Science.gov

Sample records for 5-lo-activating protein flap

  1. 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

  2. Myeloid Cell 5-Lipoxygenase Activating Protein Modulates the Response to Vascular Injury

    PubMed Central

    Yu, Zhou; Ricciotti, Emanuela; Miwa, Takashi; Liu, Shulin; Ihida-Stansbury, Kaori; Landersberg, Gavin; Jones, Peter L.; Scalia, Rosario; Song, Wenchao; Assoian, Richard K.; FitzGerald, Garret A.

    2013-01-01

    Rationale Human genetics have implicated the 5- lipoxygenase (5-LO) enzyme in the pathogenesis of cardiovascular disease and an inhibitor of the 5-LO activating protein (FLAP) is in clinical development for asthma. Objective Here we determined whether FLAP deletion modifies the response to vascular injury. Methods and Results Vascular remodeling was characterized 4 weeks after femoral arterial injury in FLAP knockout (FLAP KO) mice and wild type (WT) controls. Both neointimal hyperplasia and the intima/media ratio of the injured artery were significantly reduced in the FLAP KOs while endothelial integrity was preserved. Lesional myeloid cells were depleted and vascular smooth muscle cell (VSMC) proliferation, as reflected by bromodeoxyuridine (BrdU) incorporation, was markedly attenuated by FLAP deletion. Inflammatory cytokine release from FLAP KO macrophages was depressed and their restricted ability to induce VSMC migration ex vivo was rescued with leukotriene B4 (LTB4). FLAP deletion restrained injury and attenuated upregulation of the extracellular matrix protein, tenascin C (TNC), which affords a scaffold for VSMC migration. Correspondingly, the phenotypic modulation of VSMC to a more synthetic phenotype, reflected by morphological change, loss of α-smooth muscle cell actin and upregulation of vascular cell adhesion molecule (VCAM) -1 was also suppressed in FLAP KO mice. Transplantation of FLAP replete myeloid cells rescued the proliferative response to vascular injury. Conclusion Expression of lesional FLAP in myeloid cells promotes LTB4 dependent VSMC phenotypic modulation, intimal migration and proliferation. PMID:23250985

  3. 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

  4. N protein from lambdoid phages transforms NusA into an antiterminator by modulating NusA-RNA polymerase flap domain interactions

    PubMed Central

    Mishra, Saurabh; Sen, Ranjan

    2015-01-01

    Interaction of the lambdoid phage N protein with the bacterial transcription elongation factor NusA is the key component in the process of transcription antitermination. A convex surface of E. coli NusA-NTD, located opposite to its RNA polymerase-binding domain (the β-flap domain), directly interacts with N in the antitermination complex. We hypothesized that this N-NusA interaction induces allosteric effects on the NusA-RNAP interaction leading to transformation of NusA into a facilitator of the antitermination process. Here we showed that mutations in β-flap domain specifically defective for N antitermination exhibited altered NusA-nascent RNA interaction and have widened RNA exit channel indicating an intricate role of flap domain in the antitermination. The presence of N reoriented the RNAP binding surface of NusA-NTD, which changed its interaction pattern with the flap domain. These changes caused significant spatial rearrangement of the β-flap as well as the β′ dock domains to form a more constricted RNA exit channel in the N-modified elongation complex (EC), which might play key role in converting NusA into a facilitator of the N antitermination. We propose that in addition to affecting the RNA exit channel and the active center of the EC, β-flap domain rearrangement is also a mechanistic component in the N antitermination process. PMID:25990722

  5. 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

  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. 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

  8. Effect of microbial transglutaminase and non-meat proteins on functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was aimed at developing value-added low sodium chloride (NaCl), phosphate-free restructured patties using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase, 0.7%) and non-meat proteins (isolated soy protein, ISP and whey protein...

  9. Use of microbial transglutaminase and non-meat proteins to improve functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was aimed at developing a value-added low sodium chloride (NaCl), phosphate-free patty using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase) and non-meat proteins (isolated soy protein, ISP and whey protein concentrate, WPC) ...

  10. Effect of microbial transglutaminase and non-meat proteins on functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was focused on developing value-added low sodium chloride (NaCl), phosphate-free restructured patties using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase, 0.7%) and non-meat proteins (isolated soy protein, ISP and whey prote...

  11. 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.

  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. The shunt from the cyclooxygenase to lipoxygenase pathway in human osteoarthritic subchondral osteoblasts is linked with a variable expression of the 5-lipoxygenase-activating protein.

    PubMed

    Maxis, Kelitha; Delalandre, Aline; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Duval, Nicolas; Lajeunesse, Daniel

    2006-01-01

    Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH

  14. 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

  15. 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.

  16. 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

  17. Effects of a synovial flap and gelatin/β-tricalcium phosphate sponges loaded with mesenchymal stem cells, bone morphogenetic protein-2, and platelet rich plasma on equine osteochondral defects.

    PubMed

    Seo, Jong-Pil; Kambayashi, Yoshinori; Itho, Megumi; Haneda, Shingo; Yamada, Kazutaka; Furuoka, Hidefumi; Tabata, Yasuhiko; Sasaki, Naoki

    2015-08-01

    This study aimed to evaluate the efficacy of a synovial flap and gelatin/β-tricalcium phosphate (GT) sponge loaded with mesenchymal stem cells (MSCs), bone morphogenetic protein-2 (BMP-2), and platelet rich plasma (PRP) for repairing of osteochondral defects in horses. Osteochondral defects were created on the medial condyle of both femurs (n=5). In the test group, a GT sponge loaded with MSCs, BMP-2, and PRP (GT/MSCs/BMP-2/PRP) was inserted into the defect and then covered with a synovial flap. In the control group, the defect was treated only with the GT/MSCs/BMP-2/PRP. The test group showed significantly higher macroscopic scores than the control group. In addition, hyaline cartilaginous tissue was detected in the test group in areas larger than those in the control group. This study demonstrated that the combination of a synovial flap and GT sponge loaded with MSCs, BMP-2, and PRP promoted osteochondral regeneration in an equine model. PMID:26267104

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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 ...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Enamel matrix proteins (Emdogain) in combination with coronally advanced flap or subepithelial connective tissue graft in the treatment of shallow gingival recessions.

    PubMed

    Berlucchi, Ignazio; Francetti, Luca; Del Fabbro, Massimo; Testori, Tiziano; Weinstein, Roberto L

    2002-12-01

    This article describes two different surgical techniques of root coverage using Emdogain and shows preliminary results on 26 shallow recessions in 14 patients. For the treatment of 13 recessions, Emdogain was used in combination with a coronally advanced flap (CAF+EMD group). In the other 13 recessions, Emdogain and the flap were used in combination with a subepithelial connective tissue graft (CAF+CTG+EMD group). For the CAF+EMD group, the root coverage at 6 months was 93.97%, with an attachment gain of 3.2 mm; for the CAF+CTG+EMD group, the root coverage was 93.59%, with an attachment gain of 3.4 mm (no statistically significant difference between groups). When complete root coverage was not achieved, the residual recession was 1 mm in four cases and 2 mm in one case. Keratinized gingiva was increased for both groups, but more for the CAF+CTG+EMD group (1.38 mm versus 0.69 mm; statistically significant difference). Clinical attachment level decreased significantly in both groups, from 4.46 to 1.23 mm in the CAF+EMD group, and from 4.62 to 1.23 mm in the CAF+CTG+EMD group. Preliminary results show that Emdogain, in combination with CAF or CAF+CTG for the treatment of Miller Class I or II gingival recessions, displays good clinical results, with percentage of root coverage comparable or superior to other techniques. Further experimental studies on the dynamics of wound healing are needed to prove that EMD is really responsible for improving the percentage of regenerated versus repaired tissues with respect to other techniques. PMID:12516830

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. Benefit of HSP90α intervention on ischemia-reperfusion injury of venous blood-congested flaps

    PubMed Central

    HU, XIAO-YING; CHEN, ZHEN-YU; ZHANG, BIN; LENG, XIANG-FENG; FAN, XIAO-JIAN; LIU, TAO

    2016-01-01

    In order to decrease the incidence of flap necrosis after reconstructive surgeries, new approaches are required. In the present study, a model of venous congested flaps in rats was established to test the heat shock protein (HSP) 90α, ‘F-5’, protein as an intervention therapy to alleviate ischemia-reperfusion injury. A recombinant plasmid pET15b-F-5 carrying the HSP90α gene was constructed and the induced protein was purified from bacterial cell cultures. The rats in the study were divided into three different intervention groups: group A rats were treated with normal saline prior to flap establishment, group B rats were treated with HSP90α, ‘F-5’, protein prior to flap establishment, and group C rats were treated with the same ‘F-5’ protein after the surgical procedure. Additionally, the reperfusion time-points, ischemia for 6 or 8 h (5 rats each), were established in each group. After set periods of time, the flaps were observed for skin appearance, blood flow, survival rate and histological changes including neovascularization and re-epithelialization. The results showed that the flaps in the rats pre-treated with ‘F-5’ protein performed better than the flaps of rats in the other two groups: the blood flow was higher, flap survival rate was increased, inflammatory cell infiltration was decreased and angiogenesis increased, and new skin structure was better completed by the end of the experiment. The parameters examind were improved for all the groups when the ischemia time was 6 h instead of 8 h. In conclusion, HSP90α intervention prior to flap establishment was shown to be beneficial in the model of ischemia-reperfusion injury in venous-congested flaps. PMID:27347036

  17. 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

  18. 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...

  19. 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...

  20. 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...

  1. 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.

  2. 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

  3. Etanercept protects myocutaneous flaps from ischaemia reperfusion injury: An experimental study in a rat tram flap model.

    PubMed

    Ersoy, Burak; Çevik, Özge; Çilingir, Özlem Tuğçe

    2016-08-01

    Background Being an inevitable component of free tissue transfer, ischemia-reperfusion injury tends to contribute to flap failure. TNF-α is an important proinflammatory cytokine and a prominent mediator of the ischemia-reperfusion injury. Etanercept, a soluble TNF-α binding protein, has shown anti-inflammatory and anti-apoptotic effects in animal models of renal and myocardial ischemia-reperfusion injury. We have designed an experimental study to investigate the effect of etanercept on myocutaneous ischemia-reperfusion injury on transverse rectus abdominis myocutaneous flap model in rats. Methods Twenty-four male Sprague-Dawley rats were divided into 3 groups: In group 1 (sham), the TRAM flap was raised and sutured back without further intervention. In group 2 (control), the flap was raised and the ischemia-reperfusion protocol was followed. In group 3, etanercept (10 mg/kg, i.v.) was administered 10 minutes before reperfusion. At the end of the reperfusion period, biochemical and histolopathological evaluations were performed on serum and tissue samples. Results In the etanercept group the IMA and 8-OHdG levels (p = 0.005 and p = 0.004, respectively) were found significantly lower, and the GSH and SOD levels (p = 0.01 and p < 0.001, respectively) significantly higher in comparison to the control group. The histopathological analysis has revealed a lower degree of hyalinization, degenerated muscle fibers and nuclear change in the etanercept group compared to the control group. Conclusion The results of our experimental study indicate that etanercept offers protection against ischemia-reperfusion injury in skeletal muscle tissue, enhancing the TRAM flap viability. The ability of etanercept to induce ischemic tolerance suggests that it may be applicable in free-flap surgery. PMID:26950289

  4. BCL-2 and Bax Expression in Skin Flaps Treated with Finasteride or Azelaic Acid

    PubMed Central

    Ayatollahi, Seyyed Abdulmajid; Ajami, Marjan; Reyhanfard, Hamed; Asadi, Yasin; Nassiri-Kashani, Mansour; Rashighi Firoozabadi, Mehdi; Davoodi, Sayed Hossein; Habibi, Esmaeil; Pazoki-Toroudi, Hamidreza

    2012-01-01

    Despite all modern surgical techniques, skin flap that is considered as the main method in most reconstructive surgeries puts the skin tissue at danger of necrosis and apoptosis derived from ischemia. Therefore, finding a treatment for decreasing the apoptosis derived from flap ischemia will be useful in clinic. In present study, we evaluated the effect of azelaic acid 20% and finasteride on expression of BCL-2 and bax proteins after the skin flap surgery. For this purpose, 21 rats were entered in three groups including control, azelaic acid 20% and finasteride, all experienced skin flap surgery and then flap tissue was assessed for determining the expression of proteins in 5 slices prepared from each rat that were graded between – to +++ scales. Both azelaic acid and finasteride increased the expression of BCL-2 protein (p < 0.05) and decrease the expression of bax protein (p < 0.05). These results suggested an antiapoptotic role for finasteride and azelaic acid in preserving the flap after the ischemia reperfusion insult. PMID:24250563

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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,...

  14. 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,...

  15. 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,...

  16. 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,...

  17. 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

  18. 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.

  19. 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...

  20. 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...

  1. 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...

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. [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

  16. 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

  17. 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

  18. 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

  19. 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...

  20. 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...

  1. 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

  2. 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....

  3. 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....

  4. 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....

  5. 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....

  6. 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....

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. A Novel Native Derived Coronary Artery Tissue-Flap Model

    PubMed Central

    Kranz, Alexander; Hülsmann, Jörn; Pinto, Antonio; Barth, Mareike; Fomin, Andrey; Lichtenberg, Artur; Akhyari, Payam

    2013-01-01

    Although tissue-engineering approaches have led to significant progress in the quest of finding a viable substitute for dysfunctional myocardium, the vascularization of such bioartificial constructs still remains a major challenge. Hence, there is a need for model systems that allow us to study and better understand cardiac and vascular biology to overcome current limitations. Therefore, in this study, in toto decellularized rat hearts with a patent vessel system were processed into standardized coronary artery tissue flaps adherent to the ascending aorta. Protein diffusivity analysis and blood perfusion of the coronary arteries showed proper sealing of the de-endothelialized vessels. Retrograde aortic perfusion allowed for selective seeding of the coronary artery system, while surface seeding of the tissue flaps allowed for additional controlled coculture with cardiac cells. The coronary artery tissue-flap model offers a patent and perfusable coronary vascular architecture with a preserved cardiac extracellular matrix, therefore mimicking nature's input to the highest possible degree. This offers the possibility to study re-endothelialization and endothelial function of different donor cell types and their interaction with cardiac cells in a standardized biologically derived cardiac in vitro model, while establishing a platform that could be used for in vitro drug testing and stem cell differentiation studies. PMID:23631507

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. ["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

  10. 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.

  11. 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.

  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. 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

  15. 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

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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...

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. 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...

  13. 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

  14. 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...

  15. 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...

  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. 4-Phenylbutyrate protects rat skin flaps against ischemia-reperfusion injury and apoptosis by inhibiting endoplasmic reticulum stress

    PubMed Central

    YUE, ZHEN-SHUANG; ZENG, LIN-RU; QUAN, REN-FU; TANG, YANG-HUA; ZHENG, WEN-JIE; QU, GANG; XU, CAN-DA; ZHU, FANG-BING; HUANG, ZHONG-MING

    2016-01-01

    4-phenylbutyrate (4-PBA) is a low molecular weight fatty acid, which has been demonstrated to regulate endoplasmic reticulum (ER) stress. ER stress-induced cell apoptosis has an important role in skin flap ischemia; however, a pharmacological approach for treating ischemia-induced ER dysfunction has yet to be reported. In the present study, the effects of 4-PBA-induced ER stress inhibition on ischemia-reperfusion injury were investigated in the skin flap of rats, and transcriptional regulation was examined. 4-PBA attenuated ischemia-reperfusion injury and inhibited cell apoptosis in the skin flap. Furthermore, 4-PBA reversed the increased expression levels of two ER stress markers: CCAAT/enhancer-binding protein-homologous protein and glucose-regulated protein 78. These results suggested that 4-PBA was able to protect rat skin flaps against ischemia-reperfusion injury and apoptosis by inhibiting ER stress marker expression and ER stress-mediated apoptosis. The beneficial effects of 4-PBA may prove useful in the treatment of skin flap ischemia-reperfusion injury. PMID:26648447

  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...

  1. 14 CFR 23.1511 - 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. 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...

  2. CHARACTERISTICS OF FLAP GATES AT THE END OF DRAIN PIPES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flap gates are commonly used at the end of pipe drains and pump outlets to prevent back flows of water and entry of small animals. Flap gates are relatively inexpensive, with low maintenance costs, but can trap debris in their hinge systems. Many texts refer to studies performed on flap gates at t...

  3. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  4. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  5. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  6. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  7. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  8. Prospective evaluation of outcome measures in free-flap surgery.

    PubMed

    Kelly, John L; Eadie, Patricia A; Orr, David; Al-Rawi, Mogdad; O'Donnell, Margaret; Lawlor, Denis

    2004-08-01

    Free-flap failure is usually caused by venous or arterial thrombosis. In many cases, lack of experience and surgical delay also contribute to flap loss. The authors prospectively analyzed the outcome of 57 free flaps over a 28-month period (January, 1999 to April, 2001). The setting was a university hospital tertiary referral center. Anastomotic technique, ischemia time, choice of anticoagulant, and the grade of surgeon were recorded. The type of flap, medications, and co-morbidities, including preoperative radiotherapy, were also documented. Ten flaps were re-explored (17 percent). There were four cases of complete flap failure (6.7 percent) and five cases of partial failure (8.5 percent). In patients who received perioperative systemic heparin or dextran, there was no evidence of flap failure (p = .08). The mean ischemia time was similar in flaps that failed (95 +/- 29 min) and in those that survived (92 +/- 34 min). Also, the number of anastomoses performed by trainees in flaps that failed (22 percent), was similar to the number in flaps that survived (28 percent). Nine patients received preoperative radiotherapy, and there was complete flap survival in each case. This study reveals that closely supervised anastomoses performed by trainees may have a similar outcome to those performed by more senior surgeons. There was no adverse effect from radiotherapy or increased ischemia time on flap survival. PMID:15356760

  9. Clinical outcomes of suture delay in forehead flap.

    PubMed

    Isik, Daghan; Kiroglu, Faruk; Isik, Yasemin; Goktas, Ugur; Atik, Bekir

    2012-01-01

    The delay phenomenon is a surgical procedure performed to raise a wider skin flap and to improve the survival of skin flaps. Surgery, chemicals, sutures, and lasers can be used for the delay procedure. In this study, delayed forehead flaps created by suturing were used for coverage of nasal skin defects in eleven patients. In 7 patients, the cross-paramedian forehead flap was used to increase the extent of flap lengthening. In the first session, suture delay was performed on both sides of the forehead flap margin. In the second session, the flap was elevated and sutured to its new position, 7 to 10 days after the initial surgery. All flaps were completely viable, and patient satisfaction was optimal in all cases. The positive effect of surgical delay on flap survival has been shown in experimental and clinical studies. However, experimentally, suture delay or chemical delay procedures have been shown to be beneficial in flap survival only. Suture delay seems to be an inexpensive, effective, easily performed, atraumatic, and safe technique, especially among patients with systemic diseases such as diabetes or cardiovascular diseases, smoking patients who may lose the flap, or patients who need very wide and long flaps. PMID:22337378

  10. 14 CFR 23.1511 - 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. 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...

  11. 14 CFR 23.1511 - 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. 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...

  12. Collective Flow Enhancement by Tandem Flapping Wings.

    PubMed

    Gravish, Nick; Peters, Jacob M; Combes, Stacey A; Wood, Robert J

    2015-10-30

    We examine the fluid-mechanical interactions that occur between arrays of flapping wings when operating in close proximity at a moderate Reynolds number (Re≈100-1000). Pairs of flapping wings are oscillated sinusoidally at frequency f, amplitude θ_{M}, phase offset ϕ, and wing separation distance D^{*}, and outflow speed v^{*} is measured. At a fixed separation distance, v^{*} is sensitive to both f and ϕ, and we observe both constructive and destructive interference in airspeed. v^{*} is maximized at an optimum phase offset, ϕ_{max}, which varies with wing separation distance, D^{*}. We propose a model of collective flow interactions between flapping wings based on vortex advection, which reproduces our experimental data. PMID:26565499

  13. Collective Flow Enhancement by Tandem Flapping Wings

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Peters, Jacob M.; Combes, Stacey A.; Wood, Robert J.

    2015-10-01

    We examine the fluid-mechanical interactions that occur between arrays of flapping wings when operating in close proximity at a moderate Reynolds number (Re ≈100 - 1000 ). Pairs of flapping wings are oscillated sinusoidally at frequency f , amplitude θM, phase offset ϕ , and wing separation distance D*, and outflow speed v* is measured. At a fixed separation distance, v* is sensitive to both f and ϕ , and we observe both constructive and destructive interference in airspeed. v* is maximized at an optimum phase offset, ϕmax, which varies with wing separation distance, D*. We propose a model of collective flow interactions between flapping wings based on vortex advection, which reproduces our experimental data.

  14. Numerical linearized MHD model of flapping oscillations

    NASA Astrophysics Data System (ADS)

    Korovinskiy, D. B.; Ivanov, I. B.; Semenov, V. S.; Erkaev, N. V.; Kiehas, S. A.

    2016-06-01

    Kink-like magnetotail flapping oscillations in a Harris-like current sheet with earthward growing normal magnetic field component Bz are studied by means of time-dependent 2D linearized MHD numerical simulations. The dispersion relation and two-dimensional eigenfunctions are obtained. The results are compared with analytical estimates of the double-gradient model, which are found to be reliable for configurations with small Bz up to values ˜ 0.05 of the lobe magnetic field. Coupled with previous results, present simulations confirm that the earthward/tailward growth direction of the Bz component acts as a switch between stable/unstable regimes of the flapping mode, while the mode dispersion curve is the same in both cases. It is confirmed that flapping oscillations may be triggered by a simple Gaussian initial perturbation of the Vz velocity.

  15. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE... AND ANADROMOUS SPECIES Pt. 223, Fig. 16 Figure 16 to Part 223—Escape Opening and Flap Dimensions...

  16. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE... AND ANADROMOUS SPECIES Pt. 223, Fig. 16 Figure 16 to Part 223—Escape Opening and Flap Dimensions...

  17. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES... for the Double Cover Flap TED ER02JN04.003...

  18. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES... for the Double Cover Flap TED ER02JN04.003...

  19. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES... for the Double Cover Flap TED ER02JN04.003...

  20. Flap Edge Aeroacoustic Measurements and Predictions

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    2000-01-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a Small Aperture Directional Array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by Computational Fluid Dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady surface pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that much of the physics is captured by the prediction models. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define the noise production. For the different edge conditions, extensive spectra and directivity are presented. Significantly, for each edge configuration, the spectra for different flow speeds, flap angles, and

  1. Flap-edge aeroacoustic measurements and predictions

    NASA Astrophysics Data System (ADS)

    Brooks, Thomas F.; Humphreys, William M.

    2003-03-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a small aperture directional array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by computational fluid dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady-surface-pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that the prediction models capture much of the physics. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define the noise production. For the different edge conditions, extensive spectra and directivity are presented. The complexity of the directivity results demonstrate the strong role of edge source geometry and frequency in

  2. The trapezius osteomusculocutaneous flap in dogs.

    PubMed

    Philibert, D; Fowler, J D

    1993-01-01

    A pedicled osteomusculocutaneous flap, composed of the cervical part of the trapezius muscle with its overlying skin and the central spine and body of the scapula, was elevated on the prescapular branch of the superficial cervical vascular pedicle in four dogs. The flap was replaced in an orthotopic location. Bone viability was evaluated using histology, fluorescence bone labeling, and angiography. Bone from the scapular spines had a high percentage of viable osteocytes, positive fluorescence, and vessels were outlined in the angiographic study. Bone from the body of the scapula was not viable based on similar criteria. PMID:8116199

  3. Flap Edge Aeroacoustic Measurements and Predictions

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    2000-01-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a Small Aperture Directional Array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by Computational Fluid Dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady-surface-pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that much of the physics is captured by the prediction models. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define, the noise production. For the different edge conditions, extensive spectra and directivity are presented. Significantly, for each edge configuration, the spectra for different flow speeds, flap angles, and

  4. Flap Endonuclease 1 Limits Telomere Fragility on the Leading Strand*

    PubMed Central

    Teasley, Daniel C.; Parajuli, Shankar; Nguyen, Mai; Moore, Hayley R.; Alspach, Elise; Lock, Ying Jie; Honaker, Yuchi; Saharia, Abhishek; Piwnica-Worms, Helen; Stewart, Sheila A.

    2015-01-01

    The existence of redundant replication and repair systems that ensure genome stability underscores the importance of faithful DNA replication. Nowhere is this complexity more evident than in challenging DNA templates, including highly repetitive or transcribed sequences. Here, we demonstrate that flap endonuclease 1 (FEN1), a canonical lagging strand DNA replication protein, is required for normal, complete leading strand replication at telomeres. We find that the loss of FEN1 nuclease activity, but not DNA repair activities, results in leading strand-specific telomere fragility. Furthermore, we show that FEN1 depletion-induced telomere fragility is increased by RNA polymerase II inhibition and is rescued by ectopic RNase H1 expression. These data suggest that FEN1 limits leading strand-specific telomere fragility by processing RNA:DNA hybrid/flap intermediates that arise from co-directional collisions occurring between the replisome and RNA polymerase. Our data reveal the first molecular mechanism for leading strand-specific telomere fragility and the first known role for FEN1 in leading strand DNA replication. Because FEN1 mutations have been identified in human cancers, our findings raise the possibility that unresolved RNA:DNA hybrid structures contribute to the genomic instability associated with cancer. PMID:25922071

  5. [Aseptic bone flap osteonecrosis following cranioplasty after decompressive cranietomy].

    PubMed

    Smoll, Nicolas R; Stienen, Martin N; Schaller, Karl; Gautschi, Oliver P

    2013-06-19

    This case report discusses a case of aseptic osteonecrosis in a cranioplasty bone flap after decompressive craniectomy, which is a known, but rare complication after autologous cranioplasty. We suggest that the pathophysiology of cranial bone flap necrosis may have a similar pathophysiology to free flap necrosis/failure. The key suggested problem causing the osteonecrosis is vessel thrombosis within the smaller vessels of the bone flap due to the prothrombotic effects of the factors released during drilling of the bone flap. Suspicious local findings like wound dehiscence or fluid leakage should lead to a head computed tomography in order to discuss a prophylactic artificial second cranioplasty if necessary. PMID:23773942

  6. [The gracilis muscle as musculocutaneous flap. Evaluation of 20 cases].

    PubMed

    Gholam, D; Trevidic, P; Kleimann, P; Hautefeuille, P; Nicoletis, C

    1991-01-01

    The use of gracilis as muscular or myocutaneous flap is very well-known. The authors report 20 cases of gracilis flap including 13 reconstructions of the vaginal cavity following extended abdomino-perineal resection. Some technical points concerning the localization of the cutaneous part of the flap and the pedicle dissection are discussed. The use of gracilis flap is still limited in surgical teams following extended abdomino-perineal resection, nevertheless it is a very useful flap because of its low morbidity, the shortening of patient hospitalization and the very satisfying aesthetic result of the neo-vaginal cavity. PMID:1726389

  7. Long term follow up of neurovascular island flaps.

    PubMed

    Henderson, H P; Reid, D A

    1980-06-01

    The results of a ten year mean follow up of twenty Neurovascular Island Flaps and two Radial Nerve Innervated Cross Finger Flaps are presented. Sensory acuity sufficient for tactile gnosis was achieved in nineteen cases. In only one case had sensory acuity deteriorated since operation. Use of the flap was hampered in one patient by a pre-existing neuroma. Complete sensory reorientation occurred in five patients. Sensory misreference persisted more commonly on dominant hands. It was our impression that Porter's Letter Test revealed the patients making most use of their neurovascular island flaps. The place of neurovascular island flaps in the management of the mutilated hand is discussed. PMID:7409615

  8. 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

  9. Rectus abdominis myocutaneous flap for primary vaginal reconstruction.

    PubMed

    Carlson, J W; Soisson, A P; Fowler, J M; Carter, J R; Twiggs, L B; Carson, L F

    1993-12-01

    Reconstructive procedures are being performed with increasing frequency in conjunction with pelvic exenterations and other radical gynecologic surgeries. The most common reconstructive procedures include continent urinary diversion, rectosigmoid anastomosis, and vaginal reconstruction. Historically, the gracilis myocutaneous flap has been the procedure of choice for vaginal reconstruction. However, the gracilis myocutaneous flap has a history of partial to severe necrosis, a propensity to prolapse, and leaves ipsilateral donor scars on the thigh. In contrast, neovaginal reconstruction using a relatively new procedure, the distally based rectus abdominis myocutaneous flaps, has the advantage of using a large, single flap that can be incorporated into the primary incision. This flap is mobilized on a long vascular pedicle, the rectus muscle. In relation to the underlying rectus muscle, the orientation of the cutaneous portion of this flap may be customized to accommodate the pelvic defect or the surgeon's preference. Depending on their primary orientation, they are referred to as either a vertical or transverse rectus abdominis myocutaneous flap. The versatility and reliability of the rectus flap is demonstrated here through the presentation of a small pilot series of seven patients. The technique was used for vaginal reconstruction, primarily in conjunction with pelvic exenteration. The flaps were mobilized from the supraumbilical area and had a flap viability of 100% for the 2 years that they have been followed. There were no postoperative incisional or flap infections. There was one infraumbilical fascial dehiscence. The advantages of primary pelvic reconstruction along with the description of the operative techniques are presented. PMID:8112640

  10. The keystone flap: expanding the dermatologic surgeon's armamentarium.

    PubMed

    Hessam, Schapoor; Sand, Michael; Bechara, Falk G

    2015-01-01

    First described in 2003, the keystone flap has become an established plastic and reconstructive surgery technique for the closure of soft tissue defects following the excision of skin tumors. Complex reconstruction procedures may thus be avoided [3]. In dermatosurgery, however, the keystone flap remains largely unknown.Compared to subcutaneous pedicle flaps, the keystone flap technique warrants better vascular supply by additional-ly preserving musculocutaneous and fasciocutaneous perforator vessels [4]. Moreover, the flap is hyperemic compared to the surrounding skin [5]. Adequate perfusion and its specific design result in high safety of the flap. According to both published data and the authors’ experience, the keystone flap technique is associated with a low complication rate [1, 6].In summary, the keystone flap method yields good aesthetic and functional results by preserving shape and cont-our, avoiding differences in skin coloration and preserving sensitivity (Figure 1b). The flap is particularly well suited for deep defects with exposed bones or tendons, especially on the extremities or the trunk. Alternative closing options such as secondary intention healing, primary closure, or local flaps appear less adequate in these cases. In addition, skin grafting without long-term wound conditioning–for example negative pressure wound therapy–or expensive der-mal replacement products are not very promising. Thus, the keystone flap provides the dermatosurgeon with an effective alternative to reconstruction techniques. PMID:25640508

  11. Switch Flap for Upper Eyelid Reconstruction—How Soon Should the Flap Be Divided?

    PubMed Central

    Yanai, Tetsu; Yasuta, Masato; Kawano, Hiroshige; Ishihara, Yasuhiro; Kikuchi, Mamoru

    2016-01-01

    Background: The results of a cohort of patients treated at one institution for upper eyelid reconstruction with the switch flap method after a defect due to excision of malignant tumor were reviewed. Methods: A retrospective data file review of all patients who had undergone total upper eyelid reconstruction with the switch flap method was conducted at the Saga University Hospital between April 2000 and October 2014. The follow-up lasted for varying periods during which the preoperative and postoperative photographs were compared as well. Results: A total of 10 patients with upper eyelid tumors, that is, 7 sebaceous carcinoma, 2 squamous cell carcinoma, and 1 basal cell carcinoma, underwent reconstructive surgery. With the switch flap technique, the defects resulting from tumor excision were completely covered in all cases. The mean of defect widths after tumor excision (A) was 18.8 mm (range, 15–25 mm), the mean of widths of switch flaps (B) was 13.3 mm (range, 8–22 mm), and the mean of B/A ratios was 0.69 (range, 0.5–0.88). When the switch flap was divided at 7 to 14 days, there was no flap loss, trichiasis, or corneal ulcer. Conclusion: Our protocol managed to make flaps with a B/A ratio of 0.5–0.7, and the flaps were divided at 7 to 14 days after surgery, the timing of which was much earlier than in the conventional method, lessening the possibility of complications. PMID:27200257

  12. Delineation of LASIK Flaps with Prednisolone Acetate Eyedrops

    PubMed Central

    Fahd, Daoud C; Fahed, Sharbel D

    2014-01-01

    We describe the use and safety of prednisolone acetate eyedrops at the end of laser in situ keratomileusis (LASIK) to aid proper positioning of the corneal flap. The LASIK flap is created using the preferred technique. Following laser ablation and flap repositioning, one drop of prednisolone acetate is instilled on the eye. This delineates the flap “gutters” and allows perfect flap positioning and centration. We used this technique in 425 eyes undergoing LASIK for correction of spherocylindrical refractive errors. Flap margins were adequately delineated intraoperatively. The only complication related to the use of the steroid suspension was crystal deposition under the flap in one case which resolved completely in 48 hours. PMID:24982743

  13. Aerodynamic characteristics of NACA 4412 airfoil sction with flap

    NASA Astrophysics Data System (ADS)

    Ockfen, Alex E.; Matveev, Konstantin I.

    2009-09-01

    Wing-in-Ground vehicles and aerodynamically assisted boats take advantage of increased lift and reduced drag of wing sections in the ground proximity. At relatively low speeds or heavy payloads of these craft, a flap at the wing trailing-ground-effect flow id numerically investigated in this study. The computational method consists of a steady-state, incompressible, finite volume method utilizing the Spalart-Allmaras turbulence model. Grid generation and solution of the Navier-Stokes equations are completed flow with a flap, as well as ground-effect motion without a flap. Aerodynamic forces are plain flap. Changes in the flow introduced with the flap addition are also discussed. Overall, the use of a flap on wings with small attack angles is found to be beneficial for small flap deflections up to 5% of the chord, where the contribution of lift augmentation exceeds the drag increase, yielding an augmented lift-to-drag ratio

  14. The double opposing myomucosal cheek flap in hard palate reconstruction.

    PubMed

    Pabiszczak, Maciej; Banaszewski, Jacek; Pastusiak, Tomasz; Buczkowska, Agata; Wierzbicka, Małgorzata

    2015-01-01

    Limited defects in the oral cavity can be treated with local and pedicled cheek flaps. It allows to preserve the functions of the resected organ. Large defects in the midline of the hard palate can be reconstructed with double opposing myomucosal cheek flaps. The aim of this study was to discuss the methodology of the flap harvest and to show our experiences of treatment in a group of 15 patients with oral cavity cancer. In 1 patient the double opposing myomucosal cheek flap was harvested due to the wider local defect. The small size of the flap with ability to use the double opposing cheek flap in more extended defects as well as short duration of the surgery procedure can lead to reduced risk of postoperative complications. Finally, cheek flaps form an effective method of treatment of defects in the oral cavity. PMID:26388355

  15. The comparative study on the flapping motion of Venusian magnetotail

    NASA Astrophysics Data System (ADS)

    Rong, Zhaojin; Barabash, Stas; Wieser Stenberg, Gabriella; Futaana, Yoshifumi; Wan, Weixing; Wei, Yong; Wang, Xiaodong; Chai, Lihui; Zhong, Jun

    2016-04-01

    With a newly developed technique and magnetic field measurements obtained by the magnetometer on Venus Express, we study the flapping motion of the Venusian magnetotail. We find that the flapping motion generally comprises contributions both from a nonpropagating steady flapping and a propagating kink-like flapping. The flapping motion tilts the current sheet normal significantly in the plane perpendicular to the Venus-Sun line. The kink-like flapping waves traveling along solar wind electric field or its antidirection can be found in either magnetotail hemisphere where solar wind electric field pointing toward/away. The traveling behaviors suggest that the locations of the triggers for kink-like flappings are near the boundaries between magnetotail current sheet and magnetosheath, not near the central region of magnetotail as is for the Earth's magnetotail.

  16. 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

  17. Tubularized Penile-Flap Urethroplasty Using a Fasciocutaneous Random Pedicled Flap for Recurrent Anterior Urethral Stricture

    PubMed Central

    Lee, Byung Kwon

    2012-01-01

    This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia), and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique. PMID:22783537

  18. The "open book" flap: a heterodigital cross-finger skin flap and adipofascial flap for coverage of a circumferential soft tissue defect of a digit.

    PubMed

    Tadiparthi, S; Akali, A; Felberg, L

    2009-02-01

    A case of circumferential digital skin loss with exposed tendons from the proximal phalanx to the distal interphalangeal joint is presented. This was treated with a two-layer heterodigital cross-finger ("open book") flap from the adjacent digit, utilising a skin-only cross-finger flap to cover the palmar defect and an adipofascial flap to cover the dorsal defect. PMID:19129359

  19. Microsurgery flap in endodontic surgery: case report

    PubMed Central

    CECCHETTI, F.; RICCI, S.; DI GIORGIO, G.; PISACANE, C.; OTTRIA, L.

    2009-01-01

    SUMMARY In periodontal plastic surgery it is increasingly more evident the relavance of the protection of the gingival marginal anatomy through the realization of a conservative flap. Minimizing the recession of the treated tissue. A correct healing always needs to take into account the diameter and type of the suture and the time of removal from the wound. PMID:23285354

  20. Neural Anatomy of the Anterolateral Thigh Flap.

    PubMed

    Luenam, Suriya; Prugsawan, Krit; Kosiyatrakul, Arkaphat; Chotanaphuti, Thanainit; Sriya, Piyanee

    2015-06-01

    The anterolateral thigh (ALT) flap is one of the commonly used sensate flaps for intra-oral, hand, and foot reconstruction. The objective of this study was to describe the anatomic location of the sensory nerves supplying the ALT flap in relation to the surface landmarks and with the vascular pedicles. The dissections were carried out in 28 embalmed specimens. An axial line from the anterior superior iliac spine to the superolateral border of the patella and two circles with radii of 5 and 10 cm centered on the midpoint of the former line were used for the surface landmarks. At the intersection point of the axial line and the 10-cm circle, the main lateral femoral cutaneous nerve (LFCN) and its anterior branch were located within 1 and 2.4 cm, respectively. At the intersection point of the axial line and the 5-cm circle, the anterior branch of the LFCN was located within 2.8 cm. The anterior branch of the LFCN can be detected within 3 cm from the central perforator pedicle in all specimens. The posterior branch of the LFCN, superior perforator nerve, and median perforator nerve were found in more variable locations. The findings from our study provide additional information for clinical use in the planning of sensate ALT flap harvest. PMID:26078503

  1. 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.

  2. Periodic and chaotic flapping of insectile wings

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Kanso, E.

    2015-11-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the energy level at which they are operating, insects can maintain periodic flapping mechanically for a range of operating conditions.

  3. Computation of Lifting Wing-Flap Configurations

    NASA Technical Reports Server (NTRS)

    Cantwell, Brian; Kwak, Dochan

    1996-01-01

    Research has been carried out on the computation of lifting wing-flap configurations. The long term goal of the research is to develop improved computational tools for the analysis and design of high lift systems. Results show that state-of-the-art computational methods are sufficient to predict time-averaged lift and overall flow field characteristics on simple high-lift configurations. Recently there has been an increased interest in the problem of airframe generated noise and experiments carried out in the 7 x 10 wind tunnel at NASA Ames have identified the flap edge as an important source of noise. A follow-on set of experiments will be conducted toward the end of 1995. The computations being carried out under this project are coordinated with these experiments. In particular, the model geometry being used in the computations is the same as that in the experiments. The geometry consists of a NACA 63-215 Mod B airfoil section which spans the 7 x lO tunnel. The wing is unswept and has an aspect ratio of two. A 30% chord Fowler flap is deployed modifications of the flap edge geometry have been shown to be effective in reducing noise and the existing code is currently being used to compute the effect of a modified geometry on the edge flow.

  4. Peritoneal flap ureteropexy for idiopathic retroperitoneal fibrosis.

    PubMed

    Fowler, J W

    1987-07-01

    Eight patients had 13 ureters treated by peritoneal flap ureteropexy. There were no significant post-operative complications. Eleven ureters were functioning normally after an average follow-up of 28 months. The operation is suggested as a method of choice where omental wrapping is not possible. PMID:3620842

  5. Free Surface and Flapping Foil Interactions

    NASA Astrophysics Data System (ADS)

    Ananthakrishnan, Palaniswamy

    2014-11-01

    Flapping foils for station-keeping of a near-surface body in a current is analyzed using a finite-difference method based on boundary-fitted coordinates. The foils are hinge-connected to the aft of the body and subject to pitch oscillation. Results are obtained for a range of Strouhal number, Froude number, unsteady frequency parameter τ, Reynolds number and the depth of foil submergence. Results show that at low Strouhal number (St < 0 . 1) and sub-critical unsteady parameter τ < 0 . 25 , the flapping generates drag instead of thrust. At high Strouhal number and super-critical value of the unsteady parameter (τ > 0 . 25) flapping generates high thrust with low efficiency. Thrust and efficiency are found to decrease with decreasing submergence depth of the foil. At the critical τ = 0 . 25 and shallow submergence of the foil, the standing wave generated above the foil continues to grow until breaking; both the thrust and efficiency of the foil are reduced at the critical τ. The necessary conditions for optimal thrust generation by a flapping foil underneath the free surface are found to be (i) Strouhal number in the range from 0.25 to 0.35, (ii) unsteady parameter τ > 0 . 25 and (iii) the maximum angle of attack less than 15° for the flat-plate foil. Supported by the US Office of Naval Research through the Naval Engineering Education Center (NEEC) Consortium of the University of Michigan, Ann Arbor.

  6. Flapping wing aerodynamics: from insects to vertebrates.

    PubMed

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight. PMID:27030773

  7. High-energy war wounds: flap reconstruction.

    PubMed

    Stanec, Z; Skrbić, S; Dzepina, I; Hulina, D; Ivrlac, R; Unusić, J; Montani, D; Prpić, I

    1993-08-01

    In this article, we emphasize that knowledge of terminal ballistics is essential for understanding the pathophysiology of war wounds. We present our own experiences in treatment of high-energy war wounds in 75 patients treated in the Institute of Plastic and Reconstructive Surgery, Department of Surgery, Clinical Hospital Center in Zagreb. Patients were divided into three groups with regard to the time of definite reconstruction, using local or free microvascular flaps. About 12% of patients underwent flap reconstruction in the acute phase, associated with low complication rate and the shortest hospital stay. Group II was comprised by 18% of the patients and, considering the number of complications, presented the most unfavorable time for reconstruction. Flap reconstruction in the chronic phase resulted in a substantial prolongation of the hospital stay in 82% of patients. Therefore, we advocate proper primary treatment of wounds aimed at early flap closure. This type of management results in a significantly shorter hospitalization and leads to more effective rehabilitation and recovery of patients. PMID:8215140

  8. 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

  9. 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

  10. 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

  11. The Retrograde Ulnar Dorsal Flap: Surgical Technique and Experience as Island Flap in Coverage of Hand Defects.

    PubMed

    Vergara-Amador, Enrique

    2015-09-01

    Flaps from the forearm are often used to reconstruct soft-tissue defects in the hand. The retrograde ulnar dorsal flap has the advantage that it does not sacrifice a major vascular axis. The anatomic bases of this flap are the proximal and distal branch of the ulnar dorsal artery. The distal branch is partially accompanied with the dorsal branch of the ulnar nerve, and arrives under the abductor digiti quinti muscle making anastomoses with the deep branch of the ulnar artery. The proximal branch reaching the proximal third of the forearm, and anastomose with perforating branches of the ulnar artery. I used this island flap in 12 patients with coverage defects on the hand. The biggest flap was 13×6 cm. Only 1 flap had partial necrosis which did not lead to problems. The retrograde ulnar dorsal flap is a flap designed with reverse flow from the distal branch of the ulnar dorsal artery, and which does not sacrifice the ulnar artery. The donor defect on the forearm ulnar side had a greater esthetic acceptance. Knowing other distal anastomoses, described by other authors later, dorsal at the base of the fourth interdigital space grant greater security to the retrograde ulnar dorsal flap. It is worth highlighting the importance of preserving the adipofascial tissue around the pedicle. Experience with this flap permits us to state that it is a safe and reproducible flap to cover any defect on the dorsal of the hand as well as the first web space. PMID:26079665

  12. Assessing safety of negative-pressure wound therapy over pedicled muscle flaps: A retrospective review of gastrocnemius muscle flap.

    PubMed

    Lance, Samuel; Harrison, Lindsey; Orbay, Hakan; Boudreault, David; Pereira, Gavin; Sahar, David

    2016-04-01

    The use of negative-pressure wound therapy (NPWT) for management of open wounds and immobilization of split-thickness skin grafts (STSGs) over wounds has been well described. However, there is a concern for potential compromise of flap viability when NPWT is used for skin grafts over pedicled muscle flaps. We have used NPWT to immobilize STSGs in eight patients who underwent a pedicled gastrocnemius muscle flap operation in our department. We applied a negative pressure of -75 mmHg on the muscle flaps for 5 days postoperatively. All wounds healed successfully, with a 97.5 ± 5.5% mean STSG uptake. No flap necrosis was observed. In our series, the use of NPWT for fixation of STSGs over pedicled gastrocnemius muscle flap was effective and had no negative impact on flap viability. PMID:26732293

  13. Wing loading on a 60 degree delta wing with vortex flaps

    NASA Technical Reports Server (NTRS)

    Marchman, J. F., III; Donatelli, D. A.; Terry, J. E.

    1983-01-01

    Wind tunnel tests were conducted on a 60 deg delta wing with three vortex flap designs to determine pressure distributions over the wing and flap. The results showed that an optimum vortex flap design depends on proper definition of the vortex flap deflection angle. They also revealed that flap thickness plays an important role in the behavior of the vortex flow over the flap and wing and can have a substantial effect on wing and flap pressure loading. Design codes which fail to account for thickness may result in a much less than optimum flap and deprive the designer of an important tool in designing an effective flap with optimum loading.

  14. Pedicle versus free flap reconstruction in patients receiving intraoperative brachytherapy.

    PubMed

    Geiger, Erik J; Basques, Bryce A; Chang, Christopher C; Son, Yung; Sasaki, Clarence T; McGregor, Andrew; Ariyan, Stephan; Narayan, Deepak

    2016-08-01

    Introduction This study compared complication rates between pedicle flaps and free flaps used for resurfacing of intraoperative brachytherapy (IOBT) implants placed following head and neck tumour extirpation to help clarify the ideal reconstructive procedure for this scenario. Patients and methods A retrospective review of reconstructions with IOBT at our institution was conducted. Patient and treatment details were recorded, as were the number and type of flap complications, including re-operations. Logistic regressions compared complications between flap groups. Results Fifty free flaps and 55 pedicle flaps were included. On multivariate analysis, free flap reconstruction with IOBT was significantly associated with both an increased risk of having any flap complication (OR = 2.9, p = 0.037) and with need for operative revision (OR = 3.5, p = 0.048) compared to pedicle flap reconstruction. Conclusions In the setting of IOBT, free flaps are associated with an increased risk of having complications and requiring operative revisions. PMID:26983038

  15. Coverage of Amputation Stumps Using a Latissimus Dorsi Flap With a Serratus Anterior Muscle Flap: A Comparative Study.

    PubMed

    Kim, Sang Wha; Jeon, Seung Bae; Hwang, Kyu Tae; Kim, Youn Hwan

    2016-01-01

    Amputation of the extremities is a definitive reconstructive option, and surgeons should aim to preserve maximum overall function. If the exposed bone cannot be adequately covered using local tissues, the stump can be reconstructed using a number of well-described free flap transfer techniques. Between January 2002 and December 2011, 31 patients with severe injuries to the lower extremities underwent above-the-knee, below-the-knee, and Chopart and Ray amputations. Bony stumps were covered using latissimus dorsi myocutaneous flaps alone (group 1), or together with serratus anterior muscle flaps (group 2). The groups were compared with respect to age, flap survival, skin flap size, immediate complications, wound sloughing, deep ulceration, need for bone amputation, limb visual analog scale score, time to prosthesis, and follow-up duration. The mean area of the latissimus dorsi skin flap was 255.9 cm, and immediate complications occurred in 8 (25.8%) patients. In the double-padding group, there were fewer cases of deep ulceration than in the single-flap group, and prostheses could be worn sooner. There were no statistically significant differences in other parameters. Successful reconstruction of amputation stumps requires an adequate, durable, weight-bearing, and well-contoured soft tissue cover. A latissimus dorsi musculocutaneous flap together with a serratus anterior muscle flap provides well-vascularized muscle tissue and a durable skin paddle, leading to less ulceration than conventional flap techniques. PMID:25003415

  16. Repeated Elevation of the Anterolateral Thigh Flap for Lower Extremity Orthopedic Trauma Does Not Affect Flap Viability.

    PubMed

    Kotick, James D; Mitchell, William; Bayouth, Lilly; Klein, Richard; Lee, Ken

    2016-03-01

    Background The anterolateral thigh (ALT) flap has a key role regarding limb salvage and has facilitated the preservation of function and esthetics in lower extremity reconstruction. The purpose of this study is to review the advantages of the ALT flap when used early in the reconstruction of the trauma patient; specifically, its long-term viability when ALT flap reconstruction is followed by recurrent flap elevation performed to allow a variety of sequential orthopedic operations including washout, antimicrobial disc placement, and reinstrumentation. Methods A retrospective analysis was performed to review all ALT flaps performed by the authors from January 2009 to October 2012 at the Orlando Regional Medical Center. A total of 69 patients with an average age of 38 years were included in the study leading to a total of 69 ALT flaps indicated for traumatic orthopedic wounds. Out of these, 29 flaps were elevated at least once leading to a total of 49 flap elevations. Results The median number of days to flap elevation was 117 with a minimum of 1 day and a maximum of 540 days. A total of 42% flaps were elevated at least once after initial placement for reinstrumentation, washout, or antibiotic disk placement. Overall, 52% of the flaps were lifted once, 34% were lifted twice, and 14% were lifted more than thrice. There is no statistically significant difference in the complication rate between elevating the flap compared with primary ALT placement. Conclusion We conclude, therefore, there is no elevated risk to long-term viability by elevating the ALT flap. This combined with the ease of elevation makes it a safe procedure to be performed as needed for access to the deep tissues. PMID:26382873

  17. Canine lateral thoracic fasciocutaneous flap: an experimental study.

    PubMed

    Trinh, Cao Minh; Hoàng, Văn Lu'o'ng; Pham, Thi Ngoc; Hoàng, Manh An

    2009-10-01

    For the purpose of reconstructive surgery training and research, we have developed a new skin flap model: canine lateral thoracic fasciocutaneous flap. Anatomical study found that the lateral thoracic arteries in dogs have similar anatomical characteristics to human's ones. Based on these vessels, if a skin flap was designed within the vessels territory (size 5 x 8 cm) it could survive completely, whereas, if designed beyond the vessels territory (size 5 x 14 cm) would result in partial necrosis of the flap. This fasciocutaneous flap model closely simulates the human surgery and could be valuable for training and research. Furthermore, this flap could be applied in the veterinary practice for reconstruction of canine forelimbs and cervical area. PMID:19638323

  18. Versatility of V-Y Flap in Gluteal Area

    PubMed Central

    El-Sabbagh, Ahmed

    2016-01-01

    BACKGROUND Lesions in perineal area are common. The usual treatment is coverage by skin graft and flaps which may be local, pedicled or free types. In this paper V-Y flaps were used to cover the defects. METHODS V-Y flaps were used in the gluteal area in 15 patients. Lesions were due to different causes. RESULTS Of 15 patients, 11 were males and 4 were females. Their ages ranged from 3 weeks to 52 years old. Two cases were due to myelomeningocele, necrotizing fasciitis (2 cases) and the rest were due to bed sores (11 cases). The flaps were located over the trochanter (3 cases), ischial (6 cases) and sacral (6 cases). Good healing and durable coverage were obtained in all cases except one case. CONCLUSION V-Y flap as a working horse flap is recommended in the gluteal area. PMID:27579271

  19. Vertical electrostatically 90° turning flaps for reflective MEMS display

    NASA Astrophysics Data System (ADS)

    Jutzi, Fabio; Noell, Wilfried; de Rooij, Nico F.

    2011-03-01

    A new kind of MEMS reflective display is being developed having high contrast and reflectivity, better than on printed paper. The system is based on novel vertical flaps, which can be electrostatically turned by 90° to horizontal position. After fabrication, the poly-silicon flaps are vertical to the wafer surface and on the top suspended by torsion beams. In this state the pixel is black, incoming ambient light passes by the flaps and is absorbed by an underlying absorptive layer. When the flaps are turned to horizontal position light is reflected back and the pixel gets white. A self-aligning four masks bulk microfabrication process is employed, which uses poly-silicon filling of high aspect-ratio cavities. Parylene was also employed as flap material. Thanks to auto stress-compensation the flaps are not deformed due to intrinsic stresses. Low actuation voltages down to 20V can be achieved.

  20. Flap Necrosis after Palatoplasty in Patients with Cleft Palate

    PubMed Central

    Rossell-Perry, Percy

    2015-01-01

    Palatal necrosis after palatoplasty in patients with cleft palate is a rare but significant problem encountered by any cleft surgeon. Few studies have addressed this disastrous complication and the prevalence of this problem remains unknown. Failure of a palatal flap may be attributed to different factors like kinking or section of the pedicle, anatomical variations, tension, vascular thrombosis, type of cleft, used surgical technique, surgeon's experience, infection, and malnutrition. Palatal flap necrosis can be prevented through identification of the risk factors and a careful surgical planning should be done before any palatoplasty. Management of severe fistulas observed as a consequence of palatal flap necrosis is a big challenge for any cleft surgeon. Different techniques as facial artery flaps, tongue flaps, and microvascular flaps have been described with this purpose. This review article discusses the current status of this serious complication in patients with cleft palate. PMID:26273624

  1. Dynamics of Flapping Flag in Axial Flow

    NASA Astrophysics Data System (ADS)

    Abderrahmane, Hamid Ait; Fayed, Mohamed; Gunter, Amy-Lee; Paidoussis, Michael P.; Ng, Hoi Dick

    2010-11-01

    We investigate experimentally the phenomenon of the flapping of a flag, placed within a low turbulent axial flow inside a small scale wind tunnel test section. Flags of different sizes and flexural rigidities were used. Image processing technique was used and the time series of a given point on the edge of the flag was analyzed. The stability condition of the flag was obtained and compared to the recent theoretical models and numerical simulations. Afterwards, the nonlinear dynamics of the flapping was investigated using nonlinear time series method. The nonlinear dynamics is depicted in phase space and the correlation dimension of the attractors is determined. On the basis of observations made in this study, some conclusions on the existing models were drawn.

  2. Forward speed effects on blown flap noise

    NASA Technical Reports Server (NTRS)

    Pennock, A. P.

    1977-01-01

    The effects of forward speed on the noise of under-the-wing (externally blown flaps, EBF) and over-the-wing (upper surface blown, USB) blown flap configurations were measured in wind tunnel model tests with cold jets. The results are presented without correction for the effects (e.g., signal convection, shear layer refraction) associated with flight simulation in a wind tunnel or free jet facility. Noise decreases were generally observed at microphones forward of the wing. The reductions were larger at the low frequencies (below peak SPL) than at the high (above peak SPL). Noise increases of 10 dB or more were observed at the aft microphones, especially in the high frequency range.

  3. Flap Coverage of Anterior Abdominal Wall Defects

    PubMed Central

    Sacks, Justin M.; Broyles, Justin M.; Baumann, Donald P.

    2012-01-01

    Reconstruction of complex defects of the anterior abdomen is both challenging and technically demanding for reconstructive surgeons. Advancements in the use of pedicle and free tissue transfer along with the use of bioprosthetic and synthetic meshes have provided for novel approaches to these complex defects. Accordingly, detailed knowledge of abdominal wall and lower extremity anatomy in combination with insight into the design, implementation, and limitations of various flaps is essential to solve these complex clinical problems. Although these defects can be attributed to a myriad of etiologic factors, the objectives in abdominal wall reconstruction are consistent and include the restoration of abdominal wall integrity, protection of intraabdominal viscera, and the prevention of herniation. In this article, the authors review pertinent anatomy and the various local, regional, and distant flaps that can be utilized in the reconstruction of these complex clinical cases of the anterior abdomen. PMID:23372457

  4. Flight test pilot evaluation of a delayed flap approach procedure

    NASA Technical Reports Server (NTRS)

    Bull, J. S.; Edwards, F. G.; Foster, J. D.; Hegarty, D. M.; Drinkwater, F. J., III

    1977-01-01

    Using NASA's CV-990 aircraft, a delayed flap approach procedure was demonstrated to nine guest pilots from the air transport industry. Four demonstration flights and 37 approaches were conducted under VFR weather conditions. A limited pilot evaluation of the delayed flap procedure was obtained from pilot comments and from questionaires they completed. Pilot acceptability, pilot workload, and ATC compatibility were quantitatively rated. The delayed flap procedure was shown to be feasible, and suggestions for further development work were obtained.

  5. USB noise reduction by nozzle and flap modifications

    NASA Technical Reports Server (NTRS)

    Hayden, R. E.

    1976-01-01

    The development of concepts for reducing upper surface blown flap noise at the source through flap modifications and special nozzles is reviewed. In particular, recent results obtained on the aerodynamic and acoustic performance of flaps with porous surfaces near the trailing edge and multi-slotted nozzles are reviewed. Considerable reduction (6-10 db) of the characteristic low frequency peak is shown. The aerodynamic performance is compared with conventional systems, and prospects for future improvements are discussed.

  6. 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.

  7. 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

  8. Aerodynamics of high frequency flapping wings

    NASA Astrophysics Data System (ADS)

    Hu, Zheng; Roll, Jesse; Cheng, Bo; Deng, Xinyan

    2010-11-01

    We investigated the aerodynamic performance of high frequency flapping wings using a 2.5 gram robotic insect mechanism developed in our lab. The mechanism flaps up to 65Hz with a pair of man-made wing mounted with 10cm wingtip-to-wingtip span. The mean aerodynamic lift force was measured by a lever platform, and the flow velocity and vorticity were measured using a stereo DPIV system in the frontal, parasagittal, and horizontal planes. Both near field (leading edge vortex) and far field flow (induced flow) were measured with instantaneous and phase-averaged results. Systematic experiments were performed on the man-made wings, cicada and hawk moth wings due to their similar size, frequency and Reynolds number. For insect wings, we used both dry and freshly-cut wings. The aerodynamic force increase with flapping frequency and the man-made wing generates more than 4 grams of lift at 35Hz with 3 volt input. Here we present the experimental results and the major differences in their aerodynamic performances.

  9. 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.

  10. Flapping inertia for selected rotor blades

    NASA Technical Reports Server (NTRS)

    Berry, John D.; May, Matthew J.

    1991-01-01

    Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

  11. Locomotion of a flapping flexible plate

    NASA Astrophysics Data System (ADS)

    Hua, Ru-Nan; Zhu, Luoding; Lu, Xi-Yun

    2013-12-01

    The locomotion of a flapping flexible plate in a viscous incompressible stationary fluid is numerically studied by an immersed boundary-lattice Boltzmann method for the fluid and a finite element method for the plate. When the leading-edge of the flexible plate is forced to heave sinusoidally, the entire plate starts to move freely as a result of the fluid-structure interaction. Mechanisms underlying the dynamics of the plate are elucidated. Three distinct states of the plate motion are identified and can be described as forward, backward, and irregular. Which state to occur depends mainly on the heaving amplitude and the bending rigidity of the plate. In the forward motion regime, analysis of the dynamic behaviors of the flapping flexible plate indicates that a suitable degree of flexibility can improve the propulsive performance. Moreover, there exist two kinds of vortex streets in the downstream of the plate which are normal and deflected wake. Further the forward motion is compared with the flapping-based locomotion of swimming and flying animals. The results obtained in the present study are found to be consistent with the relevant observations and measurements and can provide some physical insights into the understanding of the propulsive mechanisms of swimming and flying animals.

  12. Theoretical and experimental study on the ejector augmented jet flap

    NASA Technical Reports Server (NTRS)

    Stewart, H. J.

    1974-01-01

    The analytical concept used in determining the characteristics of jet flap or related propulsive systems suitable for VTOL and STOL applications was examined. The configuration chosen was a two dimensional wing with a biplane flap, having a jet injected on the upper surface of the wing at the flap hinge axis and discharging into the channel between the two elements of the flap. The experimental work was conducted in a two dimensional test installation in a subsonic wind tunnel. The model description, the test conditions, and a summary of the experimental results are presented.

  13. [Superficial ulnar artery while harvesting a radial forearm flap].

    PubMed

    Moullot, P; Gay, A-M; Guidicelli, T; Rouabah, K; Legré, R

    2015-02-01

    Forearm vascular anatomical variations are common and may have complications during flaps harvesting. This article describes the presence of an ulnar superficial artery, revealed while harvesting a radial forearm flap. The prevalence of this anatomical variation is between 0.7 and 9.4%. It may have important consequences while covering loss of substance with a radial forearm flap. Unknown, there is a risk of vascular injury which may lead to distal ischemia of the upper limb. Preoperative diagnosis can anticipate this risk and harvest a fascio-cutaneous flap centered on a perforator of this artery. PMID:24095106

  14. Vortex leading edge flap assembly for supersonic airplanes

    NASA Technical Reports Server (NTRS)

    Rudolph, Peter K. C. (Inventor)

    1997-01-01

    A leading edge flap (16) for supersonic transport airplanes is disclosed. In its stowed position, the leading edge flap forms the lower surface of the wing leading edge up to the horizontal center of the leading edge radius. For low speed operation, the vortex leading edge flap moves forward and rotates down. The upward curve of the flap leading edge triggers flow separation on the flap and rotational flow on the upper surface of the flap (vortex). The rounded shape of the upper fixed leading edge provides the conditions for a controlled reattachment of the flow on the upper wing surface and therefore a stable vortex. The vortex generates lift and a nose-up pitching moment. This improves maximum lift at low speed, reduces attitude for a given lift coefficient and improves lift to drag ratio. The mechanism (27) to move the vortex flap consists of two spanwise supports (24) with two diverging straight tracks (64 and 68) each and a screw drive mechanism (62) in the center of the flap panel (29). The flap motion is essentially normal to the airloads and therefore requires only low actuation forces.

  15. Rotational flaps in oncologic breast surgery. Anatomical and technical considerations.

    PubMed

    Acea Nebril, Benigno; Builes Ramírez, Sergio; García Novoa, Alejandra; Varela Lamas, Cristina

    2016-01-01

    Local flaps are a group of surgical procedures that can solve the thoracic closure of large defects after breast cancer surgery with low morbidity. Its use in skin necrosis complications after conservative surgery or skin sparing mastectomies facilitates the initiation of adjuvant treatments and reduces delays in this patient group. This article describes the anatomical basis for the planning of thoracic and abdominal local flaps. Also, the application of these local flaps for closing large defects in the chest and selective flaps for skin coverage by necrosis in breast conserving surgery. PMID:27140865

  16. Gynecologic reconstruction with a rectus abdominis myocutaneous flap: an update.

    PubMed

    Carlson, J W; Carter, J R; Saltzman, A K; Carson, L F; Fowler, J M; Twiggs, L B

    1996-06-01

    This series reports the outcomes and significant complications associated with the rectus myocutaneous flap when used for pelvic or inguinal reconstruction in patients with gynecologic cancers. Perioperative variables were retrospectively reviewed to identify social and medical risk factors as well as intraoperative and postoperative complications that predisposed to rectus flap failure. Fifteen patients with gynecologic malignancies underwent reconstructive procedures using a vertically oriented rectus abdominis myocutaneous flap for either vaginal (n = 14) or inguinal (n = 1) reconstruction. The patients' primary cancers were cervical (n = 11), rectal (n = 1), ovarian (n = 1), vulvar (n = 1), and vaginal (n = 1). The median age was 50 years. The median follow-up was 17 months. All flaps were mobilized in conjunction with a radical salvage operation. There were no cases of vaginal prolapse and no abdominal wound infections. However, 4 patients (27%) had major postoperative morbidity in this small series. There was one wound dehiscence and three episodes of necrosis of the subcutaneous and cutaneous portions of the flap. All 4 of these patients required additional operative intervention or debridement. Eleven patients had complete healing of the flap. The rectus abdominis myocutaneous flap is a valuable option for gynecologic reconstructive procedures. Perioperative strategies for improving flap viability include the identification of risk factors that may compromise flap perfusions such as prior abdominal incisions, peripheral vascular disease, and obesity. Meticulous surgical technique is required to preserve the vascular pedicle. These strategies may be useful in preoperative counseling, the perioperative evaluation, and the intraoperative management. PMID:8641616

  17. Computational Investigation of a Semi-Span Flap

    NASA Technical Reports Server (NTRS)

    Mathias, Donovan, L.; Roth, Karlin R.; Ross, James C.; Rogers, Stuart E.; Cummings, Russell M.; Olson, Lawrence E. (Technical Monitor)

    1995-01-01

    The current study computationally examines one of the principle three-dimensional features of the flow over a high-lift system, the flow associated with a flap edge. Structured, overset grids were used in conjunction with an incompressible Navier-Stokes solver to compute the flow over a two-element high-lift configuration. The computations were run in a fully turbulent mode using the one-equation Baldwin-Barth model. Specific interest was given to the details of the flow in the vicinity of the flap edge, so the geometry was simplified to isolate this region. The geometry consisted of an unswept wing, which spanned a wind tunnel test section, equipped with a single element flap. Two flap configurations were computed; a full-span and a half-span Fowler flap. The chord based Reynolds number was 3.7 million for all cases. The results for the full-span flap agreed with two-dimensional experimental results and verified the method. Grid topologies and related issues for the half-span flap geometry are discussed. Results of the half-span flap case are presented with emphasis on the flow features associated with the flap edge.

  18. Flap noise characteristics measured by pressure cross correlation techniques

    NASA Astrophysics Data System (ADS)

    Miller, W. R.

    1980-03-01

    The aerodynamic sound generated by a realistic aircraft flap system was investigated through the use of cross correlations between surface pressure fluctuations and far field sound. Measurements were conducted in two subsonic wind tunnel studies to determine the strength, distribution, and directivity of the major sources of flap noise at speeds up to 79.0 m/sec. A pilot study was performed on a single flap model to test the measurement technique and provide initial data on the characteristics of flap noise. The major portion of this investigation studied the sound radiated by a realistic large scale model of a triple slotted flap system mounted on a sweptback 6.7 meter semispan model wing. The results of this investigation have identified the major sources of flap generated noise and their dependence of flow defining parameters. In addition, a possible avenue toward the reduction of flap generated noise has been identified via the placement of the flap actuator fairings on the flap system.

  19. 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

  20. Oropharyngeal reconstruction with a pedicled submandibular gland flap.

    PubMed

    Mashrah, Mubarak A; Zhou, Shang-Hui; Abdelrehem, Ahmed; Ma, Chunyue; Xu, Liqun; He, Yue; Zhang, Chen-Ping

    2016-05-01

    Locoregional flaps are widely used for reconstruction of small and medium defects in the oral cavity. The submandibular gland flap is a pedicled flap, which derives its blood supply from the facial artery, based on the submandibular gland. We describe the use of the flap in 20 patients who required oropharyngeal reconstruction with a pedicled submandibular gland flap after resection of a tumour between July 2012 and October 2014. Patients with squamous cell carcinoma were excluded. All flaps were pedicled on the facial vessels (inferiorly in 17 patients and superiorly in 3). The indications were: reconstruction of intraoral mucosal defects (n=13), filling the parapharyngeal dead space (n=6), and obliteration of the mastoid (n=1). All the flaps atrophied, but with no clinical effect. One patient developed partial loss of the flap, and one early leakage. There were no cases of xerostomia, and no signs of recurrence during the postoperative follow-up period of 3-26 months. The flap is useful, as it is simple and reliable for reconstruction of small to medium oropharyngeal defects in carefully selected cases, and gives good cosmetic and functional results. PMID:26388070

  1. Skew flap for staged below-knee amputation in sepsis.

    PubMed

    Matthews, Christopher O; Williams, Ian M; Lewis, Peter; McLain, A David; Twine, Christopher P

    2016-04-01

    Skew flap amputation was first described in the 1980s but was never as popular as the long posterior flap amputation. This report describes a staged below-knee amputation in sepsis, with pus throughout the leg and a lack of skin coverage. One benefit of skew flaps never previously published is the fact that the suture line is not directly over the tibia. Therefore, an open wound or incomplete skin coverage is not as important as in long posterior flaps where it often leads to bone exposure and revision amputation. These benefits were utilized in this case leading to stump healing. PMID:26002782

  2. Effects of primary rotor parameters on flapping dynamics

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.

    1980-01-01

    The effects of flapping dynamics of four main rotor design features that influence the agility, stability, and operational safety of helicopters are studied. The parameters include flapping hinge offset, flapping hinge restraint, pitch-flap coupling, and blade lock number. First, the flapping equations of motion are derived that explicitly contain the design parameters. The dynamic equations are then developed for the tip-path plane, and the influence of individual and combined variations in the design parameters determined. The steady state flapping response is examined with respect to control input and aircraft angular rate which leads to a feedforward control law for control decoupling through cross feed, and a feedback control law to decouple the steady state flapping response. The condition for achieving perfect decoupling of the flapping response due to aircraft pitch and roll rates without using feedback control is also found for the hover case. It is indicated that the frequency of the regressing flapping mode of the rotor system can become low enough to require consideration in the assessment of handling characteristics.

  3. Development of a morphing flap using shape memory alloy actuators: the aerodynamic characteristics of a morphing flap

    NASA Astrophysics Data System (ADS)

    Ko, Seung-Hee; Bae, Jae-Sung; Rho, Jin-Ho

    2014-07-01

    The discontinuous contour of a wing with conventional flaps diminishes the aerodynamic performance of an aircraft. A wing with a continuous contour does not experience extreme flow stream fluctuations during flight, and consequently has good aerodynamic characteristics. In this study, a morphing flap using shape memory alloy actuators is proposed, designed and fabricated, and its aerodynamic characteristics are investigated using aerodynamic analyses and wind tunnel tests. The ribs of the morphing flap are designed and fabricated with multiple elements joined together in a way that allows relative rotations of adjacent elements and forms a smooth contour of the morphing flap. The aerodynamic analyses of this multiple-element morphing-flap wing are performed using XFLR pro; its aerodynamic performance is compared with that of a mechanical-flap wing, and is measured through wind-tunnel tests.

  4. 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

  5. Aerodynamic characteristics of wings with cambered external airfoil flaps, including lateral control, with a full-span flap

    NASA Technical Reports Server (NTRS)

    Platt, Robert C

    1936-01-01

    The results of a wind-tunnel investigation of the NACA 23012, the NACA 23021, and the Clark Y airfoils, each equipped with a cambered external-airfoil flap, are presented in this report. The purpose of the research was to determine the relative merit of the various airfoils in combination with the cambered flap and to investigate the use of the flap as a combined lateral-control and high-lift device.

  6. 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

  7. A propeller flap for single-stage nose reconstruction in selected patients: supratrochlear artery axial propeller flap.

    PubMed

    Cordova, Adriana; D'Arpa, Salvatore; Massimiliano, Tripoli; Toia, Francesca; Moschella, Francesco

    2014-06-01

    The paramedian forehead flap is the gold standard technique for nose reconstruction. It requires two different surgical operations which prolonged the postoperative dressing and care. We present our 5-year experience with a propeller flap based on the supratrochlear artery, which allows one-stage transfer of the forehead skin to the nose without the need for pedicle division. This technique is indicated in a selected group of patients who are not suitable for multiple-stage reconstructions because they have concurrent medical conditions, reduced mobility, or live far away from specialized medical centers. We have renamed this procedure as supratrochlear artery axial propeller flap, from the acronym STAAP flap, to stress the axial, well known and constant, vascularization of the flap. In the past 5 years, we have been performing 25 STAAP flaps; full-thickness nasal reconstruction was performed in 11 cases. The patients were 16 males and 9 females, with a mean age of 79.5 years. All patients had multiple comorbidities. Complete flap survival was observed in 23 cases and healing was complete in 7 days. In two cases, there was a partial distal necrosis of the flap treated conservatively. Cosmetic results were good and the patient's satisfaction was significant. These results indicate that the STAAP flap is a reliable and useful technique in selected cases, as old or noncompliant patients who benefit from a one-stage technique of nose reconstruction. PMID:24918712

  8. 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

  9. Effect of wing aspect ratio and flap span on aerodynamic characteristics of an externally blown jet-flap STOL model

    NASA Technical Reports Server (NTRS)

    Smith, C. C., Jr.

    1973-01-01

    An investigation has been conducted to determine the effects of flap span and wing aspect ratio on the static longitudinal aerodynamic characteristics and chordwise and spanwise pressure distributions on the wing and trailing-edge flap of a straight-wing STOL model having an externally blown jet flap without vertical and horizontal tail surfaces. The force tests were made over an angle-of-attack range for several thrust coefficients and two flap deflections. The pressure data are presented as tabulated and plotted chordwise pressure-distribution coefficients for angles of attack of 1 and 16. Pressure-distribution measurements were made at several spanwise stations.

  10. Navier-Stokes Computations of a Wing-Flap Model With Blowing Normal to the Flap Surface

    NASA Technical Reports Server (NTRS)

    Boyd, D. Douglas, Jr.

    2005-01-01

    A computational study of a generic wing with a half span flap shows the mean flow effects of several blown flap configurations. The effort compares and contrasts the thin-layer, Reynolds averaged, Navier-Stokes solutions of a baseline wing-flap configuration with configurations that have blowing normal to the flap surface through small slits near the flap side edge. Vorticity contours reveal a dual vortex structure at the flap side edge for all cases. The dual vortex merges into a single vortex at approximately the mid-flap chord location. Upper surface blowing reduces the strength of the merged vortex and moves the vortex away from the upper edge. Lower surface blowing thickens the lower shear layer and weakens the merged vortex, but not as much as upper surface blowing. Side surface blowing forces the lower surface vortex farther outboard of the flap edge by effectively increasing the aerodynamic span of the flap. It is seen that there is no global aerodynamic penalty or benefit from the particular blowing configurations examined.

  11. [Elimination of isolated gingival atrophy by laterally positioned flap and free mucogingival autografts in combination with coronally positioned flap].

    PubMed

    Kovaćević, K; Leković, V

    1991-01-01

    Mucogingival surgical procedures such as laterally (horizontally) positioned flap, double papillae positioned flap and free mucogingival autografts have been recommended for the prevention and treatment of isolated gingival atrophy. These procedures can bi performed either independently or in combination with coronally positioned flap. In our study, for covering of exposed tooth roots, we applied laterally positioned flap and free mucogingival autografts in combination with coronally positioned flap. The obtained therapeutic results showed that six months after the surgery the exposure of tooth necks in patients treated by laterally positioned flap, decreased by 2.54 mm. Somewhat better results were obtained in the group of patients treated by fre mucogingival autografts in combination with coronally positioned flap. Within the same time interval, the total surface area of exposed tooth roots decreased by 59.76% in the group of patients treated by laterally positioned flap, i.e. by 62.25% in the group of patients treated by free mucogingival autografts in combination with coronally positioned flap. PMID:1785128

  12. Ex Vivo Prefabricated Rat Skin Flap Using Cell Sheets and an Arteriovenous Vascular Bundle

    PubMed Central

    Fujisawa, Daisuke; Sekine, Hidekazu; Okano, Teruo; Sakurai, Hiroyuki

    2015-01-01

    Background: Recently, research on tissue-engineered skin substitutes have been active in plastic surgery, and significant development has been made in this area over the past several decades. However, a regenerative skin flap has not been developed that could provide immediate blood flow after transplantation. Here, we make a regenerative skin flap ex vivo that is potentially suitable for microsurgical transplantation in future clinical applications. Methods: In rats, for preparing a stable vascular carrier, a femoral vascular pedicle was sandwiched between collagen sponges and inserted into a porous chamber in the abdomen. The vascular bed was harvested 3 weeks later, and extracorporeal perfusion was performed. A green fluorescent protein positive epidermal cell sheet was placed on the vascular bed. After perfusion culture, the whole construct was harvested and fixed for morphological analyses. Results: After approximately 10 days perfusion, the epidermal cell sheet cornified sufficiently. The desquamated corneum was positive for filaggrin. The basement membrane protein laminin 332 and type 4 collagen were deposited on the interface area between the vascular bed and the epidermal cell sheet. Moreover, an electron microscopic image showed anchoring junctions and keratohyalin granules. These results show that we were able to produce native-like skin. Conclusions: We have succeeded in creating regenerative skin flap ex vivo that is similar to native skin, and this technique could be applied to create various tissues in the future. PMID:26180725

  13. Folding in and out: passive morphing in flapping wings.

    PubMed

    Stowers, Amanda K; Lentink, David

    2015-04-01

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  14. Quantifying Blood Flow in the DIEP Flap: An Ultrasonographic Study

    PubMed Central

    Pennington, David G.

    2014-01-01

    Background: The maximum weight of tissue that a single perforator can perfuse remains an important question in reconstructive microsurgery. An empirically based equation, known as the flap viability index (FVI), has been established to determine what weight of tissue will survive on one or more perforators. The equation is FVI = Sum d(n)^4/W, where d is the internal diameter of each perforator and W is the final weight of the flap. It has been shown that if FVI exceeds 10, total flap survival is likely, but if under 10, partial flap necrosis is probable. The aim of this study was to measure absolute flow rates in deep inferior epigastric perforator (DIEP) flap pedicles and assess correlation with the determinants of the FVI, perforator diameter and flap weight. Methods: Color Doppler ultrasound was used to quantify arterial flow in 10 consecutive DIEP flap pedicles 24 hours after anastomosis. Results: In single-perforator DIEP flaps, flow rate was highly correlated with perforator diameter (r = 0.82, P = 0.01). Mean arterial flow rate was significantly reduced in DIEP flaps with 2 or more perforators (6 vs 38 cm3/min; P < 0.05). Conclusions: This study confirms that perforator size is a critical factor in optimizing blood flow in perforator-based free tissue transfer. Further research is required to understand the flow dynamics of perforator flaps based on multiple perforators. However, surgeons should be cognizant that a single large perforator may have substantially higher flow rates than multiple small perforators. Routine FVI calculation is recommended to ensure complete flap survival. PMID:25426345

  15. Intraoperative Flap Complications in LASIK Surgery Performed by Ophthalmology Residents

    PubMed Central

    Romero-Diaz-de-Leon, Lorena; Serna-Ojeda, Juan Carlos; Navas, Alejandro; Graue-Hernández, Enrique O.; Ramirez-Miranda, Arturo

    2016-01-01

    Purpose: To report the rate of flap-related complications in LASIK surgery performed by in-training ophthalmology residents and to analyze the risk factors for these complications. Methods: We analyzed 273 flap dissections in 145 patients from March 2013 to February 2014. We included all LASIK surgeries performed by 32 ophthalmology residents using a Moria M2 microkeratome. All the flap-related complications were noted. Comparison between both groups with and without complications was performed with an independent Student's t-test and relative risks were calculated. Results: There were 19 flap-related complications out of the 273 flap dissections (6.95%). The most common complication was incomplete flap dissection (n = 10; 3.66%), followed by free-cap (n = 5; 1.83%), and flap-buttonhole (n = 2; 0.73%). There was no significant difference between the complicated and uncomplicated cases in terms of the right versus the left eye, pachymetry results, white-to-white diameter, and spherical equivalent. But this difference was significant for mean keratometry (P = 0.008), K-min (P = 0.01), and K-max (P = 0.03) between these groups. Final visual acuity after rescheduling laser treatment was similar in both groups. Relative risks for flap-related complications were 2.03 for the first LASIK surgery (CI 95% 0.64 to 6.48; P = 0.22) and 1.26 (CI 95% 0.43 to 3.69; P = 0.66) for the surgeon's flap-related complications. Female gender presented an odds ratio of 2.48 (CI 95% 0.68 to 9.00; P = 0.16) for complications. Conclusion: Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye.

  16. 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

  17. [Free rectus abdominis muscle perforating artery flaps for reconstruction of the head and neck defects].

    PubMed

    Koshima, I; Handa, T; Satoh, Y; Akisada, K; Orita, Y; Yamamoto, H

    1995-01-01

    During the past eight years, tissue defects of the head and neck region in a total of 45 patients were repaired with free rectus abdominis muscle perforating artery flaps. These flaps are subclassified into (1) reduced musculocutaneous flaps, (2) thin reduced musculocutaneous flaps, (3) paraumbilical perforator-based flaps, and (4) thin paraumbilical perforator-based flaps. The advantages of these flaps are as follows. Since the flaps involve no or only a small portion of the rectus abdominis muscle, (1) the muscle can be left intact on the abdominal wall, and (2) a thin flap can be easily created by simple defatting of the flap. These flaps overcome the major disadvantages of the conventional rectus abdominis musculocutaneous flap, i.e., bulkiness of the flap and frequent postoperative abdominal herniation. The territory of the thin flaps is within 10 cm around the perforator. These flaps are suitable for defects in the head and neck region, because simultaneous flap elevation is possible at the time of tumor resection. Paraumbilical perforator-based flaps are suitable for young females and elderly patients. PMID:7897566

  18. 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.

  19. The gust-mitigating potential of flapping wings.

    PubMed

    Fisher, Alex; Ravi, Sridhar; Watkins, Simon; Watmuff, Jon; Wang, Chun; Liu, Hao; Petersen, Phred

    2016-01-01

    Nature's flapping-wing flyers are adept at negotiating highly turbulent flows across a wide range of scales. This is in part due to their ability to quickly detect and counterract disturbances to their flight path, but may also be assisted by an inherent aerodynamic property of flapping wings. In this study, we subject a mechanical flapping wing to replicated atmospheric turbulence across a range of flapping frequencies and turbulence intensities. By means of flow visualization and surface pressure measurements, we determine the salient effects of large-scale freestream turbulence on the flow field, and on the phase-average and fluctuating components of pressure and lift. It is shown that at lower flapping frequencies, turbulence dominates the instantaneous flow field, and the random fluctuating component of lift contributes significantly to the total lift. At higher flapping frequencies, kinematic forcing begins to dominate and the flow field becomes more consistent from cycle to cycle. Turbulence still modulates the flapping-induced flow field, as evidenced in particular by a variation in the timing and extent of leading edge vortex formation during the early downstroke. The random fluctuating component of lift contributes less to the total lift at these frequencies, providing evidence that flapping wings do indeed provide some inherent gust mitigation. PMID:27481211

  20. Free flap transfer for complex regional pain syndrome type II

    PubMed Central

    Matsuda, Ken; Kikuchi, Mamoru; Murase, Tsuyoshi; Hosokawa, Ko; Shibata, Minoru

    2014-01-01

    Abstract A patient with complex regional pain syndrome type II was successfully treated using free anterolateral thigh flap transfer with digital nerve coaptation to the cutaneous nerve of the flap. Release of the scarred tissue and soft tissue coverage with targeted sensory nerve coaptation were useful in relieving severe pain.

  1. Segmentals and Global Foreign Accent: The Japanese Flap in EFL.

    ERIC Educational Resources Information Center

    Riney, Timothy J.; Takada, Mari; Ota, Mitsuhiko

    2000-01-01

    Reports the results of research on the extent to which global foreign accent in English is related to a discrete segmental feature of pronunciation, substitution of the Japanese flap for /l/ and /r/ in two phonological environments. Results showed a strong negative correlation between a nativelike accent and flap substitution. (Author/VWL)

  2. 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

  3. Pectoralis myocutaneous flap for salvage of necrotic wounds

    SciTech Connect

    Price, J.C.; Davis, R.K.; Koltai, P.J.

    1985-02-01

    The authors have utilized six pectoralis major myocutaneous flaps in attempts to salvage extensive necrotic wounds of the pharynx and neck. The flap was employed in the following situations: massive necrosis of the entire neck skin with both carotid artery systems exposed, radiation necrosis of the neck skin with exposure of carotid artery, dehiscence of gastric pull-up from pharynx with resultant carotid exposure, failed trapezius flap in a radionecrotic oral cavity, and two cases of pharyngocutaneous fistula with extensive soft tissue necrosis. These flaps achieved healing in all cases. One death occurred 3 weeks following complete cutaneous healing secondary to a ruptured carotid pseudoaneurysm. One flap underwent total skin loss but the entirety of the muscle survived and the fistula was successfully closed with the back of the muscle being subsequently skin grafted. One case of dehiscence of the flap from oral mucosa resulted in a minor exposure of mandible with limited osteoradionecrosis controlled by topical means. This flap has performed extremely well in these precarious and difficult situations that previously may not have been salvageable. It has also been effective in abbreviating the required hospitalization and wound care. The authors conclude that the pectoralis myocutaneous flap should be the primary choice for the management of extensive postsurgical wound necrosis.

  4. 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

  5. Monitoring microvascular free flaps with tissue oxygen measurement and PET.

    PubMed

    Schrey, Aleksi R; Kinnunen, Ilpo A J; Grénman, Reidar A; Minn, Heikki R I; Aitasalo, Kalle M J

    2008-07-01

    Tissue oxygen measurement and positron emission tomography (PET) were evaluated as methods for predicting ischemia in microvascular free flaps of the head and neck. Ten patients with head and neck squamous cell cancer underwent resection of the tumour followed by microvascular reconstruction with a free flap. Tissue oxygenation of the flap (P(ti)O(2)) was continuously monitored for three postoperative (POP) days and the blood flow of the flap was assessed using oxygen-15 labelled water and PET. In three free flaps a perfusion problem was suspected due to a remarkable drop in P(ti)O(2)-values, due to two anastomosis problems and due to POP turgor. No flap losses occurred. During the blood flow measurements with PET [mean 8.5 mL 100 g(-1) min(-1 )(SD 2.5)], the mean P(ti)O(2) of the flaps [46.8 mmHg (SD 17.0)] appeared to correlate with each other in each patient (p<0.05, n=10). Tissue oxygenation measurement is a feasible monitoring system of free flaps. The perfusion-study with PET correlates with P(ti)O(2)-measurement. PMID:18231800

  6. Flap advancement coverage after excision of large mucous cysts.

    PubMed

    Shin, Eon K; Jupiter, Jesse B

    2007-06-01

    Mucous cysts are common problems seen by hand surgeons. Surgical excision of symptomatic cysts is the most commonly accepted treatment. Removal of large mucous cysts often requires simultaneous flap coverage or skin grafting for the resulting defect. We present the use of a dorsal advancement flap to permit excellent skin coverage after cyst excision with a tension-free closure. PMID:17549023

  7. The use of free flaps in skull base reconstruction.

    PubMed

    Macía, G; Picón, M; Nuñez, J; Almeida, F; Alvarez, I; Acero, J

    2016-02-01

    Skull base tumours are rare, comprising less than 1% of all tumours of the head and neck. Surgical treatment of these tumours involves the approach, the resection, and the reconstruction of the defect, which present a challenge due to the technical difficulty and anatomical complexity. A retrospective study of 17 patients with tumours involving the skull base, treated by resection and immediate reconstruction using microsurgical free flaps, is presented; 11 were men and six were women. The following types of flap were used: osteocutaneous fibula flaps, fasciocutaneous anterolateral thigh flaps, and myocutaneous latissimus dorsi flaps. The most common histology of the tumours was squamous cell carcinoma. The most frequent point of origin was the paranasal sinuses (58.8%). All of the free flaps used for reconstruction were viable. A cerebrospinal fluid fistula occurred in two patients, and in one of these cases, meningoencephalitis led to death. In conclusion, the reconstruction of large defects of the skull base after ablation requires a viable tissue that in many cases can be obtained only through the use of microvascular free flaps. The type of flap to be selected depends on the anatomical structures and size of the defect to be restored. PMID:26421478

  8. Acoustic characteristics of externally blown flap systems with mixer nozzles

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.; Dorsch, R. G.; Wagner, J. M.

    1974-01-01

    Noise tests were conducted on a large scale, cold flow model of an engine-under-the-wing externally blown flap lift augmentation system employing a mixer nozzle. The mixer nozzle was used to reduce the flap impingement velocity and, consequently, try to attenuate the additional noise caused by the interaction between the jet exhaust and the wing flap. Results from the mixer nozzle tests are summarized and compared with the results for a conical nozzle. The comparison showed that with the mixer nozzle, less noise was generated when the trailing flap was in a typical landing setting (e.g., 60 deg). However, for a takeoff flap setting (20 deg), there was little or no difference in the acoustic characteristics when either the mixer or conical nozzle was used.

  9. A method for calculating externally blown flap noise

    NASA Technical Reports Server (NTRS)

    Fink, M. R.

    1978-01-01

    Several basic noise components were described. These components are: (1) compact lift dipoles associated with the wing and flaps; (2) trailing edge noise associated with the last trailing edge; and (3) quadrupole noise associated with the undeflected exhaust jet and the free jet located downstream of the trailing edge. These noise components were combined to allow prediction of directivity and spectra for under the wing (UTW) slotted flaps with conventional or mixer nozzles, UTW slotless flaps, upper surface blowing (USB) slotless flaps, and engine in front of the wing slotted flaps. A digital computer program listing was given for this calculation method. Directivities and spectra calculated by this method were compared with free field data for UTW and USB configurations. The UTRC method best predicted the details of the measured noise emission, but the ANOP method best estimated the noise levels directly below these configurations.

  10. 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

  11. Simultaneous Extended ALT Flaps for Foot Salvage After Severe Frostbite.

    PubMed

    Fodor, Marius; Bota, Olimpiu; Fodor, Lucian

    2016-01-01

    Plantar area reconstruction represents the most challenging part of the lower limb. The anterolateral thigh (ALT) flap proved to be a versatile flap for this special area. Herein, we present the application of bilateral ALT free flaps for foot salvage after frostbite injury and long-term follow-up. Single perforator bilateral ALT flaps (304 and 320 cm) were harvested and anastomosed to posterior tibial vessels. The lateral femoral cutaneous nerve was anastomosed to the calcaneal branches of the posterior tibial nerve. The two-point discrimination test showed values from 16 to 28 mm in different flap areas 5 years later. The patient is able to walk with crutches. This is the first case report of bilateral ALT for foot salvage. PMID:26284647

  12. Works on theory of flapping wing. [considering boundary layer

    NASA Technical Reports Server (NTRS)

    Golubev, V. V.

    1980-01-01

    It is shown mathematically that taking account of the boundary layer is the only way to develop a theory of flapping wings without violating the basic observations and mathematics of hydromechanics. A theory of thrust generation by flapping wings can be developed if the conventional downstream velocity discontinuity surface is replaced with the observed Karman type vortex streets behind a flapping wing. Experiments show that the direction of such vortices is the reverse of that of conventional Karman streets. The streets form by breakdown of the boundary layer. Detailed analysis of the movements of certain birds and insects during flight 'in place' is fully consistent with this theory of the lift, thrust and drag of flapping wings. Further directions for research into flight with flapping wings are indicated.

  13. Study of Flapping Flight Using Discrete Vortex Method Based Simulations

    NASA Astrophysics Data System (ADS)

    Devranjan, S.; Jalikop, Shreyas V.; Sreenivas, K. R.

    2013-12-01

    In recent times, research in the area of flapping flight has attracted renewed interest with an endeavor to use this mechanism in Micro Air vehicles (MAVs). For a sustained and high-endurance flight, having larger payload carrying capacity we need to identify a simple and efficient flapping-kinematics. In this paper, we have used flow visualizations and Discrete Vortex Method (DVM) based simulations for the study of flapping flight. Our results highlight that simple flapping kinematics with down-stroke period (tD) shorter than the upstroke period (tU) would produce a sustained lift. We have identified optimal asymmetry ratio (Ar = tD/tU), for which flapping-wings will produce maximum lift and find that introducing optimal wing flexibility will further enhances the lift.

  14. Multi-staged flap reconstruction for complex radiation thoracic ulcer

    PubMed Central

    Valença-Filipe, Rita; Horta, Ricardo; Costa, Joana; Carvalho, Jorge; Martins, Apolino; Silva, Álvaro

    2014-01-01

    INTRODUCTION Chest wall reconstruction due to previous radiation therapy can be challenging and complex, requiring a multidisciplinary approach. PRESENTATION OF CASE The authors present the case of a 84-year-old woman with a right chest wall radionecrosis ulcer, that was submitted to an ablative surgery resulting in a full-thickness defect of 224 cm2, firstly reconstructed with a pedicled omental flap. Due to partial flap necrosis, other debridements and chest wall multi-staged flap reconstruction were performed. DISCUSSION This case highlights that the reconstructive choice should be individualized and dependent on patient and local factors. The authors advise that surgical team should work closely and be well versed in chest wall reconstruction with a variety of pedicled flaps, when a complication occurs. CONCLUSION A multi-staged flap reconstruction could be a salvage procedure for the coverage of complex, great and complicated chest wall defects due to previous radiation therapy. PMID:25437678

  15. 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

  16. Distally Based Abductor Hallucis Adipomuscular Flap for Forefoot Plantar Reconstruction.

    PubMed

    Lee, Sanglim; Kim, Min Bom; Lee, Young Ho; Baek, Jeong Kook; Baek, Goo Hyun

    2015-09-01

    Soft tissue and bone defects of the lower leg, ankle, and heel region often require coverage by local or distant flaps. The authors successfully used the distally based adipomuscular abductor hallucis flap for the treatment of 7 patients with soft tissue defect on the plantar forefoot after diabetic ulcer (n = 2), excision of melanoma at the medial forefoot (n = 3), and posttraumatic defects of the plantar forefoot (n = 2). The size of the defects ranged from 6 to 36 cm. All defects were covered successfully without major complications. The distally based adipomuscular flap from the abductor hallucis muscle provides a reliable coverage for small and moderate defects of the plantar and medial forefoot. This flap is often preferable to the use of free flaps because the surgery is rapidly performed and does not require microsurgical expertise. PMID:25565013

  17. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    2009-05-01

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  18. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  19. Immediate nipple reconstruction with thoracodorsal artery perforator flap in breast reconstruction by latissimus dorsi myocutaneous flap in patients with Poland's syndrome.

    PubMed

    He, Jinguang; Xu, Hua; Wang, Tao; Qiao, Yufei; Zhang, Yi; Dong, Jiasheng

    2016-01-01

    Loss of long-term projection is the major disadvantage of nipple reconstruction using local flaps. We report a technique of immediate perforator flap nipple reconstruction in breast reconstruction by latissimus dorsi (LD) myocutaneous flap in patients with Poland's syndrome. From March 2007 to July 2012, 12 female patients (age range, 15-21 years) underwent breast reconstructions and immediate nipple reconstructions. A thoracodorsal artery perforator (TAP) flap was simultaneously raised on the LD muscle flap and folded by itself to form the nipple. Both the LD flap and TAP flaps survived postoperatively. The nipple projection was measured by a caliper, and the average loss was 29% by the 1-year follow-up. Eleven patients considered the aesthetic appearance of reconstructed breast and nipple to be very good or good. The immediate nipple reconstruction with TAP flap could be safely performed and results in considerable satisfaction in breast reconstruction by LD myocutaneous flap in patients with Poland's syndrome. PMID:25752505

  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. 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

  2. Intravascular heparin protects muscle flaps from ischemia/reperfusion injury.

    PubMed

    Li, X; Cooley, B C; Fowler, J D; Gould, J S

    1995-01-01

    Heparin has been found to decrease ischemia/reperfusion injury in skeletal muscle and other tissue/organ systems. The timing of heparin administration to the muscle vasculature has not been explored. We investigated the use of heparinized blood as a washout solution during ischemia to reduce ischemia/reperfusion injury. A rat cutaneous maximus muscle free flap was subjected to a 10-hr period of room temperature ischemia, then was heterotopically transplanted to the groin via microsurgical revascularization to the femoral vessels. In three experimental groups, flaps were subjected to brief ex vivo perfusion with autologous heparinized blood, at 2, 5, or 8 hr into the 10-hr ischemic interval. In the two other groups, the flaps were not perfused, and the animals were systemically heparinized either before ischemia or before transplantation, respectively. A control group underwent no flap perfusion or systemic heparinization. After transplantation, flaps were given a 48-hr period of in vivo reperfusion, then were harvested for evaluation. Flaps undergoing ex vivo perfusion or preischemic heparinization had no significant differences in weight gain (edema) compared with flaps receiving posttransplant heparinization or no heparinization (controls). The dehydrogenase staining of muscle biopsies was significantly faster (indicative of viable tissue) for perfused flaps and the flaps for which the animals received preischemic heparinization, when compared with flaps for which the animals received posttransplant heparinization or no heparinization. From these results, we conclude that heparin offers protection from ischemia/reperfusion injury when it can be introduced into the vascular network either prior to or during the ischemia period. These findings suggest the possibility of using heparinized washout solutions to enhance survival in amputated extremities. PMID:7783611

  3. Reconstructive Surgery for Severe Penile Inadequacy: Phalloplasty with a Free Radial Forearm Flap or a Pedicled Anterolateral Thigh Flap

    PubMed Central

    Lumen, N.; Monstrey, S.; Ceulemans, P.; van Laecke, E.; Hoebeke, P.

    2008-01-01

    Objectives. Severe penile inadequacy in adolescents is rare. Phallic reconstruction to treat this devastating condition is a major challenge to the reconstructive surgeon. Phallic reconstruction using the free radial forearm flap (RFF) or the pedicled anterolateral thigh flap (ALTF) has been routinely used in female-to-male transsexuals. Recently we started to use these techniques in the treatment of severe penile inadequacy. Methods. Eleven males (age 15 to 42 years) were treated with a phallic reconstruction. The RFF is our method of choice; the ALTF is an alternative when a free flap is contraindicated or less desired by the patient. The RFF was used in 7 patients, the ALTF in 4 patients. Mean followup was 25 months (range: 4–49 months). Aesthetic and functional results were evaluated. Results. There were no complications related to the flap. Aesthetic results were judged as “good” in 9 patients and “moderate” in 2 patients. Sensitivity in the RFF was superior compared to the ALTF. Four patients developed urinary complications (stricture and/or fistula). Six patients underwent erectile implant surgery. In 2 patients the erectile implant had to be removed due to infection or erosion. Conclusion. In case of severe penile inadequacy due to whatever condition, a phalloplasty is the preferred treatment nowadays. The free radial forearm flap is still the method of choice. The anterolateral thigh flap can be a good alternative, especially when free flaps are contraindicated, but sensitivity is markedly inferior in these flaps. PMID:19009034

  4. Pressure Distributions for the GA(W)-2 Airfoil with 20% Aileron, 25% Slotted Flap and 30% Fowler Flap

    NASA Technical Reports Server (NTRS)

    Wentz, W. H., Jr.; Fiscko, K. A.

    1978-01-01

    Surface pressure distributions were measured for the 13% thick GA(W)-2 airfoil section fitted with 20% aileron, 25% slotted flap and 30% Fowler flap. All tests were conducted at a Reynolds number of 2.2 x 10 to the 6th power and a Mach number of 0.13. Pressure distribution and force and moment coefficient measurements are compared with theoretical results for a number of cases. Agreement between theory and experiment is generally good for low angles of attack and small flap deflections. For high angles and large flap deflections where regions of separation are present, the theory is inadequate. Theoretical drag predictions are poor for all flap-extended cases.

  5. Structural insights into 5‧ flap DNA unwinding and incision by the human FAN1 dimer

    NASA Astrophysics Data System (ADS)

    Zhao, Qi; Xue, Xiaoyu; Longerich, Simonne; Sung, Patrick; Xiong, Yong

    2014-12-01

    Human FANCD2-associated nuclease 1 (FAN1) is a DNA structure-specific nuclease involved in the processing of DNA interstrand crosslinks (ICLs). FAN1 maintains genomic stability and prevents tissue decline in multiple organs, yet it confers ICL-induced anti-cancer drug resistance in several cancer subtypes. Here we report three crystal structures of human FAN1 in complex with a 5‧ flap DNA substrate, showing that two FAN1 molecules form a head-to-tail dimer to locate the lesion, orient the DNA and unwind a 5‧ flap for subsequent incision. Biochemical experiments further validate our model for FAN1 action, as structure-informed mutations that disrupt protein dimerization, substrate orientation or flap unwinding impair the structure-specific nuclease activity. Our work elucidates essential aspects of FAN1-DNA lesion recognition and a unique mechanism of incision. These structural insights shed light on the cellular mechanisms underlying organ degeneration protection and cancer drug resistance mediated by FAN1.

  6. Aeroacoustic Measurements of a Wing-Flap Configuration

    NASA Technical Reports Server (NTRS)

    Meadows, Kristine R.; Brooks, Thomas F.; Humphreys, William M.; Hunter, William H.; Gerhold, Carl H.

    1997-01-01

    Aeroacoustic measurements are being conducted to investigate the mechanisms of sound generation in high-lift wing configurations, and initial results are presented. The model is approximately 6 percent of a full scale configuration, and consists of a main element NACA 63(sub 2) - 215 wing section and a 30 percent chord half-span flap. Flow speeds up to Mach 0.17 are tested at Reynolds number up to approximately 1.7 million. Results are presented for a main element at a 16 degree angle of attack, and flap deflection angles of 29 and 39 degrees. The measurement systems developed for this test include two directional arrays used to localize and characterize the noise sources, and an array of unsteady surface pressure transducers used to characterize wave number spectra and correlate with acoustic measurements. Sound source localization maps show that locally dominant noise sources exist on the flap-side edge. The spectral distribution of the noise sources along the flap-side edge shows a decrease in frequency of the locally dominant noise source with increasing distance downstream of the flap leading edge. Spectra are presented which show general spectral characteristics of Strouhal dependent flow-surface interaction noise. However, the appearance of multiple broadband tonal features at high frequency indicates the presence of aeroacoustic phenomenon following different scaling characteristics. The scaling of the high frequency aeroacoustic phenomenon is found to be different for the two flap deflection angles tested. Unsteady surface pressure measurements in the vicinity of the flap edge show high coherence levels between adjacent sensors on the flap-side edge and on the flap edge upper surface in a region which corresponds closely to where the flap-side edge vortex begins to spill over to the flap upper surface. The frequency ranges where these high levels of coherence occur on the flap surface are consistent with the frequency ranges in which dominant features

  7. 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

  8. Uncertainty Analysis for a Jet Flap Airfoil

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Cruz, Josue

    2006-01-01

    An analysis of variance (ANOVA) study was performed to quantify the potential uncertainties of lift and pitching moment coefficient calculations from a computational fluid dynamics code, relative to an experiment, for a jet flap airfoil configuration. Uncertainties due to a number of factors including grid density, angle of attack and jet flap blowing coefficient were examined. The ANOVA software produced a numerical model of the input coefficient data, as functions of the selected factors, to a user-specified order (linear, 2-factor interference, quadratic, or cubic). Residuals between the model and actual data were also produced at each of the input conditions, and uncertainty confidence intervals (in the form of Least Significant Differences or LSD) for experimental, computational, and combined experimental / computational data sets were computed. The LSD bars indicate the smallest resolvable differences in the functional values (lift or pitching moment coefficient) attributable solely to changes in independent variable, given just the input data points from selected data sets. The software also provided a collection of diagnostics which evaluate the suitability of the input data set for use within the ANOVA process, and which examine the behavior of the resultant data, possibly suggesting transformations which should be applied to the data to reduce the LSD. The results illustrate some of the key features of, and results from, the uncertainty analysis studies, including the use of both numerical (continuous) and categorical (discrete) factors, the effects of the number and range of the input data points, and the effects of the number of factors considered simultaneously.

  9. 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.

  10. Flapping flight: effect of asymmetric kinematics

    NASA Astrophysics Data System (ADS)

    Pande, Nakul; Krithivasan, Siddharth; K. R., Sreenivas

    2014-11-01

    Flapping flight has received considerable attention in the past with its relevance in the design of micro-air vehicles. In this regard, asymmetric flapping of wings offers simple kinematics. Nevertheless, it leads to symmetry-breaking in the flow field and generation of sustained lift. It has been observed previously with flow visualization experiments and Discrete Vortex Method (DVM) simulations that if the down-stroke time period is lesser than the up-stroke time, there is a net downward momentum imparted to the fluid. This is seen as a switching the flow field from a four-jet (symmetric) to a two-jet (asymmetric) configuration when the stroke-time ratio is progressively varied. This symmetry breaking has been studied experimentally using Particle Image Velocimetry (PIV) across a range of Reynolds Numbers and asymmetry ratios. Results are also corroborated with results from 3-D numerical simulations. Study helps in shedding light on the effectiveness of asymmetric kinematics as a lift generation mechanism.

  11. Design and construction of pre-stressed piezoelectric unimorph for trailing edge flap actuation

    NASA Astrophysics Data System (ADS)

    Kang, Lae-Hyong; Lee, Jong-Won; Han, Jae-Hung

    2009-07-01

    This paper presents a trailing edge flap actuation mechanism using a novel pre-stressed piezoelectric unimorph, PUMPS (Piezoelectric Unimorph with Mechanically Pre-stressed Substrate). Experimental evaluation of actuation performance such as force-displacement characteristics of PUMPS actuators showed that the performance of PUMPS satisfied the requirements for trailing edge flap actuation. Subsequently, flap actuation mechanisms were designed and constructed with several slot types in the flaps, and stacked PUMPS actuators were applied to the flap actuation mechanisms. Experimental study of the test wing models with four flaps was accomplished, and the flap angle was achieved up to +/-5.5° within 15Hz under maximum applicable voltage.

  12. Temporal muscle flap in reconstruction of maxillo-facial tissues

    PubMed Central

    Krzymański, Grzegorz; Dąbrowski, Jarosław; Przybysz, Jan; Domański, Wojciech; Biernacka, Barbara

    2012-01-01

    Aim of the study Presents our experience in reconstruction of postsurgical defects with use of temporal muscle flap. Material and methods In the years 1996–2010 we treated 10 patients with malignant neoplasms of maxillo-facial region. Following tumor removal the fascia-muscle flaps of temporal muscle were used for reconstruction. Temporal muscle flaps were applied in 5 cases for reconstructing the defect of eye socket tissue after extensive resections and in the other 5 patients was used for reconstructing the defect of palate following maxillary resections. Results All the flaps of temporal muscle that were used for reconstructing eye sockets incorporated with no local reaction. In one case of flap applied into the oral cavity for tightly separate from nasal, partial necrosis of flap's edge and oro-nasal fistula occurred. Conclusions Fascia-muscular flap of temporal muscle is a simple, easy and effective method of tissue reconstruction in maxillo-facial region following extensive oncologic procedures. PMID:23788888

  13. 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

  14. Vascular Endothelium Growth Factor, Surgical Delay, and Skin Flap Survival

    PubMed Central

    Lineaweaver, William C.; Lei, Man-Ping; Mustain, William; Oswald, Tanya M.; Cui, Dongmei; Zhang, Feng

    2004-01-01

    Objective: Cytokines may be a mechanism by which surgical delay can increase flap survival. We previously found that preoperative vascular endothelium growth factor (VEGF) administration in the rat transverse rectus abdominis myocutaneous (TRAM) flap could improve skin paddle survival. In this study, we used partial elevation of the rat TRAM flap as a surgical delay to assess endogenous cytokine expression and tissue survival comparable to undelayed TRAM flaps. Methods: In Part I, TRAM flaps underwent surgical delay procedures; 7 days later, the flaps were completely elevated and reinset. At the same time, other flaps were raised and reinset without delay. Skin paddle survival in both groups was evaluated at 7 days. In Part II, skin biopsies from TRAM zones I to IV were taken at the time of delay and at intervals of 12, 24, 48, and 72 hours. Specimens were assessed for selected cytokine gene expression by reverse transcription-polymerase chain reaction analysis (TR-PCR). Results: Surgical delay significantly (P < 0.001) increased skin paddle survival in the delayed TRAM flaps (16.14 ± 1.53 cm, 81.9%) compared with undelayed flaps (7.68 ± 3.16 cm, 40.9%). TGF-β and PDGF expressions were not changed by surgical delay, but basic fibroblast growth factor (bFGF) and VEGF expressions increased significantly (P < 0.05 and P < 0.01) after delay. Conclusions: In the rat TRAM model, surgical delay resulted in increased VEGF expression and increased skin paddle survival. These results correlate with previous studies showing the preoperative injection of VEGF increases skin paddle survival. VEGF may be an important element in the delay phenomenon and may be an agent for pharmacological delay. PMID:15166966

  15. 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

  16. The flap by flap dissection in terminal ballistic applied to less lethal weapons.

    PubMed

    de Freminville, Humbert; Rongieras, Fréderic; Prat, Nicolas; Voiglio, Eric J

    2011-06-01

    Medical examiners often have to solve questions such as firing distance and bullet trajectory for lethal weapons. Knowledge in the field of terminal ballistics has increased during the last 30 years and layer by layer dissection reveals superficial wounds that can be linked with the permanent cavity. At the end of the 1990s, terminal ballistics also focused on less lethal weapons and their wounds. Here, 2 different less lethal weapons with single bullets were tested on nonembalmed and undressed cadavers (N = 26) at different ranges and speeds. We have developed a technique for dissection which we call flap by flap dissection that reveals the advantage of the bullet-skin-bone entity, the absence of wounds linking its components and range of less lethal weapons. PMID:20110799

  17. Extracorporeal Free Flap Perfusion in Case of Prolonged Ischemia Time

    PubMed Central

    Präbst, K.; Beier, J. P.; Meyer, A.; Horch, R. E.

    2016-01-01

    Summary: In free flap surgery, a clinically established concept still has to be found for the reduction of ischemia-related cell damage in the case of prolonged ischemia. Although promising results using extracorporeal free flap perfusion in the laboratory have been published in the past, until now this concept has not yet paved its way into clinical routine. This might be due to the complexity of perfusion systems and a lack of standardized tools. Here, we want to present the results of the first extracorporeal free flap perfusion in a clinical setting using a simple approach without the application of a complex perfusion machinery. PMID:27200244

  18. Comparison of calculated and measured helicopter rotor lateral flapping angles

    NASA Technical Reports Server (NTRS)

    Johnson, W.

    1980-01-01

    Calculated and measured values of helicopter rotor flapping angles in forward flight are compared for a model rotor in a wind tunnel and an autogiro in gliding flight. The lateral flapping angles can be accurately predicted when a calculation of the nonuniform wake-induced velocity is used. At low advance ratios, it is also necessary to use a free wake geometry calculation. For the cases considered, the tip vortices in the rotor wake remain very close to the tip-path plane, so the calculated values of the flapping motion are sensitive to the fine details of the wake structure, specifically the viscous core radius of the tip vortices.

  19. Spectacles under Pedicles: Eyewear Modification with the Paramedian Forehead Flap.

    PubMed

    Qu, Linda T; Kelpin, John P; Eichhorn, Mitchell G; Komorowska-Timek, Ewa

    2016-08-01

    The paramedian forehead flap is a widely used method of nasal reconstruction. The flap requires a bridge of tissue from forehead to the nose, for a period of 2 to 3 weeks, before it can be divided at a second procedure. During this time, patients often have difficulty positioning and wearing their eyewear underneath the pedicle of the flap. Here we present a novel approach to the problem. It requires only a simple modification to the patient's eyewear and greatly facilitates wear and removal. PMID:27622084

  20. Spectacles under Pedicles: Eyewear Modification with the Paramedian Forehead Flap

    PubMed Central

    Qu, Linda T.; Kelpin, John P.; Komorowska-Timek, Ewa

    2016-01-01

    Summary: The paramedian forehead flap is a widely used method of nasal reconstruction. The flap requires a bridge of tissue from forehead to the nose, for a period of 2 to 3 weeks, before it can be divided at a second procedure. During this time, patients often have difficulty positioning and wearing their eyewear underneath the pedicle of the flap. Here we present a novel approach to the problem. It requires only a simple modification to the patient’s eyewear and greatly facilitates wear and removal.

  1. Tolerance of gastric mucosal flap to postoperative irradiation

    SciTech Connect

    Devineni, V.R.; Hayden, R.; Fredrickson, J.; Sicard, G. )

    1991-05-01

    When malignant lesions of the oral cavity, base of tongue, and oropharynx are treated with radical resection, adequate reconstruction is required. The free gastric mucosal flap with microvascular transfer is being used with increasing frequency at Washington University Medical Center. Because of the advanced nature of the primary lesions, most patients also require postoperative radiation therapy. In this paper the tolerance of the gastric mucosal flap to postoperative radiation therapy is reviewed. The changes resulting from radiation therapy in the mucosal flap were found to be acceptable, and no major complications were encountered.

  2. 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.

  3. Upper lip reconstruction with a radial forearm free flap.

    PubMed

    Mandrekas, A D; Page, R; O'Neill, T J

    1994-05-01

    Although there are several methods available for lip reconstruction, the challenge for plastic surgeons is young children, in whom there is no laxity of skin. Free-tissue transfer is the method of choice in young children to avoid large unsightly scars and severe distortion of facial appearance. The radial forearm free flap is an ideal flap for lip reconstruction because it is thin and can be folded to restore both the skin and the inner lining. We present reconstruction of half the upper lip in a young girl, in whom the radial forearm free flap was folded to replace the full-thickness defect. PMID:7918852

  4. 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

  5. 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

  6. Does body mass index matter while selecting the flap type for pharyngeal reconstructions?

    PubMed

    Calli, Caglar; Teknos, Theodoros N; Agrawal, Amit; Schuller, David E; Ozer, Enver; Songu, Murat

    2014-05-01

    The aim of our study was to investigate the effect of patient-related factors, such as the body mass index (BMI) and tumor size, in selecting the flap type for the reconstruction of pharyngeal defects. This retrospective review included 182 patients with pharyngeal defect reconstructions with free and pedicled flaps at the Ohio State University from January 2005 to December 2008. We conducted a retrospective comparison of variety of different flap reconstruction techniques. We compared different flap reconstruction with BMI and tumor size without functional outcome such as swallowing and speech data. Although there was no statistically significant correlation (P > 0.05) when comparing the free flaps with pedicled flaps according to the BMI and tumor size, there was an obvious tendency to prefer radial forearm free flap over anterolateral thigh free flap in patients who are overweight and those with obesity with a ratio of 32:3. In the same group of patients, a similar tendency was observed to prefer fibular free flap over iliac crest free flap with a ratio of 14:5, whereas the ratio was becoming 3:5 in favor of iliac crest free flap over fibular free flap in patients with BMI of 24 or lower. Despite the fact that surgeons' experience with a certain flap type is one of the most important factors while determining which flap to reconstruct, BMI might have a significant impact while selecting the free flap types for the reconstruction of pharyngeal defects. PMID:24785755

  7. Comparison of Modified Limberg Flap and Karydakis Flap Operations in Pilonidal Sinus Surgery: Prospective Randomized Study

    PubMed Central

    Tokac, Mehmet; Dumlu, Ersin Gurkan; Aydin, Murat Seyit; Yalcın, Abdussamed; Kilic, Mehmet

    2015-01-01

    The best surgical technique for pilonidal sinus disease (PSD) is still disputed. The objective of this prospective randomized study is to compare the short and long-term results of modified Limberg flap and Karydakis flap surgeries that have been widely used in recent years. Ninety one patients were included in the study. The patients were divided into two groups: modified Limberg flap (MLF; n = 46) and Karydakis flap (KF; n = 45). Preoperative findings of the patients, their surgical findings, and short and long-term postoperative findings were recorded and statistically compared. While no significant difference was discovered between the groups in terms of postoperative analgesic need, hospital stay, postoperative infection rate, drain stay time, painless sitting time, painless toilet-sitting time, and painless walking time, return to work or school time was shorter in the MLF group compared with the KF group (20.61 ± 7.89 days, 23.29 ± 6.42, respectively; P < 0.05). Cosmetically, the visual analog scale (VAS) of the KF group was significantly higher than that of the MLF group (VAS score 7.12 ± 1.28, 5.45 ± 1.77, respectively; P < 0.05). Considering recurrence rates, no statistically significant difference was found between the groups. Our study found out that short and long-term results of the MLF and KF procedures are similar. We believe both methods can be safely used in surgical PSD treatment given that in the MLF procedure, shorter return-to-work time is achieved, while the procedure provides better cosmetic results. PMID:26011208

  8. Facial Artery Musculomucosal (FAMM) flap for nasal lining in reconstruction of large full thickness lateral nasal defects

    PubMed Central

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2015-01-01

    Obviously, restoring the nasal lining is a great challenge in the reconstruction of nasal defects. Full thickness nasal defects usually require special flaps for reconstructing the nasal lining. Intranasal mucosal flaps, hinge over flaps, perinasal second flaps, folded or second forehead flaps and finally free flaps are examples that can be used for this purpose. Moreover, the case presented in this article expresses a new role for the superiorly based Facial Artery Musculomucosal (FAMM) flap in this topic. Furthermore, mucosal island variant of this flap is presented to reduce the tension on this flap while restoring the nasal lining in large full thickness nasal defect. PMID:26566439

  9. 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

  10. 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

  11. Soap Films Burst Like Flapping Flags

    NASA Astrophysics Data System (ADS)

    Lhuissier, Henri; Villermaux, Emmanuel

    2009-07-01

    When punctured, a flat soap film bursts by opening a hole driven by liquid surface tension. The hole rim does not, however, remain smooth but soon develops indentations at the tip of which ligaments form, ultimately breaking and leaving the initially connex film into a mist of disjointed drops. We report on original observations showing that these indentations result from a flaglike instability between the film and the surrounding atmosphere inducing an oscillatory motion out of its plane. Just like a flag edge flaps in the wind, the film is successively accelerated on both sides perpendicularly to its plane, inducing film thickness modulations and centrifuging liquid ligaments that finally pinch off to form the observed spray. This effect exemplifies how the dynamics of fragile objects such as thin liquid films is sensitive to their embedding medium.

  12. Computational Investigation of Flap-Edges

    NASA Technical Reports Server (NTRS)

    Cummings, Russell M.

    1997-01-01

    The current study expands the application of computational fluid dynamics to three-dimensional multi-element high-lift systems by investigating the flow dynamics created by a slat edge. Flow is computed over a three-element high-lift configuration using an incompressible Navier-Stokes solver with structured, overset grids processed assuming full turbulence with the one-equation Baldwin-Barth turbulence model. The geometry consists of an unswept wing, which spans the wind tunnel test section, a single element half-span Fowler flap, and a three-quarter span slat. Results are presented for the wing configured for landing with a chord based Reynolds number of 3.7 million. Results for the three-quarter span slat case are compared to the full-span slat and two-dimensional investigations.

  13. Oblique waves lift the flapping flag.

    PubMed

    Hœpffner, Jérôme; Naka, Yoshitsugu

    2011-11-01

    The flapping of the flag is a classical model problem for the understanding of fluid-structure interaction: How does the flat state lose stability? Why do the nonlinear effects induce hysteretic behavior? We show in this Letter that, in contrast with the commonly studied model, the full three-dimensional flag with gravity has no stationary state whose stability can be formally studied: The waves are oblique and must immediately be of large amplitude. The remarkable structure of these waves results from the interplay of weight, geometry, and aerodynamic forces. This pattern is a key element in the force balance which allows the flag to hold and fly in the wind: Large amplitude oblique waves are responsible for lift. PMID:22181612

  14. Splash jet and slamming generated by a rotating flap

    NASA Astrophysics Data System (ADS)

    Sun, S. Y.; Sun, S. L.; Ren, H. L.; Wu, G. X.

    2015-09-01

    The hydrodynamic problem of slamming generated by a rotating flap, commonly known as Oyster in the wave energy sector, plunging into water, is analysed based on the incompressible velocity potential theory. The problem is solved through the boundary element method in the time domain. Two typical case studies are undertaken. One is the flap plunging into calm water and the other into an incoming wave. The splash jet formed during the flap plunging is included in the simulation. When the jet meets the main flow, it is treated through the domain decomposition method without taking account the secondary impact, which is similar to the mathematical method of Riemann's second sheet in the complex plane. The problem is solved in each non-overlapping subdomain, and the velocity and pressure continuity condition is imposed on the interface of the subdomains. Detailed results for the flap plunging into water with different velocities or accelerations are provided. The gravity and wave effects are also investigated.

  15. The Vascularized Medial Femoral Corticoperiosteal Flap for Thumb Reconstruction

    PubMed Central

    Amin, Kavit; Darhouse, Nagham; Sivakumar, Bran; Floyd, David

    2015-01-01

    Summary: We present an interesting method of shaping a vascularized medial femoral condyle (MFC) flap into a “neophalanx” for phalangeal reconstruction. Our patient presented with limited strength and function secondary to fracture nonunion of the proximal phalanx of the dominant thumb. Following excision of the pseudarthrosis, an MFC corticoperiosteal flap was harvested, sculpted into a prism shape and inset. The superomedial genicular pedicle was anastomosed to the princeps pollicis artery and a cephalic tributary. On follow-up, new bone growth was seen on radiographs and the patient had substantially improved function, with full metacarpophalangeal extension, a Kapandji score of 9, and a markedly reduced Disabilities of the Arm, Shoulder and Hand score of 2.68. The MFC flap is useful for reconstruction of bony defects, with minimal donor morbidity. This versatile vascularized flap can be crafted to requisite shapes and is useful for small defects in the hand, including phalangeal reconstruction. PMID:26495205

  16. Development of Variable Camber Continuous Trailing Edge Flap System

    NASA Technical Reports Server (NTRS)

    Urnes, Jim, Sr.; Nguyen, Nhan T.; Dykman, John

    2012-01-01

    This presentation describes the current status of the joint NASA/Boeing collaboration on the development of a variable camber continuous trailing edge flap system for use in wing shaping control for cruise drag reduction.

  17. Vortex Flap Technology: a Stability and Control Assessment

    NASA Technical Reports Server (NTRS)

    Carey, K. M.; Erickson, G. E.

    1984-01-01

    A comprehensive low-speed wind tunnel investigation was performed of leading edge vortex flaps applied to representative aircraft configurations. A determination was made of the effects of analytically- and empirically-designed vortex flaps on the static longitudinal and lateral-directional aerodynamics, stability, and control characteristics of fighter wings having leading-edge sweep angles of 45 to 76.5 degrees. The sensitivity to several configuration modifications was assessed, which included the effects of flap planform, leading- and trailing-edge flap deflection angles, wing location on the fuselage, forebody strakes, canards, and centerline and outboard vertical tails. Six-component forces and moments, wing surface static pressure distributions, and surface flow patterns were obtained using the Northrop 21- by 30-inch low-speed wind tunnel.

  18. Noninvasive Free Flap Monitoring Using Eulerian Video Magnification

    PubMed Central

    Liu, Yuan Fang; Vuong, Christopher; Walker, Paul Charles; Peterson, Nathaniel Ray; Inman, Jared Christian; Filho, Pedro Alcantara Andrade; Lee, Steve Choon-Sung

    2016-01-01

    Eulerian Video Magnification (EVM) can enhance subtle changes in videos to reveal what was once invisible to the naked eye. In this proof of concept study, we investigated using EVM as a novel form of free flap monitoring. Free flaps with skin paddles were filmed in the operating room with manipulation of their pedicles. In a representative 77-year-old female who received a latissimus dorsi-serratus-rib composite free flap, EVM was able to detect blockage of arterial or venous supply instantaneously, providing a visible representation through degree of color change in videos. EVM has the potential to serve as a powerful free flap monitoring tool with the benefit of being noninvasive, sensitive, easy-to-use, and nearly cost-free. PMID:27092284

  19. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... wing flap control lever settings corresponding to those positions must be positively located such that a definite change of direction of movement of the lever is necessary to select settings beyond...

  20. Free posterior tibial flap reconstruction for hypopharyngeal squamous cell carcinoma

    PubMed Central

    2014-01-01

    Objectives The aim of this article was to determine outcomes in patients with squamous cell carcinoma of the hypopharynx (SCCHP) in whom the free posterior tibial flap was used for primary reconstruction of hypopharynx defects after cancer resection. Subjects and methods Between August 2009 and February 2012, 10 patients with SCCHP underwent posterior tibial flap reconstruction for hypopharynx defects. The corresponding clinical data were retrospectively collected and analyzed. Results Despite the multistep and time-consuming procedure, the posterior tibial flap survival rate was 100%. Operation-induced complications did not occur in four patients. Six patients developed postoperative hypoproteinemia, four patients developed postoperative pulmonary infections, and four patients developed pharyngeal fistula. The pharyngeal and laryngeal functions of all patients were preserved. Conclusion Our experience demonstrates that the posterior tibial flap is a safe and reliable choice for the reconstruction of hypopharynx defects. PMID:24884631

  1. Optimization of Kinematics of a Flapping Wing Mechanism

    NASA Astrophysics Data System (ADS)

    George, Ryan; Thomson, Scott; Mattson, Christopher; Colton, Mark; Tree, Mike

    2010-11-01

    Flapping flight offers several potential advantages over conventional fixed wing flight, such as agility and maneuverability in confined spaces, potentially decreased noise and detectability, and hovering capability. In this presentation, a water tunnel-based flapping wing apparatus is introduced that allows for arbitrary wing trajectories in three rotational degrees of freedom and simultaneous measurements of lift and thrust production. An optimal flapping trajectory for takeoff is found using hardware-in-the-loop optimization methodology. Wing motion derived from high-speed imaging of a ladybug during takeoff is used as a first iteration of the hardware-in-the-loop optimization. Using real-time force measurements and a gradient-based optimization approach, the algorithm searches for the optimal trajectory for a variety of parameters such as lift or efficiency. Hardware performance is assessed. Results from the optimization routine, including the final flapping trajectory are reported for both rigid and compliant wings.

  2. Breast reconstruction with the fasciocutaneous infragluteal free flap (FCI).

    PubMed

    Papp, Christoph; Windhofer, Christian; Gruber, Sabine

    2007-02-01

    Thin patients who will not accept breast reconstruction with foreign material may not have enough tissue associated with the TRAM or latissimus muscle to achieve an acceptable reconstruction. We feel the next choice is tissue from the infragluteal region raised and moved as a free fasciocutaneous flap (FCI) based on the descending branch of the inferior gluteal artery. This (FCI) has not been described for this to our knowledge. Thirty-five FCI flaps were done for 28 patients between 1998 and 2005 for autologous breast reconstruction, as well as simultaneous augmentation of the contralateral breast in 4 of these patients. There was no flap loss. Complications include seroma, scar pain, and fat necrosis and are reported and discussed. We suggest that the FCI flap be considered as a worthy alternative for autologous breast reconstruction in thin patients. PMID:17245137

  3. 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

  4. High-flaps for natural laminar flow airfoils

    NASA Technical Reports Server (NTRS)

    Morgan, Harry L.

    1986-01-01

    A review of the NACA and NASA low-drag airfoil research is presented with particular emphasis given to the development of mechanical high-lift flap systems and their application to general aviation aircraft. These flap systems include split, plain, single-slotted, and double-slotted trailing-edge flaps plus slat and Krueger leading-edge devices. The recently developed continuous variable-camber high-lift mechanism is also described. The state-of-the-art of theoretical methods for the design and analysis of multi-component airfoils in two-dimensional subsonic flow is discussed, and a detailed description of the Langley MCARF (Multi-Component Airfoil Analysis Program) computer code is presented. The results of a recent effort to design a single- and double-slotted flap system for the NASA high speed natural laminar flow (HSNLF) (1)-0213 airfoil using the MCARF code are presented to demonstrate the capabilities and limitations of the code.

  5. Flap motion of helicopter rotors with novel, dynamic stall model

    NASA Astrophysics Data System (ADS)

    Han, Wei; Liu, Jie; Liu, Chun; Chen, Lei; Su, Xichao; Zhao, Peng

    2016-07-01

    In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  6. Buccinator Myomucosal Flap for Treatment of Osteoradionecrosis of the Mandible

    PubMed Central

    Woo, Seung Hoon

    2016-01-01

    The use of a myomucosal flap from the buccinator muscle is a valuable reconstruction method for intraoral defects. In this paper, we report the clinical advantages of using a buccinator myomucosal flap for the treatment of partial mandibular defects caused by osteoradionecrosis. We implemented a buccinator myomucosal flap for the reconstruction of a partial mandibular defect in a 55-year-old man with tonsil cancer and partial mandibular defects caused by osteoradionecrosis. The total operating time was 90 minutes. Twelve months after the reconstruction, the patient remains free of disease. A buccinator myomucosal flap can be used for the reconstruction of partial mandibular defects caused by osteoradionecrosis. It is a reliable method for reconstructing small mandibular defects. PMID:26976033

  7. Numerical simulation of self-propulsion of flapping flexible plates

    NASA Astrophysics Data System (ADS)

    Lu, Xi-Yun; Hua, Ru-Nan; Fluid Mechanics Team

    2012-11-01

    Self-propulsion of flapping flexible plates has been studied numerically by means of an immersed boundary-lattice Boltzmann method for the fluid dynamics around the plate and a finite element method for the deformable flapping motion of the plate. Both the two- and three-dimensional flexible plates are investigated to reveal the propulsion properties and their differences. As a result of the fluid-plate interaction, three typical movement regimes have been identified and can be briefly described as forward, backward, and irregular movements which mainly depend on the flapping amplitude and bending rigidity. It is found that there exists an optimal range of the bending rigidity for large propulsive speed or high efficiency in the forward movement regime, consistent with the observation and measurement of swimming and flying animals. The results obtained in this study provide physical insights into understanding of the propulsive mechanisms of the flapping fin or wing of animals.

  8. Post-facelift flap necrosis treatment using charged polystyrene microspheres

    PubMed Central

    Weissman, Oren; Farber, Nimrod; Remer, Eric; Tessone, Ariel; Trivizki, Omer; Bank, Jonathan; Winkler, Eyal; Zilinsky, Isaac; Haik, Josef

    2013-01-01

    BACKGROUND: Flap necrosis following facial rhytidectomy constitutes a vexing and grievous complication to the patient and the surgeon. Treatment modalities that can expedite wound healing and re-epithelialization rates are highly desired. OBJECTIVES: To assess wound healing and re-epithelialization rates of open wounds following postrhytidectomy flap necrosis treated with commercially available charged polystyrene microspheres (Polyheal-1, Polyheal Ltd, Israel). METHODS: Flap necrosis following rhytidectomy with open wounds in three female patients were treated using dressings soaked with Polyheal-1. Wound closure rates were documented. RESULTS: The wounds demonstrated both accelerated granulation tissue formation and rapid re-epithelialization rates. No complications or side effects were encountered. CONCLUSIONS: Charged polystyrene microspheres may offer a new and efficacious way to treat open wounds due to flap necrosis following facial rhytidectomy. Further research with larger patient numbers is still needed to verify these findings. PMID:24431937

  9. Computer study of a jet flap ASTVOL 'Harrier'

    NASA Technical Reports Server (NTRS)

    Wilson, S. B., III; Liperra, L. D.

    1984-01-01

    A study of the costs/benefits trade-off was conducted for an Advanced Supersonic Short Takeoff and Vertical Landing (ASTOVL) aircraft incorporating a jet flap. The data used were the theory of jet flaps and high aspect ratio nozzles, experience with a V/STOL aircraft study performed for NASA Ames Research Center in February 1982, and a high performance aircraft-synthesis program (ACSYNT). The methodology was to accurately model the supersonic Harrier V/STOL aircraft design on ACSYNT, and then modify the design by both adding high aspect-ratio nozzles in place of the rear (core-flow) nozzles on the Pegasus-type turbofan engine, and integrating these nozzles on each wing's trailing edge, thus creating a jet flap. The predicted performance advantages (increase in maximum lift coefficient with flap deflection and horizontal thrust recovery) were traded off against the disadvantages (additional weight and thrust loss due to ducting) on two representative missions.

  10. 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.

  11. [Reconstruction of the thumb using a forearm osseofasciocutaneous reverse flap].

    PubMed

    Jevtović, Dobrica; Dordević, Boban; Gacević, Milomir; Sijan, Goran

    2002-01-01

    This paper presents the experiences of the thumb reconstruction with osteofasciocutaneous reverse flap (OFCR flap). In the period between 1987 and 2000 the OFCR flap was used in 15 patients. The youngest of them was 18 and the oldest was 38 years of age. The average age was 25.4. All the patients had posttraumatic amputations. Defects on proximal phalangae and a part of metacarpal bone occurred in two cases. In one case there was an amputation on the base level of proximal phalanx and the metacarpophalangeal (MPH) joint was preserved. In all cases of reconstruction the OFCR flap was used, which included antebrachial skin nervs that were anastomosed with digital nerv. The flap nutrition was carried out through the reverse circulation of a. radialis, and the venous drainage through the comitant vein of a. radialis. Superficial veins were not anastomosed. Secondary defects were covered with a free skin graft. All the flaps survived. The bone graft was healed in the period of eight weeks. The sensibility of this flap was regained in the period of three to six months after the surgery. The distance of two-point discrimination (TPD) was increased for 30% compared to the same region on the other hand after six months. The opposition of the reconstructed thumb to the other fingers was possible, as well as abduction, adduction and normal grasp. The method of reconstruction of the amputated thumb with the OFCR flap was better than other classical methods because it allowed the reconstruction of all the structures in one surgical operation. The sensibility that was regained represented good protection from injuries. There were no functional damages on the secondary defect. The esthetic result was not good due to the lack of a fingernail. PMID:12557617

  12. Versatility of the hatchet flap in facial reconstruction.

    PubMed

    Gargano, F; Alfano, C

    2005-01-01

    The hatchet flap, well known for repair of the nasal pyramid, laterofacial defects and pressure sores, is used to reconstruct different aesthetic units of the face. The authors describe the surgical technique and its clinical applications to the different face subunits in 38 patients, highlighting the easy learning curve, the versatility of the flap and the good aesthetic results when the principles of the facial units are respected. No previous detailed report has been described in the literature. PMID:16173514

  13. Flap Side Edge Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  14. The innervated free toe web flap for clitoris reconstruction.

    PubMed

    Dabernig, Jörg; Shelley, Odhran P; Schaff, Jürgen

    2007-01-01

    Clitoris reconstruction is often used in transgender reassignment. Most techniques now reconstruct the clitoris using glans pedicled on the dorsal phallic neurovascular bundle. Other techniques of clitoris reconstruction re-shape retained elements of the proximal segment of the corpora cavernosa, as well as techniques mobilising local flaps. We are presenting a new technique for clitoris reconstruction using an innervated free web space flap. The operative technique and outcome are illustrated and discussed in this case report. PMID:17368123

  15. 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

  16. Code For Analysis Of Wing-And-Flap Systems

    NASA Technical Reports Server (NTRS)

    Darden, Christine M.; Carlson, Harry W.

    1990-01-01

    SUBAERF2 program developed to provide for analysis of subsonic aerodynamics and design by iteration of low-speed wing/flap systems. Based on linearized-theory lifting-surface solution but also accounts for some nonlinear characteristics. Effects of leading- and trailing-edge flaps included. New and improved version of programs described in LAR-13116 and LAR-12987, and replaces both of them. Written in FORTRAN V.

  17. The lateral calcaneal flap for sensate heel reconstruction revisited.

    PubMed

    Korentager, R

    1994-06-01

    Defects of the heel can be difficult to treat because they require a thin, sensate, soft-tissue cover. The lateral calcaneal flap can provide this type of reconstruction in selected patients. A 27-year-old man had a painful defect in a grafted heel that prevented him from working. A satisfactory painless heel was provided by resurfacing the area with a lateral calcaneal flap. The donor defect was minimized by interfascicular dissection of the sural nerve. PMID:8199942

  18. Phase II simulation evaluation of the flying qualities of two tilt-wing flap control concepts

    NASA Technical Reports Server (NTRS)

    Birckelbaw, Lourdes G.; Corliss, Lloyd D.

    1992-01-01

    A simulation study was initiated to investigate alternative wing and flap controls for tilt-wing aircraft. The initial phase of the study compared the flying qualities of both a conventional (programmed) flap and an innovative geared flap. The second phase of the study, reported in this paper, introduced an alternate method for pilot control of the geared flap and further studied the flying qualities of the programmed flap, and two geared flap configurations. The results showed little difference among the three flap control configurations except during a longitudinal reposition task where the programmed flap configuration was the best. The addition of pitch attitude stabilization greatly enhanced the aircraft handling qualities. This paper describes the tilt-wing aircraft and the flap control concepts, and presents the results of the second simulation experiment.

  19. Full-scale upper-surface-blown flap noise. [for short haul STOL aircraft

    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 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.

  20. 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

  1. Pressure distribution over NACA 23012 airfoil with a slotted and a split flap

    NASA Technical Reports Server (NTRS)

    Harris, Thomas A; Lowry, John G

    1941-01-01

    A pressure-distribution investigation has been conducted in the NACA 4 by 6-foot vertical wind tunnel to determine the air loads on an NACA 23012 airfoil in combination with a 25.66-percent-chord slotted flap and a 20-percent-chord split flap. Pressures were measured on both the upper and the lower surfaces of the main airfoil and the flaps for several angles of attack and at several flap settings. The data, presented as pressure diagrams and as graphs of the section coefficients for the flap alone and for the airfoil-flap combinations, are applicable to rib and flap design for a combination of a thick airfoil and a slotted or a split flap. The results of previous tests of a NACA 23012 airfoil with a slotted flap are compared with the present results.

  2. Clinical reliability of radial forearm free flap in repair of buccal defects

    PubMed Central

    2013-01-01

    Background The ideal method for buccal defects should provide good outcome of both function and appearance; our goal is to highlight the reliability of radial forearm flap in buccal reconstruction. Methods A retrospective study was conducted. From 2005 to 2012, 20 radial forearm flaps were used to repair the defects. We analyzed the superiority and reliability of the flap; in addition, we reviewed some related literature and made a comparison between radial forearm flap and platysma flap. Results All radial forearm flaps totally survived, but two flaps suffered venous obstruction, hematoma, respectively. Radial forearm flap preserved the original interincisal distance well. In our follow-up, all patients had sufficient mouth-opening width (mean: 4.3 cm). Conclusion Radial forearm flap is a reliable method for buccal defect reconstruction. PMID:23363472

  3. Surgical anatomy and utility of pedicled vascularized tissue flaps for multilayered repair of skull base defects.

    PubMed

    Safavi-Abbasi, Sam; Komune, Noritaka; Archer, Jacob B; Sun, Hai; Theodore, Nicholas; James, Jeffrey; Little, Andrew S; Nakaji, Peter; Sughrue, Michael E; Rhoton, Albert L; Spetzler, Robert F

    2016-08-01

    OBJECT The objective of this study was to describe the surgical anatomy and technical nuances of various vascularized tissue flaps. METHODS The surgical anatomy of various tissue flaps and their vascular pedicles was studied in 5 colored silicone-injected anatomical specimens. Medical records were reviewed of 11 consecutive patients who underwent repair of extensive skull base defects with a combination of various vascularized flaps. RESULTS The supraorbital, supratrochlear, superficial temporal, greater auricular, and occipital arteries contribute to the vascular supply of the pericranium. The pericranial flap can be designed based on an axial blood supply. Laterally, various flaps are supplied by the deep or superficial temporal arteries. The nasoseptal flap is a vascular pedicled flap based on the nasoseptal artery. Patients with extensive skull base defects can undergo effective repair with dual flaps or triple flaps using these pedicled vascularized flaps. CONCLUSIONS Multiple pedicled flaps are available for reconstitution of the skull base. Knowledge of the surgical anatomy of these flaps is crucial for the skull base surgeon. These vascularized tissue flaps can be used effectively as single or combination flaps. Multilayered closure of cranial base defects with vascularized tissue can be used safely and may lead to excellent repair outcomes. PMID:26613175

  4. Superficial circumflex iliac artery pure skin perforator-based superthin flap for hand and finger reconstruction.

    PubMed

    Narushima, Mitsunaga; Iida, Takuya; Kaji, Nobuyuki; Yamamoto, Takumi; Yoshimatsu, Hidehiko; Hara, Hisako; Kikuchi, Kazuki; Araki, Jun; Yamashita, Shuji; Koshima, Isao

    2016-06-01

    For hand and finger reconstruction, thin and flexible skin coverage is ideally required. A free flap is one of the surgical options used for large defects. However, a flap containing the fat layer is bulky. Several debulking surgeries are often needed for aesthetic and functional purposes. To overcome this disadvantage, we herein report our experience of six cases of hand and finger reconstruction using a pure skin perforator (PSP) flap concept. A PSP flap is a thin skin flap that is vascularized by a perforator branch penetrating the dermis. The thickness of the PSP flap could be approximately ≤2 mm as needed. The superficial circumflex iliac artery and superficial inferior epigastric artery were used as a flap pedicle. Secondary defatting operations were not required. For the success of PSP flap elevation, we applied three techniques: the microdissection technique for vessel separation, thin flap elevation at the superficial fascial layer, and the temporary clamping method. Temporary clamping was applied for the main trunk of pedicle vessels during debulking to prevent unwanted bleeding, which allowed us to freely perform three-dimensional defatting. Using these three techniques, the PSP flap can be elevated and adjusted for complex contouring of the hand and finger. Although the use of the PSP flap requires further study, the PSP flap is an effective, superthin flap with the advantages of both skin graft and perforator flaps. PMID:27085610

  5. 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

  6. Wind-tunnel investigation of an NACA 23030 airfoil with various arrangements of slotted flaps

    NASA Technical Reports Server (NTRS)

    Recant, I G

    1940-01-01

    AN investigation was made of a large-chord NACA 23030 airfoil with a 40- and a 25.66 percent-chord slotted flap to determine the section aerodynamic characteristics of the airfoil affected by flap chord, slot shape, flap position, and flap deflection. The flap positions for maximum lift, the position for minimum drag at moderate and high lift coefficients, and the complete section aerodynamic characteristics of selected optimum arrangements are given. Envelope polar of various flap arrangements are included. The relative merits of slotted flaps of different chords on the NACA 23030 airfoil are discussed, and a comparison is made of each flap size with a corresponding flap size on the NACA 23021 and 23012 airfoils. The lowest profile drags at moderate lift coefficients were obtained with an easy entrance to the slot. The 25.66-percent-chord slotted flap gave lower drag than the 40-percent-chord flap for lift coefficients less than 1.8, but the 40-percent-chord flap gave considerably lower drag for lift coefficients. The drag coefficients at moderate and high lift coefficients were greater with both sizes of flap on the NACA 23030 airfoil than on either the NACA 23021 or the NACA 23012 airfoil. The maximum lift coefficient for the deflections tested with either flap was practically independent of airfoil.

  7. 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

  8. 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.

  9. The Science of Hyperbaric Oxygen for Flaps and Grafts.

    PubMed

    Gould, Lisa J; May, Todd

    2016-04-01

    Hyperbaric oxygen (HBO) therapy is a versatile modality that has applications across several medical fields. HBO therapy has become a valuable asset in the management of compromised tissue grafts and flaps. Although classified together, grafts and flaps are distinctly different, in that grafts depend on the wound bed for revascularization, whereas flaps have an inherent blood supply. Evidence has shown that in a compromised graft suffering from hypoxia, HBO can maximize viability and reduce the need for repeat grafting. By comparison, compromised flaps can suffer from both ischemic and reperfusion injury, which can also be attenuated by HBOT to maximize viability. The beneficial effects of HBO occur by several mechanisms, including hyper-oxygenation, fibroblast proliferation, collagen deposition, angiogenesis, and vasculogenesis. Animal studies have demonstrated several of these mechanisms, including an increase in the number, size, and growth distance of blood vessels after HBO. Likewise, clinical studies have found positive responses in multiple types of tissue grafts and flaps, with some cases involving irradiated fields. Altogether, the data emphasizes that early identification of flap or graft compromise is absolutely critical, with maximized chance for viability when HBO is initiated as soon as possible. PMID:27042776

  10. "Reposition-flap": A therapeutic alternative in fingertips amputations.

    PubMed

    Robert, N; Chassat, R; Couturier, C; Delpit, X; Masmejean, E

    2015-08-01

    After trans-phalanx fingertips amputations, there is usually a therapeutic problem related to the distal fragment quality. Replantation is not always possible. The aim of this study was to propose the "reposition-flap" surgical procedure as an alternative solution to various surgical strategies for distal stump coverage. It consisted in the association of a bone fragment osteosyntesis and a pedicular local flap implementation. Between 2001 and 2011, the reposition-flap surgical procedure was retrospectively tested in two hand trauma centers. We reviewed a cohort of 51 patients divided in two groups. The first one (20 patients) was the "reposition-flap" group, the second (31 patients) had a coverage with an other surgical procedure (simple regularisation or local flap). Sensibility, pulp trophicity, fingers mobility, digital length, nail appearance and radiologic consolidation of each patient were reviewed. "Reposition-flap" allowed 80% length of phalanx conservation. In comparison with regularisation, the aesthetic aspects of the nail's finger (no claw) were improved with this surgical procedure. However, the Quick DASH average revealed significant statistical differences instead of the statistics obtained with the mobility of the IPD and the sensitivity of the pulp. This procedure gave best aesthetic and functional results. PMID:25001417

  11. [PELVIC FLOOR RECONSTRUCTION AFTER PELVIC EVISCERATION USING GRACILIS MUSCULOCUTANEOUS FLAP].

    PubMed

    Pavlov, V N; Bakirov, A A; Kabirov, I R; Izmajlov, A A; Kutlijarov, L M; Safiullin, R L; Urmancev, M F; Sultanov, I M; Abdrahimov, R V

    2015-01-01

    Evisceration of the pelvic organs (EPO) is a fairly uncommon surgical treatment that removes all organs from a patient's pelvic cavity. We use gracilis musculocutaneous flap to repair pelvic floor after EPO. Over the period from November 2013 to December 2014 we carried out EPO with reconstructive repair of the pelvic floor with gracilis musculocutaneous flap in 10 patients with locally advanced pelvic tumors. We describe the surgical procedure and surgical outcomes in these patients. Mean age of the patients was 55 years. Mean duration of EPO with the pelvic floor repair was 285 min., mean blood loss--595 mL and the average length of hospital stay--19 days. Gracilis musculocutaneous flap has a sufficient arterial supply and mobility for pelvic floor reconstruction. Necrosis of flap's distal edge occurred in one of the 10 clinical cases, while the remaining flaps were fully preserved. Complete healing of wounds with no signs of weakening of the pelvic floor muscles was observed in all cases. Pelvic floor reconstruction is an essential procedure in order to reduce complications associated with the evisceration of the pelvic organs. The Gracilis musculocutaneous flap is the logical alternative to repair pelvic floor defect. It does not contribute to complications like functional deficiency of the lower limbs, complications of stoma formation or weakening of the muscles of the anterior abdominal wall. PMID:26390558

  12. 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.

  13. 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

  14. Compliant topology optimization for planar passive flap micro valve.

    PubMed

    Yoon, Gil Ho

    2014-10-01

    This paper reports the compliant topology optimization for planar passive flap micro valve considering fluid-structure interaction with a monolithic approach. Although flap valve type check valve is easy to manufacture and use for the applications for Bio/Nano/MEMS, its structural optimization has been seldom conducted so far. The size of the Bio/Nano/MEMS devices becomes smaller and the simple straight type micro valve structure is required to be optimized considering fluid speed. To address this optimization problem, the structural topology optimization scheme which designs optimal topologies is applied for a flap type check valve structure. To consider the coupling effects of fluid domain and structural domain, the monolithic finite element approach is employed. In the new analysis approach, solid domain is simulated by introducing the inverse permeability in the Navier-Stokes equation and the fluid stress filter in the linear elasticity equation. Also it is a new idea that fluid domain is simulated by finite elements with a weak Young's modulus in the linear elasticity equation. The mutual couplings between fluid and structure are considered by the introduction of the deformation tensor which is one of the basic concepts of the continuum mechanism. By distributing material properties inside a design domain for compliant flap, optimal flap structures can be constructed with different fluid speeds. By investigating the optimal layouts of several passive flap designs, we prove that the structural topology optimization can provide optimal layouts for Bio, Nano, and MEMS applications. PMID:25942830

  15. Predictive risk factors of free flap thrombosis in breast reconstruction surgery.

    PubMed

    Masoomi, Hossein; Clark, Emily G; Paydar, Keyianoosh Z; Evans, Gregory R D; Nguyen, Audrey; Kobayashi, Mark R; Wirth, Garrett A

    2014-11-01

    Vascular thrombosis is one of the major postoperative complications of free flap microvascular breast reconstruction operations. It is associated with higher morbidity, higher cost, increased length of hospital stay, and potentially flap loss. Our purpose is to evaluate the rate of this complication and whether patient characteristics play a role. Using the Nationwide Inpatient Sample (NIS) database, we examined the clinical data of patients who underwent free flap breast reconstruction between 2009 and 2010 in the United States. Multivariate and univariate regression analyses were performed to identify independent risk factors of flap thrombosis. A total of 15,211 patients underwent free flap breast reconstruction surgery (immediate reconstruction: 43%). The most common flap was the free deep inferior epigastric perforator (DIEP) flap (53.6%), followed by free transverse rectus abdominis myocutaneous (TRAM) flap (43.1%), free superficial inferior epigastric artery (SIEA) flap (2%), and free gluteal artery perforator (GAP) flap (1.3%). The overall rate of flap thrombosis was 2.4 %, with the highest rate seen in the SIEA group (11.4%) and the lowest in the TRAM group (1.7%). Peripheral vascular disease (adjusted odds ration [AOR] 10.61), SIEA flap (AOR, 4.76) and delayed reconstruction (AOR, 1.42) were found to be statistically significant risk factors for flap thrombosis. Other comorbidities were not linked. While the overall rate of flap thrombosis in free flap breast reconstruction was relatively low (2.4%), Plastic Surgeons should be aware that patients with peripheral vascular disease and those undergoing free SIEA flap are at higher risk of flap thrombosis and they should closely monitor flaps to increase the chance for early salvage. PMID:24665051

  16. Identification of independent risk factors for flap failure: A retrospective analysis of 1530 free flaps for breast, head and neck and extremity reconstruction.

    PubMed

    Las, David E; de Jong, Tim; Zuidam, J Michiel; Verweij, Norbert M; Hovius, Steven E R; Mureau, Marc A M

    2016-07-01

    Reconstructive microsurgery is a powerful method of treating various complex defects. However, flap loss remains a possibility, leading to additional surgery, hospitalisation and costs. Consequently, it is important to know which factors lead to an increased risk of flap failure, so that measures can be undertaken to reduce this risk. Therefore, we analysed our results over a 20-year period to identify risk factors for flap failure after breast, head and neck and extremity reconstruction. The medical files of all patients treated between 1992 and 2012 were reviewed. Patient characteristics, surgical data and post-operative complications were scored, and independent risk factors for flap loss were identified. Reconstruction with a total of 1530 free flaps was performed in 1247 patients. Partial and total flap loss occurred in 5.5% and 4.4% of all free flaps, respectively. In all flaps, signs of compromised flap circulation were a risk factor for flap failure. More specifically, the risk factors for flap failure in breast reconstruction were previous radiotherapy, venous anastomosis revision, gluteal artery perforator (GAP) flap choice and post-operative bleeding. In head and neck reconstruction, pulmonary co-morbidity and anastomosis to the lingual vein or superficial temporal artery were risk factors, whereas a radial forearm flap reduced the risk. In extremity reconstruction, diabetes, prolonged anaesthesia time and post-operative wound infection were risk factors. Independent pre-, intra- and post-operative risk factors for flap failure after microvascular breast, head and neck and extremity reconstruction were identified. These results may be used to improve patient counselling and to adjust treatment algorithms to further reduce the chance of flap failure. PMID:26980600

  17. The evaluation of flap growth and long-term results of pediatric mandible reconstructions using free fibular flaps.

    PubMed

    Temiz, Gökhan; Bilkay, Ufuk; Tiftikçioğlu, Yiğit Özer; Mezili, Candan Tevfik; Songür, Ecmel

    2015-05-01

    Currently, the free fibular flap is well accepted as the first choice for mandibular reconstruction. Achieving functional results in pediatric patients requires a different approach than that employed for mature patients. Because the pediatric craniofacial skeleton continues to grow, reconstruction is more challenging, and the long-term results can be different from those of adult patients. In this study, we sought to measure flap growth objectively in our series. Ten pediatric patients who underwent reconstruction with free fibular flaps were retrospectively reviewed. Flap growth was evaluated by comparing the intraoperative photographs with photographs of the control panoramic mandibular radiographs taken using photo-anthropometric techniques. The measurements were converted to proportionality indices (PI), and these indices were compared. Subsequent complications and functional results were also evaluated. The mean patient age was 11.8 years, and the mean follow up was 57.7 months. The mean preoperative PI value was 10.74  ±  2.47. The mean postoperative PI value was 12.52  ±  2.34. The mean difference between the preoperative and postoperative PI values was -1.78 ± 0.53. These photo-anthropometric data clearly illustrated the growth of the fibular flaps (P = 0.001). None of these patients exhibited nonunion of the fractures; however, one patient experienced a delayed union, one had chronic temporomandibular joint pain, and one had chronic temporomandibular joint luxation. In two patients, the inter-incisive measurements were below the third percentile, and two additional patients had grade 2 eating abilities, which can be regarded as poor. All of the patients had symmetric mandibular contours. Free fibular flaps continue to grow in pediatric patients. This flap is a "workhorse" flap in children because it adapts to the craniofacial skeleton via its ability to grow, and this ability results in subsequent good cosmetic and functional results. PMID

  18. Innovative techniques in preventing and salvaging neurovascular pedicle flaps in reconstructive foot and ankle surgery.

    PubMed

    Zgonis, Thomas; Stapleton, John J

    2008-04-01

    Pedicle flaps to cover soft tissue defects of the foot, ankle, and lower extremity are invaluable. However, venous congestion and flap necrosis, a common complication, poses greater morbidity to the patient as few remaining options for attempted limb salvage remain. The authors discuss how to prevent flap failure by allowing close observation and strict offloading of the pedicle flap through current external fixation designs. This article also discusses the role of medicinal leeches in reestablishing blood flow through the pedicle flap to prevent tissue necrosis. In addition, the use of hydrosurgery as an innovative technique offers the surgeon another option if faced with pedicle flap necrosis. PMID:19825700

  19. Three cross leg flaps for lower leg reconstruction of Gustilo type III C open fracture

    PubMed Central

    Sano, Kazufumi; Ozeki, Satoru; Sugimoto, Ichiro; Ogawa, Masato

    2016-01-01

    A 60 year old male had Gustilo type III C open fracture of the right lower leg. After radical debridement, the large open defect including certain loss of the bone tissue was successfully augmented and covered, by consecutive three cross-leg flaps, which consisted of the free rectus abdominis musculocutaneous flap, the fibula osteocutaneous flap and the conventional sural flap. Although indication for amputation or preservation is decided with multiple factors in each case, a strategic combination of cross-leg flap, free flap, external fixation and vascular delay could increase the potential of preservation of the lower leg with even disastrous Gustilo type III C. PMID:27293297

  20. Vector control of two-dimensional turbulent free jet by both-side flaps

    NASA Astrophysics Data System (ADS)

    Enokida, K.; Okamoto, T.

    1985-05-01

    This paper presents an experimental investigation of the characteristics of a two-dimensional turbulent jet deflected by the flaps attached at both sides of the nozzle. It was found that the deflection angle was nearly equal to the flap angle when the flap angle was less than the critical angle and it approached the deflection angle for one-side flap. And the length of potential core, decay of maximum velocity and spread of jet were varied with the flap angle, but were unchanged by the flap width.

  1. 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

  2. Combining flaps. Medical canthal/lateral nasal root reconstruction utilizing glabellar "fan" and cheek rotation flaps--an O-to-Z variation.

    PubMed

    Field, L M; Dachow-Siwiec, E; Szymanczyk, J

    1994-03-01

    An increased use of multiple flaps applied to single reconstructive problems is encouraged. Removal of a basal cell carcinoma involving the medial canthus and adjacent lateral nasal root skin resulted in significant defect. When a glabellar "fan" flap failed to provide adequate tissue for canthal reconstruction without undue distortion, a preplanned medial cheek rotation flap followed sequentially in the repair process. The basic principles of an O-to-Z flap reconstruction were therefore fulfilled by conjoining two different flap design applications. PMID:8151035

  3. 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

  4. Enhancement of flap survival and changes in angiogenic gene expression after AAV2-mediated VEGF gene transfer to rat ischemic flaps.

    PubMed

    Wang, Xiao Tian; Avanessian, Bella; Ma, Qiangzhong; Durfee, Heather; Tang, Yu Qing; Liu, Paul Y

    2011-01-01

    Necrosis of surgically transferred flaps due to ischemia is a serious wound problem. We evaluated the improvement of flap survival and changes in angiogenic gene expression profiles after transfer of the VEGF gene by means of adeno-associated virus type 2 (AAV2) vector to rat ischemic flaps. Thirty rats were divided into one experimental group, one AAV2-GFP group, and one saline group. AAV2-VEGF or AAV2-GFP were injected intradermally into the rat dorsum in the AAV2-VEGF or AAV2-GFP group. The saline group received saline injection. A 3 × 10 cm flap was raised in each rat two weeks post-injection. One week after surgery, flap viability was evaluated. Angiogenesis real-time PCR array was performed to analyze the expression of angiogenesis-associated genes. The AAV2-VEGF treatment significantly improved flap survival (p<0.05). Immunohistochemical staining showed increased VEGF expression in AAV2-VEGF treated flaps. The PCR array identified remarkable changes in 6 out of the 84 angiogenesis-associated genes in AAV2-VEGF treated flaps. Particularly, EGF, PDGF-A and VEGF-B genes were up-regulated in these flaps. In contrast, FGF2 gene expression was down-regulated. In conclusion, AAV2-VEGF improves flap survival and affects the expression of a series of endogenous growth factor genes, which likely play critical roles in the enhancement of ischemic flap survival. PMID:21649787

  5. 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

  6. Development of a Mouse Model of Abdominal Cutaneous Flaps for Breast Reconstruction

    PubMed Central

    Womac, Daniel John; Palanisamy, Arun Prathap; Eslick, Rene; Schimpf, Dennis Kenneth; Chavin, Kenneth David

    2013-01-01

    Autologous tissue transfer, in addition to replacing tissue that was lost during injury or surgery, offers women an excellent option to improve cosmetic appearance and self-confidence following mastectomy due to breast cancer. However, flap necrosis is a complication in obese patients undergoing this procedure. We created a mouse model to study the flap-related complications that leads to decreased flap survival in autologous breast reconstruction. Methods Left superficial inferior epigastric (SIE) pedicle abdominal-cutaneous flaps were elevated in 8 week-old, obese ob/ob male mice and their lean littermates. Flaps were followed by serial photography. Area of flap necrosis was measured at 7 days. Statistical analysis was performed. Results Necrosis was observed at the distal margin of the flaps, in both lean and obese groups. Lean left SIE flaps (n = 8) had a total area flap necrosis of 9.1% at 7 days whereas obese left SIE flaps (n = 8) had a total area flap necrosis of 45.5% at 7 days. Obese flaps had a statistically significant increase in necrosis compared to the lean flaps, p = 0.001. Conclusions There was a significant difference between flap survival in lean and obese SIE pedicle flaps in our mouse model. We have developed the first flap model of obesity utilizing the superficial epigastric pedicle in the mouse. This model is optimal for future studies to dissect out mechanisms that lead to the complications related to flap survival for breast reconstruction, especially in obese subjects. PMID:23308122

  7. Piloted simulation study of two tilt-wing flap control concepts, phase 2

    NASA Technical Reports Server (NTRS)

    Birckelbaw, Lourdes G.; Corliss, Lloyd D.; Hindson, William S.; Churchill, Gary B.

    1994-01-01

    A two phase piloted simulation study has been conducted in the Ames Vertical Motion Simulator to investigate alternative wing and flap controls for tilt-wing aircraft. This report documents the flying qualities results and findings of the second phase of the piloted simulation study and describes the simulated tilt-wing aircraft, the flap control concepts, the experiment design and the evaluation tasks. The initial phase of the study compared the flying qualities of both a conventional programmed flap and an innovative geared flap. The second phase of the study introduced an alternate method of pilot control for the geared flap and further studied the flying qualities of the programmed flap and two geared flap configurations. In general, the pilot ratings showed little variation between the programmed flap and the geared flap control concepts. Some differences between the two control concepts were noticed and are discussed in this report. The geared flap configurations had very similar results. Although the geared flap concept has the potential to reduce or eliminate the pitch control power requirements from a tail rotor or a tail thruster at low speeds and in hover, the results did not show reduced tail thruster pitch control power usage with the geared flap configurations compared to the programmed flap configuration. The addition of pitch attitude stabilization in the second phase of simulation study greatly enhanced the aircraft flying qualities compared to the first phase.

  8. 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

  9. Extended Anterolateral Thigh Flaps for Reconstruction of Extensive Defects of the Foot and Ankle

    PubMed Central

    Liu, Lifeng; Cao, Xuexin; Zou, Lin; Li, Zongyu; Cao, Xuecheng; Cai, Jinfang

    2013-01-01

    The anterolateral thigh flap has been used for coverage of defects in the foot and ankle for years. Conventional extended anterolateral thigh flaps do not undergo thinning procedures, which limit their application. Here, a clinical series of 24 patients is reported in which extended anterolateral thigh flaps were used for posttraumatic foot and ankle reconstruction. Of the 24 flaps, 14 were simple extended anterolateral thigh fasciocutaneous flaps and 10 were thinned extended anterolateral thigh flaps. One artery and two veins, including a superficial vein and an accompanying vein, were anastomosed to vascularize each flap. Follow-up of the 24 patients ranged from 10 months to 4 years postoperatively. All 24 flaps survived successfully, except one case that had partial flap necrosis distally due to excessive thinning. The cutaneous flap territory ranged from 250 cm2 to 400 cm2 (mean, 297 cm2). Only one patient received a debulking procedure. No ulceration occurred in any of the flaps due to contact with the shoe. The extended anterolateral thigh flap is a good alternative for extensive soft tissue defects of the foot and ankle. This study also supports the high reliability and excellent vascular supply of moderate thinned extended ALT flaps. PMID:24376731

  10. Increasing options in autologous microsurgical breast reconstruction: four free flaps for 'stacked' bilateral breast reconstruction.

    PubMed

    Rozen, Warren Matthew; Patel, Nakul Gamanlal; Ramakrishnan, Venkat V

    2016-04-01

    For autologous breast reconstruction, there are cases where one free flap cannot provide the volume of tissue required, and the concept of 'stacked' bilateral deep inferior epigastric artery (DIEP) flaps was developed, in which hemi-abdominal flaps are raised on each deep inferior epigastric artery (DIEA), and both flaps transferred to the chest. In cases of bilateral breast reconstruction, stacked flaps may be required to achieve volume replacement, however options are not described. We demonstrate the use of stacked free flaps for bilateral breast reconstruction, using one DIEP flap stacked with one transverse upper gracilis (TUG) flap for each side. A 49-year-old woman, with BRCA1 mutation, presented for risk reduction mastectomies. Flap design was planned to achieve maximal projection and primary nipple reconstruction. This was able to be achieved by using the DIEP flap de-epithelialised and completely buried, with the flap orientated with the pedicle on its superficial surface, and the TUG flap lying superficially with its skin paddle used for nipple reconstruction and able to be monitored clinically. There were no flap or donor related complications and good aesthetic outcomes were achieved. This technique offers a further option in microsurgical breast reconstruction for patients in whom there is a paucity of abdominal tissue for reconstruction. PMID:27047791

  11. 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

  12. Novel Biomarkers of Arterial and Venous Ischemia in Microvascular Flaps

    PubMed Central

    Nguyen, Gerard K.; Monahan, John F. W.; Davis, Gabrielle B.; Lee, Yong Suk; Ragina, Neli P.; Wang, Charles; Zhou, Zhao Y.; Hong, Young Kwon; Spivak, Ryan M.; Wong, Alex K.

    2013-01-01

    The field of reconstructive microsurgery is experiencing tremendous growth, as evidenced by recent advances in face and hand transplantation, lower limb salvage after trauma, and breast reconstruction. Common to all of these procedures is the creation of a nutrient vascular supply by microsurgical anastomosis between a single artery and vein. Complications related to occluded arterial inflow and obstructed venous outflow are not uncommon, and can result in irreversible tissue injury, necrosis, and flap loss. At times, these complications are challenging to clinically determine. Since early intervention with return to the operating room to re-establish arterial inflow or venous outflow is key to flap salvage, the accurate diagnosis of early stage complications is essential. To date, there are no biochemical markers or serum assays that can predict these complications. In this study, we utilized a rat model of flap ischemia in order to identify the transcriptional signatures of venous congestion and arterial ischemia. We found that the critical ischemia time for the superficial inferior epigastric fasciocutaneus flap was four hours and therefore performed detailed analyses at this time point. Histolgical analysis confirmed significant differences between arterial and venous ischemia. The transcriptome of ischemic, congested, and control flap tissues was deciphered by performing Affymetrix microarray analysis and verified by qRT-PCR. Principal component analysis revealed that arterial ischemia and venous congestion were characterized by distinct transcriptomes. Arterial ischemia and venous congestion was characterized by 408 and 1536>2-fold differentially expressed genes, respectively. qRT-PCR was used to identify five candidate genes Prol1, Muc1, Fcnb, Il1b, and Vcsa1 to serve as biomarkers for flap failure in both arterial ischemia and venous congestion. Our data suggests that Prol1 and Vcsa1 may be specific indicators of venous congestion and allow clinicians to

  13. Perfusion and Oxygenation of Random Advancement Skin Flaps Depend More on the Length and Thickness of the Flap Than on the Width to Length Ratio

    PubMed Central

    Memarzadeh, Khashayar; Sheikh, Rafi; Blohmé, Jonas; Torbrand, Christian

    2016-01-01

    Objective: The aim was to investigate the relationship between the dimensions (length, width, and thickness) of random advancement skin flaps and retained tissue perfusion and oxygenation. Methods: Flaps were raised on the flanks of pigs. The flaps were either 0.5 or 1.0 cm wide, thin (dissected halfway through the subcutaneous tissue) or thick (dissected down to the muscle fascia). Tissue perfusion was measured by laser Doppler velocimetry, and tissue oxygenation (pO2) was measured using a Licox system, every 0.5 cm along the flaps’ length. Tissue temperature was visualized by high-resolution infrared camera. Results: Perfusion and oxygenation decreased gradually from the base to the tip of the flap, reaching approximately 40% of presurgical values (2.0 cm) and approximately 20% (2.5 cm) from the base of the flap. There was virtually no blood flow, nor oxygen tension, 3.0 cm from the base of the flap. The width to length ratio of the flap did not determine blood flow or oxygenation, being approximately 30% in a 0.5 cm wide and 2 cm long flap, and 0% in a 1.0 cm wide and 4 cm long flap, both with a width to length ratio of 1:4. Blood flow and oxygenation were preserved to a greater extent in the thick flaps (∼40%) than in the thin flaps (∼20%), in a 0.5 cm wide and 2 cm long flap. Conclusions: The dissection of a random advancement flap results in hypoperfusion and oxygenation that cannot be predicted by the width to length ratio but depend on the length and thickness of the flap. PMID:26958105

  14. Theoretical studies on flapped delta wings

    NASA Technical Reports Server (NTRS)

    Oh, S.; Tavella, D.; Roberts, L.

    1988-01-01

    The effects of leading edge flaps on the aerodynamic characteristics of a low aspect-ratio delta wing are studied theoretically. As an extension of the classical crossflow plane analysis and in order to include separated shear layers, an analogy between three dimensional steady conical and two dimensional unsteady self-similar flows is explored. This analogy provides a simple steady-unsteady relationship. The criteria for the validity of the steady-unsteady analogy are also examined. Two different theoretical techniques are used to represent the separated shear layers based on the steady-unsteady analogy, neglecting the trailing edge effect. In the first approach, each vortex system is represented by a pair of concentrated vortices connected to the separation points by straight feeding sheets. In the second approach, the vortex cloud method is adopted for simulating the flow field in the crossflow plane. The separated shear layers are replaced with a cloud of discrete vortices and the boundary element method is employed to represent the wing trace by a vorticity distribution. A simple merging scheme is used to model the core region of the vortical flow as a single vortex by imposing a restriction on the shear layer rotation angle. The results are compared with experiments and with results from 3-D panel calculations.

  15. 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.

  16. Regional anesthesia alone for pediatric free flaps.

    PubMed

    Bjorklund, Kim A; Venkatramani, Hari; Venkateshwaran, Govindaswamy; Boopathi, Vadivel; Raja Sabapathy, S

    2015-05-01

    Microvascular surgery plays an important reconstructive role in the pediatric population. Successful outcomes rely on surgical technique as well as anesthesia. Regional anesthesia contributes to successful free tissue transfer through sympathetic blockade, postoperative pain control, and elimination of risks and costs associated with general anesthesia. While regional anesthesia in microsurgery is discussed in the literature for adult and elderly patients, no studies focus on the pediatric population. Accordingly, this paper reviews 20 pediatric patients undergoing microvascular surgery (anterolateral thigh, n = 9; gracilis, n = 3; toe transfer, n = 6; and fibula, n = 2) with regional anesthesia and sedation. All patients underwent spinal epidural anesthesia, and seven also received brachial plexus blocks. The average duration of anesthesia was 3-4 h (anterolateral thigh (ALT) and gracilis) and 6-8 h (toe transfer and fibula). No anesthesia-related complications or flap failures occurred. We conclude that regional anesthesia has important benefits in pediatric microsurgery and it is a safe and cost-effective alternative to general anesthesia. PMID:25858275

  17. ``Schooling'' of wing pairs in flapping flight

    NASA Astrophysics Data System (ADS)

    Ramananarivo, Sophie; Zhang, Jun; Ristroph, Leif; AML, Courant Collaboration; Physics NYU Collaboration

    2015-11-01

    The experimental setup implements two independent flapping wings swimming in tandem. Both are driven with the same prescribed vertical heaving motion, but the horizontal motion is free, which means that the swimmers can take up any relative position and forward speed. Experiments show however clearly coordinated motions, where the pair of wings `crystallize' into specific stable arrangements. The follower wing locks into the path of the leader, adopting its speed, and with a separation distance that takes on one of several discrete values. By systematically varying the kinematics and wing size, we show that the set of stable spacings is dictated by the wavelength of the periodic wake structure. The forces maintaining the pair cohesion are characterized by applying an external force to the follower to perturb it away from the `stable wells'. These results show that hydrodynamics alone is sufficient to induce cohesive and coordinated collective locomotion through a fluid, and we discuss the hypothesis that fish schools and bird flocks also represent stable modes of motion.

  18. An experimental study of pressures on 60 deg Delta wings with leading edge vortex flaps

    NASA Technical Reports Server (NTRS)

    Marchman, J. F., III; Terry, J. E.; Donatelli, D. A.

    1983-01-01

    An experimental study was conducted in the Virginia Tech Stability Wind Tunnel to determine surface pressures over a 60 deg sweep delta wing with three vortex flap designs. Extensive pressure data was collected to provide a base data set for comparison with computational design codes and to allow a better understanding of the flow over vortex flaps. The results indicated that vortex flaps can be designed which will contain the leading edge vortex with no spillage onto the wing upper surface. However, the tests also showed that flaps designed without accounting for flap thickness will not be optimum and the result can be oversized flaps, early flap vortex reattachment and a second separation and vortex at the wing/flap hinge line.

  19. 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

  20. Aeroacoustic performance of an externally blown flap configuration with several flap noise suppression devices

    NASA Technical Reports Server (NTRS)

    Mckinzie, D. J., Jr.

    1982-01-01

    Small scale model acoustic experiments were conducted to measure the noise produced in the flyover and sideline planes by an engine under the wing externally blown flap configuration in its approach attitude. Broadband low frequency noise reductions as large as 9 dB were produced by reducing the separation distance between the nozzle exhaust plane and the flaps. Experiments were also conducted to determine the noise suppression effectiveness in comparison with a reference configuration of three passive types of devices that were located on the jet impingement surfaces of the reference configuration. These devices produced noise reductions that varied up to 10 dB at reduced separation distances. In addition, a qualitative estimate of the noise suppression characteristics of the separate devices was made. Finally static aerodynamic performance data were obtained to evaluate the penalties incurred by these suppression devices. The test results suggest that further parametric studies are required in order to understand more fully the noise mechanisms that are affected by the suppression devices used.

  1. Aeroacoustic performance of an externally blown flap configuration with several flap noise suppression devices

    NASA Astrophysics Data System (ADS)

    McKinzie, D. J., Jr.

    1982-05-01

    Small scale model acoustic experiments were conducted to measure the noise produced in the flyover and sideline planes by an engine under the wing externally blown flap configuration in its approach attitude. Broadband low frequency noise reductions as large as 9 dB were produced by reducing the separation distance between the nozzle exhaust plane and the flaps. Experiments were also conducted to determine the noise suppression effectiveness in comparison with a reference configuration of three passive types of devices that were located on the jet impingement surfaces of the reference configuration. These devices produced noise reductions that varied up to 10 dB at reduced separation distances. In addition, a qualitative estimate of the noise suppression characteristics of the separate devices was made. Finally static aerodynamic performance data were obtained to evaluate the penalties incurred by these suppression devices. The test results suggest that further parametric studies are required in order to understand more fully the noise mechanisms that are affected by the suppression devices used.

  2. An improved flapping wing system actuated by the LIPCA

    NASA Astrophysics Data System (ADS)

    Syaifuddin, Moh.; Park, Hoon C.; Lee, Sang K.; Byun, Do Y.

    2006-03-01

    This paper presents an improved version of the insect-mimicking flapping-wing mechanism actuated by LIPCA (Lightweight Piezo-Composite Actuator). As the previous version, the actuation displacement of the actuator is converted into flapping-wing motion by a mechanical linkage system that functioned as displacement amplifier as well. In order to provide feathering motion, the wing is attached to the axis through a hinge system that allows the wing rotation at each end of half-stroke, due to air resistance. In this improved version, the total weight has been reduced to the half of the previous one. The device could produce about 90 degree of flapping angle when it operated at around 10 Hz, which was the natural flapping-frequency. Several flapping tests under different parameter configurations were conducted in order to investigate the characteristic of the generated lift. In addition, the smoke-wire test was also conducted, so that the vortices around the wing can be visually observed. Even though the present wing has smaller wing area, it could produce higher lift then before.

  3. [Submental island flap: a review of the literature].

    PubMed

    Bertrand, B; Foletti, J-M; Noël, W; Duron, J-B; Bardot, J

    2015-02-01

    The submental island flap is a precious tool in reconstructive surgery. It was described by Martin in 1993, inspired by platysma flaps. In our days, we can find many reliable techniques for this procedure. We reviewed the main studies of the literature that described a total of 528 patients. The rate of partial necrosis was 5.1%, complete necrosis 1.7%, and reversible lesions of the marginal mandibular branch of the facial nerve 1.1%. His versatility makes this flap appropriate for the reconstruction of every part of the face: cheeks, nose, forehead, moustache, beard, and hairs. It can also be used de-epidermised with very good results, for the reconstruction of the buccal cavity, the tongue, the roof of the mouth, the larynx, and the proximal part of the esophagus. The SMAP (Submentalis Artery Perforator flap) is an alternative flap that provides even better cosmetic results. The development of indocyanine green and infrared cameras will allow in a close future to decrease the postoperative complications. PMID:25213485

  4. A Large Scale PIV Investigation of a Flap Edge Vortex

    NASA Astrophysics Data System (ADS)

    Walker, Stephen M.; Alkislar, M. B.; Lourenco, L.; Krothapalli, A.

    1996-11-01

    A recent experiment at NASA/Ames Research Center demonstrated the application of a large scale 'on-line' Particle Image Velocimetry, (PIV), in a 7' x 10' wind tunnel. Data was collected for freestream velocities in the range from approximately 40 m/sec to 100 m/sec. The flow field of interest for this investigation was a vortex that was generated by a flap edge. The model was an unswept wing, having a span of 5 ft and a chord, (c), of 2.5 ft., fitted with a half-span Fowler flap. The flap had a chord of 9 inches. Cross plane flow field velocity measurements were made at 0.6 c, (18 inches), downstream of the trailing edge of the flap. The baseline model was also tested with a three quarter-span slat, and a flap edge fence. The fence is designed to reduce noise from high-lift devices. The area of the flow encompassed within this investigation was 40 cm by 40 cm. A high resolution CCD Camera, (2048 pixels x 2048 pixels), was used to capture the double exposure images. The light source used in this experiment was a Spectra Physics PIV-400 Nd:Yag double pulsed laser, and the particle seeding was generated from a Roscoe 4500 fog machine. The velocity data obtained from the experiment was used to determine both the vorticity and the circulation.

  5. Orbital Floor Reconstruction with Free Flaps after Maxillectomy

    PubMed Central

    Sampathirao, Leela Mohan C. S. R.; Thankappan, Krishnakumar; Duraisamy, Sriprakash; Hedne, Naveen; Sharma, Mohit; Mathew, Jimmy; Iyer, Subramania

    2013-01-01

    Background The purpose of this study is to evaluate the outcome of orbital floor reconstruction with free flaps after maxillectomy. Methods This was a retrospective analysis of 34 consecutive patients who underwent maxillectomy with orbital floor removal for malignancies, reconstructed with free flaps. A cross-sectional survey to assess the functional and esthetic outcome was done in 28 patients who were alive and disease-free, with a minimum of 6 months of follow-up. Results Twenty-six patients had bony reconstruction, and eight had soft tissue reconstruction. Free fibula flap was the commonest flap used (n = 14). Visual acuity was normal in 86%. Eye movements were normal in 92%. Abnormal globe position resulted in nine patients. Esthetic satisfaction was good in 19 patients (68%). Though there was no statistically significant difference in outcome of visual acuity, eye movement, and patient esthetic satisfaction between patients with bony and soft tissue reconstruction, more patients without bony reconstruction had abnormal globe position (p = 0.040). Conclusion Free tissue transfer has improved the results of orbital floor reconstruction after total maxillectomy, preserving the eye. Good functional and esthetic outcome was achieved. Though our study favors a bony orbital reconstruction, a larger study with adequate power and equal distribution of patients among the groups would be needed to determine this. Free fibula flap remains the commonest choice when a bony reconstruction is contemplated. PMID:24436744

  6. 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

  7. Rotation flaps for coverage after total knee arthroplasty

    PubMed Central

    Pozzobon, Leonardo Rafael; Helito, Camilo Partezani; Guimarães, Tales Mollica; Gobbi, Riccardo Gomes; Pécora, José Ricardo; Camanho, Gilberto Luis

    2013-01-01

    OBJECTIVE: To evaluate the results obtained using local myocutaneous rotation flaps in cases of wound dehiscence after total knee arthroplasty. METHODS: Patients undergoing these surgical procedures were selected in the 2000-2012 period. The nine selected cases during this period were subjected to flap coverage due to skin dehiscence associated with infection. In eight cases we used rotation flaps of the medial gastrocnemius, and in one case we used advancing skin. RESULTS: Eighty nine percent of the cases were successful in the coverage of the prosthesis and the viability of the flaps. In four cases it was possible to maintain or review the prosthesis. Four other cases progressed to amputation due to failure on treatment of infections, and one case remained without the prosthesis. The functional evaluation showed an unsatisfactory outcome in 89% of cases. CONCLUSION: Coverage flaps are a good option for the treatment of cases of dehiscence with exposure of the prosthesis and the functional failure was associated with the inability to control the infection and the damage it caused. Level of Evidence IV, Case Series. PMID:24453672

  8. Repair of a canine forelimb skin deficit by microvascular transfer of a caudal superficial epigastric flap.

    PubMed

    Lewin, G A; Smith, J H

    2010-02-01

    Extensive skin loss from the forelimb of a Border collie was repaired by a microvascular caudal superficial epigastric flap, with secondary meshing of the flap to increase coverage. The caudal superficial epigastric artery and vein were anastomosed to the brachial artery and vein. End-to-end anastomosis to the brachial artery and vein did not compromise peripheral blood flow, and no flap necrosis was observed after subsequent limited meshing of the flap. PMID:20070493

  9. Internal-external flow integration for a thin ejector-flapped wing section

    NASA Technical Reports Server (NTRS)

    Woolard, H. W.

    1979-01-01

    Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.

  10. 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

  11. Effect of flap deflection on the lift coefficient of wings operating in a biplane configuration

    NASA Technical Reports Server (NTRS)

    Stasiak, J.

    1977-01-01

    Biplane models with a lift flap were tested in a wind tunnel to study the effect of flap deflection on the aerodynamic coefficient of the biplane as well as of the individual wings. Optimization of the position flap was carried out, and the effect of changes in the chord length of the lower wing was determined for the aerodynamic structure of a biplane with a lift flap on the upper wing.

  12. Submental Perforator Flap Design with a Near-Infrared Fluorescence Imaging System: The Relation between Number of Perforators, Flap Perfusion, and Venous Drainage

    PubMed Central

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

    2009-01-01

    Background The submental flap is a reliable alternative to microsurgical reconstruction of facial deformities, providing an excellent cosmetic match with the contour and color of the face. In this study, we evaluated submental flap design by employing near-infrared (NIR) fluorescence angiography to identify perforator arteries (PAs). The impact of the number of preserved PAs on flap perfusion and venous drainage were quantified. Methods Indocyanine green was injected intravenously into n = 18 pigs. Three groups of 6 animals each had one, two, or three PAs preserved. The FLARE™ NIR fluorescence imaging system was employed for image acquisition. Images were recorded before and after flap creation, and every h, for 6 h. The time to maximum perfusion, the drainage ratio (an indicator of venous drainage), and the percentage of perfused flap area were analyzed statistically at each time point. Results Flaps with a single dominant PA had an initial mean perfused area of 80%, which improved to 97% at 6 h. For flaps with two and three preserved PAs, perfused area at 6 h was 99.8% and 100%, respectively. A significant increase was observed in all three metrics as more vessels were preserved. Regardless of the number of PAs preserved, though, all three metrics improved over 6 h. Conclusions NIR fluorescence angiography can reliably identify submental PAs for flap design, and can be used to assess flap perfusion and venous drainage in real-time. Flap metrics at 6 h were equivalent when either one, or multiple PAs, were preserved. PMID:19935293

  13. My First 100 Consecutive Microvascular Free Flaps: Pearls and Lessons Learned in First Year of Practice

    PubMed Central

    2013-01-01

    Background: Microvascular reconstruction for oncologic defects is a challenging and rewarding endeavor, and successful outcomes are dependent on a multitude of factors. This study represents lessons learned from a personal prospective experience with 100 consecutive free flaps. Methods: All patients’ medical records were reviewed for demographics, operative notes, and complications. Results: Overall 100 flaps were performed in 84 consecutive patients for reconstruction of breast, head and neck, trunk, and extremity defects. Nineteen patients underwent free flap breast reconstruction with 10 patients undergoing bilateral reconstruction and 2 patients receiving a bipedicle flap for reconstruction of a unilateral breast defect. Sixty-five free flaps were performed in 61 patients with 3 patients receiving 2 free flaps for reconstruction of extensive head and neck defects and 1 patient who required a second flap for partial flap loss. Trunk and extremity reconstruction was less common with 2 free flaps performed in each group. Overall, 19 patients (22.6%) developed complications and 14 required a return to the operating room. There were no flap losses in this cohort. Thorough preoperative evaluation and workup, meticulous surgical technique and intraoperative planning, and diligent postoperative monitoring and prompt intervention are critical for flap success. Conclusions: As a young plastic surgeon embarking in reconstructive plastic surgery at an academic institution, the challenges and dilemmas presented in the first year of practice have been daunting but also represent opportunities for learning and improvement. Skills and knowledge acquired from time, experience, and mentors are invaluable in optimizing outcomes in microvascular free flap reconstruction. PMID:25289221

  14. Investigation of drag reduction through a flapping mechanism on circular cylinder

    NASA Astrophysics Data System (ADS)

    Asif, Md. Asafuddoula; Gupta, Avijit Das; Rana, M. D. Juwel; Ahmed, Dewan Hasan

    2016-07-01

    During flapping wing, a bird develops sufficient lift force as well as counteracts drag and increases its speed through different orientations of feathers on the flapping wings. Differently oriented feathers play a significant role in drag reduction during flying of a bird. With an objective to investigate the effect of installation of such flapping mechanism as a mean of drag reduction in case of flow over circular cylinder, this concept has been implemented through installation of continuous and mini flaps, made of MS sheet metal, where flaps are oriented at different angles as like feathers of flapping wings. The experiments are carried out in a subsonic wind tunnel. After validation and comparison with conventional result of drag analysis of a single cylinder, effects of flapping with Reynolds number variation, implementation of different orientations of mini flaps and variation of different interspacing distance between mini flaps are studied to find the most effective angle of attack of drag reduction on the body of circular cylinder. This research show that, installation of continuous flap reduces value of drag co-efficient, CD up to 66%, where as mini flaps are found more effective by reducing it up to 73%. Mini flaps of L/s=6.25, all angled at 30O, at the 30O angular position on the body of circular cylinder has been found the most effective angle of attack for drag reduction in case of flow over circular cylinder.

  15. Analytic review of 2372 free flap transfers for head and neck reconstruction following cancer resection.

    PubMed

    Nakatsuka, Takashi; Harii, Kiyonori; Asato, Hirotaka; Takushima, Akihiko; Ebihara, Satoshi; Kimata, Yoshihiro; Yamada, Atsushi; Ueda, Kazuki; Ichioka, Shigeru

    2003-08-01

    Microvascular free tissue transfer has gained world-wide acceptance as a means of reconstructing post-oncologic surgical defects in the head and neck region. Since 1977, the authors have introduced this reconstructive procedure to head and neck reconstruction after cancer ablation, and a total of 2372 free flaps were transferred in 2301 patients during a period of over 23 years. The most frequently used flap was the rectus abdominis flap (784 flaps: 33.1 percent), followed by the jejunum (644 flaps: 27.2 percent) and the forearm flap (384 flaps: 16.2 percent). In the reported series, total and partial flap necrosis accounted for 4.2 percent and 2.5 percent of cases, respectively. There was a significant statistical difference ( p < 0.05) in complete flap survival rate between immediate and secondary reconstruction cases. The authors believe that the above-mentioned three flaps have been a major part of the armamentarium for head and neck reconstruction because of a lower rate of flap necrosis, compared to other flaps. PMID:14515225

  16. 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

  17. [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

  18. Application of free radial forearm flap in reconstruction of the face and oral cavity.

    PubMed

    Tvrdek, M; Nejedlý, A; Kletenský, J; Pros, Z

    1994-01-01

    The authors have shown the possibilities of application of the free radial forearm flap in clinical cases when reconstructing defects in the region of the face and of oral cavity. This flap is particularly useful in cases where it is necessary to duplicate the flap and to reconstruct two layers at the same time. PMID:7618399

  19. Deep circumflex iliac artery (DCIA) free flap without DCIA: report of a unique case.

    PubMed

    Jairath, David; Hage, J Joris

    2004-10-01

    The iliac crest free flap is a reliable source of cancellous bone, muscle, and skin. The vascularization of this flap arises from the deep circumflex iliac artery (DCIA) which allegedly is always present. The authors report a unique case of successful microvascular transplantation of an iliac crest osteomyocutaneous free flap in a patient in whom the DCIA and DCIV were absent. PMID:15534778

  20. All in a Flap About Reading: Catherine Morland, Spot, and Mister Wolf.

    ERIC Educational Resources Information Center

    Smith, Vivienne

    2001-01-01

    Considers how lift-the-flap books attract very little critical attention. Attempts to redress this imbalance by suggesting that lift-the-flap books provide useful lessons in reading both literature and pictures for the young reader, that a grammar of lift-the-flap books can be postulated to facilitate their description and discussion, and that the…

  1. Combination Nasolabial Transposition Flap and Island Pedicle Flap Following Mohs Surgery of Simultaneous Basal Cell Carcinomas Involving Both Nasal Alae

    PubMed Central

    Lee, Chae Young; Lee, Yeong Kyu; Choi, Kyu Won; Lee, Chae Wook; Kim, Ki Ho

    2008-01-01

    The nasal ala is a challenging area for surgical reconstruction, with thick sebaceous skin, the lack of an ample tissue reservoir, and an adjacent free margin. Numerous flaps have been reported for the repair of alae defects. A 71-year-old woman with simultaneous basal cell carcinomas involving both nasal alae was treated by Mohs micrographic surgery. The surgical defects measured 1.5×1.5 cm on the center of the right nasal ala and 1.0×1.0 cm on the left nasal ala, including the alar crease and rim. The right nasal ala was used as a nasolabial transposition flap and the left nasal ala was reconstructed by an island pedicle flap. The final shape and texture were satisfactory. The flaps survived and nasal symmetry was preserved. Combined nasolabial transposition and island pedicle flaps thus offer a superior esthetic and functional result owing to minimized tension. This may be a valuable reconstructive option in the repair of bilateral nasal alae defects.

  2. Interaction of Two Flapping Flags in Axial Flow

    NASA Astrophysics Data System (ADS)

    Gunter, Amy-Lee; Fayed, Mohamed; Abderrahmane, Hamid Ait; Paidoussis, Michael P.; Ng, Hoi Dick

    2010-11-01

    The flapping of two parallel flags in axial low turbulence flow is investigated experimentally inside a small scale wind tunnel test section. The variables of the problem are the size and flexural rigidity of the flags, and the distance that separates the two flags. The flow velocity represents the control parameter that governs the coupling and flapping mode of the flags. Two flapping modes, in-phase and out-of-phase modes, were observed in the experiment. Image processing technique was used and the time series of a given point on the flag edge was analyzed. The stability condition of the flags was obtained and compared to the recent theoretical models. The dynamics of the coupling between the two flags is also studied.

  3. An Experimental Investigation on Flapping Flexible Membrane Wings

    NASA Astrophysics Data System (ADS)

    Hu, Hui; Abate, Gregg; Albertani, Roberto

    2008-11-01

    Thin and flexible membrane wings are unique to flying and gliding mammals, such as bats, flying squirrels and sugar gliders. These animals exhibit extraordinary flight capabilities with respect to maneuvering and agility that are not observed in other species of comparable size. In this study, comprehensive wind tunnel experiments are conducted to assess the effects of membrane flexibility (rigidity) on the aerodynamic performance of the flapping flexible membrane wings to quantify the benefits of using flexible membrane wings compared with conventional rigid wings for flapping-wing Micro-Air-Vehicle (MAV) applications. The present study is conducted from the viewpoint of aerospace engineers to try to leverage the unique feature of flexible membrane airfoils/wings found in bats and other flying/gliding mammals as an effective aerodynamic control method to explore the potential applications of such non-traditional, bio-inspired flexible membrane wings to flapping-wing MAVs to improve their flight agility and maneuverability.

  4. The Autospreader Flap for Midvault Reconstruction following Dorsal Hump Resection.

    PubMed

    Moubayed, Sami P; Most, Sam P

    2016-02-01

    Dorsal hump reduction without adequate reconstitution of the midvault can often result in cosmetic or functional problems. One of the simplest techniques to avoid these problems is the use of the excess upper lateral cartilage to reconstruct the midvault (the spreader flap or autospreader). Herein we outline the history of the technique and present the specific indications and contraindications, as well as describe our method for achieving it successfully. Case studies are presented with the specific indications. Grafting alternatives to the spreader flap are also outlined. The spreader flap technique offers multiple advantages, including maximal use of local tissues, simplicity, and airway preservation. Disadvantages are the use of an external approach and the inability to use it alone in the presence of severe asymmetries. PMID:26862962

  5. Video measurements of instantaneous forces of flapping wing vehicles

    NASA Astrophysics Data System (ADS)

    Jennings, Alan; Mayhew, Michael; Black, Jonathan

    2015-12-01

    Flapping wings for small aerial vehicles have revolutionary potential for maneuverability and endurance. Ornithopters fail to achieve the performance of their biological equivalents, despite extensive research on how animals fly. Flapping wings produce peak forces due to the stroke reversal of the wing. This research demonstrates in-flight measurements of an ornithopter through the use of image processing, specifically measuring instantaneous forces. Results show that the oscillation about the flight path is significant, being about 20% of the mean velocity and up to 10 g's. Results match forces with deformations of the wing to contrast the timing and wing shape of the upstroke and the downstroke. Holding the vehicle fixed (e.g. wind tunnel testing or simulations) structural resonance is affected along with peak forces, also affecting lift. Non-contact, in-flight measurements are proposed as the best method for matching the flight conditions of flapping wing vehicles.

  6. The role of flaps and grafts in modern hypospadiology

    PubMed Central

    Wallis, M. Chad; Braga, Luis; Khoury, Antoine

    2008-01-01

    The modern hypospadiologist must be proficient in the use of both vascularized flaps and free grafts. When choosing a repair for any given patient with hypospadias, one must consider the length of the urethroplasty, the presence and degree of ventral curvature and perhaps most importantly, the surgeon’s own experience. Not all repairs are created equally and different complication rates and cosmetic outcomes can be seen among different surgeons utilizing the same technique. Each surgeon tends to infuse their own modifications to any given technique and many of these modifications go unreported. It is incumbent upon each surgeon to be familiar with a wide variety of techniques, which invariably includes the use of flaps and grafts. We present a spectrum of the uses of flaps and grafts in modern hypospadiology. PMID:19468398

  7. Acute effects of cigarette smoke exposure on experimental skin flaps

    SciTech Connect

    Nolan, J.; Jenkins, R.A.; Kurihara, K.; Schultz, R.C.

    1985-04-01

    Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smoking in the perioperative period are suggested by this study.

  8. Flapping dynamics of a flexible propulsor near ground

    NASA Astrophysics Data System (ADS)

    Ryu, Jaeha; Park, Sung Goon; Kim, Boyoung; Sung, Hyung Jin

    2016-06-01

    The flapping motion of a flexible propulsor near the ground was simulated using the immersed boundary method. The hydrodynamic benefits of the propulsor near the ground were explored by varying the heaving frequency (St) of the leading edge of the flexible propulsor. Propulsion near the ground had some advantages in generating thrust and propelling faster than propulsion away from the ground. The mode analysis and flapping amplitude along the Lagrangian coordinate were examined to analyze the kinematics as a function of the ground proximity (d) and St. The trailing edge amplitude (a_tail ) and the net thrust (overline{{F}}_x ) were influenced by St of the flexible propulsor. The vortical structures in the wake were analyzed for different flapping conditions.

  9. Chord-wise Tip Actuation on Flexible Flapping Plates

    NASA Astrophysics Data System (ADS)

    Martin, Nathan; Gharib, Morteza

    2015-11-01

    The aerodynamic characteristics of low aspect ratio flapping plates are strongly influenced by the interaction between tip and edge vortices. This has led to the development of tip actuation mechanisms which bend the tip towards the root of the plate in the span-wise direction during oscillation to investigate its impact. In our current work, a tip actuation mechanism to bend a flat plate's two free corners towards one another in the chord-wise direction is developed using a shape memory alloy. The aerodynamic forces and resulting flow field are investigated from dynamically altering the tip chord-wise curvature while flapping. The frequency of oscillation, stroke angle, flexibility, and tip actuation timing are independently varied to determine their individual effects. These results will further the fundamental understanding of flapping wing aerodynamics. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE 1144469.

  10. Aircraft wake-vortex minimization by use of flaps

    NASA Technical Reports Server (NTRS)

    Corsiglia, V. R.; Dunham, R. E., Jr.

    1977-01-01

    A survey was made of research on the alleviation of the trailing vortex hazard by altering span loading with flaps on the generator airplane. Flap configurations of the generator that shed multiple vortices were found to have wakes that dispersed by vortex merging and sinusoidal instability. Reductions of approximately 50 percent in both the wake rolling moment imposed on a following aircraft and the aircraft separation requirement were achieved in the ground based and flight test experiments by deflecting the trailing edge flaps more inboard than outboard. Significantly, this configuration did not increase the drag or vibration on the generating aircraft compared to the conventional landing configuration. Ground based results of rolling moment measurement and flow visualization are shown, using a water tow facility, an air tow facility, and a wind tunnel. Flight test results are also shown, using a full scale B-747 airplane. General agreement was found among the results of the various ground based facilities and the flight tests.

  11. Interactions between butterfly scales and unsteady flows during flapping flight

    NASA Astrophysics Data System (ADS)

    Jones, Robert; Lang, Amy

    2008-11-01

    Recent research has shown that the highly flexible wings of butterflies in flapping flight develop vortices along their leading and trailing edges. Butterfly scales (approximately 100 microns) have a shingled pattern and extend into the boundary layer. These scales could play a part in controlling separation in this 3-dimensional complex flow field. Biomimetic applications of butterfly scales may aid in the development of flapping wing micro air vehicles. In this study, we observed that the orientation of the scales may relate to the local flow field, and might move or shift during flight. Monarch butterflies were trained to fly in a low speed smoke tunnel for visualization. Scales were removed from the leading and trailing edges and specimens were photographed at 500 frames per second. Variation in flapping pattern and flight fitness are discussed.

  12. Finite element analysis of aeroacoustic jet-flap flows

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Manhardt, P. D.

    1977-01-01

    A computational analysis was performed on the steady, turbulent aerodynamic flowfields associated with a jet-blown flap. For regions devoid of flow separation, a parabolic approximation to the governing time-averaged Navier-Stokes equations was applied. Numerical results are presented for the symmetry plane flow of a slot-nozzle planar jet flap geometry, including prediction of flowfield evolution within the secondary mixing region immediately downstream of the trailing edge. Using a two equation turbulence kinetic energy closure model, rapid generation and decay of large spatial gradients in mean and correlated fluctuating velocity components within the immediate wake region were predicted. Modifications to the turbulent flow structure, as induced by porous surface treatment of the flap, were evaluated. The recirculating flow within a representative discrete slot in the surface was evaluated, using the two dimensional, time-averaged Navier-Stokes equations.

  13. Efficient flapping flight using flexible wings oscillating at resonance

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Masoud, Hassan

    2010-11-01

    Using a fully-coupled computational approach that integrates the lattice Boltzmann and lattice spring models, we investigate the three-dimensional aerodynamics of flexible flapping wings at resonance. The wings are tilted from the horizontal and oscillate vertically driven by a force applied at the wing root. Our simulations reveal that resonance oscillations drastically enhance the aerodynamic efficiency of low-Reynolds-number plunging, and yield lift and lift-to-weight ratio comparable to the values typical for small insects. Within the resonance band, we identify two flapping regimes leading to the maximum lift and the maximum efficiency, which are characterized by different bending modes of flexible flapping wings. Our results indicate the feasibility of using flexible wings driven by a simple harmonic stroke for designing efficient microscale flying machines.

  14. Detached Eddy Simulation of Flap Side-Edge Flow

    NASA Technical Reports Server (NTRS)

    Balakrishnan, Shankar K.; Shariff, Karim R.

    2016-01-01

    Detached Eddy Simulation (DES) of flap side-edge flow was performed with a wing and half-span flap configuration used in previous experimental and numerical studies. The focus of the study is the unsteady flow features responsible for the production of far-field noise. The simulation was performed at a Reynolds number (based on the main wing chord) of 3.7 million. Reynolds Averaged Navier-Stokes (RANS) simulations were performed as a precursor to the DES. The results of these precursor simulations match previous experimental and RANS results closely. Although the present DES simulations have not reached statistical stationary yet, some unsteady features of the developing flap side-edge flowfield are presented. In the final paper it is expected that statistically stationary results will be presented including comparisons of surface pressure spectra with experimental data.

  15. 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

  16. 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

  17. Hyperbaric oxygen (HBO2) treatment for a failing facial flap.

    PubMed

    McCrary, Brian F

    2007-01-01

    Hyperbaric oxygen (HBO2) is an approved treatment for 13 pathological entities. One of these indications--a failing facial flap--is presented in this case report of a traumatic wound to the face and right axilla after an unprovoked pit bull attack on a 4 year old girl. Surgical repair was started acutely but the facial flap became congested and ischaemic, indicating deterioration of the blood supply. HBO2 treatments were initiated twice a day, resulting in remarkably decreased swelling and discomfort after the first treatment. Leeching was also used to assist with reduction of venous congestion in the flap. The patient was discharged 5 days later with a well perfused, mostly intact, incision with minimal tenderness. Surgical repair was required for a small area of wound dehiscence. Photographs documenting the patient's progress with HBO2 are presented. A discussion of the mechanisms of action of HBO2 and its beneficial effects is provided in this case. PMID:17267665

  18. 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

  19. Flap Side-Edge Noise: Acoustic Analysis of Sen's Model

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.; Martin, James E.

    1996-01-01

    The two-dimensional flap side-edge flow model developed by Sen is analyzed to reveal the noise production potential of the proposed mechanism. The model assumes that a vortex will form at the equilibrium position off the side edge of the flap. The vortex is then perturbed away from the equilibrium position by incoming turbulence causing it to oscillate and thus radiate sound. The noise field is calculated three-dimensionally by taking the flap to have a finite chord. Spectra and directivity of the farfield sound are presented. In addition, the effect of retarded time differences is evaluated. The parameters in the model are related to typical aircraft parameters and noise reduction possibilities are proposed.

  20. Passive Porous Treatment for Reducing Flap Side-Edge Noise

    NASA Technical Reports Server (NTRS)

    Choudhari, Meelan M.; Khorrami, Mehdi R.

    2008-01-01

    A passive porous treatment has been proposed as a means of suppressing noise generated by the airflow around the side edges of partial-span flaps on airplane wings when the flaps are extended in a high-lift configuration. The treatment proposed here does not incur any aerodynamic penalties and could easily be retrofit to existing airplanes. The treatment could also be applied to reduce noise generated by turbomachinery, including wind turbines. Innovative aspects of the proposed treatment include a minimum treatment area and physics-based procedure for treatment design. The efficacy of the treatment was confirmed during wind-tunnel experiments at NASA Ames, wherein the porous treatment was applied to a minute surface area in the vicinity of a flap edge on a 26-percent model of Boeing 777-200 wing.

  1. T-FLAP improvement for VOS Program

    NASA Astrophysics Data System (ADS)

    Marcelli, Marco; Piermattei, Viviana; Madonia, Alice; Mainardi, Umberto; Manzella, Giuseppe M. R.

    2010-05-01

    The operational oceanography has been engaged in the development of new acquisition, transmission and assimilation systems in order to have the widest possible coverage of real time informations, reflecting the guidelines of the World Meteorological Organization (WMO) and of the Intergovernmental Oceanographic Commission (IOC). Physical and biological processes of marine ecosystems have a high spatial and temporal variability, whose study is possible only through high resolution and synoptic observations. More than for the physical variables, the biological ones have to be observed in situ. Especially in the mid-high latitudes, a deep observation of the water column is needed, because of the typical distribution of phytoplankton's biomass (Mann and Lazier, 1991). In the last times an extensive use of XBT was performed in order to provide near real time analysis of the ocean temperature, but there is still a lack in the biomass estimation. T-FLAP technology (Temperature and Fluorescence LAunchable Probe - Marcelli et al. 2007) was designed to answer to the claim of a cost effective temperature and fluorescence autonomous probe, to be used on ships of opportunity for the Voluntary Observing Ship Program (VOS). During the last three years the probe was upgraded and improved both in materials and in measure sensitivity. New LEDs were mounted to increase the radiant power of the excitation source.. In order to evaluate the red filter efficiency to detect fluorescence chlorophyll a emission wavelengths, transmittance of new available filters in the range 682-685 nm was calculated. In vivo fluorescence spectra of each filter were also performed on samples from Chlorella sp. cultures, to assess the percentage of the fluorescence emission peak transmitted by the filters. A multiple system was designed and realized for a high accuracy dynamic calibration of the probes.

  2. 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

  3. Paradoxical effects of heme arginate on survival of myocutaneous flaps

    PubMed Central

    Czopek, Alicja; Wigmore, Stephen J.; Kluth, David C.

    2013-01-01

    Ischemia reperfusion injury (IRI) contributes to partial flap and solid organ transplant failure. Heme-oxygenase 1 (HO-1) is an inducible, cytoprotective enzyme which protects against IRI in solid organ transplant models. Heme arginate (HA), a HO-1 inducer, is a promising, translatable, preconditioning agent. This study investigated the effects of preconditioning with HA on the clinical outcome of a myocutaneous IRI model. Forty male Lewis rats were randomized to intravenously receive 1) Control-NaCl, 2) HA, 3) HA and tin mesoporphyrin (SnMP), a HO-1 inhibitor; and 4) SnMP alone. Twenty-four hours later, an in situ transverse rectus abdominis myocutaneous flap was performed under isoflurane anesthesia. Viability of flaps was measured clinically and by laser-Doppler perfusion scanning. In vitro work on human epidermal keratinocytes (HEKa) assessed the effects of HA, SnMP, and the iron chelator desferrioxamine on 1) cytotoxicity, 2) intracellular reactive oxygen species (ROS) concentration, and 3) ROS-mediated DNA damage. In contrast to our hypothesis, HA preconditioning produced over 30% more flap necrosis at 48 h compared with controls (P = 0.02). HA-containing treatments produced significantly worse flap perfusion at all postoperative time points. In vitro work showed that HA is cytotoxic to keratinocytes. This cytotoxicity was independent of HO-1 and was mediated by the generation of ROS by free heme. In contrast to solid organ data, pharmacological preconditioning with HA significantly worsened clinical outcome, thus indicating that this is not a viable approach in free flap research. PMID:24089372

  4. Reconstruction of Female Urethra with Tubularized Anterior Vaginal Flap

    PubMed Central

    Sawant, Ajit; Kumar, Vikash; Pawar, Prakash; Tamhankar, Ashwin; Bansal, Sumit; Kapadnis, Lomesh; Savalia, Abhishek

    2016-01-01

    Introduction Female urethral injury is a rare disease. Causes of urethral injuries are prolonged obstructed labour, gynaecological surgeries like vaginoplasty and post traumatic urethral injuries. The present study was conducted to evaluate outcome of female urethral reconstruction using tubularized anterior vaginal wall flap covered with fibroadipose martius flap and autologous fascia sling in patients with urethral loss. Aim Aim of study was to evaluate outcome of reconstruction of female urethra with tubularized anterior vaginal flap. Materials and Methods Retrospective analysis of all the patients with complete urethral loss was done from August 2008 to July 2015. Total seven patients were included in study. All patients presenting with total urethral loss were included. These patients were treated with tubularized anterior vaginal flap. Neourethra was covered with Martius labial flap and autologous fascia lata or rectus abdominis fascia sling. Most common cause of urethral loss was obstructed labour (57.1%). Postoperatively patients were assessed for continence, urine flow rate, ultrasound for upper urinary tract and post void residue. Results Mean operative time was 180 minutes (160-200 minutes) and Intraoperative blood loss was 220ml (170-260 ml). Mean postoperative hospital stay was eight days (seven to nine days) Mean post surgery maximum urine flow rate was more than 15ml/sec (6.7-18.2ml/sec) and mean post void residual urine was 22.5ml (10-50ml). Median follow-up time was 35 months. All patients were catheter free and continent post three weeks of surgery except one patient who developed mild stress urinary incontinence. One patient developed urethral stenosis which was managed by intermittent serial urethral dilatation. Conclusion Female neourethral reconstruction with tabularized anterior vaginal flap and autologous pubovaginal sling is feasible in patients of total urethral loss with success rate of approximately 86%. It should be considered in

  5. Aeroelastic Airworthiness Assesment of the Adaptive Compliant Trailing Edge Flaps

    NASA Technical Reports Server (NTRS)

    Herrera, Claudia Y.; Spivey, Natalie D.; Lung, Shun-fat; Ervin, Gregory; Flick, Peter

    2015-01-01

    The Adaptive Compliant Trailing Edge (ACTE) demonstrator is a joint task under the National Aeronautics and Space Administration Environmentally Responsible Aviation Project in partnership with the Air Force Research Laboratory and FlexSys, Inc. (Ann Arbor, Michigan). The project goal is to develop advanced technologies that enable environmentally friendly aircraft, such as adaptive compliant technologies. The ACTE demonstrator flight-test program encompassed replacing the Fowler flaps on the SubsoniC Aircraft Testbed, a modified Gulfstream III (Gulfstream Aerospace, Savannah, Georgia) aircraft, with control surfaces developed by FlexSys. The control surfaces developed by FlexSys are a pair of uniquely-designed unconventional flaps to be used as lifting surfaces during flight-testing to validate their structural effectiveness. The unconventional flaps required a multidisciplinary airworthiness assessment to prove they could withstand the prescribed flight envelope. Several challenges were posed due to the large deflections experienced by the structure, requiring non-linear analysis methods. The aeroelastic assessment necessitated both conventional and extensive testing and analysis methods. A series of ground vibration tests (GVTs) were conducted to provide modal characteristics to validate and update finite element models (FEMs) used for the flutter analyses for a subset of the various flight configurations. Numerous FEMs were developed using data from FlexSys and the ground tests. The flap FEMs were then attached to the aircraft model to generate a combined FEM that could be analyzed for aeroelastic instabilities. The aeroelastic analysis results showed the combined system of aircraft and flaps were predicted to have the required flutter margin to successfully demonstrate the adaptive compliant technology. This paper documents the details of the aeroelastic airworthiness assessment described, including the ground testing and analyses, and subsequent flight

  6. Paradoxical effects of heme arginate on survival of myocutaneous flaps.

    PubMed

    Edmunds, Marie-Claire; Czopek, Alicja; Wigmore, Stephen J; Kluth, David C

    2014-01-01

    Ischemia reperfusion injury (IRI) contributes to partial flap and solid organ transplant failure. Heme-oxygenase 1 (HO-1) is an inducible, cytoprotective enzyme which protects against IRI in solid organ transplant models. Heme arginate (HA), a HO-1 inducer, is a promising, translatable, preconditioning agent. This study investigated the effects of preconditioning with HA on the clinical outcome of a myocutaneous IRI model. Forty male Lewis rats were randomized to intravenously receive 1) Control-NaCl, 2) HA, 3) HA and tin mesoporphyrin (SnMP), a HO-1 inhibitor; and 4) SnMP alone. Twenty-four hours later, an in situ transverse rectus abdominis myocutaneous flap was performed under isoflurane anesthesia. Viability of flaps was measured clinically and by laser-Doppler perfusion scanning. In vitro work on human epidermal keratinocytes (HEKa) assessed the effects of HA, SnMP, and the iron chelator desferrioxamine on 1) cytotoxicity, 2) intracellular reactive oxygen species (ROS) concentration, and 3) ROS-mediated DNA damage. In contrast to our hypothesis, HA preconditioning produced over 30% more flap necrosis at 48 h compared with controls (P = 0.02). HA-containing treatments produced significantly worse flap perfusion at all postoperative time points. In vitro work showed that HA is cytotoxic to keratinocytes. This cytotoxicity was independent of HO-1 and was mediated by the generation of ROS by free heme. In contrast to solid organ data, pharmacological preconditioning with HA significantly worsened clinical outcome, thus indicating that this is not a viable approach in free flap research. PMID:24089372

  7. Therapeutic Outcomes of Pectoralis Major Muscle Turnover Flap in Mediastinitis

    PubMed Central

    Bagheri, Reza; Tashnizi, Mohammad Abbasi; Haghi, Seyed Ziaollah; Salehi, Maryam; Rajabnejad, Ata’ollah; Safa, Mohsen Hatami Ghale; Vejdani, Mohammad

    2015-01-01

    Background This study aimed to evaluate the therapeutic results and safety of pectoralis major muscle turnover flaps in the treatment of mediastinitis after coronary artery bypass grafting (CABG) procedures. Methods Data regarding 33 patients with post-CABG deep sternal wound infections (DSWIs) who underwent pectoralis major muscle turnover flap procedures in the Emam Reza and Ghaem Hospitals of Mashhad, Iran were reviewed in this study. For each patient, age, sex, hospital stay duration, remission, recurrence, and associated morbidity and mortality were evaluated. Results Of the 2,447 CABG procedures that were carried out during the time period encompassed by our study, DSWIs occurred in 61 patients (2.5%). Of these 61 patients, 33 patients (nine females [27.3%] and 24 males [72.7%]) with an average age of 63±4.54 years underwent pectoralis major muscle turnover flap placement. Symptoms of infection mainly occurred within the first 10 days after surgery (mean, 10.24±13.62 days). The most common risk factor for DSWIs was obesity (n=16, 48.4%) followed by diabetes mellitus (n=13, 39.4%). Bilateral and unilateral pectoralis major muscle turnover flaps were performed in 20 patients (60.6%) and 13 patients (39.4%), respectively. Complete remission was achieved in 25 patients (75.7%), with no recurrence in the follow-up period. Four patients (12.1%) needed reoperation. The mean hospitalization time was 11.69±6.516 days. Four patients (12.1%) died during the course of the study: three due to the postoperative complication of respiratory failure and one due to pulmonary thromboembolism. Conclusion Pectoralis major muscle turnover flaps are an optimal technique in the treatment of post-CABG mediastinitis. In addition to leading to favorable therapeutic results, this flap is associated with minimal morbidity and mortality, as well as a short hospitalization time. PMID:26290837

  8. Protein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the major structural and functional components of all cells in the body. They are macromolecules that comprise 1 or more chains of amino acids that vary in their sequence and length and are folded into specific 3-dimensional structures. The sizes and conformations of proteins, therefor...

  9. Proteins.

    ERIC Educational Resources Information Center

    Doolittle, Russell F.

    1985-01-01

    Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

  10. Unsteady wake measurements of an oscillating flap at transonic speeds

    NASA Technical Reports Server (NTRS)

    Bodapati, S.; Lee, C.-S.

    1984-01-01

    The steady and unsteady wake profiles of an airfoil with an oscillating flap were measured at nominal free stream Mach number of 0.8 in the NASA Ames 11 x 11-foot wind tunnel. The instantaneous wake velocity and pressure profiles at four axial locations are presented up to one chord length from the trailing edge. Both fundamental harmonic frequency and typical time history data are presented to observe the effects of airfoil incidence and flap angle. The drag coefficient obtained from the wake pressure measurements is compared with that obtained from the airfoil pressure distribution.

  11. 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

  12. Nasolabial Flap in Maxillofacial Gunshot Trauma: A Case Series

    PubMed Central

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2016-01-01

    Introduction The nasolabial flap (NLF) has many advantages in oromaxillary reconstruction, but the majority of cases are reconstructions after pathologic resections. Its usage in trauma surgery, especially in the management of gunshot wounds, is rarely mentioned. Case Presentation Three cases involving gunshot injuries to the face are presented: one for reconstruction of the nasal ala, another for bone graft coverage in mandibular reconstruction, and the third for the repair of premaxillary hard and soft tissue avulsive defects. Conclusions The NLF is a thin, pliable flap and is useful for intraoral and facial reconstruction of trauma patients with small to moderate soft tissue loss. PMID:27148497

  13. Chimeric Anterolateral Thigh Flap for Total Thoracic Esophageal Reconstruction.

    PubMed

    Ruiz-Moya, Alejandro; Segura-Sampedro, Juan J; Sicilia-Castro, Domingo; Carvajo-Pérez, Francisco; Gómez-Cía, Tomás; Vázquez-Medina, Antonio; Ibáñez-Delgado, Francisco

    2016-01-01

    Gastric pull-up is generally the first choice for a total thoracic esophageal reconstruction. Malfunction of this gastric conduit is uncommon, but devastating when it occurs: it causes marked comorbidity to the patient, preventing oral intake and worsening quality of life. Secondary salvage thoracic esophageal reconstruction surgery is usually performed with free or pedicled jejunum flaps or colon interposition. We present a case of a total thoracic esophageal reconstruction with an externally monitored chimeric anterolateral thigh flap, extending from the cervical esophagus to the retrosternal gastroplasty remnant. Intestinal reconstructive techniques were not an available option for this patient. PMID:26694271

  14. Treatment of Sternal Wound Infection Using a Free Myocutaneous Flap.

    PubMed

    Chiang, I-han; Chen, Shyi-Gen; Wang, Chih-Hsin

    2015-11-01

    Deep sternal wound infections are potentially life-threatening complications after cardiac operations because they can spread into the mediastinum and cause postoperative morbidity and mortality. We present a 65-year-old man with a history of coronary artery bypass grafting. A large sternal defect was left after debridement. After brief vacuum-assisted closure (VAC), a free myocutaneous flap of the anterolateral thigh (ALT) was used to fill the dead space. At the 9-month follow-up, the wound had healed completely without tissue loss or complications, and the patient returned to normal life. This was a successful treatment of a deep sternal wound with free flap coverage. PMID:26522542

  15. Experimental study of flapping jets in a soap film

    NASA Astrophysics Data System (ADS)

    Lee, Julia; Kim, Ildoo; Mandre, Shreyas

    2015-11-01

    Plateau and Rayleigh's observation and explanation on jet instability have inspired us over the years and there has been a significant advance in understanding the jet dynamics. Here, we present a quasi-two-dimensional experimental study of flapping jets in a soap film. Newtonian and non-Newtonian solutions are injected in a flowing soap film. Thinning, break-ups, and beads-on-a-string of the jets, and axisymmetric vortices shredded from the flapping jets are visualized. We employ PIV of the flow motion around the jets to gain an understanding of the roles of instabilities in the flow.

  16. Spreader flaps for middle vault contour and stabilization.

    PubMed

    Kovacevic, Milos; Wurm, Jochen

    2015-02-01

    Nasal hump excision is common during septorhinoplasty. Without appropriate restoration of the middle nasal vault, cosmetic and functional problems may ensue. Recently, spreader flaps have become an established alternative to traditional spreader grafts. Typical indications include primary rhinoplasty patients with hump noses, hump/tension noses, and moderately hooked or crooked noses. When suitable patients are selected, spreader flaps and their modifications represent a reliable alternative to the standard spreader graft, and when all of the necessary prerequisites are met, this technique obviates the need for additional cartilage grafting in most cases. PMID:25430925

  17. Noise generation at the side edges of flaps

    NASA Astrophysics Data System (ADS)

    Hardin, J. C.

    1980-06-01

    The recently observed phenomenon of high noise radiation from the side edges of flaps is investigated by way of a two-dimensional model based upon a physical picture of chordwise boundary layer vorticity being swept around the edge by spanwise flow on the flap. The trajectory and resulting noise radiation for a discrete vortex in such a flow is obtained. Further, a mathematical condition for the vortex to be captured by the flow and swept around the edge is derived. The sound generation depends strongly upon the vortex strength and distance from the edge and can be more intense than trailing edge noise in agreement with experimental observations.

  18. 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

  19. Free style perforator based propeller flaps: Simple solutions for upper extremity reconstruction!

    PubMed Central

    Panse, Nikhil; Sahasrabudhe, Parag

    2014-01-01

    Background: The introduction of perforator flaps by Koshima et al. was met with much animosity in the plastic surgery fraternity. The safety concerns of these flaps following the intentional twist of the perforators have prevented widespread adoption of this technique. Use of perforator based propeller flaps in the lower extremity is gradually on the rise, but their use in upper extremity reconstruction is infrequently reported, especially in the Indian subcontinent. Materials and Methods: We present a retrospective series of 63 free style perforator flaps used for soft tissue reconstruction of the upper extremity from November 2008 to June 2013. Flaps were performed by a single surgeon for various locations and indications over the upper extremity. Patient demographics, surgical indication, defect features, complications and clinical outcome are evaluated and presented as an uncontrolled case series. Results: 63 free style perforator based propeller flaps were used for soft tissue reconstruction of 62 patients for the upper extremity from November 2008 to June 2013. Of the 63 flaps, 31 flaps were performed for trauma, 30 for post burn sequel, and two for post snake bite defects. We encountered flap necrosis in 8 flaps, of which there was complete necrosis in 4 flaps, and partial necrosis in four flaps. Of these 8 flaps, 7 needed a secondary procedure, and one healed secondarily. Although we had a failure rate of 12-13%, most of our failures were in the early part of the series indicative of a learning curve associated with the flap. Conclusion: Free style perforator based propeller flaps are a reliable option for coverage of small to moderate sized defects. Level of Evidence: Therapeutic IV. PMID:24987209

  20. The Modified 3-square Flap Method for Reconstruction of Toe Syndactyly

    PubMed Central

    Watanabe, Ayako

    2016-01-01

    Bandoh reported the 3-square-flap method as a procedure for interdigital space reconstruction in patients with minor syndactyly. We recently modified this flap design so that it could be used in the treatment of toe syndactyly involving fusion of the areas distal to the proximal interphalangeal joint. With our method, the reconstructed interdigital space consists of 4 oblong flaps (A through D). Flaps A and D are designed on the dorsal side, flap B is designed on the frontal plane of the interdigital space, and flap C is designed on the plantar side. Flaps A, B, and C are raised immediately below the dermis in a manner that allowed slight fat tissue to adhere to each flap. Flap D is freed to a degree minimally needed for dislocation, while leaving a thick subcutaneous pedicle. Flaps A, B, and C are each folded in 90 degrees; flap D is dislocated to the proximal plane of the reconstructed digit, followed by skin suturing. In this process, suturing is avoided between flaps A and C, between flaps A and D, and between flaps B and D. During the period of 2011 to 2015, we treated 8 patients of toe syndactyly involving fusion distal to the proximal interphalangeal joint. Cases of congenital syndactyly received surgery between the ages of 8 and 11 months. Using this technique, flap ischemia/necrosis was not observed. During the postoperative follow-up period, the interdigital space retained sufficient depth without developing any scar contracture. No case required additional surgery. PMID:27536472

  1. The Modified 3-square Flap Method for Reconstruction of Toe Syndactyly.

    PubMed

    Iida, Naoshige; Watanabe, Ayako

    2016-07-01

    Bandoh reported the 3-square-flap method as a procedure for interdigital space reconstruction in patients with minor syndactyly. We recently modified this flap design so that it could be used in the treatment of toe syndactyly involving fusion of the areas distal to the proximal interphalangeal joint. With our method, the reconstructed interdigital space consists of 4 oblong flaps (A through D). Flaps A and D are designed on the dorsal side, flap B is designed on the frontal plane of the interdigital space, and flap C is designed on the plantar side. Flaps A, B, and C are raised immediately below the dermis in a manner that allowed slight fat tissue to adhere to each flap. Flap D is freed to a degree minimally needed for dislocation, while leaving a thick subcutaneous pedicle. Flaps A, B, and C are each folded in 90 degrees; flap D is dislocated to the proximal plane of the reconstructed digit, followed by skin suturing. In this process, suturing is avoided between flaps A and C, between flaps A and D, and between flaps B and D. During the period of 2011 to 2015, we treated 8 patients of toe syndactyly involving fusion distal to the proximal interphalangeal joint. Cases of congenital syndactyly received surgery between the ages of 8 and 11 months. Using this technique, flap ischemia/necrosis was not observed. During the postoperative follow-up period, the interdigital space retained sufficient depth without developing any scar contracture. No case required additional surgery. PMID:27536472

  2. Combined Use of the Latissimus Dorsi Musculocutaneous Flap and the Anterolateral Thigh Flap to Reconstruct an Extensive Shoulder Defect in an NF-1 Patient

    PubMed Central

    Fujiki, Masahide; Sakisaka, Masanobu; Kawai, Akira

    2016-01-01

    Summary: Soft tissue coverage after the resection of a large malignant peripheral neural sheath tumor (MPNST) is a challenge. We report the successful reconstruction of an extensive shoulder defect after MPNST resection in a patient with a type 1 neurofibromatosis with a novel combination of flaps. A 70-year-old man with type 1 neurofibromatosis presented with a recurrent MPNST on his right shoulder. He underwent a wide excision of the tumor, which resulted in a huge soft tissue defect around the shoulder joint. The resultant defect was reconstructed with a pedicled latissimus dorsi musculocutaneous flap and a free anterolateral thigh flap. The flaps survived, and the wounds healed uneventfully. His affected arm was useful. The combination of a pedicled latissimus dorsi musculocutaneous flap and a free anterolateral thigh flap is a versatile option for the reconstruction of an extensive shoulder defect. PMID:27200231

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Treatment of postburn ear defect with expanded upper arm flap and consequent expansion without skin grafting.

    PubMed

    Hu, Jintian; Liu, Tun; Zhou, Xu; Zhang, Yong-Biao; Zhang, Qingguo

    2014-04-01

    Total ear reconstruction in the postburn auricle is one of the most challenging procedures for plastic surgeons. Adverse factors associated with these procedures include reduced or damaged blood supply, poor elasticity of scar tissue, increased risk of infection, and the possible destruction of skin, temporoparietal fascia, or retroauricular fascia. In cases where patients are severely burned, free flaps, such as radial forearm flaps, contralateral temporoparietal fascial flaps, or omental flaps, can be used as framework envelopes. In this work, we introduced a novel method of expanded upper arm flap transfer, followed by an expansion method of total ear reconstruction without skin grafting. PMID:24589517

  8. Study of external dynamic flap loads on a 6 percent B-1B model

    NASA Technical Reports Server (NTRS)

    Seiner, John M.; Manning, James C.; Capone, Francis J.; Pendergraft, Odis C., Jr.

    1991-01-01

    The origin of dynamic pressure loads on external divergent engine nozzle flaps of the B-1B aircraft was investigated in the NASA/LaRC 16 foot transonic tunnel using a 6 percent full span model with powered engine nacelles. External flap dynamic loads and afterbody drag associated with flap removal were measured using this model. Both dry and max. A/B power nozzles were evaluated in this study. As a result of this study, the principal mechanisms responsible for high dynamic external flap loads were determined along with performance penalty associated with flap removal.

  9. Total lower eyelid reconstruction with superficial temporal fascia flap and porous polyethylene implant: a case report.

    PubMed

    Sahin, Ismail; Aykan, Andac; Acikel, Cengiz; Alhan, Dogan; Isik, Selcuk

    2012-01-01

    Total reconstruction of the eyelid after serious periorbital injury is a challenging procedure for plastic and reconstructive surgery. Although several methods have been used for reconstructing the eyelids, such as advancement flap with fascia lata sling, island mucochrondrocutaneous flap, prefabricated temporal island flap, porous polyethylene and superficial temporal fascia flap, creating a supportive eyelid for housing an artificial eye without complication is still an ongoing problem. In the case presented, superficial temporal fascia flap with porous polyethylene was used for the reconstruction of total lower eyelid. PMID:21778127

  10. Interpolated subcutaneous fat pedicle melolabial flap for large nasal lining defects

    PubMed Central

    Griffin, Garrett R.; Chepeha, Douglas C.; Moyer, Jeffrey S.

    2016-01-01

    Full-thickness nasal deformities are a reconstructive challenge. Restoration of a reliable internal lining is critical for a successful reconstruction. Septal hinge flaps are the workhorse for internal lining defects. However, these and other intranasal mucosal flaps are sometimes unavailable due to prior harvest or previous oncologic resection. We present the two-stage interpolated subcutaneous fat pedicle melolabial flap for lining large defects when traditional intranasal flaps are unavailable. This approach is particularly useful when one forehead flap has already been expended, preserving the patient's remaining forehead tissue for external cover. PMID:22965480

  11. Span load distribution for tapered wings with partial-span flaps

    NASA Technical Reports Server (NTRS)

    Pearson, H A

    1937-01-01

    Tables are given for determining the load distribution of tapered wings with partial-span flaps placed either at the center or at the wing tips. Seventy-two wing-flap combinations, including two aspect ratios, four taper ratios, and nine flap lengths, are included. The distributions for the flapped wing are divided into two parts, one a zero lift distribution due primarily to the flaps and the other an additional lift distribution due to an angle of attack of the wing as a whole. Comparison between theoretical and experimental results for wings indicate that the theory may be used to predict the load distribution with sufficient accuracy for structural purposes.

  12. Distally based sural lesser saphenous neuro-veno-adipo-fascial (NVAF) flap for reconstruction in the foot: lessons learned.

    PubMed

    Patel, Kamlesh B; Bartholomew, Samuel V; Wong, Michael S; Stevenson, Thomas R

    2010-09-01

    We report nine cases in which the neuro-veno-adipo-fascial (NVAF) flap was used to perform reconstruction of foot wounds over a 7-year period. Complications occurred in five (56%) patients. One patient suffered total loss of the flap and four experienced partial loss of the NVAF flap. Complications are to be expected with the use of the NVAF flap for foot wounds, but in most cases the flap is salvageable. The NVAF flap is an option in foot reconstruction when free tissue transfer is not available, contraindicated due to patient factors or when a prior free flap has failed. PMID:20655007

  13. Natural Hirudin Increases Rat Flap Viability by Anti-Inflammation via PARs/p38/NF-κB Pathway

    PubMed Central

    Peng, Liu; Pan, Xinyuan; Yin, Guoqian

    2015-01-01

    The present study aimed to evaluate the effect of natural hirudin on rat random skin flap viability and to determine the mechanism. Forty-eight rats were randomly divided into 2 groups. After the dorsal skin flap operation (3 cm × 10 cm in size), subcutaneous injections of 6 ATU hirudin were administered to group H (n = 24) every 12 h, while group C (n = 24) received an equal volume of 0.9% normal saline. Six rats from each group were euthanized 1, 2, 4, and 7 days after the operation. A full skin sample was collected from these rats to measure the p38-mitogen-activated protein kinase (p38-MAPK), phospho-p38- (Pp38-) MAPK, nuclear factor-κB (NF-κB) p65, phosphor-NF-κB (pNF-κB) p65, tumour necrosis factor- (TNF-) α, interleukin- (IL-) 6, and intercellular adhesion molecule- (ICAM-) 1 levels via western blot (WB) assays. The results showed that flap viability was significantly higher in the hirudin-treated group, which showed a reduced inflammatory response compared with the control group. The Pp38/p38, pNF-κB p65/NF-κB p65, TNF-α, IL-6, and ICAM-1 levels in the hirudin-treated group were lower than those in the control group. The results demonstrated that hirudin could improve random skin flap viability and suggested that this effect maybe occurs by blocking the thrombin/proteinase-activated receptors (PARs)/p38/NF-κB signalling pathway, thus decreasing the inflammatory response. PMID:26770977

  14. Differential Interaction Kinetics of a Bipolar Structure-Specific Endonuclease with DNA Flaps Revealed by Single-Molecule Imaging

    PubMed Central

    Rezgui, Rachid; Lestini, Roxane; Kühn, Joëlle; Fave, Xenia; McLeod, Lauren; Myllykallio, Hannu; Alexandrou, Antigoni; Bouzigues, Cedric

    2014-01-01

    As DNA repair enzymes are essential for preserving genome integrity, understanding their substrate interaction dynamics and the regulation of their catalytic mechanisms is crucial. Using single-molecule imaging, we investigated the association and dissociation kinetics of the bipolar endonuclease NucS from Pyrococcus abyssi (Pab) on 5′ and 3′-flap structures under various experimental conditions. We show that association of the PabNucS with ssDNA flaps is largely controlled by diffusion in the NucS-DNA energy landscape and does not require a free 5′ or 3′ extremity. On the other hand, NucS dissociation is independent of the flap length and thus independent of sliding on the single-stranded portion of the flapped DNA substrates. Our kinetic measurements have revealed previously unnoticed asymmetry in dissociation kinetics from these substrates that is markedly modulated by the replication clamp PCNA. We propose that the replication clamp PCNA enhances the cleavage specificity of NucS proteins by accelerating NucS loading at the ssDNA/dsDNA junctions and by minimizing the nuclease interaction time with its DNA substrate. Our data are also consistent with marked reorganization of ssDNA and nuclease domains occurring during NucS catalysis, and indicate that NucS binds its substrate directly at the ssDNA-dsDNA junction and then threads the ssDNA extremity into the catalytic site. The powerful techniques used here for probing the dynamics of DNA-enzyme binding at the single-molecule have provided new insight regarding substrate specificity of NucS nucleases. PMID:25412080

  15. 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.

  16. 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

  17. Flight Tests of a Balanced Split Flap with Particular Reference to Rapid Operation

    NASA Technical Reports Server (NTRS)

    Soule, H A

    1935-01-01

    The flight path of a small parasol monoplane equipped with a special type of balanced split flap was determined for a series of glides during which the time taken to deflect or retract the flap was varied from 1 to 15 seconds in order to study the effect of the time taken to complete a flap movement on the motion of an airplane between the start of a flap movement and the attainment of steady flight with the new flap setting. For flap movements accompanied by a change of lift characteristics, and consequently of velocity, there is an appreciable delay in obtaining a desired change in glide angle even though the flap is operated instantaneously. Immediate control of the glide path is obtained only when the speed is maintained during the flap movement. When the speed is changed, the deviation from the desired path during the transition increases in proportion to the rapidity with which the flap is moved so that, with a high-lift flap, abrupt retraction at speeds less than the minimum speed with the flap retracted may be dangerous if practiced close to the ground.

  18. 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

  19. 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

  20. Calculated effect of various types of flap on take-off over obstacles

    NASA Technical Reports Server (NTRS)

    Wetmore, J W

    1936-01-01

    In order to determine whether or not flaps could be expected to have any beneficial effect on take-off performance, the distances required to take off and climb to an altitude of 50 feet were calculated for hypothetical airplanes, corresponding to relatively high-speed types and equipped with several types of flap. The types considered are the Fowler wing, the Hall wing, the split flap, the balanced split flap, the plain flap, and the external-airfoil flap. The results indicate that substantial reductions in take-off distance are possible through the use of flaps, provided that the proper flap angle corresponding to a given set of conditions is used. The best flap angle for taking off varies inversely as power loading and, to a much smaller extent, varies inversely with wing loading. Apparently, the best take-off characteristics are provided by the type of device in which the flap forms an extension to the main wing as in the case of the Fowler wing and the external-airfoil flap.

  1. Effects of Wing Platform on the Aerodynamic Performance of Finite-Span Flapping Wings

    NASA Astrophysics Data System (ADS)

    Yu, Meilin; Wang, Z. J.; Hu, Hui

    2010-11-01

    A numerical study is conducted to investigate the effects of wing platform on the aerodynamics performance of finite-span flapping wings. A three-dimensional high-order Navier-Stokes compressible flow solver was developed using the spectral difference method and dynamic grids. An AUSM^+-up Riemann solver was implemented to simulate the unsteady low Mach number flows over finite-span flapping wings with explicit third order Runge-Kutta time integration. The studied finite-span flapping wings, which include a rectangular flapping wing, an elliptic flapping wing and a bio-inspired flapping wing, have the same wing span, aspect ratio of the platform and the characteristics of the flapping motion (i.e., sinusoidal trajectory of the flapping wing tip, Strouhal number and reduced frequency). In the present study, the Strouhul number (Str) of the finite-span flapping wings was selected to be well within the optimal range usually used by flying insects and birds and swimming fishes (i.e., 0.2 < Str < 0.4). The effects of the wing platform on the aerodynamics performance of the finite-span flapping wings were elucidated in the terms of the evolutions and dynamic interaction between the leading edge vortices (LEV) and the wing tip vortices as well as the resultant aerodynamic forces (both lift and thrust) generated by the flapping wings.

  2. 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

  3. Optimal placement of trailing-edge flaps for helicopter vibration reduction using response surface methods

    NASA Astrophysics Data System (ADS)

    Viswamurthy, S. R.; Ganguli, Ranjan

    2007-03-01

    This study aims to determine optimal locations of dual trailing-edge flaps to achieve minimum hub vibration levels in a helicopter, while incurring low penalty in terms of required trailing-edge flap control power. An aeroelastic analysis based on finite elements in space and time is used in conjunction with an optimal control algorithm to determine the flap time history for vibration minimization. The reduced hub vibration levels and required flap control power (due to flap motion) are the two objectives considered in this study and the flap locations along the blade are the design variables. It is found that second order polynomial response surfaces based on the central composite design of the theory of design of experiments describe both objectives adequately. Numerical studies for a four-bladed hingeless rotor show that both objectives are more sensitive to outboard flap location compared to the inboard flap location by an order of magnitude. Optimization results show a disjoint Pareto surface between the two objectives. Two interesting design points are obtained. The first design gives 77 percent vibration reduction from baseline conditions (no flap motion) with a 7 percent increase in flap power compared to the initial design. The second design yields 70 percent reduction in hub vibration with a 27 percent reduction in flap power from the initial design.

  4. 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

  5. Aerodynamic characteristics of a large-scale model with a swept wing and a jet flap having an expandable duct

    NASA Technical Reports Server (NTRS)

    Aiken, T. N.; Aoyagi, K.; Falarski, M. D.

    1973-01-01

    The data from an investigation of the aerodynamic characteristics of the expandable duct-jet flap concept are presented. The investigation was made using a large-scale model in the Ames 40- by 80-foot Wind Tunnel. The expandable duct-jet flap concept uses a lower surface, split flap and an upper surface, Fowler flap to form an internal, variable area cavity for the blowing air. Small amounts of blowing are used on the knee of the upper surface flap and the knee of a short-chord, trailing edge control flap. The bulk of the blowing is at the trailing edge. The flap could extend the full span of the model wing or over the inboard part only, with blown ailerons outboard. Primary configurations tested were two flap angles, typical of takeoff and landing; symmetric control flap deflections, primarily for improved landing performance; and asymmetric aileron and control flap deflections, for lateral control.

  6. Noise reduction tests of large-scale-model externally blown flap using trailing-edge blowing and partial flap slot covering. [jet aircraft noise reduction

    NASA Technical Reports Server (NTRS)

    Mckinzie, D. J., Jr.; Burns, R. J.; Wagner, J. M.

    1976-01-01

    Noise data were obtained with a large-scale cold-flow model of a two-flap, under-the-wing, externally blown flap proposed for use on future STOL aircraft. The noise suppression effectiveness of locating a slot conical nozzle at the trailing edge of the second flap and of applying partial covers to the slots between the wing and flaps was evaluated. Overall-sound-pressure-level reductions of 5 db occurred below the wing in the flyover plane. Existing models of several noise sources were applied to the test results. The resulting analytical relation compares favorably with the test data. The noise source mechanisms were analyzed and are discussed.

  7. Heterogeneity of Nasolabial Flap- Role in Prevention of Morbidity Associated with Reconstruction of Orofacial Defects.

    PubMed

    Abida, Roshni; Ayyallil, Muhamed Sajid

    2015-09-01

    Reconstructive technique after surgical excision of malignancy in orofacial region should be planned in preoperative period itself. Surgery is the preferred modality of treatment if the tumour is small and located in an accessible area. Nasolabial flap is a versatile flap which is well suited to cover small defects in maxillofacial region. Nasolabial flap can be used as an alternative to other distant pedicled flaps in selected cases. A retrospective analysis of 12 cases of oral cancer treated with primary excision and reconstruction using nasolabial flap was done. Patients who underwent resection of tumour and reconstruction with nasolabial flap in selected cases reduced the morbidity associated with Distant pedicled flaps. Two selected cases are described in detail. PMID:26501027

  8. Salvage Free Anterolateral Thigh Composite Flap Transfer Based on the Musculocutaneous Perforator Retrograde Blood Flow Principle.

    PubMed

    Zhao, Jingyi; Chan, Fuan Chiang; Yang, Xiaonan; Zong, Xianlei; Sun, Hengyun; Qi, Zuoliang; Jin, Xiaolei

    2016-03-01

    An anterolateral thigh myo-adipofascial flap was used in the definitive management of a patient presented with chronic infective process associated with a large fronto-nasal defect. Unfortunately, the risk of free flap transfer failure emerged when intraoperative dissection showed absence of a reliable ipsilateral superficial temporal artery as the recipient artery. This rare incident happened at the stage whereby the anterolateral thigh flap was nearly completely raised with a distal perforator in situ. In this article, the authors presented an innovative strategy to salvage the flap by transforming the flap into a modified composite flap based on the retrograde blood flow principle. To the best of our knowledge, this is the first report of using such a technique in reconstructive microsurgery. This successful salvage strategy has clinical application and could potentially minimize free flap transfer failure. PMID:26854778

  9. Dynamic perfusion assessment during perforator flap surgery: an up-to-date

    PubMed Central

    MUNTEAN, MAXIMILIAN VLAD; MUNTEAN, VALENTIN; ARDELEAN, FILIP; GEORGESCU, ALEXANDRU

    2015-01-01

    Flap monitoring technology has progressed alongside flap design. The highly variable vascular anatomy and the complexity associated with modern perforator flaps demands dynamic, real-time, intraoperative information about the vessel location, perfusion patterns and flap physiology. Although most surgeons still assess flap perfusion and viability based solely on clinical experience, studies have shown that results may be highly variable and often misleading. Poor judgment of intraoperative perfusion leads to major complications. Employing dynamic perfusion imaging during flap reconstruction has led to a reduced complication rate, lower morbidity, shorter hospital stay, and an overall better result. With the emergence of multiple systems capable of intraoperative flap evaluation, the purpose of this article is to review the two systems that have been widely accepted and are currently used by plastic surgeons: Indocyanine green angiography (ICGA) and dynamic infrared thermography (DIRT). PMID:26609259

  10. Pressure investigation of NASA leading edge vortex flaps on a 60 deg Delta wing

    NASA Technical Reports Server (NTRS)

    Marchman, J. F., III; Donatelli, D. A.; Terry, J. E.

    1983-01-01

    Pressure distributions on a 60 deg Delta Wing with NASA designed leading edge vortex flaps (LEVF) were found in order to provide more pressure data for LEVF and to help verify NASA computer codes used in designing these flaps. These flaps were intended to be optimized designs based on these computer codes. However, the pressure distributions show that the flaps wre not optimum for the size and deflection specified. A second drag-producing vortex forming over the wing indicated that the flap was too large for the specified deflection. Also, it became apparent that flap thickness has a possible effect on the reattachment location of the vortex. Research is continuing to determine proper flap size and deflection relationships that provide well-behaved flowfields and acceptable hinge-moment characteristics.

  11. Experimental evaluation of a flapping-wing aerodynamic model for MAV applications

    NASA Astrophysics Data System (ADS)

    Lee, Jun-Seong; Kim, Dae-Kwan; Lee, Jin-Young; Han, Jae-Hung

    2008-03-01

    In the preliminary design phase of the bio-inspired flapping-wing MAV (micro air vehicle), it is necessary to predict the aerodynamic forces around the flapping-wing under flapping-wing motion at cruising flight. In this study, the efficient quasi-steady flapping-wing aerodynamic model for MAV application is explained and it is experimentally verified. The flapping-wing motion is decoupled to the plunging and pitching motion, and the plunging-pitching motion generator with load cell assembly is developed. The compensation of inertial forces from the measured lift and thrust is studied to measure the pure aerodynamic loads on the flapping-wing. Advanced ratio is introduced to evaluate the unsteadiness of the flow and to make an application range of flapping-wing aerodynamic model.

  12. 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

  13. 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.

  14. 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

  15. Tadalafil significantly reduces ischemia reperfusion injury in skin island flaps

    PubMed Central

    Kayiran, Oguz; Cuzdan, Suat S.; Uysal, Afsin; Kocer, Ugur

    2013-01-01

    Introduction: Numerous pharmacological agents have been used to enhance the viability of flaps. Ischemia reperfusion (I/R) injury is an unwanted, sometimes devastating complication in reconstructive microsurgery. Tadalafil, a specific inhibitor of phosphodiesterase type 5 is mainly used for erectile dysfunction, and acts on vascular smooth muscles, platelets and leukocytes. Herein, the protective and therapeutical effect of tadalafil in I/R injury in rat skin flap model is evaluated. Materials and Methods: Sixty epigastric island flaps were used to create I/R model in 60 Wistar rats (non-ischemic group, ischemic group, medication group). Biochemical markers including total nitrite, malondialdehyde (MDA) and myeloperoxidase (MPO) were analysed. Necrosis rates were calculated and histopathologic evaluation was carried out. Results: MDA, MPO and total nitrite values were found elevated in the ischemic group, however there was an evident drop in the medication group. Histological results revealed that early inflammatory findings (oedema, neutrophil infiltration, necrosis rate) were observed lower with tadalafil administration. Moreover, statistical significance (P < 0.05) was recorded. Conclusions: We conclude that tadalafil has beneficial effects on epigastric island flaps against I/R injury. PMID:23960309

  16. 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

  17. A Rapid, Simple, Effective, and Inexpensive Reconstructed Nipple Flap Guard.

    PubMed

    Khan, Khurrum; Chevray, Pierre M

    2015-10-01

    Nipple reconstruction is a commonly performed component of breast reconstruction. A nipple reconstructed using local skin flaps requires protection from trauma. Here we describe a novel, effective, simple, rapid, inexpensive, and convenient method to protect a reconstructed nipple in the early postoperative period. PMID:26579352

  18. Fast-flap Actuation for Attenuating Gust Response

    NASA Astrophysics Data System (ADS)

    Ol, Michael; Granlund`, Kenneth; Medina, Albert

    2015-11-01

    Airfoil flow control actuators can respond at perhaps O(10E-3) convective-times, but the flowfield response requires typically 2-4 convective times, and initial force-transients can be negative. A conventional trailing-edge mechanical flap is ``slow'' to deflect in flight applications, of questionable efficacy in separated flows, and is plagued by a response nonlinear with deflection angle. We consider a half-chord airfoil flap actuated O(10) times faster than one convective time, taking advantage of scaling-effects in a water tunnel. The motivation is recent work on accelerating flat plates at high incidence, where despite zero bound-circulation, the lift transient follows Wagner's solution. Force-measurements for high-rate large-incidence flap deflection show similar trends, and offer promise in cancelling lift-transients from gusts (modeled by plunging or surging the airfoil). Parameter-studies of rate, amplitude and initial incidence suggest first-order-system relaxation to steady-state, with a time constant commensurate with 1-3 convective times, no negative transients and no discernible lag. Rapid flap actuation induces entrainment that augments the flow's propensity to attach/reattach, perhaps paradoxically comporting with theory better, the faster the actuation.

  19. Bio-inspired flapping UAV design: a university perspective

    NASA Astrophysics Data System (ADS)

    Han, Jae-Hung; Lee, Jun-Seong; Kim, Dae-Kwan

    2009-03-01

    Bio-inspired design to make artificial flappers fly does not just imitate biological systems as closely as possible, but also transferring the flappers' own functionalities to engineering solutions. This paper summarizes some key technical issues and the states-of-art of bio-inspired design of flapping UAVs with an introduction to authors' recent research results in this field.

  20. The role of passive avian head stabilization in flapping flight.

    PubMed

    Pete, Ashley E; Kress, Daniel; Dimitrov, Marina A; Lentink, David

    2015-09-01

    Birds improve vision by stabilizing head position relative to their surroundings, while their body is forced up and down during flapping flight. Stabilization is facilitated by compensatory motion of the sophisticated avian head-neck system. While relative head motion has been studied in stationary and walking birds, little is known about how birds accomplish head stabilization during flapping flight. To unravel this, we approximate the avian neck with a linear mass-spring-damper system for vertical displacements, analogous to proven head stabilization models for walking humans. We corroborate the model's dimensionless natural frequency and damping ratios from high-speed video recordings of whooper swans (Cygnus cygnus) flying over a lake. The data show that flap-induced body oscillations can be passively attenuated through the neck. We find that the passive model robustly attenuates large body oscillations, even in response to head mass and gust perturbations. Our proof of principle shows that bird-inspired drones with flapping wings could record better images with a swan-inspired passive camera suspension. PMID:26311316

  1. Effects of vinpocetine on random skin flap survival in rats.

    PubMed

    Xiao-Xiao, Tao; Sen-Min, Wu; Ding-Sheng, Lin

    2013-07-01

    The effect of vinpocetine on flap survival, vascular endothelial growth factor (VEGF) expression, and superoxide dismutase (SOD) and malondialdehyde (MDA) contents were evaluated in this study. The McFarlane flap model was established in 20 rats and evaluated within two groups. Postoperative celiac injection was given for 7 days in the two groups: vinpocetine was applied in Group 1, and the same volume of saline was applied in Group 2. Flap necrosis was measured on day 7 by cellophane in all groups. VEGF expression was determined using immunohistochemical methods on tissue samples taken after 7 days of injections. SOD and MDA contents were examined according to the Kit (reagent instructions). Vinpocetine significantly reduced necrosis area in Group 1 (p < 0.05). VEGF expression and SOD contents were significantly increased in Group 1 compared with Group 2 (p < 0.01), whereas MDA level was reduced (p < 0.05). This experimental study demonstrates that vinpocetine improves survival of random skin flaps, promotes neovascularization, and increases VEGF expression. Meanwhile, vinpocetine has a protective effect against ischemia-reperfusion injury by improving SOD vitality and decreasing MDA value. PMID:23588551

  2. Adjacent flaps for lower lip reconstruction after mucocele resection.

    PubMed

    Ying, Binbin

    2012-03-01

    Mucocele forms because of salivary gland mucous extravasation or retention and is usually related to trauma in the area of the lower lip. It is a common benign lesion in the oral region. Although there are many conservative treatments such as the creation of a pouch (marsupialization), freezing (cryosurgery), micromarsupialization, and CO2 laser vaporization, surgical resection is the most commonly used means. Generally speaking, an elliptic incision was made to fully enucleate the lesion along with the overlying mucosa and the affected glands, then direct suturing is adequate. However, in some cases, direct suturing could cause lower lip deformity, and adjacent flaps for lower lip reconstruction after mucocele resection might be quite necessary. Based on our experience, adjacent mucosal flaps could be used when lesions were close to or even break through the vermilion border or their diameters were much more than 1 cm. A-T advancement flaps and transposition flaps were the mostly applied ones. Follow-up showed that all patients realized primary healing after 1 week postoperatively with satisfactory lower lip appearance, and there was no sign of increasing incidence of relapse. PMID:22421867

  3. The Japanese Flap in EFL: Variability and Accent.

    ERIC Educational Resources Information Center

    Riney, Timothy J.; Takada, Mari

    1998-01-01

    A study investigated the substitution of the Japanese flap for English liquids /r/ and /l/ by 11 Japanese students in their first and fourth years of college. Phonological patterns were examined at the two different stages, in reading vs. spontaneous oral language tasks, and for word-initial singleton vs. word-initial cluster environments. The…

  4. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  5. Aeroacoustic Evaluation of Flap and Landing Gear Noise Reduction Concepts

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Humphreys, William M., Jr.; Lockard, David P.; Ravetta, Patricio A.

    2014-01-01

    Aeroacoustic measurements for a semi-span, 18% scale, high-fidelity Gulfstream aircraft model are presented. The model was used as a test bed to conduct detailed studies of flap and main landing gear noise sources and to determine the effectiveness of numerous noise mitigation concepts. Using a traversing microphone array in the flyover direction, an extensive set of acoustic data was obtained in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel with the facility in the acoustically treated open-wall (jet) mode. Most of the information was acquired with the model in a landing configuration with the flap deflected 39 deg and the main landing gear alternately installed and removed. Data were obtained at Mach numbers of 0.16, 0.20, and 0.24 over directivity angles between 56 deg and 116 deg, with 90 deg representing the overhead direction. Measured acoustic spectra showed that several of the tested flap noise reduction concepts decrease the sound pressure levels by 2 - 4 dB over the entire frequency range at all directivity angles. Slightly lower levels of noise reduction from the main landing gear were obtained through the simultaneous application of various gear devices. Measured aerodynamic forces indicated that the tested gear/flap noise abatement technologies have a negligible impact on the aerodynamic performance of the aircraft model.

  6. Flapping dynamics of a flexible flag in a uniform flow

    NASA Astrophysics Data System (ADS)

    Lee, Jae Hwa; Huang, Wei-Xi; Sung, Hyung Jin

    2014-10-01

    Numerical simulations using the immersed boundary method were performed to investigate the flapping dynamics of a flexible flag in a uniform flow. The relevant parameters related to the problem are the mass ratio (ρ ={{ρ }1}/{{ρ }f}L), the bending rigidity of the flag ({{K}B}=EI/{{ρ }f}U∞ 2{{L}3}) and the Reynolds number ≤ft( \\operatorname{Re}={{U}∞ }L/ν \\right), where ρ1 denotes the line density difference between the flag and the surrounding fluid. By varying the parameters over the ranges 0 ≦̸ ρ ≦̸ 10 and 10-4 ≦̸ KB ≦̸ 10-1 for Re = 200, we identified three dynamical states: the stretched-straight state (I), the regular flapping state (II), and the irregular flapping state (III) with a region in which violent snapping events occurred, characterized by rapid changes in velocity, tension and drag. The description of the flapping dynamics at each dynamic state was provided through a sequence of time-evolving instantaneous fields, and was examined in detail with respect to the frequency and the energy rank based on the dynamic mode decomposition technique. Furthermore, the hysteresis phenomena with varying the mass ratio and the Reynolds number was examined, and the results showed that the hysteresis loop width was varied for approximately 20-65%, depending on the values of the relevant parameters employed.

  7. 6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP ...

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

    6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP VALVES OF THE PUMPING UNITS 8, 6, AND 7 (L TO R) AND PART OF THE DISCHARGE WEIR OF THE INDIVIDUAL DISCHARGE CHAMBER OF PUMP NO. 5, LOOKING NORTHEAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  8. Detail view of the underside of the Body Flap of ...

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

    Detail view of the underside of the Body Flap of the Orbiter Discovery as it is being rotated into a vertical position in the Vehicle Assembly Building at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. DETAIL OF GASPROOF DOOR SHOWING THE THREE ROUND FLAP VALVES ...

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

    DETAIL OF GAS-PROOF DOOR SHOWING THE THREE ROUND FLAP VALVES AT THE BASE OF THE DOOR - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  10. Evaluating visual perception for assessing reconstructed flap health

    PubMed Central

    Ponticorvo, Adrien; Taydas, Eren; Mazhar, Amaan; Ellstrom, Christopher L.; Rimler, Jonathan; Scholz, Thomas; Tong, June; Evans, Gregory R.D.; Cuccia, David J.

    2015-01-01

    Background Detecting failing tissue flaps before they are clinically apparent has the potential to improve post-operative flap management and salvage rates. This study demonstrates a model to quantitatively compare clinical appearance, as recorded via digital camera, with spatial frequency domain imaging (SFDI), a non-invasive imaging technique utilizing patterned illumination to generate images of total hemoglobin and tissue oxygen saturation. Methods Using a swine pedicle model where blood flow was carefully controlled with occlusion cuffs and monitored with ultrasound probes, throughput was reduced by 25%, 50%, 75%, and 100% of baseline values in either the artery or the vein of each of the flaps. The color changes recorded by a digital camera were quantified in order to predict which occlusion levels were visible to the human eye. SFDI was also used to quantify the changes in physiological parameters including total hemoglobin and oxygen saturation associated with each occlusion. Results There were no statistically significant changes in color above the noticeable perception levels associated with human vision during any of the occlusion levels. However there were statistically significant changes in total hemoglobin and tissue oxygen saturation levels detected at the 50%, 75%, and 100% occlusion levels for arterial and venous occlusions. Conclusion As demonstrated by the color imaging data, visual flap changes are difficult to detect until significant occlusion has occurred. SFDI is capable of detecting changes in total hemoglobin and tissue oxygen saturation as a result of partial occlusions before they are perceivable, thereby potentially improving response times and salvage rates. PMID:25935469

  11. A Rapid, Simple, Effective, and Inexpensive Reconstructed Nipple Flap Guard

    PubMed Central

    Khan, Khurrum

    2015-01-01

    Summary: Nipple reconstruction is a commonly performed component of breast reconstruction. A nipple reconstructed using local skin flaps requires protection from trauma. Here we describe a novel, effective, simple, rapid, inexpensive, and convenient method to protect a reconstructed nipple in the early postoperative period. PMID:26579352

  12. The role of passive avian head stabilization in flapping flight

    PubMed Central

    Pete, Ashley E.; Kress, Daniel; Dimitrov, Marina A.; Lentink, David

    2015-01-01

    Birds improve vision by stabilizing head position relative to their surroundings, while their body is forced up and down during flapping flight. Stabilization is facilitated by compensatory motion of the sophisticated avian head–neck system. While relative head motion has been studied in stationary and walking birds, little is known about how birds accomplish head stabilization during flapping flight. To unravel this, we approximate the avian neck with a linear mass–spring–damper system for vertical displacements, analogous to proven head stabilization models for walking humans. We corroborate the model's dimensionless natural frequency and damping ratios from high-speed video recordings of whooper swans (Cygnus cygnus) flying over a lake. The data show that flap-induced body oscillations can be passively attenuated through the neck. We find that the passive model robustly attenuates large body oscillations, even in response to head mass and gust perturbations. Our proof of principle shows that bird-inspired drones with flapping wings could record better images with a swan-inspired passive camera suspension. PMID:26311316

  13. Local Vascularized Flaps for Augmentation of Reinke’s Space

    PubMed Central

    Dailey, Seth H.; Gunderson, McLean; Chan, Roger; Torrealba, Jose; Kimura, Miwako; Welham, Nathan V.

    2011-01-01

    Objectives/Hypothesis The purpose of this study is to describe and test a novel surgical strategy for augmentation of Reinke’s space using vascularized flaps: a thyroid ala perichondrium flap (TAP) and a composite thyroid ala perichondrium flap (CTAP) from the anterior larynx. We hypothesized that these specially designed vascularized flaps would remain viable once inset into the lamina propria, and that they would not disrupt rheologic, biomechanical, and histologic properties of the native vocal fold. Study Design Experimental. In vivo canine model. Methods The length and volume of test flaps harvested in six adult human cadaveric larynges were analyzed to determine suitability for use in augmentation in the lamina propria. Also, 12 beagles randomly underwent unilateral placement of either TAP or CTAP, which were designed in accordance with the human adult cadaveric experiments. Flap perfusion was measured before and after harvest with laser Doppler. After 1 month, the beagles were humanely sacrificed and their larynges subjected to aerodynamic and acoustic evaluation using an excised larynx apparatus. The vocal fold lamina propria of four larynges—two TAP and two CTAP—underwent rheologic evaluation using a simple-shear rheometer. The remaining eight larynges underwent quantitative histologic and immunohistochemical evaluation. The survival and complication (swallowing, airway, local wound) rates of all dogs were noted. Results Initial studies with adult human cadaveric larynges established that TAP and CTAP possessed length and volume greater than native lamina propria. In the canine experiments, the perfusion change in the flaps was similar between flap groups. The damping ratio (ζ), dynamic viscosity (η′), elastic shear modulus (G′), and viscous shear modulus (G″) of treated and untreated native vocal folds were not statistically different. The glottic function measures of vocal efficiency, laryngeal resistance, jitter, shimmer, and harmonics

  14. SUBAERF2 - WING AND FLAP SYSTEM ANALYSIS CODE

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.

    1994-01-01

    The SUBAERF2 program was developed to provide for the aerodynamic analysis and design of low speed wing flap systems. SUBAERF2 is based on a linearized theory lifting surface solution. It is particularly well suited to configurations which, because of high speed flight requirements, must employ thin wings with highly swept leading edges. The program is applicable to wings with either sharp or rounded leading edges. This program is a new and improved version of LAR-13116 and LAR-12987, which it replaces. The low speed aerodynamic analysis method used in SUBAERF2 provides estimates of wing performance which include the effects of attainable leading-edge thrust and vortex lift. This basic aerodynamic analysis method has been improved to provide for the convenient, efficient and accurate treatment of simple leading-edge and trailing-edge flap systems. The user inputs flap geometry directly. Solutions can be found for various combinations of leading and trailing edge flap deflections. The program provides for the simultaneous analysis of up to 25 pairs of leading-edge and trailing-edge flap deflection schedules. A revised attainable thrust algorithm improves accuracy at the low Mach numbers sometimes encountered in wind tunnel testing. Also added is a means of estimating the distribution of leading edge separation vortex forces. The revised program has been particularly useful in the subsonic analysis of vehicles designed for supersonic cruise. The SUBAERF2 program is written in FORTRAN V for batch execution and has been implemented on a CDC 175 computer operating under NOS 2.4 with a central memory requirement of approximately 115K (octal) of 60 bit words. This program was originally developed in 1983 and later revised in 1988.

  15. Orandi flap for penile urethral stricture: Polishing the gold standard

    PubMed Central

    Goel, Apul; Kumar, Manoj; Singh, Manmeet

    2015-01-01

    Introduction: We describe the combined use of the Orandi flap and the scrotal skin advancement flap to reduce complications for pendulous urethral stricture in men >40 years old. Methods: Over the last 40 months, 10 men underwent urethroplasty for pendulous stricture by the modified Orandi urethroplasty. In this, additionally, a midline hairless scrotal skin flap of the size of the ventral skin defect on the pendulous portion was raised based on the dartos fascia. This flap was mobilized so that it reached the pendulous portion without tension and covered the penile defect. The catheter was removed after 4 weeks. Patients were followed every 3 months using uroflowmetry and the American Urological Association (AUA) symptom score. Results: The mean age was 55.5. Of the 10 patients, the etiology was post-catheterization in 5 and idiopathic in the remaining 5. Three men also had stricture extending into the bulbous urethra (repaired using buccal graft). The mean additional time needed for the flap coverage was 36.2 minutes (range: 30–45). The median follow-up was 12 months (range: 3–40). The mean postoperative symptom score was 5.2 and the mean flow rate was 20.1 mL/sec. In 2 men, the meatus got retracted to the distal penile part (probably due to downward traction by scrotal skin). No patient complained of disfigurement. Two men reported recurrence (1 each in bulbous and penile urethra). The limitations are small number of patients and the observational nature of this study. Conclusions: The intermediate-term results show that the modified Orandi urethroplasty is an acceptable treatment option with acceptable cosmetic results. PMID:26085873

  16. Flexible flapping wings with self-organized microwrinkles.

    PubMed

    Tanaka, Hiroto; Okada, Hiroyuki; Shimasue, Yosuke; Liu, Hao

    2015-08-01

    Bio-inspired flapping wings with a wrinkled wing membrane were designed and fabricated. The wings consist of carbon fibre-reinforced plastic frames and a polymer film with microscale wrinkles inspired by bird feathers and the corrugations of insect wings. The flexural and tensile stiffness of the wrinkled film can be controlled by modifying the orientations and waveforms of the wrinkles, thereby expanding the design space of flexible wings for micro flapping-wing aerial robots. A self-organization phenomenon was exploited in the fabrication of the microwrinkles such that microscale wrinkles spanning a broad wing area were spontaneously created. The wavy shape of these self-organized wrinkles was used as a mould, and a Parylene film was deposited onto the mould to form a wrinkled wing film. The effect of the waveforms of the wrinkles on the film stiffness was investigated theoretically, computationally and experimentally. Compared with a flat film, the flexural stiffness was increased by two orders of magnitude, and the tensile stiffness was reduced by two orders of magnitude. To demonstrate the effect of the wrinkles on the actual deformation of the flapping wings and the resulting aerodynamic forces, the fabricated wrinkled wings were tested using a tethered electric flapping mechanism. Chordwise unidirectional wrinkles were found to prevent fluttering near the trailing edge and to produce a greater aerodynamic lift compared with a flat wing or a wing with spanwise wrinkles. Our results suggest that the fine stiffness control of the wing film that can be achieved by tuning the microwrinkles can improve the aerodynamic performance of future flapping-wing aerial robots. PMID:26119657

  17. The median forehead flap reviewed: a histologic study on vascular anatomy.

    PubMed

    Skaria, A M

    2015-05-01

    Local skin flaps can be divided into two types: random flaps and axial flaps. An axial flap is defined as a flap containing a named artery in its pedicle. For the paramedian forehead flap (PMFF) a lot of surgeons insist on the point that the pedicle must contain the supratrochlear artery. To demonstrate that median forehead flaps (MFF) need not contain a named artery, we selected first 8 patients with a PMFF and further 12 patients who had undergone reconstructive surgery using a MFF. After division, we analysed the pedicle of the flap histologically and measured the diameter of the arteries or arterioles and compared them to anatomical descriptions of the frontal arteries. In none of the 12 cases could we find a functional artery of approximately 1 mm in diameter that could correspond to the supratrochlear artery. The MFF is an axial flap but not in accordance with the current definition of this term. In contrast to published literature, we show that only in a part of cases a named artery was present in the pedicle. Despite this fact, the MFF is a secure flap for full thickness defect repair on the nose. PMID:24756613

  18. 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

  19. 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

  20. 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