Science.gov

Sample records for locked plate fixation

  1. Locking versus nonlocking palmar plate fixation of distal radius fractures.

    PubMed

    Osti, Michael; Mittler, Christoph; Zinnecker, Richard; Westreicher, Christoph; Allhoff, Clemens; Benedetto, Karl Peter

    2012-11-01

    This study compared functional and radiological outcomes after treatment of extension-type distal radius fractures with conventional titanium nonlocking T-plates or titanium 1.5-mm locking plates. A total of 60 patients were included and followed for 4 to 7 years after receiving nonlocking T-plates (group A; n=30) or locking plates (group B; n=30) with and without dorsal bone grafting. Bone grafting was significantly more often performed in the nonlocking group to increase dorsal fracture fixation and stability (P<.003). Pre- and postoperative and follow-up values for palmar tilt, radial inclination, radial shortening, and ulnar variance were recorded. Age, sex, and fracture type were similarly distributed between the 2 groups. Postoperative and follow-up evaluation revealed equal allocation of intra-articular step formation and osteoarthritic changes to both groups. The overall complication rate was 25%. Compared with the nonlocking system, patients undergoing locking plate fixation presented with statistically significantly better values for postoperative palmar tilt (5.53° vs 8.15°; P<.02) and radial inclination (22.13° vs 25.03°; P<.02). However, forearm pronation was significantly better in group A (P<.005). At follow-up, radial inclination tended to approach a statistically significant difference in favor of group B. All clinical assessment, including Mayo wrist score, Disabilities of the Arm, Shoulder, and Hand score, Green and O'Brien score, Gartland and Werley score, visual analog scale score, and grip strength, yielded no statistically significant difference between the 2 groups. Locking plates seem to provide benefits regarding surgical technique and comfort, improvement in implant anchorage (especially in osteoporotic bone), and reduce the necessity of additional bone grafting. PMID:23127452

  2. Mechanical comparison of cortical screw fixation versus locking plate fixation in first metatarsal base osteotomy.

    PubMed

    Smith, Kevin; Lidtke, Roy H; Oliver, Noah G; Maker, Jared M

    2014-01-01

    The oblique closing base wedge osteotomy has been used for surgical treatment of moderate to severe hallux valgus deformities with an intermetatarsal angle typically greater than 15°. Several postoperative complications have been identified that relate to failure of the fixation construct used to fixate the osteotomy, especially when that construct has been subjected to a vertical load. We performed a mechanical analysis comparing 2 constructs used to fixate oblique osteotomies of the first metatarsal using composite first metatarsals. An oblique base osteotomy was uniformly performed on 40 composite first metatarsals. Of the 40 specimens, 20 were fixated with a locking plate construct and 18 with a cortical screw construct, consisting of an anchor and compression screw (2 specimens from the latter group were excluded because of hinge fracture). Each specimen was loaded in a materials testing machine to measure the maximum load at construct failure when a vertical force was applied to the plantar aspect of the metatarsal head. The mean load to failure for the locking plate construct was significantly greater than the cortical screw construct (190.0 ± 70 N versus 110.3 ± 20.3 N, p < .001). Our study results have demonstrated that the locking plate construct was able to withstand a significantly greater vertical load before failure than was the 2-cortical screw construct in oblique osteotomies performed at the base of composite first metatarsals. PMID:24954919

  3. Treatment of Palatal Fractures by Osteosynthesis with 2.0-mm Locking Plates as External Fixator

    PubMed Central

    Cienfuegos, Ricardo; Sierra, Eduardo; Ortiz, Benjamin; Fernández, Gerardo

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  4. Fixation of Traumatic Sternal Fractures Using SternaLock Plating System.

    PubMed

    Park, Jong Bin; Lee, Han Pil; Yoo, Dong Gon; Kim, Jong Wook; Cho, Won Chul

    2013-08-01

    A 43-year-old man experienced chest trauma due to a car accident. Compound sternal fractures with severe dislocation were seen on computed tomography of the chest. Using a SternaLock plating system with manual reduction, fixation of the sternal fracture was successfully performed. There were no complications related to the operation. PMID:24003417

  5. A Pitfall in Fixation of Distal Humeral Fractures with Pre-Contoured Locking Compression Plate

    PubMed Central

    Jayakumar, Prakash; Ring, David

    2015-01-01

    Anatomically precontoured locking plates are intended to facilitate the fixation of articular fractures and particularly those associated with osteoporosis. Fractures of the distal humerus are relatively uncommon injuries where operative intervention can be exceptionally challenging. The distal humeral trochlea provides a very narrow anatomical window through which to pass a fixed-angle locking screw, which must also avoid the olecranon, coronoid, and radial fossae. We describe 3 patients (ages 27, 49, and 73 years) with a bicolumnar fracture of the distal humerus where very short distal locking screws were used. Intra-articular screw placement was avoided but loss of fixation occurred in two patients and a third was treated with a prolonged period of immobilization. We postulate that fixed-angle screw trajectories may make it difficult for the surgeon to place screws of adequate length in this anatomically confined region, and may lead to insufficient distal fixation. Surgical tactics should include placement of as many screws as possible into the distal fragment, as long as possible and that each screw passes through a plate without necessarily locking in. PMID:26110181

  6. A Pitfall in Fixation of Distal Humeral Fractures with Pre-Contoured Locking Compression Plate.

    PubMed

    Jayakumar, Prakash; Ring, David

    2015-04-01

    Anatomically precontoured locking plates are intended to facilitate the fixation of articular fractures and particularly those associated with osteoporosis. Fractures of the distal humerus are relatively uncommon injuries where operative intervention can be exceptionally challenging. The distal humeral trochlea provides a very narrow anatomical window through which to pass a fixed-angle locking screw, which must also avoid the olecranon, coronoid, and radial fossae. We describe 3 patients (ages 27, 49, and 73 years) with a bicolumnar fracture of the distal humerus where very short distal locking screws were used. Intra-articular screw placement was avoided but loss of fixation occurred in two patients and a third was treated with a prolonged period of immobilization. We postulate that fixed-angle screw trajectories may make it difficult for the surgeon to place screws of adequate length in this anatomically confined region, and may lead to insufficient distal fixation. Surgical tactics should include placement of as many screws as possible into the distal fragment, as long as possible and that each screw passes through a plate without necessarily locking in. PMID:26110181

  7. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    PubMed

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution. PMID:26497086

  8. Percutaneous fixation with Kirschner wires versus volar locking plate fixation in adults with dorsally displaced fracture of distal radius: randomised controlled trial

    PubMed Central

    Achten, Juul; Parsons, Nick R; Rangan, Amar; Griffin, Damian; Tubeuf, Sandy; Lamb, Sarah E

    2014-01-01

    Objectives To compare the clinical effectiveness of Kirschner wire fixation with locking plate fixation for patients with a dorsally displaced fracture of the distal radius. Design A multicentre two arm parallel group assessor blind randomised controlled trial with 1:1 treatment allocation. Setting 18 trauma centres in the United Kingdom. Participants 461 adults with a dorsally displaced fracture of the distal radius within 3 cm of the radiocarpal joint that required surgical fixation. Patients were excluded if the surgeon thought that the surface of the wrist joint was so badly displaced it required open reduction. Interventions Kirschner wire fixation: wires are passed through the skin over the dorsal aspect of the distal radius and into the bone to hold the fracture in the correct anatomical position. Locking plate fixation: a locking plate is applied through an incision over the volar (palm) aspect of the wrist and secured to the bone with fixed angle locking screws. Main outcome measures Primary outcome measure: validated patient rated wrist evaluation (PRWE). This rates wrist function in two (equally weighted) sections concerning the patient’s experience of pain and disability to give a score out of 100. Secondary outcomes: disabilities of arm, shoulder, and hand (DASH) score, the EuroQol (EQ-5D), and complications related to the surgery. Results The baseline characteristics of the two groups were well balanced, and over 90% of patients completed follow-up. The wrist function of both groups of patients improved by 12 months. There was no clinically relevant difference in the patient rated wrist score at three, six, or 12 months (difference in favour of the plate group was ?1.3, 95% confidence interval ?4.5 to 1.8; P=0.40). Nor was there a clinically relevant difference in health related quality of life or the number of complications in each group. Conclusions Contrary to the existing literature, and against the rapidly increasing use of locking plate fixation, this trial found no difference in functional outcome in patients with dorsally displaced fractures of the distal radius treated with Kirschner wires or volar locking plates. Kirschner wire fixation, however, is cheaper and quicker to perform. Trial registration Current Controlled Trials ISCRTN 31379280. UKCRN 8956. PMID:25096595

  9. Stability of unicortical locked fixation versus bicortical non-locked fixation for forearm fractures.

    PubMed

    Pater, Timothy J; Grindel, Steve I; Schmeling, Gregory J; Wang, Mei

    2014-01-01

    Locking plate fixation is being widely applied for fixation of forearm fractures and has many potential advantages, such as fixed angle fixation and improved construct stability, especially in osteoporotic bone. Biomechanical data comparing locking devices to commonly used Low Contact Dynamic Compression (LCDCP) plates for the fixation of forearm fractures has been lacking. The purpose of this study was to compare the fixation stability of a 3.5-mm unicortical locked plate with bicortical non-locked LCDCP plates. Six matched pairs of fresh frozen cadaveric forearms were randomly assigned to unicortical locked and bicortical unlocked groups. Non-destructive four-point bending and torsional test was performed on the ulna and radius separately, using a servohydraulic testing system to obtain construct stiffness of the intact specimens and specimens after osteotomy and plating. The specimens were then loaded to failure to test the fixation strength. The locked unicortical fixation showed significantly higher bending stiffness than the unlocked bicortical fixation, but with significantly lower stiffness and strength in torsion. Fixation strength was comparable between the two groups under bending, but significantly greater in the bicortical non-locked group under torsion. Findings from this study suggest that postoperative rehabilitation protocols may need modification to limit torsional loading in the early stage when using locked unicortical fixation. The study also points out the potential advantage of a hybrid fixation that combines locked unicortical and unlocked bicortical screws. PMID:26273524

  10. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species. PMID:21877449

  11. Comparison between cast immobilization versus volar locking plate fixation of distal radius fractures in active elderly patients, the Asian perspective.

    PubMed

    Chan, Ying-Ho; Foo, Tun-Lin; Yeo, Chong-Jin; Chew, Winston Yoon-Chong

    2014-01-01

    Displaced distal radius fractures in active elderly patients with high functional demand present a clinical dilemma because current evidence is equivocal in the recommendation of treatment. Internal fixation is an increasingly popular option with proposed superior results. Our study aims to evaluate the results among a population of active elderly patients with displaced fractures managed with either cast immobilization or internal fixation with volar locking plate. Seventy-five patients (35 cast immobilization and 40 internal fixation) with mean age of 74 ± 7.5 years with minimum of 12 months follow-up were studied. The radiological and clinical parameters were assessed at three, six, and 12 months. Functional outcomes (DASH, Green-O'Brien) were assessed at 12 months. Patients who underwent surgery regain wrist motion and grip strength earlier, but this was not statistically significant after six months. PMID:24641736

  12. Minimally invasive plate osteosynthesis with a locking compression plate is superior to open reduction and internal fixation in the management of the proximal humerus fractures

    PubMed Central

    2014-01-01

    Background The use of minimally invasive plate osteosynthesis (MIPO) via anterolateral deltoid splitting has good outcomes in the management of proximal humerus fractures. While using this approach has several advantages, including minimal soft tissue disruption, preservation of natural biology and minimal blood loss, there is an increased risk for axillary nerve damage. This study compared the advantages and clinical and radiological outcomes of MIPO or open reduction and internal fixation (ORIF) in patients with proximal humerus fractures. Methods A matched-pair analysis was performed, and patient groups were matched according to age (±3 years), sex and fracture type. Forty-three pairs of patients (average age: MIPO, 63 and ORIF, 61) with a minimum follow-up of 12 months were enrolled in the study group. The patients were investigated radiographically and clinically using the Constant score. Results The MIPO technique required less surgery time and caused less blood loss compared to ORIF (p?Fixation) fracture classification, did not significantly influence the functional results. The complication rate was comparable between both groups. Conclusion The use of MIPO with a locking compression plate in the management of proximal humerus fractures is a safe and superior option compared to ORIF. PMID:24934152

  13. Stainless steel versus titanium volar multi-axial locking plates for fixation of distal radius fractures: a randomised clinical trial

    PubMed Central

    2014-01-01

    Background Distal radius fractures are among the most common fractures seen in the hospital emergency department. Of these, over 40% are considered unstable and require some form of fixation. In recent years with the advent of low profile plating, open reduction and internal fixation (ORIF) using volar plates has become the surgical treatment of choice in many hospitals. However, it is currently unknown which plating system has the lowest complication rate and/or superior clinical and radiological outcomes following surgery. Few studies have compared different types of plates, which may have various features, different plate and screw designs or may be manufactured from different materials (for example, stainless steel or titanium). This study will specifically investigate and compare the clinical and radiological outcomes and complication rates of two commonly used volar plating systems for fixation of distal radius fractures: one made from stainless steel (Trimed™ Volar Plate, Trimed™, California, USA) and the other made from titanium (Medartis® Aptus Volar Plate, Medartis®, Basel, Switzerland). The primary aim of this study is to determine if there is a difference on the Patient Reported Wrist Evaluation six months following ORIF using a volar plate for adult patients with a distal radius fracture. Methods/Design This study will implement a randomized prospective clinical trial study design evaluating the outcomes of two different types of volar plates: one plate manufactured from stainless steel (Trimed™ Volar Plate) and one plate manufactured from titanium (Medartis® Aptus Volar Plate). The surgery will be performed at a major trauma hospital in Brisbane, Australia. Outcome measures including function, adverse events, range of movement, strength, disability, radiological findings and health-related quality of life will be collected at 6 weeks, 3, 6, 12 and 24 months following surgery. A parallel economic analysis will also be performed. This randomized clinical trial is due to deliver results in December 2016. Discussion Results from this trial will contribute to the evidence on operative management of distal radius fractures and plate material type. Trial registration ACTRN12612000969864 PMID:24612524

  14. UK Fixation of Distal Tibia Fractures (UK FixDT): protocol for a randomised controlled trial of ‘lockingplate fixation versus intramedullary nail fixation in the treatment of adult patients with a displaced fracture of the distal tibia

    PubMed Central

    Achten, Juul; Parsons, Nicholas R; McGuinness, Katie R; Petrou, Stavros; Lamb, Sarah E; Costa, Matthew L

    2015-01-01

    Introduction The treatment of displaced, extra-articular fractures of the distal tibia remains controversial. These injuries are difficult to manage due to limited soft tissue cover, poor vascularity of the area and proximity to the ankle joint. Surgical treatment options are expanding and include locked intramedullary nails, plate and screw fixation and external fixator systems. The nail and plate options are most commonly used in the UK, but controversy exists over which treatment is most clinically and cost-effective. In this multicentre randomised controlled trial we aim to assess ratings of disability 6?months postinjury in patients who have sustained a distal tibia fracture treated with either an intramedullary nail or plate and locking screw fixation. Methods and analysis Adult patients presenting at trial centres with an acute fracture of the distal tibia will be considered for inclusion. A total of 320 patients will provide 90% power to detect a difference of 8 points in Disability Rating Index (DRI) score at 6?months at the 5% level. The randomisation sequence is stratified by trial centre and age, and administered via web-based service with 1:1 treatment allocation. Baseline demographic and pre-injury functional data and radiographs will be collected using the DRI, Olerud and Molander, and EuroQol EQ-5D questionnaire. Clinical assessment, early complications and radiographs will be recorded at 6–8?weeks. Functional outcome, health-related quality of life and resource use will be collected at 3, 6 and 12?months postoperatively. The main analysis will investigate differences in DRI 6?months postsurgery, between the two treatment groups, on an intention-to-treat basis. Tests will be two-sided and considered to provide evidence for a significant difference if p values are <0.05. Ethics and dissemination NRES Committee West-Midlands, 6/11/2012 (ref:12/WM/0340). The results of the trial will be disseminated via peer-reviewed publications and presentations at relevant conferences. Trial registration number ISRCTN99771224. PMID:26384729

  15. Intermittent Internal Fixation With a Locking Plate to Preserve Epiphyseal Growth Function During Limb-Salvage Surgery in a Child With Osteosarcoma of the Distal Femur

    PubMed Central

    Mei, Jiong; Ni, Ming; Jia, Guang-Yao; Chen, Yan-Xi; Zhu, Xiao-Zhong

    2015-01-01

    Abstract Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur. The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed. The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient's height had increased 52?cm, shortening of the affected limb was only 1?cm, and the circumference of the affected limb was 2?cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers. In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and provides good functional recovery. PMID:25997058

  16. Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

    PubMed Central

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th.; Mauerer, Andreas; Hennig, Friedrich F.; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID:25590989

  17. Surgical fixation of sternal fractures: preoperative planning and a safe surgical technique using locked titanium plates and depth limited drilling.

    PubMed

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th; Mauerer, Andreas; Hennig, Friedrich F; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture's morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID:25590989

  18. Functional Outcome and Complications at 2.5 Years Following Volar Locking Plate Fixation of Distal Radius Fractures.

    PubMed

    MacFarlane, Robert J; Miller, David; Wilson, Lynn; Meyer, Carl; Kerin, Cronan; Ford, David James; Cheung, Graham

    2015-06-01

    Distal radius fractures are increasingly treated by internal fixation, but there have been relatively few studies relating to functional outcome at 12 months or more. The aim of this study was to ascertain the patient reported function of the wrist at a minimum of 12 months following fixation of a distal radius fracture, the time taken to return to work, and the complication rate. We conducted a retrospective review of 187 consecutive patients treated by a specialist hand and wrist trauma team at a tertiary referral unit over a 5 year period. Mean age was 57.3 years (range 16-93). Median time to surgery was 4 days (interquartile range 2-9). Median follow up was 31 months (interquartile range 23-41 months). The median PRWE score was 3; (range 0-83). There was no difference in outcome in patients who had surgery delayed by greater than 2 weeks (p?>?0.05). The median time to return to work was 5 weeks (interquartile range 1-8 weeks). There were 15 complications (8 %) including 3 tendon injuries. We have demonstrated an early return to work in patients who were employed, a low complication rate, and highly favourable functional outcomes at a mean of 30 months postoperatively. We recommend the use of the DVR plate and involvement of a dedicated hand and wrist trauma team for treatment of unstable fractures of the distal radius. PMID:26078498

  19. Screw Versus Plate Fixation for Chevron Osteotomy: A Retrospective Study.

    PubMed

    Andrews, Boyd J; Fallat, Lawrence M; Kish, John P

    2016-01-01

    The chevron osteotomy is a popular procedure used for the correction of moderate hallux abducto valgus deformity. Fixation is typically accomplished with Kirschner wires or bone screws; however, in cystic or osteoporotic bone, these could be inadequate, resulting in displacement of the capital fragment. We propose using a locking plate and interfragmental screw for fixation of the chevron osteotomy that could reduce the healing time and decrease the incidence of displacement. We performed a retrospective cohort study for chevron osteotomies on 75 feet (73 patients). The control groups underwent fixation with 1 screw in 30 feet (40%) and 2 screws in 30 feet (40%). A total of 15 feet (20%) were included in the locking plate and interfragmental screw group. The patients were followed up until bone healing was achieved at a median of 7 (range 6 to 14) weeks. Our hypothesis was that those treated with the locking plate and interfragmental screw would have a faster healing time and fewer incidents of capital fragment displacement compared with the 1- or 2-screw groups. The corresponding mean intervals to healing for the 1-screw group was 7.71 ± 1.28 (range 6 to 10) weeks, for the 2-screw group was 7.27 ± 1.57 (range 6 to 14) weeks, and for the locking plate and interfragmental screw group was 7.01 ± 1.00 (range 6 to 9) weeks. One case of capital fragment displacement occurred in the single screw group and one in the 2-screw group. No displacement occurred in the locking plate and interfragmental screw group. Neither finding was statistically significant. However, we believe the locking plate and interfragmental screw could be a viable option in patients with osteoporotic and cystic bone changes for correction of hallux abducto valgus. PMID:26277241

  20. Mechanical testing of 3.5 mm locking and non-locking bone plates.

    PubMed

    DeTora, M; Kraus, K

    2008-01-01

    Locking plate technologies are being developed in order to provide the surgeon with advantages over previous bone plate systems (both locking and non-locking). Locking plate systems possess inherent biological advantages in fracture fixation by preserving the periosteal blood supply, serving as internal fixators. It is important to consider the strength of each orthopaedic implant as an important selection criterion while utilizing the reported advantages of locking plate systems to prevent catastrophic fracture failure. Mechanical testing of orthopaedic implants is a common method used to provide a surgeon with insight on mechanical capabilities, as well as to form a standardized method of plate comparison. The purpose of this study was to demonstrate and to quantify observed differences in the bending strength between the LCP (Limited Contact Plate), LC-DCP, 3.5 mm Broad LC-DCP (Limited Contact Dynamic Compression Plate), and SOP (String of Pearls) orthopaedic bone plates. The study design followed the ASTM standard test method for static bending properties of metallic bone plates, which is designed to measure mechanical properties of bone plates subjected to bending, the most common loading encountered in vivo. Single cycle four point bending was performed on each orthopaedic implant. The area moment of inertia, bending stiffness, bending strength, and bending structural stiffness were calculated for each implant. The results of this study demonstrated significant differences (p<0.001) in bending strength and stiffness between the four orthopaedic implants (3.5 Broad LC-DCP>SOP>LCP=LC-DCP). The 3.5 mm LCP should be expected to provide in vivo strength and stiffness similar to a comparable LC-DCP. The SOP should provide strength and stiffness that is greater than a comparable LC-DCP but less than a 3.5 mm Broad LC-DCP. PMID:18704237

  1. Prospects of implant with locking plate in fixation of subtrochanteric fracture: experimental demonstration of its potential benefits on synthetic femur model with supportive hierarchical nonlinear hyperelastic finite element analysis

    PubMed Central

    2012-01-01

    Background Effective fixation of fracture requires careful selection of a suitable implant to provide stability and durability. Implant with a feature of locking plate (LP) has been used widely for treating distal fractures in femur because of its favourable clinical outcome, but its potential in fixing proximal fractures in the subtrochancteric region has yet to be explored. Therefore, this comparative study was undertaken to demonstrate the merits of the LP implant in treating the subtrochancteric fracture by comparing its performance limits against those obtained with the more traditional implants; angle blade plate (ABP) and dynamic condylar screw plate (DCSP). Materials and Methods Nine standard composite femurs were acquired, divided into three groups and fixed with LP (n?=?3), ABP (n?=?3) and DCSP (n?=?3). The fracture was modeled by a 20?mm gap created at the subtrochanteric region to experimentally study the biomechanical response of each implant under both static and dynamic axial loading paradigms. To confirm the experimental findings and to understand the critical interactions at the boundaries, the synthetic femur/implant systems were numerically analyzed by constructing hierarchical finite element models with nonlinear hyperelastic properties. The predictions from the analyses were then compared against the experimental measurements to demonstrate the validity of each numeric model, and to characterize the internal load distribution in the femur and load bearing properties of each implant. Results The average measurements indicated that the constructs with ABP, DCPS and LP respectively had overall stiffness values of 70.9, 110.2 and 131.4?N/mm, and exhibited reversible deformations of 12.4, 4.9 and 4.1?mm when the applied dynamic load was 400?N and plastic deformations of 11.3, 2.4 and 1.4?mm when the load was 1000?N. The corresponding peak cyclic loads to failure were 1100, 1167 and 1600?N. The errors between the displacements measured experimentally or predicted by the nonlinear hierarchical hyperelastic model were less than 18?%. In the implanted femur heads, the principal stresses were spatially heterogeneous for ABP and DCSP but more homogenous for LP, meaning LP had lower stress concentrations. Conclusion When fixed with the LP implant, the synthetic femur model of the subtrochancteric fracture consistently exceeds in the key biomechanical measures of stability and durability. These capabilities suggest increased resistance to fatigue and failure, which are highly desirable features expected of functional implants and hence make the LP implant potentially a viable alternative to the conventional ABP or DCSP in the treatment of subtrochancteric femur fractures for the betterment of clinical outcome. PMID:22545650

  2. Fractures of the Distal Tibia Treated with Polyaxial Locking Plating

    PubMed Central

    Zhang, Chang-Qing; Luo, Cong-Feng; Zhou, Zu-Bin; Zeng, Bing-Fang

    2008-01-01

    We evaluated the healing rate, complications, and functional outcomes in 32 adult patients with very short metaphyseal fragments in fractures of the distal tibia treated with a polyaxial locking system. The average distance from the distal extent of the fracture to the tibial plafond was 11 mm. All fractures healed and the average time to union was 14 weeks. Six patients (19%) reported occasional local disturbance over the medial malleolus. There were two cases of postoperative superficial infections and evidence of delayed wound healing. Using the American Orthopaedic Foot and Ankle Society ankle score, the average functional score was 87.3 points (of 100 total possible points). Our results show the polyaxial locking plates, which offer more fixation versatility, may be a reasonable treatment option for distal tibia fractures with very short metaphyseal segments. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18719970

  3. Management of distal femoral periprosthetic fractures by distal femoral locking plate: A retrospective study.

    PubMed Central

    Thukral, Rajiv; Marya, SKS; Singh, Chandeep

    2015-01-01

    Background: Management of periprosthetic supracondylar femoral fractures is difficult. Osteoporosis, comminution and bone loss, compromise stability with delayed mobility and poor functional outcomes. Open reduction and internal fixation (ORIF) with anatomic distal femoral (DF) locking plate permits early mobilization. However, this usually necessitates bone grafting (BG). Biological fixation using minimally invasive techniques minimizes periosteal stripping and morbidity. Materials and Methods: 31 patients with comminuted periprosthetic DF fractures were reviewed retrospectively from October 2006 to September 2012. All patients underwent fixation using a DF locking compression plate (Synthes). 17 patients underwent ORIF with primary BG, whereas 14 were treated by closed reduction (CR) and internal fixation using biological minimally invasive techniques. Clinical and radiological followup were recorded for an average 36 months. Results: Mean time to union for the entire group was 5.6 months (range 3-9 months). Patients of ORIF group took longer (Mean 6.4 months, range 4.5-9 months) than the CR group (mean 4.6 months, range 3-7 months). Three patients of ORIF and one in CR group had poor results. Mean knee society scores were higher for CR group at 6 months, but nearly identical at 12 months, with similar eventual range of motion. Discussion: Locked plating of comminuted periprosthetic DF fractures permits stable rigid fixation and early mobilization. Fixation using minimally invasive biological techniques minimizes morbidity and may obviate the need for primary BG. PMID:26015610

  4. Plate Versus Intramedullary Fixation Care of Displaced Midshaft Clavicular Fractures

    PubMed Central

    Wang, Xin-Hua; Cheng, Lin; Guo, Wei-Jun; Li, A-Bing; Cheng, Guang-Jun; Lei, Tao; Zhao, You-Ming

    2015-01-01

    Abstract In recent decades, there has been a growing trend to the operative treatment of displaced midshaft clavicular fractures. Open reduction and internal plate fixation, and intramedullary nailing fixation are 2 of the widely used techniques for operative treatment, but the optimal fixation method for these types of fractures remains a topic of debate. The objective of this study was to determine the effectiveness of plate fixation versus intramedullary nailing fixation for displaced midshaft clavicle fractures by comparing their clinical results. Literature searches of the Pubmed, EMBASE, and Web of Science were performed from 1966 to April, 2015. Only randomized controlled clinical trials comparing plate and intramedullary nailing treatment for displaced midshaft clavicle fractures were included. Literature was screened, data were extracted, and methodological quality of the eligible trials was assessed by 2 independent reviewers accordingly. Seven randomized controlled trials involving 421 patients were included. Compared to intramedullary nailing fixation, plate fixation had a relatively longer mean surgical time and a trend towards a faster functional improvement during the first 6 months after surgery; apart from this, the pooled results revealed no significant differences in functional scores after 6 months postoperatively, complication rate and patients’ satisfaction between plate fixation and intramedullary fixation. Our results demonstrated that these 2 methods were comparable and safe in the treatment of displaced midshaft clavicle fractures. We advocate both techniques for the treatment of displaced midshaft clavicle fractures, and the superior surgical technique was those that the surgeon was originally trained to perform. PMID:26469924

  5. Minimally invasive metatarsal fracture repair with locking plates in a guanaco (Lama guanicoe).

    PubMed

    Bertuglia, Andrea; Piga, Sara; Bullone, Michela; Piras, Lisa; von Degerfeld, Mitzy Mauthe

    2014-12-01

    An open grade I transverse diaphyseal fracture of the metatarsal bone in a 5-yr-old female guanaco (Lama guanicoe) was successfully stabilized with a locking plate system, which is a minimally invasive approach. A conical coupling screw-plate locking system with 3.0-mm-thick plates and 3.5-mm locking head screws was applied, after closed and indirect reduction of the bone segments, with an orthogonal configuration of the plates. The implants were protected postoperatively with a splinted bandage. The fracture healed without complications, the limb function was successfully recovered, and no major complications were observed at the 2-yr follow-up. The surgical procedure was carried out with biologic internal fixation supports and an adequate functional union within a time period similar to that reported for this species following other fracture fixation methods. This case highlights the potential benefit of combining minimally invasive plate osteosynthesis and plate-locking systems for fracture repair in camelids. PMID:25632682

  6. Custom-made locked plating for acetabular fracture: a pilot study in 24 consecutive cases.

    PubMed

    Xu, Meng; Zhang, Li-Hai; Zhang, Ying-Ze; Zhang, Li-Cheng; He, Chun-Qing; Wang, Yan; Tang, Pei-Fu

    2014-07-01

    Clinical implementation of site-specific locking plates for acetabular fracture remains untested. Custom-made locking plates were manufactured using computer-aided design and computer-aided manufacture techniques for acetabular fractures to test this procedure. The 3-dimensional images constructed from computed tomography data of pelvises in patients with acetabular fractures were used for preoperative planning and to design the plates. Data for each plate were input into software for programming, and the generated code was transferred into a computerized numerical control digital milling machine for manufacturing. These plates were clinically implemented, and the implementation parameters, reduction quality, and Postel Merle d'Aubigné score were evaluated. Forty-nine custom-made locking plates were manufactured for 24 unilateral acetabular fractures. The manufacturing process for the plates averaged 6.9±2.2 days. Processing the plates delayed operations by 2.6±1.3 days in one-third of the cases. Plate contouring was avoided in 48 plates. The plates had anatomical shapes, excellently matching reduced bone surface. The screws locked with the obtained plates avoided intra-articular penetration and provided secure fixation that allowed early out-of-bed rehabilitation. No indications of implant failures or observations of screw back-outs were observed during follow-up. The clinical application of such plates is associated with the avoidance of plate contouring, low risk of intra-articular penetration, early out-of-bed rehabilitation, and a low rate of implant failure. Implementing such plates in clinical practice is worthy of further investigation, with a focus on selecting patient population and minimizing the time required for and cost of plate manufacturing. PMID:24992064

  7. Optimal Positioning for Volar Plate Fixation of a Distal Radius Fracture: Determining the Distal Dorsal Cortical Distance.

    PubMed

    Vosbikian, Michael M; Ketonis, Constantinos; Huang, Ronald; Ilyas, Asif M

    2016-01-01

    Distal radius fractures are currently among the most common fractures of the musculoskeletal system. With a population that is living longer, being more active, and the increasing incidence of osteoporosis, these injuries will continue to become increasingly prevalent. When operative fixation is indicated, the volar locking plate has recently become the treatment of choice. However, despite its success, suboptimal position of the volar locking plate can still result in radiographic loss of reduction. The distal dorsal cortical distance is being introduced as an intraoperative radiographic tool to help optimize plate position and minimize late loss of fracture reduction. PMID:26614937

  8. Failure analysis of stainless steel femur fixation plate.

    PubMed

    Hussain, P B; Mohammad, M

    2004-05-01

    Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed. PMID:15468877

  9. Construction and Biomechanical Properties of PolyAxial Self-Locking Anatomical Plate Based on the Geometry of Distal Tibia

    PubMed Central

    Liang, Weiguo; Ye, Weixiong; Ye, Dongping; Zhou, Ziqiang; Chen, Zhiguang; Li, Aiguo; Xie, Zong-Han; Zhang, Lihai; Xu, Jiake

    2014-01-01

    In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial loading, 4-point bending, and axial torsion loading on the fracture fixation models of fresh cadaver tibias. Our results showed that variation in twisting angles of lateral tibia surface was found in various segments of the distal tibia. The polyaxial self-locking anatomical plate was constructed based on the geometry of the distal tibia. Compared to the conventional anatomical locking plate, the polyaxial self-locking anatomical plate of the distal tibia provides a better fit to the geometry of the distal tibia of the domestic population, and the insertion angle of locking screws can be regulated up to 30°. Collectively, this study assesses the geometry of the distal tibia and provides variable locking screw trajectory to improve screw-plate stability through the design of a polyaxial self-locking anatomical plate. PMID:25025051

  10. Biomechanical comparison of volar locked plate constructs using smooth and threaded locking pegs.

    PubMed

    Yao, Jeffrey; Park, Min Jung; Patel, Chirag S

    2014-02-01

    The goal of this study was to determine whether there is any biomechanical difference in terms of construct strength with axial loading between volar fixed-angle locking plates with threaded locking vs smooth locking pegs. The control group comprised 7 cadaveric specimens with threaded locking pegs, and the test group comprised 7 cadaveric specimens from the same donor with smooth locking pegs. The DVR plate (Biomet, Warsaw, Indiana) was applied to the volar surface. A 15-mm dorsal wedge osteotomy was created near the level of Lister's tubercle. The radii were potted in polymethylmethacrylate for biomechanical testing. The loading protocol consisted of 3 parts: ramp loading, cyclic loading, and failure loading. The outcome measures of stiffness and failure were used to test the plates fixed with threaded and smooth locking pegs. When comparing each cycle, the difference in mean stiffness between threaded and smooth locking pegs was as follows: 122 N/mm, -9.09 N/mm, -14.7 N/mm, 49.4 N/mm, 57.4 N/mm, 71.9 N/mm, 52.3 N/mm, 35.8 N/mm. The difference in mean failure load between the threaded and smooth locking pegs was -11.3 N. There was no difference in stiffness throughout all cycles. Failure analysis showed no significant difference between the smooth (962 N) and threaded (951 N) locking pegs. The difference in stiffness between the 2 constructs (smooth minus threaded locking pegs) in ramp loading ranged from -122 to 15 N/mm. The results of this study showed no significant differences in stiffness and failure load between constructs consisting of threaded locking pegs or smooth locking pegs in the distal rows of the DVR distal radius volar locking plate. Based on the results of this study, there may be no benefit to using threaded locking pegs vs smooth locking pegs when treating distal radius fractures with a volar locking plate. PMID:24679204

  11. Development of site-specific locking plates for acetabular fractures.

    PubMed

    Xu, Meng; Zhang, Li-Hai; Zhang, Ying-Ze; He, Chun-Qing; Zhang, Li-Cheng; Wang, Yan; Tang, Pei-Fu

    2013-05-01

    Site-specific locking plates have gained popularity for the treatment of fractures. However, the clinical use of a site-specific locking plate for acetabular fractures remains untested due to production limits. To design a universal site-specific locking plate for acetabular fractures, the 3-dimensional (3D) photographic records of 171 pelvises were retrospectively studied to generate a universal posterior innominate bone surface. Using 3D photographical processing software, the 3D coordinate system was reset according to bony landmarks and was scaled based on the acetabular diameter to allow a direct comparison between surfaces. The measured surface was separated into measurement units. At each measurement unit, the authors calculated the average z-axis values in all samples and obtained the 3D coordinate values of the point cloud that could be reconstructed into the universal surface. A plate was subsequently designed in 3D photographical processing software, and the orientation and distribution of locking screws was included. To manufacture a plate, the data were entered into Unigraphics NX version 6.0 software (Siemens PLM Software, Co, Ltd, Plano, Texas) and a CNC digital milling machine (FANUC Co, Ltd, Yamanashi, Japan). The resulting locking plate fit excellently with the reduced bone surface intraoperatively. Plate contouring was avoided intraoperatively. Universal 3.5-mm locking screws locked successfully into the plate, and their orientations were consistent with the design. No screw yielded to acetabular penetration. This method of designing a site-specific acetabular locking plate is practical, and the plates are suitable for clinical use. These site-specific locking plates may be an option for the treatment of acetabular fractures, particularly in elderly patients. PMID:23672911

  12. Treatment of unstable distal radius fractures with the volar locking plate

    PubMed Central

    2011-01-01

    Background Open reduction and internal fixation using an interlocking plate system has gained popularity for the treatment of dorsally displaced distal radius fractures. Purpose To evaluate the functional and radiological results of treating unstable distal radius fractures with the volar locking plate. Patients and methods A retrospective review was conducted of patients from one institution using the volar locking plate to treat intra-articular and extra-articular distal radius fractures. Unstable distal radius fractures in 15 patients, comprising 3 men and 12 women with a mean age of 64.4 years (34–76 years), were treated with a volar locking compression plate (Acu-Loc distal radius plate system; Acumed, Oregon, USA) and followed up for a minimum of 1 year. Fractures were classified using the AO classification. Radiographic parameters of preoperative, postoperative, and final follow-up radiographs were compared. The time to initiation of active range of motion was determined. Final follow-up range of motion and complications were reported. Results At final functional assessment, the scores of 5 patients were excellent, 7 patients good, and 3 patients fair according to Cooney's Clinical Scoring Chart. No non-union or infection occurred. Rupture of the flexor pollicis longus tendon occurred in 1 patient. Conclusion Treatment of unstable distal radius fractures with a volar locking plate leads to satisfactory results, provided the operative technique is carefully performed to prevent complications. PMID:21702730

  13. Comparison of outcome of unilateral locking plate and dual plating in the treatment of bicondylar tibial plateau fractures

    PubMed Central

    2014-01-01

    Background Tibial plateau fracture (TPF) includes different fracture patterns with varied degrees of articular depression and displacement. Many kinds of fixators, including newly designed plate with locking screws, were applied to treat these complicated fractures. We intended to follow up the surgical outcomes of (1) unilateral locking plate, (2) classic dual plates, or (3) hybrid dual plates for TPF. Materials and methods We retrospectively reviewed 76 patients with TPF, Schatzker types V and VI, who we operated from June 2006 to May 2009 in our institute. Excluding patients who expired due to other medical conditions and without complete follow-up, 45 patients were sorted out in this series. The scheme of surgical intervention was designed by visiting staff, and 15 patients, as group I, were treated with unilateral locking plate. The other 19 patients, as group II, were treated with classic dual plates. The residual 11 patients, as group III, were treated with hybrid dual plates (one lateral approach locking compression plate (LCP)?+?medial anti-gliding plate). All patients were under periodic F/U at about 6 weeks interval for at least 18 months postoperatively. Results In group I, 13 cases achieved solid bony union without obvious traumatic OA change, limitation of ROM, or malalignment. In groups II and III, 15 and 10 patients reached the same goal, respectively. By analysis of the recorded parameters with statistical software (SPSS 12.0), there were five parameters with significant difference, including Schatzker classification, operation time, staged treatment or not, hospitalization period, and hardware impingement. Conclusions There was no significant statistical difference of union rate between these three groups in our series. Based on our clinical follow-up, several key points were emphasized: (1) Soft tissue problems should be kept in mind, and usage of locking plate can reduce the discomfort of hardware impingement effectively. (2) The single lateral approach technique for TPF with locking plate results in less operation time and shorter hospitalization period. (3) If the medial buttress cannot be established by reduction of the lateral fracture, then open reduction of the medial side is necessary and buttresses the medial fragment by dual plates. PMID:25038620

  14. Biomechanical comparison of different volar fracture fixation plates for distal radius fractures.

    PubMed

    Sobky, Kareem; Baldini, Todd; Thomas, Kenneth; Bach, Joel; Williams, Allison; Wolf, Jennifer Moriatis

    2008-06-01

    The purpose of this study was to compare the biomechanical properties of four volar fixed-angle fracture fixation plate designs in a novel sawbones model as well as in cadavers. Four volar fixed angle plating systems (Hand Innovations DVR-A, Avanta SCS/V, Wright Medical Lo-Con VLS, and Synthes stainless volar locking) were tested on sawbones models using an osteotomy gap model to simulate a distal radius fracture. Based on a power analysis, six plates from each system were tested to failure in axial compression. To simulate loads with physiologic wrist motion, six plates of each type were then tested to failure following 10,000 cycles applying 100N of compression. To compare plate failure behavior, two plates of each type were implanted in cadaver wrists and similar testing applied. All plate constructs were loaded to failure. All failed with in apex volar angulation. The Hand Innovations DVR-A plate demonstrated significantly more strength in peak load to failure and failure after fatigue cycling (p value < 0.001 for single load and fatigue failure). However, there was no significant difference in stiffness among the four plates in synthetic bone. The cadaveric model demonstrated the same mode of failure as the sawbones. None of the volar plates demonstrated screw breakage or pullout, except the tine plate (Avanta SCS/V) with 1 mm of pullout in 2 of 12 plates. This study demonstrates the utility of sawbones in biomechanical testing and indicates that volar fixation of unstable distal radius fractures with a fixed angle device is a reliable means of stabilization. PMID:18780084

  15. Torsion properties of biological fixation utilizing a plate with and without an intramedullary rod 

    E-print Network

    Keiser, Michael

    1995-01-01

    failure. The research reported here analyzed this biological fixation technique during torsional loading. The strain values on the surface of the plate alone were compared to those of a plate with an intramedullary rod during simulated fracture fixation...

  16. Clinical application of locked plating system in children. An orthopaedic view

    PubMed Central

    Zafra-Jimenez, Jose Alberto; Rodriguez Martin, Juan

    2010-01-01

    In recent years, the locked plating system has gained favour in the treatment of certain fractures in adults; however, there is not much information regarding its use in children. We think there could be some advantages and applications such as: an alternative to external fixation, the bridge plating technique, unicortical screws, removal of hardware, metadiaphyseal fractures, periarticular fractures, poor quality bone, and allograft fixation. However, there are some disadvantages to keep in mind and the final decision for using it should be based on the osteosynthesis method principle the surgeon would like to apply. In this review article we discuss the up-to-date possible clinical applications and issues of this system. PMID:20162415

  17. Complication with Removal of a Lumbar Spinal Locking Plate

    PubMed Central

    Crawford, Brooke; Lenarz, Christopher; Watson, J. Tracy; Alander, Dirk

    2015-01-01

    Introduction. The use of locking plate technology for anterior lumbar spinal fusion has increased stability of the vertebral fusion mass over traditional nonconstrained screw and plate systems. This case report outlines a complication due to the use of this construct. Case. A patient with a history of L2 corpectomy and anterior spinal fusion presented with discitis at the L4/5 level and underwent an anterior lumbar interbody fusion (ALIF) supplemented with a locking plate placed anterolaterally for stability. Fifteen months after the ALIF procedure, he returned with a hardware infection. He underwent debridement of the infection site and removal of hardware. Results. Once hardware was exposed, removal of the locking plate screws was only successful in one out of four screws using a reverse thread screw removal device. Three of the reverse thread screw removal devices broke in attempt to remove the subsequent screws. A metal cutting drill was then used to break hoop stresses associated with the locking device and the plate was removed. Conclusion. Anterior locking plates add significant stability to an anterior spinal fusion mass. However, removal of this hardware can be complicated by the inherent properties of the design with significant risk of major vascular injury. PMID:25838956

  18. A Novel Fixation System for Acetabular Quadrilateral Plate Fracture: A Comparative Biomechanical Study

    PubMed Central

    Zha, Guo-Chun; Sun, Jun-Ying; Dong, Sheng-Jie; Zhang, Wen; Luo, Zong-Ping

    2015-01-01

    This study aims to assess the biomechanical properties of a novel fixation system (named AFRIF) and to compare it with other five different fixation techniques for quadrilateral plate fractures. This in vitro biomechanical experiment has shown that the multidirectional titanium fixation (MTF) and pelvic brim long screws fixation (PBSF) provided the strongest fixation for quadrilateral plate fracture; the better biomechanical performance of the AFRIF compared with the T-shaped plate fixation (TPF), L-shaped plate fixation (LPF), and H-shaped plate fixation (HPF); AFRIF gives reasonable stability of treatment for quadrilateral plate fracture and may offer a better solution for comminuted quadrilateral plate fractures or free floating medial wall fracture and be reliable in preventing protrusion of femoral head. PMID:25802849

  19. Biomechanical Performance of Lateral Versus Dual Locking Plates for Calcaneal Fractures.

    PubMed

    Maxwell, Abby B; Owen, John R; Gilbert, Todd M; Romash, Michael M; Wayne, Jennifer S; Adelaar, Robert S

    2015-01-01

    Given the high rates of wound complications with a standard lateral extensile incision, small dual incision techniques might result in less soft tissue destruction. The goal of the present study was to compare the biomechanical performance between a single locking plate and a dual locking plating system for an intra-articular calcaneal fracture model. A Sanders IIB type joint depression calcaneal fracture was created in 10 paired, fresh-frozen, cadaveric calcanei (age 47 ± 12, range 35 to 78 years). The calcanei of each pair were randomly assigned for fixation using either a lateral locking reconstruction plate or lateral and medial locking reconstruction plates. The specimens were axially loaded in cyclic fashion for 1000 cycles, followed by load to failure. The relative fragment movement was monitored optically in both the sagittal and the coronal planes. The amount of overall construct displacement increased with cycling, although no difference was found between the plating techniques. For fragment movement during cycling, the lateral joint fragment migrated anteroinferiorly along the fracture line relative to the tuberosity fragment for dual plated specimens by a small, but statistically significant, amount. This same translation was smaller for lateral plated specimens but was not found to be significant. During load to failure testing, no statistically significant differences were found for construct stiffness. A tendency was seen toward more interfragmentary motion in the sagittal plane (lateral joint fragment movement relative to the fracture line), with less movement overall in the coronal plane (anterior fragment translation and twist) for dual plating, although the difference from the lateral plate was not statistically significant. The present study demonstrated that for this calcaneal fracture model, the dual plating technique experienced a small amount of fragment translation during cycling that was significantly different statistically from that with lateral plating but was not clinically relevant. During the load to failure, the dual plating technique was comparable to the lateral plate. Thus, dual plating could be a viable biomechanical option for fracture reduction if avoidance of a large extensile lateral approach associated with lateral plating is warranted. PMID:25960057

  20. Cost effectiveness of treatment with percutaneous Kirschner wires versus volar locking plate for adult patients with a dorsally displaced fracture of the distal radius: analysis from the DRAFFT trial.

    PubMed

    Tubeuf, S; Yu, G; Achten, J; Parsons, N R; Rangan, A; Lamb, S E; Costa, M L

    2015-08-01

    We present an economic evaluation using data from the Distal Radius Acute Fracture Fixation Trial (DRAFFT) to compare the relative cost effectiveness of percutaneous Kirschner wire (K-wire) fixation and volar locking-plate fixation for patients with dorsally-displaced fractures of the distal radius. The cost effectiveness analysis (cost per quality-adjusted life year; QALY) was derived from a multi-centre, two-arm, parallel group, assessor-blind, randomised controlled trial which took place in 18 trauma centres in the United Kingdom. Data from 460 patients were available for analysis, which includes both a National Health Service cost perspective including costs of surgery, implants and healthcare resource use over a 12-month period after surgery, and a societal perspective, which includes the cost of time off work and the need for additional private care. There was only a small difference in QALYs gained for patients treated with locking-plate fixation over those treated with K-wires. At a mean additional cost of £714 (95% confidence interval 588 to 865) per patient, locking-plate fixation presented an incremental cost effectiveness ratio (ICER) of £89,322 per QALY within the first 12 months of treatment. Sensitivity analyses were undertaken to assess the ICER of locking-plate fixation compared with K-wires. These were greater than £30,000. Compared with locking-plate fixation, K-wire fixation is a 'cost saving' intervention, with similar health benefits. PMID:26224825

  1. Screw locking elements: a means to modify the flexibility of osteoporotic fracture fixation with DCPs without compromising system strength or stability.

    PubMed

    Yánez, A; Cuadrado, A; Carta, J A; Garcés, G

    2012-07-01

    This paper analyses whether it is possible to use dynamic compression plates (DCPs) and screw locking elements (SLEs) to vary the flexibility of osteoporotic fracture fixation without compromising the strength and stability of the construct. Compression, torsion and four-point bending static strength tests were conducted. Cyclic load tests of up to 10,000 load cycles were also carried out to determine stiffness performance. Four fixation systems were mounted onto polyurethane bone models. Group 1 consists of the DCP and six cortical screws. Group 2, idem, but with the addition of two SLEs. Group 3, idem, but with the addition of six SLEs. Group 4 used the locking compression plate (LCP) and locking screws. The results indicated no significant difference (p>0.05) in the strength of groups 2-4. It was also observed that the torsional stiffness of group 3 (0.30 Nm/°) was higher than that of group 2 (0.23 Nm/°) and similar to that of group 4 (0.28 Nm/°). Compression stiffness of group 4 (124 N/mm) was higher than that of group 2 (102 N/mm), but lower than that of group 3 (150 N/mm). No notable differences were observed for structural bending stiffness. It is concluded that by using the DCP with SLEs it is possible to modify the stiffness of the fixation construct for the repair of osteoporotic fractures and, in this way, facilitate the conditions suitable on secondary bone healing. PMID:21982962

  2. Analysis and design of an adjustable bone plate for mandibular fracture fixation

    E-print Network

    Cervantes, Thomas Michael

    2011-01-01

    This thesis presents the design, analysis and testing of a bone plate for mandibular fracture fixation. Conventional bone plates are commonly used to set fractures of the mandible in a surgical setting. If proper alignment ...

  3. Comminuted olecranon fracture fixation with pre-contoured plate: Comparison of composite and cadaver bones

    PubMed Central

    Hamilton Jr, David A; Reilly, Danielle; Wipf, Felix; Kamineni, Srinath

    2015-01-01

    AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model. METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry (DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test. RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones (n = 5) and human cadaver bones (n = 5) specimens were 10.67 nm (range 9.40-11.91 nm) and 13.05 nm (range 12.59-15.38 nm) respectively. This difference was statistically significant (P ? 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm (range 4.69-6.80 nm/mm) and 7.55 nm/mm (range 6.31-7.72 nm/mm). There was a significant difference for stiffness (P ? 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric specimens. Failure of 4/5 cadaveric specimens was defined when a fracture gap of 2 mm was observed, but 1/5 cadaveric specimens failed due to a failure of the triceps mechanism. All failures occurred at forces greater than that expected in postoperative period prior to healing. CONCLUSION: The pre-contoured olecranon plate provides adequate fixation to withstand physiologic force in a composite bone and cadaveric comminuted olecranon fracture model. PMID:26495247

  4. Scaphoid Excision and Limited Wrist Fusion: A Comparison of K-Wire and Circular Plate Fixation

    PubMed Central

    Holt, Gary; Finnerty, Edward P.; Miller, Blake

    2008-01-01

    The purpose of this study was to compare the clinical outcome, union rate, and complications of a consecutive series of Scaphoid excision and limited wrist arthrodesis performed by a single surgeon using distal radius bone graft and K-wires or circular plate fixation. A sequential series of ten patients(11 wrists) who were stabilized with temporary K-wires were compared to 11 patients (11 wrists) who were stabilized with a circular plate. Minimum follow-up was 1 year. One patient in the K-wire group was converted to a wrist fusion. Six of the remaining ten patients in the K-wire fixation group and 8 of the 11 patients in the circular plate fixation group returned for the following blinded evaluations: Quick DASH, analog pain scale, range of motion, grip and pinch strength, plain x-ray, and multi-detector computed tomography evaluation. One non-union occurred in the K-wire group. There were no non-unions in the circular plate fixation group. There was no difference in any of remaining measures or rate of complications. This study shows that equivalent results can be obtained using circular plate fixation compared to K-wires when equivalent bone graft source and fusion technique are used. If K-wire removal requires a return to the OR, circular plate fixation is more cost-effective. PMID:18780110

  5. Technical tips: dualplate fixation technique for comminuted proximal humerus fractures.

    PubMed

    Choi, Sungwook; Kang, Hyunseong; Bang, Hyeongsig

    2014-08-01

    The authors report dualplate fixation technique for providing stable fixation in comminuted proximal humerus fractures. This technique has been used for proximal humerus fractures with metaphyseal comminution and provides excellent anatomical reduction and neck shaft angle (NSA). The recently locking plate is clinically more widely used due to its small size, low rigidity, high elasticity, and biomechanical properties such as fixed initial angle and rotational stability. However, in severely comminuted complex type proximal metaphyseal humerus fractures, the use of locking plate alone does not provide stable fixation, leading to complications such as varus collapse, anterior-posterior angulation, screw cutout, nonunion, malunion, and metal failure. Therefore, a more robust and enhanced fixation method, the dual plating technique using the locking compression plate (Proximal Humeral Internal Locking System and Variable Angle Locking Compression Plate) was developed. PMID:24813097

  6. Locking compression plate osteosynthesis of complicated mandibular fractures in six horses.

    PubMed

    Kuemmerle, J M; Kummer, M; Auer, J A; Nitzl, D; Fürst, A E

    2009-01-01

    Complicated mandibular fractures were recognised in one foal, one pony and four horses. The foal was two months old while the adult animals ranged in age from 12 to 24 years. Three horses had a unilateral horizontal ramus fracture. Two fractures were open and one was closed. Comminution was present in one of these patients while the other two horses had marked displacement of the fragments. Two suffered from comminuted fractures of the horizontal and vertical ramus of the mandible. One of these patients had open and infected fractures. One foal had a bilateral horizontal ramus fracture with marked periosteal 'new bone' formation and malalignement which required corrective osteotomy. Each horse underwent locking compression plate (LCP) osteosynthesis consisting of open fracture reduction and application of one to three 4.5/5.0 mm LCP at the ventral, lateral or caudal aspect of the mandible under fluoroscopic control. Two 3.5 mm LCP were used in the foal. Plate fixation was supported by application of a cerclage wire construct between the incisor and premolar teeth in most patients. Complete fracture healing, with an excellent functional and cosmetic outcome, was achieved in all of the patients. Complications encountered included seroma formation, screw and wire breakage, as well as implant and apical tooth root infections. The LCP was removed after fracture healing had occurred in four patients. PMID:19151871

  7. A Gustilo type IIIB open forearm fracture treated by negative pressure wound therapy and locking compression plates: a case report.

    PubMed

    Takeuchi, Naohide; Mae, Takao; Hotokezaka, Shunsuke; Sasaki, Kosuke; Matsushita, Akinobu; Miake, Go; Kuchiishi, Rintaro; Noguchi, Yasuo

    2011-10-01

    A 91-year-old female sustained injuries to her left forearm while walking across a crosswalk. X-rays showed left radial shaft and ulna shaft fractures, and the injury was a type IIIB open fracture. On the day of admission, irrigation and debridement of the open wound, and temporary fixation of the radius and ulna using an external fixator and a Kirschner wire were peformed. Six days after the surgery, we used negative pressure wound therapy (NPWT) using the V.A.C.ATS system for the open wound. Thirteen days after the first surgery, definitive fixation was performed by using locking compression plates, and full thickness skin grafting was undertaken for the open wound. NPWT is a treatment that accelerates the wound healing process through the delivery of continuous subatmospheric pressure within a closed environment. In our case, we could reduce the healing period of the soft tissue and could convert to the definitive fixation in a timely fashion. NPWT is thought to be a useful adjunct in the management of the soft tissues of open fractures. PMID:22171501

  8. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation. PMID:26444295

  9. Flexor tendon repair after rupture caused by volar plate fixation of the distal radius.

    PubMed

    Rubensson, Carin C; Ydreborg, Karin; Boren, Linda; Karlander, Lars-Erik

    2015-04-01

    Volar plate fixation of unstable fractures of the distal radius is preferred by a majority of surgeons today. One known complication is the rupture of flexor tendons. The aim of this paper is to present flexor tendon ruptures after volar plate fixation analysing the clinical outcome after tendon surgery, aetiology, and methods of prevention. Seventeen consecutive ruptures in 14 patients were included. The incidence was 1.4%. Three patients declined tendon surgery. Eleven patients were treated with a free tendon graft. Only two patients showed excellent results regarding mobility in the thumb and/or fingers. Analysis of radiographs demonstrated sub-optimal placement of plate or screws in all cases. Rupture of a flexor tendon is a serious complication where the functional outcome after surgical reconstruction is uncertain. Early removal of the plate when the placement is sub-optimal or when local volar tenderness appears would probably prevent many ruptures. PMID:25162925

  10. Analysis of gene expression profiles in healing rat fractures treated with nail and plate fixation.

    PubMed

    Wang, S D; Li, X L; Liu, H P

    2014-01-01

    To compare fracture healing therapies, the gene expression profiles of rat fracture samples treated with nail and plate fixation were analyzed at 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks after surgery. The gene expression profiles GSE1685, which include 19 samples, were downloaded from the Gene Expression Omnibus database. After preprocessing, the gene expression profiles were subjected to time series analysis using the Short Time-series Expression Miner software, and the significantly differentially expressed gene (DEG) sets were selected. Further, the distributions of those DEG sets on the corresponding chromosomes were identified using the functional classification tool. Finally, the DEGs were subjected to function and pathway enrichment analysis. DEG analysis indicated that the number of DEGs (854 genes) from nail fixation was significantly lower than that of DEGs (1029 genes) from plate fixation. The DEGs were mainly enriched in cell proliferation, cellular localization, and response to wounding functions. Several critical DEGs expressed during the fracture healing process were screened, and 2 common pathways were enriched for the DEGs in the nail fixation and plate fixation. These DEGs and pathways may be potential targets or predictive markers during fracture healing. PMID:25366739

  11. Displaced avulsion fractures of the posterior cruciate ligament: Treated by stellate steel plate fixation

    PubMed Central

    Li, Lijun; Tian, Wei

    2015-01-01

    Background: The open reduction with internal fixation is an effective approach for treatment of avulsion fracture of posterior cruciate ligament. The previously used internal fixation materials including hollow screws, absorbable screw, tension bands and sutures have great defects such as insufficient fixation strength, susceptibility to re-fracture, etc. Stellate steel plate is novel material for internal fixation which has unique gear-like structure design. We used stellate steel plate for treatment of displaced avulsion fractures of posterior cruciate ligament in this study. Materials and Methods: 14 patients (9 men, 5 women; aged, 19–35 years; mean age, 28 years) with displaced avulsion fractures of the tibial insertion of the posterior cruciate ligament were retrospectively analyzed between June 2009 and June 2011. The mean duration from injury to the operation was 8.3 days (range 6–15 days). All the patients were treated with open reduction and internal fixation of a stellate steel plate (DePuy, Raynham, MA 02767, USA). The Lysholm-Tegner knee function score criteria were used to analyze results. Results: The mean followup was 24.6 months (range 18–32 months). After 6 months, all the fractures healed and knee joint activity was normal, with no knee stiffness or instability. The Lysholm-Tegner scores were 97.1 ± 1.7 points at the final followup. Conclusion: Owing to its unique gear structure, the stellate steel plate design can effectively fix an avulsion fracture block and it is a simple operation with short postoperative rehabilitation time and firm fixation. PMID:26015605

  12. Surgical repair of a severely comminuted maxillary fracture in a dog with a titanium locking plate system.

    PubMed

    Illukka, E; Boudrieau, R J

    2014-01-01

    A four-year old male Labrador Retriever was admitted with head trauma after being hit by a car. The dog had sustained multiple nasal, maxillary, and frontal bone fractures that resulted in separation of the maxilla from the base of the skull. A severely comminuted left zygomatic arch fracture was also present. These fractures were all repaired using a point contact, locking titanium plate system, in a single procedure that resulted in excellent postoperative occlusion and immediate function. Healing was uneventful. Full function and excellent cosmetic appearance were evident 13 months after surgery. This case illustrates the ease of repair and the success of treatment of severely comminuted maxillofacial fractures by conforming to basic biomechanical principles taken directly from the human experience and successfully applied to the dog; these included multiple plate application along the buttresses and trusses of the facial skeleton. The plate fixation was applied to bridge the multiple fractures along the most appropriate lines of stress. The small size of the plates, and the ability to easily contour them to adapt to the bone surface in three-dimensions, allowed their placement in the most appropriate positions to achieve sufficient rigidity and lead to uncomplicated healing without any postoperative complications. PMID:25088587

  13. Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware

    PubMed Central

    2010-01-01

    Background Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic compression plate) and LCP (locking compression plate) stabilization, in a human cadaveric diaphyseal gap model. Methods In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. Results The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p ? 0.011, torsion p ? 0.015) but revealed similar performance under cyclic loading (p = 0.43). The Fence instrumentation with established bone-plate contact revealed larger fracture gap motion under axial compression compared to the conventional LC-DCP osteosynthesis (p ? 0.017). However, all contact Fence specimens survived the cyclic test, whereas all LC-DCP constructs failed early during torsion testing (p < 0.001). All failures occurred due to breakage of the screw heads. Conclusions Even though accentuated fracture gap motion became obvious, the "Fence" technique is considered an alternative to cost-intensive locking-head devices. The concept can be of interest in cases were angle-stable implants are unavailable and can lead to new strategies in implant design. PMID:20492707

  14. Biomechanical effects of plate area and locking screw on medial open tibial osteotomy.

    PubMed

    Luo, Chu-An; Lin, Shang-Chih; Hwa, Su-Yang; Chen, Chun-Ming; Tseng, Ching-Shiow

    2015-01-01

    Medial open high tibial osteotomy (HTO) has been used to treat osteoarthritis of the medial compartment of the knee. However, weaker plate strength, unstable plate/screw junction and improper surgery technique are highly related to the HTO outcomes. Two ?-shape plates were designed and eight variations (two supporting area × four locking stiffness) were compared by finite-element method. The computed tomography-based tibia was reconstructed and both wedge micromotion and implant stresses were chosen as the comparison indices. The construct was subjected to surgical and physiological loads. The medial-posterior region is the most loaded region and the load through the posterior leg is about four times that through the anterior leg. This indicates that the two-leg design can form a force-couple mechanism to effectively reduce the implant stresses. The use of locking screws significantly decrease the screw and hole stresses. However, the extending plate reduces the stresses of screws and holes above the wedge but makes the distal screws and holes much stressed. Wedge micromotion is affected by extending plate rather than locking screw. Three factors contribute to effective stabilisation of unstable HTO wedge: (1) intimate tibia-plate contact at medial-posterior regions, (2) sufficient rigidity at plate-screw junctions and (3) effective moment-balancing design at distal tibia-plate interfaces. PMID:24617553

  15. Bioabsorbable plates and screws fixation in mandible fractures: clinical retrospective research during a 10-year period.

    PubMed

    Rha, Eun Young; Paik, Hyewon; Byeon, Jun Hee

    2015-04-01

    We present the basic guidelines for the safe fixation of a mandible fracture using a bioabsorbable system with less strength than the metallic system based on our 10 years of experience.We conducted a retrospective review of 75 patients who had undergone fixation using a bioabsorbable system for a mandible fracture. We analyzed the method of fixation and the size and thickness of the plates and screws that were selected depending on the mandible's fracture site.Minor complications including intraoral wound disruptions and infections occurred in 12 (16%) patients, and 2 (2.7%) patients among 10 patients who presented with infections had nonunion; therefore, they underwent replacement of the absorbable system with the titanium system. Bone resorption that was caused by the absorbable plate occurred in 12 (16%) patients.The bioabsorbable system also may be able to replace the metallic system in the fixation of comminuted mandible fractures if further research on the development of the system is supported. PMID:25551864

  16. Open reduction and internal fixation of posterior pilon fractures with buttress plate

    PubMed Central

    Chen, Da-wei; Li, Bing; Aubeeluck, Ashwin; Yang, Yun-feng; Zhou, Jia-qian; Yu, Guang-rong

    2014-01-01

    Objective: Posterior pilon fractures are rare injuries and have not yet gained well recognition. The purpose of this study was to present the treatment outcome for patients with posterior pilon fractures treated with buttress plate. Method: In this retrospective study we identified patients with posterior pilon fractures of the distal tibia who had undergone open reduction and internal fixation at our institute. Between January 2007 and December 2009, 10 patients (mean age, 46.5 years) who had undergone buttress plating via either a posterolateral approach or a dual posterolateral-posteromedial approach, were selected. All 10 patients were available for follow-up. The clinical outcome was evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS). The radiological evaluation was performed using the osteoarthritis-score (OA-score). Results: Satisfactory reduction and stable fixation were accomplished in all patients. At a mean follow-up of 36.2 months, all patients had good radiological results and showed satisfactory clinical recovery. The mean AOFAS sore was 87.8, the mean OA-score was 0.6, and the mean VAS scores during rest, active motion, and weight-bearing walking were 0.6, 0.8, and 1.4, respectively. Conclusion: Buttress plating for posterior pilon fractures gave satisfactory clinical outcomes. It also ensured rigid fixation which in turn enabled earlier postoperative mobilization. Level of Evidence IV, Retrospective Study. PMID:24644421

  17. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation

    PubMed Central

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    Background This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. Material/Methods We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. Results All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. Conclusions Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  18. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation.

    PubMed

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. RESULTS All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. CONCLUSIONS Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  19. The application of Diapason spinal fixator device: a comparison with the Steffee VSP plate.

    PubMed

    Izawa, K; Yonenobu, K; Kawatsu, N; Hirotsuji, M; Wada, E; Hosono, N

    1995-01-01

    Twenty-five consecutive patients who had a variety of lumbar disorders and who underwent lumbar spinal fusion using the Diapason fixator were followed for a mean period of 20 months. The operations included 16 posterior lumbar interbody fusion (PLIF), 7 posterolateral fusion (PLF), and 2 combined PLIF and PLF (PLIF/PLF). As a control group, 38 patients undergoing PLIF using a Steffee VSP plate (VSP) were followed for a mean period of 24 months. There were no significant differences between the two groups regarding the operation time, blood loss, and improvement of preoperative symptoms. However, incidence of incomplete bony union and radiolucent zone around the screws were higher in the Diapason group than in the VSP group. Our study suggests that there was a possibility of insufficient rigidity of screw-rod fixation in the Diapason system. PMID:7787342

  20. Comparing the effect of volar plate fixators and external fixators on outcome of patients with intra-articular distal radius fractures: A clinical trial

    PubMed Central

    Safdari, Mohammadreza; Koohestani, Mahmoodreza Mohajer

    2015-01-01

    Background: Distal radius fractures (DRFs) are much more prone to malunion than unstable extra-articular fractures. There is no clear consensus concerning what the proper treatment should be, and the best approach to use for displaced DRFs remains challenging. Objective: To compare the effect of two different therapeutic surgical methods, i.e., volar plate fixators and external fixators, on outcomes of patients with intra-articular distal radius fractures. Methods: From May 2010 to November 2014, 76 subjects who had experienced intra-articular fractures of the distal radius were enrolled in this double-blind, randomized, controlled trial in Imam Ali Hospital in Bojnourd, Iran. The patients were divided into two groups, i.e., 1) patients who were treated with internal fixation using the volar plate (group A) and 2) patients who were treated with external fixators (group B). The primary outcome was a composite measure of the patient’s quality of life using three different scores, i.e., 1) the MAYO score, 2) Disabilities of the Arm, Shoulder, and Hand (DASH (score, and 3) the Short Form (36) (SF-36) Health Survey score. Results: A total of 76 patients were allocated randomly to groups A and B. The mean ages for external fixator cases and volar plate cases were 51.7 and 46.3, respectively. No significant age distribution was seen between the two groups (p=0.348). Gender distribution between the two groups was not significantly different (p=0.022). Grip power was significantly different between the two groups, but no significant differences were detected in range of motion (p=0.008, p=0.367, respectively). The MAYO score was significantly higher in the open reduction and internal fixation (ORIF) group, and, according to the SF-36 test, the ORIF group also a higher level of general mental and physical health, social functioning, and personal physical functioning than the other group. However, postoperatively, the mental discomfort and physical discomfort were more prevalent in the external fixator group. The DASH score was not significantly different between the two groups (p=0.124). Conclusions: ORIF and its subtitle, volar plate fixation, is a more preferred surgical procedure than the external fixator for the treatment of intra-articular distal radius fractures. This conclusion is important when one considers cost-effectiveness and an earlier return to work. Trial registration: The trial is registered at the Thai Clinical Trial Registry (clinicaltrials.in.th) with the TCR identification number TCTR20150609002 Funding: The authors received no financial support for the research, authorship, and/or publication of this article. PMID:26120419

  1. Comparison of Results between Hook Plate Fixation and Ligament Reconstruction for Acute Unstable Acromioclavicular Joint Dislocation

    PubMed Central

    Yoon, Jong Pil; Lee, Byoung-Joo; Nam, Sang Jin; Chung, Seok Won; Jeong, Won-Ju; Min, Woo-Kie

    2015-01-01

    Background In the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation. Methods Forty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs. Results The mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I. Conclusions In cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option. PMID:25729525

  2. Second generation locked plating of proximal humerus fractures--a prospective multicentre observational study.

    PubMed

    Röderer, Götz; Erhardt, Johannes; Kuster, Markus; Vegt, Paul; Bahrs, Christian; Kinzl, Lothar; Gebhard, Florian

    2011-03-01

    Surgical treatment of most displaced proximal humerus fractures is challenging due to osteoporosis. Locking plates are intended to provide superior mechanical stability. In a prospective multicentre study 131 patients were treated with second generation locked plating (NCB-PH, Zimmer, Inc.). The open procedure (n = 78) was performed using a deltopectoral approach; the minimally invasive technique (n = 53) involved percutaneous reduction and an anterolateral deltoid split approach. Clinical and radiological follow-up was obtained. Improvement in function (ROM) was statistically significant. Fracture type (AO) had the most significant impact on the incidence of complications. The most frequent complications detected were intra-articular screw perforation (15%) and secondary displacement (8%). Complication rate and functional outcome of the NCB-PH are comparable to reports in the literature. Not all problems are likely to be solved by this new generation of implants, i.e. secondary dislocation still occurred in 8% of our patients. PMID:20419453

  3. A video guided solution for screw insertion in orthopedic plate fixation

    NASA Astrophysics Data System (ADS)

    Magaraggia, J.; Kleinszig, G.; Graumann, R.; Angelopoulou, E.; Hornegger, J.

    2013-03-01

    In orthopedic and trauma surgery, metallic plates are used for reduction and fixation of bone fractures. In clinical practice, the intra-operative planning for screw fixation is usually based on fluoroscopic images. Screw fixation is then performed on a free-hand basis. As such, multiple attempts may be required in order to achieve an optimal positioning of the fixing screws. To help the physician insert the screws in accordance to the planned position, we propose a method for screw insertion guidance. Our approach uses a small video camera, rigidly placed on the drill, and a set of small markers that are rigidly fixed on a variable angle drill sleeve. In order to investigate the achievable accuracy of our setup, we simulate the estimation of the drill bit position under two different marker arrangements, planar and 3D, and different noise levels. Furthermore, we motivate our choices for marker design and position given the limited space available for marker positioning, the requirement for accurate position estimation of the drill bit and the illumination changes that could affect the surgical site. We also describe our proposed marker detection and tracking pipeline. Our simulation results let us conclude that we can achieve an accuracy of 1° and 1mm in the estimation of angular orientation and tip position of the drill bit respectively, provided that we have accurate marker detection.

  4. Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants.

    PubMed

    Scolaro, John A; Hsu, Jason E; Svach, David J; Mehta, Samir

    2014-12-01

    Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs. Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy. In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater bending stiffness, torsional stiffness, and yield strength than a single 3.5mm LCP plate for osteotomies created 80mm from the trochlea. At the more distal osteotomy, dual plating was biomechanically superior. Our results suggest that single posterolateral column fixation of extra-articular humerus fractures is appropriate for more proximal fractures but that dual plate fixation is superior for more distal fractures. PMID:25249244

  5. Is cross-screw fixation superior to plate for radial neck fractures?

    PubMed

    Li, S L; Lu, Y; Wang, M Y

    2015-06-01

    This study compares the outcomes of two methods of fixation of displaced fractures of the radial neck. The 58 patients with a mean age of 38.5 years (18 to 56), were treated in a non randomised study with screws (n = 29) or a plate and screws (n = 29) according to the surgeon's preference. The patients were reviewed at one year. Radiographs and functional evaluations were carried out up to one year post-operatively, using the Broberg and Morrey functional evaluation score, range of movement, and assessment of complications. The mean functional scores did not differ significantly between groups (90 (55 to 100) vs 84; 50 to 100, p = 0.09), but the mean range of forearm rotation in screw group was significantly better than in the plate group (152°; 110° to 170° vs 134°; 80° to 170°, p = 0.001). Although not statistically significant, the screw group had a lower incidence of heterotopic ossification than the plate group (n = 1) than the plated group (n = 3) and the pathology was graded as less severe. PMID:26033065

  6. Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?

    PubMed Central

    Wu, Yong-De; Cai, Xian-Hua; Liu, Xi-Ming; Zhang, Hong-Xi

    2013-01-01

    OBJECTIVE: The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area. METHODS: A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations. RESULTS: As the load was added, the displacements were Aplate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting. PMID:23917670

  7. Comparison of interface contact profiles of a new minimum contact locking compression plate and the limited contact dynamic compression plate

    PubMed Central

    Xiong, Yan; Zhao, Yu Feng; Xing, Shu Xing; Du, Quan Yin; Sun, Hong Zhen; Wang, Zi Ming; Wu, Si Yu

    2009-01-01

    In this study, we investigated whether or not a new minimum contact locking compression plate (MC-LCP) can provide advantages over the limited contact dynamic compression plate (LC-DCP) in the context of interface contact area and force. Six matched pairs of cadaveric bones were used for each of three bone types of the humerus, radius and ulna. For each bone type, one of two bone plates was fixed to either of two matched cadaveric bones at the middle of the diaphysis. The interface contact area and force of the plate fixed to three types of human cadaveric bones were evaluated using Fuji prescale pressure sensitive film. Data were quantitated using computer-assisted image analysis. Results showed that the average force between the MC-LCP and humerus or radius was about half of that of the LC-DCP. And the average force between the MC-LCP and ulna was one third less than that of the LC-DCP. Meanwhile, the interface contact area between the MC-LCP and humerus or radius was also about half of that of the LC-DCP, and the interface contact area between the MC-LCP and ulna was less than one third of that of the LC-DCP. These results indicate that the MC-LCP has lower interface contact area and lower average force than that of the LC-DCP. Thus, the MC-LCP system may be a good alternate to treat forearm diaphyseal fractures. PMID:19603166

  8. Treatment of Humeral Shaft Fractures: Minimally Invasive Plate Osteosynthesis Versus Open Reduction and Internal Fixation

    PubMed Central

    Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad; Ashoori, Keyqobad

    2015-01-01

    Background: The optimal technique for operative fixation of humeral shaft fractures remains controversial and warrants research. Objectives: The purpose of the current study was to compare the functional and clinical outcomes of conventional open reduction and internal fixation (ORIF) with minimally invasive plate osteosynthesis (MIPO) in patients with fractures in two-third distal humeral shaft. Patients and Methods: In the current prospective case-control study, 65 patients with humeral shaft fractures were treated using ORIF (33 patients) or MIPO (32 patients). Time of surgery, time of union, incidence of varus deformity and complications were compared between the two groups. Also, the university of California-Los Angeles (UCLA) shoulder rating scale and Mayo Elbow performance score (MEPS) were used to compare the functional outcomes between the two groups. Results: The median of union time was shorter in the MIPO group (4 months versus 5 months). The time of surgery and functional outcomes based on the UCLA and MEPS scores were the same. The incidence of varus deformity was more than 5° and was higher and the incidence of nonunion, infection and iatrogenic radial nerve injury were lower in the MIPO group; however, the differences were not significant. Conclusions: Due to the shorter union time, to some extent less complication rate and comparable functional and clinical results, the authors recommend to use the MIPO technique in treating the mid-distal humeral shaft fracture. PMID:26543844

  9. Treatment of type 2 and 4 olecranon fractures with locking compression plate osteosynthesis in horses: a prospective study (2002-2008).

    PubMed

    Jackson, M; Kummer, M; Auer, J; Hagen, R; Fuerst, A

    2011-01-01

    This prospective study describes a series of 18 olecranon fractures in 16 horses that were treated with locking compression plates (LCP). Twelve of the 18 fractures were simple (type 2), whereas six were comminuted (type 4). Six fractures were open and 12 were closed. Each horse underwent LCP osteosynthesis consisting of open reduction and application of one or two LCP. Complete fracture healing was achieved in 13 horses. Three horses had to be euthanatized: two because of severe infection and one because of a comminuted radial fracture 11 days after fixation of the olecranon fracture. Complications encountered after discharge of the horses from the Equine Hospital at the Vetsuisse Faculty (University of Zurich) included implant infection (n=2) and lameness (n=3), which were successfully treated with implant removal. Despite being easier to use, LCP osteosynthesis resulted in a clinical outcome similar to DCP osteosynthesis. PMID:21103649

  10. Evaluation of trapezoidal-shaped 3-D plates for internal fixation of mandibular subcondylar fractures in adults

    PubMed Central

    Chaudhary, Manoj; Pant, Harshvardhan; Singh, Manpreet; Vashistha, Arpit; Kaur, Gagandeep

    2015-01-01

    Aims The purpose of this study is to evaluate the clinical results and to assess the efficacy, stability, and rigidity of trapezoidal 3-D plates for osteosynthesis in adult mandibular subcondylar fracture patients. Methods This study included 15 cases of trauma having mandibular subcondylar fractures, in which open reduction and internal fixation are indicated. After selecting patient according to the inclusion criteria, all patients underwent open reduction and rigid fixation. Fracture was then stabilized using 4 hole, 2.0 mm trapezoidal-shaped 3-D titanium plates using retromandibular incision. Postoperative clinical examination was carried out on 3rd day; 1st, 2nd, and 4th weeks; and 3rd and 6th months. Results The results of this study suggest that the fixation of mandibular subcondylar fracture with trapezoidal-shaped 3-D plates provides three-dimensional stability and carries low morbidity. Conclusion Patients with gross displacement of condylar fragment, major reduction in posterior facial height, and deranged occlusion can be successfully managed by open reduction of condylar fracture and its fixation using 3-D plates. PMID:26587378

  11. Percutaneous fixation of first metacarpal base fractures using locked K-wires: a series of 14 cases.

    PubMed

    Adi, Mohamed; Miyamoto, Hideaki; Taleb, Chihab; Zemirline, Ahmed; Gouzou, Stéphanie; Facca, Sybille; Liverneaux, Philippe

    2014-06-01

    The treatment of choice for first metacarpal base fractures is surgical. Open fixation is stable but causes tendinous adhesions. Percutaneous fixation is minimally invasive but is often followed by secondary displacement. Herein, we describe an alternative approach that combines advantages of both techniques through increasing stability of the Iselin technique by externally connecting the K-wires. Our series included 13 men of mean age 28 years. There were 13 fractures, 6 of which were extra-articular; there were 7 Bennett fractures, 5 of which had a large fracture fragment. After reduction, two 18 mm K-wires were driven medially crossing the 3 cortices of the first and second metacarpals. After bending them at 90-degree angles, the K-wires were connected externally in a construction allowing adaptation of the gap between the K-wires. Gentle immediate mobilization was allowed and the K-wires were removed 6 weeks later in clinic. At 16-month follow-up, mean pain score was 0.2/10 and Quick DASH was 2.9/100. Pinch grip was 81.8% of the contralateral side and grip strength 91.2%. The first web space opening was 79.1%. There was 1 secondary displacement with a good final result and 2 malunions. No arthritis was noted, but the follow-up was short. Our results show that the Iselin technique using locked K-wires is minimally invasive, stable, allows immediate mobilization, and K-wire removal in the office. Its indications may be extended to all fractures of the base of the first metacarpal whether articular or extra-articular. PMID:24621457

  12. The Use of 2.4-mm Locking Plate System in Treating Comminuted Mandibular Fracture by Firearm

    PubMed Central

    Pereira, Cassiano Costa Silva; Letícia dos Santos, Pâmela; Jardim, Ellen Cristina Gaetti; Júnior, Idelmo Rangel Garcia; Shinohara, Elio Hitoshi; Araujo, Marcelo Marotta

    2012-01-01

    Maxillofacial trauma caused by firearms has considerably increased, in which the mandibular body is the site of highest incidence of firearm projectiles. In these cases, the use of titanium plates and screws allows the early restoration of form and function of the mandible with stable and predictable results. Recently, conventional plates have been extensively used to treat comminuted mandibular fractures. Nevertheless, the conventional system presents several limitations such as screw compression against the bone interface and the necessity of precise fit of plate to the bone. To overcome such drawbacks, the locking plates have emerged. The present clinical case reported the operative treatment of mandibular fracture caused by firearm projectiles with the use of locking plate. The indications, advantages, and disadvantages of this system are presented. PMID:23730424

  13. Conservative treatment, plate fixation, or prosthesis for proximal humeral fracture. A prospective randomized study

    PubMed Central

    2012-01-01

    Background Proximal humerus fracture is the third most common fracture type after hip and distal radius fracture in elderly patients. A comprehensive study by Palvanen et al. demonstrated an increase in the annual fracture rate of 13.7% per year over the past 33 years. Should this trend continue, the fracture rate would triple over the next three decades. The increasing incidence of low-energy fractures raises questions about the optimal treatment in terms of functional outcome, pain, and rehabilitation time, as well as the economical impact. Despite the high incidence and costs of proximal humerus fractures, there is currently no valid scientific evidence for the best treatment method. Several publications, including a Cochrane review outline the need for high-quality, well-designed randomized controlled trials. Methods/Design The study is a prospective, randomized, national multi-center trial. The hypothesis of the trial is that surgical treatment of displaced proximal humerus fractures achieves better functional outcome, pain relief, and patient satisfaction compared to conservative treatment. The trial is designed to compare conservative and surgical treatment of proximal humerus fractures in patients 60 years and older. The trial includes two strata. Stratum I compares surgical treatment with locking plates to conservative treatment for two-part fractures. Stratum II compares multi-fragmented fractures, including three- and four-part fractures. The aim of Stratum II is to compare conservative treatment, surgical treatment with the Philos locking plate, and hemiarthroplasty with an Epoca prosthesis. The primary outcome measure will be the Disabilities of the Arm, Shoulder and Hand (DASH) score and the secondary outcome measures will be the EuroQol-5D (EQ-5D) value, OSS, Constant-Murley Score, VAS, and 15D. Recruiting time will be 3 years. The results will be analyzed after the 2-year follow-up period. Discussion This publication presents a prospective, randomized, national multi-center trial. It gives details of patient flow, randomization, aftercare and also ways of analysis of the material and ways to present and publish the results. Trial registration ClinicalTrials.gov identifier: NCT01246167 PMID:22954329

  14. A novel murine model of established Staphylococcal bone infection in the presence of a fracture fixation plate to study therapies utilizing antibiotic-laden spacers after revision surgery.

    PubMed

    Inzana, Jason A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2015-03-01

    Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. To first determine the ideal time point for revision following infection, a 0.7 mm osteotomy in the femoral mid-shaft was stabilized with a radiolucent PEEK fixation plate. The defect was inoculated with bioluminescent Staphylococcus aureus, and the infection was monitored over 14 days by bioluminescent imaging (BLI). Osteolysis and reactive bone formation were assessed by X-ray and micro-computed tomography (micro-CT). The active bacterial infection peaked by 5 days post-inoculation, however the stability of the implant fixation became compromised by 10-14 days post-inoculation due to osteolysis around the screws. Thus, day 7 was defined as the ideal time point to perform the revision surgery. During the revision surgery, the infected tissue was debrided and the osteotomy was widened to 3mm to place a poly-methyl methacrylate spacer, with or without vancomycin. Half of the groups also received systemic vancomycin for the remaining 21 days of the study. The viable bacteria remaining at the end of the study were measured using colony forming unit assays. Volumetric bone changes (osteolysis and reactive bone formation) were directly measured using micro-CT image analysis. Mice that were treated with local or systemic vancomycin did not display gross pathology at the end of the study. While localized vancomycin delivery alone tended to decrease the bacterial burden and osteolysis, these effects were only significant when combined with systemic antibiotic therapy. This novel mouse model replicates key features of implant-associated osteomyelitis that make treatment extremely difficult, such as biofilm formation and osteolysis, and imitates the clinical practice of placing an antibiotic-laden spacer after infected tissue debridement. In addition, the model demonstrates the limitations of current PMMA spacers and could be an invaluable tool for evaluating alternative antimicrobial treatments for implant-associated bone infection. PMID:25459073

  15. Retrospective study of two fixation methods for 4-corner fusion: Shape-memory staple vs. dorsal circular plate.

    PubMed

    Le Corre, A; Ardouin, L; Loubersac, T; Gaisne, E; Bellemère, P

    2015-12-01

    The purpose of this study was to compare the results of two groups of patients with four-corner fusion, one group fixed with shape-memory staples and the other with locked circular plates. This retrospective study compared 52 wrists operated for scaphoid excision and four-corner fusion between 2005 and 2011. The arthrodesis was ensured by a shape-memory quadripodal staple (4Fusion(®), Memometal™) in 37 cases and a locking dorsal circular plate (Xpode(®), Biotech Ortho™) in 15 cases. In the staple group, the mean age was 58.5 years and the average follow-up was 4.3 years. In the circular plate group, the mean age was 58.6 years and the average follow-up was 3.1 years. Pain, range of motion, grip strength, functional scores (QuickDASH and PWRE), fusion of the midcarpal joint, complications (implant fracture and reoperation) and patients' satisfaction were used as outcome measures. There was no pain in 43% of patients in the staple group and 40% of patients in the circular plate group at the follow-up; range of motion and functional scores were similar in both groups. Seventy-five percent of patients in the staple group were satisfied or very satisfied versus 60% in the circular plate group. The implant broke in 24.3% of cases in the staple group and 60% in the circular plate group. Reoperation was needed in 18% of the staple cases and 14% of the plate cases. There was no difference between the implants in terms of pain, range of motion, functional scores and patient satisfactory. The implant fracture rate in the plate group was high. This study brings into question implant reliability for the four-corner fusion procedure. PMID:26525608

  16. Quality of life after volar locked plating: a 10-year follow-up study of patients with intra-articular distal radius fractures

    PubMed Central

    2014-01-01

    Background This study aimed to present functional results and patient’s health related quality of life (HRQOL) data ten years after volar locked plate fixation (VPF) of unstable intra-articular distal radial fractures (DRF). Methods Thirty-nine patients with a mean age of sixty-one years were operatively treated with VPF after intra-articular distal radial fractures. They were evaluated two, six, and ten years postoperatively according to the Gartland and Werley score. For subjective evaluation the Short Form 36 (SF-36) and the Disability of Arm, Shoulder and Hand (DASH) questionnaires were adopted. Results Overall, wrist function did not differ significantly two, six and ten years after the operation. Over 90% patients achieved “good” or “excellent” results ten years after surgery according to the Gartland and Werley score. Ten years postoperatively the results of the SF 36 did not differ significantly from the two- and six-year follow-up. Overall findings from the SF-36 did not differ significantly from the data of Austrian and American norm populations. Only in the subscale of mental health (MH) the ten-year follow-up did show significantly poorer results (p?=?0.045) compared to the Austrian norm population. The median DASH scores did not show significant differences during the ten-year follow-up period. Conclusion The ten-year results of this single-center study suggest that operative treatment of intra-articular DRF with volar locked plates is a useful and satisfactory therapy option, both in terms of function and HRQOL. PMID:25059690

  17. Does medial support decrease major complications of unstable proximal humerus fractures treated with locking plate?

    PubMed Central

    2013-01-01

    Background The purpose of this study was to evaluate the role of medial support and clinical factors responsible on outcomes and major complications associated with treatment of unstable proximal humerus fractures using a locking plate and suture augmentation. Methods Sixty-three cases in 62 patients (42 female, 20 male) were evaluated between September 2004 and October 2008. Cases were divided into either a medial support group (36 cases) or non-medial support group (27 cases). Clinical and radiographic evaluations included Neer’s evaluation criteria, the neck-shaft angle using the Paavolainen method, and complications. We analyzed the correlation between bone- and fracture- related complications and three independent clinical variables, such as the presence of medial support, fracture type, and osteoporosis by way of multivariate logistic regression. Results There were statistically significant differences in the overall incidence of complications based on the presence of medial support (p = 0.014) and preoperative fracture type (p = 0.018), but no differences based on the presence of osteoporosis (p = 0.157). According to multivariate logistic regression analysis, the restoration of medial support was the most reliable factor to prevent bone- and fracture- related complications. In addition, when we compared the incidence of bone- and fracture-related complications in the presence or absence of medial support among 30 patients with osteoporosis, the group with restoration of medial support had only one complication of humeral head osteonecrosis despite the presence of osteoporosis (5.9% vs. 46.2%, p = 0.025). According to Neer’s criteria, excellent or satisfactory clinical results accounted for seventy-three percent of the total cases (46 of 63 cases). Seventy-eight percent (49 of 55 cases) showed good radiographic results by the Paavolainen method. There were 14 complications in 13 of 63 cases (20.6%). Conclusions In the treatment of unstable proximal humerus fractures with locking plate technology and suture augmentation, we suggest that obtaining medial support is an important factor in preventing major bone- and fracture-related postoperative complications such as reduction loss or nonunion. PMID:23517539

  18. Biomechancis of biological fixation utilizing a plate with and without an intramedullary rod 

    E-print Network

    Nori, Meera

    1994-01-01

    A wide range of prosthetic devices for internal fixation of the skeleton exist. Each aims to lend support to the injured limb, so as to restore the traumatized osseous and associated soft tissue to pre-fracture strength and functionality...

  19. Comparison of limited-contact dynamic compression plate and locking compression plate constructs for proximal interphalangeal joint arthrodesis in the horse

    PubMed Central

    Rocconi, Richard A.; Carmalt, James L.; Sampson, Sarah N.; Elder, Steve H.; Gilbert, Eric E.

    2015-01-01

    This study compared in vitro monotonic and cyclic mechanical properties of equine proximal interphalangeal joint arthrodeses stabilized using an open or closed technique combined with axial 4.5 mm narrow limited-contact dynamic compression plate (LC-DCP) or 4.5 mm narrow locking compression plate (LCP). Ten forelimb pairs were randomly assigned to LCP or LC-DCP groups. One limb in each pair was assigned to either open or closed technique. Limbs were tested for cyclic fatigue at 20 000 cycles and then single-cycle to failure under 3-point dorsopalmar bending. There was no significant difference in stiffness of constructs during cyclic fatigue testing or on force or stiffness at failure in single cycle to failure testing between open and closed techniques or between plate types. Both implants, surgical technique, or combinations thereof are suitable for clinical use. More work is necessary to define the interaction between implant type and surgical technique. PMID:26028685

  20. Comparison of limited-contact dynamic compression plate and locking compression plate constructs for proximal interphalangeal joint arthrodesis in the horse.

    PubMed

    Rocconi, Richard A; Carmalt, James L; Sampson, Sarah N; Elder, Steve H; Gilbert, Eric E

    2015-06-01

    This study compared in vitro monotonic and cyclic mechanical properties of equine proximal interphalangeal joint arthrodeses stabilized using an open or closed technique combined with axial 4.5 mm narrow limited-contact dynamic compression plate (LC-DCP) or 4.5 mm narrow locking compression plate (LCP). Ten forelimb pairs were randomly assigned to LCP or LC-DCP groups. One limb in each pair was assigned to either open or closed technique. Limbs were tested for cyclic fatigue at 20 000 cycles and then single-cycle to failure under 3-point dorsopalmar bending. There was no significant difference in stiffness of constructs during cyclic fatigue testing or on force or stiffness at failure in single cycle to failure testing between open and closed techniques or between plate types. Both implants, surgical technique, or combinations thereof are suitable for clinical use. More work is necessary to define the interaction between implant type and surgical technique. PMID:26028685

  1. A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model

    PubMed Central

    Müller, Christian W.; Pfeifer, Ronny; Meier, Karen; Decker, Sebastian; Reifenrath, Janin; Gösling, Thomas; Wesling, Volker; Krettek, Christian; Hurschler, Christof; Krämer, Manuel

    2015-01-01

    Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0?mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, µCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery. PMID:26167493

  2. A Biomechanical Comparison of Three 1.5-mm Plate and Screw Configurations and a Single 2.0-mm Plate for Internal Fixation of a Mandibular Condylar Fracture

    PubMed Central

    Aquilina, Peter; Parr, William C.H.; Chamoli, Uphar; Wroe, Stephen; Clausen, Philip

    2014-01-01

    The most stable pattern of internal fixation for mandibular condyle fractures is an area of ongoing discussion. This study investigates the stability of three patterns of plate fixation using readily available, commercially pure titanium implants. Finite element models of a simulated mandibular condyle fracture were constructed. The completed models were heterogeneous in bone material properties, contained approximately 1.2 million elements and incorporated simulated jaw adducting musculature. Models were run assuming linear elasticity and isotropic material properties for bone. No human subjects were involved in this investigation. The stability of the simulated condylar fracture reduced with the different implant configurations, and the von Mises stresses of a 1.5-mm X-shaped plate, a 1.5-mm rectangular plate, and a 1.5-mm square plate (all Synthes (Synthes GmbH, Zuchwil, Switzerland) were compared. The 1.5-mm X plate was the most stable of the three 1.5-mm profile plate configurations examined and had comparable mechanical performance to a single 2.0-mm straight four-hole plate. This study does not support the use of rectangular or square plate patterns in the open reduction and internal fixation of mandibular condyle fractures. It does provide some support for the use of a 1.5-mm X plate to reduce condylar fractures in selected clinical cases. PMID:25136411

  3. Fixation of metatarsal fracture with bone plate in a dromedary heifer

    PubMed Central

    Siddiqui, S.A.; Siddiqui, M.I.; Telfah, M.N.; Hashmi, S.

    2013-01-01

    An oblique fracture of the distal third of the right metatarsus in a three-year-old dromedary heifer weighing about 300 kilograms was immobilized with a 4.5 mm broad-webbed 12-hole dynamic compression bone plate and two interfragmental compression screws. The animal showed slight lameness after 16 weeks of surgery that disappeared after removal of the plate. The result was quite encouraging and the fracture healed in 16 weeks without major complications. It is concluded that the fracture of this bone can be successfully handled with bone plating at least in young, light weight animals.

  4. [Mechanical principle and clinical application of the combined spinal rod-plate and transpedicular screws fixation system].

    PubMed

    Zhang, G H

    1989-12-01

    Twenty-one patients with unstable burst fractures of the lower thoracic and lumbar spine were treated with a combined spinal rod-plate and transpedicular screws (CSRP-TPS) fixation system. This system is a new device for disorders of the lower thoracic and lumbar spine. In treatment of spinal fractures, it provided three-column axial distraction and stabilized the injured vertebra in a lordotic position-this maximized the reduction and indirectly achieved a neurologic decompression by ligamentotaxis. This "indirect" neurologic decompression was more successful in cases treated early after injury as the spinal canal area (measured by pre- and postoperative CT) increased 35% in cases treated within one week after injury; 25% in cases treated 7-14 days after injury; and there was little improvement in cases treated more than two weeks following injury. All patients had a minimum follow-up of 12 months. There were no infections, iatrogenic neurologic deficits or instrumentation failures. The CSRP-TPS system gave more improved results over conventional Harrington and segmental spinal instrumentation systems and only required fixation and fusion of three vertebral levels. PMID:2636110

  5. Biomechanical study of different plate configurations for distal humerus osteosynthesis.

    PubMed

    Bogataj, M; Kosel, F; Norris, R; Krkovic, M; Brojan, M

    2015-05-01

    Fractures of the distal humerus are most commonly fixed by open reduction and internal fixation, using plates and screws, either in a locking or in a non-locking construct. Three different plating systems are commonly used in practice. The most important differences between them are in plate orientation, which affects both the rigidity of the osteosynthesis and invasiveness of the surgical procedure. Unfortunately, there is no common agreement between surgeons about which plate configuration brings the best clinical outcome. In this study, we investigate the theoretical rigidity of plate osteosyntheses considering two types of AO/ASIF configurations (90° angle between plates), Mayo clinic (Acumed) configuration (180° between plates) and dorsal fixation of both plates. We also compared the results for cases with and without contact between the bone fragments. In the case of no bone contact, the Mayo clinic plate configuration is found to be the most rigid, followed by both AO/ASIF plate configurations, and the least rigid system is the Korosec plate configuration. On the other hand, no significant differences between all types of fixation configurations are found in cases with contact in-between the bone fragments. Our findings show that this contact is very important and can compensate for the lack of load carrying capacity of the implants. This could therefore incite other implant fixation solutions, leading to less invasive surgical procedures and consequently improved clinical outcome. PMID:25663513

  6. First Metatarsalphalangeal Joint Arthrodesis: A Retrospective Comparison of Two Methods of Fixation

    PubMed Central

    Rashid, M.A; Parnell, M; Khan, W.S; Khan, A

    2015-01-01

    First metatarsalphalangeal joint arthrodesis is a well established and successful treatment; however there still remains controversy over the best choice of construct. We performed a retrospective study of patients undergoing first metatarsalphalangeal fusion over eighteen months (n=52) using either dorsal non-locking plate with additional compression lag screw fixation or dorsal non-locking plate alone. We found when assessing clinical criteria, patients with dorsal non-locking plates and additional compression lag screw fixation had a significantly higher rate of fusion (100% vs 77.8%), significantly higher rate of fusion within the first two months (55.6% vs 83.3%), significantly earlier time to fusion (52.2 days vs 75.6 days), and significantly lower rate of non-union (0% vs 22.2%). When blindly assessing radiographic criteria, the patients treated with the plate and compression screw had a significantly higher rate of fusion and lower rate of non-union (0% vs 33%). There was no statistically significant difference between the frequencies of complications in the groups. We believe that the interfragmentary compression is a crucial factor in achieving good union rates and recommend the use of non-locking pre-contoured plating with additional interfragmentary compression screw as the fixation method of choice for these procedures. PMID:26587065

  7. Minimally invasive proximal interphalangeal joint arthrodesis using a locking compression plate and tissue engineering in horses: A pilot study

    PubMed Central

    Seo, Jong-pil; Yamaga, Takashi; Tsuzuki, Nao; Yamada, Kazutaka; Haneda, Shingo; Furuoka, Hidefumi; Tabata, Yasuhiko; Sasaki, Naoki

    2014-01-01

    This pilot study assessed the efficacy of 2 minimally invasive techniques for proximal interphalangeal (PIP) joint arthrodesis in horses. The PIP joints of both forelimbs (n = 6) were stabilized with locking compression plates (LCP) using a minimally invasive technique (LCP technique). Subsequently, for 1 randomly selected PIP joint of each horse, surgical drilling (SurD) was performed and tissue engineering (TE) was applied (LCP/SurD/TE technique). Minimally invasive PIP joint arthrodesis with LCP demonstrated low postoperative infection rates. Gross and histological evaluations revealed considerable destruction of the articular cartilage in the LCP/SurD/TE-treated joints. In contrast, almost no destruction of the cartilage was observed in the LCP-treated joints. Our results suggest that the LCP technique alone is not sufficient for PIP joint arthrodesis and that the LCP/SurD/TE technique may be useful for PIP joint arthrodesis in horses. PMID:25392547

  8. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    PubMed

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility. PMID:24964903

  9. Locked Intramedullary Total Wrist Arthrodesis

    PubMed Central

    Orbay, Jorge L.; Feliciano, Eric; Orbay, Carolina

    2012-01-01

    Total wrist arthrodesis is commonly performed using fixation plates, which can produce soft tissue irritation, often require removal, and limit the ability to position the hand in space. The Skeletal Dynamics IMPLATE is an intramedullary total wrist fusion device designed to provide stable fixation while avoiding the problems associated with plates. Radial and metacarpal locked intramedullary nails are inserted and joined by a connector. Desired hand placement is achieved by selecting the proper connector length and angle, then orienting it appropriately. Fusion mass compression is obtained by virtue of longitudinal threads on the radial nail that allow for length adjustment. Seven wrists in three men and four women were treated with this device and followed for a minimum of 24 weeks. In all cases, local cancellous bone graft was used and the third carpometacarpal (CMC) joint incorporated into the fusion. The median age was 49 (range, 28–71) years. Indications for fusion were two posttraumatic arthritides, three rheumatoid arthritides, one spastic deformity, and one infection. Patients were evaluated before surgery and at final follow-up using the Fernandez pain score and grip strength measurements using a hand-held dynamometer. All patients improved their grip strength and decreased their pain scores. All fusions united, and none of the patients presented dorsal soft tissue problems or required implant removal. One rheumatoid patient required secondary surgery for removal of a retained palmar osteophyte. This device delivers stable fixation, facilitates hand placement, and does not require removal. PMID:24179725

  10. [Unstable fracture of the distal radius and its treatment: comparison of three techniques: external fixation, intramedullary pinning and AO plates].

    PubMed

    Sennwald, G R; Della Santa, D

    2001-06-01

    This retrospective study compares 94 distal radius fractures. Sixty one women (median age 66) and 33 men (median age 42) were reviewed clinically and radiologically by a surgeon not involved in treatment. Fractures were classified into three AO groups. Standard X-rays were used for radiological evaluation. Fractures of the distal ulna were evaluated separately. Chi-square tests, Wilcoxon, Mann-Whitney and Fisher's tests were used for statistical evaluation. Women presented mainly "A" type fractures. They were treated by intramedullary pinning. Forty two fractures were grafted, using autogenous bone for young patients and bone substitute for the elderly. Twelve scapholunate dissociations were recorded, all but one were detected in women, 50 years of age or more. Four were painfree, two presented climatic pain and six claimed pain during effort; none had snapping. Radio-ulnar laxity was similar with or without styloid fractures. External fixator and autogenous grafts appeared the most efficient technique for maintaining radial length. Ulnar head fractures were related to a significant higher incidence of sympathetic dystrophy with reduced prono-supination, a correlation not previously noted to your knowledge. This suggests that radius and ulnar head fracture should be classified independently. The amount of pain was not related to classification, internal fixation or gender. PMID:11496608

  11. A new radiological method to detect dorsally penetrating screws when using volar locking plates in distal radial fractures. The dorsal horizon view.

    PubMed

    Haug, L C; Glodny, B; Deml, C; Lutz, M; Attal, R

    2013-08-01

    Penetration of the dorsal screw when treating distal radius fractures with volar locking plates is an avoidable complication that causes lesions of the extensor tendon in between 2% and 6% of patients. We examined axial fluoroscopic views of the distal end of the radius to observe small amounts of dorsal screw penetration, and determined the ideal angle of inclination of the x-ray beam to the forearm when making this radiological view. Six volar locking plates were inserted at the wrists of cadavers. The actual screw length was measured under direct vision through a dorsal approach to the distal radius. Axial radiographs were performed for different angles of inclination of the forearm at the elbow. Comparing axial radiological measurements and real screw length, a statistically significant correlation could be demonstrated at an angle of inclination between 5° and 20°. The ideal angle of inclination required to minimise the risk of implanting over-long screws in a dorsal horizon radiological view is 15°. PMID:23908427

  12. Investigation of a HA/PDLGA/Carbon Foam Material System for Orthopedic Fixation Plates Based on Time-Dependent Properties 

    E-print Network

    Rodriguez, Douglas E.

    2010-01-14

    .1 Significance, Objectives, and Outcomes .............................................. 1 1.2 Background ........................................................................................... 6 1.2.1 Bioresorbable Polymers and Characterization... ................................................................. 25 2.5 Aluminum mold with cavity dimensions of 16mm x 10mm x 10mm ............ 28 2.6 Polymer mass variation of PDLA and PGA under isothermal holding [44]... 29 2.7 Picture of glass mold used to create PDLGA plate...

  13. Plate on plate osteosynthesis for the treatment of nonhealed periplate fractures.

    PubMed

    Arealis, Georgios; Nikolaou, Vassilios S; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

    Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation. PMID:24967127

  14. Development of a Titanium Plate for Mandibular Angle Fractures with a Bone Defect in the Lower Border: Finite Element Analysis and Mechanical Test

    PubMed Central

    Goulart, Douglas Rangel; Kemmoku, Daniel Takanori; Noritomi, Pedro Yoshito

    2015-01-01

    ABSTRACT Objectives The aim of the present study was to develop a plate to treat mandibular angle fractures using the finite element method and mechanical testing. Material and Methods A three-dimensional model of a fractured mandible was generated using Rhinoceros 4.0 software. The models were exported to ANSYS®, in which a static application of displacement (3 mm) was performed in the first molar region. Three groups were assessed according to the method of internal fixation (2 mm system): two non-locking plates; two locking plates and a new design locking plate. The computational model was transferred to an in vitro experiment with polyurethane mandibles. Each group contained five samples and was subjected to a linear loading test in a universal testing machine. Results A balanced distribution of stress was associated with the new plate design. This plate modified the mechanical behavior of the fractured region, with less displacement between the fractured segments. In the mechanical test, the group with two locking plates exhibited greater resistance to the 3 mm displacement, with a statistically significant difference when compared with the new plate group (ANOVA, P = 0.016). Conclusions The new plate exhibited a more balanced distribution of stress. However, the group with two locking plates exhibited greater mechanical resistance. PMID:26539287

  15. A biomechanical comparison of four different fixation methods for midshaft clavicle fractures.

    PubMed

    Chen, Yang; Yang, Yang; Ma, Xinlong; Xu, Weiguo; Ma, Jianxiong; Zhu, Shaowen; Ma, Baoyi; Xing, Dan

    2016-01-01

    Clavicle fractures may occur in all age groups, and 70%-80% of clavicle fractures occur in the midshaft. Many methods for treating midshaft clavicular fractures have been reported and remain controversial. To provide some guidance for clinical treatment, 30 artificial polymethyl methacrylate models of the clavicle were sewn obliquely at the midshaft to simulate the most common type of clavicular fractures, and the fracture models were divided into five groups randomly and were fixed as follows: the reconstruction plates were placed at the superior position of the fracture model (R-S group), the reconstruction plates were placed at the anteroinferior position of the fracture model (R-AI group), the locking plates were placed at the superior position (L-S group), the locking plates were placed at the anteroinferior position (L-AI group); and the control models were unfixed (control group). The strain gauges were attached to the bone surface near the fracture fragments, and then, the biomechanical properties of the specimens were measured using the compression test, torsion test and three-point bending test. The results showed that plate fixation can provide a stable construct to help with fracture healing and is the preferred method in the treatment of clavicle fractures. The locking plate provides the best biomechanical stability when placed at the anteroinferior position, and this surgical method can reduce the operation time and postoperative complications; thus, it would be a better choice in clinical practice. PMID:26586526

  16. Along-strike variations in seismic structure of the locked-sliding transition on the plate boundary beneath the southern part of Kii Peninsula, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Kurashimo, E.; Iidaka, T.; Iwasaki, T.; Saiga, A.; Umeyama, E.; Tsumura, N.; Sakai, S.; Hirata, N.

    2013-12-01

    The Nankai trough region, where the Philippine Sea Plate (PHS) subducts beneath the SW Japan arc, is a well-known seismogenic zone of interplate earthquakes. A narrow zone of nonvolcanic tremor has been found in the SW Japan fore-arc, along strike of the arc (Obara, 2002). The epicentral distribution of tremor corresponds to the locked-sliding transition estimated from thermal and deformation models (Hyndman et al., 1995). The spatial distribution of the tremor is not homogeneous in a narrow belt but is spatially clustered. Obara [2002] suggested fluids as a source for tremor because of the long duration and the mobility of the tremor activity. The behavior of fluids at the plate interface is a key factor in understanding fault slip processes. Seismic reflection characteristics and seismic velocity variations can provide important information on the fluid-related heterogeneity of structure around plate interface. However, little is known about the deeper part of the plate boundary, especially the transition zone on the subducting plate. To reveal the seismic structure of the transition zone, we conducted passive and active seismic experiments in the southern part of Kii Peninsula, SW Japan. Sixty 3-component portable seismographs were installed on a 60-km-long line (SM-line) nearly perpendicular to the direction of the subduction of the PHS with approximately 1 km spacing. To improve accuracy of hypocenter locations, we additionally deployed six 3-component seismic stations around the survey line. Waveforms were continuously recorded during a five-month period from December, 2009. In October of 2010, a deep seismic profiling was also conducted. 290 seismometers were deployed on the SM-line with about 200 m spacing, on which five explosives shots were fired as controlled seismic sources. Arrival times of local earthquakes and explosive shots were used in a joint inversion for earthquake locations and 3-D Vp and Vp/Vs structures, using the iterative damped least-squares algorithm, simul2000 (Thurber and Eberhart-Phillips, 1999). To obtain the detailed structure image of the transition zone on the subducting plate, the explosive shot data recorded on the SM-line were processed using the seismic reflection technique. Seismic reflection image shows the lateral variation of the reflectivity along the top of the PHS. A clear reflection band is present where the clustered tremors occurred. The depth section of Vp/Vs structure shows the lateral variation of the Vp/Vs values along the top of the PHS. Clustered tremors are located in and around the high Vp/Vs zone. These results suggest the occurrence of the tremors may be associated with fluids dehydrated from the subducted oceanic lithosphere.

  17. Intramedullary Nail versus Dynamic Compression Plate Fixation in Treating Humeral Shaft Fractures: Grading the Evidence through a Meta-Analysis

    PubMed Central

    Ma, XinLong; Gao, Feng; Wei, Qiang; Jia, HaoBo; Feng, Rui; Yu, JingTao; Wang, Jie

    2013-01-01

    There is a debate regarding the choice of operative intervention in humeral shaft fractures that require surgical intervention. The choices for operative interventions include intramedullary nailing (IMN) and dynamic compression plate (DCP). This meta-analysis was performed to compare fracture union, functional outcomes, and complication rates in patients treated with IMN or DCP for humeral shaft fractures and to develop GRADE (Grading of Recommendations, Assessment, Development, and Evaluation)-based recommendations for using the procedures to treat humeral shaft fractures. A systematic search of all the studies published through December 2012 was conducted using the Medline, Embase, Sciencedirect, OVID and Cochrane Central databases. The randomized controlled trials (RCTs) and quasi-RCTs that compared IMN with DCP in treating adult patients with humeral shaft fractures and provided data regarding the safety and clinical effects were identified. The demographic characteristics, adverse events and clinical outcomes were manually extracted from all of the selected studies. Ten studies that included a total of 448 patients met the inclusion criteria. The results of a meta-analysis indicated that both IMN and DCP can achieve similar fracture union with a similar incidence of radial nerve injury and infection. IMN was associated with an increased risk of shoulder impingement, more restriction of shoulder movement, an increased risk of intraoperative fracture comminution, a higher incidence of implant failure, and an increased risk of re-operation. The overall GRADE system evidence quality was very low, which reduces our confidence in the recommendations of this system. DCP may be superior to IMN in the treatment of humeral shaft fractures. Because of the low quality evidence currently available, high-quality RCTs are required. PMID:24358141

  18. Fibular fixation as an adjuvant to tibial intramedullary nailing in the treatment of combined distal third tibia and fibula fractures: a biomechanical investigation

    PubMed Central

    Morin, Paul M.; Reindl, Rudolf; Harvey, Edward J.; Beckman, Lorne; Steffen, Thomas

    2008-01-01

    Objective Distal third tibia fractures have classically been treated with standard plating, but intramedullary (IM) nailing has gained popularity. Owing to the lack of interference fit of the nail in the metaphyseal bone of the distal tibia, it may be beneficial to add rigid plating of the fibula to augment the overall stability of fracture fixation in this area. This study sought to assess the biomechanical effect of adding a fibular plate to standard IM nailing in the treatment of distal third tibia and fibula fractures. Methods Eight cadaveric tibia specimens were used. Tibial fixation consisted of a solid titanium nail locked with 3 screws distally and 2 proximally, and fibular fixation consisted of a 3.5 mm low-contact dynamic compression plate. A section of tibia and fibula was removed. Testing was accomplished with an MTS machine. Each leg was tested 3 times; with and without a fibular plate and with a repetition of the initial test condition. Vertical displacements were tested with an axial load up to 500 N, and angular rotation was tested with torques up to 5 N•m. Results The difference in axial rotation was the only statistically significant finding (p = 0.003), with fibular fixation resulting in 1.1° less rotation through the osteotomy site (17.96° v. 19.10°). Over 35% of this rotational displacement occurred at the nail–locking bolt interface with the application of small torsional forces. Conclusion Fibular plating in addition to tibial IM fixation of distal third tibia and fibula fractures leads to slightly increased resistance to torsional forces. This small improvement may not be clinically relevant. PMID:18248705

  19. Complications of Rigid Internal Fixation

    PubMed Central

    Campbell, Chris A.; Lin, Kant Y.

    2009-01-01

    Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as “open internal fixation” of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery. PMID:22110796

  20. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3060 Spinal intervertebral body fixation...fixation orthosis is a device intended to be implanted made of titanium. It consists of various vertebral plates that are...

  1. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3060 Spinal intervertebral body fixation...fixation orthosis is a device intended to be implanted made of titanium. It consists of various vertebral plates that are...

  2. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3060 Spinal intervertebral body fixation...fixation orthosis is a device intended to be implanted made of titanium. It consists of various vertebral plates that are...

  3. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3060 Spinal intervertebral body fixation...fixation orthosis is a device intended to be implanted made of titanium. It consists of various vertebral plates that are...

  4. Effectiveness of 2.0 mm Standard and 2.0 mm Locking Miniplates in Management of Mandibular Fractures: A Clinical Comparative Study.

    PubMed

    Shaik, Mahaboob; Subba Raju, T; Rao, N Koteswara; Reddy, Chandra Kiran

    2014-03-01

    To compare and evaluate the effectiveness of 2.0 mm locking miniplates versus 2.0 mm standard miniplates in treatment of mandible fractures. Sixty randomly selected patients who sustained mandibular fractures were selected for this study. The fractured fragments were stabilized using 2.0 mm locking miniplates in 30 cases and in the remaining 30 cases the fractured fragments were fixed with conventional 2.0 mm miniplates. Post-operative stability was assessed with radiographs at 7th day, 1st, and 3rd months. The stability of the reduced fracture was assessed clinically and both the types of plates were assessed with an OPG or conventional radiographs. This study shows favorable results on use of locking miniplates in mandibular fractures. The results show that there were no significant differences in the post-operative complications between the conventional and the locking plate/screw mandibular systems. The locking plate/screw system was more rigid than conventional plate/screw system, thereby reducing the need and duration of intermaxillary fixation (IMF). PMID:24644396

  5. Retrospective study of mandibular angle fractures treated with three different fixation systems

    PubMed Central

    Bhatt, Krushna; Arya, Satyavrat; Bhutia, Ongkila; Pandey, Sandeep; Roychoudhury, Ajoy

    2015-01-01

    Aim: To evaluate the outcomes of mandibular angle fractures treated with metal 2.0 mm locking, metal 2.0 mm nonlocking, and 2.5 mm resorbable systems. Study Design: Retrospective cohort study. Materials and Methods: Trauma records were screened for linear angle fractures treated with open-reduction and internal semi-rigid fixation with single metal/bioresorbable plates, and baseline variables were tabulated. The outcome variable was the presence or absence of any complication. Statistical Analysis Used: The Fisher's exact test and analysis of covariance (ANCOVA) using STATA 11. Results: A total of 60 case records of over four years were included. The mean age of the patients was 27.4 (SD 9.7) years. Fifty-five were male and five female. There were 20 nonlocking and 16 locking metal miniplates and 24 bioresorbable plates. In 55 (91.6%) cases there was a third molar in the fracture line. In 51/55 (92.7%) cases the third molar was retained. In seven patients postoperative complications were seen. There was no difference between the complication rates of the three treatment groups. Infection was the most common complication followed by delayed union and hardware failure. Conclusions: This retrospective study found no difference in the complication rate when fractures of the mandibular angle were treated with locking or nonlocking miniplates or bioresorbable plates.

  6. Two fixation methods for acromioclavicular joint reduction during coracoclavicular ligament reconstruction: a biomechanical analysis.

    PubMed

    Dierckman, Brian D; Karas, Spero G; Hammond, Kyle E; Brantley, Steven P; Hutton, William C

    2014-01-01

    One specimen from each of six pairs of cadaveric shoulders underwent a semitendinosus coracoclavicular ligament reconstruction with a hook plate used for acromioclavicular joint reduction, while on the other specimen a polydioxanone (PDS) suture braid was utilized. Cyclical loading followed by maximal load-to-failure testing was performed. Displacement during cyclical loading, loads to 50% and 100% displacement, stiffness, and maximal load to failure were determined for all specimens. Results showed that the locking hook plate allowed significantly less displacement of the coracoclavicular interval during cyclical loading (3.41 vs. 9.67 mm, p = .0081) and withstood significantly higher loads before both 50% (225.5 vs. 107.7 N, p = .0197) and 100% displacement (410.6 vs. 240.1 N, p = .0077). The locking hook plate was found to be significantly stiffer than the PDS suture braid (28.2 vs. 18.4 N/mm, p = .0029), but there was no difference in maximal load to failure between the two fixation methods (hook plate, 434.4 N; PDS, 476.7 N; p = .76). PMID:25153813

  7. Biologic Fixation through Bridge Plating for Comminuted Shaft Fracture of the Clavicle: Technical Aspects and Prospective Clinical Experience with a Minimum of 12-Month Follow-up

    PubMed Central

    Park, Chang-Min; Kim, Jae-Do

    2013-01-01

    For comminuted shaft fracture of clavicle, the operative goal, aside from sound bone healing without complications of direct reduction, is maintenance of the original length in order to maintain the normal biomechanics of adjacent joint. Our bridge plating technique utilizing distraction through a lumbar spreader was expected to be effective for restoring clavicular length with soft tissue preservation. However, there are two disadvantages. First, there is more exposure to radiation compared to conventional plating; and second, it is difficult to control the rotational alignment. Despite these disadvantages, our technique has important benefits, in particular, the ability to preserve clavicular length without soft tissue injury around the fracture site. PMID:24340154

  8. Locking mechanism

    DOEpatents

    Williams, Gary L. (428 E. Third Avenue, Kennewick, WA 99336); Goin, Jr., Jesse L. (480 Kau Trail, Pasco, WA 99301); Kirby, Patrick G. (1010 W. Fifteenth Pl., Kennewick, WA 99337); McKenna, John P. (Rt. 3, Box 1818, Benton City, WA 99320)

    1997-01-01

    The invention is a motorized linkage for operating a door strike. A six volt power source, controlled by a security code, rotates a small electric motor when a proper security code is given. The motor rotates a shaft which engages a coil spring. This moves a locking cam. When a catch on the locking cam separates from the locking lever catch, the latch bolt keeper may be manipulated by a user.

  9. Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

    PubMed

    Araújo, Marcelo Marotta; Lauria, Andrezza; Mendes, Marcelo Breno Meneses; Claro, Ana Paula Rosifini Alves; Claro, Cristiane Aparecida de Assis; Moreira, Roger William Fernandes

    2015-12-01

    The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P?plate region of pre-bent titanium presented the best results. PMID:25944727

  10. Locking support for nuclear fuel assemblies

    DOEpatents

    Ledin, Eric (San Diego, CA)

    1980-01-01

    A locking device for supporting and locking a nuclear fuel assembly within a cylindrical bore formed by a support plate, the locking device including a support and locking sleeve having upwardly extending fingers forming wedge shaped contact portions arranged for interaction between an annular tapered surface on the fuel assembly and the support plate bore as well as downwardly extending fingers having wedge shaped contact portions arranged for interaction between an annularly tapered surface on the support plate bore and the fuel assembly whereby the sleeve tends to support and lock the fuel assembly in place within the bore by its own weight while facilitating removal and/or replacement of the fuel assembly.

  11. Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques

    PubMed Central

    Kojima, K.; Gueorguiev, B.; Seva, G.; Stoffel, K.; de Oliveira, R. Garcia; Eberli, U.; Nicolino, T.; Lenz, M.

    2015-01-01

    Abstract Reliable osteosynthesis of intraarticular fractures depends on lasting interfragmentary compression. Its amount differs in the applied fixation method. The interfragmentary compression of cancellous and cortical lag screws and angle stable locking plates was quantified in an osteoporotic and non-osteoporotic synthetic human bone model. A split fracture of the lateral tibia plateau (AO/OTA type 41-B1.1) was mimicked by an osteotomy in right adult synthetic human tibiae with hard or soft cancellous bone. Specimens were fixed with either two 6.5?mm cancellous, four 3.5?mm cortical lag screws, or 3.5?mm LCP proximal lateral tibia plate preliminary compresed by a reduction clamp (n?=?5 per group). A pressure sensor film was used to register the interfragmentary compression. One-way analysis of variance (ANOVA) with Bonferroni post hoc correction was performed for statistical analysis (p?locking plate itself maintained the compression in non-osteoporotic (0.53?±?0.11?MPa) and osteoporotic bone (0.50?±?0.14?MPa). Four 3.5?mm cortical lag screws provided a compression of 1.69?±?0.65?MPa in non-osteoporotic bone, being not significantly different to the osteoporotic bone group (1.43?±?0.47?MPa, P?=?1.0). Two 6.5?mm cancellous lag screws showed a significantly higher compression in non-osteoporotic (2.1?±?0.59?MPa) compared to osteoporotic (0.77?±?0.21?MPa, P?locking plates maintained the compression preliminarily applied by a reduction clamp. Two 6.5?mm cancellous lag screws are especially suited for non-osteoporotic bone, whereas four 3.5?mm cortical screws exhibited comparable compression in both bone qualities. PMID:25569643

  12. Healing Results of Periprosthetic Distal Femur Fractures Treated with Far Cortical Locking Technology: A Preliminary Retrospective Study

    PubMed Central

    Ries, Zachary; Hansen, Kirk; Bottlang, Michael; Madey, Steven; Fitzpatrick, Daniel; Marsh, J.L.

    2013-01-01

    Introduction Periprosthetic distal femur fractures are severe injuries occurring in the often osteoporotic bone of the elderly. Far cortical locking (FCL) screws, which have been shown to promote increased callus formation in animal models, have recently become available for clinical use. The purpose of this study is to report preliminary healing and complication rates of periprosthetic distal femur fractures treated with FCL constructs. Materials and Methods A retrospective review of 20 patients who underwent open reduction and internal fixation of periprosthetic distal femur fractures using FCL constructs was performed. Healing was assessed radiographically and clinically at 6, 12 and 24 weeks post-operatively. Construct failure was defined as any hardware breakage or bone-implant dissociation leading to loss of reduction. Results Complete data through the 24 week study period was available for 18/20 patients. Bridging callus was identified in 16/18 patients by the 24 week follow up for a healing rate of 88.9%. In patients that healed, the average time to medial bridging callus formation was 10.7±6.7 weeks, 11.0±6.6 weeks for anterior fracture line and 13.4±7.5 weeks for the posterior fracture line. both patients that failed to heal underwent revision surgery. Discussion The initial results of this study are comparable to results reported for distal femur periprosthetic fractures treated with locking plate fixation without FCL screws, although it was difficult to compare time to healing between previously published studies. It is the impression of the authors that callus appears earlier and is more robust and uniform between the three cortices in FCL cases compared to their previous experiences with traditional locking plate periprosthetic distal femur fractures. This work suggests that FCL screws may be superior to traditional locking constructs but further studies are needed to directly compare the two methods. PMID:24027454

  13. Early postoperative failure of a new intramedullary fixation device for midshaft clavicle fractures.

    PubMed

    Wilson, David J; Weaver, DeWayne L; Balog, Todd P; Arrington, Edward D

    2013-11-01

    The Sonoma CRx device (Sonoma Orthopedic Products, Santa Rosa, California) is a recently introduced intramedullary device with a flexible shaft that becomes rigid once actuated to allow deployment within the sigmoidal contour of the clavicular shaft. Medial intramedullary cortical purchase is obtained by grippers and lateral purchase through a locking bicortical buttressing screw. This article describes 2 cases of early hardware failure using this device. In both cases, early postoperative radiographs demonstrate adequate initial fracture reduction and implant position. Both patients sustained repeat injuries, one under low physiologic load and the other after returning to mixed martial arts 4 months postoperatively. Implant failure was noted after reinjury in both cases. Complete healing and full return to function was documented for both patients at 2 years. Proper patient selection and counseling regarding the limitations of this intramedullary fixation device are important. Biomechanical comparison of this implant to plate fixation under physiologic loads of combined axial compression and torsion may shed light on differences in fixation stability. PMID:24200452

  14. Strength analysis of clavicle fracture fixation devices and fixation techniques using finite element analysis with musculoskeletal force input.

    PubMed

    Marie, Cronskär

    2015-08-01

    In the cases, when clavicle fractures are treated with a fixation plate, opinions are divided about the best position of the plate, type of plate and type of screw units. Results from biomechanical studies of clavicle fixation devices are contradictory, probably partly because of simplified and varying load cases used in different studies. The anatomy of the shoulder region is complex, which makes it difficult and expensive to perform realistic experimental tests; hence, reliable simulation is an important complement to experimental tests. In this study, a method for finite element simulations of stresses in the clavicle plate and bone is used, in which muscle and ligament force data are imported from a multibody musculoskeletal model. The stress distribution in two different commercial plates, superior and anterior plating position and fixation including using a lag screw in the fracture gap or not, was compared. Looking at the clavicle fixation from a mechanical point of view, the results indicate that it is a major benefit to use a lag screw to fixate the fracture. The anterior plating position resulted in lower stresses in the plate, and the anatomically shaped plate is more stress resistant and stable than a regular reconstruction plate. PMID:25850983

  15. 12. VIEW OF TYPICAL CELL LOCKING MECHANISM, BUILDING 220 CELL ...

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

    12. VIEW OF TYPICAL CELL LOCKING MECHANISM, BUILDING 220 CELL BLOCK 'A'. THE FACE PLATE OF THE CELL LOCK IS SHOWN REMOVED, EXPOSING THE ELECTROMAGNETIC LOCKING MECHANISM COMPRISING OF 2 MICROSWITCHES FOR LOCK POSITION INDICATION (FRONT LEFT CENTER AND REAR RIGHT CENTER OF PANEL); KEY SLOT MECHANICAL LOCK; LOCK SPRING (UPPER RIGHT OF PANEL); ELECTRIC SOLENOID (BOTTOM RIGHT CORNER OF PANEL); AND MISCELLANEOUS MECHANICAL LINKAGES. - U.S. Naval Base, Pearl Harbor, Brig, Neville Way near Ninth Street at Marine Barracks, Pearl City, Honolulu County, HI

  16. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a device intended to be implanted made of titanium. It consists of various vertebral plates that are punched into each of a series of vertebral bodies. An eye-type...

  17. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  18. Application of Additional Medial Plate in Treatment of Proximal Humeral Fractures With Unstable Medial Column

    PubMed Central

    He, Yu; He, Jiliang; Wang, Fu; Zhou, Dongsheng; Wang, Yan; Wang, Bomin; Xu, Shihong

    2015-01-01

    Abstract The purpose of this study was to use finite element analysis to compare the biomechanical characteristics after lateral locking plate (LLP) or LLP with a medial anatomical locking plate (LLP-MLP) fixation of proximal humeral fractures with an unstable medial column. First, a 3-dimensional, finite element analysis model was developed. Next, LLP and LLP-MLP implants were instrumented into the proximal humeral fracture models. Compressive and rotational loads were then applied to the humerus model to determine the biomechanical characteristics. Both normal and osteoporotic proximal humerus fractures were simulated using 2 internal fixation methods each under 7 loading conditions. To assess the biomechanical characteristics, the construct stiffness, fracture micromotion, and stress distribution on the implants were recorded and compared. The LLP-MLP method provided both lateral and medial support that reduced the stress on the LLP and the amount of displacement in the fracture region. In contrast, the LLP method resulted in more instability in the medial column and larger magnitudes of stress. In osteoporotic bone, the LLP was more inclined to fail than LLP-MLP. The LLP-MLP method provides a strong support for the medial column and increases the stability of the region surrounding the fracture. PMID:26469918

  19. Biomechanical Analysis of the Fixation System for T-Shaped Acetabular Fracture

    PubMed Central

    Fan, Yanping; Lei, Jianyin; Zhu, Feng; Li, Zhiqiang; Chen, Weiyi; Liu, Ximing

    2015-01-01

    This study aims to evaluate the biomechanical mechanism of fixation systems in the most frequent T-shaped acetabular fracture using finite element method. The treatment of acetabular fractures was based on extensive clinical experience. Three commonly accepted rigid fixation methods (double column reconstruction plates (P × 2), anterior column plate combined with posterior column screws (P + PS), and anterior column plate combined with quadrilateral area screws (P + QS)) were chosen for evaluation. On the basis of the finite element model, the biomechanics of these fixation systems were assessed through effective stiffness levels, stress distributions, force transfers, and displacements along the fracture lines. All three fixation systems can be used to obtain effective functional outcomes. The third fixation system (P + QS) was the optimal method for T-shaped acetabular fracture. This fixation system may reduce many of the risks and limitations associated with other fixation systems. PMID:26495030

  20. Safety lock-out device for electrical appliances

    DOEpatents

    Cliff, P.L. Jr.

    1996-07-09

    A safety lock-out device prevents the insertion of an electrical power cord into an electrical power cord receptacle of an electrical appliance. The device comprises a mounting plate fastened to the appliance and a hinged cover plate attached to the appliance. The cover plate is movable between a first position and a second position such that, in the first position, the cover plate covers and prevents insertion of a power cord into the appliance receptacle. In said second position, the appliance receptacle is uncovered to permit insertion of a power cord into the receptacle. Extending a lock shank through aligned openings formed in flange members extending from the mounting plate, the cover plate locks the cover plate in the first position. 15 figs.

  1. Dynamic-locking-screw (DLS)–leads to less secondary screw perforations in proximal humerus fractures

    PubMed Central

    2014-01-01

    Background Loss of reduction and screw perforation causes high failure rates in the treatment of proximal humerus fractures. The purpose of the present study was to evaluate the early postoperative complications using modern Dynamic Locking Screws (DLS 3.7) for plating of proximal humerus fractures. Methods Between 03/2009 and 12/2010, 64 patients with acute proximal humerus fractures were treated by angular stable plate fixation using DLSs in a limited multi-centre study. Follow-up examinations were performed three, six, twelve and twenty-four weeks postoperatively and any complications were carefully collected. Results 56 of 64 patients were examined at the six-month follow-up. Complications were observed in 12 patients (22%). In five cases (9%), a perforation of the DLS 3.7 occurred. Conclusions Despite the use of modern DLS 3.7, the early complications after plating of proximal humerus fractures remain high. The potential advantage of the DLS 3.7 regarding secondary screw perforation has to be confirmed by future randomized controlled trials. PMID:24894637

  2. Anterior subcutaneous internal fixation for treatment of unstable pelvic fractures

    PubMed Central

    2014-01-01

    Background Fractures of the pelvic ring including disruption of the posterior elements in high-energy trauma have both high morbidity and mortality rates. For some injury pattern part of the initial resuscitation includes either external fixation or plate fixation to close the pelvic ring and decrease blood loss. In certain situations – especially when associated with abdominal trauma and the need to perform laparotomies – both techniques may put the patient at risk of either pintract or deep plate infections. We describe an operative approach to percutaneously close and stabilize the pelvic ring using spinal implants as an internal fixator and report the results in a small series of patients treated with this technique during the resuscitation phase. Findings Four patients were treated by subcutaneous placement of an internal fixator. Screw fixation was carried out by minimally invasive placement of two supra-acetabular iliac screws. Afterwards, a subcutaneous transfixation rod was inserted and attached to the screws after reduction of the pelvic ring. All patients were allowed to fully weight-bear. No losses of reduction or deep infections occurred. Fracture healing was uneventful in all cases. Conclusion Minimally invasive fixation is an alternative technique to stabilize the pelvic ring. The clinical results illustrate that this technique is able to achieve good results in terms of maintenance of reduction the pelvic ring. Also, abdominal surgeries no longer put the patient at risk of infected pins or plates. PMID:24606833

  3. Purge Lock Server

    SciTech Connect

    2012-08-21

    The software provides a simple web api to allow users to request a time window where a file will not be removed from cache. HPSS provides the concept of a "purge lock". When a purge lock is set on a file, the file will not be removed from disk, entering tape only state. A lot of network file protocols assume a file is on disk so it is good to purge lock a file before transferring using one of those protocols. HPSS's purge lock system is very coarse grained though. A file is either purge locked or not. Nothing enforces quotas, timely unlocking of purge locks, or managing the races inherent with multiple users wanting to lock/unlock the same file. The Purge Lock Server lets you, through a simple REST API, specify a list of files to purge lock and an expire time, and the system will ensure things happen properly.

  4. Purge Lock Server

    Energy Science and Technology Software Center (ESTSC)

    2012-08-21

    The software provides a simple web api to allow users to request a time window where a file will not be removed from cache. HPSS provides the concept of a "purge lock". When a purge lock is set on a file, the file will not be removed from disk, entering tape only state. A lot of network file protocols assume a file is on disk so it is good to purge lock a file beforemore »transferring using one of those protocols. HPSS's purge lock system is very coarse grained though. A file is either purge locked or not. Nothing enforces quotas, timely unlocking of purge locks, or managing the races inherent with multiple users wanting to lock/unlock the same file. The Purge Lock Server lets you, through a simple REST API, specify a list of files to purge lock and an expire time, and the system will ensure things happen properly.« less

  5. Early Experience with Biodegradable Fixation of Pediatric Mandibular Fractures.

    PubMed

    Mazeed, Ahmed Salah; Shoeib, Mohammed Abdel-Raheem; Saied, Samia Mohammed Ahmed; Elsherbiny, Ahmed

    2015-09-01

    This clinical study aims to evaluate the stability and efficiency of biodegradable self-reinforced poly-l/dl-lactide (SR-PLDLA) plates and screws for fixation of pediatric mandibular fractures. The study included 12 patients (3-12 years old) with 14 mandibular fractures. They were treated by open reduction and internal fixation by SR-PLDLA plates and screws. Maxillomandibular fixation was maintained for 1?week postoperatively. Clinical follow-up was performed at 1?week, 6 weeks, 3 months, and 12 months postoperatively. Radiographs were done at 1?week, 3 months, and 12 months postoperatively to observe any displacement and fracture healing. All fractures healed both clinically and radiologically. No serious complications were reported in the patients. Normal occlusion was achieved in all cases. Biodegradable osteofixation of mandibular fractures offers a valuable clinical solution for pediatric patients getting the benefit of avoiding secondary surgery to remove plates, decreasing the hospital stay, further painful procedures, and psychological impact. PMID:26269728

  6. 56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND ...

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

    56. LOCK AND DAM NO. 26 (REPLACEMENT). AUXILIARY LOCK AND REMAINDER OF DAM -- CONCRETE MONOLITH PLAN AND WALL ELEVATIONS (WITH LOCK APPURTENANCES). Drawing V-601 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  7. Some factors affecting retention forces with the use of denture fixatives in vivo.

    PubMed

    Ghani, F; Picton, D C; Likeman, P R

    1991-07-01

    Using the UCL retentiometer, the effect of three proprietary denture fixatives has been clinically investigated in 14 dentate subjects wearing mucosal-borne acrylic palatal plates over periods of 6 hours. The results showed that retention forces with saliva for the well-fitting plates were significantly better when compared with the forces for the ill-fitting plates. A substantial improvement in retention on all occasions was seen for both types of plate after the application of fixatives. An interesting observation of this study was that the use of paste and liquid fixatives rendered the ill-fitting plates as retentive as the well-fitting plates with the same fixatives. The test fixatives, however, showed significant differences regarding the onset and duration of action, depending on their physical formulation. The paste and liquid fixatives were found to have more delayed action than the powder fixative, but maintained the improved retention for a post-insertion period of more than 6 hours for both well-fitting and ill-fitting plates. Investigation of the effect on retention of different quantities of fixatives showed that larger amounts were associated with greater retention. The findings of these studies predict that a single application of 0.6 ml of either the paste or liquid fixatives used in this study is a recommended quantity which would provide and maintain the desirable retention for more than 6 hours in most cases of well-fitting complete dentures and those with retention problems. The powder fixatives though very effective immediately, would, however, require repeated applications every 3 hours or so, depending to some extent upon the use that the product will be put to. PMID:1931278

  8. Concept of variable angle locking--evolution and mechanical evaluation of a recent technology.

    PubMed

    Lenz, Mark; Wahl, Dieter; Gueorguiev, Boyko; Jupiter, Jesse B; Perren, Stephan Marcel

    2015-07-01

    Applications for fracture-adapted screw positioning offered by variable angle locking screws are increasing. The locking strength of the variable angle locking mechanism at different insertion angles was compared to conventional fixed angle locking screws. Stainless steel (S) and titanium (Ti) variable and fixed angle 2.4?mm locking screws, inserted at different inclinations (0°-15°), and locked at 0.8?Nm were subjected to a load-to-failure test. Ultimate failure moment at the screw-head interface and failure mode of the screws were determined. Significant differences were detected by one-way ANOVA (p?locking screws inserted at 2°-10° inclination exhibited a failure moment comparable to the 0° position (S 1.67±?0.04?Nm; Ti 1.67?±?0.14?Nm) and failed predominantly at the screw neck, with the head remaining fixed to the plate. Inserted at 15° inclination, screws revealed a lower failure moment (S 1.33?±?0.06?Nm, Ti 1.58?±?0.05Nm), and failed predominantly by breakout of the head thread. Fixed angle locking screws inserted at an inclination >2° did not lock properly in the plate hole, providing insufficient locking strength. Variable angle locking screws offer a stable head-locking mechanism at different inclinations, comparable to the locking strength of orthogonal inserted fixed angle locking screws. Marginal inclinations >15° should be used with care. PMID:25676391

  9. Safety of Navigation Locks

    SciTech Connect

    Kolosov, M. A.

    2002-03-15

    The author's observations and studies of safety of navigation locks are described. A mathematical model of lock reliability and its graphical interpretation are presented. The possibility of determination of the accident risk level by processing statistical data is discussed.

  10. Minimal locked trees

    E-print Network

    Ballinger, Brad

    Locked tree linkages have been known to exist in the plane since 1998, but it is still open whether they have a polynomial-time characterization. This paper examines the properties needed for planar trees to lock, with a ...

  11. Application of Additional Medial Plate in Treatment of Proximal Humeral Fractures With Unstable Medial Column: A Finite Element Study and Clinical Practice.

    PubMed

    He, Yu; He, Jiliang; Wang, Fu; Zhou, Dongsheng; Wang, Yan; Wang, Bomin; Xu, Shihong

    2015-10-01

    The purpose of this study was to use finite element analysis to compare the biomechanical characteristics after lateral locking plate (LLP) or LLP with a medial anatomical locking plate (LLP-MLP) fixation of proximal humeral fractures with an unstable medial column.First, a 3-dimensional, finite element analysis model was developed. Next, LLP and LLP-MLP implants were instrumented into the proximal humeral fracture models. Compressive and rotational loads were then applied to the humerus model to determine the biomechanical characteristics. Both normal and osteoporotic proximal humerus fractures were simulated using 2 internal fixation methods each under 7 loading conditions. To assess the biomechanical characteristics, the construct stiffness, fracture micromotion, and stress distribution on the implants were recorded and compared.The LLP-MLP method provided both lateral and medial support that reduced the stress on the LLP and the amount of displacement in the fracture region. In contrast, the LLP method resulted in more instability in the medial column and larger magnitudes of stress. In osteoporotic bone, the LLP was more inclined to fail than LLP-MLP.The LLP-MLP method provides a strong support for the medial column and increases the stability of the region surrounding the fracture. PMID:26469918

  12. Fast flux locked loop

    DOEpatents

    Ganther, Jr., Kenneth R. (Olathe, KS); Snapp, Lowell D. (Independence, MO)

    2002-09-10

    A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

  13. Overview of locking systems

    SciTech Connect

    Gee, K.T.; Scott, S.H.; Wilde, M.G.; Highland, S.E.

    1993-12-01

    The purpose of this document is to present technical information that should be useful for understanding and applying locking systems for physical protection and control. There are major sections on hardware for locks, vaults, safes, and security containers. Other topics include management of lock systems and safety considerations. This document also contains notes on standards and specifications and a glossary.

  14. Lock For Valve Stem

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.; Guirguis, Kamal S.

    1991-01-01

    Simple, cheap device locks valve stem so its setting cannot be changed by unauthorized people. Device covers valve stem; cover locked in place with standard padlock. Valve lock made of PVC pipe and packing band. Shears, drill or punch, and forming rod only tools needed.

  15. Comparison of Internal Fixations for Distal Clavicular Fractures Based on Loading Tests and Finite Element Analyses

    PubMed Central

    Sakai, Rina; Matsuura, Terumasa; Tanaka, Kensei; Nakao, Masaki

    2014-01-01

    It is difficult to apply strong and stable internal fixation to a fracture of the distal end of the clavicle because it is unstable, the distal clavicle fragment is small, and the fractured region is near the acromioclavicular joint. In this study, to identify a superior internal fixation method for unstable distal clavicular fracture, we compared three types of internal fixation (tension band wiring, scorpion, and LCP clavicle hook plate). Firstly, loading tests were performed, in which fixations were evaluated using bending stiffness and torsional stiffness as indices, followed by finite element analysis to evaluate fixability using the stress and strain as indices. The bending and torsional stiffness were significantly higher in the artificial clavicles fixed with the two types of plate than in that fixed by tension band wiring (P < 0.05). No marked stress concentration on the clavicle was noted in the scorpion because the arm plate did not interfere with the acromioclavicular joint, suggesting that favorable shoulder joint function can be achieved. The stability of fixation with the LCP clavicle hook plate and the scorpion was similar, and plate fixations were stronger than fixation by tension band wiring. PMID:25136691

  16. The effect of external fixation stiffness on early healing of transverse osteotomies.

    PubMed

    Gilbert, J A; Dahners, L E; Atkinson, M A

    1989-01-01

    The effect of bending stiffness of external fixators on the early healing of transverse tibial osteotomies was studied in a canine model to determine whether there is a particular range of fixation stiffness where healing is poor. Five unilateral fixators with different stiffnesses were developed and employed along with a dynamic compression plate to fix experimental osteotomies of dog tibias and the contralateral intact tibias served as controls. The six experimental fixation devices were: plate (P), stainless steel sidebar fixator (SS), stiff aluminum sidebar fixator (SA), intermediate aluminum sidebar fixator (IA), flexible aluminum sidebar fixator (FA), and Delrin sidebar fixator (D). Compared with human tibial fixation methods, the fixators ranged from a rigidity greater than a plate on a human tibia to a flexibility similar to a plaster cast on a human lower leg. Sixty-four adult male mongrel dogs (29 +/- 3 kg) underwent surgery and 52 completed the 9-week study, leaving 7 to 10 dogs in each experimental group (P = 8, SS = 7, SA = 9, IA = 9, FA = 10, D = 9). After the 9-week survival period the experimental tibias were radiographed and callus area was digitized. Both the experimental and control tibias were then tested to failure in four-point bending, and failure moment, stiffness, and energy to failure were determined. Of the 52 osteotomies, only four developed nonunions: 3 of 10 in the FA group and 1 of 7 in the SS group. Using analysis of variance, no statistical differences were detected in failure force, stiffness, or energy to failure as a function of fixator groups.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2703930

  17. Improving carbon fixation pathways

    SciTech Connect

    Ducat, DC; Silver, PA

    2012-08-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that novel pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials.

  18. VIEW OF LOCK GATE CLOSED AND THE LOCK FILLED TO ...

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

    VIEW OF LOCK GATE CLOSED AND THE LOCK FILLED TO THE HIGH SIDE LEVEL. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

  19. 12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS ...

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

    12. LOCK, ELECTRICAL SYSTEM, LOCK, DAM, AND NAVIGATION LIGHTING UNITS (October 1935) - Mississippi River 9-Foot Channel Project, Lock & Dam No. 18, Upper Mississippi River, Gladstone, Henderson County, IL

  20. 76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. ...

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

    76. LOCK, ELECTRICAL SYSTEM, LOCK, DAM AND NAVIGATION LIGHTING UNITS. February 1938 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 17, Upper Mississippi River, New Boston, Mercer County, IL

  1. West Branch Pennsylvania Canal, Lock No. 34 Lock Keeper's House, ...

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

    West Branch Pennsylvania Canal, Lock No. 34 Lock Keeper's House, South of State Route 664 along North bank of West Branch of Susquehanna River, 2,000 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  2. Locked-in syndrome.

    PubMed

    Cardwell, Michael S

    2013-02-01

    Locked-in syndrome is a rare neuropsychological disorder. Its primary features are quadriplegia and paralysis of the cranial nerves except for those responsible for vertical eye movements. The differential diagnosis includes persistent vegetative state, brain death, minimally conscious states, C3 transection of the spinal cord, and conversion locked-in syndrome. Etiologies of locked-in syndrome include hemorrhagic and thrombotic events, tumors affecting the ventral pons, infectious agents, iatrogenic causes, trauma, metabolic abnormalities, and other miscellaneous causes. The clinical manifestations, differential diagnosis, neuropsychological assessment, rehabilitation, and prognosis of patients with locked-in syndrome are discussed. PMID:23378122

  3. Update: Biological Nitrogen Fixation.

    ERIC Educational Resources Information Center

    Wiseman, Alan; And Others

    1985-01-01

    Updates knowledge on nitrogen fixation, indicating that investigation of free-living nitrogen-fixing organisms is proving useful in understanding bacterial partners and is expected to lead to development of more effective symbioses. Specific areas considered include biochemistry/genetics, synthesis control, proteins and enzymes, symbiotic systems,…

  4. The Fixation of Nitrogen.

    ERIC Educational Resources Information Center

    Andrew, S. P. S.

    1978-01-01

    Discusses the fixation of atmospheric nitrogen in the form of ammonia as one of the foundations of modern chemical industry. The article describes ammonia production and synthesis, purifying the hydrogen-nitrogen mix, nitric acid production, and its commericial plant. (HM)

  5. Continuous variable entanglement measurement without phase locking

    E-print Network

    Dong Wang; Xianshan Huang

    2011-06-15

    A new simple entanglement measurement method is proposed for the bright EPR beams generated from a non-degenerate optical parametric amplifier operating at deamplification. Due to the output signal and idler modes are frequency degenerate and in phase, the needed phase shift of interference for the measurement of the correlated phase quadratures and anti-correlated amplitude quadratures can be accomplished by a quarter-wave plate and a half wave plate without separating the signal and idler beam. Therefore, phase locking and local oscillators are avoided.

  6. An evaluation of the bending stiffness of various tibial fixation methods.

    PubMed

    Carter, M D; Gilbert, J A; Dahners, L E

    1987-11-01

    The relative stiffness of human tibial fixation by plaster casts, intramedullary rods, external fixators, and dynamic compression plates was compared to the stiffness of the intact tibia. Four-point bending was performed on each specimen, first intact, and then after sequential instrumentation, thus allowing each specimen to serve as its own control. The mean stiffnesses obtained for the bone-device complexes, as a percentage of the intact tibial stiffness, were 113 +/- 9% for the delta frame fixator, 57 +/- 14% for the dynamic compression plate, 28 +/- 2% for the unilateral external fixator (UEF) with stainless steel sidebar, 18 +/- 1% for the UEF with aluminum sidebar, 7 +/- 2% for the flexible intramedullary (IM) rods, and 6 +/- 2% for the cast. Even relatively flexible unilateral external fixators are much stiffer than cast or IM rod fixation, methods that usually lead to satisfactory union by secondary healing. If secondary union with callus formation is desirable, modifications of the external fixator may be necessary to provide more flexible fixation. This study may be one of the first attempts to quantitate the stiffness of tibial fixation in a standard cast and compare it with other devices. PMID:3665252

  7. Parallel analysis of finite element model controlled trial and retrospective case control study on percutaneous internal fixation for vertical sacral fractures

    PubMed Central

    2013-01-01

    Background Although percutaneous posterior-ring tension-band metallic plate and percutaneous iliosacral screws are used to fix unstable posterior pelvic ring fractures, the biomechanical stability and compatibility of both internal fixation techniques for the treatment of Denis I, II and III type vertical sacral fractures remain unclear. Methods Using CT and MR images of the second generation of Chinese Digitized Human “male No. 23”, two groups of finite element models were developed for Denis I, II and III type vertical sacral fractures with ipsilateral superior and inferior pubic ramus fractures treated with either a percutaneous metallic plate or a percutaneous screw. Accordingly, two groups of clinical cases that were fixed using the above-mentioned two internal fixation techniques were retrospectively evaluated to compare postoperative effect and function. Parallel analysis was performed with a finite element model controlled trial and a case control study. Results The difference of the postoperative Majeed standards and outcome rates between two case groups was no statistically significant (P?>?0.05). Accordingly, the high values of the maximum displacements/stresses of the plate-fixation model group approximated those of the screw-fixation model group. However, further simulation of Denis I, II and III type fractures in each group of models found that the biomechanics of the plate-fixation models became increasingly stable and compatible, whereas the biomechanics of the screw-fixation models maintained tiny fluctuations. When treating Denis III fractures, the biomechanical effects of the pelvic ring of the plate-fixation model were better than the screw-fixation model. Conclusions Percutaneous plate and screw fixations are both appropriate for the treatment of Denis I and II type vertical sacral fractures; whereas percutaneous plate fixation appears be superior to percutaneous screw fixation for Denis III type vertical sacral fracture. Biomechanical evidence of finite element evaluations combined with clinical evidence will contribute to our ability to distinguish between indications that require plate or screw fixation for vertical sacral fractures. PMID:23879618

  8. Pessimistic Software Lock-Elision

    E-print Network

    Afek, Yehuda

    2012-01-01

    Read-write locks are one of the most prevalent lock forms in concurrent applications because they allow read accesses to locked code to proceed in parallel. However, they do not offer any parallelism between reads and ...

  9. Rotatable stem and lock

    DOEpatents

    Deveney, J.E.; Sanderson, S.N.

    1981-10-27

    A valve stem and lock is disclosed which includes a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  10. Rotatable stem and lock

    DOEpatents

    Deveney, Joseph E. (Albuquerque, NM); Sanderson, Stephen N. (Albuquerque, NM)

    1984-01-01

    A valve stem and lock include a housing surrounding a valve stem, a solenoid affixed to an interior wall of the housing, an armature affixed to the valve stem and a locking device for coupling the armature to the housing body. When the solenoid is energized, the solenoid moves away from the housing body, permitting rotation of the valve stem.

  11. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  12. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  13. A Biomechanical Comparison of Locked and Unlocked Long Cephalomedullary Nails in a Stable Intertrochanteric Fracture Model

    PubMed Central

    Kane, P; Vopat, B; Paller, D; Koruprolu, S; Daniels, AH; Born, C

    2015-01-01

    Objectives This study compared the torsional properties of stable intertrochanteric femur fractures in a cadaveric bone model utilizing two different distal fixation strategies: unlocked long cephalomedullary nailing versus dynamically locked nailing. Methods 14 matched pairs of cadaveric femora were randomly assigned to one of two distal fixation treatment groups; a single distal interlock screw placed in the dynamic orientation or no distal screw fixation. A stable two part intertrochanteric fracture was produced. Specimens were potted and mounted in a double gimbal fixture facilitating unconstrained motion in the sagittal and coronal planes. Specimens were cyclically loaded dynamically in both internal and external rotation. Range of motion, internal and external rotation stiffness, torsion stiffness, torsion yield and ultimate torsion magnitude were calculated. Results The samples instrumented with a distal locking screw reported statistically significantly greater internal (1.54 ± 0.81Nm/° versus 1.08 ± 0.35Nm/°, p = 0.026) and external rotational stiffness (1.42 ± 0.72Nm/° versus 0.86 ± 0.36Nm/°, p = 0.009). Samples with locked distal fixation were statistically stiffer and displayed statistically less displacement at the yield and peak torque. The yield torque was statistically significantly higher in the samples without distal fixation (14.2 ± 3.3Nm versus 10.6 ± 3.8Nm, p = 0.037). The peak torque was comparable between locked an unlocked samples (15.0 ± 4.6Nm versus 16.2 ± 4.2Nm, p = 0.492). Conclusion Distal locking of femoral intramedullary nails increases the stiffness of the nail-femur construct. Unlocked samples displayed statistically significant higher yield torque while maintaining comparable peak torque as the locked samples. This study indicates that treating stable intertrochanteric fractures with unlocked, long intramedullary nails may be an acceptable option, although further clinical study will be needed to test this assertion. PMID:24978941

  14. "Blocking without Locking" or LFTHREADS: A lock-free

    E-print Network

    Waldmann, Uwe

    "Blocking without Locking" or LFTHREADS: A lock-free thread library Anders Gidenstam Marina and Engineering Chalmers University of Technology SE 412 96 Göteborg Sweden. #12;Abstract This paper presents the synchronization in LFTHREADS, a thread library entirely based on lock-free methods, i.e. no spin-locks or similar

  15. 35. INTERIOR VIEW OF THE GUARD LOCKS LOCK HOUSE: CLOSED ...

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

    35. INTERIOR VIEW OF THE GUARD LOCKS LOCK HOUSE: CLOSED LOCK GATES AND TWO SETS OF MACHINERY TO ASSIST IN OPERATING THEM. VIEW FROM THE FAST END OF THE BUILDING LOOKING WEST 1976 - Pawtucket Canal, Guard Locks, Lowell, Middlesex County, MA

  16. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity

    PubMed Central

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  17. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    PubMed

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  18. Electronic door locking mechanism

    DOEpatents

    Williams, G.L.; Kirby, P.G.

    1997-10-21

    The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch. 6 figs.

  19. Electronic door locking mechanism

    DOEpatents

    Williams, Gary Lin (428 E. Third Ave., Kennewick, WA 99336); Kirby, Patrick Gerald (1010 W. Fifteenth Pl., Kennewick, WA 99337)

    1997-01-01

    The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch.

  20. Open Reduction and Internal Fixation of Mandibular Fracture without Rigid Maxillomandibular Fixation

    PubMed Central

    El-Anwar, Mohammad Waheed; Sayed El-Ahl, Magdy Abdalla; Amer, Hazem Saed

    2015-01-01

    Introduction?The ability to treat fracture with open reduction and internal fixation (OR/IF) has dramatically revolutionized the approach to mandible fracture. With OR/IF, the postoperative role of rigid maxillomandibular fixation (MMF) has declined, but it is used to maintain proper occlusion until internal fixation of the fracture is achieved. Objective?To assess intraoperative manual MMF during OR/IF of selected cases of mandibular fractures. Methods?This prospective study was conducted on 80 patients with isolated mandibular fractures managed by OR/IF using two titanium miniplates. The patients were classified into two groups: a control group (40 patients) treated by OR/IF after intraoperative rigid MMF followed by immediate MMF removal, and a study group (40 patients) treated by rigid MMF, which was replaced by temporary intraoperative manual MMF (3MF) until plate fixation. Results?There were no significant differences of the postoperative complication and dental occlusion, although a highly significant reduction of operative time was achieved in the 3MF group. Patient who received the 3MF technique had statistically significantly better average intrinsic vertical mouth opening in the early postoperative period (1?week after surgery), and normal mouth opening could be achieved in all cases in both groups 8 weeks after surgery. Conclusions?Intraoperative rigid MMF is not mandatory and can be replaced in selected cases of fracture mandible by manual maintenance of proper dental occlusion until hardware fixation, gaining the advantages of shorter operative time and less risk of blood-transmitted diseases to the surgical team and the patient in addition to the benefits of immediate postoperative mandible mobilization. PMID:26491477

  1. Quantum Noise Locking

    E-print Network

    Kirk McKenzie; Eugeniy Mikhailov; Keisuke Goda; Ping Koy Lam; Nicolai Grosse; Malcolm B. Gray; Nergis Mavalvala; David E. McClelland

    2005-05-22

    Quantum optical states which have no coherent amplitude, such as squeezed vacuum states, can not rely on standard readout techniques to generate error signals for control of the quadrature phase. Here we investigate the use of asymmetry in the quadrature variances to obtain a phase-sensitive readout and to lock the phase of a squeezed vacuum state, a technique which we call noise locking (NL). We carry out a theoretical derivation of the NL error signal and the associated stability of the squeezed and anti-squeezed lock points. Experimental data for the NL technique both in the presence and absence of coherent fields are shown, including a comparison with coherent locking techniques. Finally, we use NL to enable a stable readout of the squeezed vacuum state on a homodyne detector.

  2. Nitrogen fixation apparatus

    DOEpatents

    Chen, Hao-Lin (Walnut Creek, CA)

    1984-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  3. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  4. Eighth international congress on nitrogen fixation

    SciTech Connect

    Not Available

    1990-01-01

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  5. Surgical rib fixation - technical aspects.

    PubMed

    Marasco, Silvana; Saxena, Pankaj

    2015-05-01

    Surgical rib fixation (SRF) for severe rib fracture injuries is increasingly becoming an accepted treatment modality. There is now adequate evidence in randomised controlled trials that rib fixation in flail chest patients reduces ventilator times, intensive care stay and costs of treatment in ventilator dependent patients [1-3]. Despite this, rib fixation has not become standard of care for these patients and remains a treatment modality practised by few centres, usually those with large trauma loads who see high volumes of severe rib fracture injury patients. The purpose of this article is to outline the available prostheses, indications, operative planning and techniques of rib fixation. Surgical approaches to rib fractures in anterior, lateral and posterior positions are described as are the use of currently available cortical and medullary fixation prostheses. PMID:25624272

  6. A Novel Technique for Attaining Maxillomandibular Fixation in the Edentulous Mandible Fracture

    PubMed Central

    Knotts, Christopher; Workman, Meredith; Sawan, Kamal; El Amm, Christian

    2012-01-01

    Edentulous mandible fractures present a unique and challenging surgical problem, particularly because of lack of occlusive dental surfaces to capitalize upon maxillomandibular fixation (MMF). We present a novel technique to achieve MMF using rigid plates spanning the oral cavity to fixate the maxilla to the mandible. The process is rapid and allows stability using the established principles of rigidity, external fixation, and osteosynthesis. This technique allows for a faster MMF than with a Gunning splint and allows for easier oral hygiene. An illustrative case and pre- and postoperative imaging are provided. PMID:23449752

  7. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection.

    PubMed

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-07-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates ("wave-plate-enhanced RBS") that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia. PMID:21750772

  8. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection

    PubMed Central

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-01-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates (“wave-plate-enhanced RBS”) that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia. PMID:21750772

  9. 49 CFR 236.379 - Route locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Route locking. 236.379 Section 236.379 Transportation...Interlocking Inspection and Tests § 236.379 Route locking. Route locking or other type of switch locking shall...

  10. Hot Topics in Biomechanics: Hip Fracture Fixation.

    PubMed

    Olson, Steven A; Schemitsch, Geoffrey; Morwood, Michael; Schemitsch, Emil; Russell, Thomas A; Latta, Loren L

    2015-12-01

    Geriatric hip fractures continue to increase in frequency as the population ages, and intertrochanteric femur fractures are a significant part of these injuries. Plate fixation for intertrochanteric fractures of the proximal femur has been in use for many years, and application of the sliding hip screw has also been a mainstay of treatment. Recent data suggest there may be a benefit to using implants that add rotational stability to the proximal intertrochanteric fragment. Although preliminary data are promising, there is need for improved investigation to demonstrate the benefit of these new implant designs. In this era of increasing emphasis on cost, quality, and value, better data are needed to help clinicians determine the best therapy for their patients. PMID:26584258

  11. Positioning and locking apparatus

    DOEpatents

    Hayward, M.L.; Harper, W.H.

    1985-06-19

    A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

  12. Roller Locking Brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  13. Positioning and locking apparatus

    DOEpatents

    Hayward, Milton L. (2305 Greenbrook Blvd., Richland, WA 99352); Harper, William H. (1454 Amon Dr., Richland, WA 99352)

    1987-01-01

    A positioning and locking apparatus including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member.

  14. Positioning and locking apparatus

    DOEpatents

    Hayward, M.L.; Harper, W.H.

    1987-06-30

    A positioning and locking apparatus are disclosed including a fixture having a rotatable torque ring provided with a plurality of cam segments for automatically guiding a container into a desired location within the fixture. Rotation of the ring turns the container into a final position in pressure sealing relation against a hatch member. 6 figs.

  15. Molecular Biology of Nitrogen Fixation

    ERIC Educational Resources Information Center

    Shanmugam, K. T.; Valentine, Raymond C.

    1975-01-01

    Reports that as a result of our increasing knowledge of the molecular biology of nitrogen fixation it might eventually be possible to increase the biological production of nitrogenous fertilizer from atmospheric nitrogen. (GS)

  16. Evaluation of Bone Fixation Implants 

    E-print Network

    Perkins, Luke 1990-

    2012-12-10

    This research investigates the effects of the human body on the mechanical, chemical, and morphological properties of the surface of internal fixation devices. Stainless steel and titanium devices that had failed were provided from the Shandong...

  17. Unusual mode of failure of intertrochanteric femur fracture fixation.

    PubMed

    Roy, Kunal; Nemade, Pradip; Aggarwal, Rishi; Patil, Nirmal

    2015-01-01

    The dynamic hip screw fixation is a commonly used modality of treatment for intertrochanteric femur (ITF) fractures. Various modes of failure in an operated case of ITF fracture have been described. The most frequent mode of failure is screw cut-out through the head. Occurrence of mechanical failure is rare and usually involves the shaft of the plate. We describe an unusual case with failure at the barrel of the plate and hip screw. A middle-aged man with a previously operated ITF fracture presented with pain in the same hip. Radiographs revealed non-union of the fracture with an implant failure. Revision surgery was performed during which a unique mode of implant failure was found to have occurred. The barrel of the plate had broken resulting in a bent Richard's screw. This case underlines the importance of high stress failure in non-union as opposed to high cycle, low stress failure, which is more frequently seen. PMID:26564119

  18. Data port security lock

    DOEpatents

    Quinby, Joseph D. (Albuquerque, NM); Hall, Clarence S. (Albuquerque, NM)

    2008-06-24

    In a security apparatus for securing an electrical connector, a plug may be fitted for insertion into a connector receptacle compliant with a connector standard. The plug has at least one aperture adapted to engage at least one latch in the connector receptacle. An engagement member is adapted to partially extend through at least one aperture and lock to at least one structure within the connector receptacle.

  19. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  20. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  1. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  2. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  3. 49 CFR 236.306 - Facing point lock or switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Standards § 236.306 Facing point lock or switch-and-lock movement. Facing point lock or switch-and-lock movement shall be provided for mechanically operated switch, movable-point frog, or split-point...

  4. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  5. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  6. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  7. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  8. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect....

  9. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...required in accordance with locking sheet and dog chart. 236.338 Section 236.338...required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

  10. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...required in accordance with locking sheet and dog chart. 236.338 Section 236.338...required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

  11. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...required in accordance with locking sheet and dog chart. 236.338 Section 236.338...required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

  12. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...required in accordance with locking sheet and dog chart. 236.338 Section 236.338...required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

  13. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...required in accordance with locking sheet and dog chart. 236.338 Section 236.338...required in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in...

  14. 4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON ...

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

    4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON RIGHT. 20TH CENTURY ELECTRIC LIFT LOCKS ON LEFT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  15. Multistability and hysteresis phenomena in passively mode-locked fiber lasers

    SciTech Connect

    Komarov, Andrey; Leblond, Herve; Sanchez, Francois

    2005-05-15

    A passively mode-locked fiber laser is theoretically investigated. The mode locking is achieved using the nonlinear polarization technique. We consider the practical case of the ytterbium-doped fiber laser operating in the normal dispersion regime. The effect of the phase plates is explicitly taken into account. The resulting model reduces to one iterative equation for the optical Kerr nonlinearity, the phase plates and the polarizer, and one partial differential equation for the gain and the dispersion. Numerical simulations allow us to describe several features observed in passively mode-locked fiber lasers such as bistability between the mode lock and the continuous regime, multiple pulse behavior, hysteresis phenomena. The dynamics of the number of pulses as a function of the pumping power is also reported. Pump power hysteresis is demonstrated.

  16. Evaluation of Bite Force After Open Reduction and Internal Fixation Using Microplates

    PubMed Central

    Kumar, S Tharani; Saraf, Saurabh; Devi, S Prasanna

    2013-01-01

    The primary aim of this study is to determine maximum bite force in molar and incisor regions of healthy individuals, to evaluate the bite force after open reduction and internal fixation of mandibular fractures using micro plates, for a period of up to 6 weeks and to determine the rate of recovery of maximum bite force in an Indian population. PMID:24910656

  17. Modified fixation of acrylic cranioplasty in the setting of titanium allergy.

    PubMed

    Sinkin, Jeremy C; Loftin, Sara; Baker, Stephen B

    2015-01-01

    Cranioplasty can be performed using a number of materials ranging from autologous tissue to metallic or acrylic alloplastic implants. In this report, we present a unique case of revision cranioplasty in a patient with titanium allergy using a prefabricated, custom-made polymethylmethacrylate implant and a modified fixation technique without plates or screws. PMID:25565231

  18. Safe-haven locking device

    DOEpatents

    Williams, J.V.

    1984-04-26

    Disclosed is a locking device for eliminating external control of a secured space formed by fixed and movable barriers. The locking device uses externally and internally controlled locksets and a movable strike, operable from the secured side of the movable barrier, to selectively engage either lockset. A disengagement device, for preventing forces from being applied to the lock bolts is also disclosed. In this manner, a secured space can be controlled from the secured side as a safe-haven. 4 figures.

  19. Molybdenum Trafficking for Nitrogen Fixation

    PubMed Central

    Hernandez, Jose A.; George, Simon J.; Rubio, Luis M.

    2009-01-01

    The molybdenum nitrogenase is responsible for most biological nitrogen fixation, a prokaryotic metabolic process that determines the global biogeochemical cycles of nitrogen and carbon. Here we describe the trafficking of molybdenum for nitrogen fixation in the model diazotrophic bacterium Azotobacter vinelandii. The genes and proteins involved in molybdenum uptake, homeostasis, storage, regulation, and nitrogenase cofactor biosynthesis are reviewed. Molybdenum biochemistry in A. vinelandii reveals unexpected mechanisms and a new role for iron-sulfur clusters in the sequestration and delivery of molybdenum. PMID:19772354

  20. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  1. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  2. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  3. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  4. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Locking dog of switch-and-lock movement. 236.330...Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock movement shall extend...

  5. NCI-Frederick PHL - Fixatives and Solutions

    Cancer.gov

    Services Price List Courier Services & Shipment Procedures Scheduling Contact Information Related Links Establishing an Account PHL Forms Staff Publications PHL Portal Fixatives and Solutions Routine fixatives: 10% Neutral Buffered Formalin (NBF) 37

  6. Missing nitrogen fixation in the Benguela region

    NASA Astrophysics Data System (ADS)

    Wasmund, Norbert; Struck, Ulrich; Hansen, Anja; Flohr, Anita; Nausch, Günther; Grüttmüller, Annett; Voss, Maren

    2015-12-01

    Opposing opinions on the importance of nitrogen fixation in the northern Benguela upwelling region provoked us to investigate the magnitude of nitrogen fixation in front of northern Namibia and southern Angola. Measurements of nitrogen fixation rates using the 15N method at 66 stations during seven cruises from 2008 to 2014 showed that, in general, the 15N content in the biomass did not increase after tracer incubation with 15N2, indicating that no nitrogen fixation occurred. Correspondingly, the filamentous nitrogen-fixing cyanobacterium Trichodesmium was almost not present. The abundant picocyanobacteria did obviously not perform nitrogen fixation to a significant degree. The artificial improvement of conditions for nitrogen fixation in mesocosm experiments, including phosphate and iron additions and a warmer temperature, failed to induce nitrogen fixation. A plausible explanation of these findings is a lack of conditioned cells for nitrogen fixation in the Benguela region.

  7. Robust Photon Locking

    SciTech Connect

    Bayer, T.; Wollenhaupt, M.; Sarpe-Tudoran, C.; Baumert, T.

    2009-01-16

    We experimentally demonstrate a strong-field coherent control mechanism that combines the advantages of photon locking (PL) and rapid adiabatic passage (RAP). Unlike earlier implementations of PL and RAP by pulse sequences or chirped pulses, we use shaped pulses generated by phase modulation of the spectrum of a femtosecond laser pulse with a generalized phase discontinuity. The novel control scenario is characterized by a high degree of robustness achieved via adiabatic preparation of a state of maximum coherence. Subsequent phase control allows for efficient switching among different target states. We investigate both properties by photoelectron spectroscopy on potassium atoms interacting with the intense shaped light field.

  8. 49 CFR 236.408 - Route locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Route locking. 236.408 Section 236.408 Transportation...Traffic Control Systems Standards § 236.408 Route locking. Route locking shall be provided where switches are...

  9. Tissue fixation and the effect of molecular fixatives on downstream staining procedures

    PubMed Central

    Howat, William J.; Wilson, Beverley A.

    2014-01-01

    It is impossible to underplay the importance of fixation in histopathology. Whether the scientist is interested in the extraction of information on lipids, proteins, RNA or DNA, fixation is critical to this extraction. This review aims to give a brief overview of the current “state of play” in fixation and focus on the effect fixation, and particularly the effect of the newer brand of “molecular fixatives” have on morphology, histochemistry, immunohistochemistry and RNA/DNA analysis. A methodology incorporating the creation of a fixation tissue microarray for the study of the effect of fixation on histochemistry is detailed. PMID:24561827

  10. Binocular Fixation Disparity in Single Word Displays

    ERIC Educational Resources Information Center

    Paterson, Kevin B.; Jordan, Timothy R.; Kurtev, Stoyan

    2009-01-01

    It has been claimed that the recognition of words displayed in isolation is affected by the precise location at which they are fixated. However, this putative role for fixation location has yet to be reconciled with the finding from reading research that binocular fixations are often misaligned and, therefore, more than 1 location in a word is…

  11. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for...

  12. Weakly Supervised Human Fixations Prediction.

    PubMed

    Zhang, Luming; Li, Xuelong; Nie, Liqiang; Yang, Yi; Xia, Yingjie

    2016-01-01

    Automatically predicting human eye fixations is a useful technique that can facilitate many multimedia applications, e.g., image retrieval, action recognition, and photo retargeting. Conventional approaches are frustrated by two drawbacks. First, psychophysical experiments show that an object-level interpretation of scenes influences eye movements significantly. Most of the existing saliency models rely on object detectors, and therefore, only a few prespecified categories can be discovered. Second, the relative displacement of objects influences their saliency remarkably, but current models cannot describe them explicitly. To solve these problems, this paper proposes weakly supervised fixations prediction, which leverages image labels to improve accuracy of human fixations prediction. The proposed model hierarchically discovers objects as well as their spatial configurations. Starting from the raw image pixels, we sample superpixels in an image, thereby seamless object descriptors termed object-level graphlets (oGLs) are generated by random walking on the superpixel mosaic. Then, a manifold embedding algorithm is proposed to encode image labels into oGLs, and the response map of each prespecified object is computed accordingly. On the basis of the object-level response map, we propose spatial-level graphlets (sGLs) to model the relative positions among objects. Afterward, eye tracking data is employed to integrate these sGLs for predicting human eye fixations. Thorough experiment results demonstrate the advantage of the proposed method over the state-of-the-art. PMID:26168451

  13. Transit Fixatives: An Innovative Study

    PubMed Central

    A, Ravi Prakash; G, Sreenath; JK, Sonia Bai; NDVN, Shyam

    2015-01-01

    Background: Universally accepted fixative is 10% formalin which has been used for preserving the tissues and their architecture. In certain conditions, formalin might not be readily available for immediate fixation. We here by explore more economical, eco-friendly and easily available solutions that can be used as transit media/ transporting media for tissue specimens. Materials and Methods: The study included commonly available solutions like Spirit, Saline, Betadine solution, Hydrogen peroxide (H2O2), Local anesthesia (L.A), Rose water, Coconut oil, Coconut water, Ice cold water, Honey and Milk while keeping formalin as control. The fresh tissue sample was cut into multiple bits and placed in different containers for a period of 8 hours before transferring to formalin solution. Conclusion: Transit fixatives are very important in certain situations where formalin is not readily available. These fixatives can be used to fix the tissues for a period of at least 8 hours without causing any damage or distortion before they are fixed in formalin solution. PMID:25954725

  14. Options for acetabular fixation surfaces.

    PubMed

    Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have been reported to have excellent bone graft incorporation of the acetabular component based on serial radiograph data at a minimum 1-year follow-up. Tritanium is a porous metal, which has emerged as a promising new surface technology for acetabular shells. While no clinical data are yet available, basic science research has demonstrated enhanced bone ingrowth and mechanical strength. PMID:19023943

  15. Intraoperative Periprosthetic Femur Fracture: A Biomechanical Analysis of Cerclage Fixation.

    PubMed

    Frisch, Nicholas B; Charters, Michael A; Sikora-Klak, Jakub; Banglmaier, Richard F; Oravec, Daniel J; Silverton, Craig D

    2015-08-01

    Intraoperative periprosthetic femur fracture is a known complication of total hip arthroplasty (THA) and a variety of cerclage systems are available to manage these fractures. The purpose of this study was to examine the in situ biomechanical response of cerclage systems for fixation of periprosthetic femur fractures that occur during cementless THA. We compared cobalt chrome (CoCr) cables, synthetic cables, monofilament wires and hose clamps under axial compressive and torsional loading. Metallic constructs with a positive locking system performed the best, supporting the highest loads with minimal implant subsidence (both axial and angular) after loading. Overall, the CoCr cable and hose clamp had the highest construct stiffness and least reduction in stiffness with increased loading. They were not demonstrably different from each other. PMID:25765131

  16. Understanding Nitrogen Fixation

    SciTech Connect

    Paul J. Chirik

    2012-05-25

    The purpose of our program is to explore fundamental chemistry relevant to the discovery of energy efficient methods for the conversion of atmospheric nitrogen (N{sub 2}) into more value-added nitrogen-containing organic molecules. Such transformations are key for domestic energy security and the reduction of fossil fuel dependencies. With DOE support, we have synthesized families of zirconium and hafnium dinitrogen complexes with elongated and activated N-N bonds that exhibit rich N{sub 2} functionalization chemistry. Having elucidated new methods for N-H bond formation from dihydrogen, C-H bonds and Broensted acids, we have since turned our attention to N-C bond construction. These reactions are particularly important for the synthesis of amines, heterocycles and hydrazines with a range of applications in the fine and commodity chemicals industries and as fuels. One recent highlight was the discovery of a new N{sub 2} cleavage reaction upon addition of carbon monoxide which resulted in the synthesis of an important fertilizer, oxamide, from the diatomics with the two strongest bonds in chemistry. Nitrogen-carbon bonds form the backbone of many important organic molecules, especially those used in the fertilizer and pharamaceutical industries. During the past year, we have continued our work in the synthesis of hydrazines of various substitution patterns, many of which are important precursors for heterocycles. In most instances, the direct functionalization of N{sub 2} offers a more efficient synthetic route than traditional organic methods. In addition, we have also discovered a unique CO-induced N{sub 2} bond cleavage reaction that simultaneously cleaves the N-N bond of the metal dinitrogen compound and assembles new C-C bond and two new N-C bonds. Treatment of the CO-functionalized core with weak Broensted acids liberated oxamide, H{sub 2}NC(O)C(O)NH{sub 2}, an important slow release fertilizer that is of interest to replace urea in many applications. The synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from atmospheric nitrogen could, in principle, be more energy-efficient. This is particularly attractive giv

  17. In vitro biomechanical evaluation of four fixation techniques for distractive–flexion injury stage 3 of the cervical spine

    PubMed Central

    Henriques, Thomas; Cunningham, Bryan W.; Mcafee, Paul C.

    2015-01-01

    Purpose Anterior plate fixation has been reported to provide satisfactory results in cervical spine distractive flexion (DF) injuries stages 1 and 2, but will result in a substantial failure rate in more unstable stage 3 and above. The aim of this investigation was to determine the biomechanical properties of different fixation techniques in a DF-3 injury model where all structures responsible for the posterior tension band mechanism are torn. Methods The multidirectional three-dimensional stiffness of the subaxial cervical spine was measured in eight cadaveric specimens with a simulated DF-3 injury at C5–C6, stabilized with four different fixation techniques: anterior plate alone, anterior plate combined with posterior wire, transarticular facet screws, and a pedicle screw–rod construct, respectively. Results The anterior plate alone did not improve stability compared to the intact spine condition, thus allowing considerable range of motion around all three cardinal axes (p > 0.05). The anterior plate combined with posterior wire technique improved flexion–extension stiffness (p = 0.023), but not in axial rotation and lateral bending. When the anterior plate was combined with transarticular facet screws or with a pedicle screws–rod instrumentation, the stability improved in flexion–extension, lateral bending, and in axial rotation (p < 0.05). Conclusions These findings imply that the use of anterior fixation alone is insufficient for fixation of the highly unstable DF-3 injury. In these situations, the use of anterior fixation combined with a competent posterior tension band reconstruction (e.g. transarticular screws or a posterior pedicle screws–rod device) improves segmental stability. PMID:25742755

  18. DVR plating of distal radius fractures.

    PubMed

    Vanhaecke, J; Fernandez, D L

    2015-11-01

    Volar plating has become the standard of care for most distal radius fractures. When done for the right indication and with adequate mastering of the technique complication ratio is low. The concept of subchondral support is key in this technique. Osteoporotic patients will especially benefit from this type of fixation which allows early immobilization, quick return to activities of daily living and early good outcome. PMID:26319206

  19. Payload Launch Lock Mechanism

    NASA Technical Reports Server (NTRS)

    Young, Ken (Inventor); Hindle, Timothy (Inventor)

    2014-01-01

    A payload launch lock mechanism includes a base, a preload clamp, a fastener, and a shape memory alloy (SMA) actuator. The preload clamp is configured to releasibly restrain a payload. The fastener extends, along an axis, through the preload clamp and into the base, and supplies a force to the preload clamp sufficient to restrain the payload. The SMA actuator is disposed between the base and the clamp. The SMA actuator is adapted to receive electrical current and is configured, upon receipt of the electrical current, to supply a force that causes the fastener to elongate without fracturing. The preload clamp, in response to the fastener elongation, either rotates or pivots to thereby release the payload.

  20. External fixation in the elderly.

    PubMed

    Andruszkow, Hagen; Pfeifer, Roman; Horst, Klemens; Hildebrand, Frank; Pape, Hans-Christoph

    2015-09-01

    Orthopaedic trauma is an increasingly common problem in geriatric patients. As demands of daily life and recreational activities are increasing in these patients, surgeons need to be able to manage geriatric fractures to achieve good functional results. Reduced bone quality in the elderly presents a considerable challenge and may preclude the use of established surgical stabilisation techniques that are performed in younger trauma patients. Furthermore, pre-existing medical conditions and considerable comorbidities in the elderly could complicate standard surgical procedures that younger patients would be offered. In this respect, application of external fixators represents a validated, minimally-invasive treatment opportunity. This review article summarises the use of external fixation in geriatric trauma patients for wrist fractures, proximal femoral fractures, pelvic fractures, and ankle fractures. Modern modifications, like pin coating with hydroxyapatite, and aspects of pin care will be discussed. PMID:26458299

  1. Lock cohorting: A general technique for designing NUMA locks

    E-print Network

    Dice, David

    Multicore machines are quickly shifting to NUMA and CC-NUMA architectures, making scalable NUMA-aware locking algorithms, ones that take into account the machines' non-uniform memory and caching hierarchy, ever more ...

  2. Fixation strategies for retinal immunohistochemistry.

    PubMed

    Stradleigh, Tyler W; Ishida, Andrew T

    2015-09-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  3. A Lock-Free B+ Anastasia Braginsky

    E-print Network

    Petrank, Erez

    A Lock-Free B+ tree Anastasia Braginsky Erez Petrank June 19, 2012 Abstract Lock-free data and livelocks, and providing guaranteed system responsiveness. In this paper we present a design for a lock, and is used in various storage-system products. As far as we know this is the first design of a lock

  4. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  5. 49 CFR 236.765 - Locking, mechanical.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus...

  6. Percutaneous Screw Fixation of Crescent Fracture-Dislocation of the Sacroiliac Joint.

    PubMed

    Shui, Xiaolong; Ying, Xiaozhou; Mao, Chuanwan; Feng, Yongzeng; Chen, Linwei; Kong, Jianzhong; Guo, Xiaoshan; Wang, Gang

    2015-11-01

    Crescent fracture-dislocation of the sacroiliac joint (CFDSIJ) is a type of lateral compression pelvic injury associated with instability. Open reduction and internal fixation is a traditional treatment of CFDSIJ. However, a minimally invasive method has never been reported. The purpose of this study was to assess the outcome of closed reduction and percutaneous fixation for different types of CFDSIJ and present their clinical outcome. The authors reviewed 117 patients diagnosed with CFDSIJ between July 2003 and July 2013. Closed reduction and percutaneous fixation was performed in 73 patients. Treatment selection was based on Day's fracture classification. For type I fractures, fixation perpendicular to the fracture line were performed. For type II fractures, crossed fixation was performed. For type III fractures, fixation was performed with iliosacral screws. Forty-four patients were treated by open reduction and plate fixation. Demographics, fracture pattern distribution, blood loss, incision lengths, revision surgeries, radiological results, and functional scores were compared. All 117 patients were followed for more than 6 months (mean, 14 months [range, 6-24 months]). Blood loss, extensive exposure, duration of posterior ring surgery, duration of hospital stay, and infection rates were lower in the closed group (P<.01). Patients in the closed group achieved better functional performance (P<.01). There were no significant differences in reduction quality (P=.32), revision surgery rates (P=.27), and iatrogenic neurologic injuries (P=.2) between the 2 groups. The authors' results indicate that closed reduction and percutaneous fixation is a safe and effective surgical method for CFDSIJ. [Orthopedics. 2015; 38(11):e976-e982.]. PMID:26558677

  7. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  8. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  9. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  10. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  11. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of...

  12. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

  13. 49 CFR 236.337 - Locking faces of mechanical locking; fit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking faces of mechanical locking; fit. 236.337 Section 236.337 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.337 Locking faces of mechanical locking; fit. Locking faces shall...

  14. Abortable Reader-Writer Locks are No More Complex Than Abortable Mutex Locks

    E-print Network

    Abortable Reader-Writer Locks are No More Complex Than Abortable Mutex Locks Dartmouth Computer on designing abortable mutual exclusion locks, and fairly efficient algorithms of O(log n) RMR complexity have). The abort feature is just as important for a reader-writer lock as it is for a mutual exclusion lock

  15. RH Lock: A Scalable Hierarchical Spin Lock Zoran Radovic and Erik Hagersten

    E-print Network

    Hagersten, Erik

    RH Lock: A Scalable Hierarchical Spin Lock Zoran Radovi´c and Erik Hagersten Uppsala University as create more locality for the data accessed in the critical region. We also propose the new RH lock traffic compared with the test- and-set locks. A critical section guarded by the RH lock is shown to take

  16. Cavity-locked ring down spectroscopy

    DOEpatents

    Zare, Richard N. (Stanford, CA); Paldus, Barbara A. (Stanford, CA); Harb, Charles C. (Palo Alto, CA); Spence, Thomas (Union City, CA)

    2000-01-01

    Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.

  17. Identification of frequency lock-on using Koopman spectral analysis

    NASA Astrophysics Data System (ADS)

    Tu, Jonathan; Rowley, Clarence; Aram, Shawn; Mittal, Rajat

    2011-11-01

    The separated flow past an airfoil at a high angle-of-attack is characterized by the frequencies of the wake, shear layer, separation bubble, and zero-net-mass-flux (ZNMF) actuation (if applied). In certain configurations, ``lock-on'' may occur, in which some or all of these frequencies take on the same value. Previous studies have shown that the presence of lock-on may be related to the effectiveness of ZNMF forcing at a particular frequency. As a model for separated airfoil flows, we analyze the high Reynolds number flow past a finite-thickness flat plate with an elliptical leading edge, inducing separation via a blowing and suction boundary condition rather than angle-of-attack. 3-D large eddy simulations are performed and the resulting data are analyzed using Koopman spectral analysis and proper orthogonal decomposition (POD). Koopman analysis clearly identifies the characteristic flow frequencies and provides corresponding spatial modes. From the spatial support in these modes we determine whether or not lock-on occurs and which structures (wake, shear layer, or separation bubble) are involved. A combination of Koopman and POD analyses shows that ZNMF forcing is most effective when lock-on is achieved in the most energetic modes. Supported by AFOSR grant FA9550-09-1-0257, NSF GRFP.

  18. Locked-in, walked out

    PubMed Central

    Kearney, Seamus; McCann, John; Hawkins, Stanley

    2011-01-01

    Locked in syndrome is typically associated with significant morbidity and mortality. We report a patient who had an unusually good recovery from locked in syndrome due to pontine infarction. The good recovery exhibited by our patient may have resulted from resolution of oedema at the site of infarction and brainstem plasticity being augmented by initial supportive measures in the intensive care unit and early, intensive rehabilitation. PMID:23526844

  19. Locking device for fluid coupling

    NASA Astrophysics Data System (ADS)

    Beatrice, Kenneth J.; Christie, George M.

    1994-12-01

    A mechanical locking device for use with conventional quick disconnect fluid coupling having a release collar on the female component spaced from a flange or nut also on the female component. Upper and lower half shells of the locking device fit between the release collar and flange to prevent inadvertent movement of the release collar. The half shells are assembled by two threaded fasteners which must be unthreaded to remove the device from the fluid coupling.

  20. Overcoming fixation with repeated memory suppression.

    PubMed

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information. PMID:24575886

  1. Fixational eye movements and binocular vision

    PubMed Central

    Otero-Millan, Jorge; Macknik, Stephen L.; Martinez-Conde, Susana

    2014-01-01

    During attempted visual fixation, small involuntary eye movements–called fixational eye movements–continuously change of our gaze’s position. Disagreement between the left and right eye positions during such motions can produce diplopia (double vision). Thus, the ability to properly coordinate the two eyes during gaze fixation is critical for stable perception. For the last 50 years, researchers have studied the binocular characteristics of fixational eye movements. Here we review classical and recent studies on the binocular coordination (i.e., degree of conjugacy) of each fixational eye movement type: microsaccades, drift and tremor, and its perceptual contribution to increasing or reducing binocular disparity. We also discuss how amblyopia and other visual pathologies affect the binocular coordination of fixational eye movements. PMID:25071480

  2. Finite Element Analysis of a New Pedicle Screw-Plate System for Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Zhou, Yue; Li, Changqing; Liu, Huan

    2015-01-01

    Purpose Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disc diseases. The constructs intended for segmental stability are varied in MI-TLIF. We adopted finite element (FE) analysis to compare the stability after different construct fixations using interbody cage with posterior pedicle screw-rod or pedicle screw-plate instrumentation system. Methods A L3–S1 FE model was modified to simulate decompression and fusion at L4–L5 segment. Fixation modes included unilateral plate (UP), unilateral rod (UR), bilateral plate (BP), bilateral rod (BR) and UP+UR fixation. The inferior surface of the S1 vertebra remained immobilized throughout the load simulation, and a bending moment of 7.5 Nm with 400N pre-load was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Range of motion (ROM) and Von Mises stress were evaluated for intact and instrumentation models in all loading planes. Results All reconstructive conditions displayed decreased motion at L4–L5. The pedicle screw-plate system offered equal ROM to pedicle screw-rod system in unilateral or bilateral fixation modes respectively. Pedicle screw stresses for plate system were 2.2 times greater than those for rod system in left lateral bending under unilateral fixation. Stresses for plate were 3.1 times greater than those for rod in right axial rotation under bilateral fixation. Stresses on intervertebral graft for plate system were similar to rod system in unilateral and bilateral fixation modes respectively. Increased ROM and posterior instrumentation stresses were observed in all loading modes with unilateral fixation compared with bilateral fixation in both systems. Conclusions Transforaminal lumbar interbody fusion augmentation with pedicle screw-plate system fixation increases fusion construct stability equally to the pedicle screw-rod system. Increased posterior instrumentation stresses are observed in all loading modes with plate fixation, and bilateral fixation could reduce stress concentration. PMID:26649749

  3. External fixation in contemporary fracture management

    PubMed Central

    McCoy, G F; Orr, J F; Templeton, J

    1987-01-01

    Important advances have been made within the last two decades in the field of fracture management. The development of the AO internal fixation system and the advances in cast bracing techniques are but two of the improvements worthy of mention. It is, however, in the field of external fixation of fractures that the greatest advances have been made. This paper traces the history of external fixation up to the present day and discusses, with examples, the application of external fixation in the management of complex limb fractures. ImagesFig 3Fig 4Fig 5Fig 6Fig 7Fig 8Fig 9 PMID:3328364

  4. Do Fixation Cues Ensure Fixation Accuracy in Split-Fovea Studies of Word Recognition?

    ERIC Educational Resources Information Center

    Jordan, Timothy R.; Paterson, Kevin B.; Kurtev, Stoyan; Xu, Mengyun

    2009-01-01

    Many studies have claimed that hemispheric processing is split precisely at the foveal midline and so place great emphasis on the precise location at which words are fixated. These claims are based on experiments in which a variety of fixation procedures were used to ensure fixation accuracy but the effectiveness of these procedures is unclear. We…

  5. Minimally invasive plate osteosynthesis for humerus diaphyseal fractures

    PubMed Central

    Shetty, M Shantharam; Kumar, M Ajith; Sujay, KT; Kini, Abhishek R; Kanthi, Kiran G

    2011-01-01

    Background: Minimally invasive plate osteosynthesis (MIPO) technique is reported as a satisfactory procedure for the treatment of humeral shaft fractures by the anterior approach by several authors. However, none of the published reports had a significant follow-up nor have they reported patient outcomes. We evaluated the clinical, radiographic, and functional outcome over a minimum follow-up of 2 years using the same MIPO technique to humeral shaft fracture. Materials and Methods: 32 adult patients with diaphyseal fractures of the humerus treated with MIPO between June 2007 and October 2008 were included in the study. Patients with metabolic bone disease, polytrauma, and Gustilo and Anderson type 3 open fractures with injury severity score >16 were excluded from the study. All cases were treated with closed indirect reduction and locking plate fixation using the MIPO technique. The surgery time, radiation exposure, and time for union was noted. The shoulder and elbow function was assessed using the UCLA shoulder and Mayo elbow performance scores, respectively. Results: Of the 32 patients in the study, 19 were males and 13 were females. The mean age was 39 years (range: 22–70 years). Twenty-seven of the thirty-two patients (84.3%) had the dominant side fractured. We had eight cases of C2 type; five cases of C1 and A2 type; four cases of B2 type; three cases each of B3, B1, and A1 type; and one case of A3 type of fracture. The mean surgical time was 91.5 minutes (range: 70–120 minutes) and mean radiation exposure was 160.3 seconds (range: 100–220 seconds). The mean radiological fracture union time was 12.9 weeks (range: 10–20 weeks). Shoulder function was excellent in 27 cases (84.3%) and good in remaining 5 cases (15.6%) on the UCLA score. Elbow function was excellent in 26 cases (81.2%), good in 5 cases (15.6%), and fair in 1 case (3.1%) who had an associated olecranon fracture that was fixed by tension band wire in the same sitting. Conclusion: MIPO of the humerus gives good functional and cosmetic results and should be considered one of the management options in the treatment of humeral diaphyseal fractures. PMID:22144745

  6. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, H.L.

    1983-08-16

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O[sub 2]/cm promotes the formation of vibrationally excited N[sub 2]. Atomic oxygen interacts with vibrationally excited N[sub 2] at a much quicker rate than unexcited N[sub 2], greatly improving the rate at which NO is formed. 1 fig.

  7. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin (Walnut Creek, CA)

    1983-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  8. Dicondylar humeral fracture stabilisation in a dog using a transilial rod and external fixation.

    PubMed

    Au, K; Mattern, K L; Lewis, D D

    2008-03-01

    Repair of a Salter-Harris type IV dicondylar humeral fracture was performed on a 15-week-old pitbull terrier. Interfragmentary compression of the intracondylar component of the fracture was achieved with a transilial rod and locking nuts (Trans-ilial Rod; IMEX Veterinary, Inc.). The transilial rod was articulated with a modified type I external fixator which functioned as adjunctive stabilisation for the supracondylar component of the fracture. Fracture healing was confirmed radiographically five weeks following surgery. The dog had no appreciable lameness when examined 12 months after fracture repair. PMID:17725586

  9. Neodymium laser with negative feedback: Suppression of self-mode-locking, control of mode-locking regime

    NASA Astrophysics Data System (ADS)

    Kozlova, M. V.; Smirnov, A. M.; Al-Khuzheyri, R. M.; Mantsevich, V. N.; Dneprovskii, V. S.

    2015-08-01

    A simple way of suppression of self-mode-locking in a nanosecond Q-switched Nd3+:YAlO3 laser by placing an element introducing a negative feedback into the laser cavity, which consists of a plate of singlecrystal GaAs exhibiting two-photon absorption (complete suppression) or a cell containing colloidal solution of CdSe/ZnS quantum dots (partial suppression), is implemented. Placing the element introducing the negative feedback into the cavity of a pulsed picosecond mode-locked Nd3+:Y3Al5O12 laser allowed an increase in the number of pulses in the pulse train and a change in the energy distribution between the pulses. Specificities of laser oscillation regimes in the presence of a nonlinear absorbing element in the cavity were analyzed by numerically solving the set of balance equations describing the population inversion density and the photon flux density in the cavity.

  10. COMPLEMENT FIXATION IN DISEASED TISSUES

    PubMed Central

    Burkholder, Peter M.

    1961-01-01

    An immunohistologic complement fixation test has been used in an effort to detect immune complexes in sections of kidney from rats injected with rabbit anti-rat kidney serum and in sections of biopsied kidneys from four humans with membranous glomerulonephritis. Sections of the rat and human kidneys were treated with fluorescein-conjugated anti-rabbit globulin or antihuman globulin respectively. Adjacent sections in each case were incubated first with fresh guinea pig serum and then in a second step were treated with fluorescein-conjugated antibodies against fixed guinea pig complement to detect sites of fixation of the complement. It was demonstrated that the sites of rabbit globulin in glomerular capillary walls of the rat kidneys and the sites of localized human globulin in thickened glomerular capillary walls and swollen glomerular endothelial cells of the human kidneys were the same sites in which guinea pig complement was fixed in vitro. It was concluded from these studies that rabbit nephrotoxic antibodies localize in rat glomeruli in complement-fixing antigen-antibody complexes. Furthermore, it was concluded that the deposits of human globulin in the glomeruli of the human kidneys behaved like antibody globulin in complement-fixing antigen-antibody complexes. The significance of demonstrating complement-fixing immune complexes in certain diseased tissues is discussed in regard to determination of the causative role of allergic reactions in disease. PMID:19867205

  11. Eighth international congress on nitrogen fixation. Final program

    SciTech Connect

    Not Available

    1990-12-31

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  12. Theoretical analysis of the operating regime of a passively-mode-locked fiber laser through nonlinear polarization rotation

    SciTech Connect

    Komarov, Andrey; Leblond, Herve; Sanchez, Francois

    2005-12-15

    The dynamics of a fiber laser passively mode-locked through nonlinear polarization rotation is theoretically investigated. The model is based on an iterative equation for the nonlinear polarization rotation and the phase plates and on a scalar differential equation for the gain, the Kerr nonlinearity, and the dispersion. It is demonstrated that depending on the orientation of the phase plates, the laser can be continuous, mode-locked, or Q-switched. In the latter case, an additional equation for the gain dynamics must be taken into account. Hysteresis dependence of the operating regime versus the orientation angles of the phase plates is shown. A large bistability domain between the Q-switch and the continuous regimes is demonstrated. This model allows us to obtain the main features observed in passively-mode-locked fiber lasers.

  13. Biomechanics of four techniques for fixation of the four-part humeral head fracture

    PubMed Central

    da Graça, Elpídio; Okubo, Rodrigo; Shimano, Antônio Carlos; Mazzer, Nilton; Barbieri, Cláudio Henrique

    2013-01-01

    OBJECTIVE: To carry out a biomechanical study of four techniques for fixation of four-part humeral head fractures. METHODS: The fracture was reproduced in 40 plastic humeri, divided into groups of ten according to the fixation technique, each one employing different fixation resources, in different configurations. The humeral models were mounted on an aluminum scapula, with leather straps simulating the rotator cuff tendons, and submitted to bending and torsion tests in a universal testing machine, using relative stiffness as an evaluation parameter. Assemblies with intact humeri were analyzed for comparison. RESULTS: The biomechanical behavior of the fixation techniques varied within a wide range, where the assemblies including the DCP plate and the 4.5mm diameter screws were significantly more rigid than the assemblies with the Kirschner wires and the 3.5mm diameter screws. CONCLUSION: The four fixation techniques were able to bear loads compatible with the physiological demand, but those with higher relative stiffness should be preferred for clinical application. Laboratory investigation . PMID:24453641

  14. INVESTIGATION Population Growth Enhances the Mean Fixation

    E-print Network

    Waxman, David

    INVESTIGATION Population Growth Enhances the Mean Fixation Time of Neutral Mutations of population genetics states that a new mutation, at an unlinked neutral locus in a randomly mating diploid population, has a mean time of fixation of 4Ne generations, where Ne is the effective population size

  15. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  16. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  17. Whole Animal Perfusion Fixation for Rodents

    PubMed Central

    Gage, Gregory J.; Kipke, Daryl R.; Shain, William

    2012-01-01

    The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small pieces of tissue, larger specimens like the intact brain pose a problem for immersion fixation because the fixative does not reach all regions of the tissue at the same rate 5,7. Often, changes in response to hypoxia begin before the tissue can be preserved 12. The advantage of directly perfusing fixative through the circulatory system is that the chemical can quickly reach every corner of the organism using the natural vascular network. In order to utilize the circulatory system most effectively, care must be taken to match physiological pressures 3. It is important to note that physiological pressures are dependent on the species used. Techniques for perfusion fixation vary depending on the tissue to be fixed and how the tissue will be processed following fixation. In this video, we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain for immunohistochemistry. The main advantage of this technique (vs. gravity-fed systems) is that the circulatory system is utilized most effectively. PMID:22871843

  18. Biochemical Approaches to Improved Nitrogen Fixation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving symbiotic nitrogen fixation by legumes has emerged again as an important topic on the world scene due to the energy crisis and lack of access to nitrogen fertilizer in developing countries. We have taken a biochemical genomics approach to improving symbiotic nitrogen fixation in legumes. L...

  19. All-Arthroscopic Suprapectoral Long Head of Biceps Tendon Tenodesis With Interference Screw–Like Tendon Fixation After Modified Lasso-Loop Stitch Tendon Securing

    PubMed Central

    Patzer, Thilo; Kircher, Jörn; Krauspe, Ruediger

    2012-01-01

    Arthroscopic suprapectoral techniques for tenodesis of the long head of the biceps tendon (LHB) are appropriate for the treatment of proximal biceps lesions. Several types of techniques and fixation devices have been described and evaluated in biomechanical studies regarding primary stability. In this technical note, we describe an all-arthroscopic suprapectoral technique using the 6.25-mm Bio-SwiveLock device (Arthrex, Naples, FL) for an interference screw–like bony fixation after having armed the tendon with a lasso-loop stitch. Both the interference screw fixation and securing of the lasso-loop tendon have been well described and approved in biomechanical tests concerning the primary stability. One advantage of this technique performed from the glenohumeral space, in addition to the strong and secure fixation with ingrowth of the tendon in a bony canal, is the avoidance of touching the soft tissue above the bicipital groove, which results in a smooth fitting of the tendon into its natural canal and therefore avoids mechanical irritation of the stump at the rotator interval. In conclusion, the all-arthroscopic suprapectoral LHB tenodesis performed from the glenohumeral space with the modified lasso-loop stitch for securing of the tendon and the 6.25-mm Bio-SwiveLock suture anchor for interference screw–like bony tendon fixation is an appropriate technique for the treatment of LHB-associated lesions. PMID:23766976

  20. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Prosthetic Devices § 888.3050 Spinal interlaminal fixation orthosis. (a) Identification. A spinal interlaminal fixation orthosis...spondylolisthesis (a dislocation of the spinal column), and lower back syndrome....

  1. 21 CFR 888.3050 - Spinal interlaminal fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Prosthetic Devices § 888.3050 Spinal interlaminal fixation orthosis. (a) Identification. A spinal interlaminal fixation orthosis...spondylolisthesis (a dislocation of the spinal column), and lower back syndrome....

  2. Obituary: Martha Locke Hazen, 1931-2006

    NASA Astrophysics Data System (ADS)

    Williams, Thomas R.; Willson, Lee Anne

    2007-12-01

    Longtime Harvard Curator of Astronomical Photographs and AAVSO officer Martha Hazen passed away on 23 December 2006 at Hingham, Massachusetts, after a short illness due to acute myelogenous leukemia. One of four children of Harold Locke and Katherine (neé Salisbury) Hazen, Martha was born in Cambridge, Massachusetts, on 15 July 1931, and raised in the Town of Belmont, near Cambridge, where she lived for most of her life. Her father coined the term "servo-mechanism" while serving as an engineering professor and dean for graduate students at the Massachusetts Institute of Technology. Her mother majored in chemistry at Mount Holyoke College. After receiving an A.B. in astronomy from Mount Holyoke College in 1953, Martha earned a Ph.D. in astronomy in 1958 from the University of Michigan, defending a dissertation on the distribution of intensity in elliptical galaxies in the Virgo cluster. Martha's marriage to William Liller in 1959, and the births of two children, inevitably slowed down her progress in observational astronomy. As a research fellow of the Harvard College Observatory, Martha continued to observe two to three weeks a year in Chile, and to reduce those observations and publish the results for sixteen years. Martha's first publication, at least as far as Astrophysics Data System includes the literature, was with Alice Farnsworth on the 1952 occultations of stars by the Moon, published in the Astronomical Journal (1953). In 1958 she joined L. R. Doherty and D. H. Menzel on a short note about the calculation of line profiles in a stratified atmosphere, her only theory paper. Martha's most cited paper is "The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster," (ApJ, 132, p.306, 1960). There she acknowledges Allan Sandage for suggesting the problem and providing some of the data. Her second most cited paper is "Photometric histories of QSOs - Two QSOs with large light amplitude," (Liller, M. H. & Liller, W., ApJ (Letters), 199, p. L133-L135, 1975). Progressing to smaller objects, other frequently cited papers are on eta Carinae and spectroscopic binaries in the globular cluster M3. All of these, and most of her other papers, involve photographic photometry, mostly using archival data. In 1969, Harvard appointed Martha Curator of Astronomical Photographs, placing her in responsible charge of the world renowned Harvard Plate Archives. Under attack during the mid-1950s because it occupied too much physical space, the collection had been neglected for over a decade when Martha assumed this additional responsibility. Though she continued to observe for a few years thereafter, her stewardship of the invaluable plate archives gradually demanded her full attention, which it held until her retirement in 2002. In her thirty-three years as curator of the plate stacks, as the archive is popularly known, Martha made numerous friends in both the professional and amateur communities. Astronomical researchers on a wide variety of topics relied on her detailed knowledge of the collection to guide them to important discoveries or discovery confirmations on the old plates, and to historical understanding of results in which some detail of origin needed clarification. Martha researched and documented the characteristics of nearly a hundred separate telescopic cameras used to take the plates archived in the collection. Much of this information was ephemeral, having been passed orally from observer to observer and was in danger of passing from human memory. This was, in itself, an enormous and valuable undertaking as it ensures the utility of the plates for future research. More importantly, Martha conserved and catalogued the all important logbooks that record the date, time, and other exposure circumstances for each of the plates in the collection. The full measure of Martha's long-term contribution in this regard undoubtedly will be realized as the digitization of the entire collection of plates is completed. The Digital Access to a Sky Century from Harvard (DASCH) project will ow

  3. Coupled optical resonance laser locking.

    PubMed

    Burd, S C; du Toit, P J W; Uys, H

    2014-10-20

    We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to coupled transitions of ions in the same spectroscopic sample, by detecting only the absorption of the UV laser. Separate signals for locking the different lasers are obtained by modulating each laser at a different frequency and using lock-in detection of a single photodiode signal. Experimentally, we simultaneously lock a 369 nm and a 935 nm laser to the (2)S(1/2) ? (2)(P(1/2) and (2)D(3/2) ? (3)D([3/2]1/2) transitions, respectively, of Yb(+) ions generated in a hollow cathode discharge lamp. Stabilized lasers at these frequencies are required for cooling and trapping Yb(+) ions, used in quantum information and in high precision metrology experiments. This technique should be readily applicable to other ion and neutral atom systems requiring multiple stabilized lasers. PMID:25401537

  4. Changes in the computed tomography (pixel) value of mandibular ramus bone and fixation screws after sagittal split ramus osteotomy.

    PubMed

    Ueki, K; Moroi, A; Iguchi, R; Kosaka, A; Ikawa, H; Yoshizawa, K

    2015-11-01

    The purpose of this retrospective study was to evaluate the changes in computed tomography (CT) values of ramus bone and screws after sagittal split ramus osteotomy (SSRO) setback surgery. The subjects were 64 patients (128 sides) who underwent bilateral SSRO setback surgery. They were divided into six groups according to the fixation plate type used and the use or not of self-setting ?-tricalcium phosphate (Biopex): group 1: titanium plate and screws; group 2: titanium plate and screws with Biopex; group 3: poly-l-lactic acid (PLLA) plate and screws; group 4: PLLA plate and screws with Biopex; group 5: uncalcined and unsintered hydroxyapatite particles and poly-l-lactic acid (uHA/PLLA) plate and screws; group 6: PLLA/uHA plate and screws with Biopex. CT values (pixel values) of the lateral cortex, medial cortex, osteotomy site, and screws were measured preoperatively, immediately after surgery, and 1 year postoperatively using horizontal CT images at the mandibular foramen taken parallel to the Frankfort horizontal plane. There were significant differences in the time-course change of pixel values for the lateral cortex (P<0.0001) and the osteotomy site (P<0.0001) among the six groups. This study suggests that the fixation plate type and use of bone alternative material may affect bone quality during the process of bone healing after SSRO. PMID:26139563

  5. Zero-Lock Laser Gyro

    NASA Astrophysics Data System (ADS)

    Fernandez, Manny; Ebner, Bob; Dahlen, Neal

    Advantages of Litton's Zero-Lock Laser Gyro (ZLG) over the conventional ring laser gyro (RLG) are discussed. While conventional RLGs use mechanical dithering or rate biasing for circumvention, ZLGs are multioscillator type RLGs that effectively circumvent the frequency-locking phenomenon by removing it from the gyro's angular-rate input operation-region. Low noise, high bandwidth, low quantization, and immunity to transients under high dynamic environments are features of the ZLG that make it applicable to space satellite attitude control system and pointing and tracking applications. Test data demonstrate the superior performance of ZLGs for these applications.

  6. Locking mechanism for orthopedic braces

    NASA Technical Reports Server (NTRS)

    Chao, J. I.; Epps, C. H., Jr.

    1981-01-01

    An orthopedic brace locking mechanism is described which under standing or walking conditions cannot be unlocked, however under sitting conditions the mechanism can be simply unlocked so as to permit bending of the patient's knee. Other features of the device include: (1) the mechanism is rendered operable, and inoperable, dependent upon the relative inclination of the brace with respect to the ground; (2) the mechanism is automatically locked under standing or walking conditions and is manually unlocked under sitting conditions; and (3) the mechanism is light in weight and is relatively small in size.

  7. Line locking and SS 433

    NASA Technical Reports Server (NTRS)

    Pekarevich, M.; Piran, T.; Shaham, J.

    1984-01-01

    The general problem of acceleration by line locking in an optically thin medium is considered. Analytic solutions to the coupled equations of radiation transfer and matter motion are presented. Using these solutions, restrictions on the physical conditions of the accelerated matter are derived. By applying these conditions to SS 433, it is found that if the absorbing ion is light (hydrogen or helium), the matter must be highly clumped, and the acceleration has to begin at approximately 10 to the 12th cm. Line-locking acceleration with a hydrogen-like heavy ion such as iron demands higher than solar ion abundance.

  8. Automatic locking knee brace joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce (inventor)

    1995-01-01

    This invention is an apparatus for controlling the pivotal movement of a knee brace comprising a tang-and-clevis joint that has been uniquely modified. Both the tang and the clevis have a set of teeth that, when engaged, can lock the tang and the clevis together. In addition, the tang is biased away from the clevis. Consequently, when there is no axial force (i.e., body weight) on the tang, the tang is free to pivot within the clevis. However, when an axial force is exerted on the tang, the tang is pushed into the clevis, both sets of teeth engage, and the tang and the clevis lock together.

  9. Circuit breaker lock out assembly

    DOEpatents

    Gordy, Wade T. (Jackson, SC)

    1984-01-01

    A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly "S" shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

  10. Robust quantum data locking from phase modulation

    E-print Network

    Lupo, Cosmo

    Quantum data locking is a uniquely quantum phenomenon that allows a relatively short key of constant size to (un)lock an arbitrarily long message encoded in a quantum state, in such a way that an eavesdropper who measures ...

  11. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  12. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  13. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  14. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  15. 49 CFR 236.762 - Locking, indication.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Locking, indication. Electric locking which prevents manipulation of levers that would result in an unsafe... corresponding to that of its controlling lever, or which directly prevents the operation of a signal, switch,...

  16. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Air locks. 154.345 Section 154.345 Shipping COAST GUARD....345 Air locks. (a) An air lock may be used for access from a gas-dangerous zone on the weather deck to a gas-safe space. (b) Each air lock must: (1) Consist of two steel doors, at least 1.5 m (4.9...

  17. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Air locks. 154.345 Section 154.345 Shipping COAST GUARD....345 Air locks. (a) An air lock may be used for access from a gas-dangerous zone on the weather deck to a gas-safe space. (b) Each air lock must: (1) Consist of two steel doors, at least 1.5 m (4.9...

  18. 46 CFR 154.345 - Air locks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Air locks. 154.345 Section 154.345 Shipping COAST GUARD....345 Air locks. (a) An air lock may be used for access from a gas-dangerous zone on the weather deck to a gas-safe space. (b) Each air lock must: (1) Consist of two steel doors, at least 1.5 m (4.9...

  19. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  20. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  1. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  2. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  3. 49 CFR 236.766 - Locking, movable bridge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge....

  4. 49 CFR 236.378 - Time locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Time locking. 236.378 Section 236.378 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.378 Time locking. Time locking shall be tested when placed in service and...

  5. 49 CFR 236.768 - Locking, time.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined...

  6. 75 FR 2129 - Lock+TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... Energy Regulatory Commission Lock+ TM Hydro Friends Fund XXX, LLC; Notice of Preliminary Permit... January 6, 2010. On November 13, 2009, Lock+ TM Hydro Friends Fund XXX, LLC filed an application, pursuant...,018 megawatt-hours. Applicant Contact: Wayne F. Krouse, Lock+ TM Hydro Friends Fund XXX, LLC,...

  7. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  8. 49 CFR 236.376 - Mechanical locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical locking. 236.376 Section 236.376 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.376 Mechanical locking. Mechanical locking in interlocking machine shall be...

  9. 46 CFR 108.157 - Locked doors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Locked doors. 108.157 Section 108.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.157 Locked doors. No door to the required means of escape may be designed to lock except— (a)...

  10. 49 CFR 236.768 - Locking, time.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined...

  11. 49 CFR 236.378 - Time locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Time locking. 236.378 Section 236.378 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.378 Time locking. Time locking shall be tested when placed in service and...

  12. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  13. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  14. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  15. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  16. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  17. 49 CFR 236.742 - Dog, locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Dog, locking. 236.742 Section 236.742 Transportation...SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog, locking. A steel block attached to a locking bar or...

  18. 49 CFR 236.378 - Time locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Time locking. 236.378 Section 236.378 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.378 Time locking. Time locking shall be tested when placed in service and...

  19. 49 CFR 236.768 - Locking, time.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined...

  20. Distal Humerus Fractures: Open Reduction Internal Fixation.

    PubMed

    Mighell, Mark A; Stephens, Brent; Stone, Geoffrey P; Cottrell, Benjamin J

    2015-11-01

    Distal humerus fractures are challenging injuries for the upper extremity surgeon. However, recent techniques in open reduction internal fixation have been powerful tools in getting positive outcomes. To get such results, the surgeon must be aware of how to properly use these techniques in their respective practices. The method of fixation depends on the fracture, taking the degree of comminution and the restoration of the columns and articular surface into account. This article helps surgeons understand the concepts behind open reduction internal fixation of the distal humerus and makes them aware of pitfalls that may lead to negative results. PMID:26498548

  1. Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI.

    PubMed

    Henderson, John M; Choi, Wonil; Luke, Steven G; Desai, Rutvik H

    2015-10-01

    A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading. PMID:26151101

  2. Mechanistic models of oceanic nitrogen fixation

    E-print Network

    Monteiro, Fanny

    2009-01-01

    Oceanic nitrogen fixation and biogeochemical interactions between the nitrogen, phosphorus and iron cycles have important implications for the control of primary production and carbon storage in the ocean. The biological ...

  3. ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation

    E-print Network

    Hansell, Dennis

    ORIGINAL ARTICLE Sulfur oxidizers dominate carbon fixation at a biogeochemical hot spot in the dark clade of marine gamma-proteobacterial sulfur oxidizers (GSOs) are distributed throughout proteins for sulfur oxidation (adenosine phosphosulfate reductase, sox (sulfur oxidizing system

  4. A simple and inexpensive external fixator.

    PubMed

    Noor, M A

    1988-11-01

    A simple and inexpensive external fixator has been designed. It is constructed of galvanized iron pipe and mild steel bolts and nuts. It can easily be manufactured in a hospital workshop with a minimum of tools. PMID:3267638

  5. An examination of fixation in brainstorming 

    E-print Network

    Kohn, Nicholas William

    2009-05-15

    Shortcomings....................................................... 5 ttempts to Eliminate Brainstorming Deficits...............................16 Use of Stimuli and Analogies When Problem Solving.................. 21 Fixation in Individual Problem Solving... in Brainstorming.......................................... Productivity Deficit........................................109 Temporal Findings......................................... 110 Incubation Effects..........................................111...

  6. Methanotrophy Induces Nitrogen Fixation in Boreal Mosses

    NASA Astrophysics Data System (ADS)

    Tiirola, M. A.

    2014-12-01

    Many methanotrophic bacterial groups fix nitrogen in laboratory conditions. Furthermore, nitrogen (N) is a limiting nutrient in many environments where methane concentrations are highest. Despite these facts, methane-induced N fixation has previously been overlooked, possibly due to methodological problems. To study the possible link between methanotrophy and diazotrophy in terrestrial and aquatic habitats, we measured the co-occurrence of these two processes in boreal forest, peatland and stream mosses using a stable isotope labeling approach (15 N2 and 13 CH4 double labeling) and sequencing of the nifH gene marker. N fixation associated with forest mosses was dependent on the annual N deposition, whereas methane stimulate N fixation neither in high (>3 kg N ha -1 yr -1) nor low deposition areas, which was in accordance with the nifH gene sequencing showing that forest mosses (Pleurozium schreberi and Hylocomium splendens ) carried mainly cyanobacterial N fixers. On the other extreme, in stream mosses (Fontinalis sp.) methane was actively oxidized throughout the year, whereas N fixation showed seasonal fluctuation. The co-occurrence of the two processes in single cell level was proven by co-localizing both N and methane-carbon fixation with the secondary ion mass spectrometry (SIMS) approach. Methanotrophy and diazotrophy was also studied in peatlands of different primary successional stages in the land-uplift coast of Bothnian Bay, in the Siikajoki chronosequence, where N accumulation rates in peat profiles indicate significant N fixation. Based on experimental evidence it was counted that methane-induced N fixation explained over one-third of the new N input in the younger peatland successional stages, where the highest N fixation rates and highest methane oxidation activities co-occurred in the water-submerged Sphagnum moss vegetation. The linkage between methanotrophic carbon cycling and N fixation may therefore constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. It is still an open issue whether methanotrophy induces N fixation directly or by enhancing phototrophic or heterotrophic N fixation.

  7. Performance of arm locking in LISA

    SciTech Connect

    McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

    2009-11-15

    For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time-delay error of 3 ns (equivalent of 1 m interspacecraft ranging error), time-delay interferometry (TDI) is capable of suppressing 300 Hz/{radical}(Hz) of laser frequency noise to the required level. We show that if no interspacecraft laser links fail, arm locking alone surpasses this noise performance for the entire mission. If one interspacecraft laser link fails, arm locking alone will achieve this performance for all but approximately 1 h per year, when the arm length mismatch of the two remaining arms passes through zero. Therefore, the LISA sensitivity can be realized with arm locking and time-delay interferometry only, without any form of prestabilization.

  8. 2010 Maule earthquake slip correlates with pre-seismic locking of Andean subduction zone.

    PubMed

    Moreno, Marcos; Rosenau, Matthias; Oncken, Onno

    2010-09-01

    The magnitude-8.8 Maule (Chile) earthquake of 27 February 2010 ruptured a segment of the Andean subduction zone megathrust that has been suspected to be of high seismic potential. It is the largest earthquake to rupture a mature seismic gap in a subduction zone that has been monitored with a dense space-geodetic network before the event. This provides an image of the pre-seismically locked state of the plate interface of unprecedentedly high resolution, allowing for an assessment of the spatial correlation of interseismic locking with coseismic slip. Pre-seismic locking might be used to anticipate future ruptures in many seismic gaps, given the fundamental assumption that locking and slip are similar. This hypothesis, however, could not be tested without the occurrence of the first gap-filling earthquake. Here we show evidence that the 2010 Maule earthquake slip distribution correlates closely with the patchwork of interseismic locking distribution as derived by inversion of global positioning system (GPS) observations during the previous decade. The earthquake nucleated in a region of high locking gradient and released most of the stresses accumulated in the area since the last major event in 1835. Two regions of high seismic slip (asperities) appeared to be nearly fully locked before the earthquake. Between these asperities, the rupture bridged a zone that was creeping interseismically with consistently low coseismic slip. The rupture stopped in areas that were highly locked before the earthquake but where pre-stress had been significantly reduced by overlapping twentieth-century earthquakes. Our work suggests that coseismic slip heterogeneity at the scale of single asperities should indicate the seismic potential of future great earthquakes, which thus might be anticipated by geodetic observations. PMID:20829792

  9. Growth Plate Fractures

    MedlinePLUS

    .org Growth Plate Fractures Page ( 1 ) The bones of children and adults share many of the same risks for injury. But because they ... to a unique injury called a growth plate fracture. Growth plates are areas of cartilage located near ...

  10. Fixational eye movements predict visual sensitivity.

    PubMed

    Scholes, Chris; McGraw, Paul V; Nyström, Marcus; Roach, Neil W

    2015-10-22

    During steady fixation, observers make small fixational saccades at a rate of around 1-2 per second. Presentation of a visual stimulus triggers a biphasic modulation in fixational saccade rate-an initial inhibition followed by a period of elevated rate and a subsequent return to baseline. Here we show that, during passive viewing, this rate signature is highly sensitive to small changes in stimulus contrast. By training a linear support vector machine to classify trials in which a stimulus is either present or absent, we directly compared the contrast sensitivity of fixational eye movements with individuals' psychophysical judgements. Classification accuracy closely matched psychophysical performance, and predicted individuals' threshold estimates with less bias and overall error than those obtained using specific features of the signature. Performance of the classifier was robust to changes in the training set (novel subjects and/or contrasts) and good prediction accuracy was obtained with a practicable number of trials. Our results indicate a tight coupling between the sensitivity of visual perceptual judgements and fixational eye control mechanisms. This raises the possibility that fixational saccades could provide a novel and objective means of estimating visual contrast sensitivity without the need for observers to make any explicit judgement. PMID:26468244

  11. Cost of external fixation vs external fixation then nailing in bone infection

    PubMed Central

    Emara, Khaled Mohamed; Diab, Ramy Ahmed; Ghafar, Khaled Abd EL

    2015-01-01

    AIM: To study the cost benefit of external fixation vs external fixation then nailing in treatment of bone infection by segment transfer. METHODS: Out of 71 patients with infected nonunion tibia treated between 2003 and 2006, 50 patients fitted the inclusion criteria (26 patients were treated by external fixation only, and 24 patients were treated by external fixation early removal after segment transfer and replacement by internal fixation). Cost of inpatient treatment, total cost of inpatient and outpatient treatment till full healing, and the weeks of absence from school or work were calculated and compared between both groups. RESULTS: The cost of hospital stay and surgery in the group of external fixation only was 22.6 ± 3.3 while the cost of hospital stay and surgery in the group of early external fixation removal and replacement by intramedullary nail was 26.0 ± 3.2. The difference was statistically significant regarding the cost of hospital stay and surgery in favor of the group of external fixation only. The total cost of medical care (surgery, hospital stay, treatment outside the hospital including medications, dressing, physical therapy, outpatient laboratory work, etc.) in group of external fixation only was 63.3 ± 15.1, and total absence from work was 38.6 ± 6.6 wk. While the group of early removal of external fixation and replacement by IM nail, total cost of medical care was 38.3 ± 6.4 and total absence from work or school was 22.7 ± 4.1. The difference was statistically significant regarding the total cost and absence from work in favor of the group of early removal and replacement by IM nail. CONCLUSION: Early removal of external fixation and replacement by intramedullary nail in treatment of infected nonunion showed more cost effectiveness. Orthopaedic society needs to show the cost effectiveness of different procedures to the community, insurance, and health authorities. PMID:25621219

  12. Digital phase-lock loop

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess B. (Inventor)

    1991-01-01

    An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

  13. Locking mechanism for indexing device

    DOEpatents

    Lindemeyer, Carl W. (Aurora, IL)

    1984-01-01

    Disclosed is a locking mechanism for an indexing spindle. A conventional r gear having outwardly extending teeth is affixed to the spindle. Also included is a rotatably mounted camshaft whose axis is arranged in skewed relationship with the axis of the spindle. A disk-like wedge having opposing camming surfaces is eccentrically mounted on the camshaft. As the camshaft is rotated, the camming surfaces of the disc-like member are interposed between adjacent gear teeth with a wiping action that wedges the disc-like member between the gear teeth. A zero backlash engagement between disc-like member and gear results, with the engagement having a high mechanical advantage so as to effectively lock the spindle against bidirectional rotation.

  14. Self-locking threaded fasteners

    DOEpatents

    Glovan, Ronald J. (Butte, MT); Tierney, John C. (Butte, MT); McLean, Leroy L. (Butte, MT); Johnson, Lawrence L. (Butte, MT)

    1996-01-01

    A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy.

  15. Self-locking threaded fasteners

    DOEpatents

    Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.

    1996-01-16

    A threaded fastener with a shape memory alloy (SMA) coatings on its threads is disclosed. The fastener has special usefulness in high temperature applications where high reliability is important. The SMA coated fastener is threaded into or onto a mating threaded part at room temperature to produce a fastened object. The SMA coating is distorted during the assembly. At elevated temperatures the coating tries to recover its original shape and thereby exerts locking forces on the threads. When the fastened object is returned to room temperature the locking forces dissipate. Consequently the threaded fasteners can be readily disassembled at room temperature but remains securely fastened at high temperatures. A spray technique is disclosed as a particularly useful method of coating of threads of a fastener with a shape memory alloy. 13 figs.

  16. Phase-locked laser array

    NASA Technical Reports Server (NTRS)

    Botez, Dan (Inventor); Ackley, Donald E. (Inventor)

    1988-01-01

    A phase-locked laser array comprises a substrate with two spaced-apart pluralities of channels extending towards different reflecting surfaces of the array. The axes of symmetry of the channels of one plurality are offset from the axes of symmetry of the channels of the second plurality. Coupling of light propagating in the optical waveguides over one plurality of channels into the waveguides over the second plurality of channels induces a zero phase difference between the laser oscillations of adjacent channels.

  17. Korean Type Distal Radius Anatomical Volar Plate System: A Preliminary Report

    PubMed Central

    Kim, Jeong Hwan; Kim, Jihyeung; Kim, Min Bom; Rhee, Seung Hwan; Gong, Hyun Sik; Lee, Young Ho

    2014-01-01

    Background Distal radius fracture is the most common fracture of the upper extremity, and approximately 60,000 distal radius fractures occur annually in Korea. Internal fixation with an anatomical volar locking plate is widely used in the treatment of unstable distal radius fractures. However, most of the currently used distal radius anatomical plate systems were designed based on the anatomical characteristics of Western populations. Recently, the Korean-type distal radius anatomical volar plate (K-DRAVP) system was designed and developed based on the anatomical characteristics of the distal radius of Koreans. The purpose of this study was to evaluate the preliminary results of the new K-DRAVP system, and to compare its radiologic and functional results with those of the other systems. Methods From March 2012 to October 2012, 46 patients with acute distal radius fractures who were treated with the K-DRAVP system at three hospitals were enrolled in this study. Standard posteroanterior and lateral radiographs were obtained to assess fracture healing, and three radiographic parameters (volar tilt, radial inclination, and radial length) were assessed to evaluate radiographic outcomes. The range of motion and grip strength, the Gartland and Werley scoring system, and the disabilities of the arm, shoulder and hand (DASH) questionnaire were used to assess clinical and functional outcomes. Results All radiologic parameters were restored to normal values, and maintained without any loosening or collapse until the time of final follow-up. Grip strength was restored to 84% of the value for the unaffected side. The mean range of motion of the wrist at final follow-up was restored to 77%-95% of the value for the unaffected side. According to the Gartland and Werley scoring system, there were 16 excellent, 26 good, and 4 fair results. The mean DASH score was 8.4 points. There were no complications after surgery. Conclusions The newly developed K-DRAVP system could be used to restore and maintain good anatomical parameters, and provide good clinical outcomes with low complication rates. This system is a promising surgical option for the treatment of distal radius fractures in the Korean population. PMID:25177449

  18. [Visual fixation features after treatment of exudative age macular degeneration].

    PubMed

    Surguch, V K; Surnina, Z V; Sizova, M V

    2011-01-01

    Changes of visual fixation in patients with choroidal neovascularitation (CNV) associated with age macular degeneration (AMD) after bevacizumab are studied. 45 patients (45 eyes) with active CNV treated with intravitreal bevacizumab were enrolled into the study. Visual fixation was studied before and 3-6 months after treatment using original method that included fundus foto and fluorescein angiography. Fixation relative to fovea and lesion was evaluated. Foveal fixation beyond lesion was found in 9%, foveal fixation within lesion--in 47%, extrafoveal fixation beyond lesion--in 18%, extrafoveal fixation within lesion--in 26% of patients. Changes of fixation localization after treatment was found in 24% patients. Examination of visual fixation may be useful for prognosis of anti-VEGF treatment efficacy in patients with CNV. PMID:21721271

  19. Indications and limitations of the fixator TGF "Gex-Fix" in proximal end humeral fractures.

    PubMed

    Parlato, A; D'Arienzo, A; Ferruzza, M; Galvano, N; D'Arienzo, M

    2014-12-01

    The incidence of fractures of the humerus has increased exponentially in recent years. The most used classifications for humerus fracture are morphological (Neer), biological (AO/ASIF) and descriptive (Hertel). The types of surgical treatment for humerus fracture include prosthetic replacement and synthesis using different devices, including the Tension Guide Fixator (TGF), Gex-Fix. External fixation for displaced proximal humeral fractures avoids dissection and soft tissue stripping and has been reported by some authors to be associated with higher union rates, a lower incidence of avascular necrosis, less scarring of the scapulohumeral interface, and faster rehabilitation compared with open reduction and internal fixation. Other authors have reported that external fixation does not ensure acceptable reduction and fracture stability, particularly in patients with osteoporosis. The external fixation technique involves the introduction of Steinmann's pin to keep manual reduction, the introduction of two K-wires in the humeral head, the removal of the Steinmann's pin, and the introduction of two fiches on the humeral shaft. Hub connectors are mounted on the wires and on the chips to connect the outer bar and tensioning system. A total of 84 patients aged 42-84 years with proximal end humeral fractures (66% had two-part fractures) were treated with Fixator TGF in this study from December 2007 to June 2012. The postoperative recovery was earlier and the active-assisted motion was less painful than has been reported with other surgical techniques. The TGF was removed without anaesthesia at the outpatient clinic at a mean of 7 weeks (range 5-8 weeks) after surgery, and there was no loss of reduction or secondary displacement after removal. These results, after five years of experience, confirm that the best indication for this fixator is two- or three-part fractures because the device enables early active mobilisation. The limitations of this fixator are evident in fractures in which closed reduction is not possible and in three-part fractures with varus displacement because the TGF has less stability than other systems, such as the plate or cage. The short learning curve, reduced surgical time and risk, and low cost encourage the use of this technique. PMID:25457319

  20. Phase-lock loop frequency control and the dropout problem

    NASA Technical Reports Server (NTRS)

    Attwood, S.; Kline, A. J.

    1968-01-01

    Technique automatically sets the frequency of narrow band phase-lock loops within automatic lock-in-range. It presets a phase-lock loop to a desired center frequency with a closed loop electronic frequency discriminator and holds the phase-lock loop to that center frequency until lock is achieved.

  1. Copyright, Dennis Fischette, Practical Phase-Locked LoopPractical Phase-Locked Loop

    E-print Network

    McNeill, John A.

    Copyright, Dennis Fischette, 2004 1 Practical Phase-Locked LoopPractical Phase-Locked Loop Design... · Are a novice PLL designer · Specify PLL requirements · Integrate PLL's on-chip · Test/debug PLL's · Review PLL

  2. Copper Map Plate Detail

    USGS Multimedia Gallery

    A portion of the engraving on the plate used to print points, lines, and text in black ink. Engravings on the plate are left-to-right reversed. This plate was cleaned and treated to improve the visibility of the engraving. The plate was used to print the Washington [D.C.] and vicinity, 1:31,680-sca...

  3. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  4. Microcontroller-based locking in optics experiments

    SciTech Connect

    Huang, K.; Le Jeannic, H.; Ruaudel, J.; Morin, O.; Laurat, J.

    2014-12-15

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

  5. Robust quantum data locking from phase modulation

    NASA Astrophysics Data System (ADS)

    Lupo, Cosmo; Wilde, Mark M.; Lloyd, Seth

    2014-08-01

    Quantum data locking is a uniquely quantum phenomenon that allows a relatively short key of constant size to (un)lock an arbitrarily long message encoded in a quantum state, in such a way that an eavesdropper who measures the state but does not know the key has essentially no information about the message. The application of quantum data locking in cryptography would allow one to overcome the limitations of the one-time pad encryption, which requires the key to have the same length as the message. However, it is known that the strength of quantum data locking is also its Achilles heel, as the leakage of a few bits of the key or the message may in principle allow the eavesdropper to unlock a disproportionate amount of information. In this paper we show that there exist quantum data locking schemes that can be made robust against information leakage by increasing the length of the key by a proportionate amount. This implies that a constant size key can still lock an arbitrarily long message as long as a fraction of it remains secret to the eavesdropper. Moreover, we greatly simplify the structure of the protocol by proving that phase modulation suffices to generate strong locking schemes, paving the way to optical experimental realizations. Also, we show that successful data locking protocols can be constructed using random code words, which very well could be helpful in discovering random codes for data locking over noisy quantum channels.

  6. Interchangeable breech lock for glove boxes

    SciTech Connect

    Lemonds, David Preston

    2015-11-24

    A breech lock for a glove box is provided that may be used to transfer one or more items into the glove box. The breech lock can be interchangeably installed in place of a plug, glove, or other device in a port or opening of a glove box. Features are provided to aid the removal of items from the breech lock by a gloved operator. The breech lock can be reused or, if needed, can be replaced with a plug, glove, or other device at the port or opening of the glove box.

  7. Green River Locks and Dams 3, 4, 5, 6 and Barren River Lock and Dam 1 Disposition, Kentucky

    E-print Network

    US Army Corps of Engineers

    Green River Locks and Dams 3, 4, 5, 6 and Barren River Lock and Dam 1 Disposition, Kentucky 16 September 2014 ABSTRACT: Green River Locks and Dams 3 through 6 and Barren River Lock and Dam 1 were. The Green River Locks and Dams 5 and 6 ceased operations in 1951 due to a marked decline in navigation

  8. Border locking and the Caf Wall illusion 1 Border locking and

    E-print Network

    Feeny, Brian

    Border locking and the Café Wall illusion 1 Border locking and the Café Wall illusion Richard L Abstract The Cafe Wall illusion (seen on the tiles of a local café) is a Münsterberg chequerboard figure register by locking from common luminance boundaries. The Café Wall illusion is attributed to this border

  9. Double lock joint for attaching top nozzle to guide thimbles of nuclear fuel assembly

    SciTech Connect

    Feild, A.L. Jr.

    1987-10-13

    In a reconstitutable fuel assembly including at least one guide thimble with an upper end portion having a central axis and a top nozzle with an adapter plate having top and bottom spaced apart surfaces and at least one passageway extending between the surfaces, a double lock joint structure is described for attaching the top nozzle adapter plate in releasable locking engagement upon the guide thimble upper end portion, comprising: (a) means defined in the upper end portion of the guide thimble to permit inward elastic collapse; (b) upper means formed in the upper end portion of the guide thimble so as to provide the upper end portion at the location of the upper means with a diametric size greater than that of the adapter plate passageway; (c) lower means formed in the upper end portion of the guide thimble so as to provide the upper end portion at the location of the lower means with a diametric size greater than that of the adapter plate passageway when the guide thimble upper end portion is at either one of its expanded and collapsed positions; (d) the upper means being axially displaced from the lower means through a distance approximately equal to that between the top and bottom surfaces of the adapter plate.

  10. Wire-free fixation of jaw fractures.

    PubMed

    Cousin, G C S

    2009-10-01

    Stainless steel wire is often used in the management of jaw fractures to provide intraoperative or postoperative intermaxillary fixation (IMF). Wiring of the jaws is time-consuming, a second procedure is needed to remove it, and needlestick injuries occur during placement. We report on 151 consecutive patients who had wire-free fixation of jaw fractures, and outline the value of a system of plastic anchorage points applied to individual teeth in both jaws that allows for wire-free IMF when they are linked by elastics (Rapid IMF, Synthes, PA, USA). A total of 150 successive patients had wire-free fixation of 146 mandibular and 5 maxillary fractures. Ninety-eight were hand-held in occlusion, and 52 were treated using Rapid IMF. There were few complications. PMID:19608310

  11. Locking mechanism for orthopedic braces

    NASA Technical Reports Server (NTRS)

    I-Lechao, J.; Epps, C. H., Jr. (inventors)

    1976-01-01

    A locking mechanism for orthopedic braces is described which automatically prevents or permits the relative pivotable movement between a lower brace member and an upper brace member. The upper and lower brace members are provided with drilled bores within which a slidable pin is disposed, and depending upon the inclination of the brace members with respect to a vertical plane, the slidable pin will be interposed between both brace members. The secondary or auxiliary latching device includes a spring biased, manually operable lever bar arrangement which is manually unlatched and automatically latched under the influence of the spring.

  12. UPSTREAM LOCK GATE DETAIL AND DOG HOUSE. NOTE ARM AND ...

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

    UPSTREAM LOCK GATE DETAIL AND DOG HOUSE. NOTE ARM AND GEARING FOR CONTROLLING LOCK GATE. LOOKING WEST SOUTHWEST. - Illinois Waterway, Brandon Road Lock and Dam , 1100 Brandon Road, Joliet, Will County, IL

  13. DOWNSTREAM LOCK GATE DETAIL VIEW WITH DOG HOUSE. NOTE CONTROL ...

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

    DOWNSTREAM LOCK GATE DETAIL VIEW WITH DOG HOUSE. NOTE CONTROL ARM AND GEAR FOR GATE. LOOKING NORTHWEST. - Illinois Waterway, Dresden Island Lock and Dam , 7521 North Lock Road, Channahon, Will County, IL

  14. 49 CFR 236.302 - Track circuits and route locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 4 2010-10-01 2010-10-01 false Track circuits and route locking. 236.302 Section...APPLIANCES Interlocking Standards § 236.302 Track circuits and route locking. Track circuits and route locking shall be...

  15. 49 CFR 236.302 - Track circuits and route locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 4 2011-10-01 2011-10-01 false Track circuits and route locking. 236.302 Section...APPLIANCES Interlocking Standards § 236.302 Track circuits and route locking. Track circuits and route locking shall be...

  16. 10. Detail of bridge underside showing gears for locking mechanism ...

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

    10. Detail of bridge underside showing gears for locking mechanism at south end of bridge. View to east. - Locke Avenue Bridge, Locke Avenue (County Route 671) Spanning Raccoon Creek, Swedesboro, Gloucester County, NJ

  17. 89. LOCK 13 EAST. WOODEN TIMBERS (FOREGROUND LEFT AND RIGHT ...

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

    89. LOCK 13 EAST. WOODEN TIMBERS (FOREGROUND LEFT AND RIGHT OF LOCK ENTRANCE) ARE BEING USED AS BUMPERS TO HELP GUIDE SHIP INTO LOCK WHILE AVOIDING CONTACT WITH WALLS. - Morris Canal, Phillipsburg, Warren County, NJ

  18. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  19. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  20. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  1. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  2. 49 CFR 236.764 - Locking, lever operated.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Locking, lever operated. 236.764 Section 236.764... Locking, lever operated. The mechanical locking of an interlocking machine which is actuated by means of the lever....

  3. Surgical Strategies to Improve Fixation in the Osteoporotic Spine: The Effects of Tapping, Cement Augmentation, and Screw Trajectory

    PubMed Central

    Kuhns, Craig A.; Reiter, Michael; Pfeiffer, Ferris; Choma, Theodore J.

    2013-01-01

    Study Design?Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective?To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods?Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw insertion. Then we evaluated load to failure of screws placed in bone block models with a straight-ahead screw trajectory as well as with screws having a 23-degree cephalad trajectory (toward the end plate). These techniques were tested with nonaugmented (NA) screws as well as with bioactive cement (BioC) augmentation prior to screw insertion. Results?In the NA group, pretapping decreased fixation strength in a dose-dependent fashion. In the BioC group, the tapped screws had significantly greater loads to failure (p?fixation is often inadequate in the osteoporotic spine, but this study suggests tapping prior to cement augmentation will substantially improve fixation when compared with not tapping. Angulating screws more cephalad also seems to enhance aging spine fixation. PMID:24494181

  4. Surgical strategies to improve fixation in the osteoporotic spine: the effects of tapping, cement augmentation, and screw trajectory.

    PubMed

    Kuhns, Craig A; Reiter, Michael; Pfeiffer, Ferris; Choma, Theodore J

    2014-02-01

    Study Design?Biomechanical study of pedicle screw fixation in osteoporotic bone. Objective?To investigate whether it is better to tap or not tap osteoporotic bone prior to placing a cement-augmented pedicle screw. Methods?Initially, we evaluated load to failure of screws placed in cancellous bone blocks with or without prior tapping as well as after varying the depths of tapping prior to screw insertion. Then we evaluated load to failure of screws placed in bone block models with a straight-ahead screw trajectory as well as with screws having a 23-degree cephalad trajectory (toward the end plate). These techniques were tested with nonaugmented (NA) screws as well as with bioactive cement (BioC) augmentation prior to screw insertion. Results?In the NA group, pretapping decreased fixation strength in a dose-dependent fashion. In the BioC group, the tapped screws had significantly greater loads to failure (p?fixation is often inadequate in the osteoporotic spine, but this study suggests tapping prior to cement augmentation will substantially improve fixation when compared with not tapping. Angulating screws more cephalad also seems to enhance aging spine fixation. PMID:24494181

  5. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. ...An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as...

  6. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3020 Intramedullary fixation rod. ...An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as...

  7. THE CONUNDRUM OF MARINE N2 FIXATION CLAIRE MAHAFFEY

    E-print Network

    Capone, Douglas G.

    -sea partitioning of CO2 on climate time-scales. The question remains: does the importance of marine N2 fixation estimates of N2 fixation, largely of the planktonic cyanobacte- rium, Trichodesmium, can account for only

  8. Between Linguistic Attention and Gaze Fixations in Multimodal Conversational Interfaces

    E-print Network

    Between Linguistic Attention and Gaze Fixations in Multimodal Conversational Interfaces Rui Fang attention in multimodal conversational interfaces. To address this issue, we conducted a preliminary Linguistic Attention, Gaze Fixation, Multimodal Conversational Interfaces 1. INTRODUCTION In human machine

  9. A Lock-Free B+ Anastasia Braginsky

    E-print Network

    Petrank, Erez

    - Israel Institute of Technology Haifa 32000, Israel erez@cs.technion.ac.il ABSTRACT Lock-free dataA Lock-Free B+ tree Anastasia Braginsky Dept. of Computer Science Technion - Israel Institute of Technology Haifa 32000, Israel anastas@cs.technion.ac.il Erez Petrank Dept. of Computer Science Technion

  10. 49 CFR 236.793 - Rod, lock.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

  11. 49 CFR 236.793 - Rod, lock.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

  12. 49 CFR 236.793 - Rod, lock.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

  13. 49 CFR 236.793 - Rod, lock.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

  14. 49 CFR 236.793 - Rod, lock.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...APPLIANCES Definitions § 236.793 Rod, lock. A rod, attached to the front rod or lug of a switch, movable-point frog or derail, through which a locking plunger may extend when the switch points or derail are in the normal or reverse...

  15. Thoughts About Locke's Thoughts About Education.

    ERIC Educational Resources Information Center

    Crittenden, P.J.

    1981-01-01

    Considers Locke's philosophy of education within the philosophical and religious contexts of seventeenth-century Europe. Rejecting the view that man is innately corrupt, Locke argued that man's nature is malleable, and the purpose of education is to train children through rewards and punishment. Moral education is a process of habituation. (AM)

  16. 77 FR 71590 - Lock+TM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lock+ TM Hydro Friends Fund XI, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On October 1, 2012, Lock+ TM Hydro Friends Fund...

  17. 46 CFR 108.157 - Locked doors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Locked doors. 108.157 Section 108.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Means of Escape § 108.157 Locked doors. No door to the required means of...

  18. Self-Injection Locking Of Diode Lasers

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1991-01-01

    Simple optical coupling scheme locks array of gain-guided diode lasers into oscillation in single mode and with single-lobed output beam. Selective feedback from thin etalon self-injection-locks array into desired mode. One application of new scheme for pumping of neodymium: yttrium aluminum garnet lasers with diode-laser arrays.

  19. Past, Present, Future Erosion at Locke Island

    SciTech Connect

    Bjornstad, Bruce N.

    2006-08-08

    This report describes and documents the erosion that has occurred along the northeast side of Locke Island over the last 10 to 20 years. The principal cause of this erosion is the massive Locke Island landslide complex opposite the Columbia River along the White Bluffs, which constricts the flow of the river and deflects the river's thalweg southward against the island.

  20. Regional alterations in long bone /sup 85/Sr clearance produced by internal fixation devices. Part II. Histomorphometry

    SciTech Connect

    Simmons, D.J.; Daum, W.J.; Calhoun, J.H.

    1988-01-01

    The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal /sup 85/Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association.

  1. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraosseous fixation screw or wire. 872.4880... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended to be...

  2. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraosseous fixation screw or wire. 872.4880... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4880 Intraosseous fixation screw or wire. (a) Identification. An intraosseous fixation screw or wire is a metal device intended to be...

  3. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a...

  4. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a...

  5. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a...

  6. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a...

  7. 21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Spinal intervertebral body fixation orthosis. 888.3060 Section 888.3060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... body fixation orthosis. (a) Identification. A spinal intervertebral body fixation orthosis is a...

  8. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to hold a tracheal tube in... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tracheal tube fixation device. 868.5770...

  9. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube fixation device is a device used to hold a tracheal tube in... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tracheal tube fixation device. 868.5770...

  10. FLOODING STRESS Dinitrogen Fixation by Winter Chickpea Across Scales in

    E-print Network

    van Kessel, Chris

    FLOODING STRESS Dinitrogen Fixation by Winter Chickpea Across Scales in Waterlogged Soil a single tillage management system, however, considerable variation in N2 fixation by Keywords chickpea fixation by rain-fed chickpea (Cicer arietinum L.) at the field- and micro-scales (0.15 m spacing) after

  11. Unfixing Design Fixation: From Cause to Computer Simulation

    ERIC Educational Resources Information Center

    Dong, Andy; Sarkar, Somwrita

    2011-01-01

    This paper argues that design fixation, in part, entails fixation at the level of meta-representation, the representation of the relation between a representation and its reference. In this paper, we present a mathematical model that mimics the idea of how fixation can occur at the meta-representation level. In this model, new abstract concepts…

  12. Trichodesmium and nitrogen fixation in the Kuroshio

    NASA Astrophysics Data System (ADS)

    Shiozaki, T.; Takeda, S.; Itoh, S.; Kodama, T.; Liu, X.; Hashihama, F.; Furuya, K.

    2015-07-01

    Nitrogen fixation in the Kuroshio influences nitrogen balance in the North Pacific Ocean. The genus Trichodesmium is recognized as a major diazotroph in the Kuroshio. Although its abundance is higher in the Kuroshio than in adjacent waters, the reason for this difference remains unclear. The present study investigated the abundance of Trichodesmium spp. and nitrogen fixation together with concentrations of dissolved iron and phosphate, whose availabilities potentially control diazotrophy, in the Kuroshio and its marginal seas. We performed the observations near the Miyako Islands, which form part of the Ryukyu Islands, situated along the Kuroshio, since satellite analysis suggested that material transport could occur from the islands to the Kuroshio. Trichodesmium spp. bloomed (> 20 000 filaments L-1) near the Miyako Islands, and the abundance was high in the Kuroshio and the Kuroshio bifurcation region of the East China Sea, but was low in the Philippine Sea. The abundance of Trichodesmium spp. was significantly correlated with the total nitrogen fixation activity. The surface concentrations of dissolved iron (0.19-0.89 nM) and phosphate (< 3-36 nM) were similar for all of the study areas, indicating that the nutrient distribution could not explain the spatial differences in Trichodesmium spp. abundance and nitrogen fixation. We used a numerical model to simulate the transportation of water around the Ryukyu Islands to the Kuroshio. Our results indicate that Trichodesmium growing around the islands situated along the Kuroshio is potentially important for determining diazotrophy in this region.

  13. Treating Somatic Fixation: A Biopsychosocial Approach

    PubMed Central

    McDaniel, Susan H.; Campbell, Thomas; Seaburn, David

    1991-01-01

    Somatic fixation occurs when the patient or physician focuses exclusively on the biomedical aspects of a complex illness. Individual, family, and cultural factors promote the expression of emotional experience through physical symptoms. The physician or treatment team establishes a collaborative relationship with the patient and family, integrating biomedical and psychosocial evaluations and respecting the patient's defenses. PMID:21228995

  14. Biological nitrogen fixation in Louisiana sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) is a major input for sugarcane with crops in Louisiana receiving between 90 and 180 kg/ha with the cost of N increasing 75% in the last decade. Biological N fixation (BNF) may be a viable alternative to fertilizer N. The process relies on endophytic bacteria (bacteria that live among th...

  15. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls on the fovea centralis (the center of the macular retina of the eye.)...

  16. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls on the fovea centralis (the center of the macular retina of the eye.)...

  17. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls on the fovea centralis (the center of the macular retina of the eye.)...

  18. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls on the fovea centralis (the center of the macular retina of the eye.)...

  19. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...device intended for use as a fixation target for the patient during ophthalmological examination. The patient directs his or her gaze so that the visual image of the object falls on the fovea centralis (the center of the macular retina of the eye.)...

  20. The performance of arm locking in LISA

    E-print Network

    Kirk McKenzie; Robert E. Spero; Daniel A. Shaddock

    2009-08-04

    For the laser interferometer space antenna (LISA) to reach it's design sensitivity, the coupling of the free running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. This paper details an implementation of arm locking, studies orbital effects, the impact of errors in the Doppler knowledge, and noise limits. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultra stable oscillator (clock) noise, spacecraft motion, and shot noise. Studying these issues reveals that although dual arm locking [A. Sutton & D. A Shaddock, Phys. Rev. D 78, 082001 (2008).] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a hybrid sensor, retaining the benefits of common and dual arm locking sensors. We present a detailed design of an arm locking controller and perform an analysis of the expected performance when used with and without laser pre-stabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. We show that the LISA frequency noise goal can be realized with arm locking and Time-Delay Interferometry only, without any form of pre-stabilization.

  1. Mechanical performance of Ilizarov circular external fixators in comparison with other external fixators.

    PubMed

    Podolsky, A; Chao, E Y

    1993-08-01

    The fundamental difference of the Ilizarov fixator is the type of pins used for bone fixation, i.e., Kirschner wires 1.5 mm and 1.8 mm in diameter, pretensioned from 50 to 130 kg before being affixed to the rings that are connected and fixed by threaded rods. The mechanical characteristics of external fixators may influence the biologic environment at the fracture site and ultimately decide the outcome of a surgical procedure. Thus, knowledge of the mechanical properties of the Ilizarov fixator is essential to a surgeon using it in clinical practice. The main objective of this study was to quantitate the mechanical behavior of the standard Ilizarov fixator under different loading conditions and fixator frame/wire configurations. The fixator was found to have a nonlinear stiffness behavior under axial compression. The nonlinearity in axial stiffness also varied with wire pretension. Such characteristics, however, were not as pronounced under torsion and bending loads within the test range studied. Besides the wire pretension, the most important factor affecting the structural stiffness of the Ilizarov device was the diameter of the wire. Offset bone position provided greater stiffness in loads up to 45 kg in axial compression, in torsion up to 5 degrees of rotation, and in the final loading range under bending. Fixators with wires crossing at 45 degrees had significantly greater stiffness in torsion as compared with 90 degrees crossing wires, but the opposite was true in axial compression. Torsional stiffness increased significantly under coupled axial compression applied through the bone ends. All four-point bending tests demonstrated two distinct stiffness curves that were probably due to slippage of the bone model on the wires. This information should help to understand the mechanical behavior of the Ilizarov device and thereby improve its clinical performance. PMID:8339510

  2. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  3. MyPlate

    MedlinePLUS

    ... a Budget Create a Grocery Game Plan Shop Smart to Fill Your Cart Prepare Healthy Meals Sample 2-Week Menus Resources for Professionals 10 Tips ... are here Home / MyPlate MyPlate Error message Notice : Undefined index: title ...

  4. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence. PMID:17799689

  5. Planet Earth: Plate Tectonics

    E-print Network

    Watts, A. B. "Tony"

    Planet Earth: Plate Tectonics Recommended Books: An Introduction to Our Dynamic Planet (ODP), 2007, ice and sediment for long periods of geological time (>105 a). · Controlled and passive (e, Problem sets etc Lecture 1: Plate Mechanics and Kinematics The Earth comprises 7 major plates and a number

  6. Delay locked loop integrated circuit.

    SciTech Connect

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  7. Locking apparatus for gate valves

    DOEpatents

    Fabyan, Joseph (Livermore, CA); Williams, Carl W. (Manteca, CA)

    1988-01-01

    A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing futher movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

  8. Dark Carbon Fixation: An Important Process in Lake Sediments

    PubMed Central

    Santoro, Ana Lúcia; Bastviken, David; Gudasz, Cristian; Tranvik, Lars; Enrich-Prast, Alex

    2013-01-01

    Close to redox boundaries, dark carbon fixation by chemoautotrophic bacteria may be a large contributor to overall carbon fixation. Still, little is known about the relative importance of this process in lake systems, in spite the potentially high chemoautotrophic potential of lake sediments. We compared rates of dark carbon fixation, bacterial production and oxygen consumption in sediments from four Swedish boreal and seven tropical Brazilian lakes. Rates were highly variable and dark carbon fixation amounted up to 80% of the total heterotrophic bacterial production. The results indicate that non-photosynthetic carbon fixation can represent a substantial contribution to bacterial biomass production, especially in sediments with low organic matter content. PMID:23776549

  9. Wing-locking mechanisms in aquatic Heteroptera.

    PubMed

    Gorb, Stanislav N; Goodwyn, P J Perez

    2003-08-01

    This account provides a detailed morphological and ultrastructural study of wing-locking mechanisms (LM) in some aquatic Heteroptera. Scanning and transmission electron microscopy were used to describe the functional significance of macro- and microstructures holding wings tightly against the body at rest and those involved in functional diptery in flight. There are two types of LM holding the forewings (hemelytra) at rest: 1) wing-to-wing LM, and 2) wing-to-body LM. The first type includes the brush-to-brush LM, the clavus-clavus clamp and the clavus-clavus locking ridge. The second type includes devices locking the hemelytra to the body: the subcostal border of the hemelytra to the lateral border of mesepimeron, the knob-and-socket locking mechanism of the hemelytra, and the clavus-locking mechanism to the scutellum groove. The hindwing is locked by a pair of microtrichial fields situated on the hindwing-articulated pad at the basal area of the hindwing and on the thoracic pad in the vicinity of the wing articulation. Morphological and ultrastructural data suggest that different LM are parts of one mechanism holding wings to the body at rest. An additional locking mechanism, connecting the hemelytra with the hindwing, is the only LM providing functional diptery in flight. PMID:12833375

  10. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  11. Bio-Environment-Induced Degradation and Failure of Internal Fixation Implants.

    PubMed

    Zhou, Yan; Perkins, Luke A; Wang, Guodong; Zhou, Dongsheng; Liang, Hong

    2015-01-01

    Internal fixations provide fast healing but their failure remains problematic to patients. Here, we report an experimental study in failure of three typical cases of metals: a bent intramedullary stainless steel nail, a broken exterior pure Ti plate, and a broken intramedullary stainless steel nail. Characterization of the bent nail indicates that those metals are vulnerable to corrosion with the evidence of increased surface roughness and embrittlement. Depredated surface of the Ti plate resulted debris particles in the surrounding tissue of 15.2 ± 6.5 ?m in size. Nanoparticles were observed in transmission electron microscope. The electron diffraction pattern of the debris indicates a combination of nanocrystalline and amorphous phases. The failure mode of the broken nail made of stainless steel was found to be fatigue initiated from the surface. This study clearly shows the biological-attack induced surface degradation resulting in debris and fatigue. Future design and selection of implant materials should consider such factors for improvement. PMID:26501330

  12. Application of alternative fixatives to formalin in diagnostic pathology.

    PubMed

    Benerini Gatta, L; Cadei, M; Balzarini, P; Castriciano, S; Paroni, R; Verzeletti, A; Cortellini, V; De Ferrari, F; Grigolato, P

    2012-01-01

    Fixation is a critical step in the preparation of tissues for histopathology. The objective of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved the best fixative for morphology. The morphology obtained with Bouin was comparable to that with formalin. Hollande was the best fixative for histochemistry. Bouin proved equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved possible to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis. PMID:22688293

  13. Delayed Union of a Sacral Fracture: Percutaneous Navigated Autologous Cancellous Bone Grafting and Screw Fixation

    SciTech Connect

    Huegli, R. W. Messmer, P.; Jacob, A. L.; Regazzoni, P.; Styger, S.; Gross, T.

    2003-09-15

    Delayed or non-union of a sacral fracture is a serious clinical condition that may include chronic pain, sitting discomfort, gait disturbances, neurological problems, and inability to work. It is also a difficult reconstruction problem. Late correction of the deformity is technically more demanding than the primary treatment of acute pelvic injuries. Open reduction, internal fixation (ORIF), excision of scar tissue, and bone grafting often in a multi-step approach are considered to be the treatment of choice in delayed unions of the pelvic ring. This procedure implies the risk of neurological and vascular injuries, infection, repeated failure of union, incomplete correction of the deformity, and incomplete pain relief as the most important complications. We report a new approach for minimally invasive treatment of a delayed union of the sacrum without vertical displacement. A patient who suffered a Malgaigne fracture (Tile C1.3) was initially treated with closed reduction and percutaneous screw fixation (CRPF) of the posterior pelvic ring under CT navigation and plating of the anterior pelvic ring. Three months after surgery he presented with increasing hip pain caused by a delayed union of the sacral fracture. The lesion was successfully treated percutaneously in a single step procedure using CT navigation for drilling of the delayed union, autologous bone grafting, and screw fixation.

  14. VIEW LOOKING SOUTH EAST INTO THE LOCK, SHOWING THE GATES ...

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

    VIEW LOOKING SOUTH EAST INTO THE LOCK, SHOWING THE GATES TO THE LOCK, NOTE THE SCALE OF THE BOAT RELATIVE TO THE SCALE OF THE LOCK. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

  15. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

  16. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

  17. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

  18. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

  19. 49 CFR 236.759 - Lock, facing point.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...APPLIANCES Definitions § 236.759 Lock, facing point. A mechanical lock for a switch, derail, or movable-point frog, comprising a plunger stand and a plunger which engages a lock rod attached to the switch point to lock the operated...

  20. 49 CFR 236.758 - Lock, electric, forced drop.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric, forced drop. 236.758 Section 236.758 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.758 Lock, electric, forced drop. An electric lock in which the locking member is...

  1. Coarse-grained and fine-grained locking

    E-print Network

    other #12;Art of Multiprocessor Programming 11 Hand-over-Hand locking a b c #12;Art of Multiprocessor Programming 12 Hand-over-Hand locking a b c #12;Art of Multiprocessor Programming 13 Hand-over-Hand locking a b c #12;Art of Multiprocessor Programming 14 Hand-over-Hand locking a b c #12;Art of Multiprocessor

  2. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  3. 49 CFR 236.339 - Mechanical locking, maintenance requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Mechanical locking, maintenance requirements. 236... Interlocking Rules and Instructions § 236.339 Mechanical locking, maintenance requirements. Locking and... prevented: (a) Mechanical machine—(1) Latch-operated locking. Raising lever latch block so that...

  4. VIEW LOOKING NORTHEAST INTO LOCK 71. NOTE THE SEDIMENT BUILD ...

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

    VIEW LOOKING NORTHEAST INTO LOCK 71. NOTE THE SEDIMENT BUILD UP. THIS IS BY DESIGN, NOT ONLY ARE THE OLDER LOCKS USED AS AN OVERFLOW SPILLWAY FOR THE CURRENT LOCKS, THEY ARE ALSO USED FOR SEDIMENT AND DEBRIS CONTROL. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  5. 1. VIEW SOUTH ACROSS SUSQUEHANNA RIVER, LOCK SETTING (Opening of ...

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

    1. VIEW SOUTH ACROSS SUSQUEHANNA RIVER, LOCK SETTING (Opening of lock on bank by shrubs, near center of photograph) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

  6. [Osteosynthesis of subcondylar fractures using a rectangular 3-dimensional stabilization plate].

    PubMed

    Wilk, A; Biotchane, I; Rosenstiel, M; Charles, X; Meyer, C

    1997-11-01

    The current international opinion for the treatment of displaced subcondylar fractures has become more aggressive after the rediscovery of the submandibular incision and the creation of new fixation material. We report 19 patients with displaced subcondylar fractures who were treated with reinforced rectangular plates. The pure titanium plates are slightly concave and measure 13 by 9 mm. We evaluated dental articulation, mouth opening, propulsion and duction and observed rapid recovery of mandibular kinetics and mandibular function. Use of this plate is a major progress in the treatment of fractures of the condyle. PMID:9471693

  7. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility.

    PubMed

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  8. Secondary Radial Nerve Palsy after Minimally Invasive Plate Osteosynthesis of a Distal Humeral Shaft Fracture

    PubMed Central

    Bichsel, Ursina; Nyffeler, Richard Walter

    2015-01-01

    Minimally invasive plate osteosynthesis is a widely used procedure for the treatment of fractures of the femur and the tibia. For a short time it is also used for the treatment of humeral shaft fractures. Among other advantages, the ambassadors of this technique emphasize the lower risk of nerve injuries when compared to open reduction and internal fixation. We report the case of secondary radial nerve palsy caused by percutaneous fixation of a plate above the antecubital fold. The nerve did not recover and the patient needed a tendon transfer to regain active extension of the fingers. This case points to the importance of adequate exposure of the bone and plate if a humeral shaft fracture extends far distally. PMID:26558125

  9. The penny drops: change blindness at fixation.

    PubMed

    Smith, Tim J; Lamont, Peter; Henderson, John M

    2012-01-01

    Our perception of the visual world is fallible. Unattended objects may change without us noticing as long as the change does not capture attention (change blindness). However, it is often assumed that changes to a fixated object will be noticed if it is attended. In this experiment we demonstrate that participants fail to detect a change in identity of a coin during a magic trick even though eyetracking indicates that the coin is tracked by the eyes throughout the trick. The change is subsequently detected when participants are instructed to look for it. These results suggest that during naturalistic viewing, attention can be focused on an object at fixation without including all of its features. PMID:22896921

  10. Lagged Syndesmotic Fixation: Our Clinical Experience.

    PubMed

    Kwaadu, Kwasi Yiadom; Fleming, Justin James; Salmon, Trudy

    2015-01-01

    Ankle fractures are very common, and although algorithms are in place for osseous management, consensus has not been reached regarding treatment of associated ligamentous injuries. Although tibiofibular syndesmotic stabilization can be done using different forms of fixation, the biomedical literature has long emphasized the risk of long-term restriction of ankle mobility with the use of lagged transfixation. However, when reduction cannot be maintained with positional fixation, we found that lagging the syndesmotic screw helped to maintain the reduction without causing functional restriction. In this report, we describe our experience with patients who had undergone lagged tibiofibular transfixation and were available for short- to intermediate-term follow-up to assess ankle function. A total of 31 patients (32.63% of 95 consecutive patients) were available at a mean of 34.87 (range 18 to 52) months to complete the American Orthopedic Foot and Ankle Society ankle-hindfoot questionnaire. The mean score was 88.38 (range 42 to 100) points at a mean follow-up interval of 34.87 (range 18 to 52) months. Of 31 patients, 19 had an AOFAS score of 90 points, 9 an AOFAS score of 80 to 89 points, 2 an AOFAS score of 60 to 69 points, and 1 an AOFAS score of <60 points. Because all syndesmotic screws were placed using the lag technique, unrestricted motion compared with the uninjured limb was used as the endpoint. All subjects had unrestricted motion compared with the uninjured limb, refuting the assertion that lagged syndesmotic screw fixation confers more restriction in ankle kinematics than positional syndesmotic fixation. PMID:25736445

  11. Definitive fixation of tibial plateau fractures.

    PubMed

    Yoon, Richard S; Liporace, Frank A; Egol, Kenneth A

    2015-07-01

    Tibial plateau fractures present in a wide spectrum of injury severity and pattern, each requiring a different approach and strategy to achieve good clinical outcomes. Achieving those outcomes starts with a thorough evaluation and preoperative planning period, which leads to choosing the most appropriate surgical approach and fixation strategy. Through a case-based approach, this article presents the necessary pearls, techniques, and strategies to maximize outcomes and minimize complications for some of the more commonly presenting plateau fracture patterns. PMID:26043050

  12. Carbon Dioxide Fixation in Cultured Animal Cells

    E-print Network

    Kyner, David Smith

    1969-01-01

    Plage ACKNOWIJBDOMElfTS ü TAB1E OF CONTENTS i ü LIST OF TABIÄS *i LIST OF FTOUKES l r l i i CHAPTER I. INTRODUCTION 1 EL HISTORICAL REVIEW 3 The Cultivation of Animal Cells in the Presence and Absence of Carbon Dioxide . * * • 3 Substitutions... for Carbon Dioxide 5 Some Physical and Chemical Characteristics of Carbon Dioxide and its Buffering Capacity 8 Qluooneoftenesis 10 Control of Oluconeogenesis • • • • 12 Oluooneogenesls and Carbon Dioxide Fixation Iii Effects of Olucose 15 Effects...

  13. Binding kinetics of lock and key colloids.

    PubMed

    Colón-Meléndez, Laura; Beltran-Villegas, Daniel J; van Anders, Greg; Liu, Jun; Spellings, Matthew; Sacanna, Stefano; Pine, David J; Glotzer, Sharon C; Larson, Ronald G; Solomon, Michael J

    2015-05-01

    Using confocal microscopy and first passage time analysis, we measure and predict the rates of formation and breakage of polymer-depletion-induced bonds between lock-and-key colloidal particles and find that an indirect route to bond formation is accessed at a rate comparable to that of the direct formation of these bonds. In the indirect route, the pocket of the lock particle is accessed by nonspecific bonding of the key particle with the lock surface, followed by surface diffusion leading to specific binding in the pocket of the lock. The surprisingly high rate of indirect binding is facilitated by its high entropy relative to that of the pocket. Rate constants for forward and reverse transitions among free, nonspecific, and specific bonds are reported, compared to theoretical values, and used to determine the free energy difference between the nonspecific and specific binding states. PMID:25956122

  14. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  15. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  16. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  17. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  18. 49 CFR 236.757 - Lock, electric.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  19. 49 CFR 236.756 - Lock, bolt.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for... will prevent a movement of the switch, derail or movable-point frog unless the signal displays its...

  20. 49 CFR 236.756 - Lock, bolt.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for... will prevent a movement of the switch, derail or movable-point frog unless the signal displays its...

  1. 49 CFR 236.756 - Lock, bolt.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for... will prevent a movement of the switch, derail or movable-point frog unless the signal displays its...

  2. 49 CFR 236.756 - Lock, bolt.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for... will prevent a movement of the switch, derail or movable-point frog unless the signal displays its...

  3. 49 CFR 236.756 - Lock, bolt.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position for... will prevent a movement of the switch, derail or movable-point frog unless the signal displays its...

  4. Internal impacted screw-locking pellet

    NASA Technical Reports Server (NTRS)

    MacMartin, Malcolm J. (Inventor)

    1994-01-01

    An elongate fastener having an engaging surface engageable with an engaging surface of a fastener's mate includes a hole extending through a portion of the fastener and having a top opening and a bottom floor, a locking pellet disposed near the bottom floor, a discharge channel communicating between the pellet and through the engaging surface of the fastener and opening out toward the engaging surface of the fastener's mate, and an impact pin in the hole having a top portion protruding through the top opening and a bottom portion near the locking pellet, whereby the pin drives the locking pellet through the discharge channel against the engaging surfaces of the fastener and the fastener's mate whereby to lock the fastener against the fastener's mate.

  5. Pneumatic wall-locking geophone system

    DOEpatents

    Kuhlman, Harland L. (Minneapolis, MN); Cumerlato, Calvin L. (Minneapolis, MN); Tweeton, Daryl R. (Apple Valley, MN)

    1991-01-01

    A seismic signal receiving system is provided for use in boreholes to receive seismic waves in carrying out geophysical investigations. The system includes three pairs of opposed plates, each of the pairs of plates including oppositely facing outer surfaces for engagement with opposite sides of a borehole. A seismic receiver is mounted on the inner surface of each of the plates for receiving seismic signals. A double-acting, fluid-operated actuator selectively causes relative movement of the plates of the pairs of plates away from each other to provide expansion thereof so as to enable the plates to engage the walls of a borehole and selectively causes relative movement of the plates of the pairs of plates toward each other to provide retraction thereof so as to enable the system to be removed from a borehole. The pairs of plates each comprise a relatively long plate and a relatively short plate. An expandable linkage interconnects the long plates at the distal ends thereof. The plates are mechanically biassed into the retracted state so that the plates return to this state in the event of a system failure.

  6. Tunable triple-wavelength mode-locked ytterbium fiber laser with birefringence filter

    NASA Astrophysics Data System (ADS)

    Lv, Zhiguo; Teng, Hao; Wang, Rui; Wang, Lina; Wang, Junli; Wei, Zhiyi

    2015-10-01

    A mode-locked ytterbium fiber laser based on all normal dispersion (ANDi) technique and nonlinear polarization rotation (NPR) is investigated with birefringent plate as a spectral filter in this paper. Tunable triple-wavelength simultaneous operation is realized at central wavelengths of 1031.4, 1046.8 and 1066.5 nm, respectively. A maximum output power up to 161.4 mW is obtained at 1031.4 nm wavelength. By only changing the direction of the optical axis of the uniaxial birefringent filter, tunable range as wide as 19 nm is demonstrated. To the best of our knowledge, this is the widest tuning range and highest power reported so far for ANDi mode-locked ytterbium fiber lasers with triple-wavelength operation. Our analysis shows that the mechanism of the triple-wavelength mode-locked operation results mainly from the four-wave mixing in optical fibers; in addition, the wide gain bandwidth of Yb also plays a critical role for the stable oscillation of the third mode-locked wavelength. The energy conversion process governed by a set of four coupled equations is realized experimentally through the adjustment of the polarization controller, which is related to the phase matching.

  7. Assessment of the RIVET fixation system for cranioplasty using the pull-out technique.

    PubMed

    Sakamoto, Yoshiaki; Minabe, Toshiharu; Kato, Tatsuya; Kishi, Kazuo

    2015-03-01

    Cranioplasty using custom-made hydroxyapatite (HAP) ceramic implants is a common procedure to repair skull defects. However, commercially available titanium screws are only minimally stabilized due to characteristic brittleness. We developed the RIVET technique which involves fixing a bioabsorbable plate atop a HAP block using bioabsorbable screws extending beyond both layers, and evaluated fixation strength using the pull-out test and microtomography. Three experimental conditions were compared: a non-RIVET group, RIVET group, and dry skull control group. Pull-out strength significantly differed across groups (non-RIVET group, 1.33 ± 1.21 kgf; RIVET group, 4.46 ± 0.84 kgf; and control group, 6.99 ± 1.14 kgf, P < 0.01). Microtomography of the dry skull control group revealed thread grooves fitted to the screws. The non-RIVET and RIVET groups presented fewer thread grooves than the control group, and the screws did not fit perfectly to the HAP block. However, fixation in the RIVET group was more stable, as the rivet was firmly lodged into the implant. In conclusion, by melting and creating the rivet, pull-out strength can be increased and rigid stabilization of HAP can be obtained. This technique uses commercially available absorbable plate and screws, and thus can be used widely in clinical applications involving HAP blocks with different porosities and thicknesses. PMID:25555895

  8. Gradual unlocking of plate boundary controlled initiation of the 2014 Iquique earthquake.

    PubMed

    Schurr, Bernd; Asch, Günter; Hainzl, Sebastian; Bedford, Jonathan; Hoechner, Andreas; Palo, Mauro; Wang, Rongjiang; Moreno, Marcos; Bartsch, Mitja; Zhang, Yong; Oncken, Onno; Tilmann, Frederik; Dahm, Torsten; Victor, Pia; Barrientos, Sergio; Vilotte, Jean-Pierre

    2014-08-21

    On 1 April 2014, Northern Chile was struck by a magnitude 8.1 earthquake following a protracted series of foreshocks. The Integrated Plate Boundary Observatory Chile monitored the entire sequence of events, providing unprecedented resolution of the build-up to the main event and its rupture evolution. Here we show that the Iquique earthquake broke a central fraction of the so-called northern Chile seismic gap, the last major segment of the South American plate boundary that had not ruptured in the past century. Since July 2013 three seismic clusters, each lasting a few weeks, hit this part of the plate boundary with earthquakes of increasing peak magnitudes. Starting with the second cluster, geodetic observations show surface displacements that can be associated with slip on the plate interface. These seismic clusters and their slip transients occupied a part of the plate interface that was transitional between a fully locked and a creeping portion. Leading up to this earthquake, the b value of the foreshocks gradually decreased during the years before the earthquake, reversing its trend a few days before the Iquique earthquake. The mainshock finally nucleated at the northern end of the foreshock area, which skirted a locked patch, and ruptured mainly downdip towards higher locking. Peak slip was attained immediately downdip of the foreshock region and at the margin of the locked patch. We conclude that gradual weakening of the central part of the seismic gap accentuated by the foreshock activity in a zone of intermediate seismic coupling was instrumental in causing final failure, distinguishing the Iquique earthquake from most great earthquakes. Finally, only one-third of the gap was broken and the remaining locked segments now pose a significant, increased seismic hazard with the potential to host an earthquake with a magnitude of >8.5. PMID:25119049

  9. Biomechanical analysis of a new carbon fiber/flax/epoxy bone fracture plate shows less stress shielding compared to a standard clinical metal plate.

    PubMed

    Bagheri, Zahra S; Tavakkoli Avval, Pouria; Bougherara, Habiba; Aziz, Mina S R; Schemitsch, Emil H; Zdero, Radovan

    2014-09-01

    Femur fracture at the tip of a total hip replacement (THR), commonly known as Vancouver B1 fracture, is mainly treated using rigid metallic bone plates which may result in "stress shielding" leading to bone resorption and implant loosening. To minimize stress shielding, a new carbon fiber (CF)/Flax/Epoxy composite plate has been developed and biomechanically compared to a standard clinical metal plate. For fatigue tests, experiments were done using six artificial femurs cyclically loaded through the femoral head in axial compression for four stages: Stage 1 (intact), stage 2 (after THR insertion), stage 3 (after plate fixation of a simulated Vancouver B1 femoral midshaft fracture gap), and stage 4 (after fracture gap healing). For fracture fixation, one group was fitted with the new CF/Flax/Epoxy plate (n?=?3), whereas another group was repaired with a standard clinical metal plate (Zimmer, Warsaw, IN) (n?=?3). In addition to axial stiffness measurements, infrared thermography technique was used to capture the femur and plate surface stresses during the testing. Moreover, finite element analysis (FEA) was performed to evaluate the composite plate's axial stiffness and surface stress field. Experimental results showed that the CF/Flax/Epoxy plated femur had comparable axial stiffness (fractured?=?645?±?67?N/mm; healed?=?1731?±?109?N/mm) to the metal-plated femur (fractured?=?658?±?69?N/mm; healed?=?1751?±?39?N/mm) (p?=?1.00). However, the bone beneath the CF/Flax/Epoxy plate was the only area that had a significantly higher average surface stress (fractured?=?2.10?±?0.66?MPa; healed?=?1.89?±?0.39?MPa) compared to bone beneath the metal plate (fractured?=?1.18?±?0.93?MPa; healed?=?0.71?±?0.24?MPa) (p?plated femurs at the vicinity of nearest screw just proximal to fracture (stage 3), 21?MPa for composite and 24?MPa for metal-plated femurs at the vicinity of screw farthest away distally from fracture (stage 4). These results confirm that the new CF/Flax/Epoxy material could be a potential candidate for bone fracture plate applications as it can simultaneously provide similar mechanical stiffness and lower stress shielding (i.e., higher bone stress) compared to a standard clinical metal bone plate. PMID:24828985

  10. Plates and FEM

    NASA Astrophysics Data System (ADS)

    Blaauwendraad, J.

    The word plate is a collective term for systems in which transfer of forces occurs in two directions; walls, deep beams, floors and bridge slabs are all plates. We distinguish two main categories, plates that are loaded in their plane, and plates loaded perpendicularly to their plane. For both categories we give an approach with differential equations, such that a basic understanding is provided and for certain characteristic cases an exact solution can be determined. We follow the displacement method, working with differential equations. In plates that are loaded in their plane, the plane stress state is called the membrane state. All stress components are parallel to the mid- plane of the plate. In special cases we can simply determine the stresses.

  11. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  12. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  13. Weigners fixative-an alternative to formalin fixation for histology with improved preservation of nucleic acids.

    PubMed

    Klopfleisch, R; von Deetzen, M; Weiss, A Th; Weigner, J; Weigner, F; Plendl, J; Gruber, A D

    2013-01-01

    Formalin fixation and paraffin embedding (FFPE) is the standard method for tissue storage in histopathology. However, FFPE has disadvantages in terms of user health, environment, and nucleic acid integrity. Weigners fixative has been suggested as an alternative for embalming cadavers in human and veterinary anatomy. The present study tested the applicability of Weigners for histology and immunohistochemistry and the preservation of nucleic acids. To this end, a set of organs was fixed for 2 days and up to 6 months in Weigners (WFPE) or formalin. WFPE tissues from the skin, brain, lymphatic tissues, liver, and muscle had good morphologic preservation, comparable to formalin fixation. The quality of kidney and lung samples was inferior to FFPE material due to less accentuated nuclear staining and retention of proteinaceous interstitial fluids. Azan, Turnbull blue, toluidin, and immunohistochemical stainings for CD79a, cytokeratin, vimentin, and von Willebrand factor led to comparable results with both fixates. Of note, immunohistochemical detection of CD3 was possible after 6 months in WFPE but not in FFPE tissues. mRNA, miRNA, and DNA from WFPE tissues had superior quality and allowed for amplification of miRNA, 400-bp-long mRNA, and 1000-bp-long DNA fragments after 6 months of fixation in WFPE. In summary, Weigners fixative is a nonhazardous alternative to formalin, which provides a good morphologic preservation of most organs, a similar sensitivity for protein detection, and a superior preservation of nucleic acids. Weigners may therefore be a promising alternative to cryopreservation and may be embraced by people affected by formalin allergies. PMID:22539409

  14. Acceleration of metal plates

    SciTech Connect

    Marsh, S.P.; McQueen, R.G.; Tan, T.H.

    1989-01-01

    High-explosive charges have been used to accelerate stainless steel plates to velocities of 6-7 km/s. A two-stage system has been used in which the first stage is a plane-wave detonating system that accelerates the plate down a short barrel. The second stage consists of a hollow cylindrical charge through which the moving plate passes. After an adjustable delay this charge is detonated on the outer circumference of the entry side of the charge. Flash radiographs and witness plates show no breakup in the first stage but bowing and frequent breakup in the second stage. 6 figs.

  15. Communication: SHG-detected circular dichroism imaging using orthogonal phase-locked laser pulses.

    PubMed

    Jarrett, Jeremy W; Liu, Xiaoying; Nealey, Paul F; Vaia, Richard A; Cerullo, Giulio; Knappenberger, Kenneth L

    2015-04-21

    We demonstrate a novel method for second harmonic generation-detected circular dichroism (CD) imaging based on the use of phase-locked, temporally delayed femtosecond laser pulses. The polarization state of the fundamental wave was controllably changed over 2? rad by using a birefringent delay line, which provided attosecond inter-pulse delays for orthogonal phase-locked replicas; the achievable phase stability was 14 as. By introducing either a positive or negative delay of ?667 as, we induced a ±?/2 phase shift between the orthogonally polarized pulses, resulting in left circularly polarized or right circularly polarized light. CD imaging performance using the pulse sequence was compared to results obtained for plasmonic nanoantennas using a rotating quarter-wave plate. The pulse sequence is expected to simplify polarization-resolved optical imaging by reducing experimental artifacts and decreasing image acquisition times. This method can be easily extended to other CD spectroscopy measurements. PMID:25903859

  16. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

  17. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

  18. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

  19. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

  20. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Electromechanical interlocking machine; locking between electrical and mechanical...340 Electromechanical interlocking machine; locking between electrical and mechanical... In electro-mechanical interlocking machine, locking between electric and...

  1. Lock Coarsening: Eliminating Lock Overhead in Automatically Parallelized ObjectBased Programs \\Lambda

    E-print Network

    Rinard, Martin

    Lock Coarsening: Eliminating Lock Overhead in Automatically Parallelized Object­Based Programs Massachusetts Institute of Technology \\Lambda The research reported in this article was conducted while of Technology, 545 Technology Square, Cambridge, Mass., 02139. E­mail: rinard@lcs.mit.edu 1 #12; Abstract Atomic

  2. Lock Coarsening: Eliminating Lock Overhead in Automatically Parallelized Object-Based Programs

    E-print Network

    Rinard, Martin

    Lock Coarsening: Eliminating Lock Overhead in Automatically Parallelized Object-Based Programs Massachusetts Institute of Technology The research reported in this article was conducted while the authors were@isi.edu; Martin C. Rinard, Laboratory for Computer Science, Massachusetts Institute of Technology, 545 Technology

  3. Plate Motion and Crustal Deformation Estimated with Geodetic Data from the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Argus, Donald F.; Heflin, Michael B.

    1995-01-01

    We use geodetic data taken over four years with the Global Positioning System (GPS) to estimate: (1) motion between six major plates and (2) motion relative to these plates of ten sites in plate boundary zones. The degree of consistency between geodetic velocities and rigid plates requires the (one-dimensional) standard errors in horizontal velocities to be approx. 2 mm/yr. Each of the 15 angular velocities describing motion between plate pairs that we estimate with GPS differs insignificantly from the corresponding angular velocity in global plate motion model NUVEL-1A, which averages motion over the past 3 m.y. The motion of the Pacific plate relative to both the Eurasian and North American plates is observed to be faster than predicted by NUVEL-1A, supporting the inference from Very Long B ase- line Interferometry (VLBI) that motion of the Pacific plate has speed up over the past few m.y. The Eurasia-North America pole of rotation is estimated to be north of NUVEL-1A, consistent with the independent hypothesis that the pole has recently migrated northward across northeast Asia to near the Lena River delta. Victoria, which lies above the main thrust at the Cascadia subduction zone, moves relative to the interior of the overriding plate at 30% of the velocity of the subducting plate, reinforcing the conclusion that the thrust there is locked beneath the continental shelf and slope.

  4. Arthroscopic Bony Bankart Fixation Using a Modified Sugaya Technique

    PubMed Central

    Gupta, Anil K.; McCormick, Frank M.; Abrams, Geoffrey D.; Harris, Joshua D.; Bach, Bernard R.; Romeo, Anthony A.; Verma, Nikhil N.

    2013-01-01

    Arthroscopic fixation of bony Bankart lesions in the setting of anterior shoulder instability has had successful long-term results. Key factors such as patient positioning, portal placement, visualization, mobilization of bony/soft tissues, and anatomic reduction and fixation are crucial to yield such results. We present a modified Sugaya technique that is reproducible and based on such key principles. This technique facilitates ease of anchor and suture placement to allow for anatomic reduction and fixation. PMID:24265994

  5. Flexibly controllable multi-pulse mode-locked MOPA Yb-doped fiber laser in all normal dispersion regime

    NASA Astrophysics Data System (ADS)

    Bu, Chenxi; Wang, Chinhua

    2013-09-01

    A Controllable, high energy, all normal dispersion (ANDi), passively mode-locked Yb-doped fiber laser is demonstrated with a Master Oscillator Power-Amplifier (MOPA) structure. The mode-locking is achieved by nonlinear polarization evolution (NPE). different types of laser pulse are achieved from fundamental mode-locked (FML) single pulse to twin pulse and then to harmonically mode-locked (HML) pulses (the maximum order is 7 times) by adjusting quarter-wave plates (QWPS) and a half-wave plate (HWP) in our system. Using a cascaded long-period fiber grating as the spectral filter, the center wavelength of our laser is fixed at 1034nm.The repetition frequency rate of the FML pulse is 1.53MHz with a pulse width of 817ps. The maximum average energy is 450 mW and the maximum pulse energy of FML single pulse is 294 nJ. Besides, the 517nm green laser output is also achieved by using a LiB3O5 (LBO) crystal as the frequency doubling crystal. The maximum average of the green pulse is 4.71mW.

  6. Author's personal copy Plate tectonic reconstructions with continuously closing plates$

    E-print Network

    Bower, Dan J.

    Author's personal copy Plate tectonic reconstructions with continuously closing plates$ Michael May 2011 Keywords: Geodynamics Plate tectonics a b s t r a c t We present a new algorithm for modeling margins and plates, traditional global plate tectonic reconstructions have become inadequate

  7. Inter-seismic deformation and plate coupling along the Andaman micro-plate margin: geodetic constraints using 1996-2004 GPS data.

    NASA Astrophysics Data System (ADS)

    Earnest, A.; Puchakayala, J.; Rajendran, C. C. P.; Rajendran, K.

    2014-12-01

    Oblique convergence of the Andaman microplate with the Sunda margin results in permanent deformation within the overriding plate and had generated giant plate-boundary ruptures like the 2004 Mw 9.3 Sumatra- Andaman earthquake. Inter-seismic upper plate deformation of this part of the subduction zone remains poorly constrained due to lack of availability of spatially well distributed data. Through this study we are reanalyzing the available GPS geodetic data sets collected by various agencies over different times between 1996-2004 to constrain the pre-earthquake convergence values using a consistent reference frame to determine the crustal deformation in the Andaman Nicobar region, to infer strain rates in the overriding plate, how Andaman microplate was moving relative to Indian plate and what was the extent of plate locking. We will also discuss the details on spatial and temporal variations of convergence rates and variations in plate coupling. To quantify the change in coupling, we calculated the interseismic surface deformation using Okada's formulation, in which locked faults are modelled as dislocations in a halfspace. We defined the subduction zone geometry as three elastically deforming blocks (India, Andaman fore-arc, and Sunda) separated by two faults: the West Andaman Fault and the Sumatra-Andaman megathrust. The bennioff-zone dip and orientation is re-defined using the recently relocated epicentral solutions with higher accuracy and from the slip-distribution models constrained from the various co-seismic geodetic offsets reported from the near-field and far-field GPS sites . The rigid-body motion of each block is specified by a pole of rotation. We modelled the variation in coupling by specifying for each node and integrating the slip deficit over the fault surfaces. The West Andaman Fault is modeled as a vertical strike- lip fault, locked to a depth of ~20 km, with a dextral slip.

  8. Flows past Long Plates under Cross-Stream Oscillatory Forcing

    NASA Astrophysics Data System (ADS)

    Tan, Boon T.; Thompson, Mark C.; Hourigan, Kerry

    1998-11-01

    The long rectangular plate exhibits shedding from both the leading and trailing edges. The interaction between the shear layers results in a feedback loop and has been clasified as the impinging leading edge vortex instability. This instability is weak and at low Reynolds numbers( Re plate length. At higher Reynolds numbers, it can be excited when a perturbation is applied. The incompressible Navier-Stokes equations were solved numerically using a high-order spectral element technique in space and a classical three step time-splitting temporal scheme. Three dimensional simulations use a Fourier expansion in the third dimension. The instability is receptive to small sinusoidal cross-flow perturbations (2.5% of free stream applied at the boundaries) and locks over a wide range of Strouhal numbers (St?0.12-0.2) at Re=400 based on plate thickness. A comparison of mean base pressure obtained numerically from two-dimensional simulations and observed experimentally show similar trends when forcing is applied. Three-dimensional simulations without forcing show the vortices on the surface of the plate form a staggered hair-pin pattern. These vortices, and streamwise vortecies that form in the trailing edge shear layers, strongly affect the drag experienced by the plate. Animations of several simulations can be obtained plate.html>here.

  9. An in vivo evaluation of PLLA/PLLA-gHA nano-composite for internal fixation of mandibular bone fractures.

    PubMed

    Peng, Weihai; Zheng, Wei; Shi, Kai; Wang, Wangshu; Shao, Ying; Zhang, Duo

    2015-01-01

    Internal fixation of bone fractures using biodegradable poly(L-lactic-acid) (PLLA)-based materials has attracted the attention of many researchers. In the present study, 36 male beagle dogs were randomly assigned to two groups: PLLA/PLLA-gHA (PLLA-grafted hydroxyapatite) group and PLLA group. PLLA/PLLA-gHA and PLLA plates were embedded in the muscular bags of the erector spinae and also implanted to fix mandibular bone fractures in respective groups. At 1, 2, 3, 6, 9, and 12 months postoperatively, the PLLA/PLLA-gHA and PLLA plates were evaluated by adsorption and degradation tests, and the mandibles were examined through radiographic analysis, biomechanical testing, and histological analysis. The PLLA/PLLA-gHA plates were non-transparent and showed a creamy white color, and the PLLA plates were transparent and faint yellow in color. At all time points following surgery, adsorption and degradation of the PLLA/PLLA-gHA plates were significantly less than those of the PLLA plates, and the lateral and longitudinal bending strengths of the surgically treated mandibles of the beagle dogs in the PLLA/PLLA-gHA group were significantly greater than those of the PLLA group and reached almost the value of intact mandibles at 12 months postoperatively. Additionally, relatively rapid bone healing was observed in the PLLA/PLLA-gHA group with the formation of new lamellar bone tissues at 12 months after the surgery. The PLLA/PLLA-gHA nano-composite can be employed as a biodegradable material for internal fixation of mandibular bone fractures. PMID:26551378

  10. Blue Willow Story Plates

    ERIC Educational Resources Information Center

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  11. Genetic regulation of nitrogen fixation in rhizobia.

    PubMed Central

    Fischer, H M

    1994-01-01

    This review presents a comparison between the complex genetic regulatory networks that control nitrogen fixation in three representative rhizobial species, Rhizobium meliloti, Bradyrhizobium japonicum, and Azorhizobium caulinodans. Transcription of nitrogen fixation genes (nif and fix genes) in these bacteria is induced primarily by low-oxygen conditions. Low-oxygen sensing and transmission of this signal to the level of nif and fix gene expression involve at least five regulatory proteins, FixL, FixJ, FixK, NifA, and RpoN (sigma 54). The characteristic features of these proteins and their functions within species-specific regulatory pathways are described. Oxygen interferes with the activities of two transcriptional activators, FixJ and NifA. FixJ activity is modulated via phosphorylation-dephosphorylation by the cognate sensor hemoprotein FixL. In addition to the oxygen responsiveness of the NifA protein, synthesis of NifA is oxygen regulated at the level of transcription. This type of control includes FixLJ in R. meliloti and FixLJ-FixK in A. caulinodans or is brought about by autoregulation in B. japonicum. NifA, in concert with sigma 54 RNA polymerase, activates transcription from -24/-12-type promoters associated with nif and fix genes and additional genes that are not directly involved in nitrogen fixation. The FixK proteins constitute a subgroup of the Crp-Fnr family of bacterial regulators. Although the involvement of FixLJ and FixK in nifA regulation is remarkably different in the three rhizobial species discussed here, they constitute a regulatory cascade that uniformly controls the expression of genes (fixNOQP) encoding a distinct cytochrome oxidase complex probably required for bacterial respiration under low-oxygen conditions. In B. japonicum, the FixLJ-FixK cascade also controls genes for nitrate respiration and for one of two sigma 54 proteins. Images PMID:7968919

  12. Titanium alloys for fracture fixation implants.

    PubMed

    Disegi, J A

    2000-12-01

    This paper is intended to provide an overview of the composition, mechanical properties, biocompatibility, and clinical applications for titanium alloys that are used for fracture fixation implants. A new class of titanium implant alloys has emerged in recent years that exhibits a beta microstructure and a unique combination of mechanical properties. Important information regarding notch sensitivity testing and clinical significance is also discussed. Attributes such as stress corrosion cracking resistance, fatigue strength, and wear characteristics are also essential for specific clinical applications, but are beyond the scope of this presentation. PMID:11270074

  13. Plate Tectonics Prof. Thomas Herring

    E-print Network

    Herring, Thomas

    1 Plate Tectonics Prof. Thomas Herring MIT 05/14/02 Lexington HS Plate tectonics 2 Contact/14/02 Lexington HS Plate tectonics 3 Overview · Development of the Plate tectonic theory · Geological Data ­ Sea-floor spreading ­ Fault types from earthquakes ­ Transform faults ­ Today's measurements of plate tectonics 05

  14. Plating To Reinforce Welded Joints

    NASA Technical Reports Server (NTRS)

    Otousa, J. E.

    1982-01-01

    Electrodeposition used to strengthen welded joints gouged, nicked, or suffered other mechanical damage. Plating cell, typically of acrylic plastic such as poly (Methylmetacrylate), is assembled around part to be plated. Areas not to be plated are masked with plater's tape. Weld area is plated in standard nickel-plating process.

  15. Biological nitrogen fixation and biomass accumulation within poplar clones as a result of inoculations with diazotrophic

    E-print Network

    Doty, Sharon Lafferty

    Biological nitrogen fixation and biomass accumulation within poplar clones as a result: biomass, diazotrophic endophytes, nitrogen (N) -fixation, phenotypic plasticity, poplar. Summary the enhancement of biological nitrogen fixation (BNF). Endophytes isolated from native poplar growing in nutrient

  16. Self-locking telescoping manipulator arm

    NASA Technical Reports Server (NTRS)

    Nesmith, M. F. (inventor)

    1985-01-01

    A telescoping manipulator arm and pivotable finger assembly are disclosed. The telescoping arm assembly includes a generally T-shaped arm having three outwardly extending fingers guided on grooved roller guides to compensate for environmental variations. The pivotable finger assembly includes four pivoting fingers. Arcuate teeth are formed on the ends of the fingers. A rack having teeth on four sides meshes with each one of the fingers. One surface of the rack includes teeth along its entire surface which mesh with teeth of one of the fingers. The teeth at the remote end of the rack engage teeth of a gear wheel. The wheel includes a worm which meshes with a worn drive shaft of the drive motor providing a ninety degree self-locking drive for locking the fingers in a desired position. A similar drive provides a self-locking drive for positioning the telescoping arm.

  17. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  18. Double reference pulsed phase locked loop

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (inventor)

    1986-01-01

    A double reference pulse phase locked loop is described which measures the phase shift between tone burst signals initially derived from the same periodic signal source (voltage controlled oscillator) and delayed by different amounts because of two different paths. A first path is from the transducer to the surface of a sample and back. A second path is from the transducer to the opposite surface and back. A first pulse phase locked loop including a phase detector and a phase shifter forces the tone burst signal delayed by the second path in phase quadrature with the periodic signal source. A second pulse phase locked loop including a second phase detector forces the tone burst signals delayed by the first path into phase quadrature with the phase shifted periodic signal source.

  19. Using river locks to teach hydrodynamic concepts

    E-print Network

    Carvalho-Santos, Vagson L; Silva, Enisvaldo C; Rios, Márcio L; Silva, Anderson A P

    2013-01-01

    In this work, the use of a river lock as a non-formal setting for teaching Q2 hydrodynamical concepts is proposed. In particular, we describe the operation of a river lock situated at the Sobradinho dam, on the S\\~ao Francisco River (Brazil). A model to represent and to analyse the dynamics of river lock operation is presented and we derive the dynamical equations for the rising of the water column as an example to understand the Euler equation. Furthermore, with this activity, we enable the integration of content initially introduced in the classroom with practical applications, thereby allowing the association of physical themes to content relevant in disciplines such as history and geography. In addition, experiences of this kind enable teachers to talk about the environmental and social impacts caused by the construction of a dam and, consequently, a crossover of concepts has been made possible, leading to more meaningful learning for the students.

  20. Phase locking and frequency locking of a 140 GHz klystron and a 280 GHz carcinotron

    SciTech Connect

    Sprehn, D.W.; Rettig, C.L.; Luhmann, N.C. Jr. )

    1992-10-01

    A phase and frequency-locked loop to synchronize two microwave tube oscillators for a high density plasma collective scattering diagnostic has been designed, assembled, and tested. A Varian (VRT2121A16) reflex klystron was down converted by mixing with the eighth harmonic of a 17.437 GHz phase-locked Gunn oscillator, and the resulting baseband was used to lock the klystron phase to a 200 MHz crystal. The down-converted 140 GHz klystron frequency spectrum shows a linewidth {lt}50 Hz and sideband power {lt}50 dB below the carrier (dBc). Frequency locking of a Thomson CSF TH4224S 280 GHz carcinotron was performed and the klystron was then down converted by the stabilized carcinotron and phase locked to the 200 MHz crystal. The klystron would track the frequency excursions of the carcinotron when the system was perturbed by direct modulation with frequencies of up to 10 MHz and remained locked as long as modulation sidebands were kept {lt}15 dBc. The locked states of both configurations show 3 to 4 orders of magnitude improvement in short and long term stability over the unlocked states.

  1. Hiatus Hernia Repair with Bilateral Oesophageal Fixation

    PubMed Central

    Martin, David

    2015-01-01

    Background. Despite advances in surgical repair of hiatus hernias, there remains a high radiological recurrence rate. We performed a novel technique incorporating bilateral oesophageal fixation and evaluated outcomes, principally symptom improvement and hernia recurrence. Methods. A retrospective study was performed on a prospective database of patients undergoing hiatus hernia repair with bilateral oesophageal fixation. Retrospective and prospective quality of life (QOL), PPI usage, and patient satisfaction data were obtained. Hernia recurrence was assessed by either barium swallow or gastroscopy. Results. 87 patients were identified in the database with a minimum of 3 months followup. There were significant improvements in QOL scores including GERD HRQL (29.13 to 4.38, P < 0.01), Visick (3 to 1), and RSI (17.45 to 5, P < 0.01). PPI usage decreased from a median of daily to none, and there was high patient satisfaction (94%). 57 patients were assessed for recurrence with either gastroscopy or barium swallow, and one patient had evidence of recurrence on barium swallow at 45 months postoperatively. There was an 8% complication rate and no mortality or oesophageal perforation. Conclusions. This study demonstrates that our technique is both safe and effective in symptom control, and our recurrence investigations demonstrate at least short term durability. PMID:26065030

  2. Fixation of basicervical and related fractures

    PubMed Central

    2009-01-01

    We prospectively studied 42 patients in order to identify a group of proximal femoral fractures having liability for axial and rotational instability, and to present results of their fixation using the dynamic hip screw (DHS) with derotation screw (DRS). At 12 months postoperatively, patients were functionally evaluated and the radiological outcome was analysed. All fractures united within an average period of 11.5 weeks. The mean sliding distance was 5.5 mm and mean shortening of the limbs was 2 mm. According to the criteria of Kyle et al. (J Bone Joint Surg [Am] 61-A:216–221), 39 patients obtained excellent results, two good and one fair. We conclude that the AO types B2.1, A1.1, A2.1, A2.2 and A2.3 have a common instability denominator and therefore should be treated alike. The sliding component of the DHS allows solid fixation of the two major fragments in two planes and the DRS in the third plane. PMID:19475407

  3. Heterodyne Doppler velocity measurement of moving targets by mode-locked pulse laser.

    PubMed

    Bai, Yan; Ren, Deming; Zhao, Weijiang; Qu, Yanchen; Qian, Liming; Chen, Zhenlei

    2012-01-16

    In this study, heterodyne detection is adopted to measure the velocity of a target simulated by a rapidly rotating plate by using a mode-locked pulse laser as the resource. The coherent beat frequency of the signal light reflected by target and local oscillation light occurred on the surface of the detector. Then the waveform of beat frequency was processed by filtering to obtain the Doppler frequency shift of the signal light induced by target. With this frequency shift, the velocity of target could be obtained by calculation. Results indicate that the measurement has a high precision. The error on average is within 0.4 m/s. PMID:22274421

  4. Earthquakes and plate tectonics.

    USGS Publications Warehouse

    Spall, H.

    1982-01-01

    Earthquakes occur at the following three kinds of plate boundary: ocean ridges where the plates are pulled apart, margins where the plates scrape past one another, and margins where one plate is thrust under the other. Thus, we can predict the general regions on the earth's surface where we can expect large earthquakes in the future. We know that each year about 140 earthquakes of magnitude 6 or greater will occur within this area which is 10% of the earth's surface. But on a worldwide basis we cannot say with much accuracy when these events will occur. The reason is that the processes in plate tectonics have been going on for millions of years. Averaged over this interval, plate motions amount to several mm per year. But at any instant in geologic time, for example the year 1982, we do not know, exactly where we are in the worldwide cycle of strain build-up and strain release. Only by monitoring the stress and strain in small areas, for instance, the San Andreas fault, in great detail can we hope to predict when renewed activity in that part of the plate tectonics arena is likely to take place. -from Author

  5. Soliton Dynamics in Mode-Locked Lasers

    NASA Astrophysics Data System (ADS)

    Cundiff, S. T.

    Mode-locked lasers generate ultra-short optical pulses, with durations ranging from hundreds of picoseconds (ps) down to a few femtoseconds (fs). The pulse circulating in the cavity of a mode-locked laser can be thought of as a dissipative soliton, where the dissipation is due to the inevitable presence of loss, which must be compensated by gain. In addition to gain and loss, the pulse experiences nonlinearity and dispersion, the key ingredients for any soliton system. These effects occur in physical elements that do not completely fill the cavity, thus there is a similarity to the dispersion management that is used in telecommunications systems.

  6. Integrated injection-locked semiconductor diode laser

    DOEpatents

    Hadley, G. Ronald (Albuquerque, NM); Hohimer, John P. (Albuquerque, NM); Owyoung, Adelbert (Albuquerque, NM)

    1991-01-01

    A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet.

  7. Integrated injection-locked semiconductor diode laser

    DOEpatents

    Hadley, G.R.; Hohimer, J.P.; Owyoung, A.

    1991-02-19

    A continuous wave integrated injection-locked high-power diode laser array is provided with an on-chip independently-controlled master laser. The integrated injection locked high-power diode laser array is capable of continuous wave lasing in a single near-diffraction limited output beam at single-facet power levels up to 125 mW (250 mW total). Electronic steering of the array emission over an angle of 0.5 degrees is obtained by varying current to the master laser. The master laser injects a laser beam into the slave array by reflection of a rear facet. 18 figures.

  8. Hydrodynamic phase-locking of swimming microorganisms

    E-print Network

    Gwynn J. Elfring; Eric Lauga

    2009-07-06

    Some microorganisms, such as spermatozoa, synchronize their flagella when swimming in close proximity. Using a simplified model (two infinite, parallel, two-dimensional waving sheets), we show that phase-locking arises from hydrodynamics forces alone, and has its origin in the front-back asymmetry of the geometry of their flagellar waveform. The time-evolution of the phase difference between co-swimming cells depends only on the nature of this geometrical asymmetry, and microorganisms can phase-lock into conformations which minimize or maximize energy dissipation.

  9. Cultivar effects on nitrogen fixation in peas and lentils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing nitrogen fixation in legume crops could increase cropping productivity and reduce nitrogen fertilizer use. Studies have found that crop genotype, rhizobial strain, and occasionally genotype-specific interactions affect N fixation, but this knowledge has not yet been used to evaluate or br...

  10. Identifying Fixations and Saccades in Eye-Tracking Protocols

    E-print Network

    Salvucci, Dario D.

    Identifying Fixations and Saccades in Eye-Tracking Protocols Dario D. Salvucci Nissan Cambridge identification--separating and labeling fixations and saccades in eye-tracking protocols--is an essential part algorithms in terms of how they utilize spatial and temporal information in eye-tracking protocols. Using

  11. Humor Preference as a Function of Preoedipal Fixation.

    ERIC Educational Resources Information Center

    Juni, Samuel

    1982-01-01

    Psychoanalytic theory predicts that humor preference is a derivative of unresolved childhood conflicts. Analyzed students' (N=104) Rorschach protocols to yield measures of preoedipal fixation. Students ranked jokes from most to least funny. Results showed that the ranking of jokes was a function of the fixation measures for women only. (Author/RC)

  12. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  13. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  14. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  15. FIXATION OF FISH TISSUES. IN: THE LABORATORY FISH.

    EPA Science Inventory

    This chapter deals with the fixation of fish tissues and whole fish. Traditionally, fixation has been applied to animal tissues mainly for histological or pathological studies. Development of new molecular and immunologic tools now allows tissue and cellular localization of nucle...

  16. ORIGINAL PAPER Biological nitrogen fixation by common beans

    E-print Network

    Lehmann, Johannes

    ORIGINAL PAPER Biological nitrogen fixation by common beans (Phaseolus vulgaris L.) increases biological N2 fixation (BNF) by common beans (Phaseolus vulgaris L.) through bio-char additions (charcoal- tox cropped to a potentially nodulating bean variety (CIAT BAT 477) in comparison to its non

  17. Overcoming Organizational Fixation: Creating and Sustaining an Innovation Culture

    ERIC Educational Resources Information Center

    Stempfle, Joachim

    2011-01-01

    Fixation on established paradigms and practices can severely limit the capability of organizations to change, thereby jeopardizing the ability of organizations to keep up with changes in their environment and new technological developments. Overcoming organizational fixation is therefore a requirement for any organization that strives to achieve…

  18. Characteristics of Fixational Eye Movements in People With Macular Disease

    PubMed Central

    Kumar, Girish; Chung, Susana T. L.

    2014-01-01

    Purpose. Fixation stability is known to be poor for people with macular disease and has been suggested as a contributing factor for the poor visual performance of these individuals. In this study, we examined the characteristics of the different components of fixational eye movements and determined the component that plays a major role in limiting fixation stability in people with macular disease. Methods. Sixteen observers with macular disease and 14 older adults with normal vision (control observers) monocularly fixated a small cross presented using a Rodenstock scanning laser ophthalmoscope, for trials of 30 seconds. The retinal image and the position of the cross on the retina were recorded digitally. Eye movements were extracted from the recorded videos at a sampling rate of 540 Hz using a cross-correlation technique. A velocity criterion of 8°/s was used to differentiate between slow drifts and microsaccades. Results. Observers with macular disease demonstrated higher fixation instability, larger amplitudes of slow drifts and microsaccades, and lower drift velocities, when compared with older adults with normal vision. The velocity and the rate of microsaccades were comparable between the two groups of observers. Multiple linear regression analysis showed that the amplitude of microsaccades, and to a smaller extent, the amplitude of slow drifts, play a major role in limiting fixation stability. Conclusions. Fixation stability in people with macular disease is primarily limited by the amplitude of microsaccades, implying that rehabilitative strategies targeted at reducing the amplitude of microsaccades should improve fixation stability, and may lead to improved visual functions. PMID:25074769

  19. CRISP: A Computational Model of Fixation Durations in Scene Viewing

    ERIC Educational Resources Information Center

    Nuthmann, Antje; Smith, Tim J.; Engbert, Ralf; Henderson, John M.

    2010-01-01

    Eye-movement control during scene viewing can be represented as a series of individual decisions about where and when to move the eyes. While substantial behavioral and computational research has been devoted to investigating the placement of fixations in scenes, relatively little is known about the mechanisms that control fixation durations.…

  20. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheal tube fixation device. 868.5770 Section 868.5770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5770 Tracheal tube fixation device. (a) Identification. A tracheal tube...

  1. Application of monorail fixator for femoral gap nonunion.

    PubMed

    Agrawal, Hemendra-Kumar; Jaiman, Ashish; Khatkar, Vipin; Sharma, Vinod-Kumar

    2014-01-01

    Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration. PMID:25098853

  2. Ancestral recombination-selection graph and fixation probability

    E-print Network

    Leclercq, Remi

    Ancestral recombination-selection graph and fixation probability Application to the Hill;Ancestral recombination-selection graph and fixation probability Application to the Hill-Robertson effect;Recombination #12;Recombination T Negative linkage disequilibrium D Recombination T Negative linkage

  3. VIEW LOOKING EAST AT PLEASURE CRAFTS ENTERING THE NAVIGATION LOCK. ...

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

    VIEW LOOKING EAST AT PLEASURE CRAFTS ENTERING THE NAVIGATION LOCK. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

  4. VIEW LOOKING SOUTH AT THE LOCK GATES AND OPERATING MECHANISM. ...

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

    VIEW LOOKING SOUTH AT THE LOCK GATES AND OPERATING MECHANISM. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

  5. 49 CFR 236.775 - Movement, switch-and-lock.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

  6. 49 CFR 236.775 - Movement, switch-and-lock.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

  7. 49 CFR 236.775 - Movement, switch-and-lock.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

  8. 49 CFR 236.775 - Movement, switch-and-lock.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

  9. 49 CFR 236.775 - Movement, switch-and-lock.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...APPLIANCES Definitions § 236.775 Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or...

  10. 2. Distant view of lock and dam to northwest ...

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

    2. Distant view of lock and dam to northwest - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  11. 1. Distant view of lock and dam to northeast ...

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

    1. Distant view of lock and dam to northeast - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  12. 3. Down river view of lock and dam to southwest ...

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

    3. Down river view of lock and dam to southwest - Mississippi River 9-Foot Channel, Lock & Dam No. 1, In Mississippi River at Mississippi Boulevard, below Ford Parkway Bridge, Saint Paul, Ramsey County, MN

  13. 49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

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

    49. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- TYPICAL PIER ISOMETRIC. M-L 26(R) 40/1 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  14. 50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM ...

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

    50. LOCK AND DAM NO. 26 (REPLACEMENT). FIRST STAGE DAM -- DAM CONCRETE -- GENERAL ARRANGEMENT -- SECTION AND ELEVATIONS. M-L 26(R) 40/3 - Upper Mississippi River 9-Foot Channel Project, Lock & Dam 26R, Alton, Madison County, IL

  15. LOCK NO. 1 ST. LUCIE CANAL. ATTENDANT'S QUARTERS SINGLE ...

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

    LOCK NO. 1 - ST. LUCIE CANAL. ATTENDANT'S QUARTERS SINGLE HOUSE B - PLANS AND ELEVATIONS - St. Lucie Canal, Lock No. 1, Attendant's Quarters, St. Lucie, Cross State Canal, Okeechobee Intracoastal Waterway, Stuart, Martin County, FL

  16. 30 CFR 56.12068 - Locking transformer enclosures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against unauthorized...

  17. 30 CFR 56.12068 - Locking transformer enclosures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against unauthorized...

  18. 20. LOCK GATES, 3 FOOT WALKWAY, ADJUSTMENT AT GUDGEON PIN ...

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

    20. LOCK GATES, 3 FOOT WALKWAY, ADJUSTMENT AT GUDGEON PIN AND QUOIN SHOE. May 1933 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 17, Upper Mississippi River, New Boston, Mercer County, IL

  19. DOG HOUSE AT UPSTREAM LOCK GATE. ALSO SEEN AT LEFT ...

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

    DOG HOUSE AT UPSTREAM LOCK GATE. ALSO SEEN AT LEFT IN PHOTO NO. IL-164-A-23. - Illinois Waterway, La Grange Lock and Dam, 3/4 mile south of Country 795N at Illinois River, Versailles, Brown County, IL

  20. 10. LOCK CONSTRUCTION PHOTO SHOWING CONCRETE MONOLITHS FOR WALLS, LOOKING ...

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

    10. LOCK CONSTRUCTION PHOTO SHOWING CONCRETE MONOLITHS FOR WALLS, LOOKING NORTH. August 1934 - Mississippi River 9-Foot Channel Project, Lock & Dam No. 16, Upper Mississippi River, Muscatine, Muscatine County, IA