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Sample records for established fixation techniques

  1. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  2. Porcine Intestinal Mast Cells. Evaluation of Different Fixatives for Histochemical Staining Techniques Considering Tissue Shrinkage

    PubMed Central

    Rieger, J.; Twardziok, S.; Huenigen, H.; Hirschberg, R.M.; Plendl, J.

    2013-01-01

    Staining of mast cells (MCs), including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF) has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkagedifferences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from data using different

  3. 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

  4. A novel technique for attaining maxillomandibular fixation in the edentulous mandible fracture.

    PubMed

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

    2012-03-01

    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.

  5. Acrylic Resin Molding Based Head Fixation Technique in Rodents.

    PubMed

    Roh, Mootaek; Lee, Kyungmin; Jang, Il-Sung; Suk, Kyoungho; Lee, Maan-Gee

    2016-01-12

    Head fixation is a technique of immobilizing animal's head by attaching a head-post on the skull for rigid clamping. Traditional head fixation requires surgical attachment of metallic frames on the skull. The attached frames are then clamped to a stationary platform resulting in immobilization of the head. However, metallic frames for head fixation have been technically difficult to design and implement in general laboratory environment. In this study, we provide a novel head fixation method. Using a custom-made head fixation bar, head mounter is constructed during implantation surgery. After the application of acrylic resin for affixing implants such as electrodes and cannula on the skull, additional resins applied on top of that to build a mold matching to the port of the fixation bar. The molded head mounter serves as a guide rails, investigators conveniently fixate the animal's head by inserting the head mounter into the port of the fixation bar. This method could be easily applicable if implantation surgery using dental acrylics is necessary and might be useful for laboratories that cannot easily fabricate CNC machined metal head-posts.

  6. Cemented and cementless fixation: results and techniques.

    PubMed

    Silverton, Craig D

    2006-01-01

    There are multiple reports of successful cemented and cementless total knee arthroplasty in the current literature. Although technically more demanding to implant, selected cementless designs, with nearly 20 years of follow-up, demonstrate near-equal success compared with cemented implants, the gold standard. Far more important than the decision to use a cemented or cementless implant is the use of precise technique, adequate balancing of the soft tissues, and proper overall alignment. Failure to achieve these basic principles can lead to early failure in any total knee replacement system.

  7. Simplified technique of mesh fixation during laparoscopic repair of abdominal ventral hernia.

    PubMed

    Piskun, G; Shaftan, G; Fogler, R

    1999-04-01

    The current techniques for intraperitoneal mesh fixation are complex and time-consuming. We present here a simple technique for the fixation of the mesh during laparoscopic intraperitoneal ventral hernia repair.

  8. A new and easy technique for maxillomandibular fixation

    PubMed Central

    Singh, Virendra; Bhagol, Amrish; Kumar, Ish

    2010-01-01

    Maxillomandibular fixation (MMF) is important in the treatment of maxillofacial fractures and is usually applied by wiring together the fixed upper and lower arch bars. Here, we report a new type of MMF technique, Rohtak Dental College (RDC) technique using 26-gauze stainless steel wires. It is a simple, quick, economical and minimally invasive technique. Its mechanical principle provides an advantage in preventing postoperative periodontal problems. Typical indications for its use are minimally displaced fractures, orthognathic surgeries and in tumor resection surgeries. PMID:22442545

  9. Relative strength of tailor's bunion osteotomies and fixation techniques.

    PubMed

    Haddon, Todd B; LaPointe, Stephan J

    2013-01-01

    A paucity of data is available on the mechanical strength of fifth metatarsal osteotomies. The present study was designed to provide that information. Five osteotomies were mechanically tested to failure using a materials testing machine and compared with an intact fifth metatarsal using a hollow saw bone model with a sample size of 10 for each construct. The osteotomies tested were the distal reverse chevron fixated with a Kirschner wire, the long plantar reverse chevron osteotomy fixated with 2 screws, a mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, the mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, and an additional cerclage wire and a transverse closing wedge osteotomy fixated with a box wire technique. Analysis of variance was performed, resulting in a statistically significant difference among the data at p <.0001. The Tukey-Kramer honestly significant difference with least significant differences was performed post hoc to separate out the pairs at a minimum α of 0.05. The chevron was statistically the strongest construct at 130 N, followed by the long plantar osteotomy at 78 N. The chevron compared well with the control at 114 N, and they both fractured at the proximal model to fixture interface. The other osteotomies were statistically and significantly weaker than both the chevron and the long plantar constructs, with no statistically significant difference among them at 36, 39, and 48 N. In conclusion, the chevron osteotomy was superior in strength to the sagittal and transverse plane osteotomies and similar in strength and failure to the intact model.

  10. "The Dendritic Bonding Technique": A Newly-devised Technique for the Fixation of Mesh Skin Graft.

    PubMed

    Sakamoto, Yoshiaki; Kishi, Kazuo

    2012-07-01

    We describe a newly designed technique for the quick, easy, and cost-effective fixation of mesh skin grafts in a range of skin conditions and patients. We fixed the skin graft using octyl-2-cyanoacrylate (Dermabond; Ethicon), which was termed "Dendritic bonding." This technique exhibits several advantages over surgical stapling and suturing with absorbable sutures.

  11. A new adhesive technique for internal fixation in midfacial surgery

    PubMed Central

    Endres, Kira; Marx, Rudolf; Tinschert, Joachim; Wirtz, Dieter Christian; Stoll, Christian; Riediger, Dieter; Smeets, Ralf

    2008-01-01

    Background The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could offer a viable alternative for fixing the plates without screws. In order to achieve the adhesive bonding of bone cement to cortical bone in the viscerocranium, an amphiphilic bone bonding agent was created, analogous to the dentin bonding agents currently on the market. Methods The adhesive bonding strengths were measured using tension tests. For this, metal plates with 2.0 mm diameter screw holes were cemented with PMMA bone cement to cortical bovine bone samples from the femur diaphysis. The bone was conditioned with an amphiphilic bone bonding agent prior to cementing. The samples were stored for 1 to 42 days at 37 degrees C, either moist or completely submerged in an isotonic NaCl-solution, and then subjected to the tension tests. Results Without the bone bonding agent, the bonding strength was close to zero (0.2 MPa). Primary stability with bone bonding agent is considered to be at ca. 8 MPa. Moist storage over 42 days resulted in decreased adhesion forces of ca. 6 MPa. Wet storage resulted in relatively constant bonding strengths of ca. 8 MPa. Conclusion A new amphiphilic bone bonding agent was developed, which builds an optimizied interlayer between the hydrophilic bone surface and the hydrophobic PMMA bone cement and thus leads to adhesive bonding between them. Our in vitro investigations demonstrated the adhesive bonding of PMMA bone cement to cortical bone, which was also stable against hydrolysis. The newly developed adhesive fixing technique could be applied clinically when the fixation of osteosynthesis plates with screws is impossible. With

  12. Subaxial cervical and cervicothoracic fixation techniques--indications, techniques, and outcomes.

    PubMed

    Pelton, Miguel A; Schwartz, Joseph; Singh, Kern

    2012-01-01

    The subaxial and cervicothoracic junction is a relatively difficult area for spine surgeons to navigate. Because of different transitional stressors at the junction of the smaller cervical vertebrae and the larger thoracic segments, proximity to neurovascular structures, and complex anatomy, extreme care and precision must be assumed during fixation in these regions. Lateral mass screws, pedicle screws, and translaminar screws are currently the standard of choice in the subaxial cervical and upper thoracic spine. This article addresses the relevant surgical anatomy, pitfalls, and pearls associated with each of these fixation techniques.

  13. Double-eyelid operation: orbicularis oculi-levator aponeurosis fixation technique.

    PubMed

    Park, Jung I; Park, Min S

    2007-08-01

    Incision techniques in the past focused on fixing the pretarsal skin to either the tarsal plate or to the levator aponeurosis. High relapse rate remains one of the main concerns in double-eyelid surgery. To address these issues, the author developed a pretarsal orbicularis oculi muscle-levator aponeurosis fixation technique. This technique results in better fixation between the skin and the levator aponeurosis by recruiting a bulky, pretarsal orbicularis oculi muscle in the fixation mechanism. This technique provides for a solidly fixed, tightly stretched pretarsal skin when the eyes are open with significantly reduced chances of relapse.

  14. Tibial Lengthening Using a Fixator-Assisted Lengthening Plate: A New Technique

    PubMed Central

    Tosun, Haci Bayram; Agir, Ismail; Gumustas, Seyitali; Serbest, Sancar; Uludag, Abuzer; Celik, Suat

    2016-01-01

    Background There are many techniques that are used for limb lengthening. Lengthening a limb over a plate is an alternative choice used in children or when using an intramedullary nail is difficult. Objectives In this study, we presented a new technique for tibial lengthening using a monolateral external fixator over a lengthening plate. Materials and Methods For tibial lengthening, a monolateral external fixator was attached to the composite bone model medially. After a corticotomy was performed, the lengthening plate was placed laterally. Three locking screws were inserted proximally, and two cortical screws were inserted into a lengthening hole that was 1 cm below the osteotomy site. We avoided contact between the screws of the lengthening plate and the pins of the external fixator. During bone lengthening with the monolateral external fixator, the screws at the lengthening hole were able to slide distally with the distal segment of the tibia to allow for tibial elongation. Two locking screws were fixed at the distal locking holes of the plate when the bone elongation was complete. The external fixator was then removed. Results The fixator-assisted lengthening plate allowed bone lengthening without malalignment. There were no mechanical problems associated with the external fixator during the lengthening process. Plate osteosynthesis was stable after the fixator was removed. There was no contact between the screws of plate and the Schanz pins of the external fixator under C-arm fluoroscopy. Conclusions The fixator-assisted lengthening plate technique helps to maintain the stability and alignment at both sides of an osteotomy during tibial elongation. It allows the early removal of the external fixator immediately after lengthening is completed. This technique can be applied in children with open physes and in patients with a narrow medullary canal who are unsuitable for limb lengthening over an intramedullary nail. PMID:28184364

  15. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    PubMed

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

  16. Biomechanical analyses of static and dynamic fixation techniques of retrograde interlocking femoral nailing using nonlinear finite element methods.

    PubMed

    Shih, Kao-Shang; Hsu, Ching-Chi; Hsu, Tzu-Pin; Hou, Sheng-Mou; Liaw, Chen-Kun

    2014-02-01

    Femoral shaft fractures can be treated using retrograde interlocking nailing systems; however, fracture nonunion still occurs. Dynamic fixation techniques, which remove either the proximal or distal locking screws, have been used to solve the problem of nonunion. In addition, a surgical rule for dynamic fixation techniques has been defined based on past clinical reports. However, the biomechanical performance of the retrograde interlocking nailing systems with either the traditional static fixation technique or the dynamic fixation techniques has not been investigated by using nonlinear numerical modeling. Three-dimensional nonlinear finite element models were developed, and the implant strength, fixation stability, and contact area of the fracture surfaces were evaluated. Three types of femoral shaft fractures (a proximal femoral shaft fracture, a middle femoral shaft fracture, and a distal femoral shaft fracture) fixed by three fixation techniques (insertion of all the locking screws, removal of the proximal locking screws, or removal of the distal locking screws) were analyzed. The results showed that the static fixation technique resulted in sufficient fixation stability and that the dynamic fixation techniques decreased the failure risk of the implant and produced a larger contact area of the fracture surfaces. The outcomes of the current study could assist orthopedic surgeons in comprehending the biomechanical performances of both static and dynamic fixation techniques. In addition, the surgeons could also select a fixation technique based on the specific patient situation using the numerical outcomes of this study.

  17. Open reduction internal fixation for proximal humerus fractures indications, techniques, and pitfalls.

    PubMed

    Shulman, Brandon S; Egol, Kenneth A

    2013-01-01

    Proximal humerus fractures account for approximately 5% of all fractures. It is estimated that due to our aging population, orthopaedic surgeons will see a three-fold increase in proximal humerus fractures over the next 30 years. Internal fixation with locked plating is the current mainstay of treatment for functionally active patients who desire minimal loss of function. A thorough understanding of the indications, techniques, and drawbacks of treatment with internal fixation is essential to achieve the highest quality of patient care.

  18. Autologous Hamstring Anterior Cruciate Ligament Graft Failure Using the Anteromedial Portal Technique With Suspensory Femoral Fixation

    PubMed Central

    Galdi, Balazs; Reyes, Allan; Brabston, Eugene W.; Levine, William N.

    2015-01-01

    Background: The anteromedial portal technique for drilling of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction has been advocated by many surgeons as allowing improved access to the anatomical footprint. Furthermore, suspensory fixation of soft tissue grafts has become popularized because of complications associated with cross-pin fixation. Concerns regarding the use of both have recently arisen. Purpose: To raise awareness of the increased risk of graft failure when using the anteromedial portal technique with suspensory femoral fixation during ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: From November 1998 to August 2012, a total of 465 primary ACL reconstructions were performed using quadrupled hamstring autograft tendons, with drilling of the femoral tunnel performed via the transtibial portal. Graft fixation on the femur was achieved with cross-pin fixation, while interference screw fixation was used on the tibia. From September 2012 to October 2013, there were 69 reconstructions performed through an anteromedial portal. While there was no change in graft choice, a change was made to using suspensory femoral fixation. No other surgical or postoperative rehabilitation changes were made. Results: During the 14-year period in which ACL reconstructions were performed via the transtibial portal and with cross-pin fixation, 2 graft failures (0.4% failure rate) were reported. After switching to the anteromedial portal with suspensory fixation, 7 graft failures (10.1% failure rate) were reported over a 13-month period. These were 5 male and 2 female patients, with a mean age of 18.8 years—all elite athletes. The same surgical technique was used in all patients, and all patients had at least an 8 mm–diameter graft. Patients were cleared to return to sport at an average of 8.4 months postoperatively, after completing functional performance tests. Of the 7 patients, 6 sustained a rerupture of the graft within

  19. Femoral neck fracture fixation: rigidity of five techniques compared.

    PubMed Central

    Mackechnie-Jarvis, A C

    1983-01-01

    Artificial cadaveric femoral neck fractures were internally fixed with five different devices and subjected to cyclical loading of 0-1.0 kilonewtons (approximately one body weight) whilst in an anatomical position. Displacement of the proximal fragment was detected by a transducer and charted. Bone strength was assessed by a preliminary control loading phase on the intact bone. Efficiency of each fracture fixator could then be directly compared by the relative movement in each case. Five specimens each were tested with Moore's Pins, Trifin Nail, Garden Screws and a sliding screw-plate (OEC Ltd). By the criteria of the experiment, which put a severe shearing load on the implant, none of these devices reliably bore the representative body weight. An extended barrel-plate, which supported the sliding screw almost up to the fracture line, was then made. This device, employing some of Charnley's concepts, tolerated body weight in four cases out of five. PMID:6887186

  20. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  1. Pelvic Fixation in Adult and Pediatric Spine Surgery: Historical Perspective, Indications, and Techniques: AAOS Exhibit Selection.

    PubMed

    Jain, Amit; Hassanzadeh, Hamid; Strike, Sophia A; Menga, Emmanuel N; Sponseller, Paul D; Kebaish, Khaled M

    2015-09-16

    Achieving solid osseous fusion across the lumbosacral junction has historically been, and continues to be, a challenge in spine surgery. Robust pelvic fixation plays an integral role in achieving this goal. The goals of this review are to describe the history of and indications for spinopelvic fixation, examine conventional spinopelvic fixation techniques, and review the newer S2-alar-iliac technique and its outcomes in adult and pediatric patients with spinal deformity. Since the introduction of Harrington rods in the 1960s, spinal instrumentation has evolved substantially. Indications for spinopelvic fixation as a means to achieve lumbosacral arthrodesis include a long arthrodesis (five or more vertebral levels) or use of three-column osteotomies in the lower thoracic or lumbar spine, surgical treatment of high-grade spondylolisthesis, and correction of lumbar deformity and pelvic obliquity. A variety of techniques have been described over the years, including Galveston iliac rods, Jackson intrasacral rods, the Kostuik transiliac bar, iliac screws, and S2-alar-iliac screws. Modern iliac screws and S2-alar-iliac screws are associated with relatively low rates of pseudarthrosis. S2-alar-iliac screws have the advantages of less implant prominence and inline placement with proximal spinal anchors. Collectively, these techniques provide powerful methods for obtaining control of the pelvis in facilitating lumbosacral arthrodesis.

  2. The "medio-latero-superior trajectory technique": an alternative cortical trajectory for pedicle fixation.

    PubMed

    Mobbs, Ralph J

    2013-02-01

    An alternative pedicle trajectory for use at the superior end of a construct to limit dissection of the mobile superior facet joint and reduce incision length and muscle dissection, thus minimizing approach-related trauma during pedicle fixation, is reported. The medio-latero-superior trajectory technique involves a starting point on the medial aspect of the pars and angulation of the pedicle screw in a mediolateral and caudocranial direction. This approach takes advantage of a predominantly cortical trajectory to assist with bone fixation. Drawbacks of this new screw trajectory are discussed along with its potential benefits.

  3. Dual Fixation of Calcaneal Tuberosity Avulsion with Concomitant Achilles Tendon Rupture: A Novel Hybrid Technique

    PubMed Central

    Kusnezov, Nicholas; Rensing, Nicholas

    2017-01-01

    Fracture of the calcaneal tuberosity with a concomitant Achilles tendon rupture presents a difficult challenge for the treating surgeon. The ultimate goal of treatment is to restore function of both the gastrocnemius-soleus complex and the Achilles tendon. This particular subset of fractures occurs often in diabetics and elderly patients with osteoporosis making fixation of the displaced fragment rather complex. If the Achilles tendon disruption is only discovered later once the fracture is healed, subsequent management is difficult with surgical treatment being more morbid. While this is a rare injury, the consequences of a missed chronic Achilles tendon disruption are severe with significant dysfunction. It is therefore important to have a high index of suspicion for concomitant injury and to be prepared for dual fixation. We present a novel hybrid surgical fixation technique, which may be used in this instance. PMID:28357147

  4. The innovative safe fixative for histology, histopathology, and immunohistochemistry techniques: "pilot study using shellac alcoholic solution fixative".

    PubMed

    Ali Jamal, Awatif; Abd El-Aziz, Gamal Said; Hamdy, Raid Mahmoud; Al-Hayani, Abdulmonem; Al-Maghrabi, Jaudah

    2014-05-01

    The concerns over health and workplace hazards of formalin fixative, joined to its cross-linking of molecular groups that results in suboptimal immunohistochemistry, led us to search for an innovative safe fixative. Shellac is a natural material which is used as a preservative in foods and pharmaceutical industries. This study was undertaken to evaluate the fixation adequacy and staining quality of histopathological specimens fixed in the "shellac alcoholic solution" (SAS), and also to determine the validity of immunohistochemical staining of SAS-fixed material in comparison to those fixed in formalin. Fresh samples from 26 cases from various human tissues were collected at the frozen section room of King Abdulaziz University Hospital, and fixed in SAS fixative or in neutral buffered formaldehyde (NBF) for 12, 18, 24, and 48 h, and processed for paraffin sectioning. Deparaffinized sections were stained with hematoxylin and eosin (H&E) and immunostained for different antigens. The tissues fixed in SAS for >18 h showed best staining quality of H&E comparable to NBF-fixed tissues. Comparison of the immunohistochemical staining of different tissues yielded nearly equivalent readings with good positive nuclear staining quality in both fixatives. These findings support the fixation and preservation adequacy of SAS. Furthermore, it was concluded that the good staining quality obtained with SAS-fixed tissues, which was more or less comparable with the quality obtained with the formalin fixed tissues, supports the validity of this new solution as a good innovative fixative.

  5. An eye movement technique for correlating fixational target eye movements with location on the retinal image.

    PubMed

    Barrett, S F; Zwick, H

    2000-01-01

    Recent investigation demonstrate that ocular motility in eyes with retinal pathology may show a lower propensity to visit such areas of the retina as compared to non-pathological retinal sites. While current ophthalmic instruments with the ability to image both the retina and visual function test target placement on the retina have provided this observation, the ability to quantify in real time these images as an eye movement measurement is presently lacking and the objective of this paper. A Rodenstock confocal scanning ophthalmoscope (CSLO) was used to image the retina during the performance of a visual fixation task. Direct observation of acuity target placement at the retina under continuous viewing conditions was possible with this apparatus. Target fixation eye movement images of the retina were rapidly digitized from video tape records and registered using a specialized rapid retinal image tracking algorithm. Fixational eye movement pattern densities at the retina were derived from these data. Preliminary data obtained demonstrate the utility of this technique in quantifying fixation eye movement patterns observed in three human patients with vocation-related laser retinal injury. In all patients, areas of severe retinal damage was generally avoided. The density of ocular eye movement tends to reflect regions of retinal normality and avoidance of retinal regions with severe pathology. Variation in eye movement density may exist where pathology is less severe.

  6. Radiomics: a new application from established techniques

    PubMed Central

    Parekh, Vishwa; Jacobs, Michael A.

    2016-01-01

    The increasing use of biomarkers in cancer have led to the concept of personalized medicine for patients. Personalized medicine provides better diagnosis and treatment options available to clinicians. Radiological imaging techniques provide an opportunity to deliver unique data on different types of tissue. However, obtaining useful information from all radiological data is challenging in the era of “big data”. Recent advances in computational power and the use of genomics have generated a new area of research termed Radiomics. Radiomics is defined as the high throughput extraction of quantitative imaging features or texture (radiomics) from imaging to decode tissue pathology and creating a high dimensional data set for feature extraction. Radiomic features provide information about the gray-scale patterns, inter-pixel relationships. In addition, shape and spectral properties can be extracted within the same regions of interest on radiological images. Moreover, these features can be further used to develop computational models using advanced machine learning algorithms that may serve as a tool for personalized diagnosis and treatment guidance. PMID:28042608

  7. Radiomics: a new application from established techniques.

    PubMed

    Parekh, Vishwa; Jacobs, Michael A

    2016-01-01

    The increasing use of biomarkers in cancer have led to the concept of personalized medicine for patients. Personalized medicine provides better diagnosis and treatment options available to clinicians. Radiological imaging techniques provide an opportunity to deliver unique data on different types of tissue. However, obtaining useful information from all radiological data is challenging in the era of "big data". Recent advances in computational power and the use of genomics have generated a new area of research termed Radiomics. Radiomics is defined as the high throughput extraction of quantitative imaging features or texture (radiomics) from imaging to decode tissue pathology and creating a high dimensional data set for feature extraction. Radiomic features provide information about the gray-scale patterns, inter-pixel relationships. In addition, shape and spectral properties can be extracted within the same regions of interest on radiological images. Moreover, these features can be further used to develop computational models using advanced machine learning algorithms that may serve as a tool for personalized diagnosis and treatment guidance.

  8. Two-Tension-Band Technique in Revision Surgery for Fixation Failure of Patellar Fractures

    PubMed Central

    Xue, Zichao; Qin, Hui; Ding, Haoliang; Xu, Haitao; An, Zhiquan

    2016-01-01

    Background Failed patellar fracture fixation is rare, and is usually attributed to technical errors. There are no specific details available on how to address this problem. We present our two-tension-band technique for fixing patellar fractures. Material/Methods Between March 2010 and March 2013, 4 men and 2 women with failed fixation patellar fractures were treated in our department. Their average age was 34 years (range 23–49 years). The initial fracture type was C1 in 3, C2 in 1, and C3 in 2, according to the AO classification. The initial fracture patterns included 3 transverse and 3 comminuted fractures. There were no open fractures. All patients underwent internal fixation with a modified anterior tension band (MATB) supplemented with cerclage wiring. All failures were caused by tension bands sliding past the tip of the Kirschner wires. The mean time between the primary and revision operations was 16.2 months (range 2–63 months). We revised the fractures by two-separate-tension-band technique. Results The mean follow-up was 52 months (range 31–67 months). All patients healed radiographically without complications at an average of 14.7 weeks (range 8–20 weeks). The Bostman knee score was excellent in 3 and good in 3. All patients regained full extension and the mean range of flexion was 147.5° (135–155°). Conclusions Use of this two-tension-band technique can avoid technical errors and provide more secure fixation. We recommend it for both primary and revision surgery of patellar fractures. PMID:27485104

  9. Proximal screws placement in intertrochanteric fractures treated with external fixation: comparison of two different techniques

    PubMed Central

    2011-01-01

    Background To compare two different techniques of proximal pin placement for the treatment of intertrochanteric fractures in elderly patients utilizing the Orthofix Pertrochanteric Fixator. Methods Seventy elderly high-risk patients with an average age of 81 years were treated surgically for intertrochanteric fracture, resulting from a low energy trauma. Patients were randomly divided in two groups regarding to the proximal pin placement technique. In Group A the proximal pins were inserted in a convergent way, while in Group B were inserted in parallel. Results All fractures healed uneventfully after a mean time of 98 days. The fixator was well accepted and no patient had significant difficulties while sitting or lying. The mean VAS score was 5.4 in group A and 5.7 in group B. At 12 months after surgery, in group A the average Harris Hip Score and the Palmer and Parker mobility score was 67 and 5.8, respectively. In group B, the average Harris Hip Score and the Palmer and Parker mobility score was 62 and 5.6, respectively. No statistically significant difference was found regarding the functional outcome. The mean radiographic exposure during pin insertion in Group A and Group B was 15 and 6 seconds, respectively. The difference between the two groups, regarding the radiographic exposure, was found to be significant. Conclusion Proximal screw placement in a parallel way is simple, with significant less radiation exposure and shorter intraoperative duration. In addition, fixation stability is equal compared to convergent pin placement. PMID:21939534

  10. Effect of meniscus replacement fixation technique on restoration of knee contact mechanics and stability.

    PubMed

    D'Lima, D D; Chen, P C; Kessler, O; Hoenecke, H R; Colwell, C W

    2011-06-01

    The menisci are important biomechanical components of the knee. We developed and validated a finite element model of meniscal replacement to assess the effect of surgical fixation technique on contact behavior and knee stability. The geometry of femoral and tibial articular cartilage and menisci was segmented from magnetic resonance images of a normal cadaver knee using MIMICS (Materialise, Leuven, Belgium). A finite element mesh was generated using HyperWorks (Altair Inc, Santa Ana, CA). A finite element solver (Abaqus v6.9, Simulia, Providence, RI) was used to compute contact area and stresses under axial loading and to assess stability (reaction force generated during anteroposterior translation of the femur). The natural and surgical attachments of the meniscal horns and peripheral rim were simulated using springs. After total meniscectomy, femoral contact area decreased by 26% with a concomitant increase in average contact stresses (36%) and peak contact stresses (33%). Replacing the meniscus without suturing the horns did little to restore femoral contact area. Suturing the horns increased contact area and reduced peak contact stresses. Increasing suture stiffness correlated with increased meniscal contact stresses as a greater proportion of tibiofemoral load was transferred to the meniscus. A small incremental benefit was seen of simulated bone plug fixation over the suture construct with the highest stiffness (50 N/mm). Suturing the rim did little to change contact conditions. The nominal anteroposterior stiffness reduced by 3.1 N/mm after meniscectomy. In contrast to contact area and stress, stiffness of the horn fixation sutures had a smaller effect on anteroposterior stability. On the other hand suturing the rim of the meniscus affected anteroposterior stability to a much larger degree. This model emphasizes the importance of the meniscus in knee biomechanics. Appropriate meniscal replacement fixation techniques are likely to be critical to the clinical

  11. Bicondylar tibial plateau fractures managed with the Sheffield Hybrid Fixator. Biomechanical study and operative technique.

    PubMed

    Ali, A M; Yang, L; Hashmi, M; Saleh, M

    2001-12-01

    The two main challenges in the management of bicondylar tibial plateau fractures are: Firstly, the compromised skin and soft tissue envelope which invite a high rate of complications following attempted open reduction and dual plating. Secondly, poor bone quality and comminuted fracture patterns, which create difficulty in achieving stable fixation. Although dual plating is considered to be the best mechanical method of stabilizing these complex fractures, there remains concern regarding the high rate of complications associated with extensive soft tissue dissection, required for the insertion of these plates in an already compromised knee. The Sheffield Hybrid fixator (SHF) technique offers a solution to the two main problems of these difficult fractures by minimizing soft tissue dissection, since bone fragments are reduced and fixed percutaneously, and providing superior cancellous bone purchase with beam loading stabilization for comminuted fractures. Our biomechanical testing showed the SHF with four tensioned wires to be as strong as dual plating and able to provide adequate mechanical stability in the fixation of bicondylar tibial plateau fractures. This was confirmed clinically by a prospective review of the use of the SHF at our centre, for managing complex and high-energy tibial plateau fractures with a good final outcome and no cases of deep infection or septic arthritis.

  12. In Vitro Evaluation of Inflow Cannula Fixation Techniques in Left Ventricular Assist Device Surgery.

    PubMed

    Hanke, Jasmin S; Krabatsch, Thomas; Rojas, Sebastian V; Deniz, Ezin; Ismail, Issam; Martens, Andreas; Shrestha, Malakh; Haverich, Axel; Netuka, Ivan; Schmitto, Jan D

    2017-03-01

    The therapy of terminal heart failure with left ventricular assist devices has become a standard in cardiac surgery. Yet the surgical implantation technique is not standardized and differs from center to center. Complications associated with left ventricular assist device (LVAD) inflow cannula placement are thrombosis, suction events, and flow disturbances. Within this in vitro study we aimed to investigate if the fixation technique of the sewing ring has an impact on the position of the inflow cannula. For this in vitro study the HeartMate III LVAD (Thoratec Corporation, Pleasanton, CA, USA) was used. In five sessions, two approaches were considered for coring of the ventricle for LVAD inflow cannula insertion: "sew-then-core" and "core-then-sew." In the "sew-then-core" technique, the sewing cuff is first affixed to the heart, usually with 8-16 interrupted pledgeted mattress sutures. Subsequently, a cylindrical knife is used to resect a cylindrical core of myocardium to permit cannula insertion. In the "core-then-sew" technique, the sequence is reversed such that the knife is used before the suture ring is affixed. When the "sew-then-core" technique is used, the mattress sutures may be placed with full-thickness bites that penetrate the endocardium (i.e., transmural stitching) or partial-thickness bites that do not penetrate the endocardium (i.e., epicardial stitching). When the "core-then-sew" technique is used, the suture is passed fully into the ventricular lumen and fed back through the cored hole, at which point the needle may be reinserted into the freshly cored myocardium such that it exits the epicardium (i.e., transmural stitching with back stitch) or not (i.e., transmural stitching without back stitch). These four different sewing ring fixation suturing techniques were tested by experienced surgeons to affix the sewing ring: transmural stitching, epicardial stitching, transmural stitching with back stitch, and transmural stitching without back stitch

  13. Hybrid Decompression and Fixation Technique for the Treatment of Multisegmental Cervical Spondylotic Myelopathy

    PubMed Central

    Araos-Silva, Walter; Reyes-Sánchez, Alejandro; Rosales-Olivarez, Luis Miguel; Alpizar-Aguirre, Armando; Melendez, Francisco Lopez

    2016-01-01

    Background Cervical spondilotic myelopathy (CSM) is defined as the compromise of the spinal cord due to degenerative changes of the cervical spine. It is the most common cause of spinal cord dysfunction in patients over 55 years. An early surgical management it is paramount to achieve better neurological outcome. There is still controversy regarding the appropriate surgical treatment for multisegmental CSM involving three or more levels. The hybrid decompression and fixation technique combines one or two level corpectomy and a single level discectomy in order to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy Methods A prospective case-control study was made between 2011 and 2013. A total of 15 patients with diagnosis of CSM received surgical treatment with an anterior hybrid decompression and fixation technique procedure. Inclusion criteria were myelopathy confirmed by radiographic studies, magnetic resonance image (MRI) and electromyography. Results During the 2010-2013 period 15 patients were managed by hybrid decompression and fixation technique. Average age 64.8 years SD9.4. The follow up period was 29.6 SD ± 9.8 months. The JOA score improved significantly to 13.8 +/- 1.9 points at follow-up (paired t test, P = 0.001), Nurick Scale preoperative was 3.3 and improved to 2.4 mean, was significantly (Wilcoxon signed rank test p=0.006) The mean C2-C7 lordosis angle was 10.8° +/- 8.9 before surgery, and 14.3° +/- 8.8 at follow-up, there was no significant loss of lordosis angle between the preoperative and follow-up measurements (Wilcoxon signed rank test, P =0.149); At follow-up, graft non fusion was seen in 1 patient (7%, k=1); Conclusions In this small number, single surgeon, prospective series the use of a single level corpectomy and an adjacent discectomy was shown to provide similar outcomes and complication rates as alternative surgical techniques. The authors thus consider this a viable surgical alternative with

  14. Comparison of histopathologic criteria and skeletal muscle fixation techniques for the diagnosis of polysaccharide storage myopathy in horses.

    PubMed

    Firshman, A M; Valberg, S J; Bender, J B; Annandale, E J; Hayden, D W

    2006-05-01

    The purpose of the study reported here was to determine the effect of three methods of fixation of skeletal muscle biopsy specimens on the histopathologic appearance of muscle sections and to determine criteria that were most consistently associated with a diagnosis of polysaccharide storage myopathy (PSSM) in horses. Surgically excised semimembranosus muscle biopsy specimens were obtained from nine horses previously diagnosed with PSSM and from 15 control horses. Portions of each specimen were fixed in formalin, frozen immediately, and chilled for 24 hours prior to freezing. Sections stained with hematoxylin and eosin (HE), periodic acid-Schiff (PAS), and amylase-PAS were scored for histopathologic criteria by three investigators blinded to the sample origin. The presence of amylase-resistant, abnormal polysaccharide was found to be the most sensitive and specific diagnostic indicator for PSSM, and was readily detected regardless of the fixation technique or investigator. Other less-specific features associated with PSSM included atrophy and cytoplasmic and subsarcolemmal vacuoles; however, their histologic scores varied among fixation technique and investigators. Scores for subsarcolemmal and cytoplasmic amylase-sensitive glycogen in horses with PSSM were similar to those for control horses and varied among fixation techniques. In conclusion, PSSM is most accurately diagnosed in muscle biopsy specimens on the basis of appearance of amylase-resistant, abnormal polysaccharide, not amylase-sensitive glycogen, regardless of fixation technique. In general, frozen sections appeared to be better suited for studying myopathies because many histopathologic features of skeletal muscle were obscured by formalin fixation.

  15. A New and Easy Technique of Maxillomandibular Fixation in Treatment of Mandibular Fractures

    PubMed Central

    Singh, Virendra; Bhagol, Amrish

    2011-01-01

    The present work evaluated the success of maxillomandibular fixation (MMF) by a new and simplified technique in management of minimally displaced mandibular fractures. A total of 20 patients who sustained various types of mandibular fractures were treated at the Government Dental College, Rohtak, India by a new MMF technique. The patients were evaluated by preoperative and postoperative radiography, and clinical testing was performed to assess the degree of tooth mobility adjacent to the site of MMF. The time required for MMF was also noted. Patient recovery was uneventful in all 20 cases, and the period of MMF ranged from 2 to 4 weeks (mean 21 days). The outcome was good. The mean time for performing MMF was 12 minutes (range, 10 to 15 minutes). It is a simple, quick, economical, and minimally invasive technique. Its mechanical principle provides an advantage in preventing postoperative periodontal problems. PMID:22942948

  16. Triangular Fixation Technique for Bicolumn Restoration in Treatment of Distal Humerus Intercondylar Fracture

    PubMed Central

    Kang, Seung-Hoon; Jeong, Min; Lim, Hae-Seong

    2016-01-01

    Background Distal humerus intercondylar fractures are intra-articular and comminuted fractures involving soft tissue injury. As distal humerus is triangle-shaped, parallel plating coupled with articular fixation would be suitable for bicolumn restoration in treatment of distal humerus intercondylar fracture. Methods This study included 38 patients (15 males and 23 females) who underwent olecranon osteotomy, open reduction and internal fixation with the triangle-shaped cannulated screw and parallel locking plates (triangular fixation technique). Functional results were assessed with the visual analog scale (VAS) scores, Mayo elbow performance (MEP) scores and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires. Anteroposterior and lateral elbow radiographs were assessed for reduction, alignment, fracture union, posttraumatic arthrosis, and heterotopic ossification, and computed tomography (CT) scans were used to obtain more accurate measurements of articular discrepancy. Results All fractures healed primarily with no loss of reduction. The mean VAS, MEP, and DASH scores of the affected elbow were not significantly different from those of the unaffected elbow (p = 0.140, p = 0.090, and p = 0.262, respectively). The mean degree of flexion was significantly lower in the affected elbow than in the unaffected elbow, but was still considered as functional (p = 0.001, > 100° in 33 of 38 patients). Two cases of articular step-offs (> 2 mm) were seen on follow-up CT scans, but not significantly higher in the affected elbow than in the unaffected elbow (p = 0.657). Binary logistic regression analysis revealed that only Association for Osteosynthesis (AO) type C3 fractures correlated with good/excellent functional outcome (p = 0.012). Complications occurred in 12 of the 38 patients, and the overall reoperation rate for complications was 10.5% (4 of 38 patients). Conclusions Triangular fixation technique for bicolumn restoration was an effective and reliable

  17. Novel Intramedullary-Fixation Technique for Long Bone Fragility Fractures Using Bioresorbable Materials

    PubMed Central

    Nishizuka, Takanobu; Kurahashi, Toshikazu; Hara, Tatsuya; Hirata, Hitoshi; Kasuga, Toshihiro

    2014-01-01

    Almost all of the currently available fracture fixation devices for metaphyseal fragility fractures are made of hard metals, which carry a high risk of implant-related complications such as implant cutout in severely osteoporotic patients. We developed a novel fracture fixation technique (intramedullary-fixation with biodegradable materials; IM-BM) for severely weakened long bones using three different non-metallic biomaterials, a poly(l-lactide) (PLLA) woven tube, a nonwoven polyhydroxyalkanoates (PHA) fiber mat, and an injectable calcium phosphate cement (CPC). The purpose of this work was to evaluate the feasibility of IM-BM with mechanical testing as well as with an animal experiment. To perform mechanical testing, we fixed two longitudinal acrylic pipes with four different methods, and used them for a three-point bending test (N = 5). The three-point bending test revealed that the average fracture energy for the IM-BM group (PLLA + CPC + PHA) was 3 times greater than that of PLLA + CPC group, and 60 to 200 times greater than that of CPC + PHA group and CPC group. Using an osteoporotic rabbit distal femur incomplete fracture model, sixteen rabbits were randomly allocated into four experimental groups (IM-BM group, PLLA + CPC group, CPC group, Kirschner wire (K-wire) group). No rabbit in the IM-BM group suffered fracture displacement even under full weight bearing. In contrast, two rabbits in the PLLA + CPC group, three rabbits in the CPC group, and three rabbits in the K-wire group suffered fracture displacement within the first postoperative week. The present work demonstrated that IM-BM was strong enough to reinforce and stabilize incomplete fractures with both mechanical testing and an animal experiment even in the distal thigh, where bone is exposed to the highest bending and torsional stresses in the body. IM-BM can be one treatment option for those with severe osteoporosis. PMID:25111138

  18. COMPLICATIONS OF THE SCREW/WASHER TIBIAL FIXATION TECHNIQUE FOR KNEE LIGAMENT RECONSTRUCTION

    PubMed Central

    Almeida, Alexandre; Roveda, Gilberto; Valin, Márcio Rangel; Almeida, Nayvaldo Couto de; Sartor, Vanderlei; Alves, Soraya Melina

    2015-01-01

    To evaluate the presence of pain at the site of the surgical incision and the need to remove the tibial fixation screw in anterior cruciate ligament (ACL) reconstruction, in relation to sex and body mass index (BMI). Methods: A group of 265 patients who underwent ACL reconstruction with ipsilateral flexor tendon grafts from the thigh in which the tibial fixation technique consisted of using a cortical screw and metal washer, between July 2000 and November 2007, were evaluated. Results: 176 patients were evaluated for an average of 33.3 ± 19.5 months; median of 29.5 months; IIQ: 17-45 months; minimum of 8 and maximum of 87 months. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.272) and the need to remove the tibial screw (p = 0.633) between sexes. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.08) and the need to remove the tibial screw (p = 0.379) according to BMI. Conclusion: The pain complaint rate at the screw site from the screw and metal washer method used for tibial fixation in ACL reconstruction was of the order of 25%, and the screw had to be removed in 10.8% of the cases. There was no predominance of pain complaints at the surgical wound between the sexes. There was a greater tendency to complain about pain among patients with BMI < 25. There was no predominance of screw and washer removal between the sexes or between individuals with different BMIs. PMID:27022587

  19. A new surgical technique using steel suture for trans-scleral fixation of posterior chamber intraocular lenses

    PubMed Central

    Ram, Jagat; Gupta, Nishant; Chaudhary, Manish; Verma, Neelam

    2013-01-01

    Background: A new emerging complication of trans-scleral fixation of posterior chamber (PC) intraocular lens (IOL) with polypropylene suture is high rates of spontaneous dislocation of the IOL due to disintegration or breakage of suture. Materials: We report a new surgical technique of trans-scleral fixation of posterior chamber intraocular lens (SF PCIOL) with steel suture to eliminate the complication of dislocation of IOL fixed with polypropylene suture in one adult and a child. Results: We successfully achieved stable fixation and good centration of IOL after SF PCIOL with steel suture in these patient having inadequate posterior capsular support. Both eyes achieved best corrected visual acuity 20/40 at 18 months follow-up. Conclusions: Steel suture is a viable option for trans-scleral fixation of posterior chamber intraocular lens. PMID:23619504

  20. Using biomechanics to improve the surgical technique for internal fixation of intracapsular femoral neck fractures.

    PubMed

    Wu, Chi-Chuan

    2010-01-01

    Despite advances in science and technology, the success rate for the treatment of displaced intracapsular femoral neck fractures in high-energy injuries remains disappointing. The blood supply system in the femoral head of humans does not favor recovery from these fractures. Once these fractures occur, osteonecrosis and nonunion rates may be as high as 30%, even if the newest technique is used. There are some surgical techniques used to supplement internal fixation to reestablish the blood supply in the femoral head, but none have been evidently successful. After analysis of related studies, the author concludes that immediate surgical treatment using improved techniques incorporating the principles of biomechanics can improve the success rate of treatment of these fractures. Using these principles, the fracture site can achieve sufficient stability. Consequently, the blood supply in the femoral head and neck can be reestablished earlier and loss of reduction of fragments during treatment can be minimized. Thus, the chance of full recovery from these complicated fractures can be maximized. In this study, the biomechanical characteristics of these fractures and the principles associated with the surgical techniques used for treating them are reviewed and clarified. Finally, a surgical technique which is ideal from the author's viewpoint is presented. The author believes that the recommended surgical technique may become the best method for treating these complicated fractures.

  1. Decontamination Techniques and Fixative Coatings Evaluated in the Building 235-F Legacy Source Term Removal Study

    SciTech Connect

    WAYNE, FARRELL

    2005-04-21

    Savannah River Site Building 235-F was being considered for future plutonium storage and stabilization missions but the Defense Nuclear Facilities Safety Board (DNFSB) noted that large quantities of Plutonium-238 left in cells and gloveboxes from previous operations posed a potential hazard to both the existing and future workforce. This material resulted from the manufacture of Pu-238 heat sources used by the NASA space program to generate electricity for deep space exploration satellites. A multi-disciplinary team was assembled to propose a cost- effective solution to mitigate this legacy source term which would facilitate future DOE plutonium storage activities in 235-F. One aspect of this study involved an evaluation of commercially available radiological decontamination techniques to remove the legacy Pu-238 and fixative coatings that could stabilize any residual Pu-238 following decontamination activities. Four chemical methods were identified as most likely to meet decontamination objectives for this project and are discussed in detail. Short and long term fixatives will be reviewed with particular attention to the potential radiation damage caused by Pu-238, which has a high specific activity and would be expected to cause significant radiation damage to any coating applied. Encapsulants that were considered to mitigate the legacy Pu-238 will also be reviewed.

  2. Cement technique for reducing post-operative bursitis after trochanteric fixation.

    PubMed

    Derman, Peter B; Horneff, John G; Kamath, Atul F; Garino, Jonathan

    2013-02-01

    Post-operative trochanteric bursitis is a known complication secondary to the surgical approach in total hip arthroplasty. This phenomenon may be partially attributable to repetitive microtrauma generated when soft tissues rub against implanted hardware. Significant rates of post-operative trochanteric bursitis have been observed following procedures in which a trochanteric fixation device, such as a bolt-washer mechanism or a cable-grip/claw system, is used to secure the trochanteric fragment after trochanteric osteotomy. We present a simple technique for use with a bolt-washer system or grip plate in which trochanteric components are covered in bone wax followed by a layer of cement to decrease friction and to diminish the risk of post-operative bursitis.

  3. Combined use of Ilizarov external fixation and Papineau technique for septic pseudoarthrosis of the distal tibia in a patient with diabetes mellitus

    PubMed Central

    Koutsostathis, Stefanos D.; Lepetsos, Panagiotis; Polyzois, Vasilios D.; Pneumaticos, Spyros G.; Macheras, George A.

    2014-01-01

    The surgical treatment of open pilon fractures has a high complication rate especially in diabetic patients. In this article, we present a case of an infected tibial non-union after an open reduction and internal fixation in a diabetic patient, treated with Ilizarov external fixation combined with Papineau technique. Combined use of external fixation and Papineau technique can provide an alternative option for the treatment of septic pseudoarthrosis of the distal tibia. PMID:24563728

  4. Locking plate fixation of distal femoral fractures is a challenging technique: a retrospective review

    PubMed Central

    Toro, Giuseppe; Calabrò, Giampiero; Toro, Antonio; de Sire, Alessandro; Iolascon, Giovanni

    2015-01-01

    Summary Distal femoral fractures have typically a bimodal occurrence: in young people due to a high-energy trauma and in older people related to a low-energy trauma. These fractures are associated to a very high morbidity and mortality in elderly. Distal femoral fractures might be treated with plates, intramedullary nails, external fixations, and prosthesis. However, difficulties in fracture healing and the rate of complications are important clinical issues. The purpose of this retrospective review was to present our experience in treatment of distal femoral fracture in a sample of older people in order to evaluate the technical pitfalls and strategies used to face up the fractures unsuccessfully treated with locking plates. We included people aged more than 65 years, with a diagnosis of distal femoral fracture, treated with locking plates. We considered ‘unsuccessfully treated’ the cases with healing problems or hardware failures. Of the 12 patients (9 females and 3 males; mean aged 68.75 ± 3.31 years) included, we observed 3 ‘unsuccessfully cases’, 2 due to nonunions and 1 due to an early hardware failure, all treated using a condylar blade plate with a bone graft. One patient obtained a complete fracture healing after 1 year and in the other cases there was a nonunion. We observed as most common technical pitfalls: inadequate plate lengthening, fracture bridging, and number of locking screws. The use of locking plates is an emerging technique to treat these fractures but it seems more challenging than expected. In literature there is a lack of evidences about the surgical management of distal femoral fractures that is still an important challenge for the orthopaedic surgeon that has to be able to use all the fixation devices available. PMID:27134634

  5. A Technique of Superficial Medial Collateral Ligament Reconstruction Using an Adjustable-Loop Suspensory Fixation Device.

    PubMed

    Deo, Shaneel; Getgood, Alan

    2015-06-01

    This report describes superficial medial collateral ligament reconstruction of the knee using a novel method of graft fixation with the ACL Tightrope RT (Arthrex, Naples, FL). After tibial fixation with either a standard interference screw or staple, femoral fixation of the semitendinosus tendon is performed with the adjustable-loop suspensory fixation device, which allows for both initial graft tensioning and re-tensioning after cyclical knee range of motion. This provides the ability for the graft to accommodate for resultant soft-tissue creep and stress relaxation, thereby allowing for optimal soft-tissue tension and reduction in laxity at the end of the procedure.

  6. Anterior cruciate ligament reconstruction using the Bio-TransFix femoral fixation device and anteromedial portal technique.

    PubMed

    Hantes, Michael E; Dailiana, Zoe; Zachos, Vasilios C; Varitimidis, Sokratis E

    2006-05-01

    The cross-pin femoral fixation technique for soft tissue grafts is a popular option in anterior cruciate ligament (ACL) reconstruction. One of these devices is the Bio-TransFix (Arthrex Inc., Naples, FL, USA) which provides high fixation strength. According to the manufacturer, the femoral tunnel is created by placing the femoral aiming device through the tibial tunnel (transtibial technique). However, using this technique it is very difficult or even impossible to place the graft at the anatomical ACL attachment site at the "10 o'clock" position. In this report, we describe the use of the Bio-TransFix device with an anteromedial portal technique. Using this technique, the surgeon has more freedom to place the graft in an anatomical position, while combining the advantages of the excellent biomechanical properties of this device.

  7. “Two-step” technique with OsiriX™ to evaluate feasibility of C2 pedicle for surgical fixation

    PubMed Central

    Marques, Luis Miguel Sousa; d’Almeida, Gonçalo Neto; Cabral, José

    2016-01-01

    Background: Surgical treatment of craniovertebral junction pathology has evolved considerably in recent decades with the implementation of short atlanto-axial fixation techniques, notwhithstanding increasing neurovascular risks. Also, there is strong evidence that fixation of C2 anatomical pedicle has the best biomechanical profile of the entire cervical spine. However, it is often difficult and misleading, to evaluate anatomical bony and vascular anomalies using the three orthogonal planes (axial, coronal, and sagittal) of CT. Objectives: The authors describe an innovative and simple technique to evaluate the feasibility of C2 pedicle for surgical screw fixation using preoperative planning with the free DICOM (Digital Imaging and Communications in Medicine) software OsiriX™. Materials and Methods: The authors report the applicatin of this novel technique in 5 cases (3 traumatic, 1 Os Odontoideum, and 1 complex congenital malformation) collected from our general case series of the Department in the last 5 years. Results: In this proof of concept study, the pre-operative analysis with the two-step tecnique was detrimental for choosing the surgical tecnique. Detailed post-operative analysis confirmed correct position of C2 screws without cortical breach. There were no complications or mortality reported. Conclusion: This two-step technique is an easy and reliable way to determine the feasibility of C2 pedicle for surgical fixation. The detailed tridimensional radiological preoperative evaluation of craniovertebral junction anatomy is critical to the sucess and safety of this surgeries, and can avoid, to certain degree, expensive intra-operative tridimensional imaging facilities. PMID:27217652

  8. NON-UNIONS AFTER FIXATION OF HUMERAL FRACTURES USING HACKETHAL'S BUNDLE NAILING TECHNIQUE

    PubMed Central

    OBRUBA, PETR; RAMMELT, STEFAN; KOPP, LUBOMIR; EDELMANN, KAREL; AVENARIUS, JAKUB

    2016-01-01

    ABSTRACT Objective: The aim of the study was to identify factors contributing to the development of non-union after fixation of diaphyseal humeral fractures using Hackethal's intramedullary nailing technique. Methods: In the time period from 2001 to 2010 156 patients with diaphyseal humeral fractures were treated surgically using Hackethal's technique. Six of them (3.8%) developed non-union. This group included three women and two men aged 63-69 years and one woman aged 37 years. The following parameters of the patients were recorded: age, gender, comorbidities, substance abuse, mechanism of injury, fracture type and location according to the AO/ASIF classification, and the operative technique. Results: A non-union developed in six patients treated with Hackethal´s method (3.8%). Five of six non-unions (83%) were observed in patients in their sixties. In the subgroup of sexagenarians, non-union developed in 20.8% of surgically treated patients, as compared to 3.8 % in entire group. In the union group, fractures have been caused by high energy trauma in 52% of patients. In patients who developed non-union, high energy trauma caused 67% of fractures. With correct surgical technique the development of a non-union was observed in 0.7% of patients, with incorrect technique in 35.7% (p<0.001). Conclusion: Treatment of diaphyseal humeral fractures with Hackethal's intramedullary elastic bundle nailing resulted in an overall high union rate. Factors contributing to the development of non-union were extension of this method to AO type B3 and C fractures and technical imperfection during implantation. Level of Evidence III, Prospective, Case-Control Study. PMID:28149195

  9. Transtrapezial Approach for Fixation of Acute Scaphoid Fractures: Rationale, Surgical Techniques, and Results: AAOS Exhibit Selection.

    PubMed

    Verstreken, Frederik; Meermans, Geert

    2015-05-20

    The ideal position for a screw used for scaphoid fixation is central. The purpose of this study was to compare the current volar percutaneous approaches used for scaphoid fracture fixation, explore different options to improve central screw placement, and describe our experience with the transtrapezial approach.

  10. Wiring Techniques for the Fixation of Trochanteric Fragments during Bipolar Hemiarthroplasty for Femoral Intertrochanteric Fracture: Clinical Study and Technical Note

    PubMed Central

    Cho, Yongsuk; Kim, Junhyun; Kim, Dong-Won

    2017-01-01

    Purpose Femoral intertrochanteric fractures are common in the elderly. Appropriate surgical fixation of trochanteric fracture fragments can restore normal anatomical structure and ambulation, and can aid in the recovery of biomechanical function of the hip. We evaluated clinical outcomes of bipolar hemiarthroplasty using a wiring technique for trochanteric fracture fragment fixation. Materials and Methods From September 2006 to February 2015, a total of 260 cases underwent simultaneous bipolar hemiarthroplasty and wire fixation. A total of 65 patients (69 hips) with an average age of 78 years and more than one year of follow-up was included in the study. Using pre-, postoperative and follow-up radiograms, we evaluated wire fixation failure and also assessed changes in walking ability. Results Loosening or osteolysis around the stem was not observed; however, we did observe bone growth around the stem (54 cases), cortical hypertrophy (6 cases), a wide range of sclerotic lines but no stem subsidence (1 case), wire breakage (9 cases), and fracture fragment migration with no significant functional deficiency (2 cases). Conclusion Our study showed that additional wiring for trochanteric fracture fragment fixation following bipolar hemiarthroplasty can help restore normal anatomy. The added stability results in faster rehabilitation, and good clinical and radiographic outcomes. We recommend this procedure in this type of fracture. PMID:28316962

  11. Cervical pedicle screw fixation in traumatic cervical subluxation after laminectomy using the pedicle axis view technique under fluoroscopy.

    PubMed

    Machino, Masaaki; Yukawa, Yasutsugu; Ito, Keigo; Nakashima, Hiroaki; Kanbara, Shunsuke; Morita, Daigo; Kato, Fumihiko

    2012-10-10

    Cervical pedicle screw (CPS) fixation has recently been performed in patients in need of cervical reconstruction. We report the case of a 50-year-old man who was operated for traumatic cervical vertebra subluxation using CPS fixation, in whom laminectomy had been performed in the past. We performed CPS fixation using the pedicle axis view technique under fluoroscopy. The four pedicle screws were accurately inserted within the pedicles without perforating the bone cortex of the pedicles. A navigation system is useful for cervical spine surgery because it enables a surgeon to perform relatively safe and accurate surgery during transpedicular screw fixation. However, attachment of the stereotactic reference arc to the spinous process is impossible, and the application of a navigation system is limited in cases in which laminectomy has been performed in the past. We have been using the pedicle axis view technique under fluoroscopy and have found that if we take care of the entry point accurately, we can safely insert the pedicle screw in cases with fewer landmarks.

  12. Review of techniques for monitoring the healing fracture of bones for implementation in an internally fixated pelvis.

    PubMed

    Wong, Lydia Chwang Yuh; Chiu, Wing Kong; Russ, Matthias; Liew, Susan

    2012-03-01

    Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.

  13. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate

    PubMed Central

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Background Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. Methods We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Results Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Conclusions Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation. PMID:26908972

  14. A Novel Technique Using Customized Headgear for Fixation of Rigid External Distraction Device in an Infant With Crouzon Syndrome.

    PubMed

    Hariri, Firdaus; Rahman, Zainal Ariff Abdul; Mahdah, Saridah; Mathaneswaran, Vickneswaran; Ganesan, Dharmendra

    2015-11-01

    Rigid external distraction device is often indicated for superior midfacial advancement in pediatric syndromic craniosynostosis patients. Even though the technique is proven reliable to treat the functional issues related to the craniofacial deformity, major complications associated with its fixation, such as intracranial pin perforation and migration have been reported. We report a novel technique of using a customized headgear to prevent intracranial pin perforation over a very thin temporal bone region in an 8-month-old infant with Crouzon syndrome who underwent monobloc Le Fort III distraction osteogenesis using a combination of bilateral internal and a rigid external distraction device. The customized headgear provides a protective platform at the temporal region thus preventing intracranial pin perforation and allows stable fixation during the early phase of consolidation period to prevent central component relapse. The headgear can be used short term when rigid external distractor is indicated in infant patient but requires close monitoring because of risks of skin necrosis and temporal region indentation.

  15. Excision Versus Fixation of the Radial Head: A Comparative Study of the Functional Outcomes of the Two Techniques

    PubMed Central

    Shetty, Sanath Kumar; Shetty, Ashwin; Balan, Bijith; Rai, H.Ravindranath; Hegde, Anoop

    2017-01-01

    Introduction The management of displaced and comminuted radial head fractures has been a matter of debate amongst surgeons for many years. Radial head excision formed the mainstay of surgical management of these injuries. Over the years, there have been improvements in the surgical techniques and availability of better implants and instrumentation techniques, hence, open reduction and internal fixation of these fractures is gaining popularity. Aim To compare the outcome of elbow function between radial head excision and open reduction and internal fixation of the radial head with mini screws of Mason Type II and Type III radial head fractures and to assess the complications that occur in both techniques. Materials and Methods A prospective study was conducted in the Department of Orthopaedic Surgery of Justice K.S.Hegde Charitable hospital. A total of 40 patients between the age group of 30-50 years with Mason Type II and Type III fresh closed radial head fractures were included in the study. Group I consisted of 20 patients who underwent radial head excision and Group II consisted of 20 patients who underwent open reduction and internal fixation with mini screws. Patients were reviewed at postoperative week 3, 6 and 24. Radiographs were taken and functional outcome assessment of the elbow was done during all the follow ups. Elbow physiotherapy was started on postoperative week three. Scoring of elbow function was done as per the Disabilities of the Arm, Shoulder and Hand (DASH) scoring system. Results were tabulated, compared and analysed statistically using the ‘chi-square test’. Results At the end of six months, the patients of the open reduction and internal fixation group had lower DASH scores (4.82±2.73 points) than the radial head excision group (14.23±5.60 points). This inferred that patients who underwent open reduction and internal fixation had better functional outcomes than the excision group. Complications of proximal radial migration was noted

  16. Technique for rapid establishment of American lotus in remediation efforts

    SciTech Connect

    Ryon, M. G.; Jett, R. T.; McCracken, M. K.; Morris, G. W.; Roy, W. K.; Fortner, A. M.; Goins, K. N.; Riazi, A. S.

    2013-03-01

    A technique for increasing the establishment rate of American lotus (Nelumbo lutea) and simplifying planting was developed as part of a pond remediation project. Lotus propagation techniques typically require scarification of the seed, germination in heated water, and planting in nursery containers. Then mature (~ 1 yr) nursery-grown stock is transferred to planting site or scarified seed are broadcast applied. Mature plants should grow more quickly, but can be sensitive to handling, require more time to plant, and cost more. Scarified seeds are easier to plant and inexpensive, but have a lag time in growth, can fail to germinate, and can be difficult to site precisely. We developed an intermediate technique using small burlap bags that makes planting easier, provides greater germination success, and avoids lag time in growth. Data on survival and growth from experiments using mature stock, scarified seeds, and bag lotus demonstrate that bag lotus grow rapidly in a variety of conditions, have a high survival rate, can be processed and planted easily and quickly, and are very suitable for a variety of remediation projects

  17. Arthroscopic Labral Reconstruction of the Hip Using Iliotibial Band Allograft and Front-to-Back Fixation Technique

    PubMed Central

    White, Brian J.; Herzog, Mackenzie M.

    2016-01-01

    Labral repair has been shown to be an effective treatment option with excellent early outcomes; however, in cases of severe labral damage or when the labral tissue is too large or diminutive, labral repair may be less effective. The purpose of this article is to present a modified technique for hip labral reconstruction using iliotibial band allograft tissue and a front-to-back fixation technique. The described technique is modified from the original report of a technique for arthroscopic labral reconstruction. The front-to-back technique allows the surgeon to make a graft that is longer than necessary and cut excess graft after front-to-back fixation, resulting in the correct graft size and a reproducible procedure. Allograft tissue offers several advantages, including the ability to control graft thickness and length, as well as the ability to eliminate donor-site morbidity. This procedure adds to the available techniques for treatment of labral pathology by providing a labral reconstruction technique using allograft tissue. PMID:27073784

  18. Clinical Results of Technique for Double Bundle Anterior Cruciate Ligament Reconstruction Using Hybrid Femoral Fixation and Retroscrew

    PubMed Central

    Kim, Doo-Sup; Yi, Chang-Ho; Chung, Hoi-Jung

    2011-01-01

    Background Anatomic anterior cruciate ligament (ACL) reconstruction has been presented as a means to more accurately restore the native anatomy of this ligament. This article describes a new method that uses a double bundle to perform ACL reconstruction and to evaluate the clinical outcome. Methods Grafts are tibialis anterior tendon allograft for anteromedial bundle (AMB) and hamstring tendon autograft without detachment of the tibial insertion for posterolateral bundle (PLB). This technique creates 2 tunnels in both the femur and tibia. Femoral fixation was done by hybrid fixation using Endobutton and Rigidfix for AMB and by biointerference screw for PLB. Tibial fixations are done by Retroscrew for AMB and by native insertion of hamstring tendon for PLB. Both bundles are independently and differently tensioned. We performed ACL reconstruction in 63 patients using our new technique. Among them, 47 participated in this study. The patients were followed up with clinical examination, Lysholm scales and International Knee Documentation Committee (IKDC) scoring system and radiological examination with a minimum 12 month follow-up duration. Results Significant improvement was seen on Lachman test and pivot-shift test between preoperative and last follow-up. Only one of participants had flexion contracture about 5 degrees at last follow-up. In anterior drawer test by KT-1000, authors found improvement from average 8.3 mm (range, 4 to 18 mm) preoperatively to average 1.4 mm (range, 0 to 6 mm) at last follow-up. Average Lysholm score of all patients was 72.7 ± 8.8 (range, 54 to 79) preoperatively and significant improvement was seen, score was 92.2 ± 5.3 (range, 74 to 97; p < 0.05) at last follow-up. Also IKDC score was normal in 35 cases, near normal in 11 cases, abnormal in 1 case at last follow-up. Conclusions Our new double bundle ACL reconstruction technique used hybrid fixation and Retroscrew had favorable outcomes. PMID:22162791

  19. Radiological Evaluation of the Initial Fixation between Cortical Bone Trajectory and Conventional Pedicle Screw Technique for Lumbar Degenerative Spondylolisthesis

    PubMed Central

    Iwatsuki, Koichi; Ohnishi, Yu-Ichiro; Yoshimine, Toshiki

    2016-01-01

    Study Design Retrospective study. Purpose To compare initial fixation using the cortical bone trajectory (CBT) technique versus conventional pedicle screws (PS) in radiographs of postsurgical lumbar degenerative spondylolisthesis. Overview of Literature Few reports have documented the holding strength of CBT technique for spondylolisthesis cases. Methods From October 2009 to June 2014, 21 cases of degenerative spondylolisthesis were surgically treated in our institution. Ten were treated with conventional PS technique and 11 of with CBT technique. Mean lumbar lordosis and percent slippage were evaluated preoperatively, immediately after surgery, and 6 months and 1 year postoperatively using radiographs. We also investigated percent loss of slip reduction. Results There were statistically significant differences between preoperative percent slippage and postoperative slippage in both PS and CBT procedures over 1 year, and both techniques showed good slip reduction. On the other hand, lumbar lordosis did not change significantly in either the PS or CBT groups over 1 year. Conclusions CBT technique showed similarly good initial fixation compared with the PS procedure in the treatment of lumbar degenerative spondylolisthesis. PMID:27114765

  20. Neck of femur fracture fixation in a bilateral amputee: an uncommon condition requiring an improvised fracture table positioning technique.

    PubMed

    Berg, Andrew James; Bhatia, Chandra

    2014-02-21

    While neck of femur fractures are common it is rare to see this injury in a bilateral leg amputee. Special consideration needs to be given to the management of these patients. We report the case of a 58-year-old man with bilateral leg amputation who presented to the emergency department with left hip pain following a fall. A fracture of the left neck of femur with extension into the femoral shaft was diagnosed. Internal fixation was planned with a dynamic hip screw. Standard fracture table setup, which allows for traction of the fractured limb and positioning of the contralateral limb such that anteroposterior and lateral X-rays can be obtained, was not possible in this case due to the amputations. We highlight considerations that need to be made in positioning a bilateral amputee for neck of femur fracture fixation and also highlight an improvised technique that can be utilised by other surgeons.

  1. An Effective and Feasible Method, “Hammering Technique,” for Percutaneous Fixation of Anterior Column Acetabular Fracture

    PubMed Central

    Zhang, Lihai; Zhang, Wei; Li, Tongtong; Li, Jiantao; Chen, Hua

    2016-01-01

    Objective. The objective of this study was to evaluate the effectiveness and advantages of percutaneous fixation of anterior column acetabular fracture with “hammering technique.” Materials and Methods. We retrospectively reviewed 16 patients with percutaneous fixation of anterior column acetabular fracture with “hammering technique.” There were 11 males and 5 females with an average age of 38.88 years (range: 24–54 years) in our study. Our study included 7 nondisplaced fractures, 6 mild displaced fractures (<2 mm), and 5 displaced fractures (>2 mm). The mean time from injury to surgery was 4.5 days (range: 2–7 days). Results. The average of operation time was 27.56 minutes (range: 15–45 minutes), and the mean blood loss was 55.28 mL (range: 15–100 mL). The mean fluoroscopic time was 54.78 seconds (range: 40–77 seconds). The first pass of the guide wire was acceptable without cortical perforation or intra-articular perforation in 88.89% (16/18) of the procedures, and the second attempt was in 11.11% (2/18). Conclusion. Our study suggested that percutaneous fixation of anterior column acetabular fracture with “hammering technique” acquired satisfying surgical and clinical outcomes. It may be an alternative satisfying treatment for percutaneous fixation of anterior column acetabular fracture by 2D fluoroscopy using a C-arm with less fluoroscopic time. PMID:27493962

  2. Evaluation of a minimally invasive surgical fixation technique for young children with the Concerto Pin cochlear implant system.

    PubMed

    Schnabl, Johannes; Wolf-Magele, Astrid; Pok, Stefan Marcel; Url, Christoph; Zorowka, Patrick; Sprinzl, Georg

    2015-08-01

    In 2011, Med-El (Innsbruck, Austria) introduced a new cochlear implant system, designed to require a minimally invasive surgical technique and allow greater positional flexibility for its fixation on the skull. The Concerto Pin implant system is a good option for patients with thinner bone, such as children and elderly. The aim of this study was to investigate the implant’s stability in children using our minimally invasive surgical technique. This was a prospective, longitudinal study with a single-subject, repeated-examination design. Six children, implanted with a Concerto Pin using our minimally invasive surgical technique between October 2011 and September 2012, were assessed 1, 3 and 6 months after surgery. In each case, the implant remained in a stable position and no adverse events or problems with healing were observed at any time during the investigation. The minimally invasive technique and the method of implant fixation that bypass drilling a deep implant bed constitute a good option for patients with thinner bone, such as children. This clinical study shows the safety and stability of the Concerto Pin implant system using a minimally invasive surgical technique.

  3. The Kapandji technique for fixation of distal radius fractures--a biomechanical comparison of primary stability.

    PubMed

    Mittelmeier, W; Braun, C; Schäfer, R

    2001-01-01

    The goal of this study was to compare Kapandji-K-wiring and established K-wiring techniques of the distal radius fracture for primary stability in a biomechanical model: dorsal K-wiring according to Kapandji using different angles of the K-wire, parallel and diagonal alignment of the K-wires. A new testing system which uses a synthetic material enabled us to carry out the cantilever bending test. By application of a lower load, the Kapandji procedure shows a higher reactive torque and stiffness. A higher reaction force of the other techniques, especially of the parallel wiring, are only observable under high-grade bending stress. Application of the Kapandji procedure with K-wires at a smaller angle to the axis of the radius results in the highest primary stability of the procedures investigated in the essential range of initial deformation.

  4. Techniques for establishing local breeding populations of wood ducks

    USGS Publications Warehouse

    Doty, H.A.; Kruse, A.D.

    1972-01-01

    A study was conducted on the Arrowwood National Wildlife Refuge in east-central North Dakota to further evaluate a technique for establishing nesting wood ducks (Aix sponsa) by releasing propagated birds and installing nest houses. No wood duck nesting had been recorded previously in the area. During May-July 1968, 253 ducklings, hand-reared at the Northern Prairie Wildlife Research Center near Jamestown, North Dakota, were released when 9 to 16 days old into a 0.5-acre enclosure on the refuge, where they grew to flight stage and departed. Seventy-eight nest houses were installed in August on the refuge. About 76 percent of the ducks survived until late September, when southward migration began. The first-year band recovery rate by hunters of 4.7 percent was comparable to that of wild immature wood ducks. Most recoveries occurred between North Dakota and Minnesota in the north and Texas and Louisiana in the south. There were 16 nesting attempts, which produced 175 ducklings, by homing female wood ducks in the boxes in 1969. The number of nesting attempts increased to 34 in 1970, with a production of 311 ducklings.

  5. Comparison between the fixation of peritoneal dialysis catheters to the peritoneal wall and the conventional placement technique: clinical experience and follow-up of a new implant technique for peritoneal dialysis catheters.

    PubMed

    Io, Hiroaki; Maeda, Kunimi; Sekiguchi, Yoshimi; Shimaoka, Tetsutaro; Aruga, Seiki; Nakata, Junichiro; Nakamoto, Hirotaka; Hotta, Yoko; Koyanagi, Ichiro; Inaba, Masanori; Kanda, Reo; Nakano, Takanori; Wakabayashi, Keiichi; Sasaki, Yuu; Inuma, Jiro; Kaneko, Kayo; Hamada, Chieko; Fukui, Mitsumine; Tomino, Yasuhiko

    2014-01-01

    Peritoneal dialysis (PD) catheters often become severely dislocated, which may lead to malfunction. With the aim of preventing this complication, we have developed a simple method of fixing the catheter downwards in the peritoneal cavity (fixation technique), a technique that does not require a laparoscope. Sixteen patients were implanted using the conventional placement technique and 25 patients were implanted using the fixation technique. The location of the catheter tip was classified from grade 1 (downward, normal) to 5 (dislocated). The frequency of dislocation (defined as the extended time and/or decrease in volume when draining the PD solution) was measured for both the fixation technique and conventional placement technique. There was a significant difference in grade between the fixation technique (2.72 ± 1.01) and conventional technique (3.92 ± 1.31). The time until first dislocation was significantly different between the fixation technique (59.3 ± 48.1 days) and conventional technique (8.8 ± 14.6 days). The time until any dislocation was significantly different between the fixation technique (69.2 ± 41.9 days) and conventional technique (12.9 ± 13.7 days). Complications were not significantly different between the fixation technique and conventional technique. The fixation technique appears to be simple, safe, and useful for preventing severe dislocation and for lengthening the time until dislocation in PD patients.

  6. Rapid and simple fixation-staining technique of fresh frozen cryostat sections for SIMS microscopy.

    PubMed

    Li, H; Okabe, M; Yoshida, T; Takaya, K

    2001-12-01

    Before observing freeze-dried cryosections by ion microscopy, it is necessary to perform localization of the analysis site by light microscopy. The present study reports a rapid fixation-staining method for preparing freeze-dried or air-dried cryosections, wherein cryosections are observed after immersion in Carnoy-Lebrun fixative for 30 s and staining in undiluted Giemsa solution for 30 s. Cryostat sections of goldfish intestine and kidney tissue on the silicon wafer substratum were subsequently examined by SIMS. Positive cesium ion images showed a general histology of the intestinal villi with goblet cells. Their granules contained large amounts of sodium, magnesium, potassium and calcium on ion images. By contrast, iron, copper and CsFe ion images showed diffuse distribution throughout the sections.

  7. Comparison of five different fixation techniques of sagittal split ramus osteotomy using three-dimensional finite elements analysis.

    PubMed

    Sato, F R L; Asprino, L; Noritomi, P Y; da Silva, J V L; de Moraes, M

    2012-08-01

    The aim of this study was to compare the mechanical stress over hemimandible substrate and hardware after sagittal split ramus osteotomy (SSRO) fixed with five different techniques using three-dimensional (3D) finite element analysis. A 3D finite element model of a hemimandible was created and a 5mm advancement SSRO was simulated on a computer model. The model was fixed with five different techniques: 3 linear 60° screw arrangement; 3 linear 90° screw arrangement; 3 inverted L screw arrangement; 1 conventional miniplate; and 1 locking miniplate with four monocortical screws. Load was applied until 3mm displacement was reached and the results were compared with previous mechanical and photoelastic tests, thus analysing the mechanical stresses developed in the proximity of miniplates and screws and within the fixation system itself. The maximum principal stress values demonstrate a lower mechanical stress rate in bone and in the fixation system with the inverted L arrangement, followed by the linear 90° and linear 60° arrangements. The locking miniplate/screw system presented lower maximum principal stress and better stress distribution compared with the conventional system. Under the conditions tested, the reversed L arrangement provided the most favourable stress dissipation behaviour.

  8. Open Versus Minimally Invasive Fixation Techniques for Thoracolumbar Trauma: A Meta-Analysis

    PubMed Central

    McAnany, Steven J.; Overley, Samuel C.; Kim, Jun S.; Baird, Evan O.; Qureshi, Sheeraz A.; Anderson, Paul A.

    2015-01-01

    Study Design Systematic literature review and meta-analysis of studies published in English. Objective This study evaluated differences in outcome variables between percutaneous and open pedicle screws for traumatic thoracolumbar fractures. Methods A systematic review of PubMed, Cochrane, and Embase was performed. The variables of interest included postoperative visual analog scale (VAS) pain score, kyphosis angle, and vertebral body height, as well as intraoperative blood loss and operative time. The results were pooled by calculating the effect size based on the standardized difference in means. The studies were weighted by the inverse of the variance, which included both within- and between-study error. Confidence intervals were reported at 95%. Heterogeneity was assessed using the Q statistic and I 2. Results After two-reviewer assessment, 38 studies were eliminated. Six studies were found to meet inclusion criteria and were included in the meta-analysis. The combined effect size was found to be in favor of percutaneous fixation for blood loss and operative time (p < 0.05); however, there were no differences in vertebral body height (VBH), kyphosis angle, or VAS scores between open and percutaneous fixation. All of the studies demonstrated relative homogeneity, with I 2 < 25. Conclusions Patients with thoracolumbar fractures can be effectively managed with percutaneous or open pedicle screw placement. There are no differences in VBH, kyphosis angle, or VAS between the two groups. Blood loss and operative time were decreased in the percutaneous group, which may represent a potential benefit, particularly in the polytraumatized patient. All variables in this study demonstrated near-perfect homogeneity, and the effect is likely close to the true effect. PMID:26933621

  9. Evaluation of different screw fixation techniques and screw diameters in sagittal split ramus osteotomy: finite element analysis method.

    PubMed

    Sindel, A; Demiralp, S; Colok, G

    2014-09-01

    Sagittal split ramus osteotomy (SSRO) is used for correction of numerous congenital or acquired deformities in facial region. Several techniques have been developed and used to maintain fixation and stabilisation following SSRO application. In this study, the effects of the insertion formations of the bicortical different sized screws to the stresses generated by forces were studied. Three-dimensional finite elements analysis (FEA) and static linear analysis methods were used to investigate difference which would occur in terms of forces effecting onto the screws and transmitted to bone between different application areas. No significant difference was found between 1·5- and 2-mm screws used in SSRO fixation. Besides, it was found that 'inverted L' application was more successful compared to the others and that was followed by 'L' and 'linear' formations which showed close rates to each other. Few studies have investigated the effect of thickness and application areas of bicortical screws. This study was performed on both advanced and regressed jaws positions.

  10. Translaminar screws of the axis--an alternative technique for rigid screw fixation in upper cervical spine instability.

    PubMed

    Meyer, D; Meyer, F; Kretschmer, Th; Börm, W

    2012-04-01

    C2 pedicle screws or transarticular atlantoaxial screws are technically demanding and carry an increased risk of vertebral artery injury. In up to 20% of cases, pedicle and transarticular screw placement is not possible due to a high-riding vertebral artery or very small C2 pedicles in addition to other anatomical variations. Translaminar screws have been reported to rigidly capture posterior elements of C2 and therefore appear to be a suitable alternative. We present our first experiences and clinical results with this new method in two neurosurgical spine centers. Twenty-seven adult patients were treated between 2007 and 2010 in two neurosurgical spine departments with C2 translaminar screw fixation for upper cervical spine instability of various origins (e.g., trauma, tumor, dens pseudarthrosis). Eight patients were men and 19 were women. Mean age was 68.9 years. In most cases, translaminar screws were used because of contraindications for pedicle or transarticular screws as a salvage technique. All patients were clinically assessed and had CT scans postoperatively to verify correct screw placement. Follow-up was performed with reexamination on an ambulatory basis. Mean follow-up was 7.6 months for all patients. In 27 patients, 52 translaminar screws were placed. There were no intraoperative complications. Postoperatively, we identified four screw malpositions using a new accuracy grading scale. One screw had to be revised because of violation of the spinal canal >4 mm. None of the patients had additional neurological deficits postoperatively, and all showed stable cervical conditions at follow-up. Two patients died due to causes not associated with the stabilization technique. The fusion rate for patients with C1/C2 fixation is 92.9%. Translaminar screws can be used at least as an additional technique for cases of upper cervical spine instability when pedicle screw placement is contraindicated or not possible. The current data suggest comparable

  11. Single-Row or Double-Row Fixation Technique for Full-Thickness Rotator Cuff Tears: A Meta-Analysis

    PubMed Central

    Zhou, Jiaojiao; Yuan, Chaoqun; Chen, Kai; Cheng, Biao

    2013-01-01

    Background The single-row and double-row fixation techniques have been widely used for rotator cuff tears. However, whether the double-row technique produces superior clinical or anatomic outcomes is still considered controversial. This study aims to use meta-analysis to compare the clinical and anatomical outcomes between the two techniques. Methods The Pubmed, Embase, and Cochrane library databases were searched for relevant studies published before November 1, 2012. Studies clearly reporting a comparison of the single-row and double-row techniques were selected. The Constant, ASES, and UCLA scale systems and the rotator cuff integrity rate were evaluated. The weighted mean differences and relative risks were calculated using a fixed-effects or random-effects model. Results Eight studies were included in this meta-analysis. The weighted mean differences of the ASES (−0.84; P = 0.04; I2 = 0%) and UCLA (−0.75; P = 0.007; I2 = 0%) scales were significantly low in the single-row group for full-thickness rotator cuff tears. For tear sizes smaller than 3 cm, no significant difference was found between the groups no matter in Constant (P = 0.95; I2 = 0%), ASES (P = 0.77; I2 = 0%), or UCLA (P = 0.24; I2 = 13%) scales. For tear sizes larger than 3 cm, the ASES (−1.95; P = 0.001; I2 = 49%) and UCLA (−1.17; P = 0.006; I2 = 0%) scales were markedly lower in the single-row group. The integrity of the rotator cuff (0.81; P = 0.0004; I2 = 10%) was greater and the partial thickness retear rate (1.93; P = 0.007; I2 = 10%) was less in the double-row group. Full-thickness retears showed no difference between the groups (P = 0.15; I2 = 0%). Conclusion The meta-analysis suggests that the double-row fixation technique increases post-operative rotator cuff integrity and improves the clinical outcomes, especially for full-thickness rotator cuff tears larger than 3 cm. For tear sizes smaller than 3 cm

  12. Establishment of microbial eukaryotic enrichment cultures from a chemically stratified antarctic lake and assessment of carbon fixation potential.

    PubMed

    Dolhi, Jenna M; Ketchum, Nicholas; Morgan-Kiss, Rachael M

    2012-04-20

    phototrophic and mixotrophic protists from Lake Bonney. Sampling depths in the water column were chosen based on the location of primary production maxima and protist phylogenetic diversity (4, 11), as well as variability in major abiotic factors affecting protist trophic modes: shallow sampling depths are limited for major nutrients, while deeper sampling depths are limited by light availability. In addition, lake water samples were supplemented with multiple types of growth media to promote the growth of a variety of phototrophic organisms. RubisCO catalyzes the rate limiting step in the Calvin Benson Bassham (CBB) cycle, the major pathway by which autotrophic organisms fix inorganic carbon and provide organic carbon for higher trophic levels in aquatic and terrestrial food webs (12). In this study, we applied a radioisotope assay modified for filtered samples (13) to monitor maximum carboxylase activity as a proxy for carbon fixation potential and metabolic versatility in the Lake Bonney enrichment cultures.

  13. Comparison of a reverse-transverse cross pin technique with a same side cross pin type II external skeletal fixator in 89 dogs.

    PubMed

    Tsai, Kun-Yang; Pead, Matthew

    2015-01-01

    The objective of this study was to determine whether a novel reverse-transverse cross pin insertion technique could increase the stability of type II external skeletal fixators (ESF) in dogs compared with an alternate, same side cross pin ESF. Reverse-transverse cross pin technique and type II ESFs same side cross pin technique were applied and compared among subjects. Two of 42 ESFs (4.8%) applied with the reverse-transverse cross pin technique and 39 of 47 ESFs (83%) applied with the same side cross pin technique were subjectively unstable at the time of fixator removal (P < 0.001). The same side cross pin ESFs had significantly more pin tract new bone formation than the reverse-transverse ESFs (P = 0.038). In summary, this approach may provide a method of treating a variety of musculoskeletal conditions and soft tissue cases, which reverse-transverse cross pin ESFs are tolerated in dogs for a variety of conditions.

  14. Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-Compliant Article: Erratum.

    PubMed

    2015-02-01

    [In the article "Biomechanical Evaluation of Interfragmentary Compression At Tibia Plateau Fractures In Vitro Using Different Fixation Techniques: A CONSORT-compliant" article, which appeared in Volume 94, Issue 1 of Medicine, a line denoting dual authorship was omitted. K. Kojima and B. Gueorguiev contributed equally to the article.].

  15. Comparison of two tension-band fixation materials and techniques in transverse patella fractures: a biomechanical study.

    PubMed

    Rabalais, R David; Burger, Evalina; Lu, Yun; Mansour, Alfred; Baratta, Richard V

    2008-02-01

    This study compared the biomechanical properties of 2 tension-band techniques with stainless steel wire and ultra high molecular weight polyethylene (UHMWPE) cable in a patella fracture model. Transverse patella fractures were simulated in 8 cadaver knees and fixated with figure-of-8 and parallel wire configurations in combination with Kirschner wires. Identical configurations were tested with UHMWPE cable. Specimens were mounted to a testing apparatus and the quadriceps was used to extend the knees from 90 degrees to 0 degrees; 4 knees were tested under monotonic loading, and 4 knees were tested under cyclic loading. Under monotonic loading, average fracture gap was 0.50 and 0.57 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.16 and 0.04 mm, respectively, in the parallel wire construct. Under cyclic loading, average fracture gap was 1.45 and 1.66 mm for steel wire and UHMWPE cable, respectively, in the figure-of-8 construct compared with 0.45 and 0.60 mm, respectively, in the parallel wire construct. A statistically significant effect of technique was found, with the parallel wire construct performing better than the figure-of-8 construct in both loading models. There was no effect of material or interaction. In this biomechanical model, parallel wires performed better than the figure-of-8 configuration in both loading regimens, and UHMWPE cable performed similarly to 18-gauge steel wire.

  16. Knee Osteochondritis Dissecans Treated by the AO Hook Fixation System: A Four Year Follow-Up of an Alternative Technique

    PubMed Central

    Pengas, Ioannis P; Assiotis, Angelos; Kokkinakis, Michail; Khan, Wasim S; Meyers, Paul; Arbuthnot, James; Mcnicholas, Michael J

    2014-01-01

    Surgical fixation is recommended for stable osteochondritis dissecans (OCD) lesions that have failed nonoperative management and for all unstable lesions. In this study we set out to describe and evaluate an alternative method of surgical fixation for such lesions. Five knees with unstable OCD lesions in four male adolescent patients with open physes were treated with the AO Hook Fixation System. The outcome was evaluated both clinically and with three separate outcome systems (IKDC 2000, KOOS, Lysholm) at one and a mean four year follow-up. We demonstrated excellent clinical results in all patients. At four years, all scoring systems demonstrated statistically significant improvement when compared to the preoperative status. Our study suggests that the AO Hook Fixation System is an alternative method of surgical intervention with comparable medium term results with other existing modes of fixation and the added biomechanical advantage of the absence of distracting forces during hardware removal. PMID:25067976

  17. A comparative study of pedicle screw fixation in dorsolumbar spine by freehand versus image-assisted technique: A cadaveric study

    PubMed Central

    Agarwal, Archit; Chauhan, Vijendra; Singh, Deepa; Shailendra, Raghuvanshi; Maheshwari, Rajesh; Juyal, Anil

    2016-01-01

    Background: New and expensive technology such as three-dimensional computer assisted surgery is being used for pedicle screw fixation in dorsolumbar spine. Their availability, expenses and amount of radiation exposure are issues in a developing country. On the contrary, freehand technique of pedicle screw placement utilizes anatomic landmarks and tactile palpation without fluoroscopy or navigation to place pedicle screws. The purpose of this study was to analyze and compare the accuracy of freehand and image-assisted technique to place pedicle screws in the dorsolumbar spine of cadavers by an experienced surgeon and a resident. Evaluation was done using dissection of pedicle and computed tomography (CT) imaging. Materials and Methods: Ten cadaveric dorsolumbar spines were exposed by a posterior approach. Titanium pedicle screws were inserted from D5 to L5 vertebrae by freehand and image-assisted technique on either side by an experienced surgeon and a resident. CT was obtained. A blinded radiologist reviewed the imaging. The spines were then dissected to do a macroscopic examination. Screws, having evidence of cortical perforation of more than 2 mm on CT, were considered to be a significant breach. Results: A total of 260 pedicle screws were placed. The surgeon and the resident placed 130 screws each. Out of 130 screws, both of them placed 65 screws each by freehand and image- assisted technique each. The resident had a rate of 7.69% significant medial and 10.76% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 9.23% significant lateral breach. The expert surgeon had a rate of 6.15% significant medial and 1.53% significant lateral breach with freehand technique while with image-assisted had a rate of 3.07% significant medial and 6.15% significant lateral breach on CT evaluation. Conclusion: Freehand technique is as good as the image-assisted technique. Under appropriate supervision, residents

  18. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction

    PubMed Central

    Dillard, Stacy; Roe, Simon

    2015-01-01

    Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments. PMID:26312169

  19. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction.

    PubMed

    Early, Peter; Mente, Peter; Dillard, Stacy; Roe, Simon

    2015-01-01

    Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments.

  20. Miniarthrotomy assisted percutaneous screw fixation for displaced medial malleolus fractures – A novel technique

    PubMed Central

    Saini, Pramod; Aggrawal, Abhinav; Meena, Sanjay; Trikha, Vivek; Mittal, Samarth

    2014-01-01

    Aim To describe here a technique of miniarthrotomy assisted percutaneous screw insertion for displaced Herscovici type B and C medial malleolar fractures. Method Incision was made centred over the superomedial angle of the ankle mortise, about half a cm medial to tibialis anterior. Arthrotomy was done and reduction obtained. Percuntaneously, two 4 mm cancellous cannulated screws were inserted through medial malleolus. Results and conclusion This approach allows direct visualization of reduction, removal of entrapped soft tissue and preservation of saphenous vein and nerve. PMID:25983507

  1. Pars plana suture fixation for intraocular lenses dislocated into the vitreous cavity using a closed-eye cow-hitch technique.

    PubMed

    Nakashizuka, Hiroyuki; Shimada, Hiroyuki; Iwasaki, Yutaka; Matsumoto, Yoko; Sato, Yukihiro

    2004-02-01

    We describe a modified intraocular cow-hitch technique for pars plana suture fixation of intraocular lenses (IOLs) that dislocated into the vitreous cavity in 3 patients who had a 3-port vitrectomy and IOL implantation because of retinal disease. To reposition the dislocated IOL after the residual vitreous was removed, 2 additional sclerotomies for suture fixation were made 3.0 mm posterior to the limbus. A loop (cow-hitch knot) was made with 10-0 polypropylene for suture fixation. After the neck of the cow-hitch loop was grasped with an intraocular forceps, the loop was used to lasso a haptic of the dislocated IOL, which was then pulled forward to the sclerotomy. The same procedure was used for the other haptic, and both sutures were secured to the sclera under scleral flaps. In all patients, the dislocated IOLs were repositioned without the need for extraction. The procedures were uneventful. Pars plana suture fixation with the intraocular cow-hitch technique can be used to reposition an IOL that has dislocated into the vitreous cavity.

  2. Safety screw fixation technique in a case of coracoid base fracture with acromioclavicular dislocation and coracoid base cross-sectional size data from a computed axial tomography study.

    PubMed

    Kawasaki, Yoshiteru; Hirano, Tetsuya; Miyatake, Katsutoshi; Fujii, Koji; Takeda, Yoshitsugu

    2014-07-01

    Coracoid base fracture accompanied by acromioclavicular joint dislocation with intact coracoclavicular ligaments is a rare injury. Generally, an open reduction with screw fixation is the first treatment choice, as it protects the important structures around the coracoid process. This report presents a new technique of screw fixation for coracoid base fracture and provides anatomic information on cross-sectional size of the coracoid base obtained by computed tomography (CT). An axial image of the coracoid base was visualized over the neck of the scapula, and a guidewire was inserted into this circle under fluoroscopic guidance. The wire was inserted easily into the neck of scapula across the coracoid base fracture with imaging in only 1 plane. In addition, 25 measurements of the coracoid base were made in 25 subjects on axial CT images. Average length of the long and short axes at the thinnest part of the coracoid base was 13.9 ± 2.0 mm (range 10.6-17.0) and 10.5 ± 2.2 mm (6.6-15.1), respectively. This new screw fixation technique and measurement data on the coracoid base may be beneficial for safety screw fixation of coracoid base fracture.

  3. Biomechanical in vitro evaluation of three stable internal fixation techniques used in sagittal osteotomy of the mandibular ramus: a study in sheep mandibles

    PubMed Central

    de OLIVERA, Leandro Benetti; SANT'ANA, Eduardo; MANZATO, Antonio José; GUERRA, Fábio Luis Bunemer; ARNETT, G. William

    2012-01-01

    Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR) is the most common, allowing a great range of movements and stable internal fixation (SIF), therefore eliminating the need of maxillomandibular block in the postoperative period. Objectives: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. Material and methods: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group). In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group). In group III, fixation was performed with two 4-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group). All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. Results: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. Conclusion: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR. PMID:23032203

  4. Catheter fixation and ligation: a simple technique for ventriculostomy management following endovascular stenting.

    PubMed

    Sweeney, Justin M; Vasan, Rohit; van Loveren, Harry R; Youssef, A Samy; Agazzi, Siviero

    2013-05-01

    The object of this study was to describe a unique method of managing ventriculostomy catheters in patients on antithrombotic therapy following endovascular treatment of ruptured intracranial aneurysms. The authors retrospectively reviewed 3 cases in which a unique method of ventriculostomy management was used to successfully avoid catheter-related hemorrhage while the patient was on dual antiplatelet therapy. In this setting, ventriculostomy catheters are left in place and fixed to the calvarium with titanium straps effectively ligating them. The catheter is divided and the distal end is removed. The proximal end can be directly connected to a distal shunt system during this stage or at a later date if necessary. The method described in this report provided a variety of management options for patients requiring external ventricular drainage for subarachnoid hemorrhage. No patient suffered catheter-related hemorrhage. This preliminary report demonstrates a safe and effective method for discontinuing external ventricular drainage and/or placing a ventriculoperitoneal shunt in the setting of active coagulopathy or antithrombotic therapy. The technique avoids both the risk of hemorrhage related to catheter removal and reinsertion and the thromboembolic risks associated with the reversal of antithrombotic therapy. Some aneurysm centers have avoided the use of stent-assisted coiling in cases of ruptured aneurysms to circumvent ventriculostomy-related complications; however, the method described herein should allow continued use of this important treatment option in ruptured aneurysm cases. Further investigation in a larger cohort with long-term follow-up is necessary to define the associated risks of infection using this method.

  5. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models.

    PubMed

    Mondon, J A; Howitt, J; Tosiano, M; Kwok, K W H; Hinton, D E

    2011-01-01

    Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  6. Percutaneous reduction and fixation of an intra-articular calcaneal fracture using an inflatable bone tamp: description of a novel and safe technique

    PubMed Central

    2012-01-01

    Calcaneal fractures are common injuries involving the hind foot and often a source of significant long-term morbidity. Treatment options have changed throughout the ages from periods of preferred nonoperative management to closed reduction with a mallet, and more recently, open reduction and anatomic internal fixation. The current treatment of choice; however, is often debated, as open management of these fractures carries many risks to include wound breakdown and infection. A less invasive form of surgical management through small incisions, while maintaining the ability to obtain joint congruency, anatomic alignment, and restore calcaneal height and width would be ideal. We propose a novel form of fracture reduction using an inflatable bone tamp and percutaneous fracture fixation. Preoperative planning and experienced fluoroscopy is crucial to successful management using this method. Although we achieved successful radiographic outcome in this case, long-term functional outcome of this technique are yet to be published. PMID:22420710

  7. Posterior C1-C2 Fixation Using Absorbable Suture for Type II Odontoid Fracture in 2-Year-Old Child: Description of a New Technique and Literature Review.

    PubMed

    Labbe, Jean L; Peres, Olivier; Leclair, Olivier; Goulon, Renaud; Scemama, Patrice; Jourdel, François; Bertrou, Véronique; Murgier, Jerome

    2016-12-01

    Odontoid synchondrosis fractures are rare in children, even though they are the more common cervical fracture in children less than 7 years old. Nonoperative treatment with external orthosis immobilization is the treatment of choice for stable undisplaced or minimally displaced injuries. In unstable fractures, when reduction cannot be achieved or maintained, surgical fixation is recommended. We report a 2-year-old boy with an unstable fracture of the odontoid treated surgically using an absorbable monofilament suture for C1-C2 interlaminar fixation without bone grafting. This suture was strong enough to provide the stability necessary to allow healing of the synchondrosis and the delayed resorption of the suture was followed by complete restoration of the mobility between C1 and C2. This case illustrates that surgical stabilization using an absorbable suture in young children with an unstable odontoid fracture is a safe and effective alternative to other surgical techniques.

  8. Symbiotic N2-Fixation Estimated by the 15N Tracer Technique and Growth of Pueraria phaseoloides (Roxb.) Benth. Inoculated with Bradyrhizobium Strain in Field Conditions

    PubMed Central

    Sarr, Papa Saliou; Okon, Judith Wase; Begoude, Didier Aime Boyogueno; Araki, Shigeru; Ambang, Zachée; Shibata, Makoto; Funakawa, Shinya

    2016-01-01

    This field experiment was established in Eastern Cameroon to examine the effect of selected rhizobial inoculation on N2-fixation and growth of Pueraria phaseoloides. Treatments consisted of noninoculated and Bradyrhizobium yuanmingense S3-4-inoculated Pueraria with three replications each. Ipomoea batatas as a non-N2-fixing reference was interspersed in each Pueraria plot. All the twelve plots received 2 gN/m2 of 15N ammonium sulfate 10% atom excess. At harvest, dry matter yields and the nitrogen derived from atmospheric N2-fixation (%Ndfa) of inoculated Pueraria were significantly (P < 0.05) higher (81% and 10.83%, resp.) than those of noninoculated Pueraria. The inoculation enhanced nodule dry weight 2.44-fold. Consequently, the harvested N significantly (P < 0.05) increased by 83% in inoculated Pueraria, resulting from the increase in N2-fixation and soil N uptake. A loss of 55 to 60% of the N fertilizer was reported, and 36 to 40% of it was immobilized in soil. Here, we demonstrated that both N2-fixing potential of P. phaseoloides and soil N uptake are improved through field inoculations using efficient bradyrhizobial species. In practice, the inoculation contributes to maximize N input in soils by the cover crop's biomass and represent a good strategy to improve soil fertility for subsequent cultivation. PMID:26904363

  9. [Underlying mechanisms and related techniques of stand establishment of cotton on coastal saline-alkali soil].

    PubMed

    Dong, He-Zhong

    2012-02-01

    Stand establishment is the most difficult step for cotton planting on coastal saline-alkali soil. To establish and improve the techniques for stand establishment is the key in the production of high-yielding cotton on saline-alkali soil. Based on the previous studies and our own research progress in this field, this paper reviewed the effects and the underlying mechanisms of making unequal salt distribution in root zone, increasing soil moisture and temperature, establishing under-mulching greenhouse, and introducing seed coating agent in promoting stand establishment of cotton on saline-alkali soil. It was suggested that under the conditions of the average salt content in topsoil being not able to reduce, improving at least partial root zone environment through the induction of unequal salt distribution in the root zone and increasing soil moisture and temperature could significantly reduce salt injury and improve stand establishment. Flat seeding under plastic mulching on low-salinity soil, furrow seeding with mulching on moderate- or high-salinity soil, early mulching before sowing on rain-fed saline soil, and late sowing of short-season cotton in heat-limited area were the efficient techniques for improving the stand establishment of cotton on coastal saline-alkali soil. This review could provide full guarantee for the cotton stand establishment on coastal saline-alkali soil.

  10. Management of Gustilo Anderson III B open tibial fractures by primary fascio-septo-cutaneous local flap and primary fixation: The ‘fix and shift’ technique

    PubMed Central

    Ramasamy, P R

    2017-01-01

    Background: Open fractures of tibia have posed great difficulty in managing both the soft tissue and the skeletal components of the injured limb. Gustilo Anderson III B open tibial fractures are more difficult to manage than I, II, and III A fractures. Stable skeletal fixation with immediate soft tissue cover has been the key to the successful outcome in treating open tibial fractures, in particular, Gustilo Anderson III B types. If the length of the open wound is larger and if the exposed surface of tibial fracture and tibial shaft is greater, then the management becomes still more difficult. Materials and Methods: Thirty six Gustilo Anderson III B open tibial fractures managed between June 2002 and December 2013 with “fix and shift” technique were retrospectively reviewed. All the 36 patients managed by this technique had open wounds measuring >5 cm (post debridement). Under fix and shift technique, stable fixation involved primary external fixator application or primary intramedullary nailing of the tibial fracture and immediate soft tissue cover involved septocutaneous shift, i.e., shifting of fasciocutaneous segments based on septocutaneous perforators. Results: Primary fracture union rate was 50% and reoperation rate (bone stimulating procedures) was 50%. Overall fracture union rate was 100%. The rate of malunion was 14% and deep infection was 16%. Failure of septocutaneous shift was 2.7%. There was no incidence of amputation. Conclusion: Management of Gustilo Anderson III B open tibial fractures with “fix and shift” technique has resulted in better outcome in terms of skeletal factors (primary fracture union, overall union, and time for union and malunion) and soft tissue factors (wound healing, flap failure, access to secondary procedures, and esthetic appearance) when compared to standard methods adopted earlier. Hence, “fix and shift” could be recommended as one of the treatment modalities for open III B tibial fractures. PMID:28216752

  11. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique

    SciTech Connect

    Amoretti, Nicolas Gallo, Giacomo Bertrand, Anne-Sophie; Bard, Robert L.; Kelekis, Alexis

    2016-01-15

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4–L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  12. Distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator in the reconstruction of massive postosteomyelitis skeletal defects of the femur

    PubMed Central

    Li, Zhihong; Zhang, Xiangsheng; Duan, Liqun; Chen, Xiaoming

    2009-01-01

    Background Large skeletal defects due to postosteomyelitis are uncommon, and they present a challenging reconstructive problem. The aim of our study was to summarize our experience performing a distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator in the reconstruction of massive postosteomyelitis skeletal defects of the femur. Methods Between January 1998 and October 2004, 17 patients with massive postosteomyelitis skeletal defects of the femur (11 men and 6 women), underwent the reconstruction procedure. After osteotomy of diaphysis of the femur, we inserted an intramedullary nail into the femur, and we placed a monolateral external fixator with half-pins lateral to the nail. Lengthening was started on the seventh postoperative day at a rate of 1 mm/d. Once we achieved solid bone union, we removed the monolateral external fixator; the intramedullary nail remained for bone consolidation until reconsruction was complete. We assessed the outcomes clinically and radiographically at a mean of 70.3 months postoperatively. Results At follow-up (mean 70.3, range 14.0–96.0 mo), all the skeletal defects were filled, bone union at docking sites was achieved without bone graft and leg length discrepancies were less than 2.5 cm in all patients. The mean gain in length was 12.9 (range 10.2–18.4) cm. According to Paley and Maar's evaluation criteria, we graded the bone results as excellent for 10 patients, good for 5, fair for 1 and poor for 1. We graded the functional results as excellent for 12 patients, good for 4 and fair for 1. The mean external fixator index was 18.1 d/cm; the consolidation index was 35.7 d/cm. Ten patients experienced pin infection, and 1 patient experienced a recurrence of deep infection. There were no neurologic or vascular injuries. Conclusion Our study demonstrates that a distraction osteogenesis technique using an intramedullary nail and a monolateral external fixator is a reliable method for the

  13. Less invasive lumbopelvic fixation technique using a percutaneous pedicle screw system for unstable pelvic ring fracture in a patient with severe multiple traumas.

    PubMed

    Yano, Sei; Aoki, Yasuchika; Watanabe, Atsuya; Nakajima, Takayuki; Takazawa, Makoto; Hirasawa, Hiroyuki; Takahashi, Kazuhisa; Nakagawa, Koichi; Nakajima, Arata; Takahashi, Hiroshi; Orita, Sumihisa; Eguchi, Yawara; Suzuki, Takane; Ohtori, Seiji

    2017-02-01

    Pelvic ring fractures are defined as life-threatening injuries that can be treated surgically with external or internal fixation. The authors report on an 81-year-old woman with an unstable pelvic fracture accompanying multiple traumas that was successfully treated with a less invasive procedure. The patient was injured in a traffic accident and sustained a total of 20 fractures, including pelvic ring, bilateral rib, and lumbar transverse processes fractures, and multiple fractures of both upper and lower extremities. The pelvic ring fracture was unstable with fractures of the bilateral sacrum with right sacroiliac disruption, right superior and inferior pubic rami, left superior pubic ramus, and ischium. During emergency surgery, bilateral external fixation was applied to the iliac crest to stabilize the pelvic ring. Second and third surgeries were performed 11 and 18 days after the first emergency surgery, respectively, to treat the multiple fractures. At the third surgery, the pelvic ring fracture was stabilized surgically using a less invasive posterior fixation technique. In this technique, 2 iliac screws were inserted on each side following an 8-cm midline posterior incision from the S-1 to S-3 spinous process, with the subcutaneous tissue detached from the fascia of the paraspinal muscles. The S-2 spinous process was removed and 2 rods were connected to bilateral iliac screws to stabilize the bilateral ilium in a switchback fashion. A crosslink device was applied to connect the 2 rods at the base of the S-2 spinous process. Following pelvic fixation, percutaneous pedicle screws were inserted into L-4 and L-5 vertebral bodies on both sides, and connected to the cranial rod connecting the bilateral iliac screws, thus completing the lumbopelvic fixation. The postoperative course was favorable with no postoperative complications. At the 10-month follow-up, bone union had been achieved at the superior ramus of the pubis, the patient did not complain of pain, and

  14. Mechanical evaluation of six techniques for stable fixation of the sagittal split osteotomy after counterclockwise mandibular advancement.

    PubMed

    De Oliveira, Leandro Benetti; Reis, Jose Mauricio Nunes; Spin-Neto, Rubens; Gabrielli, Marisa Aparecida Cabrini; Oguz, Yener; Pereira-Filho, Valfrido Antonio

    2016-06-01

    We have evaluated the resistance to displacement of six stable methods of fixation of a sagittal split ramus osteotomy (SSRO) in the mandibular advancement with counterclockwise rotation. We tested 60 synthetic hemimandibles in six groups of 10 each: Group I - fixation with a straight four-hole 2.0mm miniplate; Group II - a straight six-hole 2.0mm miniplate; Group III - two straight 2.0mm four-hole miniplates; Group IV - an eight-hole 2.0mm (grid plate); Group V - a 2.0mm four-hole straight miniplate and 2.0×12mm bicortical screw; and Group VI - a straight four-hole 2.0mm locking miniplate. We applied a linear force in the region between the canine and the first premolar using a universal testing machine (EMIC- DL2000) with a loading cell of 10 KN. The loads at 1, 3, and 5mm displacement were recorded (N) and the data transmitted from the load cell to a computer. Results were analysed using analysis of variance (ANOVA) (p<0.001) and the Tukey post-test for comparison of the significance of the differences between the groups. For the three degrees of displacement, fixation with two straight 2.0mm plates and with the grid plate gave higher load values.

  15. Surgical technique: establishing a pre-clinical large animal model to test aortic valve leaflet substitute

    PubMed Central

    Knirsch, Walter; Cesarovic, Niko; Krüger, Bernard; Schmiady, Martin; Frauenfelder, Thomas; Frese, Laura; Dave, Hitendu; Hoerstrup, Simon Philipp; Hübler, Michael

    2016-01-01

    To overcome current limitations of valve substitutes and tissue substitutes the technology of tissue engineering (TE) continues to offer new perspectives in congenital cardiac surgery. We report our experiences and results implanting a decellularized TE patch in nine sheep in orthotropic position as aortic valve leaflet substitute. Establishing the animal model, feasibility, cardiopulmonary bypass issues and operative technique are highlighted. PMID:28149571

  16. Contact angle hysteresis on polymer substrates established with various experimental techniques, its interpretation, and quantitative characterization.

    PubMed

    Bormashenko, Edward; Bormashenko, Yelena; Whyman, Gene; Pogreb, Roman; Musin, Albina; Jager, Rachel; Barkay, Zahava

    2008-04-15

    The effect of contact angle hysteresis (CAH) was studied on various polymer substrates with traditional and new experimental techniques. The new experimental technique presented in the article is based on the slow deformation of the droplet, thus CAH is studied under the constant volume of the drop in contrast to existing techniques when the volume of the drop is changed under the measurement. The energy of hysteresis was calculated in the framework of the improved Extrand approach. The advancing contact angle established with a new technique is in a good agreement with that measured with the needle-syringe method. The receding angles measured with three experimental techniques demonstrated a very significant discrepancy. The force pinning the triple line responsible for hysteresis was calculated.

  17. A Challenging Case of Limb Salvage Requiring a Combination of Composite Fixation and Masquelet Technique to Address Significant Segmental Bone Loss

    PubMed Central

    Blair, C.; Simela, A. T.; Cross, B. J.

    2015-01-01

    Cases of limb salvage following skeletal trauma involving significant bone loss pose a particular challenge to the reconstructive surgeon. Certain techniques for addressing this complex issue have been advanced in recent years and have met with considerable success. The Masquelet technique involves a staged procedure in which a temporary skeletal stabilization is paired with implantation of an antibiotic spacer and left in place for 6–8 weeks, during which time a “pseudomembrane” forms around the cement spacer. During the second stage of the procedure, the pseudomembrane is incised, the antibiotic spacer removed, and bone graft is placed. We present a case of significant segmental femur loss in a 19-year-old male opting for limb salvage in which a 17-centimeter segmental loss of bone was essentially regrown using a combination of the Masquelet technique with supplemental endosteal fixation. PMID:25789190

  18. Anatomical evaluation of the groove for the vertebral artery in the axis vertebrae for atlanto-axial transarticular screw fixation technique.

    PubMed

    Kazan, S; Yildirim, F; Sindel, M; Tuncer, R

    2000-01-01

    Anatomical measurements were studied on 40 dry axis vertebrae to determine the suitability of the groove for the vertebral artery for atlanto-axial transarticular screw fixation technique. We measured 13 parameters including three angular and 10 linear dimensions related to the groove of the vertebral artery, pedicle, and pars interarticularis and evaluated 80 measurements for each parameter. All measurements were done after placing a Kischner guide wire through the pedicle. We found that differences between measurements on the left and right sides of each vertebra were nonsignificant. In spite of the variability in measurements such as height, width, and median angle of the pedicle, the decline angle for instrumentation, the depth of the groove for the vertebral artery, and the internal height of the pars interarticularis, all of these had good symmetry. However, there were statistically significant differences between the sides in measurements for both the width (P=0.05) and the angle (P<0.02) of the pedicle allowing instrumentation and they did not show good symmetry. The risk of vertebral artery injury was found to be 22.5% per specimen, or 16.25% per screw inserted because the internal height of the pars interarticularis at point of fixation was technique would be extremely dangerous in 7.5% of specimens. In conclusion, the internal height of the pars interarticularis and the width of the pedicle for instrumentation should be evaluated together in thin CT sections preoperatively, because of the risk of vertebral artery injury in patients upon which atlanto-axial transarticular screw fixation is to be performed.

  19. Using a freeze substitution fixation technique and histological crimp analysis for characterizing regions of strain in ligaments loaded in situ.

    PubMed

    Boorman, Richard S; Norman, Tony; Matsen, Frederick A; Clark, John M

    2006-04-01

    Type I collagen fibrils in tendons and ligaments assume a sinusoidal wave shape, or crimp, which straightens only with tensile load. The load response of crimp has been studied primarily in isolated subunits and not in complex, intact structures. The purpose of our study was to determine if freeze substitution fixation of an entire ligament could preserve changes in crimp morphology induced by functionally relevant loading conditions. We hypothesized that, in ligaments prepared by freeze-substitution fixation under load, crimp would progressively extinguish with increasing loads, and nonuniform strain following partial section could be detected from crimp morphology. Tensile loads ranging from 0 to 220 N were applied to patellar ligaments of 16 fresh rabbit stifle joints using simulated isometric quadriceps pull through the patella. The loaded joints were flash frozen with isopentane cooled in liquid nitrogen, then fixed using freeze substitution. Another six ligaments were loaded to 150 N following incision of the anterior third and evaluated under polarized light microscopy for crimp distribution. Ligaments with no or low loads could be identified by the presence of crimp on mid-sagittal sections. Strain distribution was inhomogeneous, in that the ligament displayed a consistent pattern of collagen fiber recruitment among three morphologically distinct bands seen on coronal sections. At very low loads (about 18 N), the fibers in a central band were uncrimped; anterior and deep bands uncrimped at higher loads. The crimp in the entire specimen was extinguished at about 67 N, which correlates closely with the previously reported toe-region of the stress-strain curve of the rabbit patellar ligament. When the anterior third was transected, fibers within that segment retained a crimp in ligaments prepared under loads that ordinarily would ablate all crimp. These findings suggest that freeze fixation could be used to map the functional microstructure of ligaments or

  20. Novel labeling technique illustrates transfer of 15N2 from Sphagnum moss to vascular plants via diazotrophic nitrogen fixation

    NASA Astrophysics Data System (ADS)

    Thorp, N. R.; Vile, M. A.; Wieder, R.

    2013-12-01

    We used 15N2 gas to trace nitrogen (N) from biological N2-fixation to vascular plant uptake in an Alberta bog in order to determine if neighboring bog plants acquire recently fixed N from diazotrophs associating with Sphagnum mosses. Recent evidence indicates high rates of N2-fixation in Sphagnum mosses of Alberta bogs (Vile et al. 2013). Our previous work has shown that mosses can assimilate fixed N from associated diazotrophs as evidenced by the high N content of mosses despite minimal inputs from atmospheric deposition, retranslocation, and N mineralization. Therefore, the potential exists for vascular plants to obtain N from ';leaky' tissues of live mosses, however, this phenomenon has not been tested previously. Here we document the potential for relatively rapid transfer to vascular plants of N fixed by Sphagnum moss-associated diazotrophs. We utilized the novel approach of incubating mosses in 15N2 to allow the process of diazotrophic N2-fixation to mechanistically provide the 15N label, which is subsequently transferred to Sphagnum mosses. The potential for vascular bog natives to tap this N was assessed by planting the vascular plants in the labeled moss. Sphagnum mosses (upper 3 cm of live plants) were incubated in the presence of 98 atom % 15N2 gas for 48 hours. Two vascular plants common to Alberta bogs; Picea mariana and Vaccinium oxycoccus were then placed in the labeled mosses, where the mosses served as the substrate. Tissue samples from these plants were collected at three time points during the incubation; prior to 15N2 exposure (to determine natural abundance 15N), and at one and two months after 15N2 exposure. Roots and leaves were separated and run separately on a mass spectrometer to determine 15N concentrations. Sphagnum moss capitula obtained N from N2-fixation (δ15N of -2.43 × 0.40, 122.76 × 23.78, 224.92 × 68.37, 143.74 × 54.38 prior to, immediately after, and at 1 and 2 months after exposure to 15N2, respectively). Nitrogen was

  1. Comparison of Surgical Outcomes Between Short-Segment Open and Percutaneous Pedicle Screw Fixation Techniques for Thoracolumbar Fractures

    PubMed Central

    Fu, Zhiguo; Zhang, Xi; Shi, Yaohua; Dong, Qirong

    2016-01-01

    Background This study aimed to compare the surgical outcomes between open pedicle screw fixation (OPSF) and percutaneous pedicle screw fixation (PPSF) for the treatment of thoracolumbar fractures, which has received scant research attention to date. Material/Methods Eight-four patients with acute and subacute thoracolumbar fractures who were treated with SSPSF from January 2013 to June 2014 at the Changzhou Hospital of Traditional Chinese Medicine (Changzhou, China) were retrospectively reviewed. The patients were divided into 4 groups: the OPSF with 4 basic screws (OPSF-4) group, the OPSF with 4 basic and 2 additional screws (OPSF-6) group, the PPSF with 4 basic screws (PPSF-4) group, and the PPSF with 4 basic and 2 additional screws (PPSF-6) group. The intraoperative, immediate postoperative, and over 1-year follow-up outcomes were evaluated and compared among these groups. Results Blood loss in the PPSF-4 group and the PPSF-6 group was significantly less than in the OPSF-4 group and the OPSF-6 group (P<0.05). The OPSF-6 group exhibited significantly higher immediate postoperative correction percentage of anterior column height of fractured vertebra than the other 3 groups (P<0.05), and higher correction of sagittal regional Cobb angle and kyphotic angle of injured vertebra than in the PPSF-4 and -6 groups (P<0.05). In addition, there was no significant difference in the correction loss of percentage of anterior column height, and loss of sagittal Cobb angle and kyphotic angle of fractured vertebrae at final follow-up among the 4 groups (P>0.05). Conclusions OPSF with 6 screws had an advantage in the correction of injured vertebral height and kyphosis, and PPSF reduced the intraoperative blood loss of patients. PMID:27602557

  2. Closed reduction using the percutaneous leverage technique and internal fixation with K-wires to treat angulated radial neck fractures in children-case report.

    PubMed

    Jiang, Hai; Wu, Yongtao; Dang, Youting; Qiu, Yusheng

    2017-01-01

    Pediatric radial neck fractures are uncommon. Severely displaced and angulated fractures usually require treatment. Our goals for treatment are to avoid incision, reduce the fracture adequately with no reduction loss, and achieve good postoperative function. We aimed to observe the clinical outcomes of closed reduction with the percutaneous leverage technique and internal fixation with Kirschner-wires (K-wires) to treat angulated radial neck fractures in children.From January 2011 to April 2013, we treated 16 cases of angulated radial neck fracture in 12 boys and 4 girls. Five fractures were type II and 11 fractures were type III using the O'Brien classification. One K-wire was percutaneously introduced into the fracture site using the leverage technique to attain good reduction. Two K-wires were introduced from the proximal to the distal areas of the fracture site. The elbow was immobilized by cast in 90° of flexion and the forearm in supination for 3 to 4 weeks. The K-wires were removed at 3 to 4 weeks postoperatively. All cases were followed up for a mean duration of 3 years 6 months.According to the Metaizeau reduction classification, 12 cases were excellent, and 4 cases were good. According to the Metaizeau clinical classification, 14 cases were excellent, and 2 cases were good. There was no necrosis of the radial head. There was no infection, radioulnar synostosis, and damage of the radial nerve deep branch. There was no limitation in the pronation and supination functions of the forearm.Closed reduction using the percutaneous leverage technique and internal fixation using K-wires is easy to perform. It is encouraged to use this approach as the clinical outcome is good.

  3. Closed reduction using the percutaneous leverage technique and internal fixation with K-wires to treat angulated radial neck fractures in children-case report

    PubMed Central

    Jiang, Hai; Wu, Yongtao; Dang, Youting; Qiu, Yusheng

    2017-01-01

    Abstract Pediatric radial neck fractures are uncommon. Severely displaced and angulated fractures usually require treatment. Our goals for treatment are to avoid incision, reduce the fracture adequately with no reduction loss, and achieve good postoperative function. We aimed to observe the clinical outcomes of closed reduction with the percutaneous leverage technique and internal fixation with Kirschner-wires (K-wires) to treat angulated radial neck fractures in children. From January 2011 to April 2013, we treated 16 cases of angulated radial neck fracture in 12 boys and 4 girls. Five fractures were type II and 11 fractures were type III using the O’Brien classification. One K-wire was percutaneously introduced into the fracture site using the leverage technique to attain good reduction. Two K-wires were introduced from the proximal to the distal areas of the fracture site. The elbow was immobilized by cast in 90° of flexion and the forearm in supination for 3 to 4 weeks. The K-wires were removed at 3 to 4 weeks postoperatively. All cases were followed up for a mean duration of 3 years 6 months. According to the Metaizeau reduction classification, 12 cases were excellent, and 4 cases were good. According to the Metaizeau clinical classification, 14 cases were excellent, and 2 cases were good. There was no necrosis of the radial head. There was no infection, radioulnar synostosis, and damage of the radial nerve deep branch. There was no limitation in the pronation and supination functions of the forearm. Closed reduction using the percutaneous leverage technique and internal fixation using K-wires is easy to perform. It is encouraged to use this approach as the clinical outcome is good. Level of evidence: level IV-retrospective case, treatment study. PMID:28072734

  4. Conversion from temporary external fixation to definitive fixation: shaft fractures.

    PubMed

    Dougherty, Paul J; Silverton, Craig; Yeni, Yener; Tashman, Scott; Weir, Robb

    2006-01-01

    Temporary external fixation is the most common method of initial stabilization of diaphyseal fractures in forward surgical hospitals. Once the patient arrives at a stable environment, usually the United States, the fracture is managed with intramedullary nailing, small-pin external fixation, or a modified external fixator. Future research should be directed toward improving methods of care. It is not precisely known when is the best time to convert to definitive fixation without increasing the risk of infection. The risk factors leading to infection and nonunion are not well-established, making that determination even more difficult. Clinical studies of a suitable size should provide insight into these problems. Although temporary external fixation is commonly used, an optimal construct has not been determined. Data from studies of in vivo fracture-site motion after application of the temporary external fixator should be compared with biomechanical testing of similar constructs. These data could be used to recommend optimal temporary external fixation constructs of tibia, femur, and humerus fractures using currently available devices as well as to provide groundwork for the next generation of fixators.

  5. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    PubMed

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  6. Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

    PubMed Central

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture. PMID:28179950

  7. Extrusion - back to the future: Using an established technique to reform automated chemical synthesis.

    PubMed

    Crawford, Deborah E

    2017-01-01

    Herein, the benefits which extrusion can provide for the automated continuous synthesis of organic compounds are highlighted. Extrusion is a well-established technique that has a vital role in the manufacturing processes of polymers, pharmaceuticals and food products. Furthermore, this technique has recently been applied to the solvent-free continuous synthesis of co-crystals and coordination compounds including metal-organic frameworks (MOFs). To date, a vast amount of research has already been conducted into reactive extrusion (REX), particularly in the polymer industry, which in many cases has involved organic transformations, however, it has not received significant recognition for this. This review highlights these transformations and discusses how this previous research can be applied to the future of organic compound manufacture.

  8. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    PubMed

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  9. Mini external fixation in the hand.

    PubMed

    Ugwonali, Obinwanne Fidelis C; Jupiter, Jesse B

    2006-09-01

    External fixation is an effective means of addressing several pathologies of the hand. The advantages of its use include the ability to achieve stable fixation, minimize soft tissue trauma at the site of injury, and allow wound care and mobilization of adjacent joints. External fixators can be constructed from material readily available in the operating room or obtained from a commercial source. Sufficient rigidity can be achieved by any of these means. Improper placement, although achieving rigid fixation, may compromise motion and overall function if basic principles of external fixation are not followed or if the anatomy of the hand is not taken into consideration. The objective of this article is to describe the technique of application of mini external fixation, emphasizing the basic principles of external fixation as they relate to the specific anatomy of the hand. In addition to fracture fixation, various other uses are described including distraction lengthening, arthrodesis, treatment of nonunion, and infection.

  10. Effect of induced aniseikonia on fixation performance.

    PubMed

    Remole, A

    1988-01-01

    The purpose of the study was to determine to what extent induced aniseikonia affects fixation performance. Aniseikonia was induced in the vertical meridian only, whereas fixation alignment was monitored in the horizontal meridian. A previously developed technique based on the dependency of border enhancement bandwidth on fixation eccentricity was used to monitor deviations from central fixation during fusion. Stress on the fusion mechanism was supplied by controlled increments of forced horizontal vergence. It was found that deviation from central fixation in the horizontal meridian generally increases with increasing amounts of vertical aniseikonia. The effect is particularly pronounced for small amounts of aniseikonia.

  11. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  12. The simple wire interosseous fixation technique (SWIFT) for reattachment of FDP avulsions with a large bony fragment.

    PubMed

    Markeson, Daniel B; Mughal, Maleeha; Subramanian, Padmanabhan; Iyer, Srinivasan

    2012-12-01

    Avulsion injuries of the flexor digitorum profundus tendon can be with or without a bony fragment. Types 3, 4, and 5 injuries often have a sizeable bony fragment. In the past, they have been repaired with either a screw, plate, or pull-out wire with a dorsal button, often in combination with a K wire to immobilize the distal interphalangeal joint. We illustrate with 2 cases a simple technique for secure repair of the flexor digitorum profundus avulsions with a bony fragment. In contrast to previously described techniques, our technique involves minimal dissection, has a significantly reduced risk of fracture to the bony fragment, is completely internalized thereby reducing the risk of postoperative infection and allows immediate mobilization.

  13. EVALUATION OF PATIENTS UNDERGOING FIXATION OF DIAPHYSEAL HUMERAL FRACTURES USING THE MINIMALLY INVASIVE BRIDGE-PLATE TECHNIQUE

    PubMed Central

    Superti, Mauro José; Martynetz, Fábio; Falavinha, Ricardo Sprenger; Fávaro, Rodrigo Caldonazzo; Boas, Luis Felipe Villas; Filho, Salim Mussi; Martynetz, Juliano; Ribas, Bruno

    2015-01-01

    Objective: The aim was to describe the experience of our group in treating humeral shaft fractures using the bridge–plate technique via an anterior approach. Methods: Seventeen patients with acute diaphyseal humeral fractures with an indication for surgical treatment who were operated in 2006–2010 were evaluated. The AO and Gustilo & Anderson classifications were used. All the patients were operated using the anterior bridge-plate technique and completed a follow–up period of at least twelve months. Results: Sixteen men and one woman were treated. Their mean age was 31.8 years (18–52). Among the injury mechanisms found were: five motorcycle accidents, four car accidents, three fractures due to firearm projectiles, two falls to the ground and finally, with one case each, assault, crushing and being run over. Eight patients had open fractures: two grade I, one grade II, four grade IIIa and one grade IIIb, according to the Gustilo-Anderson classification. In relation to the AO classification, we found: one 12A1, three 12A2, four 12A3, one 12B1, four 12 B2, three 12B3 and one 12C2. The mean postoperative follow-up was 25 months (12–48). As complications, two patients had pain in the elbow and a ROM deficit and one had deep infection. The mean time taken to achieve consolidation was 17.5 weeks. There was no loss of reduction, pseudarthrosis or malunion in this series of patients. Conclusion: The authors believe that the technique described has low rates of complications and morbidity, with good initial results, although the series is limited by the small sample. PMID:27042639

  14. FIXATION OF FRACTURES OF THE DISTAL EXTREMITY OF THE RADIUS USING THE MODIFIED KAPANDJI TECHNIQUE: EVALUATION OF THE RADIOLOGICAL RESULTS

    PubMed Central

    Neto, Antonio Piva; Lhamby, Fabio Colla

    2015-01-01

    To demonstrate a simple and efficacious option for treating fractures of the distal extremity of the radius using Kirschner wires. Methods: Between September 2008 and April 2009, 48 patients with fractures of the distal extremity of the radius, classified as A3 according to the AO classification, were treated surgically using a modification of the Kapandji technique. Results: Out of the 48 wrists operated, 42 (87.5%) presented postoperative measurements within the acceptable limits. We used the parameters of McQuenn and Caspers who considered that the radial angulation should be wider than 19° and the volar angulation should be narrower than -12°. All the postoperative volar inclination measurements were narrower than -3°. The mean preoperative radial inclination was 13.14° and the mean postoperative value was 21.18°. The mean preoperative volar inclination was 28.75° and the mean postoperative value was 3.31°. The mean preoperative radial height was 5.25 mm and the mean postoperative value was 9.48 mm. Conclusion: The technique described here had excellent stability for treating fractures of the distal extremity of the radius classified as A3. It was easy to implement and minimally invasive, with minimal surgical complications, and it was inexpensive. PMID:27027023

  15. Internal fixation: a historical review.

    PubMed

    Greenhagen, Robert M; Johnson, Adam R; Joseph, Alison

    2011-08-01

    Internal fixation has become a pillar of surgical specialties, yet the evolution of these devices has been relatively short. The first known description of medical management of a fracture was found in the Edwin Smith Papyrus of Ancient Egypt (circa 2600 bc). The first description of internal fixation in the medical literature was in the 18th century. The advancement of techniques and technology over the last 150 years has helped to preserve both life and function. The pace of advancement continues to accelerate as surgeons continue to seek new technology for osseous fixation. The authors present a thorough review of the history of internal fixation and the transformation into a multibillion dollar industry.

  16. Fixation of chiral smectic liquid crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate using UV curing techniques

    SciTech Connect

    Afrizal, Nurdelima,; Umeir; Hikam, Muhammad; Soegiyono, Bambang; Riswoko, Asep

    2014-03-24

    Chiral Smectic Liquid Crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate has been synthesized using method of steglich esterification at room temperature. The mesomorphic behavior of chiral smectic at 55°C that showed schlieren texture in POM analysis. Fixation of structure chiral smectic liquid crystal by means of photopolymerization of monomer (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate under UV irradiation which called UV curing techniques. The curing process using UV 3 lamps 100 volt at 60°C for an hour. The product of photopolymerization could be seen by analysis of FTIR spectra both monomer and polymer. FTIR spectra of monomer, two peaks for ester carbonyl and C-C double bond groups appeared at 1729.09 cm-1and 3123.46 cm{sup −1}. After UV curing process, peak for the carbonyl group at 1729.09 cm{sup −1} decreased and a new peak at 1160.21 cm{sup −1} appeared due to the carbonyl group attached to a C-C bond group and then peak at 3123.46 cm{sup −1} for C-C double bond group was disappeared.

  17. Shape memory alloy fixator system for suturing tissue in minimal access surgery.

    PubMed

    Xu, W; Frank, T G; Stockham, G; Cuschieri, A

    1999-01-01

    A new technique for suturing human tissue is described in which tissue closure is achieved by means of small fixators made from shape memory alloy. The aim of the development is to provide an alternative to thread suturing in minimal access surgery, which is quicker and requires less skill to achieve the required suturing quality. The design of the fixators is described in terms of the thermal shape recovery of shape memory alloy and a novel form of finite element analysis, which uses a nonlinear elastic element for the material property. Thermal analysis of the fixators and surrounding tissue is used to predict the temperature distribution during and after the application of electric current heating. This was checked in an in vitro experiment, which confirmed that deployment caused no detectable collateral damage to surrounding tissue. In vivo animal studies on the use of the shape memory alloy fixator for suturing tissue are ongoing to establish safety and healing effects.

  18. Determination of protein loss during aqueous and phase partition fixation using formalin and glutaraldehyde

    SciTech Connect

    Mays, E.T.; Feldhoff, R.C.; Nettleton, G.S.

    1984-10-01

    In phase partition fixation tissue is immersed in an organic solvent at equilibrium with an aqueous phase containing a fixing agent. By using radioisotope labeling techniques the effects of phase partition fixation on protein retention during fixation of tissue with formalin and glutaraldehyde have been determined and compared with those of standard aqueous fixation using these fixatives. It has been shown that retention of protein in tissue during phase partition fixation was as good or better than during aqueous fixation. Improved retention provides further evidence that phase partition fixation may be a useful alternative to aqueous fixation.

  19. Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques

    PubMed Central

    Karlas, Thomas; Berger, Joachim; Garnov, Nikita; Lindner, Franziska; Busse, Harald; Linder, Nicolas; Schaudinn, Alexander; Relke, Bettina; Chakaroun, Rima; Tröltzsch, Michael; Wiegand, Johannes; Keim, Volker

    2015-01-01

    AIM: To compare ultrasound-based acoustic structure quantification (ASQ) with established non-invasive techniques for grading and staging fatty liver disease. METHODS: Type 2 diabetic patients at risk of non-alcoholic fatty liver disease (n = 50) and healthy volunteers (n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography (TE), controlled attenuation parameter (CAP), proton magnetic resonance spectroscopy (1H-MRS; only available for the diabetic cohort), and ASQ. ASQ parameters mode, average and focal disturbance (FD) ratio were compared with: (1) the extent of liver fibrosis estimated from TE and non-alcoholic fatty liver disease (NAFLD) fibrosis scores; and (2) the amount of steatosis, which was classified according to CAP values. RESULTS: Forty-seven diabetic patients (age 67.0 ± 8.6 years; body mass index 29.4 ± 4.5 kg/m²) with reliable CAP measurements and all controls (age 26.5 ± 3.2 years; body mass index 22.0 ± 2.7 kg/m²) were included in the analysis. All ASQ parameters showed differences between healthy controls and diabetic patients (P < 0.001, respectively). The ASQ FD ratio (logarithmic) correlated with the CAP (r = -0.81, P < 0.001) and 1H-MRS (r = -0.43, P = 0.004) results. The FD ratio [CAP < 250 dB/m: 107 (102-109), CAP between 250 and 300 dB/m: 106 (102-114); CAP between 300 and 350 dB/m: 105 (100-112), CAP ≥ 350 dB/m: 102 (99-108)] as well as mode and average parameters, were reduced in cases with advanced steatosis (ANOVA P < 0.05). However, none of the ASQ parameters showed a significant difference in patients with advanced fibrosis, as determined by TE and the NAFLD fibrosis score (P > 0.08, respectively). CONCLUSION: ASQ parameters correlate with steatosis, but not with fibrosis in fatty liver disease. Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies. PMID:25945002

  20. Latarjet Fixation

    PubMed Central

    Alvi, Hasham M.; Monroe, Emily J.; Muriuki, Muturi; Verma, Rajat N.; Marra, Guido; Saltzman, Matthew D.

    2016-01-01

    Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option. PMID:27158630

  1. Established and Emerging Atmospheric Pressure Surface Sampling/Ionization Techniques for Mass Spectrometry

    SciTech Connect

    Van Berkel, Gary J; Pasilis, Sofie P; Ovchinnikova, Olga S

    2008-01-01

    The number and type of atmospheric pressure techniques suitable for sampling analytes from surfaces, forming ions from those analytes, and subsequently transporting those ions into vacuum for interrogation by mass spectrometry has rapidly expanded over the last several years. Moreover, the literature in this area is complicated by an explosion in acronyms for these techniques, many of which provide no information relating to the chemical or physical processes involved. In this review, we sort this vast array of techniques into a relatively few categories on the basis of the approaches used for surface sampling and ionization. For each technique, we explain, as best known, many of the underlying principles of operation, describe representative applications, and in some cases, discuss needed research or advancements and attempt to forecast their future analytical utility.

  2. Techniques of Play Activity at Physical Education Classes at Specialized Secondary Educational Establishments

    ERIC Educational Resources Information Center

    Martynova, Victoria A.; Kapustin, Aleksandr G.

    2016-01-01

    The issue is urgent today because at present the organization and content of Physical Education (PE) classes at specialized secondary educational establishments (SSEEs) do not completely meet contemporary requirements. The following negative trends prove that, namely: the physical and psychological health decline in school leavers and students,…

  3. One unit's experiences when establishing buttonhole technique, analysis of reasons for failure of procedure: a report.

    PubMed

    Galante, Nelson Zocoler; Rabelo, Lúcia Lima; Yamamoto, Atsuko; Bonato, Rozana Aparecida; Azevedo, Luiz Sergio

    2010-06-01

    The buttonhole technique of access of needle insertion into a single selected site in the arteriovenous fistula has proved to be a reliable alternative to older methods due to its overall low complication rates. Although the use of blunt needles improves the technique, the success rate of cannulation with these needles is difficult to predict. We analysed the short-term outcome of 16 patients receiving in-centre haemodialysis and compared clinical relevant parameters between patients with and without buttonhole technique failure. Our dialysis unit treats about 180 patients and is located in a tertiary hospital in Sao Paulo, Brazil. The variables as discussed in the paper were the same for both groups. The incidence of technique failure was 43.7%. Patients enrolled later in the study had a better buttonhole failure-free survival rates than patients enrolled at the beginning (p < 0.05). Patients' clinical characteristics did not predict the success rate of buttonhole tunnel tracks cannulation with blunt needles. This paper also reports on our successes and failures in buttonhole technique and gives some reasons and reflections for both.

  4. Re-establishing esthetics of fluorosis-stained teeth using enamel microabrasion and dental bleaching techniques.

    PubMed

    Pontes, Danielson Guedes; Correa, Ketlen Michele; Cohen-Carneiro, Flávia

    2012-01-01

    Dental fluorosis manifests itself as white stains on the enamel of teeth exposed to excessive doses of fluoride during their formation. Fluorosis usually occurs as a result of the ingestion of dentifrices, gels and fluoridated solutions. It may be diagnosed as mild, moderate or severe, and in some cases, it may cause the loss of the surface structure of dental enamel. The aim of this study was to report the clinical case of a female patient of 18 years with moderate fluorosis, whose smile was reestablished by the use of an enamel microabrasion technique, followed by in-office bleaching. A microabrasion technique with 6% hydrochloric acid associated with silica carbide showed to be a safe and efficient method for removing white fluorosis stains, while dental bleaching was useful for obtaining a uniform tooth shade. The association of these techniques presented excellent results and the patient was satisfied. Both techniques are painless, fast and easy to perform, in addition to preserving the dental structure. Treatment showed immediate and permanent results; this technique must be divulged among professionals and their patients.

  5. [Establishment of loop-mediated isothermal amplification technique for rapid detection of NDM-1 gene].

    PubMed

    Zhang, Yuanyi; Wu, Na; Zhu, Baoli; Chen, Lei; Zhu, Yuzhuo

    2011-08-01

    We established a rapid detection method of New Delhi Metallo-beta-Lactamase Gene (NDM-1) based on Loop-mediated Isothermal Amplification (LAMP). With the application of LAMP, we designed four sets of LAMP premiers, using NDM-1 gene as the target sequence, and selected the set of optimal primers. Meanwhile, we established optimal reaction systems and conditions to carry out the sensitivity and specificity experiments. The experiment results showed that the whole detection process took only one hour and could be observed visually. In the experiment of sensitivity, NDM-1 gene had a detection limit of 6 copies in each reaction. In the experiment of specificity, we detected NDM-1 gene in 4 pathogen strains (Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae), and the total DNA from intestinal microbes and the total DNA from soil microbes. We had not detected the amplification reactions. The detection method established could rapidly detect NDM-1 gene and visualize the experiment result. The method is easy to operate and has high sensitivity and specificity and thus has great application value in basic research laboratories, emergent detection and spot detection.

  6. The Role of Neuroimaging Techniques in Establishing Diagnosis, Prognosis and Therapy in Disorders of Consciousness

    PubMed Central

    Gosseries, Olivia; Pistoia, Francesca; Charland-Verville, Vanessa; Carolei, Antonio; Sacco, Simona; Laureys, Steven

    2016-01-01

    Non-communicative brain damaged patients raise important clinical and scientific issues. Here, we review three major pathological disorders of consciousness: coma, the unresponsive wakefulness syndrome and the minimally conscious state. A number of clinical studies highlight the difficulty in making a correct diagnosis in patients with disorders of consciousness based only on behavioral examinations. The increasing use of neuroimaging techniques allows improving clinical characterization of these patients. Recent neuroimaging studies using positron emission tomography, functional magnetic resonance imaging, electroencephalography and transcranial magnetic stimulation can help assess diagnosis, prognosis, and therapeutic treatment. These techniques, using resting state, passive and active paradigms, also highlight possible dissociations between consciousness and responsiveness, and are facilitating a more accurate understanding of brain function in this challenging population. PMID:27347265

  7. MM&T Program for the Establishment of Production Techniques for High Power Bulk Semiconductor Limiters.

    DTIC Science & Technology

    1979-07-01

    F. Jellison, ’"-Band, High Power Solid State Receiv6:. IProtector Employing a Bulk Semiconductor Limiter", 1979 IEEE, MTT-S- INTERNATIONAL , Orlando...Techniques for High-Power Bulk Semiconductor Limiters", First Quaterly Report for Contract DAAB07-76-C-0039, ECOM, U.S. Army Electronics Research and...Electronics Supply Ctr Palo Alto, CA 94304 Directorate of Engineering & Standardization Rockwell International ATTN: (DESC-ECS) Mr. N.A. Hauck Science

  8. Establishing the skill of climate field reconstruction techniques for precipitation with pseudoproxy experiments

    NASA Astrophysics Data System (ADS)

    Gómez-Navarro, Juan José; Werner, Johannes; Wagner, Sebastian; Luterbacher, Jürg; Zorita, Eduardo

    2015-09-01

    This study aims at assessing the skill of several climate field reconstruction techniques (CFR) to reconstruct past precipitation over continental Europe and the Mediterranean at seasonal time scales over the last two millennia from proxy records. A number of pseudoproxy experiments are performed within the virtual reality of a regional paleoclimate simulation at 45 km resolution to analyse different aspects of reconstruction skill. Canonical Correlation Analysis (CCA), two versions of an Analog Method (AM) and Bayesian hierarchical modeling (BHM) are applied to reconstruct precipitation from a synthetic network of pseudoproxies that are contaminated with various types of noise. The skill of the derived reconstructions is assessed through comparison with precipitation simulated by the regional climate model. Unlike BHM, CCA systematically underestimates the variance. The AM can be adjusted to overcome this shortcoming, presenting an intermediate behaviour between the two aforementioned techniques. However, a trade-off between reconstruction-target correlations and reconstructed variance is the drawback of all CFR techniques. CCA (BHM) presents the largest (lowest) skill in preserving the temporal evolution, whereas the AM can be tuned to reproduce better correlation at the expense of losing variance. While BHM has been shown to perform well for temperatures, it relies heavily on prescribed spatial correlation lengths. While this assumption is valid for temperature, it is hardly warranted for precipitation. In general, none of the methods outperforms the other. All experiments agree that a dense and regularly distributed proxy network is required to reconstruct precipitation accurately, reflecting its high spatial and temporal variability. This is especially true in summer, when a specifically short de-correlation distance from the proxy location is caused by localised summertime convective precipitation events.

  9. Open reduction and internal fixation of OTA type C2-C4 fractures of the calcaneus with a triple-plate technique.

    PubMed

    Brunner, Alexander; Müller, Jochen; Regazzoni, Pietro; Babst, Reto

    2012-01-01

    The purpose of this study was to present a surgical technique of open reduction and internal fixation of displaced intra-articular calcaneal fractures with 3 AO mini-fragment plates and to evaluate the clinical and radiological outcome of a consecutive group of patients after a mean follow-up of 41.7 months. A series of 54 patients (16 women and 38 men) with 62 calcaneal fractures were treated over a period of 6.5 years. Forty-five patients with 50 calcaneal fractures were completely clinically and radiologically followed up. Clinical follow-up included assessment of range of motion, pain according to a visual analogue scale, the American Orthopaedic Foot and Ankle Society hindfoot score, and the short-form 36 health survey. Radiological follow-up included plain axial and lateral radiographs and measurement of the Böhler's angle and Gissane's angle. Independent Student's t test and paired Student's t test were used alongside the chi-square test to compare clinical and radiological data and score values between different groups of patients. Eleven patients showed breakage of the osteosynthesis material during the healing process and 2 patients sustained deep wound infection requiring revision surgery. At the final follow-up all fractures had healed. The average range of motion was supination 26.4° (range 0° to 50°; SD 11.6°), pronation 15.4° (range 0° to 30°; SD 6.4°), dorsal extension 14.3° (range -10° to 30°; SD 8.0°), and plantarflexion 39.6° (range 20° to 65°; SD 11.7°). Patients with OTA type C4 fractures achieved significantly lower supination (p < .01) and plantarflexion (p < .01) compared with other fracture types. The mean visual analog scale pain score was 3.6 (range 0 to 8; SD 2.3) points, average American Orthopaedic Foot and Ankle Society hindfoot score was 70.8 (range 33 to 100; SD 17.1) points, and the mean short-form 36 score was 60.98 (range 22.9 to 93.0; SD 18.4) points. The mean postoperative Böhler's angle was 28.9° (range 8

  10. Transmission Electron Microscopy for Nanomedicine: Novel Applications for Long-established Techniques

    PubMed Central

    2016-01-01

    During the last twenty years, the research in nanoscience and nanotechnology has dramatically increased and, in the last decade, the interest has progressively been oriented towards biomedical applications, giving rise to a new field termed nanomedicine. Transmission electron microscopy is a valuable technique not only for the thorough physico-chemical characterization of newly synthesized nanoparticulates, but especially to explore the effects of nanocomposites on biological systems, providing essential information for the development of efficient therapeutic and diagnostic strategies. Thus, for the progress of nanotechnology in the biomedical field, experts in cell biology, histochemistry and ultramicroscopy should always support the chemists, physicists and pharmacologists engaged in the synthesis and characterization of innovative nanoconstructs. PMID:28076938

  11. The effectiveness of two novel techniques in establishing the mechanical and contractile responses of biceps femoris.

    PubMed

    Ditroilo, Massimiliano; Hunter, Angus M; Haslam, Samuel; De Vito, Giuseppe

    2011-08-01

    Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 ± 4.9 years), at three knee joint angles (0°, 45° and 90°), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p < 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p < 0.01). Conversely, TMG could detect changes only at two knee angles (0° and 45°, p < 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation < 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

  12. Scaling Analysis Techniques to Establish Experimental Infrastructure for Component, Subsystem, and Integrated System Testing

    SciTech Connect

    Sabharwall, Piyush; O'Brien, James E.; McKellar, Michael G.; Housley, Gregory K.; Bragg-Sitton, Shannon M.

    2015-03-01

    Hybrid energy system research has the potential to expand the application for nuclear reactor technology beyond electricity. The purpose of this research is to reduce both technical and economic risks associated with energy systems of the future. Nuclear hybrid energy systems (NHES) mitigate the variability of renewable energy sources, provide opportunities to produce revenue from different product streams, and avoid capital inefficiencies by matching electrical output to demand by using excess generation capacity for other purposes when it is available. An essential step in the commercialization and deployment of this advanced technology is scaled testing to demonstrate integrated dynamic performance of advanced systems and components when risks cannot be mitigated adequately by analysis or simulation. Further testing in a prototypical environment is needed for validation and higher confidence. This research supports the development of advanced nuclear reactor technology and NHES, and their adaptation to commercial industrial applications that will potentially advance U.S. energy security, economy, and reliability and further reduce carbon emissions. Experimental infrastructure development for testing and feasibility studies of coupled systems can similarly support other projects having similar developmental needs and can generate data required for validation of models in thermal energy storage and transport, energy, and conversion process development. Experiments performed in the Systems Integration Laboratory will acquire performance data, identify scalability issues, and quantify technology gaps and needs for various hybrid or other energy systems. This report discusses detailed scaling (component and integrated system) and heat transfer figures of merit that will establish the experimental infrastructure for component, subsystem, and integrated system testing to advance the technology readiness of components and systems to the level required for commercial

  13. Mouse tissue fixation.

    PubMed

    Cardiff, Robert D; Miller, Claramae H; Munn, Robert J

    2014-05-01

    One of the primary goals of fixation is to stop postmortem changes that degrade the tissue and allow optimal preservation of morphologic and cytological detail as well as nucleic acid integrity. Following death, tissues soon undergo autolysis, and if organisms from the gastrointestinal, urinary, or respiratory tracts are present, their colonization can soon cause putrefaction. Time is of the essence because warmer temperatures accelerate both types of degradation. Placing the tissue into a fixative stops the postmortem changes. Fixatives have their effect on tissue by cross-linking, coagulation, or a combination of both. This article outlines the basic tissue fixation procedure and offers guidance on choosing an appropriate fixative, the timing and duration of fixation, sample storage, and quality issues.

  14. Iris fixation of posterior chamber intraocular lenses.

    PubMed

    Yazdani-Abyaneh, Alireza; Djalilian, Ali R; Fard, Masoud Aghsaei

    2016-12-01

    We introduce a technique for iris fixation of a posterior chamber intraocular lens (IOL) in which most of the procedure is done outside the eye. This minimizes intraocular manipulation, maximizes corneal endothelial preservation, and avoids the risk for IOL drop into the vitreous cavity intraoperatively. The IOL is fixated to the most peripheral part of the iris, resulting in a rounder pupil. Sutures are placed at exact positions on the haptics, resulting in a well-centered IOL.

  15. Minimally invasive (sinus tarsi) approach for open reduction and internal fixation of intra-articular calcaneus fractures in children: surgical technique and case report of two patients.

    PubMed

    Abdelgawad, Amr A; Kanlic, Enes

    2015-01-01

    Calcaneus fractures in children differ from those in adults. Most calcaneus fractures in children can be managed nonoperatively, with good long-term results expected. The width and height of the calcaneus can remodel with time in children. Recently, there has been a trend toward operative treatment of displaced intra-articular fractures of the calcaneus in children to correct the articular deformity. Studies of calcaneal fracture fixation in children used an extended lateral approach, with its possible complications. In the present report, we describe the operative treatment of 2 children (12 and 13 years old), who had a displaced intra-articular fracture of the calcaneus, using a minimally invasive sinus tarsi approach. Adequate reduction was obtained in both cases with no soft tissue complications or implant discomfort. Fixation was obtained using 3.5-mm cortical screws. Anatomic joint alignment was restored. The children were followed up until they had both resumed their full activities with no complications. We recommend this approach for operative treatment of displaced intra-articular fractures of the calcaneus, because it addresses the intra-articular displacement, which is the most important element of the deformity in children.

  16. Establishment of temporomandibular joint puncture technique in rats using in vivo micro-computed tomography (R_mCT®)

    PubMed Central

    Kameoka, S; Matsumoto, K; Kai, Y; Yonehara, Y; Arai, Y; Honda, K

    2010-01-01

    The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague–Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0.05 ml of contrast media was injected under micro-CT fluoroscopic guidance. After confirmation that the joint cavity was filled with contrast media, micro-CT imaging was carried out. The puncture for LPT was accurate in 5 of the 11 animals. The ASPT was accurate in all 13 animals. The AIPT punctured 3 of the 6 animals. Furthermore, the ASPT and AIPT demonstrated improved preservation of the needle; it was harder to detach the needle, which led to greater stability. These results suggest that ASPT assisted by R-mCT® is useful for basic research, including drug discovery and pathogenesis of TMJ diseases. PMID:20841463

  17. Establishment of temporomandibular joint puncture technique in rats using in vivo micro-computed tomography (R_mCT®).

    PubMed

    Kameoka, S; Matsumoto, K; Kai, Y; Yonehara, Y; Arai, Y; Honda, K

    2010-10-01

    The aim of the report was to establish puncture techniques for the temporomandibular joint (TMJ) cavity in rats. The experimental sample comprised 30 male Sprague-Dawley rats. Under general anaesthesia the superior joint cavity of the rat was punctured either laterally (lateral puncture technique (LPT), n = 11), anteriorly (anterosuperior puncture technique (ASPT), n = 13) or anteroinferior puncture technique (AIPT), n = 6) using a 27-gauge needle. After the tip of the needle was confirmed by micro-CT (R-mCT®, Rigaku, Tokyo, Japan) located on the mandibular fossa, 0.05 ml of contrast media was injected under micro-CT fluoroscopic guidance. After confirmation that the joint cavity was filled with contrast media, micro-CT imaging was carried out. The puncture for LPT was accurate in 5 of the 11 animals. The ASPT was accurate in all 13 animals. The AIPT punctured 3 of the 6 animals. Furthermore, the ASPT and AIPT demonstrated improved preservation of the needle; it was harder to detach the needle, which led to greater stability. These results suggest that ASPT assisted by R-mCT® is useful for basic research, including drug discovery and pathogenesis of TMJ diseases.

  18. Endotracheal tube fixation methods for optimal stability: a comparison of adhesive tape, suture, and tape-suture fixation.

    PubMed

    Farbod, Frank; Tuli, Puneet; Robertson, Bernard F; Jackson, Ian T

    2010-07-01

    Accidental extubation of an intubated patient is a serious consideration in the surgical patient. Adequate fixation in the intubated patient is essential to prevent potentially life-threatening complications. Several methods of endotracheal tube fixation have been described in the literature. In this study, we examine 3 common methods of fixation: adhesive tape alone, suture, and tape-suture. Testing occurred in a laboratory setting with 2 fresh cadavers. Endotracheal tubes were inserted, using the methods of fixation in question. We subjected each fixation technique to progressively increasing weight to determine which technique is most resistant to accidental removal. We found that fixation of the tube by combining tape around the tube with a suture through the tape is the best noninvasive technique of the 3 methods evaluated in cases where movement of the head is anticipated.

  19. Single-Specimen Technique to Establish the J-Resistance of Linear Viscoelastic Solids with Constant Poisson's Ratio

    NASA Technical Reports Server (NTRS)

    Gutierrez-Lemini, Danton; McCool, Alex (Technical Monitor)

    2001-01-01

    A method is developed to establish the J-resistance function for an isotropic linear viscoelastic solid of constant Poisson's ratio using the single-specimen technique with constant-rate test data. The method is based on the fact that, for a test specimen of fixed crack size under constant rate, the initiation J-integral may be established from the crack size itself, the actual external load and load-point displacement at growth initiation, and the relaxation modulus of the viscoelastic solid, without knowledge of the complete test record. Since crack size alone, of the required data, would be unknown at each point of the load-vs-load-point displacement curve of a single-specimen test, an expression is derived to estimate it. With it, the physical J-integral at each point of the test record may be established. Because of its basis on single-specimen testing, not only does the method not require the use of multiple specimens with differing initial crack sizes, but avoids the need for tracking crack growth as well.

  20. Guide to radiation fixatives

    SciTech Connect

    Tawil, J.J.; Bold, F.C.

    1983-11-01

    This report identifies and then characterizes a variety of substances available in the market place for potential effectiveness as a fixative on radiologically contaminated surfaces. The substances include both generic chemicals and proprietary products. In selecting a fixative for a particular application, several attributes of the fixative may be relevant to the choice. These attributes include: toxicity, durability, and cleanliness and removability. In addition to the attributes of the fixative, one should also take into account certain characteristics of the site to be treated. These characteristics relate to climate, nature of the surface, use to which the treated surface will be put, subsequent cleanup operations, and type of neighboring surfaces. Finally, costs and potential environmental effects may influence the decision. A variety of fixatives are evaluated with respect to these various attributes and summarized in a reference table.

  1. Cell fixatives for immunostaining.

    PubMed

    Jamur, Maria Célia; Oliver, Constance

    2010-01-01

    Fixation is one of the most critical steps in immunostaining. The object of fixation is to achieve good morphological preservation, while at the same time preserving antigenicity. Tissue blocks, sections, cell cultures or smears are usually immersed in a fixative solution, while in other situations, whole body perfusion of experimental animals is preferable. Fixation can be accomplished by either chemical or physical methods. The chemical methods include cross-linking agents such as formaldehyde, glutaraldehyde and succinimide esters as well as solvents such as acetone and methanol, which precipitate proteins. Of the physical methods, freezing tissue and air drying are most widely used. This chapter deals with the chemical fixation methods most commonly used for light microscopy.

  2. When femoral fracture fixation fails: salvage options.

    PubMed

    Petrie, J; Sassoon, A; Haidukewych, G J

    2013-11-01

    Most hip fractures treated with modern internal fixation techniques will heal. However, failures occasionally occur and require revision procedures. Salvage strategies employed during revision are based on whether the fixation failure occurs in the femoral neck, or in the intertrochanteric region. Patient age and remaining bone stock also influence decision making. For fractures in young patients, efforts are generally focused on preserving the native femoral head via osteotomies and repeat internal fixation. For failures in older patients, some kind of hip replacement is usually selected. Disuse osteopenia, deformity, bone loss, and stress-risers from previous internal fixation devices all pose technical challenges to successful reconstruction. Attention to detail is important in order to minimise complications. In the majority of cases, good outcomes have been reported for the various salvage strategies.

  3. Application of plant growth regulators, a simple technique for improving the establishment success of plant cuttings in coastal dune restoration

    NASA Astrophysics Data System (ADS)

    Balestri, Elena; Vallerini, Flavia; Castelli, Alberto; Lardicci, Claudio

    2012-03-01

    Exogenous application of plant growth regulators (PGRs) may be an effective technique for increasing the rooting ability and the growth of vegetative fragments (cuttings) of plants used in dune restoration programs. Various concentrations (0, 50 and 100 mg l-1) of two auxins, alpha-naphtaleneacetic acid (NAA) and indole-3-butyric acid (IBA), and two cytokinins, 6-furfurylaminopurine (Kinetin) and 6-benzylaminopurine (BAP), were applied separately to cuttings of two widely used species for restoration, Ammophila arenaria and Sporobuls virginicus. Root development and production of new buds in cuttings were examined under laboratory conditions one month after application. Cuttings were also examined one year after transplanting into a sandy substratum under natural conditions, to test for possible long term effects of PGRs on plant establishment success and growth. The response of the two study species to PGRs differed substantially. In A. arenaria the auxin NAA at 100 mg l-1 reduced the time for root initiation and increased the rooting capacity of cuttings, while the cytokinin Kinetin at 50 mg l-1 facilitated root growth. No auxin had effect on rooting or growth of S. virginicus cuttings, but treatment with 100 mg l-1 Kinetin resulted in higher rooting success than the control. One year after planting, the cuttings of A. arenaria treated with 100 mg l-1 NAA showed a higher establishment success (90% vs. 55%) and produced more culms and longer roots than the control; those treated with cytokinins did not differ in the establishment success from the control, but had longer roots, more culms and rhizomes. On the other hand, the cuttings of S. virginicus treated with 100 mg l-1 Kinetin showed a higher establishment success (75% vs. 35%) and had more culms than the control. Therefore, in restoration activities that involved A. arenaria, a pre-treatment of cuttings with NAA would be beneficial, as it allows the production of a higher number of well-developed plants with

  4. Systematic comparison of tissue fixation with alternative fixatives to conventional tissue fixation with buffered formalin in a xenograft-based model.

    PubMed

    Nietner, Thorben; Jarutat, Tiantom; Mertens, Alfred

    2012-09-01

    In our study we systematically compared the alternative fixatives acidified formal alcohol (AFA), PAXgene®, HOPE®, and combinations of AFA or formalin with ultrasound treatment to standard (buffered) formalin fixation. We examined general morphology and detectability of protein structures by immunohistochemistry of the membrane receptors epidermal growth factor receptor (EGFR), insulin-like growth factor 1 receptor (IGF-1R), and phosphorylated human epidermal growth factor receptor 2 (phospho-HER2). In order to allow for stringent comparability of different fixation techniques, we used matched mouse xenograft tumor samples from three different human cancer cell lines (colon, ovarian, and non-small cell lung cancer), either fixed conventionally with formalin or an alternative fixative. Tissue morphology after fixation with AFA and PAXgene® was comparable to formalin-fixed paraffin-embedded tissue (FFPET) morphology. Ultrasound fixations resulted in slightly inferior morphology and HOPE® fixation preserved morphology only poorly compared to FFPET in this system. None of the tested alternative fixatives enabled immunohistochemical detectability of all three targets in the same manner as FFPET. Pronounced staining was possible for EGFR and IGF-1R with all alternative fixatives but HOPE®, and phospho-HER2 staining was only noteworthy with formalin-ultrasound-fixed tissue. Therefore, the use of alternative fixatives comes with the need for careful validation of obtained IHC results individually for each target.

  5. The Establishment of an On-Campus Neurotraining Center at a Small University: Internship Experience Using Neuropsychological Techniques

    PubMed Central

    Schicatano, Edward J.; Bohlander, Robert

    2016-01-01

    In 2015, Wilkes University’s Neuroscience Program and Psychology Department established a unique training and learning center on a small liberal arts undergraduate campus - The NeuroTraining & Research Center. This paper shares the purpose of the Center, as a learning tool for Neuroscience majors who engage in internships and research opportunities, and as a means of promoting well-being on the campus by offering training in techniques such as Neurofeedback, Biofeedback and Audio-Visual Entrainment to the college community. The role that the center plays in connecting real world applications to concepts in Neuroscience, and the approach that the authors have taken to assess student learning is presented in this article. PMID:27980472

  6. Establishment of a trimodality analytical platform for tracing, imaging and quantification of gold nanoparticles in animals by radiotracer techniques.

    PubMed

    Chen, Chien-Hung; Lin, Fong-Sian; Liao, Wei-Neng; Liang, Sanching L; Chen, Min-Hua; Chen, Yo-Wen; Lin, Wan-Yu; Hsu, Ming-Hua; Wang, Mei-Ya; Peir, Jinn-Jer; Chou, Fong-In; Chen, Ching-Ya; Chen, Sih-Yu; Huang, Su-Chin; Yang, Mo-Hsiung; Hueng, Dueng-Yuan; Hwu, Yeukuang; Yang, Chung-Shi; Chen, Jen-Kun

    2015-01-06

    This study aims to establish a (198)Au-radiotracer technique for in vivo tracing, rapid quantification, and ex vivo visualization of PEGylated gold nanoparticles (GNPs) in animals, organs and tissue dissections. The advantages of GNPs lie in its superior optical property, biocompatibility and versatile conjugation chemistry, which are promising to develop diagnostic probes and drug delivery systems. (198)Au is used as a radiotracer because it simultaneously emits beta and gamma radiations with proper energy and half-life; therefore, (198)Au can be used for bioanalytical purposes. The (198)Au-tagged radioactive gold nanoparticles ((198)Au-GNPs) were prepared simply by irradiating the GNPs in a nuclear reactor through the (197)Au(n,γ)(198)Au reaction and subsequently the (198)Au-GNPs were subjected to surface modification with polyethylene glycol to form PEGylated (198)Au-GNPs. The (198)Au-GNPs retained physicochemical properties that were the same as those of GNP before neutron irradiation. Pharmacokinetic and biodisposition studies were performed by intravenously injecting three types of (198)Au-GNPs with or without PEGylation into mice; the γ radiation in blood specimens and dissected organs was then measured. The (198)Au-radiotracer technique enables rapid quantification freed from tedious sample preparation and shows more than 95% recovery of injected GNPs. Clinical gamma scintigraphy was proved feasible to explore spatial- and temporal-resolved biodisposition of (198)Au-GNPs in living animals. Moreover, autoradiography, which recorded beta particles from (198)Au, enabled visualizing the heterogeneous biodisposition of (198)Au-GNPs in different microenvironments and tissues. In this study, the (198)Au-radiotracer technique facilitated creating a trimodality analytical platform for tracing, quantifying and imaging GNPs in animals.

  7. 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…

  8. The halo fixator.

    PubMed

    Bono, Christopher M

    2007-12-01

    The halo fixator may be used for the definitive treatment of cervical spine trauma, preoperative reduction in the patient with spinal deformity, and adjunctive postoperative stabilization following cervical spine surgery. Halo fixation decreases cervical motion by 30% to 96%. Absolute contraindications include cranial fracture, infection, and severe soft-tissue injury at the proposed pin sites. Relative contraindications include severe chest trauma, obesity, advanced age, and a barrel-shaped chest. In children, a computed tomography scan of the head should be obtained before pin placement to determine cranial bone thickness. Complications of halo fixation include pin loosening, pin site infection, and skin breakdown. A concerning rate of life-threatening complications, such as respiratory distress, has been reported in elderly patients. Despite a paucity of contemporary data, recent retrospective studies have demonstrated acceptable results for halo fixation in managing some upper and lower cervical spine injuries.

  9. Photographic fixative poisoning

    MedlinePlus

    Photographic fixatives are chemicals used to develop photographs. This article discusses poisoning from swallowing such chemicals. This article is for information only. DO NOT use it to treat or manage an ...

  10. Arthroscopic Control for Safe and Secure Seating of Suspensory Devices for Femoral Fixation in Anterior Cruciate Ligament Reconstruction Using Three Different Techniques

    PubMed Central

    Kang, Seo Goo; Lee, Yong Seuk

    2017-01-01

    Purpose The purpose of this study was to evaluate the efficacy of our technique that allows direct visualization of seating of suspensory devices in anterior cruciate ligament (ACL) reconstruction. Materials and Methods Three different suspensory devices (TightRope RT, RetroButton, and EndoButton) were used in ACL reconstruction using 3 different techniques (outside-in, anteromedial [AM] portal, and transtibial techniques). Positioning of a guiding material and seating pattern of the suspensory devices were evaluated according to the surgical technique and suspensory device used. Results On the transtibial technique, 21 of total 26 cases (81%) of single bundle reconstructions and 22 of total 22 cases (100%) of double bundle reconstructions required superolateral capsulotomy where buttons were found in 21 of total 21 cases (100%) and 17 of 22 cases (77%), respectively. On the AM portal technique, all patients required capsulotomy and the button was found in only 18 of total 32 cases (56%) even after capsulotomy. On the outside-in technique, all patients required capsulotomy and the button was found in 86 of total 86 cases (100%). Conclusions Our technique for direct visualization of seating of the suspensory devices was more effective in outside-in and single bundle transtibial ACL reconstruction. However, it was less effective in double bundle transtibial and AM portal ACL reconstructions. PMID:28231646

  11. 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

  12. Introduction to Lumbosacral and Sacropelvic Fixation Strategies.

    PubMed

    Hsieh, Patrick C; Mummaneni, Praveen V

    2016-07-01

    We are pleased to present this Neurosurgical Focus video supplement on lumbosacral and sacropelvic fixation strategies. Despite advancement in surgical techniques and technologies in spine, achieving consistent solid fusion across the lumbosacral junction remains a major challenge. The anatomy of the lumbosacral junction allows for a higher range of motion compared to other areas of the thoracolumbar spine. The L5-S1 interspace is exposed to significant shear forces. As a result, complications such as pseudoarthrosis, screw pull-out, implant fracture, or sacral fractures can occur. Complications are particularly seen in long fusion constructs ending across the lumbosacral junction. To reduce these complications, various lumbosacral and sacropelvic fixation techniques have been developed and utilized. The current supplement is intended to provide instructional videos that illustrate several current techniques for lumbosacral and sacropelvic fixation. The collection includes techniques for anterior L5-S1 interbody fusion, minimally invasive L5-S1 interbody fusions, lumbosacral pedicle screw placement, sacroiliac fusion, and sacro-alar-iliac screw placement. The authors of the videos in the supplement have provided detailed narration and video illustration to describe the nuances of the various open and minimally invasive techniques for lumbosacral and sacral-pelvic fixation. We are pleased to have such a collection of quality video illustration from experts in the field. It's been our privilege to serve as guest editors for this supplement and we believe that you will enjoy the contents of this supplement.

  13. Bone Plug Versus Suture-Only Fixation of Meniscal Grafts

    PubMed Central

    Wang, Hongsheng; Gee, Albert O.; Hutchinson, Ian D.; Stoner, Kirsten; Warren, Russell F.; Chen, Tony O.; Maher, Suzanne A.

    2014-01-01

    Background Meniscus allograft transplantation (MAT) is primarily undertaken to relieve the symptoms associated with meniscal deficiencies. However, its ability to restore normal knee joint contact mechanics under physiological loads is still unclear. Purpose To quantify the dynamic contact mechanics associated with 2 commonly used fixation techniques in MAT of the medial compartment: transosseous suture fixation via bone plugs and suture-only fixation at the horns. Study Design Controlled laboratory study. Methods Physiological loads to mimic gait were applied across 7 human cadaveric knees on a simulator. A sensor placed on the medial tibial plateau recorded dynamic contact stresses under the following conditions: (1) intact meniscus, (2) MAT using transosseous suture fixation via bone plugs at the anterior and posterior horns, (3) MAT using suture-only fixation, and (4) total medial meniscectomy. A “remove-replace” procedure was performed to place the same autograft for both MAT conditions to minimize the variability in graft size, geometry, and material property and to isolate the effects of the fixation technique. Contact stress, contact area, and weighted center of contact stress (WCoCS) were quantified on the medial plateau throughout the stance phase. Results Knee joint contact mechanics were sensitive to the meniscal condition primarily during the first half of the gait cycle. After meniscectomy, the mean peak contact stress increased from 4.2 ± 1.2 MPa to 6.2 ± 1.0 MPa (P = .04), and the mean contact area decreased from 546 ± 132 mm2 to 192 ± 122 mm2 (P = .01) compared with the intact meniscus during early stance (14% of the gait cycle). After MAT, the mean contact stress significantly decreased with bone plug fixation (5.0 ± 0.7 MPa) but not with suture-only fixation (5.9 ± 0.7 MPa). Both fixation techniques partially restored the contact area, but bone plug fixation restored it closer to the intact condition. The location of WCoCS in the

  14. 15 CFR 923.42 - State establishment of criteria and standards for local implementation-Technique A.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... standards for local implementation-Technique A. 923.42 Section 923.42 Commerce and Foreign Trade Regulations...—Technique A. (a) The management program must provide for any one or a combination of general techniques... zone. The first such control technique, at subsection 306(d)(11)(A) of the Act, is state...

  15. [Visualization for Traditional Quality Management Techniques--Characterization Method for Spikenard of INUBUSHI SEIYAKU Established in the Edo Period].

    PubMed

    Ito, Ken; Inubushi, Soichiro; Moriwaki, Takafumi; Matsunaga, Kazuhiro; Takahashi, Kyoko; Ueda, Takahiro; Hashizume, Setsuya; Takemoto, Hiroaki; Kobayashi, Yoshinori; Ota, Tomoe; Nakamura, Seiko; Matsuda, Hisashi

    2015-01-01

    INUBUSHI SEIYAKU, a Japanese pharmaceutical company established in 1807, manufactures KEISHIN-TAN. This is an original drug developed by the company, and consists of 14 exotic natural medicines, spikenard, oriental bezoar, musk, agarwood, etc. It has been used for adjusting the autonomic nervous system and physical conditions. We studied the original methods of the traditional quality management techniques handed down within INUBUSHI SEIYAKU in selecting the appropriate spikenard (Nardostachys chinensis) for medicinal use. Currently, spikenards are mainly used as incense rather than medicine. KEISHIN-TAN is a rare case in that the bulk powder of the spikenards is used for pharmaceutical products in Japan. We examined the morphological characteristics and made an analysis of the component of spikenards selected by traditional methods. The raw material of the spikenards was purchased from the Japanese market, and was classified into two categories-superior, fit for medicinal use and defective, to be discarded-by traditional methods of INUBUSHI SEIYAKU. The methods of the characterization of the spikenard by INUBUSHI SEIYAKU were investigated. As a result, only thick spikenard roots over 2.0 cm in length and approximately 0.5 cm in diameter were found to be used, and the total weight of the superior was only 15% of the raw material. By comparing the weights of hexane extracts and GC-MS analyses, the content of calarene--main sedative compound in spikenards--in the superior material was 2.8 times higher than the raw material and 4.3 times higher than the defective material. The ways to devise how to enhance the pharmacological effects of spikenards may be contained in this method. These results revealed the traditional spikenard selection criteria, and may show the indications of using spikenard or its compounds for medicinal purposes.

  16. PRE-OPERATIVE PLANNING AND SURGICAL TECHNIQUE OF THE OPEN WEDGE SUPRACONDYLAR OSTEOTOMY FOR CORRECTION OF VALGUS KNEE AND FIXATION WITH A FIXED-ANGLE IMPLANT

    PubMed Central

    Paccola, Cleber Antonio Jansen

    2015-01-01

    The step-by-step preoperative planning for supracondylar opening wedge osteotomy of the femur for precise correction of the load axis of the lower limb using a fixed-angle implant (95° AO blade plate) is presented. The surgical technique and the use of a bone graft from the same site for filling in the defect are also presented. PMID:27026976

  17. The surgical correction of mandibular prognathism using rigid internal fixation--a report of a new technique together with its long-term stability.

    PubMed Central

    Reitzik, M.

    1988-01-01

    A historical review of the literature for the surgical correction of mandibular prognathism is presented, together with a list of ideal conditions for the successful treatment of this condition. This is a report of a new surgical technique which satisfies the majority of these principles and demonstrates stability at the osteotomy site. PMID:3207331

  18. [A study on the appropriate fixation for the procedures for the better preservation of cellular antigenicity and morphology of the blood smear in immunocytochemistry: an improvement of the immunostain technique using alkaline-phosphatase (ALP) as a labeling enzyme].

    PubMed

    Aoki, J; Sasaki, N; Hino, N; Nanba, K

    1991-01-01

    The authors previously reported a new coloration method which utilized hexazotized newfuchsin as a coupler for the immuno-enzyme-cytochemistry. This procedure used alkaline-phosphatase (ALP) as the labeling enzyme. The insolubility of the reaction product to organic solvents made it possible to prepare permanent slides. However, this suffered from several drawbacks, due to the fixation procedures, in the preservation of better morphology and antigenicity of the cell. The present study was undertaken to overcome such problems by modifying the fixation procedure. The study utilized twenty monoclonal and polyclonal antibodies commonly used in immunohematological staining. Various fixative solutions and timing of fixation were evaluated. The results indicated that; 1) the best fixative solution was a mixture of buffered paraformaldehyde (PFA) and acetone (10 ml 40% PFA solution, 10 ml pH 6.6 0.02 M phosphate buffer, 20 ml distilled water, 60 ml acetone, with pH adjusted to 6.6-7.4 with HCl) and 2) the fixation should be performed just before the immunostain. The results further showed that unstained smear slides, when freshly air dried and stored in a desicator, could maintain various differentiation antigens (CD2, 3, 4, 5, 8, 10, 14, 15, 16, 19, 25, L26, HLA-DR) for at least 4 weeks without any change in the immuno-reactivity. Thus, we conclude that this improved fixation procedure is an optimum fixative and should be used in routine application of the immunostain method for blood smears.

  19. Arthroscopically assisted percutaneous fixation of Bennett fractures.

    PubMed

    Culp, Randall W; Johnson, Jeff W

    2010-01-01

    Arthroscopic-assisted reduction and fixation of Bennett-type fractures of the thumb metacarpal allow for the confirmation of reduction as well as the assessment of the degree of chondral damage. With use of a 1.9-mm arthroscope and a traction tower, direct visualization and reduction is possible. Traditional methods of fixation are used to secure the fracture fragment. Postoperative rehabilitation follows the usual protocol used in both open and percutaneous techniques. However, the potential to obtain and confirm a more accurate articular reduction may reduce the incidence of late arthritis of the thumb carpometacarpal articulation.

  20. [Exposed distal radio-ulnar dislocation by dog bite. Reconstructive surgical technique using a soft tissue graft and a syndesmotic fixation implant. Case report].

    PubMed

    Vélez-de Lachica, J C; Brambila-Botello, C A; Valdez-Jiménez, L A

    2015-01-01

    The main function of the forearm is the supination, which is achieved largely through the biomechanical characteristics and stability of the distal radio-ulnar joint. There are several surgical techniques for the treatment of distal radio-ulnar dislocations isolated or associated with a fracture. We report the case of a canine trainer who was bitten at the wrist and distal forearm that came to the emergency department in where distal ulnar dislocation with muscle tendon exposure was diagnosed. Due to the offending agent and multiple soft tissue injuries the treatment with standard techniques was impossible. We describe the technique of treatment of this patient by placing autologous gracilis tendon graft, platelet rich plasma and two anchoring systems for ankle syndesmosis. Immobilization was maintained for six weeks with a subsequent rehabilitation and posterior valuation at 12, 18 and 28 weeks by the scale of MAYO, PRWE and DASH and finding a good result which implies the return to work and daily activities of the patient with minimal pain and limitation.

  1. Improving Carbon Fixation Pathways

    PubMed Central

    Ducat, Daniel C.

    2012-01-01

    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 alternative pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. PMID:22647231

  2. Fixation of tendo Achilles avulsion fracture.

    PubMed

    Lui, T H

    2009-01-01

    Achilles tendon ruptures occur commonly in the midsubstance of the tendon, usually 2-6 cm proximal to the insertion to the calcaneus. Ruptures near its insertion into the calcaneus are less common and mostly found in hyperpronators with a heel spur (Haglund's deformity). Avulsion of the bony insertion of the Achilles tendon at the calcaneus is infrequent and is diagnosed by radiography. Open reduction and internal fixation is indicated to achieve bone to bone healing and restoration of the function and continuity of the triceps surae mechanism. Screw fixation is not effective to resist the pull out tension of the triceps surae. Moreover, the prominent screw head may cause skin impingement. More secure fixation method is necessary in order to allow early functional rehabilitation. We describe a technique to fix the avulsed fragment of Achilles tendon insertion with 2 suture anchors. This can neutralize the pull of the triceps surae and early post-operative rehabilitation programme is allowed.

  3. Periosteal Fixation Procedures in the Management of Incomitant Strabismus

    PubMed Central

    Saxena, Rohit; Phuljhele, Swati; Sharma, Pradeep; Pinto, C. N.

    2015-01-01

    Managing a case of incomitant strabismus from nerve palsy or extraocular muscle loss is a major challenge. Among possible management options are globe or extraocular muscle fixation to the orbital wall coupled with weakening or strengthening of the relevant antagonist. Extraocular muscle fixation to the orbital wall can also be used in cases of abnormal synkinesis to eliminate the abnormal eye movements of a misfiring extraocular muscle, which thereby allows the use of standard paralytic strabismus surgery techniques. This review article summarizes indications and techniques of periosteal fixation procedures for incomitant strabismus. PMID:26180470

  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. Revision of Minimally Invasive Sacroiliac Joint Fixation: Technical Considerations and Case Studies Using Decortication and Threaded Implant Fixation

    PubMed Central

    Fielding, Louis C

    2017-01-01

    Background Sacroiliac joint (SIJ) disease is increasingly recognized as a common source of low back pain. Arthrodesis of the SIJ has been shown to be clinically effective for this condition. In the last decade, minimally invasive (MI) SIJ fusion procedures have been developed to achieve the clinical effectiveness of open fusion procedures, with lower operative morbidity and faster recovery. However, SIJ fusion patients occasionally present with symptomatic nonunions necessitating revision. Methods Four patients who previously underwent MI SIJ arthrodesis returned with complaints of SIJ related pain confirmed by examination. Radiographic assessment showed lucency after fixation with triangular titanium interference implants. Loose implants were removed, and the patients were revised with a different MI SIJ fusion system that utilizes decortication, placement of autograft and graft extender, and fixation with cannulated threaded implants. The trajectory of the revision implants was in a more ventral-to-dorsal and caudal-to-cranial trajectory to place the implants perpendicularly through the articular portion of the SIJ. Results The triangular implants typically exhibited haloing lucency on radiographs and CT scans, and most were easily removed using the manufacturer’s instrumentation; only one implant was left in place as it was well-fixed. The removed implants exhibited little or no bony ongrowth. Decortication of the SIJ was performed, followed by placement of local autograft and fixation with 12.5 mm or 14.5mm diameter implants, as required. A more ventral-todorsal and caudal-to-cranial trajectory was established for the revision implants through the center of the articular region of the joint in order to maximize implant purchase in residual bone stock and achieve bony fusion through the articular portion of the SIJ. By six to twelve months post-revision, the presenting symptoms were successfully resolved in all patients. Conclusions Patients demonstrating

  6. Ganglion cysts of the shoulder: technique of arthroscopic decompression and fixation of associated type II superior labral anterior to posterior lesions.

    PubMed

    Westerheide, Kenneth J; Karzel, Ronald P

    2003-10-01

    Ganglion cysts of the shoulder and concomitant suprascapular nerve compression should be considered in the differential diagnosis of shoulder pain. They are associated commonly with labral tears, most commonly SLAP lesions. MRI has become commonplace in evaluating shoulder pain and has led to the increased awareness of shoulder cysts. MRI accurately demonstrates the size and location of ganglions, which is critical when planning surgical intervention. It also has shown the frequent association of intra-articular pathology with these cysts. Despite that MRI can detect atrophy, the diagnosis of suprascapular nerve compression can be confirmed only by EMG/NCS, because the presence of a cyst does not necessarily mean the nerve is compressed. Likewise, a positive EMG does not confirm that the compression is caused by a ganglion cyst. EMG/NCVs are necessary for confirming the diagnosis and evaluating nerve and muscle function. A trial of nonoperative management is warranted; however, this is associated with a high failure rate. Aspiration techniques are successful for decompression of the cysts and initial pain relief; however, the intra-articular pathology is not addressed and there is a higher rate of recurrence. Open resection of the ganglion cyst is successful; however, the intra-articular labral tears are not addressed, which can lead to recurrence and the morbidity of the cyst excision is not warranted. Shoulder arthroscopy has led to the identification of associated intra-articular pathology such as SLAP lesions. These were not appreciated previously with open surgery and therefore were not addressed. Arthroscopic techniques have evolved to allow decompression of the ganglion cysts and repair of the labral lesions. This should decrease the possibility of recurrence of the cyst by eliminating the cyst and the pathologic lesion that created it. Arthroscopic excision also avoids much of the morbidity of the open approach and allows intra-articular pathology to be

  7. Methods to shorten the duration of an external fixator in the management of tibial infections

    PubMed Central

    Emara, Khaled M; Ghafar, Khaled Abd Al; Al Kersh, Mohamed Ahmed

    2011-01-01

    Massive segmental bone loss due to chronic osteomyelitis represents a considerable challenge to orthopedic surgeons and is a limb threatening condition. The only option available in such a clinical situation is segment transport using the Ilizarov technique of distraction osteogenesis; yet the most common problem in cases of bone transport with the Ilizarov technique in massive bone loss, is the long duration of the fixator. In addition to autologous bone grafting, several mechanical, biologic, and external physical treatment modalities may be employed to promote bone formation and maturation during segment transport in osteomyelitis patients. Mechanical approaches include compressive loading of the distraction regenerate, increased frequency of small increments of distraction, and compression-distraction. Intramedullary nailing and hemicorticotomy can reduce the time in external fixation; however, these techniques are associated with technical difficulties and complications. Exogenous application of low-intensity pulsed ultrasound or pulsed electromagnetic fields may shorten the duration of external fixation. Other promising modalities include diphosphonates, physician-directed use (off-label use) of bone morphogenetic proteins, and local injection of bone marrow aspirate and platelet gel at the osteotomy site. Well-designed clinical studies are needed to establish safe and effective guidelines for various modalities to enhance new bone formation during distraction osteogenesis after segment transfer. PMID:22474640

  8. Percutaneous fixation of hand fractures using locked K-wires: mechanical analysis and clinical application.

    PubMed

    De Spirito, Daniele

    2013-09-01

    Closed percutaneous wire fixation of hand fractures frequently requires protection with external splintage. This splintage increases the risk of joint stiffness, prolongs recovery time, and increases therapy input. We have developed a method of linking external Kirschner wires (K-wires), using a metal clamp, after their insertion, so as to increase the security of fixation and facilitate postoperative mobilization. The mechanical properties of this method have been assessed in vitro and compared with conventionally fixed, unlinked, K-wires. We have been able to establish that the linked K-wire system is better able to resist loosening. This work proposes that linkage of K-wires permits omission of all additional external splintage, with no detriment to management. The technique has been applied in clinical cases over the past 8 years and results of treatments were evaluated mainly to detect unexpected complications. We report a low rate of complications and good results in terms of bone healing and recovery of function.

  9. Percutaneous K-wire fixation versus palmar plating with locking screws for Colles' fractures.

    PubMed

    Hollevoet, Nadine; Vanhoutie, Tom; Vanhove, Wim; Verdonk, René

    2011-04-01

    Different methods exist to treat distal radius fractures. A prospective randomized study was conducted to establish whether palmar plate fixation with locking screws gave better results than percutaneous K-wire fixation in patients over 50 years of age. Only fractures with dorsal displacement after a simple fall were included in the study. Twenty wrists were treated with K-wires and 20 with a plate. Radiological parameters were measured on preoperative radiographs and at five weeks postoperatively. Clinical results and DASH scores were determined at three months postoperatively and at more than one year. No significant difference in radial inclination, palmar tilt, clinical outcome and DASH score was found between plating and K-wires, but the mean difference in ulnar variance between pre- and postoperative radiographs was significantly better with plates. It can be concluded that plates were superior to K-wires in restoring ulnar variance, but functional outcome was similar with both techniques.

  10. [Fixation of cells for analysis by laser microdissection--comparative studies in forensic trace material].

    PubMed

    Fischer, Elisabeth J; Laberke, Patrick J; Kübler, Eric; Balitzki, Beate

    2012-01-01

    This paper is focused on the preparation of samples for laser microdissection (LM) in forensic casework. In forensic genetics, it is essential to preserve and separate cellular traces during sample preparation, as they are usually gathered in very small amounts and are often contaminated with undesired cells. This is made possible by laser microdissection, a technique developed to cut cells or tissue of a certain type from a microscopical specimen by UV laser and catapult them directly into a PCR reactor. This method minimizes the risk of getting inconclusive, mixed DNA profiles due to contamination by foreign DNA and also supplies information about the cellular origin of a DNA profile. A method for optimized fixation and staining of spermatozoa for laser microdissection was established. Four different fixation methods combined with two staining methods were tested on two different microscope slides. Moreover, the effect of a blocker pen to contain the specimen on the slide was investigated.

  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. Establishing the Concepts and Techniques of Performance-Oriented Training in Army Training Centers: A Summary Report

    DTIC Science & Technology

    1975-06-01

    Military Police), (d) qcIf-pacing of instruction in supply and heavy equipment courses, ,e NCO leadership and instructor training courses, and ( f ) training...for Reserve Components: and I f ) NCO Leadership /instructor Training. When specifi" projects were undertaken, attempts were made to establish a...and heavy equipment courses; (e) NCO leadership and instructor training courses; and ( f ) Training for Reserv. Components. Performance training and

  14. 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

  15. Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries.

    PubMed

    Ji, Wei; Zheng, Minghui; Qu, Dongbin; Zou, Lin; Chen, Yongquan; Chen, Jianting; Zhu, Qingan

    2016-08-01

    Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury.Fifty normal cervical spines had radiographs to determine the proposed screw trajectory (the screw length and insertion angle) and the interbody graft-related parameters (the disc height and depth, and the distance between anterior vertebral margin and the screw) for all levels of the subaxial cervical spine. Following screw insertion in 8 preserved human cadaver specimens, surgical simulation and dissection verified the feasibility and safety of the ATAS fixation.Radiographic measurements showed the mean axial screw length and cephalic incline angle of all levels were 41.2 mm and 25.2°, respectively. The suitable depth of the interbody graft was >11.7 mm (the distance between anterior vertebral margin and the screw), but <17.1 mm (disc depth). Except the axial screw length, increase in all the measurements was seen with level up to C5-C6 segment. Simulated procedure in the preserved specimens demonstrated that ATAS fixation could be successfully performed at C2-C3, C3-C4, C4-C5, and C5-C6 levels, but impossible at C6-C7 due to the obstacle of the sternum. All screws were placed accurately. None of the screws penetrated into the spinal canal and caused fractures determined by dissecting the specimens.The anterior transdiscal axial screw fixation, as an alternative or supplementary instrumentation for subaxial cervical spine injuries, is feasible and safe with meticulous surgical planning.

  16. Retrospective Comparison of Percutaneous Fixation and Volar Internal Fixation of Distal Radius Fractures

    PubMed Central

    Lozano-Calderón, Santiago A.; Doornberg, Job N.

    2007-01-01

    A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery. The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire. There were no significant differences on the average scores for the percutaneous and volar plating groups, respectively: Gartland and Werley, 4 vs 5; Mayo, 82 vs 83; and DASH score 13 for both cohorts. Motion, grip, and radiographical parameters were likewise comparable. Volar internal plate and screw fixation can achieve results comparable to percutaneous fixation techniques in the treatment of fractures of the distal radius. PMID:18780085

  17. [Use of zinc-containing dehydrating fixatives for neurohistological studies].

    PubMed

    Korzhevskiĭ, D E; Grigor'ev, I P; Otellin, V A

    2006-01-01

    The suitability of zinc-containing dehydrating fixatives for neurohistological study of paraffin sections using Nissl staining and immunocytochemical techniques was examined. It was found that zinc-containing dehydrating fixatives (zinc-ethanol-formaldehyde and zinc-acetone-isopropanol-formaldehyde) had a capacity for good preservation of both structure and antigenic properties of the nervous tissue and could be recommended for application in neurohistological studies.

  18. Temporary External Fixation is Safe In a Combat Environment

    DTIC Science & Technology

    2010-07-01

    fixation. Clin Orthop Relat Res. 1988;230:98–115. 23. Paley D. Problems, obstacles, and complications of limb lengthening by the Ilizarov technique...controlling hemorrhage, restoring limb perfusion, soft-tissue debride- ment, and achieving bony stability without disrupting resus- citation of the patient.24...B, Jovanovic S, Wertheimer B, Mikolasević I, Grdic P. External fixation as a primary and definitive treatment of open limb fractures. Injury

  19. Morphology of the fetal rat testis preserved in different fixatives.

    PubMed

    Howroyd, Paul; Hoyle-Thacker, Renee; Lyght, Otis; Williams, Delorise; Kleymenova, Elena

    2005-01-01

    Histopathological examination of the testes of exposed fetuses and neonates is important in assessing the developmental effects of environmental toxins, including sex hormone modulators. Modified Davidson's fluid (mDF) has been suggested as a superior substitute for Bouin's fluid for fixation of adult animal testes. We compared the morphology of fetal rat testes stained with hematoxylin and eosin (H&E) or immunochemically after fixation in 10% neutral buffered formalin (NBF), Bouin's fluid, or mDF. Fixation in mDF resulted in more sharply defined nuclear detail and better preservation of cellular cytoplasm on H&E-stained sections of rat testes on gestation day 19. Use of Bouin's fluid did not allow satisfactory detection of apoptotic cells by fluorescent terminal deoxynucleotide transferase-mediated deoxy-UTP nick labeling. Staining with the immunoperoxidase system and the conventional chromogen diaminobenzidine tetrahydrochloride to visualize 5-bromo-2-deoxyuridine-positive cells demonstrated that the number of positive nuclei and intensity of staining were similar with all 3 fixatives. Immunostaining for cytoskeletal protein vimentin was more intense and provided better details of the Sertoli cell cytoplasm with formalin fixation than with mDF. Our study demonstrates that fixation in mDF provided better morphologic detail in the fetal rat testis compared with 10% NBF and Bouin's fluid and illustrates the importance of establishing the correct fixation conditions for each immunostaining protocol.

  20. Nitrogen fixation apparatus

    DOEpatents

    Chen, Hao-Lin

    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.

  1. Ensuring precision in lower limb deformity correction through a combination of temporary external fixation followed by internal fixation: Results of a retrospective study

    PubMed Central

    Ganjwala, Dhiren; Shah, Shrenik; Shah, Snehal

    2014-01-01

    Background: It is important to plan preoperatively when contemplating internal fixation following deformity correction. Surgeons often find it difficult to retain the achieved correction till the end of internal fixation. To maintain precise correction we used hybrid technique which uses both external and internal fixation. The objective of the study was to evaluate the effectiveness of this hybrid technique in achieving and retaining desired correction. Materials and Methods: In this retrospective study, we evaluated the magnitude of deformity with radiological parameters. We compared correction which was planned and correction which was achieved. The technique was used during surgery for corrective osteotomies. Before carrying out the osteotomy, rail fixator with two swivel clamps was applied. After osteotomy swivel clamps were loosened. Desired correction was achieved. While fixator held the fragments in corrected position, definitive internal fixation was carried out. External fixator was removed after completion of internal fixation. Position of mechanical axis ratio, mechanical lateral distal femoral angle and mechanical medial proximal tibial angle were measured before and 12 weeks after surgery. Student t-test was used to analyze the difference between correction which was planned and correction which was achieved. Results: There was no statistical difference between the desired correction and the correction achieved. Conclusions: Temporary use of external fixator while correcting angular deformities of lower limb allows to achieve accurate correction. PMID:25298557

  2. LIVER ULTRASONOGRAPHY IN DOLPHINS: USE OF ULTRASONOGRAPHY TO ESTABLISH A TECHNIQUE FOR HEPATOBILIARY IMAGING AND TO EVALUATE METABOLIC DISEASE-ASSOCIATED LIVER CHANGES IN BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS).

    PubMed

    Seitz, Kelsey E; Smith, Cynthia R; Marks, Stanley L; Venn-Watson, Stephanie K; Ivančić, Marina

    2016-12-01

    The objective of this study was to establish a comprehensive technique for ultrasound examination of the dolphin hepatobiliary system and apply this technique to 30 dolphins to determine what, if any, sonographic changes are associated with blood-based indicators of metabolic syndrome (insulin greater than 14 μIU/ml or glucose greater than 112 mg/dl) and iron overload (transferrin saturation greater than 65%). A prospective study of individuals in a cross-sectional population with and without elevated postprandial insulin levels was performed. Twenty-nine bottlenose dolphins ( Tursiops truncatus ) in a managed collection were included in the final data analysis. An in-water ultrasound technique was developed that included detailed analysis of the liver and pancreas. Dolphins with hyperinsulinemia concentrations had larger livers compared with dolphins with nonelevated concentrations. Using stepwise, multivariate regression including blood-based indicators of metabolic syndrome in dolphins, glucose was the best predictor of and had a positive linear association with liver size (P = 0.007, R(2) = 0.24). Bottlenose dolphins are susceptible to metabolic syndrome and associated complications that affect the liver, including fatty liver disease and iron overload. This study facilitated the establishment of a technique for a rapid, diagnostic, and noninvasive ultrasonographic evaluation of the dolphin liver. In addition, the study identified ultrasound-detectable hepatic changes associated primarily with elevated glucose concentration in dolphins. Future investigations will strive to detail the pathophysiological mechanisms for these changes.

  3. Chromium and its speciation in water samples by HPLC/ICP-MS--technique establishing metrological traceability: a review since 2000.

    PubMed

    Markiewicz, Barbara; Komorowicz, Izabela; Sajnóg, Adam; Belter, Magdalena; Barałkiewicz, Danuta

    2015-01-01

    Chromium holds a special position among living organisms because depending on its species it can be either essential or toxic. Cr(VI) even at very low concentrations is harmful and carcinogenic, while Cr(III) is a necessary microelement for cellular metabolism. Therefore, a simple analysis of Cr concentration in collected samples will not be able to distinguish these differences effectively: for a proper chemical analysis we need to perform a reliable detection and quantification of Cr species. Separation and detection of chromium can be accomplished with high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC/ICP-MS) in a one-step. Our review assembles articles published since 2000 regarding chromium speciation in water samples with the use of HPLC/ICP-MS. It addresses the following issues: chromium chemistry, the possibilities of dealing with interferences, metrological aspects, analytical performance and speciated isotope dilution mass spectrometry (SIDMS) which is a definitive measurement method. The authors would like to advocate this hyphenated advanced technique as well as the metrological approach in speciation analysis of chromium.

  4. Biological Nitrogen Fixation In Tropical Dry Forests Of Costa Rica

    NASA Astrophysics Data System (ADS)

    Gei, M. G.; Powers, J. S.

    2012-12-01

    Evidence suggests that tropical dry forests (TDF) are not nitrogen (N) deficient. This evidence includes: high losses of gaseous nitrogen during the rainy season, high ecosystem soil N stocks and high N concentrations in leaves and litterfall. Its been commonly hypothesized that biological nitrogen fixation is responsible for the high availability of N in tropical soils. However, the magnitude of this flux has rarely if ever been measured in tropical dry forests. Because of the high cost of fixing N and the ubiquity of N fixing legume trees in the TDF, at the individual tree level symbiotic fixation should be a strategy down-regulated by the plant. Our main goal was to determine the rates of and controls over symbiotic N fixation. We hypothesized that legume tree species employ a facultative strategy of nitrogen fixation and that this process responds to changes in light availability, soil moisture and nutrient supply. We tested this hypothesis both on naturally established trees in a forest and under controlled conditions in a shade house by estimating the quantities of N fixed annually using the 15N natural abundance method, counting nodules, and quantifying (field) or manipulating (shade house) the variation in important environmental variables (soil nutrients, soil moisture, and light). We found that in both in our shade house experiment and in the forest, nodulation varied among different legume species. For both settings, the 15N natural abundance approach successfully detected differences in nitrogen fixation among species. The legume species that we studied were able to regulate fixation depending on the environmental conditions. They showed to have different strategies of nitrogen fixation that follow a gradient of facultative to obligate fixation. Our data suggest that there exists a continuum of nitrogen fixation strategies among species. Any efforts to define tropical legume trees as a functional group need to incorporate this variation.

  5. Salivary bacterial fingerprints of established oral disease revealed by the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS) technique

    PubMed Central

    Belstrøm, Daniel; Paster, Bruce J.; Fiehn, Nils-Erik; Bardow, Allan; Holmstrup, Palle

    2016-01-01

    Background and objective The composition of the salivary microbiota, as determined using various molecular methods, has been reported to differentiate oral health from diseases. Thus, the purpose of this study was to utilize the newly developed molecular technique HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) for comparison of the salivary microbiota in patients with periodontitis, patients with dental caries, and orally healthy individuals. The hypothesis was that this method could add on to the existing knowledge on salivary bacterial profiles in oral health and disease. Design Stimulated saliva samples (n=30) were collected from 10 patients with untreated periodontitis, 10 patients with untreated dental caries, and 10 orally healthy individuals. Salivary microbiota was analyzed using HOMINGS and statistical analysis was performed using Kruskal–Wallis test with Benjamini–Hochberg's correction. Results From a total of 30 saliva samples, a mean number of probe targets of 205 (range 120–353) were identified, and a statistically significant higher mean number of targets was registered in samples from patients with periodontitis (mean 220, range 143–306) and dental caries (mean 221, range 165–353) as compared to orally healthy individuals (mean 174, range 120–260) (p=0.04 and p=0.04). Nine probe targets were identified with a different relative abundance between groups (p<0.05). Conclusions Cross-sectional comparison of salivary bacterial profiles by means of HOMINGS analysis showed that different salivary bacterial profiles were associated with oral health and disease. Future large-scale prospective studies are needed to evaluate if saliva-based screening for disease-associated oral bacterial profiles may be used for identification of patients at risk of acquiring periodontitis and dental caries. PMID:26782357

  6. Understanding Nitrogen Fixation

    SciTech Connect

    Paul J. Chirik

    2012-05-25

    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

  7. Design and Optimization of Resorbable Silk Internal Fixation Devices

    NASA Astrophysics Data System (ADS)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  8. 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.

  9. Effects of different fixatives on beta-galactosidase activity.

    PubMed

    Ma, Wenbin; Rogers, Keith; Zbar, Berton; Schmidt, Laura

    2002-10-01

    beta-Galactosidase (beta-Gal) staining is widely used to demonstrate specific gene expression during evaluation of gene targets in vivo. This technique is extremely sensitive to fixation. Optimal fixation conditions are necessary to obtain the maximal beta-Gal activity. In this experiment, Carnoy's and three different aldehyde fixatives were used at different temperatures and over different time points. Kidneys from LacZ-stop-human alkaline phosphatase (ZA/P) double reporter mice were used to generate positive material for the experiment. The results show that glutaraldehyde combinative solution (LacZ) produced the most consistent and reliable results. Paraformaldehyde and formaldehyde were effective as fixatives only at 4C for a period of less than 4 hr, and Carnoy's solution destroyed beta-Gal activity.

  10. Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

    SciTech Connect

    Braatz, Brett G.; Cumblidge, Stephen E.; Doctor, Steven R.; Prokofiev, Iouri

    2012-12-31

    The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional and phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for

  11. Emergency department external fixation for provisional treatment of pilon and unstable ankle fractures

    PubMed Central

    Lareau, Craig R.; Daniels, Alan H.; Vopat, Bryan G.; Kane, Patrick M.

    2015-01-01

    Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix) is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited. PMID:25709258

  12. Neuronal control of fixation and fixational eye movements

    PubMed Central

    2017-01-01

    Ocular fixation is a dynamic process that is actively controlled by many of the same brain structures involved in the control of eye movements, including the superior colliculus, cerebellum and reticular formation. In this article, we review several aspects of this active control. First, the decision to move the eyes not only depends on target-related signals from the peripheral visual field, but also on signals from the currently fixated target at the fovea, and involves mechanisms that are shared between saccades and smooth pursuit. Second, eye position during fixation is actively controlled and depends on bilateral activity in the superior colliculi and medio-posterior cerebellum; disruption of activity in these circuits causes systematic deviations in eye position during both fixation and smooth pursuit eye movements. Third, the eyes are not completely still during fixation but make continuous miniature movements, including ocular drift and microsaccades, which are controlled by the same neuronal mechanisms that generate larger saccades. Finally, fixational eye movements have large effects on visual perception. Ocular drift transforms the visual input in ways that increase spatial acuity; microsaccades not only improve vision by relocating the fovea but also cause momentary changes in vision analogous to those caused by larger saccades. This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’. PMID:28242738

  13. A graduated method of tip graft fixation in rhinoplasty.

    PubMed

    Papel, I D

    1995-06-01

    Projection of the nasal tip has gained increased recognition as a measurable and visual characteristic that has an impact on the results of aesthetic rhinoplasty. Autologous cartilage tip grafts have been used in many techniques to increase tip projection and contour the tip during rhinoplasty. This article introduces a graduated method of tip graft fixation correlated with specific clinical measurements related to tip projection. After careful analysis of tip projection and contour, a predictable graft fixation technique can be selected to obtain the desired degree of nasal tip projection and sculpting.

  14. Limits of internal fixation in long-bone fracture.

    PubMed

    Nieto, H; Baroan, C

    2017-02-01

    Alternatives to internal fixation of long-bone fracture comprise, depending on location, external fixation or joint replacement. Limitations comprise risk of infection and functional outcome quality, which vary according to technique. The present study examines these limitations, based on comparative or large-scale studies from which certain significant results emerge. Four main questions are dealt with: (1) the present role of locking plates; (2) conditions for intramedullary nailing in Gustilo grade IIIb open fracture; (3) the limitations of conversion from external fixation to intramedullary nailing in open lower leg fracture; (4) and the limitations of definitive anterograde femoral nailing in multiple trauma. Locking plate fixation has yet to prove clinical superiority in any of the anatomic sites for which good-quality comparative analyses are available. Infection risk in Gustilo grade IIIb open lower leg fracture is equivalent when treated by intramedullary nailing or external fixation, if wound care and debridement are effective, antibiotherapy is initiated rapidly and skin cover is restored within 7days. Conversion from primary external fixation to intramedullary nailing is possible if the external fixator was fitted less than 28days previously and skin cover was restored within 7days. The pulmonary and systemic impact of peripheral lesions or definitive anterograde intramedullary nailing of femoral fracture in multiple trauma calls for caution and what is known as "damage-control orthopedics" (DCO), a term covering the general consequences of both the initial trauma and its treatment. Femoral intramedullary nailing is thus contraindicated in case of hemorrhagic shock (blood pressure<90mmHg), hypothermia (<33°C), coagulation disorder (platelet count<90,000) or peripheral lesions such as multiple long-bone fractures, crushed limb or primary pulmonary contusion. In such cases, external fixation or retrograde nailing with a small-diameter nail and without

  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. Treatment of infected non-unions with segmental defects with a rail fixation system.

    PubMed

    Mudiganty, Srikanth; Daolagupu, Arup Kumar; Sipani, Arun Kumar; Das, Satyendra Kumar; Dhar, Arijit; Gogoi, Parag Jyoti

    2017-04-01

    We conducted this study to evaluate the use of rail fixation system in infected gap non-union of femur and tibia as an alternative to the established Ilizarov circular fixator technique. Prospective study. The study was done in the Department of Orthopaedic surgery in a medical school and level I trauma center to which the authors are/were affiliated. Between June 2010 and June 2015, 40 patients with infected gap non-union of femur and tibia were treated with the rail fixation system. Patients who were willing to undergo surgery and participate in the post-operative rehabilitation were included in the study. After radical debridement, the system was applied and corticotomy done. For closure of bone gap, acute docking and distraction was done in 18 cases and segmental bone transport in 22 cases. Early mobilization of patient was done along with aggressive physiotherapy. Bone and functional results were calculated according to ASAMI scoring system, and complications were classified according to Paley classification. The mean follow-up period was 22.56 months (range 8-44). Bone union with eradication of infection was achieved in all but 1 case (97.5%). Bone results were excellent in 57.5%, good 40%, fair 0% and poor in 2.5% cases, while functional result was excellent in 32.5%, good 65%, fair 0% and poor in 2.5% cases. The rail fixation system is an excellent alternative method to treat infected gap non-union of femur and tibia. It is simple, easy to use and patient-friendly.

  17. The pathologist's guide to fixatives.

    PubMed

    Qidwai, Kiran; Afkhami, Michelle; Day, Christina E

    2014-01-01

    Proper tissue fixation is essential to ensure the highest level of specimen evaluation. Pathologists and laboratory staff are frequently consulted by clinical counterparts regarding what fixative should be used for different tissues or to enable a diagnosis of a specific condition. It is vital for the patient that the pathologist provides accurate information to ensure proper fixation. Frequently, once a tissue has been fixed inadequately or inappropriately, remedial changes may no longer be possible. Most often formalin is an adequate choice, if not the optimal one; however, there are certain situations when placing the tissue in formalin may limit the ability to reach a definitive diagnosis. It is imperative for pathologists to have the knowledge to communicate which fixative is optimal. Furthermore, as we move into a world of personalized medicine, where ancillary testing has both diagnostic and specific therapeutic implications, knowledge about how different fixatives affect immunohistochemistry, cytogenetics, and molecular studies becomes even more significant. This chapter provides practical information regarding common fixatives, their mechanism of action and optimal uses.

  18. Percutaneous Lumbopelvic Fixation for Reduction and Stabilization of Sacral Fractures With Spinopelvic Dissociation Patterns

    PubMed Central

    Quinnan, Stephen M.

    2016-01-01

    Summary: Sacral fractures that result in spinopelvic dissociation are unstable injuries that are often treated surgically, with iliosacral screw fixation and/or lumbopelvic fixation from L4 to the pelvis. Open lumbopelvic fixation allows for direct fracture reduction and immediate postoperative weight bearing, but is associated with a relatively high wound complication rate. Open surgery often takes several hours and can be associated with significant blood loss, and therefore may not be well tolerated physiologically in these patients who often have multiple injuries. We developed a percutaneous lumbopelvic reduction and fixation technique to address these issues. PMID:26894767

  19. Biomechanics of external fixation and limb lengthening.

    PubMed

    Younger, Alastair S E; Morrison, James; MacKenzie, William G

    2004-09-01

    Surgeons who use external fixators for foot and ankle conditions need to understand the biomechanical principles to ensure good outcomes. Fixators can be used for fracture fixation, correction of contractures, distraction osteogenesis, and distraction arthroplasty. A two-ring fixator with wire fixation remains the gold standard with which all other frames are compared. Small changes in mechanical characteristics can have major implications on new bone or cartilage formation.

  20. Microwave-Assisted Tissue Preparation for Rapid Fixation, Decalcification, Antigen Retrieval, Cryosectioning, and Immunostaining

    PubMed Central

    2016-01-01

    Microwave irradiation of tissue during fixation and subsequent histochemical staining procedures significantly reduces the time required for incubation in fixation and staining solutions. Minimizing the incubation time in fixative reduces disruption of tissue morphology, and reducing the incubation time in staining solution or antibody solution decreases nonspecific labeling. Reduction of incubation time in staining solution also decreases the level of background noise. Microwave-assisted tissue preparation is applicable for tissue fixation, decalcification of bone tissues, treatment of adipose tissues, antigen retrieval, and other special staining of tissues. Microwave-assisted tissue fixation and staining are useful tools for histological analyses. This review describes the protocols using microwave irradiation for several essential procedures in histochemical studies, and these techniques are applicable to other protocols for tissue fixation and immunostaining in the field of cell biology. PMID:27840640

  1. Minimally invasive dynamic hip screw for fixation of hip fractures

    PubMed Central

    Ho, Michael; Garau, Giorgio; Walley, Gayle; Oliva, Francesco; Panni, Alfredo Schiavone; Longo, Umile Giuseppe

    2008-01-01

    We compared a minimally invasive surgical technique to the conventional (open approach) surgical technique used in fixation of hip fractures with the dynamic hip screw (DHS) device. Using a case-control design (44 cases and 44 controls), we tested the null hypothesis that there is no difference between the two techniques in the following outcome measures: duration of surgery, time to mobilisation and weight bearing postoperatively, length of hospital stay, mean difference of pre- and postoperative haemoglobin levels, position of the lag screw of the DHS device in the femoral head, and the tip–apex distance. The minimally invasive DHS technique had significantly shorter duration of surgery and length of hospital stay. There was also less blood loss in the minimally invasive DHS technique. The minimally invasive DHS technique produces better outcome measures in the operating time, length of hospital stay, and blood loss compared to the conventional approach while maintaining equal fixation stability. PMID:18478227

  2. Endoscopically assisted reduction and fixation of condylar neck/base fractures--The learning curve.

    PubMed

    Loukota, R A

    2006-12-01

    Following the introduction of a new technique for fixation of fractures of the condylar neck and base in our department, the operative times were compared with those for the traditional and frequently used method of open reduction and internal fixation. A distinct learning curve was seen.

  3. The role of external fixation and emergency fracture management in bovine orthopedics.

    PubMed

    Adams, S B

    1985-03-01

    External fixation is a very useful method of treating selected fractures in cattle. The economics of therapy and the availability of the techniques to all veterinarians will continue to make external fixation the most frequently used method of fracture repair in cattle.

  4. Establishment and rapid detection of a heterozygous missense mutation in the CACNA1F gene by ARMS technique with double-base mismatched primers.

    PubMed

    Yang, W C; Zhu, L; Zhou, B X; Tania, S; Zhou, Q; Khan, M A; Fu, X L; Cheng, J L; Lv, H B; Fu, J J

    2015-09-25

    Retinitis pigmentosa (RP) is a retinal degenerative disorder that often causes complete blindness. Mutations of more than 50 genes have been identified as associated with RP, including the CACNA1F gene. In a recent study, by employing next-generation sequencing, we identified a novel mutation in the CACNA1F gene. In this study, we used the amplification refractory mutation system (ARMS) and identified a single nucleotide change c.1555C>T in exon 13 of the CACNA1F gene, leading to the substitution of arginine by tryptophan (p.R519W) in a Chinese individual affected by RP. This study actually confirms this novel mutation, and establishes the ARMS technique for the detection of mutations in RP.

  5. Mini-plate fixation versus suture suspensory fixation in cervical laminoplasty

    PubMed Central

    Liu, Feng-Yu; Ma, Lei; Huo, Li-Shuang; Cao, Yan-Xiang; Yang, Da-Long; Wang, Hui; Yang, Si-Dong; Ding, Wen-Yuan

    2017-01-01

    Abstract Background: Both the mini-plate fixation and suture suspensory fixation techniques are extensively applied in cervical laminoplasty, but which technique is superior has not been ascertained. The purpose of this meta-analysis is to compare the results between mini-plate fixation and suture suspensory fixation in cervical laminoplasty for the patients with multilevel cervical compressive myelopathy. Methods: PubMed, Embase, the Cochrane library, CNKI, and WANFANG were searched for studies that compared mini-plate fixation and suture suspensory fixation in cervical laminoplasty up to November 1, 2016. We calculated odds ratio (OR) with 95% confidence interval (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Review Manager 5.3 was used for the statistical analyses. Results: A total of 25 studies, involving 1603 participants, were included in this review. The results of this meta-analysis indicated that there were statistically significant differences in postoperative Japanese Orthopedic Association (JOA) scores (MD = 0.67, 95% CI: 0.34–0.99, P < 0.001), JOA scores improvement rate (MD = 4.00, 95% CI: 2.51–5.50, P < 0.001), postoperative Visual Analogue Score (VAS) (MD = −0.81, 95% CI: −1.36 to −0.26, P = 0.004), postoperative range of motion (ROM) (MD = 4.15, 95% CI: 2.06–6.23, P < 0.001), postoperative cervical lordosis (MD = 3.1, 95% CI: 2.02–4.18, P < 0.001), postoperative anteroposterior diameter of the spinal canal (MD = 1.53, 95% CI: 0.11–2.95, P = 0.03), postoperative open angle (MD = 1.93, 95% CI: 0.14–3.71, P = 0.03), postoperative cross-sectional area of the spinal canal (MD = 37.10, 95% CI: 26.92–47.29, P < 0.001), axial symptoms (OR = 0.28, 95% CI: 0.20–0.37, P < 0.001), operation time (MD = 4.46, 95% CI: 0.74–8.19, P = 0.02), and blood loss (MD = 9.24, 95% CI: 6.86–11.62, P < 0.001). However

  6. Outcomes of C1 and C2 posterior screw fixation for upper cervical spine fusion.

    PubMed

    De Iure, F; Donthineni, R; Boriani, S

    2009-06-01

    To achieve stable fixation of the upper cervical spine in posterior fusions, the occiput is often included. With the newer techniques, excluding fixation to the occiput will retain the occiput-cervical motion, while still allowing a stable fixation. Harms's technique has been adapted at our institution and its effectiveness for indications such as C2 complex fractures and tumors using C1 or C2 as endpoints of a posterior fixation are reviewed. Fourteen cases were identified, consisting of one os odontoideum; four acute fractures and four non-unions of the odontoid; three tumors and two complex fractures of C2 vertebral body, and one C2-C3 post-traumatic instability. One misplaced screw without clinical consequences was the only complication recorded. Screw loosening or migration was not observed at follow-up, showing a stable fixation.

  7. Effects of tissue fixation on coherent anti-Stokes Raman scattering images of brain

    NASA Astrophysics Data System (ADS)

    Galli, Roberta; Uckermann, Ortrud; Koch, Edmund; Schackert, Gabriele; Kirsch, Matthias; Steiner, Gerald

    2014-07-01

    Coherent anti-Stokes Raman scattering (CARS) microscopy is an emerging multiphoton technique for the label-free histopathology of the central nervous system, by imaging the lipid content within the tissue. In order to apply the technique on standard histology sections, it is important to know the effects of tissue fixation on the CARS image. Here, we report the effects of two common fixation methods, namely with formalin and methanol-acetone, on mouse brain and human glioblastoma tissue. The variations induced by fixation on the CARS contrast and intensity were compared and interpreted using Raman microspectroscopy. The results show that, whenever unfixed cryosections cannot be used, fixation with formalin constitutes an alternative which does not deteriorate substantially the contrast generated by the different brain structures in the CARS image. Fixation with methanol-acetone strongly modifies the tissue lipid content and is therefore incompatible with the CARS imaging.

  8. Prevention and management of external fixator pin track sepsis.

    PubMed

    Ferreira, Nando; Marais, Leonard Charles

    2012-08-01

    Pin track-associated complications are almost universal findings with the use of external fixation. These complications are catastrophic if it leads to the failure of the bone-pin interface and could lead to pin loosening, fracture non-union and chronic osteomyelitis. Strategies proposed for the prevention and management of pin track complications are diverse and constantly changing. Prevention of external fixation pin track infection is a complex and ongoing task that requires attention to detail, meticulous surgical technique and constant vigilance.

  9. Trochanteric osteotomy and fixation during total hip arthroplasty.

    PubMed

    Archibeck, Michael J; Rosenberg, Aaron G; Berger, Richard A; Silverton, Craig D

    2003-01-01

    Once used routinely, trochanteric osteotomy in total hip arthroplasty now is usually limited to difficult primary and revision cases. There are three types: the standard trochanteric osteotomy and its variations, the trochanteric slide, and the extended trochanteric osteotomy. Each has unique indications, fixation techniques, and complications. Primary total hip arthroplasty procedures requiring the enhanced exposure provided by trochanteric osteotomy may be needed in patients with hip ankylosis or fusion, protrusio acetabuli, proximal femoral deformities, developmental dysplasia, or abductor muscle laxity. Trochanteric osteotomies in revision arthroplasties, primarily the extended trochanteric osteotomy, facilitate the removal of well-fixed femoral components, provide direct access to the diaphysis for distal fixation, and enhance acetabular exposure.

  10. Complications in operative fixation of calcaneal fractures

    PubMed Central

    Li, Ying; Bao, Rong-Hua; Jiang, Zhi-Qiang; Wu, Huo-Yan

    2016-01-01

    Objective: The purpose of this study focused on a number of factors that have been implicated in calcaneal complications and find the incidence of wound complications. Methods: This was a retrospective study. A total of 162 patients (176 feet) who underwent calcaneal fractures between 2007 and 2012 were included. The patient’s personal details, age, time from injury to surgery, cause of injury, type of fracture, operative details, operating and tourniquet times were collected from hospital computers and paper records. Evidence of complications including wound infection, wound necrosis, pain, malunion, nonunion, impingement, loss of fixation, ect were studied. Results: Forty-seven of one hundred and seventy-six fractures (26.704%) had complications, wound infection was noted in seven fractures (3.977%), twelve fractures developed necrosis (6.818%), 14 fractures (7.955%) developed pain. Malunion was found in five fractures (2.841%), nonunion in two fractures (1.136%) and loss of fixation in four fractures (2.272%). Three neurologic injury was also seen in our study (1.705%). Operating time, time from injury to surgery and type of fracture had some association with complications in operative fixation of calcaneal fractures, which showed a statistically significant improvement (P=0.000, 0.031, 0.020, respectively), but there were no evidence that age and tourniquet time affect the incidence of complication after calcaneal fracture surgery (P=0.119, 0.682, respectively). Conclusions: Despite developments in the surgical treatment of calcaneal fracture, wound complications still remain inevitable. Advanced imaging techniques, less invasive surgical procedures, wealth of anatomical knowledge, surgical experience and better postoperative care should be ensured. PMID:27648028

  11. Phase-contrast Hounsfield units of fixated and non-fixated soft-tissue samples

    SciTech Connect

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; Herzen, Julia; Rozhkova, Elena A.

    2015-08-31

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. In addition, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.

  12. Phase-contrast Hounsfield units of fixated and non-fixated soft-tissue samples

    DOE PAGES

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; ...

    2015-08-31

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissuemore » specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. In addition, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.« less

  13. 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.

  14. Complement fixation test to C. burnetii

    MedlinePlus

    ... ency/article/003520.htm Complement fixation test to C burnetii To use the sharing features on this ... JavaScript. The complement fixation test to Coxiella burnetii ( C burnetti ) is a blood test that checks for ...

  15. The influence of alternative plant propagation and stand establishment techniques on survival and growth of eastern cottonwood (Populus deltoides Bartr.) clones.

    SciTech Connect

    Kaczmarek, Donald J.; et. al.,

    2014-02-09

    Four eastern cottonwood clones, including standard operational clone ST66 and three advanced clonal selections were produced and included in a test utilizing five different plant propagation methods. Despite relatively large first-year growth differences among clones, all clones demonstrated similar responses to the treatments and clone 9 cutting treatment interactions were generally non-significant. The effects of changing cutting lengths are consistent with previous studies which indicated the potential for increased plant survival and growth with increased cutting lengths. Differences in stored carbohydrate reserves alone do not appear to completely control first-year growth and development of cuttings. First-year growth of 51 cm long cuttings planted 30.5 cm deep was greater than the same cuttings planted 48 cm deep. Stem form of plants derived from whip-tip propagation did not differ from plants derived from standard, unrooted cuttings. This propagation method offers the potential of far greater production capacity from a cutting orchard and rapid bulk-up of new or limited clones. Stand uniformity assessments suggest that surviving trees of each individual cutting treatment exhibit similar levels of growth variation. Optimization of plantation establishment techniques has the potential to increase growth of young Populus plantations.

  16. 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

  17. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered 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...

  18. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered 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...

  19. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered 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...

  20. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered 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...

  1. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered 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...

  2. 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…

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

    PubMed

    Howat, William J; Wilson, Beverley A

    2014-11-01

    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.

  4. The time course of contextual influences during lexical ambiguity resolution: evidence from distributional analyses of fixation durations.

    PubMed

    Sheridan, Heather; Reingold, Eyal M

    2012-10-01

    In the lexical ambiguity literature, it is well-established that readers experience processing difficulties when they encounter biased homographs in a subordinate-instantiating prior context (i.e., the subordinate bias effect). To investigate the time course of this effect, the present study examined distributional analyses of first-fixation durations on 60 biased homographs that were each read twice: once in a subordinate-instantiating context and once in a dominant-instantiating context. Ex-Gaussian fitting revealed that the subordinate context distribution was shifted to the right of the dominant context distribution, with no significant contextual differences in the degree of skew. In addition, a survival analysis technique showed a significant influence of the subordinate versus dominant contextual manipulation as early as 139 ms from the start of fixation. These results indicate that the contextual manipulation had a fast-acting influence on the majority of fixation durations, which is consistent with the reordered access model's assumption that prior context can affect the lexical access stage of reading.

  5. Fixed-angle screws vs standard screws in acetabular prosthesis fixation: a cadaveric biomechanical study.

    PubMed

    Hugate, Ronald R; Dickey, Ian D; Chen, Qingshan; Wood, Christina M; Sim, Franklin H; Rock, Michael G

    2009-08-01

    Secure fixation of acetabular components in total hip arthroplasty can be challenging. The purpose of this study was to perform biomechanical analysis of cup fixation strength using fixed-angle vs standard screw fixation. Multihole, porous-backed acetabular prostheses were implanted in both acetabuli of 8 cadaveric pelves using standard press-fit techniques. Fixed-angle screws were used on the left side, and standard cancellous screws were used in the right. The use of fixed-angle screws enhanced acetabular fixation substantially under subfailure cyclic loading conditions and load-to-failure. The triradiate screw configuration increases the bending moment required to fail the specimens as well. Fixed-angle screws may be useful for achieving rigid fixation of acetabular prostheses in challenging clinical scenarios.

  6. Influence of Target Parameters on Fixation Stability in Normal and Strabismic Monkeys

    PubMed Central

    Pirdankar, Onkar H.; Das, Vallabh E.

    2016-01-01

    Purpose The purpose of this study was to assess the effect of fixation target parameters on fixation instability in strabismic monkeys. Methods One normal and three exotropic monkeys were presented with four differently shaped fixation targets, with three diameters, during monocular or binocular viewing. Fixation targets were white on a black background or vice versa. Binocular eye movements were recorded using the magnetic search coil technique and fixation stability quantified by calculating the bivariate contour ellipse area (BCEA). Results Fixation instability was greater in all the strabismic monkeys compared with the normal monkey. During monocular viewing, strabismic monkeys showed significantly greater instability in the covered eye compared to the fixating eye. Multifactorial ANOVA suggested statistically significant target parameter influences, although effect sizes were small. Thus, a disk-shaped target resulted in greater instability than other target shapes in the viewing eyes of the normal monkey and two of three strabismic monkeys. A similar target-shape effect was also observed in the covered eye. Least instability was elicited with a 0.5° target in the normal monkey and a 1.0° target in the strabismic monkeys, both in the viewing and the covered eye. Target/background polarity effects were idiosyncratic. In strabismic monkeys, stability of the fixating eye during binocular viewing was not different from the stability of the same eye during monocular viewing. Conclusions Abnormal drifts and nystagmus contribute to increased fixation instability in strabismic monkeys. Target parameters (shape and size) that influence fixation stability in a normal animal also affected fixation stability in our sample of strabismic monkeys. PMID:26968739

  7. Establishment of the 1st World Health Organization International Standard for Plasmodium falciparum DNA for nucleic acid amplification technique (NAT)-based assays

    PubMed Central

    Padley, David J; Heath, Alan B; Sutherland, Colin; Chiodini, Peter L; Baylis, Sally A

    2008-01-01

    Background In order to harmonize results for the detection and quantification of Plasmodium falciparum DNA by nucleic acid amplification technique (NAT)-based assays, a World Health Organization (WHO) collaborative study was performed, evaluating a series of candidate standard preparations. Methods Fourteen laboratories from 10 different countries participated in the collaborative study. Four candidate preparations based upon blood samples parasitaemic for P. falciparum were evaluated in the study. Sample AA was lyophilized, whilst samples BB, CC and DD were liquid/frozen preparations. The candidate standards were tested by each laboratory at a range of dilutions in four independent assays, using both qualitative and quantitative NAT-based assays. The results were collated and analysed statistically. Results Twenty sets of data were returned from the participating laboratories and used to determine the mean P. falciparum DNA content for each sample. The mean log10 "equivalents"/ml were 8.51 for sample AA, 8.45 for sample BB, 8.35 for sample CC, and 5.51 for sample DD. The freeze-dried preparation AA, was examined by accelerated thermal degradation studies and found to be highly stable. Conclusion On the basis of the collaborative study, the freeze-dried material, AA (NIBSC code No. 04/176) was established as the 1st WHO International Standard for P. falciparum DNA NAT-based assays and has been assigned a potency of 109 International Units (IU) per ml. Each vial contains 5 × 108 IU, equivalent to 0.5 ml of material after reconstitution. PMID:18652656

  8. Subaxial subluxation after atlantoaxial transarticular screw fixation in rheumatoid patients.

    PubMed

    Ito, Hiromu; Neo, Masashi; Sakamoto, Takeshi; Fujibayashi, Shunsuke; Yoshitomi, Hiroyuki; Nakamura, Takashi

    2009-06-01

    The most common cervical abnormality associated with rheumatoid arthritis (RA) is atlantoaxial subluxation, and atlantoaxial transarticular screw fixation has proved to be one of the most reliable, stable fixation techniques for treating atlantoaxial subluxation. Following C1-C2 fixation, however, subaxial subluxation reportedly can bring about neurological deterioration and require secondary operative interventions. Rheumatoid patients appear to have a higher risk, but there has been no systematic comparison between rheumatoid and non-rheumatoid patients. Contributing radiological factors to the subluxation have also not been evaluated. The objective of this study was to evaluate subaxial subluxation after atlantoaxial transarticular screw fixation in patients with and without RA and to find contributing factors. Forty-three patients who submitted to atlantoaxial transarticular screw fixation without any concomitant operation were followed up for more than 1 year. Subaxial subluxation and related radiological factors were evaluated by functional X-ray measurements. Statistical analyses showed that aggravations of subluxation of 2.5 mm or greater were more likely to occur in RA patients than in non-RA patients over an average of 4.2 years of follow-up, and postoperative subluxation occurred in the anterior direction in the upper cervical spine. X-ray evaluations revealed that such patients had a significantly smaller postoperative C2-C7 angle, and that the postoperative AA angle correlated negatively with this. Furthermore, anterior subluxation aggravation was significantly correlated with the perioperative atlantoaxial and C2-C7 angle changes, and these two changes were strongly correlated to each other. In conclusion, after atlantoaxial transarticular screw fixation, rheumatoid patients have a greater risk of developing subaxial subluxations. The increase of the atlantoaxial angel at the operation can lead to a decrease in the C2-C7 angle, followed by anterior

  9. PRESERVATION OF THE ULTRASTRUCTURE OF BACILLUS SUBTILIS BY CHEMICAL FIXATION AS VERIFIED BY FREEZE-ETCHING

    PubMed Central

    Nanninga, N.

    1969-01-01

    The present study on the ultrastructure of Bacillus subtilis was undertaken in order to examine by means of the freeze-etching technique possible structural changes occurring during the chemical fixation procedure (Ryter-Kellenberger (R-K) fixation). Three stages were followed by freeze-etching, viz.: (a) fixation in osmium tetroxide, (b) fixation in osmium tetroxide and posttreatment with uranyl acetate, and (c) fixation in osmium tetroxide, posttreatment in uranyl acetate, and dehydration in a graded series of acetone. Preparations were made after each stage in the presence of 20% glycerol. Good preservation of ultrastructure was observed, after any of the three treatments, of the outer surface of the plasma membrane, and the inner surface of the plasma membrane. No alteration in fracturing properties could be observed. However, if we are to judge by the results of freeze-etching, any of the successive steps of the chemical fixation procedure achieve strong contrast between the nucleoplasmic region and the cytoplasm. Dependent on the quality of fixation, very delicately preserved DNA fibrils or strongly aggregated ones were seen. It appears that R-K fixation is capable of producing more or less distinctly visible changes in the native state of the nucleoplasm in young cells of B. subtilis. PMID:4979363

  10. Biomechanical analysis on transverse tibial fixation in anterior cruciate ligament reconstructions☆

    PubMed Central

    Filho, Edmar Stieven; Mendes, Mariane Henseler Damaceno; Claudino, Stephanie; Baracho, Filipe; Borges, Paulo César; da Cunha, Luiz Antonio Munhoz

    2015-01-01

    Objective To verify whether the combination of tibial cross pin fixation and femoral screw fixation presents biomechanical advantages when compared to femoral cross pin fixation and tibial screw fixation for the reconstruction of the anterior cruciate ligament (ACL). Methods Thirty-eight porcine knees and bovine extensor digitorum tendons were used as the graft materials. The tests were performed in three groups: (1) standard, used fourteen knees, and the grafts were fixated with the combination of femoral cross pin and a tibial screw; (2) inverted, used fourteen knees with an inverted combination of tibial cross pin and a femoral screw; (3) control, ten control tests performed with intact ACL. After the grafts fixation, all the knees were subjected to tensile testing to determine yield strength and ultimate strength. Results There was no statistically significant difference in survival techniques in regard to strength, yield load and tension. There was a higher survival compared in the standard curves of yield stress (p < 0.05). Conclusion There is no biomechanical advantage, observed in animal models testing, in the combination of tibial cross pin fixation and femoral screw when compared to femoral cross pin fixation and tibial screw. PMID:26229913

  11. Tailor's bunion. Is fixation necessary?

    PubMed

    Pontious, J; Brook, J W; Hillstrom, H J

    1996-02-01

    Tailor's bunion or bunionette are terms that describe a pathologic enlargement occurring laterally on the fifth metatarsophalangeal joint. Regardless of the etiology that precipitates the deformity, the resulting abnormal protrusion of soft tissue or bone can result in pain for the patient. Symptoms can range from mild discomfort to severe, debilitating pain. The patient may present with pain dorsolaterally, laterally, or plantarly. The symptoms are mechanically induced, and are often associated with hyperkeratotic lesions and adventitious bursae. Patients complain most often that they cannot find comfortable shoes. The authors compare the effectiveness of fixated versus nonfixated distal osteotomies of the fifth metatarsal for the correction of tailor's bunion. This study shows that fixation can help control postoperative dorsal displacement of the fifth metatarsal capital fragment (p < 0.0001) and produce less shortening of the metatarsal resulting in fewer complications.

  12. Nitrogen fixation by marine cyanobacteria.

    PubMed

    Zehr, Jonathan P

    2011-04-01

    Discrepancies between estimates of oceanic N(2) fixation and nitrogen (N) losses through denitrification have focused research on identifying N(2)-fixing cyanobacteria and quantifying cyanobacterial N(2) fixation. Previously unrecognized cultivated and uncultivated unicellular cyanobacteria have been discovered that are widely distributed, and some have very unusual properties. Uncultivated unicellular N(2)-fixing cyanobacteria (UCYN-A) lack major metabolic pathways including the tricarboxylic acid cycle and oxygen-evolving photosystem II. Genomes of the oceanic N(2)-fixing cyanobacteria are highly conserved at the DNA level, and genetic diversity is maintained by genome rearrangements. The major cyanobacterial groups have different physiological and ecological constraints that result in highly variable geographic distributions, with implications for the marine N-cycle budget.

  13. Smaller Fixation Target Size Is Associated with More Stable Fixation and Less Variance in Threshold Sensitivity

    PubMed Central

    Okano, Kana; Koshiji, Risako; Funaki, Wakana; Shoji, Nobuyuki

    2016-01-01

    The aims of this randomized observational case control study were to quantify fixation behavior during standard automated perimetry (SAP) with different fixation targets and to evaluate the relationship between fixation behavior and threshold variability at each test point in healthy young participants experienced with perimetry. SAP was performed on the right eyes of 29 participants using the Octopus 900 perimeter, program 32, dynamic strategy. The fixation targets of Point, Cross, and Ring were used for SAP. Fixation behavior was recorded using a wearable eye-tracking glass. All participants underwent SAP twice with each fixation target in a random fashion. Fixation behavior was quantified by calculating the bivariate contour ellipse area (BCEA) and the frequency of deviation from the fixation target. The BCEAs (deg2) of Point, Cross, and Ring targets were 1.11, 1.46, and 2.02, respectively. In all cases, BCEA increased significantly with increasing fixation target size (p < 0.05). The logarithmic value of BCEA demonstrated the same tendency (p < 0.05). A positive correlation was identified between fixation behavior and threshold variability for the Point and Cross targets (ρ = 0.413–0.534, p < 0.05). Fixation behavior increased with increasing fixation target size. Moreover, a larger fixation behavior tended to be associated with a higher threshold variability. A small fixation target is recommended during the visual field test. PMID:27829030

  14. Enhanced fixation of implants by bone ingrowth to titanium fiber mesh: effect of incorporation of hydroxyapatite powder.

    PubMed

    Tsukeoka, Tadashi; Suzuki, Masahiko; Ohtsuki, Chikara; Tsuneizumi, Yoshikazu; Miyagi, Jin; Sugino, Atsushi; Inoue, Takayuki; Michihiro, Ryouichi; Moriya, Hideshige

    2005-10-01

    Tight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Titanium fiber mesh is an attractive structure for the establishment of tight fixation between bone and implant by bone ingrowth into the spaces among the fibers. Enhancement of bone ingrowth is desired not only for tight fixation but also for a fast recovery. Our hypothesis is that just the presence of hydroxyapatite (HA) particles ensures improved bone ingrowth, and that long-term stability can be obtained by mechanical anchoring of bone in the spaces among titanium fibers. In this study, we examine our hypothesis by in vivo experiment using dog femur. HA particles were incorporated in titanium fiber mesh coated on titanium alloy rod by dipping in a slurry of HA with hydroxy-propyl-cellulose in an ethanol solution. Specimens were implanted for 3, 5, and 8 weeks, and were then compared with the results from specimens without the use of HA. Bonding strength was evaluated by push-out test, and histomorphometric measurements were made with analysis software to calculate the average value of bone ingrowth. A significantly higher bonding strength was observed for the specimens with HA-incorporated implant at 3 and 5 weeks, and larger bone ingrowth deep inside the titanium fiber mesh was measured at 3 weeks. Our proposed method has the additional advantage of not requiring a high temperature that may result in changes in characters of HA powder such as phase transition, grain growth, and decomposition. Moreover, this technique of HA powder incorporation without high-temperature treatment allows the use of several types of metallic fiber mesh, as well as the application to fiber mesh made of organic polymers. We conclude that this simple modification of titanium fiber mesh with HA powder can improve the fixation of implant to bone in the initial stage after operation.

  15. 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.

  16. Fixation Strategies For Retinal Immunohistochemistry

    PubMed Central

    Stradleigh, Tyler W.; Ishida, Andrew T.

    2015-01-01

    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

  17. Bacteria on External Fixators: Which Prep is Best?

    DTIC Science & Technology

    2012-01-01

    Wenke, PhD, and Joseph R. Hsu, MD, San Antonio, Texas BACKGROUND: There are no established guidelines for the surgical prep of an external fixator in...were then randomized into four treatment groups: chlorhexidine- gluconate (CHG) (4%) scrub , CHG (4%) spray, povidone-iodine (PI) (10%) scrub , and PI...reimaged. Spatial distribution of bacteria and total bacteria counts were compared. RESULTS: There was a similar reduction in bacteria after surgical

  18. STIFF ELBOW TREATMENT BY INTERPOSING ARTHROPLASTY ASSOCIATED TO HINGED EXTERNAL FIXATOR

    PubMed Central

    Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; Silva, Luciana Andrade da; Junior, Nelson Gennaro; Checchia, Sergio Luiz

    2015-01-01

    Objective: Assess the results of the elbow/fascia lata interposing arthroplasty technique associated to the use of a hinged external fixator in the treatment of stiff elbow. Methods: Between 2001 and 2006, five cases of stiff elbow were operated and followed up by the Shoulder and Elbow Group of the Santa Casa Misericórdia de São Paulo Medical Sciences School, establishing the following as inclusion criteria: patients with below-functional elbow range of motion associated to degeneration on that joint, for whom total prosthesis had not been indicated. Patients' ages ranged from 21 to 55 years (mean: 38). Male gender was prevalent (four cases), and, in all cases, the dominant side was operated. Concerning etiology, two cases of infectious arthritis sequels, one post-trauma sequel, and two rheumatoid arthritis were found. Preoperative range of motion ranged from 20° to 30° of flexion-extension; in two cases, fixed contracture existed in flexion at 30° and 65°. The patients were assessed according to Bruce-modified AMA criteria. Results: The mean follow up time was 54 months. All patients showed improvement of the Bruce index, which, preoperatively, was 43.5, increasing to 88.2 postoperatively. We found two excellent cases, one good, one fair, and one poor. Conclusion: Fascia lata interposing arthroplasty associated to the use of a dynamic external fixator on stiff elbows is a feasible alternative for patients not indicated to total elbow arthroplasty. PMID:27022516

  19. Maxillo Mandibular Fixation in Edentulous Scenarios: Combined MMF Screws and Gunning Splints.

    PubMed

    Chaudhary, Zainab; Sharma, Rakesh; Krishnan, Sriram

    2014-06-01

    A fracture of the maxillary or mandibular bone requires the afflicted to undergo a maxillo mandibular fixation for the establishment of pre traumatic occlusion. This process is quiet tedious and consumes a considerable period of time before any surgical procedure can commence. Such a situation can be complicated in case the individual with maxillomandibular fracture has sparse or absent dentition; for such cases a splint is fabricated or an erstwhile existing denture is used for maintaining a vertical jaw proportion. Stabilizing such splints to the jaw requires various invasive approaches that can bring into harm's way, adjacent soft tissue vital structures. We describe here an innovative technique combining the time tested method of the "gunning splint" and the advanced minimally invasive MMF screws for obtaining closed reduction in edentulous jaw fractures.

  20. Circular External Fixation as a Primary or Adjunctive Therapy for the Podoplastic Approach of the Diabetic Charcot Foot.

    PubMed

    Short, Daniel J; Zgonis, Thomas

    2017-01-01

    Numerous techniques have been described for surgical management of the diabetic Charcot foot. External fixation has become a main surgical tool for the reconstructive foot and ankle surgeon when dealing with the ulcerated diabetic Charcot foot. In the presence of an open wound and/or osteomyelitis, staged reconstruction with circular external fixation becomes ideal for salvage of the diabetic lower extremity. Also, circular external fixation can provide simultaneous compression and stabilization, correct the underlying osseous or soft tissue deformities, and surgically offload the diabetic Charcot foot. This article describes a variety of circular external fixation applications for the diabetic Charcot foot.

  1. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    PubMed

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery.

  2. Two-Pin Fixation of Proximal Interphalangeal Joint Fusion for Hammertoe Correction.

    PubMed

    Boffeli, Troy J; Thompson, Jonathan C; Tabatt, Jessica A

    2016-01-01

    Single-pin external Kirschner wire (K-wire) fixation has traditionally been a mainstay in proximal interphalangeal joint fusion for central hammertoe repair. Concerns over cosmesis, inconvenience, pin tract infection, hardware failure, nonunion, and early hardware removal have led to the development of implantable internal fixation devices. Although numerous implantable devices are now available and represent viable options for hammertoe repair, they are costly and often pose a challenge in the event removal becomes necessary. An alternative fixation option not typically used is a 2-pin K-wire fixation technique. The perceived advantage of obtaining 2 points of fixation compared with 1 across the fusion site is improved stability against the rotational and bending forces, thus decreasing the potential for pin-related complications. A retrospective assessment of 91 consecutive hammertoe repairs consisting of proximal interphalangeal joint fusion with 2-pin fixation in 60 patients was performed. The K-wires were removed at 6 weeks postoperatively, and the overall postoperative follow-up duration was 28.56 (range 1.40 to 86.83) months. Of the 91 digits, 89 (98%) did not encounter a complication postoperatively and 2 (2.20%) had sustained loosened or broken hardware. No postoperative infection was encountered. The low incidence of complications observed supports the 2-pin K-wire fixation technique as a low-cost and viable construct for proximal interphalangeal joint fusion hammertoe repair.

  3. Hybrid fixation in the bilateral sagittal split osteotomy for lower jaw advancement

    PubMed Central

    PEREIRA, Felipe Ladeira; JANSON, Marcos; SANT'ANA, Eduardo

    2010-01-01

    Miniplate and screw fixation has been widely used in bilateral sagittal split osteotomy, but some issues remain unclear concerning its lack of rigidity when compared to Spiessl's bicortical technique. This paper demonstrates the hybrid fixation technique in a case report. A 34-year-old female patient underwent a double jaw surgery with counter-clockwise rotation of the mandible fixed using the hybrid fixation technique. The patient evolved well in the postoperative period and is still under follow up after 14 months, reporting satisfaction with the results and no significant deviation from the treatment plan up to now. No damage to tooth roots was done, maxillomandibular range of motion was within normality and regression of the inferior alveolar nerve paresthesia was observed bilaterally. The hybrid mandibular fixation is clearly visible in the panoramic and cephalometric control radiographs. It seems that the hybrid fixation can sum the advantages of both monocortical and bicortical techniques in lower jaw advancement, increasing fixation stability without significant damage to the mandibular articulation and the inferior alveolar nerve. A statistical investigation seems necessary to prove its efficacy. PMID:20379687

  4. Arthrodesis tarsocrural or tarsometatarsal in 2 dogs using circular external skeletal fixator

    PubMed Central

    Rahal, Sheila C.; Volpi, Reinaldo S.; Hette, Khadije; Teixeira Neto, Francisco J.; Vulcano, Luiz C.

    2006-01-01

    An external fixation technique, using a circular fixator, to obtain arthrodesis was evaluated in 2 dogs with infected open lesions and soft tissue damage. In both cases, articular cartilage was curetted, and devitalized bone and necrotic soft tissue were removed. No bone graft was used. The wounds were maintained open and the dogs received postoperative antibiotic therapy. The arthrodesis site was compressed progressively as needed. Infection was eradicated and bony union was obtained in both dogs. It was concluded that the use of a circular fixator is an effective method to achieve arthrodesis. PMID:17017656

  5. Mechanical considerations in using tensioned wires in a transosseous external fixation system.

    PubMed

    Aronson, J; Harp, J H

    1992-07-01

    Factors that affect wire tension were examined using external mechanical testing units as well as in-line load cells. The circular external fixator with wires supported at each end exhibits a self-stiffening effect such that wire stiffness increases with wire deflection. Mechanical slippage between wire and fixation bolt is the primary reason for loss of wire tension. Slippage can be avoided by adequate torque on the fixation nut (20 N.m). Guidelines are presented for proper and safe tensioning techniques to achieve clinically indicated tensions without risk of breakage.

  6. Resorbable bone fixation alloys, forming, and post-fabrication treatments.

    PubMed

    Ibrahim, Hamdy; Esfahani, Sajedeh Nasr; Poorganji, Behrang; Dean, David; Elahinia, Mohammad

    2017-01-01

    Metallic alloys have been introduced as biodegradable metals for various biomedical applications over the last decade owing to their gradual corrosion in the body, biocompatibility and superior strength compared to biodegradable polymers. Mg alloys possess advantageous properties that make them the most extensively studied biodegradable metallic material for orthopedic applications such as their low density, modulus of elasticity, close to that of the bone, and resorbability. Early resorption (i.e., <3months) and relatively inadequate strength are the main challenges that hinder the use of Mg alloys for bone fixation applications. The development of resorbable Mg-based bone fixation hardware with superior mechanical and corrosion performance requires a thorough understanding of the physical and mechanical properties of Mg alloys. This paper discusses the characteristics of successful Mg-based skeletal fixation hardware and the possible ways to improve its properties using different methods such as mechanical and heat treatment processes. We also review the most recent work pertaining to Mg alloys and surface coatings. To this end, this paper covers (i) the properties and development of Mg alloys and coatings with an emphasis on the Mg-Zn-Ca-based alloys; (ii) Mg alloys fabrication techniques; and (iii) strategies towards achieving Mg-based, resorbable, skeletal fixation devices.

  7. Nitrogen Fixation (Acetylene Reduction) Associated with Duckweed (Lemnaceae) Mats

    PubMed Central

    Zuberer, D. A.

    1982-01-01

    Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N2-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N2-fixation (C2H2) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 μmol of C2H4 g (dry weight)−1 day−1 for samples incubated aerobically in light. Dark N2 fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 μM) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N2-fixing heterotrophic bacteria (105 cells g [wet weight]−1 and cyanobacteria (105 propagules g [wet weight]−1 were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992

  8. Pullout strength of fixation screws from polymethylmethacrylate bone cement.

    PubMed

    Flahiff, C M; Gober, G A; Nicholas, R W

    1995-05-01

    Polymethylmethacrylate bone cement is often used to fill voids and increase the strength of osteoporotic and pathological bone. However, it is unclear as to which method of cement augmentation provides optimal screw fixation. This study was conducted to determine which of the current cement augmentation techniques provides the strongest construct when used in association with orthopaedic fixation screws. Pullout strength was determined for screws placed in sawbones with no cement, soft cement, doughy cement and hard cement after drilling and tapping. All cement-screw constructs were significantly stronger than the no cement group. Screws placed in doughy cement had a significantly higher pullout force than those placed in hard cement. Pullout strength of screws placed in soft cement was intermediate between the other cement techniques but not significantly different from either group.

  9. 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.

  10. Methanotrophy induces nitrogen fixation during peatland development.

    PubMed

    Larmola, Tuula; Leppänen, Sanna M; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-14

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation.

  11. Methanotrophy induces nitrogen fixation during peatland development

    PubMed Central

    Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-01

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

  12. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin

    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.

  13. 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.

  14. Image recorder with microwave fixation

    SciTech Connect

    Hosono, N.; Isaka, K.

    1984-11-13

    The present invention is directed to improvement in an image recorder for recording developed images or toner images by microwave fixation. According to the invention there is used a novel thermoplastic developer comprising of two components. The first component contains a dielectric material which is able to absorb microwave and generate heat by dielectric loss. The second component contains magnetic loss exothermic material. The microwave absorbing power of the first component is improved by heating the first component with heat generated from the second component.

  15. 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…

  16. Effect of tissue fixatives on the immunohistochemical expression of ABH blood group isoantigens.

    PubMed

    Gokhale, Sumita; Ololade, Omiyosoye; Adegboyega, Patrick A

    2002-09-01

    Immunohistochemical analysis of ABH blood group isoantigens has been shown to be a useful ancillary technique for resolving problems associated with specimen mix-ups in the daily practice of surgical pathology. However, the effects of different fixatives on the expression of these antigens in paraffin-embedded tissues are not known. Therefore, the effects of seven different fixatives on the immunohistochemical expression of ABH blood group isoantigens were studied in tissues from several organs. The following fixatives were used: acetone, 70% ethanol, B5, Bouin, Carnoy, methanol, and 10% formalin. After fixation for 6, 12, and 72 hours, the tissue blocks were embedded in paraffin, and immunohistochemistry was performed on 4 microm-thick tissue sections using monoclonal antibodies to blood group isoantigens (A, B, and H) and the avidin-biotin detection method. Also, immunostaining was performed on step tissue sections with and without antigen retrieval using citrate buffer at pH 6.0. The expression of the blood group isoantigens was concordant with the blood group of the patient in all the cases studied, irrespective of the fixative and time of fixation. However, in the absence of antigen retrieval, the intensity of the staining reaction was diminished. These results showed that irrespective of the fixative used, immunohistochemical staining of paraffin-embedded tissue sections with ABH blood group antibodies is a rapid, reliable, and cost-effective method for sorting out interpretative problems of tissue contaminants (floaters) and specimen mix-ups in surgical pathology.

  17. An intermaxillary fixation screw traction wire: an aid for facial bone fracture repair.

    PubMed

    Kim, Myung-Good; Yoo, Roh-Eul; Chang, Hak; Kwon, Sung-Tack; Baek, Rong-Min; Minn, Kyung-Won

    2009-07-01

    We have devised a new technique to improve stabilization of fractured facial bone fractures (frontal sinus fractures, zygomatic fractures, mandibular condyle fractures) by intermaxillary fixation screw traction wires (stainless steel wires through intermaxillary fixation screws). A retrospective study evaluating intermaxillary fixation screw traction wires was performed. We have used this technique for 3 cases of frontal sinus fractures, 9 cases of zygomatic fractures, and 7 cases of mandibular condyle fractures. After dissection of a fractured site, a hole is drilled on the fractured bone where it does not interfere with positioning the plate across the fracture line. After an intermaxillary fixation screw is inserted, a stainless steel wire is tied through a hole in the screw head. By the aid of wire for traction, the displaced fractured bone is easily aligned to the proper position. Plates and screws are applied readily on the predetermined area. A retrospective study on 19 patients using intermaxillary fixation screw traction wires was performed. The diagnoses and associated complications of the cases were recorded. No associated complication as a result of using this technique was identified. The use of intermaxillary fixation screw traction wire enhances stabilization and visualization without possible risk for surrounding soft tissue injury using, a sharp traction device like a bone hook. An intermaxillary fixation screw traction wire is an useful aid for visualization and stabilization during facial bone fracture reduction, particularly where exposure is difficult such as in the condylar region of the mandible. And unlike a classic traction wire, the intermaxillary fixation screw traction wire has almost no risk of having it loosened from the screw.

  18. The cost of screening radiographs after stable fracture fixation

    PubMed Central

    Tufescu, Ted

    2017-01-01

    Background Currently up to 58% of Canadian surgeons would forego screening radiographs after stable fracture fixation. It is therefore expected that reducing screening radiographs will be well accepted, provided that patient safety is not compromised, resulting in a cost reduction. The study objective was to measure the savings of a simplified radiographic protocol for well-fixed fractures and establish feasibility for a noninferiority trial that proves patient safety. Methods Patients were randomized after fixation. The control group received screening radiographs immediately after fixation and at 2 weeks. The experimental group received radiographs only when clinically indicated. At 6 weeks all patients received radiographs. The cost of imaging, time spent in clinic and patient satisfaction was measured. A blinded reviewer documented adverse events, either detected or missed. Results Of the 90 patients screened, 39 were randomized and 26 had complete follow-up. The mean cost of radiographs over the first 6 weeks was $44.51 (95% confidence interval [CI] 38.64–50.38) per patient in the experimental group, and $129.23 (95% CI 120.23–138.23) in the control group (p < 0.001). The mean time spent in clinic at 2 weeks was 46 min (95% CI 32–60) per patient for the experimental group and 68 min (95% CI 55–81) for the control group (p = 0.018). Two complications occurred in the experimental group. Both were detected clinically and did not qualify as missed events. Conclusion Implementing a simplified radiography protocol after stable fracture fixation saves time and money. Additionally, no adverse events were missed with the study protocol. Recommendations are made toward a noninferiority trial to establish protocol safety. PMID:28234590

  19. A new method for typing bovine major histocompatibility complex class II DRB3 alleles by combining two established PCR sequence-based techniques.

    PubMed

    Takeshima, S-N; Matsumoto, Y; Miyasaka, T; Arainga-Ramirez, M; Saito, H; Onuma, M; Aida, Y

    2011-09-01

    Recently, two polymerase chain reaction sequence-based typing (PCR-SBT) methods were reported for the genotyping of the bovine leukocyte antigen (BoLA)-DRB3. One technique is a single PCR-SBT (sPCR-SBT) method that generates heterozygous sequences that are subsequently analyzed by the haplofinder program, while the other technique is a nested PCR-SBT (nPCR-SBT) method that allows the analysis of heterozygous sequences using the assign 400ATF software. In this study, these techniques were compared and then integrated to produce an improved genotyping method. The primer set used for sPCR-SBT was more accurate than those used for nPCR-SBT. Combining sPCR-SBT with the assign 400ATF software previously reported for nPCR-SBT enables rapid and accurate genotyping of a large number of DNA samples.

  20. 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...

  1. Do fixation cues ensure fixation accuracy in split-fovea studies of word recognition?

    PubMed

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

    2009-07-01

    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 investigated this issue using procedures matched to the original studies and an eye-tracker to monitor the locations actually fixated. Four common types of fixation cues were used: cross, two vertical gapped lines, two vertical gapped lines plus a secondary task in which a digit was presented at the designated fixation point, and a dot. Accurate fixations occurred on <35% of trials for all fixation conditions. Moreover, despite the usefulness often attributed to a secondary task, no increase in fixation accuracy was produced in this condition. The indications are that split-fovea theory should not assume that fixation of specified locations occurs in experiments without appropriate eye-tracking control or, indeed, that consistent fixation of specified locations is plausible under normal conditions of word recognition.

  2. 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.

  3. Biomechanical evaluation of three ventral fixation methods for canine atlantoaxial instability: a cadaveric study

    PubMed Central

    TAKAHASHI, Fumitaka; HAKOZAKI, Takaharu; KANNO, Nobuo; HARADA, Yasuji; YAMAGUCHI, Shinya; HARA, Yasushi

    2016-01-01

    We evaluated comparatively the mechanical strength in three kinds of surgical fixation techniques for canine atlantoaxial joint. Atlantoaxial plate fixation (APF), polymethylmethacrylate (PMMA) fixation (PMF) and transarticular fixation (TAF) were applied to the atlas and axis harvested from healthy beagle dogs, and then, the specimens were tested. The PMF group had significantly higher resistance to flexion than the APF group (P=0.030) and the TAF group (P=0.004). There were no significant differences in resistance to torsion between the APF group and the PMF group, while the APF group had significantly higher resistance to torsion than the TAF group (P=0.037). Considering the possible drawbacks of using PMMA, the APF method is proposed as an alternative to the PMF method. PMID:27593982

  4. Antibodies in research of thymosin β4: investigation of cross-reactivity and influence of fixatives.

    PubMed

    Knop, Jana; App, Christine; Hannappel, Ewald

    2012-10-01

    Antibodies against thymosin β4 are available from various sources and have been used in immunohistochemistry, ELISA, and Western blot analyses. None of these antibodies have been fully characterized for specificity and influence of fixation techniques. This presents a difficulty because many tissues express more than one member of the β-thymosin family; in addition, highly homologous sequences are typical elements of β-thymosins. It is also important to scrutinize the influence of fixatives on the antibody-binding capability. Fixatives such as formaldehyde are well known as cross-linking reagents. Chemical modifications within the thymosin β4 molecule might change the putative epitope recognized by the antibody. These considerations suggest that investigations on thymosin β4 antibodies available to the scientific community are important and necessary before any experiment can be performed to exclude cross-reactivity with other β-thymosins that are coexistent in the examined tissue and to prove antibody binding after fixation steps.

  5. The use of pedicle-screw internal fixation for the operative treatment of spinal disorders.

    PubMed

    Gaines, R W

    2000-10-01

    Pedicle screws have dramatically improved the outcomes of spinal reconstruction requiring spinal fusion. Short-segment surgical treatments based on the use of pedicle screws for the treatment of neoplastic, developmental, congenital, traumatic, and degenerative conditions have been proved to be practical, safe, and effective. The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine. Carefully applied pedicle-screw fixation does not produce severe or frequent complications. Pedicle-screw fixation can be effectively and safely used wherever a vertebral pedicle can accommodate a pedicle screw--that is, in the cervical, thoracic, or lumbar spine. Training in pedicle-screw application should be standard in orthopaedic training programs since pedicle-screw fixation represents the so-called gold standard of spinal internal fixation.

  6. Shape modifications of porous hydroxyapatite prostheses to improve rigid implant fixation: Experience in 12 cases

    PubMed Central

    Rienzo, Alessandro Di; Iacoangeli, Maurizio; di Somma, Lucia G. M.; Alvaro, Lorenzo; Nocchi, Niccolò; Scerrati, Massimo

    2012-01-01

    Background: Various methods of fixation have been described for custom made hydroxyapatite cranial implants. Their poor malleability limits most of the common used fixation techniques because of the high risk of cranioplasty's fracturing or higher exposure to infections. We present our experience with a new fixation technique, based on an appositely premodified hydroxyapatite implants. Methods: In a 2-year time period, 12 patients underwent cranioplasty by a modified custom made porous hydroxyapatite implant. Once the three-dimensional computer model of the prostheses was performed, three semicircular extensions placed at strategic positions were drawn and the final prosthesis was realized. At surgery, holes fitting the extensions were drilled into the skull borders and the implant was easily embedded inside the defect. Small titanium meshes overlying the extensions were fixed by screws to the surrounding bone. Results: A minimal increase of operative times was recorded, with drilling and fixation requiring additional 30 and 15 minutes, respectively. Optimal contact between cranioplasty and skull borders was always observed at control computed tomography (CT) scans. Permanent rigid fixation was obtained in all cases, with good functional and aesthetic results at follow-up. Conclusions: Modifications of hydroxyapatite implants are obtained without additional costs. The minimal increase of operative times is largely counterbalanced by optimal fixation results. Finally, the bone drilling and the immediate proximity of bone to prosthesis might enhance the potential for osteogenesis and osteointegration. PMID:23372977

  7. Abnormal Fixational Eye Movements in Amblyopia

    PubMed Central

    Shaikh, Aasef G.; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F.

    2016-01-01

    Purpose Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Methods Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. Results We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. Discussion This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity. PMID:26930079

  8. The challenging image-guided abdominal mass biopsy: established and emerging techniques 'if you can see it, you can biopsy it'.

    PubMed

    Sainani, Nisha I; Arellano, Ronald S; Shyn, Paul B; Gervais, Debra A; Mueller, Peter R; Silverman, Stuart G

    2013-08-01

    Image-guided percutaneous biopsy of abdominal masses is among the most commonly performed procedures in interventional radiology. While most abdominal masses are readily amenable to percutaneous biopsy, some may be technically challenging for a number of reasons. Low lesion conspicuity, small size, overlying or intervening structures, motion, such as that due to respiration, are some of the factors that can influence the ability and ultimately the success of an abdominal biopsy. Various techniques or technologies, such as choice of imaging modality, use of intravenous contrast and anatomic landmarks, patient positioning, organ displacement or trans-organ approach, angling CT gantry, triangulation method, real-time guidance with CT fluoroscopy or ultrasound, sedation or breath-hold, pre-procedural image fusion, electromagnetic tracking, and others, when used singularly or in combination, can overcome these challenges to facilitate needle placement in abdominal masses that otherwise would be considered not amenable to percutaneous biopsy. Familiarity and awareness of these techniques allows the interventional radiologist to expand the use of percutaneous biopsy in clinical practice, and help choose the most appropriate technique for a particular patient.

  9. WRIST ARTHRODESIS WITH MINIMAL FIXATION PRESERVING THE CARPOMETACARPAL JOINTS

    PubMed Central

    Pardini, Arlindo Gomes; Pádua Gonçalves, Rodolfo Fonseca; Freitas, Afrânio Donato; Chaves, Antonio Barbosa

    2015-01-01

    Objective: Wrist arthrodesis is a surgical procedure that should always be considered in cases of pathological conditions in which anatomical and functional structures are altered. In general, the results are very satisfactory, particularly for pain relief, and in the majority of cases, there is considerable functional improvement. Various techniques have been described, with different methods of internal fixation, most of which include the carpometacarpal joints in the fusion. The objective of this study was to evaluate the results from wrist arthrodesis using a technique that is simpler, more biological, less expensive, and does not involve the carpometacarpal joints. Methods: Fifteen patients with wrist arthrodesis were evaluated (six with sequelae from trauma, four with rheumatoid arthritis, three with Kienbock grade IV, one with Preiser and one with panarthrosis). The technique consisted of using an iliac bone plate and internal fixation with Kirschner wires, avoiding the carpometacarpal joints. Results: The evaluation was based on consolidation time (93% in seven weeks); movements of the fingers and pronosupination; pinch and grasp strength; functional evaluation through the DASH, pain and patient satisfaction questionnaires. In general, the results were similar to those of other, more aggressive techniques, and the non-inclusion of the carpometacarpal joints did not affect the final result. Conclusion: Wrist arthrodesis with fixation using Kirschner wires and an iliac bone plate, preserving the carpometacarpal joints, gives good or excellent results that are not inferior to those of other techniques that have been described. However, it presents major advantages over other methods: it is less aggressive and cheaper, and does not have the inconvenience and complications associated with the use of plates and screws. PMID:27022522

  10. Dinitrogen fixation in aphotic oxygenated marine environments

    PubMed Central

    Rahav, Eyal; Bar-Zeev, Edo; Ohayon, Sarah; Elifantz, Hila; Belkin, Natalia; Herut, Barak; Mulholland, Margaret R.; Berman-Frank, Ilana

    2013-01-01

    We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO−3)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L−1 d−1 to 0.38 nmol N L−1 d−1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2–3.5 fold and N2 fixation rates by ~2-fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2–6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP and heterotrophic N2 fixation were carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particle (TEP) concentrations and N2 fixation rates. This suggests that sinking organic material and high carbon (C): nitrogen (N) micro-environments (such as TEP-based aggregates or marine snow) could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75% of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets. PMID:23986748

  11. Motorized injector-assisted intrascleral intraocular lens fixation.

    PubMed

    Hung, Jia-Horung; Wang, Shih-Hao; Teng, Yu-Ti; Hsu, Sheng-Min

    2017-03-01

    For eyes with deficient capsular support, intraocular lens (IOL) implantation has long been a technical challenge. Recently, intrascleral fixation of the haptics of a three-piece posterior chamber IOL has become a popular option. In this procedure, externalization of the leading haptic during IOL injection is a stressful step. We present a modified technique to improve the ease and safety of this step. Our modified technique involves IOL injection with a motorized injector with several important modifications described here. With these modifications, a surgeon can easily maintain the correct orientation of the IOL in a well-controlled manner during IOL injection. The records of 13 patients who underwent this technique were retrospectively evaluated. Corrected-distance visual acuity improved significantly after surgery (p<0.05). No postoperative retinal detachment, endophthalmitis, IOL decentration, or vitreous hemorrhage was noted during the follow-up period. In conclusion, the motorized injector-assisted intrascleral IOL fixation technique is a safe and effective alternative to the conventional procedure. This technique makes the process of leading haptic externalization easier and more controllable.

  12. ESTABLISHING A STEREOSCOPIC TECHNIQUE FOR DETERMINING THE KINEMATIC PROPERTIES OF SOLAR WIND TRANSIENTS BASED ON A GENERALIZED SELF-SIMILARLY EXPANDING CIRCULAR GEOMETRY

    SciTech Connect

    Davies, J. A.; Perry, C. H.; Harrison, R. A.; Trines, R. M. G. M.; Lugaz, N.; Möstl, C.; Liu, Y. D.; Steed, K.

    2013-11-10

    The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This has led to the development of numerous stereoscopic techniques to investigate the three-dimensional structure and kinematics of solar wind transients such as coronal mass ejections (CMEs). Two such methods—triangulation and the tangent to a sphere—can be used to determine time profiles of the propagation direction and radial distance (and thereby radial speed) of a solar wind transient as it travels through the inner heliosphere, based on its time-elongation profile viewed by two observers. These techniques are founded on the assumption that the transient can be characterized as a point source (fixed φ, FP, approximation) or a circle attached to Sun-center (harmonic mean, HM, approximation), respectively. These geometries constitute extreme descriptions of solar wind transients, in terms of their cross-sectional extent. Here, we present the stereoscopic expressions necessary to derive propagation direction and radial distance/speed profiles of such transients based on the more generalized self-similar expansion (SSE) geometry, for which the FP and HM geometries form the limiting cases; our implementation of these equations is termed the stereoscopic SSE method. We apply the technique to two Earth-directed CMEs from different phases of the STEREO mission, the well-studied event of 2008 December and a more recent event from 2012 March. The latter CME was fast, with an initial speed exceeding 2000 km s{sup –1}, and highly geoeffective, in stark contrast to the slow and ineffectual 2008 December CME.

  13. Universality of fixation probabilities in randomly structured populations.

    PubMed

    Adlam, Ben; Nowak, Martin A

    2014-10-27

    The stage of evolution is the population of reproducing individuals. The structure of the population is known to affect the dynamics and outcome of evolutionary processes, but analytical results for generic random structures have been lacking. The most general result so far, the isothermal theorem, assumes the propensity for change in each position is exactly the same, but realistic biological structures are always subject to variation and noise. We consider a finite population under constant selection whose structure is given by a variety of weighted, directed, random graphs; vertices represent individuals and edges interactions between individuals. By establishing a robustness result for the isothermal theorem and using large deviation estimates to understand the typical structure of random graphs, we prove that for a generalization of the Erdős-Rényi model, the fixation probability of an invading mutant is approximately the same as that of a mutant of equal fitness in a well-mixed population with high probability. Simulations of perturbed lattices, small-world networks, and scale-free networks behave similarly. We conjecture that the fixation probability in a well-mixed population, (1 - r(-1))/(1 - r(-n)), is universal: for many random graph models, the fixation probability approaches the above function uniformly as the graphs become large.

  14. Kennedy Space Center Fixation Tube (KFT)

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E.; Levine, Howard G.; Romero, Vergel

    2016-01-01

    Experiments performed on the International Space Station (ISS) frequently require the experimental organisms to be preserved until they can be returned to earth for analysis in the appropriate laboratory facility. The Kennedy Fixation Tube (KFT) was developed to allow astronauts to apply fixative, chemical compounds that are often toxic, to biological samples without the use of a glovebox while maintaining three levels of containment (Fig. 1). KFTs have been used over 200 times on-orbit with no leaks of chemical fixative. The KFT is composed of the following elements: a polycarbonate main tube where the fixative is loaded preflight, the sample tube where the plant or other biological specimens is placed during operations, the expansion plug, actuator, and base plug that provides fixative containment (Fig. 2). The main tube is pre-filled with 25 mL of fixative solution prior to flight. When actuated, the specimen contained within the sample tube is immersed with approximately 22 mL (+/- 2 mL) of the fixative solution. The KFT has been demonstrated to maintain its containment at ambient temperatures, 4degC refrigeration and -100 C freezing conditions.

  15. Establishing operations

    PubMed Central

    Michael, Jack

    1993-01-01

    The first two books on behavior analysis (Skinner, 1938; Keller & Schoenfeld, 1950) had chapter-length coverage of motivation. The next generation of texts also had chapters on the topic, but by the late 1960s it was no longer being given much treatment in the behavior-analytic literature. The present failure to deal with the topic leaves a gap in our understanding of operant functional relations. A partial solution is to reintroduce the concept of the establishing operation, defined as an environmental event, operation, or stimulus condition that affects an organism by momentarily altering (a) the reinforcing effectiveness of other events and (b) the frequency of occurrence of that part of the organism's repertoire relevant to those events as consequences. Discriminative and motivative variables can be distinguished as follows: The former are related to the differential availability of an effective form of reinforcement given a particular type of behavior; the latter are related to the differential reinforcing effectiveness of environmental events. An important distinction can also be made between unconditioned establishing operations (UEOs), such as food deprivation and painful stimulation, and conditioned establishing operations (CEOs) that depend on the learning history of the organism. One type of CEO is a stimulus that has simply been paired with a UEO and as a result may take on some of the motivative properties of that UEO. The warning stimulus in avoidance procedures is another important type of CEO referred to as reflexive because it establishes its own termination as a form of reinforcement and evokes the behavior that has accomplished such termination. Another CEO is closely related to the concept of conditional conditioned reinforcement and is referred to as a transitive CEO, because it establishes some other stimulus as a form of effective reinforcement and evokes the behavior that has produced that other stimulus. The multiple control of human

  16. SU-C-BRD-05: Implementation of Incident Learning in the Safety and Quality Management of Radiotherapy: The Primary Experience in a New Established Program with Advanced Techniques

    SciTech Connect

    Yang, R; Wang, J

    2014-06-15

    Purpose: To explore the implementation and effectiveness of incident learning for the safety and quality of radiotherapy in a new established radiotherapy program with advanced technology. Methods: Reference to the consensus recommendations by American Association of Physicist in Medicine, an incident learning system was specifically designed for reporting, investigating, and learning of individual radiotherapy incidents in a new established radiotherapy program, with 4D CBCT, Ultrasound guided radiotherapy, VMAT, gated treatment delivered on two new installed linacs. The incidents occurring in external beam radiotherapy from February, 2012 to January, 2014 were reported. Results: A total of 33 reports were analyzed, including 28 near misses and 5 incidents. Among them, 5 originated in imaging for planning, 25 in planning, 1 in plan transfer, 1 in commissioning and 1 in treatment delivery. Among them, three near misses originated in the safety barrier of the radiotherapy process. In terms of error type, 1 incident was classified as wrong patient, 7 near misses/incidents as wrong site, 6 as wrong laterality, 5 as wrong dose, 7 as wrong prescription, and 7 as suboptimal plan quality. 5 incidents were all classified as grade 1/2 of dosimetric severity, 1 as grade 0, and the other 4 as grade 1 of medical severity. For the causes/contributory factors, negligence, policy not followed, inadequate training, failure to develop an effective plan, and communication contributed to 19, 15, 12, 5 and 3 near misses/incidents, respectively. The average incident rate per 100 patients treated was 0.4; this rate fell to 0.28% in the second year from 0.56% in the first year. The rate of near miss fell to 1.24% from 2.22%. Conclusion: Effective incident learning can reduce the occurrence of near miss/incidents, enhance the culture of safety. Incident learning is an effective proactive method for improving the quality and safety of radiotherapy.

  17. The Galveston technique using Luque or Cotrel-Dubousset rods.

    PubMed

    Lonstein, J E

    1994-04-01

    The Galveston technique for pelvic fixation in long fusions to the sacrum in neuromuscular and adult scoliosis is an effective technique to help obtain a solid fusion. With careful technique and accurate rod bending, rod insertion, rod contouring, and wire tightening, excellent fixation is obtained that maximizes the fusion rate.

  18. Finite element analysis of the stability of combined plate internal fixation in posterior wall fractures of acetabulum

    PubMed Central

    Liu, Xi-Ming; Pan, Chang-Wu; Wang, Guo-Dong; Cai, Xian-Hua; Chen, Lei; Meng, Cheng-Fei; Huang, Jin-Cheng

    2015-01-01

    Objective: This study aims to explore the mechanical stability of combined plate internal fixation in posterior wall fractures of the acetabulum. Methods: The fracture and internal fixation models were established in this study and they were divided into four kinds of internal fixation models, finite element analysis was performed. The four groups were 2 mini-plates and 1 reconstruction plate fixation (A), Reconstruction plate internal fixation group (B), 2 screws internal fixation group (C) and mini-plates internal fixation group (D). The displacement of each node was measured and evaluated. Results: There was no distortion in the geometric shape of the finite element model. The results of stress showed that it was less in the anterior pelvic ring and distributed uniform in labrum acetabulare; the stress was bigger in the upper and middle of sacroiliac joint and sciatic notch in sitting position. Conclusions: Combined plate internal fixation for posterior wall fractures of acetabular were stable and reliable, it is better than the other three methods. PMID:26550272

  19. Influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in Kaneohe Bay, Hawaii.

    PubMed Central

    Hanson, R B; Gundersen, K

    1976-01-01

    Nitrogen fixation was investigated in Kaneohe Bay, Oahu, Hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. No active, planktonic, N2-fixing blue-green algae or bacteria were observed. However, Calothrix and Nostoc capable of fixing N2 were cultured from navigational buoys and dead coral heads. Nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. Experiments demonstrated that the fixation was photosynthetically dependent. Examination of the data showed that there was no significant correlation between rates of nitrogen fixation and concentration of combined nitrogen compounds in the Bay water. Fixation was significantly correlated to the inorganic N/P (atomic) ratio in the south and middle sectors but not in the north sector. The nutrient data indicate there was a flux of combined nitrogen, but not phosphate, from the reef flats. PMID:7198

  20. Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems

    PubMed Central

    Hassan, Ahmed Salah Aldin

    2016-01-01

    Study Design The efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected. Purpose This study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems. Overview of Literature Percutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available. Methods We conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared. Results Percutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident. Conclusions Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients. PMID:26949466

  1. Thermodynamic constraints shape the structure of carbon fixation pathways.

    PubMed

    Bar-Even, Arren; Flamholz, Avi; Noor, Elad; Milo, Ron

    2012-09-01

    Thermodynamics impose a major constraint on the structure of metabolic pathways. Here, we use carbon fixation pathways to demonstrate how thermodynamics shape the structure of pathways and determine the cellular resources they consume. We analyze the energetic profile of prototypical reactions and show that each reaction type displays a characteristic change in Gibbs energy. Specifically, although carbon fixation pathways display a considerable structural variability, they are all energetically constrained by two types of reactions: carboxylation and carboxyl reduction. In fact, all adenosine triphosphate (ATP) molecules consumed by carbon fixation pathways - with a single exception - are used, directly or indirectly, to power one of these unfavorable reactions. When an indirect coupling is employed, the energy released by ATP hydrolysis is used to establish another chemical bond with high energy of hydrolysis, e.g. a thioester. This bond is cleaved by a downstream enzyme to energize an unfavorable reaction. Notably, many pathways exhibit reduced ATP requirement as they couple unfavorable carboxylation or carboxyl reduction reactions to exergonic reactions other than ATP hydrolysis. In the most extreme example, the reductive acetyl coenzyme A (acetyl-CoA) pathway bypasses almost all ATP-consuming reactions. On the other hand, the reductive pentose phosphate pathway appears to be the least ATP-efficient because it is the only carbon fixation pathway that invests ATP in metabolic aims other than carboxylation and carboxyl reduction. Altogether, our analysis indicates that basic thermodynamic considerations accurately predict the resource investment required to support a metabolic pathway and further identifies biochemical mechanisms that can decrease this requirement.

  2. X-Ray Diffraction Residual Stress Analysis: One of the Few Advanced Physical Measuring Techniques That Have Established Themselves for Routine Application in Industry

    NASA Astrophysics Data System (ADS)

    Nierlich, Wolfgang; Gegner, Jürgen

    The conventional procedure of X-ray diffraction (XRD) residual stress measurement is improved by means of a modification of the beam path of the diffractometer and an iterative technique that includes a pre-analysis of the nearpeak line-profile. The achieved short measuring times of 5 and around 10 min per residual stress value and retained austenite content, respectively, serve as precondition for routine industrial applications over the last three decades within SKF. The line width represents a measure of material ageing within the lifetime cycle of a rolling bearing: calibration curves for the (near-) surface and the sub-surface failure mode are presented. Material response analysis permits differentiation of these failure modes and between low- and high-cycle fatigue.

  3. The mixture problem in computer mapping of terrain: Improved techniques for establishing spectral signature, atmospheric path radiance, and transmittance. [in Colorado

    NASA Technical Reports Server (NTRS)

    Smedes, H. W.; Hulstrom, R. L.; Ranson, K. J.

    1975-01-01

    The results of LANDSAT and Skylab research programs on the effects of the atmosphere on computer mapping of terrain include: (1) the concept of a ground truth map needs to be drastically revised; (2) the concept of training areas and test areas is not as simple as generally thought because of the problem of pixels that represent a mixture of terrain classes; (3) this mixture problem needs to be more widely recognized and dealt with by techniques of calculating spectral signatures of mixed classes, or by other methods; (4) atmospheric effects should be considered in computer mapping of terrain and in monitoring changes; and (5) terrain features may be used as calibration panels on the ground, from which atmospheric conditions can be determined and monitored. Results are presented of a test area in mountainous terrain of south-central Colorado for which an initial classification was made using simulated mixture-class spectral signatures and actual LANDSAT-1-MSS data.

  4. Spinal fixation. Part 3. Complications of spinal instrumentation.

    PubMed

    Slone, R M; MacMillan, M; Montgomery, W J

    1993-07-01

    Spinal fixation devices can be used to form a rigid construct with the spine to replace bone, restore alignment, maintain position, and prevent motion in the treatment of fractures, degenerative disease, neoplasm, and congenital deformities. Because most spinal constructs will eventually fail if bone fusion does not occur, bone graft material is often used along with the implant to promote fusion. Conventional radiographs, obtained in two projections, remain the mainstay of implant evaluation, demonstrating the position of the spinal elements, hardware, graft material, and evidence of complication. Possible complications connected with use of fixation devices include intraoperative soft-tissue injuries, postoperative hematomas, and infection. The components (through incorrect use, malpositioning at surgery, and later dislodgment or fracture) may also contribute to complications such as instability; failure of fusion; or pain, with possible resultant neurologic damage. Bone graft material can migrate or hypertrophy, resulting in impingement on the spinal canal or neural foramen. Radiologists should be familiar with the various spinal fixation devices and techniques to better identify evolving complications.

  5. Nitrogen fixation (acetylene reduction) by epiphytes of freshwater macrophytes.

    PubMed

    Finke, L R; Seeley, H W

    1978-07-01

    The involvement of epiphytic microorganisms in nitrogen fixation was investigated in a shallow freshwater pond near Ithaca, N.Y. The acetylene reduction technique was used to follow diel and seasonal cycles of nitrogen fixation by epiphytes of Myriophyllum spicatum. Acetylene-reducing activity was maximal between noon and 6 p.m., but substantial levels of activity relative to daytime rates continued through the night. Experiments with the seasonal course of activity showed a gradual decline during the autumn months and no activity in January or February. Activity commenced in May, with an abrupt increase to levels between 0.45 and 0.95 nmol of ethylene formed per mg (dry weight) of plant per h. Through most of the summer months, mean rates of acetylene reduction remained between 0.15 and 0.60 nmol/mg (dry weight) per h. It was calculated from diel and seasonal cycles that, in the pond areas studied, epiphytes were capable of adding from 7.5 to 12.5 mug of N per mg of plant per year to the pond. This amount is significant relative to the total amount of nitrogen incorporated into the plant. Blue-green algae (cyanobacteria), particularly Gloeotrichia, appeared to bear prime responsibility for nitrogen fixation, but photosynthetic bacteria of the genus Rhodopseudomonas were isolated from M. spicatum and shown to support high rates of acetylene reduction.

  6. Tree species control rates of free-living nitrogen fixation in a tropical rain forest.

    PubMed

    Reed, Sasha C; Cleveland, Cory C; Townsend, Alan R

    2008-10-01

    Tropical rain forests represent some of the most diverse ecosystems on earth, yet mechanistic links between tree species identity and ecosystem function in these forests remains poorly understood. Here, using free-living nitrogen (N) fixation as a model, we explore the idea that interspecies variation in canopy nutrient concentrations may drive significant local-scale variation in biogeochemical processes. Biological N fixation is the largest "natural" source of newly available N to terrestrial ecosystems, and estimates suggest the highest such inputs occur in tropical ecosystems. While patterns of and controls over N fixation in these systems remain poorly known, the data we do have suggest that chemical differences among tree species canopies could affect free-living N fixation rates. In a diverse lowland rain forest in Costa Rica, we established a series of vertical, canopy-to-soil profiles for six common canopy tree species, and we measured free-living N fixation rates and multiple aspects of chemistry of live canopy leaves, senesced canopy leaves, bulk leaf litter, and soil for eight individuals of each tree species. Free-living N fixation rates varied significantly among tree species for all four components, and independent of species identity, rates of N fixation ranged by orders of magnitude along the vertical profile. Our data suggest that variations in phosphorus (P) concentration drove a significant fraction of the observed species-specific variation in free-living N fixation rates within each layer of the vertical profile. Furthermore, our data suggest significant links between canopy and forest floor nutrient concentrations; canopy P was correlated with bulk leaf litter P below individual tree crowns. Thus, canopy chemistry may affect a suite of ecosystem processes not only within the canopy itself, but at and beneath the forest floor as well.

  7. Reference Clinical Database for Fixation Stability Metrics in Normal Subjects Measured with the MAIA Microperimeter

    PubMed Central

    Morales, Marco U.; Saker, Saker; Wilde, Craig; Pellizzari, Carlo; Pallikaris, Aristophanes; Notaroberto, Neil; Rubinstein, Martin; Rui, Chiara; Limoli, Paolo; Smolek, Michael K.; Amoaku, Winfried M.

    2016-01-01

    Purpose The purpose of this study was to establish a normal reference database for fixation stability measured with the bivariate contour ellipse area (BCEA) in the Macular Integrity Assessment (MAIA) microperimeter. Methods Subjects were 358 healthy volunteers who had the MAIA examination. Fixation stability was assessed using two BCEA fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2). Statistical analysis was performed with linear regression and Pearson's product moment correlation coefficient. Results Average areas of 0.80 deg2 (min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg2 (min = 0.20, max = 11.70, SD = 2.04) for the index BCEA@95% were found. The average values of P1 and P2 were 95% (min = 76, max = 100, SD = 5.31) and 99% (min = 91, max = 100, SD = 1.42), respectively. The Pearson's product moment test showed an almost perfect correlation index, r = 0.999, between BCEA@63% and BCEA@95%. Index P1 showed a very strong correlation with BCEA@63%, r = −0.924, as well as with BCEA@95%, r = −0.925. Index P2 demonstrated a slightly lower correlation with both BCEA@63% and BCEA@95%, r = −0.874 and −0.875, respectively. Conclusions The single parameter of the BCEA@95% may be taken as accurately reporting fixation stability and serves as a reference database of normal subjects with a cutoff area of 2.40 ± 2.04 deg2 in MAIA microperimeter. Translational Relevance Fixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index. PMID:27867756

  8. The pattern of embryonic fixation and its relationship to pregnancy loss in thoroughbred mares.

    PubMed

    Sharma, S; Davies Morel, M C G; Dhaliwal, G S; Dadarwal, D

    2010-10-01

    Ultrasonographic pregnancy records of 195 mares from six Thoroughbred stud farms, over a period of 7 years were retrospectively analysed to assess the effect of various factors on embryonic vesicle (EV) fixation pattern and pregnancy outcome. Of the total of 746 pregnancies analysed, significantly (p < 0.01) more EV fixations were evident in the right uterine horn than in the left (53.35% vs 46.65% respectively). There was no significant effect of either, the side of ovulation, or age of the mare, on the side of EV fixation. However, EV fixation, was significantly (p < 0.001) more likely to occur in the right uterine horn in maiden and barren mares (65.75% vs 57.45% respectively). The age and reproductive status of the mare as well as foal heat breeding failed to demonstrate a consistent effect on pregnancy loss relative to the side of EV fixation. In lactating and foal heat bred mares, EVs were significantly (p < 0.0001) more frequently established in the contralateral horn to the one from which the mare delivered her most recent foal. In lactating mares, significantly (p < 0.05) higher embryonic and pregnancy losses were observed in the ipsilateral horn. In conclusion, (a) side of EV fixation was (i) independent of the side of ovulation and mare age (ii) significantly (p < 0.001) affected by reproductive status, (b) neither age of mare nor reproductive status had any effect on pregnancy loss rates relative to the side of EV fixation and (c) in lactating mares the EV had a greater chance of fixation and survival in the horn contralateral to the one from which the mare delivered her most recent foal.

  9. Experimental fracture model versus osteotomy model in metacarpal bone plate fixation.

    PubMed

    Ochman, S; Vordemvenne, T; Paletta, J; Raschke, M J; Meffert, R H; Doht, S

    2011-01-01

    Introduction. Osteotomy or fracture models can be used to evaluate mechanical properties of fixation techniques of the hand skeleton in vitro. Although many studies make use of osteotomy models, fracture models simulate the clinical situation more realistically. This study investigates monocortical and bicortical plate fixation on metacarpal bones considering both aforementioned models to decide which method is best suited to test fixation techniques. Methods. Porcine metacarpal bones (n = 40) were randomized into 4 groups. In groups I and II bones were fractured with a modified 3-point bending test. The intact bones represented a further control group to which the other groups after fixation were compared. In groups III and IV a standard osteotomy was carried out. Bones were fixated with plates monocortically (group I, III) and bicortically (group II, IV) and tested for failure. Results. Bones fractured at a mean maximum load of 482.8 N ± 104.8 N with a relative standard deviation (RSD) of 21.7%, mean stiffness was 122.3 ± 35 N/mm. In the fracture model, there was a significant difference (P = 0.01) for maximum load of monocortically and bicortically fixed bones in contrast to the osteotomy model (P = 0.9). Discussion. In the fracture model, because one can use the same bone for both measurements in the intact state and the bone-plate construct states, the impact of inter-individual differences is reduced. In contrast to the osteotomy model there are differences between monocortical and bicortical fixations in the fracture model. Thus simulation of the in vivo situation is better and seems to be suitable for the evaluation of mechanical properties of fixation techniques on metacarpals.

  10. Local bleaching thresholds established by remote sensing techniques vary among reefs with deviating bleaching patterns during the 2012 event in the Arabian/Persian Gulf.

    PubMed

    Shuail, Dawood; Wiedenmann, Jörg; D'Angelo, Cecilia; Baird, Andrew H; Pratchett, Morgan S; Riegl, Bernhard; Burt, John A; Petrov, Peter; Amos, Carl

    2016-04-30

    A severe bleaching event affected coral communities off the coast of Abu Dhabi, UAE in August/September, 2012. In Saadiyat and Ras Ghanada reefs ~40% of the corals showed signs of bleaching. In contrast, only 15% of the corals were affected on Delma reef. Bleaching threshold temperatures for these sites were established using remotely sensed sea surface temperature (SST) data recorded by MODIS-Aqua. The calculated threshold temperatures varied between locations (34.48 °C, 34.55 °C, 35.05 °C), resulting in site-specific deviations in the numbers of days during which these thresholds were exceeded. Hence, the less severe bleaching of Delma reef might be explained by the lower relative heat stress experienced by this coral community. However, the dominance of Porites spp. that is associated with the long-term exposure of Delma reef to elevated temperatures, as well as the more pristine setting may have additionally contributed to the higher coral bleaching threshold for this site.

  11. 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.

  12. Nitrogen Inputs via Nitrogen Fixation in Northern Plants and Soils

    NASA Astrophysics Data System (ADS)

    Thorp, N. R.; Wieder, R. K.; Vile, M. A.

    2015-12-01

    Dominated by cold and often acidic water logged environments, mineralization of organic matter is slow in the majority of northern ecosystems. Measures of extractable ammonium and nitrate are generally low and can be undetectable in peat pore waters. Despite this apparent nitrogen limitation, many of these environments produce deep deposits of soil organic matter. Biological nitrogen fixation carried out by autotrophic and heterotrophic diazotrophs associated with cryptograms provides the majority of known nitrogen inputs in these northern ecosystems. Nitrogen fixation was assessed in a variety of northern soils within rhizospheres of dominant plant communities. We investigated the availability of this newly fixed nitrogen to the vascular plant community in nitrogen limited northern plant communities. We tracked nitrogen flow from 15N2 gas fixed in Sphagnum mosses into tissues of two native vascular plant species, boreal cranberry (Vaccinium oxycoccus) and black spruce (Picea mariana). 15N-labeled Sphagnum microcosms were grown within variable mesh size exclusion/inclusion fabrics in a nitrogen addition experiment in situ in order to investigate the role of mycorrhizal fungi in the uptake of newly fixed nitrogen. Up to 24% of daily fixed 15N label was transferred to vascular plant tissues during 2 months. Nitrogen addition resulted in decreased N2 fixation rates; however, with higher nitrogen availability there was a higher rate of 15N label uptake into the vascular plants, likely the result of increased production of dissolved organic nitrogen. Reliance on mycorrhizal networks for nitrogen acquisition was indicated by nitrogen isotope fractionation patterns. Moreover, N2 fixation activities in mosses were stimulated when vascular plants were grown in moss microcosms versus "moss only" treatments. Results indicate that bog vascular plants may derive considerable nitrogen from atmospheric N2 biologically fixed within Sphagnum mosses. This work demonstrates that

  13. Critical importance of appropriate fixation conditions for faithful imaging of receptor microclusters

    PubMed Central

    Stanly, Tess A.; Fritzsche, Marco; Banerji, Suneale; García, Esther; Bernardino de la Serna, Jorge; Jackson, David G.

    2016-01-01

    ABSTRACT Receptor clustering is known to trigger signalling events that contribute to critical changes in cellular functions. Faithful imaging of such clusters by means of fluorescence microscopy relies on the application of adequate cell fixation methods prior to immunolabelling in order to avoid artefactual redistribution by the antibodies themselves. Previous work has highlighted the inadequacy of fixation with paraformaldehyde (PFA) alone for efficient immobilisation of membrane-associated molecules, and the advantages of fixation with PFA in combination with glutaraldehyde (GA). Using fluorescence microscopy, we here highlight how inadequate fixation can lead to the formation of artefactual clustering of receptors in lymphatic endothelial cells, focussing on the transmembrane hyaluronan receptors LYVE-1 and CD44, and the homotypic adhesion molecule CD31, each of which displays their native diffuse surface distribution pattern only when visualised with the right fixation techniques, i.e. PFA/GA in combination. Fluorescence recovery after photobleaching (FRAP) confirms that the artefactual receptor clusters are indeed introduced by residual mobility. In contrast, we observed full immobilisation of membrane proteins in cells that were fixed and then subsequently permeabilised, irrespective of whether the fixative was PFA or PFA/GA in combination. Our study underlines the importance of choosing appropriate sample preparation protocols for preserving authentic receptor organisation in advanced fluorescence microscopy. PMID:27464671

  14. Is the Erich arch bar the best intermaxillary fixation method in maxillofacial fractures? A systematic review

    PubMed Central

    Douglas-de-Oliveira, Dhelfeson-Willya; Stella, Paulo-Eduardo-Melo; Rocha-dos Santos, Cássio-Roberto

    2015-01-01

    Background Intermaxillary fixation is used to achieve proper occlusion during and after oral and maxillofacial fracture surgery. The aim of this systematic review was to compare Erich arch bar fixation with other intermaxillary fixation methods in terms of the operating time, safety during installation, oral health maintenance and occlusal stability. Material and Methods An electronic online search was conducted of the Scirus, PubMed, Ovid, Cochrane Library and VHL databases. A clinical trial dating from the inception of the data bases until August 2013 was selected. Studies that compared Erich arch bars with other intermaxillary fixation methods in patients older than 18 years-old were included. The studies were assessed by two independent reviewers. The methodological quality of each article was analyzed. Results Nine hundred and twenty-five manuscripts were found. Seven relevant articles were analyzed in this review. The risk of bias was considered moderate for four studies and high for three clinical trials. Conclusions There is not enough evidence to conclude that the Erich arch bar is the best intermaxillary fixation method in cases of oral and maxillofacial fractures. Key words: Facial injuries, jaw fixation techniques, mandible, maxilla. PMID:26034929

  15. Influences of fixatives on flow cytometric measurements of platelet P-selectin expression and fibrinogen binding.

    PubMed

    Hu, H; Daleskog, M; Li, N

    2000-11-01

    Sample fixation is an important issue in flow cytometric platelet assays. However, previous reports were less than consistent regarding the influence of sample fixation on the assays. We evaluated the effects of formaldehyde and paraformaldehyde fixation on platelet P-selectin expression and fibrinogen binding using whole-blood flow cytometry and a Coulter EPICS XL-MCL cytometer. Fluorescent-labeled whole-blood samples were diluted with HEPES-buffered saline or fixed with formaldehyde (0.2, 0.5, and 1. 0%) or paraformaldehyde (0.5, 1.0, and 2.0%). Platelet P-selectin expression was 1.1+/-0.3% and 39.6+/-13.7% in unfixed resting and 10(-5) M ADP stimulated samples, respectively. Resting P-selectin expression was not significantly altered by 0.2 or 0.5% formaldehyde fixation, but was slightly decreased by 1.0% formaldehyde fixation or PFA fixation. Formaldehyde fixation caused small increases of P-selectin expression in ADP-stimulated samples. Compared to platelet fibrinogen binding of unfixed resting (4.5+/-2.1%) and ADP-stimulated (56.7+/-22.6%) samples, formaldehyde or paraformaldehyde fixation had no significant influence on resting samples, but mildly increased fibrinogen binding in stimulated samples. Unfixed samples were stable for 2 h. Fixed samples were generally stable for at least 6 h, but not thereafter. Thus, formaldehyde and paraformaldehyde have mild but complex influences on platelet P-selectin expression and fibrinogen binding measurements. To evaluate the stabilities of unfixed and fixed samples, samples were analyzed after different durations (0, 1, 2, 4, 6, 12, and 24 h) of storage at 4 degrees C in the dark. The results suggest that sample manipulation without fixation may be used when the samples are analyzed within 2 h, and that fixation with 0.5-1.0% formaldehyde or paraformaldehyde seems to be preferable when sample analysis is delayed. Effects of fixation should be carefully evaluated when establishing flow cytometric platelet assays in

  16. Ocular Fixation Abnormality in Patients with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Shirama, Aya; Kanai, Chieko; Kato, Nobumasa; Kashino, Makio

    2016-01-01

    We examined the factors that influence ocular fixation control in adults with autism spectrum disorder (ASD) including sensory information, individuals' motor characteristics, and inhibitory control. The ASD group showed difficulty in maintaining fixation especially when there was no fixation target. The fixational eye movement characteristics of…

  17. Applications of In Ovo Technique for the Optimal Development of the Gastrointestinal Tract and the Potential Influence on the Establishment of Its Microbiome in Poultry

    PubMed Central

    Roto, Stephanie M.; Kwon, Young Min; Ricke, Steven C.

    2016-01-01

    As the current poultry production system stands, there is a period of time when newly hatched chicks are prevented from access to feed for approximately 48–72 h. Research has indicated that this delay in feeding may result in decreased growth performance when compared to chicks that are fed immediately post-hatch. To remedy this issue, in ovo methodology may be applied in order to supply the embryo with additional nutrients prior to hatching and those nutrients will continue to be utilized by the chick post-hatch during the fasting period. Furthermore, in ovo injection of various biologics have been researched based on the ability of not only supplying the chick embryo with additional nutrients that would promote improved growth but also compounds that may benefit the future health of the chicken host. Such compounds include various immunostimulants, live beneficial bacteria, prebiotics, and synbiotics. However, it is important to determine the site and age of the in ovo injection for the most productive effects. The primary focus of the current review is to address these two issues [the most effective site(s) and age(s) of in ovo injection] as well as provide the framework for the development of the gastrointestinal tract (GIT) of the chick embryo. Additionally, recent research suggests the colonization of the microbiota in the developing chick may occur during the late stages of embryogenesis. Therefore, we will also discuss the potentials of the in ovo injection method in establishing a healthy and diverse community of microorganisms to colonize the developing GIT that will provide both protection from pathogen invasion and improvement in growth performance to developing chicks. PMID:27583251

  18. 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

  19. New analytical technique for establishing the quality of Soil Organic Matter affected by a wildfire. A first approach using Fourier transform ion cyclotron resonance mass spectrometry

    NASA Astrophysics Data System (ADS)

    Jiménez-Morillo, Nicasio T.; González-Pérez, José A.; Waggoner, Derek C.; Almendros, Gonzalo; González-Vila, Francisco J.; Hatcher, Patrick G.

    2016-04-01

    Introduction: Fire is one of the most important modulator factors of the environment and the forest. It is able to induce chemical and biological shifts and these, in turn, can alter the physical properties of soil. Generally, fire affects the most reactive fraction, soil organic matter (SOM) (González-Pérez et al., 2004) resulting in changes to several soil properties and functions. To study changes in SOM following a wildfire, researchers can count on several traditional as well as new analytical techniques. One of the most recently employed techniques is Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). This new powerful ultra-high resolution mass spectral technique, together with graphic interpretation tools such as van Krevelen diagrams (Kim et al, 2003), may be used to shed light on alterations caused by the burning of SOM. The objective of this research is to study fire impacts on SOM, using a sandy soil collected under a Cork oak (Quercus suber) in Doñana National Park, Southwest Spain. that was affected by a wildfire in August 2012. Methods: The impact of fire on SOM was studied in various different sieve fractions (coarse, 1-2 mm, and fine, <0.05 mm) collected in a burned area and an adjacent unburned control site with the same physiographic conditions. Alkaline extracts of SOM from each soil sample were examined using a Bruker Daltonics 12 Tesla Apex Qe FT-ICR-MS equipped with an Apollo II ESI ion source (operating in negative ion mode). The ESI voltages were optimized for each sample, and all spectra were internally calibrated following the procedure of (Sleighter and Hatcher, 2007), after which, peaks were assigned unique molecular formulas using a MatLab script written in house by Dr. Wassim Obeid of Old Dominion University. Results: The van Krevelen diagrams together with the relative intensity of each chemical compound, both obtained by FT-ICR-MS, allowed us to assess SOM quality for each sample and size fractions. The

  20. Multifaceted Investigation of Metabolites During Nitrogen Fixation in Medicago via High Resolution MALDI-MS Imaging and ESI-MS

    NASA Astrophysics Data System (ADS)

    Gemperline, Erin; Jayaraman, Dhileepkumar; Maeda, Junko; Ané, Jean-Michel; Li, Lingjun

    2015-01-01

    Legumes have developed the unique ability to establish a symbiotic relationship with soil bacteria known as rhizobia. This interaction results in the formation of root nodules in which rhizobia thrive and reduce atmospheric dinitrogen into plant-usable ammonium through biological nitrogen fixation (BNF). Owing to the availability of genetic information for both of the symbiotic partners, the Medicago truncatula- Sinorhizobium meliloti association is an excellent model for examining the BNF process. Although metabolites are important in this symbiotic association, few studies have investigated the array of metabolites that influence this process. Of these studies, most target only a few specific metabolites, the roles of which are either well known or are part of a well-characterized metabolic pathway. Here, we used a multifaceted mass spectrometric (MS) approach to detect and identify the key metabolites that are present during BNF using the Medicago truncatula- Sinorhizobium meliloti association as the model system. High mass accuracy and high resolution matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) Orbitrap instruments were used in this study and provide complementary results for more in-depth characterization of the nitrogen-fixation process. We used well-characterized plant and bacterial mutants to highlight differences between the metabolites that are present in functional versus nonfunctional nodules. Our study highlights the benefits of using a combination of mass spectrometric techniques to detect differences in metabolite composition and the distributions of these metabolites in plant biology.

  1. Multifaceted Investigation of Metabolites During Nitrogen Fixation in Medicago via High Resolution MALDI-MS Imaging and ESI-MS

    PubMed Central

    Gemperline, Erin; Jayaraman, Dhileepkumar; Maeda, Junko; Ané, Jean-Michel; Li, Lingjun

    2014-01-01

    Legumes have developed the unique ability to establish a symbiotic relationship with soil bacteria known as rhizobia. This interaction results in the formation of root nodules in which rhizobia thrive and reduce atmospheric dinitrogen into plant-usable ammonium through biological nitrogen fixation (BNF). Due to the availability of genetic information for both of the symbiotic partners, the Medicago truncatula–Sinorhizobium meliloti association is an excellent model for examining the BNF process. Although metabolites are important in this symbiotic association, few studies have investigated the array of metabolites that influence this process. Of these studies, most target only a few specific metabolites, the roles of which are either well known or are part of a well-characterized metabolic pathway. Here, we used a multifaceted mass spectrometric (MS) approach to detect and identify the key metabolites that are present during BNF using the Medicago truncatula–Sinorhizobium meliloti association as the model system. High mass accuracy and high resolution matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) Orbitrap instruments were used in this study and provide complementary results for more in-depth characterization of the nitrogen-fixation process. We used well-characterized plant and bacterial mutants to highlight differences between the metabolites that are present in functional vs. non-functional nodules. Our study highlights the benefits of using a combination of mass spectrometric techniques to detect differences in metabolite composition and the distributions of these metabolites in plant biology. PMID:25323862

  2. Dorsal fracture-dislocation of the proximal interphalangeal joint: a comparative study of percutaneous Kirschner wire fixation versus open reduction and internal fixation.

    PubMed

    Aladin, A; Davis, T R C

    2005-05-01

    Nineteen patients with a dorsal fracture-dislocation of the proximal interphalangeal joint of a finger were treated with either closed reduction and transarticular Kirschner wire fixation (eight cases) or open reduction and internal fixation, using either one or two lag screws (six cases) or a cerclage wire (five cases). At a mean follow-up of 7 (range 6-9) years, most patients reported satisfactory finger function, even though some of the injuries healed with proximal interphalangeal joint incongruency (seven cases) or subluxation (four cases). Those treated by open reduction complained of more "loss of feeling" in the affected finger and those specifically treated by cerclage wire fixation reported more cold intolerance and had a significantly larger fixed flexion deformity (median, 30 degrees : range 18-38 degrees ) and a smaller arc of motion (median, 48 degrees : range 45-60 degrees ) at the proximal interphalangeal joint, despite having the best radiological outcomes. Closed reduction and transarticular Kirschner wire fixation produced satisfactory results, with none of the eight patients experiencing significant persistent symptoms despite a reduced arc of proximal interphalangeal joint flexion (median=75 degrees ; range 60-108 degrees ). The results of this relatively simple treatment appear at least as satisfactory as those obtained by the two techniques of open reduction and internal fixation, both of which were technically demanding.

  3. Variable Nitrogen Fixation in Wild Populus

    PubMed Central

    Doty, Sharon L.; Sher, Andrew W.; Fleck, Neil D.; Khorasani, Mahsa; Bumgarner, Roger E.; Khan, Zareen; Ko, Andrew W. K.; Kim, Soo-Hyung; DeLuca, Thomas H.

    2016-01-01

    The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees. PMID:27196608

  4. 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.

  5. THE ROLE OF FIBRIN GLUE AND SUTURE ON THE FIXATION OF ULTRA FROZEN PRESERVED MENISCUS TRANSPLANTATION IN RABBITS

    PubMed Central

    Reckers, Leandro José; Fagundes, Djalma José; Pozo Raymundo, José Luiz; Granata Júnior, Geraldo Sérgio de Mello; Moreira, Márcia Bento; Paiva, Vanessa Carla; Negrini Fagundes, Anna Luiza; Cohen, Moises

    2015-01-01

    Objective: To evaluate the ability of fibrin adhesive in promoting the meniscus fixation within two, four and eight weeks compared to the conventional soft-tissue suture technique. Materials and Methods: 36 right medial menisci of rabbits preserved at negative 73° Celsius for 30 days were transplanted to animals of the same sample and fixed with soft-tissue suture or fibrin glue. After 2, 4 or 8 weeks, the appearance of the menisci and the quality of fixation were macroscopically checked and evaluated by a scoring system. The findings were subjected to the statistical study of variance analysis (p ≤ 0.05%). Results: The deep-frozen meniscus preservation maintained the integrity of the meniscus transplant, and, macroscopically, there was no significant reduction of the length of the meniscus in all post-transplant periods (p = 0.015). The menisci fixed with fibrin showed slight changes in color and surface roughness. There were no signs of rejection or infection in both groups. Suture fixation scoring was superior (p = 0.015) in all periods (80% of total fixation) as compared to the setting promoted by fibrin (20% of total fixation). Conclusion: The homologous transplantation of the meniscus of rabbits experienced various degrees of integration to the knee according to the fixation method; the surgical soft tissues suturing technique was shown to be superior in the evaluation of scores compared to the fixation with fibrin adhesive. PMID:27004186

  6. Retro iris suture fixation of a rigid intraocular lens.

    PubMed

    Haripriya, Aravind; Sharma, Sankalp S

    2016-11-01

    We present an iris suture fixation technique for a rigid poly(methyl methacrylate) (PMMA) intraocular lens (IOL). A 10-0 polypropylene suture on a long curved needle is used to preplace 2 iris suture bites 180 degrees apart. The suture loops below the iris are retracted through the main scleral tunnel using a Kuglen hook and a McPherson forceps. The 2 suture loops are twirled twice around the corresponding haptics of a standard 3-piece PMMA IOL, and the IOL is placed in the sulcus. After it is confirmed that the loop surrounds the haptic, the suture knot is tied to secure the IOL to the iris.

  7. 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

  8. Characteristics of Fixational Eye Movements in Amblyopia: Limitations on Fixation Stability and Acuity?

    PubMed Central

    Kumar, Girish; Li, Roger W.; Levi, Dennis M.

    2015-01-01

    Persons with amblyopia, especially those with strabismus, are known to exhibit abnormal fixational eye movements. In this paper, we compared six characteristics of fixational eye movements among normal control eyes (n=16), the non-amblyopic fellow eyes and the amblyopic eyes of anisometropic (n=14) and strabismic amblyopes (n=14). These characteristics include the frequency, magnitude of landing errors, amplitude and speed of microsaccades, and the amplitude and speed of slow drifts. Fixational eye movements were recorded using retinal imaging while observers monocularly fixated a 1° cross. Eye position data were recovered using a cross-correlation procedure. We found that in general, the characteristics of fixational eye movements are not significantly different between the fellow eyes of amblyopes and controls, and that the strabismic amblyopic eyes are always different from the other groups. Next, we determined the primary factors that limit fixation stability and visual acuity in amblyopic eyes by examining the relative importance of the different oculomotor characteristics, adding acuity (for fixation stability) or fixation stability (for acuity), and the type of amblyopia, as predictive factors in a multiple linear regression model. We show for the first time that the error magnitude of microsaccades, acuity, amplitude and frequency of microsaccades are primary factors limiting fixation stability; while the error magnitude, fixation stability, amplitude of drifts and amplitude of microsaccades are the primary factors limiting acuity. A mediation analysis showed that the effects of error magnitude and amplitude of microsaccades on acuity could be explained, at least in part, by their effects on fixation stability. PMID:25668775

  9. The Combination of Chemical Fixation Procedures with High Pressure Freezing and Freeze Substitution Preserves Highly Labile Tissue Ultrastructure for Electron Tomography Applications

    PubMed Central

    Sosinsky, Gina E.; Crum, John; Jones, Ying Z.; Lanman, Jason; Smarr, Benjamin; Terada, Masako; Martone, Maryann E.; Deerinck, Thomas J.; Johnson, John E.; Ellisman, Mark H.

    2008-01-01

    The emergence of electron tomography as a tool for three dimensional structure determination of cells and tissues has brought its own challenges for the preparation of thick sections. High pressure freezing in combination with freeze substitution provides the best method for obtaining the largest volume of well-preserved tissue. However, for deeply embedded, heterogeneous, labile tissues needing careful dissection, such as brain, the damage due to anoxia and excision before cryofixation is significant. We previously demonstrated that chemical fixation prior to high pressure freezing preserves fragile tissues and produces superior tomographic reconstructions compared to equivalent tissue preserved by chemical fixation alone. Here, we provide further characterization of the technique, comparing the ultrastructure of Flock House Virus infected DL1 insect cells that were 1) high pressure frozen without fixation, 2) high pressure frozen following fixation, and 3) conventionally prepared with aldehyde fixatives. Aldehyde fixation prior to freezing produces ultrastructural preservation superior to that obtained through chemical fixation alone that is close to that obtained when cells are fast frozen without fixation. We demonstrate using a variety of nervous system tissues, including neurons that were injected with a fluorescent dye and then photooxidized, that this technique provides excellent preservation compared to chemical fixation alone and can be extended to selectively stained material where cryofixation is impractical. PMID:17962040

  10. Fixation of Winged Scapula in Facioscapulohumeral Muscular Dystrophy

    PubMed Central

    Giannini, Sandro; Faldini, Cesare; Pagkrati, Stavroula; Grandi, Gianluca; Digennaro, Vitantonio; Luciani, Deianira; Merlini, Luciano

    2007-01-01

    Objective: To verify if stabilizing the scapulothoracic joint without arthrodesis could lead to functional improvement of shoulder range of motion and clinical improvement of winged scapula, we incorporated four additional patients into our previous analysis to determine if the results obtained were long lasting, and to compare this fixation with the other techniques described in the literature, balancing the benefits with the complications. Design: A retrospective study. Participants: Thirteen patients with bilateral winged scapula affected by facioscapulohumeral muscular dystrophy. Nine of these patients had been analyzed in our previous study. Methods: Patients were operated on by bilateral fixing of the scapula to the rib cage using metal wires without arthrodesis (scapulopexy). Results: All patients experienced improvement in active range of motion of the shoulder and all of them had clinical improvement with complete resolution of the winged scapula. In all twenty-six surgical interventions of scapulopexy, a stable and long-lasting fixation of the scapula to the rib cage was achieved.The complications strictly associated to the surgical technique encountered were one pneumothorax, which was resolved spontaneously, and one wire breakage without trauma. Average follow-up was 10 years (range, 3 to 18 years). Conclusion: The scapulopexy used in this extended series of patients consisted of repositioning the scapula and fixing it to four ribs by using metal wires without performing arthrodesis.This technique has a low rate of complications, is reproducible, safe and effective, resulting in clinical and functional improvement. PMID:18056023

  11. Hip Labral Reconstruction: The "Kite Technique" for Improved Efficiency and Graft Control.

    PubMed

    Bhatia, Sanjeev; Chahla, Jorge; Dean, Chase S; Ellman, Michael B

    2016-04-01

    Although the merits of labral reconstruction have been well established, the technical difficulty of presently used reconstruction techniques-particularly with graft passage and fixation-limit its efficacy and potentiates the risk of iatrogenic damage within the hip joint. The unwieldy nature of a floating labral graft anchored on one end may impede accurate fixation of the other end, which is critical for restoration of the fluid hip seal and preservation of graft integrity. In this technique narrative, we present a "kite technique" for introduction, control, and efficient fixation of a labral reconstruction graft. The principles of this method are founded on the belief that a soft-tissue graft in an arthroscopic environment is much easier to guide into position with 2 control sutures using a pulley system similar to flying a kite with 2 fly lines. Although we herein detail the technique as it applies to labral reconstruction in the hip, the concept of the kite technique may also be employed in arthroscopic-assisted soft-tissue reconstructions of other joints.

  12. Combined external fixation and intramedullary alignment in correction of limb length discrepancies.

    PubMed

    Bukva, Bojan; Brdar, Radivoj; Nikolic, Dejan; Petronic, Ivana; Ducic, Sinisa; Abramovic, Dusan

    2013-08-01

    The aim of this study was to evaluate the influence of intramedullary (IM) alignment used in combination with external fixation on the healing index (HI) and lengthening index (LI) in the treatment of congenital and acquired leg length discrepancies (LLD). We compared duration of the external fixator application, LLD, HI and LI between two groups of children: children in Group I underwent limb lengthening by the conventional llizarov technique, and children in Group II underwent a combination of Ilizarov technique and intramedullary alignment with Kirschner wires. Two types of LLDs were treated: congenital and acquired. We found significant differences between the two groups for duration of external fixator application and HI. Significant differences were also noted in the duration of the external fixator application, HI and LI, between patients with congenital and acquired LLDs. We also noted significant differences between Group I and Group II regarding duration of external fixator application for patients with congenital LLD and also regarding HI for both congenital and acquired types of LLD.

  13. Treatment of congenital leg length discrepancies in children using an Ilizarov external fixator: a comparative study.

    PubMed

    Bukva, Bojan; Vrgoc, Goran; Brdar, Radivoj; Ducić, Sinisa; Gulan, Gordan; Jurdana, Hari

    2014-12-01

    The purpose of this study was to evaluate the influence of intramedullary (IM) alignment used in combination with an Ilizarov external fixation on the healing index (HI) and lengthening index (LI) in the treatment of congenital leg length discrepancies (LLD). This study included 35patients aged from 3.5 to 19 (average age 10.73) who underwent thl egalisation procedure using an Ilizarov external fixator. We compared the duration of the external fixator application, LLD, HI and LI between two groups of children: children in Group I underwent limb lengthening by the conventional llizarov technique using an Ilizarov external fixator alone, and children in Group II underwent a combination of Ilizarov technique and intramedullary alignment with two Kirschner wires, introduced through two mini-incisions. We found significant differences between the two groups of patients for duration of external fixator application and HI. Patients with congeni- tal LLD treated with combined method of treatment had benefit from intramedullary alignment due to its better outcome.

  14. Biomechanical evaluation of the Pinless external fixator.

    PubMed

    Stene, G M; Frigg, R; Schlegel, U; Swiontkowski, M

    1992-01-01

    In open fractures especially in those with severe soft tissue damage, fracture stabilisation is best achieved by using external fixators. There are some intrinsic complications which occur during classical external pin fixation. To overcome the problem of pin track infection and vascular damage from drilling, the Pinless external fixator was developed. It is based on the idea of a forceps with trocar points, which only penetrate the bone cortex superficially. The function of the device was tested in two mechanical trials and two in vitro tests in which one pinless clamp was put under a controlled load of 50 N, 150 cycles/day and studied over a 5 week period in sheep. The loads and time range of the experiment were chosen to simulate a temporary fracture stabilisation in a patient not bearing weight. The main question to be answered was whether the Pinless external fixator would be able to maintain stable fixation. Furthermore, it was to determine the changes at the trocar-to-bone interface. The clamp was found to maintain 72% of the initially applied clamping force after 5 weeks of in vivo application and it was found to be tight at removal. Some decrease of clamping force was found during the first 20 days and then the force tended to level off. There was no slippage nor did the clamp penetrate the cortex. There were no obvious signs of infection around the trocar-holes and in the bacterial tests no pathological cultures were grown. Histology revealed very localised bone reactions, the indentation caused by the trocar tips being only 1.2 mm deep. The study concludes, as far as could be ascertained from these tests, that it is safe to use pinless external fixation for temporary fracture fixation.

  15. 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

    2012-05-04

    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.

  16. The fixation and saccade P3.

    PubMed

    Dandekar, Sangita; Ding, Jian; Privitera, Claudio; Carney, Thom; Klein, Stanley A

    2012-01-01

    Although most instances of object recognition during natural viewing occur in the presence of saccades, the neural correlates of objection recognition have almost exclusively been examined during fixation. Recent studies have indicated that there are post-saccadic modulations of neural activity immediately following eye movement landing; however, whether post-saccadic modulations affect relatively late occurring cognitive components such as the P3 has not been explored. The P3 as conventionally measured at fixation is commonly used in brain computer interfaces, hence characterizing the post-saccadic P3 could aid in the development of improved brain computer interfaces that allow for eye movements. In this study, the P3 observed after saccadic landing was compared to the P3 measured at fixation. No significant differences in P3 start time, temporal persistence, or amplitude were found between fixation and saccade trials. Importantly, sensory neural responses canceled in the target minus distracter comparisons used to identify the P3. Our results indicate that relatively late occurring cognitive neural components such as the P3 are likely less sensitive to post saccadic modulations than sensory neural components and other neural activity occurring shortly after eye movement landing. Furthermore, due to the similarity of the fixation and saccade P3, we conclude that the P3 following saccadic landing could possibly be used as a viable signal in brain computer interfaces allowing for eye movements.

  17. The Role of Symbiotic Nitrogen Fixation in Sustainable Production of Biofuels

    PubMed Central

    Biswas, Bandana; Gresshoff, Peter M.

    2014-01-01

    With the ever-increasing population of the world (expected to reach 9.6 billion by 2050), and altered life style, comes an increased demand for food, fuel and fiber. However, scarcity of land, water and energy accompanied by climate change means that to produce enough to meet the demands is getting increasingly challenging. Today we must use every avenue from science and technology available to address these challenges. The natural process of symbiotic nitrogen fixation, whereby plants such as legumes fix atmospheric nitrogen gas to ammonia, usable by plants can have a substantial impact as it is found in nature, has low environmental and economic costs and is broadly established. Here we look at the importance of symbiotic nitrogen fixation in the production of biofuel feedstocks; how this process can address major challenges, how improving nitrogen fixation is essential, and what we can do about it. PMID:24786096

  18. The effect of altered macroclimate on N-fixation by boreal feather mosses.

    PubMed

    Gundale, Michael J; Wardle, David A; Nilsson, Marie-Charlotte

    2012-10-23

    Plant productivity is predicted to increase in boreal forests owing to climate change, but this may depend on whether N inputs from biological N-fixation also increases. We evaluated how alteration of climatic factors affects N input from a widespread boreal N-fixer, i.e. cyanobacteria associated with the feather moss Pleurozium schreberi. In each of 10 forest stands in northern Sweden, we established climate-change plots, including a control (ambient climate) plot and three plots experiencing a +2°C temperature increase, an approximately threefold reduction in precipitation frequency, and either 0.07, 0.29 or 1.16 times normal summer precipitation. We monitored N-fixation in these plots five times between 2007 and 2009, and three times in 2010 after climate treatments ended to assess their recovery. Warmer temperatures combined with less frequent precipitation reduced feather moss moisture content and N-fixation rates regardless of total precipitation. After climate treatments ended, recovery of N-fixation rates occurred on the scale of weeks to months, suggesting resilience of N-fixation to changes in climatic conditions. These results suggest that modelling of biological N-inputs in boreal forests should emphasize precipitation frequency and evaporative water loss in conjunction with elevated temperature rather than absolute changes in mean precipitation.

  19. Simultaneous measurement of denitrification and nitrogen fixation using isotope pairing with membrane inlet mass spectrometry analysis.

    PubMed

    An, S; Gardner, W S; Kana, T

    2001-03-01

    A method for estimating denitrification and nitrogen fixation simultaneously in coastal sediments was developed. An isotope-pairing technique was applied to dissolved gas measurements with a membrane inlet mass spectrometer (MIMS). The relative fluxes of three N(2) gas species ((28)N(2), (29)N(2), and (30)N(2)) were monitored during incubation experiments after the addition of (15)NO(3)(-). Formulas were developed to estimate the production (denitrification) and consumption (N(2) fixation) of N(2) gas from the fluxes of the different isotopic forms of N(2). Proportions of the three isotopic forms produced from (15)NO(3)(-) and (14)NO(3)(-) agreed with expectations in a sediment slurry incubation experiment designed to optimize conditions for denitrification. Nitrogen fixation rates from an algal mat measured with intact sediment cores ranged from 32 to 390 microg-atoms of N m(-2) h(-1). They were enhanced by light and organic matter enrichment. In this environment of high nitrogen fixation, low N(2) production rates due to denitrification could be separated from high N(2) consumption rates due to nitrogen fixation. Denitrification and nitrogen fixation rates were estimated in April 2000 on sediments from a Texas sea grass bed (Laguna Madre). Denitrification rates (average, 20 microg-atoms of N m(-2) h(-1)) were lower than nitrogen fixation rates (average, 60 microg-atoms of N m(-2) h(-1)). The developed method benefits from simple and accurate dissolved-gas measurement by the MIMS system. By adding the N(2) isotope capability, it was possible to do isotope-pairing experiments with the MIMS system.

  20. Control and Functions of Fixational Eye Movements

    PubMed Central

    Rucci, Michele; Poletti, Martina

    2016-01-01

    Humans and other species explore a visual scene by rapidly shifting their gaze 2-3 times every second. Although the eyes may appear immobile in the brief intervals in between saccades, microscopic (fixational) eye movements are always present, even when attending to a single point. These movements occur during the very periods in which visual information is acquired and processed and their functions have long been debated. Recent technical advances in controlling retinal stimulation during normal oculomotor activity have shed new light on the visual contributions of fixational eye movements and their degree of control. The emerging body of evidence, reviewed in this article, indicates that fixational eye movements are important components of the strategy by which the visual system processes fine spatial details, enabling both precise positioning of the stimulus on the retina and encoding of spatial information into the joint space-time domain. PMID:27795997

  1. Biometric recognition via fixation density maps

    NASA Astrophysics Data System (ADS)

    Rigas, Ioannis; Komogortsev, Oleg V.

    2014-05-01

    This work introduces and evaluates a novel eye movement-driven biometric approach that employs eye fixation density maps for person identification. The proposed feature offers a dynamic representation of the biometric identity, storing rich information regarding the behavioral and physical eye movement characteristics of the individuals. The innate ability of fixation density maps to capture the spatial layout of the eye movements in conjunction with their probabilistic nature makes them a particularly suitable option as an eye movement biometrical trait in cases when free-viewing stimuli is presented. In order to demonstrate the effectiveness of the proposed approach, the method is evaluated on three different datasets containing a wide gamut of stimuli types, such as static images, video and text segments. The obtained results indicate a minimum EER (Equal Error Rate) of 18.3 %, revealing the perspectives on the utilization of fixation density maps as an enhancing biometrical cue during identification scenarios in dynamic visual environments.

  2. The role of ring external fixation in Charcot foot arthropathy.

    PubMed

    Pinzur, Michael S

    2006-12-01

    These two morbidly obese patients with severe Charcot foot arthropathy were treated successfully with percutaneous correction of their deformity followed by a stepwise application of a pre-assembled neutrally aligned multiplane ring external fixator. This technique transfers well to the trauma environment in which alignment can be maintained without further violation within the zone of injury. The application of the fine wire ring external fixation has been used for many years to accomplished leg lengthening and correction of deformity. Historically it has required a great deal of experience to apply to complex frames and implement the required daily adjustments. The patient experience often has been an unpleasant ordeal with a high potential for associated morbidity. This negative exposure has prompted practicing orthopedic surgeons to avoid this technique, feeling that it best be left to those in tertiary care setting who are equipped to handle the morbidity and complications. Taking this technology from the domain of the deformity surgeon to the general orthopedic community will require the suppression of bad memories from residency. Using the device solely as a method of maintaining alignment eliminates many of the dynamic attributes that contributes to pain and morbidity. The bone and soft tissues are not stretched, eliminating much of the pain and decreasing the rate of traction-associated pin tract morbidity. Because there is no dynamic of the treatment, the simplified frame can be pre-assembled and have no adjustable components. The experience derived from this application has the potential of expanding the role of ring external fixation. Where the ring has been used previously as method of both obtaining and maintaining alignment, this application uses a simplified neutral version of a complex device to simply maintain alignment in a high risk patient population. Correction of deformity and achieving alignment/reduction of fractures is well within the

  3. Validation of an ultrasound-guided technique to establish a liver-to-coelom ratio and a comparative analysis of the ratios among acclimated and recently wild-caught southern stingrays, Dasyatis americana.

    PubMed

    Grant, Krystan R; Campbell, Terry W; Silver, Tawni I; Olea-Popelka, Francisco J

    2013-01-01

    Southern stingrays, Dasyatis americana, are a well-represented elasmobranch species in public aquaria and other facilities throughout the world. This study was conducted at a facility that experienced some mortality and replenished the collection with wild-caught stingrays. A common necropsy finding among the stingrays was a small, dark liver. The objectives of this study were to assess the reliability of an ultrasound-guided technique for establishing a liver-to-coelom ratio by calculating the approximate length of the liver with respect to the coelomic cavity length and then to compare ratios between acclimated captive and wild-caught stingrays. The ultrasound validation phase of the study measured the distance from the caudal margin of the liver to the pelvic cartilaginous girdle and compared it to the actual distance measured during the necropsy or surgery. There was no significant difference found between the ultrasound and actual distance measurements (P = 0.945). This technique was then used to establish liver-to-coelom ratios and compare two groups of stingrays, presumably under different metabolic states at different periods. Liver-to-coelom ratios were established during initial examinations as well as 8 months after cohabitation in a touch pool exhibit. There were significant differences in liver-to-coelom ratios between the two stingray groups at introduction (median difference = 30.9%, P = 0.007) and after 8 months (median difference = 20.5%, P = 0.008). There were also significant differences in the liver-to-coelom ratios within each group at introduction and at 8 months (acclimated group median difference = 20.4%, P = 0.018; wild-caught group median difference 31%, P = 0.008).

  4. Three-dimensional finite element analysis and comparison of a new intramedullary fixation with interlocking intramedullary nail.

    PubMed

    Liu, Chang-cheng; Xing, Wen-zhao; Zhang, Ya-xing; Pan, Zheng-hua; Feng, Wen-ling

    2015-03-01

    This study was set to introduce a new intramedullary fixation, explore its biomechanical properties, and provide guidance for further biomechanical experiments. With the help of CT scans and finite element modeling software, finite element model was established for a new intramedullary fixation and intramedullary nailing of femoral shaft fractures in a volunteer adult. By finite element analysis software ANSYS 10.0, we conducted 235-2,100 N axial load, 200-1,000 N bending loads and 2-15 Nm torsional loading, respectively, and analyzed maximum stress distribution, size, and displacement of the fracture fragments of the femur and intramedullary nail. During the loading process, the maximum stress of our new intramedullary fixation were within the normal range, and the displacement of the fracture fragments was less than 1 mm. Our new intramedullary fixation exhibited mechanical reliability and unique advantages of anti-rotation, which provides effective supports during fracture recovery.

  5. From prevention of pin-tract infection to treatment of osteomyelitis during paediatric external fixation.

    PubMed

    Ceroni, Dimitri; Grumetz, Catherine; Desvachez, Odile; Pusateri, Sophie; Dunand, Pierre; Samara, Eleftheria

    2016-12-01

    Pin-tract infection (PTI) is the most commonly expected problem, or even an almost inevitable complication, when using external fixation. Left unteated, PTI will progress unavoidably, lead to mechanical pin loosening, and ultimately cause instability of the external fixator pin-bone construct. Thus, PTI remains a clinical challenge, specifically in cases of limb lengthening or deformity correction. Standardised pin site protocols which encompass an understanding of external fixator biomechanics and meticulous surgical technique during pin and wire insertion, postoperative pin site care and pin removal could limit the incidence of major infections and treatment failures. Here we discuss concepts regarding the epidemiology, physiopathology and microbiology of PTI in paediatric populations, as well as the clinical presentations, diagnosis, classification and treatment of these infections.

  6. Engineering the Cyanobacterial Carbon Concentrating Mechanism for Enhanced CO2 Capture and Fixation

    SciTech Connect

    Sandh, Gustaf; Cai, Fei; Shih, Patrick; Kinney, James; Axen, Seth; Salmeen, Annette; Zarzycki, Jan; Sutter, Markus; Kerfeld, Cheryl

    2011-06-02

    In cyanobacteria CO2 fixation is localized in a special proteinaceous organelle, the carboxysome. The CO2 fixation enzymes are encapsulated by a selectively permeable protein shell. By structurally and functionally characterizing subunits of the carboxysome shell and the encapsulated proteins, we hope to understand what regulates the shape, assembly and permeability of the shell, as well as the targeting mechanism and organization of the encapsulated proteins. This knowledge will be used to enhance CO2 fixation in both cyanobacteria and plants through synthetic biology. The same strategy can also serve as a template for the production of modular synthetic bacterial organelles. Our research is conducted using a variety of techniques such as genomic sequencing and analysis, transcriptional regulation, DNA synthesis, synthetic biology, protein crystallization, Small Angle X-ray Scattering (SAXS), protein-protein interaction assays and phenotypic characterization using various types of cellular imaging, e.g. fluorescence microscopy, Transmission Electron Microscopy (TEM), and Soft X-ray Tomography (SXT).

  7. External Fixation Versus Open Reduction With Locked Volar Plating for Geriatric Distal Radius Fractures

    PubMed Central

    Lee, Daniel J.

    2014-01-01

    The optimal management of displaced dorsal radius fractures (DRFs) in older patients remains an issue of debate. Bridging external fixation is a well-accepted treatment modality for severely comminuted DRFs, while open reduction and internal fixation with locked volar plating has emerged as a promising alternative in recent years. The current body of randomized trials supports the trend toward locked volar plating, as it allows for quicker improvement in subjective and functional outcomes. There is no clear evidence to suggest that one technique carries significantly less complications than the other. Locked volar plating should be considered in patients for whom an accelerated functional recovery would be advantageous. Otherwise, both external fixation and locked volar plating provide good long-term clinical outcomes. PMID:25360346

  8. Correction of shortening and/or angular deformities by distraction osteogenesis using AO-tubular fixator.

    PubMed

    Sangkaew, Chanchit

    2003-01-01

    Eighteen patients (20 bony segments) who had shortening and/or angular deformities were treated by distraction osteogenesis using AO-tubular external fixator. The mean angular correction was 18.9 degrees (range, 8-40 degrees). Of the group in whom shortening and angulation was corrected, the mean length gained was 4.2 cm (3-6 cm). The mean treatment time was 4.9 months (range, 2-13 months) and the mean follow-up was 12 months after removal of the fixator (range, 3-30 months). Delayed union with loosening of the fixator occurred in one patient which resulted in residual shortening of 1.5 cm. The author's technique of distraction osteogenesis using AO-tubular fixator with the new distraction rate of 1 mm/48 h (1 mm/step) could adequately correct shortening and/or angular deformities. No extra equipment was needed other than the readily-available AO-tubular fixation systems. No serious complications such as neurovascular injury were encountered.

  9. Endophytic establishment of Azorhizobium caulinodans in wheat

    PubMed Central

    Sabry, S. R. S.; Saleh, S. A.; Batchelor, C. A.; Jones, J.; Jotham, J.; Webster, G.; Kothari, S. L.; Davey, M. R.; Cocking, E. C.

    1997-01-01

    Nitrogen fixing nodules are formed on the roots and stems of the tropical legume Sesbania rostrata by Azorhizobium caulinodans as a result of crack entry invasion of emerging lateral roots. Advantage was taken of this invasion capability of A. caulinodans to determine whether inoculation of the non-legume wheat with A. caulinodans would result in the endophytic establishment of azorhizobia within wheat roots. Advantage was also taken of the oxygen tolerance of the nitrogenase of free-living azorhizobia to assess the extent to which the endophytic establishment of azorhizobia in wheat roots would provide a niche for nitrogen fixation of benefit to the plant. Wheat was inoculated with A. caulinodans and grown in pots under controlled conditions, without added growth reglators and without addition of fixed nitrogen. Microscopic examination of the short lateral roots of inocluated wheat showed invasion of azorhizobia between cells of the cortex, within the xylem and the root meristem Acetylene reduction assays combined with analysis of tissue nitrogen levels indicated the likelihood that colonization led to nitrogenase activity. Inoculated wheat showed significant increases in dry weight and nitrogen content as compared with uninoculated controls. We discuss the extent to which this nitrogen fixation is likely to involve symbiotic nitrogen fixation, and we indicate the need for field trials to determine the extent to which inolculation of wheat with A. caulinodans will reduce the requirement for inputs of nitrogenous fertilizers.

  10. Posterior fixation suture and convergence excess esotropia.

    PubMed

    Steffen; Auffarth; Kolling

    1998-09-01

    The present study investigates the results of Cuppers' 'Fadenoperation' in patients with non-accommodative convergence excess esotropia. Particular attention is given to postoperative eye alignment at distance fixation. Group 1 (n=96) included patients with a 'normal' convergence excess. The manifest near angles (mean ET 16.73 degrees +/- 6.33 degrees, range 4 degrees -33 degrees ) were roughly twice the size of the distance angles (mean ET 6.50 degrees +/- 3.62 degrees, range 0 degrees -14 degrees ). These patients were treated with a bilateral fadenoperation of the medial recti without additional eye muscle surgery. Three months after surgery, the mean postoperative angles were XT 0.5 degrees +/- 3.3 degrees (range XT 11 degrees -ET 5 degrees ) for distance fixation, and ET 2.7 degrees +/- 3.6 degrees (range XT 5 degrees -ET 14 degrees ) for near fixation, respectively. Postoperative convergent angles at near fixation >ET 10 degrees were present in two patients (1.9%). Group 2 (n=21) included patients with a mean preoperative distance angle of ET 9.2 degrees +/- 3.7 degrees (range 6 degrees -16 degrees ) and a mean preoperative near angle of ET 23.4 degrees +/- 3.1 degrees (range 16 degrees -31 degrees ). These patients were operated on with a bilateral fadenoperation of the medial recti and a simultaneous recession of one or both medial rectus muscles. Mean postoperative angles were XT 0.5 degrees +/- 4.6 degrees (range XT 12 degrees -ET 7 degrees ) for distance fixation and ET 1.4 degrees +/- 4.5 degrees (range XT 8 degrees -ET 13 degrees ) for near fixation, respectively. In this group, 2 patients (10.6%) had a postoperative exotropia >XT 5 degrees at distance fixation, and two patients had residual esotropia>ET 10 degrees at near fixation. Group 3 (n=17) included patients with a pronounced non-accommodative convergence excess. Near angle values (mean of 17.8 degrees +/- 5.3 degrees, range ET 7 degrees -26 degrees ) were several times higher than the distance

  11. Screening Prosopis (mesquite) germplasm for biomass production and nitrogen fixation

    SciTech Connect

    Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.

    1980-01-01

    The nitrogen-fixing trees of the genus Prosopis (mesquite or algaroba) are well adapted to the semi-arid and often saline regions of the world. These trees may produce firewood or pods for livestock food, they may stabilize sand dunes and they may enrich the soil by production of leaf litter supported by nitrogen fixation. A collection of nearly 500 Prosopis accessions representing North and South American and African germplasm has been established. Seventy of these accessions representing 14 taxa are being grown under field conditions where a 30-fold range in biomass productivity among accessions has been estimated. In a greehouse experiment, 13 Prosopis taxa grew on nitrogen-free medium nodulated, and had a 10-fold difference in nitrogen fixation (acetylene reduction). When Prosopis is propagated by seed the resulting trees are extremely variable in growth rate and presence or absence of thorns. Propagation of 6 Prosopis taxa by stem cuttings has been achieved with low success (1 to 10%) in field-grown plants and with higher success (50 to 100%) with young actively growing greenhouse plants.

  12. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  13. 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.

  14. Synthetic biology for CO2 fixation.

    PubMed

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO2) into fuels and chemicals is a potential approach to reduce CO2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO2-derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO2-fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO2-fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO2-fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO2.

  15. Binocular Fixation in the Newborn Baby

    ERIC Educational Resources Information Center

    Slater, Alan M.; Findlay, John M.

    1975-01-01

    Three experiments are reported in which 15 babies were presented with visual stimuli which varied in shape and distance from the eye. Results indicated that the majority of subjects binocularly fixated all three stimuli and it was concluded that the newborn baby has the basic requirements for binocular vision. (Author/GO)

  16. On establishing reference values.

    PubMed Central

    Lumsden, J H; Mullen, K

    1978-01-01

    In order to establish a range of reference values for any characteristic one can use Gaussian or nonparametric techniques, whichever are most appropriate. One has the choice of calculating tolerance intervals or percentile intervals. A tolerance interval is said to contain, say 95% of the population with probability, say 0.90. A percentile interval simply simply calculates the values between which 95% of the observations fall. If the data can be said to have a Gaussian distribution, the same precision can be obtained with smaller sample sizes than using the nonparametric techniques. In some cases, data which are not Gaussian can be transformed into a Gaussian form and hence make use of the more efficient Gaussian techniques. In both cases, the data should be checked for outliers or rogue observations and these should be eliminated if the testing procedure fails to imply that they are an integral part of the data. PMID:688072

  17. Single-incision open reduction and internal fixation of comminuted trapezium fractures with distal radius cancellous autograft.

    PubMed

    Matzon, Jonas L; Reb, Christopher W; Danowski, Ryan M; Lutsky, Kevin

    2015-03-01

    Trapezium fractures comprise approximately 3% to 5% of all hand fractures. Although operative management of intra-articular trapezium fractures can result in good functional outcomes, there is very little literature addressing specific operative techniques. We describe a technique for open reduction and internal fixation of severely comminuted, intra-articular trapezium fractures, utilizing autogenous cancellous bone graft from the distal radius.

  18. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  19. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  20. 21 CFR 872.4880 - Intraosseous fixation screw or wire.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  1. 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...

  2. 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...

  3. 21 CFR 888.3010 - Bone fixation cerclage.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone fixation cerclage. 888.3010 Section 888.3010...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such...

  4. 21 CFR 888.3010 - Bone fixation cerclage.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone fixation cerclage. 888.3010 Section 888.3010...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such...

  5. 21 CFR 888.3010 - Bone fixation cerclage.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone fixation cerclage. 888.3010 Section 888.3010...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such...

  6. 21 CFR 888.3010 - Bone fixation cerclage.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone fixation cerclage. 888.3010 Section 888.3010...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such...

  7. 21 CFR 888.3010 - Bone fixation cerclage.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone fixation cerclage. 888.3010 Section 888.3010...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3010 Bone fixation cerclage. (a) Identification. A bone fixation cerclage is a device intended to be implanted that is made of alloys, such...

  8. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tracheal tube fixation device. 868.5770 Section... (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...

  9. 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... (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...

  10. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tracheal tube fixation device. 868.5770 Section... (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...

  11. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tracheal tube fixation device. 868.5770 Section... (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...

  12. 21 CFR 868.5770 - Tracheal tube fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tracheal tube fixation device. 868.5770 Section... (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...

  13. Fixator-assisted tibial lengthening over a plate in a patient with sequelae of poliomyelitis.

    PubMed

    Tosun, Haci Bayram; Serbest, Sancar; Uludag, Abuzer; Gumustas, Seyitali; Celik, Suat

    2016-11-01

    There are many techniques for limb lengthening. Lengthening over a plate is an alternative choice of fixation in children or when nailing is difficult. We present a new technique for tibial lengthening with using a monolateral external fixator over a lengthening plate.Lengthening over an intramedullary nail is a commonly used method in patients with short stature or limb-length discrepancy. However, in patients with a narrow and excessively sclerotic intramedullary cavity in the pediatric age group where the skeletal system has not yet fully developed, difficulties have been observed in lengthening methods with nailing.Therefore, in these cases, the use of lengthening techniques over a plate is an alternative treatment option. Nevertheless, in lengthening techniques over a plate, if one side of the osteotomy area cannot be fixed, associated mechanical axis problems have been reported.We applied tibia lengthening with external fixator assistance over a custom-made lengthening plate in a patient with sequelae of poliomyelitis. This new lengthening technique applied over a plate could be the solution to the problems observed in other lengthening techniques over a plate.

  14. Assessment of fixatives, fixation, and tissue processing on morphology and RNA integrity.

    PubMed

    Cox, Melissa L; Schray, Carrie L; Luster, Chandra N; Stewart, Zachary S; Korytko, Peter J; M Khan, Kanwar Nasir; Paulauskis, Joseph D; Dunstan, Robert W

    2006-04-01

    Molecular characterization of morphologic change requires exquisite tissue morphology and RNA preservation; however, traditional fixatives usually result in fragmented RNA. To optimize molecular analyses on fixed tissues, we assessed morphologic and RNA integrity in rat liver when sections were fixed in 70% neutral-buffered formalin, modified Davidson's II, 70% ethanol, UMFIX, modified Carnoy's, modified methacarn, Bouin's, phosphate-buffered saline, or 30% sucrose. Each sample was subjected to standard or microwave fixation and standard or microwave processing, and sections were evaluated microscopically. RNA was extracted and assessed for preservation of quality and quantity. Modified methacarn, 70% ethanol, and modified Carnoy's solution each resulted in tissue morphology representing a reasonable alternative to formalin. Modified methacarn and UMFIX best preserved RNA quality. Neither microwave fixation nor processing affected RNA integrity relative to standard methods, although morphology was modestly improved. We conclude that modified methacarn, 70% ethanol, and modified Carnoy's solution provided acceptable preservation of tissue morphology and RNA quality using both standard and microwave fixation and processing methods. Of these three fixatives, modified methacarn provided the best results and can be considered a fixative of choice where tissue morphology and RNA integrity are being assessed in the same specimens.

  15. A different and safe method of split thickness skin graft fixation: medical honey application.

    PubMed

    Emsen, Ilteris Murat

    2007-09-01

    Honey has been used for medicinal purposes since ancient times. Its antibacterial effects have been established during the past few decades. Still, modern medical practitioners hesitate to apply honey for local treatment of wounds. This may be because of the expected messiness of such local application. Hence, if honey is to be used for medicinal purposes, it has to meet certain criteria. The authors evaluated its use for the split thickness skin graft fixation because of its adhesive and other beneficial effects in 11 patients. No complications such as graft loss, infection, and graft rejection were seen. Based on these results, the authors advised honey as a new agent for split thickness skin graft fixation. In recent years there has been a renewed interest in honey wound management. There are a range of regulated wound care products that contain honey available on the Drug Tariff. This article addresses key issues associated with the use of honey, outlining how it may be best used, in which methods of split thickness skin graft fixations it may be used, and what clinical outcomes may be anticipated. For this reason, 11 patients who underwent different diagnosis were included in this study. In all the patients same medical honey was used for the fixation of the skin graft. No graft loss was seen during both the first dressing and the last view of the grafted areas. As a result, it has been shown that honey is also a very effective agent for split thickness skin graft fixations. Because it is a natural agent, it can be easily used in all skin graft operation for the fixation of the split thickness skin grafts.

  16. THE COMBINED EFFECTS OF FORMALIN FIXATION AND INDIVIDUAL STEPS IN TISSUE PROCESSING ON IMMUNO-RECOGNITION

    PubMed Central

    Otali, Dennis; Stockard, Cecil R.; Oelschlager, Denise K.; Wan, Wen; Manne, Upender; Watts, Stephen A.; Grizzle, William E.

    2010-01-01

    It is accepted that the aldehyde-based fixation of cells can affect the immunodetection of antigens; however, the effects of tissue processing on immunodetection have not been analyzed systematically. We therefore investigated the effects of aldehyde-based fixation and the individual steps of tissue processing on immunohistochemical detection of specific antigens. DU145 (prostate) and SKOV3 (ovarian) cancer cell lines were cultured as monolayers on microscope slides. The immunohistochemical detection of Ki67/MIB-1 and PCNA was evaluated after various times of fixation in 10% neutral-buffered formalin (NBF) plus after each of the individual cumulative steps of tissue processing. The effect of antigen retrieval (AR) was evaluated concomitantly as an additional variable. Our results indicate that, in addition to fixation, each of the different steps in tissue processing has effects on immunorecognition of the epitopes recognized by these antibodies. The extensive dehydration through ethanols to absolute ethanol had only modest effects except for the detection of Ki67/MIB-1 in SKOV-3 cells where the effect was stronger. In general, however, the establishment of a hydrophobic environment by xylene resulted in the greatest decrease in immunorecognition. Antigen retrieval was able to compensate for most, but not all of the losses in staining following fixation and exposure to xylene; however, AR gave very consistent results for most steps of tissue processing, suggesting that AR should also be used in staining for PCNA. The cellular variations that were noted indicate that the effects of fixation and other steps of tissue processing may depend upon how antigens are packaged by specific cells. PMID:19886759

  17. The flying buttress construct for posterior spinopelvic fixation: a technical note

    PubMed Central

    2011-01-01

    Background Posterior fusion of the spine to the pelvis in paediatric and adult spinal deformity is still challenging. Especially assembling of the posterior rod construct to the iliac screw is considered technically difficult. A variety of spinopelvic fixation techniques have been developed. However, extreme bending of the longitudinal rods or the use of 90-degree lateral offset connectors proved to be difficult, because the angle between the rod and the iliac screw varies from patient to patient. Methods We adopted a new spinopelvic fixation system, in which iliac screws are side-to-side connected to the posterior thoracolumbar rod construct, independent of the angle between the rod and the iliac screw. Open angled parallel connectors are used to connect short iliac rods from the posterior rod construct to the iliac screws at both sides. The construct resembles in form and function an architectural Flying Buttress, or lateral support arches, used in Gothic cathedrals. Results and discussion Three different cases that illustrate the Flying Buttress construct for spinopelvic fixation are reported here with the clinical details, radiographic findings and surgical technique used. Conclusion The Flying Buttress construct may offer an alternative surgical option for spinopelvic fixation in circumstances wherein coronal or sagittal balance cannot be achieved, for example in cases with significant residual pelvic obliquity, or in revision spinal surgery for failed lumbosacral fusion. PMID:21489256

  18. A prospective randomised trial comparing mesh types and fixation in totally extraperitoneal inguinal hernia repairs.

    PubMed

    Cristaudo, Adam; Nayak, Arun; Martin, Sarah; Adib, Reza; Martin, Ian

    2015-05-01

    The totally extraperitoneal (TEP) approach for surgical repair of inguinal hernias has emerged as a popular technique. We conducted a prospective randomised trial to compare patient comfort scores using different mesh types and fixation using this technique. Over a 14 month period, 146 patients underwent 232 TEP inguinal hernia repairs. We compared the comfort scores of patients who underwent these procedures using different types of mesh and fixation. A non-absorbable 15 × 10 cm anatomical mesh fixed with absorbable tacks (Control group) was compared with either a non-absorbable 15 × 10 cm folding slit mesh with absorbable tacks (Group 2), a partially-absorbable 15 × 10 cm mesh with absorbable tacks (Group 3) or a non-absorbable 15 × 10 cm anatomical mesh fixed with 2 ml fibrin sealant (Group 4). Outcomes were compared at 1, 2, 4 and 12 weeks using the Carolina Comfort Scale (CCS) scores. At 1, 2, 4 and 12 weeks, the median global CCS scores were low for all treatment groups. Statistically significant differences were seen only for median CCS scores and subscores with the use of partially-absorbable mesh with absorbable tacks (Group 3) at weeks 2 and 4. However, these were no longer significant at week 12. In this study, the TEP inguinal hernia repair with minimal fixation results in low CCS scores. There were no statistical differences in CCS scores when comparing types of mesh, configuration of the mesh or fixation methods.

  19. Temporal sequences quantify the contributions of individual fixations in complex perceptual matching tasks.

    PubMed

    Busey, Thomas; Yu, Chen; Wyatte, Dean; Vanderkolk, John

    2013-01-01

    Perceptual tasks such as object matching, mammogram interpretation, mental rotation, and satellite imagery change detection often require the assignment of correspondences to fuse information across views. We apply techniques developed for machine translation to the gaze data recorded from a complex perceptual matching task modeled after fingerprint examinations. The gaze data provide temporal sequences that the machine translation algorithm uses to estimate the subjects' assumptions of corresponding regions. Our results show that experts and novices have similar surface behavior, such as the number of fixations made or the duration of fixations. However, the approach applied to data from experts is able to identify more corresponding areas between two prints. The fixations that are associated with clusters that map with high probability to corresponding locations on the other print are likely to have greater utility in a visual matching task. These techniques address a fundamental problem in eye tracking research with perceptual matching tasks: Given that the eyes always point somewhere, which fixations are the most informative and therefore are likely to be relevant for the comparison task?

  20. 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

  1. Lumbo-sacro-pelvic Fixation Using Iliac Screws for the Complex Lumbo-sacral Fractures.

    PubMed

    Rhee, Woo-Tack; You, Seung-Hoon; Jang, Yeon-Gyu; Lee, Sang-Youl

    2007-12-01

    Fractures of lumbo-sacral junction involving bilateral sacral wings are rare. Posterior lumbo-sacral fixation does not always provide with sufficient stability in such cases. Various augmentation techniques including divergent sacral ala screws, S2 pedicle screws and Galveston rods have been reported to improve lumbo-sacral stabilization. Galveston technique using iliac bones would be the best surgical approach especially in patients with bilateral comminuted sacral fractures. However, original Galveston surgery is technically demanding and bending rods into the appropriate alignment is time consuming. We present a patient with unstable lumbo-sacral junction fractures and comminuted U-shaped sacral fractures treated by lumbo-sacro-pelvic fixation using iliac screws and discuss about the advantages of the iliac screws over the rod system of Galveston technique.

  2. Femoral Aperture Fixation Improves Anterior Cruciate Ligament Graft Function When Added to Cortical Suspensory Fixation

    PubMed Central

    Porter, Mark D.; Shadbolt, Bruce

    2016-01-01

    Background: Recommendations for bone tunnel placement during anterior cruciate ligament (ACL) reconstruction have become more precise. However, these recommendations differ neither with the choice of graft nor with the method of fixation used. The influence of the method of femoral fixation used on the biomechanical function of a soft tissue ACL graft remains unknown. Hypothesis: Our null hypothesis was that adding femoral aperture fixation to femoral cortical fixation, using the same bone tunnels, will not alter the control of anterior translation (AT) and internal rotation (IR) during ACL reconstruction using a hamstring graft. Study Design: Controlled laboratory study. Methods: A total of 22 patients with an acute isolated ACL rupture underwent reconstruction using a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the AT and IR during the pivot-shift test before reconstruction, after ACL reconstruction using cortical suspensory fixation, and after the addition of femoral aperture fixation. Statistical analysis (analysis of variance) was used to compare the AT and IR during the pivot shift at each stage in the procedure. Results: Before ACL reconstruction, the mean (±SD) AT was 14.2 ± 7.3 mm and mean IR was 17.2° ± 5.5°. After reconstruction using femoral cortical suspension, these figures were significantly reduced to 6.2 ± 3.5 mm and 12.5° ± 3.20°, respectively (P < .001). The addition of the aperture fixation was associated with a further significant reduction to 4.6 ± 3.2 mm and 10.4° ± 2.7°, respectively (P < .001). Conclusion: The addition of femoral aperture fixation to suspensory fixation results in a significant reduction in both the AT and IR that occurs during the pivot-shift assessment immediately after ACL reconstruction using autologous hamstring graft. Clinical Relevance: The most precise positioning of bone tunnels during soft tissue ACL reconstruction needs to take into consideration

  3. [Resorbable rods and screws for fixation of ankle fractures. A randomized clinical prospective study].

    PubMed

    Springer, M A; van Binsbergen, E A; Patka, P; Bakker, F C; Haarman, H J

    1998-05-01

    A prospective randomized clinical trial was performed to evaluate the use of self-reinforced absorbable composites (Biofix) in the fixation of ankle fractures. The aim of this study was to demonstrate that fixation with Biofix rods and screws is as good as the standard A.O. fixation. The benefits of Biofix rods and screws are: a reduction in costs since no secondary operation is needed, prevention of stress-shielding and thereby diminishing the risk of bone porosity. Patients aged between 16 and 75 years old with closed, non-comminuted fractures of the lateral and/or medial malleolus and dislocation of the fracture fragments greater than 2 mm were included in the study. 22 patients were treated with Biofix rods and screws and the control group of 19 patients with a standard technique. After 3, 6 and 12 months, rontgenograms were taken. At the same time functional results were evaluated following the criteria of Olerud and Molander. Two patients were withdrawn from the trial for non-medical reasons. 22 patients (12 from the Biofix group, 10 from the AO group) operated two or more years ago were contacted to see if any complications had occurred since they were last seen. In 4 cases a Biofix screw broke down just beneath the head during insertion. This did not result in an insufficient fixation of the fracture. There were no early post-operative complications. The functional and rontgenological results in both groups were equal. In three cases a sterile sinus developed at the site of screw insertion. Biofix rods and screws, made of polylactic acid, are a good alternative for the fixation of fractures of the ankle. The use of resorbable fracture fixation material has the advantage that a second operation to remove osteosynthesis material is not necessary. The long term results are good. There is, however, a possibility of development of tissue reaction to the resorbable material.

  4. Comparison of three cell fixation methods for high content analysis assays utilizing quantum dots.

    PubMed

    Williams, Y; Byrne, S; Bashir, M; Davies, A; Whelan, A; Gun'ko, Y; Kelleher, D; Volkov, Y

    2008-10-01

    Semiconductor nanoparticles or quantum dots are being increasingly utilized as fluorescent probes in cell biology both in live and fixed cell assays. Quantum dots possess an immense potential for use in multiplexing assays that can be run on high content screening analysers. Depending on the nature of the biological target under investigation, experiments are frequently required on cells retaining an intact cell membrane or also on those that have been fixed and permeabilized to expose intracellular antigens. Fixation of cell lines before or after the addition of quantum dots may affect their localization, emission properties and stability. Using a high content analysis platform we perform a quantitative comparative analysis of three common fixation techniques in two different cell lines exposed to carboxylic acid stabilized CdTe quantum dots. Our study demonstrates that in prefixed and permeabilized cells, quantum dots are readily internalized regardless of cell type, and their intracellular location is primarily determined by the properties of the quantum dots themselves. However, if the fixation procedures are preformed on live cells previously incubated with quantum dots, other important factors have to be considered. The choice of the fixative significantly influences the fluorescent characteristics of the quantum dots. Fixatives, regardless of their chemical nature, negatively affected quantum dots fluorescence intensity. Comparative analysis of gluteraldehyde, methanol and paraformaldehyde demonstrated that 2% paraformaldehyde was the fixative of choice. The presence of protein in the media did not significantly alter the quantum dot fluorescence. This study indicates that multiplexing assays utilizing quantum dots, despite being a cutting edge tool for high content cell imaging, still require careful consideration of the basic steps in biological sample processing.

  5. Southwick Osteotomy Stabilised with External Fixator

    PubMed Central

    Grubor, Predrag; Mitkovic, Milorad; Grubor, Milan

    2014-01-01

    ABSTRACT Introduction: Epiphysiolysis of the femoral head is the most common accident occurring towards the end of pre-puberty and puberty growth. Case report: The author describes the experience in the treatment of chronic epiphysiolysis in two patients treated by Southwick osteotomy. The site is accessed by way of a 15-cm long lateral skin incision and the trochanteric region is reached through the layers. The osteotomy angles prepared beforehand on a thin aluminium model are used to mark the Southwick osteotomy site on the anterior and lateral sides at the level of the lesser trochanter. Before performing the trochanteric osteotomy, two Mitković convergent pins type M20 are applied distally and proximally, above the planned osteotomy site. A tenotomy of the iliopsas muscle is performed, and then the previously marked bone triangle is redissected up to three quarters of the width of the femur. The distal part of the femur is rotated inwards, so that the patella is turned towards the ceiling. The osteotomised fragments of the femur are adapted, repositioned and fixated by installing an external fixator on the previously placed pins. Two more pins are placed, one proximally and one distally, with a view to adequately stabilising the femur. The patient was mobile from day two after the surgery. If, after the surgery, the lead surgeon realises that there is a requirement to make a correction of 5, 10 and 15 degrees of the valgus, varus, anteversion or retroversion deformity, the correction shall be performed without surgically opening the patient, using the fixator pins. Conclusion: After performing a Southwick osteotomy it is easier to adapt, reposition and fixate the osteotomised fragments of the femur using a fixator type M20. Adequate stability allows regaining mobility quickly, which in turn is the best prevention of chondrolysis of the hip. It is possible to make post-operative valgus, varus, anteversion and retroversion corrections of 5, 10 and 15 degrees

  6. MRI analysis of the ISOBAR TTL internal fixation system for the dynamic fixation of intervertebral discs: a comparison with rigid internal fixation

    PubMed Central

    2014-01-01

    Objectives Using magnetic resonance imaging (MRI), we analyzed the efficacy of the posterior approach lumbar ISOBAR TTL internal fixation system for the dynamic fixation of intervertebral discs, with particular emphasis on its effects on degenerative intervertebral disc disease. Methods We retrospectively compared the MRIs of 54 patients who had previously undergone either rigid internal fixation of the lumbar spine or ISOBAR TTL dynamic fixation for the treatment of lumbar spondylolisthesis. All patients had received preoperative and 6-, 12-, and 24-month postoperative MRI scans of the lumbar spine with acquisition of both routine and diffusion-weighted images (DWI). The upper-segment discs of the fusion were subjected to Pfirrmann grading, and the lumbar intervertebral discs in the DWI sagittal plane were manually drawn; the apparent diffusion coefficient (ADC) value was measured. Results ADC values in the ISOBAR TTL dynamic fixation group measured at the 6-, 12-, and 24-month postoperative MRI studies were increased compared to the preoperative ADC values. The ADC values in the ISOBAR TTL dynamic fixation group at 24 months postoperatively were significantly different from the preoperative values (P < 0.05). At 24 months, the postoperative ADC values were significantly different between the rigid fixation group and the ISOBAR TTL dynamic fixation group (P < 0.05). Conclusion MRI imaging findings indicated that the posterior approach lumbar ISOBAR TTL internal fixation system can prevent or delay the degeneration of intervertebral discs. PMID:24898377

  7. Application of alternative fixatives to formalin in diagnostic pathology

    PubMed Central

    Gatta, L. Benerini; 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 aim 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 stainings), 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 to be the best fixative for morphology. The morphology obtained with Bouin was comparable to the one with formalin. Hollande was the best fixative for histochemistry. Bouin proved to be equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved the possibility 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

  8. Comparison of theoretical fixation stability of three devices employed in medial opening wedge high tibial osteotomy: a finite element analysis

    PubMed Central

    2014-01-01

    Background Medial open wedge high tibial osteotomy is a well-established procedure for the treatment of unicompartmental osteoarthritis and symptomatic varus malalignment. We hypothesized that different fixation devices generate different fixation stability profiles for the various wedge sizes in a finite element (FE) analysis. Methods Four types of fixation were compared: 1) first and 2) second generation Puddu plates, and 3) TomoFix plate with and 4) without bone graft. Cortical and cancellous bone was modelled and five different opening wedge sizes were studied for each model. Outcome measures included: 1) stresses in bone, 2) relative displacement of the proximal and distal tibial fragments, 3) stresses in the plates, 4) stresses on the upper and lower screw surfaces in the screw channels. Results The highest load for all fixation types occurred in the plate axis. For the vast majority of the wedge sizes and fixation types the shear stress (von Mises stress) was dominating in the bone independent of fixation type. The relative displacements of the tibial fragments were low (in μm range). With an increasing wedge size this displacement tended to increase for both Puddu plates and the TomoFix plate with bone graft. For the TomoFix plate without bone graft a rather opposite trend was observed. For all fixation types the occurring stresses at the screw-bone contact areas pulled at the screws and exceeded the allowable threshold of 1.2 MPa for at least one screw surface. Of the six screw surfaces that were studied, the TomoFix plate with bone graft showed a stress excess of one out of twelve and without bone graft, five out of twelve. With the Puddu plates, an excess stress occurred in the majority of screw surfaces. Conclusions The different fixation devices generate different fixation stability profiles for different opening wedge sizes. Based on the computational simulations, none of the studied osteosynthesis fixation types warranted an intransigent full

  9. Extra Corporeal Fixation of Fractured Mandibular Condyle

    PubMed Central

    Shenoy K, Vandana; Kengagsubbiah, Srivatsa; V, Sathyabhama; Priya, Vishnu

    2014-01-01

    Condylar fracture is the second most common site in the mandibular fractures. Motor vehicle accident and fall are the major causes of such fractures. Because of the anatomical weakness of the condyle and the shape of the condylar head the antero-medial dislocation of the condyle is common. Open reduction and closed reduction is always debatable. The open reduction will bring back the normal function much earlier than closed reduction. Medially dislocated condylar fracture fragments are always managed with open method. In superior or high condylar fractures,exact reduction with conventional open reduction can be difficult due to the limited surgical and visual fields. In such cases extracorporeal fixation of condyle using vertical ramus osteotomy may be better choice to achieve perfect alignment and absolute maintaince of vertical height of the ramus and facial symmetry. We here present a case of extracorporeal fixation of unilateral left high condylar fracture. PMID:25386546

  10. 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.

  11. "False" migration of rigid fixation appliances in pediatric craniofacial surgery.

    PubMed

    Papay, F A; Hardy, S; Morales, L; Walker, M; Enlow, D

    1995-07-01

    Osseous fixation techniques have been widely used to provide rigid stabilization in the craniofacial skeleton. Reported sequelae of its usage has been limited to palpation of the screw-plate system and radiological imaging artifacts. Over the past 3 years we have identified miniplates, microplates, and wire sutures on the inner cranial table of the growing child. The observation of "false" migration of these appliances has provided the impetus to review these patients in more detail. Twenty patients underwent secondary cranial remodeling within a two-year period; 7 of these patients were seen to have "false" migration. There were no untoward sequelae in removal of these appliances, and no adverse neurological symptoms were seen.

  12. [Complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

    PubMed

    Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

    2016-12-20

    Objective: To make a systematic assessment of the complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Method: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed.The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected.The included trials were screened out strictly based on the criterion of inclusion and exclusion.The quality of included trials was evaluated.RevMan 5.0 was used for data analysis. Result: A total of 17 studies involving 1 402 patients were included.There were 687 patients with open reduction and internal fixation and 715 with external fixation.The results of Meta-analysis indicated that there were statistically significant differences with regard to the postoperatively total complications, infection, malunion, tendon rupture (I(2)=8%, RR=0.77(95%CI 0.65-0.91, Z=3.10, P<0.05). There were no statistically significant differences observed between two approaches with respect to nounion, re-operation, complex regional pain syndrome, carpal tunnel syndrome, neurapraxia, tendonitis, painful hardware, scar(P>0.05). Conclusion: Postoperative complications are present in both open reduction and internal fixation and external fixation.Compared with external fixation, open reduction and internal fixation is lower in total complications postoperatively, infection and malunion, but external fixation has lower tendon rupture incidence.

  13. The Sequoia circular fixator for limb lengthening.

    PubMed

    Hardy, J M; Tadlaoui, A; Wirotius, J M; Saleh, M

    1991-10-01

    With the Sequoia fixator, lengthenings can be achieved based on the clinical facts of the case. The device is a modular apparatus that can perform corrections in several planes, and, if necessary, in a septic environment. In our opinion, a "lengthener surgeon" is one who can foresee problems and take appropriate steps to prevent them. Likewise, the surgeon must act as the coordinator of an entire team. A successful lengthening is 5% surgery and 95% postoperative nursing and physiotherapy care. In the future, a number of changes will simplify postoperative management: 1. Composite carbon rings will make the frames radiolucent and one third lighter than those made of stainless steel. Automatic tensioners will help maintain steady tension on the wires. 2. Digital analysis of the callus will provide norms of consolidation, allowing faster fixator removal and conversion to an orthosis. 3. Incorporating the foot in the frame to overcome equinus will eliminate the need for tenotomy. We believe that monolateral and ring fixators can work together in certain locations. That is why we proposed, at the 18th Societé Internationale de Chirurgie Orthopédique et Traumatologique meeting, a combined monolateral-ring construct that can be used for lengthening throughout the proximal femoral metaphysis.

  14. Scapular thickness--implications for fracture fixation.

    PubMed

    Burke, Charity S; Roberts, Craig S; Nyland, John A; Radmacher, Paula G; Acland, Robert D; Voor, Michael J

    2006-01-01

    The purpose of this study was to measure and map scapula osseous thickness to identify the optimal areas for internal fixation. Eighteen (9 pairs) scapulae from 2 female and 7 male cadavers were used. After harvest and removal of all soft tissues, standardized measurement lines were made based on anatomic landmarks. For consistency among scapulae, measurements were taken at standard percentage intervals along each line approximating the distance between two consecutive reconstruction plate screw holes. Two-mm-diameter drill holes were made at each point, and a standard depth gauge was used to measure thickness. The glenoid fossa (25 mm) displayed the greatest mean osseous thickness, followed by the lateral scapular border (9.7 mm), the scapula spine (8.3 mm), and the central portion of the body of the scapula (3.0 mm). To optimize screw purchase and internal fixation strength, the lateral border, the lateral aspect of the base of the scapula spine, and the scapula spine itself should be used for anatomic sites of internal fixation of scapula fractures.

  15. Complement fixation and neutralization RS antibodies in maternal and neonatal sera.

    PubMed Central

    Heijtink, R. A.; Backx, G.; Van Der Horst, J. M.; Masurel, N.

    1977-01-01

    RSV complement fixation antibodies were established in 200 paired maternal and cord blood sera. Geometric mean titres in cord sera were significantly higher than in matermal sera. The differences did not depend on the virus strain used. Half of the paired sera (taken at random) were also submitted to microneutralization tests. No differences were found between geometric mean titres in maternal and cord sera. PMID:266541

  16. Molecular Ecological and Stable Isotopic Studies of Nitrogen Fixation in Modern Microbial Mats

    NASA Technical Reports Server (NTRS)

    Bebout, B. M.; Crumbliss, L. L.; DesMarais, D. J.; Hogan, M. E.; Omoregie, E.; Turk, K. A.; Zehr, J. P.

    2003-01-01

    Nitrogen is usually the element limiting biological productivity in the marine environment. Microbial mats, laminated microbial communities analogous to some of the oldest forms of life on Earth, are often the sites of high rates of N fixation (the energetically expensive conversion of atmospheric dinitrogen into a biologically useful form). The N fixing enzyme nitrogenase is generally considered to be of ancient origin, and is widely distributed throughout the Bacterial and Archaeal domains of life, indicating an important role for this process over evolutionary time. The stable isotopic signature of N fixation is purportedly recognizable in organic matter (ancient kerogens as well as present-day microbial mats) as a delta (15)N(sub organic) near zero. We studied two microbial mats exhibiting different rates of N fixation in order to better understand the impact of N fixation on the delta (15)N (sub organic) of the mats, as well as what organisms are important in this process. Mats dominated by the cyanobacterium Microcoleus chthonoplastes grow in permanently submerged hypersaline salterns, and exhibit low rates of N fixation, whereas mats dominated by the cyanobacterium Lyngbya spp grow in an intertidal area, and exhibit rates of N fixation an order of magnitude higher. To examine successional stages in mat growth, both developing and established mats at each location were sampled. PCR and RT-PCR based approaches were used to identify, respectively, the organisms containing nifH (one of the genes that encode nitrogenase) as well as those expressing nifH in these mats. Both mats exhibited a distinct diel cycle of N fixation, with highest rates occurring at night. The delta (15)N(sub organic) of the subtidal Microcoleus mats is near zero whereas the delta (15)N(sub organic) is slightly more positive (+ 2-3%), in the intertidal Lyngbya mats, an interesting difference in view of the fact that overall rates of activity in the intertidal mats are much higher that those

  17. Disruption of Fixation Reveals Latent Sensorimotor Processes in the Superior Colliculus

    PubMed Central

    Gandhi, Neeraj J.

    2016-01-01

    Executive control of voluntary movements is a hallmark of the mammalian brain. In the gaze-control network, this function is thought to be mediated by a critical balance between neurons responsible for generating movements and those responsible for fixating or suppressing movements, but the nature of this balance between the relevant elements—saccade-generating and fixation-related neurons—remains unclear. Specifically, it has been debated whether the two functions are necessarily coupled (i.e., push-and-pull) or independently controlled. Here we show that behavioral perturbation of ongoing fixation with the trigeminal blink reflex in monkeys (Macaca mulatta) alters the effective balance between fixation and saccade-generating neurons in the superior colliculus (SC) and can lead to premature gaze shifts reminiscent of compromised inhibitory control. The shift in balance is primarily driven by an increase in the activity of visuomovement neurons in the caudal SC, and the extent to which fixation-related neurons in the rostral SC play a role seems to be linked to the animal's propensity to make microsaccades. The perturbation also reveals a hitherto unknown feature of sensorimotor integration: the presence of a hidden visual response in canonical movement neurons. These findings offer new insights into the latent functional interactions, or lack thereof, between components of the gaze-control network, suggesting that the perturbation technique used here may prove to be a useful tool for probing the neural mechanisms of movement generation in executive function and dysfunction. SIGNIFICANCE STATEMENT Eye movements are an integral part of how we explore the environment. Although we know a great deal about where sensorimotor transformations leading to saccadic eye movements are implemented in the brain, less is known about the functional interactions between neurons that maintain gaze fixation and neurons that program saccades. In this study, we used a novel

  18. Minimally invasive percutaneous screw fixation of traumatic spondylolisthesis of the axis.

    PubMed

    Buchholz, Avery Lee; Morgan, Steven L; Robinson, Leslie C; Frankel, Bruce M

    2015-05-01

    OBJECT Most cases of traumatic spondylolisthesis of the axis (hangman's fracture) can be treated nonoperatively with reduction and subsequent immobilization in a rigid cervical collar or halo. However, in some instances, operative management is necessary and can be accomplished by using either anterior or posterior fusion techniques. Because open posterior procedures can result in significant blood loss, pain, and limited cervical range of motion, other less invasive options for posterior fixation are needed. The authors describe a minimally invasive, navigation-guided technique for surgical treatment of Levine-Edwards (L-E) Type II hangman's fractures. METHODS For 5 patients with L-E Type II hangman's fracture requiring operative reduction and internal fixation, percutaneous screw fixation directed through the fracture site was performed. This technique was facilitated by use of intraoperative 3D fluoroscopy and neuronavigation. RESULTS Of the 5 patients, 2 were women, 3 were men, and age range was 46-67 years. No intraoperative or postoperative complications occurred. All patients wore a rigid cervical collar, and flexion-extension radiographs were obtained at 6 months. For all patients, dynamic imaging demonstrated a stable construct. CONCLUSIONS L-E type II hangman's fractures can be safely repaired by using percutaneous minimally invasive surgical techniques. This technique may be appropriate, depending on circumstances, for all L-E Type I and II hangman's fractures; however, the degree of associated ligament injury and disc disruption must be accounted for. Percutaneous fixation is not appropriate for L-E Type III fractures because of significant displacement and ligament and disc disruption. This report is meant to serve as a feasibility study and is not meant to show superiority of this procedure over other surgical options.

  19. Ultrasound Biomicroscopy Comparison of Ab Interno and Ab Externo Intraocular Lens Scleral Fixation.

    PubMed

    Horiguchi, Lie; Garcia, Patricia Novita; Malavazzi, Gustavo Ricci; Allemann, Norma; Gomes, Rachel L R

    2016-01-01

    Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fifteen patients were enrolled in the study. The ab externo technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt when compared to the ab interno.

  20. Limb lengthening and deformity correction in children using hexapodal external fixation: preliminary results for 36 cases.

    PubMed

    Blondel, B; Launay, F; Glard, Y; Jacopin, S; Jouve, J -L; Bollini, G

    2009-10-01

    Limb deformities in children can be corrected using different techniques, notably external fixation following the Ilizarov principles. However, correction can be difficult in cases of multiple deformities. In 1994, Charles Taylor developed a new computer-assisted hexapodal external fixator system to treat these pathologies, the Taylor Spatial Frame. The objective of this study was to evaluate the results obtained with this technique in treating lower-limb deformities in children. Thirty-six patients were included in this prospective study, with a mean age of 11.1 years. The etiologies were distributed into six groups: congenital pathologies in 17 cases, fractures in five cases, post-traumatic pathologies in two cases, postinfectious sequelae in three cases, achondroplasia in three cases, and other causes in the last six cases. A total of 67 deformities in the three spatial planes were found in the entire group of patients. The procedure consisted of lengthening, correcting the axis, or both simultaneously. All the patients were managed with the same protocol: placement of an external fixator, AP and lateral X-rays, and planning of the correction using dedicated software. In this group of 36 patients, the fixator was worn for a mean 183 days; when lengthening was performed, a mean 4.3cm was gained with a healing index of 38.2 days/cm. Of the 67 initial deformities, 91% were corrected. The most frequently encountered complications were a superficial infection in 22.2% of the cases; one deep infection was also noted as well as three bone regenerate fractures. Use of this computer-assisted fixation system seems effective in treating complex deformities of the limbs in children, and allows treating several deformities simultaneously.

  1. Ab-interno scleral suture loop fixation with cow-hitch knot in posterior chamber intraocular lens decentration

    PubMed Central

    Can, Ertuğrul; Koçak, Nurullah; Yücel, Özlem Eşki; Gül, Adem; Öztürk, Hilal Eser; Sayın, Osman

    2016-01-01

    Aim of Study: To describe a simplified ab-interno cow-hitch suture fixation technique for repositioning decentered posterior chamber intraocular lens (PC IOL). Materials and Methods: Two cases are presented with the surgical correction of decentered and subluxated IOL. Ab-interno scleral suture fixation technique with hitch-cow knot in the eye was performed with a ciliary sulcus guide instrument and 1 year follow-up was completed. Results: Both of the patients had well centered lenses postoperatively. Corrected distant and near visual acuities of the patients were improved. There was no significant postoperative complication. In the follow-up period of 1 year, no evidence of suture erosion was found. Conclusions: Ab-interno scleral suture loop fixation with hitch-cow knot in the eye was effective in repositioning decentered or subluxated PC IOLs with excellent postoperative centered lenses and visual outcomes. PMID:27050346

  2. Plating of patella fractures: techniques and outcomes.

    PubMed

    Taylor, Benjamin C; Mehta, Sanjay; Castaneda, Joaquin; French, Bruce G; Blanchard, Chris

    2014-09-01

    Operative treatment of displaced patella fractures with tension band fixation remains the gold standard, but is associated with a significant rate of complications and symptomatic implants. Despite the evolution of tension band fixation to include cannulated screws, surprisingly little other development has been made to improve overall patient outcomes. In this article, we present the techniques and outcomes of patella plating for displaced patella fractures and patella nonunions.

  3. Chemical fixation methods for Raman spectroscopy-based analysis of bacteria.

    PubMed

    Read, Daniel S; Whiteley, Andrew S

    2015-02-01

    Preservation of biological samples for downstream analysis is important for analytical methods that measure the biochemical composition of a sample. One such method, Raman microspectroscopy, is commonly used as a rapid phenotypic technique to measure biomolecular composition for the purposes of identification and discrimination of species and strains of bacteria, as well as investigating physiological responses to external stressors and the uptake of stable isotope-labelled substrates in single cells. This study examines the influence of a number of common chemical fixation and inactivation methods on the Raman spectrum of six species of bacteria. Modifications to the Raman-phenotype caused by fixation were compared to unfixed control samples using difference spectra and Principal Components Analysis (PCA). Additionally, the effect of fixation on the ability to accurately classify bacterial species using their Raman phenotype was determined. The results showed that common fixatives such as glutaraldehyde and ethanol cause significant changes to the Raman spectra of bacteria, whereas formaldehyde and sodium azide were better at preserving spectral features.

  4. Fugitive dust control experiments using soil fixatives on vehicle traffic surfaces

    SciTech Connect

    Winberg, M.R.; Wixom, V.E.

    1992-08-01

    This report presents the results of engineering scale dust control experiments using soil fixative for contamination control during handling of transuranic waste. These experiments focused on controlling dust during retrieval operations of buried waste where waste and soil are intimately mixed. Sources of dust generation during retrieval operations include digging, dumping, and vehicle traffic. Because contaminants are expected to attach to soil particles and move with the generated dust, control of the dust spread may be the key to contamination control. Dust control techniques examined in these experiments include the use of soil fixatives to control generation of fugitive dusts during vehicle traffic operations. Previous experiments conducted in FY 1990 included testing of the soil fixative, ENTAC. These experiments showed that ENTAC was effective in controlling dust generation but had several undesirable properties such as slow cure times and clogged the pumps and application nozzles. Therefore, other products would have to be evaluated to find a suitable candidate. As a result, two soil fixatives were tested in these present experiments, COHEREX-PM, an asphalt emulsion product manufactured by Witco Corporation and FLAMBINDER, a calcium lignosulfonate product manufactured by Flambeau Corporation. The results of the experiments include product performance and recommended application methods for application in a field deployable contamination control unit to be built in FY 1993.

  5. Evaluating agricultural and nonagricultural carbon fixation over India using remote sensing data

    NASA Astrophysics Data System (ADS)

    Hooda, Ramesh S.; Dye, D. G.; Shibasaki, Ryosuke

    2003-03-01

    NASA/NOAA Pathfinder AVHRR Land (PAL) 10 day composited NDVI data with a spatial resolution of 8 km was used to estimate carbon-fixation and biomass over Indian territory. The study area was classified into agricultural and non-agricultural based upon the NDVI-climatological modeling technique. The Production Efficiency Model (PEM), which decomposits productivity into independent parameters, was used to evaluate the Net Primary Productivity (NPP). The NDVI data for the three years was used to estimate fraction of PAR absorbed (fAPAR) based upon the relationship provided by SAIL model. Incident PAR (IPAR) data set for India was extracted from the monthly global IPAR data set already generated using UV reflectivity data. The IPAR data when combined with the fAPAR data provided absorbed PAR (APAR). APAR was converted to NPP using the mean PAR conversion efficiency values calculated based upon literature survey. The NPP was finally converted to biomass and carbon-fixation. It was observed that about 50 per cent of the carbon-fixation and consequently biomass production over India is through agricultural crops. This appears to be quite substantial compared to the global scenario. Annual variations in carbon-fixation have been explained by changing cropping seasons whereas the inter-annual variations by the anomalies in the monsoon in the region.

  6. Fast and asymptotic computation of the fixation probability for Moran processes on graphs.

    PubMed

    Alcalde Cuesta, F; González Sequeiros, P; Lozano Rojo, Á

    2015-03-01

    Evolutionary dynamics has been classically studied for homogeneous populations, but now there is a growing interest in the non-homogeneous case. One of the most important models has been proposed in Lieberman et al. (2005), adapting to a weighted directed graph the process described in Moran (1958). The Markov chain associated with the graph can be modified by erasing all non-trivial loops in its state space, obtaining the so-called Embedded Markov chain (EMC). The fixation probability remains unchanged, but the expected time to absorption (fixation or extinction) is reduced. In this paper, we shall use this idea to compute asymptotically the average fixation probability for complete bipartite graphs K(n,m). To this end, we firstly review some recent results on evolutionary dynamics on graphs trying to clarify some points. We also revisit the 'Star Theorem' proved in Lieberman et al. (2005) for the star graphs K(1,m). Theoretically, EMC techniques allow fast computation of the fixation probability, but in practice this is not always true. Thus, in the last part of the paper, we compare this algorithm with the standard Monte Carlo method for some kind of complex networks.

  7. Retrograde intramedullary fixation of long bone fractures through ipsilateral traumatic amputation sites.

    PubMed

    Wagner, Scott C; Chi, Benjamin B; Gordon, Wade T; Potter, Benjamin K

    2015-06-01

    The technique of retrograde intramedullary fixation of fractures through open traumatic amputations has not been previously described. We performed a retrospective case series at a tertiary-care military hospital setting. Ten patients met inclusion criteria. All were male, and all were injured through improvised explosive device. Outcome measures included the incidence of fracture nonunion, osteomyelitis or acute infection, heterotopic ossification (HO), as well as successful prosthesis fitting and ambulation. Average time to fixation after injury and amputation closure was 11.7 and 12.2 days, respectively. Follow-up averaged 20.2 months. The radiographic union rate was 100%, and time to osseous union averaged 7.5 months. One patient had an amputation site infection requiring revision, but none of the nails was removed for infectious reasons. HO occurred in 7 patients, and 2 patients required revision for symptomatic HO. All patients were successfully fitted with prostheses and able to ambulate. To our knowledge, this is the only series in the literature to specifically describe retrograde intramedullary fixation of long bone fractures through the zone of traumatic amputation sites. The infectious risk is relatively low, whereas the union rate (100%) and successful prosthesis fitting are high. For patients with similar injuries, retrograde intramedullary fixation through the zone of amputation is a viable treatment option.

  8. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy

    PubMed Central

    Kaski, Diego; Yong, Keir X. X.; Paterson, Ross W.; Slattery, Catherine F.; Ryan, Natalie S.; Schott, Jonathan M.; Crutch, Sebastian J.

    2015-01-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients’ (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer’s disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer’s disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer’s disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with ‘sticky fixation’. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer’s disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large

  9. Cyanoacrylate surgical glue for mesh fixation in laparoscopic total extraperitoneal hernia repair.

    PubMed

    Garcia-Vallejo, Luis; Couto-Gonzalez, Ivan; Concheiro-Coello, Pablo; Brea-Garcia, Beatriz; Taboada-Suarez, Antonio

    2014-06-01

    In an attempt to find the ideal surgical technique for mesh fixation during laparoscopic total extraperitoneal inguinal hernia repair, we evaluate the use of a synthetic surgical glue (N-butyl-cyanoacrylate-Glubran 2) in an effort to reduce postoperative pain and the complications associated with the use of staples. We have prospectively evaluated 61 consecutive patients (73 hernias) with a minimum follow-up period of 18 months and an average of 29.7 months, without any significant complications present. The majority (59%) only required low dosages of painkillers during the first 24 hours after surgery and have not experienced any cases of chronic pain or recurring hernias in the time period described. On the basis of this initial experience, the use of the surgical glue used to repair inguinal hernias with the laparoscopic total extraperitoneal technique has been proved to be a simple and effective surgical method for mesh fixation.

  10. Anterior pre-tensioned external fixator for pelvic fractures and dislocations. Initial clinical series.

    PubMed

    Queipo-de-Llano, A; Lombardo-Torre, M; Leiva-Gea, A; Delgado-Rufino, F B; Luna-González, F

    2016-12-01

    In the treatment of unstable pelvic ring fractures, external fixators have the limitation of not adequately stabilizing the injured posterior elements. This article presents a novel and simple technique of temporary external fixation of the pelvic ring, able to produce compression of both the anterior and posterior pelvic elements. A curved flexible carbon-fiber rod is used, pre-tensioned before attachment to supra-acetabular Schanz screws. Although more extensive clinical experience is required, favorable preliminary results in a series of 13 patients with unstable pelvic fracture were encouraging: the aim of closing the posterior and anterior elements of the pelvic ring was achieved in all cases treated with this technique, and 12 patients survived. Radiological results were excellent in 3 cases and good in 9 cases. No major complications, such as secondary displacement, vertical re-displacement or deep infection, were observed. Mean operative time was 25min, compatible with emergency management.

  11. Pin guidance of reconstruction plate contour: an expanded role of external fixation.

    PubMed

    Jaquet, Yves; Higgins, Kevin M; Enepekides, Danny J

    2011-09-01

    This article presents a modification of intraoperative external fixation for mandibular reconstruction with free tissue flaps. This technique is indicated when preregistration of the reconstruction plate is not possible due to transmandibular tumor extension. Once standard external fixation has been carried out and prior to segmental mandibulectomy, additional pins are fixed to the connecting rod that delineate the mandibular contour in three-dimensional (3D) space. Following mandibulectomy, these pins allow accurate contouring of the reconstruction plate and improved restoration of mandibular contour, projection, and dental occlusion. A step-by-step description of the technique using models and intraoperative photos is presented. This method of mandibular reconstruction is a simple and time-effective alternative to intraoperative computer navigation and 3D modeling in select cases of oral carcinoma where tumor infiltration of the outer mandibular cortex precludes prebending of the reconstruction plates.

  12. Caudally directed Inferior facetal and transfacetal screws for C1-C2 and C1-2-3 fixation.

    PubMed

    Goel, Atul

    2017-01-13

    An alternative caudally directed C2 inferior facetal screw is described. Such screw insertion can form the axial stabilization point in cases undergoing atlantoaxial lateral mass plate/rod and screw fixation and those undergoing C1-2and C1-2-3 spinal fixation. The C2 screw courses from the medial point of pedicle-laminar junction and travels caudally and laterally towards the C2-3 articulation. Deploying a longer screw that traverses in a transarticular fashion into the facetal mass of C3 vertebra one can perform C1-2-3 stabilization.Sixteen patients underwent C2 inferior facetal or C2-3 transarticular screw in combination with C1 screw for atlantoaxial fixation. Three of these patients with multilevel spinal instability underwent atlantoaxial and C2-3 fixation using the discussed technique. The technical issues, anatomical subtleties and indication for the use of the C2 inferior facetal screws are discussed. With an average follow-up of 9 months, all screws have successfully provided stability that resulted in arthrodesis of the treated spinal segments. Caudally directed C2 inferior facetal screw can enhance the armamentarium of the surgeon, provide an alternative to conventional techniques or a bailout option and add to safety of the procedure of atlantoaxial lateral mass fixation in anatomically challenged situations.

  13. Bilateral C1–C2 Transarticular Screw and C1 Laminar Hook Fixation and Bone Graft Fusion for Reducible Atlantoaxial Dislocation: A Seven-Year Analysis of Outcome

    PubMed Central

    Guo, Xiang; Ni, Bin; Xie, Ning; Lu, Xuhua; Guo, Qunfeng; Lu, Ming

    2014-01-01

    Background Bilateral C1-2 transarticular screw and C1 laminar hook fixation was developed on the basis of transarticular screws fixation. The modified technique has showed a better biomechanical stability than established techniques in previous study. However, long-term (minimum follow-up 7 years) outcomes of patients with reducible atlantoaxial dislocation who underwent this modified fixation technique have not still been reported. Methods A retrospective study was conducted to evaluate the outcome of 36 patients who underwent this modified technique. Myelopathy was assessed using the Ranawat myelopathy score and Myelopathy Disability Index. Pain scores were assessed using Visual Analogue Scale. Radiological imaging was assessed and the following data were extracted: the atlantodental intervals, the space available for cord, presence of spinal cord signal change on T2 weighted image, C1–C2 angle, C2–C7 angle and fusion rates. Findings All patients achieved a minimum seven-year follow up. 95% patients with neck and suboccipital pain improved after surgery; in their Visual Analogue pain scores, there was a greater than 50% improvement in their VAS scores with a drop of 5 points on the VAS (P<0.05). 92% of patients improved in the Ranawat myelopathy grade; the Myelopathy Disability Index assessment showed a preoperative mean score of 35.62 with postoperative mean 12.75(P<0.05). There was not any significant atlantoaxial instability at each follow-up time. The space available for cord increased in all patients. Postoperative sagittal kyphosis of the subaxial spine was not observed. After six months after surgery, bone grafts of all patients were fused. No complications related to surgery were found in the period of follow-up. Conclusions The long-term outcomes of this case series demonstrate that under the condition of thorough preoperative preparations, bilateral C1–C2 transarticular screw and C1 laminar hook fixation and bone graft fusion is a reliable

  14. Arthroscopy-Assisted Reduction and Fixation of a Transversal Glenoid Fracture: About a Case

    PubMed Central

    Sali, Eric; Serane, Julien; Lefèvre, Edouard; Amsallem, Lior

    2017-01-01

    An articular glenoid fracture is an uncommon injury. Usually significantly displaced intra-articular glenoid fractures are treated with open reduction surgery. Conventional open surgery techniques involve high morbidity. Here we describe an arthroscopy-assisted reduction and fixation method of an Ideberg type III glenoid fracture. This method provides good articular reduction without extensive exposure or soft tissue dissection and without nerve and/or vascular lesion. PMID:28386498

  15. Gaze shifts and fixations dominate gaze behavior of walking cats

    PubMed Central

    Rivers, Trevor J.; Sirota, Mikhail G.; Guttentag, Andrew I.; Ogorodnikov, Dmitri A.; Shah, Neet A.; Beloozerova, Irina N.

    2014-01-01

    Vision is important for locomotion in complex environments. How it is used to guide stepping is not well understood. We used an eye search coil technique combined with an active marker-based head recording system to characterize the gaze patterns of cats walking over terrains of different complexity: (1) on a flat surface in the dark when no visual information was available, (2) on the flat surface in light when visual information was available but not required, (3) along the highly structured but regular and familiar surface of a horizontal ladder, a task for which visual guidance of stepping was required, and (4) along a pathway cluttered with many small stones, an irregularly structured surface that was new each day. Three cats walked in a 2.5 m corridor, and 958 passages were analyzed. Gaze activity during the time when the gaze was directed at the walking surface was subdivided into four behaviors based on speed of gaze movement along the surface: gaze shift (fast movement), gaze fixation (no movement), constant gaze (movement at the body’s speed), and slow gaze (the remainder). We found that gaze shifts and fixations dominated the cats’ gaze behavior during all locomotor tasks, jointly occupying 62–84% of the time when the gaze was directed at the surface. As visual complexity of the surface and demand on visual guidance of stepping increased, cats spent more time looking at the surface, looked closer to them, and switched between gaze behaviors more often. During both visually guided locomotor tasks, gaze behaviors predominantly followed a repeated cycle of forward gaze shift followed by fixation. We call this behavior “gaze stepping”. Each gaze shift took gaze to a site approximately 75–80 cm in front of the cat, which the cat reached in 0.7–1.2 s and 1.1–1.6 strides. Constant gaze occupied only 5–21% of the time cats spent looking at the walking surface. PMID:24973656

  16. Individual Objective and Subjective Fixation Disparity in Near Vision

    PubMed Central

    Jaschinski, Wolfgang

    2017-01-01

    Binocular vision refers to the integration of images in the two eyes for improved visual performance and depth perception. One aspect of binocular vision is the fixation disparity, which is a suboptimal condition in individuals with respect to binocular eye movement control and subsequent neural processing. The objective fixation disparity refers to the vergence angle between the visual axes, which is measured with eye trackers. Subjective fixation disparity is tested with two monocular nonius lines which indicate the physical nonius separation required for perceived alignment. Subjective and objective fixation disparity represent the different physiological mechanisms of motor and sensory fusion, but the precise relation between these two is still unclear. This study measures both types of fixation disparity at viewing distances of 40, 30, and 24 cm while observers fixated a central stationary fusion target. 20 young adult subjects with normal binocular vision were tested repeatedly to investigate individual differences. For heterophoria and subjective fixation disparity, this study replicated that the binocular system does not properly adjust to near targets: outward (exo) deviations typically increase as the viewing distance is shortened. This exo proximity effect—however—was not found for objective fixation disparity, which–on the average–was zero. But individuals can have reliable outward (exo) or inward (eso) vergence errors. Cases with eso objective fixation disparity tend to have less exo states of subjective fixation disparity and heterophoria. In summary, the two types of fixation disparity seem to respond in a different way when the viewing distance is shortened. Motor and sensory fusion–as reflected by objective and subjective fixation disparity–exhibit complex interactions that may differ between individuals (eso versus exo) and vary with viewing distance (far versus near vision). PMID:28135308

  17. Carbon dioxide fixation in green sulphur bacteria

    PubMed Central

    Sirevåg, Reidun; Ormerod, J. G.

    1970-01-01

    1. About one-third of the CO2 fixed during photosynthesis by washed suspensions of Chlorobium thiosulfatophilum strain 8346 gave rise to α-oxoglutarate and branched-chain oxo acids, mainly β-methyl-α-oxovalerate. Another one-third to one-half gave rise to a polyglucose. 2. The fixation of CO2 was inhibited by fluoroacetate, increasing concentrations up to 1mm stimulating the accumulation of α-oxoglutarate and causing a decrease in the formation of the branched-chain oxo acids and polyglucose. 3. Acetate was converted into the same products as was CO2. 4. Fluoroacetate (1mm) had a negligible effect on the formation of polyglucose from acetate and caused a slight inhibition of the formation of the branched-chain oxo acids and increased accumulation of α-oxoglutarate. 5. Iodoacetate (1mm) strongly inhibited polyglucose formation from acetate and caused accumulation of pyruvate. The formation of the branched-chain oxo acids from acetate was only slightly affected by this inhibitor. 6. Pyruvate can be metabolized by this organism in the presence of a suitable electron donor whether CO2 is present or not. In the absence of CO2 pyruvate is converted into polyglucose. 7. The accumulation of oxo acids during CO2 fixation is completely inhibited by NH4+ ions. The formation of the branched-chain oxo acids is considerably decreased by the presence of isoleucine, leucine or valine, or a mixture of these. 8. CO2 fixation in two other strains of Chlorobium appears to exhibit a similar pattern to that in C. thiosulfatophilum strain 8346. 9. It is concluded that in washed suspensions, CO2 is fixed mainly by a mechanism involving the reductive carboxylic acid cycle. Acetate, the product of the cycle, is converted into polyglucose via pyruvate synthase and a reversal of glycolysis or into branched-chain oxo acids by an unknown mechanism. PMID:5493862

  18. 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

  19. Alcohol-based solutions for bovine testicular tissue fixation.

    PubMed

    Cabrera, Nelson C; Espinoza, Jorge R; Vargas-Jentzsch, Paul; Sandoval, Patricio; Ramos, Luis A; Aponte, Pedro M

    2017-01-01

    Tissue fixation, a central element in histotechnology, is currently performed with chemical compounds potentially harmful for human health and the environment. Therefore, alternative fixatives are being developed, including alcohol-based solutions. We evaluated several ethanol-based mixtures with additives to study fixative penetration rate, tissue volume changes, and morphologic effects in the bovine testis. Fixatives used were Bouin solution, 4% formaldehyde (F4), 70% ethanol (E70), E70 with 1.5% glycerol (E70G), E70 with 5% acetic acid (E70A), E70 with 1.5% glycerol and 5% acetic acid (E70AG), and E70 with 1.5% glycerol, 5% acetic acid, and 1% dimethyl sulfoxide (DMSO; E70AGD). Five-millimeter bovine testicular tissue cubes could be completely penetrated by ethanol-based fixatives and Bouin solution in 2-3 h, whereas F4 required 21 h. Bouin solution produced general tissue shrinkage, whereas the other fixatives (alcohol-based and F4) caused tissue volume expansion. Although Bouin solution is an excellent fixative for testicular tissue, ethanol-based fixatives showed good penetration rates, low tissue shrinkage, and preserved sufficient morphology to allow identification of the stages of the seminiferous epithelium cycle, therefore representing a valid alternative for histotechnology laboratories. Common additives such as acetic acid, glycerol, and DMSO offered marginal benefits for the process of fixation; E70AG showed the best preservation of morphology with excellent nuclear detail, close to that of Bouin solution.

  20. Principles of intramedullary pin and wire fixation.

    PubMed

    Howard, P E

    1991-02-01

    Knowledge and experience in the proper use of IM pins, K-wires, and orthopedic wire is a valuable asset to the veterinarian's ability to successfully repair a variety of long bone fractures. Most long bone fractures are amenable to repair with this form of fixation. When the principles of application are violated or the implants are used when contraindicated, complications often occur. Proper use of these implants results in the successful management of complex fractures to the satisfaction of both the animal owner and the veterinarian (Fig 10).

  1. [The experimental investigations upon the influence of ocular fixation on habituation of postural reflexes in pigeon].

    PubMed

    Kaźmierczak, H

    1994-01-01

    The subject of investigation was the influence of ocular fixation on acquisition of habituation in experimental rotatory test in pigeons. The habituation training was performed in the three difference conditions: with full ocular fixation, fixation partly reduced and fixation excluded. Author confirmed that habituation with fixation excluded gave the best results of habituation of postural reflexes and head nystagmus in pigeons in rotatory training.

  2. Early breakage of a titanium volar locking plate for fixation of a distal radius fracture: case report.

    PubMed

    Yukata, Kiminori; Doi, Kazuteru; Hattori, Yasunori; Sakamoto, Soutetsu

    2009-01-01

    This report presents a case demonstrating the early breakage of a titanium volar locking plate implanted for internal fixation of a dorsally displaced distal radius fracture in which the dorsal cortex was severely comminuted. Careful selection of the proper plate and appropriate surgical technique and postoperative management are necessary to avoid this complication.

  3. Stoppa Approach for Anterior Plate Fixation in Unstable Pelvic Ring Injury

    PubMed Central

    Choo, Suk Kyu; Kim, Jung-Jae; Lee, Mark

    2016-01-01

    Background The Stoppa (intrapelvic) approach has been introduced for the treatment of pelvic-acetabular fractures; it allows easy exposure of the pelvic brim, where the bone quality is optimal for screw fixation. The purpose of our study was to investigate the surgical outcomes of unstable pelvic ring injuries treated using the Stoppa approach for stable anterior ring fixation. Methods We analyzed 22 cases of unstable pelvic ring injury treated with plate fixation of the anterior ring with the Stoppa approach. We excluded cases of nondisplaced rami fracture, simple symphyseal diastasis, and parasymphyseal fractures, which can be easily treated with other techniques. The average age of the study patients was 41 years (range, 23 to 61 years). There were 10 males and 12 females. According to the Young and Burgess classification, there were 12 lateral compression, 4 anteroposterior compression, and 6 vertical shear fracture patterns. The fracture location on the anterior ring was near the iliopectineal eminence in all cases and exposure of the pelvic brim was required for plate fixation. All patients were placed in the supine position. For anterior plate fixation, all screws were applied to the anterior ramus distally and directed above the hip joint proximally. Radiologic outcomes were assessed by union time and quality of reduction by Matta method. The Merle d'Aubigne-Postel score was used to evaluate the functional results. Results The average radiologic follow-up period was 16 months (range, 10 to 51 months). All fractures united at an average of 3.5 months (range, 3 to 5 months). According to the Matta method, the quality of reduction was classified as follows: 16 anatomical (73%) and 6 nearly anatomical (27%) reductions. There were no cases of screw or implant loosening before bone healing. The functional results were classified as 7 excellent (32%), 12 good (55%), and 3 fair (13%) by the Merle d'Aubigne-Postel score. There were no wound complications

  4. Ureide Assay for Measuring Nitrogen Fixation by Nodulated Soybean Calibrated by 15N Methods 1

    PubMed Central

    Herridge, David F.; Peoples, Mark B.

    1990-01-01

    of N solutes of xylem saps and extracts after flowering which were not related to a change in nitrogen fixation. Relationships between relative ureide-N and the proportion of plant N derived from nitrogen fixation were not affected by plant genotype or by strain of rhizobia. Therefore, assessment of nitrogen fixation by soybean using the ureide technique should now be possible with the standard curves presented, irrespective of genotype or strain of rhizobia occupying the nodules. PMID:16667494

  5. Randomized Prospective Study of Totally Extraperitoneal Inguinal Hernia Repair: Fixation Versus No Fixation of Mesh

    PubMed Central

    Koch, Cody A.; Greenlee, Susan M.; Larson, Dirk R.; Harrington, Jeffrey R.

    2006-01-01

    Background: Fixation of the mesh during laparoscopic totally extraperitoneal (TEP) inguinal hernia repair is thought to be necessary to prevent recurrence. However, mesh fixation may increase postoperative pain and lead to an increased risk of complications. We questioned whether elimination of fixation of the mesh during TEP inguinal hernia repair leads to decreased postoperative pain or complications, or both, without an increased rate of recurrence. Methods: A randomized prospective single-blinded study was carried out in 40 patients who underwent laparoscopic TEP inguinal hernia repair with (Group A=20) or without (Group B=20) fixation of the mesh. Results: Patients in whom the mesh was not fixed had shorter hospital length of stay (8.3 vs 16.0 hours, P=0.01), were less likely to be admitted to the hospital (P=0.001), used less postoperative narcotic analgesia in the PACU (P=0.01), and were less likely to develop urinary retention (P=0.04). No significant differences occurred in the level of pain, time to return to normal activity, or the difficulty of the operation between the 2 groups. No hernia recurrences were observed in either group (follow-up range, 6 to 30 months, median=19). Conclusions: Elimination of tack fixation of mesh during laparoscopic TEP inguinal hernia repair significantly reduces the use of postoperative narcotic analgesia, hospital length of stay, and the development of postoperative urinary retention but does not lead to a significant reduction in postoperative pain. Eliminating tacks does not lead to an increased rate of recurrence. PMID:17575757

  6. Comparison of iris-fixated foldable lens and scleral-fixated foldable lens implantation in eyes with insufficient capsular support

    PubMed Central

    Zhang, Han; Zhao, Jun; Zhang, Li-Jun; Liu, Jing; Liu, Yuan; Song, Wei; Tian, Qing-Fen; Wang, Qi; Hamilton, David-Rex

    2016-01-01

    AIM To compare the outcomes of vision using two different intraocular lens (IOL) replacement techniques, iris-fixated foldable intraocular lens (IF-IOL) and scleral-fixated foldable intraocular lens (SF-IOL) in patients with insufficient capsular support. METHODS Total 63 eyes (62 patients) with insufficient posterior capsule support underwent replacement of IF-IOL or SF-IOL between January 2008 and August 2011. Outcome measures included changes in visual acuity, slit lamp examination, refractive indices and corneal curvatures. RESULTS The mean improvement of uncorrected visual acuity (UCVA) was greater in IF-IOL group compared to the SF-IOL group (0.43 D±0.19 D vs 0.35 D±0.18 D, P<0.05). Moreover, 12 (38.71%) eyes in IF-IOL group and 4 (12.50%) in SF-IOL group had a higher postoperative UCVA than preoperative best corrected visual acuity (BCVA) while 9 (29.03%) eyes in IF-IOL group and 18 (56.25%) in SF-IOL group had a lower postoperative UCVA than preoperative BCVA. The myopic mean manifest sphere and mean cylinder magnitude were lower in the IF-IOL group than that in the SF-IOL group (-0.47 D±0.58 D vs 0.50 D±0.43 D, P<0.01; 0.84 D±0.53 D vs 1.23 D±0.70 D, P<0.05). No difference of corneal astigmatism and surgically induced astigmatism was found between the two groups. In addition, fewer complications were observed in IF-IOL eyes. CONCLUSION IF-IOL implantation can give a significant improvement in vision with fewer complications than SF-IOL in patients with insufficient capsular support. PMID:27990363

  7. Influence of tree canopy on N₂ fixation by pasture legumes and soil rhizobial abundance in Mediterranean oak woodlands.

    PubMed

    Carranca, C; Castro, I V; Figueiredo, N; Redondo, R; Rodrigues, A R F; Saraiva, I; Maricato, R; Madeira, M A V

    2015-02-15

    Symbiotic N2 fixation is of primordial significance in sustainable agro-forestry management as it allows reducing the use of mineral N in the production of mixed stands and by protecting the soils from degradation. Thereby, on a 2-year basis, N2 fixation was evaluated in four oak woodlands under Mediterranean conditions using a split-plot design and three replicates. (15)N technique was used for determination of N2 fixation rate. Variations in environmental conditions (temperature, rainfall, radiation) by the cork tree canopy as well as the age of stands and pasture management can cause great differences in vegetation growth, legume N2 fixation, and soil rhizobial abundance. In the present study, non-legumes dominated the swards, in particular beneath the tree canopy, and legumes represented only 42% of total herbage. A 2-fold biomass reduction was observed in the oldest sown pasture in relation to the medium-age sward (6 t DW ha(-1)yr(-1)). Overall, competition of pasture growth for light was negligible, but soil rhizobial abundance and symbiotic N2 fixation capacity were highly favored by this environmental factor in the spring and outside the influence of tree canopy. Nitrogen derived from the atmosphere was moderate to high (54-72%) in unsown and sown swards. Inputs of fixed N2 increased from winter to spring due to more favorable climatic conditions (temperature and light intensity) for both rhizobia and vegetation growths. Assuming a constant fixation rate at each seasonal period, N2 fixation capacity increased from about 0.10 kg N ha(-1) per day in the autumn-winter period to 0.15 kg N ha(-1) per day in spring. Belowground plant material contributed to 11% of accumulated N in pasture legumes and was not affected by canopy. Size of soil fixing bacteria contributed little to explain pasture legumes N.

  8. Comparison of screw fixation with elastic fixation methods in the treatment of syndesmosis injuries in ankle fractures.

    PubMed

    Seyhan, Mustafa; Donmez, Ferdi; Mahirogullari, Mahir; Cakmak, Selami; Mutlu, Serhat; Guler, Olcay

    2015-07-01

    17 patients with ankle syndesmosic injury were treated with a 4.5mm single cortical screw fixation (passage of screw 4 cortices) and 15 patients were treated with single-level elastic fixation material. All patients were evaluated according to the AOFAS ankle and posterior foot scale at the third, sixth and twelfth months after the fixation. The ankle range of movement was recorded together with the healthy side. The Student's t test was used for statistical comparisons. No statistical significant difference was observed between the AOFAS scores (p>0.05). The range of dorsiflexion and plantar flexion motion of the elastic fixation group at the 6th and 12th months were significantly better compared to the screw fixation group (p<0.01). Elastic fixation is as functional as screw fixation in the treatment of ankle syndesmosis injuries. The unnecessary need of a second surgical intervention for removal of the fixation material is another advantageous aspect of this method of fixation.

  9. Hemi-hamate arthroplasty versus transarticular Kirschner wire fixation for unstable dorsal fracture-dislocation of the proximal interphalangeal joint in the hand.

    PubMed

    Barksfield, R C; Bowden, B; Chojnowski, A J

    2015-01-01

    Following the introduction of the hemi-hamate arthroplasty (HHA) technique to our unit, we sought to evaluate the early clinical outcomes achieved with this method of fixation and compare these with simple trans-articular Kirschner wire (K-wire) fixation for dorsal fracture dislocations (DFD) of the proximal interphalangeal joint (PIPJ). Ninteen patients underwent fixation of these injuries with either K-wire fixation (12/19) or hemi-hamate bone grafting (7/19) between 2005 and 2011. At a mean follow-up of 14 weeks median arc of movement at the PIPJ was 65° (range 31° to 108°) following HHA and 56° (range 9° to 85°) (p = 0.82) following temporary transarticular K-wire fixation. Median fixed flexion deformity (FFD) was 20° and 15° for hemi-hamate bone grafting and K-wire fixation respectively. Based upon our findings, transarticular K-wire fixation produced equivalent outcomes to HHA for unstable DFD of the PIPJ in the hand.

  10. Phosphoribulokinase mediates nitrogenase-induced carbon dioxide fixation gene repression in Rhodobacter sphaeroides

    PubMed Central

    Farmer, Ryan M.

    2015-01-01

    In many organisms there is a balance between carbon and nitrogen metabolism. These observations extend to the nitrogen-fixing, nonsulfur purple bacteria, which have the classic family of P(II) regulators that coordinate signals of carbon and nitrogen status to regulate nitrogen metabolism. Curiously, these organisms also possess a reverse mechanism to regulate carbon metabolism based on cellular nitrogen status. In this work, studies in Rhodobacter sphaeroides firmly established that the activity of the enzyme that catalyses nitrogen fixation, nitrogenase, induces a signal that leads to repression of genes encoding enzymes of the Calvin–Benson–Bassham (CBB) CO2 fixation pathway. Additionally, genetic and metabolomic experiments revealed that NADH-activated phosphoribulokinase is an intermediate in the signalling pathway. Thus, nitrogenase activity appears to be linked to cbb gene repression through phosphoribulokinase. PMID:26306848

  11. Effect of insecticides and phenolics on nitrogen fixation by Nostoc linckia

    SciTech Connect

    Megharaj, M.; Venkateswarlu, K.; Rao, A.S.

    1988-08-01

    The nitrogen-fixing blue-green algae (cyanobacteria) significantly influence the nitrogen economy of temperate and tropical soils. Although the genera Nostoc and Tolypothrix have been particularly implicated in the fixation of significantly large amounts of atmospheric nitrogen, these diazotrophs received little attention in relation to insecticide treatment and the available few reports do not indicate a permanent deleterious effect of insecticides on their nitrogenase activity. As it has been well established that the effect of insecticides on nitrogen fixation by cyanobacteria is independent of that on growth, an attempt was, therefore, made to determine the influence of four insecticides (monocrotophos, quinalphos, cypermethrin and fenvalerate) and four phenolics (p-nitrophenol (PNP), m-nitrophenol (MNP), 2,4-dinitrophenol (DNP) and catechol) on nitrogen-fixing capacity of N.linckia, isolated from a black soil.

  12. Analysis of Bone Fixation Methods in Digital Replantation

    PubMed Central

    Lee, Seung Woo; Kim, Jin Soo; Roh, Si Young; Lee, Kyung Jin

    2017-01-01

    Background Adequate fixation of replanted digits is essential not only for short-term healing but for long-term function. Various bony fixation methods using Kirschner (K-) and intraosseous wire are available in replantation. We examined clinical and radiographic outcomes of fixation methods on bone union after digital replantation. Methods A single institutional retrospective review identified 992 patients who had undergone 1,247 successful replantations between July 2009 and September 2015. Exclusion criteria included amputations of the distal phalanx, comminuted fractures, and intra-articular fractures. Patients were classified according to 5 categories of fixation methods: single K-wire, double longitudinal K-wires, cross K-wires, wire with, and wire without K-wire support. Bone union was evaluated by 5-month postoperative X-ray and fixation outcomes were compared across the 5 groups. Results The exclusion criteria were applied, and 88 patients with 103 replanted digits remained for analysis. Single K-wire fixation was used in 40 digits, double longitudinal K-wires in 30, and cross fixation in 14. Wire with and without K-wire support was required in 15 and 4 digits. Nonunion was observed in 32 digits (31.1%), of which 13 required additional operations such as bone graft or corrective osteotomy. The highest percent of nonunion was observed after cross fixation (35.7%) and the lowest after wire alone (25.0%). Conclusions In this study, contrary to general knowledge, we found that single K-wire fixation was not associated with poorer outcomes. Successful bone union outcomes may be achieved by careful selection of bone fixation methods. This study provides useful information for planning bone fixation in digital replantation. PMID:28194348

  13. Surgical anatomy for pelvic external fixation.

    PubMed

    Solomon, L B; Pohl, A P; Chehade, M J; Malcolm, A M; Howie, D W; Henneberg, M

    2008-10-01

    Pelvic external fixators have a high rate of reported complications, most of which relate to pin placement. In this descriptive study, we analyzed the morphology of the ilium in cadaveric specimens and compared these with the measures obtained from normal human pelvic computer tomograph scans, and how these related to each of the three basic configurations of pin positioning for the external fixation of a pelvis: anterosuperior (Slätis type), anteroinferior (supra-acetabular), and subcristal. The irregular shape and size of the iliac wing and the abdominal wall overlying the pin's insertion site could hinder accurate placement of anterosuperior pins. Potential disadvantages of the use of anteroinferior pins was found related to the deep location of the anterior inferior iliac spine, interference with the hip flexion area, risk of hip joint penetration, and the variable obliquity of the ilium. As subcristal pins are positioned between two superficial bony landmarks of the iliac crest, our findings suggest that they are more likely to have a correct placement and avoid complications.

  14. Simple clearing technique as species determination tool in blowfly larvae.

    PubMed

    Niederegger, Senta; Wartenberg, Nelly; Spiess, Roland; Mall, Gita

    2011-03-20

    A simple clearing technique is presented by which species specific structures and organs of blowfly larvae can easily be visualized and displayed without any danger of mechanical damages or dislocations of delicate formations and without fixation of the object.

  15. Carbon sequestration in soybean crop soils: the role of hydrogen-coupled CO2 fixation

    NASA Astrophysics Data System (ADS)

    Graham, A.; Layzell, D. B.; Scott, N. A.; Cen, Y.; Kyser, T. K.

    2011-12-01

    Conversion of native vegetation to agricultural land in order to support the world's growing population is a key factor contributing to global climate change. However, the extent to which agricultural activities contribute to greenhouse gas emissions compared to carbon storage is difficult to ascertain, especially for legume crops, such as soybeans. Soybean establishment often leads to an increase in N2O emissions because N-fixation leads to increased soil available N during decomposition of the low C:N legume biomass. However, soybean establishment may also reduce net greenhouse gas emissions by increasing soil fertility, plant growth, and soil carbon storage. The mechanism behind increased carbon storage, however, remains unclear. One explanation points to hydrogen coupled CO2 fixation; the process by which nitrogen fixation releases H2 into the soil system, thereby promoting chemoautotrophic carbon fixation by soil microbes. We used 13CO2 as a tracer to track the amount and fate of carbon fixed by hydrogen coupled CO2 fixation during one-year field and laboratory incubations. The objectives of the research are to 1) quantify rates of 13CO2 fixation in soil collected from a field used for long-term soybean production 2) examine the impact of H2 gas concentration on rates of 13CO2 fixation, and 3) measure changes in δ13C signature over time in 3 soil fractions: microbial biomass, light fraction, and acid stable fraction. If this newly-fixed carbon is incorporated into the acid-stable soil C fraction, it has a good chance of contributing to long-term soil C sequestration under soybean production. Soil was collected in the field both adjacent to root nodules (nodule soil) and >3cm away (root soil) and labelled with 13CO2 (1% v/v) in the presence and absence of H2 gas. After a two week labelling period, δ13C signatures already revealed differences in the four treatments of bulk soil: -17.1 for root, -17.6 for nodule, -14.2 for root + H2, and -6.1 for nodule + H2

  16. Minimally-invasive internal fixation of extra-articular distal femur fractures using a locking plate: tricks of the trade.

    PubMed

    Ehlinger, M; Adam, P; Abane, L; Arlettaz, Y; Bonnomet, F

    2011-04-01

    Fractures of the distal femur are rare and occur in two distinct population categories: young patients after high energy traumas and elderly patients who fall from their full height, and often carry severe co-morbidities making especially difficult to manage theses complex injuries. In elderly patients the potential complications are numerous including infection, non-union and frequent function deterioration. We present a technique of minimally invasive internal fixation of the distal extra-articular femur using a locking plate and present the tricks of the trade to obtain successful reduction and achieve union. The hardware used includes plate fixation with a large fragment locking screw. This minimally invasive surgery combines stability of the internal fixation device with the principles of closed surgery, allowing early mobilization and immediate weight bearing to warrant good functional recovery.

  17. Revisiting Tension Band Fixation for Difficult Patellar Fractures.

    PubMed

    Hambright, Dustin S; Walley, Kempland C; Hall, Amber; Appleton, Paul T; Rodriguez, Edward K

    2017-02-01

    Patella fractures with comminution, osteoporotic bone, and/or previously failed fixation are exceedingly difficult to reduce and fix. Moreover, the risk of symptomatic constructs and patients who are poorly compliant with postoperative activity restrictions can make these complex fracture patterns an even more challenging scenario. Although there is an array of techniques described for comminuted patella fractures, there lacks an accepted surgical technique for these difficult cases. In this clinical series, we describe an enhancement to the traditional tension band construct that uses additional wires and multiple tension bands to gather and fix comminuted fracture patterns in nontransverse planes, bolster osteoporotic bone, and secure fractures in patients undergoing a revision and/or have potential to be poorly compliant with postoperative activity restrictions. The clinical outcomes of 27 patients demonstrate high rates of bony union, functional range of motion, and low rates of both infection and failure. In conclusion, using the basic principles of tension band wiring remains highly versatile, useful, and economical in approaching difficult patella fractures.

  18. Nitrogen fixation in boreal peatlands: the effects of increased N deposition on N2-fixation

    NASA Astrophysics Data System (ADS)

    Popma, J. M.; Wieder, R.; Lamers, L.; Vile, M. A.

    2013-12-01

    Boreal peatlands are of great importance to global carbon and nitrogen cycling. While covering only 3-4 % of the terrestrial surface, they account for 25-30 % of the world's soil C and 9-15 % of the world's soil N. In Western Canada atmospheric dry deposition rates are extremely low: approximately 1 kg N ha-1 yr-1. Though these systems have been functioning as net sinks over the past 11,000 years, natural and anthropogenic disturbances might compromise the historical balance of C and N. Biological N2-fixation has recently been shown to represent a very significant input of N into these systems, contributing to 62% of total N in Western Canada. Interactions between N deposition and biological N2-fixation are as yet, unknown, but the impact of elevated deposition of N-compounds from increased industrial expansion of oil sands mining to peatlands, is concerning. Given that nitrogenase, the enzyme responsible for catalyzing N2-fixation, is energetically costly when active, enhanced inputs of atmospheric N deposition could be a major determinant for enzyme activity and rates of biological N input to these bogs. Understanding interactions between N deposition and N2 fixation in boreal peatlands can aid in predicting the consequences of increased N deposition and setting critical loads. We conducted a field-fertilization experiment in a poor fen in Alberta, Canada, to determine the effects of enhanced N deposition on a dominant fen species Sphagnum angustifolium. The experiment consisted of seven N treatments: Control, 0, 5, 10, 15, 20 and 25 kg N ha-1 y1, n=3. N2-fixation was measured during summer 2012 and 2013 using the acetylene reduction assay (ARA). ARA rates were converted to rates of N2-fixation by calibrating ARA with paired 15N2-incubations. In both 2012 and 2013, with increasing N deposition from 0 kg N ha-1 yr-1 to 25 kg N ha-1 yr-1, rates of N2 fixation decreased, with highest rates in the 0 kg N ha-1 yr-1 treatment mosses (54.2 × 1.40; 48.58 × 7.12 kg N ha

  19. A modified Harrington technique for scoliosis.

    PubMed

    Allen, B L; Ferguson, R L; Stasikelis, P J

    1998-04-01

    Post-Harrington techniques for adolescent idiopathic scoliosis have increased the complexity of scoliosis surgery while contributing only biomechanically more secure fixation and sagittal contour preservation. On the the basis of principles defined by Harrington, the authors developed a simplified technique that accomplishes equivalent outcomes.

  20. TREATMENT OF POST-TRAUMATIC HUMERAL FRACTURES AND COMPLICATIONS USING THE OSTEOLINE® EXTERNAL FIXATOR: A TREATMENT OPTION

    PubMed Central

    de Azevedo, Marcos Coelho; de Azevedo, Gualter Maldonado; Hayashi, Alexandre Yoshio; Dourado Nascimento, Paulo Emilio

    2015-01-01

    To evaluate the results obtained from treatment of humeral shaft fractures and their complications using the Osteoline® uniplanar external fixator. Methods: The radiographic and functional results from 78 patients with humeral shaft fractures treated using the uniplanar external fixation technique were retrospectively assessed. The patients' ages ranged from 23 to 71 years, with a mean of 47 years. Male patients predominated (79%). Out of the 78 patients, 45 presented open fractures, 14 presented pseudarthrosis and six presented synthesis failure. There were no losses during the follow-up and all the patients were discharged after fracture consolidation and functional recovery. The results were evaluated based on the studies by Catagni, as good, fair or poor. Results: Fracture consolidation was observed in 98% of the cases treated with uniplanar external fixation. Only one pseudarthrosis case required conversion to rigid internal fixation and autologous bone grafting. At the end of the treatment, all the patients were discharged with consolidated fractures, without pain, and good limb function. Conclusion: The external fixation described in this paper was shown to be an efficient and safe method for treating humeral shaft fractures and their complications. It preserved the local biological status and enabled passive and active movement immediately after surgery. PMID:27027026

  1. Vacuum sealing drainage therapy in the presence of an external fixation device

    PubMed Central

    Sun, Dahui; Ju, Weina; Wang, Tiejun; Yu, Tiecheng; Qi, Baochang

    2016-01-01

    Abstract Rationale: Vacuum sealing drainage (VSD) is widely utilized for treating traumatic wounds. Patient concerns: It is particularly difficult and time consuming to use in combination with an external fixator. Diagnoses: This is because the hardware or pins used for fixation interfere with maintaining a seal, resulting in poor adhesion and subsequent air leakage. Interventions: To resolve this problem, we have devised a new method for sealing the wound dressing, while maintaining the required vacuum.When using this technique, a rubber strip is wrapped around each pin in 3 circles outside the plastic drape, and then tightly tied. Outcomes: After completing this procedure, a vacuum is obtained, and any air leakage stops. We employed this technique to treat a cohort of patients in our department over a period of two years, and obtained good healing of soft tissue without air leakage, as well as good clinical outcomes. Lessons: We have observed that patients treated with this method experienced good clinical outcomes without air leakage, and we recommend its use in treating cases where an external fixation device is present. PMID:27861393

  2. Implantable Subcutaneous Venous Access Devices: Is Port Fixation Necessary? A Review of 534 Cases

    SciTech Connect

    McNulty, Nancy J. Perrich, Kiley D.; Silas, Anne M.; Linville, Robert M.; Forauer, Andrew R.

    2010-08-15

    Conventional surgical technique of subcutaneous venous port placement describes dissection of the port pocket to the pectoralis fascia and suture fixation of the port to the fascia to prevent inversion of the device within the pocket. This investigation addresses the necessity of that step. Between October 8, 2004 and October 19, 2007, 558 subcutaneous chest ports were placed at our institution; 24 cases were excluded from this study. We performed a retrospective review of the remaining 534 ports, which were placed using standard surgical technique with the exception that none were sutured into the pocket. Mean duration of port use, total number of port days, indications for removal, and complications were recorded and compared with the literature. Mean duration of port use was 341 days (182,235 total port days, range 1-1279). One port inversion/flip occurred, which resulted in malfunction and necessitated port revision (0.2%). Other complications necessitating port removal included infection 26 (5%), thrombosis n = 2 (<1%), catheter fracture/pinch n = 1 (<1%), pain n = 2 (<1%), and skin erosion n = 3 (1%). There were two arrhythmias at the time of placement; neither required port removal. The overall complication rate was 7%. The 0.2% incidence of port inversion we report is concordant with that previously published, although many previous reports do not specify if suture fixation of the port was performed. Suture fixation of the port, in our experience, is not routinely necessary and may negatively impact port removal.

  3. Effects of the end fixation of airplane struts

    NASA Technical Reports Server (NTRS)

    Teichmann, Alfred

    1930-01-01

    The main purpose of this report is to give references to literature on the subject of end fixation of airplane struts and also to furnish the constructor with a general survey of the simplest methods for estimating the end-fixation effect.

  4. Microbial community shifts influence patterns in tropical forest nitrogen fixation.

    PubMed

    Reed, Sasha C; Townsend, Alan R; Cleveland, Cory C; Nemergut, Diana R

    2010-10-01

    The role of biodiversity in ecosystem function receives substantial attention, yet despite the diversity and functional relevance of microorganisms, relationships between microbial community structure and ecosystem processes remain largely unknown. We used tropical rain forest fertilization plots to directly compare the relative abundance, composition and diversity of free-living nitrogen (N)-fixer communities to in situ leaf litter N fixation rates. N fixation rates varied greatly within the landscape, and 'hotspots' of high N fixation activity were observed in both control and phosphorus (P)-fertilized plots. Compared with zones of average activity, the N fixation 'hotspots' in unfertilized plots were characterized by marked differences in N-fixer community composition and had substantially higher overall diversity. P additions increased the efficiency of N-fixer communities, resulting in elevated rates of fixation per nifH gene. Furthermore, P fertilization increased N fixation rates and N-fixer abundance, eliminated a highly novel group of N-fixers, and increased N-fixer diversity. Yet the relationships between diversity and function were not simple, and coupling rate measurements to indicators of community structure revealed a biological dynamism not apparent from process measurements alone. Taken together, these data suggest that the rain forest litter layer maintains high N fixation rates and unique N-fixing organisms and that, as observed in plant community ecology, structural shifts in N-fixing communities may partially explain significant differences in system-scale N fixation rates.

  5. 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...

  6. Complications of open reduction and internal fixation of ankle fractures.

    PubMed

    Leyes, Manuel; Torres, Raúl; Guillén, Pedro

    2003-03-01

    This article discusses the complications after open reduction and internal fixation of ankle fractures. Complications are classified as perioperative (malreduction, inadequate fixation, and intra-articular penetration of hardware), early postoperative (wound edge dehiscence, necrosis, infection and compartment syndrome), and late (stiffness, distal tibiofibular synostosis, degenerative osteoarthritis, and hardware related complications). Emphasis is placed on preventive measures to avoid such complications.

  7. 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.…

  8. 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...

  9. Low Carbon Costs of Nitrogen Fixation in Tropical Dry Forests

    NASA Astrophysics Data System (ADS)

    Gei, M. G.; Powers, J. S.

    2015-12-01

    Legume tree species with the ability to fix nitrogen (N) are highly diverse and widespread across tropical forests but in particular in the dry tropics. Their ecological success in lower latitudes has been called a "paradox": soil N in the tropics is thought to be high, while acquiring N through fixation incurs high energetic costs. However, the long held assumptions that N fixation is limited by photosynthate and that N fixation penalizes plant productivity have rarely been tested, particularly in legume tree species. We show results from three different experiments where we grew eleven species of tropical dry forest legumes. We quantified plant biomass and N fixation using nodulation and the 15N natural isotope abundance (Ndfa or nitrogen derived from fixation). These data show little evidence for costs of N fixation in seedlings grown under different soil fertility, light regimes, and with different microbial communities. Seedling productivity did not incur major costs because of N fixation: indeed, the average slope between Ndfa and biomass was positive (range in slopes: -0.03 to 0.3). Moreover, foliar N, which varied among species, was tightly constrained and not correlated with Ndfa. This finding implies that legume species have a target N that does not change depending on N acquisition strategies. The process of N fixation in tropical legumes may be more carbon efficient than previously thought. This view is more consistent with the hyperabundance of members of this family in tropical ecosystems.

  10. 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...

  11. 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...

  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. Modeling evolution using the probability of fixation: history and implications.

    PubMed

    McCandlish, David M; Stoltzfus, Arlin

    2014-09-01

    Many models of evolution calculate the rate of evolution by multiplying the rate at which new mutations originate within a population by a probability of fixation. Here we review the historical origins, contemporary applications, and evolutionary implications of these "origin-fixation" models, which are widely used in evolutionary genetics, molecular evolution, and phylogenetics. Origin-fixation models were first introduced in 1969, in association with an emerging view of "molecular" evolution. Early origin-fixation models were used to calculate an instantaneous rate of evolution across a large number of independently evolving loci; in the 1980s and 1990s, a second wave of origin-fixation models emerged to address a sequence of fixation events at a single locus. Although origin fixation models have been applied to a broad array of problems in contemporary evolutionary research, their rise in popularity has not been accompanied by an increased appreciation of their restrictive assumptions or their distinctive implications. We argue that origin-fixation models constitute a coherent theory of mutation-limited evolution that contrasts sharply with theories of evolution that rely on the presence of standing genetic variation. A major unsolved question in evolutionary biology is the degree to which these models provide an accurate approximation of evolution in natural populations.

  14. Soil fixative study progress report aerial application test:

    SciTech Connect

    Teter, A.C.

    1988-03-01

    A soil fixative has been developed (a simple wheat flour paste mixture) and tested in the laboratory that appears suitable for the temporary fixation of radioactive dusts in case of an accidental spill. A limited field test was made and the feasibility of aircraft delivery examined. A videotape was made of the operations. 3 figs.

  15. Intramedullary Allograft Fibula as a Reduction and Fixation Tool for Treatment of Complex Proximal Humerus Fractures with Diaphyseal Extension.

    PubMed

    Berkes, Marschall B; Little, Milton Tm; Lazaro, Lionel E; Cymerman, Rachel M; Pardee, Nadine C; Helfet, David L; Dines, Joshua S; Lorich, Dean G

    2013-05-15

    SUMMARY:: In this study, we present a novel technique for reduction and fixation of complex, unstable, proximal humerus fractures with diaphyseal extension with the assistance of fibula allograft. We treated 14 patients using this technique since 2009 and found that it improves the reduction and enhances fixation while making the surgical procedure technically more manageable, and allows for early postoperative motion. In the first part of this study, we describe in detail the indications and surgical technique applied to these fractures. In the second part, we review the clinical and radiographic outcomes of these patients. Using this new technique, we have achieved an excellent union rate with minimal incidence of complications when treating these challenging fractures.

  16. In vivo bone tunnel remodeling in symptomatic patients after ACL reconstruction: a retrospective comparison of articular and extra-articular fixation

    PubMed Central

    Mathis, Dominic T.; Rasch, Helmut; Hirschmann, Michael T.

    2015-01-01

    Summary Background there is only a paucity of studies dealing with bone remodeling within the tunnels after anterior cruciate ligament (ACL) reconstruction. The objective of this study was to evaluate the influence of tendon graft type and surgical fixation technique on bone tunnel remodeling in patients with symptomatic knees after ACL reconstruction. Methods in a retrospective study 99mTc-HDP bone tracer uptake (BTU) in SPECT/CT of 57 knees with symptoms of pain and/or instability after ACL reconstruction was investigated. All 57 knees were subdivided according their anatomy (femur and tibia), fixation (articular versus extra-articular fixation) and graft types into eight groups: femoral-articular versus extra-articular fixation using bone-patellar tendon-bone (BPTB) and hamstring autografts; tibial-articular versus extra-articular fixation using patellar tendon and hamstring autografts; BTU grading for each area of the localisation scheme were recorded. Tunnel diameter and length was measured in the CT scans. Results BTU was higher for the articular fixation in the femur and for the extra-articular fixation in the tibial tunnel. Patellar tendon graft fixation showed a significantly higher BTU in the superior-lateral and posterior-central area of the tibia, meaning the areas of the tibial tunnel near the entrance into the joint. Tunnel enlargement correlated significantly with increased BTU (p<0.05). Conclusion assessment of in vivo bone tunnel remodelling in symptomatic patients after ACL reconstruction revealed different patterns of BTU with regards to graft and fixation method. PMID:26958543

  17. A formalin fixative for immunochemical and ultrastructural studies on gastrointestinal endocrine cells.

    PubMed Central

    Robinson, G; Dawson, I

    1979-01-01

    Using indirect immunofluorescence, indirect immunoperoxidase, and unlabelled antibody enzyme techniques, gastrin, pancreatic glucagon, insulin, and somatostatin were localised in sections of both wax- and resin-embedded tissues that had been fixed in a buffered formalin solution. Ultrastructural preservation of the resin-embedded samples was also adequate for combined electron microscopy and light microscope immunochemistry. As the fixative concerned is stable it can be permanently available in surgical units. It is suggested, therefore, that this fixative should prove useful as an alternative to buffered formaldehyde, which must be freshly prepared from paraformaldehyde powder, in institutions where specimen collection is difficult or which have to refer cases with an endocrine involvement to other laboratories for immunochemical and fine structural examination. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:372249

  18. Use of an elastic transarticular external fixator construct for immobilization of the elbow joint.

    PubMed

    Vedrine, Bertrand

    2017-04-01

    Transarticular external skeletal fixation usually involves rigid bars that result in a stable but stiff joint. This study describes the technique and the outcome of an elastic transarticular external fixator (ETEF) applied to the elbow joint. Four cases of elbow luxation with collateral ligament injuries were managed with closed reduction and application of an ETEF to maintain the reduction. A triceps tendon avulsion was surgically managed before applying an ETEF. The clinical outcome was considered excellent in 2 cats, good in 2 dogs (1 elbow luxation and the avulsion of the triceps tendon), and poor in 1 dog presented for elbow luxation and a permanent neurological defect. The procedure was rapid, easy to perform, and inexpensive. All animals except the one with a neurological defect had an early return to weight bearing. This method maintains extension of the joint while permitting its motion thereby promoting rehabilitation.

  19. Laminar screw fixation in the subaxial cervical spine: A report on three cases

    PubMed Central

    Tanabe, Hironori; Aota, Yoichi; Saito, Tomoyuki

    2016-01-01

    Although laminar screw fixation is often used at the C2 and C7 levels, only few previous case reports have presented the use of laminar screws at the C3-C6 levels. Here, we report a novel fixation method involving the use of practical laminar screws in the subaxial spine. We used laminar screws in the subaxial cervical spine in two cases to prevent vertebral artery injury and in one case to minimize exposure of the lamina. This laminar screw technique was successful in all three cases with adequate spinal rigidity, which was achieved without complications. The use of laminar screws in the subaxial cervical spine is a useful option for posterior fusion of the cervical spine. PMID:27795952

  20. Fixation orientation in ankle fractures with syndesmosis injury.

    PubMed

    Nimick, Craig J; Collman, David R; Lagaay, Pieter

    2013-01-01

    Accurate reduction of the syndesmosis has been shown to be an important prognostic factor for functional outcome in ankle injuries that disrupt the syndesmosis. The purpose of the present case series was to assess the fixation orientation and the position of the fibula within the tibial incisura after open reduction and internal fixation of ankle fractures with syndesmosis injury. Computed tomography was used to assess the accuracy of the reduction. Twelve patients were included in the present case series. A ratio representing the relationship between the tibia and fibula and the orientation of the syndesmotic fixation was measured preoperatively and postoperatively and compared with the uninjured contralateral ankle, representing the patient's normal anatomy. The measurements were accomplished electronically to one tenth of 1 mm using Stentor Intelligent Informatics, I-site, version 3.3.1 (Phillips Electronics; Andover, MA). Posteriorly oriented syndesmotic fixation caused posterior translation of the fibula with respect to the tibia and anteriorly oriented syndesmotic fixation caused anterior translation.

  1. Surgical Revision after Sacroiliac Joint Fixation or Fusion

    PubMed Central

    Holt, Timothy

    2017-01-01

    Background Minimally invasive sacroiliac joint (SIJ) fusion has been shown to be safe and effective for the treatment of SIJ dysfunction. Multiple devices are available to perform SIJ fixation or fusion. Surgical revision rates after these procedures have not been directly compared. Methods We retrospectively identified all patients in our practice who underwent SIJ fixation or fusion between 2003 and 2015. Using both chart review and focused contact with individual patients, we determined the likelihood of surgical revision. Revision rates were compared using Kaplan-Meier survival analysis. Results Thirty-eight patients underwent SIJ fixation with screws and 274 patients underwent SIJ fusion using triangular titanium implants. Four-year cumulative revision rates were 30.8% for fixation and 5.7% for fusion. Conclusions In our study, SIJ fixation with screws had a much higher revision rate compared to SIJ fusion with triangular titanium implants designed for bone adherence.

  2. Intramedullary Tibial Nail Fixation of Simple Intraarticular Distal Tibia Fractures.

    PubMed

    Scolaro, John A; Broghammer, Francis H; Donegan, Derek J

    2016-11-01

    The optimal treatment strategy for distal tibia fractures, especially those with intraarticular extension, remains controversial. Although open reduction and internal fixation with a plate and screw device is commonly performed for these injuries, the risk of soft tissue complications using this approach is significant. Staged treatment protocols and alternative means of fixation have been proposed to address these undesired events. Although potentially more technically demanding than fixation of diaphyseal or extraarticular tibial fractures, intramedullary nail (IMN) fixation of simple intraarticular distal tibia fractures is a viable treatment alternative with unique advantages. This article presents a review of the literature and rationale for intramedullary tibial nail fixation of simple intraarticular distal tibia fractures and a surgical approach commonly utilized for successful implementation.

  3. Fixation Versus Replacement in Geriatric Hip Fractures

    PubMed Central

    Doshi, H. K.; Selvaraj, Dahshaini; Chan, William; Naidu, G.; Ramason, R.

    2015-01-01

    Introduction: Although there is evidence of improved functional outcomes with our “integrated care pathway” for geriatric hip fractures, we do not know if there is a significant difference in functional recovery of activities of daily living and attainment of independence in self-care between patients who underwent fixation and those treated with arthroplasty. Objective: To determine whether such a difference exists in surgically fixed hip fractures. Materials and Methods: Patients with hip fracture treated surgically were divided into group A (internal fixation, n = 213) and group B (arthroplasty, n = 199). Demographic data, Charlson comorbidity index (CCI) score, time to surgery, and length of stay were recorded. Inpatient complications and mortality rates were also documented. Modified Barthel Index (MBI) scores were recorded for the following intervals: prefall, discharge, 6-month, and at 1-year follow-up. Results: The mean age (A: 80 years and B: 81years), CCI (A: 5.41 and B: 5.43), and length of stay (A: 13.6 days and B: 15.2 days) were not significantly different. However, there was a significant difference (P < .05) in time to surgery (A: 102.2 hours and B: 86.6 hours). Complication rates were about 6% in both groups (A = 6.57%: urinary infections = 13, wound infections = 1 and B = 6.03%: urinary infections = 10, wound infections = 1, pressure ulcer = 1). The preinjury MBI scores were significantly different (P < .05; A: 91.65 and B: 88.19), however, there was no significant difference in scores measured at discharge (A: 60.79 and B: 59.39), 6 months (A: 77.65 and B: 77.47) and 1 year (A: 80.71 and B: 83.03). Patients who underwent surgery for hip fracture had overall recovered 90.9% of their preinjury function (overall MBI at 1 year: 81.83). Conclusion: The MBI scores reflect the extent of attainment of independence in self-care, and actual functional recovery is gauged from the percentage of recovery of preinjury function at 1 year postsurgery. We

  4. Flexible fixation of syndesmotic diastasis using the assembled bolt-tightrope system

    PubMed Central

    2013-01-01

    Background Syndesmotic diastasis is a common injury. Syndesmotic bolt and tightrope are two of the commonly used methods for the fixation of syndesmotic diastasis. Syndesmotic bolt can be used to reduce and maintain the syndesmosis. However, it cannot permit the normal range of motion of distal tibiofibular joint, especially the rotation of the fibula. Tightrope technique can be used to provide flexible fixation of the syndesmosis. However, it lacks the ability of reducing the syndesmotic diastasis. To combine the advantages of both syndemostic bolt and tightrope techniques and simultaneously avoid the potential disadvantages of both techniques, we designed the assembled bolt-tightrope system (ABTS). The purpose of this study was to evaluate the primary effectiveness of ABTS in treating syndesmotic diastasis. Methods From October 2010 to June 2011, patients with syndesmotic diastasis met the inclusion criteria were enrolled into this study and treated with ABTS. Patients were followed up at 2, 6 weeks and 6, 12 months after operation. The functional outcomes were assessed according to the American Orthopedic Foot and Ankle Society (AOFAS) scores at 12 months follow-up. Patients’ satisfaction was evaluated based upon short form-12 (SF-12) health survey questionnaire. The anteroposterior radiographs of the injured ankles were taken, and the medial clear space (MCS), tibiofibular overlap (TFOL), and tibiofibular clear space (TFCS) were measured. All hardwares were routinely removed at 12-month postoperatively. Follow-ups continued. The functional and radiographic assessments were done again at the latest follow-up. Results Twelve patients were enrolled into this study, including 8 males and 4 females with a mean age of 39.5 years (range, 26 to 56 years). All patients also sustained ankle fractures. At 12 months follow-up, the mean AOFAS score was 95.4 (range, 85 to 100), and all patients were satisfied with the functional recoveries. The radiographic MCS, TFOL

  5. Unicortical versus bicortical locked plate fixation in midshaft clavicle fractures.

    PubMed

    Bravman, Jonathan T; Taylor, Michal L; Baldini, Todd; Vidal, Armando F

    2015-05-01

    Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant.

  6. Uncertainties of Nitrogen Fixation in a Dynamic Global Vegetation Model

    NASA Astrophysics Data System (ADS)

    Steinkamp, Joerg; Werner, Christian; Weber, Bettina; Hickler, Thomas

    2015-04-01

    Nitrogen is an essential nutrient for life on earth. However, most of it is in the form of dinitrogen (N2) unutilizable to life and only few organisms are able to break the triple bond, fix the nitrogen and thus make it available for cycling in the biosphere through "fixation". In most state-of-the-art dynamic global vegetation models (DGVMs) including a nitrogen cycle, N fixation is simulated by the Cleveland et al. (1999) algorithm (O-CN, LPJ-GUESS, CLM), that correlates annual N fixation to evapotranspiration rates or net primary production. Nevertheless, this algorithm has two major uncertainties, which are investigated by us: 1. The algorithm is based on annual fixation rates that are then applied uniformly throughout the year. However, in nature nitrogen fixation is an expensive process, which occurs only under favorable conditions. Here we compare the annual fixation values evenly distributed over the year with daily-derived fixation values based on a modified version of the Cleveland algorithm. We postulate that in higher latitudinal regions with seasonal climate as well as in regions with a distinct dry/wet season, modeled growth is enhanced by daily derived values compared to evenly distributed values, whereas in tropical regions hardly any difference will be visible. 2. One distinguishes between symbiotic and unsymbiotic nitrogen fixation, where the first one is associated with higher plants as symbionts supplying the fixers with carbohydrates, whereas the second, unsymbiotic is performed by so-called cryptogamic covers (CC). We found that the fixation by CC is underrepresented by the Cleveland algorithm, and a correction thus leads to enhanced growth in forested regions of higher latitudes that feature substantial CC fractions. Overall, the improvements of the algorithm proposed by us are expected to better reflect the reality of nitrogen fixation and cause an increased growth of vegetation, especially in higher northern latitudes.

  7. Suppression of the human vestibulo-ocular reflex by visual fixation or forced convergence in the dark, with a model interpretation.

    PubMed

    Gizzi, Martin S; Harper, Harry Wms

    2003-05-01

    Six normal humans experienced yaw axis steps of velocity at 120 degrees /s in the dark. During the post-rotary period, subjects either had a null-task (do nothing); an ocular motor task (forced convergence: crossing the eyes); or a visual task (fixating a head-stationary target against a background of 10 degrees light/dark bars). Tasks started at 3 s post-rotation, and lasted either 2, 5, 10, or 15 s. Ocular motor and visual tasks were tested on different days. Five repetitions of each task duration were recorded for each subject. A mean VOR gain of 0.52 was observed, which did not vary with experimental conditions. Both convergence and fixation markedly suppressed nystagmus; in fact, the VORs obtained with the two different tasks are superficially similar in appearance. However, mean null-task time-constants were 9.4 s for convergence days, but 8.4 s for fixation days, and there was a small but significant reduction in overall null-task VOR amplitude on fixation days. Also, post-convergence slow-phase velocities were slightly enhanced, while post-fixation velocities were significantly reduced. The time-constant of velocity storage was found to be 10.1 s for convergence responses and 8.2 s for fixation responses. These differences can be understood in terms of modifications in central velocity storage during visual fixation which do not occur with convergence. The mean fixation data were analyzed in the context of a VOR model well-established for monkey data. With appropriate choice of parameters, this model accurately reproduces most features of the human data. An estimate for the human cupula time-constant of 3.3 s is obtained. Compared with the monkey, fixation suppression is greater and post-fixation velocity reduction less. Retinal slip alone accounts well for this; "velocity dumping" by an integrator shunt must be slight if present at all. The model correctly represents the post-fixation VOR for all durations of fixation.

  8. A biomechanical comparison of conventional versus an anatomic plate and compression bolts for fixation of intra-articular calcaneal fractures.

    PubMed

    Wang, Haili; Yang, Zhaoxu; Wu, Zhanpo; Chen, Wei; Zhang, Qi; Li, Ming; Li, Zhiyong; Zhang, Yingze

    2012-08-01

    The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures. Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-III calcaneal fracture model by using osteotomy. The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws. Reduction of fracture was evaluated through X radiographs. Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N, representing the partial weight bearing and full weight bearing, respectively, and then the specimens were loaded to failure. Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test. No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading (P=0.06), while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading (P=0.008). The load achieved at loss of fixation of the constructs for the two groups had significant difference: anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N (P=0.008). There was no significant difference between the ultimate displacements. Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading. The study supports the mechanical viability of using our plate and

  9. Nitrogen fixation associated with grasses in Oregon.

    PubMed

    Nelson, A D; Barber, L E; Tjepkema, J; Russell, S A; Powelson, R; Evans, H J

    1976-04-01

    Nitrogen fixation associated with both natural grasslands and grain crops of Oregon was studied using the acetylene-reduction assay. A number of the grasses collected has some acetylene-reducing activity. Agrostis tenuis Sibth. had substantially greater activity than any of the other species, with a mean rate estimated at 37 g N2 fixed per hectare per day. Assuming 100 days of activity, about 3 kg of N2 would be fixed per hectare per year. This quantity of nitrogen may be important in the maintenance of this species under natural conditions. Nitrogen-fixing microorganisms were isolated from the root surfaces of some of the grasses. Cultures of Bacillus macerans, Bacillus polymyxa, and Enterobacter cloacoa were isolated from wheat roots as were two cultures which have not been assigned a specific taxonomic classification. Strains of N2-fixing Bacillus species and Gram-negative aerobic bacteria were isolated from Festuca and Agrostis.

  10. VAC® for external fixation of flail chest.

    PubMed

    Winge, Rikke; Berg, Jais O; Albret, Rikke; Krag, Christen

    2012-05-29

    A large aterior chest wall defect following tumor resection was reconstructed with a Gore-Tex® membrane and a combined musculocutaneous rectus femoris and tensor fasciae latae free flap. Subsequent paradoxical respiration impeded weaning from the ventilator. Appliance of Vacuum Assisted Closure® (VAC®) resulted in immediate chest wall stability and a decrease in the patient's need for respiratory support. Shortly thereafter, the VAC® was discontinued and the patient was discharged from the intensive care unit (ICU). This case report is the first to describe the successful use of VAC® as an adjuvant to a one-stage procedure for large thoracic wall reconstruction, allowing sufficient temporary external fixation to eliminate paradoxical respiration and plausibly shorten the stay in the ICU. No adverse effects on flap healing or haemodynamics were recorded. It is likely that external VAC® can improve thoracic stability and pulmonary function in a patient with flail chest and decrease the need for mechanical ventilation.

  11. Oxygen relations of nitrogen fixation in cyanobacteria.

    PubMed Central

    Fay, P

    1992-01-01

    The enigmatic coexistence of O2-sensitive nitrogenase and O2-evolving photosynthesis in diazotrophic cyanobacteria has fascinated researchers for over two decades. Research efforts in the past 10 years have revealed a range of O2 sensitivity of nitrogenase in different strains of cyanobacteria and a variety of adaptations for the protection of nitrogenase from damage by both atmospheric and photosynthetic sources of O2. The most complex and apparently most efficient mechanisms for the protection of nitrogenase are incorporated in the heterocysts, the N2-fixing cells of cyanobacteria. Genetic studies indicate that the controls of heterocyst development and nitrogenase synthesis are closely interrelated and that the expression of N2 fixation (nif) genes is regulated by pO2. Images PMID:1620069

  12. Stability of extraoral vertical ramus osteotomy: plate fixation versus maxillomandibular/skeletal suspension wire fixation.

    PubMed

    Mobarak, K A; Krogstad, O; Espeland, L; Lyberg, T

    2000-01-01

    The objective of this cephalometric study was to evaluate skeletal stability and time course of postoperative changes in 2 groups of mandibular prognathism patients following extraoral oblique vertical ramus osteotomy (VRO). One group (n = 22) received maxillomandibular fixation and skeletal suspension wires (MMF group) for a period of 8 weeks. In the other group (n = 22), the segments were rigidly fixed with plates and the patients were allowed to function immediately after surgery. Lateral cephalograms were taken on 5 occasions: immediately presurgical, immediately postsurgical, 8 weeks postsurgical, 6 months postsurgical, and 1 year postsurgical. During the first 8 weeks after surgery, the MMF group demonstrated posterior movement of the mandible, with an increase in mandibular plane angle, shortening of the rami, and dental compensations. Upon release of MMF and skeletal suspension wiring, a small anterior relapse tendency was observed, but the net setback 1 year after surgery was still greater than the actual surgical setback. In the plate fixation group, postoperative changes were mainly in the form of a small anterior relapse tendency in the range of 10% of the surgical setback. The results indicate that the use of plate fixation with VRO, while eliminating the inconvenience for the patient of several weeks of MMF and preventing the early side effects observed in the MMF group, also resulted in a more predictable surgical procedure, with excellent stability 1 year after surgery.

  13. Versatile microfluidic complement fixation test for disease biomarker detection.

    PubMed

    Li, Man; Shi, ZhuanZhuan; Fang, Can; Gao, AnXiu; Li, Chang Ming; Yu, Ling

    2016-04-15

    The complement fixation test (CFT) is a serological test that can be used to detect the presence of specific antibodies or antigens to diagnose infections, particularly diseases caused by microbes that are not easily detected by standard culture methods. We report here, for the first time, a poly(dimethylsiloxane) (PDMS)/glass slide hybrid microfluidic device that was used to manipulate the solution compartment and communication within the microchannel to establish sampler and indicator systems of CFT. Two types of on-chip CFT, solution-based and solid phase agar-based assays, were successfully demonstrated for biomarker carcinoembryonic antigen (CEA) and recombinant avian influenza A (rH7N9) virus protein detection. In addition, the feasibility of the on-chip CFT in assaying real biopsy was successfully demonstrated by specifically detecting rH7N9 and CEA in human serum. The results demonstrated that the miniaturized assay format significantly reduced the assay time and sample consumption. Exemption from protein immobilization, blocking, complicated washing steps and expensive enzyme/fluorescein conjugates highlights the merits of on-chip CFT over ELISA. Most attractively, the on-chip agar-based CFT results can be imaged and analysed by smartphone, strengthening its point-of-care application potential. We anticipate that the on-chip CFT reported herein will be a useful supplemental or back-up tool for on-chip immunoassays such as ELISA for disease diagnosis and food inspection.

  14. Digital surgery: current trends and techniques.

    PubMed

    Good, James; Fiala, Kyle

    2010-10-01

    Digital deformities continue to be a common ailment among many patients who present to foot and ankle specialists. When conservative treatment fails to eliminate patient complaints, surgical correction remains a viable treatment option. Proximal interphalangeal joint arthrodesis remains the standard procedure among most foot and ankle surgeons. With continued advances in fixation technology and techniques, surgeons continue to have better options for the achievement of excellent digital surgery outcomes. This article reviews current trends in fixation of digital deformities while highlighting pertinent aspects of the physical examination, radiographic examination, and surgical technique.

  15. Pedicle screw fixation combined with intermediate screw at the fracture level for treatment of thoracolumbar fractures

    PubMed Central

    Li, Kunpeng; Zhang, Wen; Liu, Dan; Xu, Hui; Geng, Wei; Luo, Dawei; Ma, Jinzhu

    2016-01-01

    .01; P = 0.06). Conclusions: The combined screw fixation technique was associated with better reduction of the fractured vertebrae, less correction loss in the follow-up, and lower implant failure rate. Given the lack of robust clinical evidence, these findings warrant verification in large prospective registries and randomized trials with long-term follow-up. PMID:27537586

  16. Regulation of Development and Nitrogen Fixation in Anabaena

    SciTech Connect

    James W. Golden

    2008-10-17

    The regulation of development and cellular differentiation is important for all multicellular organisms. The nitrogen-fixing filamentous cyanobacterium Anabaena (also Nostoc) sp. PCC 7120 (hereafter Anabaena) provides a model of multicellular microbial development and pattern formation. Anabaena reduces N2 to ammonia in specialized terminally differentiated cells called heterocysts. A one-dimensional developmental pattern of single heterocysts regularly spaced along filaments of photosynthetic vegetative cells is established to form a multicellular organism composed of these two interdependent cell types. This multicellular growth pattern, the distinct phylogeny of cyanobacteria, and the suspected antiquity of heterocyst development make this an important model system. Our long-term goal is to understand the regulatory network required for heterocyst development and nitrogen fixation. This project is focused on two key aspects of heterocyst regulation: one, the mechanism by which HetR controls the initiation of differentiation, and two, the cis and trans acting factors required for expression of the nitrogen-fixation (nif) genes. HetR is thought to be a central regulator of heterocyst development but the partners and mechanisms involved in this regulation are unknown. Our recent results indicate that PatS and other signals that regulate heterocyst pattern cannot interact, directly or indirectly, with a R223W mutant of HetR. We plan to use biochemical and genetic approaches to identify proteins that interact with the HetR protein, which will help reveal the mechanisms underlying its regulation of development. Our second goal is to determine how the nif genes are expressed. It is important to understand the mechanisms controlling nif genes since they represent the culmination of the differentiation process and the essence of heterocyst function. The Anabaena genome lacks the genes required for expression of nif genes present in other organisms such as rpoN (sigma 54

  17. Regulation of Development and Nitrogen Fixation in Anabaena

    SciTech Connect

    James W Golden

    2004-08-05

    The nitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 is being used as a simple model of microbial development and pattern formation in a multicellular prokaryotic organism. Anabaena reduces atmospheric nitrogen to ammonia in highly specialized, terminally differentiated cells called heterocysts. Anabaena is an important model system because of the multicellular growth pattern, the suspected antiquity of heterocyst development, and the contribution of fixed nitrogen to the environment. We are especially interested in understanding the molecular signaling pathways and genetic regulation that control heterocyst development. In the presence of an external source of reduced nitrogen, the differentiation of heterocysts is inhibited. When Anabaena is grown on dinitrogen, a one-dimensional developmental pattern of single heterocysts separated by approximately ten vegetative cells is established to form a multicellular organism composed of two interdependent cell types. The goal of this project is to understand the signaling and regulatory pathways that commit a vegetative cell to terminally differentiate into a nitrogen-fixing heterocyst. Several genes identified by us and by others were chosen as entry points into the regulatory network. Our research, which was initially focused on transcriptional regulation by group 2 sigma factors, was expanded to include group 3 sigma factors and their regulators after the complete Anabaena genome sequence became available. Surprisingly, no individual sigma factor is essential for heterocyst development. We have used the isolation of extragenic suppressors to study genetic interactions between key regulatory genes such as patS, hetR, and hetC in signaling and developmental pathways. We identified a hetR R223W mutation as a bypass suppressor of patS overexpression. Strains containing the hetR R223W allele fail to respond to pattern formation signals and overexpression of this allele results in a lethal phenotype

  18. Bilateral sacrospinous fixation without hysterectomy: 18-month follow-up

    PubMed Central

    Şentürk, Mehmet Baki; Güraslan, Hakan; Çakmak, Yusuf; Ekin, Murat

    2015-01-01

    Objective The aim of this study was to evaluate the results of bilateral sacrospinous fixation (SSF), which was performed with surgical mesh interposition and bilateral vaginal repair. Material and Methods Twenty-two patients underwent SSF between 2010 and 2012, and the results were evaluated retrospectively. The results at preoperative and postoperative 6th, 12th, and 18th months of the pelvic organ prolapse quantification system (POP-Q) and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire-12 (PISQ-12) were compared using Friedman and Wilcoxon Signed Ranks tests. Values of p<0.05 and <0.01 were considered statistically significant. Results According to the POP-Q, significant healing was observed on all vaginal vault points (p=0.001), and no prolapse was observed until the 18-month follow-up stage. There were also prominent patients who felt satisfactory with respect to their sexual life according to PISQ-12 (p=0.001). Conclusion This technique appears to provide an adequate clinical resolution, and it may be the primary surgical option for women with pelvic organ prolapse. PMID:26097393

  19. Dark Fixation of CO2 by Crassulacean Plants

    PubMed Central

    Sutton, B. G.; Osmond, C. B.

    1972-01-01

    Malic acid isolated from Bryophyllum pinnatum (Lamk.) Oken (B. calycinum Salisb.), Bryophyllum tubiflorum Harv., Kalanchoë diagremontiana Hamet et Perrier and Sedum guatamalense Hemsl. after dark 14CO2 fixation was degraded by an in vitro NADP-malic enzyme technique. In the short term (5 to 30 seconds) the malic acid was almost exclusively labeled in the C-4 carboxyl carbon (greater than 90%). The percentage of 14C in the C-4 carboxyl of malic acid declined slowly with time, reaching 70% in B. tubiflorum and 54% in B. pinnatum after 14 hours of exposure to 14CO2. It was found that malic acid-adapted Lactobacillus arabinosus may seriously underestimate the C-4 carboxyl component of label in malic acid-14C. The amount of substrate which the bacteria can completely metabolize was easily exceeded; there was a significant level of randomization of label even when β-decarboxylation proceeded to completion, and in extended incubation periods, more than 25% of label was removed from malic acid-U-14C. The significance of these findings in relation to pathways of carbohydrate metabolism and malic acid synthesis in Crassulacean acid metabolism is discussed. PMID:16658174

  20. Fixation and chemical analysis of single fog and rain droplets

    NASA Astrophysics Data System (ADS)

    Kasahara, M.; Akashi, S.; Ma, C.-J.; Tohno, S.

    Last decade, the importance of global environmental problems has been recognized worldwide. Acid rain is one of the most important global environmental problems as well as the global warming. The grasp of physical and chemical properties of fog and rain droplets is essential to make clear the physical and chemical processes of acid rain and also their effects on forests, materials and ecosystems. We examined the physical and chemical properties of single fog and raindrops by applying fixation technique. The sampling method and treatment procedure to fix the liquid droplets as a solid particle were investigated. Small liquid particles like fog droplet could be easily fixed within few minutes by exposure to cyanoacrylate vapor. The large liquid particles like raindrops were also fixed successively, but some of them were not perfect. Freezing method was applied to fix the large raindrops. Frozen liquid particles existed stably by exposure to cyanoacrylate vapor after freezing. The particle size measurement and the elemental analysis of the fixed particle were performed in individual base using microscope, and SEX-EDX, particle-induced X-ray emission (PIXE) and micro-PIXE analyses, respectively. The concentration in raindrops was dependent upon the droplet size and the elapsed time from the beginning of rainfall.

  1. [Application of Ilizarov's external fixator on the basis of biology].

    PubMed

    Pan, S C

    1991-05-01

    Ilizarov's biology includes that, in the presence of tension and stress, both regeneration of bone and soft tissues with cellular proliferation and their biological synthesis become vigorous. The Ilizarov's external fixator has five functions namely: compression, distraction, de-angulation, derotation and translocation. The principles of this procedure include: corticotomy instead of conventional osteotomy, placement of 4-5 sets of 1.5 mm wires transfixed in the bones at different levels under tension of 70-110 kg on the circular rings without acute diastasis until the 5 th to 7th day, and then, callotasis-callus distraction. The quality and quantity of the regenerated bone within the widening distraction gap are closely related to the maximum preservation of bone marrow and periosseous blood supply, and a distraction of 1 mm per day and preferably done by 4 times 0.25 mm each time should be emphasized. Experiences in 17 cases of pseudarthrosis and unequal length of leg treated with Ilizarov's technique are presented.

  2. Fat Embolism Syndrome After Femur Fracture Fixation: a Case Report

    PubMed Central

    Akoh, Craig C; Schick, Cameron; Otero, Jesse; Karam, Matthew

    2014-01-01

    Fat embolism syndrome (FES) is a multi-organ disorder with potentially serious sequelae that is commonly seen in the orthopaedic patient population after femur fractures. The major clinical features of FES include hypoxia, pulmonary dysfunction, mental status changes, petechiae, tachycardia, fever, thrombocytopenia, and anemia. Due to technological advances in supportive care and intramedullary reaming techniques, the incidence of FES has been reported as low as 0.5 percent. Here, we present a rare case of FES with cerebral manifestations. A previously healthy 24-year old nonsmoking male was admitted to our hospital after an unrestrained head-on motor vehicle collision. The patient's injuries included a left olecranon fracture and closed bilateral comminuted midshaft femur fractures. The patient went on to develop cerebral fat embolism syndrome (CFES) twelve hours after immediate bilateral intramedullary nail fixation. His symptoms included unresponsiveness, disconjugate gaze, seizures, respiratory distress, fever, anemia, thrombocytopenia, and visual changes. Head computed tomography and brain magnetic resonance imaging showed pathognomonic white-matter punctate lesions and watershed involvement. With early recognition and supportive therapy and seizure therapy, the patient went on to have complete resolution of symptoms without cognitive sequelae. PMID:25328460

  3. Osteosynthesis in Distal Radius Fractures with Conventional Bridging External Fixator; Tips and Tricks for Getting Them Right

    PubMed Central

    Chilakamary, Vamshi Krishna; Koppolu, Kiran Kumar; Rapur, Shivaprasad

    2016-01-01

    Background Distal radius fractures are the commonest fractures occurring in the upper extremity, accounting for 15-20% of patients treated in emergency department. Although distal radial fractures were described 200 years ago, they still remain as unsolved fractures with no clear guidelines. It is often reported that anatomical reduction has a bearing on the functional outcome. Aim To study the management of distal end radius fracture by utilizing the principle of ligamentotaxis where in the reduction obtained by closed means is maintained by external fixator till solid bony union occurs. Materials and Methods A total of 26 cases were selected for study by scrutiny of the inclusion and exclusion criteria. Most of our cases were treated with external fixator within 8 hrs of injury. Small A.O external fixator (bridging ex-fix) with 2 pins each in radius and 2nd metacarpal percutaneously was used for all the cases. Selective k wire fixation was done in cases of instability. Fixator was removed after 6 weeks. Guided physiotherapy was ensured in all the cases. Patients were followed up for an average of 9 months. Results Modified Gartland and Werley scoring system was used to evaluate the overall functional results. Excellent to good results were achieved in 88.45% of our cases while fair result was in 11.54 %. One case had pin loosening and two other cases had malunion. Conclusion External fixator used for ligamentotaxis is an effective method of treating unstable extraarticular and complex intraarticular fractures of distal radius. Improved anatomical restoration with early rehabilitation has produced favourable functional outcome in our series. The complications like pin tract infection is rare due to the availability of superior antibiotics and sterile surgical technique. complications like wrist and finger stiffness has improved with physiotherapy. PMID:26894133

  4. The reverse abdominal reduction and the 'waistcoating' procedure for the correction of the fixated Pfannenstiel incision.

    PubMed

    Harrison, Douglas H

    2016-05-01

    The principles of a standard abdominal reduction are well understood; this technique has been used for many years. However, a reverse abdominal reduction may be considered in some cases, for example, continued weight loss, and thus skin redundancy on the upper abdomen in patients who have already undergone abdominal reduction and upper abdomen improvement in patients requiring a mastopexy or breast reduction simultaneously. Reverse abdominal reduction is rarely mentioned in the medical literature, but it can prove successful; although the scar across the lower sternum has often been considered to be unsatisfactory, often it does not prove to be so. Thus, this procedure can be proven to be successful in suitable cases. Secondly, the Pfannenstiel incision, if not satisfactorily repaired in the first instance, can become fixated to the abdominal wall; this fixation along with the inevitable migration of skin and fat at its cephalic edge causes a rather displeasing contour defect when wearing tight-fitting swimwear. The principle of the waistcoating procedure is essentially to chamfer the fat cephalically; this procedure is employed for removing the Pfannenstiel scar from the abdominal wall. The principle is simple and effective and can be applied in cases with fixated scars. These two aforementioned principles are not commonly used, but they can prove particularly effective in suitable cases. We illustrate the principles.

  5. Pupil size dynamics during fixation impact the accuracy and precision of video-based gaze estimation.

    PubMed

    Choe, Kyoung Whan; Blake, Randolph; Lee, Sang-Hun

    2016-01-01

    Video-based eye tracking relies on locating pupil center to measure gaze positions. Although widely used, the technique is known to generate spurious gaze position shifts up to several degrees in visual angle because pupil centration can change without eye movement during pupil constriction or dilation. Since pupil size can fluctuate markedly from moment to moment, reflecting arousal state and cognitive processing during human behavioral and neuroimaging experiments, the pupil size artifact is prevalent and thus weakens the quality of the video-based eye tracking measurements reliant on small fixational eye movements. Moreover, the artifact may lead to erroneous conclusions if the spurious signal is taken as an actual eye movement. Here, we measured pupil size and gaze position from 23 human observers performing a fixation task and examined the relationship between these two measures. Results disclosed that the pupils contracted as fixation was prolonged, at both small (<16s) and large (∼4min) time scales, and these pupil contractions were accompanied by systematic errors in gaze position estimation, in both the ellipse and the centroid methods of pupil tracking. When pupil size was regressed out, the accuracy and reliability of gaze position measurements were substantially improved, enabling differentiation of 0.1° difference in eye position. We confirmed the presence of systematic changes in pupil size, again at both small and large scales, and its tight relationship with gaze position estimates when observers were engaged in a demanding visual discrimination task.

  6. One size does not fit all: distal radioulnar joint dysfunction after volar locking plate fixation.

    PubMed

    Jones, Christopher W; Lawson, Richard D

    2014-02-01

    Background Fractures of the distal radius are among the most common injuries treated by orthopedic surgeons worldwide. Failure to restore distal radius alignment can lead to fracture malunion and poor clinical outcomes, including distal radioulnar joint (DRUJ) instability and limitation of motion. Case Description We present a unique case of DRUJ dysfunction following volar plate fixation of bilateral distal radius fractures and analyze the biomechanical causes of this complication. As a result of a relatively excessive tilt of the precontoured locking plate (in comparison to the patient's particular anatomy), the fracture on one side was "over-reduced," disrupting the biomechanics of the DRUJ, causing a supination block. Clinical Relevance Volar locking plates are not a panacea to all distal radius fractures. Plate selection and fixation technique must include consideration of patient anatomy. Robust plates offer the advantage of providing rigid fixation but can be difficult to contour when reconstructing normal anatomy. Restoration of patient-specific anatomy is crucial to the management of distal radius fractures.

  7. Anterior approach for operative fixation of coronoid fractures in complex elbow instability.

    PubMed

    Reichel, Lee M; Milam, Graham S; Reitman, Charles A

    2012-06-01

    The coronoid process has been shown to play a critical role in ulnohumeral stability. Coronoid process fractures can occur in isolation or as part of a complex injury pattern. The most common complex pattern, known as the "terrible triad," includes a radial head fracture and elbow dislocation along with the coronoid fracture. Failure to address these fractures and ligamentous injuries can result in recurrent instability and progression to painful arthrosis. Both medial and lateral approaches to the coronoid have been popularized in recent literature, but there is no universally accepted approach. Common fixation techniques include suture lasso, suture anchors, lag screws, and plating all of which have various drawbacks. We describe a direct anterior approach to address coronoid process fractures made in addition to a lateral approach to address radial head and lateral collateral ligament injuries. Coronoid fractures addressed through the anterior approach were stabilized with anterior to posterior screw fixation combined with buttress plating, which allowed anatomic reduction and stable internal fixation at short-term follow-up.

  8. Arthroscopic double-row suture anchor fixation of minimally displaced greater tuberosity fractures.

    PubMed

    Ji, Jong-Hun; Kim, Weon-Yoo; Ra, Ki-Hang

    2007-10-01

    In cases of displaced greater tuberosity fractures, treatments by arthroscopic-assisted reduction and percutaneous screw fixation have been reported. However, in cases in which there is a comminuted fracture or a minimally displaced fracture combined with concomitant lesions such as rotator cuff tear or labral pathology, it is difficult to reduce the fracture and to treat other pathologies by use of a percutaneous screw. Recently, many surgeons have used the double-row repair method in rotator cuff repair, which provides a tendon-bone interface better suited for biologic healing and restoring normal anatomy. In accordance with this method, we used the arthroscopic technique of double-row suture anchor fixation for a minimally displaced greater tuberosity fracture without additional incision. Initially, debridement was performed on the fracture surface by use of a shaver, and the medial-row anchor was inserted through the anterior portal or the intact cuff. Two lateral-row anchors were inserted just anterior and posterior to the lower margin of the fractured fragment under C-arm guidance. The medial-row sutures and lateral-row sutures were then placed. Arthroscopic double-row suture anchor fixation of a displaced greater tuberosity fracture restores the original footprint of the rotator cuff and normal tendon-bone interface of the displaced greater tuberosity fracture.

  9. Pitfalls during biomechanical testing - Evaluation of different fixation methods for measuring tendons endurance properties.

    PubMed

    Hangody, Gy; Pánics, G; Szebényi, G; Kiss, R; Hangody, L; Pap, K

    2016-03-01

    The goal of the study was to find a proper technique to fix tendon grafts into an INSTRON loading machine. From 8 human cadavers, 40 grafts were collected. We removed the bone-patella tendon-bone grafts, the semitendinosus and gracilis tendons, the quadriceps tendon-bone grafts, the Achilles tendons, and the peroneus longus tendons from each lower extremity. We tested the tendon grafts with five different types of fixation devices: surgical thread (Premicron 3), general mounting clamp, wire mesh, cement fixation, and a modified clamp for an INSTRON loading machine. The mean failure load in case of surgical thread fixation was (381N ± 26N). The results with the general clamp were (527N ± 45N). The wire meshes were more promising (750N ± 21N), but did not reach the outcomes we desired. Easy slippages of the ends of the tendons from the cement encasements were observed (253N ± 18N). We then began to use Shi's clamp that could produce 977N ± 416N peak force. We combined Shi's clamp with freezing of the graft and the rupture of the tendon itself demonstrated an average force of 2198 N ± 773N. We determined that our modified frozen clamp fixed the specimens against high tensile forces.

  10. Neuromuscular scoliosis and pelvic fixation in 2015: Where do we stand?

    PubMed

    Anari, Jason B; Spiegel, David A; Baldwin, Keith D

    2015-09-18

    Neuromuscular scoliosis is a challenging problem to treat in a heterogeneous patient population. When the decision is made for surgery the surgeon must select a technique employed to correct the curve and achieve the goals of surgery, namely a straight spine over a level pelvis. Pre-operatively the surgeon must ask if pelvic fixation is worth the extra complications and infection risk it introduces to an already compromised host. Since the advent of posterior spinal fusion the technology used for instrumentation has changed drastically. However, many of the common problems seen with the unit rod decades ago we are still dealing with today with pedicle screw technology. Screw cut out, pseudoarthrosis, non-union, prominent hardware, wound complications, and infection are all possible complications when extending a spinal fusion construct to the pelvis in a neuromuscular scoliosis patient. Additionally, placing pelvic fixation in a neuromuscular patient results in extra blood loss, greater surgical time, more extensive dissection with creation of a deep dead space, and an incision that extends close to the rectum in patients who are commonly incontinent. Balancing the risk of placing pelvic fixation when the benefit, some may argue, is limited in non-ambulating patients is difficult when the literature is so mottled. Despite frequent advancements in technology issues with neuromuscular scoliosis remain the same and in the next 10 years we must do what we can to make safe neuromuscular spine surgery a reality.

  11. Molybdenum and phosphorus limitation of moss-associated nitrogen fixation in boreal ecosystems.

    PubMed

    Rousk, Kathrin; Degboe, Jefferson; Michelsen, Anders; Bradley, Robert; Bellenger, Jean-Philippe

    2017-04-01

    Biological nitrogen fixation (BNF) performed by moss-associated cyanobacteria is one of the main sources of new nitrogen (N) input in pristine, high-latitude ecosystems. Yet, the nutrients that limit BNF remain elusive. Here, we tested whether this important ecosystem function is limited by the availability of molybdenum (Mo), phosphorus (P), or both. BNF in dominant mosses was measured with the acetylene reduction assay (ARA) at different time intervals following Mo and P additions, in both laboratory microcosms with mosses from a boreal spruce forest and field plots in subarctic tundra. We further used a (15) N2 tracer technique to assess the ARA to N2 fixation conversion ratios at our subarctic site. BNF was up to four-fold higher shortly after the addition of Mo, in both the laboratory and field experiments. A similar positive response to Mo was found in moss colonizing cyanobacterial biomass. As the growing season progressed, nitrogenase activity became progressively more P limited. The ARA : (15) N2 ratios increased with increasing Mo additions. These findings show that N2 fixation activity as well as cyanobacterial biomass in dominant feather mosses from boreal forests and subarctic tundra are limited by Mo availability.

  12. Mechanical testing of a device for subcutaneous internal anterior pelvic ring fixation versus external pelvic ring fixation

    PubMed Central

    2014-01-01

    Background Although useful in the emergency treatment of pelvic ring injuries, external fixation is associated with pin tract infections, the patient’s limited mobility and a restricted surgical accessibility to the lower abdomen. In this study, the mechanical stability of a subcutaneous internal anterior fixation (SIAF) system is investigated. Methods A standard external fixation and a SIAF system were tested on pairs of Polyoxymethylene testing cylinders using a universal testing machine. Each specimen was subjected to a total of 2000 consecutive cyclic loadings at 1 Hz with sinusoidal lateral compression/distraction (+/−50 N) and torque (+/− 0.5 Nm) loading alternating every 200 cycles. Translational and rotational stiffness were determined at 100, 300, 500, 700 and 900 cycles. Results There was no significant difference in translational stiffness between the SIAF and the standard external fixation when compared at 500 (p = .089), 700 (p = .081), and 900 (p = .266) cycles. Rotational stiffness observed for the SIAF was about 50 percent higher than the standard external fixation at 300 (p = .005), 500 (p = .020), and 900 (p = .005) cycles. No loosening or failure of the rod-pin/rod-screw interfaces was seen. Conclusions In comparison with the standard external fixation system, the tested device for subcutaneous internal anterior fixation (SIAF) in vitro has similar translational and superior rotational stiffness. PMID:24684828

  13. Comparison of polyvinyl alcohol fixative with three less hazardous fixatives for detection and identification of intestinal parasites.

    PubMed

    Jensen, B; Kepley, W; Guarner, J; Anderson, K; Anderson, D; Clairmont, J; De L'aune, W; Austin, E H; Austin, G E

    2000-04-01

    Polyvinyl alcohol (PVA) containing the fixative mercuric chloride is considered the "gold standard" for the fixation of ova and parasites in the preparation of permanently stained smears of stool specimens. However, mercuric chloride is potentially hazardous to laboratory personnel and presents disposal problems. We compared three new alternative, nontoxic fixatives with PVA, analyzing ease of sample preparation and quality of smears. Sixty-eight fresh stool specimens were divided into aliquots and placed in each of four different fixatives: PARASAFE (PS) (Scientific Devices Laboratory, Inc., Des Plaines, Ill.), ECOFIX (EC) (Meridian Diagnostics, Inc., Cincinnati, Ohio), Proto-Fix (PF) (Alpha-Tec Systems, Inc., Vancouver, Wash.), and low-viscosity PVA fixative (PVA) (Meridian). Specimens were processed and stained according to each manufacturer's directions. Parasites were found in 31 of 68 slide preparations with PVA, 31 with PF, 30 with EC, and 30 with PS. Blastocystis hominis and Iodamoeba bütschlii were preserved in a readily identifiable state by all methods of fixation. However, some parasites were more easily identified with some of the fixatives because of differences in parasite distortion. For example, Entamoeba histolytica (Entamoeba dispar) was detected in 13 stools fixed with PF, 7 with PVA, and 6 with EC but none with PS. Likewise, Chilomastix mesnili was identified in 13 specimens fixed with PF, 8 with EC, and 5 with PVA but only 1 with PS, while Entamoeba coli was seen much less frequently with PS than with the other three fixatives. A dirty background was observed in 41% of specimens prepared with PS, whereas background quality was acceptable with other fixatives. Sample preparation was most rapid with PS, although the EC method involved the fewest steps. In conclusion, PVA and PF produced the least parasite distortion, while PS proved unsatisfactory for the identification of E. histolytica, E. coli, and C. mesnili. Both PF and EC appear to be

  14. Comparison of Polyvinyl Alcohol Fixative with Three Less Hazardous Fixatives for Detection and Identification of Intestinal Parasites

    PubMed Central

    Jensen, B.; Kepley, W.; Guarner, J.; Anderson, K.; Anderson, D.; Clairmont, J.; De l'aune, William; Austin, E. H.; Austin, G. E.

    2000-01-01

    Polyvinyl alcohol (PVA) containing the fixative mercuric chloride is considered the “gold standard” for the fixation of ova and parasites in the preparation of permanently stained smears of stool specimens. However, mercuric chloride is potentially hazardous to laboratory personnel and presents disposal problems. We compared three new alternative, nontoxic fixatives with PVA, analyzing ease of sample preparation and quality of smears. Sixty-eight fresh stool specimens were divided into aliquots and placed in each of four different fixatives: PARASAFE (PS) (Scientific Devices Laboratory, Inc., Des Plaines, Ill.), ECOFIX (EC) (Meridian Diagnostics, Inc., Cincinnati, Ohio), Proto-Fix (PF) (Alpha-Tec Systems, Inc., Vancouver, Wash.), and low-viscosity PVA fixative (PVA) (Meridian). Specimens were processed and stained according to each manufacturer's directions. Parasites were found in 31 of 68 slide preparations with PVA, 31 with PF, 30 with EC, and 30 with PS. Blastocystis hominis and Iodamoeba bütschlii were preserved in a readily identifiable state by all methods of fixation. However, some parasites were more easily identified with some of the fixatives because of differences in parasite distortion. For example, Entamoeba histolytica (Entamoeba dispar) was detected in 13 stools fixed with PF, 7 with PVA, and 6 with EC but none with PS. Likewise, Chilomastix mesnili was identified in 13 specimens fixed with PF, 8 with EC, and 5 with PVA but only 1 with PS, while Entamoeba coli was seen much less frequently with PS than with the other three fixatives. A dirty background was observed in 41% of specimens prepared with PS, whereas background quality was acceptable with other fixatives. Sample preparation was most rapid with PS, although the EC method involved the fewest steps. In conclusion, PVA and PF produced the least parasite distortion, while PS proved unsatisfactory for the identification of E. histolytica, E. coli, and C. mesnili. Both PF and EC appear to be

  15. Nitrogen fixation by Elaeagnus angustifolia in the reclamation of degraded croplands of Central Asia.

    PubMed

    Khamzina, Asia; Lamers, John P A; Vlek, Paul L G

    2009-06-01

    Extensive degradation of irrigated croplands, due to increasing soil salinity and depletion of soil nutrient stocks, is a major problem in Central Asia (CA), one of the largest irrigated areas in the world. To assess the potential for improving the productive capacity of degraded lands by afforestation, we examined N(2) fixation of Elaeagnus angustifolia L. in mixed plantations with non-fixing Populus euphratica Oliv. and Ulmus pumila L. Fixation of N(2) was quantified by the (15)N natural abundance technique based on both foliar and whole-plant sampling during five consecutive growing seasons. Despite elevated root-zone soil salinity (6-10 dS m(-1)) and deficiency in plant-available P (4-15 mg kg(-1)), N(2) fixation (%Ndfa) increased from an initial value of 20% to almost 100% over 5 years. Within each growing season, %Ndfa steadily increased and peaked in the fall. Annual N(2) fixation, determined using foliar delta(15)N, initially averaged 0.02 Mg ha(-1), peaked at 0.5 Mg ha(-1) during the next 2 years and thereafter stabilized at 0.3 Mg ha(-1). Estimates based on whole-plant delta(15)N were <10% lower than those based on foliar delta(15)N. The increase in plant-available soil N was significantly higher in E. angustifolia plots than in P. euphratica and U. pumila plots. Increases in the concentrations of organic C (19%), total N (21%) and plant-available P (74%) in the soil were significant irrespective of tree species. This improvement in soil fertility is further evidence that afforestation with mixed-species plantations can be a sustainable land use option for the degraded irrigated croplands in CA.

  16. Use of the reamer-irrigator-aspirator may reduce tumor dissemination during intramedullary fixation of malignancies.

    PubMed

    Cipriano, Cara A; Arvanitis, Leonidas D; Virkus, Walter W

    2012-01-16

    Intramedullary nail fixation is the treatment of choice for impending and pathologic fractures secondary to metastatic cancer; however, this procedure has been shown to cause systemic embolization of intramedullary contents. This article reports the use of the reamer-irrigator-aspirator (RIA) (Synthes, Paoli, Pennsylvania) instead of a standard femoral reamer to decrease tumor intravasation during femoral intramedullary nail fixation for impending or pathologic fractures.Twenty-one consecutive patients indicated for fixation of malignant femoral lesions were treated with intramedullary nail placement. The RIA was used for canal preparation, and solid reamings were collected and submitted for analysis by a single pathologist. The volume of each specimen was recorded, and representative samples were examined histologically to determine their percent tumor content. These data were then used to estimate the volume of tumor retrieved by the RIA in each case. The mean volume of reamings collected by the RIA was 75.0 cc per case (range, 23.4-196.0 cc), and the mean tumor content was 24.8% (range, 1.0%-60.0%). The mean estimated volume of tumor retrieved in each case was 16.7 cc (range, 0.35-36.0 cc). In 2 cases, the tip of the RIA dissociated from the device intraoperatively but was retrieved without adverse consequence to the patient. Use of the RIA in cases of femoral intramedullary nail fixation for pathologic lesions or fractures effectively retrieves variable amounts of intramedullary contents, including tumor. By preventing the systemic dissemination of malignant cells, this technique may reduce the risk of distant metastases.

  17. Decision-making in information seeking on texts: an eye-fixation-related potentials investigation

    PubMed Central

    Frey, Aline; Ionescu, Gelu; Lemaire, Benoit; López-Orozco, Francisco; Baccino, Thierry; Guérin-Dugué, Anne

    2013-01-01

    Reading on a web page is known to be not linear and people need to make fast decisions about whether they have to stop or not reading. In such context, reading, and decision-making processes are intertwined and this experiment attempts to separate them through electrophysiological patterns provided by the Eye-Fixation-Related Potentials technique (EFRPs). We conducted an experiment in which EFRPs were recorded while participants read blocks of text that were semantically highly related, moderately related, and unrelated to a given goal. Participants had to decide as fast as possible whether the text was related or not to the semantic goal given at a prior stage. Decision making (stopping information search) may occur when the paragraph is highly related to the goal (positive decision) or when it is unrelated to the goal (negative decision). EFRPs were analyzed on and around typical eye fixations: either on words belonging to the goal (target), subjected to a high rate of positive decisions, or on low frequency unrelated words (incongruent), subjected to a high rate of negative decisions. In both cases, we found EFRPs specific patterns (amplitude peaking between 51 to 120 ms after fixation onset) spreading out on the next words following the goal word and the second fixation after an incongruent word, in parietal and occipital areas. We interpreted these results as delayed late components (P3b and N400), reflecting the decision to stop information searching. Indeed, we show a clear spill-over effect showing that the effect on word N spread out on word N + 1 and N + 2. PMID:23966913

  18. Integration and Fixation Preferences of Human and Mouse Endogenous Retroviruses Uncovered with Functional Data Analysis

    PubMed Central

    Pini, Alessia; Chiaromonte, Francesca; Makova, Kateryna D.

    2016-01-01

    Endogenous retroviruses (ERVs), the remnants of retroviral infections in the germ line, occupy ~8% and ~10% of the human and mouse genomes, respectively, and affect their structure, evolution, and function. Yet we still have a limited understanding of how the genomic landscape influences integration and fixation of ERVs. Here we conducted a genome-wide study of the most recently active ERVs in the human and mouse genome. We investigated 826 fixed and 1,065 in vitro HERV-Ks in human, and 1,624 fixed and 242 polymorphic ETns, as well as 3,964 fixed and 1,986 polymorphic IAPs, in mouse. We quantitated >40 human and mouse genomic features (e.g., non-B DNA structure, recombination rates, and histone modifications) in ±32 kb of these ERVs’ integration sites and in control regions, and analyzed them using Functional Data Analysis (FDA) methodology. In one of the first applications of FDA in genomics, we identified genomic scales and locations at which these features display their influence, and how they work in concert, to provide signals essential for integration and fixation of ERVs. The investigation of ERVs of different evolutionary ages (young in vitro and polymorphic ERVs, older fixed ERVs) allowed us to disentangle integration vs. fixation preferences. As a result of these analyses, we built a comprehensive model explaining the uneven distribution of ERVs along the genome. We found that ERVs integrate in late-replicating AT-rich regions with abundant microsatellites, mirror repeats, and repressive histone marks. Regions favoring fixation are depleted of genes and evolutionarily conserved elements, and have low recombination rates, reflecting the effects of purifying selection and ectopic recombination removing ERVs from the genome. In addition to providing these biological insights, our study demonstrates the power of exploiting multiple scales and localization with FDA. These powerful techniques are expected to be applicable to many other genomic investigations

  19. Ilizarov hybrid external fixation for fractures of the distal radius: Part II. Internal fixation versus Ilizarov hybrid external fixation: Stability as assessed by cadaveric simulated motion testing.

    PubMed

    Dunning, C E; Lindsay, C S; Bicknell, R T; Johnson, J A; King, G J; Patterson, S D

    2001-03-01

    The in vitro stability of an Ilizarov hybrid external fixator was compared with that of a dorsal 3.5-mm AO T-plate in 8 unpaired, fresh-frozen upper extremities. A specially designed testing device that used computer-controlled pneumatic actuators was used to simulate active finger, wrist, and forearm motions by applying loads to relevant tendons. A comminuted extra-articular distal radius fracture was modelled using a dorsally based wedge osteotomy. Fracture stability was assessed using an electromagnetic tracking device to measure motion across the fracture site after randomized application of the plate and the hybrid fixator. During simulated finger and wrist motions with the forearm pronated or supinated, motion of the distal fragment with the hybrid fixator applied was comparable to or statistically less than with the AO plate applied. During simulated forearm rotation, the stability provided by the 2 fixation types was similar, although the plate allowed statistically less radial-ulnar deviation of the fragment. In this model of a 2-part extra-articular distal radius fracture, the clinically meaningful stability of the Ilizarov hybrid external fixator was comparable to that of the dorsal AO plate.

  20. Changes in oral trace gas concentrations following orthognathic surgery and intermaxillary fixation: a case study using selected ion flow tube mass spectrometry.

    PubMed

    Ross, Brian M

    2011-07-01

    Orthognathic surgery is frequently accompanied by intermaxillary fixation. Intermaxillary fixation impedes the maintenance of effective oral hygiene and prolonged fixation can result in periodontal disease. A potential shorter term effect is the generation of oral malodour. It is unclear, however, as to how the production of malodorous compounds in the oral cavity is altered post-surgery. Oral air concentration of sulphur containing compounds, short chain organic acids, ammonia, isoprene and acetone were measured using selected ion flow tube-mass spectrometry in a patient who had undergone orthognathic surgery with subsequent intermaxillary fixation. Total sulphide levels rose approximately 5-fold during fixation with metal ties, with smaller increases recorded for the other compounds measured with the exception of isoprene which remained close to baseline levels. Organic acid levels declined markedly once elastic ties had replaced metal ties, with a lesser reduction being observed in sulphide levels, with both declining further after the commencement of a chlorhexidine-containing mouthwash. These data suggest that bacterial generation of a variety of malodorous compounds increases markedly following intermaxillary fixation. This single case also suggests that the use of elastic ties and effective oral hygiene techniques, including the use of chlorhexidine mouthwash, may help ameliorate such post-surgical effects.

  1. Ecosystem nitrogen fixation throughout the snow-free period in subarctic tundra: effects of willow and birch litter addition and warming.

    PubMed

    Rousk, Kathrin; Michelsen, Anders

    2017-04-01

    Nitrogen (N) fixation in moss-associated cyanobacteria is one of the main sources of available N for N-limited ecosystems such as subarctic tundra. Yet, N2 fixation in mosses is strongly influenced by soil moisture and temperature. Thus, temporal scaling up of low-frequency in situ measurements to several weeks, months or even the entire growing season without taking into account changes in abiotic conditions cannot capture the variation in moss-associated N2 fixation. We therefore aimed to estimate moss-associated N2 fixation throughout the snow-free period in subarctic tundra in field experiments simulating climate change: willow (Salix myrsinifolia) and birch (Betula pubescens spp. tortuosa) litter addition, and warming. To achieve this, we established relationships between measured in situ N2 fixation rates and soil moisture and soil temperature and used high-resolution measurements of soil moisture and soil temperature (hourly from May to October) to model N2 fixation. The modelled N2 fixation rates were highest in the warmed (2.8 ± 0.3 kg N ha(-1) ) and birch litter addition plots (2.8 ± 0.2 kg N ha(-1) ), and lowest in the plots receiving willow litter (1.6 ± 0.2 kg N ha(-1) ). The control plots had intermediate rates (2.2 ± 0.2 kg N ha(-1) ). Further, N2 fixation was highest during the summer in the warmed plots, but was lowest in the litter addition plots during the same period. The temperature and moisture dependence of N2 fixation was different between the climate change treatments, indicating a shift in the N2 fixer community. Our findings, using a combined empirical and modelling approach, suggest that a longer snow-free period and increased temperatures in a future climate will likely lead to higher N2 fixation rates in mosses. Yet, the consequences of increased litter fall on moss-associated N2 fixation due to shrub expansion in the Arctic will depend on the shrub species' litter traits.

  2. 21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as...

  3. 21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as...

  4. 21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as...

  5. 21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as...

  6. 21 CFR 888.3040 - Smooth or threaded metallic bone fixation fastener.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Smooth or threaded metallic bone fixation fastener... metallic bone fixation fastener. (a) Identification. A smooth or threaded metallic bone fixation fastener..., slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as...

  7. The Role of Personality and Team-Based Product Dissection on Fixation Effects

    ERIC Educational Resources Information Center

    Toh, Christine; Miller, Scarlett; Kremer, Gül E. Okudan

    2013-01-01

    Design fixation has been found to be complex in its definition and expression, but it plays an important role in design idea generation. Identifying the factors that influence fixation is crucial in understanding how to enhance the design process and reduce the negative effects of fixation. One way to potentially mitigate fixation is through…

  8. Comparison of Bioabsorbable Suture Anchor Fixation on the Tibial Side for Anterior Cruciate Ligament Reconstruction Using Free Soft Tissue Graft: Experimental Laboratory Study on Porcine Bone

    PubMed Central

    Na, Suk In; Lee, Jong Min; Park, Ju Yong

    2014-01-01

    Purpose The use of graft tissue fixation using bioabsorbable interference screws (BISs) in anterior cruciate ligament (ACL) reconstruction offers various advantages, but limited pullout strength. Therefore, additional tibial fixation is essential for aggressive rehabilitation. We hypothesized that additional graft tissue fixation using bioabsorbable suture anchors (BSA) would provide sufficient pull-out strength. Materials and Methods Twenty four fresh frozen porcine distal femur and patellar tendon preparations were used. All specimens were divided into three groups based on additional fixation methods: A, isolated BIS; B, BIS and BSA; and C, BIS and post cortical screw. Tensile testing was carried out under an axial load. Ultimate failure load and ultimate failure load after cyclic loading were recorded. Results The ultimate failure loads after load to failure testing were 166.8 N in group A, 536.4 N in group B, and 438 N in group C; meanwhile, the ultimate failure loads after load to failure testing with cyclic loading were 140 N in group A, 466.5 N in group B, and 400 N in group C. Stiffness after load to failure testing was 16.5 N/mm in group A, 33.5 N/mm in group B, and 40 N/mm in group C. An additional BSA fixation resulted in a significantly higher ultimate failure load and stiffness than isolated BIS fixation, similar to post screw fixation. Conclusion Additional fixation using a BSA provided sufficient pullout strength for ACL reconstruction. The ultimate failure load of the BSA technique was similar to that of post cortical screws. PMID:24719145

  9. Determination of the lowest concentrations of aldehyde fixatives for completely fixing various cellular structures by real-time imaging and quantification.

    PubMed

    Zeng, Fangfa; Yang, Wen; Huang, Jie; Chen, Yuan; Chen, Yong

    2013-05-01

    The effectiveness of fixatives for fixing biological specimens has long been widely investigated. However, the lowest concentrations of fixatives needed to completely fix whole cells or various cellular structures remain unclear. Using real-time imaging and quantification, we determined the lowest concentrations of glutaraldehyde (0.001-0.005, ~0.005, 0.01-005, 0.01-005, and 0.01-0.1 %) and formaldehyde/paraformaldehyde (0.01-0.05, ~0.05, 0.5-1, 1-1.5, and 0.5-1 %) required to completely fix focal adhesions, cell-surface particles, stress fibers, the cell cortex, and the inner structures of human umbilical vein endothelial cells within 20 min. With prolonged fixation times (>20 min), the concentration of fixative required to completely fix these structures will shift to even lower values. These data may help us understand and optimize fixation protocols and understand the potential effects of the small quantities of endogenously generated aldehydes in human cells. We also determined the lowest concentration of glutaraldehyde (0.5 %) and formaldehyde/paraformaldehyde (2 %) required to induce cell blebbing. We found that the average number and size of the fixation-induced blebs per cell were dependent on both fixative concentration and cell spread area, but were independent of temperature. These data provide important information for understanding cell blebbing, and may help optimize the vesiculation-based technique used to isolate plasma membrane by suggesting ways of controlling the number or size of fixation-induced cell blebs.

  10. Condylar resorption in orthognathic surgery. The role of intermaxillary fixation.

    PubMed

    Bouwman, J P; Kerstens, H C; Tuinzing, D B

    1994-08-01

    Condylar resorption that occurs after orthognathic surgery was investigated in a large sample of patients treated in the Department of Oral and Maxillofacial Surgery of the Free University in Amsterdam, the Netherlands. The findings correspond with previous publications on this subject. In a 1-year follow-up study the role of intermaxillary fixation was investigated radiologically. In a group of 158 patients prone to show occurrence of condylar resorption, 24 (26.4%) of the 91 patients treated with intermaxillary fixation showed signs of condylar resorption. In the group of 67 patients treated without intermaxillary fixation only eight (11.9%) of the patients showed signs of reduced volume of the condyle. Avoidance of intermaxillary fixation seems to reduce the incidence of condylar resorption after orthognathic surgery in patients with a mandibular deficiency with high mandibular plane angle.

  11. Fixation of tritium in a highly stable polymer form

    DOEpatents

    Steinberg, Meyer; Colombo, Peter; Pruzansky, Jacob

    1977-01-01

    A method for the fixation of tritium comprising reacting tritiated water with calcium carbide to produce calcium hydroxide and tritiated acetylene, polymerizing the acetylene, and then incorporating the polymer in a solidifying matrix.

  12. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the...

  13. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the...

  14. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the...

  15. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the...

  16. 21 CFR 888.3020 - Intramedullary fixation rod.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identification. An intramedullary fixation rod is a device intended to be implanted that consists of a rod made of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the...

  17. Mechanical evaluation of two canine iliac fracture fixation systems.

    PubMed

    Vangundy, T E; Hulse, D A; Nelson, J K; Boothe, H W

    1988-01-01

    Twenty-three canine pelves were tested bilaterally to determine the stiffness and strength of intact ilium and stabilized oblique iliac osteotomies that simulated a common clinical fracture. Fixation systems tested were three 4.0 mm cancellous screws inserted ventral to dorsal across the osteotomy site and one laterally placed five hole 3.5 mm dynamic compression plate. Specimens were mechanically tested to failure under torsional, axial, or axial plus bending loads. Lag screw fixation was stiffer and stronger than plate fixation in all testing modes. The differences were statistically significant (p less than .05) in the torsional and axial plus bending loading modes. Fatigue testing was performed on implanted specimens with low-level cyclic loading under axial plus bending loading conditions. Physiologic loading conditions failed to produce mechanical failure of either fixation system after 100,000 cycles.

  18. Stochastic dynamics of invasion and fixation

    NASA Astrophysics Data System (ADS)

    Traulsen, Arne; Nowak, Martin A.; Pacheco, Jorge M.

    2006-07-01

    We study evolutionary game dynamics in finite populations. We analyze an evolutionary process, which we call pairwise comparison, for which we adopt the ubiquitous Fermi distribution function from statistical mechanics. The inverse temperature in this process controls the intensity of selection, leading to a unified framework for evolutionary dynamics at all intensities of selection, from random drift to imitation dynamics. We derive a simple closed formula that determines the feasibility of cooperation in finite populations, whenever cooperation is modeled in terms of any symmetric two-person game. In contrast with previous results, the present formula is valid at all intensities of selection and for any initial condition. We investigate the evolutionary dynamics of cooperators in finite populations, and study the interplay between intensity of selection and the remnants of interior fixed points in infinite populations, as a function of a given initial number of cooperators, showing how this interplay strongly affects the approach to fixation of a given trait in finite populations, leading to counterintuitive results at different intensities of selection.

  19. Array tomogr