flap area. These two concepts in combination were tested on a 60-deg cropped delta wing model. Significant improvement in flap efficiency was indicated by a reduction of the flap/wing area from 11.4% of single-panel flap to 6.3% of a two segment delta flap design, with no lift/drag penalty at lift coefficients between 0.5 and 0.7. The more efficient vortex flap arrangement of this study should benefit the performance attainable with flaps of given area on wings of moderate leading-edge sweep.

  11. Differences in blood flow volume and vascular resistance between free flaps: assessment in 58 cases.

    PubMed

    Takanari, Keisuke; Kamei, Yuzuru; Toriyama, Kazuhiro; Yagi, Shunjiro; Torii, Shuhei

    2009-01-01

    In free-flap transfer, blood flow in the transferred flap contributes to wound healing and to resistance against infection in the recipient site. Successful reconstructions using free tissue transfers may be required to define and choose flaps with abundant blood flow in necessary cases. We investigated blood flow in the flap by transit-time ultrasound flowmeter in 58 free-flap transfers. Flow volume was compared between flap tissues as vascular resistance in the flap was calculated. Fasciocutaneous and osteocutaneous flaps had relatively low blood flow volume, myocutaneous flaps had more, and intraperitoneal flaps had still higher blood flow volume. These differences were statistically significant. Vascular resistance significantly decreased in the same order of comparison. Our findings will help in selecting the most suitable flaps for reconstructive surgery. PMID:18942044

  12. Slotted variable camber flap

    NASA Technical Reports Server (NTRS)

    Andrews, D. G. (Inventor)

    1984-01-01

    Variable camber actuator assemblies broaden the range of speeds at which lift to drag performance is maximized for slotted flap wings. Lift is improved over a broader range of cruising speeds by varying wing camber with rotational flap movements that do not introduce wing slots and induced drag. Forward flaps are secured to forward flange links which extended from, and are a part of forward flap linkage assemblies. The forward flaps rotate about flap pivots with their rotational displacement controlled by variable camber actuator assemblies located between the forward flaps and the forward flange links. Rear flaps are held relative to the forward flaps by rear flap linkage assemblies which may act independently from the forward flap linkage assemblies and the variable camber actuator assemblies. Wing camber is varied by rotating the flaps with the variable camber actuator assemblies while the flaps are in a deployed or tucked position. Rotating the flaps in a tucked position does not introduce significant wing surface discontinuities, and reduces aircraft fuel consumption on most flight profiles.

  13. Skin flaps and grafts - self-care

    MedlinePlus

    ... skin infection Surgery for skin cancer Venous ulcers , pressure ulcers , or diabetic ulcers that do not heal After mastectomy or amputation Donor sites for grafts and flaps are chosen ... surgery than the wound due to newly exposed nerve endings.

  14. The split radial forearm flap for lower leg defects.

    PubMed

    van Kampen, Robert J; Corten, Eveline M L; Schellekens, Pascal P A

    2014-11-01

    The conventional free radial forearm flap is a very reliable, long-pedicled flap with thin, pliable skin. These properties make it an excellent choice for high-risk reconstructions or defects requiring only a thin cover. The split radial forearm flap allows primary closure of the donor site and has a large variability in shape and size. In this report, the cutaneous perforators of the radial artery were investigated in fresh cadavers and we present our clinical experience with the split radial artery flap in 9 patients with lower leg defects. Sufficient perforators exist to safely divide the flap proximally and distally into segments. In all clinical cases, the donor site could be closed primarily. All flaps remained viable and 8 of 9 patients obtained an esthetically pleasing result. The split radial forearm free flap is an elegant option for reconstruction of small- to moderate-sized soft tissue defects in the lower extremity. PMID:23657049

  15. The clinical application of anterolateral thigh flap.

    PubMed

    Lee, Yao-Chou; Chiu, Haw-Yen; Shieh, Shyh-Jou

    2011-01-01

    The anterolateral thigh flap can provide a large skin paddle nourished by a long and large-caliber pedicle and can be harvested by two-team work. Most importantly, the donor-site morbidity is minimal. However, the anatomic variations decreased its popularity. By adapting free-style flap concepts, such as preoperative mapping of the perforators and being familiar with retrograde perforator dissection, this disadvantage had been overcome gradually. Furthermore, several modifications widen its clinical applications: the fascia lata can be included for sling or tendon reconstruction, the bulkiness could be created by including vastus lateralis muscle or deepithelization of skin flap, the pliability could be increased by suprafascial dissection or primary thinning, the pedicle length could be lengthening by proximally eccentric placement of the perforator, and so forth. Combined with these technical and conceptual advancements, the anterolateral thigh flap has become the workhorse flap for soft-tissue reconstructions from head to toe. PMID:22567234

  16. Facial artery flaps in facial oncoplastic reconstruction.

    PubMed

    Fabrizio, Tommaso

    2013-10-01

    The face is one of the common sites for cutaneous cancer localization. It is well known that the face is the localization of more than 50% of skin cancers. Nowadays, the principles of modern "oncoplasty" recommend the complete excision of the cancer and the reconstruction with respect to cosmetic features of the face in terms of good color, good softness, and good texture of the flaps, utilized in cancer repair. The oncological and cosmetic results of facial reconstruction are strictly linked and the modern plastic and reconstructive surgeon must respect both oncological and cosmetic aspects. For that reason the best solution in facial cancer repair is the utilization of locoregional flaps based on the tributary vessels of the facial artery. In consideration of the dimension of recipient area to repair, the retroangular flap (RAF) or the submental flap could be used. This article is voted to illustrate a very large and long-term casuistry dedicated to these flaps. PMID:24037925

  17. Free combined composite flaps using the lateral circumflex femoral system for repair of massive defects of the head and neck regions: an introduction to the chimeric flap principle.

    PubMed

    Koshima, I; Yamamoto, H; Hosoda, M; Moriguchi, T; Orita, Y; Nagayama, H

    1993-09-01

    Chimeric composite flaps combined using microanastomoses consist of two or more flaps or tissues, each with an isolated pedicle and a single vascular source. Free combined chimeric flaps using the lateral circumflex femoral system were used to treat massive composite defects of the head and neck in 10 cases. A combined anterolateral thigh flap and vascularized iliac bone graft based on the lateral circumflex femoral system and the deep circumflex iliac system was the most commonly used combination. An anteromedial thigh flap and a paraumbilical perforator-based flap were also combined with this principal combination. The advantages of this chimeric flap over other osteocutaneous flaps are: (1) The flap is relatively thin and the pedicle vessels are up to 10 cm longer and are wider than those of other flaps for easier harvesting of the flap. (2) It is unnecessary to reposition the patient. (3) The vascular pedicle to the skin can be separated from that of the bone. (4) The donor site is not close to the recipient site. (5) The donor scar is in an unexposed area. (6) The skin territory of this flap is extremely wide. (7) A combined anterolateral and anteromedial thigh flap and vascularized iliac bone graft can be easily obtained as an extended combined osteocutaneous flap. (8) Other neighboring skin flaps, such as a groin flap, a paraumbilical perforator-based flap, or a medial thigh flap, can be combined with this chimeric flap because several major muscle branches to be anastomosed derive from the lateral circumflex femoral system. Chimeric composite flaps using the lateral circumflex femoral system are considered suitable for the repair of massive composite defects of the head and neck. PMID:8341739

  18. The posterior calf fascial free flap.

    PubMed

    Walton, R L; Matory, W E; Petry, J J

    1985-12-01

    Six posterior calf fascial free flaps were employed to reconstruct defects of the upper and lower extremities. One flap failed due to a constricting dressing. Two flaps sustained partial loss secondary to bleeding and hematoma formation. One flap dehisced at the distal suture line due to mobility of an underlying fracture. All surviving flaps eventually healed and resulted in stable, thin coverage. Donor-site morbidity has been minimal. Shortcomings of this flap model have been defined in the peculiarities of its thinness, diffuse vascular oozing, the extent of the vascular territory, and in postoperative monitoring. These problems are analyzed and recommendations for their resolution are presented. Fascia represents a unique tissue which offers an exciting new dimension in the reconstruction of certain defects--particularly those in which thinness is a desirable option. In the posterior calf model, the inclusion of fat represents an alternative modification that allows the surgeon to tailor the design to a variety of problems where fascia alone is too thin and a cutaneous flap is too thick. This concept may find its greatest application in wounds involving the hand or foot. We believe that this and other fascial flap prototypes may offer an ideal solution for reconstruction of major wounds of the extremities. PMID:3906718

  19. Thumb Reconstruction Using Foucher’s Flap

    PubMed Central

    Kola, Nardi

    2016-01-01

    BACKGROUND: Extensive pulp defects of the thumb, with the exposure of tendon or bone, are challenging reconstructive problems. Surgical treatment includes the use of local, regional, and free flaps. AIM: This paper is focused in Foucher’s neuro vascular flap. First DMCA or Foucher’s pedicle flap is a successful thumb reconstruction method, especially in patients not disturbed by its cosmetic appearance. MATERIAL AND METHODS: The first dorsal metacarpal artery (FDMCA) arises from the radial artery in the first intermetacarpal space, just distal to the tendon of the extensor pollicis longus. Pulp area of the thumb is the area where Foucher’s flap is more utilizable. This technique has other applications such as first web reconstruction, thumb lengthening, and following resection of tumors on the dorsum of the hand. RESULTS: We have in study 7 cases with work related trauma in two years period of time, between 2012 and 2014. We had only one partial flap survival and all the other flaps survived entirely. We have also taken in consideration subjective satisfaction with a range score from 4 to 10, cold intolerance, flap area and donor site sensibility with a range score from low to medium to normal. CONCLUSION: Careful pedicle discovery, secured elevation, pedicle strangulation prevention are very important for flap survival.

  20. Tensor fascia lata flap versus tensor fascia lata perforator-based island flap for the coverage of extensive trochanteric pressure sores.

    PubMed

    Kim, Youn Hwan; Kim, Sang Wha; Kim, Jeong Tae; Kim, Chang Yeon

    2013-06-01

    Tensor fascia lata (TFL) musculocutaneous flaps often require a donor site graft when harvesting a large flap. However, a major drawback is that it also sacrifices the muscle. To overcome this disadvantage, we designed a TFL perforator-based island flap that was harvested from a site near the defect and involved transposition within 90 degrees without full isolation of the pedicles. We performed procedures on 17 musculocutaneous flaps and 23 perforator-based island flaps, and compared the outcomes of these surgeries. The overall complication rate was 27.5% (11 regions). There were 7 complications related to the musculocutaneous flaps and 4 complications related to the perforator flaps. Although there were no statistical differences between those groups, lower complication rates were associated with procedures involving perforator flaps. The TFL perforator procedure is a simple and fast operation that avoids sacrificing muscle. This decreases complication rates compared to true perforator flap techniques that require dissection around the perforator or pedicle. PMID:23392259

  1. Cross-leg repair of large soft-tissue defects in distal sites of the feet by distally based neuro-fasciocutaneous flaps with perforating vessels.

    PubMed

    Wang, Z Q; Cao, Y L; Huang, Y F; Liu, D Q; Li, X F

    2014-01-01

    The objective of this study was to introduce a method for repairing large soft-tissue defects on the foot. Distally based neuro-fasciocutaneous flaps with perforating vessels were designed along the saphenous and sural neurovascular axes. The cutaneous perforating branches of the major arteries of the lower extremities were used as pedicles, which provided a rotation arc for the cross-leg flap to cover the large-sized soft-tissue defects on the foot. We transferred 6 neurocutaneous vascular axial flaps, including 4 saphenous neurocutaneous axial flaps (ranging from 25 x 13 to 17 x 9 cm in area) with posterior tibial perforators as the pedicle, and 2 sural neurocutaneous axial flaps (ranging from 29 x 12 to 18 x 7 cm in area) supplied by the perforating branches of the peroneal vessels. These 6 cases of neuro-fasciocutaneous flaps survived with satisfactory cosmetic appearances and functional results on follow-up at 8 to 17 months post-surgery. Placing a distally based neuro-fasciocutaneous cross-leg flap with perforating vessels is an effective method for repairing large-sized soft-tissue defects on the foot. PMID:25117303

  2. Active Sites Environmental Monitoring Program: Program plan

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1990-10-01

    DOE Order 5820.2A requires that low-level waste (LLW) disposal sites active on or after September 1988 and all transuranic (TRU) waste storage sites be monitored periodically to assure that radioactive contamination does not escape from the waste sites and pose a threat to the public or to the environment. This plan describes such a monitoring program for the active LLW disposal sites in SWSA 6 and the TRU waste storage sites in SWSA 5 North. 14 refs., 8 figs.

  3. Propeller thoracodorsal artery perforator flap for breast reconstruction

    PubMed Central

    Angrigiani, Claudio; Escudero, Ezequiel; Artero, Guillermo; Gercovich, Gustavo; Deza, Ernesto Gil

    2014-01-01

    Background The thoracodorsal artery perforator (TDAP) flap has been described for breast reconstruction. This flap requires intramuscular dissection of the pedicle. A modification of the conventional TDAP surgical technique for breast reconstruction is described, utilizing instead a propeller TDAP flap. The authors present their clinical experience with the propeller TDAP flap in breast reconstruction alone or in combination with expanders or permanent implants. Methods From January 2009 to February 2013, sixteen patients had breast reconstruction utilizing a propeller TDAP flap. Retrospective analysis of patient characteristics, clinical indications, procedure and outcomes were performed. The follow-up period ranged from 4 to 48 months. Results Sixteen patients had breast reconstruction using a TDAP flap with or without simultaneous insertion of an expander or implant. All flaps survived, while two cases required minimal resection due to distal flap necrosis, healing by second intention. There were not donor-site seromas, while minimal wound dehiscence was detected in two cases. Conclusions The propeller TDAP flap appears to be safe and effective for breast reconstruction, resulting in minimal donor site morbidity. The use of this propeller flap emerges as a true alternative to the traditional TDAP flap. PMID:25207210

  4. Locoregional use of lateral thoracic artery perforator flap as a propeller flap.

    PubMed

    Baghaki, Semih; Cevirme, Mirza; Diyarbakirli, Murat; Tatar, Cihad; Aydin, Yagmur

    2015-05-01

    Although thoracodorsal system is a fundamental source of various flaps, lateral thoracic region has not been a popular flap donor area. There is limited data on the use of lateral intercostal artery perforator flap and lateral thoracic artery perforator flap. In this case series, lateral thoracic artery perforator flap has been used in locoregional (axilla, pectoral region, and arm) reconstruction as an island or propeller flap.Eighteen patients have been operated on between September 2010 and January 2013. The age of the patients ranged between 16 and 68 years with a median of 38 years. A thorough chart review has been performed with preoperative and postoperative photographs. Duration of hospitalization, complication rate and long term results have been documented.Nine patients had severe burn contracture of axilla, 7 patients had axillary hidradenitis suppurativa, 1 patient had giant neurofibroma of arm, and 1 patient had malignant peripheral nerve sheath tumor of pectoral area. Seventeen flaps survived totally, and in 1 flap, distal superficial slough of skin has been observed. No recurrence in hidradenitis or peripheral nerve sheath tumor has been observed. Donor site scar is well hidden in anatomical position. The range of motion of affected extremities returned to normal after reconstruction.Lateral thoracic area provides a reliable flap option with a wide arc of rotation when lateral thoracic artery perforators are used. PMID:25875722

  5. Platysma flap using dual skin paddles.

    PubMed

    Mustafa, El Muiz A; Bhatia, Sunil K; Hammond, Doug E

    2016-07-01

    The platysma myocutaneous flap is rarely reported as an option for reconstruction in the head and neck. In our experience it is a reliable flap that is easy to raise, has a limited risk of morbidity at the donor site, and allows for early recommencement of oral function. We report a patient with an unusually aggressive orocutaneous fistula that complicated the simple extraction of teeth. We modified the platysma flap to provide two independent skin paddles so we could reconstruct both the intraoral and cutaneous defects simultaneously with a good clinical outcome. PMID:26947107

  6. The infrahyoid flap: a comprehensive review of an often overlooked reconstructive method.

    PubMed

    Deganello, Alberto; Leemans, C René

    2014-08-01

    The infrahyoid flap is a myocutaneous pedicled flap mainly nourished by the superior thyroid vessels through the perforators of the infrahyoid muscles. This thin and pliable flap provides a skin island of about 7 by 4 cm from the central part of the anterior neck. The flap can be transferred on its pedicle of superior thyroid artery and vein to reconstruct medium sized head and neck defects created after cancer ablation. We have successfully used this flap in a series of 40 cases with no total flap loss and with 1 case of superficial skin necrosis. The aim of this review is to highlight the clinical usefulness of this pedicled flap even in the microvascular free flap era. A comprehensive review of the available literature reporting on the infrahyoid flap has been carried out using a web search. The history of the infrahyoid flap, the surgical technique with technical innovations, the clinical utility and limitations of this flap, are reported and discussed. Among the 7 larger series (cohort larger than 50 cases) a total of 956 flaps were performed, and the global success rate was 91.7%, with failures being mainly related to partial skin necrosis, as the rate of total (skin and muscle) flap necrosis was only 1%. This flap is reliable, easy to harvest during neck dissection, oncologically safe, it does carry a negligible donor site morbidity. This paper highlights how the infrahyoid flap can represent an excellent reconstructive solution in selected patients and head and neck sites. PMID:24856306

  7. Rescue of lip switch flap at risk of necrosis due to venous congestion for cleft lip deformity.

    PubMed

    Sugiyama, Madoka; Saijo, Hideto; Kazuto, Hoshi; Takato, Tsuyoshi

    2016-01-01

    In a 21-year-old male with bilateral cleft lip who developed marked venous congestion of a lip switch flap, we returned the grafted flap to the donor site to improve blood circulation of the flap and then re-transplanted it, which prevented flap necrosis. Here, we report the procedure and case. PMID:27583269

  8. Rescue of lip switch flap at risk of necrosis due to venous congestion for cleft lip deformity

    PubMed Central

    Sugiyama, Madoka; Saijo, Hideto; Kazuto, Hoshi; Takato, Tsuyoshi

    2016-01-01

    Abstract In a 21-year-old male with bilateral cleft lip who developed marked venous congestion of a lip switch flap, we returned the grafted flap to the donor site to improve blood circulation of the flap and then re-transplanted it, which prevented flap necrosis. Here, we report the procedure and case. PMID:27583269

  9. Educational Activity Sites for High School Students

    ERIC Educational Resources Information Center

    Troutner, Joanne

    2005-01-01

    Finding quality Internet resources for high school students is a continuing challenge. Several high-quality web sites are presented for educators and students. These sites offer activities to learn how an art conservator looks at paintings, create a newspaper, research and develop an end product, build geometry and physics skills, explore science…

  10. A comparative molecular dynamics study on BACE1 and BACE2 flap flexibility.

    PubMed

    Kumalo, H M; Soliman, Mahmoud E

    2016-10-01

    Beta-amyloid precursor protein cleavage enzyme1 (BACE1) and beta-amyloid precursor protein cleavage enzyme2 (BACE2), members of aspartyl protease family, are close homologs and have high similarity in their protein crystal structures. However, their enzymatic properties are different, which leads to different clinical outcomes. In this study, we performed sequence analysis and all-atom molecular dynamic (MD) simulations for both enzymes in their ligand-free states in order to compare their dynamical flap behaviors. This is to enhance our understanding of the relationship between sequence, structure and the dynamics of this protein family. Sequence analysis shows that in BACE1 and BACE2, most of the ligand-binding sites are conserved, indicative of their enzymatic property as aspartyl protease members. The other conserved residues are more or less unsystematically localized throughout the structure. Herein, we proposed and applied different combined parameters to define the asymmetric flap motion; the distance, d1, between the flap tip and the flexible region; the dihedral angle, φ, to account for the twisting motion and the TriCα angle, θ2 and θ1. All four combined parameters were found to appropriately define the observed "twisting" motion during the flaps different conformational states. Additional analysis of the parameters indicated that the flaps can exist in an ensemble of conformations, i.e. closed, semi-open and open conformations for both systems. However, the behavior of the flap tips during simulations is different between BACE1 and BACE2. The BACE1 active site cavity is more spacious as compared to that of BACE2. The analysis of 10S loop and 113S loop showed a similar trend to that of flaps, with the BACE1 loops being more flexible and less stable than those of BACE2. We believe that the results, methods and perspectives highlighted in this report would assist researchers in the discovery of BACE inhibitors as potential Alzheimer's disease therapies

  11. Unilateral Breast Reconstruction Using Bilateral Inferior Gluteal Artery Perforator Flaps

    PubMed Central

    Muto, Mayu; Ogawa, Marina; Shibuya, Mai; Yasumura, Kazunori; Kobayashi, Shinji; Ishikawa, Takashi; Maegawa, Jiro

    2015-01-01

    Background: For reconstructing moderate-to-high projection breasts in nulliparous patients with insufficient abdominal tissue or prior abdominal surgeries, a unilateral inferior gluteal artery perforator (IGAP) flap is an alternative procedure. In patients with slim hips, however, unilateral gluteal tissue is insufficient and inferior gluteal crease displacement may develop postoperatively. Donor-site asymmetry is also a major disadvantage. In these circumstances, bilateral IGAP flaps provide sufficient tissue without significant gluteal deformity. Methods: We retrospectively reviewed 20 patients who underwent unilateral breast reconstruction using bilateral IGAP flaps by a single surgeon between November 2007 and December 2012. A quantitative outcome assessment was performed and compared with that of 22 unilateral IGAP flap patients operated on by the same surgeon. Results: Twenty patients underwent reconstruction with 40 IGAP flaps. Of the 40 flaps, 39 survived and 1 developed total necrosis due to repeated venous thrombosis. In 15 of 20 patients, the size of reconstructed breast was comparable to that of the contralateral breast. Final inset flap weight was 462.3 g for bilateral flaps and 244.3 g for unilateral flaps. Total operating time was 671.1 minutes (bilateral flaps) and 486.8 minutes (unilateral flaps). Conclusions: Use of bilateral IGAP flaps for breast reconstruction helps to avoid asymmetry of the inferior buttock volume and shape. Bilateral flaps provide sufficient tissue volume and allow for reconstruction of a breast comparable to the unaffected side. In patients with moderate-to-high projection breast whose abdominal tissue cannot be used for reconstruction, IGAP flaps may be a suitable alternative. PMID:25878925

  12. Modeling of flap endonuclease interactions with DNA substrate.

    PubMed

    Allawi, Hatim T; Kaiser, Michael W; Onufriev, Alexey V; Ma, Wu-Po; Brogaard, Andrew E; Case, David A; Neri, Bruce P; Lyamichev, Victor I

    2003-05-01

    Structure-specific 5' nucleases play an important role in DNA replication and repair uniquely recognizing an overlap flap DNA substrate and processing it into a DNA nick. However, in the absence of a high-resolution structure of the enzyme/DNA complex, the mechanism underlying this recognition and substrate specificity, which is key to the enzyme's function, remains unclear. Here, we propose a three-dimensional model of the structure-specific 5' flap endonuclease from Pyrococcus furiosus in its complex with DNA. The model is based on the known X-ray structure of the enzyme and a variety of biochemical and molecular dynamics (MD) data utilized in the form of distance restraints between the enzyme and the DNA. Contacts between the 5' flap endonuclease and the sugar-phosphate backbone of the overlap flap substrate were identified using enzyme activity assays on substrates with methylphosphonate or 2'-O-methyl substitutions. The enzyme footprint extends two to four base-pairs upstream and eight to nine base-pairs downstream of the cleavage site, thus covering 10-13 base-pairs of duplex DNA. The footprint data are consistent with a model in which the substrate is bound in the DNA-binding groove such that the downstream duplex interacts with the helix-hairpin-helix motif of the enzyme. MD simulations to identify the substrate orientation in this model are consistent with the results of the enzyme activity assays on the methylphosphonate and 2'-O-methyl-modified substrates. To further refine the model, 5' flap endonuclease variants with alanine point substitutions at amino acid residues expected to contact phosphates in the substrate and one deletion mutant were tested in enzyme activity assays on the methylphosphonate-modified substrates. Changes in the enzyme footprint observed for two point mutants, R64A and R94A, and for the deletion mutant in the enzyme's beta(A)/beta(B) region, were interpreted as being the result of specific interactions in the enzyme/DNA complex

  13. Clinical experience of multiple flaps for the reconstruction of dorsal digital defects

    PubMed Central

    Jiao, Hongsheng; Ding, Xiaoheng; Liu, Yujie; Zhang, Hongxun; Cao, Xuecheng

    2015-01-01

    Objective: In this report, we present our experience with reconstruction of the skin defects on the dorsum of the digits using multiple flaps. Methods: Between November 2010 and March 2013, 45 patients with dorsal digital defects underwent reconstruction using homodigital dorsal digital fasciocutaneous flap (n = 17), heterodigital dorsal digital fasciocutaneous flap (n = 14), dorsal metacarpal artery fasciocutaneous flap (n = 8) and free venous flaps (n = 6). The average flap size was 1.5 × 1.5 cm to 2.0 × 2.5 cm. Donor sites were covered with full-thickness skin graft. Results: All flaps survived completely and the donor sites healed without complications. The mean follow-up period was 18 weeks. During the follow up period, 7 patients treated with reverse homodigital fasciocutaneous flaps developed swelling in the distal portion of flaps, 3 patients treated with reverse dorsal metacarpal artery fasciocutaneous flaps developed mild swelling in the distal portion of flaps but survive well, and 4 patients treated with free venous flaps experienced venous congestion. Of the 14 patients treated with heterodigital fasciocutaneous flaps, there were 11 cases with a retrograde pedicle and 3 cases with a direct pedicle. No full-thickness graft necrosis was noted. Conclusion: Multiple options are available for the repair of skin defects on the dorsum of the digits. Besides, the use of a heterodigital fasciocutaneous flap was a simple, safe, and less invasive regimen for repairing dorsal digital skin defects. PMID:26770401

  14. The distally based superficial sural flap for reconstruction of the lower leg and foot.

    PubMed

    Rajacic, N; Darweesh, M; Jayakrishnan, K; Gang, R K; Jojic, S

    1996-09-01

    We describe our experience with the use of distally based superficial sural flaps for coverage of defects in the lower leg and foot in 21 patients. In 18 patients the flap was successfully transferred, in 2 cases partial necrosis of the flap occurred and 1 flap failed completely. In 18 cases the flap was used as a fasciocutaneous flap and in 3 cases as a fascial flap only. The advantages of this flap are: easy and quick dissection, hence saving operating time, minimal morbidity of donor site and preservation of major arteries of the leg. Although the flap was described as reliable for covering defects around the ankle joint, we have been able to cover defects of the dorsum of the foot distally and up to the mid-third of the tibia proximally. PMID:8881785

  15. The platysma myocutaneous flap.

    PubMed

    Baur, Dale A; Williams, Jonathan; Alakaily, Xena

    2014-08-01

    Reconstructing defects of the oral mucosa or skin of the lower one-third of the face can be accomplished by a variety of techniques. This article presents two versions of the platysma myocutaneous flap, which is a reliable, axial pattern, pedicled flap capable of providing excellent one-stage reconstruction of such defects. As discussed herein, the superiorly based and posteriorly based versions of the flap have wide application in the oral and facial region. Also provided is a review of other uses of this flap in head and neck surgery. PMID:24958382

  16. Keyhole Flap Nipple Reconstruction

    PubMed Central

    Cash, Camille G.; Iman, Al-Haj; Spiegel, Aldona J.; Cronin, Ernest D.

    2016-01-01

    Summary: Nipple-areola reconstruction is often one of the final but most challenging aspects of breast reconstruction. However, it is an integral and important component of breast reconstruction because it transforms the mound into a breast. We performed 133 nipple-areola reconstructions during a period of 4 years. Of these reconstructions, 76 of 133 nipple-areola complexes were reconstructed using the keyhole flap technique. The tissue used for the keyhole dermoadipose flap technique include transverse rectus abdominus myocutaneous flaps (60/76), latissimus dorsi flaps (15/76), or mastectomy skin flaps after tissue expanders (1/76). The average patient follow-up was 17 months. The design of the flap is based on a keyhole configuration. The base of the flap determines the width of the future nipple, whereas the length of the flap determines the projection. We try to match the projection of the contralateral nipple if present. The keyhole flap is simple to construct yet reliable. It provides good symmetry and projection and avoids the creation of new scars. The areola is then tattooed approximately 3 months after the nipple reconstruction.

  17. Keyhole Flap Nipple Reconstruction.

    PubMed

    Chen, Joseph I; Cash, Camille G; Iman, Al-Haj; Spiegel, Aldona J; Cronin, Ernest D

    2016-05-01

    Nipple-areola reconstruction is often one of the final but most challenging aspects of breast reconstruction. However, it is an integral and important component of breast reconstruction because it transforms the mound into a breast. We performed 133 nipple-areola reconstructions during a period of 4 years. Of these reconstructions, 76 of 133 nipple-areola complexes were reconstructed using the keyhole flap technique. The tissue used for the keyhole dermoadipose flap technique include transverse rectus abdominus myocutaneous flaps (60/76), latissimus dorsi flaps (15/76), or mastectomy skin flaps after tissue expanders (1/76). The average patient follow-up was 17 months. The design of the flap is based on a keyhole configuration. The base of the flap determines the width of the future nipple, whereas the length of the flap determines the projection. We try to match the projection of the contralateral nipple if present. The keyhole flap is simple to construct yet reliable. It provides good symmetry and projection and avoids the creation of new scars. The areola is then tattooed approximately 3 months after the nipple reconstruction. PMID:27579228

  18. Low dielectric response in enzyme active site

    PubMed Central

    Mertz, Edward L.; Krishtalik, Lev I.

    2000-01-01

    The kinetics of charge transfer depend crucially on the dielectric reorganization of the medium. In enzymatic reactions that involve charge transfer, atomic dielectric response of the active site and of its surroundings determines the efficiency of the protein as a catalyst. We report direct spectroscopic measurements of the reorganization energy associated with the dielectric response in the active site of α-chymotrypsin. A chromophoric inhibitor of the enzyme is used as a spectroscopic probe. We find that water strongly affects the dielectric reorganization in the active site of the enzyme in solution. The reorganization energy of the protein matrix in the vicinity of the active site is similar to that of low-polarity solvents. Surprisingly, water exhibits an anomalously high dielectric response that cannot be described in terms of the dielectric continuum theory. As a result, sequestering the active site from the aqueous environment inside low-dielectric enzyme body dramatically reduces the dielectric reorganization. This reduction is particularly important for controlling the rate of enzymatic reactions. PMID:10681440

  19. Binding of single walled carbon nanotube to WT and mutant HIV-1 proteases: analysis of flap dynamics and binding mechanism.

    PubMed

    Meher, Biswa Ranjan; Wang, Yixuan

    2012-09-01

    Most of the currently treated HIV-1 protease (HIV-PR) inhibitors have been prone to suffer from the mutations associated drug resistance. Therefore, it is necessary to search for potent alternatives against the drug resistance. In the current study we have tested the single-walled carbon nanotube (SWCNT) as an inhibitor in wild type (WT) as well as in three primary mutants (I50V(PR), V82A(PR) and I84V(PR)) of the HIV-1-PR through docking the SWCNT in the active site region, and then performed all-atom MD simulations for the complexes. The conformational dynamics of HIV-PR with a 20 ns trajectory reveals that the SWCNT can effectively bind to the HIV-1-PR active site and regulate the flap dynamics such as maintaining the flap-flap closed. To gain an insight into the binding affinity, we also performed the MM-PBSA based binding free energy calculations for the four HIV-PR/SWCNT complexes. It was observed that, although the binding between the SWCNT and the HIV-PR decreases due to the mutations, the SWCNTs bind to the HIV-PRs 3-5 folds stronger than the most potent HIV-1-PR inhibitor, TMC114. Remarkably, the significant interactions with binding energy higher than 1kcal/mol focus on the flap and active regions, which favors closing flap-flap and deactivating the active residues of the HIV-PR. The flap dynamics and binding strength information for HIV-PR and SWCNTs can help design SWCNT-based HIV-1-PR inhibitors. PMID:23142620

  20. Monocortical Deep Circumflex Iliac Artery Flap in Jaw Reconstruction.

    PubMed

    Moon, Seong-Yong

    2015-06-01

    Conventionally deep circumflex iliac artery (DCIA) flap had been harvested as bicortical form. However, several complications and adverse effects occurred such as abnormal hip contour, hernia, severe bleeding tendency, gait disturbance, and hypoesthesia. All the 9 patients required reconstruction of the jaw with microvascular free flaps after radical resection. Monocortical bone segment was harvested from the anterior iliac crest, and the amount of bone harvested was from 47 to 90 mm (mean, 63 ± 14.6). Monocortical deep circumflex iliac artery flap has sufficient advantages in donor-site morbidity, which is one of the factors to choose flap. PMID:26080179

  1. The radix nasi island flap: a versatile musculocutaneous flap for defects of the eyelids, nose, and malar region.

    PubMed

    Seyhan, Tamer

    2009-03-01

    A versatile musculocutan flap from the radix nasi region, the radix nasi island flap, is described. The flap has an axial blood supply derived from the dorsal nasal branch of the ophthalmic artery which is anastomosed to the terminal branch of the facial artery. The flap includes the skin, subcutaneous tissue, and procerus muscle. Ten patients, aged 50 to 86 years, have been reconstructed with this flap for defects in the nose (in 4 cases), midface (in 4 cases) and lower eyelids (in 2 cases). The mean flap size was 17 x 23 mm (range: 15 x 20 to 20 x 27 mm). All flaps fully survived. Additional complications and morbidity were not observed. The donor sites were closed a primarily closure in all cases. Follow-up ranged from 3 to 12 months (mean: 8.2 months). The radix nasi flap is a safe flap, has minimal donor site morbidity, and is especially suited for nasal and midface reconstruction in terms of attaining a suitable color and thickness. PMID:19305249

  2. Bipedicled “Superthin” Free Perforator Flaps for Facial Burn Scar Reconstruction: Expanded Scope of Superthin Flaps: A Case Series

    PubMed Central

    Van Anh, Tran; Tien, Nguyen Gia; Hyakusoku, Hiko; Ogawa, Rei

    2015-01-01

    Background: “Superthin flap” is a distinctively thin flap that is thinned primarily to the point that the subdermal vascular network can be seen through a minimal fat layer. Reconstruction of severely disfigured neck and face can be performed using the occipito-cervico-dorsal superthin flap that is harvested from the dorsal region and supercharged by the circumflex scapular vessels. We used bipedicled superthin free perforator flaps to reconstruct scar contractures on half of the face, whole face, or the whole chin-neck area in 17 postburn patients. Methods: This case series report includes all 17 cases. Flaps in the dorsal area were designed. In all cases, one pedicle consisted of the circumflex scapular vessels. In 11, 5, and 1 flaps, the second pedicle consisted of contralateral posterior intercostal perforators (type 1), ipsilateral posterior intercostal perforators (type 2), and ipsilateral circumflex scapular vessels (type 3), respectively. Four patients underwent whole-face reconstruction after acid burn with type 1 or type 3 perforator. The recipient vessels were the superficial temporal vessels and contralateral or ipsilateral facial vessels. Intraoperatively, all adipose tissue in the flap, including between the 2 pedicles, was thinned by scissors before the pedicles were detached from the donor sites. Maximum flap size was 35 × 15 cm. Donor sites were covered by a split full-thickness skin graft. Flap survival and functional and cosmetic results were assessed retrospectively. Results: Fifteen of the 17 flaps survived completely. Two developed partial necrosis due to perforator thrombosis. Some patients developed hypertrophic scars around the flap, but these improved naturally over time. All patients were satisfied with both the cosmetic and functional outcomes of the reconstruction. Conclusion: Bipedicled superthin free perforator flaps may be an excellent choice for reconstruction of severe neck scar contracture. This report expands the scope

  3. Free Flap Reconstruction for Complex Scalp and Forehead Defects with Associated Full-Thickness Calvarial Bone Resections

    PubMed Central

    Larrañaga, Juan; Rios, Alfredo; Franciosi, Edgardo; Mazzaro, Eduardo; Figari, Marcelo

    2012-01-01

    Extensive defects of the scalp and forehead associated with calvarial bone resections demand complex reconstructions. Free flaps offer vascularized tissue of excellent quality and quantity. We report six patients with extensive scalp and forehead defects associated with calvarial bone resections reconstructed with free flaps. Five patients also required a cranioplasty. The flaps used were two anterolateral thigh flaps, one vastus lateralis flap, one myocutaneous latissimus dorsi flap, one latissimus dorsi flap, and one radial forearm flap. All flaps survived with no partial necrosis. There were no donor site complications. One patient presented an exposure of the alloplastic material used for cranioplasty. We strongly recommend the use of free flaps for this kind of reconstruction. PMID:24294403

  4. Active site specificity of plasmepsin II.

    PubMed Central

    Westling, J.; Cipullo, P.; Hung, S. H.; Saft, H.; Dame, J. B.; Dunn, B. M.

    1999-01-01

    Members of the aspartic proteinase family of enzymes have very similar three-dimensional structures and catalytic mechanisms. Each, however, has unique substrate specificity. These distinctions arise from variations in amino acid residues that line the active site subsites and interact with the side chains of the amino acids of the peptides that bind to the active site. To understand the unique binding preferences of plasmepsin II, an enzyme of the aspartic proteinase class from the malaria parasite, Plasmodium falciparum, chromogenic octapeptides having systematic substitutions at various positions in the sequence were analyzed. This enabled the design of new, improved substrates for this enzyme (Lys-Pro-Ile-Leu-Phe*Nph-Ala/Glu-Leu-Lys, where * indicates the cleavage point). Additionally, the crystal structure of plasmepsin II was analyzed to explain the binding characteristics. Specific amino acids (Met13, Ser77, and Ile287) that were suspected of contributing to active site binding and specificity were chosen for site-directed mutagenesis experiments. The Met13Glu and Ile287Glu single mutants and the Met13Glu/Ile287Glu double mutant gain the ability to cleave substrates containing Lys residues. PMID:10548045

  5. Distally Based Saphenous Neurocutaneous Perforator Flap: A Versatile Donor Site for Reconstruction of Soft Tissue Defects of the Medial Malleolar Region.

    PubMed

    Zhong, Wanrun; Lu, Shengdi; Chai, Yimin

    2016-01-01

    Repair of both simple and complex defects in the medial malleolar region continues to be a challenging task for surgeons because of the local paucity of soft tissue available for transfer. The popular neurocutaneous flap has provided a reliable and less technically demanding method for resurfacing defects of the lower extremities. We present our experience with the versatile design of the distally based saphenous neurocutaneous perforator flap to provide coverage of complex post-traumatic medial malleolar defects by harvesting multiple tissue components in various combinations. Our series included 11 patients (8 males [72.7%] and 3 females [27.3%]); mean age 39.2 (range 22 to 58) years, who were followed for a mean duration of 13.3 (range 9 to 18) months. Three flaps (27.3%) were harvested with massive subcutaneous tissue to obliterate dead space. The procedure was uneventful in 10 patients (90.9%). Venous congestion was noted in 1 patient (9.1%), in whom secondary healing was achieved with conservative treatment. PMID:26024559

  6. Management of complications and compromised free flaps following major head and neck surgery.

    PubMed

    Kucur, Cuneyt; Durmus, Kasim; Uysal, Ismail O; Old, Matthew; Agrawal, Amit; Arshad, Hassan; Teknos, Theodoros N; Ozer, Enver

    2016-01-01

    Microvascular free flaps are preferred for most major head and neck reconstruction surgeries because of better functional outcomes, improved esthetics, and generally higher success rates. Numerous studies have investigated measures to prevent flap loss, but few have evaluated the optimal treatment for free flap complications. This study aimed to determine the complication rate after free flap reconstructions and discusses our management strategies. Medical records of 260 consecutive patients who underwent free flap reconstructions for head and neck defects between July 2006 and June 2010 were retrospectively reviewed for patient and surgical characteristics and postoperative complications. The results revealed that microvascular free flaps were extremely reliable, with a 3.5 % incidence of flap failure. There were 78 surgical site complications. The most common complication was neck wound infection, followed by dehiscence, vascular congestion, abscess, flap necrosis, hematoma, osteoradionecrosis, and brisk bleeding. Twenty patients with poor wound healing received hyperbaric oxygen therapy, which was ineffective in three patients who eventually experienced complete flap loss. Eleven patients with vascular congestion underwent medicinal leech therapy, which was effective. Among the 78 patients with complications, 44 required repeat surgery, which was performed for postoperative brisk bleeding in three. Eventually, ten patients experienced partial flap loss and nine experienced complete flap loss, with the latter requiring subsequent pectoralis major flap reconstruction. Microvascular free flap reconstruction represents an essential and reliable technique for head and neck defects and allows surgeons to perform radical resection with satisfactory functional results and acceptable complication rates. PMID:25575841

  7. Management of Large Sternal Wound Infections With the Superior Epigastric Artery Perforator Flap.

    PubMed

    Eburdery, H; Grolleau, J L; Berthier, C; Bertheuil, N; Chaput, B

    2016-01-01

    The management of sternal wound infections often requires pedicled flaps. In recent years, the emergence of perforator flaps has changed our management of wounds involving tissue loss. For sternal wounds, the superior epigastric artery perforator (SEAP) flap can be used with the propeller procedure with minimal donor site morbidity. In our practice, this flap has replaced the traditional latissimus dorsi and pectoralis major flaps in the treatment of many sternal wounds. We report our experience with 4 patients with large sternal wound infection after cardiothoracic operations. The SEAP flap appears a safe alternative for low-morbidity coverage of sternal infections. Moreover, muscle flaps remain available in case the SEAP flap fails. PMID:26694288

  8. Corrosion Research And Web Site Activities

    NASA Technical Reports Server (NTRS)

    Heidersbach, Robert H.

    2001-01-01

    This report covers corrosion-related activities at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.

  9. Corrosion Research and Web Site Activities

    NASA Technical Reports Server (NTRS)

    Heidersbach, Robert H.

    2002-01-01

    This report covers corrosion-related activities at the NASA Kennedy Space Center during the summer of 2000. The NASA Kennedy Space Center's corrosion web site, corrosion.ksc.nasa.gov, was updated with new information based on feedback over the past two years. The methodology for a two-year atmospheric exposure testing program to study the effectiveness of commercial chemicals sold for rinsing aircraft and other equipment was developed and some preliminary laboratory chemical analyses are presented.

  10. Intercostal artery perforator propeller flap for reconstruction of trunk defects following sarcoma resection.

    PubMed

    Zang, Mengqing; Yu, Shengji; Xu, Libin; Zhao, Zhenguo; Zhu, Shan; Ding, Qiang; Liu, Yuanbo

    2015-06-01

    Trunk defects following soft tissue sarcoma resection are usually managed by myocutaneous flaps or free flaps. However, harvesting muscle will cause functional morbidities and some trunk regions lack reliable recipient vessels. The intercostal arteries give off multiple perforators, which distribute widely over the trunk and can supply various pedicle flaps. Our purpose is to use various intercostal artery perforator propeller flaps for trunk oncologic reconstruction. Between November 2013 and July 2014, nine intercostal artery perforator propeller flaps were performed in seven patients to reconstruct the defects following sarcoma resection in different regions of the trunk, including the back, lumbar, chest, and abdomen. Two perforators from intercostal arteries were identified for each flap using Doppler ultrasound probe adjacent to the defect. The perforator with visible pulsation was chosen as the pedicle vessel. An elliptical flap was raised and rotated in a propeller fashion to repair the defects. There were one dorsal intercostal artery perforator flap, four dorsolateral intercostal artery perforator flaps, three lateral intercostal artery perforator flaps, and one anterior intercostal artery perforator flap. The mean skin paddle dimension was 9.38 cm in width (range 6-14 cm) and 21.22 cm in length (range 13-28 cm). All intercostal artery perforator flaps survived completely, except for marginal necrosis in one flap harvested close to the previous flap donor site. The intercostal artery perforator propeller flap provides various and valuable options in our reconstructive armamentarium for trunk oncologic reconstruction. To our knowledge, this is the first case series of using intercostal artery perforator propeller flaps for trunk oncologic reconstruction and clinical application of dorsolateral intercostal artery perforator flaps. PMID:25801799

  11. Perforator propeller flaps for sacral and ischial soft tissue reconstruction

    PubMed Central

    Korambayil, Pradeoth M.; Allalasundaram, KV; Balakrishnan, TM

    2010-01-01

    The perforator-based flaps in the sacral and ischial region is designed according to the localization of perforators that penetrate the gluteus maximus muscle, reach the intra-fascial and supra-fascial planes with the overlying skin forming a rich vascular plexus. The perforator-based flaps described in this article are highly vascularized, have minimal donor site morbidity, and do not require the sacrifice of the gluteus maximus muscle. In a period between April 2008 and March 2009, six patients with sacral pressure sore were reconstructed with propeller flap method based on superior gluteal and parasacral artery perforators. One flap loss was noted. Three cases of ischial pressure sore were reconstructed with longitudinal propeller flap cover, based on inferior gluteal artery perforator. One flap suffered wound infection and dehiscence. Two cases of pilonidal sinus were reconstructed with propeller flap based on parasacral perforators. Both the flaps survived without any complications. Donor sites were closed primarily. In the light of this, they can be considered among the first surgical choices to re-surface soft tissue defects of the sacral and ischial regions. In the series of 11 patients, two patients (18%) suffered complications. PMID:21217972

  12. Flapping of Insectile Wings

    NASA Astrophysics Data System (ADS)

    Huang, Yangyang; Kanso, Eva

    2015-11-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. Yet the effects of muscle stiffness on the performance of insect wings remain unclear. Here, we construct an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring and submerged in an oscillatory flow. The wing system is free to rotate and flap. We first explore the extent to which the flyer can withstand roll perturbations, then study its flapping behavior and performance as a function of spring stiffness. We find an optimal range of spring stiffness that results in large flapping amplitudes, high force generation and good storage of elastic energy. We conclude by conjecturing that insects may select and adjust the muscle spring stiffness to achieve desired movement. These findings may have significant implications on the design principles of wings in micro air-vehicles.

  13. A study of the pharmacologic control of blood flow to delayed skin flaps using xenon washout. Part II

    SciTech Connect

    Hendel, P.M.; Lilien, D.L.; Buncke, H.J.

    1983-03-01

    These experiments indicate that there are two components to the delay phenomenon. The first component is passive vasodilation owing to loss in the acute flaps originating from the sympathetic nerve terminals. The second component is active vasodilation not involving loss of a second vasoconstrictor mechanism or sensitization of the beta-receptors. Overall, the increase in blood flow associated with the delay phenomenon was seen to begin near the base of the flap and proceed distally. While the second component could not be identified, its characteristics suggest that its site of action is directly at the smooth-muscle or vascular-architecture level without involving the beta-receptors for vasodilation.

  14. Oral reconstruction with submental flap

    PubMed Central

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2013-01-01

    Background: Submental flap is a useful technique for reconstruction of medium to large oral cavity defects. Hair bearing nature of this flap in men makes it less appropriate. Therefore, deepithelialized variant is introduced to overcome the problem of hair with this flap. Recently, application of this flap has been introduced in maxillofacial trauma patients. Materials and Methods: Deepithelialized orthograde submental flap is used for the reconstruction of oral cavity mucosal defects. Results: Four cases including two trauma patients and two squamous cell carcinomas (SCCs) of oral cavity were treated using deepithelialized orthograde submental flap. There were no complications in all four patients and secondary epithelialization occurred in raw surface of the flap which was exposed to oral cavity. Conclusion: Deepithelialized orthograde submental flap is very effective in reconstruction of oral cavity in men. The problem of hair is readily solved using this technique without jeopardizing flap blood supply. PMID:24205473

  15. Deltopectoral Flap in the Era of Microsurgery

    PubMed Central

    Chan, R. C. L.; Chan, J. Y. W.

    2014-01-01

    Background. Our study aimed to review the role of deltopectoral (DP) flap as a reconstructive option for defects in the head and neck region in the microvascular era. Methods. All patients who received DP flap reconstruction surgery at the Department of Surgery, Queen Mary Hospital, between 1999 and 2011 were recruited. Demographic data, indications for surgery, defect for reconstruction, and surgical outcomes were analyzed. Results. Fifty-four patients were included. All but two patients were operated for reconstruction after tumour resection. The remaining two patients were operated for necrotizing fasciitis and osteoradionecrosis. The majority of DP flaps were used to cover neck skin defect (63.0%). Other reconstructed defects included posterior pharyngeal wall (22.2%), facial skin defect (11.1%), and tracheal wall (3.7%). All donor sites were covered with partial thickness skin graft. Two patients developed partial flap necrosis at the tip and were managed conservatively. The overall flap survival rate was 96.3%. Conclusions. Albeit the technical advancements in microvascular surgery, DP still possesses multiple advantages (technical simplicity, reliable axial blood supply, large size, thinness, and pliability) which allows it to remain as a useful, reliable, and versatile surgical option for head and neck reconstruction. PMID:25374953

  16. The pedicled thoraco-umbilical flap: A versatile technique for upper limb coverage

    PubMed Central

    Mishra, Sharad; Sharma, Ramesh Kumar

    2009-01-01

    Injuries to upper limb has been on the increase and is invariably associated with significant soft tissue loss requiring a flap cover. Local tissue may not be available for cover in a majority of situations, necessitating import of tissue from a distant source. We have utilized the thoraco-umbilical flap taken from the trunk for this purpose. This flap is based on the perforators of the deep inferior epigastric artery that are maximally centred on the periumbilical region. This flap was used in 83 patients. The patients were observed for at least 3 weeks and any flap or donor site complications were recorded. The patients were again followed up at 3 months interval and the donor site scar was assessed. The flaps survived in 81 patients; there was marginal flap necrosis in five patients and partial flap necrosis in two patients. None of these patients required any additional procedure for coverage. The flap is technically easy to plan, almost effortless to drape around upper limb defects, with no significant donor site morbidity and also the post operative immobilization was fairly comfortable. The thoraco-umbilical flap thus is a very useful technique for coverage of the upper limb and is recommended as a first line flap for this purpose. PMID:20368851

  17. Propeller Flaps: A Review of Indications, Technique, and Results

    PubMed Central

    D'Arpa, Salvatore; Toia, Francesca; Pirrello, Roberto; Moschella, Francesco; Cordova, Adriana

    2014-01-01

    In the last years, propeller flaps have become an appealing option for coverage of a large range of defects. Besides having a more reliable vascular pedicle than traditional flap, propeller flaps allow for great freedom in design and for wide mobilization that extend the possibility of reconstructing difficult wounds with local tissues and minimal donor-site morbidity. They also allow one-stage reconstruction of defects that usually require multiple procedures. Harvesting of a propeller flap requires accurate patient selection, preoperative planning, and dissection technique. Complication rate can be kept low, provided that potential problems are prevented, promptly recognized, and adequately treated. This paper reviews current knowledge on propeller flaps. Definition, classification, and indications in the different body regions are discussed based on a review of the literature and on the authors' experience. Details about surgical technique are provided, together with tips to avoid and manage complications. PMID:24971367

  18. Preservation of Hand Function Using Muscle Perforator Flaps

    PubMed Central

    2008-01-01

    Adequate soft tissue coverage is imperative after any interventions performed to maximize or preserve hand function. Although this can most simply be achieved by primary closure or a skin graft if possible, often a vascularized flap will be preferable, especially if a later secondary procedure is planned. Even moderately sized skin deficits of the upper extremity, and especially if involving the hand itself, can be better covered using a free tissue transfer. Many reasonable options in this regard are available. Muscle perforator flaps, as a relatively new variant of a fasciocutaneous flap, have unique attributes, including availability, diversity, accessibility, large size, and lengthy vascular pedicle, and since no muscle need be included, donor site function is preserved. As is shown here in a series of nine muscle perforator flaps in eight patients, these represent yet another alternative that should be considered if selection of a free flap is indicated to maintain hand function. PMID:18780005

  19. Repair of Fingertip Defect Using an Anterograde Pedicle Flap Based on the Dorsal Perforator

    PubMed Central

    Wei, Peng; Chen, Weiwei; Mei, Jin; Ding, Maochao; Yu, Yaling; Xi, Shanshan; Zhou, Renpeng

    2016-01-01

    Background: The purposes of this article are to introduce and assess the results of a long-term follow-up of using anterograde pedicle flap based on the dorsal branches of proper digital neurovascular bundles from the dorsum of the middle phalanx for the fingertip defect. Methods: Between February 2011 and December 2012, 31 patients underwent reconstruction of fingertip defects using a homodigital flap based on the dorsal perforator in the middle phalanx. The defect size ranged from 1.3 cm × 1.5 cm to 2.4 cm × 3.0 cm. During surgery, the flap was designed on the dorsal middle phalangeal region. The pedicle was a neurovascular bundle consisting of an artery, vein, and sensory nerve; the rotation of pedicle was <90 degrees. Results: The clinical results were satisfactory after 3 to 9 months of follow-up. The flaps were considered cosmetically acceptable by both patients and doctors. The sensory recovery was excellent, 2-point discrimination was 4.96 ± 1.47 mm, and the recovery of range of motion of the interphalangeal joints was very good. Conclusions: The anterograde island flap based on the dorsal branches of proper digital neurovascular bundles is an ideal aesthetic reconstruction method for fingertip defect. A 90-degree rotated island pedicle flap was very versatile, easy to design, and had good survival. This technique is simple with less damage to the donor site, without sacrificing the branch of the digital artery and nerve. The reliable source of blood supply and satisfactory recovery of sensation can be achieved without affecting the interphalangeal joint activity. PMID:27482478

  20. Superior gluteal artery perforator flap in bilateral breast reconstruction.

    PubMed

    Werdin, Frank; Peek, Alberto; Martin, Nicolas C S; Baumeister, Steffen

    2010-01-01

    The incidence of bilateral breast reconstruction is increasing particularly due to genetic counseling and the option for bilateral prophylactic mastectomies. The decision to undergo a prophylactic mastectomy depends on the achievable outcomes of breast reconstruction. The free superior gluteal artery perforator flap (sGAP) flap is one option for autologous bilateral reconstruction which has rarely been reported.All bilateral sGAP flaps performed in the department of plastic surgery at the Behandlungszentrum Vogtareuth over a period of 4.5 years were retrospectively analyzed for indication, success rate, and complications.Thirty sGAP flaps were performed for bilateral breast reconstruction. The average age of the 15 women was 42 years and the average body mass index was 20.8. Indications for breast reconstruction were predominantly prophylactic mastectomies (60%). Indication for a sGAP flap was either a thin patient with insufficient abdominal tissue or a 2-staged bilateral reconstruction. 83% of the breast reconstructions were performed secondarily and 93% in 2 stages. The average operating time was 7 hours 12 minutes. Twenty-nine flaps (97%) were successful. Complications were fat necrosis (n = 3), hematoma (n = 3), and breast seroma (n = 1). Donor site complications were seroma (n = 8), infection (n = 1), and wound dehiscence (n = 1).Our results with bilateral breast reconstruction with the sGAP flap show cosmetically appealing results with high success and low complication rates on the breast. However, seromas on the donor site occurred in 27%. In addition, the sGAP flap is a technically demanding and time consuming operation. We recommend the sGAP flap when the abdomen has not enough tissue bulk to perform a deep inferior epigastric perforator flap or for a 2-staged bilateral reconstruction. This is often the case in women with a hereditary high risk of breast cancer who often present as young and slim patients. PMID:20010408

  1. Development of a free latissimus dorsi muscle flap in cats.

    PubMed

    Nicoll, S A; Fowler, J D; Remedios, A M; Clapson, J B; George, D

    1996-01-01

    Anatomic and experimental evaluation of the feline latissimus dorsi muscle was performed to assess its potential use as a free muscle flap. In the anatomic study, nonselective angiography of the subscapular artery was performed in nine heparinized feline cadavers. The muscle dimensions and vascular anatomy of the dissected latissimus dorsi muscle were recorded. In the experimental study four cats underwent heterotopic transplantation of a partial latissimus dorsi flap, and three cats underwent orthotopic transplantation of a complete latissimus dorsi flap. The mean length and width of the latissimus dorsi muscle was 19.0 and 5.4 cm, respectively. The dominant vascular pedicle was the thoracodorsal artery and vein. The average length and diameter of the thoracodorsal artery was 2.7 cm and 0.6 mm, respectively. Minor vascular pedicles were provided by branches of the intercostal arteries. Numerous choke anastomoses existed between the two pedicle systems. Viability of muscle flaps based on subjective evaluation, angiography, and histopathology, was 66% and 100% in the heterotopic and orthotopic studies, respectively. Flap failure seemed to be caused by both arterial and venous thrombosis. The latissimus dorsi muscle flap met criteria required for application in microvascular reconstruction. The vascular pattern was appropriate and consistent. Donor site morbidity was low, whereas surgical accessibility was high. The muscle satisfied the physical criteria of a free flap. Long-term anastomotic patency and flap viability was shown. PMID:8719085

  2. Propeller Perforator Flaps in Distal Lower Leg: Evolution and Clinical Applications

    PubMed Central

    2012-01-01

    Simple or complex defects in the lower leg, and especially in its distal third, continue to be a challenging task for reconstructive surgeons. A variety of flaps were used in the attempt to achieve excellence in form and function. After a long evolution of the reconstructive methods, including random pattern flaps, axial pattern flaps, musculocutaneous flaps and fasciocutaneous flaps, the reappraisal of the works of Manchot and Salmon by Taylor and Palmer opened the era of perforator flaps. This era began in 1989, when Koshima and Soeda, and separately Kroll and Rosenfield described the first applications of such flaps. Perforator flaps, whether free or pedicled, gained a high popularity due to their main advantages: decreasing donor-site morbidity and improving aesthetic outcome. The use as local perforator flaps in lower leg was possible due to a better understanding of the cutaneous circulation, leg vascular anatomy, angiosome and perforasome concepts, as well as innovations in flaps design. This review will describe the evolution, anatomy, flap design, and technique of the main distally pedicled propeller perforator flaps used in the reconstruction of defects in the distal third of the lower leg and foot. PMID:22783507

  3. [Experience with the s-GAP flap for autologous breast reconstruction].

    PubMed

    Werdin, F; Peek, A; Schuster, H; Baumeister, S

    2008-08-01

    In breast reconstruction with autologous tissue the DIEP flap has become the gold standard in recent years. The superior gluteal artery perforator (s-GAP) flap is an alternative harvested from the buttock. We present our experience with the s-GAP flap and discuss its role in breast reconstruction. All s-GAP flaps performed for breast reconstruction in the Department of Plastic and Hand Surgery, Behandlungszentrum Vogtareuth from June 2002 until February 2007 were retrospectively analysed. Out of 59 flaps 4 flaps failed, the success rate was 94 %. Partial or fat necrosis occurred in 2 cases. The s-GAP flap served as a safe reconstructive alternative to the DIEP flap. Advantages of the s-GAP flap are reliable perforators, the safe vascular supply and the firm fat structure which facilitates the breast reconstruction. The donor site morbidity is minimal, the gluteal muscles stay intact and the scar is easy to hide in the underwear. Disadvantages are a demanding preparation with a prolonged operating time compared to the DIEP flap. The s-GAP flap is a reliable and safe option for autologeous breast reconstruction. It is the method of choice for staged bilateral breast reconstruction or if the DIEP flap is not available, particularly in the thin patient. PMID:18716984

  4. Flow field of flexible flapping wings

    NASA Astrophysics Data System (ADS)

    Sallstrom, Erik

    The agility and maneuverability of natural fliers would be desirable to incorporate into engineered micro air vehicles (MAVs). However, there is still much for engineers to learn about flapping flight in order to understand how such vehicles can be built for efficient flying. The goal of this study is to develop a methodology for capturing high quality flow field data around flexible flapping wings in a hover environment and to interpret it to gain a better understanding of how aerodynamic forces are generated. The flow field data was captured using particle image velocimetry (PIV) and required that measurements be taken around a repeatable flapping motion to obtain phase-averaged data that could be studied throughout the flapping cycle. Therefore, the study includes the development of flapping devices with a simple repeatable single degree of freedom flapping motion. The acquired flow field data has been examined qualitatively and quantitatively to investigate the mechanisms behind force production in hovering flight and to relate it to observations in previous research. Specifically, the flow fields have been investigated around a rigid wing and several carbon fiber reinforced flexible membrane wings. Throughout the whole study the wings were actuated with either a sinusoidal or a semi-linear flapping motion. The semi-linear flapping motion holds the commanded angular velocity nearly constant through half of each half-stroke while the sinusoidal motion is always either accelerating or decelerating. The flow fields were investigated by examining vorticity and vortex structures, using the Q criterion as the definition for the latter, in two and three dimensions. The measurements were combined with wing deflection measurements to demonstrate some of the key links in how the fluid-structure interactions generated aerodynamic forces. The flow fields were also used to calculate the forces generated by the flapping wings using momentum balance methods which yielded

  5. Blowing Flap Experiment: PIV Measurements

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.; Bremmer, David M.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the flap vortex system. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  6. Active site of ribulosebisphosphate carboxylase/oxygenase

    SciTech Connect

    Hartman, F.C.; Stringer, C.D.; Milanez, S.; Lee, E.H.

    1985-01-01

    Previous affinity labeling studies and comparative sequence analyses have identified two different lysines at the active site of ribulosebisphosphate carboxylase/oxygenase and have suggested their essentiality to function. The essential lysines occupy positions 166 and 329 in the Rhodospirillum rubrum enzyme and positions 175 and 334 in the spinach enzyme. Based on the pH-dependencies of inactivations of the two enzymes by trinitrobenzene sulfonate, Lys-166 (R. rubrum enzyme) exhibits a pK/sub a/ of 7.9 and Lys-334 (spinach enzyme) exhibits a pK/sub a/ of 9.0. These low pK/sub a/ values as well as the enhanced nucleophilicities of the lysyl residues argue that both are important to catalysis rather than to substrate binding. Lys-166 may correspond to the essential base that initiates catalysis and that displays a pK/sub a/ of 7.5 in the pH-curve for V/sub max//K/sub m/. Cross-linking experiments with 4,4'-diisothiocyano-2,2'-disulfonate stilbene demonstrate that the two active-site lysines are within 12 A. 50 refs., 7 figs., 1 tab.

  7. Active Sites Environmental Monitoring Program: Program plan

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  8. Free craniotomy versus osteoplastic craniotomy, assessment of flap viability using 99mTC MDP SPECT.

    PubMed

    Shelef, Ilan; Golan, Haim; Merkin, Vladimir; Melamed, Israel; Benifla, Mony

    2016-09-01

    There are currently two accepted neurosurgical methods to perform a bony flap. In an osteoplastic flap, the flap is attached to surrounding muscle. In a free flap, the flap is not attached to adjacent tissues. The former is less common due to its complexity and the extensive time required for the surgery; yet the rate of infection is significantly lower, a clear explanation for which is unknown. The objective of this study was to test the hypothesis that the osteoplastic flap acts as a live implant that resumes its blood flow and metabolic activity; contrasting with the free flap, which does not have sufficient blood flow, and therefore acts as a foreign body. Seven patients who underwent craniotomy with osteoplastic flaps and five with free flaps had planar bone and single photon emission computed tomography (SPECT) scans of the skull at 3-7days postoperative, after injection of the radioisotope, 99m-technetium-methylene diphosphonate (99m-Tc-MDP). We compared radioactive uptake as a measure of metabolic activity between osteoplastic and free flaps. Mean normalized radioactive uptakes in the centers of the flaps, calculated as the ratios of uptakes in the flap centers to uptakes in normal contralateral bone, were [mean: 1.7 (SD: 0.8)] and [0.6 (0.1)] for the osteoplastic and free flap groups respectively and were [2.4 (0.8)] and [1.3 (0.4)] in the borders of the flaps. Our analyses suggest that in craniotomy, the use of an osteoplastic flap, in contrast to free flap, retains bone viability. PMID:27068014

  9. Externally blown flap impingement noise

    NASA Technical Reports Server (NTRS)

    Lasagna, P. L.; Putnam, T. W.

    1972-01-01

    Tests of the noise produced by the impingement of the jet exhaust on the wing and flap for an externally blown flap system were conducted with a CF700 turbofan engine and an F-111B wing panel. The noise produced with a daisy nozzle installed on the engine was greater than that produced by a conical nozzle at the same thrust. The presence of the wing next to the test nozzles increased the noise, as did increasing the flap deflection angle. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested. Tests showed that the single-slotted flap deflected 60 deg, produced less noise than the double-slotted flaps. Also, maintaining the maximum distance between the exit nozzle and flap system resulted in a minor reduction in noise.

  10. Reconstruction of complex thoraco-abdominal defects with extended anterolateral thigh flap

    PubMed Central

    Yadav, Prabha S.; Ahmad, Quazi G.; Shankhdhar, Vinay Kant; Nambi, G. I.; Pramesh, C. S.

    2010-01-01

    Background: The reconstruction of complex thoraco-abdominal defects following tumour ablative procedures has evolved over the years from the use of pedicle flaps to free flaps. The free extended anterolateral thigh flap is a good choice to cover large defects in one stage. Materials and Methods: From 2004 to 2009, five patients with complex defects of the thoracic and abdominal wall following tumour ablation were reconstructed in one stage and were studied. The commonest tumour was chondrosarcoma. The skeletal component was reconstructed with methylmethacrylate bone cement and polypropylene mesh and the soft tissue with free extended anterolateral thigh flap. The flaps were anastomosed with internal mammary vessels. The donor sites of the flaps were covered with split-skin graft. Result: All the flaps survived well. One flap required re-exploration for venous congestion and was successfully salvaged. Two flaps had post operative wound infection and were managed conservatively. All flap donor sites developed hyper-pigmentation, contour deformity and cobble stone appearance. Conclusion: Single-stage reconstruction of the complex defects of the thoraco-abdominal region is feasible with extended anterolateral thigh flap and can be adopted as the first procedure of choice. PMID:21217973

  11. Recent advances for FLAP inhibitors.

    PubMed

    Pettersen, Daniel; Davidsson, Öjvind; Whatling, Carl

    2015-07-01

    A number of FLAP inhibitors have been progressed to clinical trials for respiratory and other inflammatory indications but so far no drug has reached the market. With this Digest we assess the opportunity to develop FLAP inhibitors for indications beyond respiratory disease, and in particular for atherosclerotic cardiovascular disease. We also show how recently disclosed FLAP inhibitors have structurally evolved from the first generation FLAP inhibitors paving the way for new compound classes. PMID:26004579

  12. Lower extremity muscle perforator flaps for lower extremity reconstruction.

    PubMed

    Hallock, Geoffrey G

    2004-10-01

    A true muscle perforator flap is distinguished by the requisite intramuscular dissection of its musculocutaneous perforator to capture the same musculocutaneous territory but with total exclusion of the muscle, and thereby results in minimal functional impairment. Adhering to this definition, several lower extremity donor sites now are available, each with specific attributes especially useful for consideration in the treatment of lower extremity defects. In this author's experience over the past two decades, 20 lower extremity muscle perforator flaps using multiple donor sites proved advantageous for lower extremity coverage problems as either a local pedicled flap or as a microsurgical tissue transfer. Significant complications occurred in 30 percent of flaps (six of 20) in that further intervention was required. Venous insufficiency and bulkiness were found to be the major inherent shortcomings. However, giant flaps, lengthy and large-caliber vascular pedicles, and the possibility for combined flaps were important assets. The choice of a lower extremity muscle perforator flap for lower extremity reconstruction limited the surgical intervention and morbidity to a single body region. PMID:15457022

  13. Bilobed flap in sole surgery

    SciTech Connect

    Sanchez-Conejo-Mir, J.; Bueno Montes, J.; Moreno Gimenez, J.C.; Camacho-Martinez, F.

    1985-09-01

    The bilobed flap is a simple reconstructive technique principally used to correct substantial defects in the facial region. The authors present their experience with this local flap in the difficult plantar area, with excellent short-term functional results. They describe the special characteristics of the bilobed flap in this zone, and comment on its indications and possible complications.

  14. 7-flap perineal urethrostomy

    PubMed Central

    Parker, Daniel C.; Morey, Allen F.

    2015-01-01

    Perineal urethrostomy (PU) has been performed with success for the treatment of refractory and advanced urethral stricture disease for at least the past six decades. Here, we review the indications and outcomes of PU for indications such as complex hypospadias repair and urethral stricture disease resulting from trauma, infection, and failure of prior urethroplasty. We also describe the role of 7-flap PU, a novel alternative to the conventional approach that offers the surgeon added flexibility in tailoring urethrostomy creation based on intraoperative findings. The authors’ updated experience with 7-flap PU demonstrates a comparable 95% success rate in patients with a wide variety of stricture etiology. PU through either a conventional approach or a 7-flap technique is a valuable option for improving the quality of life in patients with debilitating urethral stricture disease. PMID:26816809

  15. Free Flap Elevation Times in Head and Neck Reconstruction Using the Harmonic Scalpel Shears

    PubMed Central

    DeSerres, Joshua J.; Barber, Brittany R.; Seikaly, Hadi; Harris, Jeffrey R.

    2016-01-01

    Summary: Free tissue transfer has become the mainstay of head and neck cancer (HNC) reconstructive surgery. The objective of the study is to examine the efficacy of the Harmonic Scalpel (HS) Shears on free flap elevation time and complication rates after HNC reconstruction compared with traditional electrocautery. A retrospective review of 215 HNC patients undergoing surgical ablation and free flap reconstruction from January 2010 to April 2013 at the University of Alberta Hospital was undertaken. All patients requiring free flap reconstruction with radial forearm free flap or fibula free flap were included. Overall, there was no significant difference demonstrated between the HS and electrocautery groups for free flap elevation time for RFFFs (P = 0.563) or FFFs (P = 0.087). No differences were observed in donor-site complications. The HS is a reliable, safe, and alternative method of free flap elevation in HNC reconstructive surgery. PMID:27579242

  16. Double free-flap for a bimalleolar defect of lower leg and ankle

    PubMed Central

    Shetty, Naren; Mashalkar, Narendra S.; Ellur, Sunder Raj; Kagodu, Karishma

    2016-01-01

    Double free-flaps are necessary when tissue cover cannot be sufficed with a single flap. The other factors to be considered when using two free flaps for resurfacing of distal limb defects are the availability of more than one recipient vessel, the risk of distal limb ischaemia and the donor site morbidity of double flap harvest. If these factors are adequately addressed, double free-flaps can be safely executed for resurfacing distal limb defects with minimal morbidity. We report the simultaneous harvest and transfer of the anterolateral and anteromedial thigh flaps inset and vascularised as double free-flaps to resurface a large bimalleolar defect in a 14-year-old boy with no additional morbidity as compared to that of a single free tissue transfer.

  17. Free Flap Elevation Times in Head and Neck Reconstruction Using the Harmonic Scalpel Shears.

    PubMed

    DeSerres, Joshua J; Barber, Brittany R; Seikaly, Hadi; Harris, Jeffrey R; O'Connell, Daniel A

    2016-05-01

    Free tissue transfer has become the mainstay of head and neck cancer (HNC) reconstructive surgery. The objective of the study is to examine the efficacy of the Harmonic Scalpel (HS) Shears on free flap elevation time and complication rates after HNC reconstruction compared with traditional electrocautery. A retrospective review of 215 HNC patients undergoing surgical ablation and free flap reconstruction from January 2010 to April 2013 at the University of Alberta Hospital was undertaken. All patients requiring free flap reconstruction with radial forearm free flap or fibula free flap were included. Overall, there was no significant difference demonstrated between the HS and electrocautery groups for free flap elevation time for RFFFs (P = 0.563) or FFFs (P = 0.087). No differences were observed in donor-site complications. The HS is a reliable, safe, and alternative method of free flap elevation in HNC reconstructive surgery. PMID:27579242

  18. Osteoradionecrosis of the olecranon: treatment by radial forearm flap

    SciTech Connect

    Thornton, J.W.; Stevenson, T.R.; VanderKolk, C.A.

    1987-12-01

    Osteoradionecrosis of the olecranon is an unusual pathologic entity, treated best by debridement and wound closure using vascularized tissue. Local skin is often unavailable for flap design and transposition. The radial forearm flap can be isolated on a proximal vascular pedicle and transposed to cover the wound. In the case presented, healing was brisk and complete, allowing early elbow mobilization. Although the donor site is not easily concealed, no functional impairment results from flap elevation and all full-thickness wounds are confined to the involved extremity.

  19. Computed Tomography Angiography for Preoperative Thoracoabdominal Flap Planning.

    PubMed

    O'Malley, Ryan B; Robinson, Tracy J; Kozlow, Jeffrey H; Liu, Peter S

    2016-01-01

    Mastectomy rates have increased, coinciding with more advanced reconstruction options. Deep inferior epigastric perforator (DIEP) flaps decrease abdominal donor site morbidity, but require considerable technical expertise. Preoperative computed tomography angiography (CTA) can accurately demonstrate DIEA anatomy and perforator courses, facilitating preoperative planning and flap design, allowing for more targeted intraoperative microdissection. Patients who undergo CTA before DIEP flap have better clinical outcomes with shorter operative times and hospital length of stay, which can decrease overall associated health care costs. Future directions include selected imaging of the thoracic anatomy and recipient vasculature, allowing for additional preoperative planning and customization. PMID:26654396

  20. Free microvascular transplantation of the trapezius musculocutaneous flap in dogs.

    PubMed

    Philibert, D; Fowler, J D; Clapson, J B

    1992-01-01

    A musculocutaneous flap based on the prescapular branch of the superficial cervical artery and including the cervical part of the trapezius muscle and overlying skin was transplanted over a defect created on the medial side of the contralateral tibia in four dogs by using microvascular technique. The donor and recipient sites in three dogs were examined clinically for 21 days, after which they were examined angiographically and histologically. All dogs were free of lameness by hour 48. Seromas formed at the donor site between days 7 and 15. One vascular pedicle was traumatized at hour 40, and the dog was euthanatized. Three flaps survived with minimal necrosis. Edema of the flaps was severe from days 5 to 11. Angiograms showed complete perfusion of the flaps, and survival was confirmed histologically. Esthetic appearance and function were good in one dog at month 7. PMID:1455645

  1. Externally blown flap impingement noise.

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.; Lasagna, P. L.

    1972-01-01

    An investigation of externally blown flap impingement noise was conducted using a full-scale turbofan engine and aircraft wing. The noise produced with a daisy nozzle installed on the engine exhaust system was greater than that produced by a conical nozzle at the same thrust. The daisy nozzle caused the jet velocity to decay about 35 percent at the flap. The presence of the wing next to the conical nozzle increased the noise, as did increasing the flap deflection. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested.

  2. In situ monitoring of surgical flap viability using THz imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Bajwa, Neha; Sung, Shijun; Grundfest, Warren; Taylor, Zachary

    2016-03-01

    This paper explores the utility of reflective THz imaging to assess the viability of surgical flaps. Flap surgery is a technique where tissue is harvested from a donor site and moved to a recipient while keeping the blood supply intact. This technique is common in head and neck tumor resection surgery where the reconstruction of complex and sensitive anatomic structures is routine following the resection of large and/or invasive tumors. Successful flap surgery results in tissue that is sufficiently perfused with both blood and extracellular water. If insufficient fluid levels are maintained, the flap tissue becomes necrotic and must be excised immediately to prevent infection developing and spreading to the surrounding areas. The goal of this work is to investigate the hydration of surgical flaps and correlate image features to successful graft outcomes. Advancement flaps were created on the abdomens of rat models. One rat model was labeled control and care was taken to ensure a successful flap outcome. The flap on the second rat was compromised with restricted blood flow and allowed to fail. The flaps of both rats were imaged once a day over the course of a week at which point the compromised flap had begun to show signs of necrosis. Significant differences in tissue water content were observed between rats over the experimental period. The results suggest that THz imaging may enable early assessment of flap viability.

  3. Anterolateral thigh adipofascial flap for the restoration of facial contour deformities.

    PubMed

    Jin, Xiaolei; Teng, Li; Xu, Jiajie; Lu, Jianjian; Zhang, Chao; Zhang, Bo; Zhao, Zhenmin

    2010-07-01

    From January 2000 to May 2008, 50 patients with facial contour deformities underwent soft tissue augmentation with 51 anterolateral thigh (ALT) adipofascial flaps. Fifty flaps survived with no complications; partial fat necrosis occurred in one flap. Mean follow-up was 16 months. Flaps ranged from 10 x 6 cm to 20 x 12 cm. Perforators were found in 50 flaps, 43 musculocutaneous perforators (84.3%) and 7 septocutaneous perforators (13.7%), with a mean of 2.5 perforators per flap. In one flap (2.0%), no perforator was found. In this case, we used an anteromedial thigh adipofascial flap using the medial branch of the descending branch of lateral circumflex femoral artery as the vascular pedicle. Relatively symmetric facial contour was achieved in 20 cases. In 30 cases, adjunctive procedures including flap debulking, fat injection, and resuspension were necessary, and 23 patients achieved satisfactory outcomes. We conclude that the ALT adipofascial flap can be successfully elevated and transplanted for the correction of soft tissue facial defects. This flap can provide tissue to fill large defects, and posses the qualities of pliability, an excellent blood supply, ease of suspension and fixation, and minimal morbidity at the donor site. PMID:20049917

  4. Pedicled-perforator (propeller) flaps in lower extremity defects: a systematic review.

    PubMed

    Gir, Phanette; Cheng, Angela; Oni, Georgette; Mojallal, Ali; Saint-Cyr, Michel

    2012-11-01

    Pedicled-perforator (propeller) flaps for lower extremity reconstruction have gained popularity due to minimal donor site morbidity, relatively simple surgical technique, and replacement of tissue using "like-by-like" principles. We reviewed and analyzed the clinical use of these flaps in regards to patient age and gender, etiology and location of the defect, size and type of flap, arc of rotation, and complications to determine the reliability of this technique. A systematic review of the PubMed database using search terms to include perforator, pedicled, and propeller flaps in the lower extremity. Data from 15 case series provided 186 cases of pedicled-perforator (propeller) flaps for analysis using Chi-square tests. The Peroneal Artery Perforator (PAP) flaps and Posterior Tibial Artery Perforator (PTAP) flaps were the most frequently used flaps. The overall complication rate was 25.8% and the failure rate was 1.1%. No significant differences were found in complication rate related to age, gender, etiology or location of the defect, type or size of the flap. The most common complications were partial flap loss and venous congestion (11.3 and 8.1%). Pedicled-perforator flaps appear to be a reliable and safe procedure for the coverage soft tissue defects of the lower extremity based on favorable results reported in the literature. PMID:22715046

  5. Noise Reduction of Aircraft Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V. (Inventor); Brooks, Thomas F. (Inventor)

    2009-01-01

    A reduction in noise radiating from a side of a deployed aircraft flap is achieved by locating a slot adjacent the side of the flap, and then forcing air out through the slot with a suitable mechanism. One, two or even three or more slots are possible, where the slot is located at one;or more locations selected from a group of locations comprising a top surface of the flap, a bottom surface of the flap, an intersection of the top and side surface of the flap, an intersection of the bottom and side surfaces of the flap, and a side surface of the flap. In at least one embodiment the slot is substantially rectangular. A device for adjusting a rate of the air forced out through the slot can also be provided.

  6. Mandibular reconstruction with vascularized fibula flap and osseointegrated implants: a clinical report.

    PubMed

    Khatami, Amir H; Toljanic, Joseph A; Kleinman, Alejandro

    2010-01-01

    Primary and secondary reconstruction of mandibular discontinuity defects with vascularized flap is currently the standard of care in many institutions. The most commonly used donor site for such flaps is fibula. Fibula provides enough bone length, allows 2-team approach, and has low donor site morbidity and abundant periosteal blood supply. The placement of endosseous implants in the vascularized fibula flap also facilitates functional dental rehabilitation. This clinical report describes the prosthetic rehabilitation and the complications of 2 mandibular discontinuity defects treated with vascularized fibula flap and implant-supported fixed prosthesis. PMID:20545535

  7. Submental Artery Island Flap in Reconstruction of Hard Palate after wide Surgical Resection of Verruccous Carcinoma, Two Case Reports

    PubMed Central

    Rahpeyma, Amin; Khajehahmadi, Saeedeh; Nakhaei, Mohammadreza

    2013-01-01

    Introduction: Reconstruction of intraoral soft tissue defects is important in restoring function and esthetic. In large defects, there will be demand for regional pedicle flaps or free flaps. Hard palate separates nasal and oral cavities. Due to the small surface area between flap and remaining palate after surgical resections, optimal blood supply of the flaps for hard palate reconstructions are needed. Case Report: This article demonstrates immediate reconstruction of two edentulous hemimaxillectomy patients with submental artery Island flap and brief review of this flap discussed. Conclusion: Submental Artery Island flap is an effective and reliable method for intraoral reconstruction of large soft tissue defects of oral cavity. Donor site morbidity is low and remaining scar is inconspicuous. Head and neck surgeons familiar with facial artery and its branching pattern make this flap an appropriate choice for clinical practice. PMID:24350101

  8. A bilobed thoracoabdominal myocutaneous flap for large thoracic defects.

    PubMed

    Charanek, Ali M

    2014-04-01

    The author presents a surgical procedure for chest-wall soft tissue reconstruction due to large losses based on a modified thoracoabdominal myocutaneous flap. Designed in a bilobed shape, it rests on the superior epigastric vessels and may include the cranial one fourth of the rectus abdominis muscle and the premuscular fascia of external oblique muscle and constitutes one of the largest flaps based on a single minor artery. Local recurrent breast tumors and adjuvant therapy associated to obesity, high blood pressure, type II diabetes, and tobacco abuse on previously debilitated patients render the usual reconstructive procedure difficulties. These become indications for this flap, whose safety is improved by maintaining the deep fascia of the external oblique muscle attached to the flap to preserve the network of the arteries close to the fascia and a wide-ranging interarterial choke anastomosis alongside the lateral projection of the flap on the thorax. Thus, a wide range of angles allows us to reach even the opposite site of the thorax over the sterna area with an easy closure of the donor site facilitated by the vertical portion of the abdominal donor site. The flap was used in 55 patients, and no serious complications, including necrosis, notable dehiscence, hematoma, seroma, or abdominal wall weakness, were observed. The overall aspect is acceptable with the visible scars over the upper part of the abdomen. PMID:23503434

  9. Expanded retroauricular skin and fascial flap in congenital microtia reconstruction.

    PubMed

    Zhang, Qingguo; Quan, Yuzhu; Su, Yuanda; Shi, Lei; Xie, Yangchun; Liu, Xinhai

    2010-04-01

    The aim of this article is to report the application of expanding retroauricular skin fascia flap, and autogenous costal cartilage for congenital microtia reconstruction. Microtia reconstruction was generally completed in 3 surgical stages. In the first surgical stage, a 50 or 80 mL kidney-shaped tissue expander was inserted subcutaneously in the retroauricular mastoid region. Inflation of saline volume increased up to 60 to 80 mL, and skin flap was expanded for 2 to 3 months postoperatively. In the second surgical stage, removal of tissue expander, formation of retroauricular skin flap, elevation of retroauricular fascia flap, and pedicles of both flaps in remnant ear side were performed. Costal cartilage was harvested from ipsilateral side chest to the ear for reconstruction. The 3D ear framework was sculpted with stabilization of structure, contour and erection. Simultaneously, intermediate full thickness skin graft of 4 x 8 cm was obtained from previous incision site from where costal cartilage was harvested. Cartilage ear framework was anchored between skin flap and fascia flap, and fixed it symmetrically to the opposite normal ear, inferior portion of the ear framework was wrapped by remnant ear lobule, expanded skin flap covered the anterior portion of the framework, fascial flap was draped to the posterior side of framework and helical rim, then fascial flap was surfaced by intermediate full thickness skin graft. Suction drain was inserted and coated between skin flap and framework, drain was removed fifth postoperative day. Tragus construction and conchal excavation with skin graft was performed in the third stage of microtia reconstruction. Between October 2000 and October 2007, 426 cases were diagnosed as unilateral microtia patients and 22 cases were bilateral microtia patients. Therefore, 448 microtia ears were treated with tissue expander and autogenous costal cartilage. In 262 cases, structure of the helix, tragus, conchal excavation

  10. Activation of an Alternative, Rec12 (Spo11)-Independent Pathway of Fission Yeast Meiotic Recombination in the Absence of a DNA Flap Endonuclease

    PubMed Central

    Farah, Joseph A.; Cromie, Gareth; Davis, Luther; Steiner, Walter W.; Smith, Gerald R.

    2005-01-01

    Spo11 or a homologous protein appears to be essential for meiotic DNA double-strand break (DSB) formation and recombination in all organisms tested. We report here the first example of an alternative, mutationally activated pathway for meiotic recombination in the absence of Rec12, the Spo11 homolog of Schizosaccharomyces pombe. Rad2, a FEN-1 flap endonuclease homolog, is involved in processing Okazaki fragments. In its absence, meiotic recombination and proper segregation of chromosomes were restored in rec12Δ mutants to nearly wild-type levels. Although readily detectable in wild-type strains, meiosis-specific DSBs were undetectable in recombination-proficient rad2Δ rec12Δ strains. On the basis of the biochemical properties of Rad2, we propose that meiotic recombination by this alternative (Rec*) pathway can be initiated by non-DSB lesions, such as nicks and gaps, which accumulate during premeiotic DNA replication in the absence of Okazaki fragment processing. We compare the Rec* pathway to alternative pathways of homologous recombination in other organisms. PMID:16118186

  11. Complications and oncologic outcomes of pedicled transverse rectus abdominis myocutaneous flap in breast cancer patients

    PubMed Central

    Somintara, Ongart; Lertsithichai, Panuwat; Kongdan, Youwanush; Supsamutchai, Chairat; Sukpanich, Rupporn

    2016-01-01

    Background There are several techniques for harvesting the pedicled transverse rectus abdominis myocutaneous (TRAM) flap after mastectomy in breast cancer patients. We examined the whole muscle with partial sheath sparing technique and determined factors associated with its complications and oncological outcomes. Methods We retrospectively reviewed the results of 168 TRAM flaps performed between January 2003 and December 2010, focusing on complications and oncologic outcomes. Results Among the 168 pedicled TRAM flap procedures in 158 patients, flap complications occurred in 34%. Most of the flap complications included some degree of fat necrosis. There was no total flap loss. Flap complications were associated with elderly patients and the presence of major donor site complications. Abdominal bulging and hernia occurred in 12% of patients. The bi-pedicled TRAM flap and higher body mass index (BMI) were significant factors associated with increased donor site complications. Seven patients (4%) developed loco-regional recurrence. Within a median follow-up of 27 months, distant metastasis and death occurred in 6% and 4% of patients, respectively. Conclusions The pedicled TRAM flap using the whole muscle with partial sheath sparing technique in the present study is consistent with the results from previous studies in flap complication rates and oncological outcomes. PMID:27563562

  12. Use of a bilobed gracilis myocutaneous flap in perineal and genital reconstruction.

    PubMed

    Vyas, Raj M; Pomahac, Bohdan

    2010-08-01

    The gracilis myocutaneous flap has limited functional donor site morbidity and effectively contours genitoperineal reconstructions. When harvested using a traditional vertical skin paddle, distal-tip necrosis (secondary to inconsistent perforator anatomy) is a well-documented complication. Orienting the skin paddle transversely provides a reliable alternative with a shorter rotational arc but results in a more conspicuous deformity and smaller skin paddle when primary closure is desired. On the basis of recent anatomic studies, we designed a pedicled gracilis myocutaneous flap with a bilobed cutaneous paddle to maximally incorporate both the transverse and longitudinal dimensions of the flap's nearly circular angiosome. The bilobed design allows harvest of a larger transverse skin flap (with a shorter arc of rotation) while a shorter, more dependable vertical skin flap is inset into the transverse flap donor site (rather than inside the critical wound bed). Herein, we detail our surgical technique and provide 2 illustrative case examples. PMID:20606582

  13. Uncommon Flaps for Chest Wall Reconstruction

    PubMed Central

    Matros, Evan; Disa, Joseph J.

    2011-01-01

    The omentum, external oblique musculocutaneous, and thoracoepigastric flaps are uncommonly used for chest wall reconstruction. Nevertheless, awareness and knowledge of these flaps is essential for reconstructive surgeons because they fill specific niche indications or serve as lifeboats when workhorse flaps are unavailable. The current report describes the anatomic basis, technical aspects of flap elevation, and indications for these unusual flaps. PMID:22294943

  14. The Free-style Gluteal Perforator Flap in the Thinning and Delay Process for Perineal Reconstruction After Necrotizing Fasciitis.

    PubMed

    Horta, Ricardo; Nascimento, Ricardo; Silva, Alvaro; Amarante, Jose

    2016-06-01

    Perineal wounds present a special challenge for reconstructive surgeons. The vacuum-assisted closure device is useful as a temporizing measure or for wounds too large or contaminated for immediate reconstruction. Compared to traditional myocutaneous flaps, perforator flaps provide thinner fasciocutaneous flaps for perineal reconstruction with favorable results and fewer donor site morbidities. The upper and lower gluteal regions are rich in perforators, which allow for more versatile flap design according to the defect. The authors combined the principles of free-style perforator flaps, flap delay, and thinning of perforator flaps to restore perineal function and aesthetics. The procedure was undertaken in a 72-year-old female who was obese with the diagnosis of necrotizing fasciitis secondary to perineal abscess. After 3 months, the flap achieved adequate and durable reconstruction with acceptable aesthetic contour and patient satisfaction; there was no loss of function at donor sites. Clinical applications and technical refinements of freestyle pedicled perforator flaps can be extended to the perineal region. Because of its many advantages and its versatility, freestyle pedicled perforator flaps constitute a valued reconstructive option and, when indicated, an alternative to pedicled axial flaps or even free flaps, in addition to vacuum therapy, to simplify the reconstructive procedure. PMID:27434419

  15. Knee extensor loss and proximal tibial soft tissue defect managed successfully with simultaneous medial gastrocnemius flap, saphenous fasciocutaneous flap and medial hemisoleus flap: a case report

    PubMed Central

    2013-01-01

    Introduction Open fractures of the proximal tibia often pose serious challenges to the treating orthopedic surgeon. Management of these complex injuries becomes difficult if they are associated with damage to the extensor mechanism and an exposed knee joint. The scenario becomes more difficult to manage when the soft tissue defect extends to the middle third of the leg. We report a case where we used an extended medial gastrocnemius flap in combination with a saphenous artery fasciocutaneous flap and a medial hemisoleus flap for treatment of an infected proximal tibia fracture with loss of the extensor mechanism and soft tissue defect. To the best of our knowledge, combined use of these three flaps for the management of such injuries has not been reported elsewhere to date. Case presentation A 28-year-old Indian man presented to our Out-patient Department with complaints of pain and pus discharge from his left proximal leg for four weeks. He had sustained an open fracture of his left proximal tibia in a road traffic accident five weeks ago and had been operated on elsewhere. He had a stiff, painful knee with an infected wound of 4×4cm over the proximal third of his leg exposing infected, necrotic patellar tendon. He was successfully managed with debridement and simultaneously elevated flaps as described. Conclusions This procedure avoids the donor site morbidity associated with free flaps harvested from sites distant from the site of injury, and also does not need the expertise of microvascular reconstruction. To the best of our knowledge, this is also the first report of the combined use of three local flaps for knee extensor reconstruction and soft tissue coverage around the knee. PMID:23506268

  16. Heart rate and estimated energy expenditure of flapping and gliding in black-browed albatrosses.

    PubMed

    Sakamoto, Kentaro Q; Takahashi, Akinori; Iwata, Takashi; Yamamoto, Takashi; Yamamoto, Maki; Trathan, Philip N

    2013-08-15

    Albatrosses are known to expend only a small amount of energy during flight. The low energy cost of albatross flight has been attributed to energy-efficient gliding (soaring) with sporadic flapping, although little is known about how much time and energy albatrosses expend in flapping versus gliding during cruising flight. Here, we examined the heart rates (used as an instantaneous index of energy expenditure) and flapping activities of free-ranging black-browed albatrosses (Thalassarche melanophrys) to estimate the energy cost of flapping as well as time spent in flapping activities. The heart rate of albatrosses during flight (144 beats min(-1)) was similar to that while sitting on the water (150 beats min(-1)). In contrast, heart rate was much higher during takeoff and landing (ca. 200 beats min(-1)). Heart rate during cruising flight was linearly correlated with the number of wing flaps per minute, suggesting an extra energy burden of flapping. Albatrosses spend only 4.6±1.4% of their time flapping during cruising flight, which was significantly lower than during and shortly after takeoff (9.8±3.5%). Flapping activity, which amounted to just 4.6% of the time in flight, accounted for 13.3% of the total energy expenditure during cruising flight. These results support the idea that albatrosses achieve energy-efficient flight by reducing the time spent in flapping activity, which is associated with high energy expenditure. PMID:23661772

  17. Towards an advanced vortex flap system: The cavity flap

    NASA Technical Reports Server (NTRS)

    Rao, D. M.

    1986-01-01

    An extension of the vortex flap concept was explored with the aim of providing high-alpha flight control capability coupled with maneuver drag reduction for highly swept wing configurations. A retractable lower surface flap mounted on a translating hinge is proposed, allowing chordwise extension as well as deflection, the two movements being independently controlled. The frontal cavity formed by the partially extended and deflected flap captures a vortex above a certain angle of attack. The cavity vortex downwash alleviates the effective incidence of the wing leading edge, thus modulating vortex lift; at the same time, the induced suction in the cavity generates thrust. These postulated aerodynamic features of the cavity flap were validated through low speed tunnel pressure and visualization tests on a 65 deg swept oblique wing model, which also provided initial trends of the leading edge vortex alleviation and cavity suction with respect to flap extension, deflection and angle of attack. Force tests on a 60 deg delta model further showed the cavity flap L/D performance to compare favorably with the conventional vortex flap. A two segment flap arrangement with independently control led segments was envisaged for exploiting the vortex modulation capability of the cavity flap for pitch, roll and yaw control, in addition to drag reduction at high angles of attack.

  18. Thin superficial circumflex iliac artery perforator flap and supermicrosurgery technique for face reconstruction.

    PubMed

    Choi, Dong Hoon; Goh, Terence; Cho, Jae Young; Hong, Joon Pio

    2014-11-01

    Distant free flaps have become a routine option for reconstruction of large, complicated facial soft tissue defects. The challenge is to find a flap that is pliable to provide good contour and function. The purpose of this paper was to evaluate the use of superficial circumflex iliac artery perforator (SCIP) flaps for facial defects. From November 2010 to June 2013, facial reconstruction was performed on 6 patients (age range, 15-79 years). The harvesting technique was modified to elevate above the deep fat, and the pedicles were taken above or just below the deep fascia. The mean size of the flap was 75.6 cm2, with a thickness of 7 mm; the mean pedicle length was 4.9 cm; and the mean artery caliber was 0.7 mm. The supermicrosurgery technique was used successfully in all 6 cases. Donor sites were all closed primarily. The mean follow-up was 16.7 months. All flaps survived without flap loss, and the donor sites healed without complications including lymphorrhea. The patients were satisfied with contour and function after reconstruction. The result of these 6 cases suggested that the SCIP flap can be a reliable flap for moderate-sized to large defects in the face. The use of new instrumentation and supermicrosurgical techniques allows use of the SCIP flap reliably while providing patients with a good contour, function, and minimal donor site morbidity. PMID:25329846

  19. Management of different kinds of head and neck defects with the submental flap for reconstruction.

    PubMed

    Tsai, Wan-Chun; Yang, Jinn-Moon; Liu, Shao-Cheng; Chu, Yueng-Hsiang; Lai, Wen-Sen; Lin, Yaoh-Shiang; Lee, Jih-Chin

    2015-12-01

    Head and neck surgeries often accompany with moderate-sized defects that require time-consuming reconstructions by free flaps. The submental flap is a versatile and time-effective option for reconstruction of orofacial defects providing acceptable cosmetic and functional results without requiring microsurgical techniques. A retrospective case series study of patients who underwent reconstruction with the submental flap between 2009 and 2013 was conducted. There were 36 patients (33 men and 3 women), with a mean age of 56.4 years, enrolled in this study. The primary lesion sites included oral cavity (24 patients), pharynx (8 patients), larynx (2 patients), neck (1 patient) as well as maxillary sinus (1 patient). All flaps were harvested as the myocutaneous flaps. All donor sites were closed primarily without the need of additional surgery. No complete loss of the flap was encountered and two cases developed marginal necrosis of the flap. The submental flap had a reliable pedicle and had minimal donor-site morbidity. It is an excellent flap option for patients with small- to medium-sized defects in head and neck region. PMID:25542248

  20. Dissecting the active site of a photoreceptor protein

    NASA Astrophysics Data System (ADS)

    Hoff, Wouter; Hara, Miwa; Ren, Jie; Moghadam, Farzaneh; Xie, Aihua; Kumauchi, Masato

    While enzymes are quite large molecules, functionally important chemical events are often limited to a small region of the protein: the active site. The physical and chemical properties of residues at such active sites are often strongly altered compared to the same groups dissolved in water. Understanding such effects is important for unraveling the mechanisms underlying protein function and for protein engineering, but has proven challenging. Here we report on our ongoing efforts on using photoactive yellow protein (PYP), a bacterial photoreceptor, as a model system for such effects. We will report on the following questions: How many residues affect active site properties? Are these residues in direct physical contact with the active site? Can functionally important residues be recognized in the crystal structure of a protein? What structural resolution is needed to understand active sites? What spectroscopic techniques are most informative? Which weak interactions dominate active site properties?

  1. Superficial ulnar artery perforator flap.

    PubMed

    Schonauer, Fabrizio; Marlino, Sergio; Turrà, Francesco; Graziano, Pasquale; Dell'Aversana Orabona, Giovanni

    2014-09-01

    Superficial ulnar artery is a rare finding but shows significant surgical implications. Its thinness and pliability make this flap an excellent solution for soft tissue reconstruction, especially in the head and neck region. We hereby report a successful free superficial ulnar artery perforator forearm flap transfer for tongue reconstruction. A 64-year-old man presenting with a squamous cell carcinoma of the left tongue underwent a wide resection of the tumor, left radical neck dissection, and reconstruction of the tongue and the left tonsillar pillar with the mentioned flap. No complications were observed postoperatively. The flap survived completely; no recurrence at 6 months of follow-up was detected. Superficial ulnar artery perforator flap has shown to be a safe alternative to other free tissue flaps in specific forearm anatomic conditions. PMID:25102397

  2. Skin flaps and grafts - self-care

    MedlinePlus

    ... Regional flaps - self-care; Distant flaps - self-care; Free flap - self-care; Skin autografting - self-care ... the dressing and area around it clean and free from dirt or sweat. Don't let the ...

  3. Externally blown flap noise research

    NASA Technical Reports Server (NTRS)

    Dorsch, R. G.

    1974-01-01

    The Lewis Research Center cold-flow model externally blown flap (EBF) noise research test program is summarized. Both engine under-the-wing and over-the-wing EBF wing section configurations were studied. Ten large scale and nineteen small scale EBF models were tested. A limited number of forward airspeed effect and flap noise suppression tests were also run. The key results and conclusions drawn from the flap noise tests are summarized and discussed.

  4. The vortex flap

    NASA Astrophysics Data System (ADS)

    Buerge, Brandon T.

    The Vortex Flap is a new type of mechanically driven high-lift device consisting of a rotating cylinder placed underneath and near the trailing edge of an airfoil. Wind tunnel tests were designed and conducted in the Washington University Low-Speed Wind Tunnel. Wind tunnel tests indicate that the Vortex Flap produces notable lift coefficient increments and increases maximum lift coefficients, particularly for the low Reynolds number range tested. The best configurations of the configurations investigated (not necessarily optimal) produce lift increments of 300-900% at low-to-moderate angles of attack, and increase the maximum lift coefficient on the order of 200%. The large lift increments found, particularly at low angles of attack, underscore the ability to drive the airfoil to high lift coefficients even at low angles of attack, a potentially useful characteristic for certain flight maneuvers. Regions of fairly high L/D (on the order of 10) as well as low L/D performance were identified. The nondimensional cylinder rotation speed was found to be the most important experimental parameter. Methods for correcting wind tunnel data were developed and outlined, and a Response Surface Method was applied to the corrected data for ease of interpretation. Performance comparisons between the Vortex Flap and other trailing-edge high-lift devices are included. To demonstrate the potential of the device, a Navy mission specification for a VTOL ship-borne UAV, currently filled by a rotary-wing aircraft, is analyzed using a hypothetical fixed wing aircraft and the Vortex Flap. It is demonstrated that, under certain reasonable wind-over-deck conditions, such an aircraft could hypothetically fill a VTOL mission.

  5. The use of bone anchors for autologous flap fixation in perineal reconstruction: a case report.

    PubMed

    Saad, Adam; Cece, John A; Arvanitis, Michael L; Elkwood, Andrew I

    2013-01-01

    The purpose of this case report is to demonstrate the use of bone anchors with an autologous flap in perineal reconstruction. This technique has not been reported before. A 64-year-old female presented to our office with a chief complaint of perineal hernia 1.5 years after abdominoperineal resection. She had a history of recurrent rectal cancer for which she received chemotherapy, radiation and surgery. To repair the hernia, a standard vertical rectus abdominismyocutaneous was harvested and de-epithelialized. It was secured into place in the pelvis utilizing several bone anchors. Mesh was used to repair the donor site defect. At 18 month follow-up, there was good healing of all the wounds and no recurrence of the hernia. She was pain free and able to resume her activities of daily living. Bone anchor fixation is a viable technique for fixation of autologous flaps in perineal reconstruction. PMID:24964462

  6. The use of bone anchors for autologous flap fixation in perineal reconstruction: a case report

    PubMed Central

    Saad, Adam; Cece, John A.; Arvanitis, Michael L.; Elkwood, Andrew I.

    2013-01-01

    The purpose of this case report is to demonstrate the use of bone anchors with an autologous flap in perineal reconstruction. This technique has not been reported before. A 64-year-old female presented to our office with a chief complaint of perineal hernia 1.5 years after abdominoperineal resection. She had a history of recurrent rectal cancer for which she received chemotherapy, radiation and surgery. To repair the hernia, a standard vertical rectus abdominismyocutaneous was harvested and de-epithelialized. It was secured into place in the pelvis utilizing several bone anchors. Mesh was used to repair the donor site defect. At 18 month follow-up, there was good healing of all the wounds and no recurrence of the hernia. She was pain free and able to resume her activities of daily living. Bone anchor fixation is a viable technique for fixation of autologous flaps in perineal reconstruction. PMID:24964462

  7. Crystal Structures of a Multidrug-Resistant Human Immunodeficiency Virus Type 1 Protease Reveal an Expanded Active-Site Cavity

    SciTech Connect

    Logsdon, Bradley C.; Vickrey, John F.; Martin, Philip; Proteasa, Gheorghe; Koepke, Jay I.; Terlecky, Stanley R.; Wawrzak, Zdzislaw; Winters, Mark A.; Merigan, Thomas C.; Kovari, Ladislau C.

    2010-03-08

    The goal of this study was to use X-ray crystallography to investigate the structural basis of resistance to human immunodeficiency virus type 1 (HIV-1) protease inhibitors. We overexpressed, purified, and crystallized a multidrug-resistant (MDR) HIV-1 protease enzyme derived from a patient failing on several protease inhibitor-containing regimens. This HIV-1 variant contained codon mutations at positions 10, 36, 46, 54, 63, 71, 82, 84, and 90 that confer drug resistance to protease inhibitors. The 1.8-{angstrom} crystal structure of this MDR patient isolate reveals an expanded active-site cavity. The active-site expansion includes position 82 and 84 mutations due to the alterations in the amino acid side chains from longer to shorter (e.g., V82A and I84V). The MDR isolate 769 protease 'flaps' stay open wider, and the difference in the flap tip distances in the MDR 769 variant is 12 {angstrom}. The MDR 769 protease crystal complexes with lopinavir and DMP450 reveal completely different binding modes. The network of interactions between the ligands and the MDR 769 protease is completely different from that seen with the wild-type protease-ligand complexes. The water molecule-forming hydrogen bonds bridging between the two flaps and either the substrate or the peptide-based inhibitor are lacking in the MDR 769 clinical isolate. The S1, S1', S3, and S3' pockets show expansion and conformational change. Surface plasmon resonance measurements with the MDR 769 protease indicate higher k{sub off} rates, resulting in a change of binding affinity. Surface plasmon resonance measurements provide k{sub on} and k{sub off} data (K{sub d} = k{sub off}/k{sub on}) to measure binding of the multidrug-resistant protease to various ligands. This MDR 769 protease represents a new antiviral target, presenting the possibility of designing novel inhibitors with activity against the open and expanded protease forms.

  8. Changes of perfusion of microvascular free flaps in the head and neck: a prospective clinical study.

    PubMed

    Mücke, Thomas; Rau, Andrea; Merezas, Andreas; Kanatas, Anastasios; Mitchell, David A; Wagenpfeil, Stefan; Wolff, Klaus-Dietrich; Steiner, Timm

    2014-11-01

    Reconstruction with a free flap is routine in head and neck surgery. However, reliable assessment of perfusion can be difficult, so we prospectively evaluated it in 4 types of microvascular free flaps in the oral cavity (n=196) and assessed differences in blood flow by non-invasive monitoring with a laser Doppler flowmetry unit. We measured oxygen saturation, haemoglobin concentration, and velocity on the surface of the flap preoperatively at the donor site, and on the flap on the first, second, and seventh postoperative days, and after 4 weeks in 186/196 patients, mean (SD) age of 60 (13) years. We studied the radial forearm (n=76, 41%), fibular (n=45, 24%), anterolateral thigh (n=53, 28%), and soleus perforator (n=12, 7%) flaps. The values for the radial forearm flap differed significantly from the others. There were significant differences in haemoglobin concentrations between the fibular and soleus perforator flaps, and between the anterolateral thigh and soleus perforator flaps (p=0.002 each). Free flaps are unique in the way that perfusion develops after microvascular anastomoses. Knowledge of how each flap is perfused may indicate different patterns of healing that could potentially influence long term rehabilitation and detection of future deficits in perfusion. PMID:25149324

  9. Dynamic properties of blood flow and leukocyte mobilization in infected flaps

    SciTech Connect

    Feng, L.J.; Price, D.C.; Mathes, S.J.; Hohn, D. )

    1990-11-01

    Two aspects of the inflammatory response to infection--blood flow alteration and leukocyte mobilization--are investigated in the canine model. The elevation of paired musculocutaneous (MC) and random pattern (RP) flaps allowed comparison of healing flaps with significant differences in blood flow (lower in random pattern flaps) and resistance to infection (greater in musculocutaneous flaps). Blood flow changes as determined by radioactive xenon washout were compared in normal skin and distal flap skin both after elevation and following bacterial inoculation. Simultaneous use of In-111 labeled leukocytes allowed determination of leukocyte mobilization and subsequent localization in response to flap infection. Blood flow significantly improved in the musculocutaneous flap in response to infection. Although total leukocyte mobilization in the random pattern flap was greater, the leukocytes in the musculocutaneous flap were localized around the site of bacterial inoculation within the dermis. Differences in the dynamic blood flow and leukocyte mobilization may, in part, explain the greater reliability of musculocutaneous flaps when transposed in the presence of infection.

  10. Extending the use of the gracilis muscle flap in perineal reconstruction surgery.

    PubMed

    Goldie, Stephen J; Almasharqah, Riyadh; Fogg, Quentin A; Anderson, William

    2016-08-01

    Reconstruction of the perineum is required following oncological resections. Plastic surgical techniques can be used to restore the aesthetics and function of the perineum. The gracilis myocutaneous flap provides a substantial skin paddle, with minimal donor site morbidity. The flap is pedicled on a perforator from the medial circumflex femoral artery, giving it limited reach across the perineum. Tunnelling the flap under the adductor longus muscle may free up more of the arterial pedicle, increasing its reach. On three female cadavers, bilateral gracilis flaps were raised in the standard surgical manner, giving six flaps in total. With the flaps pedicled across the perineum, the distance from the tip of each flap was measured to the anterior superior iliac spine (ASIS). The flaps were then tunnelled under the adductor longus muscle. The distances to the ASIS were measured again. The average pedicle length was greater than 7 cm. Tunnelling the flap under the adductor longus muscle increased the reach by more than 4 cm on average. Cadaveric dissection has shown that tunnelling of the flap in a novel way increase its reach across the perineum. This additional flexibility improves its use clinically and is of benefit to plastic surgeons operating in perineal reconstruction. PMID:27221783

  11. The Versatile Modiolus Perforator Flap

    PubMed Central

    Gunnarsson, Gudjon Leifur; Thomsen, Jorn Bo

    2016-01-01

    Background: Perforator flaps are well established, and their usefulness as freestyle island flaps is recognized. The whereabouts of vascular perforators and classification of perforator flaps in the face are a debated subject, despite several anatomical studies showing similar consistency. In our experience using freestyle facial perforator flaps, we have located areas where perforators are consistently found. This study is focused on a particular perforator lateral to the angle of the mouth; the modiolus and the versatile modiolus perforator flap. Methods: A cohort case series of 14 modiolus perforator flap reconstructions in 14 patients and a color Doppler ultrasonography localization of the modiolus perforator in 10 volunteers. Results: All 14 flaps were successfully used to reconstruct the defects involved, and the location of the perforator was at the level of the modiolus as predicted. The color Doppler ultrasonography study detected a sizeable perforator at the level of the modiolus lateral to the angle of the mouth within a radius of 1 cm. This confirms the anatomical findings of previous authors and indicates that the modiolus perforator is a consistent anatomical finding, and flaps based on it can be recommended for several indications from the reconstruction of defects in the perioral area, cheek and nose. Conclusions: The modiolus is a well-described anatomical area containing a sizeable perforator that is consistently present and readily visualized using color Doppler ultrasonography. We have used the modiolus perforator flap successfully for several indications, and it is our first choice for perioral reconstruction. PMID:27257591

  12. Flag flapping in a channel

    NASA Astrophysics Data System (ADS)

    Alben, Silas; Shoele, Kourosh; Mittal, Rajat; Jha, Sourabh; Glezer, Ari

    2015-11-01

    We study the flapping of a flag in an inviscid channel flow. We focus especially on how quantities vary with channel spacing. As the channel walls move inwards towards the flag, heavier flags become more unstable, while light flags' stability is less affected. We use a vortex sheet model to compute large-amplitude flapping, and find that the flag undergoes a series of jumps to higher flapping modes as the channel walls are moved towards the flag. Meanwhile, the drag on the flag and the energy lost to the wake first rise as the walls become closer, then drop sharply as the flag moves to a higher flapping mode.

  13. Mars Surveyor Project Landing Site Activities

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.; Briggs, Geoffrey; Saunders, R. Stephen; Gilmore, Martha; Soderblom, Larry

    1999-01-01

    The Mars Surveyor Program --now a cooperative program led by NASA and CNES along with other international partners -- is underway. It has the primary science objective of furthering our understanding of the biological potential and possible biological history of Mars and has the complementary objective of improving our understanding of martian climate evolution and planetary history The missions will develop technology and acquire data necessary for eventual human Exploration. Launches of orbiters, landers and rovers will take place in 2001 and in 2003; in 2005 a complete system will be launched capable of returning samples to Earth by 2008. A key aspect of the program is the selection of landing sites. This abstract 1) reports on the status of the landing site selection process that begins with the 2001 lander mission and 2) outlines be opportunities for the Mars community to provide input into the landing site selection process.

  14. Mars Surveyor Project Landing Site Activities

    NASA Technical Reports Server (NTRS)

    Gulick, V. C.; Briggs, Geoffrey; Saunders, R. Stephen; Gilmore, Martha; Soderblom, Larry

    1999-01-01

    The Mars Surveyor Program -- now a cooperative program led by NASA and CNES along with other international partners -- is underway. It has the primary science objective of furthering our understanding of the biological potential and possible biological history of Mars and has the complementary objective of improving our understanding of martian climate evolution and planetary history. The missions will develop technology and acquire data necessary for eventual human exploration. Launches of orbiters, landers and rovers will take place in 2001 and in 2003; in 2005 a complete system will be launched capable of returning samples to Earth by 2008. A key aspect of the program is the selection of landing sites. This abstract 1) reports on the status of the landing site selection process that begins with the 2001 lander mission and 2) outlines the opportunities for the Mars community to provide input into the landing site selection process.

  15. The bifunctional active site of s-adenosylmethionine synthetase. Roles of the active site aspartates.

    PubMed

    Taylor, J C; Markham, G D

    1999-11-12

    S-Adenosylmethionine (AdoMet) synthetase catalyzes the biosynthesis of AdoMet in a unique enzymatic reaction. Initially the sulfur of methionine displaces the intact tripolyphosphate chain (PPP(i)) from ATP, and subsequently PPP(i) is hydrolyzed to PP(i) and P(i) before product release. The crystal structure of Escherichia coli AdoMet synthetase shows that the active site contains four aspartate residues. Aspartate residues Asp-16* and Asp-271 individually provide the sole protein ligand to one of the two required Mg(2+) ions (* denotes a residue from a second subunit); aspartates Asp-118 and Asp-238* are proposed to interact with methionine. Each aspartate has been changed to an uncharged asparagine, and the metal binding residues were also changed to alanine, to assess the roles of charge and ligation ability on catalytic efficiency. The resultant enzyme variants all structurally resemble the wild type enzyme as indicated by circular dichroism spectra and are tetramers. However, all have k(cat) reductions of approximately 10(3)-fold in AdoMet synthesis, whereas the MgATP and methionine K(m) values change by less than 3- and 8-fold, respectively. In the partial reaction of PPP(i) hydrolysis, mutants of the Mg(2+) binding residues have >700-fold reduced catalytic efficiency (k(cat)/K(m)), whereas the D118N and D238*N mutants are impaired less than 35-fold. The catalytic efficiency for PPP(i) hydrolysis by Mg(2+) site mutants is improved by AdoMet, like the wild type enzyme. In contrast AdoMet reduces the catalytic efficiency for PPP(i) hydrolysis by the D118N and D238*N mutants, indicating that the events involved in AdoMet activation are hindered in these methionyl binding site mutants. Ca(2+) uniquely activates the D271A mutant enzyme to 15% of the level of Mg(2+), in contrast to the approximately 1% Ca(2+) activation of the wild type enzyme. This indicates that the Asp-271 side chain size is a discriminator between the activating ability of Ca(2+) and the

  16. Reconstruction of posterior neck and skull with vertical trapezius musculocutaneous flap

    SciTech Connect

    Mathes, S.J.; Stevenson, T.R.

    1988-10-01

    The vertical trapezius musculocutaneous flap has been successfully utilized for reconstruction in 13 patients with complex posterior skull and neck defects. This flap based on its vascular pedicle, the descending branch of the transverse cervical artery, provides well-vascularized tissue for coverage of defects related to chronic osteomyelitis, tumor extirpation, osteoradionecrosis, and dehisced cervical laminectomy wounds. Emphasis on flap design, including the location of the skin island, allows adequate wound coverage, direct donor site closure, and muscle function preservation. With its large size and wide arc of rotation, the vertical trapezius musculocutaneous flap provides reliable coverage for posterior trunk, cervical, and skull defects.

  17. Microvascular medial femoral condylar flaps in 107 consecutive reconstructions in the head and neck.

    PubMed

    Brandtner, Christian; Hachleitner, Johannes; Bottini, Gian Battista; Buerger, Heinz; Gaggl, Alexander

    2016-07-01

    We have assessed the role of the medial femoral condylar flap in 107 patients who had reconstructions of the head and neck. We retrospectively reviewed their medical records for indications, complications, and outcomes. The flap was primarily used for coverage of alveolar ridge defects (n=67), secondly for defects of the facial bone, calvaria, or skull base (n=35), and thirdly for partial laryngeal defects (n=5). Two flaps were lost. One patient fractured a femur 5 weeks postoperatively. The duration of follow up ranged from 6 months to 12 years. The medial femoral condylar flap is well-suited to individual reconstructions of the alveolar ridge, midface, calvaria, skull base, and part of the larynx with poor recipient sites. The flap does not replace other wellknown flaps, but offers new solutions for solving special problems in head and neck surgery. PMID:27020752

  18. Masseter flap for reconstruction of defects after excision of buccal mucosa cancers with intact mandible.

    PubMed

    Chaturvedi, Pankaj; Lerra, Sandeep; Ustad, Farheen; Pai, Prathamesh S; Chaukar, Devendra A; D'Cruz, Anil K

    2015-01-01

    Among the reconstructive options available for buccal mucosa defects with an intact mandible, free flap with microvascular anastomosis is the best option. However, in the developing world, with poor resources, limited infrastructure, and high patient load, this cannot be offered to all patients. We report on the success of the masseter flap for reconstruction of such defects in carefully selected patients. Despite some known limitations, this flap is easy to learn and carries acceptable complications. The results of this flap may not be comparable to those of microvascular reconstructions, but they are better than those from other options such as skin graft, nasolabial flap, submental flap, etc., in terms of surgical time required, no donor site morbidity, and minimal aesthetic deformity. PMID:26535825

  19. Direct observation of DNA threading in flap endonuclease complexes.

    PubMed

    AlMalki, Faizah A; Flemming, Claudia S; Zhang, Jing; Feng, Min; Sedelnikova, Svetlana E; Ceska, Tom; Rafferty, John B; Sayers, Jon R; Artymiuk, Peter J

    2016-07-01

    Maintenance of genome integrity requires that branched nucleic acid molecules be accurately processed to produce double-helical DNA. Flap endonucleases are essential enzymes that trim such branched molecules generated by Okazaki-fragment synthesis during replication. Here, we report crystal structures of bacteriophage T5 flap endonuclease in complexes with intact DNA substrates and products, at resolutions of 1.9-2.2 Å. They reveal single-stranded DNA threading through a hole in the enzyme, which is enclosed by an inverted V-shaped helical arch straddling the active site. Residues lining the hole induce an unusual barb-like conformation in the DNA substrate, thereby juxtaposing the scissile phosphate and essential catalytic metal ions. A series of complexes and biochemical analyses show how the substrate's single-stranded branch approaches, threads through and finally emerges on the far side of the enzyme. Our studies suggest that substrate recognition involves an unusual 'fly-casting, thread, bend and barb' mechanism. PMID:27273516

  20. Augmentation of venous drainage in deep inferior epigastric perforator flap breast reconstruction: efficacy and advancement.

    PubMed

    Xin, Qiang; Luan, Jie; Mu, Hua; Mu, Li

    2012-06-01

    Deep inferior epigastric perforator flap (DIEP) is the workhorse for autologous breast reconstruction because it is associated with less abdominal wall donor site morbidity; however, the high incidence of venous congestion of zone IV within the DIEP flap is the most important disadvantage. Venous augmentation may be an appropriate method for venous decompression of the DIEP flap. This study aims to assess retrospectively the efficacy of the venous augmented DIEP flap and to present an advanced technique for venous augmentation. A total of 79 breast reconstructions using DIEP flap from January 2006 to March 2011 were included. Thirty-two patients who underwent venous augmented DIEP flap were selected as the test group, and 47 patients who underwent the traditional DIEP flap were included as the control group. Three indices-operation time, flap size, and flap complication rate-were compared between the two groups. The operation time was 6.6 ± 0.7 hours in the test group and 6.1 ± 1.2 hours in the control group (p < 0.05). The mean flap size was 325.9 ± 20.6 cm2 in the test group and 294.7 ± 24.2 cm2 in the control group (p <0.05). In the test group, there was one partial flap loss (complication rate was 3.1%). In the control group, the total complication rate was 10.6% (p <0.05). Venous augmentation can successfully enhance the viability of a DIEP flap. The SIEV-SIEV (superficial inferior epigastric vein) reverse-flow anastomosis is an efficient and convenient method of venous augmentation for DIEP flap, with negligible drawbacks. PMID:22517574

  1. Predictive Capability of Near-Infrared Fluorescence Angiography in Submental Perforator Flap Survival

    PubMed Central

    Matsui, Aya; Lee, Bernard T.; Winer, Joshua H.; Laurence, Rita G.; Frangioni, John V.

    2010-01-01

    Background Perforator flaps have become increasingly popular in reconstructive surgery as patients experience less donor-site morbidity than with conventional musculocutaneous flaps. Previously, our laboratory described the intraoperative use of near-infrared (NIR) fluorescence angiography for patient-specific perforator-flap design. This study evaluates the predictive capability of NIR fluorescence angiography for flap survival in submental flap reconstruction. Methods NIR angiography was performed using indocyanine green at 0, 0.5, 24, 48, and 72 h post-surgery after flap creation in 12 pigs. A single perforator artery was preserved during flap creation based on location (central or non-central) and dominance (dominant or non-dominant). Venous drainage, arterial perfusion, and perfused area as percentage of total flap were analyzed. Clinical assessments of perfusion were compared with those made using NIR imaging and histology. Results Use of NIR fluorescence angiography immediately after flap creation accurately predicted areas of perfusion at 72 h (p = 0.0013), compared to the initial clinical assessment (p = 0.3085). Identification of necrosis by histology at 72 h correlated with NIR findings of insufficient arterial perfusion immediately after flap creation. No statistically significant differences in perfusion metrics were detected based on location or dominance of the preserved perforator; however, flaps containing central perforators had a higher percent perfused area than those with non-central perforators. Conclusions The use of NIR angiography immediately after flap creation can predict areas of perfusion at 72 h. This predictive capability may permit intraoperative revision of compromised flaps that have a high likelihood of failure. PMID:21042109

  2. A Miniature Controllable Flapping Wing Robot

    NASA Astrophysics Data System (ADS)

    Arabagi, Veaceslav Gheorghe

    The agility and miniature size of nature's flapping wing fliers has long baffled researchers, inspiring biological studies, aerodynamic simulations, and attempts to engineer their robotic replicas. Flapping wing flight is characterized by complex reciprocating wing kinematics, transient aerodynamic effects, and very small body lengths. These characteristics render robotic flapping wing aerial vehicles ideal for surveillance and defense applications, search and rescue missions, and environment monitoring, where their ability to hover and high maneuverability is immensely beneficial. One of the many difficulties in creating flapping wing based miniature robotic aerial vehicles lies in generating a proper wing trajectory that would result in sufficient lift forces for hovering and maneuvering. Since design of a flapping wing system is a balance between overall weight and the number of actuated inputs, we take the approach of having minimal controlled inputs, allowing passive behavior wherever possible. Hence, we propose a completely passive wing pitch reversal design that relies on wing inertial dynamics, an elastic energy storage mechanism, and low Reynolds number aerodynamic effects. Theoretical models, compiling previous research on piezoelectric actuators, four-bar transmissions, and aerodynamics effects, are developed and used as basis for a complete numerical simulation. Limitations of the model are discussed in comparison to experimental results obtained from a working prototype of the proposed passive pitch reversal flapping wing mechanism. Given that the mechanism is under-actuated, methods to control lift force generation by actively varying system parameters are proposed, discussed, and tested experimentally. A dual wing aerial platform is developed based on the passive pitch reversal wing concept. Design considerations are presented, favoring controllability and structural rigidity of the final platform. Finite element analysis and experimental

  3. Multipaddled Anterolateral Thigh Chimeric Flap for Reconstruction of Complex Defects in Head and Neck

    PubMed Central

    Li, Ning; Liu, Wen; Su, Tong; Chen, Xinqun; Zheng, Lian; Jian, Xinchun

    2014-01-01

    The anterolateral thigh flap has been the workhouse flap for coverage of soft-tissue defects in head and neck for decades. However, the reconstruction of multiple and complex soft-tissue defects in head and neck with multipaddled anterolateral thigh chimeric flaps is still a challenge for reconstructive surgeries. Here, a clinical series of 12 cases is reported in which multipaddled anterolateral thigh chimeric flaps were used for complex soft-tissue defects with several separately anatomic locations in head and neck. Of the 12 cases, 7 patients presented with trismus were diagnosed as advanced buccal cancer with oral submucous fibrosis, 2 tongue cancer cases were found accompanied with multiple oral mucosa lesions or buccal cancer, and 3 were hypopharyngeal cancer with anterior neck skin invaded. All soft-tissue defects were reconstructed by multipaddled anterolateral thigh chimeric flaps, including 9 tripaddled anterolateral thigh flaps and 3 bipaddled flaps. The mean length of skin paddle was 19.2 (range: 14–23) cm and the mean width was 4.9 (range: 2.5–7) cm. All flaps survived and all donor sites were closed primarily. After a mean follow-up time of 9.1 months, there were no problems with the donor or recipient sites. This study supports that the multipaddled anterolateral thigh chimeric flap is a reliable and good alternative for complex and multiple soft-tissue defects of the head and neck. PMID:25180680

  4. Reconstruction of Heel With Propeller Flap in Postfasciotomy and Popliteal Artery Revascularization State.

    PubMed

    Kang, Jin Seok; Choi, Hwan Jun; Tak, Min Sung

    2016-06-01

    Free flaps are still the gold standard for large defects of the lower limb, but propeller perforator flaps have become a simpler and faster alternative to free flaps because of some advantages such as reliable vascular pedicle, wide mobilization and rotation, great freedom in design, low donor site morbidity, and easy harvest with no requirement for anastomosis. But when the vessels show insufficient findings in preoperative evaluation using a Doppler probe or the vessel is injured, the surgeon should avoid performing free flap surgery to prevent flap failure and should select a propeller perforator flap as an alternative method on the condition that more than one perforator is intact. In this study, we report reconstruction of soft tissue defects of the heel with a pedicled propeller flap in postfasciotomy and popliteal artery revascularization state by making an incision on the central portion above the Achilles tendon, which can be covered by the posterior tibial artery perforator or the peroneal artery perforator based flaps. In conclusion, we showed that although the popliteal artery was injured, the soft tissue defect can be reconstructed using a perforator propeller flap if intact distal flow in the anastomosis site was confirmed. PMID:25673623

  5. The active site of ribulose-bisphosphate carboxylase/oxygenase

    SciTech Connect

    Hartman, F.C.

    1991-01-01

    The active site of ribulose-bisphosphate carboxylase/oxygenase requires interacting domains of adjacent, identical subunits. Most active-site residues are located within the loop regions of an eight-stranded {beta}/{alpha}-barrel which constitutes the larger C-terminal domain; additional key residues are located within a segment of the smaller N-terminal domain which partially covers the mouth of the barrel. Site-directed mutagenesis of the gene encoding the enzyme from Rhodospirillum rubrum has been used to delineate functions of active-site residues. 6 refs., 2 figs.

  6. Reduction of Flap Side Edge Noise - the Blowing Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, THomas F.

    2005-01-01

    A technique to reduce the noise radiating from a wing-flap side edge is being developed. As an airplane wing with an extended flap is exposed to a subsonic airflow, air is blown outward through thin rectangular chord-wise slots at various locations along the side edges and side surface of the flap to weaken and push away the vortices that originate in that region of the flap and are responsible for important noise emissions. Air is blown through the slots at up to twice the local flow velocity. The blowing is done using one or multiple slots, where a slot is located along the top, bottom or side surface of the flap along the side edge, or also along the intersection of the bottom (or top) and side surfaces.

  7. A study on the flexibility of enzyme active sites

    PubMed Central

    2011-01-01

    Background A common assumption about enzyme active sites is that their structures are highly conserved to specifically distinguish between closely similar compounds. However, with the discovery of distinct enzymes with similar reaction chemistries, more and more studies discussing the structural flexibility of the active site have been conducted. Results Most of the existing works on the flexibility of active sites focuses on a set of pre-selected active sites that were already known to be flexible. This study, on the other hand, proposes an analysis framework composed of a new data collecting strategy, a local structure alignment tool and several physicochemical measures derived from the alignments. The method proposed to identify flexible active sites is highly automated and robust so that more extensive studies will be feasible in the future. The experimental results show the proposed method is (a) consistent with previous works based on manually identified flexible active sites and (b) capable of identifying potentially new flexible active sites. Conclusions This proposed analysis framework and the former analyses on flexibility have their own advantages and disadvantage, depending on the cause of the flexibility. In this regard, this study proposes an alternative that complements previous studies and helps to construct a more comprehensive view of the flexibility of enzyme active sites. PMID:21342563

  8. Safety Oversight of Decommissioning Activities at DOE Nuclear Sites

    SciTech Connect

    Zull, Lawrence M.; Yeniscavich, William

    2008-01-15

    The Defense Nuclear Facilities Safety Board (Board) is an independent federal agency established by Congress in 1988 to provide nuclear safety oversight of activities at U.S. Department of Energy (DOE) defense nuclear facilities. The activities under the Board's jurisdiction include the design, construction, startup, operation, and decommissioning of defense nuclear facilities at DOE sites. This paper reviews the Board's safety oversight of decommissioning activities at DOE sites, identifies the safety problems observed, and discusses Board initiatives to improve the safety of decommissioning activities at DOE sites. The decommissioning of former defense nuclear facilities has reduced the risk of radioactive material contamination and exposure to the public and site workers. In general, efforts to perform decommissioning work at DOE defense nuclear sites have been successful, and contractors performing decommissioning work have a good safety record. Decommissioning activities have recently been completed at sites identified for closure, including the Rocky Flats Environmental Technology Site, the Fernald Closure Project, and the Miamisburg Closure Project (the Mound site). The Rocky Flats and Fernald sites, which produced plutonium parts and uranium materials for defense needs (respectively), have been turned into wildlife refuges. The Mound site, which performed R and D activities on nuclear materials, has been converted into an industrial and technology park called the Mound Advanced Technology Center. The DOE Office of Legacy Management is responsible for the long term stewardship of these former EM sites. The Board has reviewed many decommissioning activities, and noted that there are valuable lessons learned that can benefit both DOE and the contractor. As part of its ongoing safety oversight responsibilities, the Board and its staff will continue to review the safety of DOE and contractor decommissioning activities at DOE defense nuclear sites.

  9. A triceps musculocutaneous flap for chest-wall defects

    SciTech Connect

    Hartrampf, C.R. Jr.; Elliott, L.F.; Feldman, S. )

    1990-09-01

    A posterior upper arm flap based on the profunda brachii vessels has been described to cover soft-tissue defects in the upper anterolateral chest. In our series, the posterior upper arm skin is elevated with the long head of the triceps muscle to cover seven chest-wall defects resulting from indolent postradiation open wounds following partial TRAM flap failure (n = 2), soft-tissue deficiencies following partial TRAM flap loss (n = 3), and primarily as an ancillary flap in TRAM flap breast reconstruction (n = 2). This flap also may be used to supply well-vascularized tissue in the regions of the shoulder, axilla, and posterolateral back. A prerequisite for this operation is redundant tissue of the upper arm often present in middle-aged women and in patients with lymphedema following mastectomy. In our series of seven patients, all donor sites were closed primarily, and there was no subjective functional deficit following transfer of the long head of the triceps muscle.

  10. DOE site performance assessment activities. Radioactive Waste Technical Support Program

    SciTech Connect

    Not Available

    1990-07-01

    Information on performance assessment capabilities and activities was collected from eight DOE sites. All eight sites either currently dispose of low-level radioactive waste (LLW) or plan to dispose of LLW in the near future. A survey questionnaire was developed and sent to key individuals involved in DOE Order 5820.2A performance assessment activities at each site. The sites surveyed included: Hanford Site (Hanford), Idaho National Engineering Laboratory (INEL), Los Alamos National Laboratory (LANL), Nevada Test Site (NTS), Oak Ridge National Laboratory (ORNL), Paducah Gaseous Diffusion Plant (Paducah), Portsmouth Gaseous Diffusion Plant (Portsmouth), and Savannah River Site (SRS). The questionnaire addressed all aspects of the performance assessment process; from waste source term to dose conversion factors. This report presents the information developed from the site questionnaire and provides a comparison of site-specific performance assessment approaches, data needs, and ongoing and planned activities. All sites are engaged in completing the radioactive waste disposal facility performance assessment required by DOE Order 5820.2A. Each site has achieved various degrees of progress and have identified a set of critical needs. Within several areas, however, the sites identified common needs and questions.

  11. An extensive defect on the tibia covered by a free cross flap using m. latissimus dorsi.

    PubMed

    Tvrdek, M; Kletenský, J; Pros, Z; Stehlík, J

    1992-01-01

    Using a clinical case, the authors demonstrate the technique of covering an extensive tibial defect unmanageable, due to blood supply to the limb and extent of the defect, by conventional methods. The required amount of tissue was provided by a flap obtained from m. latissimus dorst transferred to the site of defect as a free cross flap. PMID:1284265

  12. Savannah River Site prioritization of transition activities

    SciTech Connect

    Finley, R.H.

    1993-11-01

    Effective management of SRS conversion from primarily a production facility to other missions (or Decontamination and Decommissioning (D&D)) requires a systematic and consistent method of prioritizing the transition activities. This report discusses the design of a prioritizing method developed to achieve systematic and consistent methods of prioritizing these activities.

  13. Return of lymphatic function after flap transfer for acute lymphedema.

    PubMed Central

    Slavin, S A; Van den Abbeele, A D; Losken, A; Swartz, M A; Jain, R K

    1999-01-01

    OBJECTIVE: The goals of this work were to develop animal models of lymphedema and tissue flap transfer, and to observe physiologic changes in lymphatic function that occur in these models over time, both systemically with lymphoscintigraphy (LS) and locally using fluorescence microlymphangiography (FM). SUMMARY BACKGROUND DATA: Although lymphedema has been managed by a combination of medical and surgical approaches, no effective long-term cure exists. Surgical attempts aimed at reconnecting impaired lymphatic channels or bypassing obstructed areas have failed. METHODS: The tails of rats (A groups) and mice (B groups) were used because of their different features. Lymphedema was created by ligation of the lymphatics at the tail base and quantified by diameter measurements there. In the experimental group, rectus abdominis myocutaneous flap was transferred across the ligation. In addition to the ligation (A1 and B1) and ligation + flap (A2 and B2) groups, three control groups were included: sham flap with ligation (B4), sham flap alone (B5), and normal (A3 and B3) animals. Observations were made at weekly time points for lymphatic function and continuity. RESULTS: Lymphedema was successfully created in the mouse ligation groups (B1 and B4) and sustained for the entire length of observation (up to 14 weeks). Lymphatic continuity was restored in those animals with transferred flaps across the ligation site (A2 and B2), as seen both by LS and FM. Sham flaps did not visibly affect lymphatic function nor did they cause any visible swelling in the tail. CONCLUSIONS: Acute lymphedema developing after ligation of tail lymphatics in mice can be prevented by myocutaneous flap transfer. Restored lymphatic continuity and function were demonstrable using lymphoscintigraphy and fluorescence microlymphangiography. Images Figure 2. Figure 4. Figure 5. PMID:10077056

  14. Deep circumflex iliac perforator flap.

    PubMed

    Kimata, Yoshihiro

    2003-07-01

    The increased freedom of the DCIP flap from the harvested iliac crest facilitates correct positioning. To ensure that the DCIP flap can be safely elevated, however, the presence of perforators (approximately 1 cm in diameter) must be confirmed preoperatively and intraoperatively. PMID:12916597

  15. Ionizable Side Chains at Catalytic Active Sites of Enzymes

    PubMed Central

    Jimenez-Morales, David; Liang, Jie

    2012-01-01

    Catalytic active sites of enzymes of known structure can be well defined by a modern program of computational geometry. The CASTp program was used to define and measure the volume of the catalytic active sites of 573 enzymes in the Catalytic Site Atlas database. The active sites are identified as catalytic because the amino acids they contain are known to participate in the chemical reaction catalyzed by the enzyme. Acid and base side chains are reliable markers of catalytic active sites. The catalytic active sites have 4 acid and 5 base side chains, in an average volume of 1072 Å3. The number density of acid side chains is 8.3 M (in chemical units); the number density of basic side chains is 10.6 M. The catalytic active site of these enzymes is an unusual electrostatic and steric environment in which side chains and reactants are crowded together in a mixture more like an ionic liquid than an ideal infinitely dilute solution. The electrostatics and crowding of reactants and side chains seems likely to be important for catalytic function. In three types of analogous ion channels, simulation of crowded charges accounts for the main properties of selectivity measured in a wide range of solutions and concentrations. It seems wise to use mathematics designed to study interacting complex fluids when making models of the catalytic active sites of enzymes. PMID:22484856

  16. Active Control of Flow Separation on a High-Lift System with Slotted Flap at High Reynolds Number

    NASA Technical Reports Server (NTRS)

    Khodadoust, Abdollah; Washburn, Anthony

    2007-01-01

    The NASA Energy Efficient Transport (EET) airfoil was tested at NASA Langley's Low- Turbulence Pressure Tunnel (LTPT) to assess the effectiveness of distributed Active Flow Control (AFC) concepts on a high-lift system at flight scale Reynolds numbers for a medium-sized transport. The test results indicate presence of strong Reynolds number effects on the high-lift system with the AFC operational, implying the importance of flight-scale testing for implementation of such systems during design of future flight vehicles with AFC. This paper describes the wind tunnel test results obtained at the LTPT for the EET high-lift system for various AFC concepts examined on this airfoil.

  17. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction.

    PubMed

    Hekner, D D; Roeling, T A P; Van Cann, E M

    2016-08-01

    The aim of this study was to investigate the vascular anatomy of the distal forearm in order to optimize the choice between the radial forearm free flap and the ulnar forearm free flap and to select the best site to harvest the flap. The radial and ulnar arteries of seven fresh cadavers were injected with epoxy resin (Araldite) and the perforating arteries were dissected. The number of clinically relevant perforators from the radial and ulnar arteries was not significantly different in the distal forearm. Most perforators were located in the proximal half of the distal one third, making this part probably the safest location for flap harvest. Close to the wrist, i.e. most distally, there were more perforators on the ulnar side than on the radial side. The ulnar artery stained 77% of the skin surface area of the forearm, showing the ulnar forearm free flap to be more suitable than the radial forearm free flap for the restoration of large defects. PMID:27012603

  18. Periosteal Pedicle Flap Harvested during Vestibular Extension for Root Coverage

    PubMed Central

    Kumar, Shubham; Gupta, Krishna Kumar; Agrawal, Rahul; Srivastava, Pratima; Soni, Shalabh

    2015-01-01

    Root exposure along with inadequate vestibular depth is a common clinical finding. Treatment option includes many techniques to treat such defects for obtaining predictable root coverage. Normally, the vestibular depth is increased first followed by a second surgery for root coverage. The present case report describes a single-stage technique for vestibular extension and root coverage in a single tooth by using the Periosteal Pedicle Flap (PPF). This technique involves no donor site morbidity and allows for reflection of sufficient amount of periosteal flap tissue with its own blood supply at the surgical site, thus increasing the chances of success of root coverage with simultaneous increase in vestibular depth. PMID:26788377

  19. Theory of flapping flight

    NASA Technical Reports Server (NTRS)

    Lippisch, Alexander

    1925-01-01

    Before attempting to construct a human-powered aircraft, the aviator will first try to post himself theoretically on the possible method of operating the flapping wings. This report will present a graphic and mathematical method, which renders it possible to determine the power required, so far as it can be done on the basis of the wing dimensions. We will first consider the form of the flight path through the air. The simplest form is probably the curve of ordinary wave motion. After finding the flight curve, we must next determine the change in the angle of attack while passing through the different phases of the wave.

  20. A combined superficial inferior epigastric artery flap and vascularized iliac crest flap in the reconstruction of extended composite defects of the posterior mandible and adjacent soft tissue: first clinical results.

    PubMed

    Gaggl, A J; Bürger, H; Chiari, F M

    2011-02-01

    The technique of posterior facial reconstruction using a combination of a superficial inferior epigastric artery (SIEA) flap and a microvascular iliac crest flap (deep circumflex iliac artery (DCIA) flap) is described. 12 cases are reported. The patients had unilateral squamous cell carcinoma of the posterior mandible affecting parts of the soft palate and tonsil region or the posterior cheek. In all patients unilateral neck dissection, resection of the posterior and lateral mandible, was performed. Reconstruction was carried out during primary surgical therapy, followed by postoperative radiotherapy. A flap combination of a SIEA and a DCIA flap was used. There were no problems with pedicle length or anastomoses. There was no flap loss or severe postoperative complications. All patients had good aesthetic and functional results. One patient had distant metastases 2 years postoperatively. All other patients were free of tumour relapse or metastases within 12-58 months of follow up. The SIEA flap and vascularized iliac bone flap combination is useful in reconstructing the posterior face. The iliac bone flap is well suited for posterior mandible reconstruction and the SIEA flap for reconstruction of the soft palate, lateral pharyngeal wall and cheek. Both flaps are harvested from the same donor site. PMID:21075599

  1. The Versatility of Perforator-Based Propeller Flap for Reconstruction of Distal Leg and Ankle Defects

    PubMed Central

    Karki, Durga; Narayan, R. P.

    2012-01-01

    Introduction. Soft tissue coverage of distal leg and ankle region represents a challenge and such defect usually requires a free flap. However, this may lead to considerable donor site morbidity, is time consuming, and needs facility of microsurgery. With the introduction of perforator flap, management of small- and medium-size defects of distal leg and ankle region is convenient, less time consuming, and with minimal donor site morbidity. When local perforator flap is designed as propeller and rotated to 180 degree, donor site is closed primarily and increases reach of flap, thus increasing versatility. Material and Methods. From June 2008 to May 2011, 20 patients were treated with perforator-based propeller flap for distal leg and ankle defects. Flap was based on single perforator of posterior tibial and peroneal artery rotated to 180 degrees. Defect size was from 4 cm × 3.5 cm to 7 cm × 5 cm. Results. One patient developed partial flap necrosis, which was managed with skin grafting. Two patients developed venous congestion, which subsided spontaneously without complications. Small wound dehiscence was present in one patient. Donor site was closed primarily in all patients. Rest of the flaps survived well with good aesthetic results. Conclusion. The perforator-based propeller flap for distal leg and ankle defects is a good option. This flap design is safe and reliable in achieving goals of reconstruction. The technique is convenient, less time consuming, and with minimal donor site morbidity. It provides aesthetically good result. PMID:22567253

  2. The angel flap for nipple reconstruction

    PubMed Central

    Wong, Wendy W; Hiersche, Matthew A; Martin, Mark C

    2013-01-01

    Creation of an aesthetically pleasing nipple plays a significant role in breast reconstruction as a determining factor in patient satisfaction. The goals for nipple reconstruction include minimal donor site morbidity and appropriate, long-lasting projection. Currently, the most popular techniques used are associated with a significant loss of projection postoperatively. Accordingly, the authors introduce the angel flap, which is designed to achieve nipple projection with lasting results. The lateral edges of the flap and the area surrounding the top of the nipple are de-epithelialized and the flaps are wrapped to create a nipple mound composed primarily of dermis. Decreasing the amount of fat within core of the nipple and enhancing dermal content promotes long-lasting projection. Furthermore, the incision pattern fits within a desired areolar size, preventing unnecessary superfluous extension of the incisions. Thus, the technique described herein achieves the goals of nipple reconstruction, including adequate and long-lasting projection, without extension of the lateral limb scars. PMID:24431944

  3. Abdominal perforator vs. muscle sparing flaps for breast reconstruction

    PubMed Central

    Wu, Liza C.

    2015-01-01

    Abdominally based free flaps have become the mainstay for women that desire to use their own tissue as a means of breast reconstruction after mastectomy. As the techniques have evolved, significant effort has been invested in finding the best means of minimizing morbidity to the abdominal donor site while ensuring a viable reconstructed breast that is aesthetically pleasing. This manuscript reviews and compares the muscle sparing free transverse rectus abdominis myocutaneous (MsfTRAM), the deep inferior epigastric artery perforator (DIEP), and the superficial inferior epigastric artery (SIEA) flaps, regarding flap success rate, operative times, abdominal donor site morbidity and residual functionality, hospital lengths of stay and associated costs, impact of co-morbid conditions, and resilience after adjuvant radiation treatment. PMID:26161306

  4. Abdominal perforator vs. muscle sparing flaps for breast reconstruction.

    PubMed

    Butler, Paris D; Wu, Liza C

    2015-06-01

    Abdominally based free flaps have become the mainstay for women that desire to use their own tissue as a means of breast reconstruction after mastectomy. As the techniques have evolved, significant effort has been invested in finding the best means of minimizing morbidity to the abdominal donor site while ensuring a viable reconstructed breast that is aesthetically pleasing. This manuscript reviews and compares the muscle sparing free transverse rectus abdominis myocutaneous (MsfTRAM), the deep inferior epigastric artery perforator (DIEP), and the superficial inferior epigastric artery (SIEA) flaps, regarding flap success rate, operative times, abdominal donor site morbidity and residual functionality, hospital lengths of stay and associated costs, impact of co-morbid conditions, and resilience after adjuvant radiation treatment. PMID:26161306

  5. Bowel obstruction following deep circumflex iliac artery free flap harvesting.

    PubMed

    Tan, Neil C-W; Brennan, Peter A; Senapati, Asha; Puxeddu, Roberto

    2009-12-01

    The deep circumflex iliac artery flap (DCIA) has been well described as an autograft flap used in head and neck reconstructions, particularly for large maxillary and mandibular defects. Complications, particularly at the donor site, have been well documented. Although it is considered a minor complication, herniation should not be underestimated as it can potentially lead to bowel obstruction, necessitating an emergency operation. We report a case of acute obstruction of the small bowel secondary to herniation at the donor site after harvesting a DCIA free flap for a maxillary defect, a complication that to our knowledge has been reported only once. We review the pathogenesis and possible ways to reduce the likelihood of developing this serious complication. PMID:19249144

  6. The submental flap for oral cavity reconstruction: Extended indications and technical refinements

    PubMed Central

    2011-01-01

    Background and purpose The submental flap is gaining popularity as a simple technique for reconstruction of small to moderate size defects of the oral cavity. However, its role in composite defects involving the jaw is not clearly defined. Indeed, controversy exists about the flap's interference with an oncologically sound neck dissection Patients and Methods A total of 21 patients with oral cavity cancers over a three year period were included. All patients underwent surgical resection and immediate reconstruction with submental flap except one patient who had delayed reconstruction with reversed flap. The flap was used for reconstruction of intra-oral soft tissue defect in 13 patients and composite defects in 8 patients. Results Of 21 patients 12 were males and 9 were females, age ranged from 32 to 83 years. The primary tumor sites included buccal mucosa (7), tongue (4), alveolar margin (3), floor of mouth (5) and lip (2). Eventually in this study, we adopted completing the neck dissection first before flap harvest. Complete flap loss occurred in 2 whereas 3 patients had partial flap loss. Follow up ranged from 3 to 44 months, one patient died from metastatic disease. Four patients developed neck recurrences. Conclusion The submental flap is a valid option for reconstruction of intra-oral soft tissue as well as composite oral defects particularly in elderly patients. However, oncologically sound neck dissection should be assured. PMID:22185515

  7. Dorsal Intercostal Artery Perforator Propeller Flaps: A Reliable Option in Reconstruction of Large Meningomyelocele Defects.

    PubMed

    Basterzi, Yavuz; Tenekeci, Goktekin

    2016-04-01

    Several options have been reported for the reconstruction of myelomeningocele defects. In this article, we present our experience on soft tissue reconstruction of myelomeningocele defects by using island propeller dorsal intercostal artery perforator (DIAP) flaps. Between January 2008 and February 2014, all newborns with large myelomeningocele defects (13 newborns) were reconstructed with island propeller DIAP flaps. All flaps survived completely. In 8 patients out of 13, venous insufficiency was observed which then resolved spontaneously. Flap donor sites were closed primarily. Myelomeningocele defects with a diameter larger than 5 cm require reconstruction with flaps. To mobilize a well-vascularized tissue over the defect without tension in which the suture lines will not overlap over the midline where the dura is repaired and over the meninges is one of the goals of reconstruction for such defects. Perforator propeller flaps enable us to reach those goals. Use of perforator flaps provides 2 important advantages, namely, more predictability and also more freedom in mobilizing flaps toward the defect. This study proves the reliability of DIAP propeller flaps in the reconstruction of myelomeningocele defects. PMID:26010351

  8. Pedicled TRAM Flap in Presence of Desmoid Tumor of the Rectus Sheath; a Case Report.

    PubMed

    Khater, Ashraf

    2015-12-01

    Creating TRAM flap in obese patient is a challenging issue with a hazard of flap ischemia and breast envelope loss or sepsis. In this case we show our experience in doing an interval TRAM flap in markedly obese patient (BMI index 39) in the presence of Desmoid tumor of the anterior abdominal wall on top of previous mesh hernioplasty in the contralateral side of the tumor. Interval TRAM was decided with achieving of a complete vascular delay in the same sitting with skin sparing mastectomy. On doing abdominal ultrasonography for perforator mapping a desmoid tumor was encountered in the contralateral side. The decision was to elevate the flap together with excision of the desmoid tumor with the flap to be sutured in situ at the end of operation and after 5 days to transfer the flap to the mastectomy site. There was no major complications apart from mild wound sepsis of the breast pocket that was controlled medically. According to our proposed aesthetical score, our patient expressed the outcome as good (8/10 points). Pedicled TRAM flap creation in markedly obese patients is hazardous and we recommend this new concept of interval TRAM for this situation. Moreover the presence of desmoid tumor in the rectus sheath is not a contraindication to this flap elevation. The presence of abdominal desmoid tumor is not a contraindication for TRAM flap provided that it can be resected with sparing of perforators on one side of the rectus sheath. PMID:27065672

  9. Active Sites Environmental Monitoring Program FY 1996 annual report

    SciTech Connect

    Morrissey, C.M.; Marshall, D.S.; Cunningham, G.R.

    1997-11-01

    This report summarizes the activities of the Active Sites Environmental Monitoring Program (ASEMP) from October 1995 through September 1996. The Radioactive Solid Waste Operations Group (RSWOG) of the Waste Management and Remedial Action Division (WMRAD) and the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) established ASEMP in 1989. The purpose of the program is to provide early detection and performance monitoring at active low-level waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 North as required by Chapters 2 and 3 of US Department of Energy Order 5820.2A.

  10. Active sites environmental monitoring Program - Program Plan: Revision 2

    SciTech Connect

    Morrissey, C.M.; Hicks, D.S.; Ashwood, T.L.; Cunningham, G.R.

    1994-05-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of active low-level-waste (LLW) and transuranic (TRU) waste facilities at Oak Ridge National Laboratory (ORNL). Several changes have recently occurred in regard to the sites that are currently used for waste storage and disposal. These changes require a second set of revisions to the ASEMP program plan. This document incorporates those revisions. This program plan presents the organization and procedures for monitoring the active sites. The program plan also provides internal reporting levels to guide the evaluation of monitoring results.

  11. Edmund Prince Fowler Award Thesis. Evaluation of random skin flap survival in a porcine model.

    PubMed

    Pratt, M F

    1996-06-01

    The pathophysiology of random skin flap necrosis in the pig model was studied the effects of several drugs on skin flap survival were examined. The investigated drugs included acetylsalicylic acid (ASA), pentoxifylline (PTX), prostaglandin E2 (PGE2), and an experimental 21-aminosteroid, U-74389G. Each drug altered different parameters known to be associated with tissue necrosis. Demonstrated mechanisms of skin flap failure included the alteration of erythrocyte flexibility and platelet function and the activation of neutrophils with resultant accumulation of damaging oxygen-free radicals. Random skin flap survival did not improve with ASA but did improve significantly with PTX, PGE2, and U-74389G. The results of this study underscore the importance of neutrophil-mediated necrosis in the pathophysiology of skin flap failure. The data further demonstrate the need to develop drugs aimed at reversing or preventing the tissue damage from oxygen-free radicals in order to enhance the survival of random skin flaps. PMID:8656954

  12. Effects of calcitriol on random skin flap survival in rats.

    PubMed

    Zhou, Kai-liang; Zhang, Yi-hui; Lin, Ding-sheng; Tao, Xian-yao; Xu, Hua-zi

    2016-01-01

    Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. "McFarlane flap" models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 μg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1β and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy. PMID:26732750

  13. Traumatic flap dislocation 10 years after LASIK. Case report and literature review.

    PubMed

    Khoueir, Z; Haddad, N M; Saad, A; Chelala, E; Warrak, E

    2013-01-01

    We report a case of traumatic partial flap dislocation 10 years after uneventful laser in situ keratomileusis (LASIK). The patient was treated bilaterally for hyperopia and astigmatism with LASIK. A superior-hinged corneal flap was created using the Moria M2 microkeratome (Moria SA, Antony, France) and the surgery was uneventful. Ten years later, partial flap dislocation was diagnosed after mild trauma. This case suggests that flap dislocations can occur during recreational activities up to 10 years after surgery. Full visual recovery is achievable if the case is managed promptly. Further studies should evaluate the potential protective role of an inferior hinge during LASIK. PMID:23219507

  14. The active site behaviour of electrochemically synthesised gold nanomaterials.

    PubMed

    Plowman, Blake J; O'Mullane, Anthony P; Bhargava, Suresh K

    2011-01-01

    Even though gold is the noblest of metals, a weak chemisorber and is regarded as being quite inert, it demonstrates significant electrocatalytic activity in its nanostructured form. It is demonstrated here that nanostructured and even evaporated thin films of gold are covered with active sites which are responsible for such activity. The identification of these sites is demonstrated with conventional electrochemical techniques such as cyclic voltammetry as well as a large amplitude Fourier transformed alternating current (FT-ac) method under acidic and alkaline conditions. The latter technique is beneficial in determining if an electrode process is either Faradaic or capacitive in nature. The observed behaviour is analogous to that observed for activated gold electrodes whose surfaces have been severely disrupted by cathodic polarisation in the hydrogen evolution region. It is shown that significant electrochemical oxidation responses occur at discrete potential values well below that for the formation of the compact monolayer oxide of bulk gold and are attributed to the facile oxidation of surface active sites. Several electrocatalytic reactions are explored in which the onset potential is determined by the presence of such sites on the surface. Significantly, the facile oxidation of active sites is used to drive the electroless deposition of metals such as platinum, palladium and silver from their aqueous salts on the surface of gold nanostructures. The resultant surface decoration of gold with secondary metal nanoparticles not only indicates regions on the surface which are rich in active sites but also provides a method to form interesting bimetallic surfaces. PMID:22455038

  15. Nicotinamide Cofactors Suppress Active-Site Labeling of Aldehyde Dehydrogenases.

    PubMed

    Stiti, Naim; Chandrasekar, Balakumaran; Strubl, Laura; Mohammed, Shabaz; Bartels, Dorothea; van der Hoorn, Renier A L

    2016-06-17

    Active site labeling by (re)activity-based probes is a powerful chemical proteomic tool to globally map active sites in native proteomes without using substrates. Active site labeling is usually taken as a readout for the active state of the enzyme because labeling reflects the availability and reactivity of active sites, which are hallmarks for enzyme activities. Here, we show that this relationship holds tightly, but we also reveal an important exception to this rule. Labeling of Arabidopsis ALDH3H1 with a chloroacetamide probe occurs at the catalytic Cys, and labeling is suppressed upon nitrosylation and oxidation, and upon treatment with other Cys modifiers. These experiments display a consistent and strong correlation between active site labeling and enzymatic activity. Surprisingly, however, labeling is suppressed by the cofactor NAD(+), and this property is shared with other members of the ALDH superfamily and also detected for unrelated GAPDH enzymes with an unrelated hydantoin-based probe in crude extracts of plant cell cultures. Suppression requires cofactor binding to its binding pocket. Labeling is also suppressed by ALDH modulators that bind at the substrate entrance tunnel, confirming that labeling occurs through the substrate-binding cavity. Our data indicate that cofactor binding adjusts the catalytic Cys into a conformation that reduces the reactivity toward chloroacetamide probes. PMID:26990764

  16. Flap Edge Noise Reduction Fins

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R. (Inventor); Choudhan, Meelan M. (Inventor)

    2015-01-01

    A flap of the type that is movably connected to an aircraft wing to provide control of an aircraft in flight includes opposite ends, wherein at least a first opposite end includes a plurality of substantially rigid, laterally extending protrusions that are spaced apart to form a plurality of fluidly interconnected passageways. The passageways have openings adjacent to upper and lower sides of the flap, and the passageways include a plurality of bends such that high pressure fluid flows from a high pressure region to a low pressure region to provide a boundary condition that inhibits noise resulting from airflow around the end of the flap.

  17. Dancing girl flap: a new flap suitable for web release.

    PubMed

    Shinya, K

    1999-12-01

    To create a deep web, a flap must be designed to have a high elongation effect in one direction along the mid-lateral line of the finger and also to have a shortening effect in the other direction, crossing at a right angle to the mid-lateral line. The dancing girl flap is a modification of a four-flap Z-plasty with two additional Z-plasties. It has a high elongation effect in one direction (>550%) and a shortening effect in the other direction at a right angle (<33%), creating a deep, U-shaped surface. This new flap can be used to release severe scar contracture with a web, and is most suitable for incomplete syndactyly with webs as high as the proximal interphalangeal joint. PMID:10597822

  18. Keystone Flap: Versatile Flap for Reconstruction of Limb Defects

    PubMed Central

    Janna, Rakesh K.

    2015-01-01

    Background: There is always a constant search for a new solution to tackle defects in the limbs. The technique has to be simple, easily reproducible and performed within a short duration. The answer is keystone island flap keystone flap is a simple, less time consuming, durable and easily reproducible option to reconstruct most of the limb defects. Aim: The aim of this article is to study the usefulness of keystone flap in reconstruction of various upper and lower limb defects. Materials and Methods: This retrospective review involves study of 20 patients undergoing keystone flap reconstruction for various defects from 2012 to 2014. Patient demographic data, medical histories, comorbidities, surgical indications, defect characteristics and locations, hospitalization, complications and follow-up were evaluated and are presented as uncontrolled case series. Results: Ages of the patients were ranging from 18 to 65 y with an average of 38.75y. Among the defects, 10 were following trauma (50%), 5 were due to tumour resection (25%), 3 followed debridement of abscess (15%) and another 2 defects were due to surgical wound dehiscence (10%). The largest defect covered by this flap in our study measured 45 x 18 cm and the smallest defect was 8 x4 cm. The average intra-operative time was 45.5 min (range 20-90 min). Fourteen flaps were done to cover lower limb defects (70%), 4 for upper limb defects and 2 were for defects in the axilla. Partial flap necrosis was observed in one case. The average duration of hospital stay of patients was 3.45 d. All patients were followed until they achieved stable, healed wound.The overall success rate was 95%. Conclusion: Keystone flap can be safely used to cover various limb defects with minimal pain, a sensate cover and excellent cosmetic outcome, minimizing the need for microsurgical techniques or prolonged operative time. PMID:25954659

  19. Active site - a site of binding of affinity inhibitors in baker's yeast inorganic pyrophosphatase

    SciTech Connect

    Svyato, I.E.; Sklyankina, V.A.; Avaeva, S.M.

    1986-03-20

    The interaction of the enzyme-substrate complex with methyl phosphate, O-phosphoethanolamine, O-phosphopropanolamine, N-acetylphosphoserine, and phosphoglyolic acid, as well as pyrophosphatase, modified by monoesters of phosphoric acid, with pyrophosphate and tripolyphosphate, was investigated. It was shown that the enzyme containing the substrate in the active site does not react with monophosphates, but modified pyrophosphatase entirely retains the ability to bind polyanions to the regulatory site. It is concluded that the inactivation of baker's yeast inorganic pyrophosphatase by monoesters of phosphoric acid, which are affinity inhibitors of it, is the result of modification of the active site of the enzyme.

  20. Scapular Tip Free Flap for Head and Neck Reconstruction

    PubMed Central

    Choi, Nayeon; Cho, Jae-Keun; Jang, Jeon Yeob; Cho, Jung Kyu; Cho, Young Sang

    2015-01-01

    Objectives Head and neck reconstruction is still challenging in terms of esthetic and functional outcomes. This study investigated the feasibility of the angular branch-based scapular tip free flap (STFF). Methods This was a retrospective study of 17 patients undergoing maxillectomy and mandibulectomy and either primary or secondary reconstruction by STFF. This study included surgical, esthetic, and functional outcomes, and detailed data are presented regarding the flap, such as pedicle length, size of the harvested bone, and failure rate. Medical photographs were used to estimate the esthetic outcome, and computed tomography was used to check the flap status postoperatively. Results The data were collected from April 2013 to April 2014. Eight patients underwent maxillary reconstruction, and nine underwent mandibular reconstruction. Maxillary defects usually included unilateral alveolar structures and the palate; mandibular defects were usually those involving mandibular angle and short segment. Vein grafting was not required in any of the patients. Flap failure occurred in one of the 17 patients (5.9%) with successful reconstruction after revision. Of the eight maxillectomy patients, orbital revisions for diplopia after maxillary reconstruction were performed in two patients (25%), and oroantral fistula repair was performed in one patient (12.5%). Conclusion This study demonstrated the reconstructive advantages of the angular branch-based STFF, long pedicle, low flap failure, 3-dimensional nature of bone and soft tissues (chimeric flap), and small rate of donor site morbidity with free ambulation. This flap is an excellent option for use in complex three-dimensional head and neck reconstruction. PMID:26622965

  1. A small ribozyme with dual-site kinase activity

    PubMed Central

    Biondi, Elisa; Maxwell, Adam W.R.; Burke, Donald H.

    2012-01-01

    Phosphoryl transfer onto backbone hydroxyls is a recognized catalytic activity of nucleic acids. We find that kinase ribozyme K28 possesses an unusually complex active site that promotes (thio)phosphorylation of two residues widely separated in primary sequence. After allowing the ribozyme to radiolabel itself by phosphoryl transfer from [γ-32P]GTP, DNAzyme-mediated cleavage yielded two radiolabeled cleavage fragments, indicating phosphorylation sites within each of the two cleavage fragments. These sites were mapped by alkaline digestion and primer extension pausing. Enzymatic digestion and mutational analysis identified nucleotides important for activity and established the active structure as being a constrained pseudoknot with unusual connectivity that may juxtapose the two reactive sites. Nuclease sensitivities for nucleotides near the pseudoknot core were altered in the presence of GTPγS, indicating donor-induced folding. The 5′ target site was more strongly favored in full-length ribozyme K28 (128 nt) than in truncated RNAs (58 nt). Electrophoretic mobilities of self-thiophosphorylated products on organomercurial gels are distinct from the 5′ mono-thiophosphorylated product produced by reaction with polynucleotide kinase, potentially indicating simultaneous labeling of both sites within individual RNA strands. Our evidence supports a single, compact structure with local dynamics, rather than global rearrangement, as being responsible for dual-site phosphorylation. PMID:22618879

  2. Flap monitoring using infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Keller, Alex; Wright, Leigh P.; Elmandjra, Mohamed; Mao, Jian-min

    2006-02-01

    We report results of clinical trials on flap monitoring in 65 plastic surgeries. Hemoglobin oxygen saturation of flap tissue (StO II) was monitored non-invasively by using ODISsey TM tissue oximeter, an infrared spectroscopic device. StO II measurements were conducted both intra-operatively and post-operatively. From the intra-operative measurements, we observed that StO II values dropped when the main blood vessels supplying the flap were clamped in surgery, and that StO II jumped after anastomosis to a value close to its pre-operative value. From post-operative monitoring measurements for the 65 flap cases, each lasted two days or so, we found that the StO II values approach to a level close to the baseline if the surgery was successful, and that the StO II value dropped to a value below 30% if there is a perfusion compromise, such as vascular thrombosis.

  3. Managing Flap Vortices via Separation Control

    NASA Technical Reports Server (NTRS)

    Greenblatt, David

    2006-01-01

    A pilot study was conducted on a flapped semi-span model to investigate the concept and viability of near-wake vortex management by means of boundary layer separation control. Passive control was achieved using a simple fairing and active control was achieved via zero mass-flux blowing slots. Vortex sheet strength, estimated by integrating surface pressures, was used to predict vortex characteristics based on inviscid rollup relations and vortices trailing the flaps were mapped using a seven-hole probe. Separation control was found to have a marked effect on vortex location, strength, tangential velocity, axial velocity and size over a wide range of angles of attack and control conditions. In general, the vortex trends were well predicted by the inviscid rollup relations. Manipulation of the separated flow near the flap edges exerted significant control over either outboard or inboard edge vortices while producing small lift and moment excursions. Unsteady surface pressures indicated that dynamic separation and attachment control can be exploited to perturb vortices at wavelengths shorter than a typical wingspan. In summary, separation control has the potential for application to time-independent or time-dependent wake alleviation schemes, where the latter can be deployed to minimize adverse effects on ride-quality and dynamic structural loading.

  4. Full scale upper surface blown flap noise

    NASA Technical Reports Server (NTRS)

    Heidelberg, L. J.; Homyak, L.; Jones, W. L.

    1975-01-01

    A highly noise suppressed TF 34 engine was used to investigate the noise of several powered lift configurations involving upper surface blown (USB) flaps. The configuration variables were nozzle type (i.e. slot and circular with deflector), flap chord length, and flap angle. The results of velocity surveys at both the nozzle exit and the flap trailing edge are also presented and used for correlation of the noise data. Configurations using a long flap design were 4 db quieter than a short flap typical of current trends in USB flap design. The lower noise for the long flap is attributed primarily to the greater velocity decay of the jet at the flap trailing edge. The full-scale data revealed substantially more quadrupole noise in the region near the deflected jet than observed in previous sub-scale tests.

  5. Perforator Flaps in Head and Neck Reconstruction

    PubMed Central

    Chana, Jagdeep S.; Odili, Joy

    2010-01-01

    Free tissue transfer has revolutionized the management of complex head and neck defects. Perforator flaps represent the most recent advance in the development of free flap surgery. These flaps are based on perforating vessels and can be harvested without significant damage to associated muscles, thereby reducing the postoperative morbidity associated with muscle-based flaps. Elevation of perforator flaps requires meticulous technique and can be more challenging than raising muscle-based flaps. Use of a Doppler device enables reliable identification of the perforating vessels and aids in the design of free-style free flaps, where the flaps are designed purely according to the perforator located. The major advantage of free-style free flaps is that an unlimited number of flaps can potentially be designed on much shorter pedicles. The anterolateral thigh flap is the most commonly used perforator flap in head and neck reconstruction. Its use is described in detail, as is use of other less common perforator flaps. This article also describes head and neck reconstruction in a region-specific manner and gives a short-list of suitable flaps based on the location of the defect. PMID:22550446

  6. Dashboard applications to monitor experiment activities at sites

    NASA Astrophysics Data System (ADS)

    Andreeva, Julia; Belforte, Stefano; Boehm, Max; Casajus, Adrian; Flix, Josep; Gaidioz, Benjamin; Grigoras, Costin; Kokoszkiewicz, Lukasz; Lanciotti, Elisa; Rocha, Ricardo; Saiz, Pablo; Santinelli, Roberto; Sidorova, Irina; Sciabà, Andrea; Tsaregorodtsev, Andrei

    2010-04-01

    In the framework of a distributed computing environment, such as WLCG, monitoring has a key role in order to keep under control activities going on in sites located in different countries and involving people based in many different sites. To be able to cope with such a large scale heterogeneous infrastructure, it is necessary to have monitoring tools providing a complete and reliable view of the overall performance of the sites. Moreover, the structure of a monitoring system critically depends on the object to monitor and on the users it is addressed to. In this article we will describe two different monitoring systems both aimed to monitor activities and services provided in the WLCG framework, but designed in order to meet the requirements of different users: Site Status Board has an overall view of the services available in all the sites supporting an experiment, whereas Siteview provides a complete view of all the activities going on at a site, for all the experiments supported by the site.

  7. Architecture and active site of particulate methane monooxygenase

    PubMed Central

    Culpepper, Megen A.; Rosenzweig, Amy C.

    2012-01-01

    Particulate methane monooxygenase (pMMO) is an integral membrane metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria, organisms that live on methane gas as their sole carbon source. Understanding pMMO function has important implications for bioremediation applications and for the development of new, environmentally friendly catalysts for the direct conversion of methane to methanol. Crystal structures of pMMOs from three different methanotrophs reveal a trimeric architecture, consisting of three copies each of the pmoB, pmoA, and pmoC subunits. There are three distinct metal centers in each protomer of the trimer, mononuclear and dinuclear copper sites in the periplasmic regions of pmoB and a mononuclear site within the membrane that can be occupied by copper or zinc. Various models for the pMMO active site have been proposed within these structural constraints, including dicopper, tricopper, and diiron centers. Biochemical and spectroscopic data on pMMO and recombinant soluble fragments, denoted spmoB proteins, indicate that the active site involves copper and is located at the site of the dicopper center in the pmoB subunit. Initial spectroscopic evidence for O2 binding at this site has been obtained. Despite these findings, questions remain about the active site identity and nuclearity and will be the focus of future studies. PMID:22725967

  8. Successful reconstruction of irradiated anterior skull base defect using the dual flap technique involving local pericranial flap and radial forearm free flap.

    PubMed

    Yeo, In Sung; Kim, Se-Hyuk; Park, Myong Chul; Lim, Hyoseob; Kim, Joo Hyoung; Lee, Il Jae

    2014-07-01

    Skull base reconstruction presents a challenging therapeutic problem requiring a multispecialty surgical approach and close cooperation between the neurosurgeon, head and neck surgeon, as well as plastic and reconstructive surgeon during all stages of treatment. The principal goal of skull base reconstruction is to separate the intracranial space from the nasopharyngeal and oropharyngeal cavities, creating support for the brain and providing a water-tight barrier against cerebrospinal fluid leakage and ascending infection. We present a case involving a 58-year-old man with anterior skull base defects (2.5 cm × 3 cm) secondary to the removal of olfactory neuroblastoma. The patient received conventional radiation therapy at 6000 cGy in 30 fractions approximately a month before tumor removal. The patient had radiation therapy before surgery and was planned to have postoperative radiation therapy, which would lead to a higher complication rate of reconstruction. Artificial dura was used for the packing of the dural defect, which was also suspected to increase the complication rate of reconstruction. For these reasons, we chose to apply the dual flap technique, which uses both local pericranial flap and de-epithelized radial forearm free flap for anterior skull base defect to promote wound healing. During 28 months of follow-up after coverage of the anterior skull base defect, the dual flap survived completely, as confirmed through follow-up magnetic resonance imaging. The patient was free of cerebrospinal fluid leakage, meningitis, and abscess, and there was minimal donor-site morbidity of the radial forearm free flap. Reconstruction of anterior skull base defects using the dual flap technique is safe, reliable, and associated with low morbidity, and it is ideal for irradiated wounds and low-volume defects. PMID:24902109

  9. Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site.

    PubMed

    Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

    2016-04-20

    Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2domains reveal that the (HhH)2domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide. PMID:26908655

  10. Methanopyrus kandleri topoisomerase V contains three distinct AP lyase active sites in addition to the topoisomerase active site

    PubMed Central

    Rajan, Rakhi; Osterman, Amy; Mondragón, Alfonso

    2016-01-01

    Topoisomerase V (Topo-V) is the only topoisomerase with both topoisomerase and DNA repair activities. The topoisomerase activity is conferred by a small alpha-helical domain, whereas the AP lyase activity is found in a region formed by 12 tandem helix-hairpin-helix ((HhH)2) domains. Although it was known that Topo-V has multiple repair sites, only one had been mapped. Here, we show that Topo-V has three AP lyase sites. The atomic structure and Small Angle X-ray Scattering studies of a 97 kDa fragment spanning the topoisomerase and 10 (HhH)2 domains reveal that the (HhH)2 domains extend away from the topoisomerase domain. A combination of biochemical and structural observations allow the mapping of the second repair site to the junction of the 9th and 10th (HhH)2 domains. The second site is structurally similar to the first one and to the sites found in other AP lyases. The 3rd AP lyase site is located in the 12th (HhH)2 domain. The results show that Topo-V is an unusual protein: it is the only known protein with more than one (HhH)2 domain, the only known topoisomerase with dual activities and is also unique by having three AP lyase repair sites in the same polypeptide. PMID:26908655

  11. A Novel Endoscopic-Assisted Harvesting of Pedicled Freestyle Fasciocutaneous Flaps

    PubMed Central

    Huang, Jen-Wu; Lin, Yi-Ying; Wu, Nai-Yuan; Yen, David Hung-Tsang

    2015-01-01

    Abstract The endoscopy-assisted technique has been demonstrated in harvesting muscle flaps; however, for pedicled freestyle fasciocutaneous flaps, few studies have applied this technique. We present a surgical procedure utilizing endoscopic-assisted method to identify the perforators of pedicled freestyle fasciocutaneous flaps for the reconstruction of soft tissue defects. From August to December 2012, 9 consecutive patients underwent endoscopic-assisted harvesting of fasciocutaneous flaps for the reconstruction of soft tissue defects. All of the defects were caused by trauma with tendon or bone exposure. Postoperatively, all patients were requested to return for outpatient follow-up visits for at least 3 months. The age of the 9 patients (8 men and 1 woman) ranged from 20 to 79 years (median 59 years). The defects ranged in size from 2 × 2 to 6 × 8 cm2. Two patients received anterolateral thigh transmuscular perforator flaps, 5 patients received fibular septocutaneous perforator flaps, and 2 patients received medial gastrocnemius transmuscular perforator flaps. The median incision length was 10 cm, and the median operative time was 120 minutes. None of the patients had intraoperative complications, and intraoperative bleeding was minimal (<50 mL). At the end of the 3-month follow-up period, none of the patients had any complications on either recipient or donor site, including total or partial necrosis of the flaps, flap dehiscence, hematomas, seromas, wound infections, or any conditions that indicated additional unplanned operative procedures. All of the patients had surviving flaps. Our results demonstrated that the endoscopic-assisted method could be a valuable and reliable alternative in harvesting pedicled freestyle fasciocutaneous flaps. PMID:25715266

  12. The Role of Muscle Flaps for Salvage of Failed Perforator Free Flaps

    PubMed Central

    2015-01-01

    Background: Despite the most heroic efforts, sometimes free flaps fail. Perforator free flaps are not invincible and can suffer the same fate. The real challenge is how to decide what is the next best choice for achieving the desired outcome. Methods: Over the past decade, 298 free perforator flaps were used in our institution. Total failure occurred in 16 patients, and partial failure requiring a second free flap occurred in an additional 6 patients for a true success rate of 93%. All failures had some form of secondary vascularized tissue transfer, which included the use of muscle flaps in 9 (41%) different patients. Results: Initial flap salvage after a failed perforator free flap was attempted with 12 perforator and 5 muscle free flaps as well as 1 perforator and 2 muscle local flaps. These were not all successful, with loss of 3 muscle free flaps and 3 perforator flaps. Tertiary free flap coverage was successful in 3 cases using 2 muscle flaps and 1 perforator free flap. Local fasciocutaneous flaps or primary wound closure was used in the remaining individuals. Conclusions: Microsurgical tissue transfers can be the most rewarding and at the same time the most challenging reconstructive endeavor. Persistence in achieving the desired outcome can require multiple steps. Perforator flaps are an important asset to obtain this goal. However, muscle flaps can still be a useful alternative, and the message is that they should not be overlooked as sometimes a viable option. PMID:26893989

  13. Latissimus dorsi pedicle flap for coverage of soft tissue defects about the elbow.

    PubMed

    Stevanovic, M; Sharpe, F; Thommen, V D; Itamura, J M; Schnall, S B

    1999-01-01

    Sixteen consecutive patients who were treated with a pedicled latissimus dorsi flap for complex soft tissue defects about the elbow were reviewed. The average defect size was 100 cm2. Thirteen of the 16 patients achieved stable wound healing with a single procedure. Three patients had partial necrosis of the latissimus and required additional coverage procedures. We recommend that the latissimus dorsi flap should not be routinely used to cover defects more than 8 cm distal to the olecranon. The flap should be closely monitored in the first 48 hours, drains should be routinely used at the recipient and donor sites, and the elbow should be maintained in an extended position for the first 5 days after the procedure. The latissimus dorsi flap may also have a prophylactic role in selected patients with compromised soft tissue coverage about the elbow. The pedicled latissimus flap can be performed under loupe magnification and requires no microsurgical skills or equipment. PMID:10633903

  14. Vaginal reconstruction with pedicled vertical deep inferior epigastric perforator flap (diep) after pelvic exenteration. A consecutive case series.

    PubMed

    Ferron, Gwénael; Gangloff, Dimitri; Querleu, Denis; Frigenza, Melanie; Torrent, Juan Jose; Picaud, Laetitia; Gladieff, Laurence; Delannes, Martine; Mery, Eliane; Boulet, Berenice; Balague, Gisele; Martinez, Alejandra

    2015-09-01

    Vaginal reconstruction after pelvic exenteration (PE) represents a challenge for the oncologic surgeon. Since the introduction of perforator flaps, using pedicled vertical DIEP (deep inferior epigastric perforator) flap allows to reduce the donor site complication rate. From November 2012 to December 2014, 27 PEs were performed in our institution. 13 patients who underwent PE with vaginal reconstruction and programmed DIEP procedure for gynecologic malignancies were registered. Nine patients underwent PE for recurrent disease and four for primary treatment. Six of the 13 patients have a preoperative fistula. Anterior PE was performed in 10 patients, and total PE in 3 patients. A vertical DIEP flap was performed in 10 patients using one or two medial perforators. The reasons for abortion of vertical DIEP flap procedure were: failure to localizing perforator vessels in two cases, and unavailability of plastic surgeon in one case. A vertical fascia-sparring rectus abdominis myocutaneous flap was then harvested. Median length of surgery was 335min, and 60min for DIEP harvesting and vaginal reconstruction. No flap necrosis occurred. One patient in the VRAM (vertical rectus abdominis myocutaneous) group experienced a late incisional hernia and one patient in the DIEP flap group required revision for vaginal stenosis. In our experience, DIEP flap represents our preferred choice of flap for circumferential vaginal reconstruction after PE. To achieve a high reproducibility, the technically demanding pedicled vertical DIEP flap has to be harvested by a trained surgeon, after strict evaluation of the preoperative imaging with identification and localization of perforator vessels. PMID:26121919

  15. A study of the pharmacologic control of blood flow to acute skin flaps using xenon washout. Part I

    SciTech Connect

    Hendel, P.M.; Lilien, D.L.; Buncke, H.J.

    1983-03-01

    This study was undertaken to understand the control mechanisms differentiating circulation to normal skin and acute skin flaps. The approach was to compare the effects of systemic vasoactive drugs on skin blood flow in rats in acute skin flaps and identical areas of control skin. With this model it was felt that systemic changes would affect both areas equally and any difference in response would be due to vascular control mechanisms unique to the flap. Xenon washout by percutaneous injection was chosen to measure blood flow. The results of over 8000 observations in these studies were: 1. Vasodilation enhances blood flow and flap survival. 2. Vasoconstriction decreases blood flow. 3. Depletion of sympathetic nerve terminals enhances blood flow and flap survival. 4. The acute flap is less sensitive to systemic alpha-agonists than control skin. 5. The acute flap is less sensitive to vasodilators acting at the receptor-site level than control skin. 6. Total sympathetic denervation does not occur. 7. Biologic increases in area of flap survival did occur in drug dose ranges predicted by xenon washout measurements in this model. These findings indicate that the vessels in an acutely raised skin flap have a greater vasospastic tone than is optimal for maximum nutrient blood flow. One explanation consistent with these findings is offered in which the mechanism responsible for this tone is the release of catecholamines from the sympathetic nerve terminals after the flap has been raised.

  16. Medial and Lateral Canthal Reconstruction with an Orbicularis Oculi Myocutaneous Island Flap

    PubMed Central

    Han, Jihyeon; Kwon, Sung Tack; Kim, Suk Wha

    2015-01-01

    Background The eyelid and canthal areas are common locations for cutaneous tumors. The medial canthus includes, among many other apparatuses, the canthal tendon and lacrimal canaliculi, and its characteristic thin and supple skin is hard to mimic and restore using tissue from other regions. Accordingly, reconstruction of the canthal area can prove challenging for surgeons. Although various methods, such as skin grafts and local flaps from adjacent regions, have been utilized for reconstructive purposes, they present known disadvantages. However, we were able to successfully reconstruct both lateral and medial canthal area defects by using orbicularis oculi myocutaneous island flaps. Methods Our study included seven patients who underwent medial or lateral canthal region reconstruction, using orbicularis oculi myocutaneous island flaps, between 2011 and 2014, following either cutaneous tumor excision or traumatic avulsion injury. Results Five patients had basal cell carcinoma, one had squamous cell carcinoma of the eyelid, and one had sustained a traumatic avulsion injury of the eyelid and canthal area. Entire flap loss was not observed in any patient, but one-a heavy smoker-showed partial flap loss, which healed with secondary intention and yielded acceptable results. Donor site morbidity was not observed, and all patients were satisfied with their surgical outcomes. Conclusions The canthal regions can be successfully reconstructed with orbicularis oculi myocutaneous island flaps. These flaps offer several key advantages, including similarity in texture, color, and thickness to the recipient site and a negligible incidence of donor site morbidity. PMID:25606488

  17. Cosmetic Tattooing of Free Flaps following Head and Neck Reconstruction

    PubMed Central

    Batstone, Martin D.; Fox, Carly M.; Dingley, Mary E.; Cornelius, C. Peter

    2012-01-01

    Free flap reconstruction of the head and neck is a widespread procedure. The aesthetic outcome is frequently compromised by color mismatch between the donor site skin and the complex pigmentation of the face. Various surgical procedures have been described to improve the appearance of external skin paddles. Medical tattooing is commonly used for nipple pigmentation in breast reconstruction and cosmetic procedures such as permanent makeup. This article describes the technique and its application to head and neck reconstruction. Medical tattooing can be used to improve the cosmetic appearance of head and neck free flaps. There is no donor site morbidity and subtle changes in color can be replicated. The article describes the technique of medical tattooing with the use of illustrative cases. Medical tattooing is a viable alternative for improving the appearance of cutaneous skin paddles following head and neck reconstruction with free flaps. Its advantages include no donor site morbidity, availability of an infinite range of colors, no requirement for general anesthesia, and the ability to use multiple colors in the one flap for complex pigmentation requirements. Its disadvantages include the need for specialized skills and equipment and the fading of color over time. PMID:24436738

  18. Experience in Reconstruction for Small Digital Defects With Free Flaps.

    PubMed

    Hung, Min-Hsiang; Huang, Kuo-Feng; Chiu, Haw-Yen; Chao, Wai-Nang

    2016-03-01

    Traumatic injuries to the digits resulting in soft tissue or bone loss require reconstruction. Traditionally, local flaps, such as homodigital flaps, heterodigital flaps, pedicled flaps, or distant flaps, are used for digital resurfacing. However, free tissue transfers can be used in selected patients. In this study, we present the use of different free flaps including groin skin flaps, groin osteocutaneous flaps, groin chimeric flaps, second dorsal metacarpal artery flaps, and partial toe flaps for digital reconstruction. A total of 19 digits were treated with 16 free flaps in our hospital. Of the flaps used, 5 were free groin skin flaps, 4 were free partial toe flaps, 3 were free groin chimeric flaps, 2 were free groin osteocutaneous flaps, and 2 were free second dorsal metacarpal artery flaps. The average flap size was 4.7 × 2.0 cm (range, 1.5 × 1 to 5 × 4 cm), and the average operative time was 6.0 hours (range, 4-9 hours). All flaps survived without partial or total necrosis. In conclusion, the free flap is a reliable and safe alternative for digital reconstruction. Moreover, the free groin flap provides not only a chimeric pattern for multiple fingers coverage but also an osteocutaneous pattern for thumb lengthening. The free second dorsal metacarpal artery flap provides a tenocutaneous pattern for tendon reconstruction and soft tissue coverage simultaneously, and the free partial toe flap is an excellent alternative for pulp reconstruction in terms of aesthetic appearance and functional outcome. PMID:26808771

  19. Turn over split fascial flap - a refinement for resurfacing shin defect

    PubMed Central

    Bhattacharya, Visweswar; Agrawal, Neeraj K; Chaudhuri, Gaurab R; Barooah, Partha S; SK, Tripathi; Birendra, Rana; Bhattacharya, Siddhartha; Deka, Dhruva J

    2012-01-01

    Moderate size defects of the shin of tibia are frequently encountered following trauma and infection. They may be associated with or without a fracture. Such defects require resurfacing by a flap. Many different types of flaps have been described but most of them proved to be more bulky than desired. Although these procedures cover the defects successfully the results they produce are not aesthetically appropriate. The flap looks bulkier because the native subcutaneous tissue is thin over the shin and distal leg. Hence a search for a vascularized tissue of minimal bulk for suitable resurfacing was initiated. A turnover fascial flap fulfilled the requirement. Such a flap can be made thinner by splitting its distal part into two layers while maintaining a common vascular fascial pedicle with both the layers of the fascia. This allowed a larger surface area to be covered. Such refinement is based on the following parameters (a) fresh cadaveric dissection, (b) demonstration of live microcirculation individually in the superficial and deep layers of the deep fascia and (c) intraoperative flourescein study of the split fascial flap. The technique has been used in 5 cases over the upper and middle third of the shin of tibia. The split fascial flap was turned over and inset in the defect and covered with a split skin graft. The donor site was primarily closed. The functional and aesthetic results were highly satisfactory. The follow up of 18 months proved the durability and usefulness of the flap. PMID:23071906

  20. Treatment of degloving injury involving multiple fingers with combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap

    PubMed Central

    Han, Fengshan; Wang, Guangnan; Li, Gaoshan; Ping, Juan; Mao, Zhi

    2015-01-01

    Background Our aim was to summarize the treatment of degloving injury involving multiple fingers using combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap. Patients and methods Each degloved finger was debrided under microscopic guidance and embedded in the superficial layer of the abdominal fascia. The abdominal skin was sutured to the skin on the back and side of the hand to promote circumferential healing. After removal, the only remaining injured region was on the flexor surface, and this was repaired by multiple dorsal toe flaps, toe-web flaps, and dorsalis pedis flaps to provide blood vessels and sensory nerves. All fingers had proper flap thickness 3–6 months after surgery, and required only lateral Z-plasty modification with web deepening and widening to narrow the fingers and extend their relative length. Results We completed flap-graft and finger narrowing for 25 fingers in eight patients. Abdominal skin flaps and dorsal toe flaps were grafted, and resulted in both firmness and softness, providing finger flexibility. The dorsal toe flap provided good blood circulation and sensory nerves, and was used to cover the finger-flexor surface to regain sensation and stability when holding objects. During the 1–8 years of follow-up, sensation on the finger-flexor side recovered to the S3–4 level, and patient satisfaction based on the Michigan Hand Outcomes Questionnaire was 4–5. Flap ulcers or bone/tendon necrosis were not observed. Conclusion Treatment of degloving injury involving multiple fingers with combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap was effective and reliable. PMID:26229479

  1. PIV Measurements on a Blowing Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  2. Molecular Imprint of Enzyme Active Site by Camel Nanobodies

    PubMed Central

    Li, Jiang-Wei; Xia, Lijie; Su, Youhong; Liu, Hongchun; Xia, Xueqing; Lu, Qinxia; Yang, Chunjin; Reheman, Kalbinur

    2012-01-01

    Screening of inhibitory Ab1 antibodies is a critical step for producing catalytic antibodies in the anti-idiotypic approach. However, the incompatible surface of the active site of the enzyme and the antigen-binding site of heterotetrameric conventional antibodies become the limiting step. Because camelid-derived nanobodies possess the potential to preferentially bind to the active site of enzymes due to their small size and long CDR3, we have developed a novel approach to produce antibodies with alliinase activities by exploiting the molecular mimicry of camel nanobodies. By screening the camelid-derived variable region of the heavy chain cDNA phage display library with alliinase, we obtained an inhibitory nanobody VHHA4 that recognizes the active site. Further screening with VHHA4 from the same variable domain of the heavy chain of a heavy-chain antibody library led to a higher incidence of anti-idiotypic Ab2 abzymes with alliinase activities. One of the abzymes, VHHC10, showed the highest activity that can be inhibited by Ab1 VHHA4 and alliinase competitive inhibitor penicillamine and significantly suppressed the B16 tumor cell growth in the presence of alliin in vitro. The results highlight the feasibility of producing abzymes via anti-idiotypic nanobody approach. PMID:22374998

  3. Active Sites Environmental Monitoring Program: Mid-FY 1991 report

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1991-10-01

    This report summarizes the activities of the Active Sites Environmental Monitoring Program (ASEMP) from October 1990 through March 1991. The ASEMP was established in 1989 by Solid Waste Operations and the Environmental Sciences Division to provide early detection and performance monitoring at active low-level radioactive waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 as required by chapters II and III of US Department of Energy Order 5820.2A. Monitoring results continue to demonstrate the no LLW is being leached from the storage vaults on the tumulus pads. Loading of vaults on Tumulus II began during this reporting period and 115 vaults had been loaded by the end of March 1991.

  4. An active-site peptide from pepsin C

    PubMed Central

    Kay, J.; Ryle, A. P.

    1971-01-01

    Porcine pepsin C is inactivated rapidly and irreversibly by diazoacetyl-dl-norleucine methyl ester in the presence of cupric ions at pH values above 4.5. The inactivation is specific in that complete inactivation accompanies the incorporation of 1mol of inhibitor residue/mol of enzyme and evidence has been obtained to suggest that the reaction occurs with an active site residue. The site of reaction is the β-carboxyl group of an aspartic acid residue in the sequence Ile-Val-Asp-Thr. This sequence is identical with the active-site sequence in pepsin and the significance of this in terms of the different activities of the two enzymes is discussed. PMID:4942834

  5. Wuho Is a New Member in Maintaining Genome Stability through its Interaction with Flap Endonuclease 1

    PubMed Central

    Cheng, I-Cheng; Chen, Betty Chamay; Shuai, Hung-Hsun; Chien, Fan-Ching; Chen, Peilin; Hsieh, Tao-shih

    2016-01-01

    Replication forks are vulnerable to wayward nuclease activities. We report here our discovery of a new member in guarding genome stability at replication forks. We previously isolated a Drosophila mutation, wuho (wh, no progeny), characterized by a severe fertility defect and affecting expression of a protein (WH) in a family of conserved proteins with multiple WD40 repeats. Knockdown of WH by siRNA in Drosophila, mouse, and human cultured cells results in DNA damage with strand breaks and apoptosis through ATM/Chk2/p53 signaling pathway. Mice with mWh knockout are early embryonic lethal and display DNA damage. We identify that the flap endonuclease 1 (FEN1) is one of the interacting proteins. Fluorescence microscopy showed the localization of WH at the site of nascent DNA synthesis along with other replication proteins, including FEN1 and PCNA. We show that WH is able to modulate FEN1’s endonucleolytic activities depending on the substrate DNA structure. The stimulatory or inhibitory effects of WH on FEN1’s flap versus gap endonuclease activities are consistent with the proposed WH’s functions in protecting the integrity of replication fork. These results suggest that wh is a new member of the guardians of genome stability because it regulates FEN1’s potential DNA cleavage threat near the site of replication. PMID:26751069

  6. Active chemisorption sites in functionalized ionic liquids for carbon capture.

    PubMed

    Cui, Guokai; Wang, Jianji; Zhang, Suojiang

    2016-07-25

    Development of novel technologies for the efficient and reversible capture of CO2 is highly desired. In the last decade, CO2 capture using ionic liquids has attracted intensive attention from both academia and industry, and has been recognized as a very promising technology. Recently, a new approach has been developed for highly efficient capture of CO2 by site-containing ionic liquids through chemical interaction. This perspective review focuses on the recent advances in the chemical absorption of CO2 using site-containing ionic liquids, such as amino-based ionic liquids, azolate ionic liquids, phenolate ionic liquids, dual-functionalized ionic liquids, pyridine-containing ionic liquids and so on. Other site-containing liquid absorbents such as amine-based solutions, switchable solvents, and functionalized ionic liquid-amine blends are also investigated. Strategies have been discussed for how to activate the existent reactive sites and develop novel reactive sites by physical and chemical methods to enhance CO2 absorption capacity and reduce absorption enthalpy. The carbon capture mechanisms of these site-containing liquid absorbents are also presented. Particular attention has been paid to the latest progress in CO2 capture in multiple-site interactions by amino-free anion-functionalized ionic liquids. In the last section, future directions and prospects for carbon capture by site-containing ionic liquids are outlined. PMID:27243042

  7. Experimental Study of Wake / Flap Interaction Noise and the Reduction of Flap Side Edge Noise

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.; Plassman, Gerald E.

    2016-01-01

    The effects of the interaction of a wake with a half-span flap on radiated noise are examined. The incident wake is generated by bars of various widths and lengths or by a simplified landing gear model. Single microphone and phased array measurements are used to isolate the effects of the wake interaction on the noise radiating from the flap side edge and flap cove regions. The effects on noise of the wake generator's geometry and relative placement with respect to the flap are assessed. Placement of the wake generators upstream of the flap side edge is shown to lead to the reduction of flap side edge noise by introducing a velocity deficit and likely altering the instabilities in the flap side edge vortex system. Significant reduction in flap side edge noise is achieved with a bar positioned directly upstream of the flap side edge. The noise reduction benefit is seen to improve with increased bar width, length and proximity to the flap edge. Positioning of the landing gear model upstream of the flap side edge also leads to decreased flap side edge noise. In addition, flap cove noise levels are significantly lower than when the landing gear is positioned upstream of the flap mid-span. The impact of the local flow velocity on the noise radiating directly from the landing gear is discussed. The effects of the landing gear side-braces on flap side edge, flap cove and landing gear noise are shown.

  8. The binding landscape of plasmepsin V and the implications for flap dynamics.

    PubMed

    L, McGillewie; Soliman, Mahmoud E

    2016-04-26

    Plasmepsin V belongs to the plasmepsin family of aspartic proteases. PlmV is unique compared to other plasmepsins, as this membrane bound aspartic protease resides in the endoplasmic reticulum and is responsible for the cleavage of PEXEL tagged proteins destined for export outside of the host red blood cell. Plasmepsin V is highly conserved throughout the Plasmodium species, and is essential to the survival of the parasite. Recently, two potent inhibitors of Plmv have been identified, WEHI-916 and WEHI-842. Of these inhibitors, WEHI-842 has a higher binding affinity for P. vivax PlmV, and a crystal structure of PlmV in complex with WEHI-842 has recently been resolved (). The structure of PlmV is unique compared to other plasmepsins; it is stabilised internally by seven disulfide bonds, a NAP1 insert/fold is associated with the movement of the flap covering the active site and a highly conserved helix-turn-helix is situated towards the C-terminus. Flap motion and dynamics play an important role in enzyme selectivity and function. To better understand the impact of ligand binding on the flap dynamics, molecular dynamic simulations and post-dynamic analysis were employed in the present study on PlmV in complex with WEHI-842. Previously defined parameters, which accurately accounted for the opening and closing of the active site, were used to assess the conformational changes induced in the absence and presence of WEHI-842. From the simulations it can be seen that inhibitor binding significantly reduces the flexibility and mobility of not only the flap and flexible loop but areas outside of the active site. Ligand binding leads to the formation of a more stable compact structure. This being said, there is a possibility of reducing the flexibility even further with potentially more lethal effects on the plasmodium parasite. We believe that results presented herein would assist researchers in the discovery of potent PlmV inhibitors as potential antimalarial therapies

  9. Chlorogenic Acid Enhances Abdominal Skin Flap Survival Based on Epigastric Artery in Nondiabetic and Diabetic Rats.

    PubMed

    Bagdas, Deniz; Etoz, Betul Cam; Gul, Zulfiye; Ozyigit, Musa Ozgur; Cinkilic, Nilufer; Inan, Sevda; Buyukcoskun, Naciye Isbil; Ozluk, Kasim; Gurun, Mine Sibel

    2016-08-01

    Previous studies showed that chlorogenic acid (CGA) accelerates wound healing via its antioxidant activity. We aimed to investigate the effect of CGA in an experimental epigastric abdominal skin flap model in nondiabetic and diabetic rats. Rats were firstly divided into 2 groups: nondiabetic and diabetic. Diabetes was induced by streptozotocin. Then, 4 subgroups were created for each group: vehicle as well as 0.2 mg/0.5 mL, 1 mg/0.5 mL, and 5 mg/0.5 mL CGA treatments. Right epigastric artery-based abdominal skin flaps were elevated and sutured back into their original position. Chlorogenic acid or vehicle was injected once into the femoral arteries by leaving the epigastric artery as the single artery feeding the flaps during the injection. On postoperative day 7, flap survivals were evaluated, and the rats were killed. Distal flap tissues were collected for histopathological and biochemical assays. Chlorogenic acid showed greater flap survival in both nondiabetic and diabetic rats. Capillary density was increased, and necrosis was reduced in the CGA-treated rats. Chlorogenic acid decreased malondialdehyde levels as well as increased reduced glutathione and superoxide dismutase levels in the flap tissues. This study showed that CGA significantly improved flap survival by its antioxidant activities with intra-arterial local injections. PMID:25356637

  10. Free thin paraumbilical perforator-based flaps.

    PubMed

    Koshima, I; Moriguchi, T; Soeda, S; Tanaka, H; Umeda, N

    1992-07-01

    A free paraumbilical perforator-based flap fed by a muscle perforator from the inferior deep epigastric artery and with no muscle was used in 13 patients. Among them, a free thin paraumbilical perforator-based flap with a thin layer of fat, to protect the subdermal plexus of the vessels, was used in seven patients. The dominant pedicle perforator of this thin flap is usually located around the umbilicus and a large flap can be obtained. Its critical length-to-breath ratio is considered to be 4:3. The advantages of this flap are a long and large vascular pedicle, rare postoperative abdominal herniation, little bulkiness of the flap, and a relatively large skin territory. The disadvantages are technical difficulties in dissection of the perforator and anatomical variation in the location of the perforator. We believe this flap largely overcomes the problems of the conventional rectus abdominis musculocutaneous flap. PMID:1386718

  11. Rat intestinal trehalase. Studies of the active site.

    PubMed

    Chen, C C; Guo, W J; Isselbacher, K J

    1987-11-01

    Rat intestinal trehalase was solubilized, purified and reconstituted into proteoliposomes. With octyl glucoside as the solubilizing detergent, the purified protein appeared as a single band on SDS/polyacrylamide-gel electrophoresis with an apparent molecular mass of 67 kDa. Kinetic studies indicated that the active site of this enzyme can be functionally divided into two adjacent regions, namely a binding site (with pKa 4.8) and a catalytic site (with pKa 7.2). Other findings suggested that the catalytic site contains a functional thiol group, which is sensitive to inhibition by N-ethylmaleimide, Hg2+ and iodoacetate. Substrate protection and iodoacetate labelling of the thiol group demonstrated that only a protein of 67 kDa was labelled. Furthermore, sucrose and phlorizin protected the thiol group, but Tris-like inhibitors did not. Structure-inhibition analysis of Tris-like inhibitors, the pH effect of Tris inhibition and Tris protection of 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide inactivation permitted characterization and location of a separate site containing a carboxy group for Tris binding, which may also be the binding region. On the basis of these findings, a possible structure for the active site of trehalase is proposed. PMID:3426558

  12. Active Site and Remote Contributions to Catalysis in Methylthioadenosine Nucleosidases

    PubMed Central

    Thomas, Keisha; Cameron, Scott A.; Almo, Steven C.; Burgos, Emmanuel S.; Gulab, Shivali A.; Schramm, Vern L.

    2015-01-01

    5′-Methylthioadenosine/S-adenosyl-L-homocysteine nucleosidases (MTANs) catalyze the hydrolysis of 5′-methylthioadenosine to adenine and 5-methylthioribose. The amino acid sequences of the MTANs from Vibrio cholerae (VcMTAN) and Escherichia coli (EcMTAN) are 60% identical and 75% similar. Protein structure folds and kinetic properties are similar. However, binding of transition-state analogues is dominated by favorable entropy in VcMTAN and by enthalpy in EcMTAN. Catalytic sites of VcMTAN and EcMTAN in contact with reactants differ by two residues; Ala113 and Val153 in VcMTAN are Pro113 and Ile152, respectively, in EcMTAN. We mutated the VcMTAN catalytic site residues to match those of EcMTAN in anticipation of altering its properties toward EcMTAN. Inhibition of VcMTAN by transition-state analogues required filling both active sites of the homodimer. However, in the Val153Ile mutant or double mutants, transition-state analogue binding at one site caused complete inhibition. Therefore, a single amino acid, Val153, alters the catalytic site cooperativity in VcMTAN. The transition-state analogue affinity and thermodynamics in mutant VcMTAN became even more unlike those of EcMTAN, the opposite of expectations from catalytic site similarity; thus, catalytic site contacts in VcMTAN are unable to recapitulate the properties of EcMTAN. X-ray crystal structures of EcMTAN, VcMTAN, and a multiple-site mutant of VcMTAN most closely resembling EcMTAN in catalytic site contacts show no major protein conformational differences. The overall protein architectures of these closely related proteins are implicated in contributing to the catalytic site differences. PMID:25806409

  13. Effects of calcitriol on random skin flap survival in rats

    PubMed Central

    Zhou, Kai-liang; Zhang, Yi-hui; Lin, Ding-sheng; Tao, Xian-yao; Xu, Hua-zi

    2016-01-01

    Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. “McFarlane flap” models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 μg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1β and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy. PMID:26732750

  14. Resonant active sites in catalytic ammonia synthesis: A structural model

    NASA Astrophysics Data System (ADS)

    Cholach, Alexander R.; Bryliakova, Anna A.; Matveev, Andrey V.; Bulgakov, Nikolai N.

    2016-03-01

    Adsorption sites Mn consisted of n adjacent atoms M, each bound to the adsorbed species, are considered within a realistic model. The sum of bonds Σ lost by atoms in a site in comparison with the bulk atoms was used for evaluation of the local surface imperfection, while the reaction enthalpy at that site was used as a measure of activity. The comparative study of Mn sites (n = 1-5) at basal planes of Pt, Rh, Ir, Fe, Re and Ru with respect to heat of N2 dissociative adsorption QN and heat of Nad + Had → NHad reaction QNH was performed using semi-empirical calculations. Linear QN(Σ) increase and QNH(Σ) decrease allowed to specify the resonant Σ for each surface in catalytic ammonia synthesis at equilibrium Nad coverage. Optimal Σ are realizable for Ru2, Re2 and Ir4 only, whereas other centers meet steric inhibition or unreal crystal structure. Relative activity of the most active sites in proportion 5.0 × 10- 5: 4.5 × 10- 3: 1: 2.5: 3.0: 1080: 2270 for a sequence of Pt4, Rh4, Fe4(fcc), Ir4, Fe2-5(bcc), Ru2, Re2, respectively, is in agreement with relevant experimental data. Similar approach can be applied to other adsorption or catalytic processes exhibiting structure sensitivity.

  15. Water in the Active Site of Ketosteroid Isomerase

    PubMed Central

    Hanoian, Philip; Hammes-Schiffer, Sharon

    2011-01-01

    Classical molecular dynamics simulations were utilized to investigate the structural and dynamical properties of water in the active site of ketosteroid isomerase (KSI) to provide insight into the role of these water molecules in the enzyme-catalyzed reaction. This reaction is thought to proceed via a dienolate intermediate that is stabilized by hydrogen bonding with residues Tyr16 and Asp103. A comparative study was performed for the wild-type (WT) KSI and the Y16F, Y16S, and Y16F/Y32F/Y57F (FFF) mutants. These systems were studied with three different bound ligands: equilenin, which is an intermediate analog, and the intermediate states of two steroid substrates. Several distinct water occupation sites were identified in the active site of KSI for the WT and mutant systems. Three additional sites were identified in the Y16S mutant that were not occupied in WT KSI or the other mutants studied. The number of water molecules directly hydrogen bonded to the ligand oxygen was approximately two waters in the Y16S mutant, one water in the Y16F and FFF mutants, and intermittent hydrogen bonding of one water molecule in WT KSI. The molecular dynamics trajectories of the Y16F and FFF mutants reproduced the small conformational changes of residue 16 observed in the crystal structures of these two mutants. Quantum mechanical/molecular mechanical calculations of 1H NMR chemical shifts of the protons in the active site hydrogen-bonding network suggest that the presence of water in the active site does not prevent the formation of short hydrogen bonds with far-downfield chemical shifts. The molecular dynamics simulations indicate that the active site water molecules exchange much more frequently for WT KSI and the FFF mutant than for the Y16F and Y16S mutants. This difference is most likely due to the hydrogen-bonding interaction between Tyr57 and an active site water molecule that is persistent in the Y16F and Y16S mutants but absent in the FFF mutant and significantly less

  16. Novel biogeometric designs of first dorsal metacarpal artery flap in hand reconstruction.

    PubMed

    Doğan, Fatih; Çoruh, Atilla

    2014-01-01

    Reconstruction of the soft tissue defects of the first web space and proximal dorsal thumb is still one of the most challenging problems in reconstructive surgery. Depending on the defect size, various reconstructive methods have been described, including local, regional, distant and free flaps. The authors described new biogeometric designs of first dorsal metacarpal artery flap for the reconstruction of the soft tissue defects of the first web space and the proximal dorsal thumb. These modifications are bilobed and V-Y advancement first dorsal metacarpal artery flaps. Three patients had burn wound adduction contractures of the first web space and three had acute wounds resulting from electrical burns, the defects of which were located on the first web space and on the dorsum of the thumb. The defect sizes ranged from 2.5 × 2 cm to 3.5 × 4 cm, and were reconstructed with the bilobed and V-Y advancement first dorsal metacarpal artery flaps. None of these flap modifications had any problems related to the perfusion of the flap, such as arterial insufficiency or venous congestion. The mean follow-up period was 16 months and all the patients were satisfied with the functional result and the donor site scars appearance. The bilobed and V-Y advancement first dorsal metacarpal artery flaps described by the authors for the hand reconstruction are safe, easily performed, and are versatile without skin grafts at the donor site because of inherent excellent elasticity and mobility of the dorsal hand skin. PMID:25100542

  17. Propeller Flaps and Its Outcomes - A Prospective Study of 15 Cases Over Two-years

    PubMed Central

    K.T., Ramesha; J., Vijay; M., Shankarappa

    2014-01-01

    Introduction: Cover flaps are needed in management of any bodily defect involving bone, tendon, nerve & vessels. The major objective of a plastic surgeon, facing a complex soft-tissue defect, is to replace “like with like” tissues at minimal donor site “cost” and with maximal accuracy & efficacy. Aims: To study the “Propeller Flaps” utility in reconstructive surgeries, evaluate its planning and complications involving donor site morbidity. Methodology: The prospective study was conducted on 15 cases (11 males/4 females) of propeller flaps during the period of two years (2010-12) in Department of Plastic Surgery and Burns, Bangalore Medical College and Research Institute (BMCRI), Karnataka, India. The propeller flaps were performed in cases with defects due to any cause. Exclusion criteria: Cases with Peripheral Vascular Disease (PVD). Flaps were performed and details recorded. Results: Overall results revealed problem resolution in 87% cases (13 cases). Comprehensive description of each flap type and its related cases are given in the table. It has been categorically found that there were 2 flap partial losses. Partial necrosis has been reported in heavy-smoker patients. Conclusion: This current study clearly justifies that careful application, optimal designing & judicious scientific application of local perforator flaps for lower-limb wounds including rest of the body is successful in many aspects providing high-quality reconstruction ensuring minimal morbidity. It is cost-effective as well as time-saving. PMID:24596732

  18. New model of flap-gliding flight.

    PubMed

    Sachs, Gottfried

    2015-07-21

    A new modelling approach is presented for describing flap-gliding flight in birds and the associated mechanical energy cost of travelling. The new approach is based on the difference in the drag characteristics between flapping and non-flapping due to the drag increase caused by flapping. Thus, the possibility of a gliding flight phase, as it exists in flap-gliding flight, yields a performance advantage resulting from the decrease in the drag when compared with continuous flapping flight. Introducing an appropriate non-dimensionalization for the mathematical relations describing flap-gliding flight, results and findings of generally valid nature are derived. It is shown that there is an energy saving of flap-gliding flight in the entire speed range compared to continuous flapping flight. The energy saving reaches the highest level in the lower speed region. The travelling speed of flap-gliding flight is composed of the weighted average of the differing speeds in the flapping and gliding phases. Furthermore, the maximum range performance achievable with flap-gliding flight and the associated optimal travelling speed are determined. PMID:25841702

  19. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flap interconnection. 23.701 Section 23.701... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a...

  20. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flap interconnection. 23.701 Section 23.701... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a...

  1. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Flap interconnection. 23.701 Section 23.701... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a...

  2. The bilobed flap for popliteal defect reconstruction

    PubMed Central

    Kelahmetoglu, Osman; Yagmur, Caglayan; Aslan, Ozan; Firinciogullari, Remzi

    2014-01-01

    Abstract Bilobed flaps were first introduced to close small nasal defects. We reconstructed a defect of the popliteal fossa using a random-pattern bilobed flap. We recommend the use of random-pattern bilobed flaps as a reliable technique for covering defects of the popliteal fossa.

  3. Scalp Rotation Flap for Reconstruction of Complex Soft Tissue Defects.

    PubMed

    Costa, Dary J; Walen, Scott; Varvares, Mark; Walker, Ronald

    2016-02-01

    Importance Scalp reconstructions may be required after tumor resection or trauma. The inherent anatomy of the scalp presents challenges and may limit reconstructive options. Objective To describe and investigate the scalp rotation flap as a reconstructive technique for complex soft tissue defects. Design Retrospective case series with a mean follow-up of 13 months. Setting Tertiary academic center. Participants A total of 22 patients with large scalp soft tissue defects undergoing scalp rotation flap reconstruction. Interventions The flap is designed adjacent to the defect and elevated in the subgaleal plane. The flap is rotated into the defect, and a split-thickness skin graft is placed over the donor site periosteum. Main Outcomes and Measure Data points collected included defect size, operative time, hospital stay, and patient satisfaction with cosmetic outcome. Results Mean patient age was 71 years. Mean American Society of Anesthesiologist classification was 2.8. Mean defect size was 41 cm(2) (range: 7.8-120 cm(2)), and 19 of 22 defects resulted from a neoplasm resection. Mean operative time was 181 minutes, and mean hospital stay was 2.4 days. There were no intraoperative complications. Three patients with previous radiation therapy had distal flap necrosis. Twenty-one patients (95%) reported an acceptable cosmetic result. Conclusions and Relevance The scalp rotation flap is an efficient and reliable option for reconstructing complex soft tissue defects. This can be particularly important in patients with significant medical comorbidities who cannot tolerate a lengthy operative procedure. PMID:26949586

  4. Energy transfer at the active sites of heme proteins

    SciTech Connect

    Dlott, D.D.; Hill, J.R.

    1995-12-31

    Experiments using a picosecond pump-probe apparatus at the Picosecond Free-electron Laser Center at Stanford University, were performed to investigate the relaxation of carbon monoxide bound to the active sites of heme proteins. The significance of these experiments is two-fold: (1) they provide detailed information about molecular dynamics occurring at the active sites of proteins; and (2) they provide insight into the nature of vibrational relaxation processes in condensed matter. Molecular engineering is used to construct various molecular systems which are studied with the FEL. We have studied native proteins, mainly myoglobin obtained from different species, mutant proteins produced by genetic engineering using recombinant DNA techniques, and a variety of model systems which mimic the structures of the active sites of native proteins, which are produced using molecular synthesis. Use of these different systems permits us to investigate how specific molecular structural changes affect dynamical processes occurring at the active sites. This research provides insight into the problems of how different species needs are fulfilled by heme proteins which have greatly different functionality, which is induced by rather small structural changes.

  5. Chemical Modification of Papain and Subtilisin: An Active Site Comparison

    ERIC Educational Resources Information Center

    St-Vincent, Mireille; Dickman, Michael

    2004-01-01

    An experiment using methyle methanethiosulfonate (MMTS) and phenylmethylsulfonyl flouride (PMSF) to specifically modify the cysteine and serine residues in the active sites of papain and subtilism respectively is demonstrated. The covalent modification of these enzymes and subsequent rescue of papain shows the beginning biochemist that proteins…

  6. Changes in active site histidine hydrogen bonding trigger cryptochrome activation.

    PubMed

    Ganguly, Abir; Manahan, Craig C; Top, Deniz; Yee, Estella F; Lin, Changfan; Young, Michael W; Thiel, Walter; Crane, Brian R

    2016-09-01

    Cryptochrome (CRY) is the principal light sensor of the insect circadian clock. Photoreduction of the Drosophila CRY (dCRY) flavin cofactor to the anionic semiquinone (ASQ) restructures a C-terminal tail helix (CTT) that otherwise inhibits interactions with targets that include the clock protein Timeless (TIM). All-atom molecular dynamics (MD) simulations indicate that flavin reduction destabilizes the CTT, which undergoes large-scale conformational changes (the CTT release) on short (25 ns) timescales. The CTT release correlates with the conformation and protonation state of conserved His378, which resides between the CTT and the flavin cofactor. Poisson-Boltzmann calculations indicate that flavin reduction substantially increases the His378 pKa Consistent with coupling between ASQ formation and His378 protonation, dCRY displays reduced photoreduction rates with increasing pH; however, His378Asn/Arg variants show no such pH dependence. Replica-exchange MD simulations also support CTT release mediated by changes in His378 hydrogen bonding and verify other responsive regions of the protein previously identified by proteolytic sensitivity assays. His378 dCRY variants show varying abilities to light-activate TIM and undergo self-degradation in cellular assays. Surprisingly, His378Arg/Lys variants do not degrade in light despite maintaining reactivity toward TIM, thereby implicating different conformational responses in these two functions. Thus, the dCRY photosensory mechanism involves flavin photoreduction coupled to protonation of His378, whose perturbed hydrogen-bonding pattern alters the CTT and surrounding regions. PMID:27551082

  7. Efficient flapping flight of pterosaurs

    NASA Astrophysics Data System (ADS)

    Strang, Karl Axel

    In the late eighteenth century, humans discovered the first pterosaur fossil remains and have been fascinated by their existence ever since. Pterosaurs exploited their membrane wings in a sophisticated manner for flight control and propulsion, and were likely the most efficient and effective flyers ever to inhabit our planet. The flapping gait is a complex combination of motions that sustains and propels an animal in the air. Because pterosaurs were so large with wingspans up to eleven meters, if they could have sustained flapping flight, they would have had to achieve high propulsive efficiencies. Identifying the wing motions that contribute the most to propulsive efficiency is key to understanding pterosaur flight, and therefore to shedding light on flapping flight in general and the design of efficient ornithopters. This study is based on published results for a very well-preserved specimen of Coloborhynchus robustus, for which the joints are well-known and thoroughly described in the literature. Simplifying assumptions are made to estimate the characteristics that can not be inferred directly from the fossil remains. For a given animal, maximizing efficiency is equivalent to minimizing power at a given thrust and speed. We therefore aim at finding the flapping gait, that is the joint motions, that minimize the required flapping power. The power is computed from the aerodynamic forces created during a given wing motion. We develop an unsteady three-dimensional code based on the vortex-lattice method, which correlates well with published results for unsteady motions of rectangular wings. In the aerodynamic model, the rigid pterosaur wing is defined by the position of the bones. In the aeroelastic model, we add the flexibility of the bones and of the wing membrane. The nonlinear structural behavior of the membrane is reduced to a linear modal decomposition, assuming small deflections about the reference wing geometry. The reference wing geometry is computed for

  8. Feasibility of a deepithelialized superior gluteal artery perforator propeller flap for various lumbosacral defects.

    PubMed

    Moon, Suk-Ho; Choi, Jang-Youn; Lee, Jung-Ho; Oh, Deuk-Young; Rhie, Jong-Won; Ahn, Sang-Tae

    2015-05-01

    Skin and soft tissue defects in the lumbosacral area are commonly encountered in the field of reconstructive surgery, and it is well documented that the superior gluteal artery perforator (SGAP) flap provides excellent coverage of these defects. In this article, we describe our experience using a modified version of the SGAP propeller flap, in which the distal redundant portion of an elevated SGAP flap is deepithelialized, thereby maximizing the effect of the soft tissue augmentation. Thirteen patients with lumbosacral soft tissue defects treated between May 2010 and June 2012 were included in this study. The wound causes were pressure ulcer (n = 9), pseudomeningocele (n = 2), and hardware exposure (n = 2). In all patients, an elevated SGAP flap was rotated 180 degrees over the defect area and the extra distal portion of the flap was deepithelialized and used as a soft tissue filler or tamponade. During the follow-up period (mean, 26 months), 12 of 13 flaps survived completely. One flap was totally necrosed due to progressive venous congestion and was reconstructed with local advancement flaps. No further complications were noted. Because of the redundancy and pliability of the tissue in the gluteal area, a flap relatively wider or longer than the defect can be elevated safely. Hence, the redundant tissue volume can be tucked inside to facilitate soft tissue augmentation of the area. We propose that the deepithelialized version of the SGAP propeller flap is an effective option for the reconstruction of various lumbosacral soft tissue defects because it offers thick and healthy soft tissue from a distant site to the defect areas. PMID:24149404

  9. Active sites environmental monitoring program. Annual report FY 1992

    SciTech Connect

    Morrissey, C.M.; Ashwood, T.L.; Hicks, D.S.

    1994-04-01

    This report summarizes the activities of the Active Sites Environmental Monitoring Program (ASEMP) at ORNL from October 1991 through September 1992. Solid Waste Operations and the Environmental Sciences Division established ASEMP in 1989 to provide early detection and performance monitoring at active low-level waste (LLW) disposal sites in Solid Waste Storage Area (SWSA) 6 and transuranic (TRU) waste storage sites in SWSA 5 as required by Chapter 2 and 3 of US Department of Energy Order 5820.2A. The Interim Waste Management Facility (IWMF) began operation in December 1991. Monitoring results from the tumulus and IWMF disposal pads continue to indicate that no LLW is leaching from the storage vaults. Storm water falling on the IWMF active pad was collected and transported to the Process Waste Treatment Plant while operators awaited approval of the National Pollutant Discharge Elimination System (NPDES) permit. Several of the recent samples collected from the active IWMF pad had pH levels above the NPDES limit of 9.0 because of alkali leached from the concrete. The increase in gross beta activity has been slight; only 1 of the 21 samples collected contained activity above the 5.0 Bq/L action level. Automated sample-collection and flow-measurement equipment has been installed at IWMF and is being tested. The flume designed to electronically measure flow from the IWMF pads and underpads is too large to be of practical value for measuring most flows at this site. Modification of this system will be necessary. A CO{sub 2} bubbler system designed to reduce the pH of water from the pads is being tested at IWMF.

  10. Bilateral Pedicled Superficial Inferior Epigastric Artery Flap in the Treatment of Hidradenitis Suppurativa

    PubMed Central

    Hoang, Don; Saber, Sepideh; Patel, Ketan; Carey, Joseph

    2016-01-01

    Summary: The authors present a new technique in surgically treating hidradenitis suppurativa (HS), a debilitating skin condition. In HS, surgical treatment is often the best option because of the high recurrence rates despite extensive medical treatment. A commonly successful surgical method is using skin flaps after excision of the affected area. A superficial inferior epigastric artery flap is demonstrated here as a new alternative approach to treating a case of extensive HS of the groin. By using the pedicled superficial inferior epigastric artery flap for groin reconstruction, inguinal HS can be widely excised and reconstructed with minimal donor-site morbidity and a good aesthetic outcome.

  11. Development of a Wind Turbine Test Rig and Rotor for Trailing Edge Flap Investigation: Static Flap Angles Case

    NASA Astrophysics Data System (ADS)

    Abdelrahman, Ahmed; Johnson, David A.

    2014-06-01

    One of the strategies used to improve performance and increase the life-span of wind turbines is active flow control. It involves the modification of the aerodynamic characteristics of a wind turbine blade by means of moveable aerodynamic control surfaces. Trailing edge flaps are relatively small moveable control surfaces placed at the trailing edge of a blade's airfoil that modify the lift of a blade or airfoil section. An instrumented wind turbine test rig and rotor were specifically developed to enable a wide-range of experiments to investigate the potential of trailing edge flaps as an active control technique. A modular blade based on the S833 airfoil was designed to allow accurate instrumentation and customizable settings. The blade is 1.7 meters long, had a constant 178mm chord and a 6° pitch. The modular aerodynamic parts were 3D printed using plastic PC-ABS material. The blade design point was within the range of wind velocities in the available large test facility. The wind facility is a large open jet wind tunnel with a maximum velocity of 11m/s in the test area. The capability of the developed system was demonstrated through an initial study of the effect of stationary trailing edge flaps on blade load and performance. The investigation focused on measuring the changes in flapwise bending moment and power production for different trailing edge flap spanwise locations and deflection angles. The relationship between the load reduction and deflection angle was linear as expected from theory and the highest reduction was caused by the flap furthest from the rotor center. Overall, the experimental setup proved to be effective in measuring small changes in flapwise bending moment within the wind turbine blade and will provide insight when (active) flap control is targeted.

  12. The effect of platelet rich plasma on angiogenesis in ischemic flaps in VEGFR2-luc mice.

    PubMed

    Sönmez, Tolga Taha; Vinogradov, Alexandra; Zor, Fatih; Kweider, Nisreen; Lippross, Sebastian; Liehn, Elisa Anamaria; Naziroglu, Mustafa; Hölzle, Frank; Wruck, Christoph; Pufe, Thomas; Tohidnezhad, Mersedeh

    2013-04-01

    To improve skin flap healing, one promising strategy in reconstructive surgery might be to optimize platelet rich plasma (PRP) bioactivity and the ischemia-altered expression of genes. We studied both the effect of PRP on ischemic flaps, and whether in vivo bioluminescence imaging (BLI) is a suitable method for the longitudinal monitoring of angiogenesis in surgical wounds. Axial murine skin flaps were created in four experimental groups. In vivo measurements of VEGFR2 expression levels were made every other day until the 14th day. The local VEGF level and microvessel density were quantified on the 14th day via ELISA and immunohistochemistry, and flap survival rates were measured. We demonstrated that PRP and induced ischemia have a beneficial influence on angiogenesis and flap healing. Combining the two resulted in a significantly robust increase in angiogenesis and flap survival rate that was corroborated by bioluminescence imaging of VEGFR2 activity. This study shows that angiogenic effects of PRP may be potentialized by the stimulus of induced ischemia during free flap harvesting, and thus the two procedures appear to have a synergistic effect on flap healing. This study further demonstrates that BLI of modulated genes in reconstructive surgery is a valuable model for longitudinal in vivo evaluation of angiogenesis. PMID:23352038

  13. Seromuscular Colonic Flap for Intrapelvic Soft-Tissue Coverage: A Reconstructive Option for Plastic Surgeons When Traditionally Used Flaps Are Not Available

    PubMed Central

    Aho, Johnathon; Winocour, Sebastian; Hammoudeh, Ziyad S.; Nelson, Heidi; Rose, Peter; Tran, Nho V.

    2015-01-01

    Background. Reconstruction of intrapelvic defects can be a challenging problem in patients with limited regional muscle flap options and previously resected omentum. In such situations, alternative methods of mobilizing vascularized tissue may be required. Methods. A case of a patient that underwent pelvic extirpation for recurrent rectal cancer who had limited donor sites for flap reconstruction is presented. The mucosa was removed from a blind loop of colon, and a pedicled seromuscular flap based on the colonic mesentery was placed into the pelvis for vascularized soft-tissue coverage and elimination of dead space. Results. The postoperative course was only complicated by a small subcutaneous fluid collection beneath the sacrectomy skin incision, which was drained with radiological assistance. The patient recovered without any major postoperative complications. Conclusion. Seromuscular colonic flap is a useful option for soft-tissue coverage after pelvic extirpation and should be considered by plastic surgeons when other reconstruction options are not available. PMID:26688771

  14. Probing the promiscuous active site of myo-inositol dehydrogenase using synthetic substrates, homology modeling, and active site modification.

    PubMed

    Daniellou, Richard; Zheng, Hongyan; Langill, David M; Sanders, David A R; Palmer, David R J

    2007-06-26

    The active site of myo-inositol dehydrogenase (IDH, EC 1.1.1.18) from Bacillus subtilis recognizes a variety of mono- and disaccharides, as well as 1l-4-O-substituted inositol derivatives. It catalyzes the NAD+-dependent oxidation of the axial alcohol of these substrates with comparable kinetic constants. We have found that 4-O-p-toluenesulfonyl-myo-inositol does not act as a substrate for IDH, in contrast to structurally similar compounds such as those bearing substituted benzyl substituents in the same position. X-ray crystallographic analysis of 4-O-p-toluenesulfonyl-myo-inositol and 4-O-(2-naphthyl)methyl-myo-inositol, which is a substrate for IDH, shows a distinct difference in the preferred conformation of the aryl substituent. Conformational analysis of known substrates of IDH suggests that this conformational difference may account for the difference in reactivity of 4-O-p-toluenesulfonyl-myo-inositol in the presence of IDH. A sequence alignment of IDH with the homologous glucose-fructose oxidoreductase allowed the construction of an homology model of inositol dehydrogenase, to which NADH and 4-O-benzyl-scyllo-inosose were docked and the active site energy minimized. The active site model is consistent with all experimental results and suggests that a conserved tyrosine-glycine-tyrosine motif forms the hydrophobic pocket adjoining the site of inositol recognition. Y233F and Y235F retain activity, while Y233R and Y235R do not. A histidine-aspartate pair, H176 and D172, are proposed to act as a dyad in which H176 is the active site acid/base. The enzyme is inactivated by diethyl pyrocarbonate, and the mutants H176A and D172N show a marked loss of activity. Kinetic isotope effect experiments with D172N indicate that chemistry is rate-determining for this mutant. PMID:17539607

  15. Induced-shear piezoelectric actuators for rotor blade trailing edge flaps

    NASA Astrophysics Data System (ADS)

    Centolanza, Louis R.; Smith, Edward C.; Munsky, Brian

    2002-02-01

    Much of the current rotorcraft research is focused on improving performance by reducing unwanted helicopter noise and vibration. One of the most promising active rotorcraft vibration control systems is an active trailing edge flap. In this paper, an induced-shear piezoelectric tube actuator is used in conjunction with a simple lever-cusp hinge amplification device to generate a useful combination of trailing edge flap deflections and hinge moments. A finite-element model of the actuator tube and trailing edge flap (including aerodynamic and inertial loading) was used to guide the design of the actuator-flap system. A full-scale induced shear tube actuator flap system was fabricated and bench top testing was conducted to validate the analysis. Hinge moments corresponding to various rotor speeds were applied to the actuator using mechanical springs. The testing demonstrated that for an applied electric field of 3 kV cm-1, the tube actuator deflected a representative full-scale 12 inch flap +/-2.8° at 0 rpm and +/-1.4° for a hinge moment simulating a 400 rpm condition. The per cent error between the predicted and experimental full-scale flap deflections ranged from 4% (low rpm) to 12.5% (large rpm). Increasing the electric field to 4 kV cm-1 results in +/-2.5° flap deflection at a rotation speed of 400 rpm, according to the design analysis. A trade study was conducted to compare the performance of the piezoelectric tube actuator to the state of the art in trailing edge flap actuators and indicated that the induced-shear tube actuator shows promise as a trailing edge flap actuator.

  16. Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction without Microsurgery Fellowship Training

    PubMed Central

    Orbay, Hakan; Busse, Brittany K.; Stevenson, Thomas R.; Wang, Howard T.

    2015-01-01

    Background: Deep inferior epigastric artery perforator (DIEP) flap breast reconstruction requires complex microsurgical skills. Herein, we examine whether DIEP flap breast reconstruction can be performed safely without microsurgical fellowship training. Methods: A total of 28 patients and 34 DIEP flaps were included in the study. We reviewed the medical records of patients for donor site and flap-related complications and analyzed the correlation between the complications and preoperative risk factors. We also performed a literature review to compare complication rates in our series with the literature. Results: We observed total flap necrosis in 1 patient (2.9%), partial flap necrosis in 5 patients (14.7%), infection in 1 patient (2.9%), hematoma/seroma in 3 patients (8.8%), donor site complications in 5 patients (18.5%), venous occlusion in 4 patients (11.7%), and arterial occlusion in 1 patient (2.9%). We did not observe any correlation between complications and preoperative risk factors. Literature review yielded 18 papers that met our inclusion criteria. Partial flap necrosis rate was significantly higher in our series compared with literature (14.7% vs 1.6%, P = 0.003). Venous complication rate was marginally higher in our series compared with literature (11.7% vs 3.3%, P = 0.057). However, total flap loss rate in our series was comparable with the literature (2.9% vs 2.2%, P = 0.759). Conclusion: With proper training during plastic surgery residency, DIEP flap can be performed with acceptable morbidity. PMID:26301144

  17. Active-Site-Accessible, Porphyrinic Metal;#8722;Organic Framework Materials

    SciTech Connect

    Farha, Omar K.; Shultz, Abraham M.; Sarjeant, Amy A.; Nguyen, SonBinh T.; Hupp, Joseph T.

    2012-02-06

    On account of their structural similarity to cofactors found in many metallo-enzymes, metalloporphyrins are obvious potential building blocks for catalytically active, metal-organic framework (MOF) materials. While numerous porphyrin-based MOFs have already been described, versions featuring highly accessible active sites and permanent microporosity are remarkably scarce. Indeed, of the more than 70 previously reported porphyrinic MOFs, only one has been shown to be both permanently microporous and contain internally accessible active sites for chemical catalysis. Attempts to generalize the design approach used in this single successful case have failed. Reported here, however, is the synthesis of an extended family of MOFs that directly incorporate a variety of metalloporphyrins (specifically Al{sup 3+}, Zn{sup 2+}, Pd{sup 2+}, Mn{sup 3+}, and Fe{sup 3+} complexes). These robust porphyrinic materials (RPMs) feature large channels and readily accessible active sites. As an illustrative example, one of the manganese-containing RPMs is shown to be catalytically competent for the oxidation of alkenes and alkanes.

  18. Nest predation increases with parental activity: Separating nest site and parental activity effects

    USGS Publications Warehouse

    Martin, T.E.; Scott, J.; Menge, C.

    2000-01-01

    Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection.

  19. Nest predation increases with parental activity: separating nest site and parental activity effects.

    PubMed Central

    Martin, T E; Scott, J; Menge, C

    2000-01-01

    Alexander Skutch hypothesized that increased parental activity can increase the risk of nest predation. We tested this hypothesis using ten open-nesting bird species in Arizona, USA. Parental activity was greater during the nestling than incubation stage because parents visited the nest frequently to feed their young during the nestling stage. However, nest predation did not generally increase with parental activity between nesting stages across the ten study species. Previous investigators have found similar results. We tested whether nest site effects might yield higher predation during incubation because the most obvious sites are depredated most rapidly. We conducted experiments using nest sites from the previous year to remove parental activity. Our results showed that nest sites have highly repeatable effects on nest predation risk; poor nest sites incurred rapid predation and caused predation rates to be greater during the incubation than nestling stage. This pattern also was exhibited in a bird species with similar (i.e. controlled) parental activity between nesting stages. Once nest site effects are taken into account, nest predation shows a strong proximate increase with parental activity during the nestling stage within and across species. Parental activity and nest sites exert antagonistic influences on current estimates of nest predation between nesting stages and both must be considered in order to understand current patterns of nest predation, which is an important source of natural selection. PMID:11413645

  20. [The treatment of a post-burn deformity and contracture of the neck, using extended flaps with axial type of blood supply].

    PubMed

    Zhernov, A A; Zhernov, An A

    2012-03-01

    Experience of treatment of 24 patients, suffering neck deformity and contracture, using stretched flaps with axial type of blood circulation, was summarized. In total 43 expanders were implanted. The cutaneo-fascial flaps stretching was performed in the neck and thorax. In all the flaps a nutrition artery was included. The neck-brachial flaps, including supraclavicular artery, were applied in 25 (58.1%) patients, the neck-thoracic flaps, using superficial neck artery--in 12 (27.91%), the occipital-neck flaps on a musculocutaneous perforating vessels of occipital artery--in 6 (13.95%). The methods of the expander implantation, the stretching, transposition regimes of plastic material and its fixation were elaborated. The donor sites were closed using stretched tissues, left in place after formation of flaps. Flaps were fixed, using mechanical method of the tissues connection with duplicature formation from deepidermized portion of cicatrix or with polypropylene mesh, which played a role of a dense framework. Then a strong connective tissue bolt was formed, securely fixing transposedstretched tissues. While application of a complex-component vascularized flaps a suppuration have occurred in 3 (6.97%), partial necrosis--in 2 (4.64%) observations. Inclusion of nutritive vessels permit to form large size flaps with a small risk of necrosis occurrence. The stretched perforant flaps application permits to achieve positive result in 95.3% of observations--in immediate and in 81.82%--in far remote period. PMID:22702123

  1. Cost-effectiveness of monitoring free flaps.

    PubMed

    Subramaniam, Shiva; Sharp, David; Jardim, Christopher; Batstone, Martin D

    2016-06-01

    Methods of free flap monitoring have become more sophisticated and expensive. This study aims to determine the cost of free flap monitoring and examine its cost effectiveness. We examined a group of patients who had had free flaps to the head and neck over a two-year period, and combined these results with costs obtained from business managers and staff. There were 132 free flaps with a success rate of 99%. The cost of monitoring was Aus $193/flap. Clinical monitoring during this time period cost Aus$25 476 and did not lead to the salvage of any free flaps. Cost equivalence is reached between monitoring and not monitoring only at a failure rate of 15.8%. This is to our knowledge the first study to calculate the cost of clinical monitoring of free flaps, and to examine its cost-effectiveness. PMID:27015730

  2. Scrotal reconstruction with modified pudendal thigh flaps.

    PubMed

    Mopuri, Nabil; O'Connor, Edmund Fitzgerald; Iwuagwu, Fortune C

    2016-02-01

    Scrotal skin loss can occur following trauma, Fournier's gangrene, post tumour excision, burns, etc. There are many techniques described in the literature including residual scrotal skin mobilization, skin grafts, pedicled and free flaps. The management is complex and challenging shown by the multiplicity of flaps and techniques described in the literature. We used a modified pudendal thigh flap to reconstruct scrotal defects in five patients. This study describes the vascularity of the flap, technique of elevation and the inset of the flap. The elevation and particularly the insetting make it different from other flaps raised on this vascular network for scrotal reconstruction. This pedicled flap is robust, reliable, resilient and produces a neo-scrotum that looks natural in appearance, offers good-quality skin cover and cushion to the testes as well as protective sensation. PMID:26774357

  3. Identification of Ice Nucleation Active Sites on Silicate Dust Particles

    NASA Astrophysics Data System (ADS)

    Zolles, Tobias; Burkart, Julia; Häusler, Thomas; Pummer, Bernhard; Hitzenberger, Regina; Grothe, Hinrich

    2015-04-01

    Mineral dusts originating from Earth's crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts [1-3]. Nevertheless, among those structures K-feldspar showed by far the highest ice nucleation activity. In this study, the reasons for its activity and the difference in the activity of the different feldspars were investigated in closer details. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. We give a potential explanation of the increased ice nucleation activity of K-feldspar. The ice nucleating sites are very much dependent on the alkali ion present by altering the water structure and the feldspar surface. The higher activity of K-feldspar can be attributed to the presence of potassium ions on the surface and surface bilayer. The alkali-ions have different hydration shells and thus an influence on the ice nucleation activity of feldspar. Chaotropic behavior of Calcium and Sodium ions are lowering the ice nucleation potential of the other feldspars, while kosmotropic Potassium has a neutral or even positive effect. Furthermore we investigated the influence of milling onto the ice nucleation of quartz particles. The ice nucleation activity can be increased by mechanical milling, by introducing more molecular, nucleation active defects to the particle surface. This effect is larger than expected by plane surface increase. [1] Atkinson et al. The Importance of Feldspar for Ice Nucleation by Mineral Dust in Mixed-Phase Clouds. Nature 2013, 498, 355-358. [2] Yakobi-Hancock et al.. Feldspar Minerals as Efficient Deposition Ice Nuclei. Atmos. Chem. Phys. 2013, 13, 11175-11185. [3] Zolles et al. Identification of Ice Nucleation Active Sites on Feldspar Dust Particles. J. Phys. Chem. A 2015 accepted.

  4. Anatomical variations and pre-operative imaging technique concerning the anterolateral thigh flap: guiding the surgeon.

    PubMed

    De Beule, Tom; Van Deun, Wouter; Vranckx, Jan; de Dobbelaere, Bart; Maleux, Geert; Heye, Sam

    2016-07-01

    The anterolateral thigh (ALT) flap has widespread use throughout the body because of the many engineering options. The ALT has a complex local vasculature, which can be of importance for the surgical approach. In general, the flap receives its perfusion from branches of the lateral circumflex femoral artery (LCFA). The LCFA, however, has a large anatomic variance. CT angiography can guide the surgeon in the selection of the most suitable site and aid in the surgical approach. PMID:27150071

  5. Flap--edge flowfield measurements

    NASA Astrophysics Data System (ADS)

    Pye, John D.; Cantwell, Brian J.

    1997-11-01

    Recent studies of airframe noise suggest that the wing and flap trailing--edges as well as the flap side--edge are areas of significant noise generation. To identify the fluid dynamic processes associated with these noise sources, we are examining the flow--field around a NACA 63--215 Mod B main element airfoil configured with a half--span Fowler flap. The tests are performed in a low--speed wind tunnel at a Reynolds number of ~ 6.0×10^5. A hot wire traverse system is used to map the mean velocities and turbulence intensities in the near wake region of the flow. Measurements of the pressure fluctuations along the flap side--edge and in the cove of the airfoil configuration are made with pressure transducers mounted inside the airfoil. The experimental data are in good qualitative agreement with the numerical simulation of a slightly higher Reynolds number flow ( ~ 1.5×10^6) around a geometrically similar airfoil configuration.

  6. Sternocleidomastoid Muscle Flap after Parotidectomy

    PubMed Central

    Nofal, Ahmad Abdel-Fattah; Mohamed, Morsi

    2015-01-01

    Introduction Most patients after either superficial or total parotidectomy develop facial deformity and Frey syndrome, which leads to a significant degree of patient dissatisfaction. Objective Assess the functional outcome and esthetic results of the superiorly based sternocleidomastoid muscle (SCM) flap after superficial or total parotidectomy. Methods A prospective cohort study for 11 patients subjected to parotidectomy using a partial-thickness superiorly based SCM flap. The functional outcome (Frey syndrome, facial nerve involvement, and ear lobule sensation) and the esthetic results were evaluated subjectively and objectively. Results Facial nerve palsy occurred in 5 cases (45%), and all of them recovered completely within 6 months. The Minor starch iodine test was positive in 3 patients (27%), although only 1 (9%) subjectively complained of gustatory sweating. The designed visual analog score completed by the patients themselves ranged from 0 to 3 with a mean of 1.55 ± 0.93; the scores from the blinded evaluators ranged from 1 to 3 with a mean 1.64 ± 0.67. Conclusion The partial-thickness superiorly based SCM flap offers a reasonable cosmetic option for reconstruction following either superficial or total parotidectomy by improving the facial deformity. The flap also lowers the incidence of Frey syndrome objectively and subjectively with no reported hazard of the spinal accessory nerve. PMID:26491478

  7. Force Generation by Flapping Foils

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, P. R.; Donnelly, M.

    1996-11-01

    Aquatic animals like fish use flapping caudal fins to produce axial and cross-stream forces. During WW2, German scientists had built and tested an underwater vehicle powered by similar flapping foils. We have examined the forces produced by a pair of flapping foils. We have examined the forced produced by a pair of flapping foils attached to the tail end of a small axisymmetric cylinder. The foils operate in-phase (called waving), or in anti-phase (called clapping). In a low-speed water tunnel, we have undertaken time-dependent measurements of axial and cross-stream forces and moments that are exerted by the vortex shedding process over the entire body. Phase-matched LDV measurements of vorticity-velocity vectors, as well as limited flow visualization of the periodic vortex shedding process have also been carried out. The direction of the induced velocity within a pair of shed vortices determines the nature of the forces produced, viz., thrust or drag or cross-stream forces. The clapping mode produces a widely dispersed symmetric array of vortices which results in axial forces only (thrust and rag). On the other hand, the vortex array is staggered in the waving mode and cross-stream (maneuvering) forces are then generated.

  8. Active Sites Environmental Monitoring Program. FY 1993: Annual report

    SciTech Connect

    Morrissey, C.M.; Ashwood, T.L.; Hicks, D.S.; Marsh, J.D.

    1994-08-01

    This report continues a series of annual and semiannual reports that present the results of the Active Sites Environmental Monitoring Program (ASEMP) monitoring activities. The report details monitoring data for fiscal year (FY) 1993 and is divided into three major areas: SWSA 6 [including tumulus pads, Interim Waste Management Facility (IWMF), and other sites], the low-level Liquid-Waste Solidification Project (LWSP), and TRU-waste storage facilities in SWSA 5 N. The detailed monitoring methodology is described in the second revision of the ASEMP program plan. This report also presents a summary of the methodology used to gather data for each major area along with the results obtained during FY 1993.

  9. Active sites in char gasification: Final technical report

    SciTech Connect

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  10. Chimeric Superficial Circumflex Iliac Perforator Flap Including External Oblique Fascia: A Refinement of Conventional Harvesting

    PubMed Central

    Fernandez Garrido, Manuel; Vega Garcia, Carmen; Pons Playa, Gemma; Masiá Ayala, Jaume

    2016-01-01

    Summary: The superficial circumflex iliac perforator (SCIP) flap is one of the most suitable flaps to cover distal extremity defects due to its lack of bulkiness and donor site concealment. However, it is less popular than other perforator flaps due to its anatomical variations, short pedicle length, and small caliber vessels. We describe a novel design for the SCIP flap, consisting of a chimeric flap with a piece of the external oblique muscle fascia. The purpose of this design is to cover and protect the vascular anastomosis in distal lower limb defects where recipient vessels are superficial and skin coverage is poor. In addition, lengthening the pedicle with this design makes the flap more versatile. The addition of a cuff of fascia in harvesting of the SCIP flap lengthens the pedicle, allowing easier insetting of the skin paddle and providing complete protection and coverage of the vessels. This procedure allows greater versatility in inset of the skin paddle and is particularly suitable in cases where recipient vessels are superficial or when skin coverage is poor. PMID:27482505

  11. Flap raising on pulsatile perfused cadaveric tissue: a novel method for surgical teaching and exercise.

    PubMed

    Wolff, Klaus-Dietrich; Fichter, Andreas; Braun, Christian; Bauer, Florian; Humbs, Martin

    2014-10-01

    Exercising flap raising procedures on cadavers is considered a prerequisite to prepare for clinical practise. To improve teaching and create conditions as realistic as possible, a perfusion device was developed providing pulsatile flow through the vessels of different donor sites. A plastic bag filled with red stained tab water was placed into a pump, which was driven by an electric motor. The bag was set under rhythmic compression with variable frequency and pressure. The pedicles of the radial forearm, anterolateral thigh, rectus abdominis, fibular and iliac crest flap were cannulated at the origin from their source arteries. Flap raising was performed under pulsatile perfusion in 15 fresh bodies and subsequently in 6 Thiel-embalmed cadavers during a flap raising course. We regularly observed staining of the skin and skin bleeding in fresh bodies and less reliable in embalmed cadavers. All flap pedicles showed pulsatile movements, and the radial pulse became palpable. Most perforators of the anterolateral thigh and osteocutaneous fibular flap could be identified by their pulse. Bleeding from bony tissue and venous return was seldom observed. We conclude that pulsatile perfusion of cadaveric tissue creates more realistic conditions for flap raising and improves teaching for beginners and advanced surgeons. PMID:24938642

  12. Versatility of the Perforator-Based Adipose, Adipofascial, and Fasciocutaneous Flaps in Reconstruction of Distal Leg and Foot Defects.

    PubMed

    Acartürk, Tahsin Oğuz; Tunc, Suphan; Acar, Firat

    2016-01-01

    Reconstruction of the distal leg, ankle, and foot is challenging, and local perforator flaps have emerged as valuable options. The aim of the present study was to evaluate the outcomes of local perforator flaps in the distal lower extremity. A total of 14 local perforator flaps were used in 12 patients (9 males [75%] and 3 females [25%], aged 19 to 83 years). The etiologies included 7 motor vehicle accidents (50%), 2 acute burns (14.29%), 2 chronic wounds (14.29%), 1 postburn contracture (7.14%), 1 gunshot wound (7.14%), and 1 malignancy (7.14%). The defects were localized to the mid-leg in 3 cases (21.43%), ankle in 4 (28.57%), calcaneus in 4 (28.57%), and foot in 3 (21.43%). A peroneal artery perforator flap (11 sites [78.57%]) or a posterior tibial artery perforator flap (3 sites [21.43%]) was used. Of the 14 flaps, 8 (57.14%) were fasciocutaneous, 4 (28.57%) were adipofascial, and 2 (14.29%) were adipose. The flap transfers were rotational in 9 cases (64.29%), flipped in 2 (14.29%), propeller in 2 (14.29%), and transcrural in 1 (7.14%). The flap dimensions ranged from 8 cm × 5 cm to 22 cm × 5 cm. Finally, 12 flaps (85.71%) remained viable, 1 (7.14%) had partially sloughed, and 1 (7.14%) had completely died owing to a hypercoagulable state. Overall, 13 flaps (92.86%) had good outcomes after a median follow-up period of 19 (range 12 to 37) months. Perforator flaps in the lower extremity are versatile in terms of size, design, composition, and axis of rotation. They are reliable and safe when used to reconstruct local defects. PMID:25661783

  13. Potential sites of CFTR activation by tyrosine kinases.

    PubMed

    Billet, Arnaud; Jia, Yanlin; Jensen, Timothy J; Hou, Yue-Xian; Chang, Xiu-Bao; Riordan, John R; Hanrahan, John W

    2016-05-01

    The CFTR chloride channel is tightly regulated by phosphorylation at multiple serine residues. Recently it has been proposed that its activity is also regulated by tyrosine kinases, however the tyrosine phosphorylation sites remain to be identified. In this study we examined 2 candidate tyrosine residues near the boundary between the first nucleotide binding domain and the R domain, a region which is important for channel function but devoid of PKA consensus sequences. Mutating tyrosines at positions 625 and 627 dramatically reduced responses to Src or Pyk2 without altering the activation by PKA, suggesting they may contribute to CFTR regulation. PMID:26645934

  14. Brownian aggregation rate of colloid particles with several active sites

    SciTech Connect

    Nekrasov, Vyacheslav M.; Yurkin, Maxim A.; Chernyshev, Andrei V.; Polshchitsin, Alexey A.; Yakovleva, Galina E.; Maltsev, Valeri P.

    2014-08-14

    We theoretically analyze the aggregation kinetics of colloid particles with several active sites. Such particles (so-called “patchy particles”) are well known as chemically anisotropic reactants, but the corresponding rate constant of their aggregation has not yet been established in a convenient analytical form. Using kinematic approximation for the diffusion problem, we derived an analytical formula for the diffusion-controlled reaction rate constant between two colloid particles (or clusters) with several small active sites under the following assumptions: the relative translational motion is Brownian diffusion, and the isotropic stochastic reorientation of each particle is Markovian and arbitrarily correlated. This formula was shown to produce accurate results in comparison with more sophisticated approaches. Also, to account for the case of a low number of active sites per particle we used Monte Carlo stochastic algorithm based on Gillespie method. Simulations showed that such discrete model is required when this number is less than 10. Finally, we applied the developed approach to the simulation of immunoagglutination, assuming that the formed clusters have fractal structure.

  15. The possibility for use of venous flaps in plastic surgery

    NASA Astrophysics Data System (ADS)

    Baytinger, V. F.; Kurochkina, O. S.; Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    2015-11-01

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  16. The possibility for use of venous flaps in plastic surgery

    SciTech Connect

    Baytinger, V. F. Kurochkina, O. S. Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    2015-11-17

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  17. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  18. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  19. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  20. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  1. The Flap Sandwich Technique for a Safe and Aesthetic Skull Base Reconstruction.

    PubMed

    Yano, Tomoyuki; Okazaki, Mutsumi; Tanaka, Kentarou; Iida, Hideo

    2016-02-01

    For safe and reliable skull base reconstruction combined with repair of cranial bone defects, we introduce the flap sandwich technique in this study. A titanium mesh is often used to repair structural cranial bone defects because it has less donor site morbidity and is easy to handle. However, titanium mesh has disadvantages of exposure and infection postoperatively. To improve surgical outcomes, we applied the flap sandwich technique to 3 cases of skull base reconstruction combined with cranial bone defect repair. Two anterior skull base defects and 1 middle skull base defect were included in this study. The subjects were all women, aged 30, 58, and 62 years. One patient had former multiple craniotomies and another patient had preoperative radiotherapy. The flap sandwich technique involves structural cranial bone reconstruction with a titanium mesh and soft tissue reconstruction with a chimeric anterolateral thigh free flap. First, the dead space between the repaired dura and the titanium mesh is filled with vastus lateralis muscle, and then structural reconstruction is performed with a titanium mesh. Finally, the titanium mesh is totally covered with the adiposal flap of the anterolateral thigh free flap. The muscle flap protects the dead space from infection, and the adiposal flap covers the titanium mesh to reduce mechanical stress on the covered skin and thus prevent the exposure of the titanium mesh through the scalp. By applying this technique, there was no intracranial infection or titanium mesh exposure in these 3 cases postoperatively, even though 2 patients had postoperative radiotherapy. Additionally, the adiposal flap could provide a soft and natural contour to the scalp and forehead region, and this gives patients a better facial appearance even though they have had skull base surgery. PMID:25954846

  2. Flapping propulsion with tip pitch control

    NASA Astrophysics Data System (ADS)

    Huera-Huarte, Francisco; Gharib, Morteza

    2014-11-01

    The effect of flexibility in the propulsion performance and efficiency of oscillating pitching foils has received a large amount of attention in the past years. Scientists have used simplified robotic models that mimic the kinematics of flying and swimming animals, in order to get inspiration to build more efficient engineering systems. Compliance is one of the aspects that has received more attention, as it seems to be a common feature in nature's flyers and swimmers. Active or passive control elements are also common in nature. We will show how thrust generation in a pitching fin, can be greatly affected by controlling the tip pitch motion dynamically and independently of the fin itself. This is in fact a controlled local change of curvature of the end of the fin. A robotic system has been designed in a way that not only flapping amplitudes and frequencies can be controlled, but also the amplitudes and frequencies of the tip and the phase difference between the tip and the fin. We measured thrust forces and the vortex dynamics in the near wake of the system, by using planar DPIV (Digital Particle Image Velocimetry) in a wide variety of flapping situations with tip control. Funding from Spanish Ministry of Science through Grant DPI2012-37904 is gratefully acknowledged.

  3. Current activities handbook: formerly utilized sites remedial action program

    SciTech Connect

    1981-02-27

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the activities each of the thirteen state legislatures potentially affected by the Formerly Utilized Sites Remedial Action Program. It contains a description of the state legislative procedural rules and a schedule of each legislative session; a summary of pending relevant legislation; the name and telephone number of legislative and state agency contacts; and the full text of all bills identified.

  4. Sectioned Images and Surface Models of a Cadaver for Understanding the Dorsalis Pedis Flap.

    PubMed

    Shin, Dong Sun; Kim, Hyung Jun; Kim, Bong Chul

    2015-07-01

    The aim of this study was to represent the dorsalis pedis (DP) flap on sectioned images and surface models using Visible Korean for medical education and clinical training in the field of maxillofacial reconstructive surgery. Serially sectioned images of the foot were obtained from a cadaver. The important structures in the sectioned images were outlined and stacked to create a surface model. The PDF file (53 MB) of the assembled models is accessible for free download on the Department of Anatomy at Ajou University School of Medicine Web site (http://anatomy.co.kr). In this file, the significant anatomic structures of the DP flap can be inspected in the sectioned images. All surface models and stereoscopic structures of the DP flap are described in real time. We hope that these state-of-the-art sectioned images, outlined images, and surface models will help students and trainees gain a better understanding of the DP flap anatomy. PMID:26079120

  5. Shape-based 3D vascular tree extraction for perforator flaps

    NASA Astrophysics Data System (ADS)

    Wen, Quan; Gao, Jean

    2005-04-01

    Perforator flaps have been increasingly used in the past few years for trauma and reconstructive surgical cases. With the thinned perforated flaps, greater survivability and decrease in donor site morbidity have been reported. Knowledge of the 3D vascular tree will provide insight information about the dissection region, vascular territory, and fascia levels. This paper presents a scheme of shape-based 3D vascular tree reconstruction of perforator flaps for plastic surgery planning, which overcomes the deficiencies of current existing shape-based interpolation methods by applying rotation and 3D repairing. The scheme has the ability to restore the broken parts of the perforator vascular tree by using a probability-based adaptive connection point search (PACPS) algorithm with minimum human intervention. The experimental results evaluated by both synthetic and 39 harvested cadaver perforator flaps show the promise and potential of proposed scheme for plastic surgery planning.

  6. Transfer of free vascular cutaneous flaps by microvascular anastomosis. Results in six dogs.

    PubMed

    Fowler, J D; Miller, C W; Bowen, V; Johnston, G H

    1987-01-01

    Skin defects on the distal extremities of six dogs were reconstructed with free vascular cutaneous transfers by microvascular anastomosis. The donor flaps were based on the superficial cervical artery and vein. In five of the dogs, bone was exposed and skin was lost from half of the circumference of the limb. Two had infected fractures with sequestra and three had acute shearing injuries. The sixth dog had sensory denervation of the left antebrachium and a carpal acral lick granuloma. Before surgery, the patency of potential recipient vessels was confirmed with arteriography in five dogs and an ultrasonic doppler in one dog. Microvascular technique was used to reestablish circulation to the flaps after they were transferred to the recipient site. Total ischemic time of the flaps averaged 100 minutes. All flaps survived. Successful reconstruction of the cutaneous defects was achieved in these six cases. PMID:3507179

  7. Successful reconstruction after resection of malignant skin tumor on triangular fossa using anterior auricular bilobed flap.

    PubMed

    Fujioka, Masaki; Hayashida, Kenji; Morooka, Sin; Saijo, Hiroto

    2015-10-01

    Reconstruction of surgical defects is challenging, especially when they are localized in an anterior surface. The authors present two patients with a malignant skin neoplasm localized in the triangular fossa. Each tumor was removed and the cartilage-exposing wound was reconstructed using an anterior auricular bilobed flap. The donor site of the flap was primarily closed. The viability of the flap was favorable without complications and with excellent esthetic results. There are various surgical procedures for reconstruction of the anterior auricle. Among them, an anterior auricular bilobed flap can be performed quickly, has minimal associated morbidity and yields a favorable outcome. We believe that this technique is an effective option, especially for the triangular fossa skin defect resurfacing. PMID:25893369

  8. Pressure Distribution Over Airfoils with Fowler Flaps

    NASA Technical Reports Server (NTRS)

    Wenzinger, Carl J; Anderson, Walter B

    1938-01-01

    Report presents the results of tests made of a Clark y airfoil with a Clark y Fowler flap and of an NACA 23012 airfoil with NACA Fowler flaps. Some of the tests were made in the 7 by 10-foot wind tunnel and others in the 5-foot vertical wind tunnel. The pressures were measured on the upper and lower surfaces at one chord section both on the main airfoils and on the flaps for several angles of attack with the flaps located at the maximum-lift settings. A test installation was used in which the model was mounted in the wind tunnel between large end planes so that two-dimensional flow was approximated. The data are given in the form of pressure-distribution diagrams and as plots of calculated coefficients for the airfoil-and-flap combinations and for the flaps alone.

  9. Benefits of using omental pedicle flap over muscle flap for closure of open window thoracotomy

    PubMed Central

    Chikaishi, Yasuhiro; Kuwata, Taiji; Takenaka, Masaru; Oka, Soichi; Hirai, Ayako; Imanishi, Naoko; Kuroda, Koji; Tanaka, Fumihiro

    2016-01-01

    Background Open window thoracotomy (OWT) as well as its closure are challenging. Transposition of omental pedicle and muscle flaps is often performed for OWT closure; however, the better technique among the two is unknown. The purpose of this series was to evaluate the outcomes of using both omental pedicle and muscle flaps for the aforementioned closure. Methods This was an observational retrospective cohort study on 27 consecutive patients who underwent OWT closure at a single institution between January 2005 and December 2014. The operation was performed using either omental pedicle or muscle flap with thoracoplasty. We compared both techniques in terms of the patient background [sex, age, body mass index (BMI) and C-reactive protein (CRP) before OWT and serum albumin levels before OWT closure], presence of methicillin-resistant Staphylococcus aureus (MRSA) infection, rate of bronchopleural fistula (BPF), duration of OWT, recurrence of local infection, morbidity, duration of indwelling drainage after operation, success, mortality and postoperative hospital stay. Results There were 9 (33.3%) omental pedicle flap procedures and 18 (66.7%) muscle flap procedures. The rate of local recurrence after closure of OWT was significantly higher with muscle flap than with omental pedicle flap (0% vs. 50.0%, P=0.012). The median duration of postoperative hospital stay was significantly shorter with omental pedicle flap than that with muscle flap (16.0 vs. 41.5 days, P=0.037). Mortality was observed in 2 patients (11.2%) in the muscle flap group and no patient in the omental pedicle flap group. Success rate was similar between the two groups (100% for omental pedicle flap vs. 83.3% for muscle flap). Conclusions Omental pedicle flap was superior to muscle flap in terms of reducing local recurrence and shortening postoperative hospital stay. However, mortality, morbidity and success rates were not affected by the choice of flap. PMID:27499959

  10. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... flaps or slats retracted on one side and extended on the other, the motion of flaps or slats on opposite...) For airplanes with flaps or slats that are not subjected to slipstream conditions, the structure...

  11. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... flaps or slats retracted on one side and extended on the other, the motion of flaps or slats on opposite...) For airplanes with flaps or slats that are not subjected to slipstream conditions, the structure...

  12. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... flaps or slats retracted on one side and extended on the other, the motion of flaps or slats on opposite...) For airplanes with flaps or slats that are not subjected to slipstream conditions, the structure...

  13. Identification of covalent active site inhibitors of dengue virus protease

    PubMed Central

    Koh-Stenta, Xiaoying; Joy, Joma; Wang, Si Fang; Kwek, Perlyn Zekui; Wee, John Liang Kuan; Wan, Kah Fei; Gayen, Shovanlal; Chen, Angela Shuyi; Kang, CongBao; Lee, May Ann; Poulsen, Anders; Vasudevan, Subhash G; Hill, Jeffrey; Nacro, Kassoum

    2015-01-01

    Dengue virus (DENV) protease is an attractive target for drug development; however, no compounds have reached clinical development to date. In this study, we utilized a potent West Nile virus protease inhibitor of the pyrazole ester derivative class as a chemical starting point for DENV protease drug development. Compound potency and selectivity for DENV protease were improved through structure-guided small molecule optimization, and protease-inhibitor binding interactions were validated biophysically using nuclear magnetic resonance. Our work strongly suggests that this class of compounds inhibits flavivirus protease through targeted covalent modification of active site serine, contrary to an allosteric binding mechanism as previously described. PMID:26677315

  14. Four Flaps Technique for Neoumbilicoplasty

    PubMed Central

    Lee, Young Taek; Kwon, Chan; Rhee, Seung Chul; Cho, Sang Hun

    2015-01-01

    The absence or disfigurement of the umbilicus is both cosmetically and psychologically distressing to patients. The goal of aesthetically pleasing umbilical reconstruction is to create a neoumbilicus with sufficient depth and good morphology, with natural-looking superior hooding and minimal scarring. Although many reports have presented techniques for creating new and attractive umbilici, we developed a technique that we term the "four flaps technique" for creating a neoumbilicus in circumstances such as the congenital absence of the umbilicus or the lack of remaining umbilical tissue following the excision of a hypertrophic or scarred umbilicus. This method uses the neighboring tissue by simply elevating four flaps and can yield sufficient depth and an aesthetically pleasing shape with appropriate superior hooding. PMID:26015893

  15. Swiveling a Single Expanded Forehead Flap: A Novel Effective Economical Approach to Total Bilateral Upper and Lower Eyelid Reconstruction.

    PubMed

    Kang, Gavin C; Chen Ong, Wei; Lim, Jane; Sundar, Gangadhara; Lim, Thiam Chye

    2016-03-01

    In our novel approach, a single expanded forehead flap was used to reconstruct bilateral upper and lower eyelids in orbital trauma. A 40-year-old man sustained blast injury resulting in bilateral orbital exenteration and need for bilateral socket and eyelid reconstruction. The sockets were each resurfaced with a temporalis flap. A subgaleal forehead tissue expander was expanded during several weeks until enough tissue was obtained. The single expanded forehead flap was swiveled in stages to reconstruct both upper and lower eyelids beginning with the left eye then the right. With this method, the authors recreated the bilateral upper and lower eyelids with a single pedicled flap and ensured secure retention of prostheses to give an acceptable appearance. The novel approach of swiveling a single expanded pedicled forehead flap to reconstruct bilateral upper and lower eyelids is easy and effective providing adequate like for like autologous tissue, and economical requiring only 1 donor site. PMID:26845091

  16. Axial pattern skin flaps in cats.

    PubMed

    Remedios, A M; Bauer, M S; Bowen, C V; Fowler, J D

    1991-01-01

    The major direct cutaneous vessels identified in the cat include the omocervical, thoracodorsal, deep circumflex iliac, and caudal superficial epigastric arteries. Axial pattern skin flaps based on the thoracodorsal and caudal superficial epigastric arteries have been developed in cats. Rotation of these flaps as islands allows skin coverage to the carpus and metatarsus, respectively. The thoracodorsal and caudal superficial epigastric flaps provide a practical, one-step option in the reconstruction of large skin defects involving the distal extremities of cats. PMID:2011063

  17. Craniotomy flap osteomyelitis: a diagnostic approach

    SciTech Connect

    Blumenkopf, B.; Hartshorne, M.F.; Bauman, J.M.; Cawthon, M.A.; Patton, J.A.; Friedman, A.H.

    1987-01-01

    Nine cases of suspected craniotomy flap osteomyelitis evaluated by combined bone and gallium scanning are presented. In six cases, the clinical data were inconclusive and evaluation by radionuclide imaging provided an accurate negative diagnosis. The other three cases considered positive by this technique were proven infected at subsequent exploration and flap removal. The use of radionuclide bone and gallium imaging should be considered in cases of possible craniotomy flap osteomyelitis.

  18. Wing flapping with minimum energy

    NASA Technical Reports Server (NTRS)

    Jones, R. T.

    1980-01-01

    A technique employed by Prandtl and Munk is adapted for the case of a wing in flapping motion to determine its lift distribution. The problem may be reduced to one of minimizing induced drag for a specified and periodically varying bending moment at the wing root. It is concluded that two wings in close tandem arrangement, moving in opposite phase, would eliminate the induced aerodynamic losses calculated

  19. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer.

    PubMed

    Dinpajooh, Mohammadhasan; Martin, Daniel R; Matyushov, Dmitry V

    2016-01-01

    Enzymes in biology's energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work. PMID:27306204

  20. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer

    NASA Astrophysics Data System (ADS)

    Dinpajooh, Mohammadhasan; Martin, Daniel R.; Matyushov, Dmitry V.

    2016-06-01

    Enzymes in biology’s energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work.

  1. Polarizability of the active site of cytochrome c reduces the activation barrier for electron transfer

    PubMed Central

    Dinpajooh, Mohammadhasan; Martin, Daniel R.; Matyushov, Dmitry V.

    2016-01-01

    Enzymes in biology’s energy chains operate with low energy input distributed through multiple electron transfer steps between protein active sites. The general challenge of biological design is how to lower the activation barrier without sacrificing a large negative reaction free energy. We show that this goal is achieved through a large polarizability of the active site. It is polarized by allowing a large number of excited states, which are populated quantum mechanically by electrostatic fluctuations of the protein and hydration water shells. This perspective is achieved by extensive mixed quantum mechanical/molecular dynamics simulations of the half reaction of reduction of cytochrome c. The barrier for electron transfer is consistently lowered by increasing the number of excited states included in the Hamiltonian of the active site diagonalized along the classical trajectory. We suggest that molecular polarizability, in addition to much studied electrostatics of permanent charges, is a key parameter to consider in order to understand how enzymes work. PMID:27306204

  2. The copper active site of CBM33 polysaccharide oxygenases.

    PubMed

    Hemsworth, Glyn R; Taylor, Edward J; Kim, Robbert Q; Gregory, Rebecca C; Lewis, Sally J; Turkenburg, Johan P; Parkin, Alison; Davies, Gideon J; Walton, Paul H

    2013-04-24

    The capacity of metal-dependent fungal and bacterial polysaccharide oxygenases, termed GH61 and CBM33, respectively, to potentiate the enzymatic degradation of cellulose opens new possibilities for the conversion of recalcitrant biomass to biofuels. GH61s have already been shown to be unique metalloenzymes containing an active site with a mononuclear copper ion coordinated by two histidines, one of which is an unusual τ-N-methylated N-terminal histidine. We now report the structural and spectroscopic characterization of the corresponding copper CBM33 enzymes. CBM33 binds copper with high affinity at a mononuclear site, significantly stabilizing the enzyme. X-band EPR spectroscopy of Cu(II)-CBM33 shows a mononuclear type 2 copper site with the copper ion in a distorted axial coordination sphere, into which azide will coordinate as evidenced by the concomitant formation of a new absorption band in the UV/vis spectrum at 390 nm. The enzyme's three-dimensional structure contains copper, which has been photoreduced to Cu(I) by the incident X-rays, confirmed by X-ray absorption/fluorescence studies of both aqueous solution and intact crystals of Cu-CBM33. The single copper(I) ion is ligated in a T-shaped configuration by three nitrogen atoms from two histidine side chains and the amino terminus, similar to the endogenous copper coordination geometry found in fungal GH61. PMID:23540833

  3. The Copper Active Site of CBM33 Polysaccharide Oxygenases

    PubMed Central

    2013-01-01

    The capacity of metal-dependent fungal and bacterial polysaccharide oxygenases, termed GH61 and CBM33, respectively, to potentiate the enzymatic degradation of cellulose opens new possibilities for the conversion of recalcitrant biomass to biofuels. GH61s have already been shown to be unique metalloenzymes containing an active site with a mononuclear copper ion coordinated by two histidines, one of which is an unusual τ-N-methylated N-terminal histidine. We now report the structural and spectroscopic characterization of the corresponding copper CBM33 enzymes. CBM33 binds copper with high affinity at a mononuclear site, significantly stabilizing the enzyme. X-band EPR spectroscopy of Cu(II)-CBM33 shows a mononuclear type 2 copper site with the copper ion in a distorted axial coordination sphere, into which azide will coordinate as evidenced by the concomitant formation of a new absorption band in the UV/vis spectrum at 390 nm. The enzyme’s three-dimensional structure contains copper, which has been photoreduced to Cu(I) by the incident X-rays, confirmed by X-ray absorption/fluorescence studies of both aqueous solution and intact crystals of Cu-CBM33. The single copper(I) ion is ligated in a T-shaped configuration by three nitrogen atoms from two histidine side chains and the amino terminus, similar to the endogenous copper coordination geometry found in fungal GH61. PMID:23540833

  4. A water tunnel study of Gurney flaps

    NASA Technical Reports Server (NTRS)

    Neuhart, Dan H.; Pendergraft, Odis C., Jr.

    1988-01-01

    Several Gurney flap configurations were tested in the NASA Langley 16 x 24 inch Water Tunnel. These devices provided an increased region of attached flow on a wing upper surface relative to the wing without the flaps. The recirculation region behind the flap was visualized and shown to be consistent with hypotheses stated in previous research. Although the test Reynolds number for this study was several orders of magnitude below those in previous investigations, the effect of the Gurney flaps is in qualitative agreement with them. This is as would be expected from first order effects for high lift devices.

  5. An investigation of the flap edge flowfield

    NASA Astrophysics Data System (ADS)

    Pye, John David

    To identify and understand the fluid dynamic processes associated with flow in the region of a flap side edge, a NACA 63-215 Mod B main element with a half-span Fowler flap was tested in the JIAA Low Speed Wind Tunnel at Stanford University. Measurements were made using a variety of techniques to capture the effects of the flap edge vortex. Pressure sensitive paint was applied to the upper surface of both the flap and main element, as well as to the flap side edge. Fast response pressure transducers were mounted interior to the model to measure surface pressure fluctuations on the flap side edge. Single component hotwire data was taken in the near wake region of the flap edge. In addition to the data experimentally obtained, a computational data set of a geometrically similar model at a flight Reynolds number was used for comparison. The data indicates the presence of a dual vortex structure along the flap side edge. This structure is seen to grow, merge, and ultimately become a single symmetric vortex as it progresses downstream. Surface pressure fluctuations on the side edge scale as three power laws with free stream velocity as different flow regions are encountered. By varying the model rigging, indications of a confined source region for the pressure fluctuations were observed. A spatial survey of the correlation between flap side edge surface pressure fluctuations and the near-wake fluctuating velocity field shows increased correlation coefficients for the region surrounding the vortex core.

  6. Microsurgical free flaps: Controversies in maxillofacial reconstruction

    PubMed Central

    George, Rinku K.; Krishnamurthy, Arvind

    2013-01-01

    Reconstructive microsurgery for oral and maxillofacial (OMF) defects is considered as a niche specialty and is performed regularly only in a handful of centers. Till recently the pectoralis major myocutaneous flap (PMMC) was considered to be the benchmark for OMF reconstruction. This philosophy is changing fast with rapid advancement in reconstructive microsurgery. Due to improvement in instrumentation and the development of finer techniques of flap harvesting we can positively state that microsurgery has come of age. Better techniques, microscopes and micro instruments enable us to do things previously unimaginable. Supramicrosurgery and ultrathin flaps are a testimony to this. Years of innovation in reconstructive microsurgery have given us a reasonably good number of very excellent flaps. Tremendous work has been put into producing some exceptionally brilliant research articles, sometimes contradicting each other. This has led to the need for clarity in some areas in this field. This article will review some controversies in reconstructive microsurgery and analyze some of the most common microvascular free flaps (MFF) used in OMF reconstruction. It aims to buttress the fact that three flaps-the radial forearm free flap (RFFF), anterolateral thigh flap (ALT) and fibula are the ones most expedient in the surgeon's arsenal, since they can cater to almost all sizeable defects we come across after ablative surgery in the OMF region. They can thus aptly be titled as the workhorses of OMF reconstruction with regard to free flaps. PMID:23662264

  7. Optimal propulsive flapping in Stokes flows.

    PubMed

    Was, Loïc; Lauga, Eric

    2014-03-01

    Swimming fish and flying insects use the flapping of fins and wings to generate thrust. In contrast, microscopic organisms typically deform their appendages in a wavelike fashion. Since a flapping motion with two degrees of freedom is able, in theory, to produce net forces from a time-periodic actuation at all Reynolds numbers, we compute in this paper the optimal flapping kinematics of a rigid spheroid in a Stokes flow. The hydrodynamics for the force generation and energetics of the flapping motion is solved exactly. We then compute analytically the gradient of a flapping efficiency in the space of all flapping gaits and employ it to derive numerically the optimal flapping kinematics as a function of the shape of the flapper and the amplitude of the motion. The kinematics of optimal flapping are observed to depend weakly on the flapper shape and are very similar to the figure-eight motion observed in the motion of insect wings. Our results suggest that flapping could be a exploited experimentally as a propulsion mechanism valid across the whole range of Reynolds numbers. PMID:24343130

  8. Basic Perforator Flap Hemodynamic Mathematical Model

    PubMed Central

    Tao, Youlun; Ding, Maochao; Wang, Aiguo; Zhuang, Yuehong; Chang, Shi-Min; Mei, Jin; Hallock, Geoffrey G.

    2016-01-01

    Background: A mathematical model to help explain the hemodynamic characteristics of perforator flaps based on blood flow resistance systems within the flap will serve as a theoretical guide for the future study and clinical applications of these flaps. Methods: There are 3 major blood flow resistance network systems of a perforator flap. These were defined as the blood flow resistance of an anastomosis between artery and artery of adjacent perforasomes, between artery and vein within a perforasome, and then between vein and vein corresponding to the outflow of that perforasome. From this, a calculation could be made of the number of such blood flow resistance network systems that must be crossed for all perforasomes within a perforator flap to predict whether that arrangement would be viable. Results: The summation of blood flow resistance networks from each perforasome in a given perforator flap could predict which portions would likely survive. This mathematical model shows how this is directly dependent on the location of the vascular pedicle to the flap and whether supercharging or superdrainage maneuvers have been added. These configurations will give an estimate of the hemodynamic characteristics for the given flap design. Conclusions: This basic mathematical model can (1) conveniently determine the degree of difficulty for each perforasome within a perforator flap to survive; (2) semiquantitatively allow the calculation of basic hemodynamic parameters; and (3) allow the assessment of the pros and cons expected for each pattern of perforasomes encountered clinically based on predictable hemodynamic observations.

  9. A new classification of spreader flap techniques.

    PubMed

    Wurm, Jochen; Kovacevic, Milos

    2013-12-01

    The objective of this study was to introduce various spreader flap technique modifications to adjust the width of the middle nasal vault in patients who underwent rhinoplasties with humpectomy. Decisive modifications of current spreader flap techniques were performed to allow a more natural restoration of the middle nasal vault and the internal nasal valve after humpectomy. Additional steps provide tools to adjust the width and shape of the middle nasal vault according to patients' requirements. The techniques were categorized into "basic spreader flaps," "flaring spreader flaps," "support spreader flaps," and "interrupted spreader flaps." The various spreader flap techniques were used during 576 primary septorhinoplasties in patients with hump noses, hump/crooked noses, or hump/tension noses. The average follow-up was 19 months. Patients who received basic spreader flaps or a flaring spreader flaps tended to show a slightly too wide middle nasal vault, revision surgery was necessary in four of these cases. All other patients showed an appropriate width in the middle nasal vault and an aesthetically pleasing course of the dorsal aesthetic lines. No signs of inverted v deformities or collapse of the internal nasal valve were observed in any of the patients. Patients who had reported impaired nasal breathing preoperatively described clearly improved subjective symptoms. The described techniques appear to be appropriate and highly promising as a supplement to existing procedures for reconstructing the middle nasal vault and internal nasal valves. No additional cartilage grafts are needed. PMID:24327250

  10. Arterialized Venous Bone Flaps: An Experimental Investigation

    PubMed Central

    Borumandi, Farzad; Higgins, James P.; Buerger, Heinz; Vasilyeva, Anna; Benlidayi, Memmet Emre; Sencar, Leman; Gaggl, Alexander

    2016-01-01

    In arterialized venous flaps (AVFs) the venous network is used to revascularize the flap. While the feasibility of AVFs in soft tissues has been reported there is no study on osseous AVFs. In this study we aim to assess the flap survival of osseous AVFs in a pig model. Medial femoral condyle flaps were elevated in 18 pigs. Three groups were created: AVF (n = 6), conventional arterial flap (cAF, n = 6) and bone graft (BG, n = 6). The AVFs were created by anastomosis of genicular artery with one vena comitans while leaving one efferent vein for drainage. After 6 months the specimens were harvested. The histology and histomorphometry of of the bone in cAF and AVF was significantly superior to bone grafts with a higher bone volume in AVFs (p = 0.01). This study demonstrates that osseous free flaps may be supported and survive using the technique of arterialization of the venous network. The concept of AVFs in osseous flaps may be feasible for revascularization of free flaps with an inadequate artery but well developed veins. Further experimental and clinical studies are needed to assess the feasibility of clinical use of arterialized venous bone flaps. PMID:27558705

  11. Arterialized Venous Bone Flaps: An Experimental Investigation.

    PubMed

    Borumandi, Farzad; Higgins, James P; Buerger, Heinz; Vasilyeva, Anna; Benlidayi, Memmet Emre; Sencar, Leman; Gaggl, Alexander

    2016-01-01

    In arterialized venous flaps (AVFs) the venous network is used to revascularize the flap. While the feasibility of AVFs in soft tissues has been reported there is no study on osseous AVFs. In this study we aim to assess the flap survival of osseous AVFs in a pig model. Medial femoral condyle flaps were elevated in 18 pigs. Three groups were created: AVF (n = 6), conventional arterial flap (cAF, n = 6) and bone graft (BG, n = 6). The AVFs were created by anastomosis of genicular artery with one vena comitans while leaving one efferent vein for drainage. After 6 months the specimens were harvested. The histology and histomorphometry of of the bone in cAF and AVF was significantly superior to bone grafts with a higher bone volume in AVFs (p = 0.01). This study demonstrates that osseous free flaps may be supported and survive using the technique of arterialization of the venous network. The concept of AVFs in osseous flaps may be feasible for revascularization of free flaps with an inadequate artery but well developed veins. Further experimental and clinical studies are needed to assess the feasibility of clinical use of arterialized venous bone flaps. PMID:27558705

  12. An Active Site Water Network in the Plasminogen Activator Pla from Yersinia pestis

    SciTech Connect

    Eren, Elif; Murphy, Megan; Goguen, Jon; van den Berg, Bert

    2010-08-13

    The plasminogen activator Pla from Yersinia pestis is an outer membrane protease (omptin) that is important for the virulence of plague. Here, we present the high-resolution crystal structure of wild-type, enzymatically active Pla at 1.9 {angstrom}. The structure shows a water molecule located between active site residues D84 and H208, which likely corresponds to the nucleophilic water. A number of other water molecules are present in the active site, linking residues important for enzymatic activity. The R211 sidechain in loop L4 is close to the nucleophilic water and possibly involved in the stabilization of the oxyanion intermediate. Subtle conformational changes of H208 result from the binding of lipopolysaccharide to the outside of the barrel, explaining the unusual dependence of omptins on lipopolysaccharide for activity. The Pla structure suggests a model for the interaction with plasminogen substrate and provides a more detailed understanding of the catalytic mechanism of omptin proteases.

  13. Target-classification approach applied to active UXO sites

    NASA Astrophysics Data System (ADS)

    Shubitidze, F.; Fernández, J. P.; Shamatava, Irma; Barrowes, B. E.; O'Neill, K.

    2013-06-01

    This study is designed to illustrate the discrimination performance at two UXO active sites (Oklahoma's Fort Sill and the Massachusetts Military Reservation) of a set of advanced electromagnetic induction (EMI) inversion/discrimination models which include the orthonormalized volume magnetic source (ONVMS), joint diagonalization (JD), and differential evolution (DE) approaches and whose power and flexibility greatly exceed those of the simple dipole model. The Fort Sill site is highly contaminated by a mix of the following types of munitions: 37-mm target practice tracers, 60-mm illumination mortars, 75-mm and 4.5'' projectiles, 3.5'', 2.36'', and LAAW rockets, antitank mine fuzes with and without hex nuts, practice MK2 and M67 grenades, 2.5'' ballistic windshields, M2A1-mines with/without bases, M19-14 time fuzes, and 40-mm practice grenades with/without cartridges. The site at the MMR site contains targets of yet different sizes. In this work we apply our models to EMI data collected using the MetalMapper (MM) and 2 × 2 TEMTADS sensors. The data for each anomaly are inverted to extract estimates of the extrinsic and intrinsic parameters associated with each buried target. (The latter include the total volume magnetic source or NVMS, which relates to size, shape, and material properties; the former includes location, depth, and orientation). The estimated intrinsic parameters are then used for classification performed via library matching and the use of statistical classification algorithms; this process yielded prioritized dig-lists that were submitted to the Institute for Defense Analyses (IDA) for independent scoring. The models' classification performance is illustrated and assessed based on these independent evaluations.

  14. Differential Active Site Loop Conformations Mediate Promiscuous Activities in the Lactonase SsoPox

    PubMed Central

    Elias, Mikael; Chabriere, Eric

    2013-01-01

    Enzymes are proficient catalysts that enable fast rates of Michaelis-complex formation, the chemical step and products release. These different steps may require different conformational states of the active site that have distinct binding properties. Moreover, the conformational flexibility of the active site mediates alternative, promiscuous functions. Here we focused on the lactonase SsoPox from Sulfolobus solfataricus. SsoPox is a native lactonase endowed with promiscuous phosphotriesterase activity. We identified a position in the active site loop (W263) that governs its flexibility, and thereby affects the substrate specificity of the enzyme. We isolated two different sets of substitutions at position 263 that induce two distinct conformational sampling of the active loop and characterized the structural and kinetic effects of these substitutions. These sets of mutations selectively and distinctly mediate the improvement of the promiscuous phosphotriesterase and oxo-lactonase activities of SsoPox by increasing active-site loop flexibility. These observations corroborate the idea that conformational diversity governs enzymatic promiscuity and is a key feature of protein evolvability. PMID:24086491

  15. Medial sural artery perforator free flap: legitimate use as a solution for the ipsilateral distal lower extremity defect.

    PubMed

    Hallock, Geoffrey G

    2014-03-01

    The medial sural artery perforator (MSAP) flap captures the cutaneous territory of the medial calf, and can potentially be advantageous as a thin free flap, even in the most obese individual, for coverage of most foot and/or ankle defects where bulk is a liability. The anatomy is fairly constant, as usually at least one reasonably large perforator can always be found emanating from the medial head of the gastrocnemius muscle. As a microsurgical tissue transfer, a long vascular pedicle of large caliber is routinely possible which facilitates any requisite microanastomoses.Over the past decade from our free flap registry, 14 patients with distal lower extremity wounds were covered specifically with a perforator flap based on the ipsilateral medial sural artery; out of which only 2 (14%) were females.In this series using a MSAP free flap, there was only one failure requiring salvage by a different free flap. All but one case was a sequel of trauma, and these involved all zones of the foot and ankle. A skin graft of the donor site was necessary in 5/14 (36%) patients. In no cases did the flap subsequently impede the use of shoes nor hinder ambulation.The study concluded the major disadvantage of the MSAP flap is the nonaesthetic scar left at the donor site which can be quite conspicuous, especially if a skin graft had to be used. Yet even this detriment can be acceptable for ipsilateral distal lower extremity defects where reconstruction of the defect itself may be cosmetically unappealing. This may be the best indication for the MSAP flap to be considered first as the free flap of choice. PMID:24114709

  16. Inferior Gluteal Artery Perforator Flap for Sacral Pressure Ulcer Reconstruction: A Retrospective Case Study of 11 Patients.

    PubMed

    Lin, Chin-Ta; Ou, Kuang-Wen; Chiao, Hao-Yu; Wang, Chi-Yu; Chou, Chang-Yi; Chen, Shyi-Gen; Lee, Tzu-Peng

    2016-01-01

    Despite advances in reconstruction techniques, sacral pressure ulcers continue to present a challenge to the plastic surgeon. The flap from the gluteal crease derives blood supply from the inferior gluteal artery perforator (IGAP) and reliably preserves the entire contralateral side as a donor site. To incorporate the IGAP in the reconstruction of sacral pressure ulcers, a skin paddle over the gluteal crease was created and implemented by the authors. Data from 11 patients (8 men, 3 women; mean age 67 [range 44-85] years old) whose sacral ulcers were closed with an IGAP flap between June 2006 and May 2012 were retrieved and reviewed. All patients were bedridden; 1 patient in a vegetative state with a diagnosis of carbon monoxide intoxication was referred from a local clinic, 2 patients had Parkinson's disease, and 8 patients had a history of stroke. The average defect size was 120 cm(2) (range 88-144 cm(2)). The average flap size was 85.8 cm(2) (range 56-121 cm(2)). Only 1 flap failure occurred during surgery and was converted into V-Y advancement flap; 10 of the 11 flaps survived. After surgery, the patients' position was changed every 2 hours; patients remained prone or on their side for approximately 2 weeks until the flap was healed. After healing was confirmed, patients were discharged. Complications were relatively minor and included 1 donor site wound dehiscence that required wound reapproximation. No surgery-related mortality was noted; the longest follow-up period was 24 months. In this case series, flaps from the gluteal crease were successfully used for surgical closure of sacral pressure ulcers. This flap design should be used with caution in patients with hip contractures. Studies with larger sample sizes are needed to ascertain which type of flap is best suited to surgically manage extensive pressure ulcers in a variety of patient populations. PMID:26779702

  17. Reconstruction of Large Cheek Defect With/Without Sideburn Using Malar-Posterior Auricular-Cervico Flap.

    PubMed

    Hayashi, Toshihiko; Yamamoto, Yuhei; Oyama, Akihiko; Funayama, Emi; Shichinohe, Ryuji; Murao, Naoki; Furukawa, Hiroshi

    2016-08-01

    The cheek region is the most common site for malignant tumor occurrence and the treatment of malignant skin tumor requires extensive local excision. Many previous reports have covered methods of reconstruction using local flaps for skin defects in the cheek region.In this article, we describe our experience with a surgical reconstruction using a new flap method for 8 patients with missing tissue in the cheek region. This flap is based on the concept of separately designing the flap with the 3 areas comprising the malar, posterior auricular, and cervical regions. We named the flap containing these 3 regions the malar-posterior auricular-cervico flap. Esthetically satisfactory outcomes were achieved in all cases.In conclusion, we recommend our malar-posterior auricular-cervico flap to reconstruct the tissue defects of approximately 20 to 40 cm after tumor excision in the cheek region. If preauricular skin is included in the design of this flap, the sideburn can be reconstructed using a part of the nape region with hair. PMID:26559648

  18. Spectroscopic Definition of the Ferroxidase Site in M Ferritin: Comparison of Binuclear Substrate vs. Cofactor Active Sites

    PubMed Central

    Schwartz, Jennifer K.; Liu, Xiaofeng S.; Tosha, Takehiko; Theil, Elizabeth C.; Solomon, Edward I.

    2008-01-01

    Maxi ferritins, 24 subunit protein nanocages, are essential in humans, plants, bacteria, and other animals for the concentration and storage of iron as hydrated ferric oxide, while minimizing free radical generation or use by pathogens. Formation of the precursors to these ferric oxides is catalyzed at a non-heme biferrous substrate site, which has some parallels with the cofactor sites in other biferrous enzymes. A combination of circular dichroism (CD), magnetic circular dichroism (MCD), and variable-temperature, variable-field MCD (VTVH MCD) has been used to probe Fe(II) binding to the substrate active site in frog M ferritin. These data determined that the active site within each subunit consists of two inequivalent five-coordinate (5C) ferrous centers that are weakly anti-ferromagnetically coupled, consistent with a μ-1,3 carboxylate bridge. The active site ligand set is unusual and likely includes a terminal water bound to each Fe(II) center. The Fe(II) ions bind to the active sites in a concerted manner, and cooperativity among the sites in each subunit is observed, potentially providing a mechanism for the control of ferritin iron loading. Differences in geometric and electronic structure – including a weak ligand field, availability of two water ligands at the biferrous substrate site, and the single carboxylate bridge in ferritin – coincide with the divergent reaction pathways observed between this substrate site and the previously studied cofactor active sites. PMID:18576633

  19. Metal active site elasticity linked to activation of homocysteine in methionine synthases

    SciTech Connect

    Koutmos, Markos; Pejchal, Robert; Bomer, Theresa M.; Matthews, Rowena G.; Smith, Janet L.; Ludwig, Martha L.

    2008-04-02

    Enzymes possessing catalytic zinc centers perform a variety of fundamental processes in nature, including methyl transfer to thiols. Cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthases are two such enzyme families. Although they perform the same net reaction, transfer of a methyl group from methyltetrahydrofolate to homocysteine (Hcy) to form methionine, they display markedly different catalytic strategies, modular organization, and active site zinc centers. Here we report crystal structures of zinc-replete MetE and MetH, both in the presence and absence of Hcy. Structural investigation of the catalytic zinc sites of these two methyltransferases reveals an unexpected inversion of zinc geometry upon binding of Hcy and displacement of an endogenous ligand in both enzymes. In both cases a significant movement of the zinc relative to the protein scaffold accompanies inversion. These structures provide new information on the activation of thiols by zinc-containing enzymes and have led us to propose a paradigm for the mechanism of action of the catalytic zinc sites in these and related methyltransferases. Specifically, zinc is mobile in the active sites of MetE and MetH, and its dynamic nature helps facilitate the active site conformational changes necessary for thiol activation and methyl transfer.

  20. Evidence for segmental mobility in the active site of pepsin

    SciTech Connect

    Pohl, J.; Strop, P.; Senn, H.; Foundling, S.; Kostka, V.

    1986-05-01

    The low hydrolytic activity (k/sub cat/ < 0.001 s/sup -1/) of chicken pepsin (CP) towards tri- and tetrapeptides is enhanced at least 100 times by modification of its single sulfhydryl group of Cys-115, with little effect on K/sub m/-values. Modification thus simulates the effect of secondary substrate binding on pepsin catalysis. The rate of Cys-115 modification is substantially decreased in the presence of some competitive inhibitors, suggesting its active site location. Experiments with CP alkylated at Cys-115 with Acrylodan as a fluorescent probe or with N-iodoacetyl-(4-fluoro)-aniline as a /sup 19/F-nmr probe suggest conformation change around Cys-115 to occur on substrate or substrate analog binding. The difference /sup 1/H-nmr spectra (500 MHz) of unmodified free and inhibitor-complexed CP reveal chemical shifts almost exclusively in the aromatic region. The effects of Cu/sup + +/ on /sup 19/F- and /sup 1/H-nmr spectra have been studied. Examination of a computer graphics model of CP based on E. parasitica pepsin-inhibitor complex X-ray coordinates suggests that Cys-115 is located near the S/sub 3//S/sub 5/ binding site. The results are interpreted in favor of segmental mobility of this region important for pepsin substrate binding and catalysis.

  1. Perchlorate Reductase Is Distinguished by Active Site Aromatic Gate Residues.

    PubMed

    Youngblut, Matthew D; Tsai, Chi-Lin; Clark, Iain C; Carlson, Hans K; Maglaqui, Adrian P; Gau-Pan, Phonchien S; Redford, Steven A; Wong, Alan; Tainer, John A; Coates, John D

    2016-04-22

    Perchlorate is an important ion on both Earth and Mars. Perchlorate reductase (PcrAB), a specialized member of the dimethylsulfoxide reductase superfamily, catalyzes the first step of microbial perchlorate respiration, but little is known about the biochemistry, specificity, structure, and mechanism of PcrAB. Here we characterize the biophysics and phylogeny of this enzyme and report the 1.86-Å resolution PcrAB complex crystal structure. Biochemical analysis revealed a relatively high perchlorate affinity (Km = 6 μm) and a characteristic substrate inhibition compared with the highly similar respiratory nitrate reductase NarGHI, which has a relatively much lower affinity for perchlorate (Km = 1.1 mm) and no substrate inhibition. Structural analysis of oxidized and reduced PcrAB with and without the substrate analog SeO3 (2-) bound to the active site identified key residues in the positively charged and funnel-shaped substrate access tunnel that gated substrate entrance and product release while trapping transiently produced chlorate. The structures suggest gating was associated with shifts of a Phe residue between open and closed conformations plus an Asp residue carboxylate shift between monodentate and bidentate coordination to the active site molybdenum atom. Taken together, structural and mutational analyses of gate residues suggest key roles of these gate residues for substrate entrance and product release. Our combined results provide the first detailed structural insight into the mechanism of biological perchlorate reduction, a critical component of the chlorine redox cycle on Earth. PMID:26940877

  2. Eel calcitonin binding site distribution and antinociceptive activity in rats

    SciTech Connect

    Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

    1986-03-01

    The distribution of binding site for (/sup 125/I)-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing (/sup 125/I)-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain.

  3. Active Sites Environmental Monitoring Program: Program plan. Revision 1

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  4. The deep circumflex iliac artery perforator flap (DCIAP)--a reconstructive option for the large composite oro-mandibular cutaneous defect.

    PubMed

    Bisase, Brian; Sloane, James; Coombes, Darryl M; Norris, Paul M

    2013-12-01

    The deep circumflex iliac artery (DCIA) flap is often used for mandibular reconstruction but it is bulky and causes additional donor-site morbidity because of the inclusion of an "obligatory internal oblique muscle". Large composite segmental mandibular resections that consist of floor of mouth, subtotal tongue, and adjacent facial skin are a challenge in terms of reconstruction. They often require 2 free flaps or a free scapular flap and both have disadvantages. The deep circumflex iliac artery perforator (DCIAP) flap with a cutaneous component overcomes the disadvantages. We describe reconstructions with DCIAP flaps in 3 patients with large mandibular composite segmental defects. We report our experience of the flap and discuss some of the difficulties we encountered and the points we learned perioperatively. PMID:23891263

  5. Active Site and Laminarin Binding in Glycoside Hydrolase Family 55*

    PubMed Central

    Bianchetti, Christopher M.; Takasuka, Taichi E.; Deutsch, Sam; Udell, Hannah S.; Yik, Eric J.; Bergeman, Lai F.; Fox, Brian G.

    2015-01-01

    The Carbohydrate Active Enzyme (CAZy) database indicates that glycoside hydrolase family 55 (GH55) contains both endo- and exo-β-1,3-glucanases. The founding structure in the GH55 is PcLam55A from the white rot fungus Phanerochaete chrysosporium (Ishida, T., Fushinobu, S., Kawai, R., Kitaoka, M., Igarashi, K., and Samejima, M. (2009) Crystal structure of glycoside hydrolase family 55 β-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J. Biol. Chem. 284, 10100–10109). Here, we present high resolution crystal structures of bacterial SacteLam55A from the highly cellulolytic Streptomyces sp. SirexAA-E with bound substrates and product. These structures, along with mutagenesis and kinetic studies, implicate Glu-502 as the catalytic acid (as proposed earlier for Glu-663 in PcLam55A) and a proton relay network of four residues in activating water as the nucleophile. Further, a set of conserved aromatic residues that define the active site apparently enforce an exo-glucanase reactivity as demonstrated by exhaustive hydrolysis reactions with purified laminarioligosaccharides. Two additional aromatic residues that line the substrate-binding channel show substrate-dependent conformational flexibility that may promote processive reactivity of the bound oligosaccharide in the bacterial enzymes. Gene synthesis carried out on ∼30% of the GH55 family gave 34 active enzymes (19% functional coverage of the nonredundant members of GH55). These active enzymes reacted with only laminarin from a panel of 10 different soluble and insoluble polysaccharides and displayed a broad range of specific activities and optima for pH and temperature. Application of this experimental method provides a new, systematic way to annotate glycoside hydrolase phylogenetic space for functional properties. PMID:25752603

  6. Active site and laminarin binding in glycoside hydrolase family 55.

    PubMed

    Bianchetti, Christopher M; Takasuka, Taichi E; Deutsch, Sam; Udell, Hannah S; Yik, Eric J; Bergeman, Lai F; Fox, Brian G

    2015-05-01

    The Carbohydrate Active Enzyme (CAZy) database indicates that glycoside hydrolase family 55 (GH55) contains both endo- and exo-β-1,3-glucanases. The founding structure in the GH55 is PcLam55A from the white rot fungus Phanerochaete chrysosporium (Ishida, T., Fushinobu, S., Kawai, R., Kitaoka, M., Igarashi, K., and Samejima, M. (2009) Crystal structure of glycoside hydrolase family 55 β-1,3-glucanase from the basidiomycete Phanerochaete chrysosporium. J. Biol. Chem. 284, 10100-10109). Here, we present high resolution crystal structures of bacterial SacteLam55A from the highly cellulolytic Streptomyces sp. SirexAA-E with bound substrates and product. These structures, along with mutagenesis and kinetic studies, implicate Glu-502 as the catalytic acid (as proposed earlier for Glu-663 in PcLam55A) and a proton relay network of four residues in activating water as the nucleophile. Further, a set of conserved aromatic residues that define the active site apparently enforce an exo-glucanase reactivity as demonstrated by exhaustive hydrolysis reactions with purified laminarioligosaccharides. Two additional aromatic residues that line the substrate-binding channel show substrate-dependent conformational flexibility that may promote processive reactivity of the bound oligosaccharide in the bacterial enzymes. Gene synthesis carried out on ∼30% of the GH55 family gave 34 active enzymes (19% functional coverage of the nonredundant members of GH55). These active enzymes reacted with only laminarin from a panel of 10 different soluble and insoluble polysaccharides and displayed a broad range of specific activities and optima for pH and temperature. Application of this experimental method provides a new, systematic way to annotate glycoside hydrolase phylogenetic space for functional properties. PMID:25752603

  7. Active Site Loop Conformation Regulates Promiscuous Activity in a Lactonase from Geobacillus kaustophilus HTA426

    PubMed Central

    Zhang, Yu; An, Jiao; Yang, Guang-Yu; Bai, Aixi; Zheng, Baisong; Lou, Zhiyong; Wu, Geng; Ye, Wei; Chen, Hai-Feng; Feng, Yan; Manco, Giuseppe

    2015-01-01

    Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL) from Geobacillus kaustophilus HTA426 (GkaP) exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a “hot spot” in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km) toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity. PMID:25706379

  8. Anteriorly Based Partial Thickness Sternocleidomastoid Muscle Flap Following Parotidectomy.

    PubMed

    Dalmia, Deepak; Behera, Sanjaya Kumar; Bhatia, Jas Simran Singh

    2016-03-01

    The anteriorly based partial thickness sternocleidomastoid (SCM) muscle flap is among the various methods described to correct parotidectomy defects, but its indications and limitations are not clearly demonstrated in several reports. This study was done to test the aesthetic outcome of this method, its indications and limitations. At Dr. Babasaheb Ambedkar Memorial hospital, Mumbai, 20 patients presenting with benign parotid tumors underwent parotidectomy. 16 underwent superficial parotidectomy and 3 underwent adequate parotidectomy, 1 had total parotidectomy. The anteriorly based partial thickness SCM muscle flap was used to correct the contour deformity and to prevent Frey syndrome. The aesthetic result was evaluated by assessing and scoring the overall appearance of the scar, the degree of symmetry of the reconstructed parotid region and the site of the donor muscle in comparison to their contralateral normal sides. The overall aesthetic appearance was good in 17 patients, and moderate in 3 patients. 17/20 patients had an overall deep satisfaction with the result. The residual hollowness following total parotidectomy defect and the poor quality of scars were the main reasons affecting the aesthetic outcome. Superficial parotidectomy through modified Blair's incision with immediate reconstruction with anteriorly based partial thickness SCM flap allows a satisfactory aesthetic outcome and minimal donor site morbidity. Scores of the above two parameters were accessed. Patients' satisfaction was assessed by patients questionnaire. PMID:27066413

  9. Design and analysis of rotor systems with multiple trailing edge flaps and resonant actuators

    NASA Astrophysics Data System (ADS)

    Kim, Jun-Sik

    The purpose of this thesis is to develop piezoelectric resonant actuation systems and new active control methods utilizing the multiple trailing-edge flaps' configuration for rotorcraft vibration suppression and blade loads control. An aeroelastic model is developed for a composite rotor blade with multiple trailing-edge flaps. The rotor blade airloads are calculated using quasi-steady blade element aerodynamics with a free wake model for rotor inflow. A compressible unsteady aerodynamics model is employed to accurately predict the incremental trailing edge flap airloads. Both the finite wing effect and actuator saturation for trailing-edge flaps are also included in an aeroelastic analysis. For a composite articulated rotor, a new active blade loads control method is developed and tested numerically. The concept involves straightening the blade by introducing dual trailing edge flaps. The objective function, which includes vibratory hub loads, bending moment harmonics and active flap control inputs, is minimized by an integrated optimal control/optimization process. A numerical simulation is performed for the steady-state forward flight of an advance ratio of 0.35. It is demonstrated that through straightening the rotor blade, which mimics the behavior of a rigid blade, both the bending moments and vibratory hub loads can be significantly reduced by 32% and 57%, respectively. An active vibration control method is developed and analyzed for a hingeless rotor. The concept involves deflecting each individual trailing-edge flap using a compact resonant actuation system. Each resonant actuation system could yield high authority, while operating at a single frequency. Parametric studies are conducted to explore the finite wing effect of trailing-edge flaps and actuator saturation. A numerical simulation has been performed for the steady-state forward flight (mu = 0.15 ˜ 0.35). It is demonstrated that multiple trailing-edge flap configuration with the resonant actuation

  10. Development of an improved aeroelastic model for the investigation of vibration reduction in helicopter rotors using trailing edge flaps

    NASA Astrophysics Data System (ADS)

    Myrtle, Timothy Fitzgerald

    1998-12-01

    This dissertation describes the development of an aeroelastic model of a helicopter rotor incorporating partial span trailing edge flaps on the blade and its application to the investigation of vibration reduction using active control. A new two-dimensional unsteady aerodynamic model for an airfoil/flap combination is described that includes compressibility and unsteady freestream effects. This new aerodynamic model is based on a rational function approximation (RFA) approach. In this approach, oscillatory response data obtained for a selected set of generalized airfoil and flap motions is used to generate an approximate aerodynamic transfer function which can be transformed to the time domain to form a state space aerodynamic model. In this dissertation, a method is described for adapting the conventional RFA approach to include unsteady freestream effects. Excellent agreement is demonstrated between the response of the new aerodynamic model and an exact incompressible solution to the unsteady freestream case. This model provides a complete description of the unsteady flap hinge moments due to airfoil and flap motion, allowing a complete and accurate characterization of control actuation requirements. The structural model utilizes an elastic blade model which includes fully coupled flap-lag-torsional dynamics and includes the effects of moderate deflections. The aeroelastic model is formulated in the time domain, with the coupled trim/response solution obtained using direct numerical integration in combination with autopilot type controller. A conventional higher harmonic control approach is used to investigate vibration reduction. Vibration control studies are performed which compare results using the new aerodynamic model and incompressible quasisteady Theodorsen aerodynamics. Significant differences were observed in the required deflections and control moments, indicating that compressibility and unsteady effects are necessary to properly characterize the

  11. Extensive site-directed mutagenesis reveals interconnected functional units in the alkaline phosphatase active site.

    PubMed

    Sunden, Fanny; Peck, Ariana; Salzman, Julia; Ressl, Susanne; Herschlag, Daniel

    2015-01-01

    Enzymes enable life by accelerating reaction rates to biological timescales. Conventional studies have focused on identifying the residues that have a direct involvement in an enzymatic reaction, but these so-called 'catalytic residues' are embedded in extensive interaction networks. Although fundamental to our understanding of enzyme function, evolution, and engineering, the properties of these networks have yet to be quantitatively and systematically explored. We dissected an interaction network of five residues in the active site of Escherichia coli alkaline phosphatase. Analysis of the complex catalytic interdependence of specific residues identified three energetically independent but structurally interconnected functional units with distinct modes of cooperativity. From an evolutionary perspective, this network is orders of magnitude more probable to arise than a fully cooperative network. From a functional perspective, new catalytic insights emerge. Further, such comprehensive energetic characterization will be necessary to benchmark the algorithms required to rationally engineer highly efficient enzymes. PMID:25902402

  12. [The super extended sub-mental flap or combo sub-mental flap].

    PubMed

    Martin, D

    2014-08-01

    The author presents a technical variation of the sub-mental flap including in a conventional pedicled flap both sub-mental axes and their anastomoses on the midline. The assessment of the first flaps raised according to this method confirms the improvement of the distal blood supply. It allows the possibility to harvest "super extended" flaps reaching the contralateral auricular lobula. This variation can be considered as an axial flap which only the tip, located beyond the mandibular angle, is at random. The evolution of the sub-mental flap from its original description to this variation called "combo sub-mental flap" is then presented. Its reliability and the technical simplification it provides will have to be assessed in the future. PMID:24840945

  13. Secondary onlay free flap reconstruction of glossectomy defects following initial successful flap restoration.

    PubMed

    Rihani, Jordan; Lee, Thomas; Ducic, Yadranko

    2013-08-01

    Patients who undergo tongue reconstruction over time may develop gradual worsening of dysarthria and dysphagia secondary to flap atrophy. At our institution, these patients undergo a secondary flap onlay procedure for augmentation of the neotongue. We review a total of 11 patients with total glossectomy defect who underwent secondary tongue augmentation with secondary onlay free flap consisting of radial forearm free flap (n = 6) and rectus free flap (n = 5). There was improvement in swallowing in 7 of 11 patients. Five (45.4%) patients achieved gastric tube independence. Seven (63.6%) patients achieved a varying degree of oral intake. All patients achieved tracheostomy independence. Dysarthria was improved in all patients. There were no flap failures. Therefore, a secondary onlay flap technique is feasible and may improve dysphagia and dysarthria to achieve gastric tube and tracheostomy independence in total glossectomy patients with delayed tongue atrophy. PMID:23625797

  14. Distally based sural artery flap without sural nerve.

    PubMed

    Motamed, Sadrollah; Yavari, Masood; Mofrad, Hamid Reza Hallaj; Rafiee, Reza; Shahraki, Feaz Niazi

    2010-01-01

    The distal third of the tibia, ankle and heel area is difficult to reconstruct. For small to medium size defects, local flaps are often an easier alternative than free flap. In lower limb surgery, the sural flap is based on this principle and this flap is becoming increasingly popular. The distally based superficial sural artery flap, first described as a distally based neuro skin flap by masquelet et al., is a skin island flap supplied by the vascular axis of the sural nerve. The main disadvantage of distally based sural artery flap is sacrifice of the sural nerve because it is described the concept of neurocutaneus island flap. We describe one case of reverse sural flap without sural nerve .The aim of this paper is to establish the reliability of this flap even without sural nerve. PMID:21133008

  15. Aesthetic Total Reconstruction of Lower Eyelid Using Scapha Cartilage Graft on a Vascularized Propeller Flap

    PubMed Central

    Watanabe, Hidekata; Masumoto, Kazuyuki; Kikuchi, Mamoru; Satake, Yoshiyasu; Yanai, Tetsu; Harada, Yoshimi; Ishihara, Yasuhiro; Yasuta, Masato

    2016-01-01

    Background: The aim of this study was to review the results of a cohort of patients based on our experience with a new technique for total lower eyelid reconstruction after a large defect caused by malignant tumor and trauma. A scapha cartilage graft with small skin on a vascularized propeller flap was used for 16 cases requiring lower eyelid reconstruction. Methods: Patients were identified from a database, and a retrospective case note review was conducted. The scapha cartilage graft was sutured to the margin of the defect of the palpebral conjunctiva and tarsus. The propeller flap, rotated by a perforator-based lateral orbital flap or a subcutaneous-based nasolabial flap, was vascularized on the scapha cartilage graft as anterior lining of the lower eyelid. The follow-up, including results of slit-lamp examination, lasted for varying periods, but often it was for 12 months. Results: The scapha cartilage graft with small skin on a vascularized propeller flap was viable in all cases. Slit-lamp examination detected no irritation or injury of the conjunctiva and cornea, and visual acuity was maintained in all cases. A deformity in the donor helix by this technique was also improved by getting a smaller skin harvested from the scapha. Conclusion: Use of the scapha cartilage graft with small skin on a vascularized propeller flap allows for a good fit to the orbit, short operative time under local anesthesia, good graft viability, and a good esthetic result with minimal donor site morbidity. PMID:27200258

  16. Modified Facial Artery Musculomucosal Flap for Reconstruction of Posterior Skull Base Defects

    PubMed Central

    Xie, Liyue; Lavigne, Philippe; Lavigne, François; Ayad, Tareck

    2016-01-01

    Objectives The superiorly pedicled facial artery musculomucosal (FAMM) flap has been successfully used for reconstruction of head and neck defects since 1992. Common sites of defects include the oral cavity and oropharynx. This article presents a clinical case in which we have successfully used a newly developed modification of the FAMM flap for bulky nasopharyngeal and skull base reconstruction. Results Our patient is a 71-year-old man who presented with a large parapharyngeal and clival chordoma. After tumor removal through combined endoscopic and cervical approach, the internal carotid artery (ICA) in the nasopharyngeal portion was left exposed. A modified superiorly based FAMM flap measuring up to 10 cm in length and 2.5 cm in width was successfully harvested and used to completely cover the defect and the ICA. The flap survived local radiation therapy at the long-term follow-up. Conclusion We have developed a new modification of the FAMM flap, using the fascia of the masseter muscle. This is the first reported case in the literature using a modified FAMM flap for the reconstruction of nasopharyngeal and skull base defect. PMID:27330928

  17. Application of the submental island flap in the reconstruction of intraoral defects.

    PubMed

    Chaudhary, Bikash; Gong, ZhongCheng; Ling, Bin; Lin, Zhaoquan; Abbas, Keremu; Hu, Mei; Liu, Hui

    2014-07-01

    This study was conducted to evaluate the feasibility of clinically applying facial submental island flap in reconstruction of oral cancer ablation in residents of Xinjiang, China. A total of 21 patients with oral cavity cancer underwent surgical resection during 4.4 years. Immediate reconstruction with submental island flap was performed and reviewed. The site, stage, pattern of neck dissection, postoperative complication, and the technique of flap transfer were recorded. The patients were followed up to assess the status of the flap, its function, and the oncologic outcomes. Eventually in this study, all patients had undergone neck dissection and wide excision of the primary lesion. The follow-up period ranged from 3 to 52 months. Of 21 patients, 2 patients had complete flap loss. The overall survival rate in our study is found to be 90.4%. The submental island flap is an excellent alternative for reconstruction of intraoral cancer defect because of its function, reliability, versatility, and relative ease of application. However, further study depends upon the long-term follow-up of the patients and oncologically sound neck dissection. PMID:24978447

  18. Profunda Femoris Artery Perforator Propeller Flap: A Valid Method to Cover Complicated Ischiatic Pressure Sores.

    PubMed

    Scalise, Alessandro; Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni

    2015-08-01

    We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore. PMID:26495200

  19. Freestyle perforator-based propeller flap of medial arm for medial elbow reconstruction.

    PubMed

    Zang, Mengqing; Yu, Shengji; Xu, Libin; Zhao, Zhenguo; Ding, Qiang; Guo, Lingling; Liu, Yuanbo

    2015-07-01

    Elbow reconstruction is challenging for reconstructive surgeons. The purpose of this report is to present the results of the use of freestyle perforator-based propeller flap designed from the medial arm region for elbow reconstruction. The defects following soft tissue sarcoma resection at the medial and posterior elbow were repaired in two patients. The dimensions of the defects were 11 × 7 cm(2) and 10 × 7 cm(2). Two perforators were identified in each case using Doppler ultrasound probe in the medial arm, adjacent to the defect. The perforator with visible pulsation was chosen as the pedicle vessel, which was 12-cm and 7-cm proximal to the medial epicondyle. An elliptical flap, extending almost the full length of arm, was raised and rotated 180° to repair medial elbow defects. The sizes of the flaps were 17 × 8 cm(2) and 11 × 7 cm(2). The donor sites were closed directly. Both flaps survived; temporary venous congestion occurred in one case. There were no other postoperative complications. These cases illustrated that the medial arm flap might be used for reconstruction of medial elbow defects with this freestyle perforator-based propeller flap design. PMID:25417774

  20. Profunda Femoris Artery Perforator Propeller Flap: A Valid Method to Cover Complicated Ischiatic Pressure Sores

    PubMed Central

    Tartaglione, Caterina; Bolletta, Elisa; Pierangeli, Marina; Di Benedetto, Giovanni

    2015-01-01

    Summary: We report the case of a 50-year-old paraplegic man with a complicated grade III/IV ischiatic pressure sore treated with a propeller flap based on the first perforator of the profunda femoris artery. Our aim was to surgically reconstruct an ischiatic pressure sore in a patient with ankylosis using a fasciocutaneous perforator propeller flap obtained from the posterior region of the thigh. Our decision to perform a profunda femoris artery perforator propeller flap reconstruction was mainly due to the anatomical contiguity of the flap with the site of the lesion and the good quality of the skin harvested from the posterior region of the thigh. The use of the perforator fasciocutaneous flap represents a muscle-sparing technique, providing a better long-term result in surgical reconstruction. The choice of the 180-degree propeller flap was due to its ability to provide a good repair of the pressure ulcer and to pass over the ischiatic prominence in the patient in the forced decubitus position. The operatory course did not present any kind of complication. Using this reconstructive treatment, we have obtained complete coverage of the ischiatic pressure sore. PMID:26495200

  1. Individual design of the anterolateral thigh flap for functional reconstruction after hemiglossectomy: experience with 238 patients.

    PubMed

    Wang, L; Liu, K; Shao, Z; Shang, Z-J

    2016-06-01

    The aim of this study was to evaluate tongue function in patients with oral cancer treated surgically and reconstructed with anterolateral thigh free flaps (ALTFs). Patients (N=238) underwent primary reconstruction after hemiglossectomy between September 2012 and October 2014. Patients were divided into two groups according to the flap design: 'individual design' (ABC flap) and 'common design'. Patients were followed postoperatively and assessed after 6 months for the following functional outcomes: speech, deglutition, tongue mobility, and donor site morbidity. Intelligibility and deglutition were each scored by an independent investigator. Data were analyzed using SPSS version 16.0 software. No differences in mean speech intelligibility scores were observed between the two groups (good: P=0.908; acceptable: P=0.881). However, the ABC flap offered recovery advantages for swallowing capacity compared to the common design flap (MTF classification good: P=0.028; acceptable: P=0.001). The individualized ABC flap not only provides volume but also preserves mobility, speech intelligibility, and swallowing capacity. ALTFs require further improvement for the individualized functional reconstruction of the tongue after hemiglossectomy, but this work lays the foundation for these improvements. PMID:26826782

  2. Pedicled Breast Flap for Soft Tissue Coverage of a Forearm Blast Injury

    PubMed Central

    Zuriarrain, Alexander; Brooks, Christopher

    2016-01-01

    Summary: This article presents the case of a 35-year-old woman who sustained a shotgun blast injury to the left forearm and chest wall causing significant soft tissue loss of the extensor compartment. The patient suffered a Gustilo IIIB open radial shaft fracture requiring orthopedic stabilization and plastic surgery intervention. As a result, the patient eventually was reconstructed with the use of a pedicled breast flap. Because of the patient’s macromastia and her large forearm wound and morbid obesity, an individualized approach was developed such that a breast flap was designed because of its proximity to the upper extremity. The advantage of this type of reconstruction is a more natural contour to the forearm with minimal donor site morbidity. Before creation of the flap, the patient expressed interest in a reduction mammaplasty because of her symptomatic macromastia. Overall, this was a 2-step operation whereby first the breast flap was created, and then a few weeks later, once the arm healed, the reduction mammaplasty was performed. Other types of flaps for upper extremity reconstruction include the rectus abdominis myocutaneous, transverse rectus abdominis myocutaneous, vertical rectus abdominis myocutaneous, groin, and latissumus dorsi. The pedicled breast flap is an innovative approach to upper extremity soft tissue coverage and can be tailored to the specific needs of patients similar to our case presentation. PMID:27104108

  3. Treatment of a Femur Nonunion with Microsurgical Corticoperiosteal Pedicled Flap from the Medial Femoral Condyle

    PubMed Central

    Guzzini, Matteo; Guidi, Marco; Civitenga, Carolina; Ferri, Germano; Ferretti, Andrea

    2016-01-01

    Introduction. The vascularized corticoperiosteal flap is harvested from the medial femoral condyle and it is nourished by the articular branch of the descending genicular artery and the superomedial genicular artery. This flap is usually harvested as a free flap for the reconstruction of bone defects at forearm, distal radius, carpus, hand, and recently at lower limb too. Case Report. A 50-year-old Caucasian man referred to our department for hypertrophic nonunion of the distal femur, refractory to the conservative treatments. The first surgical choice was the revision of the nail and the bone reconstruction with a corticoperiosteal pedicled flap from the medial femoral condyle. We considered union to have occurred 3.5 months after surgery when radiographs showed bridging of at least three of the four bony cortices and clinically the patient was able to walk with full weight bearing without any pain. At the last follow-up (25 months), the patient was completely satisfied with the procedure. Discussion. The corticoperiosteal flap allows a faster healing of fractures with a minimal morbidity at the donor site. We suggest that the corticoperiosteal pedicled flap graft is a reliable and effective treatment for distal femur nonunion. PMID:27064589

  4. Infrahyoid flap in oropharyngeal reconstruction following carcinoma resection: A study of 6 patients and literature review

    PubMed Central

    INFANTE-COSSIO, PEDRO; GONZALEZ-CARDERO, EDUARDO; LOPEZ-MARTOS, RICARDO; NUÑEZ-VERA, VICTORIA; OLMOS-JUAREZ, ERIKA; RUIZ-MOYA, ALEJANDRO; HARO-LUNA, JUAN-JOSE; TORRES-CARRRANZA, EUSEBIO

    2016-01-01

    The present study aimed to describe the techniques used and the results obtained with the infrahyoid flap for the reconstruction of medium-sized oropharyngeal defects following resection for advanced squamous cell cancer. During a period of 1 year, six patients with oropharyngeal defects were reconstructed using the infrahyoid flap. The tumor characteristics, location and size of the defect, resective and reconstructive techniques employed and the complications and outcomes of the speech and swallowing functions, as identified in the follow-up visits every 3 months, were evaluated. All flaps were performed simultaneously in association with tumoral excision and ipsilateral supraomohyoid neck dissection. The mean size of the skin paddle was 7.0×3.5 cm. The donor site was primarily sutured. The postoperative course was uneventful and all flaps were viable. One case of marginal skin paddle loss occurred without affecting the survival of the flap. Five patients received postoperative radiotherapy and one patient received concurrent postoperative chemotherapy. During the follow-up period (mean, 63 months), all patients showed excellent oral swallowing. Speech was excellent in five patients and in one patient speech was classified as good. The aesthetic results of the cervical donor site were good. Based on the present case report and the literature review, the infrahyoid flap is a simple and safe procedure for the reconstruction of the oropharynx, with a high success rate, minimal donor site morbidity and good aesthetic and functional results. The infrahyoid flap is a valid surgical option that may be considered in selected oncological patients undergoing reconstruction of medium-size oropharyngeal defects. PMID:27123141

  5. Stacked and bipedicled abdominal free flaps for breast reconstruction: considerations for shaping

    PubMed Central

    Rozen, Warren Matthew; Chow, Whitney T.H.; Chowdhry, Muhammad; Fitzgerald O’Connor, Edmund; Sharma, Hrsikesa; Griffiths, Matthew; Ramakrishnan, Venkat V.

    2016-01-01

    Background Stacked and bipedicled abdominal flaps are useful in women who require a large breast reconstruction but have relative paucity of abdominal tissue. A new classification system is described to assist the surgeon in achieving the best possible aesthetic outcome. Methods A retrospective review of 25 consecutive stacked and/or bipedicled deep inferior epigastric perforator (DIEP) flap reconstructions was assessed from 2009 to 2014. Demographic data and key variables were prospectively collected in our breast reconstruction database and an aesthetic classification devised. There are four main subtypes, (I) folded; (II) divided; (III) coned; and (IV) divided and folded. Each of these subtypes can be moulded in a symmetrically or asymmetrically fashion depending on the contralateral breast shape together with distribution and consistency of fat within the abdominal flap. Results Of the 25 patients, three-quarter were immediate reconstruction, with an average age of 48 years and a median follow-up of 2 years 10 months. Just over half the patients (57%) had bipedicle flaps with two recipient donor vessels with the remaining 43% had stacked flaps. The most common recipient sites are the thoracodorsal vessels (62%) and intercostal perforators (26%). The average abdominal pannus weight was 610 grams (SD: 320 grams), with a hemi-abdominal weight of 305 grams. Two patients had haematomas, of which one lost their reconstruction. Another patient had a venous congestion flap which was salvaged. Conclusions Bipedicled or stacked abdominal flaps allow the all four zones of the abdominal tissue to be used in unilateral breast reconstruction. The approach of tailoring the abdominal flaps to match the contralateral breast reconstruction is largely an art form. The paper aims to bring some meaningful system to aid the surgeon to achieve the best possible outcome with the components presented to them. PMID:27047780

  6. Laparoscopic treatment of Poland’s syndrome using the omentum flap technique

    PubMed Central

    Costa, Sirlei Santos; Blotta, Rosa Maria; Mariano, Mirandolino Batista; Meurer, Luise; Edelweiss, Maria Isabel Albano

    2010-01-01

    OBJECTIVE For patients with Poland’s syndrome, a transverse skin fold in the anterior axillary pillar, infra-clavicular depression and an anomalous breast contour are the most uncomfortable disfigurements. This study aims to demonstrate that superior aesthetic results can be achieved by using a laparoscopically harvested omentum flap to treat this condition. METHODS From a prospectively maintained clinical database of patients undergoing a laparoscopic omentum flap procedure for breast reconstruction, all of the patients with Poland’s syndrome were identified and their outcomes were studied. RESULTS Thirteen consecutive patients with Poland’s syndrome were treated and evaluated regarding breast contour, reconstruction of the anterior axillary pillar and filling of the infra-clavicular depression. Implants were employed beneath the flap in 76% of cases to improve symmetry. In 23% of cases, a contra-lateral mastopexy was performed, and in 15% of cases, a breast implant was used. The consistency of the flap is similar to natural breast tissue and only a small incision in the breast fold is needed. The majority of patients (85%) were female, with a mean age of 26 (18–53). The flap is extremely malleable, adapts to irregular surfaces, and has a long vascular pedicle. Additionally, its removal does not leave a scar at the donor site as the removal of muscular flaps does. For example, the removal of the latissimus dorsi flap causes a deformity in the dorsal contour. The mean operative time was 201 minutes (80–350) and the mean hospital stay was 2.3 days (1–5). CONCLUSIONS The outcomes of these patients revealed that the omentum flap technique provided superior amelioration of the deformities caused by Poland’s syndrome when compared with other reconstructive options. PMID:20454498

  7. Spontaneous Reinnervation of Deep Inferior Epigastric Perforator Flaps after Delayed Breast Reconstruction.

    PubMed

    Stromps, Jan-Philipp; Bozkurt, Ahmet; Grieb, Gerrit; Kim, Bong-Sung; Wiezik, Martyna; Pallua, Norbert

    2016-03-01

    Background The spontaneous reinnervation of free flaps, such as deep inferior epigastric perforator (DIEP) flaps, is not fully understood, and few publications have investigated this issue. The aim of this study was to examine spontaneous reinnervation following breast reconstruction with autologous DIEP flaps without an additional nerve transfer. Methods In a retrospective clinical study, 18 female patients were investigated for a mean of 49.59 months (range, 12-88 months) following breast reconstruction with a unilateral DIEP flap. Five sensory modalities were tested: pressure perception, dynamic two-point discrimination, sharp-blunt discrimination, hot and cold discrimination, and vibration perception threshold (VPT). The measurements were performed on the reconstructed breast, flap surrounding transition zone, healthy contralateral breast, and the donor site. For a more precise analysis all breasts have been divided into five different segments (mediocranial, laterocranial, mediocaudal, laterocaudal, and reconstructed nipple-areola complex, if present). Additionally, tissue oxygen saturation and tissue hemoglobin were measured by laser Doppler spectroscopy. Results Spontaneous reinnervation of at least one modality tested was observed in all DIEP flaps (n = 18). This sensitive recovery increases over the postoperative period. The maximum difference between the controls and DIEP flaps was observed in cold perception, whereas the least difference was observed in the VPT. Regarding the different segments, we observed better sensitive recovery in the cranial parts of the DIEP flaps and the transition zone. Conclusion This study provides certain predictions for patients and surgeons, when and to which extent spontaneous reinnervation can be expected. PMID:26372687

  8. Understanding the Role of Chord-wise Flexibility in Flapping Wing Flight

    NASA Astrophysics Data System (ADS)

    Gaston, Zachary; Dong, Haibo; Wan, Hui; Ol, Michael

    2011-11-01

    Aerodynamic performance of flapping hinged plates is numerically studied to explore the effects of chord-wise flexibility in flapping wing flight. The plate with chord-wise flexibility is modeled as a two-link mechanism with a torsional spring hinge in between. The upper-link of the plate is controlled by prescribed motion and the rest of body is subjected to passive deflection due to fluid-body interaction. The effect of forced to natural frequency ratio is studied first for a flapping hinged-plate, on which prescribed hovering motion is actively applied. The effects of torsional stiffness and chord-wise flexibility are further explored for pitching and plunging plates, observing the flow phenomena and lift production as a result of this change. Comparisons between rigid plates, free-to-pivot hinged plates, and the torsional spring hinged plates are made, identifying a more optimal model for promoting lift production in flapping plates.

  9. Metavanadate at the active site of the phosphatase VHZ.

    PubMed

    Kuznetsov, Vyacheslav I; Alexandrova, Anastassia N; Hengge, Alvan C

    2012-09-01

    Vanadate is a potent modulator of a number of biological processes and has been shown by crystal structures and NMR spectroscopy to interact with numerous enzymes. Although these effects often occur under conditions where oligomeric forms dominate, the crystal structures and NMR data suggest that the inhibitory form is usually monomeric orthovanadate, a particularly good inhibitor of phosphatases because of its ability to form stable trigonal-bipyramidal complexes. We performed a computational analysis of a 1.14 Å structure of the phosphatase VHZ in complex with an unusual metavanadate species and compared it with two classical trigonal-bipyramidal vanadate-phosphatase complexes. The results support extensive delocalized bonding to the apical ligands in the classical structures. In contrast, in the VHZ metavanadate complex, the central, planar VO(3)(-) moiety has only one apical ligand, the nucleophilic Cys95, and a gap in electron density between V and S. A computational analysis showed that the V-S interaction is primarily ionic. A mechanism is proposed to explain the formation of metavanadate in the active site from a dimeric vanadate species that previous crystallographic evidence has shown to be able to bind to the active sites of phosphatases related to VHZ. Together, the results show that the interaction of vanadate with biological systems is not solely reliant upon the prior formation of a particular inhibitory form in solution. The catalytic properties of an enzyme may act upon the oligomeric forms primarily present in solution to generate species such as the metavanadate ion observed in the VHZ structure. PMID:22876963

  10. Breast reconstruction with single-pedicle TRAM flap in breast cancer patients with low midline abdominal scar

    PubMed Central

    Wu, Jun-Dong; Huang, Wen-He; Qiu, Si-Qi; He, Li-Fang; Guo, Cui-Ping; Zhang, Yong-Qu; Zhang, Fan; Zhang, Guo-Jun

    2016-01-01

    Breast reconstruction with transverse rectus abdominis myocutaneous (TRAM) flap is challenging in patients with low midline abdominal scar. In this study, we aimed to investigate the clinical feasibility of immediate breast reconstruction using single-pedicle TRAM (SP-TRAM) flaps in patients with low midline abdominal scar. There were 4 strict selection criteria: 1) presence at least 3 perforators on the pedicle side; 2) perforators with regional average flow velocity of >20 cm/s; 3) upper edge of the abdominal scar at least 4 cm from the umbilicus; and 4) scar age >1 year. Eight breast cancer patients with low midline abdominal scar (scar group) and 20 without (control group) underwent immediate breast reconstruction with SP-TRAM flaps consisting of zone I and III and zone II tissues. Flap complications, donor-site complications, and cosmetic results were compared between the two groups. All flaps survived and both groups presented similar flap and donor site complications, including fat necrosis, seroma, hematoma, infection, delayed wound healing, and abdominal hernia, and patients in both groups had similar aesthetic results (p > 0.05). Thus, the study demonstrated that breast reconstruction using SP-TRAM flap was a safe approach in carefully selected patients with low midline abdominal scar. PMID:27406872

  11. Free flap pulse oximetry utilizing reflectance photoplethysmography.

    PubMed

    Zaman, T; Kyriacou, P A; Pal, S K

    2013-01-01

    The successful salvage of a free flap is dependent on the continuous monitoring of perfusion. To date there is no widely accepted and readily available post-operative monitoring technique to reliably assess the viability of free flaps by continuously monitoring free flap blood oxygen saturation. In an attempt to overcome the limitations of the current techniques a reflectance photoplethysmographic (PPG) processing system has been developed with the capability of real-time estimation of arterial oxygen saturation (SpO2) levels implemented in LabVIEW. This system was evaluated in clinical measurements on five patients undergoing breast reconstruction using Deep Inferior Epigastric Perforator (DIEP) flap. Good quality PPG signals were obtained from the flaps and fingers simultaneously. The estimated free flap SpO2 values were in broad agreement with the oxygen saturation readings from the commercial pulse oximeter. The results suggest that reflectance free flap photoplethysmography can be used as a continuous monitoring technique to non-invasively monitor the perfusion of free flaps. PMID:24110620

  12. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap interconnection. 23.701 Section 23.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap...

  13. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Flap interconnection. 23.701 Section 23.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap...

  14. Use of free flaps in burn trauma.

    PubMed

    Tvrdek, M; Nejedlý, A; Kletenský, J; Pros, Z; Broz, L

    1994-01-01

    The present currently used method of treating and reconstructing injuries caused by electric current and deep thermal injuries is compared with the method of early reconstruction using free flaps. Brief summary of present experience substantiating this method is presented. The three presented clinical cases show subacute reconstruction in this type of injury by free flaps transfer. PMID:7618395

  15. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flaps. 25.457 Section 25.457 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps....

  16. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flaps. 25.457 Section 25.457 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps....

  17. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flaps. 25.457 Section 25.457 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps....

  18. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flaps. 25.457 Section 25.457 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps....

  19. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flaps. 25.457 Section 25.457 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps....

  20. Influence of hinge point on flexible flap aerodynamic performance

    NASA Astrophysics Data System (ADS)

    Y Zhao, H.; Ye, Z.; Wu, P.; Li, C.

    2013-12-01

    Large scale wind turbines lead to increasing blade lengths and weights, which presents new challenges for blade design. This paper selects NREL S809 airfoil, uses the parameterized technology to realize the flexible trailing edge deformation, researches the static aerodynamic characteristics of wind turbine blade airfoil with flexible deformation, and the dynamic aerodynamic characteristics in the process of continuous deformation, analyses the influence of hinge point position on flexible flap aerodynamic performance, in order to further realize the flexible wind turbine blade design and provides some references for the active control scheme. The results show that compared with the original airfoil, proper trailing edge deformation can improve the lift coefficient, reduce the drag coefficient, and thereby more efficiently realize flow field active control. With hinge point moving forward, total aerodynamic performance of flexible flap improves. Positive swing angle can push the transition point backward, thus postpones the occurrence of the transition phenomenon.

  1. Mimicking enzymatic active sites on surfaces for energy conversion chemistry.

    PubMed

    Gutzler, Rico; Stepanow, Sebastian; Grumelli, Doris; Lingenfelder, Magalí; Kern, Klaus

    2015-07-21

    Metal-organic supramolecular chemistry on surfaces has matured to a point where its underlying growth mechanisms are well understood and structures of defined coordination environments of metal atoms can be synthesized in a controlled and reproducible procedure. With surface-confined molecular self-assembly, scientists have a tool box at hand which can be used to prepare structures with desired properties, as for example a defined oxidation number and spin state of the transition metal atoms within the organic matrix. From a structural point of view, these coordination sites in the supramolecular structure resemble the catalytically active sites of metallo-enzymes, both characterized by metal centers coordinated to organic ligands. Several chemical reactions take place at these embedded metal ions in enzymes and the question arises whether these reactions also take place using metal-organic networks as catalysts. Mimicking the active site of metal atoms and organic ligands of enzymes in artificial systems is the key to understanding the selectivity and efficiency of enzymatic reactions. Their catalytic activity depends on various parameters including the charge and spin configuration in the metal ion, but also on the organic environment, which can stabilize intermediate reaction products, inhibits catalytic deactivation, and serves mostly as a transport channel for the reactants and products and therefore ensures the selectivity of the enzyme. Charge and spin on the transition metal in enzymes depend on the one hand on the specific metal element, and on the other hand on its organic coordination environment. These two parameters can carefully be adjusted in surface confined metal-organic networks, which can be synthesized by virtue of combinatorial mixing of building synthons. Different organic ligands with varying functional groups can be combined with several transition metals and spontaneously assemble into ordered networks. The catalytically active metal

  2. Fasciocutaneous flap for vaginal and perineal reconstruction

    SciTech Connect

    Wang, T.N.; Whetzel, T.; Mathes, S.J.; Vasconez, L.O.

    1987-07-01

    A skin and fascia flap from the medial thigh is proposed for vaginal and perineal reconstruction. Dissection, vascular injection, and radiographs of 20 fresh cadaver limbs uniformly demonstrated the presence of a communicating suprafascial vascular plexus in the medial thigh. Three to four nonaxial vessels were consistently found to enter the proximal plexus from within 5 cm of the perineum. Preservation of these vessels permitted reliable elevation of a 9 X 20 cm fasciocutaneous flap without using the gracilis muscle as a vascular carrier. Fifteen flaps in 13 patients were used for vaginal replacement and coverage of vulvectomy, groin, and ischial defects. Depending on the magnitude of the defect, simultaneous and independent elevation of the gracilis muscle provided additional vascularized coverage as needed. Our experience indicates that the medial thigh fasciocutaneous flap is a durable, less bulky, and potentially sensate alternative to the gracilis musculocutaneous flap for vaginal and perineal reconstruction.

  3. Piezoelectrically actuated insect scale flapping wing

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sujoy; Ganguli, Ranjan

    2010-04-01

    An energy method is used in order to derive the non-linear equations of motion of a smart flapping wing. Flapping wing is actuated from the root by a PZT unimorph in the piezofan configuration. Dynamic characteristics of the wing, having the same size as dragonfly Aeshna Multicolor, are analyzed using numerical simulations. It is shown that flapping angle variations of the smart flapping wing are similar to the actual dragonfly wing for a specific feasible voltage. An unsteady aerodynamic model based on modified strip theory is used to obtain the aerodynamic forces. It is found that the smart wing generates sufficient lift to support its own weight and carry a small payload. It is therefore a potential candidate for flapping wing of micro air vehicles.

  4. Scrubbing noise of externally blown flaps

    NASA Technical Reports Server (NTRS)

    Fink, M. R.

    1975-01-01

    An experimental study was conducted to examine the aeroacoustic mechanism that produces externally blown flap (EBF) scrubbing noise, i.e. a surface-radiated noise which is generally strongest normal to UTW deflected flaps. Scrubbing noise was not radiated from portions of the surface adjacent to strong, locally coherent turbulent eddies. Instead, scrubbing noise seemed to come from weak loading fluctuations that were coherent along the scrubbed span. These loading fluctuations probably were induced by the convected large-scale vortex structure of the attached exhaust jet. Deflecting a UTW flap would reduce the distance between the vortex trajectory and the flap surface, increasing the resulting dipole noise and rotating its directivity. In contrast, deflecting a USB flap would increase this distance, so that observable scrubbing noise would be radiated only from the undeflected forward portion of the wing.

  5. Composite tissue flap at perforating branches of saphenous artery: a new design for repairing composite tissue defects in anterior knee

    PubMed Central

    Sun, Guangfeng; Nie, Kaiyu; Jin, Wenhu; Wei, Zairong; Qi, Jianping; Wang, Dali

    2015-01-01

    So far it has been difficult to repair and reconstruct the composite tissue defects in knee. Saphenous artery flap has been widely used to repair complex wounds, but the design and clinical application of composite tissue flap at perforating branches of saphenous artery were not reported. In this research, we design a new composite tissue flap by carrying fascial flap in the medial gastrocnemius muscle with perforators flap in saphenous artery to repair and reconstruct the composite tissue defects in knee. By anatomic observation and analysis, we find that there exists blood-supply in netty form among saphenous arteries, medial artery below the knee, intermuscular branch in high-order position of posterior tibial artery and perforating branch in medial artery of calf. We chose saphenous artery as blood-supplying artery; utilized the netty blood-supplying mode in middle-up and medial part of shank; cut the composite tissue flap at perforating branches of saphenous artery with fascial flap carried in the medial gastrocnemius muscle; reconstructed the ligamentum patellae using medial head of gastrocnemius muscle and Achilles’s tendon; and covered the wounds at front side of knee with flap. Composite tissues were survived completely, free from infection at wounds and exosmosis of joint fluid. Motion function of knee-joint proved satisfactory, and ambulatory function was recovered. There was no complication in donor site. Composite tissue flap at perforating branches of saphenous artery with fascial flap carried in the medial gastrocnemius muscle is one of the most ideal solutions for repairing the composite tissue defects at front side of knee joint. PMID:26885090

  6. A Double-Lobe Flap Design Combined Nasolabial Advancement and Infraorbital Rotation for Reconstruction of Infraorbital Defect.

    PubMed

    Guo, Xiao-Ke; Sun, Yan-Fang; Liu, Bing; Zhang, Wen-Feng; Xiong, Xue-Peng

    2016-06-01

    Various adjacent flaps have been designed to close infraorbital defect, and each of them is trying to get an aesthetic outcome and meanwhile circumvent eyelid retraction, ectropion, and functional disability. Here, the authors report an adjacent double-lobe flap, which took advantage of nasolabial advancement and infraorbital rotation of the 2 lobes, combinatorially closed a pentagon infraorbital defect by removal of 2 small skin paddles as donor sites, and finally yielded an acceptable aesthetic and functional outcome. This flap may be a new option for closure of polygon infraorbital defects. PMID:27213736

  7. Hybrid [FeFe]-hydrogenases with modified active sites show remarkable residual enzymatic activity.

    PubMed

    Siebel, Judith F; Adamska-Venkatesh, Agnieszka; Weber, Katharina; Rumpel, Sigrun; Reijerse, Edward; Lubitz, Wolfgang

    2015-02-24

    [FeFe]-hydrogenases are to date the only enzymes for which it has been demonstrated that the native inorganic binuclear cofactor of the active site Fe2(adt)(CO)3(CN)2 (adt = azadithiolate = [S-CH2-NH-CH2-S](2-)) can be synthesized on the laboratory bench and subsequently inserted into the unmaturated enzyme to yield fully functional holo-enzyme (Berggren, G. et al. (2013) Nature 499, 66-70; Esselborn, J. et al. (2013) Nat. Chem. Biol. 9, 607-610). In the current study, we exploit this procedure to introduce non-native cofactors into the enzyme. Mimics of the binuclear subcluster with a modified bridging dithiolate ligand (thiodithiolate, N-methylazadithiolate, dimethyl-azadithiolate) and three variants containing only one CN(-) ligand were inserted into the active site of the enzyme. We investigated the activity of these variants for hydrogen oxidation as well as proton reduction and their structural accommodation within the active site was analyzed using Fourier transform infrared spectroscopy. Interestingly, the monocyanide variant with the azadithiolate bridge showed ∼50% of the native enzyme activity. This would suggest that the CN(-) ligands are not essential for catalytic activity, but rather serve to anchor the binuclear subsite inside the protein pocket through hydrogen bonding. The inserted artificial cofactors with a propanedithiolate and an N-methylazadithiolate bridge as well as their monocyanide variants also showed residual activity. However, these activities were less than 1% of the native enzyme. Our findings indicate that even small changes in the dithiolate bridge of the binuclear subsite lead to a rather strong decrease of the catalytic activity. We conclude that both the Brønsted base function and the conformational flexibility of the native azadithiolate amine moiety are essential for the high catalytic activity of the native enzyme. PMID:25633077

  8. Site-specific PEGylation of lidamycin and its antitumor activity.

    PubMed

    Li, Liang; Shang, Boyang; Hu, Lei; Shao, Rongguang; Zhen, Yongsu

    2015-05-01

    In this study, N-terminal site-specific mono-PEGylation of the recombinant lidamycin apoprotein (rLDP) of lidamycin (LDM) was prepared using a polyethyleneglycol (PEG) derivative (M w 20 kDa) through a reactive terminal aldehyde group under weak acidic conditions (pH 5.5). The biochemical properties of mPEG-rLDP-AE, an enediyne-integrated conjugate, were analyzed by SDS-PAGE, RP-HPLC, SEC-HPLC and MALDI-TOF. Meanwhile, in vitro and in vivo antitumor activity of mPEG-rLDP-AE was evaluated by MTT assays and in xenograft model. The results indicated that mPEG-rLDP-AE showed significant antitumor activity both in vitro and in vivo. After PEGylation, mPEG-rLDP still retained the binding capability to the enediyne AE and presented the physicochemical characteristics similar to that of native LDP. It is of interest that the PEGylation did not diminish the antitumor efficacy of LDM, implying the possibility that this derivative may function as a payload to deliver novel tumor-targeted drugs. PMID:26579455

  9. Flapping flexible fish

    NASA Astrophysics Data System (ADS)

    Root, Robert G.; Courtland, Hayden-William; Shepherd, William; Long, John H.

    In order to analyze and model the body kinematics used by fish in a wide range of swimming behaviors, we developed a technique to separate the periodic whole-body motions that characterize steady swimming from the secular motions that characterize changes in whole-body shape. We applied this harmonic analysis technique to the study of the forward and backward swimming of lamprey. We found that in order to vary the unsteadiness of swimming, lamprey superimpose periodic and secular components of their body motion, modulate the patterns and magnitudes of those components, and change shape. These kinematic results suggest the following hydromechanical hypothesis: steady swimming is a maneuver that requires active suppression of secular body reconfigurations.

  10. Pudendal thigh flap for repair of rectovaginal fistula.

    PubMed

    Sathappan, S; Rica, M A I

    2006-08-01

    The pudendal thigh flap or the Singapore flap is a versatile flap that can be used in the repair of recto-vaginal fistulae. Apart from the potential problem of hair growth, this neurovascular flap proves to be surprisingly simple in technique, robust and has a high potential for normal or near-normal function. PMID:17240589

  11. Early wound healing of laser in situ keratomileusis–like flaps after treatment with human corneal stromal stem cells

    PubMed Central

    Morgan, Siân R.; Dooley, Erin P.; Kamma-Lorger, Christina; Funderburgh, James L.; Funderburgh, Martha L.; Meek, Keith M.

    2016-01-01

    Purpose To use a well-established organ culture model to investigate the effects of corneal stromal stem cells on the optical and biomechanical properties of corneal wounds after laser in situ keratomileusis (LASIK)–like flap creation. Setting School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom. Design Experimental study. Methods The LASIK-like flaps were produced in sheep corneas. The flap beds were treated with corneal stromal stem cells and were then replaced and allowed to heal for different periods of up to 3 weeks in organ culture. The optical transmission of the cornea, the force required to detach the flap, and the presence of myofibroblasts near the flap bed were measured. Results Corneal stromal stem cell–treated flap beds were statistically significantly more transparent after 3 weeks in culture than the untreated controls. At 3 weeks, the mean force necessary to detach the flap was more than twice the force required for the respective control samples. Concurrently, there were 44% activated cells immediately below the flap margin of the controls compared with 29% in the same region of the corneal stromal stem cell–treated flaps. Conclusions In this system, the presence of corneal stromal stem cells at the wound margin significantly increased the adherence of LASIK-like flaps while maintaining corneal transparency. It is postulated that this is achieved by the deposition of extracellular connective tissue similar to that found in the normal cornea and by the paucity of activated keratocytes (myofibroblasts), which are known to scatter a significant amount of the incident light. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned. PMID:27026456

  12. Allosteric site-mediated active site inhibition of PBP2a using Quercetin 3-O-rutinoside and its combination.

    PubMed

    Rani, Nidhi; Vijayakumar, Saravanan; P T V, Lakshmi; Arunachalam, Annamalai

    2016-08-01

    Recent crystallographic study revealed the involvement of allosteric site in active site inhibition of penicillin binding protein (PBP2a), where one molecule of Ceftaroline (Cef) binds to the allosteric site of PBP2a and paved way for the other molecule (Cef) to bind at the active site. Though Cef has the potency to inhibit the PBP2a, its adverse side effects are of major concern. Previous studies have reported the antibacterial property of Quercetin derivatives, a group of natural compounds. Hence, the present study aims to evaluate the effect of Quercetin 3-o-rutinoside (Rut) in allosteric site-mediated active site inhibition of PBP2a. The molecular docking studies between allosteric site and ligands (Rut, Que, and Cef) revealed a better binding efficiency (G-score) of Rut (-7.790318) and Cef (-6.194946) with respect to Que (-5.079284). Molecular dynamic (MD) simulation studies showed significant changes at the active site in the presence of ligands (Rut and Cef) at allosteric site. Four different combinations of Rut and Cef were docked and their G-scores ranged between -6.320 and -8.623. MD studies revealed the stability of the key residue (Ser403) with Rut being at both sites, compared to other complexes. Morphological analysis through electron microscopy confirmed that combination of Rut and Cefixime was able to disturb the bacterial cell membrane in a similar fashion to that of Rut and Cefixime alone. The results of this study indicate that the affinity of Rut at both sites were equally good, with further validations Rut could be considered as an alternative for inhibiting MRSA growth. PMID:26360629

  13. Hydrodynamic schooling of flapping swimmers.

    PubMed

    Becker, Alexander D; Masoud, Hassan; Newbolt, Joel W; Shelley, Michael; Ristroph, Leif

    2015-01-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups. PMID:26439509

  14. Hydrodynamic schooling of flapping swimmers

    DOE PAGESBeta

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-06

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

  15. Hydrodynamic schooling of flapping swimmers

    NASA Astrophysics Data System (ADS)

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  16. Hydrodynamic schooling of flapping swimmers

    PubMed Central

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-01-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups. PMID:26439509

  17. Hydrodynamic schooling of flapping swimmers

    SciTech Connect

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-06

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  18. Apoptosis in extracorporeal preserved inguinal fat flaps of the rat.

    PubMed

    Herold, Christian; Rennekampff, Hans O; Ohm, Lea; Strauss, Sarah; Linkner, Jörn; Reimers, Kerstin; Allmeling, Christina; Vaske, Bernhard; Vogt, Peter M

    2012-04-01

    Fat cells are fragile cells with a short life span outside the body. Ways to reduce cell death in a biochemical way are almost unknown due to scarce information on the type of cellular death that is induced in fat tissue. This study was designed to investigate the apoptotic pathways of fat tissue in a permanent perfusion bioreactor system with the Hannover preservation solution and the Eurocollins solution in fat flaps of rats. In Lewis rats, the inguinal adipofascial flaps were elevated bilaterally and placed in a bioreactor at 37°C. To detect caspases 3, 8, 9 and 12, immunofluorescence stains of fat tissue specimen were analysed at several time points after preservation of flaps were placed in Hannover solution and Eurocollins solution for 10 days. An additional visual assessment of viability by a calcein based life/dead test was performed. It revealed a superior viability of the adipose tissue preserved in Hannover solution. Immunofluorescence staining demonstrated that apoptotic pathways via mitochondria, endoplasmatic reticulum and death receptors were activated, as Caspases 8, 9 and 12 were detected. Caspase 3 as an effector in the common apoptotic pathway was detected as well. Adipose tissue preserved at 37°C ex vivo in a bioreactor system undergoes apoptosis. Immunofluorescence examination of the fat tissue preserved ex vivo revealed that apoptotic pathways via mitochondria, endoplasmatic reticulum and death receptors are being activated. Significantly less activation of Caspase 3, 8, 9 and 12 in flaps preserved in Hannover solution in comparison to Eurocollins was found, supporting the anti apoptotic characteristics of Hannover solution. Based on these findings, further research to modify the apoptotic pathways to ameliorate viability of fat tissue can be performed. PMID:22223358

  19. Active site hydrophobicity is critical to the bioluminescence activity of Vibrio harveyi luciferase.

    PubMed

    Li, Chi-Hui; Tu, Shiao-Chun

    2005-10-01

    Vibrio harveyi luciferase is an alphabeta heterodimer containing a single active site, proposed earlier to be at a cleft in the alpha subunit. In this work, six conserved phenylalanine residues at this proposed active site were subjected to site-directed mutations to investigate their possible functional roles and to delineate the makeup of luciferase active site. After initial screening of Phe --> Ala mutants, alphaF46, alphaF49, alphaF114, and alphaF117 were chosen for additional mutations to Asp, Ser, and Tyr. Comparisons of the general kinetic properties of wild-type and mutated luciferases indicated that the hydrophobic nature of alphaF46, alphaF49, alphaF114, and alphaF117 was important to luciferase V(max) and V(max)/K(m), which were reduced by 3-5 orders of magnitude for the Phe --> Asp mutants. Both alphaF46 and alphaF117 also appeared to be involved in the binding of reduced flavin substrate. Additional studies on the stability and yield of the 4a-hydroperoxyflavin intermediate II and measurements of decanal substrate oxidation by alphaF46D, alphaF49D, alphaF114D, and alphaF117D revealed that their marked reductions in the overall quantum yield (phi( degrees )) were a consequence of diminished yields of luciferase intermediates and, with the exception of alphaF114D, emission quantum yield of the excited emitter due to the replacement of the hydrophobic Phe by the anionic Asp. The locations of these four critical Phe residues in relation to other essential and/or hydrophobic residues are depicted in a refined map of the active site. Functional implications of these residues are discussed. PMID:16185065

  20. Modified superficial circumflex iliac artery perforator flap and supermicrosurgery technique for lower extremity reconstruction: a new approach for moderate-sized defects.

    PubMed

    Hong, Joon Pio; Sun, Sang Hoon; Ben-Nakhi, Muneera

    2013-10-01

    The superficial circumflex iliac artery perforator (SCIP) flap is an evolved form of groin flap. It overcomes the inherent disadvantages of the groin flap by preserving the deep fascia but still requires challenging skills because of short pedicles and small caliber of vessels. The use of SCIP flap was evaluated for lower extremity use.From June of 2009 to August of 2011, a total of 79 cases were performed (age range, 4-80 years) on the lower extremity using supermicrosurgical approach. All flaps were harvested above the deep fat and the pedicles were taken above or just below the deep fascia to reconstruct the defects throughout the lower extremity.Supermicrosurgery technique was used in 71 cases. A total of 75 cases were performed successfully; 1 case underwent revision but failed and 2 cases were lost within 2 days of surgery. Average size of the flap was 75.5 cm, thickness 7 mm, average length of pedicle was 5 cm, and the average caliber of artery was 0.7 mm. Donor sites were all closed primarily but complications were noted with 1 dehiscence and prolong drainage of lymphatics. Flaps provided good functional coverage and appearance. The average follow-up was 12 months.With the modification of elevating the flap on the superficial fascia, we can harvest a thin flap without additional debulking and avoid complications such as lymphorrhea. Furthermore, with the perforator to perforator or perforator to small distal vessel approach, we can apply this flap on all regions of the lower extremity overcoming the difficulties with short pedicle and small vessel caliber. In our hands, the modified SCIP flap is the flap of choice for small to moderate size defects in the lower extremity. PMID:23187712

  1. Numerical Analysis of the EXPERT Open Flap Assembly in Plasma Wind Tunnel Conditions

    NASA Astrophysics Data System (ADS)

    Di Clemente, M.; Marini, M.; Di Benedetto, S.

    2009-01-01

    In the frame of the EXPERT program a number of tests to be performed in the CIRA Plasma Wind Tunnel (PWT) "Scirocco" is scheduled, [1]. Among these, one is dedicated to the Open Flap Assembly (OFA) with the aim to address some technical issues related to scientific objectives of Payload 6 (under DLR responsibility, [2]), related with the analysis of flow reattachment on the flap due to the shock wave boundary layer interaction, and Payload 8 (under RUAG responsibility, [3]) whose main objective is the measurement of the heat flux in the rear surface of the flap through an infrared camera mounted in the cavity, and to consolidate the ground-to- flight extrapolation relations for the characterization of the convective heating on the flap and the reattachment and radiative heating in the cavity. In the present work, the numerical activities carried out before the test for the definition of the experimental conditions, starting from the requirements to be reproduced on the model, will be shown. Once the preliminary model configuration, its position inside the test chamber and the preliminary PWT operating conditions have been defined, a series of facility regulations (reservoir pressure P0 and reservoir enthalpy H0) has been simulated in terms of nozzle axi-symmetric flow, flow around the PWT hemi-spherical calibration probe and two-dimensional flow around the flap model. These simulations have allowed the assessment of the typical flow features and the analysis of some effects as those related to the flow angularity at nozzle exit, the wall temperature on the flap and the gap/step in front of the flap itself, as well as an estimation of radiative heating between the flap rear surface and the cavity.

  2. Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

    NASA Technical Reports Server (NTRS)

    Platt, Robert C

    1936-01-01

    This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash.

  3. A proposed definition of the 'activity' of surface sites on lactose carriers for dry powder inhalation.

    PubMed

    Grasmeijer, Floris; Frijlink, Henderik W; de Boer, Anne H

    2014-06-01

    A new definition of the activity of surface sites on lactose carriers for dry powder inhalation is proposed which relates to drug detachment during dispersion. The new definition is expected to improve the understanding of 'carrier surface site activity', which stimulates the unambiguous communication about this subject and may aid in the rational design and interpretation of future formulation studies. In contrast to the currently prevailing view on carrier surface site activity, it follows from the newly proposed definition that carrier surface site activity depends on more variables than just the physicochemical properties of the carrier surface. Because the term 'active sites' is ambiguous, it is recommended to use the term 'highly active sites' instead to denote carrier surface sites with a relatively high activity. PMID:24613490

  4. Epidural Blood Patch Using Manometry for Sinking Skin Flap Syndrome.

    PubMed

    Turner, James D; Farmer, Justin L; Dobson, Sean W

    2016-06-01

    We describe here a 55-year-old male patient with a medical history significant for chronic back pain and substance abuse with cocaine who sustained a traumatic subarachnoid hemorrhage after a fall from a roof while acutely intoxicated on cocaine requiring decompressive hemicraniectomy and cranioplasty that was complicated by an epidural abscess requiring a repeat craniectomy. He was diagnosed with sinking skin flap syndrome consistent with altered mental status and a sunken skin flap with increased midline shift. Despite treatment with Trendelenburg positioning and appropriate fluid management, the patient continued to decline, and an epidural blood patch was requested for treatment. After placement of the epidural blood patch using manometry in the epidural space, the patient's neurologic status improved allowing him to ultimately receive a cranioplasty. The patient is now able to perform several of his activities of daily living and communicate effectively. PMID:27075425

  5. Ontogeny of aerial righting and wing flapping in juvenile birds.

    PubMed

    Evangelista, Dennis; Cam, Sharlene; Huynh, Tony; Krivitskiy, Igor; Dudley, Robert

    2014-08-01

    Mechanisms of aerial righting in juvenile chukar partridge (Alectoris chukar) were studied from hatching to 14 days-post-hatching (dph). Asymmetric movements of the wings were used from 1 to 8 dph to effect progressively more successful righting behaviour via body roll. Following 8 dph, wing motions transitioned to bilaterally symmetric flapping that yielded aerial righting via nose-down pitch, along with substantial increases in vertical force production during descent. Ontogenetically, the use of such wing motions to effect aerial righting precedes both symmetric flapping and a previously documented behaviour in chukar (i.e. wing-assisted incline running) hypothesized to be relevant to incipient flight evolution in birds. These findings highlight the importance of asymmetric wing activation and controlled aerial manoeuvres during bird development and are potentially relevant to understanding the origins of avian flight. PMID:25165451

  6. Magnetostrictively actuated control flaps for vibration reduction in helicopter rotors

    SciTech Connect

    Millott, T.; Friedmann, P.P.

    1994-12-31

    High vibration levels can impose constraints on helicopter operations and hinder passenger acceptance. Vibration reduction using blade root pitch control introduces a significant power penalty and may adversely affect the airworthiness of the flight control system. Comparable levels of vibration reduction can be achieved using considerably less power through an actively controlled trailing edge flap mounted on the blade. Such a device would have no effect on helicopter airworthiness since it is controlled by a loop separate from the primary flight control system which utilizes the swashplate. Control flap actuation using the magnetostrictive material Terfenol-D is studied in this paper by designing a minimum weight actuator, subject to a set of actuation and stress constraints. The resulting device is capable of producing vibration reduction in excess of 90% at cruise conditions.

  7. Disturbance opens recruitment sites for bacterial colonization in activated sludge.

    PubMed

    Vuono, David C; Munakata-Marr, Junko; Spear, John R; Drewes, Jörg E

    2016-01-01

    Little is known about the role of immigration in shaping bacterial communities or the factors that may dictate success or failure of colonization by bacteria from regional species pools. To address these knowledge gaps, the influence of bacterial colonization into an ecosystem (activated sludge bioreactor) was measured through a disturbance gradient (successive decreases in the parameter solids retention time) relative to stable operational conditions. Through a DNA sequencing approach, we show that the most abundant bacteria within the immigrant community have a greater probability of colonizing the receiving ecosystem, but mostly as low abundance community members. Only during the disturbance do some of these bacterial populations significantly increase in abundance beyond background levels and in few cases become dominant community members post-disturbance. Two mechanisms facilitate the enhanced enrichment of immigrant populations during disturbance: (i) the availability of resources left unconsumed by established species and (ii) the increased availability of niche space for colonizers to establish and displace resident populations. Thus, as a disturbance decreases local diversity, recruitment sites become available to promote colonization. This work advances our understanding of microbial resource management and diversity maintenance in complex ecosystems. PMID:25727891

  8. Construction of DNA recognition sites active in Haemophilus transformation.

    PubMed Central

    Danner, D B; Smith, H O; Narang, S A

    1982-01-01

    Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair (bp) sequence, 5'-A-A-G-T-G-C-G-G-T-C-A-3'. To prove that this sequence is the recognition site that identifies Haemophilus DNA to the competent cell, we have now constructed a series of plasmids, each of which contains the 11-bp sequence. Using two different assay systems we have tested the ability of fragments from these plasmids to compete with cloned Haemophilus DNA fragments that naturally contain the 11-bp sequence. We find that the addition of the 11-bp sequence to a DNA fragment is necessary and sufficient for preferential uptake of that fragment. However, plasmid DNAs containing this sequence may vary as much as 48-fold in uptake activity, and this variation correlates with the A+T-richness of the DNA flanking the 11-mer. Images PMID:6285382

  9. Characterization of active site residues of nitroalkane oxidase.

    PubMed

    Valley, Michael P; Fenny, Nana S; Ali, Shah R; Fitzpatrick, Paul F

    2010-06-01

    The flavoenzyme nitroalkane oxidase catalyzes the oxidation of primary and secondary nitroalkanes to the corresponding aldehydes and ketones plus nitrite. The structure of the enzyme shows that Ser171 forms a hydrogen bond to the flavin N5, suggesting that it plays a role in catalysis. Cys397 and Tyr398 were previously identified by chemical modification as potential active site residues. To more directly probe the roles of these residues, the S171A, S171V, S171T, C397S, and Y398F enzymes have been characterized with nitroethane as substrate. The C397S and Y398 enzymes were less stable than the wild-type enzyme, and the C397S enzyme routinely contained a substoichiometric amount of FAD. Analysis of the steady-state kinetic parameters for the mutant enzymes, including deuterium isotope effects, establishes that all of the mutations result in decreases in the rate constants for removal of the substrate proton by approximately 5-fold and decreases in the rate constant for product release of approximately 2-fold. Only the S171V and S171T mutations alter the rate constant for flavin oxidation. These results establish that these residues are not involved in catalysis, but rather are required for maintaining the protein structure. PMID:20056514

  10. Detection limit for activation measurements in ultralow background sites

    NASA Astrophysics Data System (ADS)

    Trache, Livius; Chesneanu, D.; Margineanu, R.; Pantelica, A.; Ghita, D. G.; Burducea, I.; Straticiuc, M.; Tang, X. D.

    2014-09-01

    We used 12C +13C fusion at the beam energies E = 6, 7 and 8 MeV to determine the sensitivity and the limits of activation method measurements in ultralow background sites. A 13C beam of 0.5 μA from the 3 MV Tandem accelerator of the Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH impinged on thick graphite targets. After about 24 hrs of irradiation targets were measured in two different laboratories: one with a heavy shielded Ge detector in the institute (at the surface) and one located underground in the microBequerel laboratory, in the salt mine of Slanic-Prahova, Romania. The 1369- and 2754 keV peaks from 24Na deactivation were clearly observed in the γ-ray spectra obtained for acquisitions lasting a few hours, or a few days. Determination of the detection limit in evaluating the cross sections for the target irradiated at Ec . m = 3 MeV indicates the fact that it is possible to measure gamma spectrum in underground laboratory down to Ec . m = 2 . 6 MeV. Cleaning the spectra with beta-gamma coincidences and increasing beam intensity 20 times will take as further down. The measurements are motivated by the study of the 12 C +12 C reaction at astrophysical energies.

  11. N6-Methyldeoxyadenosine Marks Active Transcription Start Sites in Chlamydomonas

    PubMed Central

    Chen, Kai; Deng, Xin; Yu, Miao; Han, Dali; Hao, Ziyang; Liu, Jianzhao; Lu, Xingyu; Dore, Louis C; Weng, Xiaocheng; Ji, Quanjiang; Mets, Laurens; He, Chuan

    2015-01-01

    SUMMARY N6-methyldeoxyadenosine (6mA or m6A) is a DNA modification preserved in prokaryotes to eukaryotes. It is widespread in bacteria, and functions in DNA mismatch repair, chromosome segregation, and virulence regulation. In contrast, the distribution and function of 6mA in eukaryotes have been unclear. Here we present a comprehensive analysis of the 6mA landscape in the genome of Chlamydomonas using new sequencing approaches. We identified the 6mA modification in 84% of genes in Chlamydomonas. We found that 6mA mainly locates at ApT dinucleotides around transcription start sites (TSS) with a bimodal distribution, and appears to mark active genes. A periodic pattern of 6mA deposition was also observed at base resolution, which is associated with nucleosome distribution near the TSS, suggesting a possible role in nucleosome positioning. The new genome-wide mapping of 6mA and its unique distribution in the Chlamydomonas genome suggest potential regulatory roles of 6mA in gene expression in eukaryotic organisms. PMID:25936837

  12. [1984-1994: Ten years of skin flaps. Development of transfer techniques. New methods of autoplasty described during this period].

    PubMed

    Martin, D

    1995-10-01

    Ten years of flaps represent a little and a lot. It is little compared to the 2600 years since the first flap in plastic surgery: the Susruta Indian flap, but it is a lot in view of the phenomenal acceleration of this speciality since the Second World War. In 1994 alone, more than two hundred references are listed under the heading "new flaps". As it is impossible to be exhaustive, the author has chosen to focus on two main aspects: a theoretical review of new transfer techniques, dealing successively with: the principles of reverse flow flaps, venous flaps, neurocutaneous flaps, so-called "extracorporeal" transfers, reverse flow YV technique; and practical aspects based on a review of eighteen autoplasties or donor sites selected for their surgical value, their reproductibility and their innovative nature. The author's objective is not to present a technical treatise, but rather to make the reader aware of several key points or even, in some cases, the very existence of these autoplasties. This paper is designed to be didactic, with extensive references, in order to act as a practical guide. It also demonstrates, as if there were any need, to what extent plastic surgery is able to create new solutions and the essential value of continuing research. PMID:8579301

  13. Total ‘rib’-preservation technique of internal mammary vessel exposure for free flap breast reconstruction: A 5-year prospective cohort study and instructional video

    PubMed Central

    Rosich-Medina, Anais; Bouloumpasis, Serafeim; Di Candia, Michele; Malata, Charles M.

    2015-01-01

    Introduction The total ‘rib’-preservation method of dissecting out the internal mammary vessels (IMV) during microvascular breast reconstruction aims to reduce free flap morbidity at the recipient site. We review our five-year experience with this technique. Patients & methods An analysis of a prospectively collected free flap data cohort was undertaken to determine the indications, operative details and reconstructive outcomes in all breast reconstruction patients undergoing IMV exposure using the total ‘rib’-preservation method by a single surgeon. Results 178 consecutive breast free flaps (156 unilateral, 11 bilateral) were performed from 1st June 2008 to 31st May 2013 in 167 patients with a median age of 50 years (range 28–71). There were 154 DIEP flaps, 14 SIEA flaps, 7 muscle-sparing free TRAMs, 2 IGAP flaps and one free latissimus dorsi flap. 75% of the reconstructions (133/178) were immediate, 25% (45/178) were delayed. The mean inter-costal space distance was 20.9 mm (range 9–29). The mean time taken to expose and prepare the recipient IMV's was 54 min (range 17–131). The mean flap ischaemia time was 95 min (range 38–190). Free flap survival was 100%, although 2.2% (4 flaps) required a return to theatre for exploration and flap salvage. No patients complained of localised chest pain or tenderness at the recipient site and no chest wall contour deformity has been observed. Discussion & conclusion The total ‘rib’-preservation technique of IMV exposure is a safe, reliable and versatile method for microvascular breast reconstruction and should be considered as a valid alternative to the ‘rib’-sacrificing techniques. PMID:26468373

  14. Dynamic response of a piezoelectric flapping wing

    NASA Astrophysics Data System (ADS)

    Kumar, Alok; Khandwekar, Gaurang; Venkatesh, S.; Mahapatra, D. R.; Dutta, S.

    2015-03-01

    Piezo-composite membranes have advantages over motorized flapping where frequencies are high and certain coupling between bending and twisting is useful to generate lift and forward flight. We draw examples of fruit fly and bumble bee. Wings with Piezo ceramic PZT coating are realized. The passive mechanical response of the wing is characterized experimentally and validated using finite element simulation. Piezoelectric actuation with uniform electrode coating is characterized and optimal frequencies for flapping are identified. The experimental data are used in an empirical model and advanced ratio for a flapping insect like condition for various angular orientations is estimated.

  15. The plane problem of the flapping wing

    NASA Technical Reports Server (NTRS)

    Birnbaum, Walter

    1954-01-01

    In connection with an earlier report on the lifting vortex sheet which forms the basis of the following investigations this will show how the methods developed there are also suitable for dealing with the air forces for a wing with a circulation variable with time. The theory of a propulsive wing flapping up and down periodically in the manner of a bird's wing is developed. This study shows how the lift and its moment result as a function of the flapping motion, what thrust is attainable, and how high is the degree of efficiency of this flapping propulsion unit if the air friction is disregarded.

  16. New drag laws for flapping flight

    NASA Astrophysics Data System (ADS)

    Agre, Natalie; Zhang, Jun; Ristroph, Leif

    2014-11-01

    Classical aerodynamic theory predicts that a steadily-moving wing experiences fluid forces proportional to the square of its speed. For bird and insect flight, however, there is currently no model for how drag is affected by flapping motions of the wings. By considering simple wings driven to oscillate while progressing through the air, we discover that flapping significantly changes the magnitude of drag and fundamentally alters its scaling with speed. These measurements motivate a new aerodynamic force law that could help to understand the free-flight dynamics, control, and stability of insects and flapping-wing robots.

  17. Blended Cutout Flap for Reduction of Jet-Flap Interaction Noise

    NASA Technical Reports Server (NTRS)

    Czech, Michael J (Inventor); Thomas, Russell H. (Inventor)

    2014-01-01

    An aircraft system includes a wing and a trailing edge device coupled to the wing. The trailing edge device is movable relative to the wing, and includes a leading edge and a trailing edge having a center flap portion and a plurality of outer edge portions integrally combined with the center flap portion such that the center flap portion is shorter in width than that of outer edge portions.

  18. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  19. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  20. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  1. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  2. 10 CFR 63.16 - Review of site characterization activities. 2

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Licenses Preapplication Review § 63.16 Review of... conduct of site characterization activities at the Yucca Mountain site, DOE shall report the nature and... activities at the Yucca Mountain site, NRC staff shall be permitted to visit and inspect the locations...

  3. Propeller Flap Reconstruction in Post Oncological Thigh Defect: "The Move in Flap".

    PubMed

    Nambi, G I; Salunke, Abhijeet Ashok

    2015-06-01

    Reconstruction of soft tissue defects of the limb after tumor resection is challenging question for oncosurgeons. The management differs from reconstruction of post traumatic defects due to the complexity of the primary surgery and subsequent radiation. The conventional propeller flap is based on a perforator which is located close to the defect; but in present case the perforator was located far away from the defect. So we describe it as "Move in flap" as the flap rotated a large volume of soft tissue lying between the defect and the perforator. We present a case of post oncological thigh defect with reconstruction using a propeller flap based on distal anteromedial perforator. PMID:26405422

  4. ["Separation delay" on random flap: an experimental and clinical practice on delayed flap].

    PubMed

    Zhao, S Q

    1990-08-01

    A new technique of delayed flap, that is called "Separation delay" by the authors, has succeeded in animal experiment and clinical practice. In the years of 1985-1989, 11 cases of random skin flaps on the patients had been performed with the new method. All the flaps look like table tennis rackets. It's pedicle is very narrow, simultaneously, the flap itself is very large. So it is quite suitable for repairing a neighbouring wound surface. It can be rotated 180 degrees. "The Separation delay" is a handy way without microsurgical technique. It is also an useful and reliable technique for resurfacing wound on plastic and reconstructive surgery. PMID:2086104

  5. Effects of diammonium glycyrrhizinate on random skin flap survival in rats: An experimental study

    PubMed Central

    Lv, Qing-Bo; Gao, Xiang; Lin, Ding-Sheng; Chen, Yun; Cao, Bin; Zhou, Kai-Liang

    2016-01-01

    Partial necrosis of skin flaps continues to restrict the survival of local skin flaps following plastic and reconstructive surgeries. The aim of the present study was to investigate the effects of diammonium glycyrrhizinate (DG), a salt of glycyrrhetinic acid that has been widely used in the therapy of chronic hepatitis and human immunodeficiency virus infection, on random skin flap survival in rats. McFarlane flaps were established in 60 male Sprague-Dawley rats randomly divided into three groups. Group I served as the control group and was injected with saline (10 mg/kg) once per day. Group II and group III were the experimental groups, and were injected with 10 mg/kg DG once and twice per day, respectively. On day 7, the survival area of the flap was measured. Tissue samples were stained with hematoxylin and eosin and immunohistochemically evaluated. Tissue edema, neutrophil density, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were evaluated. The mean survival areas of the flaps of group II were significantly larger when compared with those of group I (P<0.05), and the rats of group III exhibited significantly higher survival areas than group II (P<0.05). Histologic and immunohistochemical evaluation showed that microvessel development and the expression level of vascular endothelial growth factor were higher in the two experimental groups than in the control group. Furthermore, SOD activity was significantly increased (P<0.05), while the neutrophil density and MDA level were significantly reduced (P<0.05) in group II when compared with group I. Significant differences between group II and group III with regard to SOD activity and MDA level were also observed (P<0.05). Thus, DG may have a dose-dependent effect on promoting the survival of random skin flaps. PMID:27588181

  6. Active-site mutagenesis of tetanus neurotoxin implicates TYR-375 and GLU-271 in metalloproteolytic activity.

    PubMed

    Rossetto, O; Caccin, P; Rigoni, M; Tonello, F; Bortoletto, N; Stevens, R C; Montecucco, C

    2001-08-01

    Tetanus neurotoxin (TeNT) blocks neurotransmitter release by cleaving VAMP/synaptobrevin, a membrane associated protein involved in synaptic vesicle fusion. Such activity is exerted by the N-terminal 50kDa domain of TeNT which is a zinc-dependent endopeptidase (TeNT-L-chain). Based on the three-dimensional structure of botulinum neurotoxin serotype A (BoNT/A) and serotype B (BoNT/B), two proteins closely related to TeNT, and on X-ray scattering studies of TeNT, we have designed mutations at two active site residues to probe their involvement in activity. The active site of metalloproteases is composed of a primary sphere of residues co-ordinating the zinc atom, and a secondary sphere of residues that determines proteolytic specificity and activity. Glu-261 and Glu-267 directly co-ordinates the zinc atom in BoNT/A and BoNT/B respectively and the corresponding residue of TeNT was replaced by Asp or by the non conservative residue Ala. Tyr-365 is 4.3A away from zinc in BoNT/A, and the corresponding residue of TeNT was replaced by Phe or by Ala. The purified mutants had CD, fluorescence and UV spectra closely similar to those of the wild-type molecule. The proteolytic activity of TeNT-Asp-271 (E271D) is similar to that of the native molecule, whereas that of TeNT-Phe-375 (Y375F) is lower than the control. Interestingly, the two Ala mutants are completely devoid of enzymatic activity. These results demonstrate that both Glu-271 and Tyr-375 are essential for the proteolytic activity of TeNT. PMID:11306125

  7. GAS HYDRATES AT TWO SITES OF AN ACTIVE CONTINENTAL MARGIN.

    USGS Publications Warehouse

    Kvenvolden, K.A.

    1985-01-01

    Sediment containing gas hydrates from two distant Deep Sea Drilling Project sites (565 and 568), located about 670 km apart on the landward flank of the Middle America Trench, was studied to determine the geochemical conditions that characterize the occurrence of gas hydrates. Site 565 was located in the Pacific Ocean offshore the Nicoya Peninsula of Costa Rica in 3,111 m of water. The depth of the hole at this site was 328 m, and gas hydrates were recovered from 285 and 319 m. Site 568 was located about 670 km to the northwest offshore Guatemala in 2,031 m of water. At this site the hole penetrated to 418 m, and gas hydrates were encountered at 404 m.

  8. Dynamically Achieved Active Site Precision in Enzyme Catalysis

    PubMed Central

    2015-01-01

    Conspectus The grand challenge in enzymology is to define and understand all of the parameters that contribute to enzymes’ enormous rate accelerations. The property of hydrogen tunneling in enzyme reactions has moved the focus of research away from an exclusive focus on transition state stabilization toward the importance of the motions of the heavy atoms of the protein, a role for reduced barrier width in catalysis, and the sampling of a protein conformational landscape to achieve a family of protein substates that optimize enzyme–substrate interactions and beyond. This Account focuses on a thermophilic alcohol dehydrogenase for which the chemical step of hydride transfer is rate determining across a wide range of experimental conditions. The properties of the chemical coordinate have been probed using kinetic isotope effects, indicating a transition in behavior below 30 °C that distinguishes nonoptimal from optimal C–H activation. Further, the introduction of single site mutants has the impact of either enhancing or eliminating the temperature dependent transition in catalysis. Biophysical probes, which include time dependent hydrogen/deuterium exchange and fluorescent lifetimes and Stokes shifts, have also been pursued. These studies allow the correlation of spatially resolved transitions in protein motions with catalysis. It is now possible to define a long-range network of protein motions in ht-ADH that extends from a dimer interface to the substrate binding domain across to the cofactor binding domain, over a distance of ca. 30 Å. The ongoing challenge to obtaining spatial and temporal resolution of catalysis-linked protein motions is discussed. PMID:25539048

  9. Ostectomy and Medial Plantar Artery Flap Reconstruction for Charcot Foot Ulceration Involving the Midfoot.

    PubMed

    Sato, Tomoya; Ichioka, Shigeru

    2016-01-01

    Charcot foot is a serious complication of diabetes, characterized by deformity and overlying ulceration. The condition most commonly affects the midfoot. However, little information is available on the use of a medial plantar artery flap to treat diabetic midfoot ulceration. The purpose of the present study was to evaluate the versatility of ostectomy and medial plantar flap reconstruction for midfoot plantar ulceration associated with rocker-bottom deformity secondary to Charcot foot. Four patients underwent ostectomy and medial plantar flap reconstruction. Before flap reconstruction, the devitalized soft tissues and bone were radically resected. After the infection had been controlled, the ulcerated portion was minimally excised, and the bony prominence underlying the ulcer was removed. A medial plantar artery flap was applied to the ulcer. The donor site was covered with a split-thickness skin graft or artificial dermis. In all patients, the ulcers healed and independent ambulation was achieved. However, 1 patient experienced ulcer recurrence, and subsequent infection necessitated a major amputation. Limb salvage is challenging in the setting of deformity and intractable plantar ulceration. The advantages of medial plantar artery flap reconstruction are that tissues with a rich blood supply are used to cover the exposed bone, and the flap can withstand the pressure and shear stress of the patient's body weight. However, a dominant artery in the foot is sacrificed. Therefore, the patency of the dorsalis pedis artery must be confirmed in every patient. The results of the present study have demonstrated that a medial plantar artery can be an effective alternative for diabetic patients with a plantar ulcer secondary to Charcot foot. PMID:26190780

  10. SU-E-T-560: Commissioning An HDR Freiburg Flap Applicator for Skin Lesion Treatment

    SciTech Connect

    Dou, K; Li, B; Lerma, F; Aroumougame, V; Sarfaraz, M; Laser, B; Jacobs, M

    2014-06-01

    Purpose: Flexible Freiburg flap used with high dose rate afterloaders is easy to cut into any size for any body site and to dwell with a precise source position, conforms to curved skin surface and then to the planned target. However, unlike intracavity or interstitial situations, incomplete scatter environment due to flap applicators exposed to air might lead to dose difference between the delivered and planned. This research is focused on the dose deviation of incomplete scatter versus full scatter. Methods: A 12x12 cm of Freiburg flap applicator was used for the validation. A Nucletron Oncentra Brachy Ver. 4.3 treatment planning system (TPS) was used for treatment planning. However, no heterogeneity correction incorporated into the brachytherap TPS needs to be considered. A Philips Brilliance CT Big Bore was employed for CT scan. Radiation was delivered using a Nucletron HDR remote afterloader system. A 10cm bolus was used to cover the flap for obtaining a full scatter. An OSL, ion chamber, and Gafchromic EBT2 film were used for commissioning the flap applicator. Results: The applicator calibration at 5mm depth was performed using an OSL dosimeter. Applicator source dwelling positions with 1D and 2D array exposed to and recorded by Gafchromic EBT2 film showed an agreement within 1mm. 1D array of Freiburg flap exhibited 4.2% cooler in dose with incomplete scatter than full scatter. 2D array showed 7.1% lower in dose for incomplete scatter than full scatter. The deviation was found more than 10% beyond 8cm in depth. Conclusion: Significant dose deviation caused by the incomplete scatter environment was found to be 7.1% at 1cm depth. This deviation was increased with increasing depth. The inaccuracy resulted from the incomplete scatter can be fixed by either placing a bolus on the top of the flap or making the plan at least 7% hotter.

  11. P-47 Thunderbolt with dive recovery flaps

    NASA Technical Reports Server (NTRS)

    1946-01-01

    Caption: 'The dive recovery flaps on this P-47 Thunderbolt are barely visible underneath the wings. Photograph and caption published in Winds of Change, 75th Anniversary NASA publication (pages 52-53 and 130), by James Schultz.

  12. A dynamical system for interacting flapping swimmers

    NASA Astrophysics Data System (ADS)

    Oza, Anand; Ramananarivo, Sophie; Ristroph, Leif; Shelley, Michael

    2015-11-01

    We present the results of a theoretical investigation into the dynamics of interacting flapping swimmers. Our study is motivated by the recent experiments of Becker et al., who studied a one-dimensional array of self-propelled flapping wings that swim within each other's wakes in a water tank. They discovered that the system adopts certain ``schooling modes'' characterized by specific spatial phase relationships between swimmers. To rationalize these phenomena, we develop a discrete dynamical system in which the swimmers are modeled as heaving airfoils that shed point vortices during each flapping cycle. We then apply our model to recent experiments in the Applied Math Lab, in which two tandem flapping airfoils are free to choose both their speed and relative positions. We expect that our model may be used to understand how schooling behavior is influenced by hydrodynamics in more general contexts. Thanks to the NSF for its support.

  13. Postirradiation flap infection about the oral cavity

    SciTech Connect

    Cabbabe, E.B.; Herbold, D.R.; Sunwoo, Y.C.; Baroudi, I.F.

    1983-06-01

    Postirradiation alteration of oral flora is well documented in the literature. Infection as a complication leading to partial or complete loss of a flap used to reconstruct a defect in the oral cavity is a worrisome outcome. We describe how a flap that was judged clinically to be viable became overwhelmingly infected with the Klebsiella oxytoca, an oral cavity pathogen encountered in this patient following irradiation. Local and systemic changes led to detachment of the flap. This complication may be explained, in view of the absence of venous congestion or arterial ischemia both clinically and pathologically, by the proven contamination of the flap by the Klebsiella pathogen. Local factors resulted in lower resistance and subsequent overwhelming infection. Discussion of the case, review of pertinent literature, and proposed solutions are presented.

  14. Management of Vortices Trailing Flapped Wings via Separation Control

    NASA Technical Reports Server (NTRS)

    Greenblatt, David

    2005-01-01

    A pilot study was conducted on a flapped semi-span model to investigate the concept and viability of near-wake vortex management via separation control. Passive control was achieved by means of a simple fairing and active control was achieved via zero mass-flux blowing slots. Vortex sheet strength, estimated by integrating surface pressure ports, was used to predict vortex characteristics by means of inviscid rollup relations. Furthermore, vortices trailing the flaps were mapped using a seven-hole probe. Separation control was found to have a marked effect on vortex location, strength, tangential velocity, axial velocity and size over a wide range of angles of attack and control conditions. In general, the vortex trends were well predicted by the inviscid rollup relations. Manipulation of the separated flow near the flap edges exerted significant control over both outboard and inboard edge vortices while producing negligible lift excursions. Dynamic separation and attachment control was found to be an effective means for dynamically perturbing the vortex from arbitrarily long wavelengths down to wavelengths less than a typical wingspan. In summary, separation control has the potential for application to time-independent or time-dependent wake alleviation schemes, where the latter can be deployed to minimize adverse effects on ride-quality and dynamic structural loading.

  15. Robotics and Automation Activities at the Savannah River Site: A Site Report for SUBWOG 39F

    SciTech Connect

    Teese, G.D.

    1995-09-28

    The Savannah River Site has successfully used robots, teleoperators, and remote video to reduce exposure to ionizing radiation, improve worker safety, and improve the quality of operations. Previous reports have described the use of mobile teleoperators in coping with a high level liquid waste spill, the removal of highly contaminated equipment, and the inspection of nuclear reactor vessels. This report will cover recent applications at the Savannah River, as well as systems which SRS has delivered to other DOE site customers.

  16. Aerodynamic effects of flexibility in flapping wings

    PubMed Central

    Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P.

    2010-01-01

    Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re ≈ 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic

  17. Bilateral pedicled gracilis flap for scrotal reconstruction.

    PubMed

    Daigeler, Adrien; Behr, Björn; Mikhail, Bassem Daniel; Lehnhardt, Marcus; Wallner, Christoph

    2016-09-01

    Trauma, infection and cancer can cause severe scrotal defects. The demand to a definitive reconstruction in terms of aesthetics and function is high. Primary closure, skin grafts and local fasciocutaneous flaps do not meet these high demands in most cases. The authors treated a series of patients requiring scrotal reconstruction with bilateral pedicled gracilis muscle flaps and split thickness skin grafts, resulting in satisfying aesthetic and functional outcomes. PMID:27318782

  18. Effects of MK-886, a 5-lipoxygenase activating protein (FLAP) inhibitor, and 5-lipoxygenase deficiency on the forced swimming behavior of mice.

    PubMed

    Uz, Tolga; Dimitrijevic, Nikola; Imbesi, Marta; Manev, Hari; Manev, Radmila

    2008-05-01

    A common biological pathway may contribute to the comorbidity of atherosclerosis and depression. Increased activity of the enzymatic 5-lipoxygenase (5-LOX, 5LO) pathway is a contributing factor in atherosclerosis and a 5-LOX inhibitor, MK-886, is beneficial in animal models of atherosclerosis. In the brain, MK-886 increases phosphorylation of the glutamate receptor subunit GluR1, and the increased phosphorylation of this receptor has been associated with antidepressant treatment. In this work, we evaluated the behavioral effects of MK-886 in an automated assay of mouse forced swimming, which identifies antidepressant activity as increased climbing behavior and/or decreased rest time. Whereas a single injection of MK-886 (3 and 10 mg/kg) did not affect forced swimming behaviors assayed 30 min later, six daily injections of 3 mg/kg MK-886 slightly increased climbing and significantly reduced rest time in wild-type mice but not in 5-LOX-deficient mice. A diet delivery of MK-886, 4 micro/(100 mg(body-weight)day), required 3 weeks to affect forced swimming; it increased climbing behavior. Climbing behavior was also increased in naive 5-LOX-deficient mice compared to naive wild-type controls. These results suggest that 5-LOX inhibition and deficiency may be associated with antidepressant activity. Increased climbing in a forced swimming assay is a typical outcome of antidepressants that increase noradrenergic and dopaminergic activity. Interestingly, 5-LOX deficiency and MK-886 treatment have been shown to be capable of increasing the behavioral effects of a noradrenaline/dopamine-potentiating drug, cocaine. Future research is needed to evaluate the clinical relevance of our findings. PMID:18403121

  19. Dynamic responses of a two-dimensional flapping foil motion

    NASA Astrophysics Data System (ADS)

    Lu, Xi-Yun; Liao, Qin

    2006-09-01

    The investigation of a flapping foil, which is used as a basic mode of the flapping-based locomotion in insects, birds, and fish, is performed by solving the Navier-Stokes equations numerically. In this Brief Communication we provide insight into the understanding of dynamics of a flapping foil. A critical flapping Reynolds number based on the flapping frequency and amplitude, above which a forward flapping movement occurs, is predicted. The dynamics of the flapping foil are analyzed in two dynamic responses, i.e., an oscillatory movement and a steady movement, which depend on the density ratio between the foil and the surrounded fluid. The steady movement response is related to the forward flapping motion. The Strouhal number that governs a vortex shedding for the forward flapping foil is calculated and lies in the range where flying and swimming animals will be likely to tune for high propulsive efficiency.

  20. Quadratus lumborum catheters for breast reconstruction requiring transverse rectus abdominis myocutaneous flaps.

    PubMed

    Spence, Nicole Z; Olszynski, Patrycja; Lehan, Anne; Horn, Jean-Lois; Webb, Christopher A J

    2016-06-01

    Patients diagnosed with breast cancer may opt to undergo surgical reconstructive flaps at the time of or after mastectomies. These surgeries leave patients with significant postoperative pain and sometimes involve large surgical beds including graft sites from the abdomen to reconstruct the breast. Consequently, multimodal methods of pain management have become highly favored. Quadratus lumborum catheters offer an opioid-sparing technique that can be performed easily and safely. We present a case of a patient who underwent a breast flap reconstruction and had bilateral quadratus lumborum catheters placed for perioperative pain control. PMID:26984687

  1. The Effect of Epigallocatechin Gallate on Flap Viability of Rat Perforator Abdominal Flaps.

    PubMed

    Aksakal, İbrahim Alper; Küçüker, İsmail; Önger, Mehmet Emin; Engin, Murat Sinan; Keleş, Musa Kemal; Demir, Ahmet

    2016-05-01

    Background Epigallocatechin gallate (EGCG) is a substance abundant in green tea. In this study, the effects of EGCG on perforator flap viability were investigated. Methods A total of 40 rats were assigned to four groups of 10 each. In each subject, a 4 × 6 cm abdominal skin flap was raised and adapted back onto its place. In the control group, no further procedures were taken. In the flap group, 40 mg/kg/d EGCG was injected into the flap. In the gavage group, 100 mg/kg/d EGCG was given through a feeding tube. In the intraperitoneal group, 50 mg/kg/d EGCG was injected intraperitoneally. On the 7th postoperative day, flaps were photographed and the viable areas were measured and compared via a one-way analysis of variance. Results The ratios of viable and contracted flap area were 9.15/12.01, 4.59/16.46, 11.56/11.20, and 11.65/10.77 cm(2) for the control, flap group, gavage group, and intraperitoneal group, respectively. While the flap group yielded the worst results in the sense of flap contraction and viability (p < 0.001), the gavage and intraperitoneal groups were significantly better than those of the control group (p = 0.03). Histologically, epidermal, papillary dermal, and capillary tissue volumes were evaluated. In comparison to the control group, the flap group yielded significantly increased epidermal and dermal volumes (p = 0.03), however, these values were significantly decreased (p = 0.04) in the gavage and intraperitoneal groups. Capillary volumes were significantly decreased in EGCG treatment groups (p < 0.01). Conclusion Our experiment has shown that oral and intraperitoneal administration of EGCG increases the perforator flap viability when compared with controls, while direct injection decreases the viability. PMID:26919381

  2. Preliminary Design and Evaluation of an Airfoil with Continuous Trailing-Edge Flap

    NASA Technical Reports Server (NTRS)

    Shen, Jinwei; Thornburgh, Robert P.; Kreshock, Andrew R.; Wilbur, Matthew L.; Liu, Yi

    2012-01-01

    This paper presents the preliminary design and evaluation of an airfoil with active continuous trailing-edge flap (CTEF) as a potential rotorcraft active control device. The development of structural cross-section models of a continuous trailing-edge flap airfoil is described. The CTEF deformations with MFC actuation are predicted by NASTRAN and UM/VABS analyses. Good agreement is shown between the predictions from the two analyses. Approximately two degrees of CTEF deflection, defined as the rotation angle of the trailing edge, is achieved with the baseline MFC-PZT bender. The 2D aerodynamic characteristics of the continuous trailing-edge flap are evaluated using a CFD analysis. The aerodynamic efficiency of a continuous trailing-edge flap is compared to that of a conventional discrete trailing-edge flap (DTEF). It is found that the aerodynamic characteristics of a CTEF are equivalent to those of a conventional DTEF with the same deflection angle but with a smaller flap chord. A fluid structure interaction procedure is implemented to predict the deflection of the continuous trailingedge flap under aerodynamic pressure. The reductions in CTEF deflection are overall small when aerodynamic pressure is applied: 2.7% reduction is shown with a CTEF deflection angle of two degrees and at angle of attack of six degrees. In addition, newly developed MFC-PMN actuator is found to be a good supplement to MFC-PZT when applied as the bender outside layers. A mixed MFC-PZT and MFC-PMN bender generates 3% more CTEF deformation than an MFC-PZT only bender and 5% more than an MFC-PMN only bender under aerodynamic loads.

  3. Improving upon Nature: Active site remodeling produces highly efficient aldolase activity towards hydrophobic electrophilic substrates

    PubMed Central

    Cheriyan, Manoj; Toone, Eric J.; Fierke, Carol A.

    2012-01-01

    Substrate specificity of enzymes is frequently narrow and constrained by multiple interactions, limiting the use of natural enzymes in biocatalytic applications. Aldolases have important synthetic applications, but the usefulness of these enzymes is hampered by their narrow reactivity profile with unnatural substrates. To explore the determinants of substrate selectivity and alter the specificity of E. coli 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase, we employed structure-based mutagenesis coupled with library screening of mutant enzymes localized to the bacterial periplasm. We identified two active site mutations (T161S/S184L) that work additively to enhance the substrate specificity of this aldolase to include catalysis of retro-aldol cleavage of (4S)-2-keto-4-hydroxy-4-(2′-pyridyl)butyrate (S-KHPB). These mutations improve the value of kcat/KMS-KHPB by >450-fold, resulting in a catalytic efficiency that is comparable to that of the wild-type enzyme with the natural substrate while retaining high stereoselectivity. Moreover, the value of kcatS-KHPB for this mutant enzyme, a parameter critical for biocatalytic applications, is 3-fold higher than the maximum value achieved by the natural aldolase with any substrate. This mutant also possesses high catalytic efficiency for the retro-aldol cleavage of the natural substrate, KDPG, and a >50-fold improved activity for cleavage of 2-keto-4-hydroxy-octonoate (KHO), a non-functionalized hydrophobic analog. These data suggest a substrate binding mode that illuminates the origin of facial selectivity in aldol addition reactions catalyzed by KDPG and 2-keto-3-deoxy-6-phosphogalactonate (KDPGal) aldolases. Furthermore, targeting mutations to the active site provides marked improvement in substrate selectivity, demonstrating that structure-guided active site mutagenesis combined with selection techniques can efficiently identify proteins with characteristics that compare favorably to naturally occurring enzymes. PMID

  4. Atomically-thin two-dimensional sheets for understanding active sites in catalysis.

    PubMed

    Sun, Yongfu; Gao, Shan; Lei, Fengcai; Xie, Yi

    2015-02-01

    Catalysis can speed up chemical reactions and it usually occurs on the low coordinated steps, edges, terraces, kinks and corner atoms that are often called "active sites". However, the atomic level interplay between active sites and catalytic activity is still an open question, owing to the large difference between idealized models and real catalysts. This stimulates us to pursue a suitable material model for studying the active sites-catalytic activity relationship, in which the atomically-thin two-dimensional sheets could serve as an ideal model, owing to their relatively simple type of active site and the ultrahigh fraction of active sites that are comparable to the overall atoms. In this tutorial review, we focus on the recent progress in disclosing the factors that affect the activity of reactive sites, including characterization of atomic coordination number, structural defects and disorder in ultrathin two-dimensional sheets by X-ray absorption fine structure spectroscopy, positron annihilation spectroscopy, electron spin resonance and high resolution transmission electron microscopy. Also, we overview their applications in CO catalytic oxidation, photocatalytic water splitting, electrocatalytic oxygen and hydrogen evolution reactions, and hence highlight the atomic level interplay among coordination number, structural defects/disorder, active sites and catalytic activity in the two-dimensional sheets with atomic thickness. Finally, we also present the major challenges and opportunities regarding the role of active sites in catalysis. We believe that this review provides critical insights for understanding the catalysis and hence helps to develop new catalysts with high catalytic activity. PMID:25382246

  5. The active sites of supported silver particle catalysts in formaldehyde oxidation.

    PubMed

    Chen, Yaxin; Huang, Zhiwei; Zhou, Meijuan; Hu, Pingping; Du, Chengtian; Kong, Lingdong; Chen, Jianmin; Tang, Xingfu

    2016-08-01

    Surface silver atoms with upshifted d-orbitals are identified as the catalytically active sites in formaldehyde oxidation by correlating their activity with the number of surface silver atoms, and the degree of the d-orbital upshift governs the catalytic performance of the active sites. PMID:27406403

  6. The Scarless Latissimus Dorsi Flap Provides Effective Lower Pole Prosthetic Coverage in Breast Reconstruction

    PubMed Central

    Miteff, Kirstin G.

    2014-01-01

    Background: The evolution of surgical breast cancer treatment has led to the oncologically safe preservation of greater amounts of native skin, yet we are still often using flaps with large skin paddles, thereby resulting in significant donor-site scars. This explains the increasing appeal of acellular dermal matrix reconstructions. Acellular dermal matrices can, however, have significant problems, particularly if there is any vascular compromise of the mastectomy skin flaps. We have developed a method of raising the latissimus dorsi flap through the anterior mastectomy incisions without requiring special instruments or repositioning. This can provide autologous vascularized cover of the prosthesis. Methods: A clear surgical description of the scarless latissimus dorsi flap harvest is provided, and our results of a retrospective cohort review of 20 consecutive patients with 27 traditional latissimus dorsi breast reconstructions were compared with those of 20 consecutive patients with 30 scarless latissimus dorsi breast reconstructions. Results: Operative time, length of stay, and complication rates were reduced in the scarless group. Patients Breast-Q scores were equivalent in each group. The aesthetic assessment was good/excellent in 77% of both groups; however, subscale assessment was better in the scarless group. This was statistically significant (P = 0.0). Conclusions: Breast reconstruction using the scarless latissimus dorsi flap is time effective, requires no patient repositioning, and uses standard breast instrumentation. It is safe and versatile while reducing the risk of exposed prosthesis if native skin necrosis occurs. It is a vascularized alternative to acellular dermal matrices. PMID:25289340

  7. Incidence and types of complications after ablative oral cancer surgery with primary microvascular free flap reconstruction

    PubMed Central

    Lodders, Johannes N.; Parmar, Satyesh; Stienen, Niki LM.; Martin, Timothy J.; Karagozoglu, K. Hakki; Heymans, Martijn W.; Nandra, Baljeet

    2015-01-01

    Background The aims of the study were 1) to evaluate the incidence and types of postoperative complications after ablative oral cancer surgery with primary free flap reconstruction and 2) identify prognostic variables for postoperative complications. Material and Methods Desired data was retrieved from a computer database at the department of Oral and Maxillofacial Department, Queen Elisabeth hospital Birmingham, United Kingdom, between June 2007 and October 2012. Logistic regression was used to study relationships between preoperative variables and postoperative outcomes. Results The study population consisted 184 patients, comprising 189 composite resections with reconstruction. Complications developed in 40.2% of the patients. Three patients (1.6%) died, 11.1% returned to the operating room, 5.3% developed donor site complications and 6.9% flap complications of which 3.2% total flap failure. In the multivariable analysis systemic complications were associated with anaesthesia time and hospital stay with red cell transfusion. Conclusions A significant proportion of the patients with primary free flap reconstructions after oral cancer surgery develops postoperative complications. Prolonged anaesthesia time and red cell transfusion are possible predictors for systemic complications and hospital stay respectively. Preoperative screening for risk factors is advocated for patient selection and to have realistic information and expectations. Key words:Free flap, complications, oral cancer, risk factors, reconstruction. PMID:26116846

  8. POSTERIOR INTERBONE ARTERY FLAP FOR COVERING SERIOUS FOREARM, WRIST AND HAND INJURIES

    PubMed Central

    de Lima, Sérgio José; Domingos da Costa, Ricardo Pereira; de Oliveira, Emanoel; Prudente, Fabrício Guimarães; Mendonça, Marcelo Paris; Soares de Camargo, Christiano

    2015-01-01

    To assess the results achieved with posterior interbone artery flap covering serious injuries of the distal third of the forearm, wrist and hand, evaluating the degree of effectiveness of this procedure. Methods: 35 patients with serious injuries of the distal third of upper limbs were studied. We assessed the kind of trauma, injury site, flap size, skin coverage need, clinical outcome and complications. Results: The most frequent mechanism of trauma was motorcycle accident. The most commonly affected regions were: dorsal hand, wrist volar regions and the first commissure. In all patients, the flap size was enough to cover key tissues exposed by the injury. The donor area did not show complications, being primarily closed in 23 cases. The outcomes were good for 31 cases. In 22 patients, no complication was found, and the flap was completely lost in four. Conclusion: Posterior interbone artery flap provides good outcomes in covering serious injuries of the distal third of upper limbs, leading to a stable and reliable coverage, not compromising key irrigating arteries of the hand, enabling the performance of reconstruction procedures. Therefore, this is a useful alternative in such cases. PMID:26998451

  9. Use of the vascularized iliac-crest flap in musculoskeletal lesions.

    PubMed

    Tonoli, Cristiane; Bechara, Alexandre H S; Rossanez, Roberto; Belangero, William D; Livani, Bruno

    2013-01-01

    Bone loss was in the past treated by several methods, such as bone distraction and the use of nonvascularized or tissue-bank bone grafts. With the advent of modern microsurgical techniques, the vascularized bone flap has been used with good results; it resolves local nutritional problems, repairs soft tissue that is often damaged by severe trauma, and treats bone loss due to tumors, pseudarthroses, and osteomyelitis. This paper reports the authors' experience with the use of vascularized iliac-crest flaps to treat orthopedic pathologies in five patients with traumatic bone loss (<10 cm), three with osteomyelitis, and three with atrophic nonunion. In all cases, the same surgeon obtained a vascularized iliac-crest flap with a pedicle based on the deep iliac circumflex artery. All flaps consolidated within a mean period of 3 months. These findings demonstrate that the use of an iliac-crest flap is a treatment option in cases of bone loss and that it is associated with good functional results and minimal donor-site morbidity. PMID:24233062

  10. Use of the Vascularized Iliac-Crest Flap in Musculoskeletal Lesions

    PubMed Central

    Tonoli, Cristiane; Bechara, Alexandre H. S.; Rossanez, Roberto; Belangero, William D.; Livani, Bruno

    2013-01-01

    Bone loss was in the past treated by several methods, such as bone distraction and the use of nonvascularized or tissue-bank bone grafts. With the advent of modern microsurgical techniques, the vascularized bone flap has been used with good results; it resolves local nutritional problems, repairs soft tissue that is often damaged by severe trauma, and treats bone loss due to tumors, pseudarthroses, and osteomyelitis. This paper reports the authors' experience with the use of vascularized iliac-crest flaps to treat orthopedic pathologies in five patients with traumatic bone loss (<10 cm), three with osteomyelitis, and three with atrophic nonunion. In all cases, the same surgeon obtained a vascularized iliac-crest flap with a pedicle based on the deep iliac circumflex artery. All flaps consolidated within a mean period of 3 months. These findings demonstrate that the use of an iliac-crest flap is a treatment option in cases of bone loss and that it is associated with good functional results and minimal donor-site morbidity. PMID:24233062

  11. The figure-of-eight radix nasi flap for medial canthal defects.

    PubMed

    Seyhan, Tamer

    2010-09-01

    Basal cell carcinomas commonly involve the medial canthal region and reconstruction of medial canthal defects is a challenging problem in reconstructive surgery. A new axial pattern flap raised from radix nasi region has been successfully used for the medial canthal defects in eight patients in figure-of-eight manner. One of the ellipses of the figure of eight is the defect, the other is the radix nasi flap. The radix nasi flap with a dimension up to 25 mm is transposed to the defect based either on ipsilateral anastomosis of the dorsal nasal artery with angular artery (AA) or with the connection of its source artery (i.e. ophthalmic artery) if the AA is damaged. All flaps survived and no tumour recurrence was observed. The donor sites were closed primarily and hidden at the radix nasi crease in all cases. The radix nasi flap in figure-of-eight fashion is good alternative for defects of the medial canthal area in terms of attaining a suitable colour and texture and minimal surgical scars. PMID:20079658

  12. Breast reconstruction with a turbocharged transverse rectus abdominis myocutaneous flap on the contralateral perforator.

    PubMed

    Sbalchiero, Juliano Carlos; de Albuquerque Leal, Paulo Roberto; dos Santos, César Cabello

    2014-11-01

    Seventeen patients were submitted to delayed unilateral breast reconstruction using pedicled, muscle-sparing turbocharged transverse rectus abdominis myocutaneous flap based on the contralateral perforator vessels. The lateral portion of the rectus abdominis muscle on the pedicled side was preserved in 12 patients. Zones II and IV were included in the flap in all cases. Mean duration of surgery was 7 hours and 15 minutes. Four complications developed in the abdominal donor site: contralateral abdominal bulging (n=1), minor suture dehiscence (n=2), and epidermolysis at the border of the abdominal flap and umbilical scar (n=1). Three partial losses (10%-30%) occurred in the reconstructed breast (17.64% of cases), whereas 2 cases of fat necrosis were associated with partial losses. One patient developed deep vein thrombosis with pulmonary embolism; however, outcome was favorable. This proved a viable alternative for breast reconstruction, with satisfactory results in most patients and acceptable morbidity and surgical time. PMID:24625511

  13. Bidirectionally positioned flap surgery: a case report with 3-year follow-up.

    PubMed

    Iwano, Yoshihiro; Sato, Shuichi; Ito, Koichi

    2013-01-01

    A new technique to cover recessions to take advantage of connective tissue grafts and coronally advanced flaps is proposed. A 34-year-old woman presented with a 2-mm Class I recession on the buccal aspect of her maxillary right canine. A full-thickness flap was placed coronally to cover the exposed root, and a partial thickness flap was positioned apically. Complete root coverage was obtained, and the width of keratinized tissue had increased from 2 to 4 mm at the 6-month postoperative visit. These clinical outcomes were maintained for 3 years. This single surgical approach benefits from obtaining not only complete root coverage but also increasing width of keratinized tissue, without requiring a second surgical site. PMID:23444158

  14. Reconstruction of Extensive Volar Finger Defects with Double Cross-Finger Flaps

    PubMed Central

    Buehrer, Gregor; Arkudas, Andreas; Ludolph, Ingo; Horch, Raymund E.

    2016-01-01

    Summary: Cross-finger flaps still represent a viable option to reconstruct small- to medium-sized full-thickness finger defects but they are not commonly used if larger areas have to be covered. We present 2 cases showing a simple and pragmatic approach with homodigital double cross-finger flaps to reconstruct extensive volar finger soft-tissue defects. We observed very low donor-site morbidity and excellent functional and aesthetic outcomes. Furthermore, there is no need for microsurgical techniques or equipment when using this method. Although this case report only addresses volar defects, one might also think of applying this concept to dorsal defects using reversed double cross-finger flaps. PMID:27200255

  15. The dog-ear flap as an alternative for breast reconstruction in patients who have already undergone a DIEAP flap.

    PubMed

    Colebunders, Britt; Depypere, Bernard; Van Landuyt, Koenraad

    2016-05-01

    Breast reconstruction in patients who have previously undergone deep inferior epigastric artery perforator flap (DIEAP) reconstruction or abdominoplasty is often challenging. Depending on patients' body habitus, several second-choice flaps have been described such as the transverse upper gracilis (TUG) flap, profundus femoris artery perforator (PFAP) flap, superior gluteal artery perforator (SGAP) flap, and lumbar artery perforator (LAP) flap. Patients who have undergone a DIEAP flap reconstruction or abdominoplasty occasionally present with dog ears on both sides of the abdominal scar. The adipose tissue and skin of these dog ears are supplied by perforators of the deep circumflex iliac artery (DCIA). The DCIA flap was first described in 1979 by Taylor. We introduce this abdominal "dog-ear" flap for autologous breast reconstruction. PMID:26951847

  16. Identification of promiscuous ene-reductase activity by mining structural databases using active site constellations

    PubMed Central

    Steinkellner, Georg; Gruber, Christian C.; Pavkov-Keller, Tea; Binter, Alexandra; Steiner, Kerstin; Winkler, Christoph; Łyskowski, Andrzej; Schwamberger, Orsolya; Oberer, Monika; Schwab, Helmut; Faber, Kurt; Macheroux, Peter; Gruber, Karl

    2014-01-01

    The exploitation of catalytic promiscuity and the application of de novo design have recently opened the access to novel, non-natural enzymatic activities. Here we describe a structural bioinformatic method for predicting catalytic activities of enzymes based on three-dimensional constellations of functional groups in active sites (‘catalophores’). As a proof-of-concept we identify two enzymes with predicted promiscuous ene-reductase activity (reduction of activated C–C double bonds) and compare them with known ene-reductases, that is, members of the Old Yellow Enzyme family. Despite completely different amino acid sequences, overall structures and protein folds, high-resolution crystal structures reveal equivalent binding modes of typical Old Yellow Enzyme substrates and ligands. Biochemical and biocatalytic data show that the two enzymes indeed possess ene-reductase activity and reveal an inverted stereopreference compared with Old Yellow Enzymes for some substrates. This method could thus be a tool for the identification of viable starting points for the development and engineering of novel biocatalysts. PMID:24954722

  17. Maxillofacial reconstruction with nasolabial and facial artery musculomucosal flaps.

    PubMed

    Braasch, Daniel Cameron; Lam, Din; Oh, Esther S

    2014-08-01

    The nasolabial and facial artery musculomucosal (FAMM) flaps are predictable methods to reconstruct perioral and intraoral defects with vascularized tissue. The nasolabial flap can be harvested as an axial or random patterned flap, whereas the FAMM flap is truly an axial patterned flap, with either a superior or an inferior base. Both flaps have been widely used to provide predictable results, with low morbidity. Future studies are needed to further prove their use in compromised patients, including patients with a history of head and neck radiation and neck dissections. PMID:25086694

  18. Combined posterior flap and anterior suspended flap dacryocystorhinostomy: A modification of external dacryocystorhinostomy

    PubMed Central

    Deka, Amarendra; Saikia, S. P.; Bhuyan, S. K.

    2010-01-01

    Background: External dacryocystorhinostomy (DCR) remains a reliable surgical technique for the treatment of obstruction of lacrimal drainage system beyond the common canalicular opening. Aim: To describe a simple modified double flap external DCR technique. Materials and Methods: Ninety six consecutive cases of chronic dacryocystitis with or without mucocele were selected irrespective of age and sex. In a modification to routine external DCR, a modified technique was followed, where both anterior and posterior flaps of lacrimal sac and nasal mucosa are created and sutured. Two double armed sutures were used to join the edges of anterior flaps, and elevate them anteriorly to avoid adhesion or apposition with underlying sutured posterior flaps, and to approximate the deep plane of the wound. Results: At the end of average follow-up period of 13 months, we observed 98.9% objective and 96.8% subjective success rates. The average operation time was 45 minutes. No significant intraoperative or postoperative complications were noticed. Conclusion: We believe that combined posterior flap and anterior suspended flap DCR technique is simple to perform and has the advantage of both double flap DCR and anterior suspension of anterior flaps. The results of the study showed the efficacy of this simple modification. PMID:20606867

  19. The evolving breast reconstruction: from latissimus dorsi musculocutaneous flap to a propeller thoracodorsal fasciocutaneous flap

    PubMed Central

    Gunnarsson, Gudjon Leifur

    2014-01-01

    The aim of this editorial is to give an update on the use of the propeller thoracodorsal artery perforator flap (TAP/TDAP-flap) within the field of breast reconstruction. The TAP-flap can be dissected by a combined use of a monopolar cautery and a scalpel. Microsurgical instruments are generally not needed. The propeller TAP-flap can be designed in different ways, three of these have been published: (I) an oblique upwards design; (II) a horizontal design; (III) an oblique downward design. The latissimus dorsi-flap is a good and reliable option for breast reconstruction, but has been criticized for morbidity and complications. The TAP-flap does not seem to impair the function of the shoulder or arm and the morbidity appears to be scarce. However, an implant is often needed in combination with the TAP-flap, which results in implant related morbidity over time. The TAP-flap seems to be a promising tool for oncoplastic and reconstructive breast surgery and will certainly become an invaluable addition to breast reconstructive methods. PMID:25207206

  20. Design and experimental results for a turbine with jet flap stator and jet flap

    NASA Technical Reports Server (NTRS)

    Bettner, J. L.; Blessing, J. O.

    1973-01-01

    The overall performance and detailed stator performance of a negative hub reaction turbine design featuring a moderately low solidity jet flap stator and a jet flap rotor were determined. Testing was conducted over a range of turbine expansion ratios at design speed. At each expansion ratio, the stator jet flow and rotor jet flow ranged up to about 7 and 8 percent, respectively, of the turbine inlet flow. The performance of the jet flap stator/jet flap rotor turbine was compared with that of a turbine which used the same jet flap rotor and a conventional, high solidity plan stator. The effect on performance of increased axial spacing between the jet stator and rotor was also investigated.

  1. Comparing semilunar coronally positioned flap to standard coronally positioned flap using periodontal clinical parameters.

    PubMed

    Nassar, Carlos Augusto; da Silva, Wilson Aparecido Dias; Tonet, Karine; Secundes, Mayron Barros; Nassar, Patricia Oehlmeyer

    2014-01-01

    This study compared the effectiveness of 2 surgical root coverage techniques--semilunar coronally positioned flap and coronally advanced flap--using the clinical parameters of periodontal tissues from patients with Miller Class I gingival recession. Twenty patients (20-50 years of age) were selected. Basic periodontal treatment was performed, and plaque index, gingival index, probing depth, clinical attachment level, and height of the attached gingiva were determined. Each patient was placed into 1 of 2 groups: Group 1 patients underwent the semilunar coronally positioned flap technique, and Group 2 patients underwent the coronally advanced flap technique. Patients were assessed for 180 days. Both groups showed significant reduction of plaque and gingival indices and an improvement in clinical attachment levels and probing depth. However, results showed the standard coronally positioned flap technique was deemed more effective due to significant clinical attachment level gains. PMID:24598495

  2. Blade-Mounted Flap Control for BVI Noise Reduction Proof-of-Concept Test

    NASA Technical Reports Server (NTRS)

    Dawson, Seth; Hassan, Ahmed; Straub, Friedrich; Tadghighi, Hormoz

    1995-01-01

    This report describes a wind tunnel test of the McDonnell Douglas Helicopter Systems (MDHS) Active Flap Model Rotor at the NASA Langley 14- by 22-Foot Subsonic Tunnel. The test demonstrated that BVI noise reductions and vibration reductions were possible with the use of an active flap. Aerodynamic results supported the acoustic data trends, showing a reduction in the strength of the tip vortex with the deflection of the flap. Acoustic results showed that the flap deployment, depending on the peak deflection angle and azimuthal shift in its deployment schedule, can produce BVI noise reductions as much as 6 dB on the advancing and retreating sides. The noise reduction was accompanied by an increase in low frequency harmonic noise and high frequency broadband noise. A brief assessment of the effect of the flap on vibration showed that significant reductions were possible. The greatest vibration reductions (as much as 76%) were found in the four per rev pitching moment at the hub. Performance improvement cam results were inconclusive, as the improvements were predicted to be smaller than the resolution of the rotor balance.

  3. A bio-inspired study on tidal energy extraction with flexible flapping wings.

    PubMed

    Liu, Wendi; Xiao, Qing; Cheng, Fai

    2013-09-01

    Previous research on the flexible structure of flapping wings has shown an improved propulsion performance in comparison to rigid wings. However, not much is known about this function in terms of power efficiency modification for flapping wing energy devices. In order to study the role of the flexible wing deformation in the hydrodynamics of flapping wing energy devices, we computationally model the two-dimensional flexible single and twin flapping wings in operation under the energy extraction conditions with a large Reynolds number of 106. The flexible motion for the present study is predetermined based on a priori structural result which is different from a passive flexibility solution. Four different models are investigated with additional potential local distortions near the leading and trailing edges. Our simulation results show that the flexible structure of a wing is beneficial to enhance power efficiency by increasing the peaks of lift force over a flapping cycle, and tuning the phase shift between force and velocity to a favourable trend. Moreover, the impact of wing flexibility on efficiency is more profound at a low nominal effective angle of attack (AoA). At a typical flapping frequency f * = 0.15 and nominal effective AoA of 10°, a flexible integrated wing generates 7.68% higher efficiency than a rigid wing. An even higher increase, around six times that of a rigid wing, is achievable if the nominal effective AoA is reduced to zero degrees at feathering condition. This is very attractive for a semi-actuated flapping energy system, where energy input is needed to activate the pitching motion. The results from our dual-wing study found that a parallel twin-wing device can produce more power compared to a single wing due to the strong flow interaction between the two wings. PMID:23981650

  4. Venous-supercharged freestyle posterior thigh flap without a descending branch of the inferior gluteal artery for reconstruction in the infragluteal region.

    PubMed

    Fukunaga, Yutaka; Miyamoto, Shimpei; Kobayashi, Eisuke; Sakuraba, Minoru

    2014-12-01

    The posterior thigh flap is a workhorse flap for reconstruction in the gluteal region. The main vascular pedicle of the flap is commonly the descending branch of the inferior gluteal artery, although it is at risk for transection during sarcoma resection. We report successful reconstruction of an infragluteal defect resulting from sarcoma resection with a venous-supercharged freestyle posterior thigh flap in the absence of the descending branch of the inferior gluteal artery. A 77-year-old man underwent sarcoma resection in the infragluteal region. The descending branch of the inferior gluteal artery was sacrificed. We found a sizable perforator through the long head of the biceps femoris and harvested a posterior thigh flap on the basis of that perforator with a freestyle approach. The flap gradually developed a congestive appearance after transfer. We therefore anastomosed the vein of the second perforator to an accompanying vein of the sciatic nerve at the recipient site. The complete flap survived, and the postoperative course was uneventful. We believe that combined use of the freestyle approach and the perforator-supercharging technique can enhance the versatility and the safety of pedicled perforator flap transfer. PMID:25193397

  5. Structural mechanism of RuBisCO activation by carbamylation of the active site lysine

    PubMed Central

    Stec, Boguslaw

    2012-01-01

    Ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is a crucial enzyme in carbon fixation and the most abundant protein on earth. It has been studied extensively by biochemical and structural methods; however, the most essential activation step has not yet been described. Here, we describe the mechanistic details of Lys carbamylation that leads to RuBisCO activation by atmospheric CO2. We report two crystal structures of nitrosylated RuBisCO from the red algae Galdieria sulphuraria with O2 and CO2 bound at the active site. G. sulphuraria RuBisCO is inhibited by cysteine nitrosylation that results in trapping of these gaseous ligands. The structure with CO2 defines an elusive, preactivation complex that contains a metal cation Mg2+ surrounded by three H2O/OH molecules. Both structures suggest the mechanism for discriminating gaseous ligands by their quadrupole electric moments. We describe conformational changes that allow for intermittent binding of the metal ion required for activation. On the basis of these structures we propose the individual steps of the activation mechanism. Knowledge of all these elements is indispensable for engineering RuBisCO into a more efficient enzyme for crop enhancement or as a remedy to global warming. PMID:23112176

  6. Extended thoracodorsal artery perforator flap for breast reconstruction.

    PubMed

    Angrigiani, Claudio; Rancati, Alberto; Escudero, Ezequiel; Artero, Guillermo

    2015-12-01

    A total of 45 patients underwent partial or total autologous breast reconstruction after skin-sparing mastectomy, skin-reducing mastectomy, and quadrantectomy using a thoracodorsal artery perforator (TDAP) flap. The detailed surgical technique with its variations is explained in this report. The propeller, flip-over, conventional perforator, and muscle-sparing flaps have been described and evaluated. The flaps were partially or completely de-epithelialized. The conventional TDAP can be enlarged or "extended" as the traditional latissimus dorsi musculocutaneous (LD-MC) flap by incorporating the superior and inferior fat compartments. It can be referred to as the "extended TDAP flap". This technique augments the flap volume. In addition, this flap can serve as a scaffold for lipofilling to obtain autologous breast reconstruction in medium to large cases. There were two complete failures due to technical errors during flap elevation. Distal partial tissue suffering was observed in four flaps. These flaps were longer than usual; they reached the midline of the back. It is advisable to discard the distal medial quarter of the flap when it is designed up to the midline to avoid steatonecrosis or fibrosis. A retrospective analysis of the 39 flaps that survived completely revealed a satisfactory result in 82% of the cases. The main disadvantage of this procedure is the final scar. The TDAP flap is a reliable and safe method for partial or total breast autologous reconstruction. PMID:26645006

  7. 78 FR 33908 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... identified Wind Energy Area (WEA) on the OCS offshore Rhode Island (RI) and Massachusetts (MA). The revised... from leasing, site characterization, and site assessment in and around the Call Area (76 FR 51391). The... Bureau of Ocean Energy Management Commercial Wind Lease Issuance and Site Assessment Activities on...

  8. 77 FR 39508 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... specific project proposals on those leases) in an identified Wind Energy Area (WEA) on the OCS offshore..., site characterization, and site assessment in and around the Call Area (76 FR 51391). The Call Area is... Bureau of Ocean Energy Management Commercial Wind Lease Issuance and Site Assessment Activities on...

  9. Active Layer and Moisture Measurements for Intensive Site 0 and 1, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-04-17

    These are measurements of Active Layer Thickness collected along several lines beginning in September, 2011 to the present. The data were collected at several time periods along the Site0 L2 Line, the Site1 AB Line, and an ERT Monitoring Line near Area A in Site1.

  10. Nuclear Site Security in the Event of Terrorist Activity

    SciTech Connect

    Thomson, M.L.; Sims, J.

    2008-07-01

    This paper, presented as a poster, identifies why ballistic protection should now be considered at nuclear sites to counter terrorist threats. A proven and flexible form of multi purpose protection is described in detail with identification of trial results that show its suitability for this role. (authors)

  11. Preliminary siting activities for new waste handling facilities at the Idaho National Engineering Laboratory

    SciTech Connect

    Taylor, D.D.; Hoskinson, R.L.; Kingsford, C.O.; Ball, L.W.

    1994-09-01

    The Idaho Waste Processing Facility, the Mixed and Low-Level Waste Treatment Facility, and the Mixed and Low-Level Waste Disposal Facility are new waste treatment, storage, and disposal facilities that have been proposed at the Idaho National Engineering Laboratory (INEL). A prime consideration in planning for such facilities is the selection of a site. Since spring of 1992, waste management personnel at the INEL have been involved in activities directed to this end. These activities have resulted in the (a) identification of generic siting criteria, considered applicable to either treatment or disposal facilities for the purpose of preliminary site evaluations and comparisons, (b) selection of six candidate locations for siting,and (c) site-specific characterization of candidate sites relative to selected siting criteria. This report describes the information gathered in the above three categories for the six candidate sites. However, a single, preferred site has not yet been identified. Such a determination requires an overall, composite ranking of the candidate sites, which accounts for the fact that the sites under consideration have different advantages and disadvantages, that no single site is superior to all the others in all the siting criteria, and that the criteria should be assigned different weighing factors depending on whether a site is to host a treatment or a disposal facility. Stakeholder input should now be solicited to help guide the final selection. This input will include (a) siting issues not already identified in the siting, work to date, and (b) relative importances of the individual siting criteria. Final site selection will not be completed until stakeholder input (from the State of Idaho, regulatory agencies, the public, etc.) in the above areas has been obtained and a strategy has been developed to make a composite ranking of all candidate sites that accounts for all the siting criteria.

  12. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework

    ERIC Educational Resources Information Center

    Heo, Gyeong Mi; Lee, Romee

    2013-01-01

    This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…

  13. Active-Site Hydration and Water Diffusion in Cytochrome P450cam: A Highly Dynamic Process

    SciTech Connect

    Miao, Yinglong; Baudry, Jerome Y

    2011-01-01

    Long-timescale molecular dynamics simulations (300 ns) are performed on both the apo- (i.e., camphor-free) and camphor-bound cytochrome P450cam (CYP101). Water diffusion into and out of the protein active site is observed without biased sampling methods. During the course of the molecular dynamics simulation, an average of 6.4 water molecules is observed in the camphor-binding site of the apo form, compared to zero water molecules in the binding site of the substrate-bound form, in agreement with the number of water molecules observed in crystal structures of the same species. However, as many as 12 water molecules can be present at a given time in the camphor-binding region of the active site in the case of apo-P450cam, revealing a highly dynamic process for hydration of the protein active site, with water molecules exchanging rapidly with the bulk solvent. Water molecules are also found to exchange locations frequently inside the active site, preferentially clustering in regions surrounding the water molecules observed in the crystal structure. Potential-of-mean-force calculations identify thermodynamically favored trans-protein pathways for the diffusion of water molecules between the protein active site and the bulk solvent. Binding of camphor in the active site modifies the free-energy landscape of P450cam channels toward favoring the diffusion of water molecules out of the protein active site.

  14. Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts.

    PubMed

    Wang, Lu-Cun; Friend, C M; Fushimi, Rebecca; Madix, Robert J

    2016-07-01

    The activation of molecular O2 as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O2 activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O2 dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O2 dissociation is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O2 dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction. PMID:27376884

  15. Active Site Structure and Peroxidase Activity of Oxidatively Modified Cytochrome c Species in Complexes with Cardiolipin.

    PubMed

    Capdevila, Daiana A; Oviedo Rouco, Santiago; Tomasina, Florencia; Tortora, Verónica; Demicheli, Verónica; Radi, Rafael; Murgida, Daniel H

    2015-12-29

    We report a resonance Raman and UV-vis characterization of the active site structure of oxidatively modified forms of cytochrome c (Cyt-c) free in solution and in complexes with cardiolipin (CL). The studied post-translational modifications of Cyt-c include methionine sulfoxidation and tyrosine nitration, which lead to altered heme axial ligation and increased peroxidase activity with respect to those of the wild-type protein. In spite of the structural and activity differences between the protein variants free in solution, binding to CL liposomes induces in all cases the formation of a spectroscopically identical bis-His axial coordination conformer that more efficiently promotes lipid peroxidation. The spectroscopic results indicate that the bis-His form is in equilibrium with small amounts of high-spin species, thus suggesting a labile distal His ligand as the basis for the CL-induced increase in enzymatic activity observed for all protein variants. For Cyt-c nitrated at Tyr74 and sulfoxidized at Met80, the measured apparent binding affinities for CL are ∼4 times larger than for wild-type Cyt-c. On the basis of these results, we propose that these post-translational modifications may amplify the pro-apoptotic signal of Cyt-c under oxidative stress conditions at CL concentrations lower than for the unmodified protein. PMID:26620444

  16. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... equivalent means. (b) If a wing flap or slat interconnection or equivalent means is used, it must be designed... be designed for the loads imposed when the wing flaps or slats on one side are carrying the...

  17. Reconstruction Using Locoregional Flaps for Large Skull Base Defects.

    PubMed

    Hatano, Takaharu; Motomura, Hisashi; Ayabe, Shinobu

    2015-06-01

    We present a modified locoregional flap for the reconstruction of large anterior skull base defects that should be reconstructed with a free flap according to Yano's algorithm. No classification of skull base defects had been proposed for a long time. Yano et al suggested a new classification in 2012. The lb defect of Yano's classification extends horizontally from the cribriform plate to the orbital roof. According to Yano's algorithm for subsequent skull base reconstructive procedures, a lb defect should be reconstructed with a free flap such as an anterolateral thigh free flap or rectus abdominis myocutaneous free flap. However, our modified locoregional flap has also enabled reconstruction of lb defects. In this case series, we used a locoregional flap for lb defects. No major postoperative complications occurred. We present our modified locoregional flap that enables reconstruction of lb defects. PMID:26225296

  18. Flapping wing PIV and force measurements

    NASA Astrophysics Data System (ADS)

    Cameron, Benjamin H.

    Flapping wing aerodynamics has been of interest to engineers recently due in part to the DARPA (Defense Advanced Research Projects Agency) MAV (Micro-Aerial Vehicle) initiative. MAVs are small unmanned aerial vehicles with length scales similar to birds and insects. Flapping wing MAVs would serve as mobile and stealthy sensing platforms capable of gathering intelligence in hazardous and physically inaccessible locations. Traditional means of lift and thrust generation become inefficient when scaled to these sizes, therefore a flapping wing propulsion system will be necessary. The design of a flapping wing MAV requires the ability to measure forces and velocities around the wing. Three components of velocity were measured in the wake of a two dimensional (2D) flapping airfoil model using a novel application of stereoscopic DPIV (Digital Particle Image Velocimetry). One component of force was measured using a newly proposed method outlined in the dissertation. The force measurement technique relies on a specific sequence of data acquisition, which has the benefit of reducing measurement uncertainty and noise. No experiments of this type have been conducted, and no direct aerodynamic force data exists for the low Reynolds numbers applicable to flapping wing MAVs. The well-established stereoscopic DPIV technique produces relatively low uncertainties while the new force measurement technique has not been previously tested. Theoretical analysis and experimental results show that aerodynamic forces are attainable for chord Reynolds numbers as low as 1,000, which is significantly lower than previous studies. PIV measurements reveal symmetric and asymmetric wake topologies for a NACA 0012 and flat plate airfoil. A sinusoidally heaving flat plate airfoil produces highly deflected wakes for a wider range of flapping conditions than a NACA 0012 airfoil. Deflected wakes are of potentially interest since both lift and thrust components of force are developed. The flat plate also

  19. Exploring the drug resistance of V32I and M46L mutant HIV-1 protease to inhibitor TMC114: flap dynamics and binding mechanism.

    PubMed

    Meher, Biswa Ranjan; Wang, Yixuan

    2015-03-01

    Inhibitors of HIV-1 protease (HIV-1-pr) generally only bind to the active site of the protease. However, for some mutants such as V32I and M46L the TMC114 can bind not only to the active cavity but also to the groove of the flexible flaps. Although the second binding site suggests the higher efficiency of the drug against HIV-1-pr, the drug resistance in HIV-1-pr due to mutations cannot be ignored, which prompts us to investigate the molecular mechanisms of drug resistance and behavior of double bound TMC114 (2T) to HIV-1-pr. The conformational dynamics of HIV-1-pr and the binding of TMC114 to the WT, V32I and M46L mutants were investigated with all-atom molecular dynamic (MD) simulation. The 20 ns MD simulation shows many fascinating effects of the inhibitor binding to the WT and mutant proteases. MM-PBSA calculations explain the binding free energies unfavorable for the M46L and V32I mutants as compared to the WT. For the single binding (1T) the less binding affinity can be attributed to the entropic loss for both V32I-1T and M46L-1T. Although the second binding of TMC114 with flap does increase binding energy for the mutants (V32I-2T and M46L-2T), the considerable entropy loss results in the lower binding Gibbs free energies. Thus, binding of TMC114 in the flap region does not help much in the total gain in binding affinity of the system, which was verified from this study and thereby validating experiments. PMID:25562662

  20. Identification of Ice Nucleation Active Sites on Feldspar Dust Particles

    PubMed Central

    2015-01-01

    Mineral dusts originating from Earth’s crust are known to be important atmospheric ice nuclei. In agreement with earlier studies, feldspar was found as the most active of the tested natural mineral dusts. Here we investigated in closer detail the reasons for its activity and the difference in the activity of the different feldspars. Conclusions are drawn from scanning electron microscopy, X-ray powder diffraction, infrared spectroscopy, and oil-immersion freezing experiments. K-feldspar showed by far the highest ice nucleation activity. Finally, we give a potential explanation of this effect, finding alkali-metal ions having different hydration shells and thus an influence on the ice nucleation activity of feldspar surfaces. PMID:25584435

  1. Versatility of reverse sural fasciocutaneous flap for reconstruction of distal lower limb soft tissue defects.

    PubMed

    Pan, Hai-tao; Zheng, Qi-xin; Yang, Shu-hua; Wu, Bin; Liu, Jian-xiang

    2014-06-01

    In this study we present our experiences with the reverse sural fasciocutaneous flap to reconstruct the distal lower limb soft tissue defects caused by traumatic injuries. These flap graftings were carried out from Oct. 2010 to Dec. 2012 in our department. The series consisted of 36 patients, including 21 men and 15 women with an average age of 46.2 years (14-83 years) and with a medium follow-up period of 18 months (12-24 months). Of all the cases of acute trauma, there were 10 cases of trauma of distal tibia, 9 cases of trauma of perimalleolus, and 17 cases of trauma of midfoot and forefoot. Related risk factors in the patients were diabetes (2 cases), advanced age (>65 years, 3 cases) and cigarette smoking (6 cases). The reverse flow sural island flap irrigation depended on lower perforators of the peroneal artery. The fasciocutaneous pedicle was 3-4 cm in width and the anatomical structures consisted of the superficial and deep fascia, the sural nerve, short saphenous vein, superficial sural artery together with an islet of subcutaneous cellular tissue and skin. The most proximal border of the flap was only 1.5 cm away from the popliteal skin crease and the pivot point was 5-7 cm above the tip of the lateral malleolus. All the flaps survived. No arterial crisis occurred in any case. The venous congestion occurred in 2 cases and got better after raising the limbs and bloodletting. Only in an old man, 1.5 cm necrosis of distal margin of his flap occurred and finally healed after continuous dressing change. One-stage skin grafting was performed, and all the donor sites were sutured and successfully healed. It was concluded that the reverse sural fasciocutaneous flap is safe and reliable to extend to the proximal third even near the popliteal skin crease. We also concluded this flap can be safely and efficiently used to treat patients with large and far soft-tissue defects from the distal leg to the forefoot with more versatility and it is easier to reach the

  2. Early Site Permit Demonstration Program: Recommendations for communication activities and public participation in the Early Site Permit Demonstration Program

    SciTech Connect

    Not Available

    1993-01-27

    On October 24, 1992, President Bush signed into law the National Energy Policy Act of 1992. The bill is a sweeping, comprehensive overhaul of the Nation`s energy laws, the first in more than a decade. Among other provisions, the National Energy Policy Act reforms the licensing process for new nuclear power plants by adopting a new approach developed by the US Nuclear Regulatory Commission (NRC) in 1989, and upheld in court in 1992. The NRC 10 CFR Part 52 rule is a three-step process that guarantees public participation at each step. The steps are: early site permit approval; standard design certifications; and, combined construction/operating licenses for nuclear power reactors. Licensing reform increases an organization`s ability to respond to future baseload electricity generation needs with less financial risk for ratepayers and the organization. Costly delays can be avoided because design, safety and siting issues will be resolved before a company starts to build a plant. Specifically, early site permit approval allows for site suitability and acceptability issues to be addressed prior to an organization`s commitment to build a plant. Responsibility for site-specific activities, including communications and public participation, rests with those organizations selected to try out early site approval. This plan has been prepared to assist those companies (referred to as sponsoring organizations) in planning their communications and public involvement programs. It provides research findings, information and recommendations to be used by organizations as a resource and starting point in developing their own plans.

  3. Ultrafast ligand binding dynamics in the active site of native bacterial nitric oxide reductase.

    PubMed

    Kapetanaki, Sofia M; Field, Sarah J; Hughes, Ross J L; Watmough, Nicholas J; Liebl, Ursula; Vos, Marten H

    2008-01-01

    The active site of nitric oxide reductase from Paracoccus denitrificans contains heme and non-heme iron and is evolutionarily related to heme-copper oxidases. The CO and NO dynamics in the active site were investigated using ultrafast transient absorption spectroscopy. We find that, upon photodissociation from the active site heme, 20% of the CO rebinds in 170 ps, suggesting that not all the CO transiently binds to the non-heme iron. The remaining 80% does not rebind within 4 ns and likely migrates out of the active site without transient binding to the non-heme iron. Rebinding of NO to ferrous heme takes place in approximately 13 ps. Our results reveal that heme-ligand recombination in this enzyme is considerably faster than in heme-copper oxidases and are consistent with a more confined configuration of the active site. PMID:18420024

  4. Acute Deep Hand Burns Covered by a Pocket Flap-Graft

    PubMed Central

    Pradier, Jean-Philippe; Oberlin, Christophe; Bey, Eric

    2007-01-01

    Objective: We evaluated the long-term outcome of the “pocket flap-graft” technique, used to cover acute deep burns of the dorsum of the hand, and analyzed surgical alternatives. Methods: This was a 6-year, retrospective study of 8 patients with extensive burns and 1 patient with a single burn (11 hands in all) treated by defatted abdominal wall pockets. We studied the medical records of the patients, and conducted a follow-up examination. Results: All hands had fourth-degree thermal burns caused by flames, with exposure of tendons, bones, and joints, and poor functional prognosis. One third of patients had multiple injuries. Burns affected an average of 36% of the hand surface, and mean coverage was 92.8 cm2. One patient died. The 8 others were seen at 30-month follow-up: the skin quality of the flap was found to be good in 55% of the cases, the score on the Vancouver Scar Scale was 2.4, the Kapandji score was 4.5, and total active motion was 37% of that of a normal hand. Hand function was limited in only 2 cases, 8 patients were able to drive, and 3 patients had gone back to work. Conclusion: The pocket flap-graft allows preservation of hand function following severe burns, when local or free flaps are impossible to perform. Debulking of the flap at the time of elevation limits the need for secondary procedures. PMID:17268577

  5. Protective effect of hydrogen-rich saline on ischemia/reperfusion injury in rat skin flap*

    PubMed Central

    Zhao, Ling; Wang, You-bin; Qin, Shi-rui; Ma, Xue-mei; Sun, Xue-jun; Wang, Ming-lian; Zhong, Ru-gang

    2013-01-01

    Objective: Skin damage induced by ischemia/reperfusion (I/R) is a multifactorial process that often occurs in plastic surgery. The mechanisms of I/R injury include hypoxia, inflammation, and oxidative damage. Hydrogen gas has been reported to alleviate cerebral I/R injury by acting as a free radical scavenger. Here, we assessed the protective effect of hydrogen-rich saline (HRS) on skin flap I/R injury. Methods: Abdominal skin flaps of rats were elevated and ischemia was induced for 3 h; subsequently, HRS or physiological saline was administered intraperitoneally 10 min before reperfusion. On postoperative Day 5, flap survival, blood perfusion, the accumulation of reactive oxygen species (ROS), and levels of cytokines were evaluated. Histological examinations were performed to assess inflammatory cell infiltration. Results: Skin flap survival and blood flow perfusion were improved by HRS relative to the controls. The production of malondialdehyde (MDA), an indicator of lipid peroxidation, was markedly reduced. A multiplex cytokine assay revealed that HRS reduced the elevation in the levels of inflammatory cytokines, chemokines and growth factors, with the exception of RANTES (regulated on activation, normal T-cell expressed and secreted) growth factor. HRS treatment also reduced inflammatory cell infiltration induced by I/R injury. Conclusions: Our findings suggest that HRS mitigates I/R injury by decreasing inflammation and, therefore, has the potential for application as a therapy for improving skin flap survival. PMID:23645175

  6. Design Of A Scientific Experiment On Expert Flap At CIRA SCIROCCO Plasma Wind Tunnel

    NASA Astrophysics Data System (ADS)

    Trifoni, E.; Del Vecchio, A.; Di Clemente, M.; De Simone, V.; Martucci, A.; Purpura, C.; Savino, L.; Cipullo, A.

    2011-05-01

    A scientific experiment at CIRA SCIROCCO Plasma Wind Tunnel was conceived to assess the design of ESA EXPERT Open Flap PL6/8 under flight representative heat flux and load conditions. A specific and dedicated model holder was designed to test the Qualification Model of the instrumented CMC Flap in real size and equipped with the same flight instrumentation, on the basis of the structural architecture (actively cooled Leading Edge, TPS and cold structure) developed and successfully tested in the frame of the EXPERT PL7 SWBLI qualification test in SCIROCCO PWT facility. The Test conditions were designed in order to get significant heat flux and temperature on the Flap symmetry plane. The Test duration has been established with the aim at realizing the radiative equilibrium condition on the Flap and with respect to the duration of the entire re-entry of the Expert capsule The maximum total heat load over the Flap experienced in flight conditions during the re-entry trajectory was also evaluated. In the present paper an overview of the test design parameters, expected outcomes and preliminary experimental results are reported.

  7. Peculiar indications for the pedicled or free rectus abdominis flap in reconstructive surgery. A review of our experience.

    PubMed

    Sinsel, N K; Guelinckx, P J

    1995-01-01

    Among all known flaps, the rectus abdominis muscle flap possesses an unique diversity in flap designs due to the special vascular supply of the abdominal wall. The axial vascularization of the rectus abdominis muscle gives ofF several musculocutaneous perforators, which are mainly located in the periumbilical region. Abdominal wall skin perfusion is guaranteed by spoke-wheel like vessels arising from these perforators. Subsequently several designs (muscle, myocutaneous and myosubcutaneous) are possible, by varying the included tissue and the position of the skin island. We described 7 cases where the rectus abdominis muscle was used as a muscle or myocutaneous flap for reconstruction of large defects. In most cases a pedicled transfer was necessary, possible and sufficient to reconstruct the difficult defects in various body regions. Great amounts of well perfused tissue can be transferred with still possible primary closure of the donor site. Due to its rich perfusion and constancy of vascular pattern, it represents an excellent and safe pedicled reconstructive procedure for large defects of the thorax, the abdomen, the forearm or the hip and pelvis where free tissue transfers are impossible or contraindicated. No other local transposition would have achieved this goal, due to the lack of volume and mobility. Moreover the flap is ideal for reconstruction of contour deficiencies due to the abundance of fat, as for example in breast or buttock reconstruction. However the flap is not the first choice for traumatic and infected wounds where fat tissue is not desired. PMID:8571724

  8. 14 CFR 25.1511 - Flap extended speed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  9. 14 CFR 25.1511 - Flap extended speed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  10. 14 CFR 25.1511 - Flap extended speed.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  11. Unexpected flap thickness in laser in situ keratomileusis.

    PubMed

    Giledi, Osama; Daya, Sheraz M

    2003-09-01

    We report a case of an unexpected thick flap during laser in situ keratomileusis (LASIK) that led to abandonment of surgery. This report illustrates the importance of stromal bed measurements after flap creation in LASIK. A thicker-than-expected flap can lead to a thinner-than-anticipated residual cornea and subsequent ectasia or even perforation during laser ablation. It is possible that reports of ectasia in normal thickness corneas reflect thicker-than-anticipated flaps. PMID:14522308

  12. 14 CFR 25.1511 - Flap extended speed.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  13. 14 CFR 25.1511 - Flap extended speed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  14. Stereospecific suppression of active site mutants by methylphosphonate substituted substrates reveals the stereochemical course of site-specific DNA recombination

    PubMed Central

    Rowley, Paul A.; Kachroo, Aashiq H.; Ma, Chien-Hui; Maciaszek, Anna D.; Guga, Piotr; Jayaram, Makkuni

    2015-01-01

    Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modification. The chemical chirality of MeP, in conjunction with mutant recombinases, reveals the stereochemical contributions of Arg-I and Arg-II. The SP preference of the native reaction is specified primarily by Arg-I. MeP reaction supported by Arg-II is nearly bias-free or RP-biased, depending on the Arg-I substituent. Positional conservation of the arginines does not translate into strict functional conservation. Charge reversal by glutamic acid substitution at Arg-I or Arg-II has opposite effects on Cre and Flp in MeP reactions. In Flp, the base immediately 5′ to the scissile MeP strongly influences the choice between the catalytic tyrosine and water as the nucleophile for strand scission, thus between productive recombination and futile hydrolysis. The recombinase active site embodies the evolutionary optimization of interactions that not only favor the normal reaction but also proscribe antithetical side reactions. PMID:25999343

  15. Stereospecific suppression of active site mutants by methylphosphonate substituted substrates reveals the stereochemical course of site-specific DNA recombination.

    PubMed

    Rowley, Paul A; Kachroo, Aashiq H; Ma, Chien-Hui; Maciaszek, Anna D; Guga, Piotr; Jayaram, Makkuni

    2015-07-13

    Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modification. The chemical chirality of MeP, in conjunction with mutant recombinases, reveals the stereochemical contributions of Arg-I and Arg-II. The SP preference of the native reaction is specified primarily by Arg-I. MeP reaction supported by Arg-II is nearly bias-free or RP-biased, depending on the Arg-I substituent. Positional conservation of the arginines does not translate into strict functional conservation. Charge reversal by glutamic acid substitution at Arg-I or Arg-II has opposite effects on Cre and Flp in MeP reactions. In Flp, the base immediately 5' to the scissile MeP strongly influences the choice between the catalytic tyrosine and water as the nucleophile for strand scission, thus between productive recombination and futile hydrolysis. The recombinase active site embodies the evolutionary optimization of interactions that not only favor the normal reaction but also proscribe antithetical side reactions. PMID:25999343

  16. Calculation of the longitudinal aerodynamic characteristics of wing-flap configurations with externally blown flaps

    NASA Technical Reports Server (NTRS)

    Mendenhall, M. R.; Spangler, S. B.; Nielsen, J. N.; Goodwin, F. K.

    1976-01-01

    A theoretical investigation was carried out to extend and improve an existing method for predicting the longitudinal characteristics of wing flap configurations with externally blown flaps (EBF). Two potential flow models were incorporated into the prediction method: a wing and flap lifting-surface model and a turbofan engine wake model. The wing-flap model uses a vortex-lattice approach to represent the wing and flaps. The jet wake model consists of a series of closely spaced vortex rings normal to a centerline which may have vertical and lateral curvature to conform to the local flow field beneath the wing and flaps. Comparisons of measured and predicted pressure distributions, span load distributions on each lifting surface, and total lift and pitching moment coefficients on swept and unswept EBF configurations are included. A wide range of thrust coefficients and flap deflection angles is considered at angles of attack up to the onset of stall. Results indicate that overall lift and pitching-moment coefficients are predicted reasonably well over the entire range. The predicted detailed load distributions are qualitatively correct and show the peaked loads at the jet impingement points, but the widths and heights of the load peaks are not consistently predicted.

  17. Flap effectiveness appraisal for winged re-entry vehicles

    NASA Astrophysics Data System (ADS)

    de Rosa, Donato; Pezzella, Giuseppe; Donelli, Raffaele S.; Viviani, Antonio

    2016-05-01

    The interactions between shock waves and boundary layer are commonplace in hypersonic aerodynamics. They represent a very challenging design issue for hypersonic vehicle. A typical example of shock wave boundary layer interaction is the flowfield past aerodynamic surfaces during control. As a consequence, such flow interaction phenomena influence both vehicle aerodynamics and aerothermodynamics. In this framework, the present research effort describes the numerical activity performed to simulate the flowfield past a deflected flap in hypersonic flowfield conditions for a winged re-entry vehicle.

  18. Sural Versus Perforator Flaps for Distal Medial Leg Wounds.

    PubMed

    Schannen, Andrew P; Truchan, Lisa; Goshima, Kaoru; Bentley, Roger; DeSilva, Gregory L

    2015-12-01

    Soft tissue coverage of distal medial ankle wounds is a challenging problem in orthopedic surgery because of the limited local tissues and prominent instrumentation. Traditionally, these wounds required free tissue transfer to achieve suitable coverage and subsequent bony union. To better respect the reconstructive ladder and to avoid the inherent difficulty of free flap coverage, rotational flaps have been used to cover these wounds. Both sural fasciocutaneous flaps and rotational fasciocutaneous perforator (propeller) flaps have been described for distal medial soft tissue coverage. The authors performed a retrospective chart review of patients who underwent distal medial leg coverage with the use of either sural flaps or rotational fasciocutaneous perforator flaps. The authors identified 14 patients by Current Procedural Terminology code who met the study criteria. The average age and degree of medical comorbidities were comparable in the 2 groups. The authors reviewed their medical records to evaluate fracture healing, flap size, complications, and return to normal shoe wear. All 7 sural flaps healed without incident, with underlying fracture healing. Of the 7 perforator flaps, 6 healed without incident, with underlying fracture healing. One perforator-based flap was complicated by superficial tip necrosis and went on to heal with local wound care. All patients returned to normal shoe wear. Both sural artery rotational flaps and posterior tibial artery-based rotational flaps are viable options for coverage of the distal medial leg. Coverage can be achieved reliably without microsurgery, anticoagulation, or monitoring in the intensive care unit. PMID:26652325

  19. 14 CFR 23.1511 - Flap extended speed.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flap extended speed. 23.1511 Section 23.1511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Information § 23.1511 Flap extended speed. (a) The flap extended speed V FE must be established so that it...

  20. 14 CFR 23.1511 - Flap extended speed.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flap extended speed. 23.1511 Section 23.1511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Information § 23.1511 Flap extended speed. (a) The flap extended speed V FE must be established so that it...