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Sample records for intrapopulation fixation index

  1. Effects of intrapopulation competition on morphological and ...

    African Journals Online (AJOL)

    Effects of intrapopulation competition on morphological and agronomic characters of Jute plant ( Corchorus olitorius L.) ... There was a gradual decline in all attributes except height/plant as population density increased. These observations confirmed the occurrence of intraspecific competition in population of jute plant.

  2. Low genetic diversity and intrapopulation spatial genetic structure of the Atlantic Forest tree, Esenbeckia leiocarpa Engl. (Rutaceae

    Directory of Open Access Journals (Sweden)

    G. Forti

    2014-12-01

    Full Text Available Studies on population genetics are the key to designing effective in situ management plans for tree species, in particular, those subjected to pressure from anthropogenic processes, such as forest fragmentation and logging. To investigate genetic diversity, inbreeding and intrapopulation spatial genetic structure (SGS in a fragmented population of the insect-pollinated tropical tree, Esenbeckia leiocarpa, we developed specific microsatellite markers for this species and mapped and sampled 100 individuals in a forest plot. Two issues were addressed in particular: (i the level of genetic diversity, inbreeding and effective population size, (ii whether intrapopulation spatial genetic structure exists. Among the 14 loci developed, we only used the three that presented polymorphism to estimate the genetic parameters. Genetic diversity was low, whereby the average number of alleles per locus (A was 3.3 and observed (H0 and expected heterozygosities (He were 0.336 and 0.298, respectively. The average fixation index was significantly higher than zero (F = 0.112, suggesting inbreeding. Significant SGS was found up to 7 m and between 31 to 38 m, indicating that trees growing within these distances may be related. Estimates of the effective population size indicated that the 100 sampled trees correspond to 14 individuals that are neither related nor inbred. Our results suggest that the microsatellite markers developed in this study are suitable for studies on geneticdiversity and structure, mating systems, gene flow and SGS in this species.

  3. Does pediatric body mass index affect surgical outcomes of lower-extremity external fixation?

    Science.gov (United States)

    Fedorak, Graham T; Cuomo, Anna V; Otsuka, Norman Y

    2015-06-01

    Obese patients are highly prevalent in the pediatric orthopaedic surgeon's practice and obesity is an increasing issue in the United States. Increased body mass index (BMI) has been associated with increased complications in pediatric orthopaedic patients, but no study has looked specifically at external fixation. The purpose of this study was to determine whether obesity is a risk factor for increased complications in lower-extremity procedures requiring external fixation. A retrospective chart review was conducted of pediatric patients who underwent external fixation as definitive operative treatment for any condition at a tertiary care hospital over a 15-year period. Patients were grouped into normal weight, overweight, and obese based on Centers for Disease Control definitions. All orthopaedic complications were recorded. A total of 208 patients with a mean age of 11.2 years were identified. Ninety-four children were obese at the 95th percentile BMI or higher, 22 were overweight and 93 were normal weight. External fixation was applied to the tibia in 82 cases, to the femur in 77 and to both in 49. Mean duration of fixation was 160 days (range, 31 to 570 d) and patients were followed for a mean of 3.9 years (range, 1.0 to 12.0 y). There was no statistically significant difference in the rate of complications between the 3 groups (P=0.61). In the obese group complications occurred in 68.1% versus 66.7% in the overweight group and 61.3% in normal weight. In the setting of external fixator use for lower-extremity pathology in pediatric patients, there is no association between an increase in complications and obesity as defined by BMI. Complication rates are high when external fixation is utilized for the lower extremity, however, patients and families should not be counseled that increased BMI will add to the burden of orthopaedic complications in this situation. Level II-prognostic.

  4. Evaluation of changes in anthropometric indexes due to intermaxillary fixation following facial fractures

    Directory of Open Access Journals (Sweden)

    Javad Yazdani

    2016-12-01

    Full Text Available Background. One of the treatment modalities for facial fractures is closed reduction technique, but treatment with intermaxillary fixation (IMF interferes with normal nutrition, and malnutrition can affect the patient’s recovery. Anthropometric measurements such as skinfold thickness and body mass index (BMI are universal indexes for diagnosing malnutrition. Therefore, in this study we explain how treatment with IMF changes the anthropometric indexes. Methods. In this study 60 patients were treated with 4 weeks of IMF. Skinfold thickness and BMI of these patients were measured and compared before and after the treatment. Results. Patients’ weight, BMI and skinfold thickness decreased during the IMF period, and this decrease was statistically significant (P < 0.01. Conclusion. Although no severe and acute malnutrition was seen among our patients, IMF led to mild to moderate malnutrition in some cases, making it necessary to use nutritional supplements.

  5. Landscape heterogeneity drives intra-population niche variation and reproduction in an arctic top predator.

    Science.gov (United States)

    L'hérault, Vincent; Franke, Alastair; Lecomte, Nicolas; Alogut, Adam; Bêty, Joël

    2013-09-01

    While intra-population variability in resource use is ubiquitous, little is known of how this measure of niche diversity varies in space and its role in population dynamics. Here we examined how heterogeneous breeding environments can structure intra-population niche variation in both resource use and reproductive output. We investigated intra-population niche variation in the Arctic tundra ecosystem, studying peregrine falcon (Falco peregrinus tundrius, White) breeding within a terrestrial-marine gradient near Rankin Inlet, Nunavut, Canada. Using stable isotope analysis, we found that intra-population niches varied at the individual level; we examined within-nest and among-nest variation, though only the latter varied along the terrestrial-marine gradient (i.e., increased among-nest variability among birds nesting within the marine environment, indicating higher degree of specialization). Terrestrial prey species (small herbivores and insectivores) were consumed by virtually all falcons. Falcons nesting within the marine environment made use of marine prey (sea birds), but depended heavily on terrestrial prey (up to 90% of the diet). Using 28-years of peregrine falcon nesting data, we found a positive relationship between the proportion of terrestrial habitat surrounding nest sites and annual nestling production, but no relationship with the likelihood of successfully rearing at least one nestling reaching 25 days old. Annually, successful inland breeders raised 0.47 more young on average compared to offshore breeders, which yields potential fitness consequences for this long-living species. The analyses of niche and reproductive success suggest a potential breeding cost for accessing distant terrestrial prey, perhaps due to additional traveling costs, for those individuals with marine nest site locations. Our study indicates how landscape heterogeneity can generate proximate (niche variation) and ultimate (reproduction) consequences on a population of generalist

  6. Surgical Site Infections after Open Reduction Internal Fixation for Trauma in Low and Middle Human Development Index Countries: A Systematic Review.

    Science.gov (United States)

    McQuillan, Thomas J; Cai, Lawrence Z; Corcoran-Schwartz, Ian; Weiser, Thomas G; Forrester, Joseph D

    2018-01-17

    Musculoskeletal trauma represents a large source of morbidity in low and middle human development index countries (LMHDICs). Open reduction and internal fixation (ORIF) of traumatic long bone fractures definitively manages these injuries and restores function when conducted safely and effectively. Surgical site infections (SSIs) are a common complication of operative fracture fixation, although the risks of infection are ill-defined in LMHDIC. This study reviewed systematically all studies describing SSI after ORIF in LMDHICs. Studies were reviewed based on their qualitative characteristics, after which a quantitative synthesis of weighted pooled infection rates based on available patient-level data was performed to estimate published incidence of SSI. Forty-two studies met criteria for qualitative review and 32 studies comprising 3,084 operations were included in the quantitative analysis. Among 3,084 operations, the weighted pooled SSI rate was 6.4 infections per 100 procedures (95% confidence interval [CI] 4.6-8.2 infections per 100 procedures). Higher rates of infection were noted among the sub-group of open fractures (95% CI 13.9-23.0 infections per 100 procedures). Lower extremity injuries and procedures utilizing intra-medullary nails also had slightly higher rates of infection versus upper extremity procedures and other fixation devices. Reported rates of SSI after ORIF are higher in LMHDICs, and may be driven by high rates of infection in the sub-group of open fractures. This study provides a baseline SSI rate obtained from literature produced from LMHDICs. Infection rates are highly dependent on fracture sub-types.

  7. Identification of QTL with large effect on seed weight in a selective population of soybean with genome-wide association and fixation index analyses.

    Science.gov (United States)

    Yan, Long; Hofmann, Nicolle; Li, Shuxian; Ferreira, Marcio Elias; Song, Baohua; Jiang, Guoliang; Ren, Shuxin; Quigley, Charles; Fickus, Edward; Cregan, Perry; Song, Qijian

    2017-07-12

    Soybean seed weight is not only a yield component, but also a critical trait for various soybean food products such as sprouts, edamame, soy nuts, natto and miso. Linkage analysis and genome-wide association study (GWAS) are two complementary and powerful tools to connect phenotypic differences to the underlying contributing loci. Linkage analysis is based on progeny derived from two parents, given sufficient sample size and biological replication, it usually has high statistical power to map alleles with relatively small effect on phenotype, however, linkage analysis of the bi-parental population can't detect quantitative trait loci (QTL) that are fixed in the two parents. Because of the small seed weight difference between the two parents in most families of previous studies, these populations are not suitable to detect QTL that have considerable effects on seed weight. GWAS is based on unrelated individuals to detect alleles associated with the trait under investigation. The ability of GWAS to capture major seed weight QTL depends on the frequency of the accessions with small and large seed weight in the population being investigated. Our objective was to identify QTL that had a pronounced effect on seed weight using a selective population of soybean germplasm accessions and the approach of GWAS and fixation index analysis. We selected 166 accessions from the USDA Soybean Germplasm Collection with either large or small seed weight and could typically grow in the same location. The accessions were evaluated for seed weight in the field for two years and genotyped with the SoySNP50K BeadChip containing >42,000 SNPs. Of the 17 SNPs on six chromosomes that were significantly associated with seed weight in two years based on a GWAS of the selective population, eight on chromosome 4 or chromosome 17 had significant Fst values between the large and small seed weight sub-populations. The seed weight difference of the two alleles of these eight significant SNPs varied

  8. The EC90 of remifentanil for blunting cardiovascular responses to head fixation for neurosurgery under total intravenous anesthesia with propofol and remifentanil based on bispectral index monitoring: estimation with the biased coin up-and-down sequential method.

    Science.gov (United States)

    Lee, Jung-Man; Bahk, Jae-Hyon; Lim, Young-Jin; Lee, Jiwon; Lim, Leerang

    2017-10-10

    Head fixation can induce hemodynamic instability. Remifentanil is commonly used with propofol for total intravenous anesthesia (TIVA) during neurosurgery. This study investigated the 90% effective concentration (EC 90 ) of remifentanil for blunting of cardiovascular responses to head fixation during neurosurgery via bispectral index (BIS) monitoring. Fifty patients undergoing neurosurgery requiring head fixation were enrolled. This study was performed using the biased coin up-and-down design sequential method (BCD). After tracheal intubation, the effect-site target concentration (Ce) of remifentanil was adjusted to achieve hemodynamic stability and reset to the level preoperatively assigned to each patient, according to the BCD method, approximately 10 min before head fixation. Baseline hemodynamic values were recorded before head fixation. An ineffective response was defined as a case with a > 20% increase in hemodynamic values from baseline. Otherwise, the response was determined to be effective. The EC 90 of remifentanil was calculated as a modified isotonic estimator. Forty-three patients completed this study. The EC 90 of remifentanil for blunting cardiovascular responses to head fixation was estimated to be 6.48 ng/mL (95% CI, 5.94-6.83 ng/mL). Adjustment of the Ce of remifentanil to approximately 6.5 ng/mL before head fixation could prevent noxious cardiovascular responses in 90% of neurosurgical ASA I-II patients aged 20 to 65 years old during propofol target-controlled infusion titrated to maintain BIS between 40 and 50. ClinicalTrials.gov Identifier NCT01489137 , retrospectively registered 5 December 2011.

  9. Intra-population level variation in thresholds for physical dormancy-breaking temperature.

    Science.gov (United States)

    Liyanage, Ganesha S; Ooi, Mark K J

    2015-07-01

    Intra-population variation in seed dormancy is an advantage for population persistence in unpredictable environments. The important role played by physically dormant species in these habitats makes understanding the level of variation in their dormancy a key ecological question. Heat produced in the soil is the major dormancy-breaking stimulus and, in fire prone ecosystems, soil temperatures generated by fire may vary spatially and over time. While many studies have investigated variation in initial dormancy, a measure that is of little value in fire-prone ecosystems, where initial dormancy levels are uniformly high, intra-population variation in dormancy-breaking temperature thresholds has never been quantified. This study predicted that species would display variation in dormancy-breaking temperature thresholds within populations, and investigated whether this variation occurred between individual plants from the same maternal environment. The intra-population variation in dormancy-breaking thresholds of five common physically dormant shrub species (family Fabaceae) from fire-prone vegetation in south-eastern Australia was assessed using heat treatments and germination trials. Replicate batches of seeds from each of four maternal plants of Dillwynia floribunda, Viminaria juncea, Bossiaea heterophylla, Aotus ericoides and Acacia linifolia were treated at 40, 60, 80, 100 and 120 °C. Dormancy-breaking response to heat treatments varied significantly among individual plants for all species, with some individuals able to germinate after heating at low temperatures and others restricting germination to temperatures that only occur as a result of high-severity fires. Germination rate (T50) varied among individuals of three species. Variation detected among individuals that were in close proximity to each other indicates that strong differences in dormancy-breaking temperature thresholds occur throughout the broader population. Differences found at the individual plant

  10. Intra-population variation in behavior modification by the acanthocephalan Acanthocephalus dirus: are differences mediated by host condition?

    Science.gov (United States)

    Caddigan, Sara C; Barkauskas, Rima T; Sparkes, Timothy C

    2014-11-01

    The acanthocephalan parasite Acanthocephalus dirus infects the freshwater isopod Caecidotea intermedius as an intermediate host before completing its life cycle in a fish. Male C. intermedius infected by A. dirus parasites are less likely to engage in mating behavior than uninfected males but there is a significant intra-population variation in the occurrence of this behavioral change. Previous studies on uninfected isopods have shown that glycogen content is a predictor of male mating behavior and we examined whether the intra-population variation in the mating behavior of infected male C. intermedius could be explained by this relationship. A field-based behavioral experiment was used to quantify intra-population variation in male mating behavior, which showed that 50% of infected males were responsive to females and 50% were not responsive. Biochemical analysis of responsive and non-responsive males revealed that glycogen content was a predictor of the mating behavior for uninfected males but was not a predictor of mating behavior for infected males. For infected males, parasite intensity was a predictor of mating behavior. Males that contained more A. dirus parasites were less likely to undergo modification of mating behavior. We propose that the intra-population variation in the mating behavior of infected C. intermedius identified in nature was not mediated by host condition.

  11. Intrapopulation genome size variation in D. melanogaster reflects life history variation and plasticity.

    Directory of Open Access Journals (Sweden)

    Lisa L Ellis

    2014-07-01

    Full Text Available We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions.

  12. Intrapopulation Genotypic Variation of Foliar Secondary Chemistry during Leaf Senescence and Litter Decomposition in Silver Birch (Betula pendula

    Directory of Open Access Journals (Sweden)

    Ulla Paaso

    2017-06-01

    Full Text Available Abundant secondary metabolites, such as condensed tannins, and their interpopulation genotypic variation can remain through plant leaf senescence and affect litter decomposition. Whether the intrapopulation genotypic variation of a more diverse assortment of secondary metabolites equally persists through leaf senescence and litter decomposition is not well understood. We analyzed concentrations of intracellular phenolics, epicuticular flavonoid aglycones, epicuticular triterpenoids, condensed tannins, and lignin in green leaves, senescent leaves and partly decomposed litter of silver birch, Betula pendula. Broad-sense heritability (H2 and coefficient of genotypic variation (CVG were estimated for metabolites in senescent leaves and litter using 19 genotypes selected from a B. pendula population in southern Finland. We found that most of the secondary metabolites remained through senescence and decomposition and that their persistence was related to their chemical properties. Intrapopulation H2 and CVG for intracellular phenolics, epicuticular flavonoid aglycones and condensed tannins were high and remarkably, increased from senescent leaves to decomposed litter. The rank of genotypes in metabolite concentrations was persistent through litter decomposition. Lignin was an exception, however, with a diminishing genotypic variation during decomposition, and the concentrations of lignin and condensed tannins had a negative genotypic correlation in the senescent leaves. Our results show that secondary metabolites and their intrapopulation genotypic variation can for the most part remain through leaf senescence and early decomposition, which is a prerequisite for initial litter quality to predict variation in litter decomposition rates. Persistent genotypic variation also opens an avenue for selection to impact litter decomposition in B. pendula populations through acting on their green foliage secondary chemistry. The negative genotypic correlations

  13. Indexed

    CERN Document Server

    Hagy, Jessica

    2008-01-01

    Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

  14. Latarjet Fixation

    Science.gov (United States)

    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

  15. Intrascleral IOL Fixation.

    Science.gov (United States)

    Jacob, Soosan

    2017-01-01

    Intrascleral sutureless intraocular lens (IOL) fixation utilizes direct haptic fixation within the sclera in eyes with deficient capsular support. This has advantages of long-term stability, good control of tilt and decentration, and lesser pseudophakodonesis. This review summarizes various techniques for intrascleral haptic fixation, results, complications, adaptations in special situations, modifications of the technique, combination surgeries, and intrascleral capsular bag fixation techniques (glued capsular hook). Copyright 2017 Asia-Pacific Academy of Ophthalmology.

  16. Intra-population plasticity of Anopheles darlingi's (Diptera, Culicidae biting activity patterns in the state of Amapá, Brazil

    Directory of Open Access Journals (Sweden)

    Voorham Jaco

    2002-01-01

    Full Text Available OBJECTIVE: To assess the variation in Anopheles darlingi's biting activity compared to An. marajoara in the same locality and to biting activity data from other regions. METHODS: Using human bait, eight observations of the biting activity of An. darlingi and An. marajoara were carried out during 1999 and 2000 in the municipality of São Raimundo do Pirativa, state of Amapá, Brazil. Each observation consisted of three consecutive 13-hour collections, close to full moon. There were shifts of collectors in the observation points and nocturnal periods. RESULTS: An. darlingi revealed considerable plasticity of biting activity in contrast to An. marajoara, which showed well-defined crepuscular biting peaks. No significant correlation between density and biting activity was found, but a significant correlation existed between time and proportional crepuscular activity, indicating underlying ecological processes not yet understood. Two of the four available data sets having multiple observations at one locality showed considerable plasticity of this species' biting patterns as well. CONCLUSION: Intra-population variation of biting activity can be as significant as inter-population variation. Some implications in malaria vector control and specific studies are also discussed.

  17. Intra-population plasticity of Anopheles darlingi's (Diptera, Culicidae) biting activity patterns in the state of Amapá, Brazil.

    Science.gov (United States)

    Voorham, Jaco

    2002-02-01

    To assess the variation in Anopheles darlingi's biting activity compared to An. marajoara in the same locality and to biting activity data from other regions. Using human bait, eight observations of the biting activity of An. darlingi and An. marajoara were carried out during 1999 and 2000 in the municipality of São Raimundo do Pirativa, state of Amapá, Brazil. Each observation consisted of three consecutive 13-hour collections, close to full moon. There were shifts of collectors in the observation points and nocturnal periods. An. darlingi revealed considerable plasticity of biting activity in contrast to An. marajoara, which showed well-defined crepuscular biting peaks. No significant correlation between density and biting activity was found, but a significant correlation existed between time and proportional crepuscular activity, indicating underlying ecological processes not yet understood. Two of the four available data sets having multiple observations at one locality showed considerable plasticity of this species' biting patterns as well. Intra-population variation of biting activity can be as significant as inter-population variation. Some implications in malaria vector control and specific studies are also discussed.

  18. Guide to radiation fixatives

    International Nuclear Information System (INIS)

    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

  19. Guide to radiation fixatives

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Highly local environmental variability promotes intrapopulation divergence of quantitative traits: an example from tropical rain forest trees.

    Science.gov (United States)

    Brousseau, Louise; Bonal, Damien; Cigna, Jeremy; Scotti, Ivan

    2013-10-01

    In habitat mosaics, plant populations face environmental heterogeneity over short geographical distances. Such steep environmental gradients can induce ecological divergence. Lowland rainforests of the Guiana Shield are characterized by sharp, short-distance environmental variations related to topography and soil characteristics (from waterlogged bottomlands on hydromorphic soils to well-drained terra firme on ferralitic soils). Continuous plant populations distributed along such gradients are an interesting system to study intrapopulation divergence at highly local scales. This study tested (1) whether conspecific populations growing in different habitats diverge at functional traits, and (2) whether they diverge in the same way as congeneric species having different habitat preferences. Phenotypic differentiation was studied within continuous populations occupying different habitats for two congeneric, sympatric, and ecologically divergent tree species (Eperua falcata and E. grandiflora, Fabaceae). Over 3000 seeds collected from three habitats were germinated and grown in a common garden experiment, and 23 morphological, biomass, resource allocation and physiological traits were measured. In both species, seedling populations native of different habitats displayed phenotypic divergence for several traits (including seedling growth, biomass allocation, leaf chemistry, photosynthesis and carbon isotope composition). This may occur through heritable genetic variation or other maternally inherited effects. For a sub-set of traits, the intraspecific divergence associated with environmental variation coincided with interspecific divergence. The results indicate that mother trees from different habitats transmit divergent trait values to their progeny, and suggest that local environmental variation selects for different trait optima even at a very local spatial scale. Traits for which differentiation within species follows the same pattern as differentiation between

  1. CSF coccidioides complement fixation

    Science.gov (United States)

    Skip navigation U.S. National Library of Medicine The navigation menu has been collapsed. ... of this page: //medlineplus.gov/ency/article/003526.htm CSF coccidioides complement fixation test To use the sharing features ...

  2. Histoplasma complement fixation

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    Skip navigation U.S. National Library of Medicine The navigation menu has been collapsed. ... this page: //medlineplus.gov/ency/article/003527.htm Histoplasma complement fixation To use the sharing features on this page, ...

  3. Inter- and intrapopulation variation in the response of tree seedlings to drought: physiological adjustments based on geographical origin, water supply and species.

    Science.gov (United States)

    Carevic, Felipe S; Delatorre-Herrera, José; Delatorre-Castillo, José

    2017-09-01

    Initiatives to restore natural ecosystems have had little success in arid and hyperarid ecosystems. In this context, the natural seedling establishment is particularly affected by drought patterns and climatic variability. Likewise, the effect of plant provenance on forest restoration success remains unclear, although previous studies have concluded that some seed locations might be better able to tolerate water stress. In this study, we examined the physiological mechanisms involved in the drought stress resistance of Prosopis tamarugo and Prosopis alba seedlings from different arid and hyperarid locations of the Atacama Desert in northern Chile. We measured the xylem water potential (Ψ), cuticular transpiration (E c ), specific leaf area (SLA) and pressure-volume curves at the intrapopulation and interpopulation levels of seedlings of both species subjected to three drought-induced treatments. In addition, plant characteristics such as seedling height (Sh), stem diameter (Sd), leaf biomass (Lb), root biomass (Rb) and seedling survival (Ss) were measured during the treatments. Seedlings of most hyperarid habitats had the highest values of Ψ and water content relative to the turgor loss point, as well as decreased SLA, especially during the strongest drought treatment. Ψ was strongly correlated with Sh in both species, and soil humidity was correlated with Sd. This study highlights the high variability of physiological responses to water stress in both species at the interpopulation and intrapopulation levels, which provides us with a powerful seed selection tool for future reforestation programmes aimed at the early selection and genetic improvement of species of the Prosopis genus.

  4. Improving carbon fixation pathways

    Energy Technology Data Exchange (ETDEWEB)

    Ducat, DC; Silver, PA

    2012-08-01

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

  5. Update: Biological Nitrogen Fixation.

    Science.gov (United States)

    Wiseman, Alan; And Others

    1985-01-01

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

  6. Posterior transodontoid fixation: A new fixation (Kotil technique

    Directory of Open Access Journals (Sweden)

    Kadir Kotil

    2011-01-01

    Full Text Available Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique, through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an

  7. Improving carbon fixation pathways.

    Science.gov (United States)

    Ducat, Daniel C; Silver, Pamela A

    2012-08-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that novel pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Brow lift fixation.

    Science.gov (United States)

    Gold, Alan H; Bernard, Robert W; Hamas, Robert S; McKinney, Peter; Paul, Malcolm D

    2003-05-01

    One of the more difficult and controversial aspects of forehead and brow lift is fixation with control and stabilization of the result. Aesthetic Surgery Journal has invited Robert W. Bernard, MD; Robert S. Hamas, MD; Peter McKinney, MD; and Malcolm D. Paul, MD to share their preferred brow lift techniques. Here are their responses to questions posed by "Comparing Notes" editor, Alan H. Gold, MD. (Aesthetic Surg J 2003;23:217-219.).

  9. Improving Carbon Fixation Pathways

    OpenAIRE

    Ducat, Daniel C.; Silver, Pamela A.

    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...

  10. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Nitrogen fixation apparatus

    Science.gov (United States)

    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.

  12. Fixation Time for Evolutionary Graphs

    Science.gov (United States)

    Nie, Pu-Yan; Zhang, Pei-Ai

    Evolutionary graph theory (EGT) is recently proposed by Lieberman et al. in 2005. EGT is successful for explaining biological evolution and some social phenomena. It is extremely important to consider the time of fixation for EGT in many practical problems, including evolutionary theory and the evolution of cooperation. This study characterizes the time to asymptotically reach fixation.

  13. Complement fixation test to C burnetii

    Science.gov (United States)

    ... complement fixation test; Coxiella burnetii - complement fixation test; C burnetii - complement fixation test ... a specific foreign substance ( antigen ), in this case, C burnetii . Antibodies defend the body against bacteria, viruses, ...

  14. The role of sex and age in the architecture of intrapopulation howler monkey-plant networks in continuous and fragmented rain forests

    Directory of Open Access Journals (Sweden)

    Julieta Benitez-Malvido

    2016-03-01

    Full Text Available We evaluated the structure of intrapopulation howler monkey-plant interactions by focusing on the plant species consumed by different sex and age classes in continuous and fragmented forests in southern Mexico. For this we used network analysis to evaluate the impact of fragmentation on howler population traits and on resource availability and food choice. A total of 37 tree and liana species and seven plant items (bark, immature fruits, flowers, mature fruits, immature leaves, mature leaves and petioles were consumed, but their relative consumption varied according to sex and age classes and habitat type. Overall, adult females consumed the greatest number of plant species and items while infants and juveniles the lowest. For both continuous and fragmented forests, we found a nested diet for howler monkey-plant networks: diets of more selective monkeys represent subsets of the diets of other individuals. Nestedness was likely due to the high selectivity of early life stages in specific food plants and items, which contrasts with the generalized foraging behaviour of adults. Information on the extent to which different plant species and primate populations depend on such interactions in different habitats will help to make accurate predictions about the potential impact of disturbances on plant-animal interaction networks.

  15. Intrapopulational body size variation and cranial capacity variation in Middle Pleistocene humans: the Sima de los Huesos sample (Sierra de Atapuerca, Spain).

    Science.gov (United States)

    Lorenzo, C; Carretero, J M; Arsuaga, J L; Gracia, A; Martínez, I

    1998-05-01

    A sexual dimorphism more marked than in living humans has been claimed for European Middle Pleistocene humans, Neandertals and prehistoric modern humans. In this paper, body size and cranial capacity variation are studied in the Sima de los Huesos Middle Pleistocene sample. This is the largest sample of non-modern humans found to date from one single site, and with all skeletal elements represented. Since the techniques available to estimate the degree of sexual dimorphism in small palaeontological samples are all unsatisfactory, we have used the bootstraping method to asses the magnitude of the variation in the Sima de los Huesos sample compared to modern human intrapopulational variation. We analyze size variation without attempting to sex the specimens a priori. Anatomical regions investigated are scapular glenoid fossa; acetabulum; humeral proximal and distal epiphyses; ulnar proximal epiphysis; radial neck; proximal femur; humeral, femoral, ulnar and tibial shaft; lumbosacral joint; patella; calcaneum; and talar trochlea. In the Sima de los Huesos sample only the humeral midshaft perimeter shows an unusual high variation (only when it is expressed by the maximum ratio, not by the coefficient of variation). In spite of that the cranial capacity range at Sima de los Huesos almost spans the rest of the European and African Middle Pleistocene range. The maximum ratio is in the central part of the distribution of modern human samples. Thus, the hypothesis of a greater sexual dimorphism in Middle Pleistocene populations than in modern populations is not supported by either cranial or postcranial evidence from Sima de los Huesos.

  16. Eighth international congress on nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

    2016-11-01

    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. 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. Average areas of 0.80 deg 2 (min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg 2 (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. 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 deg 2 in MAIA microperimeter. Fixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index.

  18. Fixation of ankle syndesmotic injuries: comparison of tightrope fixation and syndesmotic screw fixation for accuracy of syndesmotic reduction.

    Science.gov (United States)

    Naqvi, Gohar A; Cunningham, Patricia; Lynch, Bernadette; Galvin, Rose; Awan, Nasir

    2012-12-01

    Ankle syndesmotic injuries are complex and require anatomic reduction and fixation to restore the normal biomechanics of the ankle joint and prevent long-term complications. The aim of this study is to compare the accuracy and maintenance of syndesmotic reduction using TightRope versus syndesmotic screw fixation. Cohort study; Level of evidence, 2. This cohort study included consecutive patients treated for ankle syndesmotic diastases between July 2007 and June 2009. Single slice axial computed tomography (CT) scans of both the ankles together were performed at the level of syndesmosis, 1 cm above the tibial plafond. A greater than 2-mm widening of syndesmosis compared with the untreated contralateral ankle was considered significant malreduction. Clinical outcomes were measured using the American Orthopaedics Foot and Ankle Society (AOFAS) and Foot and Ankle Disability Index (FADI) scores. Forty-six of 55 eligible patients participated in the study; 23 patients were in the TightRope group and 23 in the syndesmotic screw group. The average age was 42 years in the TightRope and 40 years in the syndesmotic screw group, and the mean follow-up time was 2.5 years (range, 1.5-3.5 years). The average width of normal syndesmosis was 4.03 ± 0.89 mm. In the TightRope group, the mean width of syndesmosis was 4.37 mm (SD, ±1.12 mm) (P = .30, t test) compared with 5.16 mm (SD, ±1.92 mm) in the syndesmotic screw group (P = .01, t test). Five of 23 ankles (21.7%) in the syndesmotic screw group had syndesmotic malreduction, whereas none of the TightRope group showed malreduction on CT scans (P = .04, Fisher exact test). Average time to full weightbearing was 8 weeks in the TightRope group and 9.1 weeks in the syndesmotic screw group. There was no significant difference between the TightRope and syndesmotic screw groups in mean postoperative AOFAS score (89.56 and 86.52, respectively) or FADI score (82.42 and 81.22, respectively). Regression analysis confirmed malreduction of

  19. Femoral Reconstruction Using External Fixation

    Directory of Open Access Journals (Sweden)

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  20. Intrapopulation variability in the timing of ontogenetic habitat shifts in sea turtles revealed using δ15N values from bone growth rings.

    Science.gov (United States)

    Turner Tomaszewicz, Calandra N; Seminoff, Jeffrey A; Peckham, S Hoyt; Avens, Larisa; Kurle, Carolyn M

    2017-05-01

    Determining location and timing of ontogenetic shifts in the habitat use of highly migratory species, along with possible intrapopulation variation in these shifts, is essential for understanding mechanisms driving alternate life histories and assessing overall population trends. Measuring variations in multi-year habitat-use patterns is especially difficult for remote oceanic species. To investigate the potential for differential habitat use among migratory marine vertebrates, we measured the naturally occurring stable nitrogen isotope (δ 15 N) patterns that differentiate distinct ocean regions to create a 'regional isotope characterization', analysed the δ 15 N values from annual bone growth layer rings from dead-stranded animals, and then combined the bone and regional isotope data to track individual animal movement patterns over multiple years. We used humeri from juvenile North Pacific loggerhead turtles (Caretta caretta), animals that undergo long migrations across the North Pacific Ocean (NPO), using multiple discrete regions as they develop to adulthood. Typical of many migratory marine species, ontogenetic changes in habitat use throughout their decades-long juvenile stage is poorly understood, but each potential habitat has unique foraging opportunities and spatially explicit natural and anthropogenic threats that could affect key life-history parameters. We found a bimodal size/age distribution in the timing that juveniles underwent an ontogenetic habitat shift from the oceanic central North Pacific (CNP) to the neritic east Pacific region near the Baja California Peninsula (BCP) (42·7 ± 7·2 vs. 68·3 ± 3·4 cm carapace length, 7·5 ± 2·7 vs. 15·6 ± 1·7 years). Important to the survival of this population, these disparate habitats differ considerably in their food availability, energy requirements and threats, and these differences can influence life-history parameters such as growth, survival and future fecundity. This is the first

  1. Comparison of Outcomes of Operatively Treated Bicondylar Tibial Plateau Fractures by External Fixation and Internal Fixation

    Directory of Open Access Journals (Sweden)

    CC Chan

    2012-03-01

    Full Text Available The outcome of bicondylar tibial plateau fractures treated with either external fixation (35 patients or internal fixation (24 patients was reviewed. Outcome measures included the Rasmussen score, clinical complications, development of osteoarthritis and the requirement for total knee replacement (TKR. Twenty-two (92% anatomical reductions were achieved in the internal fixation group compared to 27 (77% in the external fixation group. Infective complications were more common in the external fixation group (9 patients, 26% due to pin tract infection. There were no deep infections in the internal fixation group. The mean Rasmussen score was not significantly different (mean score 32 in external fixation and 29 in internal fixation between the two groups and the incidence of osteoarthritis was the same in both groups. Four patients in the external fixation group underwent a TKR compared to 5 patients in the internal fixation group. Bicondylar tibial plateau fractures have similar outcomes following external or internal fixation.

  2. Understanding Nitrogen Fixation

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. Flexible fixation and fracture healing

    DEFF Research Database (Denmark)

    Schmal, Hagen; Strohm, Peter C; Jaeger, Martin

    2011-01-01

    External and internal fixators use bone screws that are locked to a plate or bar to prevent periosteal compression and associated impairment of blood supply. Both osteosynthesis techniques rely on secondary bone healing with callus formation with the exception of compression plating of simple...

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

    Science.gov (United States)

    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. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Start Position Strongly Influences Fixation Patterns during Face Processing: Difficulties with Eye Movements as a Measure of Information Use

    Science.gov (United States)

    Arizpe, Joseph; Kravitz, Dwight J.; Yovel, Galit; Baker, Chris I.

    2012-01-01

    Fixation patterns are thought to reflect cognitive processing and, thus, index the most informative stimulus features for task performance. During face recognition, initial fixations to the center of the nose have been taken to indicate this location is optimal for information extraction. However, the use of fixations as a marker for information use rests on the assumption that fixation patterns are predominantly determined by stimulus and task, despite the fact that fixations are also influenced by visuo-motor factors. Here, we tested the effect of starting position on fixation patterns during a face recognition task with upright and inverted faces. While we observed differences in fixations between upright and inverted faces, likely reflecting differences in cognitive processing, there was also a strong effect of start position. Over the first five saccades, fixation patterns across start positions were only coarsely similar, with most fixations around the eyes. Importantly, however, the precise fixation pattern was highly dependent on start position with a strong tendency toward facial features furthest from the start position. For example, the often-reported tendency toward the left over right eye was reversed for the left starting position. Further, delayed initial saccades for central versus peripheral start positions suggest greater information processing prior to the initial saccade, highlighting the experimental bias introduced by the commonly used center start position. Finally, the precise effect of face inversion on fixation patterns was also dependent on start position. These results demonstrate the importance of a non-stimulus, non-task factor in determining fixation patterns. The patterns observed likely reflect a complex combination of visuo-motor effects and simple sampling strategies as well as cognitive factors. These different factors are very difficult to tease apart and therefore great caution must be applied when interpreting absolute

  6. [Ilizarov fixation of supramalleolar fractures].

    Science.gov (United States)

    Mseddi, M B E; Mseddi, M; Siala, A; Dahmene, J; Ben Hamida, R; Ben Ayeche, M

    2005-02-01

    Supramalleolar fractures are generally considered to be a difficult surgical challenge because they occur in a area where the tibia lies superficially with a precarious blood supply to the skin, exposing to the risk of infection and necrosis after internal fixation. These fractures are also situated close to the tibiotalar joint making centromedullary nailing difficult, even with distal locking. The Ilizarov external fixator could be an attractive alternative in this indication. We report a series of 17 supramalleolar fractures in 17 patients, 14 men and 3 women, treated with the Ilizarov external fixator between 1991 and 2001. Most were traffic accident victims and most had complex fractures resulting from high-energy trauma. There were many associated lesions. Fractures were open in ten patients. The Ilizarov fixator was used as the first intention treatment in seven patients and as a second line treatment in ten. The system allowed early weight bearing in all patients. Tolerance was generally good with a relatively low rate of superficial pin track infections (two cases). There was one case of osteitis which developed in a patient with an open fracture. There were no thromboembolic complications and no nerve involvement. Bone healing was achieved within three months in thirteen patients. There were three cases of late healing which were treated by the ascension technique using a cancellous graft and fibular osteotomy. The overall healing rate with this method was 94%. The one case of nonunion was successfully treated with an inter tibiofibular graft. The overall functional outcome was satisfactory in 76% of the patients, based on the Alho-Klemm criteria. Axial deformation predominated in the frontal plane: three patients had > 10 degrees varus in one case. These results could be improved by better operative technique. We advocate installing the patient in the supine position with transcalcaneal traction allowing good restitution of the leg axis. The assembly

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

    Directory of Open Access Journals (Sweden)

    Kazunori Hirasawa

    Full Text Available 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.

  8. Abnormal Fixational Eye Movements in Amblyopia.

    Science.gov (United States)

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

    2016-01-01

    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. 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. 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. 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.

  9. Abnormal fixational eye movements in strabismus.

    Science.gov (United States)

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

    2018-02-01

    Fixational saccades are miniature eye movements that constantly change the gaze during attempted visual fixation. Visually guided saccades and fixational saccades represent an oculomotor continuum and are produced by common neural machinery. Patients with strabismus have disconjugate binocular horizontal saccades. We examined the stability and variability of eye position during fixation in patients with strabismus and correlated the severity of fixational instability with strabismus angle and binocular vision. Eye movements were measured in 13 patients with strabismus and 16 controls during fixation and visually guided saccades under monocular viewing conditions. Fixational saccades and intersaccadic drifts were analysed in the viewing and non-viewing eye of patients with strabismus and controls. We found an increase in fixational instability in patients with strabismus compared with controls. We also found an increase in the disconjugacy of fixational saccades and intrasaccadic ocular drift in patients with strabismus compared with controls. The disconjugacy was worse in patients with large-angle strabismus and absent stereopsis. There was an increase in eye position variance during drifts in patients with strabismus. Our findings suggest that both fixational saccades and intersaccadic drifts are abnormal and likely contribute to the fixational instability in patients with strabismus. Fixational instability could be a useful tool for mass screenings of children to diagnose strabismus in the absence of amblyopia and latent nystagmus. The increased disconjugacy of fixational eye movements and visually guided saccades in patients with strabismus reflects the disruption of the fine-tuning of the motor and visual systems responsible for achieving binocular fusion in these patients. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Overcoming fixation with repeated memory suppression.

    Science.gov (United States)

    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.

  11. Nitrogen fixation method and apparatus

    Science.gov (United States)

    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.

  12. Polymeric media for tritium fixation. Supplement I

    International Nuclear Information System (INIS)

    Franz, J.A.; Burger, L.L.

    1976-01-01

    Procedures for the fixation of tritium as TH or THO in two different polymeric media are described. The complete procedure for THO fixation in a polyureylene-polyurethane polumer, including polymer molding procedures and leach tests is presented. The catalytic tritiation of polystyrene under very mild conditions using a rhodium catalyst is also described. Thermal stabilities and cost estimates for the polymers examined under this program are discussed. Organic polymers were found to have attractive features for the fixation and storage of concentrated tritium wastes due to the convenience of fixation procedures and favorable properties of the resulting media

  13. Percutaneous Fixation of Displaced Calcaneal Fracture

    Directory of Open Access Journals (Sweden)

    Yeung Yip-Kan

    2011-06-01

    Conclusion: Percutaneous fixation of displaced tongue-type calcaneal fractures is an effective treatment with acceptable clinical outcome, short hospital stay, minimal skin complications, and quick recovery.

  14. Arthroscopic internal fixation of osteochondritis dissecans of the femoral head.

    Science.gov (United States)

    Matsuda, Dean K; Safran, Marc R

    2013-05-01

    Osteochondritis dessicans of the femoral head is an uncommon problem. Limited literature reports the incidence of osteochondritis dessicans and its treatment. The surgical technique used and outcomes for a 40-year-old man with symptomatic femoral head osteochonditis dissecans who was treated 11 years previously with retrograde drilling and hip arthroscopy are discussed.Despite temporary symptomatic improvement without subchondral collapse after his index procedure, increasing pain a decade later was thought to be caused by a large apical osteochondritic fragment and chondrolabral dysfunction from femoroacetabular impingement. Acetabuloplasty of acetabular overcoverage permitted arthroscopic internal fixation of the bone fragment by improving screw trajectory. Labral refixation and femoroplasty were subsequently performed. At 18-month follow-up, his nonarthritic hip score improved from 53 to 76 and his osteochondritic lesion had healed radiographically.Although clinical improvement with radiographic union has been reported following open screw fixation of femoral head osteochondritis dissecans, to the authors' knowledge this is the first published case with a similar outcome using arthroscopic techniques. Clinical improvement and union of even long-standing osteochondritis dissecans of the femoral head may occur with arthroscopic fragment fixation. Hip arthroscopy may play significant therapeutic and diagnostic roles in the treatment of this condition while offering a less invasive alternative to open osteosynthesis. Copyright 2013, SLACK Incorporated.

  15. EXPERIMENTAL APPROVAL OF COMBINED FIXATION FOR FEMUR LENGTHENING

    Directory of Open Access Journals (Sweden)

    M. A. Stepanov

    2017-01-01

    Full Text Available Elimination of congenital shortening of lower limb still remains a complex and unsolved orthopaedic task which requires an improved fixation technique as well as adjusted tactics of treatment and rehabilitation procedures.Purpose of the study — experimental approval of femur lengthening technique by external fixation with Ilizarov apparatus and internal fixation by plate.Materials and methods. Femur lengthening was performed in 6 mongrel dogs. Average animal age was 1,5±0,3 years, average weight — 20±5 kg, femur length — 22±2 sm. External apparatus with two supports and a titanium plate of an original design were applied under general anesthesia on the right femur of animals. Lengthening was performed manually at a rate of1 mm per day in 4 stages at a distance of 10% from initial segment length. External apparatus was removed on the last day of distraction after locking the plate. X-ray examination was done on the day of surgery, in 7, 14 and 25 days from the onset of distraction as well as in 14, 30, 60 and 90 days after completion of distraction and removal of external apparatus. Three animals were taken out of experiment in 30 days of fixation, remaining three animals — in 90 days. After euthanasia the authors performed autopsy of the organic femur complex and tissues contacting the plate.Results. The use of operated limb was not restricted during the whole distraction period. The authors observed first roentgenological signs of distraction osteogenesis on 7th day of lengthening. By the end of distraction period, at 25th day, shadows of regenerates demonstrated longitudinal striated structures in all cases. Median lucency area of 1–5 mm was located diagonally and across the regenerate or was intermittent. In 60 days of fixation X-rays demonstrated homogeneous regenerate. External fixation index was 13,9±1,5 days/sm (p≤0,05. The authors observed no cases of implants fracture or deformity during the experiment

  16. Seed protein and nitrogen fixation in chickpea mutant variety Hyprosola

    International Nuclear Information System (INIS)

    Schroeder, H.E.; Gibson, A.H.; Oram, R.N.; Shaikh, M.A.Q.

    1989-01-01

    Full text: 'Hyprosola' is a high yielding, high protein mutant cultivar obtained after gamma irradiation from the variety 'Faridpur-1'. The mutant yields 45 % more protein per unit area. The essential amino acid index is unchanged. It is likely that the high nutritional value in 'Hyprosola' seed protein arises from an increase in the albumin:globulin ratio. Nitrogen fixation rates of the mutant during the first 7 weeks of growth were found to be similar to 'Faridpur-1'. Under field conditions, the mutant may be able to nodulate more rapidly and more extensively than the parent variety. (author)

  17. Eighth international congress on nitrogen fixation. Final program

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Transforaminal lumbar interbody fusion using unilateral pedicle screw fixation plus contralateral translaminar facet screw fixation in lumbar degenerative diseases.

    Science.gov (United States)

    Liu, Fubing; Jiang, Chun; Cao, Yuanwu; Jiang, Xiaoxing; Feng, Zhenzhou

    2014-07-01

    Transforaminal lumbar interbody fusion (TLIF) has been used in lumbar degenerative diseases. Some researchers have applied unilateral fixation in TLIF to reduce operational trauma without compromising the clinical outcome, but it is always suspected biomechanically unstable. The supplementary contralateral translaminar facet screw (cTLFS) seemed to be able to overcome the inherent drawbacks of unilateral pedicle screw (uPS) fixation theoretically. This study evaluates the safety, feasibility and efficacy of TLIF using uPS with cTLFS fixation in the treatment of lumbar degenerative diseases (LDD). 50 patients (29 male) underwent the aforementioned surgical technique for their LDD between December 2009 and April 2012. The results were evaluated based on visual analogue scale (VAS) of the leg and back, Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI) were recorded. The radiographic examinations in form of X-ray, computed tomography (CT) or magnetic resonance imaging was done preoperatively and 1 week, 3 months, 6 months, 12 months and 24 months postoperatively. The student t-test was used for comparison between the preoperative values and postoperative counterparts. P degenerative diseases short termly.

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

    Science.gov (United States)

    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.

  20. Dinitrogen fixation in aphotic oxygenated marine environments

    Directory of Open Access Journals (Sweden)

    Eyal eRahav

    2013-08-01

    Full Text Available We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO3--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 2to 3.5 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 to 6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP an heterotrophic N2 fixation are carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particles (TEP concentration 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.

  1. Kennedy Space Center Fixation Tube (KFT)

    Science.gov (United States)

    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.

  2. Sutureless Intrascleral Fixated Intraocular Lens Implantation.

    Science.gov (United States)

    Karadag, Remzi; Celik, Haci Ugur; Bayramlar, Huseyin; Rapuano, Christopher J

    2016-08-01

    To review sutureless intrascleral intraocular lens (IOL) fixation methods. Review of published literature. Sutureless intrascleral IOL fixation methods are newer and have been developed to eliminate the suture-related complications of sutured scleral fixation methods such as suture-induced inflammation or infection and IOL dislocation or subluxation due to suture degradation or suture breakage. Sutureless intrascleral fixation methods aim for intrascleral haptic fixation to achieve stability of the IOL. Various methods of sutureless scleral fixation have been described. Using a needle, a blade, or a trochar, sclerostomies are created in all techniques for intraocular access. Some surgeons prefer to create scleral tunnels, whereas others use scleral flaps for scleral fixation of haptics. The stability of IOLs is attained by the scar tissue formed around the haptics. Short-term results of these new methods are acceptable; studies including more cases with longer follow-up are needed to determine their long-term success. [J Cataract Refract Surg. 2016;32(9):586-597.]. Copyright 2016, SLACK Incorporated.

  3. Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods.

    Science.gov (United States)

    Shin, Jason J; Hamamoto, Jason T; Leroux, Timothy S; Saccomanno, Maristella F; Jain, Akshay; Khair, Mahmoud M; Mellano, Christen R; Shewman, Elizabeth F; Nicholson, Gregory P; Romeo, Anthony A; Cole, Brian J; Verma, Nikhil N

    2017-09-01

    To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. Surgeons may choose the screw type and

  4. Carbon dioxide fixation in isolated Kalanchoe chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    Levi, C.; Gibbs, M.

    1975-07-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 ..mu..moles of CO/sub 2/ per milligram of chlorophyll per hour. The dark rate of fixation was about 1 percent of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1, 6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO/sub 2/ fixation were primarily those of the photosynthetic carbon reduction cycle. (auth)

  5. A biomechanic comparison of an internal radiocarpal-spanning 2.4-mm locking plate and external fixation in a model of distal radius fractures.

    Science.gov (United States)

    Wolf, Jonathon C; Weil, Wayne M; Hanel, Douglas P; Trumble, Thomas E

    2006-12-01

    To compare the biomechanic stability of distal radius fracture fixation with a new internal radiocarpal-spanning 2.4-mm locking plate, which acts as an internal distal radius fixator, versus a standard distal radius external fixator. The number of locking screws necessary for adequate fracture fixation was also assessed. Ten cadaveric specimens were mounted in a loading fixture with cables attached to the 2 flexor and 3 extensor wrist tendons. A 1-cm osteotomy was created to simulate an unstable distal radius fracture. The radiocarpal-spanning locking plate was fixed to the radius and index metacarpal with 4 screws proximally and 4 distally. The specimen was incrementally loaded through the tendons. Motion at the fracture site was determined. Screws were sequentially removed from the construct, the specimen was again incrementally loaded, and fracture motion was measured. The fixation was then changed to an external fixator, and the loading tests were repeated. Fracture fixation with the radiocarpal-spanning 2.4-mm locking plate was significantly more stable with 4 screws proximally and 4 screws distally (4 x 4) and with the 3 x 3 configuration than with the external fixator in both flexion and extension. The 4 x 4 screw configuration was not significantly different from the 3 x 3 screw configuration. The 4 x 4 screw configuration was significantly more stable than the 2 x 2 and 1 x 1 screw configurations in both flexion and extension. All internal fixator configurations and the external fixator showed more fracture displacement at increasingly higher loads. Fracture fixation with the new internal radiocarpal-spanning 2.4-mm locking plate is more stable than with a standard distal radius external fixator. Only three 2.4-mm locking screws proximally and three 2.4-mm locking screws distally are required for adequate fixation of the locking spanning plate.

  6. Vacuum suction fixation versus staple fixation in TAPP laparoscopic hernia repair: introduction of a new technique for mesh fixation.

    Science.gov (United States)

    Zhang, Guangyong; Zhang, Xiang; Zhan, Hanxiang; Hu, Sanyuan

    2016-01-01

    Proper mesh fixation is critical for successful TAPP laparoscopic hernia repair. Conventional mesh fixation may cause chronic neuralgia, groin paresthesia or other complications. This study aimed at introducing a new vacuum suction technique for mesh fixation and evaluating its efficacy and safety compared with traditional staple fixation way. Clinical data of 242 patients undergoing TAPP from July 2011 to March 2014 were retrospectively analyzed. Patients were divided into vacuum suction fixation group and staple fixation group. The operation time, hospital stay, complications, recurrence, visual analogue scale pain score and cost were evaluated. All surgeries were successful. The operation time of staple group was (42.34 ± 10.15) min for unilateral hernia and (64.08 ± 16.01) min for bilateral hernias. The postoperative hospital stay was (2.76 ± 0.84) days. One recurrence was observed (0.90%). For vacuum group, the operation time was (42.66 ± 7.76) min and (63.92 ± 10.49) min, and hospital stay was (2.60 ± 0.74) days. No recurrence was observed. There was no significant difference in recurrence, operation time, postoperative pain and hospital stay between two groups (P > 0.05). Average cost were (11,714 ± 726) RMB for vacuum group which was lower than staple group (14,837 ± 1568) RMB (P vacuum group, they were scrotal seroma (3.82%), temporary nerve paresthesia (3.05%), scrotal emphysema (1.53%) and uroschesis (1.53%). The incidence of scrotal emphysema was lower in vacuum group (P 0.05). Both techniques for mesh fixation are safe and effective. There is no significant difference in recurrence, operation time, postoperative pain or hospital stay. The vacuum suction fixation technique is more economical with lower incidence of scrotal emphysema.

  7. Fixation of distal fibular fractures: A biomechanical study of plate fixation techniques.

    Science.gov (United States)

    Marvan, Jiri; Horak, Zdenek; Vilimek, Miloslav; Horny, Lukas; Kachlik, David; Baca, Vaclav

    2017-01-01

    Ankle fractures are complex injuries with variable prognoses that depend upon many factors. The aim of the treatment is to restore the ankle joint biomechanical stability with maximum range of motion. Most ankle fractures are fibular fractures, which have a typical oblique fracture line in the distal fibula located in the area of the tibiofibular syndesmosis. The aim of this study was to simulate numerically several fixation techniques of the distal fibular fractures, evaluate their stability, determine their impact on surrounding tissue load, and correlate the results to clinical treatment experience. The following three models of fibular fracture fixation were used: (a) plate fixation with three screws attached above/below and lag screws, (b) plate fixation with two screws attached above/below and lag screws, and (c) three lag screws only. All three fracture fixation models were analyzed according to their use in both healthy physiological bone and osteoporotic bone tissue. Based on the results of Finite Element Analysis for these simulations, we found that the most appropriate fixation method for Weber-B1 fibular fractures was an unlocked plate fixation using six screws and lag screws, both in patients with physiological and osteoporotic bone tissue. Conversely, the least appropriate fixation method was an unlocked plate fixation with four screws and lag screws. Although this fixation method reduces the stress on patients during surgery, it greatly increased loading on the bone and, thus, the risk of fixation failure. The final fixation model with three lag screws only was found to be appropriate only for very limited indications.

  8. Biomechanics of intramedullary fracture fixation.

    Science.gov (United States)

    Kyle, R F

    1985-11-01

    Intramedullary rodding allows excellent control of bending forces on long bone fractures when adequate sized rods are used. This is made possible by reaming when necessary. Torsional stability is poor if adequate bone nail contact is not obtained and there is little bone fragment interdigitation. This can be optimized with the interlocking system, especially with proximal and distal fractures. Intramedullary rods allow transmission of compressive load so there must be adequate bone to bone contact without comminution to prevent shortening. If a great deal of comminution is present, an interlocking system must be used to resist compressive loads. The interlocked devices have not been proven to be a detriment to union and indeed are a semi-rigid fixation system when used in comminuted shaft fractures. The strength of an osteosynthesis with an intramedullary rod depends on the geometry of the rod and the geometry of the fracture complex. Both locked and nonlocked intramedullary rods perform extremely well when one understands the mechanical principles involved in intramedullary rodding and pays close attention to detail.

  9. Fixation probability on clique-based graphs

    Science.gov (United States)

    Choi, Jeong-Ok; Yu, Unjong

    2018-02-01

    The fixation probability of a mutant in the evolutionary dynamics of Moran process is calculated by the Monte-Carlo method on a few families of clique-based graphs. It is shown that the complete suppression of fixation can be realized with the generalized clique-wheel graph in the limit of small wheel-clique ratio and infinite size. The family of clique-star is an amplifier, and clique-arms graph changes from amplifier to suppressor as the fitness of the mutant increases. We demonstrate that the overall structure of a graph can be more important to determine the fixation probability than the degree or the heat heterogeneity. The dependence of the fixation probability on the position of the first mutant is discussed.

  10. Fixation of Selenium by Clay Minerals and Iron Oxides

    DEFF Research Database (Denmark)

    Hamdy, A. A.; Nielsen, Gunnar Gissel

    1977-01-01

    In studying Se fixation, soil components capable of retaining Se were investigated. The importance of Fe hydrous oxides in the fixation of Se was established. The clay minerals common to soils, such as kaolinite, montmorillonite and vermiculite, all exhibited Se fixation, but greater fixation...

  11. Variable Nitrogen Fixation in Wild Populus.

    Directory of Open Access Journals (Sweden)

    Sharon L Doty

    Full Text Available 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.

  12. Variable Nitrogen Fixation in Wild Populus.

    Science.gov (United States)

    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.

  13. Maxwellian Eye Fixation during Natural Scene Perception

    Science.gov (United States)

    Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

    2012-01-01

    When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

  14. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne

    2012-01-01

    Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

  15. Fixation stability of the upward gaze in patients with myasthenia gravis: an eye-tracker study.

    Science.gov (United States)

    Mihara, Miharu; Hayashi, Atsushi; Fujita, Kazuya; Kakeue, Ken; Tamura, Ryoi

    2017-01-01

    To quantify fixation stability of the upward gaze in patients with myasthenia gravis (MG) using an eye tracker. In this study, 21 normal subjects, 5 patients with MG with diplopia, 5 patients with MG without diplopia and 6 patients with superior oblique (SO) palsy were included. Subjects fixated on a target in the upward direction for 1 min. The horizontal (X) and vertical (Y) eye positions were recorded using an eye tracker. Fixation stability was first quantified using the bivariate contour ellipse areas (BCEA) of fixation points as an index of whole stability. Then, the SDs of the X and Y eye positions (SDX and SDY, respectively) were quantified as indices of directional stability, with the data divided into three 20 s fractions to detect temporal fixation fluctuation. BCEAs were larger in patients with MG (both with and without diplopia) than normal subjects and patients with SO palsy, without significant differences among the three 20 s fractions. Compared with normal subjects, SDXs were larger only in patients with MG with diplopia; SDYs were larger in both patients with MG with and without diplopia. In addition, SDYs in patients with MG with diplopia were larger than those in patients with MG without diplopia and patients with SO palsy. Furthermore, a significant difference among the three 20 s fractions was detected for SDYs in patients with MG with diplopia. Patients with MG, especially those with diplopia, exhibit fixation instability in the upward gaze. Non-invasive quantification of fixation stability with an eye tracker is useful for precisely identifying MG-specific fatigue characteristics. UMIN000023468; pre-results.

  16. Linked linear mixed models: A joint analysis of fixation locations and fixation durations in natural reading.

    Science.gov (United States)

    Hohenstein, Sven; Matuschek, Hannes; Kliegl, Reinhold

    2017-06-01

    The complexity of eye-movement control during reading allows measurement of many dependent variables, the most prominent ones being fixation durations and their locations in words. In current practice, either variable may serve as dependent variable or covariate for the other in linear mixed models (LMMs) featuring also psycholinguistic covariates of word recognition and sentence comprehension. Rather than analyzing fixation location and duration with separate LMMs, we propose linking the two according to their sequential dependency. Specifically, we include predicted fixation location (estimated in the first LMM from psycholinguistic covariates) and its associated residual fixation location as covariates in the second, fixation-duration LMM. This linked LMM affords a distinction between direct and indirect effects (mediated through fixation location) of psycholinguistic covariates on fixation durations. Results confirm the robustness of distributed processing in the perceptual span. They also offer a resolution of the paradox of the inverted optimal viewing position (IOVP) effect (i.e., longer fixation durations in the center than at the beginning and end of words) although the opposite (i.e., an OVP effect) is predicted from default assumptions of psycholinguistic processing efficiency: The IOVP effect in fixation durations is due to the residual fixation-location covariate, presumably driven primarily by saccadic error, and the OVP effect (at least the left part of it) is uncovered with the predicted fixation-location covariate, capturing the indirect effects of psycholinguistic covariates. We expect that linked LMMs will be useful for the analysis of other dynamically related multiple outcomes, a conundrum of most psychonomic research.

  17. Posterior atlantoaxial fixation: a review of all techniques.

    Science.gov (United States)

    Huang, Da-Geng; Hao, Ding-Jun; He, Bao-Rong; Wu, Qi-Ning; Liu, Tuan-Jiang; Wang, Xiao-Dong; Guo, Hua; Fang, Xiang-Yi

    2015-10-01

    Posterior atlantoaxial fixation is an effective treatment for atlantoaxial instability. Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. However, there is no article reviewing all the posterior atlantoaxial fixation techniques yet. The aim was to review the evolution and advancements of posterior atlantoaxial fixation. This was a literature review. The application of all posterior fixation techniques in atlantoaxial stabilization, including wiring techniques, interlaminar clamp fixation, transarticular fixation, screw-plate systems, screw-rod systems, and hook-screw systems, are reviewed and discussed. Recent advancements on the novel technique of atlantoaxial fixation are described. The combination of the C1 and C2 screws in screw-rod systems are described in detail. All fixation techniques are useful. The screw-rod system appears to be the most popular approach. However, many novel or modified fixation methods have been introduced in recent years. Great advancements on posterior atlantoaxial fixation techniques have been made in the past decades. The wiring technique and interlaminar clamps technique have fallen out of favor because of the development of newer and superior fixation techniques. The C1-C2 transarticular screw technique may remain the gold standard for atlantoaxial fusion, whereas screw-rod systems, especially the C1 pedicle screw combined with C2 pedicle/pars screw fixation, have become the most popular fixation techniques. Hook-screw systems are alternatives for atlantoaxial fixation. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Graft fixation in cruciate ligament reconstruction.

    Science.gov (United States)

    Brand, J; Weiler, A; Caborn, D N; Brown, C H; Johnson, D L

    2000-01-01

    Cruciate ligament reconstruction has progressed dramatically in the last 20 years. Anatomic placement of ligament substitutes has fostered rehabilitation efforts that stress immediate and full range of motion, immediate weightbearing, neuromuscular strength and coordination, and early return to athletic competition (3 months). This has placed extreme importance on secure graft fixation at the time of ligament reconstruction. Current ligament substitutes require a bony or soft tissue component to be fixed within a bone tunnel or on the periosteum at a distance from the normal ligament attachment site. Fixation devices have progressed from metal to biodegradable and from far to near-normal native ligament attachment sites. Ideally, the biomechanical properties of the entire graft construct would approach those of the native ligament and facilitate biologic incorporation of the graft. Fixation should be done at the normal anatomic attachment site of the native ligament (aperture fixation) and, over time, allow the biologic return of the histologic transition zone from ligament to fibrocartilage, to calcified fibrocartilage, to bone. The purpose of this article is to review current fixation devices and techniques in cruciate ligament surgery.

  19. External fixation of “intertrochanteric” fractures

    Directory of Open Access Journals (Sweden)

    Naseem ul Gani

    2009-08-01

    Full Text Available In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with “intertro-chanteric” fractures remain unsuitable for open reduction and internal fixation. The aim of this study was to analyze the results of external fixation of “intertro-chanteric” fractures in high-risk geriatric patients in a developing country. The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58-90 years with “intertrochanteric” fractures, in whom external fixation was performed, are reported. Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet’s point system. Good to excellent results were achieved in 44 patients. This study demonstrated that external fixation of “intertrochantric” fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country.

  20. Surgical Site Infection Following Fixation of Acetabular Fractures.

    Science.gov (United States)

    Iqbal, Faizan; Younus, Sajid; Asmatullah; Zia, Osama Bin; Khan, Naveed

    2017-09-01

    Acetabular fractures are mainly caused by high energy trauma. Surgical fixation of these fractures requires extensive surgical exposure which increases the length of operation and blood loss as well. This may increase the risk of surgical site infection. Our aim is to evaluate the prevalence of surgical site infections and the risk factors associated with it so as to minimize its chances. A total of 261 patients who underwent acetabular fracture surgery were retrospectively reviewed. Patients were divided into 2 groups, with or without surgical site infection. Factors examined include patients' gender, age, body mass index (BMI), time between injury and surgery, operative time, estimated blood loss, number of packed red blood cell transfused, length of total intensive care unit (ICU) stay, fracture type, surgical approach, smoking status, patients' comorbids and associated injuries. Fourteen patients (5.4%) developed surgical site infection. Out of 14 infections, 4 were superficial and 10 were deep. The factors that were found to be associated with surgical site infection following acetabular fracture fixation were prolonged operation time, increased BMI, prolonged ICU stay, larger amount of packed red blood cell transfused and associated genitourinary and abdominal trauma. In our study, we conclude that measures should be undertaken to attenuate the chances of surgical site infection in this major surgery by considering the risk factors significantly associated with it.

  1. Biometric recognition via fixation density maps

    Science.gov (United States)

    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. Arthroscopic-Assisted Open Reduction Internal Fixation.

    Science.gov (United States)

    Hamilton, Graham A; Doyle, Matthew D; Castellucci-Garza, Francesca M

    2018-04-01

    The indications for arthroscopy have expanded over the years. Arthroscopic-assisted open reduction internal fixation in the setting of acute trauma is gaining popularity with foot and ankle surgeons. It serves to facilitate direct visualization of fracture fragments and allows for precise articular reduction with minimal soft tissue insult. Current evidence reports a high incidence of chondral injury with ankle fractures. Arthroscopy performed at the time of open reduction internal fixation allows for joint inspection and potential treatment of these posttraumatic defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Recent advances in fixation of the craniomaxillofacial skeleton.

    Science.gov (United States)

    Meslemani, Danny; Kellman, Robert M

    2012-08-01

    Fixation of the craniomaxillofacial skeleton is an evolving aspect for facial plastic, oral and maxillofacial, and plastic surgery. This review looks at the recent advances that aid in reduction and fixation of the craniomaxillofacial skeleton. More surgeons are using resorbable plates for craniomaxillofacial fixation. A single miniplate on the inferior border of the mandible may be sufficient to reduce and fixate an angle fracture. Percutaneous K-wires may assist in plating angle fractures. Intraoperative computed tomography (CT) may prove to be useful for assessing reduction and fixation. Resorbable plates are becoming increasingly popular in orthognathic surgery and facial trauma surgery. There are newer operative techniques for fixating the angle of the mandible. Also, the utilization of the intraoperative CT provides immediate feedback for accurate reduction and fixation. Prebent surgical plates save operative time, decrease errors, and provide more accurate fixation.

  4. Sacroiliac screw fixation for tile B fractures.

    NARCIS (Netherlands)

    Bosch, E.W. van den; Zwienen, C.M. van; Hoek van Dijke, G.A.; Snijders, C.J.; Vugt, A.B. van

    2003-01-01

    BACKGROUND: The purpose of this comparative cadaveric study was to investigate whether the stability of partially unstable pelvic fractures can be improved by combining plate fixation of the symphysis with a posterior sacroiliac screw. METHODS: In six specimens, a Tile B1 (open-book) pelvic fracture

  5. Nitrogen fixation in the phyllosphere of Gramineae

    NARCIS (Netherlands)

    Bessems, E.P.M.

    1973-01-01

    The investigation was carried out with Zea mays , grown under temperate conditions, and with Tripsacum laxum Nash, grown in the tropics. The conditions for nitrogen fixation were found to be unfavourable in the leachate, obtained by spray irrigation of the aerial plant

  6. Headspace analysis of foams and fixatives

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Truong, Thanh-Tam [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Magwood, Leroy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, Brent [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nicholson, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-27

    In the process of decontaminating and decommissioning (D&D) older nuclear facilities, special precautions must be taken with removable or airborne contamination. One possible strategy utilizes foams and fixatives to affix these loose contaminants. Many foams and fixatives are already commercially available, either generically or sold specifically for D&D. However, due to a lack of revelant testing in a radioactive environment, additional verification is needed to confirm that these products not only affix contamination to their surfaces, but also will function in a D&D environment. Several significant safety factors, including flammability and worker safety, can be analyzed through the process of headspace analysis, a technique that analyzes the off gas formed before or during the curing process of the foam/fixative, usually using gas chromatography-mass spectrometry (GC-MS). This process focuses on the volatile components of a chemical, which move freely between the solid/liquid form within the sample and the gaseous form in the area above the sample (the headspace). Between possibly hot conditions in a D&D situation and heat created in a foaming reaction, the volatility of many chemicals can change, and thus different gasses can be released at different times throughout the reaction. This project focused on analysis of volatile chemicals involved in the process of using foams and fixatives to identify any potential hazardous or flammable compounds.

  7. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  8. The effect of fixation on esterases

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1984-01-01

    The localization of reaction product for non-specific esterase from fresh and aldehyde treated glandular tissue was examined. The electrophoretical studies showed a selective inhibition of certain isoenzymes and a change in mobility of some bands caused by aldehyde fixation. In sections a granular...

  9. SIGN HIP CONSTRUCT: ACHIEVING HIP FRACTURE FIXATION ...

    African Journals Online (AJOL)

    elderly has made stable reduction and internal fixation the preferred treatment. .... anaemia, 1 had concomitant spine injury, and another had widespread ... infection (1.5%) and 8 cases of varus collapse (11.8%). (Table 4). Table 3. Stable versus unstable fracture and mechanism of injury. Type of fracture. MTA. No. (%). Fall.

  10. Large fluctuations and fixation in evolutionary games

    International Nuclear Information System (INIS)

    Assaf, Michael; Mobilia, Mauro

    2010-01-01

    We study large fluctuations in evolutionary games belonging to the coordination and anti-coordination classes. The dynamics of these games, modeling cooperation dilemmas, is characterized by a coexistence fixed point separating two absorbing states. We are particularly interested in the problem of fixation that refers to the possibility that a few mutants take over the entire population. Here, the fixation phenomenon is induced by large fluctuations and is investigated by a semiclassical WKB (Wentzel–Kramers–Brillouin) theory generalized to treat stochastic systems possessing multiple absorbing states. Importantly, this method allows us to analyze the combined influence of selection and random fluctuations on the evolutionary dynamics beyond the weak selection limit often considered in previous works. We accurately compute, including pre-exponential factors, the probability distribution function in the long-lived coexistence state and the mean fixation time necessary for a few mutants to take over the entire population in anti-coordination games, and also the fixation probability in the coordination class. Our analytical results compare excellently with extensive numerical simulations. Furthermore, we demonstrate that our treatment is superior to the Fokker–Planck approximation when the selection intensity is finite

  11. External fixation for phalangeal and metacarpal fractures

    NARCIS (Netherlands)

    Drenth, DJ; Klasen, HJ

    From 1987 to 1993 we treated 33 patients with 29 phalangeal and seven metacarpal fractures by external fixation using a mini-Hoffmann device. There were 27 open and 25 comminuted fractures, In 12 patients one or more tendons was involved, The mean follow-up was 4.4 years, Complications occurred in

  12. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard

    2005-01-01

    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  13. Synthetic biology for CO2fixation.

    Science.gov (United States)

    Gong, Fuyu; Cai, Zhen; Li, Yin

    2016-11-01

    Recycling of carbon dioxide (CO 2 ) into fuels and chemicals is a potential approach to reduce CO 2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO 2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO 2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO 2 -derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO 2 -fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO 2 -fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO 2 -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 CO 2 .

  14. Osteomyelitis in burn patients requiring skeletal fixation

    NARCIS (Netherlands)

    Barret, JP; Desai, MH; Herndon, DN

    Deep and severe burns often present with the exposure of musculoskeletal structures and severe deformities. Skeletal fixation, suspension and/or traction are part of their comprehensive treatment. Several factors put burn patients at risk for osteomyelitis, osteosynthesis material being one of them.

  15. 15N in biological nitrogen fixation studies

    International Nuclear Information System (INIS)

    Faust, H.

    1986-05-01

    A bibliography with 298 references on the use of the stable nitrogen isotope 15 N in the research on the biological fixation of dinitrogen is presented. The literature pertaining to this bibliography covers the period from 1975 to the middle of 1985. (author)

  16. Translaminar screw fixation in the lumbar spine: technique, indications, results

    OpenAIRE

    Grob, D.; Humke, T.

    1998-01-01

    Translaminar screw fixation of the lumbar spine represents a simple and effective technique for short segment fusion in the degenerative spine. Clinical experience with 173 patients who underwent translaminar screw fixation revealed a fusion rate of 94%. The indications for translaminar screw fixation as a primary fixation procedure are: segmental dysfunction, lumbar spinal stenosis with painful degenerative changes, segmental revision surgery after discectomies, and painful disc-related synd...

  17. Fibrin sealant for mesh fixation in laparoscopic umbilical hernia repair

    DEFF Research Database (Denmark)

    Eriksen, J R; Bisgaard, T; Assaadzadeh, S

    2013-01-01

    Fibrin sealant for mesh fixation has significant positive effects on early outcome after laparoscopic ventral hernia repair (LVHR) compared with titanium tacks. Whether fibrin sealant fixation also results in better long-term outcome is unknown.......Fibrin sealant for mesh fixation has significant positive effects on early outcome after laparoscopic ventral hernia repair (LVHR) compared with titanium tacks. Whether fibrin sealant fixation also results in better long-term outcome is unknown....

  18. Temporising external fixation of calcaneus fractures prior to definitive plate fixation: a case series.

    Science.gov (United States)

    Farrell, Brian M; Lin, Carol A; Moon, Charles N

    2015-09-01

    Surgical management of calcaneus fractures is technically demanding and has a high risk of wound complications. These fractures are traditionally managed with splinting until swelling has subsided, which can take weeks and leaves the fracture fragments displaced. We describe a novel protocol for the management of displaced intraarticular calcaneus fractures that utilises a temporising external fixator and staged conversion to plate fixation through a sinus tarsi approach. The goal of this technique was to enable earlier treatment with open reduction and internal fixation, minimise the amount of manipulation required at the time of definitive fixation and reduce the wound complication rate seen with the traditional extensile approach. The records of patients with displaced calcaneus fractures from 2010-2014 were reviewed retrospectively. A total of nine patients with 10 calcaneus fractures were treated using this protocol. All patients underwent ankle-spanning medial external fixation within 48 hours after injury. Patients underwent conversion to open plate fixation through a sinus tarsi approach when skin turgor had returned to normal. Time to surgery, infection rate, wound complications, radiographic alignment, and time to radiographic union were recorded. The average Bohler's angle improved from 13.2 (range -2 to 34) degrees preoperatively to 34.3 (range 26 to 42) degrees postoperatively. The average time from external fixation to conversion to internal fixation was 4.8 (range 3 to 7) days. There were no immediate post-surgical complications. The average time to weight-bearing was 8.5 weeks. The average time to radiographic union was 9.5 (range 8 to 12) weeks. There were no infections or wound complications at the time of last follow-up. Early temporising external fixation for the acute management of displaced calcaneus fractures is a safe and effective method to reduce and stabilise the foot and may decrease the time to definitive fixation. There were no

  19. The Stability of Double Jaw Surgery: A Comparison of Rigid Fixation versus Skeletal Wire Fixation

    Science.gov (United States)

    1988-08-01

    APPROVED BY THE DEPART M T OF ORTHODONTICS : (signed) 4IA Chairman APPROVED BY THE THESIS COMMITTEE: (signed) APPROVED BY THE GRADUATE COUNCIL...patients had rigid fixation to stabilize the segments and nine patients had skeletal wire fixation. Twenty- seven cephalometric parameters were examined...him has left me with a deep appreciation for his skill and dedication. For the unique opportunity to study Orthodontics here at Baylor, I must thank Dr

  20. Biomechanical study of posterior wall acetabular fracture fixation using acetabular tridimensional memory alloy-fixation system.

    Science.gov (United States)

    Xin-wei, Liu; Shuo-gui, Xu; Chun-cai, Zhang; Qing-ge, Fu; Pan-feng, Wang

    2010-05-01

    We developed the acetabular tridimensional memory alloy-fixation system (ATMFS), which is made of NiTi shape memory alloy, according to the specific mechanical properties of biological memory material, nitinol alloy and measured distribution of contact area and pressure between the acetabulum and the femoral head of cadaveric pelvis. Six formalin-preserved cadaveric pelvis were used for this investigation. Pressure-sensitive film was used to measure contact area and pressure within the anterior, superior, and posterior regions of the acetabulum. The pelvis were loaded under the following four conditions: (1) intact; (2) following a creation posterior wall fracture defect; (3) following reduction and standard internal fixation with reconstruction plate; (4) following reduction and internal fixation with a new shape memory alloy device named ATMFS. A posterior wall fracture was created along an arc of 40-90 degrees about the acetabular rim. Creation of a posterior wall defect resulted in increased load in the superior acetabulum (1422N) as compared to the intact condition (762N, P=0.007). Following reduction and internal fixation, the load distributed to the superior acetabulum (1486N) was not statistically different from the defect condition. Following the fixation with ATMFS, the load seen at the superior region of the actabulum (936N) was less than fixation with reconstruction plate and was not different from intact state (P=0.4). These data indicate that the use of ATMFS as a fracture internal fixation device resulted a partial restoration of joint loading parameters toward the intact state. ATMFS fixation may result in a clinical benefit. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Afghanistan Index

    DEFF Research Database (Denmark)

    Linnet, Poul Martin

    2007-01-01

    The Afghanistan index is a compilation of quantitative and qualitative data on the reconstruction and security effort in Afghanistan. The index aims at providing data for benchmarking of the international performance and thus provides the reader with a quick possibility to retrieve valid...... information on progress or lack of progress in the reconstruction of the post Taliban Afghanistan. The index is mainly based on information collected on the internet in order to provide quick access to the original source. The index is under development and thus new information will be added on a continuous...

  2. Comparison of skeletal stability after sagittal split ramus osteotomy among mono-cortical plate fixation, bi-cortical plate fixation, and hybrid fixation using absorbable plates and screws.

    Science.gov (United States)

    Ueki, Koichiro; Moroi, Akinori; Yoshizawa, Kunio; Hotta, Asami; Tsutsui, Takamitsu; Fukaya, Kenichi; Hiraide, Ryota; Takayama, Akihiro; Tsunoda, Tatsuta; Saito, Yuki

    2017-02-01

    The purpose of this study was to examine skeletal stability and plate breakage after sagittal split ramus osteotomy (SSRO) with the mono-cortical plate fixation, bi-cortical plate fixation, and hybrid fixation techniques using absorbable plates and screws. A total of 76 Japanese patients diagnosed with mandibular prognathism with and without maxillary deformity were divided into 3 groups randomly. A total of 28 patients underwent SSRO with mono-cortical plate fixation, 23 underwent SSRO with bi-cortical plate fixation, and 25 underwent SSRO with hybrid fixation. Skeletal stability and horizontal condylar angle were analyzed by axial, frontal, and lateral cephalograms from before the operation to 1 year postoperatively. Breakage of the plate and screws was observed by 3-dimensional computed tomography (3DCT) immediately after surgery and after 1 year. Although there was a significant difference between the mono-cortical plate fixation group and hybrid fixation group regarding right MeAg in T1 (P = 0.0488) and occlusal plane in T1 (P = 0.0346), there were no significant differences between the groups for the other measurements in each time interval. In 2 cases, namely, 6 sides in the mono-cortical plate fixation group, breakage of the absorbable plate was found by 3DCT. However, there was no breakage in the bi-cortical plate fixation group and hybrid fixation group. This study results suggested that there were no significant differences in the postoperative skeletal stability among the 3 groups, and bi-cortical fixation as well as hybrid fixation was a reliable and useful method to prevent plate breakage even if an absorbable material was used. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. Improvement in nitrogen fixation capacity could be part of the domestication process in soybean

    Science.gov (United States)

    Muñoz, N; Qi, X; Li, M-W; Xie, M; Gao, Y; Cheung, M-Y; Wong, F-L; Lam, H-M

    2016-01-01

    Biological nitrogen fixation (BNF) in soybeans is a complex process involving the interplay between the plant host and the symbiotic rhizobia. As nitrogen supply has a crucial role in growth and development, higher nitrogen fixation capacity would be important to achieve bigger plants and larger seeds, which were important selection criteria during plant domestication by humans. To test this hypothesis, we monitored the nitrogen fixation-related performance in 31 cultivated and 17 wild soybeans after inoculation with the slow-growing Bradyrhizobium diazoefficiens sp. nov. USDA110 and the fast-growing Sinorhizobium (Ensifer) fredii CCBAU45436. Our results showed that, in general, cultivated soybeans gave better performance in BNF. Electron microscopic studies indicated that there was an exceptionally high accumulation of poly-β-hydroxybutyrate bodies in bacteroids in the nodules of all wild soybeans tested, suggesting that the C/N balance in wild soybeans may not be optimized for nitrogen fixation. Furthermore, we identified new quantitative trait loci (QTLs) for total ureides and total nodule fresh weight by employing a recombinant inbred population composed of descendants from a cross between a cultivated and a wild parent. Using nucleotide diversity (θπ), divergence index (Fst) and distribution of fixed single-nucleotide polymorphisms as parameters, we found that some regions in the total ureides QTL on chromosome 17 and the total nodule fresh weight QTL on chromosome 12 exhibited very low diversity among cultivated soybeans, suggesting that these were traits specially selected during the domestication and breeding process. PMID:27118154

  4. Graft fixation with predetermined tension using a new device, the double spike plate.

    Science.gov (United States)

    Shino, Konsei; Mae, Tatsuo; Maeda, Akira; Miyama, Takahide; Shinjo, Hirotaka; Kawakami, Hideo

    2002-10-01

    To biomechanically evaluate a new fixation device, DSP (Double Spike Plate; Meira Corp, Nagoya, Aichi, Japan), for pullout graft fixation. Biomechanical study. A porcine tibia in which 8-mm diameter drill holes had been made from the medial tibial metaphysis to the anterior cruciate ligament attachment was rigidly fixed to a tension analyzer. A quadrupled graft consisting of 2 double-looped bovine tendons was prepared with No. 3 polyester sutures placed distally. The graft was passed through the drill hole, and its proximal loop ends were rigidly fixed to a load cell for monitoring graft tension. The graft's distal ends were connected to the DSP by tying the sutures to the top hole in the DSP. The graft tension was predetermined at 49 N (n = 5) or 98 N (n = 5). This tension was maintained for 5 minutes with a suture passed through the bottom hole of the DSP. The plate was fixed to the tibia by hammering its spikes into the bone under the index tension. Finally, the fixation was completed by inserting a screw. Although the graft tension immediately increased to 69 +/- 11 N or 133 +/- 14 N during hammering, it gradually reduced to 49 +/- 10 N or 100 +/- 7 N 5 minutes later. This study shows that graft fixation under a predetermined tension can be achieved with the DSP.

  5. AP Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Planetary Amplitude index - Bartels 1951. The a-index ranges from 0 to 400 and represents a K-value converted to a linear scale in gammas (nanoTeslas)--a scale that...

  6. Effects of intrapopulation competition on morphological and ...

    African Journals Online (AJOL)

    The effects of population density on some agronomic traits of Corchorus olitorius were investigated by growing the seedlings in a field experiment at densities of 1, 2, 5, 10, 25, 50 and 100 plants per m2 during the raining season of 2006, at the Ojo campus of Lagos State University (LASU), Nigeria. The randomized block ...

  7. Nitrogen fixation improvement in Faidherbia albida

    International Nuclear Information System (INIS)

    Toure, O.; Dasilva, M.C.; Badji, S.; Dianda, M.; Ndoye, I.; Gueye, M.

    1998-01-01

    A greenhouse experiment investigated growth, N accumulation and N 2 fixation (using the 15 N-dilution method) by Faidherbia albida in comparison with three species of Acacia, with Parkia biglobosa and Tamarindus indica as non-fixing reference plants. Faidherbia albida was mediocre in comparison with A. seyel, therefore seven provenances of the former were examined in a second pot experiment to investigate within-species variability for the same performance components; a provenance from Kabrousse, Senegal, showed particular promise in terms of dry weight and N accumulation, and fixation of N. This promise was confirmed with a 15-month field experiment, but revealed that there is opportunity for further improvement in N 2 -fixing ability. Faidherbia albida is a slow-growing tree, therefore further field experiments with provenance Kabrousse should be longer term in scope. The data indicate that trenching of the 15 N-labelled area may not be necessary. (author)

  8. High level waste fixation in cermet form

    International Nuclear Information System (INIS)

    Kobisk, E.H.; Aaron, W.S.; Quinby, T.C.; Ramey, D.W.

    1981-01-01

    Commercial and defense high level waste fixation in cermet form is being studied by personnel of the Isotopes Research Materials Laboratory, Solid State Division (ORNL). As a corollary to earlier research and development in forming high density ceramic and cermet rods, disks, and other shapes using separated isotopes, similar chemical and physical processing methods have been applied to synthetic and real waste fixation. Generally, experimental products resulting from this approach have shown physical and chemical characteristics which are deemed suitable for long-term storage, shipping, corrosive environments, high temperature environments, high waste loading, decay heat dissipation, and radiation damage. Although leach tests are not conclusive, what little comparative data are available show cermet to withstand hydrothermal conditions in water and brine solutions. The Soxhlet leach test, using radioactive cesium as a tracer, showed that leaching of cermet was about X100 less than that of 78 to 68 glass. Using essentially uncooled, untreated waste, cermet fixation was found to accommodate up to 75% waste loading and yet, because of its high thermal conductivity, a monolith of 0.6 m diameter and 3.3 m-length would have only a maximum centerline temperature of 29 K above the ambient value

  9. Nitrogen fixation in Red Sea seagrass meadows

    KAUST Repository

    Abdallah, Malak

    2017-05-01

    Seagrasses are key coastal ecosystems, providing many ecosystem services. Seagrasses increase biodiversity as they provide habitat for a large set of organisms. In addition, their structure provides hiding places to avoid predation. Seagrasses can grow in shallow marine coastal areas, but several factors regulate their growth and distribution. Seagrasses can uptake different kinds of organic and inorganic nutrients through their leaves and roots. Nitrogen and phosphorous are the most important nutrients for seagrass growth. Biological nitrogen fixation is the conversion of atmospheric nitrogen into ammonia by diazotrophic bacteria. This process provides a significant source of nitrogen for seagrass growth. The nitrogen fixation is controlled by the nif genes which are found in diazotrophs. The main goal of the project is to measure nitrogen fixation rates on seagrass sediments, in order to compare among various seagrass species from the Red Sea. Moreover, we will compare the fixing rates of the Vegetated areas with the bare sediments. This project will help to ascertain the role of nitrogen fixing bacteria in the development of seagrass meadows.

  10. AA Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The geomagnetic aa index provides a long climatology of global geomagnetic activity using 2 antipodal observatories at Greenwich and Melbourne- IAGA Bulletin 37,...

  11. Diversity Index

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — This map service summarizes racial and ethnic diversity in the United States in 2012.The Diversity Index shows the likelihood that two persons chosen at random from...

  12. Walkability Index

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Walkability Index dataset characterizes every Census 2010 block group in the U.S. based on its relative walkability. Walkability depends upon characteristics of...

  13. A novel fixation system for sacroiliac dislocation fracture: internal fixation system design and biomechanics analysis.

    Science.gov (United States)

    Dawei, Tian; Na, Liu; Jun, Lei; Wei, Jin; Lin, Cai

    2013-02-01

    Although there were many different types of fixation techniques for sacroiliac dislocation fracture, the treat remained challenging in posterior pelvic ring injury. The purpose of this study was to evaluate the biomechanical effects of a novel fixation system we designed. 12 human cadavers (L3-pelvic-femora) were used to compare biomechanical stability after reconstruction on the same specimens in four conditions: (1) intact, (2) cable system, (3) plate-pedicle screw system, and (4) cable system and plate-pedicle screw combination system (combination system). Biomechanical testing was performed on a material testing machine for evaluating the stiffness of the pelvic fixation construct in compression and torsion. The cable system and plate-pedicle screw system alone may be insufficient to resist vertical shearing and rotational loads; however the combination system for unstable sacroiliac dislocation fractures provided significantly greater stability than single plate-pedicle or cable fixation system. The novel fixation system for unstable sacroiliac dislocation fractures produced sufficient stability in axial compression and axial rotation test in type C pelvic ring injuries. It may also offer a better solution for sacroiliac dislocation fractures. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Lag screw fixation of dorsal cortical stress fractures of the third metacarpal bone in 116 racehorses.

    Science.gov (United States)

    Jalim, S L; McIlwraith, C W; Goodman, N L; Anderson, G A

    2010-10-01

    The effectiveness and best method to manage dorsal cortical stress fractures is not clear. This study was performed to evaluate the success of lag screw fixation of such fractures in a population of Thoroughbred racehorses. Lag screw fixation of dorsal cortical stress fractures is an effective surgical procedure allowing racehorses to return to their preoperative level of performance. The records of 116 racehorses (103 Thoroughbreds) admitted to Equine Medical Centre, California between 1986 and 2008 were assessed. Information obtained from medical records included subject details, limb(s) affected, fracture configuration, length of screw used in repair and presence of concurrent surgical procedures performed. Racing performance was evaluated relative to these factors using Fisher's exact test and nonparametric methods with a level of significance of Phorses, 83% raced preoperatively and 83% raced post operatively, with 63% having ≥5 starts. There was no statistically significant association between age, gender, limb affected, fracture configuration or presence of concurrent surgery and likelihood of racing post operatively or of having 5 or more starts. The mean earnings per start and the performance index for the 3 races following surgery were lower compared to the 3 races prior to surgery; however, 29 and 45% of horses either improved or did not change their earnings per start and performance index, respectively. Data show that lag screw fixation is successful at restoring ability to race in horses suffering from dorsal cortical stress fractures. © 2010 EVJ Ltd.

  15. Intelligent indexing

    International Nuclear Information System (INIS)

    Farkas, J.

    1992-01-01

    In this paper we discuss the relevance of artificial intelligence to the automatic indexing of natural language text. We describe the use of domain-specific semantically-based thesauruses and address the problem of creating adequate knowledge bases for intelligent indexing systems. We also discuss the relevance of the Hilbert space ι 2 to the compact representation of documents and to the definition of the similarity of natural language texts. (author). 17 refs., 2 figs

  16. Monosegmental fixation for the treatment of fractures of the thoracolumbar spine

    Directory of Open Access Journals (Sweden)

    Defino Helton

    2007-01-01

    Full Text Available Background : A short vertebral arthrodesis has been one of the objectives of the surgical treatment of fractures of the thoracolumbar spine. We present here clinical, functional and radiographic outcome obtained after monosegmental fixation (single posterior or combined anterior and posterior of specific types of unstable thoracolumbar fractures. Materials and Methods : Twenty four patients with fractures of the thoracolumbar spine submitted to monosegmental surgical treatment (Group I - 18 single posterior monosegmental fixations and Group II - 6 combined anterior and posterior fixations were retrospectively evaluated according to clinical, radiographic and functional parameters. The indication for surgery was instability or neurological deficit. All the procedures were indicated and performed by the senior surgeon (Helton LA Defino. Results : The patients from group I were followed-up from 2 to 12 years (mean: 6.65±2.96. The clinical, functional and radiographic results show that a single posterior monosegmental fixation is adequate and a satisfactory procedure to be used in specific types of thoracolumbar spine fractures, The patients from group II were followed-up from 9 to 15 years (mean: 13 ± 2,09 years. On group II the results of clinical evaluation showed moderate indices of residual pain and of satisfaction with the final result. The values obtained by functional evaluation showed that 66.6% of the patients were unable to return to their previous job and presented a moderate disability index (Oswestry = 16.6 and a significant reduction of quality of life based on the SF-36 questionnaire. Radiographic evaluation showed increased kyphosis of the fixed vertebral segment during the late postoperative period, accompanied by a reduction of the height of the intervertebral disk. Conclusion : It is possible to stabilize the fractures which have an anterior good load-bearing capacity by a standalone posterior monosegmental fixation. However

  17. Genetic structure of Xiphinema pachtaicum and X. index populations based on mitochondrial DNA variation.

    Science.gov (United States)

    Gutiérrez-Gutiérrez, Carlos; Castillo, Pablo; Cantalapiedra-Navarrete, Carolina; Landa, Blanca B; Derycke, Sofie; Palomares-Rius, Juan E

    2011-10-01

    The dagger nematodes Xiphinema pachtaicum and X. index are two of the most widespread and frequently occurring Xiphinema spp. co-infesting vineyards and other crops and natural habitats worldwide. Sexual reproduction is rare in these species. The primary objective of this study was to determine the genetic structure of X. pachtaicum and X. index populations using eight and seven populations, respectively, from different "wine of denomination of origin (D.O.) zones" in Spain and Sardinia (Italy), by studying mitochondrial (cytochrome oxidase c subunit 1 or COI) and nuclear (D2-D3 expansion segments of 28S rDNA) markers. Both Xiphinema spp. showed low intraspecific divergence among COI sequences, ranging from 0.2% (1 base substitution) to 2.3% (10 substitutions) in X. pachtaicum and from 0.2% (1 base substitution) to 0.4% (2 substitutions) in X. index. Population genetic structure was strong for both species. Nevertheless, molecular differences among grapevine-growing areas were not significant, and intrapopulation diversity was very low. It is hypothesized that this genetic homogeneity in the nematode populations reflects their predominant parthenogenetic reproduction mode and low dispersal abilities. Our results also show that X. pachtaicum populations in Spain have possibly been established from two different populations of origin. Results also demonstrated that the two DNA regions studied are suitable diagnostic markers for X. index and X. pachtaicum.

  18. Posterior Fixation with Unilateral Same Segment Pedicle Fixation and Contralateral Hook in Surgical Treatment of Thoracolumbar Burst Fractures

    Directory of Open Access Journals (Sweden)

    Farzad Omidi-Kashani

    2016-06-01

    Full Text Available Background In surgical treatment of thoracolumbar burst fractures, most authors try to lower the number of vertebrae involved during the surgery. Objectives The aim of this study was to evaluate the outcome of a medium-segment posterior spinal fixation in these patients. Patients and Methods We retrospectively reviewed 27 patients (18 male, 9 female with mean age of 39.4 ± 15.0 years old in a before-and-after study. The mean follow-up period was 38.4 ± 15.6 months. We involved 2 intact above vertebrae and one intact below vertebra, inserting a pedicular screw at the fractured level and supplemented the construct with contralateral infralaminar hook. Clinical and radiologic characteristics were assessed with American spinal injury association (ASIA scale, oswestry disability index (ODI, visual analogue scale (VAS, and plain radiography. Data analysis was carried out by SPSS version 11.5 software. Results Mean post traumatic kyphosis was + 15.7° ± 3.3° that was changed to - 8.5° ± 4.3° and +1° ± 4.4° at immediate and last visit after surgery, respectively. Mean loss of correction (LOC was 9.5° ± 1.9° (P < 0.001. At the most recent follow-up visit, mean ODI and VAS were 15.0 ± 14.4 and 2.4 ± 2.5, respectively and 24 cases (88.9% declared excellent or good clinical results. At the last follow-up visit, LOC had no significant correlation neither with VAS nor ODI. Conclusions In surgical treatment of thoracolumbar burst fractures, a medium-segment posterior spinal fixation, although cannot maintain the radiologic reduction of the fractured vertebrae efficiently, is not only associated with acceptable clinical outcome but also spare one lower intact lumbar segment and therefore recommended.

  19. Medial malleolar fractures: a biomechanical study of fixation techniques.

    Science.gov (United States)

    Fowler, T Ty; Pugh, Kevin J; Litsky, Alan S; Taylor, Benjamin C; French, Bruce G

    2011-08-08

    Fracture fixation of the medial malleolus in rotationally unstable ankle fractures typically results in healing with current fixation methods. However, when failure occurs, pullout of the screws from tension, compression, and rotational forces is predictable. We sought to biomechanically test a relatively new technique of bicortical screw fixation for medial malleoli fractures. Also, the AO group recommends tension-band fixation of small avulsion type fractures of the medial malleolus that are unacceptable for screw fixation. A well-documented complication of this technique is prominent symptomatic implants and secondary surgery for implant removal. Replacing stainless steel 18-gauge wire with FiberWire suture could theoretically decrease symptomatic implants. Therefore, a second goal was to biomechanically compare these 2 tension-band constructs. Using a tibial Sawbones model, 2 bicortical screws were compared with 2 unicortical cancellous screws on a servohydraulic test frame in offset axial, transverse, and tension loading. Second, tension-band fixation using stainless steel wire was compared with FiberWire under tensile loads. Bicortical screw fixation was statistically the stiffest construct under tension loading conditions compared to unicortical screw fixation and tension-band techniques with FiberWire or stainless steel wire. In fact, unicortical screw fixation had only 10% of the stiffness as demonstrated in the bicortical technique. In a direct comparison, tension-band fixation using stainless steel wire was statistically stiffer than the FiberWire construct. Copyright 2011, SLACK Incorporated.

  20. Fixation of displaced subcapital femoral fractures. Compression screw fixation versus double divergent pins.

    Science.gov (United States)

    Christie, J; Howie, C R; Armour, P C

    1988-03-01

    One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the femoral neck (Garden Grade III or IV) all under 80 years of age and independently mobile, were randomly allocated to fixation with either double divergent pins or a single sliding screw-plate device. The incidence of non-union and infection in the sliding screw-plate group was significantly higher, and we believe that when internal fixation is considered appropriate multiple pinning should be used. Mobility after treatment was disappointing in about half of the patients, and we feel that internal fixation can only be justified in patients who are physiologically well preserved and who maintain a high level of activity.

  1. Comparison of intermaxillary fixation screw versus eyelet interdental wiring for intermaxillary fixation in minimally displaced mandibular fracture: a randomized clinical study.

    Science.gov (United States)

    Ingole, Pranav D; Garg, Anoop; Shenoi, S Ramakrishna; Badjate, Samprati J; Budhraja, Nilima

    2014-05-01

    The aim of the present randomized study was to evaluate the efficacy of intermaxillary fixation screw (IMFS) versus eyelet interdental wiring for intermaxillary fixation (IMF) in minimally displaced mandibular fractures. A total of 50 patients with a minimally displaced mandibular fracture were enrolled, with 25 patients randomly selected for each group. In group I (study group, n = 25), the patients were treated using IMFS, and in group II (control group, n = 25), they received eyelet interdental wiring. Both techniques were assessed for the following parameters: time required for placement and removal of each type of IMF technique, time required for placement of IMF wires, postoperative occlusion, stability of the IMF wire, local anesthesia requirement during removal of each fixation type, oral hygiene status, glove perforation rate, and complications associated with both techniques. The collected data were analyzed using Student's unpaired t test or χ2 test. P wire in group I was 2.1 minutes and in group II was 6 minutes. The oral hygiene status was assessed, and the mean plaque index score for groups I and II was 1.44 and 2.12, respectively (P = .00). The glove perforation rate was much less in group I than in group II. Finally, the most common complication in both groups was mucosal growth. The results established the supremacy of IMFS compared with eyelet interdental wiring. Thus, we have concluded that IMFS, in the present scenario, is a safe and time-saving technique. IMFS is a cost-effective, straightforward, and viable alternative to cumbersome eyelet interdental and other wiring techniques for providing IMF, with satisfactory occlusion during closed reduction or intraoperative open reduction internal fixation of fractures. In addition, oral hygiene can be maintained, and the glove perforation rate was very low using IMFS. The relatively small sample size and limited follow-up period were the study limitations. Copyright © 2014 American Association of

  2. Minimal Invasive Fixation Can Decrease Infection Rates in Diabetic and Obese Patients With Severe Ankle Fracture and Syndesmotic Injury.

    Science.gov (United States)

    Ebraheim, Nabil A; Dailey, Matthew; Huff, Scott; Qu, Yihuai; White, Erik; Liu, Jiayong

    2018-03-01

    Ankle fractures involving syndesmosis disruption cause severely unstable joint conditions. Traditional invasive operations put certain patient groups at an increased risk of infection. There is limited literature discussing the outcomes of minimally invasive fixation of severe ankle fractures including syndesmotic injury, as clinicians may be tempted to treat these difficult cases with open reduction internal fixation (ORIF). A retrospective case-control study was conducted on patients treated at a level one trauma center. Patients were divided into 2 groups based on presence of diabetes and/or obesity (body mass index ≥30.0 kg/m 2 ). Those with either comorbidity were defined as high infection risk patients and placed in a comorbidity group. Patients were further divided into subgroups based on the operation's invasiveness; either traditional ORIF or percutaneous cannulated screw fixation. Comorbid patients (N = 67) were more likely to sustain Weber C fractures compared to noncomorbid patients (N = 43) (59.70% to 37.21%, P = .019). Additionally, patients receiving minimally invasive fixation procedures experienced fewer infections than those receiving ORIF (0 vs 11 incidences, P = .01), without effect on union rates, fracture reduction, pain, need for revision surgery, or time to full weightbearing. Diabetic and obese patients are at an increased risk of experiencing severe ankle fractures. The use of minimally invasive fixation methods can reduce the risk of postoperative infection without sacrificing other surgical outcomes, even with fractures involving syndesmotic injury. Therapeutic, Level III: Retrospective comparative study.

  3. Efficacy of Routine Postoperative CT Scan After Open Reduction and Internal Fixation of the Acetabulum.

    Science.gov (United States)

    Archdeacon, Michael T; Dailey, Steven K

    2015-08-01

    The purpose of this study was to evaluate the efficacy of routine postoperative computed tomography (CT) scan after open reduction and internal fixation of acetabular fractures. Retrospective review of prospectively collected acetabulum fracture database. Level I trauma center. A total of 606 consecutive patients underwent surgical fixation of 612 acetabular fractures. All patients were evaluated with intraoperative fluoroscopy in addition to 3 standard plain radiographs (AP pelvis and two 45 degrees oblique Judet views). Reduction and fixation were believed to be adequate and definitive before exiting the operative suite based on these imaging modalities. Axial postoperative CT scan of the pelvis was obtained in 563 of the patients (93%) after 569 operative cases. Revision acetabular surgery based on routine postoperative CT scan findings. There were no significant differences between index and revision surgery groups regarding age, gender, body mass index, fracture pattern, mechanism of injury, or surgical approach (P > 0.05). Evaluation of 563 postoperative CT scans of the pelvis resulted in revision acetabular surgery for 2.5% of patients (n = 14). There were 6 (1.1%) cases of intraarticular hardware not recognized on the intraoperative fluoroscopy or pelvic radiographs. Four patients (0.7%) had residual intraarticular osteochondral fragments deemed too large to leave in the hip joint. There were 3 cases (0.5%) of unacceptable malreduction, and 1 case (0.2%) of both malreduction and an intraarticular osteochondral fragment. A small percentage of patients (2.5%) will benefit from a routine CT scan after acetabular fracture fixation. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  4. Indexing mechanisms

    International Nuclear Information System (INIS)

    Wood, A.G.; Parker, G.E.; Berry, R.

    1976-01-01

    It is stated that the indexing mechanism described can be used in a nuclear reactor fuel element inspection rig. It comprises a tubular body adapted to house a canister containing a number of fuel elements located longtitudinally, and has two chucks spaced apart for displacing the fuel elements longitudinally in a stepwise manner, together with a plunger mechanism for displacing them successively into the chucks. A measuring unit is located between the chucks for measuring the diameter of the fuel elements at intervals about their circumferences, and a secondary indexing mechanism is provided for rotating the measuring unit in a stepwise manner. (U.K.)

  5. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit

    2015-04-16

    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  6. Author Index

    Indian Academy of Sciences (India)

    Author Index. Alshaary, A. A. see Sharaf, M. A., 9. Banajh, M. A. see Sharaf, M. A., 9. Burbidge Geoffrey see Narlikar Jayant, V., 67. Chen, H. D. see Li, K. J., 147. Chen, Y. Q. see Huang, C., 139. Cui Wenyuan Evolution of the Distribution of Neutron Exposures in the Galaxy. Disc: An Analytical Model, 55. Dhurde Samir see ...

  7. Author Index

    Indian Academy of Sciences (India)

    Author Index. Alecian, E. see Samadhi, R., 171; see Goupil, M.-J., 249. Antia, H. M. Helioseismology, 161. Ashoka, B. N. see Seetha, S., 301. Baudin, F. see Samadhi, R., 171. Boehm, T. see Goupil, M.-J., 249. Catala, C. see Goupil, M.-J., 249. Cunha Margarida S. Asteroseismic Theory of Rapidly Oscillating Ap Stars, 213.

  8. SUBJECT INDEX

    Indian Academy of Sciences (India)

    Unknown

    SUBJECT INDEX. Absorption. Effect of NaCl on the spectral and kinetic properties of cresyl violet (CV)-sodium dodecyl sulphate (SDS) complex. 299. Acid catalysts. Temperature-programmed desorption of water and ammonia on sulphated zirconia catalysts for measuring their strong acidity and acidity distribution. 281.

  9. Author Index

    Indian Academy of Sciences (India)

    J. Astrophys. Astr. (2008) 29, 405–409. Author Index. Aggarwal Malini see Jain Rajmal, 125; X-ray Emission Characteristics of Flares. Associated with CMEs, 195. Alyana Radharani see Rathod Jatin, 293; see Reddy Chandrasekhar, A., 313. Ambastha Ashok Helioseismic Effects of Energetic Transients, 93; see Maurya.

  10. SUBJECT INDEX

    Indian Academy of Sciences (India)

    Unknown

    SUBJECT INDEX. Ab initio calculations. Basis set effects on energy and hardness profiles of the hydrogen fluoride dimer. 549. Activation by calcinations. Highly active and reusable catalyst from Fe-Mg- hydrotalcite anionic clay for Friedel–Crafts type benzyla- tion reactions. 635. Adsorption. Adsorption studies of iron(III) on ...

  11. Author Index

    Indian Academy of Sciences (India)

    Author Index. Aggarwal Malini see Jain Rajmal, 155. Aghaee, A. Determination of the Mean Hi Absorption of the Intergalactic. Medium, 59. Agrawal, S. P. see Singh Ambika, 89. Biesiada Marek Could the Optical Transient SCP 06F6 be due to Micro- lensing?, 213. C¸ aliskan, S . see Küçük, ˙I., 135. Evans Lloyd, T. Carbon ...

  12. Author Index

    Indian Academy of Sciences (India)

    Author Index. Ahmad Farooq see Iqbal Naseer, 373. Ali Syed Salman Study of a Large Helical Eruptive Prominence Associated with. Double CME on 21 April 2001, 347; see Uddin Wahab, 267. Ali, A. Chemistry of Carbon Rich Star IRAS 15194–5115, 399. Ambastha Ashok Photospheric, Chromospheric and Helioseismic ...

  13. Subject Index

    Indian Academy of Sciences (India)

    J. Astrophys. Astr. (2006) 27, 469–472. Subject Index. Astrophysical Processes. Spatial Damping of Linear Compressional Magnetoacoustic Waves in Quiescent. Prominences (K. A. P. Singh), 321. Report on the Dynamical Evolution of an Axially Symmetric Quasar Model. (N. J. Papadopoulos & N. D. Caranicolas), 389.

  14. SUBJECT INDEX

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    SUBJECT INDEX. 1D inversion. A direct inversion scheme for deep resistivity sound- ing data using artificial neural networks. 49. 40. Ar-. 39. Ar thermochronology. Tectono-thermal evolution of the India-Asia colli- sion zone based on. 40. Ar-. 39. Ar thermochronology in. Ladakh, India. 737. ANN. Artificial neural network ...

  15. Index Fossils

    Indian Academy of Sciences (India)

    stricted geologic time range, easily preservable, of short species duration and found in multiple environment. Index fossils are used by geologists and palaeontologists as significant aids to determine the correlation and age of rock sequences [2]. Geologists use both large fossils or 'macrofossils' and microscopic fossils or ...

  16. Author Index

    Indian Academy of Sciences (India)

    user1

    Yan, X. L. see Deng, L. H., 221. Phase Relationship Between Sunspot Number, Flare Index and Solar Radio. Flux, 387. ZANINETTI, L. Revisiting the Cosmological Principle in a Cellular Framework, 399. ZHAO XIAN-FENG. Constraints on the Moment of Inertia of a Proto Neutron Star from the Hyperon Coupling Constants, ...

  17. Index Fossils

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 10. Index Fossils - Evidences from Plant Sources. Dipanjan Ghosh. General Article ... Author Affiliations. Dipanjan Ghosh1. Biological Science Department Kirnahar Shib Chandra High School Kirnahar, Birbhum 731302, West Bengal, India.

  18. Distraction osteogenesis using combined locking plate and Ilizarov fixator in the treatment of bone defect: A report of 2 cases

    Directory of Open Access Journals (Sweden)

    John Mukhopadhaya

    2017-01-01

    Full Text Available Distraction osteogenesis and bone transport has been used to reconstruct bone loss defect by allowing new bone to form in the gap. Plate-guided bone transport has been successfully described in literature to treat bone loss defect in the femur, tibia, and mandible. This study reports two cases of fracture of femur with segmental bone loss treated with locking plate fixation and bone transport with Ilizarov ring fixator. At the time of docking, when the transport segment is compressed with bone fragment, the bone fragment is fixed with additional locking or nonlocking screws through the plate. The bone defect size was 7 cm in case 1 and 8 cm in case 2 and the external fixation indexes were 12.7 days/cm and 14 days/cm. No shortening was present in either of our cases. The average radiographic consolidation index was 37 days/cm. Both cases achieved infection-free bone segment regeneration and satisfactorily functional outcome. This technique reduces the duration of external fixation during the consolidation phase, allows correction of length and alignment and provides earlier rehabilitation.

  19. Distal fingertip replantation without skeletal fixation.

    Science.gov (United States)

    Sabapathy, S Raja; Venkatramani, Hari; Bharathi, R Ravindra; Sebastin, Sandeep J

    2005-01-01

    The replantation of fingertip amputation (through the nail bed) requires repair of the artery and vein on the palmar side. These structures are present in different planes, with the artery being deeper and the veins superficial. The authors believe that vascular repair in such cases is facilitated by stabilization of the amputated part by nail-bed repair alone. This provides a certain degree of flexibility, which allows for easier placement of clamps in the limited space available. Although Kirschner wires were not used for bony fixation, bony union was achieved in all five cases in which this technique was used.

  20. Biological fixation in anterior cruciate ligament surgery

    Directory of Open Access Journals (Sweden)

    Chih-Hwa Chen

    2014-04-01

    Full Text Available Successful anterior cruciate ligament (ACL reconstruction with tendon graft requires extensive tendon-to-bone healing in the bone tunnels and progressive graft ligamentization for biological, structural, and functional recovery of the ACL. Improvement in graft-to-bone healing is crucial for facilitating early, aggressive rehabilitation after surgery to ensure an early return to pre-injury activity levels. The use of various biomaterials for enhancing the healing of tendon grafts in bone tunnels has been developed. With the biological enhancement of tendon-to-bone healing, biological fixation of the tendon graft in the tunnel can be achieved in ACL reconstruction.

  1. External skeletal fixation of the tibial shaft fractures

    OpenAIRE

    Milenković Saša; Mitković Milorad B.; Radenković Mile

    2005-01-01

    Aim. To present the possibility of a successful use of external skeletal fixation in treating the open and closed tibial shaft fractures with Mitković’s external fixator. Methods. External fixation was used in 115 patients with 118 fresh tibial shaft fractures, 82 males (71.3%) and 33 females (28.7%), average age 43.92 years (16−84). Open tibial shaft fractures were present in 37 (31.36%). All the fractures were treated with Mitković’s external fixator type M 20. Results. The results of exter...

  2. [Distraction arthrolysis with humero-ulnar motion fixator].

    Science.gov (United States)

    Pennig, D; Gausepohl, T; Mader, K; Wolfgarten, B

    2001-09-01

    Distraction arthroplasty in the treatment of elbow stiffness with an external fixator and subsequent fixator assisted mobilization is described. Joint distraction is employed to correct the shortened ligaments and capsule and permits the separation of articular surfaces. After intraoperative joint distraction, a phase of relaxation followed by fixator assisted mobilization is carried out. The use of the motion fixator is described and additional measures discussed. This technique is particularly valuable in joint subluxation or persistent joint dislocation and allows for reduction after distraction in order to secure joint congruity. Postoperative management is a key factor for the success of the management protocol.

  3. Alcohol-based solutions for bovine testicular tissue fixation.

    Science.gov (United States)

    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.

  4. LCP external fixation - External application of an internal fixator: two cases and a review of the literature

    Directory of Open Access Journals (Sweden)

    Wong Merng-Koon

    2010-03-01

    Full Text Available Abstract The locking compression plate (LCP is an angle-stable fixator intended for intracorporeal application. In selected cases, it can be applied externally in an extracorporeal location to function as a monolateral external fixator. We describe one patient with Schatzker V tibial plateau fracture and one patient with Gustillo IIIB open tibia shaft fracture treated initially with traditional external fixation for whom exchange fixation with externally applied LCPs was performed. The first case went on to bony union while the second case required bone grafting for delayed union. Both patients found that the LCP external fixators facilitated mobilization and were more manageable and aesthetically acceptable than traditional bar-Schanz pin fixators.

  5. Biomechanics of lumbar cortical screw-rod fixation versus pedicle screw-rod fixation with and without interbody support.

    Science.gov (United States)

    Perez-Orribo, Luis; Kalb, Samuel; Reyes, Phillip M; Chang, Steve W; Crawford, Neil R

    2013-04-15

    Seven different combinations of posterior screw fixation, with or without interbody support, were compared in vitro using nondestructive flexibility tests. To study the biomechanical behavior of a new cortical screw (CS) fixation construct relative to the traditional pedicle screw (PS) construct. The CS is an alternative to the PS for posterior fixation of the lumbar spine. The CS trajectory is more sagittally and cranially oriented than the PS, being anchored in the pars interarticularis. Like PS fixation, CS fixation uses interconnecting rods fastened with top-locking connectors. Stability after bilateral CS fixation was compared with stability after bilateral PS fixation in the setting of intact disc and with direct lateral interbody fixation (DLIF) or transforaminal lateral interbody fixation (TLIF) support. Standard nondestructive flexibility tests were performed in cadaveric lumbar specimens, allowing non-paired comparisons of specific conditions from 28 specimens (4 groups of 7) within a larger experiment of multiple hardware configurations. Condition tested and group from which results originated were as follows: (1) intact (all groups); (2) with L3-L4 bilateral PS-rods (group 1); (3) with bilateral CS-rods (group 2); (4) with DLIF (group 3); (5) with DLIF + CS-rods (group 4); (6) with DLIF + PS-rods (group 3); (7) with TLIF + CS-rods (group 2), and (8) with TLIF + PS-rods (group 2). To assess spinal stability, the mean range of motion, lax zone, and stiff zone at L3-L4 were compared during flexion-extension, lateral bending, and axial rotation. With intact disc, stability was equivalent after PS-rod and CS-rod fixation, except that PS-rod fixation was stiffer during axial rotation. With DLIF support, there was no significant difference in stability between PS-rod and CS-rod fixation. With TLIF support, PS-rod fixation was stiffer than CS-rod fixation during lateral bending. Bilateral CS-rod fixation provided about the same stability in cadaveric specimens

  6. Biological Nitrogen Fixation: Perspective and Limitation

    Directory of Open Access Journals (Sweden)

    N D Purwantari

    2008-03-01

    Full Text Available The demand of chemical fertilizer, N in particular will be increasing until 2020. In Indonesia, the demand of fertilizer from 1999 – 2002 increased 37.5 and 12.4% for urea and ammonium sulphate, respectively. At the same time, the price of this fertilizer is also increasing and it can not be afforded by the farmer. Other problem in using chemical fertilizer is damaging to the soil and environment. One of the problem solvings for this condition is to maximize biological nitrogen fixation (BNF. BNF is the fixation of N atmosphere by association between soil bacteria rhizobia and leguminous plant. BNF is sustainable and environmentally friendly in providing nitrogen fertilizer. Therefore, it would reduce the requirement of chemical nitrogen fertilizer for the plant. Gliricidia sepium fixes 170 kg N/ha/12 months, equivalent with 377 kg urea, Sesbania sesban 179 kg N/ha/10 months, equivalent 397 kg with urea, soybean 26 – 57 kg/2 months equivalent with 57 – 126 kg urea. The amount of N2- fixed varies, affected by species, environmental and biological factors. There are some limitations in applying this technology. The effect of N contribution is very slow at the beginning but in the long term, it would be beneficial for plant production and at the same time, maintain condition of physical and chemical of soil, soil microbes and therefore soil fertility.

  7. Ptolemaic indexing

    Directory of Open Access Journals (Sweden)

    Magnus Lie Hetland

    2015-07-01

    Full Text Available This paper discusses a new family of bounds for use in similarity search, related to those used in metric indexing, but based on Ptolemy's inequality, rather than the metric axioms. Ptolemy's inequality holds for the well-known Euclidean distance, but is also shown here to hold for quadratic form metrics in general, with Mahalanobis distance as an important special case. The inequality is examined empirically on both synthetic and real-world data sets and is also found to hold approximately, with a very low degree of error, for important distances such as the angular pseudometric and several Lp norms. Indexing experiments are performed on several data sets, demonstrating a highly increased filtering power when using certain forms of Ptolemaic filtering, compared to existing, triangular methods. It is also shown that combining the Ptolemaic and triangular filtering can lead to better results than using either approach on its own.

  8. Distal tibial fractures: evaluation of different fixation techniques.

    Science.gov (United States)

    Jöstl, Julian; Tiefenböck, Thomas Manfred; Hofbauer, Marcus; Winnisch, Markus; Lang, Nikolaus; Hajdu, Stefan; Sarahrudi, Kambiz

    2017-03-01

    The purpose of this study was the comparison of the most commonly used surgical techniques (external fixation, intramedullary nailing, and plate fixation) for the treatment of distal tibial fractures (AO/OTA classification 42-A, B, C or 43-A, B1). A retrospective cohort study of patients who underwent surgical treatment for distal tibial fractures between 1992 and 2011 was performed. A total of 93 patients (52 male/41 female) met inclusion criteria. Statistically significant differences were found regarding the consolidation time of the intramedullary-nailing (147.32 ± 91.16 days) and the plate-fixation group (135.75 ± 110.75 days) versus the external-fixation group (163.12 ± 96.79 days; P = 0.001; P = 0.01). Significant differences were also observed in the range of motion (ROM) of the ankle joint in the intramedullary-nailing and plate-fixation group versus the ROM in the external-fixation group (P = 0.044; P = 0.025). The overall complication rate was 13/93 (14 %). Out of 66 patients treated with intramedullary nailing, 8 (12 %) suffered from complications. Out of the 15 patients treated with plate and 12 patients with external fixation, 2 (13 %) and 3 (25 %) showed complications, respectively. Our results demonstrate advantages in terms of shorter mobilization time and a better ROM of the ankle joint for intramedullary nailing and plate fixation compared with external fixation. Due to our results, we suggest internal fixation (intramedullary nailing or plate fixation) whenever patient's condition and the local fracture situation allow it.

  9. Fixation to features and neural processing of facial expressions in a gender discrimination task.

    Science.gov (United States)

    Neath, Karly N; Itier, Roxane J

    2015-10-01

    Early face encoding, as reflected by the N170 ERP component, is sensitive to fixation to the eyes. Whether this sensitivity varies with facial expressions of emotion and can also be seen on other ERP components such as P1 and EPN, was investigated. Using eye-tracking to manipulate fixation on facial features, we found the N170 to be the only eye-sensitive component and this was true for fearful, happy and neutral faces. A different effect of fixation to features was seen for the earlier P1 that likely reflected general sensitivity to face position. An early effect of emotion (∼120 ms) for happy faces was seen at occipital sites and was sustained until ∼350 ms post-stimulus. For fearful faces, an early effect was seen around 80 ms followed by a later effect appearing at ∼150 ms until ∼300 ms at lateral posterior sites. Results suggests that in this emotion-irrelevant gender discrimination task, processing of fearful and happy expressions occurred early and largely independently of the eye-sensitivity indexed by the N170. Processing of the two emotions involved different underlying brain networks active at different times. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. External skeletal fixation of the tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Milenković Saša

    2005-01-01

    Full Text Available Aim. To present the possibility of a successful use of external skeletal fixation in treating the open and closed tibial shaft fractures with Mitković’s external fixator. Methods. External fixation was used in 115 patients with 118 fresh tibial shaft fractures, 82 males (71.3% and 33 females (28.7%, average age 43.92 years (16−84. Open tibial shaft fractures were present in 37 (31.36%. All the fractures were treated with Mitković’s external fixator type M 20. Results. The results of external fixation were excellent or good in 94.07% of the cases, and bad in 5.08%. Pin tract infection appeared in 7 (5.93% patients. In only 3 cases an external fixator was removed and treatment continued with the functional braces. Nonunion occurred in 6 (5.08% patients, of which 4 were with open fractures (2 Gustilo type IIIB, 1 Gustilo type IIIA, 1 Gustilo type II and 2 with the segment fractures. Compartment syndrome was observed in 1 (0.85% patient with closed fracture. Malunion was found in 2 (1.69% patients. Conclusion. External fixation of tibial shaft fractures is a simple and effective method to enable the safe healing of fractures, early mobilization of the patients, early weight-bearing, as well as early rehabilitation. Fixation of tibial shaft fractures was unilateral with convergent pins orientation, and there was also a possibility of compression and distraction.

  11. [External skeletal fixation of the tibial shaft fractures].

    Science.gov (United States)

    Milenković, Sasa; Mitković, Milorad; Radenković, Mile

    2005-01-01

    To present the possibility of a succesfful use of external skelatal fixation in treating the open and closed tibial shaft fractures with Mitković's external fixator. External fixation was used in 115 patients with 118 fresh tibial shaft fractures, 82 males (71.3%) and 33 females (28.7%), average age 43.92 years (16-84). Open tibial shaft fractures were present in 37 (31.36%). All the fractures were treated with Mitković's external fixator type M 20. The results of external fixation were excellent or good in 94.07% of the cases, and bad in 5.08%. Pin tract infection appeared in 7 (5.93%) patients. In only 3 cases an external fixator was removed and treatment continued with the functional braces. Nonunion occurred in 6 (5.08%) patients, of which 4 were with open fractures (2 Gustilo type IIIB, 1 Gustilo type IIIA, 1 Gustilo type II) and 2 with the segment fractures. Compartment syndrome was observed in 1 (0.85%) patient with closed fracture. Malunion was found in 2 (1.69%) patients. External fixation of tibial shaft fractures is a simple and effective method to enable the safe healing of fractures, early mobilization of the patients, early weight-bearing, as well as early rehabilitation. Fixation of tibial shaft fractures was unilateral with convergent pins orientation, and there was also a possibility of compression and distraction.

  12. Predicting Eye Fixations on Complex Visual Stimuli Using Local Symmetry.

    Science.gov (United States)

    Kootstra, Gert; de Boer, Bart; Schomaker, Lambert R B

    2011-03-01

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the prediction of fixations on mirror-symmetrical forms. The contrast model gives high response at the borders, whereas human observers consistently look at the symmetrical center of these forms. We propose a saliency model that predicts eye fixations using local mirror symmetry. To test the model, we performed an eye-tracking experiment with participants viewing complex photographic images and compared the data with our symmetry model and the contrast model. The results show that our symmetry model predicts human eye fixations significantly better on a wide variety of images including many that are not selected for their symmetrical content. Moreover, our results show that especially early fixations are on highly symmetrical areas of the images. We conclude that symmetry is a strong predictor of human eye fixations and that it can be used as a predictor of the order of fixation.

  13. Percutaneous pin fixation of Gartland Type III supraconylar fractures ...

    African Journals Online (AJOL)

    The remaining three (7.5%) had poor results due to varus deformity that neededcorrective surgery. One case of pin tract infection was recorded. The average hospital stay was 1.2 days. The study confirmed that percutaneous pin fixation is an effective, minimally invasive and safe method of fixation of these difficult fractures ...

  14. Predicting Eye Fixations on Complex Visual Stimuli Using Local Symmetry

    NARCIS (Netherlands)

    Kootstra, Geert; de Boer, Bart; Schomaker, Lambertus

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the

  15. Predicting eye fixations on complex visual stimuli using local symmetry

    NARCIS (Netherlands)

    Kootstra, G.; de Boer, B.; Schomaker, L.R.B.

    2011-01-01

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the

  16. Estimates of biological nitrogen fixation by Pterocarpus lucens in a ...

    African Journals Online (AJOL)

    TonukariJ

    2002-11-15

    Nov 15, 2002 ... Nitrogen fixation in Pterocarpus erinaceus and P. lucens using the. 15N labelling methods. Ar. Soil Res. Rehabil. 12:257-253. Unkovich MJ, Pate JS, Sanford P, Amstrong EL (1994). Potential precision of the 15N natural abundance method in field estimates of nitrogen fixation by crop and pasture legumes.

  17. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    Conclusions: It was concluded that the use of double 4-hole straight plates provided the sufficient stability on the osteotomy site when compared with the other rigid fixation methods used in this study. Key words: Bone plates, bone screws, finite element analysis, jaw fixation techniques, mandible, mandibular osteotomy ...

  18. Rib fracture fixation in a South African public trauma service ...

    African Journals Online (AJOL)

    Background: Rib fractures and flail chests have traditionally been treated nonoperatively. Current literature suggests that it is not only safe and feasible but also desirable to perform fixation of severe rib fractures. Our unit in the Pietermaritzburg public sector adopted rib fracture fixation in 2014 and in this audit we assess its ...

  19. Nitrogen fixation of Acacia mangium Willd. from two seed sources ...

    African Journals Online (AJOL)

    Phosphorus (P) is required to facilitate the fixation of atmospheric nitrogen (N) by leguminous species such as Acacia mangium. We studied the N fixation of A. mangium trees grown from two seed sources. These consisted of bulk seedlots collected from seed orchards in Sumatra, one based on natural provenances from ...

  20. Temporal evolution of the central fixation bias in scene viewing.

    Science.gov (United States)

    Rothkegel, Lars O M; Trukenbrod, Hans A; Schütt, Heiko H; Wichmann, Felix A; Engbert, Ralf

    2017-11-01

    When watching the image of a natural scene on a computer screen, observers initially move their eyes toward the center of the image-a reliable experimental finding termed central fixation bias. This systematic tendency in eye guidance likely masks attentional selection driven by image properties and top-down cognitive processes. Here, we show that the central fixation bias can be reduced by delaying the initial saccade relative to image onset. In four scene-viewing experiments we manipulated observers' initial gaze position and delayed their first saccade by a specific time interval relative to the onset of an image. We analyzed the distance to image center over time and show that the central fixation bias of initial fixations was significantly reduced after delayed saccade onsets. We additionally show that selection of the initial saccade target strongly depended on the first saccade latency. A previously published model of saccade generation was extended with a central activation map on the initial fixation whose influence declined with increasing saccade latency. This extension was sufficient to replicate the central fixation bias from our experiments. Our results suggest that the central fixation bias is generated by default activation as a response to the sudden image onset and that this default activation pattern decreases over time. Thus, it may often be preferable to use a modified version of the scene viewing paradigm that decouples image onset from the start signal for scene exploration to explicitly reduce the central fixation bias.

  1. Optimization of carbon dioxide fixation and starch accumulation by ...

    African Journals Online (AJOL)

    ... are very important to CO2 bio-fixation and carbohydrate accumulation in microalgae. The objective of this study was to optimize semi-continuous culture conditions of Tetraselmis subcordiformis in a rectangular airlift photobioreactor for obtaining maximized carbon dioxide fixation rate and intracellular starch productivity.

  2. Monitoring in vivo load transmission through an external fixator.

    Science.gov (United States)

    Grasa, J; Gómez-Benito, M J; González-Torres, L A; Asiaín, D; Quero, F; García-Aznar, J M

    2010-03-01

    This work presents a portable non-invasive external fixator to assess and monitor fracture healing in real time. To evaluate the potential of this fixator, a transverse osteotomy was performed in the tibia of six adult sheep (mean age 3+/-0.5 years and weight 63+/-5 kg). The fractures were stabilized by a specially designed unilateral external fixator, which was instrumented by means of a set of strain gauges. Strains in the external surface of the fixator were monitored during all the healing process. A wireless, remote monitoring of the implant was developed through a specially designed external telemetric device. The strain gauges were arranged in two different half-bridge Wheatstone configurations, allowing easy post-processing of the signal. Thus, bending loads were measured in two planes of the external fixator acting as a load cell. The load through the fixator was evaluated for the gait cycle during all the healing process. Full weight bearing of the injured leg was observed from the beginning. The load transmission mechanism in the fixator was quite similar in all operated tibias and radiographic images showed a successful healing in all animals. Although the fixator has only been tested in an animal model, after further testing this system may have clinical potential.

  3. STUDY ON SPANNING EXTERNAL FIXATORS FOR PERIARTICULAR OPEN FRACTURES

    Directory of Open Access Journals (Sweden)

    Prasanth Maddila

    2017-04-01

    Full Text Available BACKGROUND Open fractures which occur close to any fracture need immobilisation for the soft tissues to heal. Some open fractures are even fixed with provisional fixations to maintain the alignment of the fractures. The provisional fixation needs to be augmented with external support, which can be given by spanning external fixators across a joint. MATERIALS AND METHODS Our study consists of 38 open fractures of the lower limbs, which are of Gustilo-Anderson’s type IIIB, an MT4 of AO-ASIF soft tissue injury classification essentially requiring open wound management as well as fracture fixation. Wound lavage and debridements are carried out till the soft tissues show granulations. The position in which joint is immobilised is functional and with access to open wound for dressings and inspection without any displacement of the fracture as well as creeping granulation tissue. RESULTS All the cases in our study are maintained with functional position till soft tissue cover is achieved and provisional fixation is done with definitive fixation after soft tissue cover with skin grafting. CONCLUSION Spanning external fixators are useful in maintaining functional positions as well as augmenting the provisional fixation of the compound fractures.

  4. Tightrope fixation of ankle syndesmosis injuries: clinical outcome, complications and technique modification.

    LENUS (Irish Health Repository)

    Naqvi, Gohar A

    2012-06-01

    Ankle syndesmotic injuries are complex and require anatomic reduction and fixation. Tightrope fixation is a relatively new technique and we present the largest series of syndesmosis fixation using Arthrex Tightrope™ (Naples, FL, USA).

  5. Subcapital femoral neck fracture after fixation of an intertrochanteric fracture with a proximal femoral nail: a report of two cases.

    Science.gov (United States)

    Kaneko, Haruka; Matsuda, Keiji; Kim, Sungon; Maeda, Kouichi; Ikegami, Takashi; Kubota, Reiko; Nagayama, Masataka; Nozawa, Masahiko

    2009-12-01

    Subcapital femoral neck fractures are a rare complication after fixation of an intertrochanteric fracture with a proximal femoral nail. We report 2 such cases where the patients had severe osteoporosis, based on Singh's index and pathological findings. In one case there was a technical error leading to a tip-apex distance of more than 20 mm, but osteoporosis appeared to be a more significant cause than any technical problems.

  6. Compression screw fixation of the syndesmosis.

    Science.gov (United States)

    Darwish, Husam H; Glisson, Richard R; DeOrio, James K

    2012-10-01

    Screw fixation of syndesmotic injuries facilitates ligament healing and restoration of ankle stability, but little information regarding screw performance is available. This study quantified the reduction obtained with three common 2-screw configurations using different methods of reduction and novel methods of subsequently provoking and measuring diastasis. Seven fresh-frozen lower extremities were subjected to 100 N medial and lateral tibia loads with the talus restrained. Tibia displacement, indicative of ankle clear space, was recorded. The syndesmosis and distal interosseous ligament were disrupted and measurements repeated. A pressure sensor was inserted into the syndesmosis and three 2-screw fixation methods were evaluated in each specimen: 3.5-mm screws engaging both fibula cortices and the lateral tibial cortex, inserted while using a clamp to achieve syndesmosis reduction; 3.5-mm lag screws engaging both tibia cortices; and 4.5-mm lag screws engaging both tibia cortices. One thousand 100 N medial and lateral loads were applied and clear space and syndesmosis compression were quantified every 100 cycles. Normal ankle clear space averaged 1.98 mm and increased to 3.02 mm after syndesmosis disruption. Fixation decreased the clear space to 1.36 mm, 1.22 mm, and 1.19 mm for the 3.5-mm tricortical, 3.5-mm lag, and 4.5-mm lag screws, respectively, remaining steady throughout cyclic loading. Syndesmosis compression dropped markedly from 61N to 23 N on clamp release after tricortical screw insertion. The 3.5-mm and 4.5-mm lag screws exerted 112 N and 131 N, respectively, after insertion, and maintained compression several-fold greater than the tricortical screws during cyclic loading. No difference was demonstrable between the two lag screw sizes. While all screw configurations successfully reduced ankle clear space, syndesmosis reduction was more effectively maintained by lag screws than by tricortical screws inserted with clamp reduction. The transient nature of

  7. Fixation and escape times in stochastic game learning

    International Nuclear Information System (INIS)

    Realpe-Gomez, John; Szczesny, Bartosz; Galla, Tobias; Dall’Asta, Luca

    2012-01-01

    Evolutionary dynamics in finite populations is known to fixate eventually in the absence of mutation. We here show that a similar phenomenon can be found in stochastic game dynamical batch learning, and investigate fixation in learning processes in a simple 2×2 game, for two-player games with cyclic interaction, and in the context of the best-shot network game. The analogues of finite populations in evolution are here finite batches of observations between strategy updates. We study when and how such fixation can occur, and present results on the average time-to-fixation from numerical simulations. Simple cases are also amenable to analytical approaches and we provide estimates of the behaviour of so-called escape times as a function of the batch size. The differences and similarities with escape and fixation in evolutionary dynamics are discussed. (paper)

  8. Overcoming design fixation through education and creativity methods

    DEFF Research Database (Denmark)

    Howard, Thomas J.; Maier, Anja; Onarheim, Balder

    2013-01-01

    This paper reports an experiment on the topic design fixation using 12 teams of masters students working on three design problems from (Jansson and Smith 1991). The objective of the experiment is to determine the effectiveness of two interventions to help overcome fixation on example solutions....... The first intervention consisted of educating each team on the phenomena and effects of design fixation. The results showed that this intervention reduced the number of fixation elements in comparison to the control group (p=0.025). The second intervention involved using Dix et als' (2006) 'Bad Ideas......' method during a final design task. The results showed that the method did not help the teams as it caused the fixation ratio to increase and the number of ideas per team to decrease. In addition to the above mentioned interventions, the experiment also revealed a negative correlation between the number...

  9. Retrospective Evaluation of Surgical Anatomical Repair of Distal Biceps Brachii Tendon Rupture Using Suture Anchor Fixation.

    Science.gov (United States)

    Witkowski, Jarosław; Królikowska, Aleksandra; Czamara, Andrzej; Reichert, Paweł

    2017-10-17

    BACKGROUND To date, no consensus has been reached regarding the preferred fixation method to use in the repair of distal biceps brachii tendon rupture. The aim of this study was to clinically and functionally (Mayo Elbow Performance Index, MEPI) assess the upper limb after surgical anatomic reinsertion of the distal biceps brachii tendon with the use of suture anchor fixation method with regard to postoperative time and limb dominance, and to assess postoperative complications. MATERIAL AND METHODS The sample comprised 18 males (age 52.09±8.89 years) after surgical anatomical distal biceps brachii reinsertion using suture anchor fixation. A comprehensive clinical and functional evaluation and pain assessment were performed. RESULTS In terms of postoperative complications, an isolated case of surgical site sensory disturbances was noted. Circumferences (p-value 0.21-1.00) and ROM (p-value 0.07-1.00) were similar in the operated and nonoperated limbs. The isometric torque (IT) values of muscles flexing and supinating the forearm were comparable in both limbs (p-value 0.14-0.95), but in patients with the operated dominant limb, the mean IT value was not higher than the value obtained in the nonoperated nondominant one. The MEPI indicated good and excellent results (80.00±15.00-90.00±8.66 points), but a detailed individual analysis showed that reported scores were not in line with objectively measured features. CONCLUSIONS The results of the comprehensive retrospective evaluation justify the clinical use of suture anchors fixation method in the surgical anatomical reinsertion of a ruptured distal biceps brachii tendon. The assessment of a patient should always report both subjective and objective measures.

  10. Treatment of displaced supracondylar humeral fractures in children by humero-ulnar external fixation.

    Science.gov (United States)

    Bogdan, Aleksandra; Quintin, Jean; Schuind, Frédéric

    2016-11-01

    Humero-ulnar external fixation has been proposed to treat complex supracondylar humeral fractures in children. It facilitates fracture reduction and reduces the risk of ulnar nerve lesion, which can occur after cross pinning. In a ten year period, 28 children have been operated on in our centre by humero-ulnar external fixation, for Lagrange-Rigault stages III and IV supracondylar humeral fractures. The data about fracture management and early follow-up were obtained from our medical database. The long-term evaluation was done at a minimum six months' follow-up. The range of motion and carrying angle measurements were classified according to Flynn. The final X-rays were evaluated for quality of reduction, presence of malunion, late infection signs, osteo-arthritis and myositis ossificans. The elbow function was evaluated by Mayo Elbow Performance Index (MEPI), Disabilities of the Arm, Shoulder and Hand (DASH) or modified DASH scores. The treatment was well tolerated by children and parents. There was no neurological complication related to the insertion of the pins, and no Volkmann syndrome. The median duration of external fixation was 33.5 days. Twelve patients were reviewed after a median follow-up duration of seven years (mean, 7.5 years; range, 3-21 years). One child had a refracture, three years after his original fracture, which was treated non-operatively. This case ended up in a cubitus varus deformity with a pronation deficit. All other patients had excellent clinical and radiological results. For the treatment of complex supracondylar humeral fractures in children, humero-ulnar external fixation is a good alternative to lateral or crossed pinning. The advantages are the ease to obtain the reduction, the absence of neurological risk to the ulnar nerve and the possibility to obtain good stabilisation of the fracture with moderate elbow flexion.

  11. Locking compression plate distal ulna hook plate fixation versus intramedullary screw fixation for displaced avulsion fifth Metatarsal Base fractures: a comparative retrospective cohort study

    OpenAIRE

    Xie, Lin; Guo, Xin; Zhang, Shu-Jun; Fang, Zhen-Hua

    2017-01-01

    Background Intramedullary screw (IMS) fixation was wildly used in fifth metatarsal base fractures (FMBFs) and the results were satisfactory. However, in the comminuted osteoporosis or small displaced avulsion FMBFs, anatomical reduction and stable fixation could not be achieved with IMS. The Locking Compression Plate (LCP) distal ulna hook plate fixation was a novel alternative fixation method. The aim of this retrospective cohort study was to determine if LCP distal ulna hook plate fixation ...

  12. Comparison of screw fixation with elastic fixation methods in the treatment of syndesmosis injuries in ankle fractures.

    Science.gov (United States)

    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 (pfixation 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. Copyright © 2015. Published by Elsevier Ltd.

  13. Les aciers inoxydables dans les fixations

    CERN Document Server

    CETIM

    2010-01-01

    Cet ouvrage, qui fait la synthèse de plusieurs travaux menés par le Cetim, propose une vue d'ensemble sur les aciers inoxydables utilisés pour les fixations. Au sommaire : les normes EN, ISO et ATSM qui s'y rapportent , les désignations symboliques , les nuances et caractéristiques mécaniques , les différentes formes de corrosion, les méthodes pour les détecter , les règles du métier , les mises en oeuvre. L'ouvrage comprend plusieurs fiches matériaux et des tableaux qui présentent les équivalences entre les désignations.

  14. Talar dome fracture repaired using bioabsorbable fixation.

    Science.gov (United States)

    Zelent, Marek E; Neese, David J

    2006-01-01

    We describe a man with an acute osteochondral defect in the lateral talar dome associated with a supination-adduction-type ankle fracture. The osteochondral defect was readily visible on plain film radiographs, and magnetic resonance imaging was ordered to determine the full extent of soft-tissue and articular injury. It was discovered that the patient had a stage IV lesion of the talar dome, with complete inversion of the fragment, and rupture of the anterior talofibular and calcaneofibular lateral ankle ligaments. Furthermore, the patient experienced an oblique fracture of the medial malleolus with comminution. The talar dome lesion was surgically reduced and fixated using bioabsorbable pins. Nine months after surgery, the patient was fully recovered from his injury and had no functional limitations.

  15. Intraosseous fixation compared to plantar plate fixation for first metatarsocuneiform arthrodesis: a cadaveric biomechanical analysis.

    Science.gov (United States)

    Roth, Klaus Edgar; Peters, Jennifer; Schmidtmann, Irene; Maus, Uwe; Stephan, Daniel; Augat, Peter

    2014-11-01

    Metatarsocuneiform (MTC) fusion is a treatment option for management of hallux valgus. We compared the biomechanical characteristics of an internal fixation device with plantar plate fixation. Seven matched pairs of feet from human cadavers were used to compare the intramedullary (IM) device plus compression screw to plantar plate combined with a compression screw. Specimen constructs were loaded in a cyclic 4-point bending test. We obtained initial/final stiffness, maximum load, and number of cycles to failure. Bone mineral density was measured with peripheral quantitative computed tomography. Performance was compared using time to event analysis with number of cycles as time variable, and a proportional hazard model including shared frailty model fitted with treatment and bone mineral density as covariates. On average the plates failed after 7517 cycles and a maximum load of 167 N, while the IM-implants failed on average after 2946 cycles and a maximum load of 69 N. In all pairs the 1 treated with IM-implant failed earlier than the 1 treated with a plate (hazard ratio for IM-implant versus plate was 79.9 (95% confidence interval [6.1, 1052.2], P = .0009). The initial stiffness was 131 N/mm for the plantar plate and 43.3 N/mm for the IM implant. Initial stiffness (r = .955) and final stiffness (r = .952) were strongly related to the number of cycles to failure. Bone mineral density had no effect on the number of cycles to failure. Plantar plate fixation created a stronger and stiffer construct than IM fixation. A stiffer construct can reduce the risk of nonunion and shorten the period of non-weight-bearing. © The Author(s) 2014.

  16. Recovering of carbon fixation in a eucalyptus site after felling

    Science.gov (United States)

    Rodrigues, A. M.; Pita, G. P. A.; Mateus, A.; Santos Pereira, J.

    2009-04-01

    Espirra site (38°38'N,8°36'W) is located in a 300ha Eucalyptus globulus plantation, with a Mediterranean type climate with a mean annual precipitation of 709mm and a mean annual air temperature of 15.9°C. The plantation was established in 1986 with about 1100 trees ha-1. A 33m observation tower was installed in 2002, with an ultrasonic Gill anemometer R2, an open path analyzer IRGA LI-7500 and a microclimate unit at its top. A harvesting of trees was made at the end of the 2nd rotation period, from November to December 2006. During the last four years of the second rotation the coppice were 20m height. Harvesting was planned in order to initiate a new 12 year productive cycle. In October 2008 a first thinning was made in three fourths of emerging stems from stumps. At this stage the forest trees had a mean height of 6m. For the 2002-2006 period, mean annual values of carbon net ecosystem exchange (NEE), gross production(GPP) and ecosystem respiration(Reco) were -533.3 gCm-2, 1628.6 gCm-2 and 1095.2 gCm-2. Seasonal patterns of carbon fixation for the five years showed a decrease in July-August periods due to highest air temperatures, atmospheric water vapour deficits and stomata partial closure to prevent water transpiration losses. For the period 2002-2006, the dry year of 2005 with a precipitation of about 390 mm, corresponded to the smaller carbon fixation of 390 gCm-2. Similarly, values of Reco, GPP and estimated leaf area index (less than three) were also minimal in 2005. Water use efficiency, WUE (ratio GPP/precipitation) was maximum in summer periods and in driest years, reaching values of about 12g/L-1. Recovery of carbon sink capacity, after the felling, begun after August 2007. The 2007 and 2008 annual NEE values were respectively 105.8 gCm-2 and -35.78 gCm-2. This negative value of NEE for 2008 is indicative of a carbon sink recovery. Annual Reco values for 2007 and 2008 were respectively 1059.03 gCm-2 and 1148.21 gCm-2. For GPP the annual values of

  17. Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples.

    Directory of Open Access Journals (Sweden)

    Marian Willner

    Full Text Available 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. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results.

  18. Endosseous Fixation Device for Lapidus Arthrodesis: Technique, Early Experience, and Comparison With Crossed Screw Fixation.

    Science.gov (United States)

    Zelent, Marek E; Neese, David J; Peterson, Paul H

    2015-01-01

    First metatarsal cuneiform joint arthrodesis has been commonly used since the early 1900s for definitive treatment of a variety of conditions involving the medial column of the foot. Early applications of this procedure resulted in a relatively high rate of complications, including malunion and nonunion. We retrospectively examined a novel method of fixation involving an endosseous implant with a nonporous, rough exterior surface and compared it with the traditional crossed screw fixation, considered the standard of care for the procedure. Twenty-one feet in 19 patients served as the control group with crossed screws, and 18 feet in 17 patients served as the trial group using the study device. Null hypothesis testing was used to compare the outcomes parameters between the comparative groups. Postoperatively, the patients were allowed to walk in a prefabricated, removable, below-the-knee cast boot at a mean of 48.3 ± 8.2 days in the control group and 24.4 ± 9.7 days in the trial group. These differences were highly significant (p fixation of the first metatarsal cuneiform arthrodesis procedure and might allow for earlier weightbearing with fewer postoperative complications. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  19. Browse Title Index

    African Journals Online (AJOL)

    lactic acid and titanium screw in intracapsular condylar fracture fixation: An experimental study, Abstract PDF. MM Omezli, D Torul, ME Polat, E Dayi. Vol 7, No 1 (2004), Birth Weights Of Full Term Newborn Babies Among ...

  20. Quantitative analysis of an engineered CO2-fixing Escherichia coli reveals great potential of heterotrophic CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Liu, Guoxia; Zhai, Xiaoyun; Zhou, Jie; Cai, Zhen; Li, Yin

    2015-01-01

    Production of fuels from the abundant and wasteful CO2 is a promising approach to reduce carbon emission and consumption of fossil fuels. Autotrophic microbes naturally assimilate CO2 using energy from light, hydrogen, and/or sulfur. However, their slow growth rates call for investigation of the possibility of heterotrophic CO2 fixation. Although preliminary research has suggested that CO2 fixation in heterotrophic microbes is feasible after incorporation of a CO2-fixing bypass into the central carbon metabolic pathway, it remains unclear how much and how efficient that CO2 can be fixed by a heterotrophic microbe. A simple metabolic flux index was developed to indicate the relative strength of the CO2-fixation flux. When two sequential enzymes of the cyanobacterial Calvin cycle were incorporated into an E. coli strain, the flux of the CO2-fixing bypass pathway accounts for 13 % of that of the central carbon metabolic pathway. The value was increased to 17 % when the carbonic anhydrase involved in the cyanobacterial carbon concentrating mechanism was introduced, indicating that low intracellular CO2 concentration is one limiting factor for CO2 fixation in E. coli. The engineered CO2-fixing E. coli with carbonic anhydrase was able to fix CO2 at a rate of 19.6 mg CO2 L(-1) h(-1) or the specific rate of 22.5 mg CO2 g DCW(-1) h(-1). This CO2-fixation rate is comparable with the reported rates of 14 autotrophic cyanobacteria and algae (10.5-147.0 mg CO2 L(-1) h(-1) or the specific rates of 3.5-23.7 mg CO2 g DCW(-1) h(-1)). The ability of CO2 fixation was created and improved in E. coli by incorporating partial cyanobacterial Calvin cycle and carbon concentrating mechanism, respectively. Quantitative analysis revealed that the CO2-fixation rate of this strain is comparable with that of the autotrophic cyanobacteria and algae, demonstrating great potential of heterotrophic CO2 fixation.

  1. Use of tightrope fixation in ankle syndesmotic injuries

    Directory of Open Access Journals (Sweden)

    Maempel Julian

    2014-02-01

    Full Text Available 【Abstract】Objective: Conventional fixation of syndesmotic injuries with screws remains problematic. A novel fibrewire device (Tightrope® has suggested advantages. However, small case series have reported high soft tissue complication rates. The purpose of our study was to quantify complication rates and further procedures in patients treated with Tightropes. A secondary objective was to determine incidence of complications and further procedures in those treated with syndesmotic screws over the same period. Methods: All patients undergoing syndesmotic fixation for ankle fracture between May 2008 and October 2009 were retrospectively reviewed. Incidence of complications, secondary procedures, maintenance of syndesmotic reduc- tion and time spent on non-weight bearing were recorded. Family doctors were contacted for those treated with Tight- ropes to check for any complications managed elsewhere. Results: Thirty-five patients required syndesmotic fixation, in which 12 were treated with Tightropes. They were followed up in clinic for a mean of 12.4 weeks. Family doctors were contacted at mean 14.6 months after treatment to determine any complications suffered. There were no complications attributable to method of fixation. In this series, 12 patients underwent 13 procedures and no patient had recurrent diastasis at discharge; 23 patients treated with screw fixation underwent 45 procedures (19 were screw removals. There was 1 case of syndesmotic diastasis. Screw removal resulted in 2 minor complications. Conclusion: Tightrope fixation provideds effective syndesmotic fixation that is maintained at discharge. We do not experience soft tissue complications reported elsewhere.

  2. Management of Postoperative Spondylodiscitis with and without Internal Fixation.

    Science.gov (United States)

    Wang, Xiang; Tao, Hairong; Zhu, Yanhui; Lu, Xiongwei; Hu, Xiaopeng

    2015-01-01

    Postoperative spondylodiscitis is relatively uncommon. This complication is associated with increased cost, and long-term of inability to work, and even morbidity. Although the majority of postoperative spondylodiscitis cases can be well managed by conservative treatment, postoperative spondylodiscitis after internal fixation and those cases that are unresponsive to the conservative treatment present challenges to the surgeon. Here, a review was done to analyze the treatment of postoperative spondylodiscitis with/without internal fixation. This review article suggested that majority of postoperative spondylodiscitis without internal fixation could be cured by conservative treatment. Either posterior or anterior debridement can be used to treat postoperative spondylodiscitis without internal fixation when conservative treatment fails. In addition, minimally invasive debridement and drainage may also be an alternative treatment. In case of postoperative spondylodiscitis after internal fixation, surgical treatment was required. In the cervical spine, it can be well managed by anterior debridement, removal of internal fixation, and reconstruction of the spinal stability by using bone grafting/cage/anterior plate. Postoperative spondylodiscitis after internal fixation is successfully managed by combined anterior debridement, fusion with posterior approach and removal of pedicle screw or extension of pedicle screw beyond the lesion site, in the thoracic and lumbar spine.

  3. Impact of external fixation on adolescents: an integrative research review.

    Science.gov (United States)

    Patterson, Miki

    2006-01-01

    To define the state of nursing knowledge about the psychological impact of treating adolescents with external fixation devices (EFDs). An integrated research review was conducted on literature available from CINAHL, MEDLINE, and PsycINFO. Keywords used were external fixation, fracture fixation, orthopaedic or orthopaedic, limb lengthening, Ilizarov, halo traction, Orthofix, EBI fixator, pelvic fixator, ring fixator, body image, self-concept, self-esteem, self-perception, adaptation, emotional, behavior, and outcome. Inclusion criteria for studies were (a) publication from 1990 to 2003, (b) focus on psychosocial and functional outcomes of treating adolescents with EFDs, and (c) publication in English. Studies were categorized by author, year, discipline(s), design, focus, sample, measurement, findings, and research recommendations. Findings and recommendations were compared across publications. All studies reported psychological and behavioral changes after EFD treatment. Pain and pin-site infections were the most problematic physical findings. Depression was universally evident to varying degrees, with some suicidal ideation and self-destructive behaviors, although mostly reported as transient. This predominantly retrospective cohort of studies reported social isolation as well as eating and sleep disturbances. Family and nursing support, a multiple disciplinary approach, and better preoperative preparation were crucial to adolescents psychological health after EFD treatment. Adolescents treated with EFDs require significant psychosocial support. The findings reveal major gaps in the knowledge on adolescents treated with external fixation for traumatic injury and none focused on EFD treatment in the acute period.

  4. Removal of symptomatic titanium fixation plates after craniotomy.

    Science.gov (United States)

    Gupta, Raghav; Adeeb, Nimer; Griessenauer, Christoph J; Moore, Justin M; Patel, Apar S; Thomas, Ajith J; Ogilvy, Christopher S

    2016-10-01

    Titanium fixation plates are routinely used for rigid fixation of bone flaps after craniotomy. In craniofacial surgery or after craniotomy involving orbitozygomatic osteotomies, these plates are occasionally removed because of infection, pain, protrusion, soft tissue erosion, and plate malfunction. However, plate removal because of pain and protrusion after craniotomy without orbitozygomatic osteotomy has rarely been reported. A retrospective analysis of all patients who underwent removal of cranial fixation plates after craniotomy, performed by the senior authors at one institution between 2014 and 2016, was conducted. A total of 319 patients underwent bone flap fixation after craniotomy using cranial fixation plates between 2014 and 2016. Five of those patients (1.6 %) had their cranial plates removed because of pain and protrusion. An additional four patients had a cranial fixation plate removed during that time frame with the original craniotomy performed before 2014. All nine patients had immediate resolution of symptoms after plate removal. We report our experience with cranial fixation plate removal because of pain and protrusion in patients who underwent craniotomy without orbitozygomatic osteotomy, particularly frontotemporal craniotomy. In an attempt to reduce this complication, we recently stopped placing a full-size burr hole in the keyhole area of a frontotemporal craniotomy, eliminating the need for a titanium burr hole cover plate.

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

    Science.gov (United States)

    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.

  6. Design and Optimization of Resorbable Silk Internal Fixation Devices

    Science.gov (United States)

    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

  7. Overcoming design fixation through education and creativity methods

    DEFF Research Database (Denmark)

    Howard, T. J.; Maier, A. M.; Onarheim, B.

    2013-01-01

    This paper reports an experiment on the topic design fixation using 12 teams of masters students working on three design problems from (Jansson and Smith 1991). The objective of the experiment is to determine the effectiveness of two interventions to help overcome fixation on example solutions......' method during a final design task. The results showed that the method did not help the teams as it caused the fixation ratio to increase and the number of ideas per team to decrease. In addition to the above mentioned interventions, the experiment also revealed a negative correlation between the number...

  8. Overcoming Design Fixation Through Education and Creativity Methods

    DEFF Research Database (Denmark)

    Howard, Thomas J.; Maier, Anja; Onarheim, Balder

    2013-01-01

    This paper reports an experiment on the topic design fixation using 12 teams of masters students working on three design problems from (Jansson and Smith 1991). The objective of the experiment is to determine the effectiveness of two interventions to help overcome fixation on example solutions......' method during a final design task. The results showed that the method did not help the teams as it caused the fixation ratio to increase and the number of ideas per team to decrease. In addition to the above mentioned interventions, the experiment also revealed a negative correlation between the number...

  9. The Ilizarov method of external fixation: current intraoperative concepts.

    Science.gov (United States)

    Lee, Daniel K; Duong, Elizabeth Thu Anh; Chang, Douglas G

    2010-03-01

    The Ilizarov method of external fixation is used to treat fractures, complex lower extremity deformities, osteomyelitis, and soft tissue contractures and to lengthen limbs. Tremendous improvements in the Ilizarov method have occurred during the past 60 years, improving intraoperative care and limb salvage management concepts. Improved instrumentation has increased the quantity and complexity of the tray systems required for these procedures. Perioperative nurses must be well versed in optimal preparation and function of Ilizarov fixation systems to ensure safe patient care during Ilizarov external fixation procedures. Copyright 2010 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  10. Carbon Dioxide Fixation in Isolated Kalanchoe Chloroplasts 1

    Science.gov (United States)

    Levi, Carolyn; Gibbs, Martin

    1975-01-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 μmoles of CO2 per milligram of chlorophyll per hour. The dark rate of fixation was about 1% of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1,6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO2 fixation were primarily those of the photosynthetic carbon reduction cycle. PMID:16659249

  11. The knee: internal fixation techniques for osteochondritis dissecans.

    Science.gov (United States)

    Grimm, Nathan L; Ewing, Christopher K; Ganley, Theodore J

    2014-04-01

    For the athlete with a newly diagnosed osteochondritis dissecans of the knee, the first step in formulating a treatment plan is determining the stability of the lesion. When the lesion is found to be unstable but salvageable, several methods for fixation are available. Fixation of osteochondritis dissecans in the athletic population has been described and each has its own advantages and disadvantages. Determining the most appropriate method for fixation depends on several variables and should include the athlete's level of play, sport, and overall goals. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Quality of life in treatment of mandibular fractures using closed reduction and maxillomandibular fixation in comparison with open reduction and internal fixation--a randomized prospective study.

    Science.gov (United States)

    Omeje, Kevin U; Rana, Majeed; Adebola, Adetokunbo R; Efunkoya, Akinwale A; Olasoji, Hector O; Purcz, Nicolai; Gellrich, Nils-Claudius; Rana, Madiha

    2014-12-01

    Treatment of mandibular fractures by open reduction and internal fixation (ORIF) is often assumed to be superior to treatment by close reduction and maxillomandibular fixation (MMF) because patients managed by ORIF seem to be rehabilitated earlier according to functional and social aspects. This assumption is often from surgeon's perspective, not taking into account patient's view point. This study highlights a comparative assessment between ORIF and MMF from the patients' perspective. Fifty six patients with mandibular fractures within the tooth bearing areas of the mandible were prospectively studied in a randomized controlled pattern for postoperative Quality of Life (QoL) after ORIF versus MMF. Both groups were analyzed preoperatively, at 1 day, 6 and 8 weeks regarding their QoL using the General Oral Health Assessment Index questionnaire (GOHAI). No significant statistical difference was found between the groups regarding overall QoL. Patients managed by MMF were more affected by psychosocial and physical domains whereas patients managed by ORIF were more affected by the pain domain. The results demonstrate that the treatment affects the psychosocial, physical and pain domain differentially. When both treatments are possible the patient's should be enlightened on the advantages and disadvantages of both treatment modalities to guide their choice of treatment. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Biomechanical stability of a supra-acetabular pedicle screw Internal Fixation device (INFIX vs External Fixation and plates for vertically unstable pelvic fractures

    Directory of Open Access Journals (Sweden)

    Vigdorchik Jonathan M

    2012-09-01

    Full Text Available Abstract Background We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX. This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model. Methods Nine synthetic pelves with a simulated anterior posterior compression type III injury were placed into three groups (External Fixator, INFIX and Internal Fixation. Displacement, total axial stiffness, and the stiffness at the pubic symphysis and SI joint were calculated. Displacement and stiffness were compared by ANOVA with a Bonferroni adjustment for multiple comparisons Results The mean displacement at the pubic symphysis was 20, 9 and 0.8 mm for external fixation, INFIX and internal fixation, respectively. Plate fixation was significantly stiffer than the INFIX and external Fixator (P = 0.01 at the symphysis pubis. The INFIX device was significantly stiffer than external fixation (P = 0.017 at the symphysis pubis. There was no significant difference in SI joint displacement between any of the groups. Conclusions Anterior plate fixation is stiffer than both the INFIX and external fixation in single stance pelvic fracture model. The INFIX was stiffer than external fixation for both overall axial stiffness, and stiffness at the pubic symphysis. Combined with the presumed benefit of minimizing the complications associated with external fixation, the INFIX may be a more preferable option for temporary anterior pelvic fixation in situations where external fixation may have otherwise been used.

  14. Biomechanical stability of a supra-acetabular pedicle screw internal fixation device (INFIX) vs external fixation and plates for vertically unstable pelvic fractures.

    Science.gov (United States)

    Vigdorchik, Jonathan M; Esquivel, Amanda O; Jin, Xin; Yang, King H; Onwudiwe, Ndidi A; Vaidya, Rahul

    2012-09-27

    We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX). This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX) and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model. Nine synthetic pelves with a simulated anterior posterior compression type III injury were placed into three groups (External Fixator, INFIX and Internal Fixation). Displacement, total axial stiffness, and the stiffness at the pubic symphysis and SI joint were calculated. Displacement and stiffness were compared by ANOVA with a Bonferroni adjustment for multiple comparisons The mean displacement at the pubic symphysis was 20, 9 and 0.8 mm for external fixation, INFIX and internal fixation, respectively. Plate fixation was significantly stiffer than the INFIX and external Fixator (P = 0.01) at the symphysis pubis. The INFIX device was significantly stiffer than external fixation (P = 0.017) at the symphysis pubis. There was no significant difference in SI joint displacement between any of the groups. Anterior plate fixation is stiffer than both the INFIX and external fixation in single stance pelvic fracture model. The INFIX was stiffer than external fixation for both overall axial stiffness, and stiffness at the pubic symphysis. Combined with the presumed benefit of minimizing the complications associated with external fixation, the INFIX may be a more preferable option for temporary anterior pelvic fixation in situations where external fixation may have otherwise been used.

  15. A comparative study in fixation methods of medial malleolus fractures between tension bands wiring and screw fixation.

    Science.gov (United States)

    Mohammed, Ayyoub A; Abbas, Khalid Ahmed; Mawlood, Ammar Salah

    2016-01-01

    The aim of this study is to compare two methods of internal fixations of fractured medial malleolus which are simple screw fixation and tension band wiring. Over 5 years we grouped 20 patients with fractured medial malleolus into two groups of operative treatments, group1 treated by malleolar screw fixation and group2 by tension band wiring. The patients were with same age group, gender, fracture type, and etiology. We use statistical analysis for make a comparative study between the two ways of surgical treatment. The mean time for radiologic bone union was 11.8 weeks in group1 patients and 9.4 weeks in group2 patients (P = 0.03). No patients had any sign of fixation failure or Kirschner wires migration. According to the modified ankle scoring system of Olerud and Molander, excellent and good results were achieved in 80 % in group1 patients and 90 % in group2 patients (P = 0.049). Tension-band wiring may be better treatment option for internal fixation of medial malleolar fractures than screw fixation. From these findings we recommend a further randomized clinical trial of larger number of cases and longer follow-up duration in order to regard tension-band wiring a better operative option for fixation of medial malleolar fractures.

  16. Noninvasive patient fixation for extracranial stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Lohr, Frank; Debus, Juergen; Frank, Claudia; Herfarth, Klaus; Pastyr, Otto; Rhein, Bernhard; Bahner, Malte L.; Schlegel, Wolfgang; Wannenmacher, Michael

    1999-01-01

    Purpose: To evaluate the setup accuracy that can be achieved with a novel noninvasive patient fixation technique based on a body cast attached to a recently developed stereotactic body frame during fractionated extracranial stereotactic radiotherapy. Methods and Materials: Thirty-one CT studies (≥ 20 slices, thickness: 3 mm) from 5 patients who were immobilized in a body cast attached to a stereotactic body frame for treatment of para medullary tumors in the thoracic or lumbar spine were evaluated with respect to setup accuracy. The immobilization device consisted of a custom-made wrap-around body cast that extended from the neck to the thighs and a separate head mask, both made from Scotchcast. Each CT study was performed immediately before or after every second or third actual treatment fraction without repositioning the patient between CT and treatment. The stereotactic localization system was mounted and the isocenter as initially located stereo tactically was marked with fiducials for each CT study. Deviation of the treated isocenter as compared to the planned position was measured in all three dimensions. Results: The immobilization device can be easily handled, attached to and removed from the stereotactic frame and thus enables treatment of multiple patients with the same stereotactic frame each day. Mean patient movements of 1.6 mm ± 1.2 mm (laterolateral [LL]), 1.4 mm ± 1.0 mm (anterior-posterior [AP]), 2.3 mm ± 1.3 mm (transversal vectorial error [VE]) and < slice thickness = 3 mm (cranio caudal [CC]) were recorded for the targets in the thoracic spine and 1.4 mm ± 1.0 mm (LL), 1.2 mm ± 0.7 mm (AP), 1.8 mm ± 1.2 mm (VE), and < 3 mm (CC) for the lumbar spine. The worst case deviation was 3.9 mm for the first patient with the target in the thoracic spine (in the LL direction). Combining those numbers (mean transversal VE for both locations and maximum CC error of 3 mm), the mean three-dimensional vectorial patient movement and thus the mean overall

  17. Which salvage fixation technique is best for the failed initial screw fixation at the cervicothoracic junction? A biomechanical comparison study.

    Science.gov (United States)

    Hong, Jae Taek; Tomoyuki, Takigawa; Jain, Ashish; Orías, Alejandro A Espinoza; Inoue, Nozomu; An, Howard S

    2017-09-01

    The pedicle screw construct is the most widely used technique for instrumentation at cervicothoracic junction (CTJ) because of its high biomechanical stability. However, we may need salvage fixation options for it as there might be a situation when pedicle screw is not available or it initially fails in order to obviate the need to instrument an additional motion segment. We aimed to evaluate the ability of using salvage screw fixations at CTJ (C7, T1, T2), when the initial fixation method fails. Fifteen fresh-frozen cadaveric specimens (C7-T2) were tested for pull-out strength (POS, N) and insertion torque (IT, Nm) of three C7 fixation techniques (lateral mass, pedicle and laminar screw) and three upper thoracic spine instrumentation (pedicle screws with straight trajectory, anatomical trajectory pedicle screws and laminar screw). Data are shown as mean ± standard deviation (SD). C7 pedicle screws generated statistically greater IT and POS than other C7 fixation techniques (P technique, there was no significant difference between laminar screw and a pedicle screw with different trajectory (P > 0.05). Laminar screws appear to provide stronger and more reproducible salvage fixation than lateral mass screws for C7 fixation, if pedicle screw should fail. If failure of initial pedicle screw is verified at the upper thoracic spine, both laminar screw and pedicle screw with different trajectory could be an option of salvage fixation. Our results suggest that pedicle screws and laminar screw similarly provide a strong fixation for salvage applications in the cervicothoracic junction.

  18. Enhancing pedicle screw fixation in the lumbar spine using allograft bone plug interference fixation.

    Science.gov (United States)

    Chrea, Bopha; Malempati, Harsha; Campbell, Jeffrey R; Khan, Sonja; Ching, Randal P; Lee, Michael J

    2014-05-01

    A within-subjects controlled laboratory study. To examine a biological alternative to cement augmentation for pedicle screw fixation comparing bilateral axial pullout tests of augmented and nonaugmented (controls) pedicle screws. Fixation in the osteoporotic spine remains a difficult challenge with failure by loosening or backout. Pedicle screw augmentation has been attempted using polymethylmethacrylate and bioabsorbable calcium cements; however, the potential for extravasation and embolization of cement are becoming increasingly concerning and merit the search for alternative methods to improve screw-anchoring strength. Twenty-four (24) fresh human lumbar vertebrae were tested to compare the pullout strength of augmented and nonaugmented pedicle screws. Two different augmentation strategies were employed using allograft bone plugs (ABPs) and evaluated using 12 specimens per group. Bone mineral density of each specimen was obtained using dual-energy x-ray absorptiometry. The augmented versus nonaugmented pedicle was randomized for each vertebra, and bilateral testing enabled paired statistical analyses. Axial pullout tests were performed using an materials testing system servohydraulic test system, and peak force, failure displacement, and stiffness was obtained for each test and correlated with bone mineral density. Augmentation using 6-mm-diameter ABPs with 6.25-mm-diameter pedicle screws resulted in statistically weaker average pullout strength (775±455 N) than the nonaugmented controls (1233±826 N). When using smaller (5 mm diameter) AGPs with the same diameter screws, there was no statistical difference between average pullout strength for the augmented pedicle screws (1772±652 N) and the nonaugmented screws (1780±575 N). Preliminary study of pedicle screw augmentation using cannulated ABPs showed no improvement of fixation with pedicles in the spine. This was even true in osteoporotic specimens, where augmentation would seem to be of considerable benefit.

  19. Engineering carbon fixation with artificial protein organelles.

    Science.gov (United States)

    Giessen, Tobias W; Silver, Pamela A

    2017-08-01

    Based on projections for global population growth, current techniques for improving agricultural yields will not be able to address future demands for major food crops. Improving photosynthetic efficiency by engineering carbon fixation has been identified as one of the most important approaches for increasing agricultural output. Recent studies indicate that introducing cyanobacterial-like carbon concentrating mechanisms (CCMs) into plant chloroplasts represents a promising strategy for enhancing plant photosynthesis. Here, we give a general outline for transferring CCMs to plants. The proposed trajectory includes introducing bicarbonate transporters and CO 2 -fixing organelles into plant chloroplasts as well as minimizing stromal carbonic anhydrase (CA) activity. We focus on different approaches for constructing compartments that co-localize the CO 2 -fixing enzyme d-ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and CA, aimed at increasing RuBisCO turnover and decreasing wasteful photorespiration. We consider strategies based on cyanobacterial carboxysomes and on other protein-based compartments, specifically encapsulin nanocompartments. Finally, recent advances in expressing catalytic and structural carboxysomal components in plants will be highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The Effect of Formaldehyde Fixation on RNA

    Science.gov (United States)

    Evers, David L.; Fowler, Carol B.; Cunningham, Brady R.; Mason, Jeffrey T.; O'Leary, Timothy J.

    2011-01-01

    Formalin-fixed, paraffin-embedded tissues generally provide low yields of extractable RNA that exhibit both covalent modification of nucleic acid bases and strand cleavage. This frustrates efforts to perform retrospective analyses of gene expression using archival tissue specimens. A variety of conditions have been reported to demodify formaldehyde-fixed RNA in different model systems. We studied the reversal of formaldehyde fixation of RNA using a 50 base RNA oligonucleotide and total cellular RNA. Formaldehyde-adducted, native, and hydrolyzed RNA species were identified by their bioanalyzer electrophoretic migration patterns and RT–quantitative PCR. Demodification conditions included temperature, time, buffer, and pH. The reversal of formaldehyde-fixed RNA to native species without apparent RNA hydrolysis was most successfully performed in dilute Tris, phosphate, or similar buffers (pH 8) at 70°C for 30 minutes. Amines were not required for efficient formaldehyde demodification. Formaldehyde-fixed RNA was more labile than native RNA to treatment with heat and buffer, suggesting that antigen retrieval methods for proteins may impede RNA hybridization or RNA extraction. Taken together, the data indicate that reliable conditions may be used to remove formaldehyde adducts from RNA to improve the quality of RNA available for molecular studies. PMID:21497290

  1. VAC® for external fixation of flail chest

    Directory of Open Access Journals (Sweden)

    Rikke Winge

    2012-06-01

    Full Text Available A large anterior 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.

  2. A new 3-dimensional head fixation device for brain imaging

    International Nuclear Information System (INIS)

    Goto, Ryoi; Kawashima, Ryuta; Yoshioka, Seiro; Ono, Shuichi; Ito, Hiroshi; Sato, Kazunori; Akaizawa, Takashi; Koyama, Masamichi; Fukuda, Hiroshi

    1995-01-01

    We have developed a new head fixation device for studies of brain function. This device was designed to immobilize subject's heads during image scanning and to precisely reproduce the head position for two different imaging modalities such as MRI and PET. The device consists of a plastic frame, a pillow filled with beads of styrene foam, and a face mask of thermoplastic resin which was originally intended for application in radiotherapy. A bridge for biting was incorporated into the mask for stable fixation. The device enables immobilization of subject's heads with good reproducibility of position at the practical level. Our results indicate that this head fixation system is useful for fixation of head during activation studies using PET. (author)

  3. Sodium Carboxymethyl Chitosan as a Fixative for Eau de Cologne

    African Journals Online (AJOL)

    chitosan) as a fixative for eau de cologne product. Methods: SCM-chitosan was prepared by carboxymethylation reaction of chitosan with monochloroacetic acid. The solubility of SCM-chitosan was investigated in water and ethanol. Sixteen ...

  4. Necrotizing fasciitis after internal fixation of fracture of femoral trochanteric ? ??

    OpenAIRE

    Santos, Leandro Em?lio Nascimento; Pires, Robinson Esteves Santos; Figueiredo, Leonardo Brand?o; Soares, Eduardo Augusto Marques

    2014-01-01

    Necrotizing fasciitis is a rare and potentially lethal soft tissue infection. We report a case of trochanteric femur fracture in a patient who underwent fracture fixation and developed necrotizing fasciitis. A literature review on the topic will be addressed.

  5. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    hole Y plates with monocortical screws. 150 N incisal occlusal loads were simulated on the models. The commercial ANSYS software was utilized to calculate the Von Mises stresses on fixative appliances. Results: The highest Von Mises stress ...

  6. Nitrogen fixation and carbon metabolism in legume nodules.

    Science.gov (United States)

    Garg, Neera; Singla, Ranju; Geetanjali

    2004-02-01

    A large amount of energy is utilized by legume nodules for the fixation of nitrogen and assimilation of fixed nitrogen (ammonia) into organic compounds. The source of energy is provided in the form of photosynthates by the host plant. Phosphoenol pyruvate carboxylase (PEPC) enzyme, which is responsible for carbon dioxide fixation in C4 and crassulacean acid metabolism plants, has also been found to play an important role in carbon metabolism in legume root nodule. PEPC-mediated CO2 fixation in nodules results in the synthesis of C4 dicarboxylic acids, viz. aspartate, malate, fumarate etc. which can be transported into bacteroids with the intervention of dicarboxylate transporter (DCT) protein. PEPC has been purified from the root nodules of few legume species. Information on the relationship between nitrogen fixation and carbon metabolism through PEPC in leguminous plants is scanty and incoherent. This review summarizes the various aspects of carbon and nitrogen metabolism in legume root nodules.

  7. Sodium Carboxymethyl Chitosan as a Fixative for Eau de Cologne ...

    African Journals Online (AJOL)

    chitosan) as a fixative for eau de cologne product. Methods: SCM-chitosan was prepared by carboxymethylation reaction of chitosan with monochloroacetic acid. The solubility of SCM-chitosan was investigated in water and ethanol. Sixteen ...

  8. 21 CFR 888.3020 - Intramedullary fixation rod.

    Science.gov (United States)

    2010-04-01

    ... of alloys such as cobalt-chromium-molybdenum and stainless steel. It is inserted into the medullary (bone marrow) canal of long bones for the fixation of fractures. (b) Classification. Class II. ...

  9. Use of 15N methodology to assess biological nitrogen fixation

    International Nuclear Information System (INIS)

    Hardarson, G.

    1990-01-01

    One of the most important characteristics of legumes are their ability in symbiosis with Rhizobium bacteria to fix atmospheric nitrogen for growth. For proper management and a full realization of the benefits of this plant-microbial association, it is necessary to estimate how much nitrogen is fixed under different conditions in the field. It is only after this is known that various factors can be manipulated so as to increase the amount and proportion of N a plant derives from biological fixation. A suitable method for accurately measuring the amount of N crops derive from fixation is therefore an important requirement in any programme aimed at maximizing biological nitrogen fixation. There are several methods available to measure N 2 fixation (Bergersen, 1980) based on (1) increment in N yield and plant growth, (2) nitrogen balance (3) acetylene reduction and (4) the use of isotopes of N. Only isotopic methods will be illustrated here. 20 refs, 2 figs, 9 tabs

  10. Gluteus Medius Repair With Double-Row Fixation

    Science.gov (United States)

    Byrd, J. W. Thomas

    2013-01-01

    The merits of double-row tendon fixation have been well defined in the shoulder and may have greater applicability for gluteus medius tears in the hip, in which protection of the repair site can be even more of a challenge because the hip is a weight-bearing extremity. A detailed technique for double-row fixation with a reliable method and implants is highlighted in the accompanying stepwise-approach video. Standard laterally based peritrochanteric portals are used, including a viewing portal posterior to the vastus lateralis ridge and a working portal distal to the ridge, with anchors placed proximally, perpendicular to the cortex of the trochanter. Proximal fixation is accomplished with double-loaded Healicoil anchors (Smith & Nephew, Andover, MA) by use of sutures placed in a mattress fashion. Distal fixation is accomplished with a Footprint anchor (Smith & Nephew) paired to each Healicoil. PMID:24265993

  11. Improving food and agricultural production. Thailand. Biological nitrogen fixation

    International Nuclear Information System (INIS)

    Bowen, G.D.

    1991-01-01

    The aim of the mission was to assist the counterpart scientists in the analysis and interpretation of data relating to nitrogen fixation studies on grain legumes. The report briefly summarizes the discussions that were held with the counterparts

  12. An indirect reduction technique for percutaneous fixation of calcaneus fractures.

    Science.gov (United States)

    Klima, Matthew; Vlasak, Richard; Sadasivan, Kalia

    2014-07-01

    We describe a positioning and indirect reduction method that allows for earlier fixation of some displaced calcaneus fractures. Minimally invasive surgery with this technique can provide good results in high-risk patients while minimizing soft-tissue complications.

  13. Low complications after minimally invasive fixation of calcaneus fracture.

    Science.gov (United States)

    Ene, R; Popescu, D; Panaitescu, C; Circota, G; Cirstoiu, M; Cirstoiu, C

    2013-03-15

    Calcaneus fractures are still a delicate point regarding the indication for osteosynthesis. Knowing the skin's poor vascularisation of the back foot, the purpose of this study is to present the benefits of proper surgical options between an open and invasive osteosynthesis with anatomical reduction and internal fixation or minimally invasive approach preserving the quality of the soft parts. 66 interventions that targeted reduction and internal fixation of calcaneus fractures were performed between 2009-2012, in the Orthopaedic and Traumatology Department of Bucharest Emergency University Hospital. 29 cases underwent open reduction and internal fixation with plates and screws or Kirschner wires, and 37 cases underwent a minimally invasive reduction and Essex Lopresti osteosynthesis technique. No patient who underwent a minimally invasive reduction had skin lesions, but showed pain due to osteoarthritis lesions that appeared in the subtalar joint. 4 of them, who underwent open reduction and internal fixation had postoperative wound infections and skin necrosis.

  14. Percutaneous reduction and fixation of intraarticular calcaneal fractures

    NARCIS (Netherlands)

    Schepers, Tim; Vogels, Lucas M. M.; Schipper, Inger B.; Patka, Peter

    2008-01-01

    Percutaneous reduction by distraction and subsequent percutaneous screw fixation to restore calcaneal and posterior talocalcaneal facet anatomy. The aim of this technique is to improve functional outcome and to diminish the rate of secondary posttraumatic arthrosis compared to conservative treatment

  15. Technique for en-masse cryo-fixation and processing of second ...

    African Journals Online (AJOL)

    The J2 juveniles were quickly immobilized and killed before fixation using the cryo-fixation technique followed by the primary fixation in 2.5% glutaraldehyde pre-cooled at 4-8°C and then secondary vapor fixation in 1% osmium tetraoxide and drying with the series of ethanol without subsequent critical point drying.

  16. The Role of Personality and Team-Based Product Dissection on Fixation Effects

    Science.gov (United States)

    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…

  17. How I improvised an external fixator to manage open fractures

    Directory of Open Access Journals (Sweden)

    Agaba Musa

    2013-05-01

    Full Text Available Orthopaedic surgery is a technical specialty. In Nigeria, as in most developing countries, insufficient funding is available for technological advancement [1]. Indigenous hospital technology can reduce cost of managing injuries needing surgery, many of which are caused by an epidemic of road traffic accidents [2]. This paper explains how to make and use an improvised external fixator for the management of open fractures and instruments used for its clinical application. This is an improved version of an earlier external fixator

  18. Nitrogen supply of crops by biological nitrogen fixation. 2

    International Nuclear Information System (INIS)

    Jensen, E.S.; Andersen, A.J.; Soerensen, H.; Thomsen, J.D.

    1985-02-01

    In the present work the contributions from combined N-sources and symbiotic nitrogen fixation to the nitrogen supply of field-grown peas and field beans were evaluated by means of 15 N fertilizer dilution. The effect of N-fertilizer, supplied at sowing and at different stages of plant development, on nitrogen fixation, yield and protein production in peas, was studied in pot experiments. (author)

  19. Gastric Band Port Site Fixation: Which Method Is Best?

    Directory of Open Access Journals (Sweden)

    Corinne E. Owers

    2015-01-01

    Full Text Available Laparoscopic adjustable gastric banding is a popular and successful bariatric surgical technique. Although short-term complications are few in number, long-term complications are more common. One such complication is flippage of the gastric band port. This study compares three popular methods of port fixation and demonstrates that fixation with nonabsorbable mesh helps to prevent port flippage when compared to other techniques, reducing the need for repositioning operations.

  20. Chemical fixation to arrest phospholipid signaling for chemical cytometry.

    Science.gov (United States)

    Proctor, Angela; Sims, Christopher E; Allbritton, Nancy L

    2017-11-10

    Chemical cytometry is a powerful tool for measuring biological processes such as enzymatic signaling at the single cell level. Among these technologies, single-cell capillary zone electrophoresis (CZE) has emerged as a powerful tool to assay a wide range of cellular metabolites. However, analysis of dynamic processes within cells remains challenging as signaling pathways are rapidly altered in response to changes in the cellular environment, including cell manipulation and storage. To address these limitations, we describe a method for chemical fixation of cells to stop the cellular reactions to preserve the integrity of key signaling molecules or reporters within the cell and to enable the cell to act as a storage reservoir for the reporter and its metabolites prior to assay by single-cell CZE. Fluorescent phosphatidylinositol 4,5-bisphosphate reporters were loaded into cells and the cells were chemically fixed and stored prior to analysis. The reporter and its metabolites were electrophoretically separated by single-cell CZE. Chemical fixation parameters such as fixative, fixation time, storage solution, storage duration, and extraction solution were optimized. When cells were loaded with a fluorescent C6- or C16-PIP 2 followed by glutaraldehyde fixation and immediate analysis, 24±2% and 139±12% of the lipid was recoverable, respectively, when compared to an unfixed control. Storage of the cells for 24h yielded recoverable lipid of 61±3% (C6-PIP 2 ) and 55±5% (C16-PIP 2 ) when compared to cells analyzed immediately after fixation. The metabolites observed with and without fixation were identical. Measurement of phospholipase C activity in single leukemic cells in response to an agonist demonstrated the capability of chemical fixation coupled to single-cell CZE to yield an accurate snapshot of cellular reactions with the probe. This methodology enables cell assay with the reporter to be separated in space and time from reporter metabolite quantification while

  1. A Novel Handmade External Fixator for Phalangeal and Metacarpal Fractures

    Directory of Open Access Journals (Sweden)

    Davod Jafari

    2016-12-01

    Full Text Available Background The value of external fixation in complex hand injuries is well established. Expenses and technical difficulties of commercial mini external fixator sets have led to the innovation of handmade external fixators. These fixators are used as versatile facilities to treat certain hand fractures. Usually, these structures are made by k-wires crossed filled with cement plastic tube. However, these fixators have multiple deficiencies that should be addressed. Objectives In this study, we described in detail the surgical technique of a handmade concrete like mini external fixator and report its clinical use and results. Methods Our handmade external fixator was applied for 52 patients with 56 fractures. Only 5% of the fractures were closed, non-comminuted extra-articular, and the other 51 fractures were more complex injuries. The mean follow up time was 9.3 months. At the end of the follow up, radiologic and functional assessment (DASH: Disability of arm, shoulder and hand and TAM: Total active motion was evaluated. Results All 56 fractures were united completely. None of the cases experienced pin loosening or reduction loss. Of the fractures, 8.9% malunited due to fracture complexity. The mean dash score was 3.76. TAM was excellent in 45% of the fractures; it was good in 7% and fair in 4%. Conclusions This type of handmade external fixator is simple, lightweight, and cheap. Furthermore, all implements are readily available in most operating fields. The probability of loosening has been greatly diminished because of the concrete like structure. Easy and fast assembly and good clinical and functional results are the other advantages of this technique. Due to the less complication and benefits, this technique could be used for many phalangeal and metacarpal fractures with confidence.

  2. Bilateral spontaneous subluxation of scleral-fixated intraocular lenses.

    Science.gov (United States)

    Assia, Ehud I; Nemet, Arie; Sachs, Dani

    2002-12-01

    Two young men with primary ectopic lenses had intracapsular cataract extraction and scleral fixation of posterior chamber intraocular lenses (PC IOLs) using 10-0 polypropylene sutures tied to the IOL eyelets. Three to 9 years after implantation, spontaneous IOL vertical subluxation occurred in all 4 eyes (5 IOL loops), probably because of suture breakage. Late subluxation of a sutured IOL may occur several years after implantation. Double fixation and thicker sutures should be considered, especially in young patients.

  3. Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System

    Science.gov (United States)

    Liu, Xin-Wei; Xu, Shuo-Gui; Zhang, Yun-Tong; Zhang, Chun-Cai

    2011-07-01

    We developed the acetabular tridimensional memoryalloy fixation system (ATMFS), which is made of NiTi shape memory alloy, according to the specific mechanical properties of biological memory material, NiTi shape memory alloy and measured distribution of contact area and pressure between the acetabulum and the femoral head of cadaveric pelvis. Seven formalin-preserved cadaveric pelves were used for this investigation. Pressure-sensitive film was used to measure contact area and pressure within the anterior, superior, and posterior regions of the acetabulum. The pelves were loaded under the following four conditions: (1) intact; (2) following a creation posterior wall fracture defect; (3) following reduction and standard internal fixation with reconstruction plate; and (4) following reduction and internal fixation with a new shape memory alloy device named ATMFS. A posterior wall fracture was created along an arc of 40° to 90° about the acetabulur rim. Creation of a posterior wall defect resulted in increased load in the superior acetabulum (1485 N) as compared to the intact condition (748 N, P = 0.009). Following reduction and internal fixation, the load distributed to the superior acetabulum (1545 N) was not statistically different from the defect condition. Following the fixation with ATMFS, the load seen at the superior region of the actabulum (964 N) was familiar with fixation with reconstruction plate and was not different from intact state ( P = 0.45). These data indicate that the use of ATMFS as a fracture internal fixation device resulted a partial restoration of joint loading parameters toward the intact state. ATMFS fixation may result in a clinical benefit.

  4. Hybrid fixation in adult osteochondritis dissecans of the knee.

    Science.gov (United States)

    Chadli, L; Steltzlen, C; Toanen, C; Boisrenoult, P; Beaufils, P; Pujol, N

    2017-11-15

    Osteochondritis dissecans progresses to osteoarthritis if integration of the fragment is not obtained. The prognosis of osteochondritis dissecans is more severe in adults, as spontaneous integration due to physeal closure does not occur. Hybrid fixation consists in combining screw fixation of the fragment with mosaicplasty through the fragment to promote integration into the native condyle. We describe this technique with reference to 17 patients. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Parametric analysis of glenoid implant design and fixation type.

    Science.gov (United States)

    Geraldes, Diogo M; Hansen, Ulrich; Amis, Andrew A

    2017-04-01

    Common post-operative problems in shoulder arthroplasty such as glenoid loosening and joint instability may be reduced by improvements in glenoid design, shape, material choice, and fixation method. A framework for parametric analysis of different implant fixation configurations was developed in order to efficiently sift through potential glenoid component designs. We investigated the influence of design factors such as fixation type, component thickness, and peg position, number, diameter, and length in a multi-factorial design investigation. The proposed method allowed for simultaneous comparison of the mechanical performance of 344 different parametric variations of 10 different reference geometries with either large central fixation features or small peripheral pegs, undergoing four different worst-case scenario loading conditions, and averaging 64.7 s per model. The impact of design parameters were assessed for different factors responsible for post-operative problems in shoulder arthroplasty, such as bone volume preservation, stresses in the implant, central displacement or fixation stability, and the worst performing geometries all relied on conventional central fixation. Of the remaining geometries, four peripheral fixation configurations produced von Mises stresses comfortably below the material's yield strength. We show that the developed method allows for simple, direct, rapid, and repeatable comparison of different design features, material choices, or fixation methods by analyzing how they influence the bone-implant mechanical environment. The proposed method can provide valuable insight in implant design optimization by screening through multiple potential design modifications at an early design evaluation stage and highlighting the best performing combinations according to the failure mechanism to mitigate. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:775-784, 2017. © 2016 Orthopaedic Research Society

  6. Fractures of the Proximal Fifth Metatarsal: Percutaneous Bicortical Fixation

    OpenAIRE

    Mahajan, Vivek; Chung, Hyun Wook; Suh, Jin Soo

    2011-01-01

    Background Displaced intraarticular zone I and displaced zone II fractures of the proximal fifth metatarsal bone are frequently complicated by delayed nonunion due to a vascular watershed. Many complications have been reported with the commonly used intramedullary screw fixation for these fractures. The optimal surgical procedure for these fractures has not been determined. All these observations led us to evaluate the effectiveness of percutaneous bicortical screw fixation for treating these...

  7. Plant densities and modulation of symbiotic nitrogen fixation in soybean

    Directory of Open Access Journals (Sweden)

    Marcos Javier de Luca

    2014-06-01

    Full Text Available Soybean nitrogen (N demands can be supplied to a large extent via biological nitrogen fixation, but the mechanisms of source/sink regulating photosynthesis/nitrogen fixation in high yielding cultivars and current crop management arrangements need to be investigated. We investigated the modulation of symbiotic nitrogen fixation in soybean [Glycine max (L. Merrill] at different plant densities. A field trial was performed in southern Brazil with six treatments, including non-inoculated controls without and with N-fertilizer, both at a density of 320,000 plants ha−1, and plants inoculated with Bradyrhizobium elkanii at four densities, ranging from 40,000 to 320,000 plants ha−1. Differences in nodulation, biomass production, N accumulation and partition were observed at stage R5, but not at stage V4, indicating that quantitative and qualitative factors (such as sunlight infrared/red ratio assume increasing importance during the later stages of plant growth. Decreases in density in the inoculated treatments stimulated photosynthesis and nitrogen fixation per plant. Similar yields were obtained at the different plant densities, with decreases only at the very low density level of 40,000 plants ha−1, which was also the only treatment to show differences in seed protein and oil contents. Results confirm a fine tuning of the mechanisms of source/sink, photosynthesis/nitrogen fixation under lower plant densities. Higher photosynthesis and nitrogen fixation rates are capable of sustaining increased plant growth.

  8. Fixation identification: the optimum threshold for a dispersion algorithm.

    Science.gov (United States)

    Blignaut, Pieter

    2009-05-01

    It is hypothesized that the number, position, size, and duration of fixations are functions of the metric used for dispersion in a dispersion-based fixation detection algorithm, as well as of the threshold value. The sensitivity of the I-DT algorithm for the various independent variables was determined through the analysis of gaze data from chess players during a memory recall experiment. A procedure was followed in which scan paths were generated at distinct intervals in a range of threshold values for each of five different metrics of dispersion. The percentage of points of regard (PORs) used, the number of fixations returned, the spatial dispersion of PORs within fixations, and the difference between the scan paths were used as indicators to determine an optimum threshold value. It was found that a fixation radius of 1 degrees provides a threshold that will ensure replicable results in terms of the number and position of fixations while utilizing about 90% of the gaze data captured.

  9. Axial loading cross screw fixation for the Austin bunionectomy.

    Science.gov (United States)

    Rigby, Ryan B; Fallat, Lawrence M; Kish, John P

    2011-01-01

    The Austin procedure has become a common method of osteotomy for the correction of hallux abductovalgus when indicated. The V-type configuration is intrinsically stable but not without complications. One complication encountered is rotation and/or displacement of the capital fragment. We present the use of an axial loading screw in conjunction with a dorsally placed compression screw. The benefit to this technique lies in the orientation of the axial loading screw, because it is directed to resist the ground reactive forces while also providing a second point of fixation in a crossing screw design. In a head-to-head biomechanical comparison, we tested single dorsal screw fixation versus double screw fixation, including both the dorsal and the axial loading screws in 10 metatarsal Sawbones(®) (Pacific Research Laboratories Inc, Vashon, WA). Five metatarsals received single dorsal screw fixation and five received the dorsal screw and the additional axial loading screw. The metatarsals were analyzed on an Instron compression device for comparison; 100% of the single screw fixation osteotomies failed with compression at an average peak load of 205 N. Four of five axial loading double screw fixation osteotomies did not fail. This finding suggests that the addition of an axial loading screw providing cross screw orientation significantly increases the stability of the Austin osteotomy, ultimately decreasing the likelihood of displacement encountered in the surgical repair of hallux abductovalgus. Copyright © 2011 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  10. [Clinical observation of dynamic cervical implant (DCI) internal fixation in the surgical treatment of cervical spondylosis].

    Science.gov (United States)

    Li, Zhong-hai; Hou, Shu-xun; Li, Li; Yu, Shun-zhi; Hou, Tie-sheng

    2014-12-01

    To investigate the early clinical effects and radiological outcome of dynamic cervical implant (DCI) internal fixation in treating cervical spondylosis, and evaluate its safety and efficiency. From June 2009 to December 2011, 19 patients with cervical spondylosis correspond to the indication of DCI internal fixation in the study, including 5 cases of cervical spondylotic myelopathy and 14 cases of cervical spondylotic radiculopathy. There were 8 males and 11 females, aged from 35 to 54 years with a mean of 43.2 years. Pathological segments included C3,4 in 1 case, C4,5 in 6, C5,6 in 6, C6,7 in 4, C3,4 and C5,6, C6,7 in 2. All patients were treated with anterior discectomy and decompression and DCI internal fixation, meanwhile, 2 cases of them with anterior cervical corpectomy and fusion plate fixation. Clinical evaluation included Modified Japanese orthopedics association (mJOA), neck disability index (NDI), visual analogue scale (VAS) score and patient satisfaction index (PSI) at pre-operation and final follow-up. Radiographic evaluation included flexion/extension lateral view at operative level and adjacent segment. The adjacent level degeneration was analyzed according to Miyazaki classification on MRI images. All patients were followed up from 12 to 42 months with an average of 19.8 months. Preoperative mJOA score was 13.6±1.1 and at final follow-up was 16.3±1.2 with improvement rate of 85.0%. Preoperative VAS,NDI was 6.6± 1.4, 17.1±7.4 and at final follow-up was 1.4±0.8, 6.1±3.9, respectively; there was statistical significance in all above-mentioned results between preoperative and final follow-up (P0.05). Preoperative DHI at operation level was (6.3±1.1) mm and final follow-up was (7.1±0.8) mm, there was statistical significance in DHI between preoperative and final follow-up (Pspondylosis with dynamic cervical implant can got satisfactory outcome in early follow-up. Activity of operative segment obtain reservation in some degree. The incidence of

  11. Evaluation of the trauma and bone metabolism after internal absorbable screw and metal screw fixation treatment of tibia-fibula fracture

    Directory of Open Access Journals (Sweden)

    Guang-Bin Yuan

    2017-03-01

    Full Text Available Objective: To study the trauma and bone metabolism after internal absorbable screw and metal screw fixation treatment of tibia-fibula fracture. Methods: 78 patients with tibia-fibula fracture who received internal fixation surgery in our hospital between May 2013 and October 2015 were selected and randomly divided into absorbable group and metal group (n=39 who accepted internal absorbable screw fixation and internal metal screw fixation respectively. 3 d after operation, serum was collected to determine the levels of inflammatory factors, pain mediators, stress hormones and bone metabolism indexes. Results: Serum inflammatory mediators procalcitonin (PCT, Resistin, C-reactive protein (CRP, interleukin-6 (IL-6, and tumor necrosis factor-α (TNF-α, pain mediators substance P (SP, prostaglandin E2 (PGE2 and NPY, stress hormones norepinephrine (NE, epinephrine (E and cortisol (Cor as well as bone resorption marker molecules C-terminal telopeptides of type I collagen (CTX-I and C-terminal telopeptides of type II collagen (CTX-II levels of absorbable group were significantly lower than those of metal group (P<0.05 while bone formation marker molecules N-MID osteocalcin (N-MID and N-terminal propeptide of procollagen type I (PINP levels were significantly higher than those of metal group (P<0.05. Conclusions: The trauma degree of internal absorbable screw fixation treatment of tibia-fibula fracture is weaker than that of internal metal screw fixation, and the bone metabolism activity is better than that of internal metal screw fixation.

  12. Fixating on metals: new insights into the role of metals in nodulation and symbiotic nitrogen fixation.

    Science.gov (United States)

    González-Guerrero, Manuel; Matthiadis, Anna; Sáez, Ángela; Long, Terri A

    2014-01-01

    Symbiotic nitrogen fixation is one of the most promising and immediate alternatives to the overuse of polluting nitrogen fertilizers for improving plant nutrition. At the core of this process are a number of metalloproteins that catalyze and provide energy for the conversion of atmospheric nitrogen to ammonia, eliminate free radicals produced by this process, and create the microaerobic conditions required by these reactions. In legumes, metal cofactors are provided to endosymbiotic rhizobia within root nodule cortical cells. However, low metal bioavailability is prevalent in most soils types, resulting in widespread plant metal deficiency and decreased nitrogen fixation capabilities. As a result, renewed efforts have been undertaken to identify the mechanisms governing metal delivery from soil to the rhizobia, and to determine how metals are used in the nodule and how they are recycled once the nodule is no longer functional. This effort is being aided by improved legume molecular biology tools (genome projects, mutant collections, and transformation methods), in addition to state-of-the-art metal visualization systems.

  13. A note on the variance of the estimate of the fixation index F

    Indian Academy of Sciences (India)

    var. (. ˆFi. ) . Our paper deals with the population as specified by formu- las (2.22) on page 65 of Weir's monograph (Weir 1996). The virtue of the resulting approximation for the estimate of var (F) we provide is a simple formula with adequate valid- ity for multiple alleles, whereas Weir does leave his reader with details to be ...

  14. A note on the variance of the estimate of the fixation index F

    Indian Academy of Sciences (India)

    gotes (h = NAa/N) and population probabilities of the two alleles as F = 1 − h. 2pq . In this formulation, F is neither a parameter nor a sample since the right hand side of the equation contains both (h being a sample statistic and 2pq a product of two parameters, q being 1 − p). In fact, in consistency with parametric forms of ...

  15. A note on the variance of the estimate of the fixation index F

    Indian Academy of Sciences (India)

    var (F) we provide is a simple formula with adequate valid- ity for multiple alleles, whereas Weir does leave his reader with details to be supplied. Our results are presented below in three different sections: the first one deals with the case of two alleles, leading natu- rally to a second section on multiple alleles; a third section.

  16. External fixation of the pelvic ring: an experimental study on the role of pin diameter, pin position, and parasymphyseal fixator pins

    NARCIS (Netherlands)

    Ponsen, Kees-Jan; Joosse, Pieter; Hoek van Dijke, Gilbert A.; Snijders, Chris J.

    2007-01-01

    BACKGROUND: The mechanical properties of current external fixator systems for unstable (type C) pelvic ring fractures are inferior to internal fixation, and are not optimal for definitive treatment. We explored methods to increase stability of external fixator constructs. METHODS: An experimental

  17. Radiological outcome of transpedicular screws fixation in the management of thoracolumbar spine injury

    International Nuclear Information System (INIS)

    Haq, M.I.U.

    2015-01-01

    Traumatic fracture of the spine is a serious neurosurgical condition that has serious impact on the patient's quality of life. Thoracolumbar junction is the most common site of spinal injuries. The aims of management of thoracolumbar spinal fractures are to restore vertebral column stability, and to obtain spinal canal decompression. This ultimately leads to early mobilization of the patients. This study was conducted to compare preoperative and post-operative vertebral height, kyphotic angle and sagittal index in patients treated with pedicle screws and rods in thoracolumbar spine fractures. Methods: This cross-sectional study was conducted in the department of Neurosurgery, Hayatabad Medical Complex, Peshawar from 1st February 2010 to 31st July 2011. A total 161 patients with unstable thoracolumber spine fracture were included in this study. In these patients fixation was done through transpedicle screws with rods. Anteroposterior and lateral views X-rays of thoraco-lumbar spine were done pre and post operatively. Results: Out of 161 patients, 109 (67.7%) were males and 52 (32.3%) females. The age of patients ranged from 20 to 70 years (mean 42.2 years) with 71 (44.1%) in the age range of 31-40 years. Preoperative average vertebral height was 9.4194 mm while postoperative average was 19.642 mm. The mean kyphosis was 23.06 degree preoperatively. Immediately after surgery the average correction of kyphosis was 9.45 degree. The pre-operative average sagittal index was 19.38 degree, which was reduced to an average 5.41 degree post operatively. Conclusions: Transpedicular fixation for unstable thoraco-lumbar spinal fractures achieves a stable fracture segment with improvement of vertebral height, kyphotic angle and sagittal index. Hence, preventing the secondary spinal deformities. (author)

  18. The emergence and early evolution of biological carbon-fixation.

    Science.gov (United States)

    Braakman, Rogier; Smith, Eric

    2012-01-01

    The fixation of CO₂ into living matter sustains all life on Earth, and embeds the biosphere within geochemistry. The six known chemical pathways used by extant organisms for this function are recognized to have overlaps, but their evolution is incompletely understood. Here we reconstruct the complete early evolutionary history of biological carbon-fixation, relating all modern pathways to a single ancestral form. We find that innovations in carbon-fixation were the foundation for most major early divergences in the tree of life. These findings are based on a novel method that fully integrates metabolic and phylogenetic constraints. Comparing gene-profiles across the metabolic cores of deep-branching organisms and requiring that they are capable of synthesizing all their biomass components leads to the surprising conclusion that the most common form for deep-branching autotrophic carbon-fixation combines two disconnected sub-networks, each supplying carbon to distinct biomass components. One of these is a linear folate-based pathway of CO₂ reduction previously only recognized as a fixation route in the complete Wood-Ljungdahl pathway, but which more generally may exclude the final step of synthesizing acetyl-CoA. Using metabolic constraints we then reconstruct a "phylometabolic" tree with a high degree of parsimony that traces the evolution of complete carbon-fixation pathways, and has a clear structure down to the root. This tree requires few instances of lateral gene transfer or convergence, and instead suggests a simple evolutionary dynamic in which all divergences have primary environmental causes. Energy optimization and oxygen toxicity are the two strongest forces of selection. The root of this tree combines the reductive citric acid cycle and the Wood-Ljungdahl pathway into a single connected network. This linked network lacks the selective optimization of modern fixation pathways but its redundancy leads to a more robust topology, making it more

  19. The emergence and early evolution of biological carbon-fixation.

    Directory of Open Access Journals (Sweden)

    Rogier Braakman

    Full Text Available The fixation of CO₂ into living matter sustains all life on Earth, and embeds the biosphere within geochemistry. The six known chemical pathways used by extant organisms for this function are recognized to have overlaps, but their evolution is incompletely understood. Here we reconstruct the complete early evolutionary history of biological carbon-fixation, relating all modern pathways to a single ancestral form. We find that innovations in carbon-fixation were the foundation for most major early divergences in the tree of life. These findings are based on a novel method that fully integrates metabolic and phylogenetic constraints. Comparing gene-profiles across the metabolic cores of deep-branching organisms and requiring that they are capable of synthesizing all their biomass components leads to the surprising conclusion that the most common form for deep-branching autotrophic carbon-fixation combines two disconnected sub-networks, each supplying carbon to distinct biomass components. One of these is a linear folate-based pathway of CO₂ reduction previously only recognized as a fixation route in the complete Wood-Ljungdahl pathway, but which more generally may exclude the final step of synthesizing acetyl-CoA. Using metabolic constraints we then reconstruct a "phylometabolic" tree with a high degree of parsimony that traces the evolution of complete carbon-fixation pathways, and has a clear structure down to the root. This tree requires few instances of lateral gene transfer or convergence, and instead suggests a simple evolutionary dynamic in which all divergences have primary environmental causes. Energy optimization and oxygen toxicity are the two strongest forces of selection. The root of this tree combines the reductive citric acid cycle and the Wood-Ljungdahl pathway into a single connected network. This linked network lacks the selective optimization of modern fixation pathways but its redundancy leads to a more robust topology

  20. Fixation instability in anisometropic children with reduced stereopsis.

    Science.gov (United States)

    Birch, Eileen E; Subramanian, Vidhya; Weakley, David R

    2013-06-01

    Hyperopic anisometropia in children can be associated with abnormal stereoacuity and "microstrabismus," a small temporalward "flick" as each eye assumes fixation on cover testing. The prevailing hypothesis is that abnormal sensory experience leads to foveal suppression and, subsequently, secondary microstrabismus. This study investigated the hypothesis that disruption of bifoveal fusion by anisometropia directly affects ocular motor function. A total of 94 children with hyperopic anisometropia (ages 5-13 years) were evaluated prospectively between June 2010 and December 2012 with the use of the Nidek MP-1 microperimeter. Fixation instability was quantified by the area of the bivariate contour ellipse that included 95% of fixation points during a 30-second test interval. Each eye movement waveform during the 30-second test interval also was examined with the use of custom software and classified as normal, fusion maldevelopment nystagmus (FMNS), or infantile nystagmus. Finally, the Randot Preschool Stereoacuity Test (Stereo Optical Company Inc, Chicago, IL) was administered. Stereoacuity was correlated with fixation instability (Spearman r = 0.50; 95% CI, 0.33-0.64); visual acuity was more weakly correlated (r = 0.28). All children with normal stereoacuity had stable fixation, children with subnormal stereoacuity had fixation instability, and those with nil stereoacuity had the most instability. Eye movement records during attempted fixation were of sufficient quality for classification in 81 children; 61% of those with reduced stereoacuity and 88% of those with nil stereoacuity had FMNS eye movement waveforms. Our data support the hypothesis that the binocular decorrelation caused by anisometropia can disrupt ocular motor development, resulting in FMNS and its temporalward refoveating "flicks" that may mimic microstrabismus. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  1. Immediate full weightbearing after percutaneous fixation of anterior column acetabulum fractures.

    Science.gov (United States)

    Kazemi, Namdar; Archdeacon, Michael T

    2012-02-01

    To present clinical, radiographic, and functional outcomes of patients allowed immediate full weightbearing after closed reduction and percutaneous fixation of anterior column component acetabulum fractures. Retrospective review. Academic Level I trauma center. Between September 2001 and December 2008, 28 patients with anterior column or anterior column posterior hemitransverse acetabulum fractures that were determined to be amenable to percutaneous fixation (at the discretion of the senior author [M.T.A.]) were selected. All patients underwent closed reduction and anterior to posterior supra-acetabular percutaneous screw fixation followed by immediate postoperative full weightbearing. Primary outcome measures included clinical, radiographic, and functional outcomes assessed with the modified Merle d'Aubigne Score and the Short Musculoskeletal Function Assessment questionnaire. Six patients were lost to follow-up (less than 1 year), and the remaining 22 (79%) had a mean follow-up of 39 months (range, 12-74 months). There were no intraoperative complications. Radiographic grades were excellent in 19 patients, good in two patients, and fair in one patient. The mean modified Merle d'Aubigné Score was 17.4 (range, 11-18). The mean Short Musculoskeletal Function Assessment function and bothersome index were 20.2 (range, 0-72.8) and 20.1 (range, 0-72.9), respectively. Clinical, radiographic, and functional outcomes of patients in this study are comparable to other reported studies. Despite an immediate full weightbearing protocol, complications, particularly poor final radiographic grade, do not appear common. The advantage of this protocol lies in the ability to immediately ambulate postoperatively with early return to work and recreation. We believe this technique is safe and offers a reasonable alternative for anterior column acetabulum fractures.

  2. A Comparison of Screw Fixation and Suture-Button Fixation in a Syndesmosis Injury in an Ankle Fracture.

    Science.gov (United States)

    Kim, Jung-Han; Gwak, Heui-Chul; Lee, Chang-Rack; Choo, Hye-Jeung; Kim, Jeon-Gyo; Kim, Dae-Yoo

    2016-01-01

    The present study compared the quality of reduction and the clinical assessment between screw fixation and suture-button fixation with an ankle fracture accompanied by syndesmosis injury. We studied the clinical and radiologic findings 1 year postoperatively through retrospective examination of 24 patients who had undergone screw fixation from January 2011 to December 2012 and prospective examination of 20 patients who had undergone suture button fixation from January 2013 to May 2014. Regarding the tibiofibular clear space, tibiofibular overlap, and medial clear space, the screw fixation group had improvement from a preoperative mean of 6.97 (range 2.79 to 15.81) mm, 4.43 (range 0 to 7.87) mm, 7.90 (range 4.24 to 19.50) mm to a postoperative mean of 4.95 (range 2.72 to 9.08) mm, 6.29 (range 0 to 10.37) mm, and 4.32 (range 1.98 to 6.57) mm, respectively. The corresponding improvement for the suture-button fixation group was from a preoperative mean of 6.65 (range 3.94 to 13.73) mm, 5.39 (range 0 to 9.44) mm, 7.27 (range 4.04 to 16.00) mm to a postoperative mean of 5.15 (range 2.93 to 7.30) mm, 7.21 (range 2.15 to 10.30) mm, and 4.25 (range 2.97 to 5.71) mm. No statistically significant difference was found between the 2 techniques. Both suture-button and metal screw fixation are effective treatment methods for an ankle fracture accompanied by syndesmosis injury. However, a long-term and prospective analysis is needed. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Fixation of revision TKA: a review of the literature.

    Science.gov (United States)

    Beckmann, J; Lüring, C; Springorum, R; Köck, F X; Grifka, J; Tingart, M

    2011-06-01

    Early aseptic loosening is a major complication in revision total knee arthroplasty (TKA). It is well accepted that intramedullary stems improve the anchoring of the prosthetic components; however, controversy still exists about the optimal fixation technique of the stems (cementless, hybrid, cemented). A literature review was carried out in the main medical databases from 1980 to 04/2010 to evaluate the available literature by evidence-based criteria and to analyse the results of the single studies regarding fixation technique in knee revision arthroplasty. There are four studies regarding the cementless fixation. Eight studies reported the hybrid technique and five studies the cemented technique. Hybrid and cemented techniques are comparable regarding the survival of arthroplasties, the rate of aseptic loosening and the clinical outcome. However, most studies just show a low level of evidence (LoE III and IV), a small to medium number of cases and a short follow-up. Based on the current literature, no final statement can be drawn regarding the optimal fixation technique in revision TKA. Future RCTs are needed to enable conclusive statements about the possible advantages and disadvantages of the single fixation techniques, although the clinical implementation often is critical.

  4. Pediatric stapedectomy: does cause of fixation affect outcomes?

    Science.gov (United States)

    Neilan, Ryan E; Zhang, Richard W; Roland, Peter S; Isaacson, Brandon; Lee, Kenneth H; Walter Kutz, J

    2013-07-01

    To compare outcomes of stapedectomy in patients with congenital stapes fixation versus juvenile otosclerosis. A retrospective chart review was performed from January 1, 1999 until January 1, 2011 to identify patients under 18 years old who underwent a stapedectomy. Age, gender, pre- and postoperative audiograms, intraoperative findings including etiology of stapes fixation, prosthesis type, and complications were recorded. Twenty-two children were identified who had undergone a stapedectomy (two patients underwent sequential bilateral surgery) resulting in a total of 24 ears. The cause of fixation included juvenile otosclerosis (n=7) and congenital stapes fixation (n=17). The overall mean pre-operative air-bone gap (ABG) was 34.7 dB (SD: 13.5) compared to a postoperative mean ABG of 9.0 (SD: 9.3) (pdiscrimination score of 80%. Pediatric stapedectomy has comparable results to stapedectomy in adults regardless of the cause of stapes fixation; however, delayed sensorineural hearing loss may be higher in the pediatric population. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Immunohistochemistry of colorectal cancer biomarker phosphorylation requires controlled tissue fixation.

    Directory of Open Access Journals (Sweden)

    Abbey P Theiss

    Full Text Available Phosphorylated signaling molecules are biomarkers of cancer pathophysiology and resistance to therapy, but because phosphoprotein analytes are often labile, poorly controlled clinical laboratory practices could prevent translation of research findings in this area from the bench to the bedside. We therefore compared multiple biomarker and phosphoprotein immunohistochemistry (IHC results in 23 clinical colorectal carcinoma samples after either a novel, rapid tissue fixation protocol or a standard tissue fixation protocol employed by clinical laboratories, and we also investigated the effect of a defined post-operative "cold" ischemia period on these IHC results. We found that a one-hour cold ischemia interval, allowed by ASCO/CAP guidelines for certain cancer biomarker assays, is highly deleterious to certain phosphoprotein analytes, specifically the phosphorylated epidermal growth factor receptor (pEGFR, but shorter ischemic intervals (less than 17 minutes facilitate preservation of phosphoproteins. Second, we found that a rapid 4-hour, two temperature, formalin fixation yielded superior staining in several cases with select markers (pEGFR, pBAD, pAKT compared to a standard overnight room temperature fixation protocol, despite taking less time. These findings indicate that the future research and clinical utilities of phosphoprotein IHC for assessing colorectal carcinoma pathophysiology absolutely depend upon attention to preanalytical factors and rigorously controlled tissue fixation protocols.

  6. Immunohistochemistry of colorectal cancer biomarker phosphorylation requires controlled tissue fixation.

    Science.gov (United States)

    Theiss, Abbey P; Chafin, David; Bauer, Daniel R; Grogan, Thomas M; Baird, Geoffrey S

    2014-01-01

    Phosphorylated signaling molecules are biomarkers of cancer pathophysiology and resistance to therapy, but because phosphoprotein analytes are often labile, poorly controlled clinical laboratory practices could prevent translation of research findings in this area from the bench to the bedside. We therefore compared multiple biomarker and phosphoprotein immunohistochemistry (IHC) results in 23 clinical colorectal carcinoma samples after either a novel, rapid tissue fixation protocol or a standard tissue fixation protocol employed by clinical laboratories, and we also investigated the effect of a defined post-operative "cold" ischemia period on these IHC results. We found that a one-hour cold ischemia interval, allowed by ASCO/CAP guidelines for certain cancer biomarker assays, is highly deleterious to certain phosphoprotein analytes, specifically the phosphorylated epidermal growth factor receptor (pEGFR), but shorter ischemic intervals (less than 17 minutes) facilitate preservation of phosphoproteins. Second, we found that a rapid 4-hour, two temperature, formalin fixation yielded superior staining in several cases with select markers (pEGFR, pBAD, pAKT) compared to a standard overnight room temperature fixation protocol, despite taking less time. These findings indicate that the future research and clinical utilities of phosphoprotein IHC for assessing colorectal carcinoma pathophysiology absolutely depend upon attention to preanalytical factors and rigorously controlled tissue fixation protocols.

  7. Invertebrate grazers affect metal/metalloid fixation during litter decomposition.

    Science.gov (United States)

    Schaller, Jörg; Brackhage, Carsten

    2015-01-01

    Plant litter and organic sediments are main sinks for metals and metalloids in aquatic ecosystems. The effect of invertebrates as key species in aquatic litter decomposition on metal/metalloid fixation by organic matter is described only for shredders, but for grazers as another important animal group less is known. Consequently, a laboratory batch experiment was conducted to examine the effect of invertebrate grazers (Lymnaea stagnalis L.) on metal/metalloid fixation/remobilization during aquatic litter decomposition. It could be shown that invertebrate grazers facilitate significantly the formation of smaller sizes of particulate organic matter (POM), as shown previously for invertebrate shredders. The metal/metalloid binding capacity of these smaller particles of POM is higher compared to leaf litter residuals. But element enrichment is not as high as shown previously for the effect by invertebrate shredders. Invertebrate grazers enhance also the mobilization of selected elements to the water, in the range also proven for invertebrate shredders but different for the different elements. Nonetheless invertebrate grazers activity during aquatic litter decomposition leads to a metal/metalloid fixation into leaf litter as part of sediment organic matter. Hence, the effect of invertebrate grazers on metal/metalloid fixation/remobilization contrasts partly with former assessments revealing the possibility of an enhanced metal/metalloid fixation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Scleral Fixation of a One-Piece Toric Intraocular lens

    Science.gov (United States)

    Emanuel, Matthew E.; Randleman, J. Bradley; Masket, Samuel

    2013-01-01

    Purpose To describe a novel technique for toric intraocular lens (IOL) repositioning and fixation in the absence of adequate capsular support Methods Case report and literature review Results Two cases are presented with scleral fixation of a one-piece toric IOL (SN6AT series, Alcon Inc.) In both cases, toric IOLs initially placed within the capsular bag became decentered due to poor capsular support and/or posterior capsule rupture. To avoid the potential complications of lens explantation and maintain the astigmatic benefits of the toric IOL, scleral fixation of the lenses was performed. The Hoffman technique was used to create reverse scleral pockets without conjunctival dissection. A 10-0 suture was used to capture and then secure the lens haptics in a lasso-type fashion. Sutures were then buried within the previously created scleral pockets. Both patients had well centered lenses postoperatively and have remained stable at last follow-up, up to thirty months postoperatively. Conclusion In the absence of adequate capsular support, scleral fixation is a viable option for one-piece toric IOL fixation to avoid IOL explanation PMID:23380416

  9. Necessity for fibular fixation associated with distal tibia fractures.

    Science.gov (United States)

    Taylor, Benjamin C; Hartley, Brandi R; Formaini, Nathan; Bramwell, Thomas J

    2015-12-01

    Intramedullary (IM) nailing is a well-accepted treatment for distal third tibia fractures in combination with injury to the fibula. However, the indications for operative stabilisation of the fibula remain controversial. The authors performed a retrospective review on a consecutive series of patients who underwent intramedullary nailing of a non-comminuted distal third tibia fracture with or without fibular fixation at a Level I urban trauma centre. A review of surgical records identified 120 patients who initially were included in this study, while a total of 98 patients who met the inclusion criteria were included in the final analysis. Our results found no difference in the mean value of coronal and sagittal plane alignment in both the immediate post-operative and follow-up time periods. We also saw no statistically significant difference when comparing malalignment between patients treated with or without fibula fixation. There were no deep infections between the two groups. No significant differences were seen between the fibular fixation group and the non-fixation group. Distal screw removal due to prominence or pain was the most common reason for future surgery in both groups. These findings suggest that the addition of fibular fixation does not affect whether or not alignment is maintained in either the immediate post-operative or short-term follow-up period. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Improvement of a popcorn population using selection indexes from a fourth cycle of recurrent selection program carried out in two different environments.

    Science.gov (United States)

    Amaral Júnior, A T; Freitas Júnior, S P; Rangel, R M; Pena, G F; Ribeiro, R M; Morais, R C; Schuelter, A R

    2010-03-02

    We estimated genetic gains for popcorn varieties using selection indexes in a fourth cycle of intrapopulation recurrent selection developed in the campus of the Universidade Estadual do Norte Fluminense. Two hundred full-sib families were obtained from the popcorn population UNB-2U of the third recurrent selection cycle. The progenies were evaluated in a randomized block design with two replications at sites in two different environments: the Colégio Estadual Agrícola Antônio Sarlo, in Campos dos Goytacazes, and the Empresa de Pesquisa Agropecuária do Estado do Rio de Janeiro (PESAGRO-RIO), in Itaocara, both in the State of Rio de Janeiro. There were significant differences between families within sets in all traits, indicating genetic variability that could be exploited in future cycles. Thirty full-sib families were selected to continue the program. The selection indexes used to predict the gains were those of Mulamba and Mock, Smith and Hazel. The best results were obtained with the Mulamba and Mock index, which allowed the prediction of negative gains for the traits number of diseased ears and ears attacked by pests, number of broken plants and lodging, as well as ears with poor husk cover. It also provided higher gains for popping expansion and grain yield than with the other indexes, giving values of 10.55 and 8.50%, respectively, based on tentatively assigned random weights.

  11. Use of tranexamic acid in dynamic hip screw plate fixation for trochanteric fractures.

    Science.gov (United States)

    Baruah, Ranjit Kumar; Borah, Pranab Jyoti; Haque, Russel

    2016-12-01

    To evaluate perioperative blood loss and blood transfusion requirement in patients who underwent dynamic hip screw plate fixation for a stable trochanteric fracture with or without preoperative intravenous tranexamic acid (TXA). 49 men and 11 women (mean age, 56.5 years) who underwent open reduction and internal fixation with a dynamic hip screw plate for a stable trochanteric fracture by a single surgeon were equally randomised to receive either a single dose of intravenous TXA (15 mg/kg) 15 minutes prior to surgery or an equal volume of normal saline by slow infusion. Intra- and post-operative blood loss and the need for blood transfusion were assessed, as was any thromboembolic adverse event. The TXA and control groups were comparable in terms of age, gender, body mass index, blood pressure, pulse rate, time from injury to surgery, operating time, and preoperative haematological data. Blood loss was lower in the TXA than control group intraoperatively (320.3 vs. 403.33 ml, ptrochanteric fractures.

  12. Browse Title Index

    African Journals Online (AJOL)

    Items 1 - 50 of 144 ... Vol 3, No 2 (2009), Effectiveness and complications of SIGN intramedullary interlocking nailing in the management of femoral and tibial fractures at Moi ... Vol 4, No 2 (2010), Factors affecting blood loss during open reduciton and internal fixation (ORIF) of isolated closed femoral fractures at Mulago ...

  13. Browse Title Index

    African Journals Online (AJOL)

    Items 51 - 100 of 256 ... ... Comparative evaluation of pin-in-fiberglass cast and Kirschner-Ehmer external fixative in the management of radius-ulna fractures in dogs, Abstract PDF ... Vol 12, No 3 (2014), Detection of IgG and/or IgM antibodies against equine infectious anaemia virus (EIAV) in Nigerian race and polo horses ...

  14. Browse Title Index

    African Journals Online (AJOL)

    Items 101 - 144 of 144 ... Vol 10, No 1 (2016), SIGN HIP construct: Achieving hip fracture fixation without using an image intensifier, Abstract PDF. BT Haonga, EN Eliezer, JE Makupa, D Shearer, MB Liu, H Wu. Vol 1, No 1 (2007), Simultaneous Open Reduction and Salter Innominate Osteotomy for Developmental Dysplasia of ...

  15. Matched-pair cohort study of 1-year patient-reported outcomes following pelvic fixation.

    Science.gov (United States)

    Kelly, Patrick D; Sivaganesan, Ahilan; Chotai, Silky; Parker, Scott L; McGirt, Matthew J; Devin, Clinton J

    2016-06-01

    Pelvic fixation improves fusion and stability for thoracolumbar constructs that extend across the L5-S1 junction. No patient-reported outcomes have been published to evaluate patients' functional outcomes following these procedures compared with pelvis-sparing procedures. The goal of this study is to identify the effect of pelvic fixation on both objective and patient-reported outcomes. This was a retrospective, matched cohort study. The sample comprised adult patients undergoing spine surgery at our institution who had complete 1-year postoperative follow-up. Patient-reported outcome instruments (Oswestry Disability Index [ODI], Short-Form 12-item survey, and EuroQol-5D) and objective measures (length of hospital stay, discharge disposition, postoperative complications, and readmission rates) were considered. We identified patients in our outcomes registry undergoing instrumented spinal fusion involving the pelvis between October 2010 and May 2014 who had 1-year follow-up data. Nearest-neighbor 1:1 matched controls were identified using propensity scoring from the cohort of patients undergoing any spinal procedure which extended caudally to the lumbar spine or sacrum. Objective and patient-reported outcomes were compared between cases and controls. There were 44 patients who underwent spinal procedures involving the pelvis and had 1-year follow-up data. An equal number of controls were identified and had similar baseline demographic and clinical characteristics. No significant differences were found among operative variables or objective complication rates. Patients undergoing pelvic fixation had moderately greater improvement at 3 months as measured by ODI, but this difference was not present at 1 year. Other patient-reported outcome measures were equivocal between groups. This matched cohort study demonstrates that inclusion of the pelvis in spinal hardware constructs is not associated with increased complications and may slightly improve patient disability at 1

  16. [Effect of iliolumbar fixation in patients with Tile C pelvic injury and analysis of relative factors].

    Science.gov (United States)

    Ge, Zhenxin; Wang, Ben; Zhang, Dongzheng; Liu, Zhaojie; Zhang, Yinguang; Jia, Jian

    2012-11-01

    To explore the relative prognostic factors of Tile C pelvic injury after iliolumbar fixation. Between March 2007 and March 2010, 60 patients with Tile C pelvic injuries were surgically treated with iliolumbar fixation, including 39 males and 21 females with an average age of 37 years (range, 17-66 years). Of them, 27 cases were classified as Tile C1, 20 as Tile C2, and 13 as Tile C3. The preoperative injury severity score (ISS) was 12-66 (mean, 29.4). The time from injury to surgery was 2-25 days (mean, 8.1 days). Iliolumbar fixation was performed in all patients. Unconditional logistic analysis was used to analyze the relationship between the age, sex, body mass index (BMI), operation opportunity, the preoperative combined injury, classification of fracture, the postoperative complication, reduction outcome, sacral nerve injury, and the time of physical exercise and the prognosis. All 60 patients were followed up 12-56 months (mean, 27.3 months). Infection of incisions occurred in 12 cases and were cured after dressing change; healing of incision by first intention was obtained in the other patients. Delay sacral nerve injury was found in 15 patients, 6 patients underwent nerve decompression, and 9 underwent conservative treatment. Ten patients had nail protrusion of Schanz screws at the posterior superior illac spine, and 3 patients had pain, which was relieved after removal of the internal fixator. One patient had bone-grafting nonunion of sacroiliac joint, which was improved by pressured bone graft. Five patients had the beam breakage without significant effect. Six patients had deep vein thrombosis, among them 4 underwent filter and 2 underwent nonsurgical treatment. The healing time of fracture was 3-6 months (mean, 3.9 months). According to the Matta function score, the results were excellent in 31 cases, good in 24 cases, fair in 3 cases, and poor in 2 cases with an excellent and good rate of 91.7% at last follow-up. Majeed score was 58-100 (mean, 86), 28

  17. The Redox Balance in Erythrocytes, Plasma, and Periosteum of Patients with Titanium Fixation of the Jaw

    Directory of Open Access Journals (Sweden)

    Jan Borys

    2017-06-01

    Full Text Available Titanium miniplates and screws are commonly used for fixation of jaw fractured or osteotomies. Despite the opinion of their biocompatibility, in clinical practice symptoms of chronic inflammation around the fixation develop in some patients, even many years after the application of miniplates and screws. The cause of these complications is still an unanswered question. Taking into account that oxidative stress is one of the toxic action of titanium, we have evaluated the antioxidant barrier as well as oxidative stress in the erythrocytes, plasma and periosteum covering the titanium fixation of the jaw. The study group was composed of 32 patients aged 20–30 with inserted miniplates and screws. The antioxidant defense: catalase (CAT, glutathione peroxidase (GPx, superoxide dismutase-1 (SOD1, uric acid (UA, total antioxidant capacity (TAC, as well as oxidative damage products: advanced oxidation protein products (AOPP, advanced glycation end products (AGE, dityrosine, kynurenine, N-formylkynurenine, tryptophan, malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, total oxidant status (TOS, and oxidative status index (OSI were evaluated. SOD1 activity (↓37%, and tryptophan levels (↓34% showed a significant decrease while AOPP (↑25%, TOS (↑80% and OSI (↑101% were significantly elevated in maxillary periosteum of patients who underwent bimaxillary osteotomies as compared to the control group. SOD-1 (↓55%, TAC (↓58.6%, AGE (↓60% and N-formylkynurenine (↓34% was statistically reduced while AOPP (↑38%, MDA (↑29%, 4-HNE (↑114%, TOS (↑99%, and OSI (↑381% were significantly higher in the mandibular periosteum covering miniplates/screw compared with the control tissues. There were no correlations between antioxidants and oxidative stress markers in the periosteum of all patients and the blood. As exposure to the Ti6Al4V titanium alloy leads to disturbances of redox balance in the periosteum surrounding titanium implants of the maxilla

  18. Buckminsterfullerenes: a non-metal system for nitrogen fixation.

    Science.gov (United States)

    Nishibayashi, Yoshiaki; Saito, Makoto; Uemura, Sakae; Takekuma, Shin-Ichi; Takekuma, Hideko; Yoshida, Zen-Ichi

    2004-03-18

    In all nitrogen-fixation processes known so far--including the industrial Haber-Bosch process, biological fixation by nitrogenase enzymes and previously described homogeneous synthetic systems--the direct transformation of the stable, inert dinitrogen molecule (N2) into ammonia (NH3) relies on the powerful redox properties of metals. Here we show that nitrogen fixation can also be achieved by using a non-metallic buckminsterfullerene (C60) molecule, in the form of a water-soluble C60:gamma-cyclodextrin (1:2) complex, and light under nitrogen at atmospheric pressure. This metal-free system efficiently fixes nitrogen under mild conditions by making use of the redox properties of the fullerene derivative.

  19. Photosynthetic and nitrogen fixation capability in several soybean mutant lines

    International Nuclear Information System (INIS)

    Gandanegara, S.; Hendratno, K.

    1987-01-01

    Photosynthetic and nitrogen fixation capability in several soybean mutant lines. A greenhouse experiment has been carried out to study photosynthetic and nitrogen fixation capability of five mutant lines and two soybean varieties. An amount of 330 uCi of 14 CO 2 was fed to the plants including of the non-fixing reference crop (Chippewa non-nodulating isoline). Nitrogen fixation measurements was carried out using 15 N isotope dilution technique according to A-value concept. Results showed that beside variety/mutant lines, plant growth also has important role in photosynthetic and N fixing capability. Better growth and a higher photosynthetic capability in Orba, mutant lines nos. 63 and 65 resulted in a greater amount of N 2 fixed (mg N/plant) than other mutant lines. (author). 12 refs.; 5 figs

  20. Assessing N2 fixation in estuarine mangrove soils

    Science.gov (United States)

    Shiau, Yo-Jin; Lin, Ming-Fen; Tan, Chen-Chung; Tian, Guanglong; Chiu, Chih-Yu

    2017-04-01

    Nitrogen (N) limited mangrove forest may have a high potential for microbial N2 fixation. Previous research has focused on soil nitrogenase activity in pristine mangrove forests with little anthropogenic impact. This research was designed to evaluate the magnitude of nitrogenase activity of mangrove soils in a high anthropogenic N-loading environment and the way in which soil N2 fixation in mangrove forest may be related to organic carbon and salinity. The test involved an acetylene reduction method under controlled laboratory conditions. The mangrove forests with high anthropogenic N loading may have high nitrogenase activity in the soils. The diazotrophs in these mangrove soils were mostly heterotrophs and the sulfate-reducing bacteria were the major N2-fixing bacteria. The nitrogenase activity was little affected by the soil salinity, which suggests that these groups of N2 fixation bacteria adapted well to saline conditions in the estuary.

  1. Potential for nitrogen fixation in fungus-growing termite symbiosis

    DEFF Research Database (Denmark)

    Sapountzis, Panagiotis; de Verges, Jane; Rousk, Kathrin

    2016-01-01

    Termites host a gut microbiota of diverse and essential symbionts that enable specialization on dead plant material; an abundant, but nutritionally imbalanced food source. To supplement the severe shortage of dietary nitrogen (N), some termite species make use of diazotrophic bacteria to fix...... atmospheric nitrogen (N2). Fungus-growing termites (subfamily Macrotermitinae) host a fungal exosymbiont (genus Termitomyces) that provides digestive services and the main food source for the termites. This has been thought to obviate the need for N2-fixation by bacterial symbionts. Here, we challenge...... this notion by performing acetylene reduction assays of live colony material to show that N2 fixation is present in two major genera (Macrotermes and Odontotermes) of fungus-growing termites. We compare and discuss fixation rates in relation to those obtained from other termites, and suggest avenues...

  2. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  3. A comparative study of internal fixation and intermaxillary fixation on bone repair of mandibular fractures through radiographic subtraction.

    Science.gov (United States)

    Queiroz, Christiano Sampaio; Sarmento, Viviane Almeida; de Azevedo, Roberto Almeida; de Oliveira, Thaís Feitosa Leitão; Bastos, Luana Costa

    2014-07-01

    Conventional radiographic evaluation of fracture healing is not a reliable method, because it depends on the examinator's experience and the quality of the exam. Therefore, serial images differing in density, contrast and geometrical projection can lead to a misdiagnosis on the postoperative fracture healing. Even in good quality images, little changes in calcified tissues often can't be visualized, because of its little sensibility and because of the limited human sight. The use of more sensitive and objective methods could increase the accuracy of this evaluation. This study intended to compare, by digitalized panoramic radiography, the mandible fracture healing after two different types of treatment: open reduction with internal fixation (group 1) and closed reduction with intermaxillary fixation (group 2). It was taken three postoperative radiographs (within a week, a month and three months after treatment), which were digitalized (600 dpi, 8 bits) and adjusted in brightness and size in Photoshop software. Then these images were evaluated by digital subtraction in ImageTool software. The results revealed greater areas of new bone formation in the internal fixation group, in all the evaluated times. Thus, open reduction with internal fixation resulted in more rapid fracture healing than closed reduction with intermaxillary fixation. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. Percutaneous reduction and screw fixation of fracture neck talus.

    Science.gov (United States)

    Abdelgaid, Sherif Mohamed; Ezzat, Farid Fouad

    2012-12-01

    Fracture neck talus is a rare fracture represents about 1% of all fractures and usually due to high energy trauma. These fractures are usually associated with compromised soft tissues, concomitant skeletal fractures, or life threatening injuries. Talus has a tenuous blood supply which is affected by fracture displacement. Urgent fracture reduction±fracture fixation is mandatory. The associated injuries may make the conventional open reduction and internal fixation is impossible to be done in urgent base as it may impacts the already tenuous blood supply of talus increasing the risk of AVN and non union. Percutaneous fracture reduction and fixation can overcome this problem, and decrease complications associated with conventional open reduction and internal fixation. Between 2006 and 2008, 16 patients with talar neck fractures were operated on by percutaneous reduction of fracture and percutaneous fixation with 3.5mm cannulated screws. Injuries were classified according to modified Hawkins classification system. Patients were followed up over an average of 48 months. 87.5% of the patients were satisfied and resumed their preoperative activities. The mean AOFAS Hind Foot Scale was 89.25 points (range: 74-100) and no poor outcomes. Although the number of patients in this study is small, the results showed that, percutaneous reduction and fixation is a good treatment modality in treatment of fracture neck talus, especially in cases with increased risk of soft tissue complications and open reduction should be resort only when percutaneous reduction was failed. Copyright © 2012 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  5. Preliminary experience with biodegradable implants for fracture fixation

    Directory of Open Access Journals (Sweden)

    Dhillon Mandeep

    2008-01-01

    Full Text Available Background: Biodegradable implants were designed to overcome the disadvantages of metal-based internal fixation devices. Although they have been in use for four decades internationally, many surgeons in India continue to be skeptical about the mechanical strength of biodegradable implants, hence this study. Materials and Methods: A prospective study was done to assess the feasibility and surgeon confidence level with biodegradable implants over a 12-month period in an Indian hospital. Fifteen fractures (intra-articular, metaphyseal or small bone fractures were fixed with biodegradable implants. The surgeries were randomly scheduled so that different surgeons with different levels of experience could use the implants for fixation. Results: Three fractures (one humeral condyle, two capitulum, were supplemented by additional K-wires fixation. Trans-articular fixator was applied in two distal radius and two pilon fractures where bio-pins alone were used. All fractures united, but in two cases the fracture displaced partially during the healing phase; one fibula due to early walking, and one radius was deemed unstable even after bio-pin and external fixator. Conclusions: Biodegradable -implants are excellent for carefully selected cases of intra-articular fractures and some small bone fractures. However, limitations for use in long bone fractures persist and no great advantage is gained if a "hybrid" composite is employed. The mechanical properties of biopins and screws in isolation are perceived to be inferior to those of conventional metal implants, leading to low confidence levels regarding the stability of reduced fractures; these implants should be used predominantly in fracture patterns in which internal fixation is subjected to minimal stress.

  6. Dinitrogen fixation by blue-green algae from paddy fields

    International Nuclear Information System (INIS)

    Thomas, Joseph

    1977-01-01

    Recent work using radioactive nitrogen on the blue-green algae of paddy fields has been reviewed. These algae fix dinitrogen and photoassimilate carbon evolving oxygen, thereby augmenting nitrogen and carbon status of the soil and also providing oxygen to the water-logged rice paddies. Further studies using radioactive isotopes 13 N, 24 Na and 22 Na on their nitrogen fixation, nitrogen assimilation pathways; regulation of nitrogenase, heterocysts production and sporulation and sodium transport and metabolism have been carried out and reported. The field application of blue green algae for N 2 fixation was found to increase the status of soil nitrogen and yield of paddy. (M.G.B.)

  7. The use of titanium and stainless steel in fracture fixation.

    Science.gov (United States)

    Hayes, J S; Richards, R G

    2010-11-01

    The use of metal in fracture fixation has demonstrated unrivalled success for many years owing to its high stiffness, strength, biological toleration and overall reliable function. The most prominent materials used are electropolished stainless steel and commercially pure titanium, along with the more recent emergence of titanium alloys. Despite the many differences between electropolished stainless steel and titanium, both materials provide a relatively predictable clinical outcome, and offer similar success for fulfilling the main biomechanical and biological requirements of fracture fixation despite distinctive differences in implant properties and biological responses. This article explores these differences by highlighting the limitations and advantages of both materials, and addresses how this translates to clinical success.

  8. Nitrogen fixation during an unusual summer Baltic Sea

    DEFF Research Database (Denmark)

    Voss, Maren; Dalsgaard, Tage; Fabian, Jenny

    Nitrogen fixation is a major nitrogen source for the open ocean. Also the land-locked, partly anoxic Baltic Sea receives almost as much nitrogen from nitrogen fixation as it receives from eutrophied rivers. Growth conditions for cyanobacteria are usually very favorable with low N/P ratios after...... winter mixing and a strong stratification and high surface temperatures in summer. However, the summer 2012 was quite different with strong winds and cold surface waters. Blooms of cyanobacteria therefore only developed in sheltered regions but not in the central Baltic Proper. Moreover, a greater...

  9. Biological dinitrogen fixation and its economical importance for agriculture

    International Nuclear Information System (INIS)

    Ozbek, N.; Halitligil, M.B.; Korkmaz, A.

    1985-01-01

    The measurement of biological N 2 fixation is of considerable importance and recently AN values of the legume and non-nodulating crop using 1 5N labelled fertilizer were used extensively to estimate the amount of N 2 fixed legume crop growing under field conditions. The objective of this research was to estimate biological N 2 fixation under field conditions using 1 5N labelled fertilizer and growing Calland soybean and corn as the test plants. A field experiment was conducted at Cukurova (Adana) using randomized block design and 4 replications for each treatment. For the both crops 4 nitrogen rates and for soybean 4 inoculation rates were applied. (author)

  10. Aging and the control of binocular fixations during reading.

    Science.gov (United States)

    Paterson, Kevin B; McGowan, Victoria A; Jordan, Timothy R

    2013-09-01

    Older adults (65 + years) often have greater difficulty in reading than young adults (18-30 years). However, the extent to which this difficulty is attributable to impaired eye-movement control is uncertain. To address this issue, the alignment and location of the two eyes' fixations during reading were monitored for young and older adults. Older adults showed typical patterns of reading difficulty but the results revealed no age differences in the alignment or location of the two eyes' fixations. Thus, the difficulty older adults experience in reading is not related to oculomotor control, which appears to be preserved into older age.

  11. The Importance of "What": Infants Use Featural Information to Index Events

    Science.gov (United States)

    Kirkham, Natasha Z.; Richardson, Daniel C.; Wu, Rachel; Johnson, Scott P.

    2012-01-01

    Dynamic spatial indexing is the ability to encode, remember, and track the location of complex events. For example, in a previous study, 6-month-old infants were familiarized to a toy making a particular sound in a particular location, and later they fixated that empty location when they heard the sound presented alone ("Journal of Experimental…

  12. EJSCREEN Indexes 2015 Public

    Data.gov (United States)

    U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are eight EJ Indexes in EJSCREEN reflecting the 8 environmental indicators. The EJ Index names are:...

  13. EJSCREEN Indexes 2016 Public

    Data.gov (United States)

    U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are eleven EJ Indexes in EJSCREEN reflecting the 11 environmental indicators. The EJ Index names are:...

  14. Centre-of-Gravity Fixations in Visual Search: When Looking at Nothing Helps to Find Something

    Directory of Open Access Journals (Sweden)

    Dustin Venini

    2014-01-01

    Full Text Available In visual search, some fixations are made between stimuli on empty regions, commonly referred to as “centre-of-gravity” fixations (henceforth: COG fixations. Previous studies have shown that observers with task expertise show more COG fixations than novices. This led to the view that COG fixations reflect simultaneous encoding of multiple stimuli, allowing more efficient processing of task-related items. The present study tested whether COG fixations also aid performance in visual search tasks with unfamiliar and abstract stimuli. Moreover, to provide evidence for the multiple-item processing view, we analysed the effects of COG fixations on the number and dwell times of stimulus fixations. The results showed that (1 search efficiency increased with increasing COG fixations even in search for unfamiliar stimuli and in the absence of special higher-order skills, (2 COG fixations reliably reduced the number of stimulus fixations and their dwell times, indicating processing of multiple distractors, and (3 the proportion of COG fixations was dynamically adapted to potential information gain of COG locations. A second experiment showed that COG fixations are diminished when stimulus positions unpredictably vary across trials. Together, the results support the multiple-item processing view, which has important implications for current theories of visual search.

  15. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    International Nuclear Information System (INIS)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline; Hauger, Olivier; Marcy, Pierre-Yves; Boileau, Pascal

    2012-01-01

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements ± SD decreased from 7.8 ± 0.9 preoperatively to 1.5 ± 1.1 at the last 2-year follow-up, and from 62.3 ± 17.2 to 15.1 ± 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  16. Computed tomography- and fluoroscopy-guided percutaneous screw fixation of low-grade isthmic spondylolisthesis in adults: a new technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Browaeys, Patrick; Nouri, Yasir; Ibba, Caroline [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Radiology, Nice (France); Hauger, Olivier [Hopital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Bordeaux (France); Marcy, Pierre-Yves [Antoine Lacassagne Cancer Research Institute, Department of Radiology, Nice (France); Boileau, Pascal [Hopital Archet 2, Centre Hospitalo-Universitaire de Nice, Department of Orthopedic Surgery, Nice (France)

    2012-12-15

    To evaluate the feasibility of computed tomography (CT)- and fluoroscopy-guided percutaneous screw fixation for the treatment of low-grade isthmic spondylolisthesis in adults. Ten consecutive adult patients (four men and six women; mean age: 57.1 [range, 44-78 years]) were prospectively treated by percutaneous screw fixation for low-grade (six grade 1 and four grade 2) isthmic spondylolisthesis of L5. For each patient, two 4.0-mm Asnis III cannulated screws were placed to fix the pars interarticularis defects. All procedures were performed under local anaesthesia by using CT and fluoroscopy guidance. Post-operative outcome was assessed using the visual analogue scale and Oswestry Disability Index (ODI) scores. The procedure time ranged from 45 to 60 min. The mean screw length was 27 mm (range, 24-32 mm). The VAS and ODI measurements {+-} SD decreased from 7.8 {+-} 0.9 preoperatively to 1.5 {+-} 1.1 at the last 2-year follow-up, and from 62.3 {+-} 17.2 to 15.1 {+-} 6.0, respectively (P < 0.001 in both cases). Neither slip progression nor screw failure was noted. This feasibility study showed that CT- and fluoroscopy-guided percutaneous screw fixation could be a rapid, safe and effective method of treating low-grade isthmic spondylolisthesis. (orig.)

  17. A cell shrinkage artefact in growth plate chondrocytes with common fixative solutions: importance of fixative osmolarity for maintaining morphology

    Directory of Open Access Journals (Sweden)

    MY Loqman

    2010-05-01

    Full Text Available The remarkable increase in chondrocyte volume is a major determinant in the longitudinal growth of mammalian bones. To permit a detailed morphological study of hypertrophic chondrocytes using standard histological techniques, the preservation of normal chondrocyte morphology is essential. We noticed that during fixation of growth plates with conventional fixative solutions, there was a marked morphological (shrinkage artifact, and we postulated that this arose from the hyper-osmotic nature of these solutions. To test this, we fixed proximal tibia growth plates of 7-day-old rat bones in either (a paraformaldehyde (PFA; 4%, (b glutaraldehyde (GA; 2% with PFA (2% with ruthenium hexamine trichloride (RHT; 0.7%, (c GA (2% with RHT (0.7%, or (d GA (1.3% with RHT (0.5% and osmolarity adjusted to a ‘physiological’ level of ~280mOsm. Using conventional histological methods, confocal microscopy, and image analysis on fluorescently-labelled fixed and living chondrocytes, we then quantified the extent of cell shrinkage and volume change. Our data showed that the high osmolarity of conventional fixatives caused a shrinkage artefact to chondrocytes. This was particularly evident when whole bones were fixed, but could be markedly reduced if bones were sagittally bisected prior to fixation. The shrinkage artefact could be avoided by adjusting the osmolarity of the fixatives to the osmotic pressure of normal extracellular fluids (~280mOsm. These results emphasize the importance of fixative osmolarity, in order to accurately preserve the normal volume/morphology of cells within tissues.

  18. [Three-dimensional finite element investigation of lateral mass screw fixation and transarticular screw fixation in lower cervical spine].

    Science.gov (United States)

    Duan, Yang; Jin, Anmin; Zhang, Hui; Min, Shaoxiong; Hu, Konghe

    2010-12-01

    To establish sophisticated three-dimensional finite element model of the lower cervical spine and reconstruct lower cervical model by different fixation systems after three-column injury, and to research the stress distribution of the internal fixation reconstructed by different techniques. The CT scan deta were obtained from a 27-year-old normal male volunteer. Mimics 10.01, Geomagic Studio10.0, HyperMesh10.0, and Abaqus 6.9.1 softwares were used to obtain the intact model (C3-7), the model after three-column injury, and the models of reconstructing the lower cervical spine after three-column injury through different fixation systems, namely lateral mass screw fixation (LSF) and transarticular screw fixation (TSF). The skull load of 75 N and torsion preload of 1.0 N*m were simulated on the surface of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity of internal fixation system was evaluated. The intact model of C3-7 was successfully established, which consisted of 177 944 elements and 35 668 nodes. The results of the biomechanic study agreed well with the available cadaveric experimental data, suggesting that they were accord with normal human body parameters and could be used in the experimental research. The finite element models of the lower cervical spine reconstruction after three-column injury were established. The stress concentrated on the connection between rod and screw in LSF and on the middle part of screw in TSF. The peak values of Von Mises stress in TSF were higher than those in LSF under all conditions. For the reconstruction of lower cervical spine, TSF has higher risk of screw breakage than LSF.

  19. Effect of mid-frequency pulse therapy combined with external fixation on bone metabolism, inflammatory response and oxidative stress in patients with osteoporotic distal radial fractures

    Directory of Open Access Journals (Sweden)

    Bao-Ning Luo

    2017-09-01

    Full Text Available Objective: To study the effect of mid-frequency pulse therapy combined with external fixation on bone metabolism, inflammatory response and oxidative stress in patients with osteoporotic distal radial fractures. Methods: A total of 72 patients with osteoporotic distal radial fractures who were treated in the hospital between September 2015 and January 2017 were collected and divided into control group (n=36 and observation group (n=36 according to the random number table method. Control group received routine external fixation, and observation group received mid-frequency pulse therapy combined with external fixation. The differences in serum levels of bone metabolism indexes, inflammatory factors and oxidative stress indexes were compared between two groups of patients before and after treatment. Results: Before treatment, differences in serum levels of bone metabolism indexes, inflammatory factors and oxidative stress indexes were not statistically significant between the two groups. After 1 month of treatment, serum BGP, TAC and SOD levels of both groups of patients were higher than those before treatment while β-CTX, AKP, TRAP, CRP, IL-1β, IL-6 and MDA levels were lower than those before treatment, and serum BGP, TAC and SOD levels of observation group were higher than those of control group while β-CTX, AKP, TRAP, CRP, IL-1β, IL-6 and MDA levels were lower than those of control group. Conclusion: Mid-frequency pulse therapy combined with external fixation can promote fracture healing and reduce postoperative inflammatory response and oxidative stress response in patients with osteoporotic distal radial fracture.

  20. [Comparison of vacuum bag fixation and Orfit rack with thermoplastic membrane fixation for image-guided cervical cancer radiotherapy].

    Science.gov (United States)

    Li, Y B; Wang, Y L; Zhuo, Y H

    2017-06-23

    Objective: To compare the difference of displacement between the vacuum bag fixation and the Orfit rack with thermoplastic membrane fixation of the cervical cancer patients, and to explore the individual fixation of the patients. Methods: We retrospectively analyzed the clinical data of 66 patients diagnosed as cervical cancer in Zhangzhou Municipal Hospital of Fujian Province from December 2014 to April 2016. Among them, 33 patients were fixed with vacuum bag, 33 patients were fixed with the Orfit rack with thermoplastic membrane. The cone-beam computed tomography (CBCT) images were acquired daily for the first three times of the radiotherapy, followed by once every other day for a total of 15 times. The CBCT scan images were matched with the CT scan images, and the matching results were recorded and analyzed. Results: The absolute value of the displacement in the left and right directions of the vacuum bag group was (0.28±0.30) cm, significantly lower than (0.38±0.46) cm in the Orfit rack with thermoplastic membrane group( P vacuum bag group was (0.28±0.32) cm, with no significant difference of (0.27±0.23) cm in the Orfit rack with thermoplastic membrane group ( P =0.580). The absolute value of the displacement in the up and down directions was (0.33±0.60) cm, with no statistically significant difference of (0.27±0.48) cm in the Orfit rack with thermoplastic membrane group ( P =0.150). During the three times of CBCT scans, the differences of displacement in the left and right directions of the vacuum bag group were negligible, while apparently varied in the anteroposterior and up and down directions, however, the differences were not statistically significant ( P >0.05). The change of the displacement in the three-dimensional direction in the Orfit rack with thermoplastic membrane group was marginal, and all of the differences were not significant(all P >0.05). Conclusions: Both the vacuum bag fixation and the Orfit rack with thermoplastic membrane fixation

  1. [Journal selection and indexing for Index Medicus and Chinese periodicals indexed in Index Medicus].

    Science.gov (United States)

    Zhou, Qing-Hui; Ling, Chang-Quan; Bai, Yu-Jin; Yin, Hui-Xia

    2005-01-01

    Index Medicus/MEDLINE/PubMed published by U. S. National Library of Medicine (NLM) is the most important and commonly used biomedical literature retrieval system in the world. According to the"List of Journals Indexed in Index Medicus (2004)", 4,098 journals are indexed for Index Medicus, including 70 journals from mainland China and Hong Kong and 9 journals from Taiwan. Journal of Chinese Integrative Medicine established in May, 2003 is indexed in Index Medicus in 2004. This article outlines the critical elements of journal selection for Index Medicus/MEDLINE and the journal selection process for indexing at NLM, and introduces some measures for the Journal of Chinese Integrative Medicine being indexed in Index Medicus/MEDLINE.

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

    Directory of Open Access Journals (Sweden)

    Guo-Chun Zha

    2015-01-01

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

  3. The treatment of distal third humeral diaphyseal fractures: Is there still a place for the external fixation?

    Science.gov (United States)

    Tartaglia, N; Vicenti, G; Carrozzo, M; Abate, A; Rifino, F; Picca, G; Solarino, G; Moretti, B

    2016-12-01

    The treatment for humeral diaphyseal fractures is still controversial. The purpose of this study was to evaluate the clinical and radiographic outcomes of treating humeral distal third diaphyseal fractures by using external fixation technique. We retrospectively review 65 cases of diaphyseal humeral fractures (31 type A, 23 type B and 11 type C of the AO/OTA classification) treated with external fixation (Orthofix FAD small) between 2008 and 2013. The mean follow-up was 48 months (24-72 months). There were 12 open fractures; however, no cases of concomitant vascular injury were described. The transolecranic traction was always applied to promote partial reduction through ligamentotaxis. In case of interposition of soft tissues impeding reduction, a small incision was performed allowing mobilization of bone ends. All fractures resulted healed at a mean of 11 weeks (range 9-13 weeks); the average time of removal of the external fixator was 88 days (range 65-95 days). At the last follow-up, the mean elbow flexion was 132.6° (Min 126°-Max 137°) and the mean elbow extension was 6.4° (Max 0°-Min 13°). The Cassebaum's index rated as excellent in 47.8 % (31 patients), good in 37 % (24 patients), fair in 9.2 % (6 patients) and poor in 6 % (4 patients). The mean DASH score at the final follow-up was 14.7 (range 0-33); 15 patients had a range score between 10 and 20, 43 had less than 10, and seven had more than 20. We observed three cases of superficial infections and two cases of acute radial nerve palsy recovered within 3 months. According to the excellent clinical results and full rate of consolidation, we state external fixation as a valid option in the treatment of distal third humeral diaphyseal fractures.

  4. [Effectiveness of U-shape titanium screw-rod fixation system with bone autografting for lumbar spondylolysis of young adults].

    Science.gov (United States)

    Pu, Xiaobing; Yang, Shuangshi; Cao, Haiquan; Jing, Xingquan; Yin, Jun

    2014-03-01

    To investigate the effectiveness of U-shape titanium screw-rod fixation system with bone autografting for lumbar spondylolysis of young adults. Between January 2008 and December 2011, 32 patients with lumbar spondylolysis underwent U-shape titanium screw-rod fixation system with bone autografting. All patients were male with an average age of 22 years (range, 19-32 years). The disease duration ranged from 3 to 24 months (mean, 14 months). L3 was involved in spondylolysis in 2 cases, L4 in 10 cases, and L5 in 20 cases. The preoperative visual analogue scale (VAS) and Oswestry disability index (ODI) scores were 8.0 +/- 1.1 and 75.3 +/- 11.2, respectively. The operation time was 80-120 minutes (mean, 85 minutes), and the blood loss was 150-250 mL (mean, 210 mL). Primary healing of incision was obtained in all patients without complications of infection and nerve symptom. Thirty-two patients were followed up 12-24 months (mean, 14 months). Low back pain was significantly alleviated after operation. The VAS and ODI scores at 3 months after operation were 1.0 +/- 0.5 and 17.6 +/- 3.4, respectively, showing significant differences when compared with preoperative ones (t = 30.523, P = 0.000; t = 45.312, P = 0.000). X-ray films and CT showed bone fusion in the area of isthmus defects, with the bone fusion time of 6-12 months (mean, 9 months). During follow-up, no secondary lumbar spondyloly, adjacent segment degeneration, or loosening or breaking of internal fixator was found. The U-shape titanium screw-rod fixation system with bone autografting is a reliable treatment for lumbar spondylolysis of young adults because of a high fusion rate, minimal invasive, and maximum retention of lumbar range of motion.

  5. Complications of internal fixation of maxillofacial fractures with microplates

    NARCIS (Netherlands)

    Schortinghuis, J; Bos, RRM; Vissink, A

    Purpose: The aim of this retrospective study was to evaluate the complications of open reduction and internal fixation of maxillofacial fractures with microplates. Patients and Methods: In 44 patients with maxillofacial trauma, fractures of the maxillofacial skeleton were treated by open reduction

  6. Resorbable screws for fixation of autologous bone grafts

    NARCIS (Netherlands)

    Raghoebar, GM; Liem, RSB; Bos, RRM; van der Wal, JE; Vissink, A

    The aim of this study was to evaluate the suitability of resorbable screws made of poly (D,L-lactide) acid (PDLLA) for fixation of autologous bone grafts related to graft regeneration and osseointegration of dental implants. In eight edentulous patients suffering from insufficient retention of their

  7. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    fast bone healing, to avoid postoperative intermaxillary fixation, and to initiate early postoperative mandibular function and oral hygiene. Postoperative skeletal ..... torsion on the condyle, and less risk of inferior alveolar nerve injury. It is particularly advantageous in larger advancements where proximal and distal overlap is ...

  8. The clinical outcome of lateral mass fixation after decompressive ...

    African Journals Online (AJOL)

    Lateral mass cervical fixation is the technique of choice for posterior cervical stabilization of the lower cervical spine in the cases of cervical spondylotic myelopathy. It is used for patients who had extensive, multiple-level laminectomies with reversed cervical lordosis. Objective: The aim of this study was to evaluate the ...

  9. Intramedullary fixation of boxer's fractures: evaluation of functional ...

    African Journals Online (AJOL)

    Material and methods: Between May 2005 and January 2006, 42 patients (40 men and 02 female) with 42 displaced fifth metacarpal neck fractures were treated at out institution by closed intramedullary Kirschner wires fixation. The assessment of patients was based on the time to union, the functional recovery and the ...

  10. Ad gist : Ad communication in a single eye fixation

    NARCIS (Netherlands)

    Pieters, R.; Wedel, M.

    2012-01-01

    Most ads in practice receive no more than a single eye fixation. This study investigates the limits of what ads can communicate under such adverse exposure conditions. We find that consumers already know at maximum levels of accuracy and with high degree of certainty whether something is an ad or is

  11. SIGN HIP construct: Achieving hip fracture fixation without using an ...

    African Journals Online (AJOL)

    At the 6 week follow-up, there was 1 (1.5%) case of infection and 8 (11.8%) cases of varus collapse. Conclusion: Using the SIGN Hip Construct, hip fracture fixation can be achieved safely without an image intensifier. This implant may be a good alternative in developing countries where access to fluoroscopy is limited or ...

  12. Nitrogen fixation and nitrogenase activity of Azotobacter chroococcum

    NARCIS (Netherlands)

    Brotonegoro, S.

    1974-01-01

    The purpose of the present investigation was to study the effect of some chemical, physical and biological factors on growth, efficiency of nitrogen fixation and nitrogenase activity of Azotobacter chroococcum.

    From biochemical studies with cell-free

  13. Idea representation and elaboration in design inspiration and fixation experiments

    NARCIS (Netherlands)

    Vasconcelos, Luis A.; Neroni, Maria A.; Coimbra Cardoso, C.M.; Crilly, Nathan

    2018-01-01

    Design fixation experiments often report that participants exposed to an example solution generate fewer ideas than those who were not. This reduced ‘idea fluency’ is generally explained as participants’ creativity being constrained by the example they have seen. However, the inclusion of an example

  14. Bone compaction enhances fixation of weightbearing titanium implants

    DEFF Research Database (Denmark)

    Kold, Søren Vedding; Rahbek, Ole; Vestermark, Marianne Toft

    2005-01-01

    are weightbearing, the effects of compaction on weightbearing implants were examined. The hypothesis was that compaction would increase implant fixation compared with conventional drilling. Porous-coated titanium implants were inserted bilaterally into the weightbearing portion of the femoral condyles of dogs...

  15. [Complex reconstruction with internal locking plate fixation for Charcot arthropathy].

    Science.gov (United States)

    Ramadani, F; Härägus, H; Radu, P; Trieb, K; Hofstaetter, S

    2015-01-01

    Osteosynthesis and reposition of the Charcot foot is challenging with respect to choice of a proper implant. There is currently no international consensus regarding the optimal implant. Locking plates seem to be an innovative and stable method for reconstruction. The aim of this work is to analyze bone fusion, complications, pseudoarthrosis, and patient satisfaction. This paper presents a retrospective analysis of 63 consecutive Charcot feet treated between 2004 and 2014. The mean follow-up time was 2.4 years. All Charcot feet treated between 2004 and 2014 were Sanders type II or III. A bony fusion was achieved in 50 % of the cases, 26 % had a functional pseudoarthrosis with intact implants and pain-free mobility, and 22 % showed no healing with broken implants. Conclusion Internal fixation with locking plates is superior to screw fixation only with regard to biomechanics. We prefer internal fixation plates to external fixation because of stability even in the case of pseudoathrosis and because of the learning curve.

  16. Biological nitrogen fixation in Crotalaria species estimated using the ...

    African Journals Online (AJOL)

    A greenhouse experiment was conducted to measure nitrogen fixation in three Crotalaria species : C. ochroleuca, C. perrottetii and C. retusa growing in Senegal by using 15N direct isotope dilution technique. Two non-fixing plants, Senna obtusifolia and Senna occidentalis served as reference plants. The amount of ...

  17. Ender’s Nail fixation in paediatric femoral shaft fractures.

    Directory of Open Access Journals (Sweden)

    Rajeev Dwivedi

    2013-12-01

    Flynn criteria 34 had excellent and 6 had satisfactory results. No poor results were seen. Conclusion: Ender’s nail fixation can be preferred method of treatment for femoral shaft fractures in age group 5 -15 years as the results are excellent and satisfactory. It is technically simple and can be done in a closed manner. It spares the vascularity and growth plate.

  18. Evaluation of potassium release and fixation behaviour of some ...

    African Journals Online (AJOL)

    28.14 cmol kg-1) than under “wet-and-dry”-condition (5.63-14.33 cmol kg-1), representing 24.60-56.28% and 11.26-28.66% of fertilizer-K added. The fixation data obtained under “wet-and-dry”-condition, however, reflected K dynamics is the soils ...

  19. Percutaneous Pin Fixation of Gartland Type I11 Supraconylar ...

    African Journals Online (AJOL)

    This was a prospective study of 40 children with severely displaced (Gartland Type 111) supracondylar fractures of the humerus treated by lateral percutaneous pin fixation together with a 'figure of eight' plaster casting. Their mean age was 6.9 years, the mean follow up was 2 years/. Eighteen (45%) of the patients had ...

  20. Estimates of biological nitrogen fixation by Pterocarpus lucens in a ...

    African Journals Online (AJOL)

    Nitrogen (N2) fixation by Pterocarpus lucens in a natural semi arid ecosystem, in Ferlo, Senegal was estimated using 15N natural abundance (15N) procedure. Other non-fixing trees accompanying P. lucens in the same area were also investigated as control. Results showed an important variation of 15N in leaves between ...

  1. Nodulation and nitrogen fixation in common bean (Phaseolus vulgaris)

    African Journals Online (AJOL)

    Mamadou Gueye

    Nodulation and nitrogen fixation of field grown common bean (Phaseolus vulgaris) as influenced by fungicide seed treatment. Ndeye Fatou Diaw GUENE, Adama DIOUF and Mamadou GUEYE*. MIRCEN/ Laboratoire commun de microbiologie IRD-ISRA-UCAD, BP 1386, DAKAR, Senegal. Accepted 23 June 2003.

  2. Eco-physiological responses and symbiotic nitrogen fixation ...

    African Journals Online (AJOL)

    Administrator

    2010-11-01

    Nov 1, 2010 ... Nitrogen nutrition of Hedysarum carnosum, a pastoral legume common in Tunisian central and southern rangelands ... Despite the fact that Na+ accumulation decreased plant growth, both nodulation and symbiotic nitrogen fixation capacity of H. ... of the symbiotic interaction as well as nodule development.

  3. Percutaneous Pin Fixation of Gartland Type I11 Supraconylar ...

    African Journals Online (AJOL)

    S G Lungu M.Med (Orth). Specialist Orthopaedic Surgeon. Zambian Italian Orthopaedic Hospital, Lusaka. Key words: Percutaneous, pin fixation, Gartland type Ill, supracondylar, fractures, and humerus. This was a prospective study of 40 children with severely displaced (Gartland Type 111) supracondylar fractures of the ...

  4. Comparison of internal fixation techniques in metacarpal fractures.

    Science.gov (United States)

    Black, D; Mann, R J; Constine, R; Daniels, A U

    1985-07-01

    A biomechanical study assessed quantitative differences in the stability that was obtained by five commonly used types of internal fixation employed in metacarpal fractures. The techniques included dorsal plating, dorsal plating combined with an interfragmentary lag screw, crossed Kirschner wires, a single intraosseous wire combined with a single oblique Kirschner wire, and a single intraosseous wire alone. Rigidity and strength in torsion and bending were determined after transverse osteotomy and fixation of the metacarpal were performed. The failure modes for each fixation technique were also observed and described. Significant differences in rigidity were found between the plated configurations (with or without an interfragmentary lag screw) and the wired configurations in both apex dorsal bending and axial torsion. The three wired configurations were not significantly different from each other except in torsion. Analysis of the bending moments that were required to produce both yield and failure in apex dorsal bending and also the energy absorbed to yield showed similar disparity between plated and wired techniques. For metacarpal fixation, dorsal plating with or without lag screws provides significantly more stability than do wired techniques and approaches that provided by intact bones.

  5. Carbon dioxide fixation by cells of Streptococcus faecalis var. liquefaciens.

    Science.gov (United States)

    Goff, R C; Hartman, R E

    1970-10-01

    Fixation of NaH(14)CO(3) by a heavy cell suspension of Streptococcus faecalis var. liquefaciens was studied. Several nutrients, pyridoxal, riboflavine, adenine, uracil, and O(2) stimulated (14)CO(2) incorporation into cells only under conditions that were adequate for synthesis of cell macromolecules. Biotin increased CO(2) incorporation in the absence of extensive synthesis of macromolecules, whereas O(2) inhibited incorporation under these conditions. When (14)CO(2) fixation was occurring during synthesis of macromolecules, 71% of the (14)C was incorporated into cells and 29% occurred extracellularly. Ninety-three per cent of the cellular (14)C was in protein and 5.5% was in nucleic acid. Aspartic acid was the only amino acid in the protein fraction that was radioactive. Eighty-three per cent of the extracellular (14)C was resistant to precipitation by trichloroacetic acid. When (14)CO(2) fixation was occurring in cells that were not carrying on extensive synthesis of macromolecules, 38% of the (14)C was incorporated into cells and 59% occurred in the supernatant fluid. Sixty-nine per cent of the cellular (14)C was in protein, 21% was in low-molecular-weight compounds, and 9% was in nucleic acid. Addition of unlabeled aspartate to the medium inhibited incorporation of (14)CO(2). Based on studies of the rate of (14)CO(2) fixation, the cells fix CO(2) into a pool of intermediates which are either used for synthesis, primarily protein, or are excreted into the medium.

  6. Role of symbiotic nitrogen fixation in the improvement of legume ...

    African Journals Online (AJOL)

    Role of symbiotic nitrogen fixation in the improvement of legume productivity under stressed environments. R Serraj, J Adu-Gyamfi. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/wajae.v6i1.45613.

  7. N-2 fixation by non-heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bergman, B.; Gallon, J.R.; Rai, A.N.; Stal, L.J.

    1997-01-01

    Many, though not all, non-heterocystous cyanobacteria can fix N-2. However, very few strains can fix N-2 aerobically. Nevertheless, these organisms may make a substantial contribution to the global nitrogen cycle. In this general review, N-2 fixation by laboratory cultures and natural populations of

  8. Nitrogen fixation and nodulation of soybean as affected by rhizobial ...

    African Journals Online (AJOL)

    The study evaluated the efficacy of different adhesives added to rhizobial seed inoculum on soybean nodulation and biological nitrogen fixation in a screen house and under field conditions. The experiment was a 6×3 factorial arranged in Completely Randomized Design and Randomized Complete Block Design for the pot ...

  9. Results of Lateral Condylar Blade Plate Fixation of Supracondylar ...

    African Journals Online (AJOL)

    Background: The concerns about operative stabilization of supracondylar femoral fractures are complications, especially hardware infection and disturbance of normal knee function. We reviewed the results of operative fixation of supracondylar femoral fractures using the lateral condylar blade plate device in our centre.

  10. Single-suture scleral fixation of subluxated foldable intraocular lenses.

    Science.gov (United States)

    Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan

    2012-01-01

    To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

  11. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Science.gov (United States)

    2012-01-01

    Background To assess the efficacy, clinical outcomes, visual acuity (VA), incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany) were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%), 20/60 or better in 12 eyes (92%), and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method. PMID:23050659

  12. Intermediate results of sutureless intrascleral posterior chamber intraocular lens fixation.

    Science.gov (United States)

    Scharioth, Gabor B; Prasad, Som; Georgalas, Ilias; Tataru, Calin; Pavlidis, Mitrofanis

    2010-02-01

    To report the intermediate multicenter results of a technique of sutureless intrascleral fixation of a standard 3-piece posterior chamber intraocular lens (PC IOL) in the ciliary sulcus. Four European ophthalmology centers. A technique for sutureless intrascleral fixation of the haptics of a standard 3-piece PC IOL was retrospectively evaluated. The technique uses standardized maneuvers to fixate the PC IOL without need for special haptic architecture or preparation or haptic suturing. All patients having IOL implantation by the technique were evaluated for preoperative status (visual acuity, refractive error, preexisting ocular conditions, optical biometry), postoperative status, complications, and need for further surgery. The study evaluated 63 consecutive patients from 4 institutions (4 surgeons). The median follow-up was 7 months. Two dislocated PC IOLs (3.6%) were decentered; the other 61 IOLs (96.8%) were stable and well centered. There were no cases of recurrent dislocation, endophthalmitis, retinal detachment, or glaucoma. Fixation of PC IOL haptics in a limbus-parallel scleral tunnel provided exact centration and axial stability of the IOL and prevented distortion and subluxation in most cases. Copyright 2010 ASCRS and ESCRS. All rights reserved.

  13. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Directory of Open Access Journals (Sweden)

    Garcia-Rojas Leonardo

    2012-10-01

    Full Text Available Abstract Background To assess the efficacy, clinical outcomes, visual acuity (VA, incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%, 20/60 or better in 12 eyes (92%, and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method.

  14. Cyanobacteria Occurrence and Nitrogen Fixation Rates in the ...

    African Journals Online (AJOL)

    The occurrence and biological nitrogen fixation rates of epiphytic and benthic diazotrophs were studied in seagrass meadows at sites with seaweed farms and at a control site without seaweed farms from two locations, Chwaka Bay and Jambiani, along the east coast of. Zanzibar. Ten species of cyanobacteria were ...

  15. Biological nitrogen fixation and habitat of running buffalo clover

    Science.gov (United States)

    D.R. Morris; V.S. Baligar; T.M. Schuler; P.J. Harmon

    2002-01-01

    Running buffalo clover (RBC) [Trifolium stoloniferum (Muhl. ex Eat.)] is an endangered species whose survival is uncertain. An experiment was conducted on extant RBC sites to investigate biological nitrogen (N2) fixation, associated plant species, and soil conditions under natural mountain settings. Isotope (15...

  16. Aetiology and Patterns of Implant Failure Following Fracture Fixation ...

    African Journals Online (AJOL)

    Background: Implant failure is traumatic for patient as it increases the cost of treatment and may negatively affect the confidence of patients in the superior outcome of operatively treated fractures. Hence the objectives for this study were to determine the proportion of implant fixations that fail, types and causes of implant ...

  17. Combining bisphosphonates with allograft bone for implant fixation

    NARCIS (Netherlands)

    Mathijssen, N.M.C.; Buma, P.; Hannink, G.J.

    2014-01-01

    The aim of this review was to discuss the current state of research of combining bisphosphonates with allograft bone for implant fixation. The allograft bone can only be reached by the bisphosphonate once it has been revascularized. However, this can be circumvented by local administration of

  18. EARLY WEIGHT-BEARING AFTER ANKLE FRACTURE FIXATION ...

    African Journals Online (AJOL)

    Background: In early 2006 during AO-scholarship training at Hadassah Hospital in Jerusalem, I witnessed patients being walked on the same day after fixation of ankle fractures. This was contrary to my original teaching of protected non-weight bearing for six weeks. Literature review in this subject was inconclusive.

  19. Effect of Phosphorus Fertilizer on Nitrogen Fixation by Some Grain ...

    African Journals Online (AJOL)

    acer

    made by Weber (1996) that in the Northern. Guinea Savanna of Nigeria, legumes require about 30 kgPha-1 for optimal growth and N2- fixation. However, higher rate of the P (40 kgha-1) was used in this study because of the lower P level in the Sudan Savannah soils than that of Guinea Savannah coupled with continuous ...

  20. Variability in olecranon AO fracture fixation: A radiological study ...

    African Journals Online (AJOL)

    Background: Tension Band Wire(TBW) fixation of olecranon fracture is a commonly used technique by orthopaedic surgeons. However surgeons do not strictly adhere to the AO standard. Objectives: To determine the use and variability of this technique by surgeons at the hospital. Design: A hospital based retrospective ...

  1. Functional Outcome of Internal Fixation of Radial and Ulna Fracture

    Directory of Open Access Journals (Sweden)

    mehrdad Mansouri

    2006-02-01

    Conclusion: Anatomic reduction and internal fixation is the standard method for treatment of fractures by displacing radios and ulna in adults. According to results, it seems more intension to motions specially pronation and muscle strengthening foream after surgery will have affect on improving patients’ function specially pronation and Grip strength.

  2. Percutaneous reduction and fixation of intraarticular calcaneal fractures

    NARCIS (Netherlands)

    T. Schepers (Tim); L.M.M. Vogels (Lucas); I.B. Schipper (Inger); P. Patka (Peter)

    2008-01-01

    textabstractObjective: Percutaneous reduction by distraction and subsequent percutaneous screw fixation to restore calcaneal and posterior talocalcaneal facet anatomy. The aim of this technique is to improve functional outcome and to diminish the rate of secondary posttraumatic arthrosis compared to

  3. Densitometric comparison of 3 occipital regions for suitability of fixation.

    Science.gov (United States)

    Das, Chandan; Newcomb, Anna G U S; Gaudin, Daniel P; Crawford, Neil R

    2016-04-01

    Atlantooccipital fixation is an important technique in the treatment of upper cervical spine instability. Important considerations for implant devices are obtrusiveness and propagation of torque through the device caused by cervical rotation. The authors evaluated the feasibility of 3 regions of the occiput as sites for occipitocervical fixation by examining bone mineral density at these locations. Unembalmed occiputs of 9 male and 4 female cadavers were used (mean age at time of death was 61.6 years, range 36-68 years). Studies were undertaken using caliper measurements and dual-energy x-ray absorptiometry of the superior nuchal line (SNL), the external occipital protuberance (EOP), and the inferior nuchal line (INL). Data indicate that the bone at the INL has a similar volumetric bone density as the bone at the SNL, despite having half the thickness. Also, the volumetric bone density increases laterally along the nuchal lines. Most hardware fixation is centered on stabilization at the EOP and the SNL. On the basis of these radiological results, the INL shows promise as a potential alternative site for screw placement in occipitocervical fixation.

  4. Adaptation and fixation in entrepreneurial approaches of a dental laboratory

    Directory of Open Access Journals (Sweden)

    Cornelia M. Ferreira

    2014-08-01

    Research purpose: The study described how the dental laboratory adapted its entrepreneurial approaches over time in response to critical changes that occurred and how aspects in the managerial approach became fixated and proved to be essential to success. Motivation for the study: The study provided insight into how the dental laboratory transformed into a stable and prosperous laboratory by the integration of strategic, economic, cultural and social capital through a process of business decision making. Research design, approach and method: A cohort survey research design, based upon the compilation of longitudinal data over three selected time periods, was employed. The design of the measuring instruments and the interpretation of research results were derived from an adapted entrepreneurial-in-network theoretical framework. A triangulation data compilation approach was followed. Main findings: The results revealed that cultural capital in the dental laboratory became fixated on three value principles, whilst the other critical capitals prescribed exist in sufficient volumes and improve to adapt to changing circumstances in the dental market. Practical/managerial implications: Fixated cultural values acted as a ‘parent’-actor in order to guide the righteousness of behaviour, whereas adaptation required sufficient critical capitals and the proper integration thereof. Contribution/value-added: By adopting the entrepreneurship-in-network approach, the researchers incorporated the dynamic and interactive processes of entrepreneurship. Future studies may employ the same design and use multi-varied analyses to show how a business adapt or fixate its approaches in response to crises or changes in the business environment.

  5. On the relationship between C and N fixation in nodulated alfalfa (Medicago sativa)

    OpenAIRE

    Molero Milán, Gemma; Tcherkez, G.; Araus Ortega, José Luis; Nogués Mestres, Salvador; Aranjuelo Michelena, Iker

    2014-01-01

    Legumes such as alfalfa (Medicago sativa L.) are vital N2-fixing crops accounting for a global N2 fixation of ~35 MtNyear-1. Although enzymatic and molecular mechanisms of nodule N2 fixation are now well documented, some uncertainty remains as to whether N2 fixation is strictly coupled with photosynthetic carbon fixation. That is, the metabolic origin and redistribution of carbon skeletons used to incorporate nitrogen are still relatively undefined. Here, we conducted isotopic labelling with ...

  6. All-Suture Transosseous Repair for Rotator Cuff Tear Fixation Using Medial Calcar Fixation

    Science.gov (United States)

    Aramberri-Gutiérrez, Mikel; Martínez-Menduiña, Amaia; Valencia-Mora, María; Boyle, Simon

    2015-01-01

    We describe an all-suture transosseous repair technique used in the management of rotator cuff tears by means of an all-suture anchor secured on the intra-articular side of the humeral calcar. The technique uses an anterior cruciate ligament guide to ensure accurate positioning of the tunnels, avoiding the articular cartilage and minimizing risk to the neurovascular structures. The distal end of the guide is inserted through a rotator interval portal and passed down to the axillary pouch. The proximal end of the guide is approximated to the greater tuberosity at the cuff footprint, and a complete transosseous tunnel is created with a 2.4-mm drill. An all-suture implant is inserted through this tunnel down to the calcar, and its deployment is visualized under arthroscopy. Gentle traction is applied to the anchor, resulting in a 4-mm concertina of the suture anchor that rests opposed to the medial cortex. The major advantage of this technique is the fixation strength gained from the biomechanically superior cortical bone of the calcar. Furthermore, this method permits greater preservation of bone surface area at the level of the footprint for a larger tendon-to-bone healing surface. This technique also provides an excellent alternative in revision situations. PMID:26052495

  7. Unstable fragility fractures of the ankle in the elderly; Transarticular Steinmann pin or external fixation

    NARCIS (Netherlands)

    Meijer, R. P. J.; Halm, J. A.; Schepers, T.

    2017-01-01

    Because of poor skin conditions and comorbidity, open reduction and internal fixation in ankle fractures is frequently contra-indicated in the elderly. This study reports the results of two temporary fixation types in fragility fractures in the older patient: transarticular Steinmann pin fixation

  8. Pin tract infection after uniplanar external fixation of open fractures at ...

    African Journals Online (AJOL)

    Pin tract infection after uniplanar external fixation of open fractures at a national, teaching and referral hospital. ... Background: Pin tract infection is the most common complication of external fixation accounting for 43% of complications. The presence of a pin tract infection leads to subsequent pin loosening and fixation ...

  9. Look Here but Ignore What You See: Effects of Distractors at Fixation

    Science.gov (United States)

    Beck, Diane M; Lavie, Nilli

    2005-01-01

    Distractor interference effects were compared between distractors in the periphery and those placed at fixation. In 6 experiments, the authors show that fixation distractors produce larger interference effects than peripheral distractors. However, the fixation distractor effects are modulated by perceptual load to the same extent as are peripheral…

  10. Biomechanical evaluation of fixation of comminuted olecranon fractures: one-third tubular versus locking compression plating

    NARCIS (Netherlands)

    Buijze, G.A.; Blankevoort, L.; Tuijthof, G.J.M.; Sierevelt, I.N.; Kloen, P.

    2010-01-01

    New concepts in plate fixation have led to an evolution in plate design for olecranon fractures. The purpose of this study was to compare the stiffness and strength of locking compression plate (LCP) fixation to one-third tubular plate fixation in a cadaveric comminuted olecranon fracture model with

  11. Four quadrant parallel peripheral screw fixation for displaced femoral neck fractures in elderly patients

    Directory of Open Access Journals (Sweden)

    Bhava RJ Satish

    2013-01-01

    Conclusion: Closed reduction and cannulated cancellous screw fixation gives satisfactory functional results in large group of elderly patients. The four quadrant parallel peripheral (FQPP screw fixation technique gives good stability, allows controlled collapse, avoids fixation failure and achieves predictable bone healing in displaced femoral neck fracture in patients ≥50 years of age.

  12. Ethanol-Glycerin Fixation with Thymol Conservation: A Potential Alternative to Formaldehyde and Phenol Embalming

    Science.gov (United States)

    Hammer, Niels; Loffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

    2012-01-01

    Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For…

  13. Surgical treatment of neglected clubfoot using external fixator.

    Science.gov (United States)

    Fernandes, Rodrigo Mota Pacheco; Mendes, Maurilio Darcy Dos Santos; Amorim, Renato; Preti, Marcus Aurélio; Sternick, Marcelo Back; Gaiarsa, Guilherme Pelosini

    2016-01-01

    The definition of neglected clubfoot (NC) includes a variable range of complex deformities of the foot that are refractory to conventional treatments or are treated inappropriately. Several etiologies may be related to this. The Ilizarov method has become established as a tool for treating these deformities. It minimizes soft-tissue damage through gradual correction of the deformity, with a high success rate in relation to achieving a plantigrade foot, with low incidence of recurrence. The indications for treatment include severe rigid deformities (Dimeglio III and IV), or adverse skin conditions. Careful clinical and radiological examination is fundamental for proper planning and installation of the external fixator. The techniques used include selection of external fixation assemblies, which can be closed when there is a connection between the leg, hindfoot and forefoot. This closed assembly may or may not be constricted, according to whether hinges are provided or whether use of the natural anatomical hinges during correction of the deformity is envisaged. An open assembly makes it possible to add flexibility to the foot through histogenesis, while allowing closed corrections of greater precision later on. Hexapod fixators are an innovation with high potential for accuracy in correcting deformities. Procedures associated with external fixation include soft-tissue release and bone procedures. These procedures enable corrections that are more anatomical, for different degrees of severity and stiffness of deformity. It can be concluded from analyzing this case series that treatment of neglected clubfoot using an external fixator has a high rate of good and excellent results, with low frequency of complications.

  14. Surgical treatment of neglected clubfoot using external fixator

    Directory of Open Access Journals (Sweden)

    Rodrigo Mota Pacheco Fernandes

    Full Text Available ABSTRACT The definition of neglected clubfoot (NC includes a variable range of complex deformities of the foot that are refractory to conventional treatments or are treated inappropriately. Several etiologies may be related to this. The Ilizarov method has become established as a tool for treating these deformities. It minimizes soft-tissue damage through gradual correction of the deformity, with a high success rate in relation to achieving a plantigrade foot, with low incidence of recurrence. The indications for treatment include severe rigid deformities (Dimeglio III and IV, or adverse skin conditions. Careful clinical and radiological examination is fundamental for proper planning and installation of the external fixator. The techniques used include selection of external fixation assemblies, which can be closed when there is a connection between the leg, hindfoot and forefoot. This closed assembly may or may not be constricted, according to whether hinges are provided or whether use of the natural anatomical hinges during correction of the deformity is envisaged. An open assembly makes it possible to add flexibility to the foot through histogenesis, while allowing closed corrections of greater precision later on. Hexapod fixators are an innovation with high potential for accuracy in correcting deformities. Procedures associated with external fixation include soft-tissue release and bone procedures. These procedures enable corrections that are more anatomical, for different degrees of severity and stiffness of deformity. It can be concluded from analyzing this case series that treatment of neglected clubfoot using an external fixator has a high rate of good and excellent results, with low frequency of complications.

  15. Changes in North Atlantic nitrogen fixation controlled by ocean circulation.

    Science.gov (United States)

    Straub, Marietta; Sigman, Daniel M; Ren, Haojia; Martínez-García, Alfredo; Meckler, A Nele; Hain, Mathis P; Haug, Gerald H

    2013-09-12

    In the ocean, the chemical forms of nitrogen that are readily available for biological use (known collectively as 'fixed' nitrogen) fuel the global phytoplankton productivity that exports carbon to the deep ocean. Accordingly, variation in the oceanic fixed nitrogen reservoir has been proposed as a cause of glacial-interglacial changes in atmospheric carbon dioxide concentration. Marine nitrogen fixation, which produces most of the ocean's fixed nitrogen, is thought to be affected by multiple factors, including ocean temperature and the availability of iron and phosphorus. Here we reconstruct changes in North Atlantic nitrogen fixation over the past 160,000 years from the shell-bound nitrogen isotope ratio ((15)N/(14)N) of planktonic foraminifera in Caribbean Sea sediments. The observed changes cannot be explained by reconstructed changes in temperature, the supply of (iron-bearing) dust or water column denitrification. We identify a strong, roughly 23,000-year cycle in nitrogen fixation and suggest that it is a response to orbitally driven changes in equatorial Atlantic upwelling, which imports 'excess' phosphorus (phosphorus in stoichiometric excess of fixed nitrogen) into the tropical North Atlantic surface. In addition, we find that nitrogen fixation was reduced during glacial stages 6 and 4, when North Atlantic Deep Water had shoaled to become glacial North Atlantic intermediate water, which isolated the Atlantic thermocline from excess phosphorus-rich mid-depth waters that today enter from the Southern Ocean. Although modern studies have yielded diverse views of the controls on nitrogen fixation, our palaeobiogeochemical data suggest that excess phosphorus is the master variable in the North Atlantic Ocean and indicate that the variations in its supply over the most recent glacial cycle were dominated by the response of regional ocean circulation to the orbital cycles.

  16. Early Onset Sixth-Nerve Palsy with Eccentric Fixation.

    Science.gov (United States)

    Nanda, Kaajal D; Lacey, Eve; Liasis, Alki; Nischal, Ken K

    2017-01-01

    To report four cases of early onset sixth-nerve palsy all of whom had eccentric fixation. A retrospective case note review was undertaken of all cases presenting to the senior author's private and NHS practice with early onset sixth palsy between 2006 and 2012. As well as demographic information, details of ophthalmic, orthoptic, electrophysiological examinations, and radiological investigations that were extracted from the records. Four children with unilateral or asymmetric early onset sixth-nerve palsy were identified, of which three were congenital. All four had MRI and only one had a normal MRI. Age at presentation ranged from 14-42 months, but all four had marked esotropia and poor visual acuities in the worst affected eye with eccentric fixation, which became more easily or only noticeable after surgical correction. Three patients with congenital sixth-nerve palsy underwent vertical muscle transposition with Botulinum Toxin A (BTXA) to the ipsilateral medial rectus, and two of these patients also had Foster sutures to the transposed vertical muscles. The fourth patient had unilateral medial rectus recession and lateral rectus resection. The mean preoperative measurement was 55 Δ ET (range 50-60 Δ ), and the mean postoperative measurement was 11 Δ ET (range 16XT-25ET) at near, and 2 Δ XT (range 15XT-14ET) at distance. We speculate that early onset paralytic strabismus due to congenital sixth-nerve palsy results in an inability to cross fixate which results in the development of eccentric fixation. Attempts to use reverse occlusion to negate the eccentric fixation failed. We therefore recommend early surgery for this condition to avoid this sequelae. © 2017 Board of regents of the University of Wisconsin System, American Orthoptic Journal, Volume 67, 2017, ISSN 0065-955X, E-ISSN 1553-4448.

  17. Flanged Intrascleral Intraocular Lens Fixation with Double-Needle Technique.

    Science.gov (United States)

    Yamane, Shin; Sato, Shimpei; Maruyama-Inoue, Maiko; Kadonosono, Kazuaki

    2017-08-01

    To report the clinical outcomes of a new technique for transconjunctival intrascleral fixation of an intraocular lens (IOL). Prospective, noncomparative, interventional case series. One hundred eyes of 97 consecutive patients with aphakia, dislocated IOL, or subluxated crystalline lens who underwent posterior chamber sutureless implantation of an IOL were studied. Two angled incisions parallel to the limbus were made by 30-gauge thin-wall needles. Haptics of an IOL were externalized with the needles and cauterized to make a flange of the haptics. The flange of the haptics were pushed back and fixed into the scleral tunnels. Best-corrected visual acuity (VA), corneal endothelial cell density, IOL tilt, and complications were determined. The IOLs were fixed with exact centration and axial stability. The mean preoperative best-corrected VA was 0.25 logarithm of the minimum angle of resolution (logMAR) units; after surgery, it improved significantly to 0.11 logMAR, 0.09 logMAR, 0.12 logMAR, and 0.04 logMAR at 6, 12, 24, and 36 months, respectively (P IOL tilt was 3.4°±2.5°. The postoperative complications included iris capture by the IOL in 8 eyes (8%), vitreous hemorrhage in 5 eyes (5%), and cystoid macular edema in 1 eye (1%). There were no incidents of postoperative retinal detachment, endophthalmitis, or IOL dislocation. We have developed a new technique for intrascleral IOL fixation. The flanged IOL fixation technique is a simple and minimally invasive method for achieving good IOL fixation with firm haptic fixation. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  18. Effects of a fixation target on torsional optokinetic nystagmus.

    Science.gov (United States)

    Suzuki, Y; Shinmei, Y; Nara, H; Ifukube, T

    2000-09-01

    To investigate the effects of an imaginary and a visual target on torsional optokinetic nystagmus (tOKN) and directional symmetry of tOKN. Torsional OKN was induced by a rotating random dot pattern (52 degrees in diameter, constant angular velocity: +/-30 deg/sec to +/-52 deg/sec) with an imaginary or a visual target in 11 eyes of 10 healthy humans by dual-search coil methods. Intorsional OKN and extorsional OKN were symmetrical in their slow-phase gain. The mean slow-phase gain (0. 037/0.041, intorsion/extorsion) of tOKN during fixation on a visual target at the center of the rotating random dot pattern was significantly (P: extorsion) during fixation on an imaginary target at the center of the rotating random dot pattern. The mean tOKN slow-phase beat duration (840 msec/724 msec, intorsion/extorsion) during fixation on the visual target was significantly (P: extorsion) during fixation on the imaginary target. In seven eyes of six subjects, the mean slow-phase gain and beat duration (0.034 and 812 msec) of tOKN during fixation on a visual target 6.5 degrees left or right from the center of the rotating random dot pattern were not significantly different from those (0.037 and 825 msec) with a visual target at the center of the rotating random dot pattern (P: > 0.3). A visual target spot suppresses tOKN by a nonpursuit visual system. Intorsional and extorsional OKNs were symmetrical.

  19. Temporary external fixation is safe in a combat environment.

    Science.gov (United States)

    Possley, Daniel R; Burns, Travis C; Stinner, Daniel J; Murray, Clinton K; Wenke, Joseph C; Hsu, Joseph R

    2010-07-01

    External fixation has been used extensively during recent wars as a damage control measure for fractures in coalition forces being evacuated. We hypothesize that external fixation is a safe and effective initial stabilization procedure for combat-related open fractures. Records on 55 consecutive type III tibia fractures between March 2003 and September 2007 were reviewed. We stratified the complications related to external fixation as major, potential, and minor complications. We defined major complications as neurovascular injury, mechanical failure, septic joint, and pin tract osteomyelitis. Potential complications were defined as pins within 1 inch of the fracture, pin overpenetration (> or = 26 mm), pin without cortical purchase, and intracapsular pin placement. Minor complications were defined as pin tract infections, addition of pins or bars, and pin overpenetration (9-25 mm). "Successful application" was defined as the absence of major or potential complications. We recorded no major complications. There were 12 of 53 (22.6%) constructs and 21 of 228 (9.2%) pins inserted with potential complications. We detected minor complications in 27 of 53 (50.9%) constructs and 35 of 228 (15.3%) pins inserted; 41 of 53 (77.4%) constructs had no major or potential complications. Treatment of combat-related open tibia fractures with external fixation was 77% successful in our series. We recorded no major complications but demonstrated the possibility for technical improvement in one of the five constructs with potential complications. Despite the recorded potential and minor complications, external fixation is safe and effective as a temporary damage control in open fractures sustained in combat.

  20. Browse Title Index

    African Journals Online (AJOL)

    Items 551 - 600 of 823 ... Vol 22, No 1 (2017), Pin tract infection after uniplanar external fixation of open fractures at a national, teaching and referral hospital, Abstract PDF. R.M. Mohammed, E.O. Atinga, F.C. Sitati, E.M. .... SMD Muwazi, M Knwooya, S Oola, JWM Kiryabwire, D Iga-Matow. Vol 15, No 1 (2010), Primary Splenic ...

  1. A cadaveric analysis of cervical fixation: the effect of intermediate fixation points and dynamization in multilevel cervical fusions.

    Science.gov (United States)

    Lubelski, Daniel; McCormick, William E; Ferrara, Lisa; Benzel, Edward C; Kayanja, Mark

    2014-11-01

    The authors conducted a study to compare biomechanical effects on the cervical spine of bridging fixation and intermediate fixation techniques, in both fixed and dynamic modes. A biaxial, servohydraulic machine biomechanically tested 23 human cervical spines for stiffness and strain in compression, extension, flexion, and lateral bending through 3 specimen states: 1) intact, 2) defect (corpectomy and discectomy), and 3) grafting with plate application in 1 of 4 constructs: C3-7 dynamized long strut (DLS), C3-7 fixed long strut (FLS), C3-5-7 dynamized multisegment (DMS), and C3-5-7 fixed multisegment (FMS). Compared with FMS, FLS had significantly greater strain in extension (at C-3 and at the rostral and caudal parts of the graft) and in lateral bending (at C-3 and at the caudal part of the graft). Fixed (FLS and FMS) constructs had greater flexion stiffness than did dynamized (DLS and DMS) constructs and showed a trend toward greater lateral bending stiffness. Instrumentation revealed greater extension strain with the long fixed (FLS and DLS) constructs than with the multifixed (FMS and FMS) constructs at the rostral and caudal parts of the graft but no significant differences between the dynamized (DLS and DMS) and fixed (FLS and FMS) constructs. Multisegmental fixation provided greater stabilizing forces than did bridging constructs for both dynamized and fixed plates. Use of multisegmental fixation can potentially decrease strain at the screw-plate interface and reduce the rate of hardware failure.

  2. Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

    NARCIS (Netherlands)

    Claessen, F.M.; Stoop, N.; Doornberg, J.N.; Guitton, T.G.; Bekerom, M.P. van den; Ring, D.; Biert, J.; et al.,

    2016-01-01

    PURPOSE: Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after

  3. To Index or Not To Index.

    Science.gov (United States)

    Veenema, Fred

    1996-01-01

    Describes an experiment comparing the performance of an automatic full-text indexing software for personal computers (i.e., the Quick-Finder facility in WordPerfect 6.1 for Windows) with the human intellectual assignment of indexing terms to each document in a collection. Results are discussed in terms of ease of use, the time factor, and recall…

  4. Evaluation of early nodulation and Nitrogen fixation a number of Bradyrhizobium Japonicum strains to increase nitrogen fixation ability of soybean cultivars ars by using the A-value (N-15) method

    International Nuclear Information System (INIS)

    Piervali-Bieranvand, N.; Teimori, S.; Khorasani, A.

    2004-01-01

    done 25 days after planting (one week after R1) nad several parameters such as dry matter for shoot, nodule and roots , number of nodules and proportion and amount of nitrogen derived from air (Ndfa% and N-fixed) were measured. The second and third harvests were performed afterwards. Analysis of variance for data was done by MSTAC package and the means were compared by Duncan Multiple Range Test. The results showed that although effects of rhizobial strain, harvesting time and soybean cultivar on nodulation are significantly different, but for nitrogen derived for air(Ndfa%), only two former treatments effects of interaction between treatments, effects of interaction between harvesting times rhizobial strains, also interaction between soybean cultivars and rhyzobial strains for %Ndfa as most reliable index for evaluation the biological nitrogen fixation were significantly different. In view of proportion and amount of nitrogen fixed , among the harvest times, third and second harvest as well as among the strains of rhizobia, J 43 and J 3 were significantly higher than others, respectively. According to results obtained form this study, it can be hopped to enhance biological nitrogen fixation in soybean through improvement inoculation by choosing early nodulating and N 2 fixing rhizobial

  5. Evaluation of Streck tissue fixative, a nonformalin fixative for preservation of stool samples and subsequent parasitologic examination.

    Science.gov (United States)

    Nace, E K; Steurer, F J; Eberhard, M L

    1999-12-01

    We undertook a study to evaluate Streck tissue fixative (STF) as a substitute for formalin and polyvinyl alcohol (PVA) in fecal preservation. A comparison of formalin, PVA, (mercuric chloride based), and STF was done by aliquoting fecal samples into each fixative. Stool specimens were collected in Haiti, and parasites included Cyclospora cayetanensis, Giardia intestinalis, Entamoeba coli, Iodamoeba butschlii, Endolimax nana, Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, and Necator americanus. Preserved stools were examined at various predetermined times (1 week, 1 month, and 3 months) to establish the quality of the initial preservation as well as the suitability of the fixative for long-term storage. At each time point, stool samples in fixatives were examined microscopically as follows: (i) in wet mounts (with bright-field and epifluorescence microscopy), (ii) in modified acid-fast-, trichrome-, and safranin-stained smears, and (iii) with two commercial test kits. At the time points examined, morphologic features remained comparable for samples fixed with 10% formalin and STF. For comparisons of STF- and 10% formalin-fixed samples, specific findings showed that Cyclospora oocysts retained full fluorescence, modified acid-fast- and safranin-stained smears of Cryptosporidium and Cyclospora oocysts were equal in staining quality, and results were comparable in the immunofluorescence assay and enzyme immunoassay commercial kits. Stool fixed in STF and stained with trichrome showed less-than-acceptable staining quality compared with stool fixed in PVA. STF provides an excellent substitute for formalin as a fixative in routine examination of stool samples for parasites. However, modifications to the trichrome staining procedures will be necessary to improve the staining quality for protozoal cysts fixed in STF to a level comparable to that with PVA.

  6. Analysis and an overview of fixators in medicine and the methods of processing materials for producing fixators

    Directory of Open Access Journals (Sweden)

    Dalibor Milojko Đenadić

    2013-06-01

    Full Text Available The fixator is a medical device that provides support to fractured biological structures. Metal biomaterials are mainly used for replacing broken or damaged hard tissues such as bones because of their high strenght, toughness and corrosion resistance. Materials such as stainless steel, titanium and aluminium alloys (Ti-6Al-4V, cobalt and chromium alloys, composite materials and other biocompatible materials are used in orthopedy for the stabilization of connective tissue injuries or as a substitute for the bone tissues. Fixators are classified according to the place of installation to external and internal fixators. Widely used medical fixators are pins, rods plates, screws, pipes, wires, nails and external fixators. Conventional and non-conventional methods of processing are used in the production process for all types of fixators. Introduction Fixators are medical devices manufactured to support damaged biological structures. In the field of orthopedic surgery that deals with skeletal disorders such as bone, spine, joints, muscles and tendons injuries and diseases, various metals, titanium and cobalt alloys etc. are used to stabilize the supporting tissue injuries or as a substitute for bone tissues. Metallic implants are frequently used in orthopedic surgery as joint prosthesis (hip, knee and elbow fracture fixation devices (plates, screws, external fixators and devices for the fixation of the spine. In principle, fixators are devided into external and internal ones, depending on the place of installation (outside or inside the body. The most common types of medical fixators are pins, rods and plates. This paper presents some of the most common materials used for the production of fixators, their processing and possibilties of use in medicine for various purposes. Types of fixators and materials used for their production Nowadays, biocompatible materials are usually used for the production of fixators and implants. These materials show good

  7. Intratarsal fixation at the same level as the skin incision to reduce asymmetric double eyelids: evaluation of symmetry using photogrammetry.

    Science.gov (United States)

    Han, Kihwan; Yeo, Hyeonjung; Choi, Tae Hyun; Son, Daegu; Kim, Jun Hyung

    2010-03-01

    One of the most common complications of double eyelid operations is asymmetry. To reduce asymmetry, we fixed the dermis to the tarsal plate at the same level as the skin incision, and objectively evaluated the symmetry of the height using photogrammetry.Of 30 patients who had double eyelid operations by the intratarsal fixation technique, 15 patients completed a minimum follow-up of 6 months. After the skin incision and removal of the orbicularis oculi muscle and the orbital fat, the pretarsal fat pad was excised to expose the superior portion of the tarsal plate. The 3 fixation points were marked on the tarsal plate at the same level with the skin incision using a spreading caliper. The dermis was fixed to the marked points of the tarsal plate and the skin was closed.The height of the double eyelid was measured by clinical photography at 4 points when the eyes were opened and at 3 points when the eyes were closed. The height proportional index at each point was obtained by dividing the height of the left double eyelid by that of the right double eyelid. We compared each height proportional index with "1" to evaluate the symmetry of both double eyelids using a paired t test.The follow-up period was an average of 9.0 months. The mean height proportional indices were 0.97 (a), 0.96 (b), 0.98 (c), 1.08 (d), 0.97 (e), 1.02 (f), and 1.13 (g). According to a paired t test, the height of the left double eyelid was not different from that of the right double eyelid.Intratarsal fixation, along with other previously known methods, decreases asymmetric double eyelids.

  8. A Biomechanical Comparison of Fifth Metatarsal Jones Fracture Fixation Methods.

    Science.gov (United States)

    Duplantier, Neil L; Mitchell, Ronald J; Zambrano, Steve; Stone, Aaron C; Delgado, Domenica A; Lambert, Bradley S; Moreno, Michael R; Harris, Joshua D; McCulloch, Patrick C; Lintner, David M; Varner, Kevin E

    2018-04-01

    Fifth metatarsal base fractures of the metaphyseal-diaphyseal watershed junction (Jones fracture) are commonly treated with surgical fixation in athletes. Intramedullary screw fixation remains the most utilized construct, although plantar-lateral plating is an alternative. Purpose/Hypothesis: The purpose was to compare the mechanical strength of fracture fixation between an intramedullary screw and plantar-lateral plating. The hypothesis was that plantar-lateral plate fixation would allow for more cycles and higher peak loads before failure, as well as less fracture gapping, than would an intramedullary screw in cadaveric foot specimens with simulated Jones fractures exposed to cantilever bending. Controlled laboratory study. Twelve pairs of male cadaver feet were separated into 2 groups (plate or screw) to conduct contralateral comparative testing of 2 devices with equally numbered right and left feet. For each fifth metatarsal, an osteotomy with a microsagittal saw was created to simulate a Jones fracture. The plate group underwent fixation with a 3.0-mm 4-hole low-profile titanium plate placed plantar-laterally with 3 locking screws and 1 nonlocking screw. The screw group underwent fixation with a 40- or 45-mm × 5.5-mm partially threaded solid titanium intramedullary screw. After fixation, the metatarsals were excised for biomechanical testing. Cyclic cantilever failure testing was conducted with a gradient-cycle method. Sinusoidal loading forces were applied, increasing by 5.0-pound-force increments per 10 cycles, until each specimen experienced mechanical failure of implant or bone. Failure mode, number of cycles to failure, peak failure load, gap width at the last mutual prefailure loading, and video data were recorded. Paired 2-tailed t test (α = 0.05) was used to compare groups ( P Plate fixation resulted in significantly higher mean ± SD values for cycles to failure (63.9 ± 27.0 vs 37.3 ± 36.9, P = .01) and peak failure load (159.2 ± 60.5 N vs 96.5

  9. Latarjet Fixation: A Cadaveric Biomechanical Study Evaluating Cortical and Cannulated Screw Fixation.

    Science.gov (United States)

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

    2016-04-01

    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. To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Controlled laboratory study. 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. 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). 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. Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option.

  10. Distal fibula fracture fixation: Biomechanical evaluation of three different fixation implants.

    Science.gov (United States)

    Knutsen, Ashleen R; Sangiorgio, Sophia N; Liu, Chang; Zhou, Steve; Warganich, Tibor; Fleming, John; Harris, Thomas G; Ebramzadeh, Edward

    2016-12-01

    The goal of this study was to evaluate the biomechanical performance of three distal fibula fracture fixation implants in a matched pair cadaveric fibula model: (1) a 5-hole compression plate with lag screw, (2) a 5-hole locking plate with lag screw, and (3) the 6-hole tabbed-plate with locking screws. Three-dimensional motions between the proximal and distal fibular segments were measured under cyclic valgus bending, cyclic compressive axial loading, and cyclic torsional external-rotation loading. During loading, strains were measured on the surfaces of each fibula near the simulated fracture site, and on the plate, to assess load transfer. Bone quality was quantified globally for each donor using bone mineral density (BMD) measured using Dual X-ray absorptiometry (DEXA) and locally at the fracture site using bone mineral content (BMC) measured using peripheral quantitative computed tomography (pQCT). Mean failure loads were below 0.2Nm of valgus bending and below 4Nm of external-rotational torque. Mean failure angulation was below 1degree for valgus bending, and failure rotation was below 7degrees for external-rotation. In the compression plate group, significant correlations were observed between bone quality (global BMD and local BMC) and strain in every one of the five locations (Pearson correlation coefficients >0.95, p<0.05). In contrast, in the locking and tabbed-plate groups, BMD and BMC correlated with far fewer strain locations. Overall, the tabbed-plate had similar construct stability and strength to the compression and locking plates. However, the distribution of load with the locking and tabbed-plates was not as heavily dependent on bone quality. Copyright © 2016 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  11. Complications Using Bioabsorbable Cross-Pin Femoral Fixation: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Saqib Hasan

    2011-01-01

    Full Text Available The use of bioabsorbable cross-pin transcondylar fixation has remained a viable option for femoral fixation in anterior cruciate ligament reconstruction. Although numerous biomechanical studies have demonstrated high fixation strength and minimal slippage with use of this method of fixation, there have been increasing reports of a variety of clinical complications associated with these implants. We reviewed the literature for all complications associated with the Bio-TransFix implant and present a case report of a patient status after ACL reconstruction using Bio-TransFix cross-pin femoral fixation with iliotibial band friction syndrome from a broken cross-pin four month post-operatively.

  12. Deepwater Nitrogen Fixation: Who's Doing it, Where, and Why?

    Science.gov (United States)

    Montoya, J. P.; Weber, S.; Vogts, A.; Voss, M.; Saxton, M.; Joye, S. B.

    2016-02-01

    Nitrogen availability frequently limits marine primary production and N2-fixation plays an important role in supporting biological production in surface waters of many oligotrophic regions. Although subsurface waters typically contain high concentrations of nitrate and other nutrients, measurements from a variety of oceanic settings show measurable, and at times high rates of N2-fixation in deep, dark waters below the mixed layer. We have explored the distribution of N2-fixation throughout the water column of the Gulf of Mexico (GoM) during a series of cruises beginning shortly after the Deepwater Horizon (DWH) spill in 2010 and continuing at roughly annual intervals. These cruises allowed us to sample oligotrophic waters across a range of depths, and to explore the connections between the C and N cycles mediated by release of oil and gas (petrocarbon) from natural seeps as well as anthropogenic sources (e.g., the DWH). We used stable isotope abundances (15N and 13C) in particles and zooplankton in combination with experimental measurements of N2-fixation and CH4 assimilation to assess the contribution of oil- and gas-derived C to the pelagic food web, and the impact of CH4 releases on the pelagic C and N cycles. Our isotopic measurements document the movement of petrocarbon into the pelagic food web, and our experiments revealed that high rates of N2-fixation were widespread in deep water immediately after the DWH incident, and restricted to the vicinity of natural seeps in subsequent years. Unfortunately, these approaches provided no insight into the organisms actually responsible for N2-fixation and CH4-assimilation. We used nano-scale Secondary Ion Mass Spectrometry (nanoSIMS) to image the organisms responsible for these processes, and molecular approaches to explore the diversity of methanotrophs and diazotrophs present in the system. The ability to resolve isotopic distributions on the scale of individual cells is a critical part of bridging the gap between

  13. [Talar Neck Fractures Treated Using Percutaneous Screw Fixation].

    Science.gov (United States)

    Veselý, R; Kelbl, M; Kacián, J; Hulka, V; Kočiš, J; Kunovský, R

    2017-01-01

    PURPOSE OF THE STUDY Closed reduction and percutaneous fixation of nondisplaced talar neck fractures have been applied by some authors. The aim of this paper is to assess the results and complications of this minimally invasive technique. MATERIAL AND METHODS In the period from 2009 to 2014, twenty-one patients with a talar neck fracture were observed after closed reduction and percutaneous screw fixation in the Traumatological Hospital in Brno. The mean age of the patients was 38 years (range 18-56 years). The mechanism of injury was a motor vehicle accident in 11 cases, a fall from height in six cases, a sports injury in 3 cases, and a fall from stairs in one case. Injuries were classified according to the Hawkins classification. Conventional preoperative 3-dimensional CT scans of the fractures were analysed. Under the guidance of C-arm fluoroscopy, Kirscher wires were used for closed reduction and temporary percutaneous fixation. Subsequently, 3.5 and 4.5 mm diameter cannulated screws were inserted. The outcome was evaluated on the American Orthopaedic Foot and Ankle Society (AOFAS) scoring scale. RESULTS The average follow-up was 32 months (21-42 months). The average healing time was 15.5 weeks (13-19 weeks). The average AOFAS score was 82.3 points (69-96 points). 75% of patients with type I injury achieved excellent results and 72% of patients with type II injury achieved excellent or good results. None of the patients developed wound complications. Two patients developed partial avascular necrosis and three patients subtalar traumatic arthritis after surgery. DISCUSSION Talar neck fractures are relatively uncommon fractures. Most of the published studies are small. Tenuous blood supply and displaced talar neck fracture predispose to avascular necrosis of the talus. Closed reduction and percutaneous fixation can reduce the soft tissue damage and disturbance to the blood supply. CONCLUSIONS Preoperative 3D CT scans, early surgery, anatomic articular surface

  14. Analysis in indexing

    DEFF Research Database (Denmark)

    Mai, Jens Erik

    2005-01-01

    The paper discusses the notion of steps in indexing and reveals that the document-centered approach to indexing is prevalent and argues that the document-centered approach is problematic because it blocks out context-dependent factors in the indexing process. A domain-centered approach to indexing...... is presented as an alternative and the paper discusses how this approach includes a broader range of analyses and how it requires a new set of actions from using this approach; analysis of the domain, users and indexers. The paper concludes that the two-step procedure to indexing is insufficient to explain...

  15. Supersymmetry and index theory

    International Nuclear Information System (INIS)

    Alvarez-Gaume, L.

    1985-01-01

    The author presents information mainly concerned with the fact that many of the ingredients and results in index theory have very simple analogs in supersymmetric quantum mechanical systems so that using elementary quantum mechanics one can obtain new proofs of the Atiyah-Singer index theorem and related results. Simple ideas on index theorems and characteristic classes are reviewed; simple results on fermion functional integrals are outlined; supersymmetric quantum mechanical systems which appear naturally in dealing with index problems are analyzed; proof of the classical index theorem is presented; the character valued index theorem is derived; and applications of the methods developed here for the computation of anomalies are presented

  16. Arthrodesis of the first metatarsophalangeal joint: a retrospective analysis of plate versus screw fixation.

    Science.gov (United States)

    Dening, Jan; van Erve, Ruud H G P

    2012-01-01

    Arthrodesis of the first metatarsophalangeal joint is a commonly accepted technique to treat various afflictions of the hallux. Many techniques have been described to fixate the arthrodesis. However, no superior fixation technique has been identified in regard to nonunion. We performed a retrospective analysis of first metatarsophalangeal joint arthrodeses in our clinic from January 2000 to April 2010, focusing on plate and screw fixation. Our aim was to identify the best fixation construct in regard to fusion rates and radiologic nonunion. We identified 72 arthrodeses performed using 1 oblique (n = 24) or 2 crossed (n = 21) lag screws or a plate (n = 13) or a plate augmented with plantar lag screw fixation (n = 14). Our analysis showed that plate fixation alone results in significantly fewer nonunions than single screw fixation. A comparison of the other fixation types showed no significant differences with regard to nonunion. Although our analysis showed that plate fixation alone is superior to single screw fixation, no definitive conclusion can be drawn owing to methodologic shortcomings. We believe a randomized controlled trial with larger sample sizes is necessary to find the clinically superior fixation technique. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Yanping Fan

    2015-01-01

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

  18. Cementless fixation in total knee arthroplasty: down the boulevard of broken dreams - affirms.

    Science.gov (United States)

    Ranawat, C S; Meftah, M; Windsor, E N; Ranawat, A S

    2012-11-01

    There has been a recent increase in interest for non-cemented fixation in total knee arthroplasty (TKA), however the superiority of cement fixation is an ongoing debate. Whereas the results based on Level III and IV evidence show similar survivorship rates between the two types of fixation, Level I and II evidence strongly support cemented fixation. United Kingdom, Australia, Sweden, and New Zealand registry data show lower failure rates and greater usage of cemented than non-cemented fixation. Case series studies have also indicated greater functional outcomes and lower revision rates among cemented TKAs. Non-cemented fixation involves more patellofemoral complications, including increased susceptibility to wear due to a thinner polyethylene bearing on the cementless metal-backed component. The combination of results from registry data, prospective randomised studies, and meta-analyses support the current superiority of cemented fixation in TKAs.

  19. The principles of interference screw fixation: application to foot and ankle surgery.

    Science.gov (United States)

    Feldman, Kent A

    2005-01-01

    Based on the success of the anterior cruciate ligament model, interference screw fixation is now being applied to a wide variety of orthopedic conditions that require the fixation of tendon or ligament to bone. The primary focus of this article is to present the principles of interference screw fixation. By understanding the principles of interference screw fixation, the foot and ankle surgeon will be able to apply this fixation technique to a wide variety of surgical applications for tendon transfers or ligament repairs. The surgical technique, history, principles of fixation, studies of fixation strength, tissue healing, and foot and ankle indications are reviewed. A modified Girdlestone digital flexor tendon transfer procedure description is included to illustrate how interference screw techniques may be applied to foot surgery.

  20. Eye movements when reading disappearing text: the importance of the word to the right of fixation.

    Science.gov (United States)

    Rayner, Keith; Liversedge, Simon P; White, Sarah J

    2006-02-01

    In a series of experiments, the currently fixated word (word n) and/or the word to the right of fixation (word n+1) either disappeared or was masked during readers' eye fixations. Consistent with prior research, when only word n disappeared or was masked, there was little disruption to reading. However, when word n+1 either disappeared or was masked (either at the onset of fixation on word n or after 60 ms), there was considerable disruption to reading. Independent of whether word n and/or word n+1 disappeared or was masked, there were robust frequency effects on the fixation on word n. These results not only confirm the robust influence of cognitive/linguistic processing on fixation times in reading, but also again confirm the importance of preprocessing the word to the right of fixation for fluent reading.

  1. Intramedullary nail fixation of non-traditional fractures: Clavicle, forearm, fibula.

    Science.gov (United States)

    Dehghan, Niloofar; Schemitsch, Emil H

    2017-06-01

    Locked intramedullary fixation is a well-established technique for managing long-bone fractures. While intramedullary nail fixation of diaphyseal fractures in the femur, tibia, and humerus is well established, the same is not true for other fractures. Surgical fixations of clavicle, forearm and ankle are traditionally treated with plate and screw fixation. In some cases, fixation with an intramedullary device is possible, and may be advantageous. However, there is however a concern regarding a lack of rotational stability and fracture shortening. While new generation of locked intramedullary devices for fractures of clavicle, forearm and fibula are recently available, the outcomes are not as reliable as fixation with plates and screws. Further research in this area is warranted with high quality comparative studies, to investigate the outcomes and indication of these fractures treated with intramedullary nail devices compared to intramedullary nail fixation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Decreased fixation stability of the preferred retinal location in juvenile macular degeneration.

    Directory of Open Access Journals (Sweden)

    Richard A I Bethlehem

    Full Text Available Macular degeneration is the main cause for diminished visual acuity in the elderly. The juvenile form of macular degeneration has equally detrimental consequences on foveal vision. To compensate for loss of foveal vision most patients with macular degeneration adopt an eccentric preferred retinal location that takes over tasks normally performed by the healthy fovea. It is unclear however, whether the preferred retinal locus also develops properties typical for foveal vision. Here, we investigated whether the fixation characteristics of the preferred retinal locus resemble those of the healthy fovea. For this purpose, we used the fixation-offset paradigm and tracked eye-position using a high spatial and temporal resolution infrared eye-tracker. The fixation-offset paradigm measures release from fixation under different fixation conditions and has been shown useful to distinguish between foveal and non-foveal fixation. We measured eye-movements in nine healthy age-matched controls and five patients with juvenile macular degeneration. In addition, we performed a simulation with the same task in a group of five healthy controls. Our results show that the preferred retinal locus does not adopt a foveal type of fixation but instead drifts further away from its original fixation and has overall increased fixation instability. Furthermore, the fixation instability is most pronounced in low frequency eye-movements representing a slow drift from fixation. We argue that the increased fixation instability cannot be attributed to fixation under an unnatural angle. Instead, diminished visual acuity in the periphery causes reduced oculomotor control and results in increased fixation instability.

  3. Western Alaska ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...

  4. Monotest in the complement fixation test: the Chorus system

    Directory of Open Access Journals (Sweden)

    Laura Meli

    2009-06-01

    Full Text Available The complement fixation test (CFT is a method used for the detection of antibodies against pathogens of infectious diseases, it has been proved to be a useful diagnostic method in the detection of acute disease in many medical laboratories.The test performed manually is time consuming and needs very skilled personnel.This study evaluates the automated Chorus CFT system with 87 serum samples in comparison with manual method using Virion-Serion reagents, against a panel of antigens, such as Adenovirus, Influenza A and B virus, Respiratory Syncythial Virus, Parainfluenza Mix, Mycoplasma Pneumoniae, and Echinococcus. The Chorus system includes standardized reagents and a monotest device to perform the single assay. In comparison to the manual CFT method, the correlation is 91.6% (7/83.The results obtained show that the automated Chorus system can be applied for detecting complement fixation antibodies against different infectious disease agents.

  5. Symbiotic N fixation of several soybean varieties and mutants

    International Nuclear Information System (INIS)

    Gandanegara, S.; Hendratno, K.

    1988-01-01

    Symbiotic N fixation of several soybean varieties and mutants. Research activities comprising of three experiments were carried out to screen several soybean varieties and mutants for symbiotic N fixation potential. Depending on the medium used, plant response to strains was different. In sterile medium, Rhizobium strain USDA 136, 142 and TAL 102 showed a high nitrogen potential. In soil only Rhizobium strain USDA 110 had better performance and proved to be competitive to the native strains. Nitrogen-15 dilution method was used to screen nitrogen fixing ability of several soybean varieties and mutants. Guntur variety showed a better response to high dose of N fertilizer without disturbance in its fixing ability. This variety then was considered good to be introduced in the cropping system. (author). 8 refs

  6. Scleral fixation of a single-piece multifocal intraocular lens.

    Science.gov (United States)

    Can, Ertugrul; Basaran, M Resat; Gül, Adem

    2013-01-01

    We describe an ab interno technique for injector implantation of a one-piece multifocal intraocular lens (IOL). Transscleral fixation of multifocal posterior chamber IOL implantation using an injector with ab interno technique was performed in an eye of a 9-year-old girl who had undergone pars plana lensectomy 2 years before for bilateral lens subluxation with unknown etiology. No major complications were encountered during a 3-month follow-up of the patient and excellent centration was observed during the follow-up period. Her preoperative best spectacle-corrected distance visual acuity of 20/32 improved to uncorrected distance visual acuity of 20/25. Closed-loop design of IOL served the function of eyelets and position of the IOL was provided using only a 2-point fixation. Intraoperative position adjustment of the IOL provided an excellent centralization of multifocal IOL.

  7. Directional eye fixation sensor using birefringence-based foveal detection

    Science.gov (United States)

    Gramatikov, Boris I.; Zalloum, Othman H. Y.; Wu, Yi Kai; Hunter, David G.; Guyton, David L.

    2007-04-01

    We recently developed and reported an eye fixation monitor that detects the fovea by its radial orientation of birefringent nerve fibers. The instrument used a four-quadrant photodetector and a normalized difference function to check for a best match between the detector quadrants and the arms of the bow-tie pattern of polarization states surrounding the fovea. This function had a maximum during central fixation but could not tell where the subject was looking relative to the center. We propose a linear transformation to obtain horizontal and vertical eye position coordinates from the four photodetector signals, followed by correction based on a priori calibration information. The method was verified on both a computer model and on human eyes. The major advantage of this new eye-tracking method is that it uses true information coming from the fovea, rather than reflections from other structures, to identify the direction of foveal gaze.

  8. Mobile robot localization based on fixation vision geometric constraint

    Science.gov (United States)

    Li, Xiao; Zhang, Hongyue

    2003-09-01

    This paper presents a feasible algorithm for mobile robot localization. Localization system is composed of an encoder, an electronical compass, a fixation vision system including a CCD camera and a stepping motor. Multisensor information fusion technology, extended information filter, is adopted for estimating the position and heading of robot. New measurement equation which is based on fixation vision geometric constraint is proposed in this paper. The coordinates of the landmark is not needed to know in this method, in other words, any point in the observed scene can be selected as a landmark. The results of simulation show the algorithm validity. The comparative results show this algorithm has advantage in autonomous mobile robot localization application than Dead-Reckoning.

  9. Bone compaction enhances fixation of weightbearing titanium implants

    DEFF Research Database (Denmark)

    Kold, Søren Vedding; Rahbek, Ole; Vestermark, Marianne Toft

    2005-01-01

    Implant stability is crucial for implant survival. A new surgical technique, compaction, has increased in vitro implant stability and in vivo fixation of nonweightbearing implants. However, the in vivo effects of compaction on weightbearing implants are unknown. As implants inserted clinically...... are weightbearing, the effects of compaction on weightbearing implants were examined. The hypothesis was that compaction would increase implant fixation compared with conventional drilling. Porous-coated titanium implants were inserted bilaterally into the weightbearing portion of the femoral condyles of dogs....... In each dog, one knee had the implant cavity prepared with drilling, and the other knee was prepared with compaction. Eight dogs were euthanized after 2 weeks, and eight dogs were euthanized after 4 weeks. Femoral condyles from an additional eight dogs represented Time 0. Compacted specimens had higher...

  10. Biomechanical considerations in intramedullary fixation of lower-extremity fracture.

    Science.gov (United States)

    Inhofe, P D

    1992-08-01

    Since Gerhard Kuntscher's first cloverleaf design was introduced in the early 1940s, intramedullary nail geometry has become increasingly complex. Many design changes have been introduced, and these have had profound effects upon the mechanical performance of intramedullary devices, making them more versatile. The subset of long-bone fractures amenable to intramedullary fixation is expanding, largely because of these advancements in nail design. Selection of the appropriate nail and bone-nail construct for each fracture configuration requires a knowledge of basic biomechanical principles behind nail design and the implant-host interface. Appropriate clinical application of this knowledge not only ensures the best possible intramedullary fixation of long-bone fractures, but it also aids in avoiding some of the complications that may occur.

  11. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    Introduction The combined incubation of a composite scaffold with bone marrow stromal cells in a perfusion bioreactor could make up a novel hybrid graft material with optimal properties for early fixation of implant to bone. The aim of this study was to create a bioreactor activated graft (BAG...... in each sheep. The concentric gap (2 mm) surrounding the implant was filled with 1) BAG (autogenous), 2) granules, 3) granules+bone marrow aspirate (BMA, autologous) or 4) allograft. The sheep were euthanized after 6 weeks. Distal femurs were removed and implant-bone samples were divided in two parts...... calculated to assess implant fixation. Results were assessed by One-way ANOVA. P-values less than 0.05 were considered significant. Results One sheep in group 1 had to be euthanized after 4 weeks (excluded). One implant in each group was loosened and could not undergo push-out test (excluded). Group 1...

  12. The cyanobacterial nitrogen fixation paradox in natural waters.

    Science.gov (United States)

    Paerl, Hans

    2017-01-01

    Nitrogen fixation, the enzymatic conversion of atmospheric N (N 2 ) to ammonia (NH 3 ), is a microbially mediated process by which "new" N is supplied to N-deficient water bodies. Certain bloom-forming cyanobacterial species are capable of conducting N 2 fixation; hence, they are able to circumvent N limitation in these waters. However, this anaerobic process is highly sensitive to oxygen, and since cyanobacteria produce oxygen in photosynthesis, they are faced with a paradoxical situation, where one critically important (for supporting growth) biochemical process is inhibited by another. N 2 -fixing cyanobacterial taxa have developed an array of biochemical, morphological, and ecological adaptations to minimize the "oxygen problem"; however, none of these allows N 2 fixation to function at a high enough efficiency so that it can supply N needs at the ecosystem scale, where N losses via denitrification, burial, and advection often exceed the inputs of "new" N by N 2 fixation. As a result, most marine and freshwater ecosystems exhibit chronic N limitation of primary production. Under conditions of perpetual N limitation, external inputs of N from human sources (agricultural, urban, and industrial) play a central role in determining ecosystem fertility and, in the case of N overenrichment, excessive primary production or eutrophication. This points to the importance of controlling external N inputs (in addition to traditional phosphorus controls) as a means of ensuring acceptable water quality and safe water supplies. Nitrogen fixation, the enzymatic conversion of atmospheric N 2 to ammonia (NH 3 ) is a  microbially-mediated process by which "new" nitrogen is supplied to N-deficient water bodies.  Certain bloom-forming cyanobacterial species are capable of conducting N 2 fixation; hence they are able to circumvent nitrogen limitation in these waters. However, this anaerobic process is highly sensitive to oxygen, and since cyanobacteria produce oxygen in

  13. Maintaining trust while fixated to a rehabilitative robot

    DEFF Research Database (Denmark)

    Jensen, Laura U.; Winther, Trine Straarup; Jørgensen, Rasmus

    2016-01-01

    This paper investigates the trust relationship between humans and a rehabilitation robot, the RoboTrainer. We present a study in which participants let the robot guide their arms through a series of preset coordinates in a 3D space. Each participant interact with the robot twice, one time where...... participants hold on to the robotic arm, and a second time where participants are fixated to the robotic arm. Our findings show that in general participants did not feel more insecure when fixated to the robot. However, when the robot arm moves close to participants and enter their intimate space, or when...... the robot moves out into an outer position participants display significantly more signs of fear opposed to when the robot arm is in a normal position....

  14. IndexCat

    Data.gov (United States)

    U.S. Department of Health & Human Services — IndexCat provides access to the digitized version of the printed Index-Catalogue of the Library of the Surgeon General's Office; eTK for medieval Latin texts; and...

  15. Body Mass Index Table

    Science.gov (United States)

    ... Families ( We Can! ) Health Professional Resources Body Mass Index Table 1 for BMI greater than 35, go ... Health Information Email Alerts Jobs and Careers Site Index About NHLBI National Institute of Health Department of ...

  16. Human Use Index

    Data.gov (United States)

    U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...

  17. Master Veteran Index (MVI)

    Data.gov (United States)

    Department of Veterans Affairs — As of June 28, 2010, the Master Veteran Index (MVI) database based on the enhanced Master Patient Index (MPI) is the authoritative identity service within the VA,...

  18. Human Use Index (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...

  19. Minimally Invasive Transforaminal Lumbar Interbody Fusion and Unilateral Fixation for Degenerative Lumbar Disease.

    Science.gov (United States)

    Wang, Hui-Wang; Hu, Yong-Cheng; Wu, Zhan-Yong; Wu, Hua-Rong; Wu, Chun-Fu; Zhang, Lian-Suo; Xu, Wei-Kun; Fan, Hui-Long; Cai, Jin-Sheng; Ma, Jian-Qing

    2017-08-01

    To evaluate the clinical effect of the minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation using a tubular retractor in the management of degenerative lumbar disease. A retrospective analysis was conducted to analyze the clinical outcome of 58 degenerative lumbar disease patients who were treated with minimally invasive transforaminal lumbar interbody fusion combined with posterolateral fusion and unilateral fixation during December 2012 to January 2015. The spine was unilaterally approached through a 3.0-cm skin incision centered on the disc space, located 2.5 cm lateral to the midline, and the multifidus muscles and longissimus dorsi were stripped off. After transforaminal lumbar interbody fusion and posterolateral fusion the unilateral pedicle screw fixation was performed. The visual analogue scale (VAS) for back and leg pain, the Oswestry disability index (ODI), and the MacNab score were applied to evaluate clinical effects. The operation time, peri-operative bleeding, postoperative time in bed, hospitalization costs, and the change in the intervertebral height were analyzed. Radiological fusion based on the Bridwell grading system was also assessed at the last follow-up. The quality of life of the patients before and after the operation was assessed using the short form-36 scale (SF-36). Fifty-eight operations were successfully performed, and no nerve root injury or dural tear occurred. The average operation time was 138 ± 33 min, intraoperative blood loss was 126 ± 50 mL, the duration from surgery to getting out of bed was 46 ± 8 h, and hospitalization cost was 1.6 ± 0.2 ten thousand yuan. All of the 58 patients were followed up for 7-31 months, with an average of 14.6 months. The postoperative VAS scores and ODI score were significantly improved compared with preoperative data (P degenerative lumbar disease, and the short-term clinical outcome is satisfactory

  20. Tests of prototype ITS-SSD Ladder and Fixators

    CERN Document Server

    Van den Brink, D J; CERN. Geneva; Nooren, G J L; Feofilov, G A; Igolkin, S N; Daudo, F; Giraudo, G; van den Broek, D J

    2000-01-01

    Abstract A prototype carbon fibre SSD ladder, produced in St.Petersburg, was equipped in Utrecht with mounting blocks, designed in Torino, for the fixation on the ITS cone. Instead of the cone, a specially designed jig was used. The mechanical properties were measured in order to find out whether the design and the production method are compliant with the requirements given in the TDR.

  1. POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

    OpenAIRE

    Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

    2013-01-01

    Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

  2. Salvage of infected total knee arthroplasty with Ilizarov external fixator

    Directory of Open Access Journals (Sweden)

    Venkata Gurava Reddy

    2011-01-01

    Full Text Available Background: Knee arthrodesis may be the only option of treatment in cases of chronic infected total knee arthroplasty (TKA with concomitant irreparable extensor mechanism disruption, extensive bone loss or severe systemic morbidities. Circular external fixation offers possible progressive adjustment to stimulate the bony fusion and to make corrections in alignment. We evaluated the results of knee arthrodesis with one or two stage circular external fixator for infected TKA. Materials and Methods: 16 cases of femoro-tibial fusion were retrospectively evaluated. Male-to-female ratio was 10:6. Mean age of the patients was 62.2 years. Cierney-Mader classification was used for anatomical and physiological evaluation while the bone stock deficiency was classified into mild, moderate and severe. Surgical technique involved either single or two stage arthrodesis using circular external fixator. Results: Union was achieved in 15 patients (93.75%. The mean duration for union (frame application time in these patients was 28.33 weeks (range 22 to 36 weeks. Analysis showed that in the group with frame application time of less than 28 weeks, the incidence of mild to moderate bone deficiency was 83.33%, while in the frame application time more than 28 weeks group the incidence was 20% (P-value 0.034. Similarly the incidence of Cierney-Mader 4B (Bl, Bs, Bls was found to be 33.33% in the group of frame application time of less than 28 weeks, while it was 90% in the group with frame application time more than 28 weeks (P-value 0.035. Conclusion: Circular external fixator is a safe and reliable method to achieve knee arthrodesis in cases of deep infection following TKA. Severe bone stock deficiency and Cierney- Mader type B host are likely risk factors for prolonged frame application time. We recommend a two-stage procedure especially when there is compromised host or severe bone loss.

  3. CO(2) fixation through hydrogenation by chemical or enzymatic methods.

    Science.gov (United States)

    Beller, Matthias; Bornscheuer, Uwe T

    2014-04-25

    Two birds with one stone: The simulaneous fixation of the greenhouse gas carbon dioxide and storage of the alternative fuel hydrogen can be accomplished with the formation of formic acid. In principle, this is now possible either with an enzymatic system based on a newly discovered bacterial hydrogen-dependent carbon dioxide reductase or by using organometallic catalysts at room temperature and ambient pressure. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Internal Fixation of Open Ankle Fracture. Report of Two Cases

    OpenAIRE

    Yaniel Truffin Rodríguez; Juan C. Cabrera Suárez; Indira L. Gómez Gil; José Julio Requeiro Morejón

    2014-01-01

    Open ankle fracture is sporadically seen in the orthopedic practice. Its clinical course is subject to multiple factors, showing a propensity to cause ankle osteoarthritis over the years. Two cases treated at the Dr. Gustavo Aldereguía Lima University General Hospital in Cienfuegos are presented. The patients underwent emergency surgical treatment consisting of surgical cleaning of the open wound, reduction of the dislocation and internal fixation of the fracture. These cases are presented du...

  5. Biomechanical study of pedicle screw fixation in severely osteoporotic bone.

    Science.gov (United States)

    Cook, Stephen D; Salkeld, Samantha L; Stanley, Tom; Faciane, Albert; Miller, Scot D

    2004-01-01

    Obtaining adequate purchase with standard pedicle screw techniques remains a challenge in poor quality bone. The development of alternate insertion techniques and screw designs was prompted by recognition of potential fixation complications. An expandable pedicle screw design has been shown to significantly improve fixation compared to a conventional screw in poor quality bone. The purpose of this study was to determine if polymethylmethacrylate (PMMA) bone cement augmentation of an expandable pedicle screw can further improve fixation strength compared to the expandable screw alone in severely osteoporotic bone. A technique for cement insertion into the pedicle by means of the cannulated central portion of the expandable screw is also described. The axial pullout strength, stiffness and energy absorbed of cemented and noncemented expandable pedicle screws was determined in cadaveric vertebrae. Twenty-one fresh unembalmed vertebrae from the thoracolumbar spine were used. Radiographs and bone mineral density measurements (BMD) were used to characterize bone quality. Paired cemented and noncemented pedicle screw axial pullout strength was determined through mechanical testing. Mechanical pullout strength, stiffness and energy to failure was correlated with BMD. Overall, there was a 250% increase in mean pullout strength with the cemented expandable screw compared with a noncemented expandable screw including a greater than twofold increase in pullout strength in the most severely osteoporotic bone. The mean stiffness and energy absorbed to failure was also significantly increased. A cemented conventional screw achieved a pullout strength similar to the noncemented expandable screw. PMMA cement augmentation of the expandable pedicle screw may be a viable clinical option for achieving fixation in severely osteoporotic bone.

  6. Indexing Executive Compensation Contracts

    NARCIS (Netherlands)

    I. Dittmann (Ingolf); E.G. Maug (Ernst); O.G. Spalt (Oliver)

    2013-01-01

    textabstractWe analyze the efficiency of indexing executive pay by calibrating the standard model of executive compensation to a large sample of US CEOs. The benefits from linking the strike price of stock options to an index are small and fully indexing all options would increase compensation costs

  7. The Europe 2020 Index

    Science.gov (United States)

    Pasimeni, Paolo

    2013-01-01

    This paper presents a new index to quantify, measure and monitor the progress towards the objectives of the Europe 2020 strategy. This index is based on a set of relevant, accepted, credible, easy to monitor and robust indicators presented by the European Commission at the time the strategy was launched. The internal analysis of the index shows…

  8. Early embolization without external fixation in pelvic trauma.

    Science.gov (United States)

    Tanizaki, Shinsuke; Maeda, Shigenobu; Hayashi, Hiroyuki; Matano, Hideyuki; Ishida, Hiroshi; Yoshikawa, Jun; Yamamoto, Toru

    2012-02-01

    In this retrospective study, we reviewed our protocol consisting of early embolization without acute external fixation in patients with pelvic fracture. Eighty-eight patients with pelvic fracture were identified by reviewing the records of the Fukui Prefectural Hospital from April 2005 through September 2009. We managed the patients with a treatment protocol consisting of hemodynamic resuscitation and early pelvic embolization. Patients with hemodynamic instability without nonpelvic hemorrhage or extravasation of contrast in the pelvis by computed tomography (CT) were indicated to angiography and embolization. External fixation of the pelvic ring was not used in our protocol. Of the 88 patients with pelvic fractures, 43 underwent angiography. Twenty-eight patients (65%) were hemodynamically unstable. Twenty-five patients (58%) had major ligamentous disruption. Computed tomography detected extravasation in 21 patients (48%). Of the 43 patients who underwent angiography, 29 (67%) were positive. The average time from hospital arrival to angiography was 76.3 ± 34.5 minutes. The packed red blood cell requirement in the initial 24 hours was 8.4 ± 8.2 U, required in the embolization group. There was no complication-related embolization. Repeat angiography was not required in all patients. The mortality rate of patients requiring angiography was 11%. Early pelvic embolization without external fixation may be useful for the initial treatment for patients with hemodynamic instability without nonpelvic hemorrhage or with extravasation of contrast in the pelvis by CT. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  9. Fixational eye movements during viewing of dynamic natural scenes

    Directory of Open Access Journals (Sweden)

    James A. Roberts

    2013-10-01

    Full Text Available Even during periods of fixation our eyes undergo small amplitude movements. These movements are thought to be essential to the visual system because neural responses rapidly fade when images are stabilized on the retina. The considerable recent interest in fixational eye movements (FEMs has thus far concentrated on idealized experimental conditions with artificial stimuli and restrained head movements, which are not necessarily a suitable model for natural vision. Natural dynamic stimuli, such as movies, offer the potential to move beyond restrictive experimental settings to probe the visual system with greater ecological validity. Here, we study FEMs recorded in humans during the unconstrained viewing of a dynamic and realistic visual environment, revealing that drift trajectories exhibit the properties of a random walk with memory. Drifts are correlated at short time scales such that the gaze position diverges from the initial fixation more quickly than would be expected for an uncorrelated random walk. We propose a simple model based on the premise that the eye tends to avoid retracing its recent steps to prevent photoreceptor adaptation. The model reproduces key features of the observed dynamics and enables estimation of parameters from data. Our findings show that FEM correlations thought to prevent perceptual fading exist even in highly dynamic real-world conditions.

  10. Fixation probabilities of evolutionary coordination games on two coupled populations

    Science.gov (United States)

    Zhang, Liye; Ying, Limin; Zhou, Jie; Guan, Shuguang; Zou, Yong

    2016-09-01

    Evolutionary forces resulted from competitions between different populations are common, which change the evolutionary behavior of a single population. In an isolated population of coordination games of two strategies (e.g., s1 and s2), the previous studies focused on determining the fixation probability that the system is occupied by only one strategy (s1) and their expectation times, given an initial mixture of two strategies. In this work, we propose a model of two interdependent populations, disclosing the effects of the interaction strength on fixation probabilities. In the well-mixing limit, a detailed linear stability analysis is performed, which allows us to find and to classify the different equilibria, yielding a clear picture of the bifurcation patterns in phase space. We demonstrate that the interactions between populations crucially alter the dynamic behavior. More specifically, if the coupling strength is larger than some threshold value, the critical initial density of one strategy (s1) that corresponds to fixation is significantly delayed. Instead, the two populations evolve to the opposite state of all (s2) strategy, which are in favor of the red queen hypothesis. We delineate the extinction time of strategy (s1) explicitly, which is an exponential form. These results are validated by systematic numerical simulations.

  11. Nitrogen fixation in four dryland tree species in central Chile

    International Nuclear Information System (INIS)

    Ovalle, C.; Arredondo, S.; Aronson, J.; Longeri, L.; Avendano, J.

    1998-01-01

    Results are presented from a 5-year experiment using 15 N-enriched fertilizer to determine N 2 fixation in four tree species on degraded soils in a Mediterranean-climate region of central Chile in which there are 5 months of drought. Species tested included three slow-growing but long-lived savannah trees native to southers South America, (acacia caven, Prosopic alba and P. chilensis; Mimosoideae), and Tagasaste (Chamaecytisus proliferus ssp. palmensis; Papilonoideae), a fast-growing but medium-lived tree from the Canary Islands. Tagasaste produced four- to twenty-fold more biomass than the other species, but showed declining N 2 fixation and biomass accumulation during the 5th year, corresponding to the juvenile-to-adult developmental transition. Nitrogen content was significantly higher in Tagasaste and Acacia caven than in the other species. The data revealed inter-specific differences in resource allocation and phenology of N 2 fixation rarely detailed for woody plants in dryland regions. (author)

  12. Biomechanical effects of pedicle screw fixation on adjacent segments.

    Science.gov (United States)

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically possible range, and it might gradually lead to a degenerative intervertebral disc or progression of spondylolisthesis in the adjacent segments.

  13. A Mathematic Approach to Nitrogen Fixation Through Earth History

    Science.gov (United States)

    Delgado-Bonal, Alfonso; Martín-Torres, F. Javier

    Nitrogen is essential for life as we know it. According to phylogenetic studies, all organisms capable of fixing nitrogen are prokaryotes, both bacteria and archaea, suggesting that nitrogen fixation and ammonium assimilation were metabolic features of the Last Universal Common Ancestor of all organisms. At present time the amount of biologically fixed nitrogen is around 2 × 1{0}^{13} g/year (Falkowski 1997), an amount much larger than the corresponding to the nitrogen fixed abiotically (between 2. 6 ×109 and 3 × 1{0}^{11} g/year) (Navarro-González et al. 2001). The current amount of nitrogen fixed is much higher than it was on Earth before the Cambrian explosion, where the symbiotic associations with leguminous plants, the major nitrogen fixer currently, did not exist and nitrogen was fixed only by free-living organisms as cyanobacteria. It has been suggested (Navarro-González et al. 2001) that abiotic sources of nitrogen fixation during Early Earth times could have an important role triggering a selection pressure favoring the evolution of nitrogenase and an increase in the nitrogen fixation rate. In this study we present briefly a method to analyze the amount of fixed nitrogen, both biotic and abiotic, through Earth's history.

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Sorption and fixation of large cations by shale formations

    International Nuclear Information System (INIS)

    Brindley, G.W.

    1977-01-01

    Large cations such as Cs + are preferentially sorbed and partially fixed by fine-grained 2 : 1 type layer silicates such as micas, vermiculites, smectites and various mixed-layer minerals. Since these minerals are common constituents of many shale formations, these formations may provide suitable location for the burial of radioactive waste containers. However, the usual investigations of cation sorption and fixation must be extended to the conditions likely to develop in the vicinity of buried radioactive waste. Prior to possible leakage from buried containers, elevated temperatures around the burial site will develop leading to hydrothermal modification of the surrounding mineralogy. A range of temperature and of mineralogy must be envisaged. If and when leakage occurs, an outward diffusion of radioactive ions will occur by solvation in the fluids in the shale. The ratio of radioactive ions/normal ions will diminish outwards from the source. At near distances from the source high temperature modifications of the clay minerals and high concentrations of radioactive cations may lead to saturation of the fixation capacity. At greater distances, little or no thermal modification of the clay minerals and lower concentrations of ions will permit maximum sorption and fixation

  16. Anterior cervical decompression and fusion with caspar plate fixation

    International Nuclear Information System (INIS)

    Rehman, L.; Akbar, H.; Das, G.; Hashim, A.S.M.

    2013-01-01

    Objective: To evaluate the role of anterior cervical decompression and fixation with Caspar plating in cervical spine injury on neurological outcome. Study Design: A case series. Place and Duration of Study: Department of Neurosurgery, Jinnah Postgraduate Medical Centre, Karachi, from July 2008 to March 2011. Methodology: Thirty patients admitted with cervical spine injuries were inducted in the study. All cases were evaluated for their clinical features, level of injury and degree of neurological injury was assessed using Frankel grading. Pre and postoperative record with X-rays and MRI were maintained. Cervical traction was applied to patients with sub-luxation. All patients underwent anterior cervical decompression, fusion and Caspar plate fixation. The follow-up period was 6 months with clinical and radiological assessment. Results: Among 30 patients, 24 (80%) were males and 6 (20%) were females. Age ranged from 15 to 55 years. Causes of injury were road traffic accident (n = 20), fall (n = 8) and assault (n = 2). Commonest mode of injury was road traffic accident (66.6%). Postoperative follow-up showed that pain and neurological deficit were improved in 21 patients. There was no improvement in 7 patients, one patient deteriorated and one expired. All patients developed pain at donor site. Conclusion: Anterior decompression, fusion and fixation with Caspar plate is an effective method with good neurological and radiological outcome. However, it is associated with pain at donor site. (author)

  17. Exact numerical calculation of fixation probability and time on graphs.

    Science.gov (United States)

    Hindersin, Laura; Möller, Marius; Traulsen, Arne; Bauer, Benedikt

    2016-12-01

    The Moran process on graphs is a popular model to study the dynamics of evolution in a spatially structured population. Exact analytical solutions for the fixation probability and time of a new mutant have been found for only a few classes of graphs so far. Simulations are time-expensive and many realizations are necessary, as the variance of the fixation times is high. We present an algorithm that numerically computes these quantities for arbitrary small graphs by an approach based on the transition matrix. The advantage over simulations is that the calculation has to be executed only once. Building the transition matrix is automated by our algorithm. This enables a fast and interactive study of different graph structures and their effect on fixation probability and time. We provide a fast implementation in C with this note (Hindersin et al., 2016). Our code is very flexible, as it can handle two different update mechanisms (Birth-death or death-Birth), as well as arbitrary directed or undirected graphs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Potential carbon dioxide fixation by industrially important microalgae.

    Science.gov (United States)

    Sydney, Eduardo Bittencourt; Sturm, Wilerson; de Carvalho, Julio Cesar; Thomaz-Soccol, Vanete; Larroche, Christian; Pandey, Ashok; Soccol, Carlos Ricardo

    2010-08-01

    The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii SAG-30.81. Global rates of carbon dioxide and oxygen were determinated by a system developed in our laboratory. B. braunii presented the highest CO(2) fixation rate, followed by S. platensis,D. tertiolecta and C. vulgaris (496.98, 318.61, 272.4 and 251.64 mg L(-1)day(-1), respectively). Carbon dioxide fixated was mainly used for microalgal biomass production. Nitrogen, phosphorus (calcium for D. tertiolecta), potassium and magnesium consumption rates (mg gX(-1)) were evaluated for the four microalgae. Biomass composition presented a predominance of proteins but also a high amount of lipids, especially in D. tertiolecta and B. braunii. (c) 2010. Published by Elsevier Ltd.

  19. An integer programming model for distal humerus fracture fixation planning.

    Science.gov (United States)

    Maratt, Joseph D; Peaks, Ya-Sin A; Doro, Lisa Case; Karunakar, Madhav A; Hughes, Richard E

    2008-05-01

    To demonstrate the feasibility of an integer programming model to assist in pre-operative planning for open reduction and internal fixation of a distal humerus fracture. We describe an integer programming model based on the objective of maximizing the reward for screws placed while satisfying the requirements for sound internal fixation. The model maximizes the number of bicortical screws placed while avoiding screw collision and favoring screws of greater length that cross multiple fracture planes. The model was tested on three types of total articular fractures of the distal humerus. Solutions were generated using 5, 9, 21 and 33 possible screw orientations per hole. Solutions generated using 33 possible screw orientations per hole and five screw lengths resulted in the most clinically relevant fixation plan and required the calculation of 1,191,975 pairs of screws that resulted in collision. At this level of complexity, the pre-processor took 104 seconds to generate the constraints for the solver, and a solution was generated in under one minute in all three cases. Despite the large size of this problem, it can be solved in a reasonable amount of time, making use of the model practical in pre-surgical planning.

  20. External Fixation versus two-stage Open Reduction Internal Fixation of distal intra-articular Tibia fractures; a Systematic Review

    DEFF Research Database (Denmark)

    Ladeby Erichsen, Julie; Jensen, Carsten; Damborg, Frank Lindhøj

    (>18 years) were included for review. 3071 studies were identified and screened by two independent authors according to the PRISMA guidelines. Cochrane Risk of bias Tool for RCT and non-randomised studies (ROBIN-1) were used to assess risk of bias. Results: One RCT study and four cohort studies......Background: Distal Intra-Articular Tibia Fractures (DIATF) is challenging to treat and severe loss of physical function affecting working abilities has been reported. Aim: To investigate differences in physical function and complications following DIATF surgery with two-stage Open Reduction...... Internal Fixation (ORIF) or External Fixation (EF). Method : A search was conducted using PUBMED, Embase, Cochrane Central, Open Grey, Orthopaedic Proceedings and WHO International Clinical Trials Registry Platform. Studies with level of evidence I-IV comparing EF with two-stage ORIF of DIATF in patients...

  1. Improvement of external fixator performance in type C pelvic ring injuries by plating of the pubic symphysis: An experimental study on 12 external fixators

    NARCIS (Netherlands)

    Ponson, K. J.; Hoek van Dijke, G. A.; Joosse, Pieter; Snijders, C. J.; Agnew, Samuel G.

    2002-01-01

    Background: In an earlier study, we introduced a pelvic ring stability criterion for weightbearing stabilization. In a loading test, however, current external fixation systems alone did not meet this criterion. Internal fixation of the dorsal ring can significantly increase stability, but the

  2. Biomechanical Comparison of External Fixation and Compression Screws for Transverse Tarsal Joint Arthrodesis.

    Science.gov (United States)

    Latt, L Daniel; Glisson, Richard R; Adams, Samuel B; Schuh, Reinhard; Narron, John A; Easley, Mark E

    2015-10-01

    Transverse tarsal joint arthrodesis is commonly performed in the operative treatment of hindfoot arthritis and acquired flatfoot deformity. While fixation is typically achieved using screws, failure to obtain and maintain joint compression sometimes occurs, potentially leading to nonunion. External fixation is an alternate method of achieving arthrodesis site compression and has the advantage of allowing postoperative compression adjustment when necessary. However, its performance relative to standard screw fixation has not been quantified in this application. We hypothesized that external fixation could provide transverse tarsal joint compression exceeding that possible with screw fixation. Transverse tarsal joint fixation was performed sequentially, first with a circular external fixator and then with compression screws, on 9 fresh-frozen cadaveric legs. The external fixator was attached in abutting rings fixed to the tibia and the hindfoot and a third anterior ring parallel to the hindfoot ring using transverse wires and half-pins in the tibial diaphysis, calcaneus, and metatarsals. Screw fixation comprised two 4.3 mm headless compression screws traversing the talonavicular joint and 1 across the calcaneocuboid joint. Compressive forces generated during incremental fixator foot ring displacement to 20 mm and incremental screw tightening were measured using a custom-fabricated instrumented miniature external fixator spanning the transverse tarsal joint. The maximum compressive force generated by the external fixator averaged 186% of that produced by the screws (range, 104%-391%). Fixator compression surpassed that obtainable with screws at 12 mm of ring displacement and decreased when the tibial ring was detached. No correlation was found between bone density and the compressive force achievable by either fusion method. The compression across the transverse tarsal joint that can be obtained with a circular external fixator including a tibial ring exceeds that

  3. The head to foot screw fixation. A new technique of percutaneous screw fixation of the scaphoid bone.

    Science.gov (United States)

    Zaraa, Mourad; Ben Slama, Safouane; Mahjoub, Sabri; Sehli, Heithem; Hadj Salah, Méhdi; Mbarek, Mondher

    2017-01-01

    Many techniques have been described for screw fixation of the scaphoid bone. The approach is either proximal or dorsal. A new percutaneous technique is presented by the authors called the head to foot screw fixation. Indications and results are evaluated. It is a percutaneous technique with fixation of the scaphoid bone by two screws introduced in an opposite direction: a proximal screw and a distal screw. No postoperative immobilization was necessary. A prospective study was conducted in 40 patients over a period of three years. The average age was 25 years with extremes of 14 and 44 years. This technique was practiced in fractures (30 cases) and nonunion (10 cases) in which the localization was proximal, corresponding to Schernberg types I, II and III. Forms associated with perilunate dislocation of the carpus were excluded from the study. The results were analysed with a mean of 8 months (6-30). Union was obtained in all the cases. No tendon injury related to percutaneous approach was noted. The technique required a learning curve with progressive decrease in operative time from 45 to 15 minutes. It was necessary in two cases to change protruding screws which were not diagnosed during the first intervention. Percutaneous screw fixation was achieved again in both cases.   Conclusions: The combination in our experience of two screws allowed us to prevent rotation around the unthreated area of a single screw. Our technique, bringing together the head to the foot of the screw, reduces the crowding at the proximal part of the scaphoid bone. This non-invasive method permitted early mobilization with no pain until biological union.

  4. Visual memory for fixated regions of natural images dissociates attraction and recognition.

    Science.gov (United States)

    van der Linde, Ian; Rajashekar, Umesh; Bovik, Alan C; Cormack, Lawrence K

    2009-01-01

    Recognition memory for fixated regions from briefly viewed full-screen natural images is examined. Low-level image statistics reveal that observers fixated, on average (pooled across images and observers), image regions that possessed greater visual saliency than non-fixated regions, a finding that is robust across multiple fixation indices. Recognition-memory performance indicates that, of the fixation loci tested, observers were adept at recognising those with a particular profile of image statistics; visual saliency was found to be attenuated for unrecognised loci, despite that all regions were freely fixated. Furthermore, although elevated luminance was the local image statistic found to discriminate least between human and random image locations, it was the greatest predictor of recognition-memory performance, demonstrating a dissociation between image features that draw fixations and those that support visual memory. An analysis of corresponding eye movements indicates that image regions fixated via short-distance saccades enjoyed better recognition-memory performance, alluding to a focal rather than ambient mode of processing. Recognised image regions were more likely to have originated from areas evaluated (a posteriori) to have higher fixation density, a numerical metric of local interest. Surprisingly, memory for image regions fixated later in the viewing period exhibited no recency advantage, despite (typically) also being longer in duration, a finding for which a number of explanations are posited.

  5. Interference Screw vs. Suture Anchor Fixation for Open Subpectoral Biceps Tenodesis: Does it Matter?

    Directory of Open Access Journals (Sweden)

    Gobezie Reuben

    2008-09-01

    Full Text Available Abstract Background Bioabsorbable interference screw fixation has superior biomechanical properties compared to suture anchor fixation for biceps tenodesis. However, it is unknown whether fixation technique influences clinical results. Hypothesis We hypothesize that subpectoral interference screw fixation offers relevant clinical advantages over suture anchor fixation for biceps tenodesis. Study Design Case Series. Methods We performed a retrospective review of a consecutive series of 88 patients receiving open subpectoral biceps tenodesis with either interference screw fixation (34 patients or suture anchor fixation (54 patients. Average follow up was 13 months. Outcomes included Visual Analogue Pain Scale (0–10, ASES score, modified Constant score, pain at the tenodesis site, failure of fixation, cosmesis, deformity (popeye and complications. Results There were no failures of fixation in this study. All patients showed significant improvement between their preoperative and postoperative status with regard to pain, ASES score, and abbreviated modified Constant scores. When comparing IF screw versus anchor outcomes, there was no statistical significance difference for VAS (p = 0.4, ASES score (p = 0.2, and modified Constant score (P = 0.09. One patient (3% treated with IF screw complained of persistent bicipital groove tenderness, versus four patients (7% in the SA group (nonsignificant. Conclusion Subpectoral biceps tenodesis reliably relieves pain and improves function. There was no statistically significant difference in the outcomes studied between the two fixation techniques. Residual pain at the site of tenodesis may be an issue when suture anchors are used in the subpectoral location.

  6. Molybdenum and phosphorus interact to constrain asymbiotic nitrogen fixation in tropical forests.

    Directory of Open Access Journals (Sweden)

    Nina Wurzburger

    Full Text Available Biological di-nitrogen fixation (N(2 is the dominant natural source of new nitrogen to land ecosystems. Phosphorus (P is thought to limit N(2 fixation in many tropical soils, yet both molybdenum (Mo and P are crucial for the nitrogenase reaction (which catalyzes N(2 conversion to ammonia and cell growth. We have limited understanding of how and when fixation is constrained by these nutrients in nature. Here we show in tropical forests of lowland Panama that the limiting element on asymbiotic N(2 fixation shifts along a broad landscape gradient in soil P, where Mo limits fixation in P-rich soils while Mo and P co-limit in P-poor soils. In no circumstance did P alone limit fixation. We provide and experimentally test a mechanism that explains how Mo and P can interact to constrain asymbiotic N(2 fixation. Fixation is uniformly favored in surface organic soil horizons--a niche characterized by exceedingly low levels of available Mo relative to P. We show that soil organic matter acts to reduce molybdate over phosphate bioavailability, which, in turn, promotes Mo limitation in sites where P is sufficient. Our findings show that asymbiotic N(2 fixation is constrained by the relative availability and dynamics of Mo and P in soils. This conceptual framework can explain shifts in limitation status across broad landscape gradients in soil fertility and implies that fixation depends on Mo and P in ways that are more complex than previously thought.

  7. Comparison of three fixations for tibial plateau fractures by biomechanical study and radiographic observation.

    Science.gov (United States)

    Chen, Hong-wei; Liu, Guo-dong; Ou, Shan; Jiang, Xie-yuan; Fei, Jun; Wu, Li-jun

    2015-01-01

    The aim of this study was to compare the fixation effects of three fixation devices for tibial plateau fracture (AO/OTA classification 41 A1). Sixteen human cadaver tibial specimens were randomly divided into four groups. An A1 fracture model was established. The fractures were subsequently fixed by axial controlled intramedullary nail, external fixation and steel plate fixation. Each specimen was subjected to axial compression, torsion test and three-point bending test. Then a rat model was used to evaluate the therapeutic effect of these three fixations by evaluation of callus formation time and healing time. It was found that the axial controlled intramedullary nail group obtained superior biomechanical properties of resistance ability of bending, torsional and axial compressive, compared with external fixation and steel plate group. In animal experiments, the axial controlled intramedullary nail group had a significant shorter callus occurrence and healing time than steel plate and external fixator group. The axial controlled intramedullary nail fixation has a superior biomechanical characteristic and fixation effect for tibial plateau fractures than steel plate and external fixator. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  8. The retinal locus of fixation in simulations of progressing central scotomas.

    Science.gov (United States)

    Barraza-Bernal, Maria J; Rifai, Katharina; Wahl, Siegfried

    2018-01-01

    Patients with central scotoma use a preferred retinal locus (PRL) of fixation to perform visual tasks. Some of the conditions that cause central scotoma are progressive, and as a consequence, the PRL needs to be adjusted throughout the progression. The present study investigates the peripheral locus of fixation in subjects under a simulation of progressive central scotoma. Five normally sighted subjects participated in the study. A foveally centered mask of varying size was presented to simulate the scotoma. Initially, subjects developed a peripheral locus of fixation under simulation of a 6° scotoma, which was used as a baseline. The progression was simulated in two separate conditions: a gradual progression and an abrupt progression. In the gradual progression, the diameter of the scotoma increased by a fixed amount of either 1° or 2° of visual angle, thus scotomas of 8°, 10°, and 11° of visual angle were simulated. In the abrupt progression, the diameter was adjusted individually to span the area of the visual field used by the current peripheral locus of fixation. Subjects located the peripheral locus of fixation along the same meridian under simulation of scotoma progression. Furthermore, no differences between the fixation stability of the baseline locus of fixation and the incremental progression locus of fixation were found whereas, in abrupt progression, the fixation stability decreased significantly. These results provide first insight into fixation behavior in a progressive scotoma and may contribute to the development of training tools for patients with progressive central maculopathies.

  9. The bridge and barrel hoop plates as alternatives to external fixation techniques in the foot and ankle.

    Science.gov (United States)

    Cammack, Paul M; Donahue, Michael P; Manoli, Arthur

    2004-09-01

    External fixation is a useful tool for treating severe traumatic injuries to the foot and ankle. External fixation, however, does have associated complications, such as inadequate fixation and pin tract infections. Temporary bridge plating of the medial, lateral, or both columns is a useful alternative to external fixation for treating multilevel foot injuries. This article describes the technique of temporary bridge plating which may be used as an alternative to external fixation.

  10. Capture of fixation by rotational flow; a deterministic hypothesis regarding scaling and stochasticity in fixational eye movements

    Directory of Open Access Journals (Sweden)

    Nicholas Mansel Wilkinson

    2014-02-01

    Full Text Available Visual scan paths exhibit complex, stochastic dynamics. Even during visual fixation, the eye is in constant motion. Fixational drift and tremor are thought to reflect fluctuations in the persistent neural activity of neural integrators in the oculomotor brainstem, which integrate sequences of transient saccadic velocity signals into a short term memory of eye position. Despite intensive research and much progress, the precise mechanisms by which oculomotor posture is maintained remain elusive. Drift exhibits a stochastic statistical profile which has been modelled using random walk formalisms. Tremor is widely dismissed as noise. Here we focus on the dynamical profile of fixational tremor, and argue that tremor may be a signal which usefully reflects the workings of the oculomotor postural control. We identify signatures reminiscent of a certain flavour of transient neurodynamics; toric travelling waves which rotate around a central phase singularity. Spiral waves play an organisational role in dynamical systems at many scales throughout nature, though their potential functional role in brain activity remains a matter of educated speculation. Spiral waves have a repertoire of functionally interesting dynamical properties, including persistence, which suggest that they could in theory contribute to persistent neural activity in the oculomotor postural control system. Whilst speculative, the singularity hypothesis of oculomotor postural control implies testable predictions, and could provide the beginnings of an integrated dynamical framework for eye movements across scales.

  11. Solar Water Splitting and Nitrogen Fixation with Layered Bismuth Oxyhalides.

    Science.gov (United States)

    Li, Jie; Li, Hao; Zhan, Guangming; Zhang, Lizhi

    2017-01-17

    Hydrogen and ammonia are the chemical molecules that are vital to Earth's energy, environmental, and biological processes. Hydrogen with renewable, carbon-free, and high combustion-enthalpy hallmarks lays the foundation of next-generation energy source, while ammonia furnishes the building blocks of fertilizers and proteins to sustain the lives of plants and organisms. Such merits fascinate worldwide scientists in developing viable strategies to produce hydrogen and ammonia. Currently, at the forefronts of hydrogen and ammonia syntheses are solar water splitting and nitrogen fixation, because they go beyond the high temperature and pressure requirements of methane stream reforming and Haber-Bosch reaction, respectively, as the commercialized hydrogen and ammonia production routes, and inherit the natural photosynthesis virtues that are green and sustainable and operate at room temperature and atmospheric pressure. The key to propelling such photochemical reactions lies in searching photocatalysts that enable water splitting into hydrogen and nitrogen fixation to make ammonia efficiently. Although the past 40 years have witnessed significant breakthroughs using the most widely studied TiO 2 , SrTiO 3 , (Ga 1-x Zn x )(N 1-x O x ), CdS, and g-C 3 N 4 for solar chemical synthesis, two crucial yet still unsolved issues challenge their further progress toward robust solar water splitting and nitrogen fixation, including the inefficient steering of electron transportation from the bulk to the surface and the difficulty of activating the N≡N triple bond of N 2 . This Account details our endeavors that leverage layered bismuth oxyhalides as photocatalysts for efficient solar water splitting and nitrogen fixation, with a focus on addressing the above two problems. We first demonstrate that the layered structures of bismuth oxyhalides can stimulate an internal electric field (IEF) that is capable of efficiently separating electrons and holes after their formation and of

  12. [DESIGN AND CLINICAL APPLICATION OF LESSER TROCHANTERIC REDUCTION FIXATION SYSTEM].

    Science.gov (United States)

    Guo, Xiaoze; Zhang, Ying; Xiao, Jin; Xie, Huibin; Yu, Jiefeng

    2015-02-01

    To design and produce a lesser trochanteric reduction fixation system and verify its value and effectiveness. A lesser trochanteric reduction fixation system was designed and produced according to the anatomical features of the lesser trochanteric fractures. Sixty-six patients with intertrochanteric fractures of Evans type III were included between January 2010 and July 2012. Of 66 patients, 32 were treated with dynamic hip screw (DHS) assisted with the lesser trochanteric reduction fixation system (study group), and 34 cases were treated with DHS only (control group). The 2 groups were comparable with no significant difference in gender, age, the reasons, and the types of the fractures (P > 0.05). The operation time, intraoperative blood loss, neck-shaft angle, bone healing time, ratio of successful fixations, and the functional evaluation of the hip joint after operation were compared between 2 groups. The study group had shorter operation time [(58.4 ± 5.3) minutes] and less intraoperative blood loss [(186.3 ± 6.6) mL than the control group [(78.5 ± 6.2)minutes and (246.2 ± 8.7) mL], showing significant differences (t = -14.040, P = 0.000; t = -31.145, P = 0.000). There was no significant difference in neck-shaft angle between study group [(138.6 ± 3.0)] and control group [(139.4 ± 2.9) degrees] (t = -1.044, P = 0.301). The wounds healed by first intention in both groups. The 30 and 31 patients were followed up 12 to 24 months (mean, 15 months) in the study group, and 13 to 25 months (mean, 16 months) in the control group, respectively. All fractures healed well in 2 groups. The study group had significantly shorter healing time [(8.8 ± 2.0) weeks] than the control group [(10.7 ± 3.4) weeks] (t = -2.871, P = 0.006). At 12 months after operation, coxa vara happened in 2 cases of the study group with a successful fixation ratio of 93.3% and in 10 cases of the control group with a successful fixation ratio of 67.7%, showing significant difference (Χ2 = 6

  13. Biomechanical comparison of mono-segment transpedicular fixation with short-segment fixation for treatment of thoracolumbar fractures: a finite element analysis.

    Science.gov (United States)

    Xu, Guijun; Fu, Xin; Du, Changling; Ma, Jianxiong; Li, Zhijun; Tian, Peng; Zhang, Tao; Ma, Xinlong

    2014-10-01

    Mono-segment transpedicular fixation is a method for the treatment of certain types of thoracolumbar spinal fracture. Finite element models were constructed to evaluate the biomechanics of mono-segment transpedicular fixation of thoracolumbar fracture. Spinal motion (T10-L2) was scanned and used to establish the models. The superior half of the cortical bone of T12 was removed and the superior half of the cancellous bone of the T12 body was assigned the material properties of injured bone to mimic vertebral fracture. Transpedicular fixation of T11 and T12 was performed to produce a mono-segment fixation model; T11 and L1 were fixed to produce a short-segment fixation model. Motion differences between functional units and von Mises stress on the spine and implants were measured under axial compression, anterior bending, extensional bending, lateral bending and axial rotation. We found no significant difference between mono- and short-segment fixations in the motion of any functional unit. Stress on the T10/T11 nucleus pulposus and T10/T11 and L1/L2 annulus fibrosus increased significantly by about 75% on anterior bending, extensional bending and lateral bending. In the fracture model, stress was increased by 24% at the inferior endplate of T10 and by 43% at the superior endplate of L2. All increased stresses were reduced after fixation and lower stress was observed with mono-segment fixation. In summary, the biomechanics of mono-segment pedicle screw instrumentation was similar to that of conventional short-segment fixation. As a minimally invasive treatment, mono-segment fixation would be appropriate for the treatment of selected thoracolumbar spinal fractures. © IMechE 2014.

  14. Glycemic index, insulinemic index, and satiety index of kefir.

    Science.gov (United States)

    Kong, Kai Ling; Hendrich, Suzanne

    2012-08-01

    To determine glycemic, insulinemic, and satiety indices of 3 types of kefir. This study was divided into 3 phases. In phase 1, 50 g of available carbohydrate from low-fat strawberry kefir or orange kefir was tested, and in phase 2, low-fat plain kefir containing 25 g of available carbohydrates was tested for glycemic index (GI), in both cases compared with an equivalent amount of glucose. In phase 3, 1000-kJ portions of all 3 types of kefirs were compared with white bread with the same energy content to determine the insulinemic index (II) and satiety index (SI) of all 3 kefirs. In all phases, a single-meal, randomized crossover design was performed in which the test meals were given to healthy adults, 5 men and 5 women. The total incremental plasma glucose area under the curve (iAUC) for strawberry, orange, and plain kefirs was significantly lower compared with the respective high-GI control food, which was glucose solution. However, the IIs and SIs of kefir did not differ significantly from the white bread. Kefir is a low- to moderate-GI food; however, its II was high. Although kefir had higher water content, the SI of kefir was not significantly different from white bread.

  15. Mesh fixation with glue versus suture for chronic pain and recurrence in Lichtenstein inguinal hernioplasty.

    Science.gov (United States)

    Sun, Ping; Cheng, Xiang; Deng, Shichang; Hu, Qinggang; Sun, Yi; Zheng, Qichang

    2017-02-07

    Chronic pain following mesh-based inguinal hernia repair is frequently reported, and has a significant impact on quality of life. Whether mesh fixation with glue can reduce chronic pain without increasing the recurrence rate is still controversial. To determine whether tissue adhesives can reduce postoperative complications, especially chronic pain, with no increase in recurrence rate, compared with sutures for mesh fixation in Lichtenstein hernia repair. We searched the following electronic databases with no language restrictions: the Cochrane Central Register of Controlled Trials (CENTRAL; issue 4, 2016) in the Cochrane Library (searched 11 May 2016), MEDLINE Ovid (1986 to 11 May 2016), Embase Ovid (1986 to 11 May 2016), Science Citation Index (Web of Science) (1986 to 11 May 2016), CBM (Chinese Biomedical Database), CNKI (China National Knowledge Infrastructure), VIP (a full-text database in China), Wanfang databases. We also checked reference lists of identified papers (included studies and relevant reviews). We included all randomised and quasi-randomised controlled trials comparing glue versus sutures for mesh fixation in Lichtenstein hernia repair. Cluster-RCTs were also eligible. Two review authors extracted data and assessed the risk of bias independently. Dichotomous outcomes were expressed as odds ratio (OR) with 95% confidence intervals (CI). Continuous outcomes were expressed as mean differences (MD) with 95% CIs. Twelve trials with a total of 1932 participants were included in this review. The overall postoperative chronic pain in the glue group was reduced by 37% (OR 0.63, 95% CI 0.44 to 0.91; 10 studies, 1418 participants, low-quality evidence) compared with the suture group. However, the results changed when we conducted subgroup analysis with regard to the type of mesh. Subgroup analysis of included studies using lightweight mesh showed the reduction of chronic pain was less profound and insignificant (OR 0.77, 95% CI 0.50 to 1.17). Subgroup

  16. [Case-control study on effects of external fixation combined with limited internal fixation for the treatment of Pilon fractures of Rüedi-Allgower type III].

    Science.gov (United States)

    Duan, Da-Peng; You, Wu-Lin; Ji, Le; Zhang, Yong-Tao; Dang, Xiao-Qian; Wang, Kun-Zheng

    2014-01-01

    To analyze the effects of three surgical operations in the treatment of Pilon fracture of Rüedi-Allgower type III, and put forward the best therapeutic method. The clinical data of 33 patients with Pilon fracture who received surgical operations (plaster immobilization group, 10 cases; distal tibia anatomical plate group, 11 cases; external fixation with limited internal fixation group, 12 cases) from October 2009 to January 2012 were analyzed. There were 5 males and 5 females, ranging in age from 24 to 61 years in the plaster immobilization group. There were 7 males and 4 females, ranging in age from 21 to 64 years in the distal tibia anatomical plate group. There were 7 males and 5 females, ranging in age from 23 to 67 years in the external fixation with limited internal fixation group. The Ankle X-ray of Pilon fracture after operation, ankle score, early and late complications were collected. Bourne system was used to evaluate ankle joint function. After 8 months to 3 years follow-up, it was found that three kinds of treatment had significant differences in the outcomes and complications (P external fixation with limited internal fixation group got the best results. The number of anatomic reduction cases in the external fixation with limited internal fixation group (7 cases) and the distal tibia anatomical plate group (8 cases) was more than the plaster immobilization group (2 cases). According to the ankle score, 8 patients got an excellent result, 3 good and 1 poor in the limited internal fixation group ,which was better than those of distal tibia anatomical plate group (5 excellent, 4 good and 2 poor) and the plaster immobilization group (3 excellent, 4 good and 3 poor). The number of early and late complications in the external fixation with limited internal fixation group was more than those in the plaster immobilization group and the distal tibia anatomical plate group (Pexternal fixation with limited internal fixation in the treatment of Pilon fracture

  17. Cannulated screw fixation and plate fixation for displaced intra-articular calcaneus fracture: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Fan, Baoyou; Zhou, Xianhu; Wei, Zhijian; Ren, Yiming; Lin, Wei; Hao, Yan; Shi, Guidong; Feng, Shiqing

    2016-10-01

    Displaced intra-articular calcaneus fractures (DIACFs) are the most common type of calcaneus fracture. The differences in therapeutic effectiveness between cannulated screw fixation (CSF) and plate fixation are still unclear. Thus, in this meta-analysis, we evaluated the therapeutic effectiveness of these two fixation methods. We searched for all publications on DIACFs fixated with cannulated screws or plates in the following electronic databases: Pubmed, Cochrane, Embase and CNKI. Only randomized controlled studies were included. The Cochrane Handbook for Systematic Reviews of Interventions (version 5.1.0) was applied for analysis. The primary outcomes were American Orthopedic Foot and Ankle Society score (AOFAS), improvement of Bohler's angle, improvement of Gissane's angle and the width of the calcaneus. Outcomes were reported as the standard mean difference (SMD) or relative risk (RR) with the 95% confidence interval (CI). A random effects model was used to assess the pooled data. Five randomized controlled studies met our inclusion criteria, and a total of 707 patients were involved. There was no statistically significant difference between the cannulated screw fixation group and the plate fixation group in terms of excellent and good AOFAS scores (RR = 1.01, 95%CI 0.91 to 1.13, P = 0.79), improvement of Bohler's angle (SMD = 0.12, 95%CI -0.03 to 0.28, P = 0.12), improvement of Gissane's angle (SMD = 0.09, 95%CI -0.28 to 0.26, P = 0.30), or the width of the calcaneus (SMD = -0.07, 95%CI -0.24 to 0.10, p = 0.45). Compared with plate fixation, CSF showed a significant reduction in the duration of surgery (SMD = -1.74, 95%CI, -3.35 to -0.13, P = 0.03) and rate of complications (RR = 0.25, 95%CI, 0.15 to 0.44, P<0.00001). Cannulated screw fixation and plate fixation have similar fixation effectiveness and functional outcomes in the treatment of displaced intra-articular calcaneus fractures. Due to the shorter duration of surgery and

  18. Highly productive forage legume stands show no positive biodiversity effect on yield and N2-fixation

    DEFF Research Database (Denmark)

    Dhamala, Nawa Raj; Eriksen, Jørgen; Carlsson, Georg

    2017-01-01

    Background and aims While N fixation in diversified grasslands including forage legumes and non-legumes has been widely studied, N fixation in swards containing only forage legumes remains unclear. In this study, we investigated N fixation in pure stands and mixtures of three forage legumes....... Methodology N fixation, dry matter (DM) and nitrogen (N) yields were quantified in a field experiment for red clover (Trifolium pratense L.), white clover (Trifolium repens L.) and lucerne (Medicago sativa L.) pure stands and mixtures using the isotope dilution method. Results All three forage legume species...... derived most (around 85%) of their N from atmospheric N fixation (%Ndfa). However, no positive effect of species diversity was found in any of the mixtures. Species composition of the forage legume mixtures affected the amount of N from N fixation by affecting DM production and N accumulation...

  19. Effects of Long-term Fertilization on Potassium Fixation Capacity in Brown Soil

    Science.gov (United States)

    Li, Na; Guo, Chunlei; Wang, Yue; Gao, Tianyi; Yang, Jinfeng; Han, Xiaori

    2018-01-01

    This study concentrated on the research of features of fixation. The objective of this study was to provide theoretical foundation of rational application of potassium fertilizer along with improving fertilizer availability ratio. A 32 years long-term experiment was conducted to evaluate the effects of fertilizer application on potassium changes and the factors affecting K fixation on brown soil by simulation in laboratory. When the concentration of exogenous potassium was in range of 400∼4000 mg·kg-1, potassium fixation capacity increased along with the rise of concentration of exogenous potassium, whereas K fixation rate reduced; Compared with no-potassium fertilizer, application of potassium fertilizer and organic fertilizer reduced soil potassium fixation capacity. Potassium rate and fixation-release of potassium character in soil should be taken into comprehensive consideration for rational fertilization to maintain or improve soil fertility for increasing potassium fertilizers efficiency in agriculture.

  20. Dynamic Programming for Re-Mapping Noisy Fixations in Translation Tasks

    DEFF Research Database (Denmark)

    Carl, Michael

    2013-01-01

    Eyetrackers which allow for free head movements are in many cases imprecise to the extent that reading patterns become heavily distorted. The poor usability and interpretability of these gaze patterns is corroborated by a "naïve" fixation-to-symbol mapping, which often wrongly maps the possibly...... drifted center of the observed fixation onto the symbol directly below it. In this paper I extend this naïve fixation-to-symbol mapping by introducing background knowledge about the translation task. In a first step, the sequence of fixation-to- symbol mappings is extended into a lattice of several...... possible fixated symbols, including those on the line above and below the naïve fixation mapping. In a second step a dynamic programming algorithm applies a number of heuristics to find the best path through the lattice, based on the probable distance in characters, in words and in pixels between...

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Craig R Lareau

    2015-01-01

    Full Text Available 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.

  3. Comparing Functional Outcomes After Injury-Specific Fixation of Posterior Malleolar Fractures and Equivalent Ligamentous Injuries in Rotational Ankle Fractures.

    Science.gov (United States)

    Levack, Ashley E; Warner, Stephen J; Gausden, Elizabeth B; Helfet, David L; Lorich, Dean G

    2018-04-01

    To evaluate the effect of posterior bony versus ligamentous injury pattern on functional outcomes in operatively treated rotational ankle fractures. Retrospective cohort analysis of prospective registry. Academic Level I trauma center. Operatively treated supination external rotation IV and pronation external rotation IV ankle fractures. Lateral malleolus plate fixation with either posterior malleolus (PM) plate fixation or posterior inferior tibiofibular ligament (PITFL) repair. Foot and ankle outcome scores at minimum 12 months postoperatively. One hundred seventy-eight fractures were treated with injury-specific anatomic fixation of a PM fracture (n = 122) or torn PITFL (n = 56). The PM group was significantly older, contained more women, and had lower mean body mass index versus the PITFL group. There was a higher rate of medial malleolar fracture in the PM group; other fracture and baseline characteristics were similar between groups. Univariate and multivariable analysis revealed no difference in foot and ankle outcome scores for any of the 5 summary domains (symptoms, pain, activities of daily living, sports, or quality of life) at the time of most recent follow-up. The median length of follow-up was 16.3 and 12.8 months in the PM and PITFL groups, respectively. In our cohort of ankle fractures, we have demonstrated comparable outcomes in stage IV rotational ankle fractures with and without PM fractures, indicating that the presence of a PM fracture may not result in inferior outcomes compared with ligamentous equivalent injuries if these fractures are addressed in an injury-specific manner. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  4. Evaluation of fixative solutions for ultrastructural analysis of brown spider Loxosceles intermedia (araneae: sicariidae) tissues

    OpenAIRE

    Costa-Ayub,C. L. S.; Faraco,C. D.; Freire,C. A.

    2006-01-01

    In view of the widely varying compositions of fixative solutions used for studying spiders, five different fixative formulas were tested for fixing male brown-spider (Loxosceles intermedia) gonad tissues. The brown spider represents a public health problem in Curitiba (Paraná State, Brazil). Morphological study of its gonads may aid in understanding the reproductive strategies of this species, and possibly in developing a reproduction control program. The fixatives tested contained glutaralde...

  5. Biologic and biomechanic evaluation of posterior lumbar fusion in the rabbit. The effect of fixation rigidity.

    Science.gov (United States)

    Feighan, J E; Stevenson, S; Emery, S E

    1995-07-15

    The histologic and biomechanic characteristics of posterior lumbar fusion with varying rigidity of a novel internal fixation construct in the rabbit were analyzed. To evaluate this rabbit model for future studies of fusion augmentation. Previous studies in goats and dogs showed internal fixation enhances spinal arthrodesis. Twenty eight New Zealand white rabbits underwent a posterior midline fusion from L4 to L6. Some animals received autogenous iliac crest bone graft, stabilized by wiring the superior facets bilaterally, and supplementation with polymethylmethacrylate. The experimental groups were iliac crest bone graft with either no fixation, wire fixation, or wire and polymethylmethacrylate fixation; and no graft and either no fixation, wire fixation, or wire and polymethylmethacrylate fixation. Animals were killed 2 months after surgery, and the specimens were nondestructively tested biomechanically for stiffness in six modes (flexion, extension, left and right bending, compression, and torsion) and histologically for evidence of fusion, revascularization, and new bone formation. Fusions with either wire or wire and polymethylmethacrylate fixation were significantly stiffer than those without fixation (P < 0.05). There was no statistical difference between the iliac crest bone graft and wire group and the iliac crest bone graft, wire, and polymethylmethacrylate group in the modes tested. Nine of 14 motion segments receiving the stiffest construct (iliac crest bone graft, wire, and polymethylmethacrylate) had evidence of solid bony fusion. None of the 12 motion segments receiving iliac crest bone graft and wire had evidence of bony fusion, but five had a fibrocartilage union with some ossification present. Eight of 12 motion segments receiving iliac crest bone graft and no fixation had predominantly fibrous unions with some fibrocartilage, and only one motion segment of 12 showed bony fusion. This study suggests that more rigid fixation produces more successful

  6. Influence of internal fixation systems on radiation therapy for spinal tumor.

    Science.gov (United States)

    Li, Jingfeng; Yan, Lei; Wang, Jianping; Cai, Lin; Hu, Dongcai

    2015-07-08

    In this study, the influence of internal fixation systems on radiation therapy for spinal tumor was investigated in order to derive a theoretical basis for adjustment of radiation dose for patients with spinal tumor and internal fixation. Based on a common method of internal fixation after resection of spinal tumor, different models of spinal internal fixation were constructed using the lumbar vertebra of fresh domestic pigs and titanium alloy as the internal fixation system. Variations in radiation dose in the vertebral body and partial spinal cord in different types of internal fixation were studied under the same radiation condition (6 MV and 600 mGy) in different fixation models and compared with those irradiated based on the treatment planning system (TPS). Our results showed that spinal internal fixation materials have great impact on the radiation dose absorbed by spinal tumors. Under the same radiation condition, the influence of anterior internal fixation material or combined anterior and posterior approach on radiation dose at the anterior border of the vertebral body was the greatest. Regardless of the kinds of internal fixation method employed, radiation dose at the anterior border of the vertebral body was significantly different from that at other positions. Notably, the influence of posterior internal fixation material on the anterior wall of the vertebral canal was the greatest. X-ray attenuation and scattering should be taken into consideration for most patients with bone metastasis that receive fixation of metal implants. Further evaluation should then be conducted with modified TPS in order to minimize the potentially harmful effects of inappropriate radiation dose.

  7. Effects of macro nutrient concentration on biological N2 fixation by Azotobacter vinelandii ATCC 12837

    International Nuclear Information System (INIS)

    Liew Pauline Woan Ying; Nazalan Najimudin; Jong Bor Chyan; Latiffah Noordin; Khairuddin Abdul Rahim; Amir Hamzah Ahmad Ghazali

    2010-01-01

    The dynamic changes of biological N 2 fixation by Azotobacter vinelandii ATCC 12837 under the influence of various macro nutrients, specifically phosphorus (P) and potassium (K), was investigated. In this attempt, Oryza sativa L. var. MR 219 was used as the model plant. Results obtained showed changes in the biological N 2 fixation activities with different macro nutrient(s) manipulations. The research activity enables optimisation of macro nutrients concentration for optimal/ enhanced biological N 2 fixation by A. vinelandii ATCC 12837. (author)

  8. Is the Erich arch bar the best intermaxillary fixation method in maxillofacial fractures? : a systematic review

    OpenAIRE

    Falci, Saulo Gabriel; 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...

  9. Report About the Design of External Fixator for Treatment of Pelvis and Acetabulum Fractures

    Directory of Open Access Journals (Sweden)

    Martin JANEČKA

    2012-06-01

    Full Text Available Main point in this contribution is the design of external fixators applied in traumatology and orthopaedics. These fixators can be used in the treatment of open and unstable (i.e. complicated fractures of pelvis and its acetabulum. Numerical modelling (i.e. Finite Element Method, together with CAD modelling, experiments, material engineering, and nanotechnology are presented as a support for developing of a new design of external fixators.

  10. Supplement: Commodity Index Report

    Data.gov (United States)

    Commodity Futures Trading Commission — Shows index traders in selected agricultural markets. These traders are drawn from the noncommercial and commercial categories. The noncommercial category includes...

  11. Laser-assisted fixation of a nitinol stapes prosthesis.

    Science.gov (United States)

    Schrötzlmair, Florian; Suchan, Fabian; Pongratz, Thomas; Krause, Eike; Müller, Joachim; Sroka, Ronald

    2018-02-01

    Otosclerosis is an inner ear bone disease characterized by fixation of the stapes and consequently progressive hearing loss. One treatment option is the surgical replacement of the stapes by a prosthesis. When so called "smart materials" like nitinol are used, prosthesis fixation can be performed using a laser without manual crimping on the incus. However, specific laser-prosthesis interactions have not been described yet. The aim of the present study was to elucidate the thermo-mechanical properties of the NiTiBOND® prosthesis as a basis for handling instructions for laser-assisted prosthesis fixation. Closure of the NiTiBOND® prosthesis was induced ex vivo by either a diode laser emitting at λ = 940 nm or a CO 2 laser (λ = 10,600 nm). Total energy for closure was determined. Suitable laser parameters (pulse duration, power per pulse, distance between tip of the laser fiber and prosthesis) were assessed. Specific laser-prosthesis interactions were recorded. Especially the diode laser was found to be an appropriate energy source. A total energy deposit of 60 mJ by pulses in near contact application was found to be sufficient for prosthesis closure ex vivo. Energy should be transmitted through a laser fiber equipollent to the prosthesis band diameter. Specific deformation characteristics due to the zonal prosthesis composition have to be taken into account. NiTiBOND® stapes prosthesis can be closed by very little energy when appropriate energy sources like diode lasers are used, suggesting a relatively safe application in vivo. Lasers Surg. Med. 50:153-157, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Horizontal suture placement influences meniscal repair fixation strength.

    Science.gov (United States)

    Kocabey, Yavuz; Taser, Omer; Nyland, John; Ince, Haluk; Sahin, Feyzi; Sunbuloglu, Emin; Baysal, Gokhan

    2013-03-01

    This in vitro biomechanical study investigated the influence of horizontal suture placement distance from the medial meniscal lesion repair site on fixation characteristics during submaximal cyclic and load to failure test conditions. Eighteen cadaveric (20-45 years of age) medial menisci with intact joint capsules were harvested within 24-48 h after death and divided into two groups of 9 specimens each for biomechanical testing. A 2.0-cm-long antero-posterior vertical longitudinal lesion was created with a #15 scalpel 2.0-3.0 mm from the outer edge of each meniscus. Menisci were repaired using #2-0 suture material with two horizontal suture loops placed either 1.0 mm (Group 1) or 3.0 mm (Group 2) from the lesion site. Following repair, the lesion was extended completely through the meniscal horns so that no tissue secured the repair, only the two horizontal suture loops representing a "worst-case" testing scenario. Following repair, specimens were placed in a servo hydraulic device using a pair of 1.2-mm-diameter steel wire loops and underwent submaximal cyclic loading between 5 and 50 N (1 Hz) for 500 cycles prior to load to failure testing (5 mm/min crosshead speed, 20 Hz data collection). An alpha level of P lesion displayed superior repair fixation than sutures placed closer to the lesion. The superior biomechanical meniscal repair fixation provided by capturing greater tissue volume may enable safe earlier participation in functional exercise activities. Studies are needed to verify these findings in vivo.

  13. Symbiotic nitrogen fixation and nitrate uptake by the pea crop

    International Nuclear Information System (INIS)

    Jensen, E.S.

    1986-08-01

    Symbiotic nitrogen fixation and nitrate uptake by pea plants (Pisum sativum L.) were studied in field and pot experiments using the 15 N isotope dilution technique and spring barley as a non-fixing reference crop. Barley, although not ideal, seemed to be a suitable reference for pea in the 15 N-technique. Maximum N 2 fixation activity of 10 kg N fixed per ha per day was reached around the flat pod growth stage, and the activity decreased rapidly during pod-filling. The pea crop fixed between 100 and 250 kg N ha -1 , corresponding to from 45 to 80 per cent of total crop N. The amount of symbiotically fixed N 2 depended on the climatic conditions in the experimental year, the level of soil mineral N and the pea cultivar. Field-grown pea took up 60 to 70 per cent of the N-fertilizer supplied. The supply of 50 kg NO 3 -N ha -1 inhibited the N 2 fixation approximately 15 per cent. Small amounts of fertilizer N, supplied at sowing (starter-N), slightly stimulated the vegetative growth of pea, but the yields of seed dry matter and protein were not significantly influenced. In the present field experiments the environmental conditions, especially the distribution of rainfall during the growth season, seemed to be more important in determining the protein and dry matter yield of the dry pea crop, than the ability of pea to fix nitrogen symbiotically. However, fertilizer N supplied to pot-grown pea plants at the flat pod growth stage or as split applications significantly increased the yield of seed dry matter and protein. (author)

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

    Science.gov (United States)

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

    2016-01-01

    The chevron osteotomy is a popular procedure used for the correction of moderate hallux abducto valgus deformity. Fixation is typically accomplished with Kirschner wires or bone screws; however, in cystic or osteoporotic bone, these could be inadequate, resulting in displacement of the capital fragment. We propose using a locking plate and interfragmental screw for fixation of the chevron osteotomy that could reduce the healing time and decrease the incidence of displacement. We performed a retrospective cohort study for chevron osteotomies on 75 feet (73 patients). The control groups underwent fixation with 1 screw in 30 feet (40%) and 2 screws in 30 feet (40%). A total of 15 feet (20%) were included in the locking plate and interfragmental screw group. The patients were followed up until bone healing was achieved at a median of 7 (range 6 to 14) weeks. Our hypothesis was that those treated with the locking plate and interfragmental screw would have a faster healing time and fewer incidents of capital fragment displacement compared with the 1- or 2-screw groups. The corresponding mean intervals to healing for the 1-screw group was 7.71 ± 1.28 (range 6 to 10) weeks, for the 2-screw group was 7.27 ± 1.57 (range 6 to 14) weeks, and for the locking plate and interfragmental screw group was 7.01 ± 1.00 (range 6 to 9) weeks. One case of capital fragment displacement occurred in the single screw group and one in the 2-screw group. No displacement occurred in the locking plate and interfragmental screw group. Neither finding was statistically significant. However, we believe the locking plate and interfragmental screw could be a viable option in patients with osteoporotic and cystic bone changes for correction of hallux abducto valgus. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Fixation principles in metaphyseal bone--a patent based review.

    Science.gov (United States)

    Curtis, R; Goldhahn, J; Schwyn, R; Regazzoni, P; Suhm, N

    2005-03-01

    Osteoporotic changes start in cancellous bone due to the underlying pathophysiology. Consequently, the metaphyses are at a higher risk of "osteoporotic" fracture than the diaphysis. Furthermore, implant purchase to fix these fractures is also affected by the poor bone quality. In general, researchers and developers have worked on three different approaches to address the problem of fractures to osteoporotic bone: adapted anchoring techniques, improved load distribution as well as transfer with angular stable screws, and augmentation techniques using bone substitutes. A patent-based review was performed to evaluate which ideas were utilized to improve fixation in osteoporotic, metaphyseal bone, especially in the proximal femur, and to analyze whether the concept had entered clinical use. Anchoring devices that are either extramedullary or intramedullary have a long clinical history. However, demanding surgical techniques and complications, especially in poor quality bone, are justification that such implants and their corresponding surgical techniques need to be improved upon. Expanding elements have been evaluated in the laboratory. The results are promising and the potential of this approach has yet to be fully exploited in the clinics. Internal fixators with angular stable screws open the door for many new anchorage ideas and have great potential for further optimization of load distribution and transfer. Augmentation techniques may improve anchorage in osteoporotic bone. However, the properties of bone substitute materials will need to be modified and improved upon in order to meet the demanding requirements. If we summarise the development process and the clinical use of implants to date, we have to clearly state that more factors than simply biomechanical advantage will determine the clinical success of a new fixation principle or a new implant. Instead, fracture treatment of patients with osteoporosis really needs an interdisciplinary approach!

  16. Measuring dwell time percentage from head-mounted eye-tracking data--comparison of a frame-by-frame and a fixation-by-fixation analysis.

    Science.gov (United States)

    Vansteenkiste, Pieter; Cardon, Greet; Philippaerts, Renaat; Lenoir, Matthieu

    2015-01-01

    Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a 'fixation-by-fixation' manner. The fixation-based method is similar to the classic frame-by-frame method but instead of assigning frames, fixations are assigned to one of the AOIs. Although some considerable differences were found between the two methods, a Pearson correlation of 0.930 points out a good validity of the fixation-by-fixation method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach is a valuable and time-saving alternative for the classic frame-by-frame analysis.

  17. Comparative study on three surgical techniques for intra-articular calcaneal fractures: open reduction with internal fixation using a plate, external fixation and minimally invasive surgery

    Directory of Open Access Journals (Sweden)

    Missa Takasaka

    2016-06-01

    Full Text Available ABSTRACT OBJECTIVE: To evaluate, compare and identify the surgical technique with best results for treating intra-articular calcaneal fractures, taking into account postoperative outcomes, complications and scoring in the Aofas questionnaire. METHODS: This was a retrospective study on 54 patients with fractures of the calcaneus who underwent surgery between 2002 and 2012 by means of the following techniques: (1 open reduction with extended L-shaped lateral incision and fixation with double-H plate of 3.5 mm; (2 open reduction with minimal incision lateral approach and percutaneous fixation with wires and screws; and (3 open reduction with minimal incision lateral approach and fixation with adjustable monoplanar external fixator. RESULTS: Patients treated using a lateral approach, with fixation using a plate had a mean Aofas score of 76 points; those treated through a minimal incision lateral approach with screw and wire fixation had a mean score of 71 points; and those treated through a minimal incision lateral approach with an external fixator had a mean score of 75 points. The three surgical techniques were shown to be effective for treating intra-articular calcaneal fractures, without any evidence that any of the techniques being superior. CONCLUSION: Intra-articular calcaneal fractures are complex and their treatment should be individualized based on patient characteristics, type of fracture and the surgeon's experience with the surgical technique chosen.

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

    Directory of Open Access Journals (Sweden)

    Riediger Dieter

    2008-05-01

    Full Text Available Abstract 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

  19. Assessment of modified gold surfaced titanium implants on skeletal fixation

    DEFF Research Database (Denmark)

    Zainali, Kasra; Danscher, Gorm; Jakobsen, Thomas

    2013-01-01

    shown to liberate gold ions through the process termed dissolucytosis. Furthermore, gold ions are known to act in an anti-inflammatory manner by inhibiting cellular NF-κB-DNA binding. The present study investigated whether partial coating of titanium implants could augment early osseointegration...... osseointegration compared to control titanium implants in a similar model. Since sufficient early mechanical fixation is achieved with this new coating, it is reasonable to investigate the implant further in long-term studies. © 2012 Wiley Periodicals, Inc....

  20. Infra-red process for colour fixation on fabrics

    International Nuclear Information System (INIS)

    Raymond, D.J.; Biau, D.

    1983-01-01

    Infra-red radiations find wide application in industrial processes as heating, drying, stoving and forming. The results are often far better than those from the other techniques: convection oven, gas IR etc ... They come from the electric IR specific advantages: energy direct transmission, emitter and product spectral coupling, possible selectivity. That is the case in the Textile Industry, where experiments showed that infra-red process heating could be efficient for colour fixation on fabrics. Shorter production cycles and energy saving are the main results

  1. Fixation of metallic sulfosalicylate complexes on an anionic exchange resin

    International Nuclear Information System (INIS)

    Cahuzac, S.

    1969-06-01

    Since sulfosalicylate ions have acid-base properties, sulfosalicylate complexes have an apparent stability which varies with the ph. As a result, the fixation of sulfo-salicylates on an anionic exchange resin depends on the ph of the solution in equilibrium with the resin. This research has been aimed at studying the influence of the ph on the fixation on an anionic exchange resin (Dowex 1 x 4) of sulfosalicylate anions on the one hand, and of metallic sulfosalicylate complexes on the other hand. In the first part of this work, a determination has been made, by frontal analysis of the distribution of sulfosalicylate ions in the resin according to the total sulfosalicylate I concentration in the aqueous solution in equilibrium with the resin. The exchange constants of these ions between the resin and the solution have been calculated. In the second part, a study has been made of the fixation of anionic sulfosalicylate complexes of Fe(III), Al(III), Cr(III), Cu(II), Ni(II), Co(II), Zn(II), Mn(II), Cd(II), Fe(II) and UO 2 2+ . By measuring the partition coefficients of these different elements between the resin and the solution it has been possible to give interpretation for the modes of fixation of the metallic ions, and to calculate their exchange constant between the resin and the solution. The relationship has been established for each metallic element studied, between its partition coefficient, the ph and the total concentration of the complexing agent in solution. Such a relationship makes it possible to predict, for given conditions, the nature of the species in solution and in the resin, as well as the partition coefficient of a metallic, element. Finally, in the third part of the work, use has been made of results obtained previously, to carry out some separations (Ni 2+ - Co 2+ ; Ni 2+ - Co 2+ - Cu 2+ ; UO 2 2+ - Fe 3+ ; UO 2 2+ - Cr 3+ ; UO 2 2+ - Cu 2+ ; UO 2 2+ - Ni 2+ ; UO 2 2+ - Co 2+ ; UO 2 2+ - Mn 2+ and UO 2 2+ - Cd 2+ ), as well as the purification

  2. Fixation in laparoscopic incisional hernia repair: Suture versus tacks

    Directory of Open Access Journals (Sweden)

    Adil Bangash

    2013-01-01

    Full Text Available Aims and Objectives: To compare the frequency of complications of laparoscopic repair of incisional hernia using fixation of mesh with transabdominal sutures tacks. Materials and Methods: This study was conducted as part of an interventional multicenter trial at the Rehman Medical Institute, Peshawar, Peshawar Institute of Medical Sciences, and Pakistan Institute of Medical Science, Islamabad, from the 1 st of November 2008 till 31 st October 2011. The frequency of complications was calculated as the measure of comparing two methods of fixation in laparoscopic repair of incisional hernia using the IPOM technique. These patients were admitted via the outpatient department and their demographic data were collected on a pro forma basis. Forty-five patients were alternately placed in either group, and group I comprised patients with a ventral hernia that was fixed using spiral tacks whereas the other group was fixed with transabdominal sutures. A polytetraflouroethylene (Dual R mesh was applied in all cases. All data were collected onthe individual pro forma of each patient and was loaded on the SPSS R version 13.0. Results: The BMI in both groups was similar (P=0.94 The mean hospital stay was higher in the PTFE mesh group but the values were not significant (P=1.22.No perioperative death was observed in either group. One patient (2.2% from group I was readmitted with varying complaints and was diagnosed as having subacute intestinal obstruction (P>0.05. A higher but insignificant recurrence rate was observed in the polyester group over a one-year period of follow-up. Three patients (6.6% were diagnosed with recurrences in group I. Instead the PTFE group had a similar recurrence rate recurrence (P=1.00. Conclusion: The rate of recurrence in this study showed no significant difference by either mode of fixation. But statistically significant pain scores and increased operative time to fixation favors the use of tacks that limits to the few inner

  3. Tissue Fixation and Processing for the Histological Identification of Lipids.

    Science.gov (United States)

    Carriel, Víctor; Campos, Fernando; Aneiros-Fernández, José; Kiernan, John A

    2017-01-01

    Lipids are a heterogeneous group of substances characterized by their solubility in organic solvents and insolubility in water. Lipids can be found as normal components of different tissues and organs, and they can be affected by several pathological conditions. The histochemical identification of lipids plays an important role in histopathological diagnosis and research, but successful staining depends on adequate fixation and processing of the tissue. Here we describe methods to fix and process tissue samples for the histochemical identification of lipids in frozen or paraffin-embedded tissues.

  4. Methods of amniotic membrane fixation in ocular amniotic membrane surgeries

    Directory of Open Access Journals (Sweden)

    Shu-Rong Wang

    2016-05-01

    Full Text Available Various ocular surface disorders like alkali burns and corneal ulcers can all cause damage to the cornea and conjunctiva, and often induce corneal neovascularization(CNVthat affects the visual function. However, amniotic membranes(AMcan promote the rapid epithelization of acute injured corneas and conjunctiva defects, diminish scarring, and perform anti-inflammatory effect. Therefore, AM has been widely used in ocular surface reconstructions and treatment of CNV. But the key problem is how to fix the AM. Only ensuring the adhesive time and cover area with convenient operation and little stimulation can achieve the best curative effect. This article reviews the methods of AM fixation in AM patch technique.

  5. Percutaneous cannulated screw fixation for pediatric epiphyseal ankle fractures

    OpenAIRE

    ?i?ekli, ?zg?r; ?zdemir, G?zelali; Uysal, Mustafa; Bi?ici, Vedat; Bing?l, ?zzet

    2016-01-01

    Background Ankle injuries are among the most common injuries in children. The aim of this study was to compare the efficacies of two percutaneous fixation methods after closed reduction in physeal ankle fractures. Methods We reviewed the cases of 24 patients with a mean age of 12.29?years; 16 were male, and 8 were female. Only patients with fractures of Salter-Harris types 2, 3, and 4 with displacements greater than 2?mm were included in the study. Patients were treated with closed reduction ...

  6. Ultrastructure of the endolymphatic duct in the rat. Fixation and preservation

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, J

    1993-01-01

    Ten rats were vascular-perfused at subphysiologic as well as physiologic pressures, 80 mmHg and 120 mmHg, respectively, employing a pressure feed-back controlled peristaltic pump and an isotonic perfusate/fixative with colloids (2% Dextran) and a hypertonic perfusate/fixative without colloids, 300...... and 530 mOsm, respectively. In both experiments the endolymphatic duct and sac were isolated by microdissection after primary fixation. When comparing micrographs from the two experiments we observed that rats perfused at low pressure in isotonic fixative with colloids added had non-dilated lateral...

  7. [Domestic external fixator application in the treatment of limb deformities: 7 289 cases application report].

    Science.gov (United States)

    Qin, S H; Guo, B F; Zheng, X J; Jiao, S F; Xia, H T; Peng, A M; Pan, Q; Zang, J C; Wang, Z J

    2017-09-01

    Objective: To discuss the clinical application and effects of domestic external fixator in the treatment of patients with malformations of limbs. Methods: A total of 7 289 patients with malformation of limbs who had been operated in Qin Sihe orthopedic surgery team from January 1989 to June 2016 were retrospective analyzed. The patients were treated with domestic external fixator, including 4 033 males and 3 256 females, aging from 2 to 82 years with a mean age of 23.4 years. There were 2 732 patients using Ilizarov external fixator, 4 713 patients using hybrid external fixator, 57 patients using monobrachial external fixator, 232 patients using Ilizarov external fixator and hybrid external fixator. The Ilizarov, hybrid and monobrachial external fixator were used in 67, 65 and 0 patients on the upper limbs and in 2 665, 4 616 and 57 patients on the lower limbs. There were 3 028 patients operated on the left limbs, 3 260 patients operated on the right limbs and 1 001 patients operated on the bilateral limbs. The top three types of diseases were sequelae of poliomyelitis, cerebral palsy and post-traumatic stress disorder peromely. Deformity types inclued talipes equinovarus, knee flexion deformity, cavus foot and so on. Results: All the patients were followed up for a period of 2.5 months to 22.4 years, with an average follow-up time of 5.4 years. All of the external fixators were used for single once, and there was no substitute for external fixator quality problem. All the patients were completed surgery goal until removing external fixation except 1 patient gave up treatment and 1 removed the fixator because of metal allergy. The common complications included wire or pin infection and joint movement limitation and so on. Conclusions: The domestic external fixator developed and produced based on the characteristics of Chinese limb deformity disability. The domestic external fixator can be used to treat kinds of limb deformities with the advantages of practical

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

    Science.gov (United States)

    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.

  9. Biomechanical comparison of lag screw versus self-drilling screw fixation of oblique metatarsal osteotomy.

    Science.gov (United States)

    Rabenhorst, Brien M; Smith, Michael P; James, C Roger; Grimes, Jerry S

    2011-08-01

    Several fixation methods for a Weil metatarsal osteotomy have been proposed. Lag screw fixation has been described as the preferred fixation technique. The self-drilling screw has been introduced and can be used for fixation of the Weil osteotomy. The current study compared self-drilling screws with lag screw fixation. A Weil metatarsal osteotomy was performed on the second, third, and fourth metatarsals of five matched pairs of fresh frozen cadaver feet. The feet of each pair were randomly assigned ical to fixation with either a 2.0-mm cortical lag screw or a 2.0-mm self-drilling screw. The second metatarsals were stressed using cantilever bending. The third and fourth metatarsals were stressed under a shear force. Yield load, deformation at yield load, structural stiffness, and energy stored at yield load were recorded. There were no statistically significant differences (p screw. There were no significant differences in the stability of fixation of the self-drilling screw and lag screw. There was a trend toward the lag screw fixation being more stable. The clinical significance of this trend is uncertain but suggests there is not a large difference between the two methods of fixation.

  10. A comparison of two fixation methods for femoral trochanteric fractures: a new generation intramedullary system vs sliding hip screw.

    Science.gov (United States)

    Carulli, Christian; Piacentini, Federico; Paoli, Tommaso; Civinini, Roberto; Innocenti, Massimo

    2017-01-01

    Trochanteric fractures are frequent and generally associated with bone fragility. There is still debate on the best fixation device to treat stable or rather stable trochanteric fractures: we report our clinical and radiological results of fixation with Proximal Femoral Nail "antirotation" (PFNa) in a population of patients compared to a control group treated by Sliding Hip Screw (SHS). A prospective study was conducted in 71 consecutive patients treated by PFNa (group A), and 69 by a SHS (group B), with a mean age of 81.6 and 83.4 years respectively. Short Form 12 was administered to check postoperative results, and the following parameters were evaluated: range of motion, evaluation of pain, gait ability, X-rays, and Tip Apex Distance Index. A minimum follow-up was conducted in 128 patients: 66 subjects belonging to the PFNa group and 62 to the DHS group. All patients in the group A were able to reach partial or full weight-bearing on the operated leg before leaving the hospital. Forty-four patients (63.8%) of the group B were able to walk with partial weight-bearing before discharge. We recorded 17 complications with a final overall percentage of 17.2% on the overall study population with one single case of failure in both the two groups. A statistical significance (ptrochanteric fractures as well as DHS. The light superiority of PFNa may be principally related to its mechanical advantages.

  11. Posterior lumber interbody fusion with pedicle screw fixation for the management of spondylolisthesis: An analysis of 40 cases

    Directory of Open Access Journals (Sweden)

    Md. Rezaul Amin

    2017-09-01

    Full Text Available Spondylolisthesis is forward slipping of upper vertebra in relations to its lower one, commonest is L4-L5. The ideal surgical treatment of spondylolisthesis is still controversial. Posterior lumber interbody fusion with pedicle fixation is one of treatment choices for the lumber spondylolisthesis. Forty patients who operated through posterior lumber interbody fusion and pedicle screw fixation by single surgeon was included from January 2012 to March 2015. Periodical follow-up was done both clinically and radiologically up to 6 months. Patient outcome was completed based on pain relief graphic rating scale and Oswestry disability index. In our series, the excellent outcome were 25 patients (62.5%, good were 12 patients (30%, and fair were 3 patients (7.5%. There were no poor outcome and no new neurological deficit. This study concludes that posterior lumber inter-body fusion with pedicle is an effective treatment for the lumber spondylolisthesis. It helps to maintain the biomechanics, associated with less complication and improve the quality of life of patient.

  12. Surgical results of a one-stage combined anterior lumbosacral fusion and posterior percutaneous pedicle screw fixation

    Directory of Open Access Journals (Sweden)

    Chien-Yuan Huang

    2018-01-01

    Full Text Available Objectives: Lumbosacral fusion through either an anterior or a posterior approach to achieve good lordosis and stability is always a challenging surgical operation and is often accompanied by a higher rate of pseudarthrosis than when other lumbar segments are involved. This study evaluated the clinical and radiological results of lumbosacral fusions achieved through a combined anterior and posterior approach. Materials and Methods: From June 2008 to 2012, 20 patients who had L5–S1 instability and stenosis were consecutively treated, first by anterior interbody fusion using an allogenous strut bone graft through the pararectus approach and then by posterior pedicle screw fixation. A minimum of 1-year of clinical and radiological follow-up was conducted. Intraoperative blood loss, surgical time, and any surgery-related complications were recorded. Clinical outcomes were assessed using a visual analog scale (VAS and the patient's Oswestry Disability Index (ODI score. After 1 year, radiological outcomes were assessed by analyzing pelvic incidence, lumbar lordosis, and segmental lordosis using static plain films, while fusion stability was assessed using dynamic plain films. Results: The mean operative time and blood loss were 215 min and 325 cc, respectively. After 1 year, the VAS and ODI scores had significantly improved, and stable fusion with good lordotic curvature was obtained in all cases. Conclusion: The surgical results of the combined procedure are satisfactory in terms of the functional and radiological outcomes. Our method offers advantages regarding both anterior fusion and posterior fixation.

  13. [Effectiveness of posterior intrasegmental fixation with pedicle screw-lamina hook system in treatment of lumbar spondylolysis].

    Science.gov (United States)

    Zhou, Zhongjie; Song, Yueming; Zeng, Jiancheng; Liu, Hao; Liu, Limin; Kong, Qingquan; Li, Tao; Gong, Quan

    2013-03-01

    To investigate the effectiveness of posterior intrasegmental fixation with pedicle screw-lamina hook system and bone grafting for lumbar spondylolysis. Between January 2005 and October 2009, 22 patients with lumbar spondylolysis underwent posterior intrasegmental fixation with pedicle screw-lamina hook system and bone grafting. There were 19 males and 3 females with an average age of 18.4 years (range, 12-26 years). The main symptom was low back pain with an average disease duration of 16 months (range, 8-56 months). The visual analogue scale (VAS) was 6.0 +/- 1.2 and Oswestry disability index (ODI) was 72.0% +/- 10.0% preoperatively. The X-ray films showed bilateral spondylolysis at L4 in 9 cases and at L5 in 13 cases. The range of motion (ROM) at upper and lower intervertebral spaces was (11.8 +/- 2.8) degrees and (14.1 +/- 1.9) degrees, respectively. All incisions healed by first intention. All patients were followed up 12-45 months (mean, 25 months). Low back pain was significantly alleviated after operation. The VAS score (0.3 +/- 0.5) and ODI (17.6% +/- 3.4%) were significantly decreased at last follow-up when compared with preoperative scores (P spondylolysis, having a high fusion rate, low complication rate, and maximum retention of lumbar ROM.

  14. Removal of internal fixation--the effect on patients' complaints: a study of 66 cases of removal of internal fixation after malleolar fractures

    DEFF Research Database (Denmark)

    Jacobsen, S; Honnens de Lichtenberg, M; Jensen, C M

    1994-01-01

    typically soreness over implant and cicatrix, reduced movement of the ankle joint, and strain-related pain. About 75% of these patients reported improvement after removal. The AO mode of fixation, i.e., typically by lateral semitubular plating and transsyndesmotic screw and a medial screw or pins......To estimate the effect of removal of internal fixation after treatment of malleolar fractures on postoperatively presented complaints, we retrospectively evaluated 66 patients by their records and by personal questionnaires. Of all the patients, 89.4% had one or more complaints. These were...... period. We conclude that removal of internal fixation after malleolar fractures is indicated when common types of complaints are presented....

  15. EJSCREEN Supplementary Indexes 2015 Public

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are 40 supplementary EJSCREEN indexes that are divided into 5 categories: EJ Index with supplementary demographic index, Supplementary EJ Index 1 with...

  16. Ankle-Brachial Index

    Science.gov (United States)

    ... measured at your arm. A low ankle-brachial index number can indicate narrowing or blockage of the arteries in ... tell your doctor so that he or she can continue to monitor your risk. Blockage (0.9 or less). An ankle-brachial index number less than 1.0 indicates narrowing of ...

  17. Global Ecosystem Restoration Index

    DEFF Research Database (Denmark)

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  18. Rethinking image indexing?

    DEFF Research Database (Denmark)

    Christensen, Hans Dam

    2017-01-01

    Hans Dam Christensen, ”Rethinking image indexing?”, in: Journal of the Association for Information Science and Technology, vol. 68, no. 7, 2017, 1782-1785......Hans Dam Christensen, ”Rethinking image indexing?”, in: Journal of the Association for Information Science and Technology, vol. 68, no. 7, 2017, 1782-1785...

  19. Browse Title Index

    African Journals Online (AJOL)

    Browse Title Index. Journal Home > Advanced Search > Browse Title Index. Log in or Register to get access to full text downloads. ... Vol 2, No 1 (1978), Weakly Nonlinear Waves with Slowly-Varying Speed, Abstract PDF. SC Chikwendu. Vol 33, No 2 (2014), Web Portal Usability among Nigerian University Students: A Case ...

  20. ParkIndex

    DEFF Research Database (Denmark)

    Kaczynski, Andrew T; Schipperijn, Jasper; Hipp, J Aaron

    2016-01-01

    , planners, and citizens to evaluate the potential for park use for a given area. Data used for developing ParkIndex were collected in 2010 in Kansas City, Missouri (KCMO). Adult study participants (n=891) reported whether they used a park within the past month, and all parks in KCMO were mapped and audited...... using ArcGIS 9.3 and the Community Park Audit Tool. Four park summary variables - distance to nearest park, and the number of parks, amount of park space, and average park quality index within 1 mile were analyzed in relation to park use using logistic regression. Coefficients for significant park...... summary variables were used to create a raster surface (ParkIndex) representing the probability of park use for all 100m×100m cells in KCMO. Two park summary variables were positively associated with park use - the number of parks and the average park quality index within 1 mile. The ParkIndex probability...

  1. Distal Radius Fracture Treated by Internal Fixation with Plates, Screws and the RALCA® External Mini-fixator

    OpenAIRE

    Rafael López Cuellar; Yaniel Truffin Rodríguez; Yudit Pérez Álvarez

    2016-01-01

    Distal radius fractures are very common in medical practice. In our service, we may not have the most widely used devices for fixation of these fractures at a given moment. For this reason, we must consider all possible combinations within our power to correct them since most of the time, it is impossible to maintain a fracture reduction using a single technique. We present the case of a 24-year-old female patient treated at the Dr. Gustavo Aldereguía Lima University General Hospital in Cienf...

  2. Is mask-based stereotactic head-and-neck fixation as precise as stereotactic head fixation for precision radiotherapy?

    International Nuclear Information System (INIS)

    Georg, Dietmar; Bogner, Joachim; Dieckmann, Karin; Poetter, Richard

    2006-01-01

    Background: The aim of this study was to compare setup accuracy and reproducibility of a stereotactic head and a head-and-neck fixation system, both based on thermoplastic material. Methods and Material: Ten patients were immobilized with a head and a head-and-neck fixation system (both BrainLAB, Germany). Both mask systems were modified with a custom-made mouthpiece and a strip of thermoplastic material attached to the lower part of the mask. During the first treatment session, after positioning patients using room lasers, two orthogonal portal images were taken as reference. Later on, at least five sets of orthogonal portal images were acquired for each patient. The isocentric setup accuracy was determined by comparing field edges and anatomic landmarks and the repositioning accuracy in the mask was obtained by comparing individual anatomic landmarks with respect to the metal balls, fixed on the masks. Systematic and random deviations and resulting three-dimensional (3D) vectors were calculated. Additionally, margins were derived from the systematic and random component of the isocentric setup accuracy. Finally, inter- and intraobserver variations were analyzed. Results: The systematic variation of the isocentric setup accuracy was very similar for the two mask systems, but the random variations were slightly larger for the head-and-neck system, resulting in a 0.4-mm larger 3D vector. The repositioning variations for the head mask were smaller compared with the head-and-neck mask, resulting in smaller 3D vectors for the random (∼0.4 mm) and systematic variations (∼0.6 mm). For both mask systems, a 2-mm margin can be used in lateral and anteroposterior direction, whereas in craniocaudal direction, this margin should be extended to 2.5 mm for the head mask and to 3 mm for the head-and-neck mask. The average absolute differences between two observers were within 0.5 mm, maximum deviations around 1 mm. Conclusion: Thermoplastic mask-based stereotactic head

  3. A meta-analysis of external fixation versus open reduction and internal fixation for complex tibial plateau fractures.

    Science.gov (United States)

    Zhao, Xing-Wen; Ma, Jian-Xiong; Ma, Xin-Long; Jiang, Xuan; Wang, Yin; Li, Fei; Lu, Bin

    2017-03-01

    Both external fixation (ExFx) and open reduction and internal fixation(ORIF) were used to treat complex tibial plateau fractures, but it was not sure which one was better. So we did this meta-analysis to evaluate the outcomes of ExFx and ORIF in managing complex tibial plateau fractures. Articles published before August 5, 2016 were selected from PubMed, Cochrane library, and some other electronic database. Relevant journals were also searched manually with no language limited. Two independent reviewers searched and assessed the literature. A fixed effect model was initially used for meta-analyses with RevMan 5.3. When compared with ORIF, cases undergoing ExFx were more likely to return to the preinjury state at the early stage, but no difference in the later period of follow-up. However, ExFx group had higher infection rate (OR 1.98, 95% CI 1.08-3.63, P = 0.03), higher venous thromboembolism rate (OR 1.56, 95% CI 0.49-4.96, P = 0.45), higher re-operation rate (OR 0.87, 95% CI 0.47-1.62, P = 0.66) and lower compartment syndrome rate (OR 0.61, 95% CI 0.12-3.22, P = 0.56), lower TKA rate (OR 0.51, 95% CI 0.20-1.34, P = 0.17). There were no statistically significant differences in the rate of deep infection, venous thromboembolism, compartment syndrome and VTE between the two groups. Although external fixation may offer some advantages, both were acceptable strategies in managing complex tibial plateau fractures. According to our analysis results, we strongly recommend that selection of definitive fixators should base on the fracture patterns, soft-tissue condition as well as the injury stages in clinical practice. More important, further multicentered, randomized controlled studies should be implemented to get a more reliable and clear result. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  4. Lumbopelvic fixation: a surgical alternative for lumbar stability

    Directory of Open Access Journals (Sweden)

    Gabriel Virgilio Ortiz García

    2014-09-01

    Full Text Available OBJECTIVE: Lumbopelvic fixation is a valid surgical option to achieving great stability in cases where it is particularly demanded, such as in patients with poor quality bone, degenerative scoliosis, and revision surgeries with modern materials and techniques. It enables simple integration of the iliopelvic systems with the rest of the spinal structure, maintaining hemorrhagia at acceptable levels, as well as surgery time. METHODS: We analyzed a case series of 15 patients of our center, who required major construction and/or presented poor quality bone. RESULTS: A total of 15 patients was studied, of which 12 (80% were women and three (20%, men. Nine (60% of these were revision surgeries, maintaining a surgery time of 5 hours (±1 h, with average blood loss of 1380 ml (±178 ml. All the patients received six to eight transpedicular screws, including iliac screws, and in all cases, a bone graft was inserted. CONCLUSION: Lumbopelvic fixation in patients with characteristics associated with osteopenia and osteoporosis, and in major instrumentations, particularly revision surgeries, three-dimensional correction is achieved, constructing a strong, stable pelvic base that is very useful, in patients with fragile surgical anatomy, for changes of implant or extensive decompression, provided the arthrodesis technique is adequate and with the insertion of a sufficient bone graft, and obviously, taking care to maintain the sagittal balance.

  5. Magnetoactive elastomer as an element of a magnetic retina fixator

    Science.gov (United States)

    Makarova, L. A.; Nadzharyan, T. A.; Alekhina, Yu A.; Stepanov, G. V.; Kazimirova, E. G.; Perov, N. S.; Kramarenko, E. Yu

    2017-09-01

    We explore the possibility of creating an effective retinal fixator on the basis of magnetoactive elastomers (MAEs) and systems of permanent magnets. MAEs consist of silicone elastomer matrix with embedded magnetic iron microparticles. We study theoretically and experimentally magnetic forces acting between MAE samples and permanent magnets in various configurations. The theoretical model is based around classical magnetostatics and Maxwell equations with different parameters accounting for peculiarities of the material and the setup. Approximation of the experimentally measured magnetization curves for MAE samples was used to find input parameters for the theoretical model. To test the model, we conducted a series of experimental measurements of magnetic forces accompanied by model predictions for the system of one cylindrical magnet and a cuboid MAE sample. Calculated dependences of the average pressure arising from magnetic interactions on the distance between the closest faces of MAE samples and a permanent magnet are in a good agreement with the experimental data. The proof on concept for smaller magnetic systems required for eye surgery includes data for 10 magnets configuration and a thin MAE band. This research demonstrates high prospects of using MAE as an element of a magnetic fixator for treatment of complicated retinal detachments.

  6. CO2 Fixation by Membrane Separated NaCl Electrolysis

    Directory of Open Access Journals (Sweden)

    Hyun Sic Park

    2015-08-01

    Full Text Available Atmospheric concentrations of carbon dioxide (CO2, a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS, which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical disadvantages. Carbon capture and utilization (CCU, which has been introduced to cover such disadvantages, makes it possible to capture CO2, recycling byproducts as resources. However, CCU also requires large amounts of energy in order to induce reactions. Among existing CCU technologies, the process for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated at room temperature and pressure. Following the experiment, the resulting product CaCO3 was analyzed with Fourier transform infrared spectroscopy (FT-IR; field emission scanning electron microscopy (FE-SEM image and X-ray diffraction (XRD patterns were also analyzed. The results showed that the CaCO3 crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Demographic-noise-induced fixation in subdivided populations with migration

    International Nuclear Information System (INIS)

    Kang, Yung-Gyung; Park, Jeong-Man

    2017-01-01

    We investigate the stochastic dynamics of a model which consists of subdivided populations of individuals confined to a set of islands. In subdivided populations, migration acts with selection and genetic drift to determine the evolutionary dynamics. The individuals are assumed to be haploid with two types. They reproduce according to their fitness values, die at random, and migrate between the islands. The evolutionary dynamics of an individual-based model is formulated in terms of a master equation and is approximated as the multidimensional Fokker–Planck equation (FPE) and the coupled non-linear stochastic differential equations (SDEs) with multiplicative noise. We first analyze the deterministic part of the SDEs, to obtain the fixed points and determine the stability of each fixed point. We find that there is a continuous phase transition in the population distribution when the migration rate is equal to the selection strength in the antisymmetric selection scheme. Next, we take demographic stochasticity into account, and analyze the FPE by eliminating the fast variable to reduce the coupled two-variable FPE to the single-variable FPE. We derive a quasi-stationary distribution of the reduced FPE, and predict the fixation probabilities and the mean fixation times to absorbing states. We also carry out numerical simulations, in the form of the Gillespie algorithm, and find that the results of simulations are consistent with the analytic predictions. (paper)

  9. Navicular stress fractures treated with minimally invasive fixation

    Directory of Open Access Journals (Sweden)

    Korula Mani Jacob

    2013-01-01

    Early intervention with minimally invasive surgery has significantly less morbidity and a reliable early return to active sports and is therefore the best option in high-performance athletes. Materials and Methods: Nine athletes with ten stress fractures of the navicular treated at our institution between April 1991 and October 2000. The mean age of the patients was 22.8 years (range 18-50 years. All patients were treated by minimally invasive screw fixation and early weight bearing mobilization without a cast. The average followup was 7 years (range 2-11 years. Results: Seven of the nine patients returned to their pre-fracture level of sporting activity at an average of 5 months (range 3-9 months. One patient returned to full sporting activity following a delay of 2 years due to an associated tibial stress fracture and one patient had an unsatisfactory result. Long term review at an average of 7 years showed that six of these eight patients who returned to sports remained symptom free with two patients experiencing minimal intermittent discomfort after prolonged activity. Conclusions: We recommend percutaneous screw fixation as a reliable, low morbidity procedure allowing early return to full sporting activity without long term complications or recurrences.

  10. Motorized injector-assisted intrascleral intraocular lens fixation.

    Science.gov (United States)

    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 (pIOL 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. Copyright © 2017. Published by Elsevier Taiwan.

  11. Bioptics in sutureless intrascleral multifocal posterior chamber intraocular lens fixation.

    Science.gov (United States)

    Pavlidis, Mitrofanis; de Ortueta, Diego; Scharioth, Gabor B

    2011-05-01

    To present a technique for sutureless fixation of a three-piece, multifocal, posterior chamber intraocular lens (IOL) in the ciliary sulcus. A 24-year-old woman presented with bilateral subluxation of the crystalline lens. Two straight sclerotomies were prepared with a 24-gauge cannula 2.0 mm from the limbus 180° apart from each other. The cannula was used to create a 2.0- to 3.0-mm tunnel parallel to the limbus starting from the sclerotomies. The leading haptic of the multifocal IOL was grasped at its tip with end-gripping, 25-gauge forceps and pulled through the sclerotomy. The forceps was used to introduce the IOL haptic into the scleral tunnel parallel to the limbus. Multifocal posterior chamber IOLs were stable and well centered. No postoperative complications occurred in the 16-month follow-up period. Preoperative astigmatism was corrected after IOL implantation with corneal wavefront-guided laser epithelial keratomileusis. Sutureless fixation of multifocal posterior chamber IOL haptics in a scleral tunnel parallel to the limbus can be successful, resulting in long-term centration and three-dimensional axial stability for optimal refractive results. If necessary, postoperative wavefront-guided refractive correction can be performed to optimize final refraction. Copyright 2011, SLACK Incorporated.

  12. Motorized injector-assisted intrascleral intraocular lens fixation

    Directory of Open Access Journals (Sweden)

    Jia-Horung Hung

    2017-03-01

    Full Text Available 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.

  13. Fixation and transport of uranium by humic substances (1962)

    International Nuclear Information System (INIS)

    Martin, J.

    1962-03-01

    One enter upon the study of the part taken by organic substances in ores that contain uranium in a disseminated form, without mineralization, being considered the reaction between uranium and humus. 'Humic acids' are extracted from the peat by ammonia. By the fact of their ability to cationic exchange, these are forming humates with metal cations; monovalent humates, normally soluble in water, can become insoluble after treatment of humic acids with methanal. The polyvalent humates are insoluble in water, especially humates of U (IV) and uranyl U (VI). Action of Li, Na, K, Mg, Ca uranyl carbonates solutions on the humic acids results in the formation of humates containing uranyl and the other cation. 100 g of humic acids give a fixation of no more than 38 g of uranium as uranyl. In contact with uraniferous weakly concentrated solutions, they fix 4 to 8 g according to pH, with a yield in the extraction greater than 95 per cent. The action of a sodium humate solution on a humate of uranyl give a solution containing a soluble sodium and uranyl humate. The solution is precipitated at various degrees by the polyvalent cations and insoluble humic substances. In all cases, the fixation of uranium with such prepared humic acids corresponds to a chemisorption of uranyl cations. (author) [fr

  14. Demographic-noise-induced fixation in subdivided populations with migration

    Science.gov (United States)

    Kang, Yung-Gyung; Park, Jeong-Man

    2017-11-01

    We investigate the stochastic dynamics of a model which consists of subdivided populations of individuals confined to a set of islands. In subdivided populations, migration acts with selection and genetic drift to determine the evolutionary dynamics. The individuals are assumed to be haploid with two types. They reproduce according to their fitness values, die at random, and migrate between the islands. The evolutionary dynamics of an individual-based model is formulated in terms of a master equation and is approximated as the multidimensional Fokker–Planck equation (FPE) and the coupled non-linear stochastic differential equations (SDEs) with multiplicative noise. We first analyze the deterministic part of the SDEs, to obtain the fixed points and determine the stability of each fixed point. We find that there is a continuous phase transition in the population distribution when the migration rate is equal to the selection strength in the antisymmetric selection scheme. Next, we take demographic stochasticity into account, and analyze the FPE by eliminating the fast variable to reduce the coupled two-variable FPE to the single-variable FPE. We derive a quasi-stationary distribution of the reduced FPE, and predict the fixation probabilities and the mean fixation times to absorbing states. We also carry out numerical simulations, in the form of the Gillespie algorithm, and find that the results of simulations are consistent with the analytic predictions.

  15. Extracting information of fixational eye movements through pupil tracking

    Science.gov (United States)

    Xiao, JiangWei; Qiu, Jian; Luo, Kaiqin; Peng, Li; Han, Peng

    2018-01-01

    Human eyes are never completely static even when they are fixing a stationary point. These irregular, small movements, which consist of micro-tremors, micro-saccades and drifts, can prevent the fading of the images that enter our eyes. The importance of researching the fixational eye movements has been experimentally demonstrated recently. However, the characteristics of fixational eye movements and their roles in visual process have not been explained clearly, because these signals can hardly be completely extracted by now. In this paper, we developed a new eye movement detection device with a high-speed camera. This device includes a beam splitter mirror, an infrared light source and a high-speed digital video camera with a frame rate of 200Hz. To avoid the influence of head shaking, we made the device wearable by fixing the camera on a safety helmet. Using this device, the experiments of pupil tracking were conducted. By localizing the pupil center and spectrum analysis, the envelope frequency spectrum of micro-saccades, micro-tremors and drifts are shown obviously. The experimental results show that the device is feasible and effective, so that the device can be applied in further characteristic analysis.

  16. Internal Fixation of Cervical Fractures in Three Horses.

    Science.gov (United States)

    Rossignol, Fabrice; Brandenberger, Olivier; Mespoulhes-Rivière, Céline

    2016-01-01

    To describe the surgical treatment outcome of cervical fractures in 3 horses. Case report. Three client-owned horses with cervical vertebral fractures. Three horses were refered for neck stiffness, pain, and ataxia after a cervical trauma because of a fall. Radiographic examination showed an oblique displaced fracture of the caudal aspect of the body of the second cervical vertebra (C2) in horse 1, an oblique displaced fracture of the caudal aspect of C4 involving the disc between C4 and C5 in horse 2, and a displaced transverse fracture of the body of the axis (C2) extending to the lateral arches and involving the vertebral canal in horse 3. In horse 1, the fracture was reduced and stabilized using a 14-hole narrow DCP plate, applied ventrally, and fixed with cancellous screws. A cervical fusion was performed. In horses 2 and 3, fracture fixation was performed using a 5-hole narrow LCP and 5 mm locking screws. All horses showed improvement and returned to full activity. The fracture healed in all horses. Internal fixation of cervical fracture in these horses was associated with minimal complications, and was associated with healing and a highly functional outcome in all horses. The LCP was preferred and would be recommended for ventral stabilization of selected cases of vertebral fractures. © Copyright 2015 by The American College of Veterinary Surgeons.

  17. Internal fixation of severe maxillofacial fractures in dogs.

    Science.gov (United States)

    Arzi, Boaz; Verstraete, Frank J M

    2015-05-01

    To describe internal fixation for maxillofacial fractures using titanium miniplates and report outcome in 7 dogs. Prospective case series. Skeletally mature dogs (n = 7) with maxillofacial fractures. After CT evaluation of fracture configuration, using a combination of extraoral and intraoral approaches as needed, non-locking titanium miniplates were contoured to match the normal anatomy of the fractured bones. Plates were secured using non-locking titanium screws and then covered with a soft-tissue envelope followed by routine intraoral and extraoral closure. Fractures healed rapidly after reconstruction with immediate return to normal function and occlusion. Follow-up time of up to 94 months indicated excellent long-term function and general lack of complications. One dog developed nasal aspergillosis 1.5 years after surgery and the miniplates were removed without adverse consequences. Internal fixation for maxillofacial reconstruction using titanium miniplates is an excellent solution for the treatment of comminuted and displaced maxillofacial fractures in dogs. © Copyright 2014 by The American College of Veterinary Surgeons.

  18. Postoperative complications associated with external skeletal fixators in cats.

    Science.gov (United States)

    Beever, Lee; Giles, Kirsty; Meeson, Richard

    2017-07-01

    The objective of this study was to quantify complications associated with external skeletal fixators (ESFs) in cats and to identify potential risk factors. A retrospective review of medical records and radiographs following ESF placement was performed. Case records of 140 cats were reviewed; fixator-associated complications (FACs) occurred in 19% of cats. The region of ESF placement was significantly associated with complication development. Complications developed most frequently in the femur (50%), tarsus (35%) and radius/ulna (33%). Superficial pin tract infection (SPTI) and implant failure accounted for 45% and 41% of all FACs, respectively. SPTI occurred more frequently in the femur, humerus and tibia, with implant failure more frequent in the tarsus. No association between breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, degree of fracture load sharing, and the incidence or type of FAC was identified. No association between region of placement, breed, age, sex, weight, fracture type (open vs closed), ESF classification, number of pins per bone segment, fracture load sharing and the time to complication development was identified. Complication development is not uncommon in cats following ESF placement. The higher complication rate in the femur, tarsus and radius/ulna should be considered when reviewing options for fracture management. However, cats appear to have a lower rate of pin tract infections than dogs.

  19. Treatment of degenerative lumbar spondylolisthesis by using minimally invasive transforaminal lumbar interbody fusion and percutaneous pedicle screw fixation

    Directory of Open Access Journals (Sweden)

    Hao WU

    2016-04-01

    Full Text Available Objective To discuss clinical therapeutic effects of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF combined with percutaneous pedicle screw fixation for degenerative lumbar spondylolisthesis (DLS.  Methods A total of 32 DLS patients treated by MIS-TLIF and percutaneous pedicle screw fixation from January 2013 to September 2015 in Xuanwu Hospital, Capital Medical University were retrospectively reviewed. Visual Analogue Scale (VAS, Oswestry Disability Index (ODI and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36 scores were assessed and compared between preoperation and one week, 3 months after operation and in the last follow-up. Lumbar lordosis angle, coronal Cobb angle, coronal and sagittal body shifting, complication, the degree of spondylolisthesis (Meyerding classification and the rate of spondylolisthesis were measured according to preoperative and postoperative spinal X-ray examination. Fusion rate was evaluated according to X-rays or CT in the last follow-up, and MRI was used to assess the degree of decompression.  Results Thirty-two patients were under test with mean operation time 160 min, intraoperative blood loss 120 ml, postoperative hospital stay 7.22 d and follow-up 10.83 months. Decompression and fusion levels ranged from L2-S1 and interbody fusion was performed in 32 patients and 41 levels were fused. Compared with preoperation, the VAS and ODI scores were significantly increased at one week, 3 months after operation and in the last follow-up (P = 0.000, for all, while SF-36 score (P = 0.002, 0.000, 0.000, lumbar lordotic angle (P = 0.000, for all, coronal Cobb angle (P = 0.000, for all and slippage rate (P = 0.000, for all were significantly decreased. The fusion rate was 92.22%, and the improvement rate of ODI was (80.51 ± 6.02% in the last follow-up. There were 3 cases appeared complications, including one case of infection and 2 cases of cerebrospinal fluid (CSF fistula, and were

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

    Science.gov (United States)

    Pirdankar, Onkar H; Das, Vallabh E

    2016-03-01

    The purpose of this study was to assess the effect of fixation target parameters on fixation instability in strabismic monkeys. 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). 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. 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.

  1. Surgical fixation of midshaft clavicle fractures: A systematic review of biomechanical studies.

    Science.gov (United States)

    Hulsmans, Martijn H; van Heijl, Mark; Houwert, Roderick M; Burger, Bart J; Verleisdonk, Egbert Jan M; Veeger, Dirk Jan; van der Meijden, Olivier A

    2018-02-21

    Surgical treatment of displaced midshaft clavicle fractures requires a decision between plate fixation and intramedullary (IM) fixation. Numerous studies report on the biomechanical properties of various repair constructs. The goal of this systematic review was to provide an overview of studies describing the biomechanical properties of the most commonly used surgical fixations of midshaft clavicle fractures. Additionally, we aimed to translate these biomechanical results into clinically relevant conclusions. A computer-aided search of the EMBASE and PudMed/MEDLINE databases was conducted. Studies included for review compared biomechanical properties of plate fixation with IM fixation and superiorly positioned plates with anteroinferiorly positioned plates for midshaft clavicle fractures. Fifteen studies were eligible for inclusion. Plate fixation seemed to form a more robust construct than IM fixation in terms of stiffness and failure loading. The remaining clavicle was stronger after removal of the IM device than after removal of the plate. Superior plating of transverse fractures generally seemed to provide greater stiffness and strength during bending loads than anteroinferior plating did. The absence of cortical alignment in wedge and comminuted fractures directly influenced the fixation stability for both IM fixation and plate fixation, regardless of location. Each type of fracture fixation has biomechanical advantages and disadvantages. However, exact thresholds of stiffness for inducing healing and failure strength to withstand refractures are unknown. The clinical relevance of the biomechanical studies may be arguable. Since none of the studies investigate the effect of tissue adaptation over time they should be interpreted with caution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. The role of eye fixation in memory enhancement under stress - An eye tracking study.

    Science.gov (United States)

    Herten, Nadja; Otto, Tobias; Wolf, Oliver T

    2017-04-01

    In a stressful situation, attention is shifted to potentially relevant stimuli. Recent studies from our laboratory revealed that participants stressed perform superior in a recognition task involving objects of the stressful episode. In order to characterize the role of a stress induced alteration in visual exploration, the present study investigated whether participants experiencing a laboratory social stress situation differ in their fixation from participants of a control group. Further, we aimed at shedding light on the relation of fixation behaviour with obtained memory measures. We randomly assigned 32 male and 31 female participants to a control or a stress condition consisting of the Trier Social Stress Test (TSST), a public speaking paradigm causing social evaluative threat. In an established 'friendly' control condition (f-TSST) participants talk to a friendly committee. During both conditions, the committee members used ten office items (central objects) while another ten objects were present without being used (peripheral objects). Participants wore eye tracking glasses recording their fixations. On the next day, participants performed free recall and recognition tasks involving the objects present the day before. Stressed participants showed enhanced memory for central objects, accompanied by longer fixation times and larger fixation amounts on these objects. Contrasting this, fixation towards the committee faces showed the reversed pattern; here, control participants exhibited longer fixations. Fixation indices and memory measures were, however, not correlated with each other. Psychosocial stress is associated with altered fixation behaviour. Longer fixation on objects related to the stressful situation may reflect enhanced encoding, whereas diminished face fixation suggests gaze avoidance of aversive, socially threatening stimuli. Modified visual exploration should be considered in future stress research, in particular when focussing on memory for a

  3. Use of Radiographic Densitometry to Predict the Bone Healing Index in Distraction Osteogenesis

    OpenAIRE

    A Saw; S Manimaran; S Faizal; AM Bulgiba

    2008-01-01

    Bone lengthening with distraction osteogenesis involves prolonged application of an external fixator frame. Qualitative and quantitative evaluation of callus has been described using various imaging modalities but there is no simple reliable and readily available method. This study aims to investigate the use of a densitometer to analyze plain radiographic images and correlate them with the rate of new bone formation as represented by the bone healing index. A total of 34 bone lengthening pro...

  4. The Impact of Task Demands on Fixation-Related Brain Potentials during Guided Search.

    Directory of Open Access Journals (Sweden)

    Anthony J Ries

    Full Text Available Recording synchronous data from EEG and eye-tracking provides a unique methodological approach for measuring the sensory and cognitive processes of overt visual search. Using this approach we obtained fixation related potentials (FRPs during a guided visual search task specifically focusing on the lambda and P3 components. An outstanding question is whether the lambda and P3 FRP components are influenced by concurrent task demands. We addressed this question by obtaining simultaneous eye-movement and electroencephalographic (EEG measures during a guided visual search task while parametrically modulating working memory load using an auditory N-back task. Participants performed the guided search task alone, while ignoring binaurally presented digits, or while using the auditory information in a 0, 1, or 2-back task. The results showed increased reaction time and decreased accuracy in both the visual search and N-back tasks as a function of auditory load. Moreover, high auditory task demands increased the P3 but not the lambda latency while the amplitude of both lambda and P3 was reduced during high auditory task demands. The results show that both early and late stages of visual processing indexed by FRPs are significantly affected by concurrent task demands imposed by auditory working memory.

  5. Anterior lumbar interbody fusion with percutaneous pedicle screw fixation for multiple-level isthmic spondylolisthesis.

    Science.gov (United States)

    Hsieh, Chang-Sheng; Lee, Hyung Chang; Oh, Hyeong-Seok; Park, Sang-Joon; Hwang, Byeong-Wook; Lee, Sang-Ho

    2017-07-01

    Multiple-level lumbar isthmic spondylolisthesis is rarely reported. Here, we report 23 consecutive patients who underwent anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PPF) for multiple-level isthmic spondylolisthesis. From June 2008 through December 2014, multiple-level lumbar isthmic spondylolisthesis was diagnosed in 23 patients (6 men, 17 women) at Wooridul Spine Hospital (Busan, South Korea). Isthmic spondylolisthesis occurred at three spinal levels in 2 patients and at two levels in 21 patients. All patients underwent ALIF with PPF. We used the Oswestry Disability Index (ODI) and visual analog scale scores to evaluate the preoperative and postoperative functional outcome, low back pain, and radicular pain. We also evaluated segmental lordosis and the fusion status using radiographs and data from computed tomography. Isthmic spondylolisthesis occurred from L3 to S1 and mostly occurred at two consecutive spinal levels (i.e., L4-L5 and L5-S1). Significant improvements in the ODI and visual analog scale were observed in patients at final follow up (pspondylolisthesis. Copyright © 2017. Published by Elsevier B.V.

  6. Asymptomatic Flexor Tendon Damages after Volar Locking Plate Fixation of Distal Radius Fractures.

    Science.gov (United States)

    Tokunaga, Susumu; Abe, Yoshihiro

    2017-03-01

    To investigate asymptomatic flexor tendon damages after volar locking plate fixation of distal radius fractures in 32 wrists of 32 patients with distal radius fractures fixed using two plate types. Sixteen patients received the Acu-Loc volar distal radius plate, and the remaining 16 patients received the Aptus distal radius correction plate. The flexor pollicis longus (FPL) tendon and flexor digitorum profundus were evaluated according to intraoperative findings at plate removal. Ultrasonography was used to measure the distance between the FPL tendon and distal edge of the plates (FPL plate distance) before plate removal, the distance between the FPL tendon and distal edge of the radius (FPL radius distance) after plate removal, in the contralateral wrist, and the angle between an extension line of a volar surface line on the proximal FPL tendon and a second volar surface line on the distal FPL tendon (FPL angles). Erosion of the FPL tendon was identified in four wrists, and erosion of the flexor digitorum profundus of the index finger was identified in one wrist. All five cases of wrists with flexor tendon damage had Acu-Loc plates installed. The average FPL angle before plate removal was 15.4° in the wrists with tendon damage, which was statistically significantly larger than the average FPL angle in the wrists without erosion. The type of plate and larger FPL angle on ultrasonography may be the risk factors for flexor tendon damage.

  7. COMBINATION OF FIXATION TECHNIQUES IN THE MANAGEMENT OF COMPLEX DISTAL RADIUS FRACTURE- OUR EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Isaac Sunder Sen

    2016-10-01

    Full Text Available BACKGROUND The aim of the study is to categorically suggest the apt method of surgical technique for a particular type of distal radius fracture (Frykman’s type III-VI. Distal radius fracture are among the most common fractures of the upper extremity inspite of increased focus on regular prevention of osteoporosis, early identification and its prompt management. Most distal radius fractures are the result of low energy mechanisms that can be successfully treated either nonoperatively or with a variety of operative techniques if indicated. Complex distal radius fractures occur most commonly in high-energy injuries with extensive comminution or bone loss and associated soft tissue or vascular injuries. These high-energy fractures can present challenges in reconstructing the distal radius. Effective restoration of the bony architecture requires a thorough knowledge of distal radius anatomy, understanding of the goals of treatment, versatility in surgical approaches and familiarity with multiple fixation options. Although, majority of the extra-articular fracture without signs of instability can be successfully managed with POP immobilisation for a period of 4-5 weeks followed by active physiotherapy, other types (Frykman’s III-VI need surgical management that too with combination of surgical techniques namely augmented spanning external fixator with supplemented K-wire fixation or external fixation followed by fragment specific volar locking compression plate osteosynthesis. MATERIALS AND METHODS I have studied 50 cases of distal radius fractures classified using Frykman’s classification using combination of techniques namely augmented spanning external fixator application with K-wire supplementation and spanning external fixator application followed by volar LCP fixation in which external fixator had been used as a reduction tool in majority of the cases and external fixator had been removed after plate osteosynthesis. In some cases retained

  8. An in-vitro biomechanical study of different fixation techniques for the extended trochanteric osteotomy in revision THA.

    Science.gov (United States)

    Zhu, Zhonglin; Ding, Hui; Shao, Hongyi; Zhou, Yixin; Wang, Guangzhi

    2013-04-09

    The wire fixation and the cable grip fixation have been developed for the extended trochanteric osteotomy (ETO) in the revision of total hip arthroplasty (THA). Many studies reported the postoperative performance of the patients, but with little quantitative biomechanical comparison of the two fixation systems. An in-vitro testing approach was designed to record the loosening between the femoral bed and the greater trochanter after fixations. Ten cadaveric femurs were chosen in this study. Each femur underwent the THA, revision by ETO and fixations. The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively. The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system. In the vertical tension tests, the overall translation of the greater trochanter was observed 0.4 mm in the cable fixations and 7.0 mm in the wire fixations. In the lateral tension tests, the overall motion of the greater trochanter was 2.0 mm and 1.2° in the cable fixations, while it was 6.2 mm and 5.3° in the wire fixations. The result was significantly different between the two fixation systems. The stability of the proximal femur after ETO using different fixations in the revision THA was investigated. The cable grip fixation was significantly more stable than the wire fixation.

  9. [Effect evaluation of over 5 year follow up of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion for lumbar degenerative diseases].

    Science.gov (United States)

    Wang, Chong; Ying, Jin-He; Xie, Pan-Pan; Wu, Xiao-Guang

    2016-07-25

    To evaluate the clinical effects of over 5 year follow up of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion(TLIF) in treating lumbar degenerative diseases. The clinical data of 24 patients with lumbar degenerative disease underwent unilateral pedicle screw fixation with transforaminal lumbar interbody fusion from March 2007 to October 2009, were retrospectively analyzed. There were 13 males and 11 females, aged from 34 to 68 years old with an average of 52 years. Postoperative pain and functional results were analyzed by the visual analogue scale(VAS) and Oswestry Disability Index(ODI). Radiological examination was obtained for each patient to assess the height of intervertebral space, postoperative intervertebral fusion conditions and general complications. All patients were followed up from 5 to 8 years with an average of 6.7 years. VAS scores of low back pain and leg pain decreased from preoperative 7.82±0.71, 8.42±1.24 to postoperative 1.87±0.81, 2.23±1.62, respectively( P degenerative diseases according to over 5 year follow up, however, its indications should be well considered. But the problems such as intervertebral space height of operated side loss and adjacent segment degeneration after unilateral pedicle screw fixation need further clinical study.

  10. Treatment of reducible unstable fractures of the distal radius in adults: a randomised controlled trial of De Palma percutaneous pinning versus bridging external fixation

    Directory of Open Access Journals (Sweden)

    Belloti João C

    2010-06-01

    Full Text Available Abstract Background At present, there is no conclusive evidence regarding the best treatment method for reducible unstable fractures of the distal radius. This study compared the effectiveness of two methods used in surgical treatment of such fractures: percutaneous pinning and external fixation. Methods We randomly allocated 100 patients into two groups treated surgically with modified De Palma percutaneous pinning and bridging external fixation. Independent but not blinded evaluators administered the DASH quality-of-life questionnaire at postoperative months 6 and 24, performed functional assessment of pain, range of motion, and palm grip strength, and radiographic examinations (volar and radial angle, and height of the radius before the operation, immediately afterwards, and at 6 and 24 months postoperative. Modified De Palma percutaneous pinning patients used an above-elbow cast whereas external fixation group had unrestricted elbow motion after surgery. Patients who for any reason demonstrated treatment failure or required additional interventions were followed up and their results were included in the group into which these patients had initially been randomised according to the intention-to-treat principle. A significance level of 5% (alpha = 0.05. was used for all statistical tests, such that tests presenting a p-value less than 0.05 were considered statistically significant. Results Ninety one (58.8 mean age and 66 participants were female were included in the final assessment at 24 months. The DASH questionnaire evaluation showed a statistically significant result favouring the De Palma group (mean difference = -7.1 p = 0.044 after six months, but this was not maintained at 24 months. There were no statistically differences between the groups with respect to palm grip strength. Analysis of the range-of-motion limitation index (uninjured side minus affected side motion of showed a statistical difference (mean difference = 2.4 p = 0

  11. MODELING OF BONE FRAGMENTS FIXATION WITH AN EXTERNAL FIXATION DEVICE FOR BILATERAL ROTATION UNSTABLE PELVIC INJURIES B TYPE ACCORDING TO AO/ASIF CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    V. G. Vinogradov

    2014-01-01

    Full Text Available Objective: to determine the stability of bone fragments fixation with an external fixation device in the simulation of bilateral partly unstable pelvic injuries of B type according to AO/ASIF classification and to identify the role of different fixation elements in the stability of fixation. Material and methods: the study was performed on the finite element model of a system “an external fixation device - pelvis” developed for a software package MSCNastran. Formation of a fracture of pubic and ischial pelvic bones was accomplished by means of rupture in the finite element network and decrease of elasticity modulus in the ilio-sacral joint on both sides up to 35 mm at the site of a fracture. Loads were carried on top of the body of the first sacral vertebra with a force of 500H.The second area of application of the load was from the bottom-up on the acetabular roof with a force of 250H. In this study the effect of different elements of an external fixation device on the stiffness of bone fragments fixation was evaluated. Symmetrical elements were removed both separately and together. As a result, the stiffness of a system decreased and the displacement at the fracture site increased. Conclusion: in a model of partly stable pelvic injuries accompanied by general rotation instability in the horizontal and sagittal planes to 35 mm, an external fixation device provided high stability of bone fragments (to 3 mm due to introduction of bone rods in the iliac wings with the obligatory introduction of the rod in the vertical branches of pubic bones and strengthening the anterior lower bar between the subsystems. What is more, installing the anterior upper bar or introduction of bone rods in the bodies of iliac bone are not necessary.

  12. Bridging external fixation versus non-bridging external fixation for unstable distal radius fractures: A systematic review and meta-analysis.

    Science.gov (United States)

    Gu, Wan-Li; Wang, Jun; Li, Dong-Qing; Gong, Ming-Zhi; Chen, Peng; Li, Zhong-Yi; Yang, Li-Feng; Liu, Wei; Zhou, Ye

    2016-01-01

    A systematic review and meta-analysis was conducted to compare the relative effectiveness of bridging external fixation and non-bridging external fixation for distal radius fractures treatment. Relevant literature were comprehensively searched using the PubMed, Springer Link, Karger Medical and Scientific Publishers, Chinese Biomedical Database (CBM) and Chinese National Knowledge Infrastructure (CNKI) databases without any language restrictions. STATA Version 12.0 software and Comprehensive Meta-analysis 2.0 were applied. A total of 905 patients with distal radius fracture from six eligible cohort studies were selected for statistical analysis. Our meta-analysis results indicate that the non-bridging cases had a higher risk of pin track infection, rupture of the extensor pollicis longus and nerve injury than the bridging cases. Subgroup analysis stratified by country indicated non-bridging patients showed evidence of an increased risk of pin track infection and higher risk of rupture of the extensor pollicis longus compared with the patients treated with bridging external fixation in the UK population. The follow-up results showed flexion degree of patients treated with non-bridging external fixation was slightly better than that of patients treated with bridging external fixation (P review and meta-analysis to support that bridging external fixation can reduce the incidence of pin tract infections and nerve injury compared to non-bridging external fixation, but have no significant difference in other complications and the recovery of wrist joint function. Bridging external fixation could therefore be a better choice in patients with distal radius fractures. Copyright © 2015 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  13. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05). CONCLUSIONS PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  14. Comprehensive comparing percutaneous endoscopic lumbar discectomy with posterior lumbar internal fixation for treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis: A retrospective case-control study.

    Science.gov (United States)

    Sun, Yapeng; Zhang, Wei; Qie, Suhui; Zhang, Nan; Ding, Wenyuan; Shen, Yong

    2017-07-01

    The study was to comprehensively compare the postoperative outcome and imaging parameter characters in a short/middle period between the percutaneous endoscopic lumbar discectomy (PELD) and the internal fixation of bone graft fusion (the most common form is posterior lumbar interbody fusion [PLIF]) for the treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis after a previous lumbar internal fixation surgery.In this retrospective case-control study, we collected the medical records from 11 patients who received PELD operation (defined as PELD group) for and from 13 patients who received the internal fixation of bone graft fusion of lumbar posterior vertebral lamina decompression (defined as control group) for the treatment of the lumbar disc prolapse combined with stable retrolisthesis at Department of Spine Surgery, the Third Hospital of Hebei Medical University (Shijiazhuang, China) from May 2010 to December 2015. The operation time, the bleeding volume of perioperation, and the rehabilitation days of postoperation were compared between 2 groups. Before and after surgery at different time points, ODI, VAS index, and imaging parameters (including Taillard index, inter-vertebral height, sagittal dislocation, and forward bending angle of lumbar vertebrae) were compared.The average operation time, the blooding volume, and the rehabilitation days of postoperation were significantly less in PELD than in control group. The ODI and VAS index in PELD group showed a significantly immediate improving on the same day after the surgery. However, Taillard index, intervertebral height, sagittal dislocation in control group showed an immediate improving after surgery, but no changes in PELD group till 12-month after surgery. The forward bending angle of lumbar vertebrae was significantly increased and decreased in PELD and in control group, respectively.PELD operation was superior in terms of operation time, bleeding volume, recovery period, and financial

  15. Comprehensive comparing percutaneous endoscopic lumbar discectomy with posterior lumbar internal fixation for treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis

    Science.gov (United States)

    Sun, Yapeng; Zhang, Wei; Qie, Suhui; Zhang, Nan; Ding, Wenyuan; Shen, Yong

    2017-01-01

    Abstract The study was to comprehensively compare the postoperative outcome and imaging parameter characters in a short/middle period between the percutaneous endoscopic lumbar discectomy (PELD) and the internal fixation of bone graft fusion (the most common form is posterior lumbar interbody fusion [PLIF]) for the treatment of adjacent segment lumbar disc prolapse with stable retrolisthesis after a previous lumbar internal fixation surgery. In this retrospective case-control study, we collected the medical records from 11 patients who received PELD operation (defined as PELD group) for and from 13 patients who received the internal fixation of bone graft fusion of lumbar posterior vertebral lamina decompression (defined as control group) for the treatment of the lumbar disc prolapse combined with stable retrolisthesis at Department of Spine Surgery, the Third Hospital of Hebei Medical University (Shijiazhuang, China) from May 2010 to December 2015. The operation time, the bleeding volume of perioperation, and the rehabilitation days of postoperation were compared between 2 groups. Before and after surgery at different time points, ODI, VAS index, and imaging parameters (including Taillard index, inter-vertebral height, sagittal dislocation, and forward bending angle of lumbar vertebrae) were compared. The average operation time, the blooding volume, and the rehabilitation days of postoperation were significantly less in PELD than in control group. The ODI and VAS index in PELD group showed a significantly immediate improving on the same day after the surgery. However, Taillard index, intervertebral height, sagittal dislocation in control group showed an immediate improving after surgery, but no changes in PELD group till 12-month after surgery. The forward bending angle of lumbar vertebrae was significantly increased and decreased in PELD and in control group, respectively. PELD operation was superior in terms of operation time, bleeding volume, recovery period

  16. Long-term warming and litter addition affects nitrogen fixation in a subarctic heath

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Michelsen, Anders

    2011-01-01

    the measurements. We analyzed N fixation rates on both whole-ecosystem level and specifically on two moss species: Sphagnum warnstorfii and Hylocomium splendens. The whole-ecosystem N fixation of the warmed plots almost tripled compared with the control plots. However, in the Sphagnum and Hylocomium mosses we...

  17. Right Visual Field Advantage in Parafoveal Processing: Evidence from Eye-Fixation-Related Potentials

    Science.gov (United States)

    Simola, Jaana; Holmqvist, Kenneth; Lindgren, Magnus

    2009-01-01

    Readers acquire information outside the current eye fixation. Previous research indicates that having only the fixated word available slows reading, but when the next word is visible, reading is almost as fast as when the whole line is seen. Parafoveal-on-foveal effects are interpreted to reflect that the characteristics of a parafoveal word can…

  18. Exploring the Boundaries of N2-Fixation in Cereals and Grasses: A Hypothetical and Experimental Framework

    NARCIS (Netherlands)

    Giller, K.E.; Merckx, R.

    2003-01-01

    Despite more than 40 years of research on free-living and endophytic bacteria associated with cereals and grasses, conclusive examples of impacts of non-symbiotic N2-fixation in agriculture are lacking. All available methods for measurement of N2-fixation associated with cereals and grasses have

  19. Ultrastructure of the endolymphatic duct in the rat. Fixation and preservation

    DEFF Research Database (Denmark)

    Qvortrup, K; Rostgaard, J

    1993-01-01

    Ten rats were vascular-perfused at subphysiologic as well as physiologic pressures, 80 mmHg and 120 mmHg, respectively, employing a pressure feed-back controlled peristaltic pump and an isotonic perfusate/fixative with colloids (2% Dextran) and a hypertonic perfusate/fixative without colloids, 30...

  20. Closed External Fixation for Failing or Failed Femoral Shaft Plating in a Developing Country.

    Science.gov (United States)

    Aliakbar, Adil; Witwit, Ibrahim; Al-Algawy, Alaa A Hussein

    2017-08-01

    Femoral shaft fractures are one of the common injuries that is treated by open reduction, with internal fixation by plate and screws or intramedullary nailing, which can achieve a high union rate. To evaluate the outcome of using closed external fixation to augment a failing plate; with signs of screw loosening and increasing bone/plate gap; a failed plate; broken plate; screws completely out of bone with redisplacement of fracture. A retrospective study on 18 patients, aged between 17-42 years, who presented between 6-18 weeks after initial surgical fixation, with pain, difficulty in limb function, deformity and abnormal movement at fracture site, was done. X-Rays showed plating failure with acceptable amount of callus, which unfortunately had refractured. Cases associated with infection and no radiological evidence of callus formation were excluded from this study. Closed reduction was done by manipulation, then fracture fixation by AO external fixator. The patients were encouraged for full weight bearing as early as possible with dynamization later on. Of the 18 patients who underwent external fixation after close reduction, 15 cases showed bone healing in a period between 11-18 weeks (mean of 14.27 weeks) with good alignment (Radiologically). Removal of external fixator was done followed by physical therapy thereafter. Closed external fixation for treatment of failing or failed femoral plating, achieves good success rate and has less complications, is a short time procedure, especially in a hospital with limited resources.