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Sample records for facet joint arthrosis

  1. A critical evaluation of subtalar joint arthrosis associated with middle facet talocalcaneal coalition in 21 surgically managed patients: a retrospective computed tomography review. Investigations involving middle facet coalitions-part III.

    PubMed

    Kernbach, Klaus J; Barkan, Howard; Blitz, Neal M

    2010-01-01

    Symptomatic middle facet talocalcaneal coalition is frequently associated with rearfoot arthrosis that is often managed surgically with rearfoot fusion. However, no objective method for classifying the extent of subtalar joint arthrosis exists. No study has clearly identified the extent of posterior facet arthrosis present in a large cohort treated surgically for talocalcaneal coalition through preoperative computerized axial tomography. The authors conducted a retrospective review of 21 patients (35 feet) with coalition who were surgically treated over a 12-year period for coalition on at least 1 foot. Using a predefined original staging system, the extent of the arthrosis was categorized into normal or mild (Stage I), moderate (Stage II), and severe (Stage III) arthrosis. The association of stage and age is statistically significant. All of the feet with Stage III arthrosis had fibrous coalitions. No foot with osseous coalition had Stage III arthrosis. The distribution of arthrosis staging differs between fibrous and osseous coalitions. Only fibrous coalitions had the most advanced arthrosis (Stage III), whereas osseous coalitions did not. This suggests that osseous coalitions may have a protective effect in the prevention of severe degeneration of the subtalar joint. Concomitant subtalar joint arthrosis severity progresses with age; surgeons may want to consider earlier surgical intervention to prevent arthrosis progression in patients with symptomatic middle facet talocalcaneal coalition.

  2. Comparison of computed tomography and magnetic resonance imaging in the evaluation of facet tropism and facet arthrosis in degenerative cervical spondylolisthesis.

    PubMed

    Xu, C; Ding, Z H; Xu, Y K

    2014-05-30

    The aim of this study was to determine the reliability of magnetic resonance imaging (MRI) in the assessment of facet tropism and facet arthrosis of spondylolisthesis levels in degenerative cervical spondylolisthesis as compared to computed tomography (CT). The discrepancies in the interpretation of CT and MRI data in the evaluation of facet tropism and arthrosis have given rise to questions regarding the reliability of comparisons of the two techniques. Using a 4-point scale, 3 blinded readers independently graded the severity of facet tropism and facet arthrosis of 79 cervical facet joints on axial T2-weighted and sagittal T1 and T2-weighted turbo spin echo images as well as the corresponding axial CT scans. All results were subjected to the kappa coefficient statistic for strength of agreement. In the assessment of the severity of facet arthrosis, intermethod agreement (weighted κ) between CT scanning with a moderate inter-rater reliability (range κ = 0.43-0.57) and MRI with fair inter-rater reliability (range κ = 0.23-0.38) was 0.76 and 0.43 for the severity of facet tropism and facet arthrosis, respectively. Intra-rater reliability for the severity of facet arthrosis was moderate to substantial for CT and was moderate for MRI scans. Intra-rater reliability for the severity of facet tropism was substantial to very good for CT and substantial for MRI scans. MRI can reliably determine the presence or degree of facet tropism but not facet arthrosis. Therefore, for a comprehensive assessment of cervical facet joint degeneration, both a CT and an MRI scan should be performed.

  3. [Knee joint pain with signs of arthrosis].

    PubMed

    Bender, T T A; Marinova, M; Radbruch, L; Conrad, R; Jobst, D; Mücke, M

    2017-03-14

    Chronic pain in the knee joint is most commonly caused by osteoarthritis, especially in elderly patients but can be due to other causes, such as rheumatoid arthritis. The diagnostics include an exact patient medical history and a clinical examination, which often already provide clear indications of the cause of the knee pain. Subsequently, further diagnostics can then be considered, such as radiological procedures and laboratory diagnostics. The treatment is determined by the cause and the individual patient and aims to reduce pain and to preserve the mobility of the joint. Generally, therapy consists of pain management and physiotherapy as well as alternative therapeutic procedures, mostly in combination. Proximal tibial opening wedge osteotomy can be useful; however, partial or total knee arthroplasty should only be considered when conservative treatment options have been exhausted.

  4. Subdural empyema following lumbar facet joint injection: An exceeding rare complication.

    PubMed

    Fayeye, Oluwafikayo; Silva, Adikarige Haritha Dulanka; Chavda, Swarupsinh; Furtado, Navin Raoul

    2016-01-01

    Chronic low back pain is extremely common with a life time prevalence estimated at greater than 70%. Facet joint arthrosis is thought to be the causative aetiological substrate in approximately 25% of chronic low back pain cases. Facet joint injection is a routine intervention in the armamentarium for both the diagnostic and therapeutic management of chronic low back pain. In fact, a study by Carrino et al. reported in excess of 94,000 facet joint injection procedures were carried out in the US in 1999. Although generally considered safe, the procedure is not entirely without risk. Complications including bleeding, infection, exacerbation of pain, dural puncture headache, and pneumothorax have been described. We report a rare case of a 47-year-old female patient who developed a left L4/5 facet septic arthrosis with an associated subdural empyema and meningitis following facet joint injection. This case is unique, as to the best of our knowledge no other case of subdural empyema following facet joint injection has been reported in the literature. Furthermore this case serves to highlight the potential serious adverse sequelae of a routine and apparently innocuous intervention. The need for medical practitioners to be alert to and respond rapidly to the infective complications of facet joint injection cannot be understated.

  5. A biomechanical modelof the arthrosis of the hip joint - biomed 2011.

    PubMed

    Pascolo, Paolo B; Rossi, Rubens

    2011-01-01

    The hip joint has been investigated in depth, but causes of algic (pain) phenomena, especially those apparently located at the knee (referred pain), still remain unclear. Using a bi-dimensional multi-body model we investigated the effect of arthrosis on the kinematic of the hip joint and its relationship to pain. The bone was modeled as a rigid structure whereas the capsule and cartilage were assumed to be deformable. The effects of arthrosis were simulated as reduction of the thickness of the deformable tissues and increased friction. The extension velocity of the rectus femori and the trajectory of the instantaneous center of rotation (ICR) were examined for both physiological conditions and advanced degrees of arthrosis.In physiological conditions, results show that the extension velocity of the muscle has slight irregularities but is nevertheless continuous. The presence of arthrosis leads to a localized increase in friction and the model shows a migration of the location of the ICR toward the acetabulum. Changes in the ICR due to irregular surface friction, cartilage erosion as well as lack of synovial fluid, which in normal conditions ensures boundary film lubrication, induce discontinuities in the extension velocity of the muscle which are detected by the proprioceptive system (e.g. Golgi tendon organ) generating algic phenomena.The results of the model confirmed these findings and how hip arthrosis, in producing changes in the extension velocity of the muscle and in the kinematic of the movement, results in muscle and tendon pain around the knee.

  6. [The causes of arthrosis of the hip-joint. A radiologic study (author's transl)].

    PubMed

    Mutter, K; Schlegel, K F

    1975-06-01

    It is often possible to establish the origin of an arthosis of the hip joint radiologically. Only in 17 out of 445 patients were we unable to arrive at a classification because the arthrosis was already too advanced. Data relating to the history are of limited value -- only 21% of our patients knew of earlier disorders of the joint --, so definition of causes an radiographs is important. The high percentage of arthroses the origin of which is known, makes it likely that the concept of "primary arthrosis" is unnecessary, since behind it there hide those cases of apparently ill-defined arhtroses which -- as shown in our results -- can be further differentiated. This radiologically based classification will serve to increase the possibilities of progressing from symptomatic to prophylactic treatment.

  7. Image-guided facet joint injection

    PubMed Central

    Peh, WCG

    2011-01-01

    Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable. PMID:21655113

  8. Bone mineral density in patients with destructive arthrosis of the hip joint.

    PubMed

    Okano, Kunihiko; Aoyagi, Kiyoshi; Enomoto, Hiroshi; Osaki, Makoto; Chiba, Ko; Yamaguchi, Kazumasa

    2014-05-01

    Recent reports have shown the existence of subchondral insufficiency fracture in rapidly destructive arthrosis of the hip joint (RDA), and the findings suggest that osteopenia is related to the pathogenesis of the rapid progression of this disease. Therefore, we measured bone mineral density (BMD) in RDA patients. We measured BMD of the lumbar spine, radius, and calcaneus using dual-energy X-ray absorptiometry in 19 patients with RDA and 75 with osteoarthritis of the hip (OA) and compared BMD at different skeletal sites between RDA and OA patients. No significant differences were observed in BMD of the lumbar spine, ultradistal radius, mid-radius, and calcaneous between the RDA and OA groups. Our data suggest that RDA is not accompanied by generalized osteoporosis. Factors other than generalized bone status, for example, BMD around the affected hip joint before destruction, need to be analyzed to elucidate the pathophysiological mechanism of RDA.

  9. Osteoarthritis of the spine: the facet joints.

    PubMed

    Gellhorn, Alfred C; Katz, Jeffrey N; Suri, Pradeep

    2013-04-01

    Osteoarthritis (OA) of the spine involves the facet joints, which are located in the posterior aspect of the vertebral column and, in humans, are the only true synovial joints between adjacent spinal levels. Facet joint osteoarthritis (FJ OA) is widely prevalent in older adults, and is thought to be a common cause of back and neck pain. The prevalence of facet-mediated pain in clinical populations increases with increasing age, suggesting that FJ OA might have a particularly important role in older adults with spinal pain. Nevertheless, to date FJ OA has received far less study than other important OA phenotypes such as knee OA, and other features of spine pathoanatomy such as degenerative disc disease. This Review presents the current state of knowledge of FJ OA, including relevant anatomy, biomechanics, epidemiology, and clinical manifestations. We present the view that the modern concept of FJ OA is consonant with the concept of OA as a failure of the whole joint, and not simply of facet joint cartilage.

  10. [Interventions on facet joints. Techniques of facet joint injection, medial branch block and radiofrequency ablation].

    PubMed

    Artner, J; Klessinger, S

    2015-10-01

    Fluoroscopy-guided interventions on facet joints have been used for decades for the symptomatic management of pain in spinal disorders. A large number of imaging techniques are used to achieve a precise and safe needle placement in interventional procedures. Pulsed fluoroscopy is one of the most widely used and well-accepted tools for these procedures. This article presents a technical overview of commonly used fluoroscopy-guided interventions on the facet joints of the cervical and lumbar spine, such as facet joint injection, blockade of the medial nerve branches and radiofrequency ablation.

  11. Management of lumbar zygapophysial (facet) joint pain

    PubMed Central

    Manchikanti, Laxmaiah; Hirsch, Joshua A; Falco, Frank JE; Boswell, Mark V

    2016-01-01

    AIM: To investigate the diagnostic validity and therapeutic value of lumbar facet joint interventions in managing chronic low back pain. METHODS: The review process applied systematic evidence-based assessment methodology of controlled trials of diagnostic validity and randomized controlled trials of therapeutic efficacy. Inclusion criteria encompassed all facet joint interventions performed in a controlled fashion. The pain relief of greater than 50% was the outcome measure for diagnostic accuracy assessment of the controlled studies with ability to perform previously painful movements, whereas, for randomized controlled therapeutic efficacy studies, the primary outcome was significant pain relief and the secondary outcome was a positive change in functional status. For the inclusion of the diagnostic controlled studies, all studies must have utilized either placebo controlled facet joint blocks or comparative local anesthetic blocks. In assessing therapeutic interventions, short-term and long-term reliefs were defined as either up to 6 mo or greater than 6 mo of relief. The literature search was extensive utilizing various types of electronic search media including PubMed from 1966 onwards, Cochrane library, National Guideline Clearinghouse, clinicaltrials.gov, along with other sources including previous systematic reviews, non-indexed journals, and abstracts until March 2015. Each manuscript included in the assessment was assessed for methodologic quality or risk of bias assessment utilizing the Quality Appraisal of Reliability Studies checklist for diagnostic interventions, and Cochrane review criteria and the Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment tool for therapeutic interventions. Evidence based on the review of the systematic assessment of controlled studies was graded utilizing a modified schema of qualitative evidence with best evidence synthesis, variable from level I to level V

  12. Bilateral rapidly destructive arthrosis of the hip joint resulting from subchondral fracture with superimposed secondary osteonecrosis.

    PubMed

    Yamamoto, Takuaki; Schneider, Robert; Iwamoto, Yukihide; Bullough, Peter G

    2010-02-01

    A 57-year-old woman suffered rapid destruction of both hip joints over a 10 months period. At the first visit, her radiographs demonstrated slight joint space narrowing and acetabular cyst formation in both hips. Five months later, joint space narrowing had further progressed, and intra-articular injection of steroid was given in both hips. However, the hip pain gradually became worse. Five months later, both joint spaces had totally disappeared and both femoral heads had undergone massive collapse. At gross examination, both resected femoral heads showed extensive opaque yellow areas consistent with osteonecrosis. Microscopic examination of these areas revealed evidence of both extensive fracture and callus formation, as well as necrosis throughout, indicating that the osteonecrosis observed in this case was a secondary phenomenon superimposed on pre-existing osteoarthritis and subchondral fracture. There were many pseudogranulomatous lesions in the marrow space and necrotic area, where tiny fragments of bone and articular cartilage, surrounded by histiocytes and giant cells, were embedded, such as are typically seen in rapidly destructive arthrosis. No radiologic or morphologic evidence of primary osteonecrosis was noted. This case indicates that at least some cases of rapidly destructive arthritis are the result of subchondral fracture with superimposed secondary osteonecrosis.

  13. Talocalcaneal Joint Middle Facet Coalition Resection With Interposition of a Juvenile Hyaline Cartilage Graft.

    PubMed

    Tower, Dyane E; Wood, Ryan W; Vaardahl, Michael D

    2015-01-01

    Talocalcaneal joint middle facet coalition is the most common tarsal coalition, occurring in ≤2% of the population. Fewer than 50% of involved feet obtain lasting relief of symptoms after nonoperative treatment, and surgical intervention is commonly used to relieve symptoms, increase the range of motion, improve function, reconstruct concomitant pes planovalgus, and prevent future arthrosis from occurring at the surrounding joints. Several approaches to surgical intervention are available for patients with middle facet coalitions, ranging from resection to hindfoot arthrodesis. We present a series of 4 cases, in 3 adolescent patients, of talocalcaneal joint middle facet coalition resection with interposition of a particulate juvenile hyaline cartilaginous allograft (DeNovo(®) NT Natural Tissue Graft, Zimmer, Inc., Warsaw, IN). With a mean follow-up period of 42.8 ± 2.9 (range 41 to 47) months, the 3 adolescent patients in the present series were doing well with improved subtalar joint motion and decreased pain, and 1 foot showed no bony regrowth on a follow-up computed tomography scan. The use of a particulate juvenile hyaline cartilaginous allograft as interposition material after talocalcaneal middle facet coalition resection combined with adjunct procedures to address concomitant pes planovalgus resulted in good short-term outcomes in 4 feet in 3 adolescent patients.

  14. Facet joint disturbance induced by miniscrews in plated cervical laminoplasty

    PubMed Central

    Chen, Hua; Li, Huibo; Wang, Beiyu; Li, Tao; Gong, Quan; Song, Yueming; Liu, Hao

    2016-01-01

    Abstract A retrospective cohort study. Plated cervical laminoplasty is an increasingly common technique. A unique facet joint disturbance induced by lateral mass miniscrews penetrating articular surface was noticed. Facet joints are important to maintain cervical spine stability and kinetic balance. Whether this facet joint disturbance could affect clinical and radiologic results is still unknown. The objective of this study is to investigate the clinical and radiologic outcomes of patients with facet joints disturbance induced by miniscrews in plated cervical laminoplasty. A total of 105 patients who underwent cervical laminoplasty with miniplate fixation between May 2010 and February 2014 were comprised. Postoperative CT images were used to identify whether facet joints destroyed by miniscrews. According to facet joints destroyed number, all the patients were divided into: group A (none facet joint destroyed), group B (1–2 facet joints destroyed), and group C (≥3 facet joints destroyed). Clinical data (JOA, VAS, and NDI scores), radiologic data (anteroposterior diameter and Palov ratio), and complications (axial symptoms and C5 palsy) were evaluated and compared among the groups. There were 38, 40, and 27 patients in group A, B, and C, respectively. The overall facet joints destroyed rate was 30.7%. All groups gained significant JOA and NDI scores improvement postoperatively. The preoperative JOA, VAS, NDI scores, and postoperative JOA scores did not differ significantly among the groups. The group C recorded significant higher postoperative VAS scores than group A (P = 0.002) and B (P = 0.014) and had significant higher postoperative NDI scores than group A (P = 0.002). The pre- and postoperative radiologic data were not significant different among the groups. The group C had a significant higher axial symptoms incidence than group A (12/27 vs 8/38, P = 0.041). Facet joints disturbance caused by miniscrews in plated cervical laminoplasty may not influence

  15. Characterization of degenerative human facet joints and facet joint capsular tissues

    PubMed Central

    Kim, Jae-Sung; Ali, Mir H.; Wydra, Frank; Li, Xin; Hamilton, John L.; An, Howard S.; Cs-Szabo, Gabriella; Andrews, Steven; Moric, Mario; Xiao, Guozhi; Wang, James H-C; Chen, Di; Cavanaugh, John M.; Im, Hee-Jeong

    2015-01-01

    SUMMARY Objective Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue, defined as the fibrous connective tissue lined with synovium that surrounds the joint. The role of these alterations in FJC tissues in pain stimulation was also assessed. Design Lumbar facet joints (FJs) were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no medical history of back pain. Histological analyses of the FJ were performed to assess general structure, cellular morphology, and proteoglycan content; immunohistochemistry was used to reveal inflammatory factors and neovascularization. Cytokine antibody array and quantitative real- time polymerase chain reaction (qPCR) were used to determine the production of multiple pro- and anti- inflammatory cytokines, and western blotting (WB) was used to assay for cartilage-degrading enzymes and pain mediators. Studies using ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues were also performed. Results Increased neovascularization, infiltration of inflammatory cells, and pain-related axonal-promoting factors were observed in degenerative FJC tissues surgically obtained from symptomatic subjects; this was not seen in normal donor tissues. Increased angiogenic factor, VEGF, axonal promoting factor (NGF/TrkA) and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs compared to normal. The DRG and FJC tissue ex vivo co-culture results demonstrated that degenerative FJCs from subjects reporting severe LBP altered the functional properties of DRG sensory neurons, as

  16. Lumbar Facet Joint Motion in Patients with Degenerative Spondylolisthesis

    PubMed Central

    Yao, Qi; Wang, Shaobai; Shin, Jae-Hyuk; Li, Guoan; Wood, Kirkham B.

    2012-01-01

    Study Design Controlled laboratory study. Objective To investigate the in vivo biomechanical effect of degenerative lumbar spondylolisthesis (DLS) on the motion of the facet joint during various functional weight-bearing activities. Summary of Background Data Although the morphological changes of the facet joints in patients with DLS have been reported in a few studies, no data has been reported on the kinematics of these facet joints. Methods Ten patients with DLS at L4–L5 were studied. Each patient underwent a magnetic resonance imaging (MRI) scan to obtain three-dimensional (3D) models of the lumbar vertebrae from L2–L5 as well as a dual fluoroscopic imaging scan in different postures: flexion-extension, left-right bending and left-right torsion. The positions of the vertebrae were reproduced by matching the MRI-based vertebral models to the fluoroscopic images. The kinematics of the facet joint and the ranges of motion (ROMs) were compared with those of healthy subjects and those of patients with degenerative disc diseases (DDD) previously published. Results In DLS patients, the range of rotation of the facet joints was significantly less at the DLS level (L4–L5) than that at the adjacent levels (L2–L3 and L3–L4), while the range of translation was similar at all levels. The range of rotation at the facet joints of the DLS level decreased compared to those of both the DDD patients and healthy subjects at the corresponding vertebral level (L4–L5), while no significant difference was found in the range of translation. The ROM of facet joints in DLS and in DDD patients was similar at the adjacent levels (L2–L3 and L3–L4). Conclusion The range of rotation decreased at the facet joints at the DLS level (L4–L5) in patients compared to those in healthy subjects and DDD patients. This decrease in range of rotation implies that the DLS disease may cause restabilization of the joint. The data may help the selection of conservative treatment or different

  17. Three-dimensional evaluation of the facet joints

    NASA Astrophysics Data System (ADS)

    Folio, Les R.

    1990-04-01

    Computerized tomography and magnetic resonance imaging nave revolurionalized analysis of vertebral anatomy and pathology. Further advances with 3-dimensional imaging have recently become an important adjunct for diagnosis and treatment in structural abnormalities. Facets are intimately related to their surrounding musculature and malalignment may cause pain directly or indirectly. High resolution 3-dimensional reformations of CT Scans give us new insight on structure and function of facet joints, since their motion and architecture are ever complex. It is well documented in the literature that facet joint biomecnanics is a partial contributor to the myriad at causes of low back The term "facet Joint syndrome" was coined in 1933 by GhorMley.3 The osteopathic lesion complex is well defined by LeRoy and McCole and comparison of roentgenographic findings before and after manipulation has teen described by Long and Lioyd.4,5 since alterations in facet biamechanics are an important aspect of osteopathic manipulative therapy (OT), 3-dimensional hign resolution imaging will prove to be a great asset in osteopathic research. Rotating the spine allows for different viewing perspectives to provide optimal and consistent measurements of the facet joint. Rotations are performed on the X, Y and 7, axis and measurements pre and post-manipulation are performed and compared on matching axis and perspectives. Rotation about the X, Y and Z axis help appreciate the 3-dimensionality of the vertebral column to project to the viewer a feeling that the spine is floating in space before them. This does give the viewer a 3-D understanding of the object however, only at a perspective at a Lime.

  18. Rapidly destructive arthrosis of the hip joint in a young adult with systemic lupus erythematosus.

    PubMed

    Lee, Yongseung; Motomura, Goro; Yamamoto, Takuaki; Nakashima, Yasuharu; Ohishi, Masanobu; Hamai, Satoshi; Iura, Kunio; Iwamoto, Yukihide

    2015-10-01

    A 37-year-old female had been treated with corticosteroids for systemic lupus erythematosus clinically diagnosed at age 10. She suddenly had right hip pain without any antecedent trauma. Four months after the onset of pain, she visited her primary care physician. On magnetic resonance imaging, joint space narrowing at the weight-bearing area was already seen with bone marrow edematous lesions in both the femoral head and acetabulum. She was treated non-operatively; however, her pain continued to worsen in severity. Thirteen months after the onset of pain, she was referred to our hospital. A plain radiograph showed subluxation of the collapsed femoral head accompanied by destruction of the acetabular rim. Because of her severe intractable pain, she underwent total hip arthroplasty 1 month after her first visit. Histological examination of the resected femoral head revealed pseudogranulomatous lesions along with prominent callus formation, suggesting rapid destruction of the femoral head.

  19. Facet joint laser radiation: tissue effects of a new clinical laser application

    NASA Astrophysics Data System (ADS)

    Werkmann, Klaus; Thal, Dietmar R.

    1996-01-01

    Chronic unilateral and bilateral back pain with pseudoradicular symptoms, is a common clinical syndrome, which in many cases can be related to the facet joint syndrome. The pain is caused by mechanical affection of synovial and capsular nerve terminals. Therefore, current therapeutical attempts including physical therapy, intra-articular injection of local anesthetics and steroids and thermocoagulation of the facet joint with a thermocoagulator, are performed. We confirmed laser coagulation of the facet joint. Porcine cadaveric spines were treated immediately after death by intra-articular facet joint laser radiation. With the pulsed Nd:YAG laser (1064 nm) altogether 600 J were applied in three different places 4 mm apart at the top of the facet joint. The results showed that facet joint laser radiation leads to a small (about 1 - 2 mm diameter) lesion restricted to the facet joint cavity and its synovia. Histologically, we found a central carbonization zone and necrosis, including almost the whole cartilage and approximately 0.2 mm of the adjacent bone. These changes are similar to Nd:Yag-laser applications in other skeletal regions. It is suggested that these changes may lead to facet joint denervation by coagulation of the synovial nerve terminals. Cicatration of the laser lesion might cause ankylosis of this joint. In sum, facet joint laser radiation could be an alternative therapeutical tool for lower back pain of the facet joint syndrome type. Therefore, future clinical application of this technique seems to be very promising.

  20. Utilization of Facet Joint and Sacroiliac Joint Interventions in Medicare Population from 2000 to 2014: Explosive Growth Continues!

    PubMed

    Manchikanti, Laxmaiah; Hirsch, Joshua A; Pampati, Vidyasagar; Boswell, Mark V

    2016-10-01

    Increasing utilization of interventional techniques in managing chronic spinal pain, specifically facet joint interventions and sacroiliac joint injections, is a major concern of healthcare policy makers. We analyzed the patterns of utilization of facet and sacroiliac joint interventions in managing chronic spinal pain. The results showed significant increase of facet joint interventions and sacroiliac joint injections from 2000 to 2014 in Medicare FFS service beneficiaries. Overall, the Medicare population increased 35 %, whereas facet joint and sacroiliac joint interventions increased 313.3 % per 100,000 Medicare population with an annual increase of 10.7 %. While the increases were uniform from 2000 to 2014, there were some decreases noted for facet joint interventions in 2007, 2010, and 2013, whereas for sacroiliac joint injections, the decreases were noted in 2007 and 2013. The increases were for cervical and thoracic facet neurolysis at 911.5 % compared to lumbosacral facet neurolysis of 567.8 %, 362.9 % of cervical and thoracic facet joint blocks, 316.9 % of sacroiliac joints injections, and finally 227.3 % of lumbosacral facet joint blocks.

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

    SciTech Connect

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

    2016-01-15

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

  2. Factors affecting results of fluoroscopy-guided facet joint injection: Probable differences in the outcome of treatment between pure facet joint hypertrophy and concomitant diseases

    PubMed Central

    Albayrak, Akif; Ozkul, Baris; Balioglu, Mehmet Bulent; Atici, Yunus; Gultekin, Muhammet Zeki; Albayrak, Merih Dilan

    2016-01-01

    Study Design: Retrospective cohort study. Purpose: Facet joints are considered a common source of chronic low-back pain. To determine whether pathogens related to the facet joint arthritis have any effect on treatment failure. Materials and Methods: Facet joint injection was applied to 94 patients treated at our hospital between 2011 and 2012 (mean age 59.5 years; 80 women and 14 men). For the purpose of analysis, the patients were divided into two groups. Patients who only had facet hypertrophy were placed in group A (47 patients, 41 women and 6 men, mean age 55.3 years) and patients who had any additional major pathology to facet hypertrophy were placed in group B (47 patients, 39 women and 8 men, mean age 58.9 years). Injections were applied around the facet joint under surgical conditions utilizing fluoroscopy device guidance. A mixture of methylprednisolone and lidocaine was used as the injection ingredient. Results: In terms of Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, no significant difference was found between preinjection and immediate postinjection values in both groups, and the scores of group A patients were significantly lower (P < 0.005) compared with that of group B patients at the end of the third, sixth, and twelfth month. Conclusion: For low-back pain caused by facet hypertrophy, steroid injection around the facet joint is an effective treatment, but if there is an existing major pathology, it is not as effective. PMID:27041884

  3. Comparison of intra-articular lumbar facet joint pulsed radiofrequency and intra-articular lumbar facet joint corticosteroid injection for management of lumbar facet joint pain

    PubMed Central

    Do, Kyung Hee; Ahn, Sang Ho; Cho, Yun Woo; Chang, Min Cheol

    2017-01-01

    Abstract Background: This study aimed to demonstrate the effect of intra-articular (IA) lumbar facet joint (LFJ) pulsed radiofrequency (PRF) for the management of LFJ pain, and to compare the effect of IA LFJ PRF to IA corticosteroid injection (ICI). Pathology in the LFJ is a common source of lower back pain (LBP). It is responsible for chronic LBP in approximately 15% to 45% of patients. It has been reported that PRF stimulation can effectively reduce refractory joint pain. Methods: Sixty patients with LFJ pain were recruited and randomly assigned to 1 of 2 groups: the IA PRF group and the ICI group. There were 30 patients in each group. At pretreatment, 2 weeks, 1, 3, and 6 months after treatment, we assessed the severity of LBP using a numeric rating scale (NRS). Results: Compared with the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 2 weeks, and 1, 3, and 6 months after each treatment. Between groups, changes in the NRS scores were significantly different over time. At 2 weeks and 1 month after each procedure, the NRS score after ICI was significantly lower than that after the PRF stimulation. However, at 3 and 6 months after the procedures, the decrements of NRS scores were not significantly different between the 2 groups. Six months after treatment, about half of patients in both groups reported successful pain relief (pain relief of ≥50%). Conclusion: In the current study, both IA PRF stimulation and ICI into the LFJ significantly relieved LFJ pain. Their effects persisted for at least 6 months after the procedure. Thus, IA PRF is a useful therapeutic option for the management of LFJ pain. PMID:28353611

  4. The relationship between lower neck shear force and facet joint kinematics during automotive rear impacts.

    PubMed

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Maiman, Dennis J

    2011-04-01

    A primary goal of biomechanical safety research is the definition of localized injury thresholds in terms of quantities that are repeatable and easily measureable during experimentation. Recent biomechanical experimentation using human cadavers has highlighted the role of lower cervical facet joints in the injury mechanism resulting from low-speed automotive rear impacts. The present study was conducted to correlate lower neck forces and moments with facet joint motions during simulated rear impacts in an effort to define facet joint injury tolerance thresholds that can be used to assess automobile safety. Four male and four female intact head-neck complexes were obtained from cadaveric specimens and subjected to simulated automotive rear impacts using a pendulum-minisled device. Cervical spine segmental angulations and localized facet joint kinematics were correlated to shear and axial forces, and bending moments at the cervico-thoracic junction using linear regression. R(2) coefficients indicated that spinal kinematics correlated well with lower neck shear force and bending moment. Correlation slope was steeper in female specimens, indicating greater facet joint motions for a given loading magnitude. This study demonstrated that lower neck loads can be used to predict lower cervical facet joint kinematics during automotive rear impacts. Higher correlation slope in female specimens corresponds to higher injury susceptibility in that population. Although lower neck shear force and bending moment demonstrated adequate correlation with lower cervical facet joint motions, shear force is likely the better predictor due to similarity in the timing of peak magnitudes with regard to maximum facet joint motions.

  5. Calcium pyrophosphate dihydrate crystal deposition of multiple lumbar facet joints: a case report.

    PubMed

    Namazie, Mohamed Ridzwan bin Mohamed; Fosbender, Murray R

    2012-08-01

    Pseudogout of the lumbar facet joints is rare. We report on a 69-year-old woman with 2-level symptomatic synovial cysts of the facet joints caused by calcium pyrophosphate dihydrate crystal deposition. She underwent surgical decompression for sciatica and low back pain. At one-year follow-up, she had recovered completely.

  6. [Synovial cyst in the lumbar facet joint. A rare cause of lumbar-sciatic pain].

    PubMed

    Villas, C; Leyes, M

    1997-01-01

    Synovial cysts of the facet joints are uncommon lesions which may be asymptomatic or present as low back pain, with or without radicular symptoms. They are considered to be secondary to trauma or degenerative joint disease, and they occur more frequently in patients with spondylolisthesis. Diagnosis is normally achieved with computed tomography or magnetic resonance, which show a cystic lesion located laterally adjacent to the facet joint. We review the literature and report a patient who presented with first sacral nerve root symptoms attributable to a ganglion cyst of the left L5 S1 facet joint. Treatment was curative and consisted in excision of the cyst.

  7. The Interface of Mechanics and Nociception in Joint Pathophysiology: Insights From the Facet and Temporomandibular Joints.

    PubMed

    Sperry, Megan M; Ita, Meagan E; Kartha, Sonia; Zhang, Sijia; Yu, Ya-Hsin; Winkelstein, Beth

    2017-02-01

    Chronic joint pain is a widespread problem that frequently occurs with aging and trauma. Pain occurs most often in synovial joints, the body's load bearing joints. The mechanical and molecular mechanisms contributing to synovial joint pain are reviewed using two examples, the cervical spinal facet joints and the temporomandibular joint (TMJ). Although much work has focused on the macroscale mechanics of joints in health and disease, the combined influence of tissue mechanics, molecular processes, and nociception in joint pain has only recently become a focus. Trauma and repeated loading can induce structural and biochemical changes in joints, altering their microenvironment and modifying the biomechanics of their constitutive tissues, which themselves are innervated. Peripheral pain sensors can become activated in response to changes in the joint microenvironment and relay pain signals to the spinal cord and brain where pain is processed and perceived. In some cases, pain circuitry is permanently changed, which may be a potential mechanism for sustained joint pain. However, it is most likely that alterations in both the joint microenvironment and the central nervous system (CNS) contribute to chronic pain. As such, the challenge of treating joint pain and degeneration is temporally and spatially complicated. This review summarizes anatomy, physiology, and pathophysiology of these joints and the sensory pain relays. Pain pathways are postulated to be sensitized by many factors, including degeneration and biochemical priming, with effects on thresholds for mechanical injury and/or dysfunction. Initiators of joint pain are discussed in the context of clinical challenges including the diagnosis and treatment of pain.

  8. Lumbar facet joint arthritis is associated with more coronal orientation of the facet joints at the upper lumbar spine.

    PubMed

    Jentzsch, Thorsten; Geiger, James; Zimmermann, Stefan M; Slankamenac, Ksenija; Nguyen-Kim, Thi Dan Linh; Werner, Clément M L

    2013-01-01

    We retrospectively analyzed CT scans of 620 individuals, who presented to our traumatology department between 2008 and 2010. Facet joint (FJ) arthritis was present in 308 (49.7%) individuals with a mean grade of 1. It was seen in 27% of individuals ≤40 years and in 75% of individuals ≥41 years (P < 0.0001) as well as in 52% of females and 49% of males (P = 0.61). Mean FJ orientation was 30.4° at L2/3, 38.7° at L3/4, 47° at L4/5, and 47.3° at L5/S1. FJ arthritis was significantly associated with more coronal (increased degree) FJ orientation at L2/3 (P = 0.03) with a cutoff point at ≥32°. FJs were more coronally oriented (48.8°) in individuals ≤40 years and more sagittally oriented (45.6°) in individuals ≥41 years at L5/S1 (P = 0.01). Mean FJ asymmetry was 4.89° at L2/3, 6.01° at L3/4, 6.67° at L4/5, and 7.27° at L5/S1, without a significant difference for FJ arthritis. FJ arthritis is common, increases with age, and affects both genders equally. More coronally oriented FJs (≥32°) in the upper lumbar spine may be an individual risk factor for development of FJ arthritis.

  9. The characteristics of the mechanoreceptors of the hip with arthrosis

    PubMed Central

    2011-01-01

    Mechanoreceptors have been extensively studied in different joints and distinct signals that convey proprioceptive information to the cortex. Several clinical reports have established a link between the number of mechanoreceptors and a deficient proprioceptive system; however, little or no literature suggest concentration of mechanoreceptors might be affected by hip arthrosis. The purpose of this study is first to determine the existence of mechanoreceptors and free nerve endings in the hip joint and to distinguish between their conditions: those with arthrosis and without arthrosis. Samples of 45 male hips were analyzed: 30 taken from patients with arthrosis that were submitted to total arthroplasty and 15 taken from male cadavers without arthrosis. The patients' ages ranged from 38 to75 years (average 56.5) and the cadavers' ages ranged from 21 to 50 years (average 35.5). The capsule, labrum, and femoral head ligament tissues were obtained during the arthroplasty procedure from 30 patients with arthrosis and from 15 male cadavers. The tissue was cut into fragments of around 3 mm. Each fragment was then immediately stained with gold chloride 1% solution and divided into sections of 6 μm thickness. The Mann-Whitney test was used for two groups and the ANOVA, Friedman and Kruskal-Wallis tests for more than two groups. Results show the mechanoreceptors (Pacini, Ruffini and Golgi corpuscles) and free nerve endings are present in the capsule, femoral head ligament, and labrum of the hip joint. When all the densities of the nerve endings were examined with regard to those with arthrosis and those without arthrosis, the mechanoreceptors of cadavers without arthrosis were found to be more pronounced and an increase in free nerve endings could be observed (p = 0.0082). Further studies, especially electrophysiological studies, need to be carried out to clarify the functions of the mechanoreceptors in the joints. PMID:22087603

  10. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints.

    PubMed

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision.

  11. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints

    PubMed Central

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision. PMID:26170560

  12. Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions

    PubMed Central

    Manchikanti, Laxmaiah; Boswell, Mark V; Singh, Vijay; Pampati, Vidyasagar; Damron, Kim S; Beyer, Carla D

    2004-01-01

    Background Facet joints are a clinically important source of chronic cervical, thoracic, and lumbar spine pain. The purpose of this study was to systematically evaluate the prevalence of facet joint pain by spinal region in patients with chronic spine pain referred to an interventional pain management practice. Methods Five hundred consecutive patients with chronic, non-specific spine pain were evaluated. The prevalence of facet joint pain was determined using controlled comparative local anesthetic blocks (1% lidocaine or 1% lidocaine followed by 0.25% bupivacaine), in accordance with the criteria established by the International Association for the Study of Pain (IASP). The study was performed in the United States in a non-university based ambulatory interventional pain management setting. Results The prevalence of facet joint pain in patients with chronic cervical spine pain was 55% 5(95% CI, 49% – 61%), with thoracic spine pain was 42% (95% CI, 30% – 53%), and in with lumbar spine pain was 31% (95% CI, 27% – 36%). The false-positive rate with single blocks with lidocaine was 63% (95% CI, 54% – 72%) in the cervical spine, 55% (95% CI, 39% – 78%) in the thoracic spine, and 27% (95% CI, 22% – 32%) in the lumbar spine. Conclusion This study demonstrated that in an interventional pain management setting, facet joints are clinically important spinal pain generators in a significant proportion of patients with chronic spinal pain. Because these patients typically have failed conservative management, including physical therapy, chiropractic treatment and analgesics, they may benefit from specific interventions designed to manage facet joint pain. PMID:15169547

  13. Lumbar Facet Joint Motion in Patients with Degenerative Disc Disease at Affected and Adjacent Levels

    PubMed Central

    Li, Weishi; Wang, Shaobai; Xia, Qun; Passias, Peter; Kozanek, Michal; Wood, Kirkham; Li, Guoan

    2013-01-01

    Study Design Controlled laboratory study. Objective To evaluate the effect of lumbar degenerative disc diseases (DDDs) on motion of the facet joints during functional weight-bearing activities. Summary of Background Data It has been suggested that DDD adversely affects the biomechanical behavior of the facet joints. Altered facet joint motion, in turn, has been thought to associate with various types of lumbar spine pathology including facet degeneration, neural impingement, and DDD progression. However, to date, no data have been reported on the motion patterns of the lumbar facet joint in DDD patients. Methods Ten symptomatic patients of DDD at L4–S1 were studied. Each participant underwent magnetic resonance images to obtain three-dimensional models of the lumbar vertebrae (L2–S1) and dual fluoroscopic imaging during three characteristic trunk motions: left-right torsion, left-right bending, and flexion-extension. In vivo positions of the vertebrae were reproduced by matching the three-dimensional models of the vertebrae to their outlines on the fluoroscopic images. The kinematics of the facet joints and the ranges of motion (ROMs) were compared with a group of healthy participants reported in a previous study. Results In facet joints of the DDD patients, there was no predominant axis of rotation and no difference in ROMs was found between the different levels. During left-right torsion, the ROMs were similar between the DDD patients and the healthy participants. During left-right bending, the rotation around mediolateral axis at L4–L5, in the DDD patients, was significantly larger than that of the healthy participants. During flexion-extension, the rotations around anterioposterior axis at L4–L5 and around craniocaudal axis at the adjacent level (L3–L4), in the DDD patients, were also significantly larger, whereas the rotation around mediolateral axis at both L2–L3 and L3–L4 levels in the DDD patients were significantly smaller than those of the

  14. Qualitative and quantitative assessment of degeneration of cervical intervertebral discs and facet joints.

    PubMed

    Walraevens, Joris; Liu, Baoge; Meersschaert, Joke; Demaerel, Philippe; Delye, Hans; Depreitere, Bart; Vander Sloten, Jos; Goffin, Jan

    2009-03-01

    Degeneration of intervertebral discs and facet joints is one of the most frequently encountered spinal disorders. In order to describe and quantify degeneration and evaluate a possible relationship between degeneration and biomechanical parameters, e.g., the intervertebral range of motion and intradiscal pressure, a scoring system for degeneration is mandatory. However, few scoring systems for the assessment of degeneration of the cervical spine exist. Therefore, two separate objective scoring systems to qualitatively and quantitatively assess the degree of cervical intervertebral disc and facet joint degeneration were developed and validated. The scoring system for cervical disc degeneration consists of three variables which are individually scored on neutral lateral radiographs: "height loss" (0-4 points), "anterior osteophytes" (0-3 points) and "endplate sclerosis" (0-2 points). The scoring system for facet joint degeneration consists of four variables which are individually scored on neutral computed tomography scans: "hypertrophy" (0-2 points), "osteophytes" (0-1 point), "irregularity" on the articular surface (0-1 point) and "joint space narrowing" (0-1 point). Each variable contributes with varying importance to the overall degeneration score (max 9 points for the scoring system of cervical disc degeneration and max 5 points for facet joint degeneration). Degeneration of 20 discs and facet joints of 20 patients was blindly assessed by four raters: two neurosurgeons (one senior and one junior) and two radiologists (one senior and one junior), firstly based on first subjective impression and secondly using the scoring systems. Measurement errors and inter- and intra-rater agreement were determined. The measurement error of the scoring system for cervical disc degeneration was 11.1 versus 17.9% of the subjective impression results. This scoring system showed excellent intra-rater agreement (ICC = 0.86, 0.75-0.93) and excellent inter-rater agreement (ICC = 0

  15. In Vivo Cervical Facet Joint Capsule Deformation During Flexion-Extension

    PubMed Central

    Anderst, William J; Lee, Joon Y; Kang, James D

    2014-01-01

    Study Design Non-randomized controlled cohort. Objective To characterize subaxial cervical facet joint kinematics and facet joint capsule (FJC) deformation during in vivo, dynamic flexion-extension. To assess the effect of single-level anterior arthrodesis on adjacent segment FJC deformation. Summary of Background Data The cervical facet joint has been identified as the most common source of neck pain and it is thought to play a role in chronic neck pain related to whiplash injury. Our current knowledge of cervical facet joint kinematics is based on cadaveric mechanical testing. Methods 14 asymptomatic controls and 9 C5-C6 arthrodesis patients performed full range of motion (ROM) flexion-extension while biplane radiographs were collected at 30 Hz. A volumetric model-based tracking process determined 3D vertebral position with sub-millimeter accuracy. FJC fibers were modeled and grouped into anterior, lateral, posterior-lateral, posterior, and posterior-medial regions. FJC fiber deformations (total, shear and compression-distraction) relative to the static position were determined for each cervical motion segment (C2-C3 through C6-C7) during flexion-extension. Results No significant differences in the rate of fiber deformation in flexion were identified among motion segments (p = .159), however, significant differences were observed among fiber regions (p < .001). Significant differences in the rate of fiber deformation in extension were identified among motion segments (p < .001) and among fiber regions (p = .001). The rate of FJC deformation in extension adjacent to the arthrodesis was 45% less than in corresponding motion segments in control subjects (p = .001). Conclusion In control subjects, facet joint capsule deformations are significantly different among vertebral levels and capsule regions when vertebrae are in an extended orientation. In a flexed orientation, FJC deformations are only different among capsule regions. Single-level anterior arthrodesis is

  16. Urinary CTX‐II levels are associated with radiographic subtypes of osteoarthritis in hip, knee, hand, and facet joints in subject with familial osteoarthritis at multiple sites: the GARP study

    PubMed Central

    Meulenbelt, I; Kloppenburg, M; Kroon, H M; Houwing‐Duistermaat, J J; Garnero, P; Graverand, M‐P Hellio Le; DeGroot, J; Slagboom, P E

    2006-01-01

    Objective To assess the relation between the urinary concentrations of type II collagen C‐telopeptide (UCTX‐II) and radiographic signs of osteoarthritis (ROA) in the GARP (Genetics, Arthrosis and Progression) study. Methods UCTX‐II levels were measured in GARP study participants, who are sibling pairs predominantly with symptomatic osteoarthritis at multiple sites. Kellgren and Lawrence scores were used to assess ROA in the knees, hips, hands, and vertebral facet joints, and spinal disc degeneration. A proportionate score was made for each joint location, based on the number of joints with ROA. The sum total ROA score represents a measure of cartilage abnormalities within each patient. By using linear mixed models the total ROA score and the joint site specific ROA scores were correlated with the UCTX‐II level. Results In 302 subjects the mean (SD) and median (range) for UCTX‐II were 265 (168) and 219 (1346) ng/mmol creatine, respectively. There was a significant association between the total ROA score and UCTX‐II levels. Subsequent multivariate analysis showed that the joint site specific ROA score at all joint sites, except for spinal disc degeneration, contributed independently to this association. Conclusions The total ROA score of GARP patients, representing cartilage abnormalities at the most prevalent ROA joint locations, showed an excellent correlation with UCTX‐II levels. The specific ROA scores at the hip, hand, facet, and knee joints additively and independently explained this association. Even in patients with osteoarthritis at multiple sites, UCTX‐II may be a sensitive quantitative marker of ROA. PMID:16079167

  17. Spinal neuronal plasticity is evident within 1 day after a painful cervical facet joint injury.

    PubMed

    Crosby, Nathan D; Weisshaar, Christine L; Winkelstein, Beth A

    2013-05-10

    Excessive stretch of the cervical facet capsular ligament induces persistent pain and spinal plasticity at later time points. Yet, it is not known when such spinal modifications are initiated following this painful injury. This study investigates the development of hyperalgesia and neuronal hyperexcitability in the spinal cord after a facet joint injury. Behavioral sensitivity was measured in a model of painful C6/C7 facet joint injury in the rat, and neuronal hyperexcitability in the spinal cord was evaluated at 6h and 1 day after injury or a sham procedure, in separate groups. Extracellular recordings of C6/C7 dorsal horn neuronal activity (229 neurons) were used to quantify spontaneous and evoked firing. Rats exhibited no change in sensitivity to mechanical stimulation of the forepaw at 6h, but did exhibit increased sensitivity at 1 day after injury (p=0.012). At 6h, both spontaneous neuronal activity and firing evoked by light brushing, pinch, and von Frey filaments (1.4-26g) applied at the forepaw were not different between sham and injury. At 1 day, spontaneous firing was noted in a greater number of neurons after injury than sham (p<0.04). Evoked firing was also increased 1 day after injury compared to normal and sham (p<0.03). Dorsal horn hyperexcitability and increased spontaneous firing developed between 6 and 24h after painful facet injury, suggesting that the development of hyperalgesia parallels dorsal horn hyperexcitability following mechanical facet joint injury, and these spinal mechanisms are initiated as early as 1 day after injury.

  18. Navigated Pin-Point Approach to Osteoid Osteoma Adjacent to the Facet Joint of Spine

    PubMed Central

    Neo, Masashi; Takemoto, Mitsuru; Nishizawa, Kazuya; Imai, Shinji

    2016-01-01

    Osteoid osteoma (OO) is a benign osteoblastic tumor. Its curative treatment is complete removal of the nidus, where intraoperative localization of the nidus governs clinical results. However, treatment can be difficult since the lesion is often invisible over the bony surface. Accordingly, establishment of an ideal less invasive surgical strategy for spinal OO remains yet unsettled. We illustrate the efficacy of a computed tomography (CT)-based navigation system in excising OO located adjacent to the facet joint of spine. In our 2 cases, complete and pin-point removal of the nidus located close to the facet joint was successfully achieved, without excessive removal of the bone potentially leading to spinal instability and possible damage of nearby neurovascular structures. We advocate a less invasive approach to spinal OO, particularly in an environment with an available CT-based navigation system. PMID:26949472

  19. 1988 Volvo award in clinical sciences. Facet joint injection in low-back pain. A prospective statistical study.

    PubMed

    Jackson, R P; Jacobs, R R; Montesano, P X

    1988-09-01

    From January 1980 through December 1984, 454 patients were evaluated with facet joint injections. All had the chief complaint of low-back pain, normal neurologic examinations and no root tension signs. Three hundred and ninety completed the protocol, which included a lumbar motion pain assessment before and after facet injection. A total of 127 variables were studied. There were 229 males and 161 females with a median age of 38. Facet joint arthrograms were performed prior to intra-articular injection of local anesthetic and cortisone. Initial mean pain relief was only 29%. Variables correlating significantly (P less than 0.05) with more postinjection pain relief were older age, prior history of low-back pain, normal gait, maximum pain on extension following forward flexion in the standing position, and the absence of leg pain, muscle spasm and aggravation of pain on Valsalva. Greatest pain relief immediately after injection was seen with lumbar extension and rotation, motions reported to stress the facet joints or aggravate pain of facet joint origin. Patients with more pain on lumbar extension and rotation as a group, however, did not get more pain relief. From this study we were not able to identify clinical facet joint syndromes or predict patients responding better to this procedure. The facet joints were not commonly the single or primary source for low-back pain in the great majority (greater than 90%) of patients studied.

  20. Combined total ankle replacement and modified bridle tendon transfer for end-stage ankle joint arthrosis with paralytic dropfoot: report of an unusual case.

    PubMed

    Bibbo, Christopher; Baronofsky, Hyim J; Jaffe, Leland

    2011-01-01

    In recent years, total ankle replacement has become a reasonable option for many patients with end-stage ankle arthrosis. In order to be successful, total ankle replacement requires a relatively balanced alignment of the foot in relation to the leg. Such alignment is traditionally achieved surgically by means of stabilization of the hindfoot in conjunction with relocation osteotomy of the calcaneus and/or tibia. In this report, we describe the unconventional combination of total ankle replacement in an adult patient with concomitant paralysis that was addressed by means of tendon transfer.

  1. Unusual case of paediatric septic arthritis of the lumbar facet joints due to Kingella kingae.

    PubMed

    Le Hanneur, M; Vidal, C; Mallet, C; Mazda, K; Ilharreborde, B

    2016-11-01

    A 32-month-old boy presented with febrile limping that had developed over 6days, associated with right lumbosacral inflammatory swelling. Magnetic resonance imaging (MRI) showed joint effusion of the right L5-S1 zygapophyseal joint, complicated by destructive osteomyelitis of the L5 articular process and paraspinal abscess. Surgery was decided to evacuate the fluid accumulation and rule out differential diagnoses. The diagnosis of septic arthritis of the facet joint was confirmed intraoperatively; real-time quantitative PCR analysis identified Kingella kingae. This is the first substantiated paediatric case of zygapophyseal joint septic arthritis due to K. kingae. K. kingae is the most common pathogen responsible for invasive osteoarticular infection in children under 4years of age. Since empiric antibiotics are effective in early stages, physicians should consider the possibility of spinal infections due to K. kingae when a limping child under 4years of age presents with a fever.

  2. Does therapist’s attitude affect clinical outcome of lumbar facet joint injections?

    PubMed Central

    Middendorp, Marcus; Kollias, Konstantinos; Ackermann, Hanns; Splettstößer, Annina; Vogl, Thomas J; Khan, M Fawad; Maataoui, Adel

    2016-01-01

    AIM: To investigate if the clinical outcome of intra-articular lumbar facet joint injections is affected by the therapist’s attitude. METHODS: A total of 40 patients with facet joint-associated chronic low back pain were randomly divided into two groups. All patients received computed tomography-guided, monosegmental intra-articular facet joint injections. Following the therapeutic procedure, the patients of the experimental group (EG) held a conversation with the radiologist in a comfortable atmosphere. During the dialog, the patients were encouraged to ask questions and were shown four images. The patients of the control group (CG) left the clinic without any further contact with the radiologist. Outcome was assessed using a pain-based Verbal Numeric Scale at baseline, at 1 wk and at 1, 3, and 6 mo after first treatment. RESULTS: The patient demographics showed no differences between the groups. The patients of the EG received 57 interventional procedures in total, while the patients of the CG received 70 interventional procedures. In both groups, the pain scores decreased significantly over the entire observation period. Compared to the CG, the EG showed a statistically significant reduction of pain at 1 wk and 1 mo post-treatment, while at 3 and 6 mo after treatment, there were no significant differences between both groups. CONCLUSION: Our results show a significant effect on pain relief during the early post-interventional period in the EG as compared to the CG. The basic principle behind the higher efficacy might be the phenomenon of hetero-suggestion. PMID:27358691

  3. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2

  4. Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain.

    PubMed

    O'Neill, Søren; Graven-Nielsen, Thomas; Manniche, Claus; Arendt-Nielsen, Lars

    2009-07-01

    Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. Thirteen healthy volunteers were included and baseline pressure pain thresholds were assessed at eight separate sites, outside the area of evoked low back and referred pain. Using ultrasonography, two electrode needles were placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.

  5. Conservative Management of a Young Adult with Hip Arthrosis

    PubMed Central

    Cook, Kyle M.; Heiderscheit, Bryan

    2010-01-01

    Study Design Case report Background Clinical practice guidelines regarding the conservative management of degenerative hip conditions in older adults routinely incorporate therapeutic exercise and manual therapy. However, the application of these recommendations to young, active adults is less clear. The purpose of this case report is to describe the management of a young adult with advanced hip arthrosis using a multi-faceted rehabilitation program. Case Description A 28-year old female with severe left hip degeneration per diagnostic imaging was referred to physical therapy. Reduced hip range of motion and strength, sacroiliac joint asymmetries, and a modified Harris Hip Score of 76 were observed. She was seen for 12 visits over a 3-month period and treated with an individualized program including manual therapy, therapeutic exercise, and neuromuscular re-education. Outcome Substantial improvements were noted in pain, hip range of motion and strength and function (modified Harris Hip Score of 97). In addition, she discontinued the use of anti-inflammatory medications and returned to her prior level of activity. Improvements were maintained at a 3 month follow up, with symptom recurrence managed using a self mobilization technique to the left hip and massage to the left iliopsoas. Discussion Degenerative hip conditions are common among older adults but are relatively rare in the younger population. Although it is likely that this patient will experience a return of her symptoms and functional limitations as her hip disease progresses, the immediate improvements may delay the need for eventual surgical management. These outcomes suggest that physical therapy management should be considered in those with an early onset of degenerative hip disease and are consistent with results previously reported in the older population. Level of Evidence Therapy, Level 4 PMID:20026881

  6. A prospective morphological study of facet joint integrity following intervertebral disc replacement with the CHARITE Artificial Disc.

    PubMed

    Trouillier, Hans; Kern, P; Refior, H J; Müller-Gerbl, M

    2006-02-01

    In degenerative disc disease (DDD), increased loading in the posterior column increases facet joint subchondral bone density and may lead to facet joint degeneration. While spinal fusion is commonly used to treat patients with symptomatic DDD, increased stress at the levels adjacent to fusion may accelerate facet joint and adjacent segment degeneration. Artificial disc replacements have been developed as an alternative to fusion. In this prospective study, the effects of disc replacement with the CHARITE Artificial Disc on facet joint loading and integrity were evaluated. Thirteen patients aged <50 years with symptomatic DDD were recruited. Computed tomography (CT) osteoabsorptiometry was performed prior to the implantation of the CHARITE Artificial Disc and six months after. With this technique, increases or decreases in facet joint loading and integrity are indicated by corresponding changes in subchondral bone density. Changes in the distribution of load alter the distribution of the areas of maximum bone density. Clinical outcome was also assessed at pre-operative and 6 and 12 month post-operative visits using the Visual Analogue Scale back and leg pain scores, the Oswestry Disability Index and the Short Form-36 (SF-36) questionnaire. The height of the intervertebral space at the operated level was monitored by lateral X-ray. Subchondral bone density was evaluated in the facet joints of all 13 patients at the operated level, 12 patients at the level above the operated segment, and five patients at the level below the operated segment. Quantitative measurements revealed no significant increases (> or =3%) in subchondral bone density of the facet joints at any level in any patient. Significant decreases (> or =3%) in subchondral bone density were measured at the operated level in 10/13 patients, at the level above the operated segment in 6/12 patients, and at the level below the operated segment in 3/5 patients. There were no changes in the distribution of the

  7. Analysis of the Relationship between Ligamentum Flavum Thickening and Lumbar Segmental Instability, Disc Degeneration, and Facet Joint Osteoarthritis in Lumbar Spinal Stenosis

    PubMed Central

    Yoshiiwa, Toyomi; Notani, Naoki; Ishihara, Toshinobu; Kawano, Masanori; Tsumura, Hiroshi

    2016-01-01

    Study Design Cross-sectional study. Purpose To investigate the relationship between ligamentum flavum (LF) thickening and lumbar segmental instability and disc degeneration and facet joint osteoarthritis. Overview of Literature Posterior spinal structures, including LF thickness, play a major role in lumbar spinal canal stenosis pathogenesis. The cause of LF thickening is multifactorial and includes activity level, age, and mechanical stress. LF thickening pathogenesis is unknown. Methods We examined 419 patients who underwent computed tomography (CT) myelography and magnetic resonance imaging after complaints of clinical symptoms. To investigate LF hypertrophy, 57 patients whose lumbar vertebra had normal disc heights at L4–5 were selected to exclude LF buckling as a hypertrophy component. LF thickness, disc space widening angulation in flexion, segmental angulation, presence of a vacuum phenomenon, and lumbar lordosis at T12–S1 were investigated. Disc and facet degeneration were also evaluated. Facet joint orientation was measured via an axial CT scan. Results The mean LF thickness in all patients was 4.4±1.0 mm at L4–5. There was a significant correlation between LF thickness and disc degeneration; LF thickness significantly increased with severe disc degeneration and facet joint osteoarthritis. There was a tendency toward increased LF thickness in more sagittalized facet joints than in coronalized facet joints. Logistic regression analysis showed that LF thickening was influenced by segmental angulation and facet joint osteoarthritis. Patient age was associated with LF thickening. Conclusions LF hypertrophy development was associated with segmental instability and severe disc degeneration, severe facet joint osteoarthritis, and a sagittalized facet joint orientation. PMID:27994791

  8. Systematic review of patient history and physical examination to diagnose chronic low back pain originating from the facet joints.

    PubMed

    Maas, E T; Juch, J N S; Ostelo, R W J G; Groeneweg, J G; Kallewaard, J W; Koes, B W; Verhagen, A P; Huygen, F J P M; van Tulder, M W

    2017-03-01

    Patient history and physical examination are frequently used procedures to diagnose chronic low back pain (CLBP) originating from the facet joints, although the diagnostic accuracy is controversial. The aim of this systematic review is to determine the diagnostic accuracy of patient history and/or physical examination to identify CLBP originating from the facet joints using diagnostic blocks as reference standard. We searched MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Collaboration database from inception until June 2016. Two review authors independently selected studies for inclusion, extracted data and assessed the risk of bias. We calculated sensitivity and specificity values, with 95% confidence intervals (95% CI). Twelve studies were included, in which 129 combinations of index tests and reference standards were presented. Most of these index tests have only been evaluated in single studies with a high risk of bias. Four studies evaluated the diagnostic accuracy of the Revel's criteria combination. Because of the clinical heterogeneity, results were not pooled. The published sensitivities ranged from 0.11 (95% CI 0.02-0.29) to 1.00 (95% CI 0.75-1.00), and the specificities ranged from 0.66 (95% CI 0.46-0.82) to 0.91 (95% CI 0.83-0.96). Due to clinical heterogeneity, the evidence for the diagnostic accuracy of patient history and/or physical examination to identify facet joint pain is inconclusive. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies.

  9. Effect of changing lumbar stiffness by single facet joint dysfunction on the responsiveness of lumbar muscle spindles to vertebral movement

    PubMed Central

    Reed, William R.; Pickar, Joel G.; Long, Cynthia R.

    2014-01-01

    Objective: Individuals experiencing low back pain often present clinically with intervertebral joint dysfunction. The purpose of this study was to determine whether relative changes in stiffness at a single spinal joint alters neural responsiveness of lumbar muscle spindles to either vertebral movement or position. Methods: Muscle spindle discharge was recorded in response to 1mm L6 ramp and hold movements (0.5mm/s) in the same animal for lumbar laminectomy-only (n=23), laminectomy & L5/6 facet screw (n=19), laminectomy & L5/6 facetectomy (n=5) conditions. Mean instantaneous frequency (MIF) was calculated for the ramp-up, hold, ramp-down and post-ramp phases during each joint condition. Results: Mean MIFs were not significantly different between the laminectomy-only and the other two types of joint dysfunction for the ramp-up, hold, ramp-down, or post-ramp phases. Conclusion: Stiffness changes caused by single facet joint dysfunction failed to alter spindle responses during slow 1mm ramp and hold movements of the L6 vertebra. PMID:24932020

  10. 18F-Sodium Fluoride PET-CT Hybrid Imaging of the Lumbar Facet Joints: Tracer Uptake and Degree of Correlation to CT-graded Arthropathy

    PubMed Central

    Mabray, Marc C.; Brus-Ramer, Marcel; Behr, Spencer C.; Pampaloni, Miguel H.; Majumdar, Sharmila; Dillon, William P.; Talbott, Jason F.

    2016-01-01

    We aim to evaluate 18F-NaF uptake by facet joints with hybrid PET-CT technique. Specifically, we evaluate NaF uptake in the facet joints of the lower lumbar spine, and correlate with the morphologic grade of facet arthropathy on CT. 30 consecutive patients who underwent standard vertex to toes NaF PET-CT for re-staging of primary neoplastic disease without measurable or documented bony metastases were identified. Maximum (SUVmax) and average (SUVavg) standardized uptake values were calculated for each L3-4, L4-5, and L5-S1 facet joint (n = 180) and normalized to average uptake in the non-diseased femur. A Pathria grade (0-3) was assigned to each facet based upon the CT morphology. Spearman's rank correlation was performed for normalized SUVmax and SUVavg with Pathria grade. ANOVA was performed with Tukey-Kramer pairwise tests to evaluate differences in uptake between Pathria groups. Facet normalized SUVmax (r = 0.31, P < 0.001) and SUVavg (r = 0.28, P < 0.001) demonstrated a mild positive correlation with CT Pathria grade. There was a wide range of uptake values within each Pathria grade subgroup with statistically significant differences in uptake only between Pathria grade 3 as compared to grades 0, 1, and 2. In conclusion, NaF uptake and morphologic changes of the facet joint on CT are weakly correlated. Physiologic information provided by NaF uptake is often discrepant with structural findings on CT suggesting NaF PET may supplement conventional structural imaging for identification of pain generating facet joints. Prospective investigation into the relationship of facet joint NaF uptake with pain and response to pain interventions is warranted. PMID:27134557

  11. [Unilateral hip arthrosis: expression of joint haemochromatosis].

    PubMed

    Prieto Zancudo, C; Villán Villán, Y F; Tascón Guerra, M F

    2012-10-01

    Hereditary haemochromatosis is the most common genetic disorder in the Caucasian population, with an estimated prevalence of 1/200-1/400 (homozygous) and 1/8-1/10 in carriers (heterozygous). The transmission is recessive and linked to HLA. The clinical expression of disease appears only in homozygous and will depend on the time of diagnosis and the degree of organ involvement. The clinical case presented below describes the process of differential diagnosis made in a young patient with unilateral coxarthrosis and clinical suspicion of hemochromatosis. Early diagnosis of hereditary hemochromatosis in primary care can reduce morbidity and mortality of this disease by detecting homozygous at younger ages.

  12. A Modified Posterolateral Approach for Radiofrequency Denervation of the Medial Branch of the Cervical Segmental Nerve in Cervical Facet Joint Pain Based on Anatomical Considerations.

    PubMed

    van Eerd, Maarten; Lataster, Arno; Sommer, Micha; Patijn, Jacob; van Kleef, Maarten

    2016-10-13

    The cervical facet joints, also called the zygapophyseal joints, are a potential source of neck pain (cervical facet joint pain). The cervical facet joints are innervated by the cervical medial branches (CMBs) of the cervical segmental nerves. Cervical facet joint pain has been shown to respond to multisegmental radiofrequency denervation of the cervical medial branches. This procedure is performed under fluoroscopic guidance. Currently, three approaches are described and used. Those three techniques of radiofrequency treatment of the CMBs, classified on the base of the needle trajectory toward the anatomical planes, are as follows: the posterolateral technique, the posterior technique, and the lateral technique. We describe the three techniques with their advantages and disadvantages. Anatomical studies providing a topographic anatomy of the course of the CMBs are reviewed. We developed a novel approach based on the observed strengths and weaknesses of the three currently used approaches and based on recent anatomical findings. With this fluoroscopic-guided approach, there is always bone (the facet column) in front of the needle, which makes it safer, and the insertion point is easier to determine without the risk of positioning the radiofrequency needle too dorsally.

  13. Characterization of a New Animal Model for Evaluation and Treatment of Back Pain Due to Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Kroin, Jeffrey S.; Buvanendran, Asokumar; Li, Xin; van Wijnen, Andre J.; Tuman, Kenneth J.; Im, Hee-Jeong

    2011-01-01

    Degeneration of lumbar facet joints (FJs) has been implicated in lower back pain. To verify the biological links between cellular and structural alterations within FJ components and development of symptomatic chronic back pain, we generated an animal model for FJ degeneration by intra-articular injection of monosodium iodoacetate (MIA) in FJs (L3/L4, L4/L5, L5/L6) of Sprague Dawley rats followed by behavioral pain tests. The degree of primary hyperalgesia was assessed by measuring pain sensation due to pressure using an algometer, which mimics a mechanical stimulus for FJ injury. Biochemical assessments and µCT imaging revealed severely damaged FJ cartilage, proteoglycan loss and alterations of subchondral bone structure by MIA injection. The µCT analyses further suggested that the behavioral hyperalgesia from FJ degeneration is not associated with foramina stenosis. These biological and structural changes in FJs are closely related to sustained and robust chronic pain. Therapeutic modulation of chronic pain using pharmaceutical drugs was investigated in the facet joint osteoarthritis animal model. Morphine and pregabalin markedly alleviate pressure hyperalgesia while celecoxib (selective inhibitor of COX-2) and ketorolac (inhibitor of COX-1 and -2) demonstrate moderate to negligible anti-hyperalgesic effects, respectively. PMID:21953085

  14. Biomechanical analysis of press-extension technique on degenerative lumbar with disc herniation and staggered facet joint.

    PubMed

    Du, Hong-Gen; Liao, Sheng-Hui; Jiang, Zhong; Huang, Huan-Ming; Ning, Xi-Tao; Jiang, Neng-Yi; Pei, Jian-Wei; Huang, Qin; Wei, Hui

    2016-05-01

    This study investigates the effect of a new Chinese massage technique named "press-extension" on degenerative lumbar with disc herniation and facet joint dislocation, and provides a biomechanical explanation of this massage technique. Self-developed biomechanical software was used to establish a normal L1-S1 lumbar 3D FE model, which integrated the spine CT and MRI data-based anatomical structure. Then graphic technique is utilized to build a degenerative lumbar FE model with disc herniation and facet joint dislocation. According to the actual press-extension experiments, mechanic parameters are collected to set boundary condition for FE analysis. The result demonstrated that press-extension techniques bring the annuli fibrosi obvious induction effect, making the central nucleus pulposus forward close, increasing the pressure in front part. Study concludes that finite element modelling for lumbar spine is suitable for the analysis of press-extension technique impact on lumbar intervertebral disc biomechanics, to provide the basis for the disease mechanism of intervertebral disc herniation using press-extension technique.

  15. Risk analysis of occupational factors influencing the development of arthrosis of the knee.

    PubMed

    Sahlström, A; Montgomery, F

    1997-09-01

    The aim of this study was to identify occupational activities important for the development of arthrosis of the knee, taking into account the confounding factors that were suspected or could be recognized. In the archives of the Department of Diagnostic Radiology at the Malmö University Hospital all radiographs of weight-bearing knees of patients with painful knee joints from the period 1982-1986 were reassessed. We found 340 probands, i.e., subjects with arthrosis of the knee of at least grade 1 in the Ahlback classification. These probands and their age- and sex-matched controls (680) were analyzed by a validated questionnaire for details of activities at work inducing knee moment over three 15-year-periods as well as their history of knee injuries at work or in their leisure time. The questionnaire was answered by 266 (79%) arthrosis probands and 463 controls (70%). The results of the questionnaire answers and of the recorded history of knee injuries were statistically analyzed by logistic regression. The relative risk of knee arthrosis was slightly increased (RR: 1.9; CI: 1.4-2.7) in probands with weight-bearing knee bending, i.e., dynamic load of the knee joint when bending, whereas knee injuries (meniscectomies and haemarthrosis) were associated with a higher risk. Weight-bearing knee bending corrected for confounders was not a significant factor for knee arthrosis. Overweight was observed to increase the relative risk. A sedentary profession had, on the other hand, a low risk. The knee injuries (66) were, but for 9 probands, sustained in leisure activities, mainly soccer. We thus conclude that work which induces weight-bearing knee bending by itself does not significantly increase the risk of developing arthrosis of the knee - knee injuries and overweight are more important.

  16. Subtalar Joint Instability and Calcaneal Spurs Associated with the Configuration of the Articular Facets of Adult Human Calcaneum in Indian Population

    PubMed Central

    Garg, Shilpi; Vasudeva, Neelam

    2016-01-01

    Introduction Morphological variations of articular facets of calcaneum may predispose people to joint instability, ligamentous laxity and development of arthritic changes in the subtalar joint. Knowledge of such variations is essential for treatment and diagnostic procedures in orthopaedic surgeries. Aim The aim of this study was to determine patterns of articular facets of calcanei and to establish its correlation with calcaneal spurs. Materials and Methods The study was conducted on 580 adult calcanei of Indian origin at Maulana Azad Medical College and pattern of articular facets were observed and classified according to five patterns described in literature. A digital vernier calliper was used to measure separation between anterior and middle facet. Degree of intersecting angle between anterior and medial facets was calculated using UTHSCSA Image Tool software. The calcaneal spurs were observed by visual inspection. Results Out of 580 calcanei, 66.55% had fused anterior and middle facets (Pattern I), 27.59% had all three facets separate (Pattern II), 5.52% had absence of anterior facet (Pattern III), 0.17% had all three facets fused (Pattern IV) and 0.17% had fused middle and posterior facets (Pattern V). A significant side variation was present in Pattern III with predominance on left side. Mean angle of intersection was 147.700 in Pattern I and 133.340 in Pattern II calcaneum. Calcaneal spurs were found in 61.38% out of which it was associated with Pattern I in 43.62%, Pattern II in 14.66% and Pattern III in 2.76%. Conclusion Individuals with Pattern I and III calcaneum were found to be at a greater risk of subtalar joint instability than individuals with Pattern II. Angle of intersection was obtuse in Pattern I which resulted in ligament laxity and unstable joint. Pattern I was more common in Indian population and this fact necessitates modifications of the western surgical techniques to suit the Indian scenario. An association between the presence of spur

  17. Biochemical T2* MR quantification of ankle arthrosis in pes cavovarus.

    PubMed

    Krause, Fabian G; Klammer, Georg; Benneker, Lorin M; Werlen, Stefan; Mamisch, Tallal C; Weber, Martin

    2010-12-01

    Pes cavovarus affects the ankle biomechanics and may lead to ankle arthrosis. Quantitative T2 STAR (T2*) magnetic resonance (MR) mapping allows high resolution of thin cartilage layers and quantitative grading of cartilage degeneration. Detection of ankle arthrosis using T2* mapping in cavovarus feet was evaluated. Eleven cavovarus patients with symptomatic ankle arthrosis (13 feet, mean age 55.6 years, group 1), 10 cavovarus patients with no or asymptomatic, mild ankle arthrosis (12 feet, mean age 41.8 years, group 2), and 11 controls without foot deformity (18 feet, mean age 29.8 years, group 3) had quantitative T2* MR mapping. Additional assessment included plain radiographs and the American Orthopaedic Foot and Ankle Society (AOFAS) score (groups 1 and 2 only). Mean global T2* relaxation time was significantly different between groups 1 and 2 (p = 0.001) and groups 1 and 3 (p = 0.017), but there was no significance for decreased global T2* values in group 2 compared to group 3 (p = 0.345). Compared to the medial compartment T2* values of the lateral compartment were significantly (p = 0.025) higher within group 1. T2* values in the medial ankle joint compartment of group 2 were significantly lower than those of group 1 (p = 0.019). Ankle arthrosis on plain radiographs and the AOFAS score correlated significantly with T2* values in the medial compartment of group 1 (p = 0.04 and 0.039, respectively). Biochemical, quantitative T2* MR mapping is likely effective to evaluate ankle arthrosis in cavovarus feet but further studies are required.

  18. Lumbar disc degeneration was not related to spine and hip bone mineral densities in Chinese: facet joint osteoarthritis may confound the association.

    PubMed

    Pan, Jianjiang; Lu, Xuan; Yang, Ge; Han, Yongmei; Tong, Xiang; Wang, Yue

    2017-12-01

    A sample of 512 Chinese was studied and we observed that greater disc degeneration on MRI was associated with greater spine DXA BMD. Yet, this association may be confounded by facet joint osteoarthritis. BMD may not be a risk factor for lumbar disc degeneration in Chinese.

  19. Evaluation of a Robotic Assistance-System For Percutaneous Computed Tomography-Guided (CT-Guided) Facet Joint Injection: A Phantom Study

    PubMed Central

    Beyer, Lukas Philipp; Michalik, Katharina; Niessen, Christoph; da Silva, Natascha Platz Batista; Wiesinger, Isabell; Stroszczynski, Christian; Wiggermann, Philipp

    2016-01-01

    Background The aim of this study was to compare robotic assisted and freehand facet joint puncture on a phantom model in regards to time requirements and puncture accuracy. Material/Methods Forty facet joints were punctured, 20 using a robotic guidance system and 20 using a freehand procedure. Side and height of the facet joints were randomized and identical for both groups. Procedural accuracy, defined as axial and sagittal deviation, as well as the number of corrections were assessed. Procedure times for each step were documented and time requirements for pre-positioning, reconstruction, planning, and total intervention were calculated. Results Total procedure time for robotic guidance was 259±111 seconds versus 119±77 seconds for freehand procedure (p=1.0). Procedural accuracy for robotic guidance was significantly higher with 0 corrections versus 1.3 corrections for freehand procedure (p=0.02). Needle deviation in the robotics arm was 0.35±1.1 mm in the axial and 2.15±1.2 mm in the sagittal reconstruction. Conclusions Robotic assisted puncture of the facet joint allowed accurate positioning of the needle with a lower number of needle readjustments. Higher procedural accuracy was marginally offset by a slightly longer intervention time. PMID:27648509

  20. Evaluation of a Robotic Assistance-System For Percutaneous Computed Tomography-Guided (CT-Guided) Facet Joint Injection: A Phantom Study.

    PubMed

    Beyer, Lukas Philipp; Michalik, Katharina; Niessen, Christoph; Platz Batista da Silva, Natascha; Wiesinger, Isabell; Stroszczynski, Christian; Wiggermann, Philipp

    2016-09-20

    BACKGROUND The aim of this study was to compare robotic assisted and freehand facet joint puncture on a phantom model in regards to time requirements and puncture accuracy. MATERIAL AND METHODS Forty facet joints were punctured, 20 using a robotic guidance system and 20 using a freehand procedure. Side and height of the facet joints were randomized and identical for both groups. Procedural accuracy, defined as axial and sagittal deviation, as well as the number of corrections were assessed. Procedure times for each step were documented and time requirements for pre-positioning, reconstruction, planning, and total intervention were calculated. RESULTS Total procedure time for robotic guidance was 259±111 seconds versus 119±77 seconds for freehand procedure (p=1.0). Procedural accuracy for robotic guidance was significantly higher with 0 corrections versus 1.3 corrections for freehand procedure (p=0.02). Needle deviation in the robotics arm was 0.35±1.1 mm in the axial and 2.15±1.2 mm in the sagittal reconstruction. CONCLUSIONS Robotic assisted puncture of the facet joint allowed accurate positioning of the needle with a lower number of needle readjustments. Higher procedural accuracy was marginally offset by a slightly longer intervention time.

  1. Indian Hedgehog signaling pathway members are associated with magnetic resonance imaging manifestations and pathological scores in lumbar facet joint osteoarthritis

    NASA Astrophysics Data System (ADS)

    Shuang, Feng; Zhou, Ying; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhang, Chun-Li; Tang, Jia-Guang

    2015-05-01

    Indian Hedgehog (HH) has been shown to be involved in osteoarthritis (OA) in articular joints, where there is evidence that Indian HH blockade could ameliorate OA. It seems to play a prominent role in development of the intervertebral disc (IVD) and in postnatal maintenance. There is little work on IHH in the IVD. Hence the aim of the current study was to investigate the role of Indian Hedgehog in the pathology of facet joint (FJ) OA. 24 patients diagnosed with lumbar intervertebral disk herniation or degenerative spinal stenosis were included. Preoperative magnetic resonance imaging (MRI) and Osteoarthritis Research Society International (OARSI) histopathology grading system was correlated to the mRNA levels of GLI1, PTCH1, and HHIP in the FJs. The Weishaupt grading and OARSI scores showed high positive correlation (r = 0.894) (P < 0.01). MRI Weishaupt grades showed positive correlation with GLI1 (r = 0.491), PTCH1 (r = 0.444), and HHIP (r = 0.654) mRNA levels (P < 0.05 in each case). OARSI scores were also positively correlated with GLI1 (r = 0. 646), PTCH1 (r = 0. 518), and HHIP (r = 0.762) mRNA levels (P < 0.01 in each case). Cumulatively our findings indicate that Indian HH signaling is increased in OA and is perhaps a key component in OA pathogenesis and progression.

  2. Early Afferent Activity from the Facet Joint after Painful Trauma to its Capsule Potentiates Neuronal Excitability and Glutamate Signaling in the Spinal Cord

    PubMed Central

    Crosby, Nathan D.; Gilliland, Taylor M.; Winkelstein, Beth A.

    2014-01-01

    Cervical facet joint injury induces persistent pain and central sensitization. Preventing the peripheral neuronal signals that initiate sensitization attenuates neuropathic pain. Yet, there is no clear relationship between facet joint afferent activity, development of central sensitization, and pain, which may be hindering effective treatments for this pain syndrome. This study investigates how afferent activity from the injured cervical facet joint affects induction of behavioral sensitivity and central sensitization. Intra-articular bupivacaine was administered to transiently suppress afferent activity immediately or 4 days after facet injury. Mechanical hyperalgesia was monitored after injury, and spinal neuronal hyperexcitability and spinal expression of proteins that promote neuronal excitability were measured on day 7. Facet injury with saline vehicle treatment induced significant mechanical hyperalgesia (p<0.027), dorsal horn neuronal hyperexcitability (p<0.026), upregulation of pERK1/2, pNR1, mGluR5, GLAST, and GFAP, and downregulation of GLT1 (p<0.032). However, intra-articular bupivacaine immediately after injury significantly attenuated hyperalgesia (p<0.0001), neuronal hyperexcitability (p<0.004), and dysregulation of excitatory signaling proteins (p<0.049). In contrast, intra-articular bupivacaine at day 4 had no effect on these outcomes. Silencing afferent activity during the development of neuronal hyperexcitability (4hr, 8hr, 1 day) attenuated hyperalgesia and neuronal hyperexcitability (p<0.045) only for the treatment given 4 hours after injury. This study suggests that early afferent activity from the injured facet induces development of spinal sensitization via spinal excitatory glutamatergic signaling. Peripheral intervention blocking afferent activity is only effective over a short period of time early after injury and before spinal modifications develop, and is independent of modulating spinal glial activation. PMID:24978827

  3. Development Of an Experimental Animal Model For Lower Back Pain By Percutaneous Injury-Induced Lumbar Facet Joint Osteoarthritis

    PubMed Central

    Kim, Jae-Sung; Ahmadinia, Kasra; Li, Xin; Hamilton, John L; Andrews, Steven; Haralampus, Chris A.; Xiao, Guozhi; Sohn, Hong-Moon; You, Jae-Won; Seo, Yo-Seob; Stein, Gary S.; Wijnen, Andre J Van; Kim, Su-Gwan; Im, Hee-Jeong

    2015-01-01

    We report generation and characterization of pain-related behavior in a minimally-invasive facet joint degeneration (FJD) animal model in rats. FJD was produced by a non-open percutaneous puncture-induced injury on the right lumbar FJs at three consecutive levels. Pressure hyperalgesia in the lower back was assessed by measuring the vocalization response to pressure from a force transducer. After hyperalgesia was established, pathological changes in lumbar FJs and alterations of intervertebral foramen size were assessed by histological and imaging analyses. To investigate treatment options for lumber FJ osteoarthritis-induced pain, animals with established hyperalgesia were administered with analgesic drugs, such as morphine, a selective COX-2 inhibitor, a non-steroidal anti-inflammatory drug (NSAID) (ketorolac), or pregabalin. Effects were assessed by behavioral pain responses. One week after percutaneous puncture-induced injury of the lumbar FJs, ipsilateral primary pressure hyperalgesia developed and was maintained for at least 12 weeks without foraminal stenosis. Animals showed decreased spontaneous activity, but no secondary hyperalgesia in the hind paws. Histopathological and microfocus X-ray computed tomography analyses demonstrated that the percutaneous puncture injury resulted in osteoarthritis-like structural changes in the FJs cartilage and subchondral bone. Pressure hyperalgesia was completely reversed by morphine. The administration of celecoxib produced moderate pain reduction with no statistical significance while the administration of ketorolac and pregabalin produced no analgesic effect on FJ osteoarthritis-induced back pain. Our animal model of non-open percutanous puncture-induced injury of the lumbar FJs in rats shows similar characteristics of low back pain produced by human facet arthropathy. PMID:25858171

  4. Cervical Facet Joint Infection and Associated Epidural Abscess with Streptococcus intermedius from a Dental Infection Origin A Case Report and Review.

    PubMed

    Kaye, Ian David; Protopsaltis, Themistocles S

    2016-09-01

    Pyogenic cervical facet joint infections are rare and such infections from a dental origin are even less common. Of these few cases, none have described infection with Streptococcus intermedius as the pathogen. A 65-year-old orthopaedic surgeon complained of fevers, right-sided radiating neck pain, stiffness, swelling, erythema, and right upper extremity weakness one month after he had broken a crown over his right mandibular premolar, a continued source of pain. Imaging of the cervical spine showed a right C4-C5 facet inflammatory arthropathy and a small epidural abscess that was cultured and initially treated with intravenous antibiotics. The oral maxillofacial surgery team performed an extraction of the infected, symptomatic tooth. For continued right upper extremity weakness, the patient underwent C4-C5 laminoforaminotomy and irrigation and debridement of the right C4-C5 facet joint. After 6 weeks of intravenous antibiotics, the patient's infectious and inflammatory markers had normalized. By 4 months, he had regained full strength at his upper extremity and a painless and full range of motion of his cervical spine.Pyogenic cervical facet joint infection is very rare and potentially dangerous. A high clinical suspicion and appropriate imaging, including magnetic resonance imaging, are important for correct diagnosis. Prompt medical and surgical treatment may avert complications, and although the patient presented made a complete recovery, patients may be left with neurological compromise.

  5. Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

    PubMed Central

    Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

    2016-01-01

    OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

  6. Incorporation of lower neck shear forces to predict facet joint injury risk in low-speed automotive rear impacts.

    PubMed

    Stemper, Brian D; Storvik, Steven G

    2010-06-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact tests were conducted at two velocities and with two seatback orientations using a Hybrid III anthropomorphic test device (ATD) and stock automobile seats from 2007 model year vehicles. Higher velocities and more vertical seatback orientations were associated with higher injury risk based on computational modeling simulations performed in this study. Six cervical spine injury criteria including NIC, Nij, Nkm, LNL, and lower neck shear force and bending moment, increased with impact velocity. NIC, Nij, and shear force were most sensitive to changes in impact velocity. Four metrics, including Nkm, LNL, and lower neck shear force and bending moment, increased for tests with more vertical seatback orientations. Shear force was most sensitive to changes in seatback orientation. Peak values for shear force, NIC, and Nij occurred approximately at the time of head restraint contact for all four test conditions. Therefore, of the six investigated metrics, lower neck shear force was the only metric to demonstrate consistency with regard to injury risk and timing of peak magnitudes. These results demonstrate the ability of lower neck shear force to predict injury risk during low velocity automotive rear impacts and warrant continued investigation into the sensitivity and applicability of this metric for other rear-impact conditions.

  7. [Two cases of temporomandibular arthrosis of young children].

    PubMed

    Ono, Y; Lin, Y F; Iijima, H; Miwa, Z; Ono, H

    1989-01-01

    Two cases of temporomandibular arthrosis were reported. Case 1 was a 6 years 4 months old female with pain in her left mandibular region in moving her jaw. Opening of the mouth by herself was slightly limited. Clicking noise was seen and felt from both of her temporomandibular joints. She was in the dental developmental stage IIA by Hellman, and had deep overbite (5mm). Roentogenographic examination revealed a bony defect on her left condylar head. Treatment was performed with an activator. Pain was not felt and the mandibular opening recovered after 2 weeks of treatment. Roetogenographs showed no bony defect on her left condylar head after 5 months of treatment. Case 2 was a 3 years 2 months old male with clicking noise from both of his temporomandibular joints. There was no pain and no limitation of his mouth opening. He was in the dental developmental stage IIA by Hellman, and had large overjet (8mm). He has thumb sucking habit since the age of one year. He is now under regular observation.

  8. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies

    PubMed Central

    Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques. PMID:26463233

  9. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies.

    PubMed

    Filippiadis, Dimitrios K; Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques.

  10. An International Multicenter Study Assessing the Role of Ethnicity on Variation of Lumbar Facet Joint Orientation and the Occurrence of Degenerative Spondylolisthesis in Asia Pacific: A Study from the AOSpine Asia Pacific Research Collaboration Consortium.

    PubMed

    Williams, Richard; Cheung, Jason Pui Yin; Goss, Ben; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D K; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Sham, Phoebe; Samartzis, Dino

    2016-02-01

    Study Design A multinational, multiethnic, cross-sectional image-based study was performed in 33 institutions, representing 10 countries, which were part of the AOSpine Asia Pacific Research Collaboration Consortium. Objective Lumbar facet joint orientation has been reported to be associated with the development of degenerative spondylolisthesis (DS). The role of ethnicity regarding facet joint orientation remains uncertain. As such, the following study was performed across a wide-ranging population base to assess the role of ethnicity in facet joint orientation in patients with DS in the Asia Pacific region. Methods Lateral standing X-rays and axial magnetic resonance imaging scans were obtained for patients with lumbar DS. The DS parameters and facet joint angulations were assessed from L3-S1. Sex, age, body mass index (BMI), and ethnicity were also noted. Results The study included 371 patients with known ethnic origin (mean age: 62.0 years; 64% males, 36% females). The mean BMI was 25.6 kg/m(2). The level of DS was most prevalent at L4-L5 (74.7%). There were 28.8% Indian, 28.6% Japanese, 18.1% Chinese, 8.6% Korean, 6.5% Thai, 4.9% Caucasian, 2.7% Filipino, and 1.9% Malay patients. Variations in facet joint angulations were noted from L3 to S1 and between patients with and without DS (p < 0.05). No differences were noted with regards to sex and overall BMI to facet joint angulations (p > 0.05); however, increasing age was found to increase the degree of angulation throughout the lumbar spine (p < 0.05). Accounting for age and the presence or absence of DS at each level, no statistically significant differences between ethnicity and degree of facet joint angulations from L3-L5 were noted (p > 0.05). Ethnic variations were noted in non-DS L5-S1 facet joint angulations, predominantly between Caucasian, Chinese, and Indian ethnicities (p < 0.05). Conclusions This study is the first to suggest that ethnicity may not play a role in facet

  11. Fluoroscopic cervical epidural injections in chronic axial or disc-related neck pain without disc herniation, facet joint pain, or radiculitis

    PubMed Central

    Manchikanti, Laxmaiah; Cash, Kimberly A; Pampati, Vidyasagar; Malla, Yogesh

    2012-01-01

    Background While chronic neck pain is a common problem in the adult population, with a typical 12-month prevalence of 30%–50%, there is a lack of consensus regarding its causes and treatment. Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain. Methods A randomized, double-blind, active, controlled trial was conducted to evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of chronic neck pain with or without upper extremity pain in patients without disc herniation, radiculitis, or facet joint pain. Results One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain by means of controlled diagnostic medial branch blocks were randomly assigned to one of two treatment groups, ie, injection of local anesthetic only (group 1) or local anesthetic mixed with nonparticulate betamethasone (group 2). The primary outcome of significant pain relief and improvement in functional status (≥50%) was demonstrated in 72% of group 1 and 68% of group 2. The overall average number of procedures per year was 3.6 in both groups with an average total relief per year of 37–39 weeks in the successful group over a period of 52 weeks. Conclusion Cervical interlaminar epidural injections of local anesthetic with or without steroids may be effective in patients with chronic function-limiting discogenic or axial pain. PMID:22826642

  12. Symptomatic anterior subtalar arthrosis after ankle arthrodesis.

    PubMed

    Lui, Tun Hing

    2014-05-13

    A 76-year-old man reported right lateral heel pain 11 years after ankle arthrodesis. Clinically, there was tenderness in the right sinus tarsi and over the junction point between the talonavicular and calcaneocuboid joints. Radiographs showed that the joint spaces of the posterior subtalar joint and the talonavicular joint were preserved although there were osteophytes at both joints. Arthroscopic findings showed degeneration of the anterior subtalar and talonavicular joints. The symptoms subsided after arthroscopic debridement.

  13. Muscular response to physiologic tensile stretch of the caprine c5/6 facet joint capsule: dynamic recruitment thresholds and latencies.

    PubMed

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Cavanaugh, John M

    2011-11-01

    This study examined the cervical muscle response to physiologic, high-rate (100 mm/s) tensile facet joint capsule (FJC) stretch. Six in-vivo caprine C5/6 FJC preparations were subjected to an incremental tensile loading paradigm. EMG activity was recorded from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels; and from the sternomastoid (SM) and longus colli (LC) muscle groups bilaterally at the C5/6 level; during FJC stretch. Capsule load during the displacement applications was recorded via a miniature load cell, and 3D capsule strains (based on stereoimaging of an array of markers on the capsule surface) were reconstructed using finite element methods. EMG traces from each muscle were examined for onset of muscular activity. Capsule strains and loads at the time of EMG onset were recorded for each muscle, as was the time from the onset of FJC stretch to the onset of muscle activity. All muscles were responsive to physiologic high-rate FJC stretch. The deep muscles (MF and LC) were recruited at significantly smaller capsule loads and onset latencies than the superficial muscles (TR and SM). MF activation strain was significantly smaller than LC and TR activation strains. These data were also compared to previously published low-rate data. MF was the first muscle group to be recruited regardless of the activation criterion under consideration (i.e. strain, load, or latency) or the rate of FJC stretch. LC recruitment occurred significantly sooner under high-rate vs. low-rate FJC stretch. The results of this study provide further evidence of extensive ligamento-muscular reflex pathways between the FJC and the cervical musculature, which are responsive to both low-rate and high-rate FJC stretch. These data add to our knowledge of the dynamic response of paraspinal muscles relative to facet joint motion and provide a unique contribution to enhance the precision of computer-simulated impacts.

  14. Strain and load thresholds for cervical muscle recruitment in response to quasi-static tensile stretch of the caprine C5-C6 facet joint capsule.

    PubMed

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Lu, Ying; Cavanaugh, John M

    2009-12-01

    The aim of this study was to investigate the response of cervical muscles to physiologic tensile stretch of cervical facet joint capsule (FJC) at a quasi-static displacement rate of 0.5mm/s. In vivo caprine left C5-C6 FJC preparations were subjected to an incremental tensile displacement paradigm. EMG activity was recorded during FJC stretch from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels and bilaterally from the sternomastoid (SM) and longus colli (LC) muscle groups at the C5-C6 level. Onset of muscular activity was later analyzed using visual and computer-based methods. Capsule load and strain at the time of onset were recorded and compared between the muscle groups. Results indicated capsule load was a better indicator of the tensile stretch thresholds for muscular recruitment than capsule strain. MF responded at significantly smaller capsule loads than TR and LC, while TR and LC activation loads were not significantly different. SM did not respond to physiologic FJC stretch. Muscle group recruitment order reflected the muscles' fiber type compositions and functional roles in the spine. This study provides the first evidence that the cervical ligamento-muscular reflex pathways are activated via tensile FJC stretch and extend to superficial and deep musculature on the anterior and posterior aspects of the neck, ipsilateral and contralateral to the side of FJC stretch.

  15. FacetGist: Collective Extraction of Document Facets in Large Technical Corpora.

    PubMed

    Siddiqui, Tarique; Ren, Xiang; Parameswaran, Aditya; Han, Jiawei

    2016-10-01

    Given the large volume of technical documents available, it is crucial to automatically organize and categorize these documents to be able to understand and extract value from them. Towards this end, we introduce a new research problem called Facet Extraction. Given a collection of technical documents, the goal of Facet Extraction is to automatically label each document with a set of concepts for the key facets (e.g., application, technique, evaluation metrics, and dataset) that people may be interested in. Facet Extraction has numerous applications, including document summarization, literature search, patent search and business intelligence. The major challenge in performing Facet Extraction arises from multiple sources: concept extraction, concept to facet matching, and facet disambiguation. To tackle these challenges, we develop FacetGist, a framework for facet extraction. Facet Extraction involves constructing a graph-based heterogeneous network to capture information available across multiple local sentence-level features, as well as global context features. We then formulate a joint optimization problem, and propose an efficient algorithm for graph-based label propagation to estimate the facet of each concept mention. Experimental results on technical corpora from two domains demonstrate that Facet Extraction can lead to an improvement of over 25% in both precision and recall over competing schemes.

  16. FacetGist: Collective Extraction of Document Facets in Large Technical Corpora

    PubMed Central

    Siddiqui, Tarique; Ren, Xiang; Parameswaran, Aditya; Han, Jiawei

    2017-01-01

    Given the large volume of technical documents available, it is crucial to automatically organize and categorize these documents to be able to understand and extract value from them. Towards this end, we introduce a new research problem called Facet Extraction. Given a collection of technical documents, the goal of Facet Extraction is to automatically label each document with a set of concepts for the key facets (e.g., application, technique, evaluation metrics, and dataset) that people may be interested in. Facet Extraction has numerous applications, including document summarization, literature search, patent search and business intelligence. The major challenge in performing Facet Extraction arises from multiple sources: concept extraction, concept to facet matching, and facet disambiguation. To tackle these challenges, we develop FacetGist, a framework for facet extraction. Facet Extraction involves constructing a graph-based heterogeneous network to capture information available across multiple local sentence-level features, as well as global context features. We then formulate a joint optimization problem, and propose an efficient algorithm for graph-based label propagation to estimate the facet of each concept mention. Experimental results on technical corpora from two domains demonstrate that Facet Extraction can lead to an improvement of over 25% in both precision and recall over competing schemes. PMID:28210517

  17. Treatment of patients with arthrosis of hip or knee with an aqueous extract of devil's claw (Harpagophytum procumbens DC.).

    PubMed

    Wegener, Tankred; Lüpke, Niels-Peter

    2003-12-01

    Preparations made from the secondary tubers of Devil's claw (Harpagophytum procumbens) are successfully used in patients with rheumatic diseases (arthrosis and low back pain). In order to add data on the efficacy and long-term safety of an aqueous extract (Doloteffin; 2400 mg extract daily, corresponding to 50 mg harpagoside), which has been tested successfully in patients with low back pain, an uncontrolled multicentre drug surveillance study for about 12 weeks was conducted in 75 patients with arthrosis of the hip or knee. To standardize the assessment of treatment effects, the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index (10 point scale) as well as the 10 cm VAS pain scale were used. The results of the study revealed a strong reduction of pain and the symptoms of osteoarthritis. There was a relevant improvement of each WOMAC subscale as well as of the total WOMAC index: 23.8% for the pain subscale, 22.2% for the stiffness subscale and 23.1% for the physical function subscale. The WOMAC total score was reduced by 22.9%. VAS pain scores were decreased by 25.8% for actual pain, 25.2% for average pain, 22.6% for worst pain and 24.5% for the total pain score. The physicians reported a continuous improvement in typical clinical findings such as 45.5% for pain on palpation, 35% for limitation of mobility and 25.4% for joint crepitus. Only two cases of possible adverse drug reactions were reported (dyspeptic complaints and a sensation of fullness). Although this was an open clinical study, the results suggest that this Devil's claw extract has a clinically beneficial effect in the treatment of arthrosis of the hip or knee.

  18. Analysis of IL-17+ cells in facet joints of patients with spondyloarthritis suggests that the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response

    PubMed Central

    2011-01-01

    Introduction In this study, we analysed the number of IL-17+ cells in facet joints, in the peripheral blood (PB) and synovial fluid (SF) of spondyloarthritis (SpA) patients and compared these results with those of patients with other rheumatic diseases and controls. Methods Immunohistochemical analysis of IL-17+ cells was performed in facet joints of 33 ankylosing spondylitis (AS) patients and compared with data from 20 osteoarthritis (OA) patients. The frequency of IL-17+CD4+ T cells in PB and SF of SpA patients (PB n = 30, SF n = 11), rheumatoid arthritis (RA) patients (PB n = 14, SF n = 7), OA patients (PB n = 10) and healthy controls (PB n = 12) was analysed after stimulation with Staphylococcus aureus Enterotoxin B and phorbol 12-myristate 13-acetate/ionomycin and quantified by flow cytometry. Results In AS facet joints, the frequency of IL-17-secreting cells was significantly higher than in samples obtained from OA patients (P < 0.001), with a slight predominance of IL-17+ cells among the mononuclear cells (61.5% ± 14.9%) compared to cells with polysegmental nuclei. Immunofluorescence microscopy revealed that the majority of IL-17+ cells were myeloperoxidase-positive (35.84 ± 13.06/high-power field (HPF) and CD15+ neutrophils (24.25 ± 10.36/HPF), while CD3+ T cells (0.51 ± 0.49/HPF) and AA-1+ mast cells (2.28 ± 1.96/HPF) were less often IL-17-positive. The frequency of IL-17+CD4+ T cells in the PB and SF of SpA patients did not differ significantly compared to RA patients, OA patients or healthy controls. Conclusions Our data suggest an important role for IL-17 in the inflammatory processes in AS. However, the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response. PMID:21689402

  19. The effect of different design concepts in lumbar total disc arthroplasty on the range of motion, facet joint forces and instantaneous center of rotation of a L4-5 segment.

    PubMed

    Schmidt, Hendrik; Midderhoff, Stefan; Adkins, Kyle; Wilke, Hans-Joachim

    2009-11-01

    Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. For the different implant designs, a three-dimensional finite element model was created and subsequently inserted into a validated model of a L4-5 lumbar spinal segment. The unconstrained design was represented by two implants, the Charité disc and a newly developed disc prosthesis: Slide-Disc. The constrained design was obtained by a modification of the Slide-Disc whereby the inner core was rigidly connected to the lower metallic endplate. The models were exposed to an axial compression preload of 1,000 N. Pure unconstrained moments of 7.5 Nm were subsequently applied to the three anatomical main planes. Except for extension, the models predicted only small and moderate inter-implant differences. The calculated values were close to those of the intact segment. For extension, a large difference of about 45% was calculated between both Slide-Disc designs and the Charité disc. The models predicted higher facet forces for the implants with an unconstrained core compared to an implant with a constrained core. All implants caused a moving center of rotation. Except for axial rotation, the unconstrained and constrained configurations mimicked the intact situation. In axial rotation, only the Slide- Disc with mobile core reproduced the intact behavior. Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location

  20. [Chronic knee joint discomfort].

    PubMed

    Wittke, R

    2005-06-23

    Chronic pain in the knee joint is frequently a sign of arthrosis in adults. This must be clearly differentiated from other knee problems. Patellofemoral stress syndrome (occurs mostly in young people) and arthritis with effusion in the knee joint after long and mostly unusual stress also allow only a reduced function of the knee joint. However, even when the knee joint is still fully functional, chronic problems could already exist: For example, for joggers, iliotibial band friction syndrome (runner's knee) or after high unphysiological stress, patellar tendinopathy (jumper's knee). These must be differentiated from pes anserinus syndrome and a plica mediopatellaris.

  1. [Long-term treatment of arthrosis using Arumalon].

    PubMed

    Schiavetti, L; Tuzi, T; Galeazzi, M

    1977-04-21

    Cartilage and bone marrow extracts have been used to enhance cartilage mucopolysaccharide levels. The value of this form of treatment was appraised in 250 groups of 250 patients with well established arthrosis. Comparison was made between standard management with anti-inflammatory drugs, analgesics, anti-rheumatic compounds, physiotherapy and heat treatment, and management with the addition of cartilage and bone marrow extracts (Arumalon) over a period of 5 yr. Patients who received Arumalon had a lower frequency of painful exacerbations, a lower and more delayed frequency of functional incapacity, and a slower and less striking radiological progression. These results corroborate experimental and clinical data in the literature. They were particularly marked in 50 cases of gonarthrosis.

  2. The Cause and Prevention of Sacroiliac Arthrosis in the Standardbred Horse: A Theoretical Study

    PubMed Central

    Rooney, J. R.

    1981-01-01

    Sacroiliac arthrosis is a major cause of “hiking” lameness (often, so-called “stifle lameness”) in Standardbred horses. The cause of this arthrosis is found in the moment forces generated as horses negotiate unbanked and underbanked turns and in the forces generated on cambered racing surfaces. The prediction is that such lameness could be virtually eliminated if racetrack and training track turns were properly banked and camber held to a minimum. PMID:7337910

  3. The cause and prevention of sacroiliac arthrosis in the Standardbred horse: a theoretical study.

    PubMed

    Rooney, J R

    1981-11-01

    Sacroiliac arthrosis is a major cause of "hiking" lameness (often, so-called "stifle lameness") in Standardbred horses. The cause of this arthrosis is found in the moment forces generated as horses negotiate unbanked and underbanked turns and in the forces generated on cambered racing surfaces. The prediction is that such lameness could be virtually eliminated if racetrack and training track turns were properly banked and camber held to a minimum.

  4. [The scaphoid-trapezium-trapezoid arthrosis. A clinical study 1982-1985].

    PubMed

    Wilhelm, K; Rolle, A; Hild, A

    1989-02-01

    The present study deals with patients in whom the diagnostic procedures applied in rhizoid arthrosis were considered to reveal scaphoid-trapezium-trapezoid (STT) arthrosis. Between 1982 and 1985, 21 of 396 rhizoid arthrosis patients developed symptoms of STT arthosis. Examination of the case histories showed that in 20 STT patients the pathogenesis included trauma. In addition, the majority of these 396 patients (71.5%) had to be retreated because of new traumata and the resultant problems. The time lapse between the first trauma considered sufficiently severe to have caused STT arthrosis and its diagnosis was up to 7.1 years. Our improved facilities for diagnosis of pathologic conditions of the wrist enabled us to distinguish four types of STT arthrosis. Persistent complex instability of the capsular ligament appears to be the major cause of post-traumatic STT arthrosis. Extended diagnostic techniques based on standardized radiograms allow the development of a design for treatment aimed at preventing posttraumatic STT of the hand as far as possible.

  5. An observational feasibility study to assess the safety and effectiveness of intranasal fentanyl for radiofrequency ablations of the lumbar facet joints

    PubMed Central

    Bartoszek, Michael W; McCoart, Amy; Hong, Kyung-soo Jason; Haley, Chelsey; Highland, Krista Beth; Plunkett, Anthony R

    2017-01-01

    Purpose The purpose of the present observational, feasibility study is to assess the preliminary safety and effectiveness of intranasal fentanyl for lumbar facet radiofrequency ablation procedures. Patients and methods This cohort observational study included 23 adult patients. Systolic and diastolic blood pressures, heart rate, oxygen saturation percent, Pasero Opioid-Induced Sedation Scale score, and the Defense and Veterans Pain Rating Scale pain score were assessed prior to the procedure and intranasal fentanyl (100 μg) administration and every 15 minutes after administration, up to 60 minutes post administration. Follow-up of patient satisfaction with pain control and treatment was assessed 24 hours after discharge. The primary outcome was safety as evidenced by adverse events. Secondary outcomes included the above-mentioned vital signs and pain ratings. Results No adverse events occurred in the present study and all participants maintained an acceptable level of awareness throughout the assessment period. One-way repeated measures analyses of covariance tests with Bonferroni-adjusted means indicated that oxygen saturation, blood pressure, and heart rate changed from baseline, whereas pain scores were lower at post-administration levels compared with baseline. Finally, the majority of participants reported being satisfied with pain control and treatment. Conclusion Preliminary evidence indicates that intranasal fentanyl is safe and effective for lumbar facet radiofrequency ablation procedures. Future rigorous randomized control trials are needed to confirm the present results and to examine the effects of intranasal fentanyl on intraoperative and postoperative opioid use. PMID:28243139

  6. The importance of severity of arthrosis for the reliability of bone mineral density measurement in women.

    PubMed

    Hayirlioglu, Alper; Gokaslan, Husnu; Cimsit, Canan; Baysal, Begumhan

    2009-02-01

    The objective of this study is to investigate the effect of the severity of degenerative changes on measurements of A-P lumbar spines BMD values and to determine the reliability of DEXA measurements associated with severity of the disease on A-P lumbar spines BMD values using DEXA. The measurements using DEXA were taken from L2-L4 spines and femoral neck of total 271 female cases. One hundred and ten of them had mild arthrosis (Group 0), and 69 had severe arthrosis (Group 1). Ninety-two cases without arthrosis were chosen as control group (Group 2). The cases with arthrosic changes were grouped according to their degree of severity of arthrosis. The groups were compared two by two and Tukey multiple comparison test was used for the analysis of the difference of the means of the groups. The mean age of cases was 61.79, 61.84, and 60.47, respectively. The average height was 157.26, 155.93, and 15.92 cm while the average weight was 69.21, 70.78, and 71.45 kg, respectively. The mean body mass index (BMI) was 0.00283, 0.00291, and 0.00293, respectively. L2-L4 A-P spinal BMD values were 0.9870, 0.9848, and 1.0836 g/cm(2) while the femoral neck BMD values were 0.7964, 0.8056, and 0.8223 g/cm(2), respectively. There was no statistical significance between study and control groups in terms of age, weight, height, BMI, and BMD values obtained from femoral neck. However, lumbar region BMD values of the cases with severe arthrosis were statistically significantly high when compared with other two groups. The femoral neck measurement is the prominent alternative method in severe arthrosis while taking measurements from lumbar region is still the most appropriate method in cases with mild arthrosis without having giant osteophytes.

  7. Multiwalled nanotube faceting unravelled

    NASA Astrophysics Data System (ADS)

    Leven, Itai; Guerra, Roberto; Vanossi, Andrea; Tosatti, Erio; Hod, Oded

    2016-12-01

    Nanotubes show great promise for miniaturizing advanced technologies. Their exceptional physical properties are intimately related to their morphological and crystal structure. Circumferential faceting of multiwalled nanotubes reinforces their mechanical strength and alters their tribological and electronic properties. Here, the nature of this important phenomenon is fully rationalized in terms of interlayer registry patterns. Regardless of the nanotube identity (that is, diameter, chirality, chemical composition), faceting requires the matching of the chiral angles of adjacent layers. Above a critical diameter that corresponds well with experimental results, achiral multiwalled nanotubes display evenly spaced extended axial facets whose number equals the interlayer difference in circumferential unit cells. Elongated helical facets, commonly observed in experiment, appear in nanotubes that exhibit small interlayer chiral angle mismatch. When the wall chiralities are uncorrelated, faceting is suppressed and outer layer corrugation, which is induced by the Moiré superlattice, is obtained in agreement with experiments. Finally, we offer an explanation for the higher incidence of faceting in multiwalled boron nitride nanotubes with respect to their carbon-based counterparts.

  8. Use of circular external fixation for combined subtalar joint fusion and ankle distraction.

    PubMed

    Zgonis, Thomas; Stapleton, John J; Roukis, Thomas S

    2008-10-01

    The authors discuss a novel technique not previously published that incorporates a subtalar joint arthrodesis with an ankle joint arthrodiastasis as an alternative to a tibiotalocalcaneal arthrodesis. Young and active patients who experience refractory pain and stiffness to the rearfoot and ankle secondary to combined severe subtalar and ankle arthrosis are suitable candidates for this surgical procedure. This new approach is based on sound principles in the treatment of severe arthrosis affecting the ankle and subtalar joint. The authors are currently prospectively reviewing their surgical experience with this procedure and believe that it provides an alternative option for the patient, with potentially promising long-term results.

  9. FDG uptake in cervical facet subchondral cysts demonstrated by PET/CT.

    PubMed

    Lin, Eugene; Sicuro, Paul

    2008-04-01

    F-18 fluorodeoxyglucose (FDG) uptake in facet joints related to degenerative disease has been previously described. However, FDG uptake in subchondral cysts is the subject of this report. We describe 2 cases of intense focal FDG uptake in subchondral cysts in the cervical facets seen on positron emission tomography/computed tomography (PET/CT) exams. The location of these cysts immediately adjacent to the facet joints and the presence of associated facet joint degenerative changes are helpful in distinguishing this uptake from metastatic disease or other bone lesions.

  10. SLAC All Access: FACET

    ScienceCinema

    Hogan, Mark

    2016-07-12

    SLAC's Facility for Advanced Accelerator Experimental Tests, or FACET, is a test-bed where researchers are developing the technologies required for particle accelerators of the future. Scientists from all over the world come to explore ways of improving the power and efficiency of the particle accelerators used in basic research, medicine, industry and other areas important to society. In this video, Mark Hogan, head of SLAC's Advanced Accelerator Research Department, offers a glimpse into FACET, which uses part of SLAC's historic two-mile-long linear accelerator.

  11. Facets of Subjectification

    ERIC Educational Resources Information Center

    Visconti, Jacqueline

    2013-01-01

    Subjectification, as the diachronic facet of subjectivity, has raised in the last two decades a number of interesting questions in grammaticalization and semantic change theory. In this paper I shall reflect on the nature and construal of subjectification, focusing on the question, formulated by Traugott (2010a, p. 58), "whether it is possible to…

  12. Beam Diagnostics for FACET

    SciTech Connect

    Li, S.Z.; Hogan, M.J.; /SLAC

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to about 20 {micro}m long and focussed to about 10 {micro}m wide. Characterization of the beam-plasma interaction requires complete knowledge of the incoming beam parameters on a pulse-to-pulse basis. FACET diagnostics include Beam Position Monitors, Toroidal current monitors, X-ray and Cerenkov based energy spectrometers, optical transition radiation (OTR) profile monitors and coherent transition radiation (CTR) bunch length measurement systems. The compliment of beam diagnostics and their expected performance are reviewed. Beam diagnostic measurements not only provide valuable insights to the running and tuning of the accelerator but also are crucial for the PWFA experiments in particular. Beam diagnostic devices are being set up at FACET and will be ready for beam commissioning in summer 2011.

  13. Craniovertebral Junction Instability: A Review of Facts about Facets

    PubMed Central

    2015-01-01

    Craniovertebral junction surgery involves an appropriate philosophical, biomechanical and anatomical understanding apart from high degree of technical skill and ability of controlling venous and arterial bleeding. The author presents his 30-year experience with treating complex craniovertebral junction instability related surgical issues. The facets of atlas and axis form the primary site of movements at the craniovertebral junction. All craniovertebral junction instability is essentially localized to the atlantoaxial facet joint. Direct manipulation and fixation of the facets forms the basis of treatment for instability. PMID:26240728

  14. Self-healing photo-neuropathy and cervical spinal arthrosis in four sisters with brachioradial pruritus.

    PubMed

    Wallengren, Joanna

    2009-11-17

    The cause of brachioradial pruritus (a localized itching on the arms or shoulders) is controversial. The role of sun and cervical spine disease has been discussed. This is a report on four sisters suffering from brachioradial pruritus recurring every summer. The sisters spent much time outdoors and exposed themselves extensively to the sun. They also had occupations requiring heavy lifting. Cervical radiographs indicated arthrosis. The density of sensory nerve fibers in the skin biopsies from the itchy skin of the arms, visualized by antibodies against a pan-neuronal marker, protein gene product 9.5, was reduced compared with biopsies from the same skin region during the symptom-free period in the winter. This data exemplifies that brachioradial pruritus is a self healing photoneuropathy occurring in middle aged adults predisposed by cervical arthrosis.

  15. Self-healing photo-neuropathy and cervical spinal arthrosis in four sisters with brachioradial pruritus

    PubMed Central

    2009-01-01

    The cause of brachioradial pruritus (a localized itching on the arms or shoulders) is controversial. The role of sun and cervical spine disease has been discussed. This is a report on four sisters suffering from brachioradial pruritus recurring every summer. The sisters spent much time outdoors and exposed themselves extensively to the sun. They also had occupations requiring heavy lifting. Cervical radiographs indicated arthrosis. The density of sensory nerve fibers in the skin biopsies from the itchy skin of the arms, visualized by antibodies against a pan-neuronal marker, protein gene product 9.5, was reduced compared with biopsies from the same skin region during the symptom-free period in the winter. This data exemplifies that brachioradial pruritus is a self healing photoneuropathy occurring in middle aged adults predisposed by cervical arthrosis. PMID:19919691

  16. The results of ankle arthrodesis with screws for end stage ankle arthrosis.

    PubMed

    Torudom, Yingyong

    2010-02-01

    Aim of this study was to evaluate the results of ankle arthrodesis with screws in patients with ankle arthrosis. The author studied 19 patients (20 feet) who had been treated by ankle arthrodesis with screws from 2003 to 2008. Ten patients were men (11 feet) and nine (9 feet) were women. Their mean age was 56 years (30 to 65), and the average duration of follow-up was four years (2 to 6). Two compression screws were used in all feet. Union was achieved in 19 of the 20 feet (95%). Average scores for pain and clinical condition are increase after operation. One re-operation was performed for nonunion. Author conclude that ankle arthrodesis with screws was effective treatment for ankle arthrosis.

  17. Hip arthrosis and surgical intervention: what and when?

    PubMed Central

    Innocenti, Massimo; Nistri, Lorenzo; Biondi, Marco; Del Prete, Armando; Giorgini, Marco; Macera, Armando; Soderi, Stefano

    2013-01-01

    Summary Osteoarthritis of the hip is a common pathology and involves forms of disability and need for treatments that affect the quality of life of patients and their families, and in general of the whole society. It should be considered as such degenerative joint disease is increasing as the increase in life expectancy and musculoskeletal trauma, the latter responsible for secondary forms of osteoarthritis. The treatment of osteoarthritis of the hip has changed a lot over the years, since the earlier diagnosis and, before, with prevention through proper lifestyle. More in-depth knowledge of the biology of the tissues involved, first of all hyaline cartilage, has lead to non-surgical treatments such as infiltration with hyaluronic acid (viscosupplementation) and autologous growth factors derived from platelets (platelet rich plasma). Surgical therapy with prosthetic replacement is finally a choice to share with the patient based on pain and functional limitation, bearing in mind always the best technology and tribology and the possibility of less invasive surgical access, while recognizing that there are not still eternal prosthesis. Of particular importance then is the age of the patient. There are also other types of surgery (hip arthroscopy, forage) for other pathologies of the hip which can be resolutive, or, in a sense, can delay the arrival to the prosthetic replacement. We will discuss below the decision-making process that leads the surgeon with the patient to the surgery option. PMID:23858310

  18. Preoperative gait characterization of patients with ankle arthrosis.

    PubMed

    Khazzam, Michael; Long, Jason T; Marks, Richard M; Harris, Gerald F

    2006-08-01

    The purpose of this study was to evaluate the kinematic changes that occur about the foot and ankle during gait in patients with degenerative joint disease (DJD). By comparing a normal adult population with what was found in the DJD population we determined how the motion of theses groups differed, thereby characterizing how this pathology affects foot and ankle motion. A 15-camera Vicon Motion Analysis System was used in conjunction with weight bearing radiographs to obtain three-dimensional motion of the foot and ankle during ambulation. The study was comprised of 34 patients and 35 ankles diagnosed with DJD (19 men and 15 women) of the ankle and 25 patients with normal ankles (13 men and 12 women). Dynamic foot and ankle motion was analyzed using the four-segment Milwaukee Foot Model (MFM). The data from this model resulted in three-dimensional (3D) kinematic parameters in the sagittal, coronal, and transverse planes as well as spatial-temporal parameters. Patient health status was evaluated using the SF-36 Health Survey and American Orthopaedics Foot and Ankle Society (AOFAS) hindfoot scores. The DJD group showed significant differences (p<0.001) as compared to normals with prolonged stance time, shortened stride length, reduced cadence and a walking speed which was only 66.96% of normal. Overall, kinematic data in the DJD cohort showed significant differences (p<0.001) in all planes of motion for tibial, hindfoot and forefoot motion as compared to normals. The average preoperative AOFAS hindfoot score was 26. DJD of the ankle results in decreased range of motion during gait. This decreased range of motion may be related to several factors including bony deformity, muscle weakness, and attempts to decrease the pain associated with weight bearing. To date there has not been a study which describes the effect of this disease process on motion of the foot and ankle. These findings may prove to be useful in the pre-operative assessment of these patients.

  19. Facet control of gold nanorods

    SciTech Connect

    Zhang, Qingfeng; Han, Lili; Jing, Hao; Blom, Douglas A.; Lin, Ye; Xin, Huolin L.; Wang, Hui

    2016-01-21

    While great success has been achieved in fine-tuning the aspect ratios and thereby the plasmon resonances of cylindrical Au nanorods, facet control with atomic level precision on the highly curved nanorod surfaces has long been a significantly more challenging task. The intrinsic structural complexity and lack of precise facet control of the nanorod surfaces remain the major obstacles for the atomic-level elucidation of the structure–property relationships that underpin the intriguing catalytic performance of Au nanorods. Here we demonstrate that the facets of single-crystalline Au nanorods can be precisely tailored using cuprous ions and cetyltrimethylammonium bromide as a unique pair of surface capping competitors to guide the particle geometry evolution during nanorod overgrowth. By deliberately maneuvering the competition between cuprous ions and cetyltrimethylammonium bromide, we have been able to create, in a highly controllable and selective manner, an entire family of nanorod-derived anisotropic multifaceted geometries whose surfaces are enclosed by specific types of well-defined high-index and low-index facets. This facet-controlled nanorod overgrowth approach also allows us to fine-tune the particle aspect ratios while well-preserving all the characteristic facets and geometric features of the faceted Au nanorods. Furthermore, taking full advantage of the combined structural and plasmonic tunability, we have further studied the facet-dependent heterogeneous catalysis on well-faceted Au nanorods using surface-enhanced Raman spectroscopy as an ultrasensitive spectroscopic tool with unique time-resolving and molecular finger-printing capabilities.

  20. The Many Facets of PISA

    ERIC Educational Resources Information Center

    Berliner, David C.

    2015-01-01

    Trying to understand PISA is analogous to the parable of the blind men and the elephant. There are many facets of the PISA program, and thus many ways to both applaud and critique this ambitious international program of assessment that has gained enormous importance in the crafting of contemporary educational policy. One of the facets discussed in…

  1. Facet control of gold nanorods

    DOE PAGES

    Zhang, Qingfeng; Han, Lili; Jing, Hao; ...

    2016-01-21

    While great success has been achieved in fine-tuning the aspect ratios and thereby the plasmon resonances of cylindrical Au nanorods, facet control with atomic level precision on the highly curved nanorod surfaces has long been a significantly more challenging task. The intrinsic structural complexity and lack of precise facet control of the nanorod surfaces remain the major obstacles for the atomic-level elucidation of the structure–property relationships that underpin the intriguing catalytic performance of Au nanorods. Here we demonstrate that the facets of single-crystalline Au nanorods can be precisely tailored using cuprous ions and cetyltrimethylammonium bromide as a unique pair ofmore » surface capping competitors to guide the particle geometry evolution during nanorod overgrowth. By deliberately maneuvering the competition between cuprous ions and cetyltrimethylammonium bromide, we have been able to create, in a highly controllable and selective manner, an entire family of nanorod-derived anisotropic multifaceted geometries whose surfaces are enclosed by specific types of well-defined high-index and low-index facets. This facet-controlled nanorod overgrowth approach also allows us to fine-tune the particle aspect ratios while well-preserving all the characteristic facets and geometric features of the faceted Au nanorods. Furthermore, taking full advantage of the combined structural and plasmonic tunability, we have further studied the facet-dependent heterogeneous catalysis on well-faceted Au nanorods using surface-enhanced Raman spectroscopy as an ultrasensitive spectroscopic tool with unique time-resolving and molecular finger-printing capabilities.« less

  2. Continuum Modeling of Facet Evolution

    NASA Astrophysics Data System (ADS)

    Kandel, Daniel

    2000-03-01

    Standard continuum models of surface dynamics are very useful for studying thin film evolution on the micron length scale. Unfortunately, they are inadequate below the roughening transition, since they do not appropriately describe faceting. Our goal is to propose a continuum approach which deals with facet dynamics in a physically accurate way. We studied in detail the dynamics of faceting in simple submicron surface structures [1], and proposed two approaches for the development of continuum models. First, we rigorously derived continuum kinetic models of the systems of interest, starting from step flow models. These models break down at singular points, which we identify as facet edges. The models are not applicable on facets, and the surface profile is obtained as a solution of the continuum model with boundary conditions at the singular points. Secondly, we showed [2] that if the existence of both steps and anti-steps in regions of small surface slope is taken into account, it is possible to construct continuum models that are valid even on facets. The solutions of both types of continuum models are in excellent agreement with step flow models. The resulting surface profiles are of relevance to experiments on decay of one dimensional periodic gratings. Our work points to a possible general continuum model for an accurate description of kinetics of crystalline surfaces below the roughening transition. [1] N. Israeli and D. Kandel, Phys. Rev. Lett. 80, 3300 (1998); N. Israeli and D. Kandel, Phys. Rev. B 60, 5946 (1999). [2] N. Israeli and D. Kandel, preprint.

  3. End-stage hindfoot arthrosis: outcomes of tibiocalcaneal fusion using internal and Ilizarov fixation.

    PubMed

    Crawford, Brooke; Watson, J Tracy; Jackman, James; Fissel, Brian; Karges, David E

    2014-01-01

    End-stage post-traumatic pantalar arthrosis from ankle, pilon, and talus fractures has often been complicated by infection, bone loss, and a soft tissue deficit. Patients can present with neuropathy, diabetes, tobacco use, and previously failed arthrodesis. Fusion in this population has been challenging, with nonunion rates up to 30%, often leading to amputation. We reviewed the results of a standardized protocol that combined simultaneous internal fixation with the Ilizarov technique to achieve fusion in high-risk patients. With institutional review board approval, a retrospective review of the patients treated with simultaneous internal fixation and an Ilizarov frame was undertaken. The records and radiographs allowed identification of the comorbidities and the presence or absence of successful fusion. Complications were acknowledged and treated. Fifteen patients had undergone the procedure. The mean follow-up period was 27.9 (range 9 to 67) months. Thirteen patients (86.67%) had had previous fusion failure. Twelve patients (80%) had developed post-traumatic arthrosis, 5 (33.33%) of whom had open injuries. All patients had 1 comorbidity, and 10 (66.67%) had multiple, including rheumatoid arthritis, diabetes (types 1 and 2), and smoking. Four patients (26.67%) presented with deep infection and bone loss. Union was achieved in 11 (73.33%), with 12 (80%) patients experiencing profound pain relief. Seven patients (46.67%) required symptomatic hardware removal. Three patients (20%) eventually underwent below-the-knee amputation for recalcitrant nonunion. Statistically significant correlations were found between smoking and wound infection and revision and between nonunion and amputation. Our results have indicated that combined internal fixation with Ilizarov application can provide a strong surgical option for the management of end-stage, pantalar arthritis. More studies are needed to compare the cohort outcomes and gait analysis in these patients with those who have

  4. L5 – S1 Segmental Kinematics After Facet Arthroplasty

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Rosler, David M.; Sjovold, Simon G.; Rogers, Susan L.; Carandang, Gerard; Ochoa, Jorge A.; Yuan, Hansen; Webb, Scott

    2009-01-01

    Background Facet arthroplasty is a motion restoring procedure. It is normally suggested as an alternative to rigid fixation after destabilizing decompression procedures in the posterior lumbar spine. While previous studies have reported successful results in reproducing normal spine kinematics after facet replacement at L4-5 and L3-4, there are no data on the viability of facet replacement at the lumbosacral joint. The anatomy of posterior elements and the resulting kinematics at L5-S1 are distinctly different from those at superior levels, making the task of facet replacement at the lumbosacral level challenging. This study evaluated the kinematics of facet replacement at L5-S1. Methods Six human cadaveric lumbar spines (L1-S1, 46.7 ± 13.0 years) were tested in the following sequence: (1) intact (L1-S1), (2) complete laminectomy and bilateral facetectomy at L5-S1, and (3) implantation of TFAS-LS (Lumbosacral Total Facet Arthroplasty System, Archus Orthopedics, Redmond, Washington) at L5-S1 using pedicle screws. Specimens were tested in flexion (8Nm), extension (6Nm), lateral bending (LB, ± 6Nm), and axial rotation (AR, ± 5Nm). The level of significance was α = .017 after Bonferroni correction for three comparisons: (1) intact vs. destabilized, (2) destabilized vs. reconstructed, and (3) intact vs. reconstructed. Results Laminectomy-facetectomy at L5-S1 increased the L5-S1 angular range of motion (ROM) in all directions. Flexion-extension (F-E) ROM increased from 15.3 ± 2.9 to 18.7 ± 3.5 degrees (P < .017), LB from 8.2 ± 1.8 to 9.3 ± 1.6 degrees (P < .017), and AR from 3.7 ± 2.0 to 5.9 ± 1.8 degrees (P < .017). The facet arthroplasty system decreased ROM compared to the laminectomy-facetectomy condition in all tested directions (P < .017). The facet arthroplasty system restored the L5-S1 ROM to its intact levels in LB and AR (P > .017). F-E ROM after the facet arthroplasty system implantation was smaller than the intact value (10.1 ± 2.2 vs. 15.3 ± 2

  5. Minimally invasive facet restoration implant for chronic lumbar zygapophysial pain: 1-year outcomes

    PubMed Central

    2014-01-01

    Background The zygapophysial (facet) joint is the primary pain generator in one third of chronic low back pain cases. Current treatment options include temporarily palliative nonsurgical approaches, facet injections, radiofrequency denervation, and, rarely, lumbar arthrodesis. The purpose of this study was to assess the safety and effectiveness of a minimally invasive implant intended to restore facet joint function in patients with chronic lumbar facetogenic pain. Methods This prospective, multi-center feasibility study enrolled patients with confirmed lumbar facetogenic joint pain at 1 or 2 levels who underwent at least 6 months of unsuccessful nonoperative care. Patients received a minimally invasive implant (Glyder® Facet Restoration Device, Zyga Technology, Inc., Minnetonka, MN) intended to restore facet joint function while preserving the native anatomy. Main outcomes included back pain severity using a visual analogue scale, back-specific disability using the Oswestry Disability Index (ODI), and adverse events adjudicated by an independent Clinical Events Committee. Results Of 40 enrolled patients, 37 patients received the facet restoration implant and 34 patients had complete 1-year follow-up data available. Over the 1-year follow-up period, back pain severity decreased 41% and ODI decreased 34%, on average. Freedom from a device- or procedure-related serious adverse event through 1 year was 84%. Implant migration was observed in 3 patients and implant expulsion from the facet joint occurred in 3 patients. In total, 2 (5.4%) patients underwent implant removal through 1 year post-treatment. Conclusions A minimally invasive facet restoration implant is a promising treatment option in select patients with chronic lumbar zygapophysial pain who have exhausted nonsurgical treatments, with therapeutic benefit persisting at 1 year follow-up. PMID:26628910

  6. Plasma Wakefield Experiments at FACET

    SciTech Connect

    Hogan, M.J.; England, R.J.; Frederico, J.; Hast, C.; Li, S.Z.; Litos, M.; Walz, D.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; Muggli, P.; Pinkerton, S.; Shi, Y.; /Southern California U.

    2011-08-19

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to {approx}20{micro}m long and focused to {approx}10{micro}m wide. The intense fields of the FACET bunches will be used to field ionize neutral lithium or cesium vapor produced in a heat pipe oven. Previous experiments at the SLAC FFTB facility demonstrated 50GeV/m gradients in an 85cm field ionized lithium plasma where the interaction distance was limited by head erosion. Simulations indicate the lower ionization potential of cesium will decrease the rate of head erosion and increase single stage performance. The initial experimental program will compare the performance of lithium and cesium plasma sources with single and double bunches. Later experiments will investigate improved performance with a pre-ionized cesium plasma. The status of the experiments and expected performance are reviewed. The FACET Facility is being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The facility will begin commissioning in summer 2011 and conduct an experimental program over the coming five years to study electron and positron beam driven plasma acceleration with strong wake loading in the non-linear regime. The FACET experiments aim to demonstrate high-gradient acceleration of electron and positron beams with high efficiency and negligible emittance growth.

  7. Is arthrodesis still a good indication for non-inflammatory arthrosis of the wrist?☆

    PubMed Central

    de Araujo Silva, Bruno; de Souza, Marcos Vinícius Marciano Campos; Carrasco, Felipe Moura; Melo, Gustavo Adolfo Costa; Barreiros, Luiz Eduardo Luz; Labronici, Pedro José

    2015-01-01

    Objective The aim of this study was to objectively and subjectively evaluate wrist function after total arthrodesis, among patients with sequelae of non-inflammatory arthritis who were treated with rigid internal fixation using a DCP plate. Methods Thirty-two patients with sequelae of non-inflammatory degenerative arthritis were treated using total arthrodesis of the wrist. Of these, two patients were treated with Kirschner wires and four discontinued the treatment, thus leaving 26 patients. The indication for arthrodesis of the wrist was the presence of intracarpal pathological conditions: eight wrists presented sequelae from fractures of the distal radius; 13 had sequelae from fractures of the scaphoid; and five had sequelae from Kienbock's disease. The cases were evaluated using the visual analogue scale (VAS), the muscle strength test, the Jebsen–Taylor functional test and the Buck-Gramcko test. Results It was observed that there were no significant differences at the level of 5%, in the variables of grip strength, VAS, Jebsen–Taylor functional test or Buck-Gramcko/Lohmann test, between the pathological conditions. Conclusion Total arthrodesis of the wrist using a plate in the dorsal region was shown to be a safe and efficient technique for patients with different types of pathological arthrosis of the wrist, since it did not cause any important functional incapacity and brought great pain relief. PMID:26535206

  8. Topical analgesics for knee arthrosis: a parallel study of ketoprofen gel and diclofenac emulgel.

    PubMed

    Waikakul, S; Penkitti, P; Soparat, K; Boonsanong, W

    1997-09-01

    The clinical efficacy of the two topical analgesics, ketoprofen hydroalcoholic gel (Fastum gel) and diclofenac emulgel, for osteoarthritis of the knee was studied. There were 85 patients who underwent the trial. They were randomly allocated into 2 groups, the diclofenac group, 42 patients (4 males and 38 females) receiving the diclofenac emulgel at the painfull site four times a day for 4 weeks, and the ketoprofen group, 43 patients (9 males and 34 females) receiving the ketoprofen hydroalcoholic gel four times a day for 4 weeks at the painful knee. Golberg's knee scoring was used to evaluate the patients before the trial, at the end of the first, second and fourth weeks. The ketoprofen group had poorer a score before the trial, however, both groups had improvement in their knee functions, knee score and pain. There was no significant difference between the groups at the end of the study. There was no serious side effect in both groups. Ketoprofen hydroalcoholic gel gave persuasive results in the treatment of knee arthrosis stage I and II.

  9. Design of a lattice-based faceted classification system

    NASA Technical Reports Server (NTRS)

    Eichmann, David A.; Atkins, John

    1992-01-01

    We describe a software reuse architecture supporting component retrieval by facet classes. The facets are organized into a lattice of facet sets and facet n-tuples. The query mechanism supports precise retrieval and flexible browsing.

  10. Morphological Stability of Faceted Interfaces

    NASA Technical Reports Server (NTRS)

    Abbaschian, Reza; Golyshev, V. D.; Gonik, M.; Tsvetivsky, V.; deVahlDavis, G.; Leonardi, E.

    2001-01-01

    The major focus of this investigation is to study the fundamentals of layer spreading mechanisms during growth of doped Ge (a facet forming material), and to determine the conditions for morphological instability of vicinal solid-liquid interfaces. The investigation will also lead to the determination of the effect of dopants on the layer growth kinetics, step free energy, and dopant capture by the advancing ledges. The theoretical treatment of growth of faceted interfaces indicates that the kinetics of a step on a growing vicinal interface considerably depends on its angle of inclination, the melt concentration, and characteristics of flow currents in the melt. The morphological stability of the interface also depends on these parameters, as well as on the density and spreading velocity of the steps. However, the treatment of the instability of the interface by the layer growth mechanism is rather difficult because it requires exact knowledge of the thermal and solutal fields, hydrodynamics of the melt, and supercooling at the interface. The results of recent space experiments of the principal investigator involving directional solidification of faceted Bi-Sn alloys have shown that the morphological stability of various crystallographic orientations is significantly affected by the anistropy in interfacial properties of the faceted alloy in general, and the interface kinetics in particular. These findings have also raised many important and fundamental questions, particularly with respect to the behavior of interfacial steps, which need to be addressed via additional groundbased and microgravity experiments. For the present investigation we will use a novel crystal growth technique which provides axial heat flux close to the solid-liquid boundary. The Axial Heat Processing (AHP) technique allows for precise control and determination of the heat and mass transfer close to the crystallization front, and the establishment of a planar interface over the entire cross

  11. Lumbar facet injection for the treatment of chronic piriformis myofascial pain syndrome: 52 case studies

    PubMed Central

    Huang, Jen-Ting; Chen, Han-Yu; Hong, Chang-Zern; Lin, Ming-Ta; Chou, Li-Wei; Chen, Hsin-Shui; Tsai, Chien-Tsung; Chang, Wen-Dien

    2014-01-01

    Background and aims The aim of this study was to demonstrate the effectiveness of lumbar facet joint injection for piriformis myofascial pain syndrome. Methods Fifty-two patients with chronic myofascial pain in the piriformis muscle each received a lumbar facet injection into the ipsilateral L5–S1 facet joint region, using the multiple insertion technique. Subjective pain intensity, trunk extension range, and lumbar facet signs were measured before, immediately after, and 2 weeks after injection. Thirty-six patients received follow-up for 6 months. Results Immediately after the injection, 27 patients (51.9%) had complete pain subsidence, 19 patients (36.5%) had pain reduction to a tolerable level, and only 6 patients (11.5%) had no pain relief to a tolerable level. Mean pain intensity was reduced from 7.4±0.9 to 1.6±2.1 after injection (P<0.01). This effectiveness lasted for 2 weeks in 49 patients (94.2%), and lasted for approximately 6 months in 35 (97.2%) of 36 patients. The mean range of motion increased from 13.4±6.8 degrees to 22.1±6.0 degrees immediately after injection, and further increased 2 weeks and 6 months later. Immediately after injection, 45 patients (86.5%) had no facet sign. In addition, 90.4% and 94.4% of patients had no facet sign after 2 weeks and after 6 months, respectively. Conclusions It is important to identify the possible cause of piriformis myofascial pain syndrome. If this pain is related to lumbar facet lesions, lumbar facet joint injection can immediately suppress piriformis myofascial pain symptoms. This effectiveness may last for at least 6 months in most patients. This study further supports the importance of eliminating the underlying etiological lesion for complete and effective relief of myofascial pain syndrome. PMID:25170256

  12. Pseudotumor of temporomandibular joint: destructive calcium pyrophosphate dihydrate arthropathy.

    PubMed

    Pritzker, K P; Phillips, H; Luk, S C; Koven, I H; Kiss, A; Houpt, J B

    1976-03-01

    The clinical and pathological features of a tumor of the temporamandibular joint occurring in a 55 year old man, and subsequently identified as a calcium pyrophosphate dihydrate (CPPD) arthropathy, are reported. Crystalline deposits were identified by compensated light microscopy and confirmed with X-ray diffraction, transmission, and scanning electron microscopy. The relationship of this unique case to other clinical presentations of CPPD deposition disease and the implications of the histological features to the pathogenesis of pseudogout are discussed. This case demonstrates that CPPD arthropathy should be included in the differential diagnosis of an arthrosis or of a tumor involving the temporomandibular joint.

  13. Can extra-articular strains be used to measure facet contact forces in the lumbar spine? An in-vitro biomechanical study.

    PubMed

    Zhu, Q A; Park, Y B; Sjovold, S G; Niosi, C A; Wilson, D C; Cripton, P A; Oxland, T R

    2008-02-01

    Experimental measurement of the load-bearing patterns of the facet joints in the lumbar spine remains a challenge, thereby limiting the assessment of facet joint function under various surgical conditions and the validation of computational models. The extra-articular strain (EAS) technique, a non-invasive measurement of the contact load, has been used for unilateral facet joints but does not incorporate strain coupling, i.e. ipsilateral EASs due to forces on the contralateral facet joint. The objectives of the present study were to establish a bilateral model for facet contact force measurement using the EAS technique and to determine its effectiveness in measuring these facet joint contact forces during three-dimensional flexibility tests in the lumbar spine. Specific goals were to assess the accuracy and repeatability of the technique and to assess the effect of soft-tissue artefacts. In the accuracy and repeatability tests, ten uniaxial strain gauges were bonded to the external surface of the inferior facets of L3 of ten fresh lumbar spine specimens. Two pressure-sensitive sensors (Tekscan) were inserted into the joints after the capsules were cut. Facet contact forces were measured with the EAS and Tekscan techniques for each specimen in flexion, extension, axial rotation, and lateral bending under a +/- 7.5 N m pure moment. Four of the ten specimens were tested five times in axial rotation and extension for repeatability. These same specimens were disarticulated and known forces were applied across the facet joint using a manual probe (direct accuracy) and a materials-testing system (disarticulated accuracy). In soft-tissue artefact tests, a separate set of six lumbar spine specimens was used to document the virtual facet joint contact forces during a flexibility test following removal of the superior facet processes. Linear strain coupling was observed in all specimens. The average peak facet joint contact forces during flexibility testing was greatest in

  14. Gabapentin alleviates facet-mediated pain in the rat through reduced neuronal hyperexcitability and astrocytic activation in the spinal cord

    PubMed Central

    Dong, Ling; Crosby, Nathan D.; Winkelstein, Beth A.

    2013-01-01

    Although joint pain is common, its mechanism(s) remain undefined, with little known about the spinal neuronal responses that contribute to this type of pain. Afferent activity and sustained spinal neuronal hyperexcitability correlate to facet joint loading and the extent of behavioral sensitivity induced after painful facet injury, suggesting spinal neuronal plasticity is induced in association with facet-mediated pain. This study used a rat model of painful C6/C7 facet joint stretch, together with intrathecal administration of gabapentin, to investigate the effects of one aspect of spinal neuronal function on joint pain. Gabapentin or saline vehicle was given via lumbar puncture prior to and at 1 day after painful joint distraction. Mechanical hyperalgesia was measured in the forepaw for 7 days. Extracellular recordings of neuronal activity and astrocytic and microglial activation in the cervical spinal cord were evaluated at day 7. Gabapentin significantly (p=0.0001) attenuated mechanical hyperalgesia and the frequency of evoked neuronal firing also significantly decreased (p<0.047) with gabapentin treatment. Gabapentin also decreased (p<0.04) spinal GFAP expression. Although spinal Iba1 expression was doubled over sham, gabapentin did not reduce it. Facet joint-mediated pain appears to be sustained through spinal neuronal modifications that are also associated with astrocytic activation. PMID:24094695

  15. New facets of antifungal therapy.

    PubMed

    Chang, Ya-Lin; Yu, Shang-Jie; Heitman, Joseph; Wellington, Melanie; Chen, Ying-Lien

    2017-02-17

    Invasive fungal infections remain a major cause of morbidity and mortality in immunocompromised patients, and such infections are a substantial burden to healthcare systems around the world. However, the clinically available armamentarium for invasive fungal diseases is limited to 3 main classes (i.e., polyenes, triazoles, and echinocandins), and each has defined limitations related to spectrum of activity, development of resistance, and toxicity. Further, current antifungal therapies are hampered by limited clinical efficacy, high rates of toxicity, and significant variability in pharmacokinetic properties. New antifungal agents, new formulations, and novel combination regimens may improve the care of patients in the future by providing improved strategies to combat challenges associated with currently available antifungal agents. Likewise, therapeutic drug monitoring may be helpful, but its present use remains controversial due to the lack of available data. This article discusses new facets of antifungal therapy with a focus on new antifungal formulations and the synergistic effects between drugs used in combination therapy.

  16. Traumatic unilateral lumbosacral jumped facet without fracture in a child - presentation of a safe treatment strategy for a rare injury.

    PubMed

    Szentirmai, Oszkar; Seinfeld, Joshua; Beauchamp, Kathryn; Patel, Vikas

    2008-11-10

    The vast majority of pediatric lumbosacral spondylolisthesis have developmental etiology. Of the very rare type of pediatric lumbosacral facet dislocations, there are only three reported cases of a pediatric unilateral jumped facet injury. All of these cases are associated with fracture dislocation of L5-S1. Hyperflexion with rotation is thought to provoke this uncommon type of spine injury.The authors report the first pediatric patient reported in literature to date with a traumatic unilateral jumped facet at the lumbosacral joint without fracture. The presentation, surgical treatment, hospital course, outcome and management options with the review of the literature is summarized.

  17. Accuracy and repeatability of a new method for measuring facet loads in the lumbar spine.

    PubMed

    Wilson, Derek C; Niosi, Christina A; Zhu, Qingan A; Oxland, Thomas R; Wilson, David R

    2006-01-01

    We assessed the repeatability and accuracy of a relatively new, resistance-based sensor (Tekscan 6900) for measuring lumbar spine facet loads, pressures, and contact areas in cadaver specimens. Repeatability of measurements in the natural facet joint was determined for five trials of four specimens loaded in pure moment (+/- 7.5 N m) flexibility tests in axial rotation and flexion-extension. Accuracy of load measurements in four joints was assessed by applying known compressive loads of 25, 50, and 100 N to the natural facet joint in a materials testing machine and comparing the known applied load to the measured load. Measurements of load were obtained using two different calibration approaches: linear and two-point calibrations. Repeatability for force, pressure, and area (average of standard deviation as a percentage of the mean for all trials over all specimens) was 4-6% for axial rotation and 7-10% for extension. Peak resultant force in axial rotation was 30% smaller when calculated using the linear calibration method. The Tekscan sensor overestimated the applied force by 18 +/- 9% (mean+/-standard deviation), 35 +/- 7% and 50 +/- 9% for compressive loads of 100, 50, and 25 N, respectively. The two-point method overestimated the loads by 35 +/- 16%, 45 +/- 7%, and 56 +/- 10% for the same three loads. Our results show that the Tekscan sensor is repeatable. However, the sensor measurement range is not optimal for the small loads transmitted by the facets and measurement accuracy is highly dependent on calibration protocol.

  18. FACET: SLAC___s New User Facility

    SciTech Connect

    Clarke, C.I.; Decker, F.-J.; England, R.J.; Erickson, R.A.; Hast, C.; Hogan, M.J.; Li, S.Z.; Litos, M.D.; Nosochkov, Y.; Seeman, J.T.; Sheppard, J.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-05-16

    FACET (Facility for Advanced Accelerator Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. The first User Run started in spring 2012 with 20 GeV, 3 nC electron beams. The facility is designed to provide short (20 {micro}m) bunches and small (20 {micro}m wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. The creation of drive and witness bunches and shaped bunch profiles is possible with 'Notch' Collimation. FACET is also a source of THz radiation for material studies. Positrons will be available at FACET in future user runs. We present the User Facility and the available tools and opportunities for future experiments.

  19. Surface Activation of Faceted Photocatalyst: When Metal Cocatalyst Determines the Nature of the Facets.

    PubMed

    Wang, Bin; Liu, Maochang; Zhou, Zhaohui; Guo, Liejin

    2015-11-01

    Pt nanoparticles with tunable size are prepared on the entire surface of facet-engineered Cu2WS4 decahedral photocatalyst via a kinetic-controlled chemical reduction process. The {101} facets of the photocatalyst which featured photo-oxidation, are successfully activated for photoreduction by Pt. The resulting photocatalyst shows an activity nine times higher compared to that of the only {001}-facets activated catalyst obtained by a conventional in situ photodeposition route.

  20. FACET: Future ATM Concepts Evaluation Tool

    NASA Technical Reports Server (NTRS)

    Bilmoria, Karl D.; Banavar, Sridhar; Chatterji, Gano B.; Sheth, Kapil S.; Grabbe, Shon

    2000-01-01

    FACET (Future ATM Concepts Evaluation Tool) is an Air Traffic Management research tool being developed at the NASA Ames Research Center. This paper describes the design, architecture and functionalities of FACET. The purpose of FACET is to provide E simulation environment for exploration, development and evaluation of advanced ATM concepts. Examples of these concepts include new ATM paradigms such as Distributed Air-Ground Traffic Management, airspace redesign and new Decision Support Tools (DSTs) for controllers working within the operational procedures of the existing air traffic control system. FACET is currently capable of modeling system-wide en route airspace operations over the contiguous United States. Airspace models (e.g., Center/sector boundaries, airways, locations of navigation aids and airports) are available from databases. A core capability of FACET is the modeling of aircraft trajectories. Using round-earth kinematic equations, aircraft can be flown along flight plan routes or great circle routes as they climb, cruise and descend according to their individual aircraft-type performance models. Performance parameters (e.g., climb/descent rates and speeds, cruise speeds) are obtained from data table lookups. Heading, airspeed and altitude-rate dynamics are also modeled. Additional functionalities will be added as necessary for specific applications. FACET software is written in Java and C programming languages. It is platform-independent, and can be run on a variety of computers. FACET has been designed with a modular software architecture to enable rapid integration of research prototype implementations of new ATM concepts. There are several advanced ATM concepts that are currently being implemented in FACET airborne separation assurance, dynamic density predictions, airspace redesign (re-sectorization), benefits of a controller DST for direct-routing, and the integration of commercial space transportation system operations into the U.S. National

  1. MultiFacet: A Faceted Interface for Browsing Large Multimedia Collections

    SciTech Connect

    Henry, Michael J.; Hampton, Shawn D.; Endert, Alexander; Roberts, Ian E.; Payne, Deborah A.

    2013-10-31

    Faceted browsing is a common technique for exploring collections where the data can be grouped into a number of pre-defined categories, most often generated from textual metadata. Historically, faceted browsing has been applied to a single data type such as text or image data. However, typical collections contain multiple data types, such as information from web pages that contain text, images, and video. Additionally, when browsing a collection of images and video, facets are often created based on the metadata which may be incomplete, inaccurate, or missing altogether instead of the actual visual content contained within those images and video. In this work we address these limitations by presenting MultiFacet, a faceted browsing interface that supports multiple data types. MultiFacet constructs facets for images and video in a collection from the visual content using computer vision techniques. These visual facets can then be browsed in conjunction with text facets within a single interface to reveal relationships and phenomena within multimedia collections. Additionally, we present a use case based on real-world data, demonstrating the utility of this approach towards browsing a large multimedia data collection.

  2. Dynesys dynamic stabilization-related facet arthrodesis.

    PubMed

    Fay, Li-Yu; Chang, Peng-Yuan; Wu, Jau-Ching; Huang, Wen-Cheng; Wang, Chun-Hao; Tsai, Tzu-Yun; Tu, Tsung-Hsi; Chang, Hsuan-Kan; Wu, Ching-Lan; Cheng, Henrich

    2016-01-01

    OBJECTIVE Dynamic stabilization devices are designed to stabilize the spine while preserving some motion. However, there have been reports demonstrating limited motion at the instrumented level of the lumbar spine after Dynesys dynamic stabilization (DDS). The causes of this limited motion and its actual effects on outcomes after DDS remain elusive. In this study, the authors investigate the incidence of unintended facet arthrodesis after DDS and clinical outcomes. METHODS This retrospective study included 80 consecutive patients with 1- or 2-level lumbar spinal stenosis who underwent laminectomy and DDS. All medical records, radiological data, and clinical evaluations were analyzed. Imaging studies included pre- and postoperative radiographs, MR images, and CT scans. Clinical outcomes were measured by a visual analog scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores. Furthermore, all patients had undergone postoperative CT for the detection of unintended arthrodesis of the facets at the indexed level, and range of motion was measured on standing dynamic radiographs. RESULTS A total of 70 patients (87.5%) with a mean age of 64.0 years completed the minimum 24-month postoperative follow-up (mean duration 29.9 months). Unintended facet arthrodesis at the DDS instrumented level was demonstrated by CT in 38 (54.3%) of the 70 patients. The mean age of patients who had facet arthrodesis was 9.8 years greater than that of the patients who did not (68.3 vs 58.5 years, p = 0.009). There were no significant differences in clinical outcomes, including VAS back and leg pain, ODI, and JOA scores between patients with and without the unintended facet arthrodesis. Furthermore, those patients older than 60 years were more likely to have unintended facet arthrodesis (OR 12.42) and immobile spinal segments (OR 2.96) after DDS. Regardless of whether unintended facet arthrodesis was present or not, clinical

  3. Surface Processes of Faceted Growth

    NASA Technical Reports Server (NTRS)

    Chernov, A.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Atomic force microscopy and high precision optical interferometry allow to analyze the processes that are in the core of our present understanding of faceted crystal growth. Some of these processes will be reviewed. Recent experiments suggest that the Gibbs-Thomson Law (GTL) may not be applicable to the weakly fluctuating strongly polygonized steps, with low kink density. Propagation rate of a straight short step segment changes with the segment length much steeper than predicted by GTL. If the step fluctuations are still well developed, the typical transition length may be determined just by the radius of rounded comers of the polygonized step. If fluctuations do not have enough time to develop, the kinetic effects may be essential. Indeed, 'communications' between comers of a short straight step segment may occur and, thus, the GTL may be implemented only via kink exchange. E.g., dissolutions of this short segment at macroscopic equilibrium occurs as follows: The kinks are split from one comer as a result of fluctuations, and annihilate with kinks of the opposite sign generated by another comer. Similarly, an exchange via chain of kinks on a rough step is the mechanism to implement the GT Law. If there is a supersaturation with respect to a large crystal, the kinks not only diffuse along the step, but move back the generating comers. This 'wind' prevents communication between the comers and places upper limit supersaturation only below which GTL is applicable. Steps replace kinks in the 3D case, though, of course, another dimensionality brings about another physics. Another specific problem to think about is if fluctuations are always fast enough to provide enough kinks for linear dependence of step rate on supersaturation. Increasing azimuthal polygonization of growth hillocks is a sign of insufficient fluctuation rate. Morphological stability of vicinal faces is usually considered on the basis of mutually parallel steps. Azimuthal anisotropy and interlacing of

  4. Accessory Anterolateral Talar Facet as an Etiology of Painful Talocalcaneal Impingement in the Rigid Flatfoot: A New Diagnosis

    PubMed Central

    Martus, Jeffrey E.; Femino, John E.; Caird, Michelle S.; Kuhns, Lawrence R.; Craig, Clifford L.; Farley, Frances A.

    2008-01-01

    A retrospective review identified six patients with seven painful rigid flatfeet. In each case, pain was localized laterally to an accessory facet of the anterolateral talus. cross-sectional imaging demonstrated no evidence of tarsal coalition. In five of the six, preoperative magnetic resonance imaging (MRI) was obtained and in each case demonstrated focal abutting bone marrow edema consistent with impingement between the accessory facet and the anterior calcaneus. Seven feet in six patients underwent resection of the accessory facet with additional subtalar joint-sparing reconstructive procedures. At an average follow-up of 11 months, clinical results were graded as four good and two fair. An association between this accessory facet and pain in the rigid flatfoot has not been previously reported. Obesity was universal and may represent a risk factor for facet impingement. At early follow-up, facet resection with subtalar joint-sparing flatfoot reconstruction provided good results with symptomatic and functional improvement in the majority of patients. PMID:19223941

  5. Identification of microRNA-181a-5p and microRNA-4454 as mediators of facet cartilage degeneration

    PubMed Central

    Nakamura, Akihiro; Sharma, Anirudh; Lewis, Stephen J.; Wu, Brian; Datta, Poulami; Sundararajan, Kala; Endisha, Helal; Rossomacha, Evgeny; Rockel, Jason S.; Jurisica, Igor

    2016-01-01

    Osteoarthritis (OA) of spine (facet joints [FJs]) is one of the major causes of severe low back pain and disability worldwide. The degeneration of facet cartilage is a hallmark of FJ OA. However, endogenous mechanisms that initiate degeneration of facet cartilage are unknown, and there are no disease-modifying therapies to stop FJ OA. In this study, we have identified microRNAs (small noncoding RNAs) as mediators of FJ cartilage degeneration. We first established a cohort of patients with varying degrees of facet cartilage degeneration (control group: normal or mild facet cartilage degeneration; FJ OA group: moderate to severe facet cartilage degeneration) and then screened 2,100 miRNAs and identified 2 miRNAs (miR-181a-5p and miR-4454) that were significantly elevated in FJ OA cartilage compared with control facet cartilage. We further explored their role, function, and signaling mechanisms using computational, in vitro functional, and in vivo studies. We specifically indicate that miR-181a-5p and miR-4454 are involved in promoting inflammatory, catabolic, and cell death activity in FJ chondrocytes. This is the first report to our knowledge that identifies miR-181a-5p and miR-4454 as mediators of cartilage degeneration in FJs and potential therapeutic targets for stopping cartilage degeneration. PMID:27699225

  6. FACET ORIENTATION AND TROPISM: ASSOCIATION WITH ACCELERATED DEGENERATION OF STABILIZING STRUCTURES IN LOWER LUMBAR SPINE.

    PubMed

    Jelec, Vjekoslav; Turner, Rajka; Franić, Miljenko; Korušić, Anđelko; Rotim, Krešimir

    2016-03-01

    The influence of facet orientation and tropism on the process of spinal degeneration has been extensively studied during the last few decades, but there are still many controversies and conflicting results in this field of research. The biomechanical cause of accelerated degeneration of stabilizing structures in lower lumbar spine lies within the combination of several factors, but two most important ones are compressive load and more coronal facet orientation that offers less resistance against torsional loading. Axial rotation of lower lumbar spine is undoubtedly associated with higher strain in disc annulus, and enhanced range of secondary rotational movements may be even more significant for the progression of annular degeneration. Accordingly, more pronounced facet tropism could be having part in faster progression of disc degeneration in lower lumbar spine, as indicated by a number of recent studies. More sagittal facet orientation in patients with a higher facet osteoarthritis score at lower lumbar segments is very likely related to arthritic remodeling commonly seen in other synovial joints. There is also a possibility that it could be associated with the adaptation to partial loss of lumbar lordosis, as both coincide with advanced age.

  7. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc.

    NASA Astrophysics Data System (ADS)

    Schertz, P. T.; Brown, D. C.; Konnerth, A., III

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/sq m (2.4 lbs/sq ft). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the front membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/sq m at a production rate of 10,000 facets per year and $115,000/sq m at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatability and facet performance in typical operating conditions.

  8. Facet engineering of high power single emitters

    NASA Astrophysics Data System (ADS)

    Yanson, Dan; Levi, Moshe; Shamay, Moshe; Tesler, Renana; Rappaport, Noam; Don, Yaroslav; Karni, Yoram; Schnitzer, Itzhak; Sicron, Noam; Shusterman, Sergey

    2011-03-01

    The ever increasing demand for high-power, high-reliability operation of single emitters at 9xx nm wavelengths requires the development of laser diodes with improved facet regions immune to both catastrophic and wear-out failure modes. In our study, we have evaluated several laser facet definition technologies in application to 90 micron aperture single emitters in asymmetric design (In)GaAs/AlGaAs based material emitting at 915, 925 and 980nm. A common epitaxy and emitter design makes for a straightforward comparison of the facet technologies investigated. Our study corroborates a clear trend of increasing difficulty in obtaining reliable laser operation from 980nm down to 915nm. At 980nm, one can employ dielectric facet passivation with a pre-clean cycle delivering a device lifetime in excess of 3,000 hours at increasing current steps. At 925nm, quantum-well intermixing can be used to define non-absorbing mirrors giving good device reliability, albeit with a large efficiency penalty. Vacuum cleaved emitters have delivered excellent reliability at 915nm, and can be expected to perform just as well at 925 and 980nm. Epitaxial regrowth of laser facets is under development and has yet to demonstrate an appreciable reliability improvement. Only a weak correlation between start-of-life catastrophic optical mirror damage (COMD) levels and reliability was established. The optimized facet design has delivered maximum powers in excess of 19 MW/sq.cm (rollover limited) and product-grade 980nm single emitters with a slope efficiency of >1 W/A and a peak efficiency of >60%. The devices have accumulated over 1,500 hours of CW operation at 11W. A fiber-coupled device emits 10W ex-fiber with 47% efficiency.

  9. The biomechanical behavior on the interface of tumor arthrosis/allograft prosthetic composite by finite element analysis

    NASA Astrophysics Data System (ADS)

    Chen, H. Z.; Jiang, W.; Zou, W.; Luo, J. M.; Chen, J. Y.; Tu, C. Q.; Xing, B. B.; Gu, Z. W.; Zhang, X. D.

    2008-11-01

    The biomechanical behavior of the uniting interface between the allograft bone and the autogenetic bone plays an important role in the treatment of the proximal femur massive defects with artificial tumor arthrosis/allograft prosthetic composite (TAAPC). According to the CT data of a patient, a 3D medical treatment model of TAAPC was established. Under the loads of 1.5 and 2.5 times standard body weight (70 kg), the mechanical behavior of the treatment model was analyzed by finite element analysis (FEA) for three typical healing periods. The results show that there are significant differences in the stress values and distribution in different healing periods. With healing of osteotomy, the hardness of the tissue of the uniting interface increases, the stress in uniting area was increased greatly and the stress concentration decreased. After cured the stress almost reached the level of normal bone. In the initial stage of healing, the healing training is not encouraged because there is an obvious risk of fracture of prosthesis and bone cement. In addition, porous hydroxyapatite (HA) ceramic used as bone tissue scaffold for this case, not only facilitates the generation of new bone, but also can avoid this risk caused by the non-uniting interface.

  10. Kinematics of total facet replacement (TFAS-TL) with total disc replacement

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Sjovold, Simon G.; Funk, Michael; Carandang, Gerard; Zindrick, Daniel; Rosler, David M.; Patwardhan, Avinash G.

    2009-01-01

    Background Total disc replacement (TDR) and total facet replacement (TFR) have been the focus of recent kinematics evaluations. Yet their concurrent function as a total joint replacement of the lumbar spine's 3-joint complex has not been comprehensively reported. This study evaluated the effect of a TFR specifically designed to replace the natural facets and supplement the function with the natural disc and with TDR. The ability to replace degenerated facets to complement a pre-existing or simultaneously implanted TDR may allow surgeons to completely address degenerative pathologies of the 3-joint complex of the lumbar spine. We hypothesized that TFR would reproduce the biomechanical function of the natural facets when implanted in conjunction with TDR. Methods Lumbar spines (L1-5, 51.3 ± 14.2 years, N = 6) were tested sequentially as follows: (1) intact, (2) after TDR implantation, and (3) after TFR implantation in conjunction with TDR, all at L3-4. Specimens were tested in flexion-extension (+ 8 Nm to − 6 Nm), lateral bending (± 6 Nm), and axial rotation (± 5 Nm). A 400 N compressive follower preload was applied during flexion-extension tests. Three-dimensional segmental motion was recorded and analyzed using analysis of variance in Systat (Systat Software Inc., Chicago, Illinois) and multiple comparisons with Bonferroni correction. Results The TDR implantation (TDR + natural facets) allowed similar lateral bending (P = .66), but it generally increased flexion-extension (P = .06) and axial rotation (P < .05) range of motion (ROM) at the implanted level compared to intact. The TFR + TDR (following replacement of the natural facets with TFR) decreased ROM to levels similar to intact in lateral bending (P = .70) and axial rotation (P = .23). The TFR + TDR flexion-extension ROM was reduced in comparison to intact and TDR + natural facets (P < .05). Conclusions The TFR with TDR was able to restore stability to the lumbar segment after bilateral facetectomy, while

  11. Alignment and focus of mirrored facets of a heliosat

    DOEpatents

    Yellowhair, Julius E; Ho, Clifford Kuofei; Diver, Richard B; Moss, Timothy A

    2013-11-12

    Various technologies pertaining to aligning and focusing mirrored facets of a heliostat are described herein. Updating alignment and/or focus of mirrored facets is undertaken through generation of a theoretical image, wherein the theoretical image is indicative of a reflection of the target via the mirrored facets when the mirrored facets are properly aligned. This theoretical image includes reference points that are overlaid on an image of the target as reflected by the mirrored facets of the heliostat. A technician adjusts alignment/focus of a mirrored facet by causing reflected reference markings to become aligned with the reference points in the theoretical image.

  12. Symptomatic sacroiliac joint disease and radiographic evidence of femoroacetabular impingement.

    PubMed

    Morgan, Patrick M; Anderson, Anthony W; Swiontkowski, Marc F

    2013-01-01

    Symptomatic sacroiliac (SI) joint disease is poorly understood. The literature provides no clear aetiology for SI joint pathology, making evaluation and diagnosis challenging. We hypothesised that patients with documented sacroiliac pain might provide insight into the aetiology of these symptoms. Specifically, we questioned whether SI joint symptoms might be associated with abnormal hip radiographs. We reviewed the pelvic and hip radiographs of a prospectively collected cohort of 30 consecutive patients with SI joint pathology. This database included 33 hips from 30 patients. Radiographic analysis included measurements of the lateral centre edge angle, Tönnis angle, and the triangular index, of the ipsilateral hip. Evidence for retrotorsion of the hemipelvis was recorded. Hips were graded on the Tönnis grading system for hip arthrosis. In this cohort 14/33 (42%) of hips had evidence of significant osteoarthrosis indicated by Tönnis grade 2 or greater and 15/33 (45%) displayed subchondral cyst formation around the hip or head neck junction. In assessing acetabular anatomy, 21% (7/33) had retroversion, 12% (4/33) had a lateral centre edge angle >40° with 3% (1/33) >45°. Tönnis angle was <0° in 27% (9/33). Coxa profunda and acetabuli protrusio were present in 47% (17/33) and 3% (1/33), respectively. When femoral head morphology was assessed, 33% (11/33) showed evidence of cam impingement. Overall, 76% (25/33) had at least one abnormality on their hip radiograph. A significant number of patients meeting strict diagnostic criteria for SI joint pain had radiographic evidence of femoroacetabular impingement (FAI) and hip arthrosis. The clinician should maintain FAI in the differential diagnosis when investigating patients with buttock pain.

  13. Problem of time: facets and Machian strategy.

    PubMed

    Anderson, Edward

    2014-10-01

    The problem of time is that "time" in each of ordinary quantum theory and general relativity are mutually incompatible notions. This causes difficulties in trying to put these two theories together to form a theory of quantum gravity. The problem of time has eight facets in canonical approaches. I clarify that all but one of these facets already occur at the classical level, and reconceptualize and re-name some of these facets as follows. The frozen formalism problem becomes temporal relationalism, the thin sandwich problem becomes configurational relationalism, via the notion of best matching. The problem of observables becomes the problem of beables, and the functional evolution problem becomes the constraint closure problem. I also outline how each of the global and multiple-choice problems of time have their own plurality of facets. This article additionally contains a local resolution to the problem of time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical, and a combined semiclassical-histories-timeless records scheme. I end by delineating the current frontiers of this program toward resolution of the problem of time in the cases of full general relativity and of slightly inhomogeneous cosmology.

  14. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  15. Vertical Reduction Using Atlantoaxial Facet Spacer in Basilar Invagination with Atlantoaxial Instability

    PubMed Central

    Kim, Il Sup; Sung, Jae Hoon; Byun, Jae Hoon

    2011-01-01

    Although posterior segmental fixation technique is becoming increasingly popular, surgical treatment of craniovertebral junctional disorders is still challenging because of its complex anatomy and surrounding critical neurovascular structures. Basilar invagination is major pathology of craniovertebral junction that has been a subject of clinical interest because of its various clinical presentations and difficulty of treatment. Most authors recommend a posterior occipitocervical fixation following transoral decompression or posterior decompression and occipitocervical fixation. However, both surgical modalities inadvertently sacrifice C0-1 and C1-2 joint motion. We report two cases of basilar invagination reduced by the vertical distraction between C1-2 facet joint. We reduced the C1-2 joint in an anatomical position and fused the joint with iliac bone graft and C1-2 segmental fixation using the polyaxial screws and rods C-1 lateral mass and the C-2 pedicle. PMID:22323942

  16. The elephant knee joint: morphological and biomechanical considerations

    PubMed Central

    Weissengruber, G E; Fuss, F K; Egger, G; Stanek, G; Hittmair, K M; Forstenpointner, G

    2006-01-01

    Elephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. In elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. In addition, the knee joint is affected frequently by arthrosis. Here we examined structures of the knee joint by means of standard anatomical techniques in eight African (Loxodonta africana) and three Asian elephants (Elephas maximus). Furthermore, we performed radiography in five African and two Asian elephants and magnetic resonance imaging (MRI) in one African elephant. Macerated bones of 11 individuals (four African, seven Asian elephants) were measured with a pair of callipers to give standardized measurements of the articular parts. In one Asian and three African elephants, kinematic and functional analyses were carried out using a digitizer and according to the helical axis concept. Some peculiarities of healthy and arthrotic knee joints of elephants were compared with human knees. In contrast to those of other quadruped mammals, the knee joint of elephants displays an extended resting position. The femorotibial joint of elephants shows a high grade of congruency and the menisci are extremely narrow and thin. The four-bar mechanism of the cruciate ligaments exists also in the elephant. The main motion of the knee joint is extension–flexion with a range of motion of 142°. In elephants, arthrotic alterations of the knee joint can lead to injury or loss of the cranial (anterior) cruciate ligament. PMID:16420379

  17. [Incidence of previous engagement in sports among patients with symptomatic arthrosis. Controlled study].

    PubMed

    Boyer, T; Delaire, M; Beranek, L; Lasserre, P P; Tekaya, M; Kahn, M F

    1981-12-01

    The authors investigated sports-related precedents in two groups of male subjects, aged 40 years and over, of French nationality. One group had consulted for a degenerative, chronic rheumatic disorder, and the control group showed no signs of this type of disorder. Care was taken to verify that the two groups did not differ in terms of profession, means of commuting from home to work, and non-sporting leisure physical activities. The authors observed that the subjects of the first group (chronic degenerative rheumatic disease) more frequently engaged in a sports activity, and in a significant manner, than did the control subjects. A separate study of the certain kinds of sports and the various arthritic localisations also revealed significant correlations. Although this involved a retrospective enquiry, the authors feel that the results provide arguments in favor of the pathogenic role of sports activity, with regard to peripheral joints and the spine. However, this role of sports is probably only partial and irregular. The risks of sports activity must be put in perspective and balanced with the various advantages afforded by the practice of sports.

  18. Facets for Discovery and Exploration in Text Collections

    SciTech Connect

    Rose, Stuart J.; Roberts, Ian E.; Cramer, Nicholas O.

    2011-10-24

    Faceted classifications of text collections provide a useful means of partitioning documents into related groups, however traditional approaches of faceting text collections rely on comprehensive analysis of the subject area or annotated general attributes. In this paper we show the application of basic principles for facet analysis to the development of computational methods for facet classification of text collections. Integration with a visual analytics system is described with summaries of user experiences.

  19. Formulation and Application of the Generalized Multilevel Facets Model

    ERIC Educational Resources Information Center

    Wang, Wen-Chung; Liu, Chih-Yu

    2007-01-01

    In this study, the authors develop a generalized multilevel facets model, which is not only a multilevel and two-parameter generalization of the facets model, but also a multilevel and facet generalization of the generalized partial credit model. Because the new model is formulated within a framework of nonlinear mixed models, no efforts are…

  20. Identifying Facets of Problem Solving in Mathematics Instruction.

    ERIC Educational Resources Information Center

    Klieme, Eckhard; Clausen, Marten

    Facets of problem solving instruction (PSI) were studied in German mathematics classrooms. Nine different facets of PSI were identified from the research literature, and a video rating form was developed to assess these facets and teacher effectiveness. Videotaped mathematics lessons (n=147) for German eighth graders from the sample for the Third…

  1. Results from Plasma Wakefield Experiments at FACET

    SciTech Connect

    Li, S.Z.; Clarke, C.I.; England, R.J.; Frederico, J.; Gessner, S.J.; Hogan, M.J.; Jobe, R.K.; Litos, M.D.; Walz, D.R.; Muggli, P.; An, W.; Clayton, C.E.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.; Tochitsky, S.; Adli, E.; /U. Oslo

    2011-12-13

    We report initial results of the Plasma Wakefield Acceleration (PWFA) Experiments performed at FACET - Facility for Advanced aCcelertor Experimental Tests at SLAC National Accelerator Laboratory. At FACET a 23 GeV electron beam with 1.8 x 10{sup 10} electrons is compressed to 20 {mu}m longitudinally and focused down to 10 {mu}m x 10 {mu}m transverse spot size for user driven experiments. Construction of the FACET facility completed in May 2011 with a first run of user assisted commissioning throughout the summer. The first PWFA experiments will use single electron bunches combined with a high density lithium plasma to produce accelerating gradients > 10 GeV/m benchmarking the FACET beam and the newly installed experimental hardware. Future plans for further study of plasma wakefield acceleration will be reviewed. The experimental hardware and operation of the plasma heat-pipe oven have been successfully commissioned. Plasma wakefield acceleration was not observed because the electron bunch density was insufficient to ionize the lithium vapor. The remaining commissioning time in summer 2011 will be dedicated to delivering the FACET design parameters for the experimental programs which will begin in early 2012. PWFA experiments require the shorter bunches and smaller transverse sizes to create the plasma and drive large amplitude wakefields. Low emittance and high energy will minimize head erosion which was found to be a limiting factor in acceleration distance and energy gain. We will run the PWFA experiments with the design single bunch conditions in early 2012. Future PWFA experiments at FACET are discussed in [5][6] and include drive and witness bunch production for high energy beam manipulation, ramped bunch to optimize tranformer ratio, field-ionized cesium plasma, preionized plasmas, positron acceleration, etc.. We will install a notch collimator for two-bunch operation as well as new beam diagnostics such as the X-band TCAV [7] to resolve the two bunches

  2. Zeroing In on Mindfulness Facets: Similarities, Validity, and Dimensionality across Three Independent Measures.

    PubMed

    Siegling, Alex B; Petrides, K V

    2016-01-01

    The field of mindfulness has seen a proliferation of psychometric measures, characterised by differences in operationalisation and conceptualisation. To illuminate the scope of, and offer insights into, the diversity apparent in the burgeoning literature, two distinct samples were used to examine the similarities, validity, and dimensionality of mindfulness facets and subscales across three independent measures: the Five Facet Mindfulness Questionnaire (FFMQ), Philadelphia Mindfulness Scale (PHLMS), and Toronto Mindfulness Scale (TMS). Results revealed problematic associations of FFMQ Observe with the other FFMQ facets and supported a four-factor structure (omitting this facet), while disputing the originally envisaged five-factor model; thus, solidifying a pattern in the literature. Results also confirmed the bidimensional nature of the PHLMS and TMS subscales, respectively. A joint Confirmatory Factor Analysis showed that PHLMS Acceptance could be assimilated within the FFMQ's four-factor model (as a distinct factor). The study offers a way of understanding interrelationships between the available mindfulness scales, so as to help practitioners and researchers make a more informed choice when conceptualising and operationalising mindfulness.

  3. Rough surface scattering based on facet model

    NASA Technical Reports Server (NTRS)

    Khamsi, H. R.; Fung, A. K.; Ulaby, F. T.

    1974-01-01

    A model for the radar return from bare ground was developed to calculate the radar cross section of bare ground and the effect of the frequency averaging on the reduction of the variance of the return. It is shown that, by assuming that the distribution of the slope to be Gaussian and that the distribution of the length of the facet to be in the form of the positive side of a Gaussian distribution, the results are in good agreement with experimental data collected by an 8- to 18-GHz radar spectrometer system. It is also shown that information on the exact correlation length of the small structure on the ground is not necessary; an effective correlation length may be calculated based on the facet model and the wavelength of the incident wave.

  4. Facets of Emotional Clarity and Suspiciousness

    PubMed Central

    Boden, Matthew Tyler; Berenbaum, Howard

    2012-01-01

    In a college student sample, we explored the relations between individual differences in facets of emotional clarity and suspiciousness. Previous theory and research has treated emotional clarity as a one-dimensional construct. Boden and Berenbaum (2011) proposed that a second facet of emotional clarity, source awareness (a general understanding of the cause of their emotions), could be distinguished from type awareness (a general understanding of the type of emotions [anger, fear] experienced). We found that source and type awareness were incrementally, inversely associated with suspiciousness when statistically accounting for the extent to which emotions are attended to, and gender. Additionally, source awareness significantly predicted suspiciousness after accounting for anger, anxious arousal, and social anxiety, whereas type awareness did not. Findings are consistent with the hypothesis that, among individuals with low source and type awareness, suspicious beliefs are formed to make sense of and explain emotional arousal. PMID:22736879

  5. How faceted liquid droplets grow tails

    PubMed Central

    Guttman, Shani; Sapir, Zvi; Schultz, Moty; Butenko, Alexander V.; Ocko, Benjamin M.; Deutsch, Moshe; Sloutskin, Eli

    2016-01-01

    Liquid droplets, widely encountered in everyday life, have no flat facets. Here we show that water-dispersed oil droplets can be reversibly temperature-tuned to icosahedral and other faceted shapes, hitherto unreported for liquid droplets. These shape changes are shown to originate in the interplay between interfacial tension and the elasticity of the droplet’s 2-nm-thick interfacial monolayer, which crystallizes at some T = Ts above the oil’s melting point, with the droplet’s bulk remaining liquid. Strikingly, at still-lower temperatures, this interfacial freezing (IF) effect also causes droplets to deform, split, and grow tails. Our findings provide deep insights into molecular-scale elasticity and allow formation of emulsions of tunable stability for directed self-assembly of complex-shaped particles and other future technologies. PMID:26733673

  6. Nonradiative Step Facets in Semiconductor Nanowires.

    PubMed

    Sanchez, Ana M; Zhang, Yunyan; Tait, Edward W; Hine, Nicholas D M; Liu, Huiyun; Beanland, Richard

    2017-04-12

    One of the main advantages of nanowires for functional applications is their high perfection, which results from surface image forces that act on line defects such as dislocations, rendering them unstable and driving them out of the crystal. Here we show that there is a class of step facets that are stable in nanowires, with no long-range strain field or dislocation character. In zinc-blende semiconductors, they take the form of Σ3 (112) facets with heights constrained to be a multiple of three {111} monolayers. Density functional theory calculations show that they act as nonradiative recombination centers and have deleterious effects on nanowire properties. We present experimental observations of these defects on twin boundaries and twins that terminate inside GaAsP nanowires and find that they are indeed always multiples of three monolayers in height. Strategies to use the three-monolayer rule during growth to prevent their formation are discussed.

  7. Effect of Retrograde Reaming for Tibiotalocalcaneal Arthrodesis on Subtalar Joint Destruction: A Cadaveric Study.

    PubMed

    Lowe, Jason A; Routh, Lucas K; Leary, Jeffrey T; Buzhardt, Paul C

    2016-01-01

    Recent published data have suggested successful union of subtalar and tibiotalar joints without formal debridement during tibiotalocalcaneal (TTC) fusion procedures. Although previous studies have reported on the importance of the proper guidewire starting point and trajectory to obtain appropriate hindfoot alignment for successful fusion, to our knowledge, no studies have quantified the amount of articular damage to the subtalar joint with retrograde reaming. We hypothesized that reaming would destroy >50% of the posterior facet of the subtalar joint. The bilateral lower extremities of 5 cadavers were obtained and the subtalar joints exposed. Retrograde TTC nail guidewires were inserted, and a 12-mm reamer was passed through the subtalar and ankle joints. Pre- and postreaming images of the subtalar joint were obtained to compare the amount of joint destruction after reaming. We found an average of 5.89% articular destruction of the talar posterior facet and an average of 4.01% articular destruction of the posterior facet of the calcaneus. No damage to the middle facets of the subtalar joint was observed. TTC nailing is a successful procedure for ankle and subtalar joint fusion. Published studies have reported successful subtalar union using TTC nailing without formal open debridement of the subtalar joint, preserving the soft tissue envelope. TTC nail insertion using a 12-mm reamer will destroy 5.89% and 4.01% of the respective talar and calcaneal posterior facets of the subtalar joint.

  8. JPL tests of a LaJet concentrator facet

    NASA Technical Reports Server (NTRS)

    Dennison, E. W.; Argoud, M. J.

    1983-01-01

    A LaJet Energy Company (LEC) concentrator facet, 60 in. in diameter, was tested for imaging quality. The following two methods were used: (1) autofocus tests with a point source of light at the facet's radius of curvature; and (2) tests with the Sun close to the horizon as a distant source. The tests of the LaJet facet indicate that all of the solar image reflected by an LEC 460 solar concentrator made of like facets should fall within a 9-in. aperture if the outer facets are carefully adjusted. Such a concentrator would have acceptable performance, but complete evaluation must be made with an assembled concentrator.

  9. Kinetics of faceting of crystals in growth, etching, and equilibrium

    NASA Astrophysics Data System (ADS)

    Vlachos, D. G.; Schmidt, L. D.; Aris, R.

    1993-03-01

    The faceting of crystals in equilibrium with the gas phase and also during crystal growth and etching conditions is studied using the Monte Carlo method. The dynamics of the transformation of unstable crystallographic orientations into hill and valley structures and the spatial patterns that develop are examined as functions of surface temperature, crystallographic orientation, and strength of interatomic potential for two transport processes: adsorption-desorption and surface diffusion. The results are compared with the continuum theory for facet formation. Thermodynamically unstable orientations break into hill and valley structures, and faceting exhibits three time regimes: disordering, facet nucleation, and coarsening of small facets to large facets. Faceting is accelerated as temperature increases, but thermal roughening can occur at high temperatures. Surface diffusion is the dominant mechanism at short times and small facets but adsorption-desorption becomes important at long times and large facets. Growth and etching promote faceting for conditions close to equilibrium but induce kinetic roughening for conditions far from equilibrium. Simultaneous irreversible growth and etching conditions with fast surface diffusion result in enhanced faceting.

  10. Interventional radiology in bone and joint

    SciTech Connect

    Bard, M.; Laredo, J.D.

    1988-01-01

    Recent radiologic procedures in bone and joints, some of which eliminate the need for surgery are exposed, including: trephine biopsies of the thoracic and lumbar spine, sacro-iliac joints, peripheral bones synovial membrane and soft tissues, using either fluoroscopic echographic or CT guidance - chemonucleolysis - vascular embolization of skeletal tumors and management of vertebral hemangiomas - selective steroid injection in a broad spectrum of diseases including vertebral facet syndrome, cervicobrachial nerve root pain, rotator cuff calcium deposit, bone cysts.

  11. Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy

    PubMed Central

    Loh, Jeffrey T; Nicol, Andrea L; Elashoff, David; Ferrante, F Michael

    2015-01-01

    Background Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. Materials and methods A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient’s chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications. Results Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. Conclusion The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief. PMID:26504407

  12. CT of facet distraction in flexion injuries of the thoracolumbar spine: the "naked" facet.

    PubMed

    O'Callaghan, J P; Ullrich, C G; Yuan, H A; Kieffer, S A

    1980-03-01

    Vertical distraction of the articular processes is an important sign of ligamentous disruption due to flexion injuries of the thoracolumbar spine. In addition to illustrating this finding in cross section (the "naked" facet), computed tomography in the transaxial plane allows assessment of the presence and position of fracture fragments that may encroach on the spinal canal. Image reconstruction in sagittal and coronal planes provides a clear demonstration of the degree of bony compression, facet distraction, and kyphosis associated with flexion injuries without additional patient manipulation or radiation exposure.

  13. FACETS -- Infrastructure for Integrated Fusion Modeling

    NASA Astrophysics Data System (ADS)

    Shasharina, Svetlana; Cary, John; Carlsson, Johan; Hakim, Ammar; Kruger, Scott; Miah, Mahmood; Pletzer, Alexander; Vadlamani, Srinath; Wade-Stein, David; Balay, Satish; McInnes, Lois; Zhang, Hong; Candy, Jeff; Fahey, Mark; Cohen, Ron; Epperly, Tom; Rognlien, Tom; Estep, Don; Pankin, Alexei; Malony, Allen; Morris, Alan; Shende, Sameer; Indireshkumar, Keshavamurthy; McCune, Douglas; Pigarov, Alexander

    2009-11-01

    It is desirable that an infrastructure for integrated fusion modeling has support for: legacy and new components used interchangeably; consistent management of components lifecycle; allocating parallel resources consistent with the nature of participating components and the problem scope; components written in multiple programming languages; composition of sequentially and concurrently executing components respecting dependencies; tight and loose coupling of components; testing and validation of separate and integrated components; and use of multiple platforms from desktops to LCFs. In this poster we will describe the status of the FACETS with respect to these features.

  14. An Integrated Facet-Based Library for Arbitrary Software Components

    NASA Astrophysics Data System (ADS)

    Schmidt, Matthias; Polowinski, Jan; Johannes, Jendrik; Fernández, Miguel A.

    Reuse is an important means of reducing costs and effort during the development of complex software systems. A major challenge is to find suitable components in a large library with reasonable effort. This becomes even harder in today's development practice where a variety of artefacts such as models and documents play an equally important role as source code. Thus, different types of heterogeneous components exist and require consideration in a component search process. One flexible approach to structure (software component) libraries is faceted classification. Faceted classifications and in particular faceted browsing are nowadays widely used in online systems. This paper takes a fresh approach towards using faceted classification in heterogeneous software component libraries by transferring faceted browsing concepts from the web to software component libraries. It presents an architecture and implementation of such a library. This implementation is used to evaluate the applicability of facets in the context of an industry-driven case study.

  15. Foundations of reusable and interoperable facet models using category theory.

    PubMed

    Harris, Daniel R

    2016-10-01

    Faceted browsing has become ubiquitous with modern digital libraries and online search engines, yet the process is still difficult to abstractly model in a manner that supports the development of interoperable and reusable interfaces. We propose category theory as a theoretical foundation for faceted browsing and demonstrate how the interactive process can be mathematically abstracted. Existing efforts in facet modeling are based upon set theory, formal concept analysis, and light-weight ontologies, but in many regards, they are implementations of faceted browsing rather than a specification of the basic, underlying structures and interactions. We will demonstrate that category theory allows us to specify faceted objects and study the relationships and interactions within a faceted browsing system. Resulting implementations can then be constructed through a category-theoretic lens using these models, allowing abstract comparison and communication that naturally support interoperability and reuse.

  16. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    SciTech Connect

    Goyal, Amit

    2013-07-09

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  17. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    SciTech Connect

    Goyal, Amit

    2012-07-24

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  18. Accommodation of angular incompatibilities between interfacial facets during precipitate growth

    NASA Astrophysics Data System (ADS)

    Pond, R. C.; Jiao, H.; Zhang, L. C.; Aindow, M.

    2006-03-01

    Precipitate growth in a duplex stainless steel and a titanium aluminide alloy has been studied using transmission electron microscopy. Particles with similar crystallography and acicular form arise in both cases, and are bounded by two principal facets. One facet, designated C, is based on a commensurate singular interface structure, and the coherency strains are accommodated by interfacial defects. The other facet, designated I, is based on a singular configuration that is incommensurate in one dimension. The orientation relationship (OR) between the particle and the matrix for the singular C structure is Kurdjumov-Sachs (K-S), whereas that for the I facet is Pitsch. The angular incompatibility between these two types of facets must be accommodated to minimize the displacement field as particles grow. The present observations suggest that this is accomplished through the generation of crystal dislocations at facet junctions and their subsequent climb along the facets. The total density of defects needed to accommodate the angular discrepancy is fixed, but the partitioning of these dislocations between C and I facets is not. The actual partitioning determines the observed OR for a particle, and is determined by the kinetics of climb, which is likely to be different in the two facets. In the stainless steel, the observations are consistent with climb occurring in both the C and I facets, but faster in the I facet, leading to a distribution of observed ORs that is skewed away from Pitsch toward K-S. In the titanium aluminide alloy, no climb into the C facets was found, so a unique OR close to K-S arises.

  19. The functional anatomy of the cricothyroid joint.

    PubMed

    Windisch, Gunther; Hammer, Georg Philipp; Prodinger, Peter Michael; Friedrich, Gerhard; Anderhuber, Friedrich

    2010-02-01

    Postoperative long-term treatment problems of male-to-female transsexuals can be caused by the underestimated mobility of the cricothyroid joint. One hundred cadaveric larynges were analysed to reveal the morphological and functional anatomy of the CTJ focusing on possible horizontal and vertical gliding movements. Furthermore, the distance of the cricothyroid space for rotational movements was measured. The articular surface of the cricothyroid joint showed three different possibilities: a well-defined facet (Type 1 61%), no definable facet (Type 2 22%) or a flat surface with or without a tiny protuberance (Type 3 17%). Side different statements and intraindividual differences between male and female specimens were included. These different types affect horizontal and vertical gliding movements, besides rotational movements. The mobility between Type 1 and the others was highly significant (P < 0.001). Regarding different motions in the cricothyroid joint, rotational movements caused significant elongation of the vocal folds, which should be taken into consideration for phonosurgical methods.

  20. Cervical Radiculopathy Due to Disc Herniation with Adjacent Facet Hypertrophy: Case Report

    PubMed Central

    YAMAHATA, Hitoshi; YASUDA, Muneyoshi; AOYAMA, Tatsuro; OSUKA, Koji; ARITA, Kazunori; TAKAYASU, Masakazu

    2014-01-01

    We report a rare case of cervical radiculopathy associated with facet hypertrophy and disc herniation. The patient was a 38-year-old woman with sudden-onset left arm pain. As conservative therapy failed to alleviate her symptoms she was referred to us. On physical examination she manifested no neurological deficits except pain and dysesthesia in the left C7 territory. Computed tomography revealed hypertrophic ossified changes in the left T1 facet joint with encroachment on the spinal canal. Magnetic resonance imaging showed compression of the spinal cord at C6/7 by disc herniation at C6/7. Anterior cervical decompression and fusion by corpectomy (C7 corpectomy and C6/T1 fixation with a titanium cage) ameliorated her pain. Facet hypertrophy in a morphologically normal cervicothoracic spine is extremely rare and its etiology is unknown. We speculate the possibility that our patient harbored a congenital anomaly and that the morphologic changes were the consequence of an injury she sustained in a traffic accident. PMID:24477059

  1. Diagnostics Challenges for FACET-II

    SciTech Connect

    Clarke, Christine

    2015-10-07

    FACET-II is a prospective user facility at SLAC National Accelerator Laboratory. The facility will focus on high-energy, high-brightness beams and their interaction with plasma and lasers. The accelerator is designed for high-energy-density electron beams with peak currents of approximately 50 kA (potentially 100 kA) that are focused down to below 10x10 micron transverse spot size at an energy of 10 GeV. Subsequent phases of the facility will provide positron beams above 10 kA peak current to the experiment station. Experiments will require well characterised beams; however, the high peak current of the electron beam can lead to material failure in wirescanners, optical transition radiation screens and other instruments critical for measurement or delivery. The radiation environment and space constraints also put additional pressure on diagnostic design.

  2. FACET Tolerances for Static and Dynamic Misalignments

    SciTech Connect

    Federico, Joel

    2012-07-13

    The Facility for AdvancedAccelerator and Experimental Tests (FACET) at the SLAC National Accelerator Laboratory is designed to deliver a beam with a transverse spot size on the order of 10 {micro}m x 10 {micro}m in a new beamline constructed at the two kilometer point of the SLAC linac. Commissioning the beamline requires mitigating alignment errors and their effects, which can be significant and result in spot sizes orders of magnitude larger. Sextupole and quadrupole alignment errors in particular can introduce errors in focusing, steering, and dispersion which can result in spot size growth, beta mismatch, and waist movement. Alignment errors due to static misalignments, mechanical jitter, energy jitter, and other physical processes can be analyzed to determine the level of accuracy and precision that the beamline requires. It is important to recognize these effects and their tolerances in order to deliver a beam as designed.

  3. Explorations in statistics: statistical facets of reproducibility.

    PubMed

    Curran-Everett, Douglas

    2016-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eleventh installment of Explorations in Statistics explores statistical facets of reproducibility. If we obtain an experimental result that is scientifically meaningful and statistically unusual, we would like to know that our result reflects a general biological phenomenon that another researcher could reproduce if (s)he repeated our experiment. But more often than not, we may learn this researcher cannot replicate our result. The National Institutes of Health and the Federation of American Societies for Experimental Biology have created training modules and outlined strategies to help improve the reproducibility of research. These particular approaches are necessary, but they are not sufficient. The principles of hypothesis testing and estimation are inherent to the notion of reproducibility in science. If we want to improve the reproducibility of our research, then we need to rethink how we apply fundamental concepts of statistics to our science.

  4. Search Interface Design Using Faceted Indexing for Web Resources.

    ERIC Educational Resources Information Center

    Devadason, Francis; Intaraksa, Neelawat; Patamawongjariya, Pornprapa; Desai, Kavita

    2001-01-01

    Describes an experimental system designed to organize and provide access to Web documents using a faceted pre-coordinate indexing system based on the Deep Structure Indexing System (DSIS) derived from POPSI (Postulate based Permuted Subject Indexing) of Bhattacharyya, and the facet analysis and chain indexing system of Ranganathan. (AEF)

  5. Possible burst-like facet growth mode at high temperatures

    NASA Astrophysics Data System (ADS)

    Lovrić, Davorin; Vučić, Zlatko; Gladić, Jadranko

    2008-07-01

    A decade ago, a burst-like growth mode of c-facets of 4He crystals growing at mK temperatures, characterized by the alternation of time intervals during which the facet does not advance with the intervals of its fast advancement, was found [J.P. Ruutu, P.J. Hakonen, A.V. Babkin, A.Y. Parshin, J.S. Penttilä, J.P. Saramäki, G. Tvalashvili, Phys. Rev. Lett. 76 (1996) 4187]. We investigate the possibility that a similar facet growth mode exists for facets at high growth temperatures. We have applied the digital laser interferometry for monitoring facet kinetics of spherical copper selenide single crystals during their growth at constant volume growth rate around 800 K. Our analysis of directly measured (1 1 1) facet advancement curves has revealed that they consist of time intervals during which the facet does not advance vertically alternating with the time intervals of enhanced growth, resembling the burst-like facet growth mode. The results are discussed in terms of the enhancement of the local supersaturation induced by the existence of nucleation barrier.

  6. Domains and Facets: A Hierarchical Approach to Personality Assessment.

    ERIC Educational Resources Information Center

    McCrae, Robert R.

    The domain and facet approach to personality assessment is discussed. The strategy used to identify and measure aspects of the five factors of personality structure is described. Evidence concerning the factorial invariance of the resulting set of 30 facet scales and some recent evidence concerning their discriminant validity are reviewed. Some…

  7. New facets of the STS polytope generated from known facets of the ATS polytope.

    SciTech Connect

    Simonetti, Neil; Fischetti, Matteo; Balas, Egon; Carr, Robert D.

    2005-05-01

    While it had been known for a long time how to transform an asymmetric traveling salesman (ATS) problem on the complete graph with n vertices into a symmetric traveling salesman (STS) problem on an incomplete graph with 2n vertices, no method was available for using this correspondence to derive facets of the symmetric polytope from facets of the asymmetric polytope until the work of E. Balas and M. Fischetti in [Lifted cycle inequalities for the asymmetric traveling salesman problem, Mathematics of Operations Research 24 (2) (1999) 273-292] suggested an approach. The original Balas-Fischetti method uses a standard sequential lifting procedure for the computation of the coefficient of the edges that are missing in the incomplete STS graph, which is a difficult task when addressing classes of (as opposed to single) inequalities. In this paper we introduce a systematic procedure for accomplishing the lifting task. The procedure exploits the structure of the tight STS tours and organizes them into a suitable tree structure. The potential of the method is illustrated by deriving large new classes of facet-defining STS inequalities.

  8. Concurrent, parallel, multiphysics coupling in the FACETS project

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Candy, J.; Cobb, J.; Cohen, R. H.; Epperly, T.; Estep, D. J.; Krasheninnikov, S.; Malony, A. D.; McCune, D. C.; McInnes, L.; Pankin, A.; Balay, S.; Carlsson, J. A.; Fahey, M. R.; Groebner, R. J.; Hakim, A. H.; Kruger, S. E.; Miah, M.; Pletzer, A.; Shasharina, S.; Vadlamani, S.; Wade-Stein, D.; Rognlien, T. D.; Morris, A.; Shende, S.; Hammett, G. W.; Indireshkumar, K.; Pigarov, A. Yu; Zhang, H.

    2009-07-01

    FACETS (Framework Application for Core-Edge Transport Simulations), is now in its third year. The FACETS team has developed a framework for concurrent coupling of parallel computational physics for use on Leadership Class Facilities (LCFs). In the course of the last year, FACETS has tackled many of the difficult problems of moving to parallel, integrated modeling by developing algorithms for coupled systems, extracting legacy applications as components, modifying them to run on LCFs, and improving the performance of all components. The development of FACETS abides by rigorous engineering standards, including cross platform build and test systems, with the latter covering regression, performance, and visualization. In addition, FACETS has demonstrated the ability to incorporate full turbulence computations for the highest fidelity transport computations. Early indications are that the framework, using such computations, scales to multiple tens of thousands of processors. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists and applied mathematicians on the team.

  9. The spreading of a void on a facet during electromigration

    SciTech Connect

    Chu, X.; Bauer, C.L.; Mullins, W.W.; Klinger, L.M.

    1997-07-01

    A void of cross sectional area A may spread perpendicular to the applied electric field E{sub a} during electromigration because its leading surface develops a facet whose advance is limited by the supply of steps. If the facet is immobile (no step source) and the remaining surface is free to move, and if E{sub a}A is less than a threshold value, then the void assumes a stationary elongated shape dictated by a balance between capillarity and electric field. If E{sub a}A exceeds the threshold value, however, a balance is no longer possible, and the void spreads along the facet without arrest. If the facet has limited mobility, a balance is possible for all values of E{sub a}A, resulting in an elongated moving steady-state shape. The treatment simplifies the void shape as rectangular but preserves the essential features of capillarity and surface electromigration. The authors argue that the motion of a facet on a void along the outward normal requires defects (e.g., intersecting screw dislocations) that act as step sources since homogeneous nucleation of steps on the facet is expected to be negligible. Since voids in fine-line interconnects are often observed to be partially faceted, restricted void motion and resultant spreading which depend sensitively on crystallographic features, such as defect structure and grain orientation, may indeed limit the lifetime of fine-line interconnects in electronic devices.

  10. Treatment of Facet Injuries in the Cervical Spine.

    PubMed

    Khezri, Navid; Ailon, Tamir; Kwon, Brian K

    2017-01-01

    Facet injuries are common in the cervical spine. Many classification systems over the years have characterized the heterogeneity of these injuries. For unilateral facet fractures with minimal displacement and no neurological deficit, there is mounting evidence that better radiographic and clinical outcomes may be achieved with surgical treatment. Anterior and posterior approaches can both be utilized successfully for the surgical management of facet injuries. The anterior approach is well tolerated, allows one to address a disc herniation, and provides a high union rate with good sagittal alignment. The posterior approach allows for easier open reduction and biomechanically superior fixation.

  11. Specifying Valid Compound Terms in Interrelated Faceted Taxonomies

    NASA Astrophysics Data System (ADS)

    Analyti, Anastasia; Tzitzikas, Yannis; Spyratos, Nicolas

    In previous work, we proposed an algebra whose operators allow to specify the valid compound terms of a faceted taxonomy, in a flexible manner (by combining positive and negative statements). In this paper, we treat the same problem but in a more general setting, where the facet taxonomies are not independent but are (possibly) interrelated through narrower/broader relationships between their terms. The proposed algebra, called Interrelated Facet Composition Algebra (IFCA), is more powerful, as the valid compound terms of a faceted taxonomy can be derived through a smaller set of declared valid and/or invalid compound terms. An optimized (w.r.t. the naive approach) algorithm that checks compound term validity, according to a well-formed IFCA expression, and its worst-time complexity are provided.

  12. Hydrothermal growth of multi-facet anatase spheres

    NASA Astrophysics Data System (ADS)

    Wu, Jin-Ming; Song, Xiao-Mei; Ma, Lu-Yao; Wei, Xiao-Dan

    2011-03-01

    Titania with various nanostructures can be synthesized by several F --mediated procedures. In this paper, we report the synthesis of a novel multi-facet microsphere consisting of etched single-crystalline anatase by simply immersing metallic Ti plates in an HF aqueous solution under hydrothermal conditions. The etched multi-facet sphere was found to grow through the nucleation and growth of truncated bipyramids on a previously precipitated one to assemble a microsphere, and its subsequent etching by HF to expose the thermodynamic stable {1 0 1} facets. The photocatalytic activity of such etched multi-facet sphere thin films was evaluated utilizing rhodamine B and sulfonic salicylic acid in water as target molecules and compared with commercial Degussa P25 titania nanoparticles.

  13. Correlation between crystallographic orientation and surface faceting in UO2

    NASA Astrophysics Data System (ADS)

    Miao, Yinbin; Mo, Kun; Yao, Tiankai; Lian, Jie; Fortner, Jeffrey; Jamison, Laura; Xu, Ruqing; Yacout, Abdellatif M.

    2016-09-01

    Here coordinated experimental efforts to quantitatively correlate crystallographic orientation and surface faceting features in UO2 are reported upon. A sintered polycrystalline UO2 sample was thermally etched to induce the formation of surface faceting features. Synchrotron Laue microdiffraction was used to obtain a precise crystallographic orientation map for the UO2 surface grains. Scanning electron microscopy (SEM) was utilized to collect the detailed information on the surface morphology of the sample. The surface faceting features were found to be highly dependent on the crystallographic orientation. In most cases, Triple-plane structures containing one {100} plane and two {111} planes were found to dominate the surface of UO2. The orientation-faceting relationship established in this study revealed a practical and efficient method of determining crystallographic orientation based on the surface features captured by SEM images.

  14. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect

    Malony, Allen D; Shende, Sameer S; Huck, Kevin A; Mr. Alan Morris, and Mr. Wyatt Spear

    2012-03-14

    The goal of the FACETS project (Framework Application for Core-Edge Transport Simulations) was to provide a multiphysics, parallel framework application (FACETS) that will enable whole-device modeling for the U.S. fusion program, to provide the modeling infrastructure needed for ITER, the next step fusion confinement device. Through use of modern computational methods, including component technology and object oriented design, FACETS is able to switch from one model to another for a given aspect of the physics in a flexible manner. This enables use of simplified models for rapid turnaround or high-fidelity models that can take advantage of the largest supercomputer hardware. FACETS does so in a heterogeneous parallel context, where different parts of the application execute in parallel by utilizing task farming, domain decomposition, and/or pipelining as needed and applicable. ParaTools, Inc. was tasked with supporting the performance analysis and tuning of the FACETS components and framework in order to achieve the parallel scaling goals of the project. The TAU Performance System® was used for instrumentation, measurement, archiving, and profile / tracing analysis. ParaTools, Inc. also assisted in FACETS performance engineering efforts. Through the use of the TAU Performance System, ParaTools provided instrumentation, measurement, analysis and archival support for the FACETS project. Performance optimization of key components has yielded significant performance speedups. TAU was integrated into the FACETS build for both the full coupled application and the UEDGE component. The performance database provided archival storage of the performance regression testing data generated by the project, and helped to track improvements in the software development.

  15. Innovative Facet Passivation for High-Brightness Laser Diodes

    DTIC Science & Technology

    2016-02-05

    Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 high-power laser diodes, catastrophic optical damage, high energy lasers REPORT...factor bar) desired for military high energy lasers (HELs). COD of the front facet (laser mirror) is the main failure mechanism that constrains scaling... energy lasers (HELs). COD of the front facet (laser mirror) is the main failure mechanism that constrains scaling LD power by 10X over the SOA to 600 W

  16. Joint pain

    MedlinePlus

    ... that may be done include: CBC or blood differential C-reactive protein Joint x-ray Sedimentation rate ... chap 256. Schaible H-G. Joint pain: basic mechanisms. In: McMahon SB, Koltzenburg M, Tracey I, Turk ...

  17. Facet-Dependent Cr(VI) Adsorption of Hematite Nanocrystals.

    PubMed

    Huang, Xiaopeng; Hou, Xiaojing; Song, Fahui; Zhao, Jincai; Zhang, Lizhi

    2016-02-16

    In this study, the adsorption process of Cr(VI) on the hematite facets was systematically investigated with synchrotron-based Cr K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, density-functional theory calculation, and surface complexation models. Structural model fitting of EXAFS spectroscopy suggested that the interatomic distances of Cr-Fe were, respectively, 3.61 Å for the chromate coordinated hematite nanoplates with exposed {001} facets, 3.60 and 3.30 Å for the chromate coordinated hematite nanorods with exposed {001} and {110} facets, which were characteristic of inner-sphere complexation. In situ ATR-FTIR spectroscopy analysis confirmed the presence of two inner-sphere surface complexes with C3ν and C2ν symmetry, while the C3ν and C2ν species were assigned to monodentate and bidentate inner-sphere surface complexes with average Cr-Fe interatomic distances of 3.60 and 3.30 Å, respectively. On the basis of these experimental and theoretical results, we concluded that HCrO4(-) as dominated Cr(VI) species was adsorbed on {001} and {110} facets in inner-sphere monodentate mononuclear and bidentate binuclear configurations, respectively. Moreover, the Cr(VI) adsorption performance of hematite facets was strongly dependent on the chromate complexes formed on the hematite facets.

  18. A diffuse interface model of grain boundary faceting

    NASA Astrophysics Data System (ADS)

    Abdeljawad, Fadi; Medlin, Douglas; Zimmerman, Jonathan; Hattar, Khalid; Foiles, Stephen

    Incorporating anisotropy into thermodynamic treatments of interfaces dates back to over a century ago. For a given orientation of two abutting grains in a pure metal, depressions in the grain boundary (GB) energy may exist as a function of GB inclination, defined by the plane normal. Therefore, an initially flat GB may facet resulting in a hill-and-valley structure. Herein, we present a diffuse interface model of GB faceting that is capable of capturing anisotropic GB energies and mobilities, and accounting for the excess energy due to facet junctions and their non-local interactions. The hallmark of our approach is the ability to independently examine the role of each of the interface properties on the faceting behavior. As a demonstration, we consider the Σ 5 < 001 > tilt GB in iron, where faceting along the { 310 } and { 210 } planes was experimentally observed. Linear stability analysis and numerical examples highlight the role of junction energy and associated non-local interactions on the resulting facet length scales. On the whole, our modeling approach provides a general framework to examine the spatio-temporal evolution of highly anisotropic GBs in polycrystalline metals. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  19. Lumbar facet cyst resolution following anterior interbody fusion.

    PubMed

    Massey, Gene M; Caputo, Adam M; Michael, Keith W; Isaacs, Robert E; Brown, Christopher R

    2013-12-01

    Facet cysts are a relatively common source of neural compression in the lumbar spine. Open decompression and fusion are frequently used to treat the stenosis and instability associated with this pathology. Recently, anterior lumbar interbody fusion (ALIF) has increased in popularity for the treatment of lumbar degenerative conditions. ALIF may achieve indirect decompression of the neural elements with less surgical morbidity than conventional open approaches. To date, there are no published reports describing the use of indirect decompression or interbody fusion for the treatment of facet cysts. We report a patient who developed an L4-L5 facet cyst secondary to degenerative changes and spondylolisthesis. ALIF with posterior instrumentation was used to address his condition. Six months after surgery, the patient had complete resolution of his symptoms. MRI revealed complete resolution of the facet cyst. This patient provides previously unreported evidence that interbody fusion alone may result in facet cyst resolution. Clinical studies are needed to evaluate if interbody fusion can consistently relieve the symptoms associated with facet cysts without the use of direct decompression.

  20. Joint Interdiction

    DTIC Science & Technology

    2016-09-09

    Purpose This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the...governmental and nongovernmental organizations, multinational forces, and other interorganizational partners. It provides military guidance for the...exercise of authority by combatant commanders and other joint force commanders (JFCs), and prescribes joint doctrine for operations and training. It

  1. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  2. Facet-selective photodeposition of gold nanoparticles on faceted ZnO crystals for visible light photocatalysis.

    PubMed

    Wang, Xuewen; Wang, Wuyou; Miao, Yuanquan; Feng, Gang; Zhang, Rongbin

    2016-08-01

    Hexagonal prism-like ZnO crystals dominated with polar facets were synthesized using a hydrothermal method. The Gold (Au) nanoparticles were selectively photodeposited on the polar surfaces of faceted ZnO crystals as a result of anisotropic photocatalytic activities of the polar and nonpolar facets. The size of Au nanoparticles uniformly dispersed on the polar facets increased with increasing Au-loading amount. These Au-loaded ZnO crystals showed an additional visible light absorption band from 400nm to 800nm. The 0.1wt% Au-loaded ZnO crystals with visible light absorption peak at approximately 690nm exhibited the highest photocatalytic activity under visible light irradiation.

  3. Structural Equation Modelling of Multiple Facet Data: Extending Models for Multitrait-Multimethod Data

    ERIC Educational Resources Information Center

    Bechger, Timo M.; Maris, Gunter

    2004-01-01

    This paper is about the structural equation modelling of quantitative measures that are obtained from a multiple facet design. A facet is simply a set consisting of a finite number of elements. It is assumed that measures are obtained by combining each element of each facet. Methods and traits are two such facets, and a multitrait-multimethod…

  4. Beyond Text Queries and Ranked Lists: Faceted Search in Library Catalogs

    ERIC Educational Resources Information Center

    Niu, Xi

    2012-01-01

    Since the adoption of faceted search in a small number of academic libraries in 2006, faceted library catalogs have gained popularity in many academic and public libraries. This dissertation seeks to understand whether faceted search improves the interactions between searchers and library catalogs and to understand ways that facets are used in…

  5. Use of land facets to design linkages for climate change.

    PubMed

    Brost, Brian M; Beier, Paul

    2012-01-01

    Least-cost modeling for focal species is the most widely used method for designing conservation corridors and linkages. However, these linkages have been based on current species' distributions and land cover, both of which will change with large-scale climate change. One method to develop corridors that facilitate species' shifting distributions is to incorporate climate models into their design. But this approach is enormously complex and prone to error propagation. It also produces outputs at a grain size (km2) coarser than the grain at which conservation decisions are made. One way to avoid these problems is to design linkages for the continuity and interspersion of land facets, or recurring landscape units of relatively uniform topography and soils. This coarse-filter approach aims to conserve the arenas of biological activity rather than the temporary occupants of those arenas. In this paper, we demonstrate how land facets can be defined in a rule-based and adaptable way, and how they can be used for linkage design in the face of climate change. We used fuzzy c-means cluster analysis to define land facets with respect to four topographic variables (elevation, slope angle, solar insolation, and topographic position), and least-cost analysis to design linkages that include one corridor per land facet. To demonstrate the flexibility of our procedures, we designed linkages using land facets in three topographically diverse landscapes in Arizona, USA. Our procedures can use other variables, including soil variables, to define land facets. We advocate using land facets to complement, rather than replace, existing focal species approaches to linkage design. This approach can be used even in regions lacking land cover maps and is not affected by the bias and patchiness common in species occurrence data.

  6. PivotPaths: Strolling through Faceted Information Spaces.

    PubMed

    Dork, M; Riche, Nathalie Henry; Ramos, G; Dumais, S

    2012-12-01

    We present PivotPaths, an interactive visualization for exploring faceted information resources. During both work and leisure, we increasingly interact with information spaces that contain multiple facets and relations, such as authors, keywords, and citations of academic publications, or actors and genres of movies. To navigate these interlinked resources today, one typically selects items from facet lists resulting in abrupt changes from one subset of data to another. While filtering is useful to retrieve results matching specific criteria, it can be difficult to see how facets and items relate and to comprehend the effect of filter operations. In contrast, the PivotPaths interface exposes faceted relations as visual paths in arrangements that invite the viewer to `take a stroll' through an information space. PivotPaths supports pivot operations as lightweight interaction techniques that trigger gradual transitions between views. We designed the interface to allow for casual traversal of large collections in an aesthetically pleasing manner that encourages exploration and serendipitous discoveries. This paper shares the findings from our iterative design-and-evaluation process that included semi-structured interviews and a two-week deployment of PivotPaths applied to a large database of academic publications.

  7. Facet tropism: comparison of plain film and computed tomography examinations.

    PubMed

    Cox, J M; Aspegren, D D; Trier, K K

    1991-01-01

    This study compares the findings of plain film X-ray and computed CT examination in the diagnosis of facet orientation and the presence of tropism. Twenty consecutive patients having lumbar disc disease with sciatica were studied utilizing plain X-ray as well as CT scanning. A chiropractic radiologist read the films to determine if facet facings were sagittally, semi-sagittally or coronally oriented on both CT and plain X-ray study. CT was accepted as the most accurate method to determine the true facet orientation, and plain X-ray interpretation of facet orientation was compared to the CT reading. There was a statistically significant relationship in diagnosing tropism between plain film X-ray and CT readings, with a predictive accuracy that ranged from 58-84% across the three segmental levels. However, the exact concordance of plain film X-ray and CT readings for right and left facet facings was very low. This raises the question of how the profession defines diagnostic accuracy.

  8. Facets of psychopathy, heart rate variability and cognitive function.

    PubMed

    Hansen, Anita Lill; Johnsen, Bjørn Helge; Thornton, David; Waage, Leif; Thayer, Julian F

    2007-10-01

    The aim of the present study was to investigate whether the four facets of Hare's Psychopathy Checklist-Revised (PCL-R; Hare, 1991; Bolt, Hare, Vitale, & Newman, 2004) were related to physiological and cognitive mechanisms. Fifty-three male prisoners participated in this study. Physiological responses were measured as heart rate variability (HRV) and heart rate (HR). Cognitive functions were measured using a continuous performance test (CPT; California Computerized Assessment Package, Abbreviated version) and a working memory test (WMT); based on Baddeley & Hitch (1974). The regression analysis of the HRV revealed that the interpersonal facet explained most of the variance during baseline (28%), CPT (16%), and WMT (12%). This was also true for the HR data during baseline (28%), CPT (20%), WMT (10%), and recovery (13%). The antisocial facet explained 10% of the variance only during baseline. Subjects scoring high compared to low on the interpersonal facet also showed better cognitive functioning. The study suggests that the different facets were differently associated with both physiological and cognitive functions.

  9. On the creep constrained diffusive cavitation of grain boundary facets

    NASA Astrophysics Data System (ADS)

    Tvergaard, Viggo

    CREEP rupture in a polycrystalline metal at a high temperature, by cavity growth on a number of grain boundary facets, is studied numerically. An axisymmetric model problem is analysed, in which a cavitating facet is represented as disk-shaped, and the model dimensions are taken to represent spacings between neighbouring cavitating facets. For the grains both power law creep and elastic deformations are taken into account, and the description of cavity growth is based on an approximate expression that incorporates the coupled influence of grain boundary diffusion and power law creep. The cases considered include creep-constrained cavity growth at low stresses, where the voids link up to form grain boundary cracks at relatively small overall strains, as well as the power law creep dominated behaviour at higher stress levels, where rupture occurs at large overall strains. The numerical results are compared with results based on various simplified analyses.

  10. New surfaces stabilized by adsorbate-induced faceting

    NASA Astrophysics Data System (ADS)

    Kaghazchi, Payam; Jacob, Timo; Ermanoski, Ivan; Chen, Wenhua; Madey, Theodore E.

    2012-07-01

    Faceting is a form of self-assembly of single-crystal surfaces at the nanometer-scale in which an initially planar surface converts to a ‘hill-and-valley’ structure, exposing new faces of low-index surfaces. Our recent studies revealed that, upon annealing in O2, three-sided nanoscale pyramids form on Ir(210) exposing smooth {311} and partially restructured (110) faces. Through a combination of scanning tunneling microscopy and density functional theory, we identify this structure to be a stepped double-missing-row reconstruction, which is only stable on nanopyramidal facets, not on a planar Ir(110) surface. This faceting-enabled stabilization of a hitherto unstable surface points to a new approach to prepare nanoscale model catalysts for structure-sensitivity studies in heterogeneous (electro-)catalysis with high selectivity and reactivity.

  11. Genetic correlations among facets of type A behavior and personality.

    PubMed

    Johnson, Andrew M; Schermer, Julie Aitken; Vernon, Philip A; Jang, Kerry L

    2012-08-01

    The purpose of this study was to examine the phenotypic, genetic, and environmental relationships between multiple dimensions of Type A behavior and personality. Adult twins (N=247 pairs) completed a self-report personality measure and a work style questionnaire that measured six facets of Type A behavior: impatience, anger, work involvement, time urgency, job dissatisfaction, and competitiveness. Univariate results suggest that only the job dissatisfaction facet of Type A behavior was explained by non-genetic (environmental) factors. Multivariate results suggest that all of the genetically determined facets of Type A behavior show some correspondence with at least one of the personality factors found in the study, suggesting that some of the phenotypic (observed) relationships could be due to common genetic factors.

  12. Unilateral facet subluxations: an example of a missed post-traumatic unilateral facet subluxation — a case report

    PubMed Central

    Tuling, Jeffrey R; Hsu, William H

    1999-01-01

    Unilateral facet injuries occur in 4-16% of patients with cervical spine injuries, (of which unilateral facet subluxations occur as a subgroup in this population). These injuries arise in motor vehicle accidents because of flexion-distraction forces, or flexion of an already rotated head. Due to the common presentation of a lack of neurological signs and symptoms, delayed diagnosis of unilateral facet subluxations are common. As a result, it is imperative that the proper diagnosis is made so that patient care can be made more effective with ultimately less sequelae. For the clinician, diagnosis can be aided by the use of radiographic analysis. Adequate radiographic analysis is an important tool to accurately assess whiplash associated disorders. Radiographic findings of facet subluxations are subtle on routine views. Utilizing oblique views, the diagnoses are usually evident. Therefore, oblique views are very useful in the clinical setting. This case report will describe a 29-year-old female with a missed unilateral facet subluxation, radiographic findings and characteristics, and the clinical utility of oblique views in patients suffering from whiplash associated disorders. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6

  13. Treatment of isolated cervical facet fractures: a systematic review.

    PubMed

    Kepler, Christopher K; Vaccaro, Alexander R; Chen, Eric; Patel, Alpesh A; Ahn, Henry; Nassr, Ahmad; Shaffrey, Christopher I; Harrop, James; Schroeder, Gregory D; Agarwala, Amit; Dvorak, Marcel F; Fourney, Daryl R; Wood, Kirkham B; Traynelis, Vincent C; Yoon, S Tim; Fehlings, Michael G; Aarabi, Bizhan

    2015-10-30

    OBJECT In this clinically based systematic review of cervical facet fractures, the authors' aim was to determine the optimal clinical care for patients with isolated fractures of the cervical facets through a systematic review. METHODS A systematic review of nonoperative and operative treatment methods of cervical facet fractures was performed. Reduction and stabilization treatments were compared, and analysis of postoperative outcomes was performed. MEDLINE and Scopus databases were used. This work was supported through support received from the Association for Collaborative Spine Research and AOSpine North America. RESULTS Eleven studies with 368 patients met the inclusion criteria. Forty-six patients had bilateral isolated cervical facet fractures and 322 had unilateral isolated cervical facet fractures. Closed reduction was successful in 56.4% (39 patients) and 63.8% (94 patients) of patients using a halo vest and Gardner-Wells tongs, respectively. Comparatively, open reduction was successful in 94.9% of patients (successful reduction of open to closed reduction OR 12.8 [95% CI 6.1-26.9], p < 0.0001); 183 patients underwent internal fixation, with an 87.2% success rate in maintaining anatomical alignment. When comparing the success of patients who underwent anterior versus posterior procedures, anterior approaches showed a 90.5% rate of maintenance of reduction, compared with a 75.6% rate for the posterior approach (anterior vs posterior OR 3.1 [95% CI 1.0-9.4], p = 0.05). CONCLUSIONS In comparison with nonoperative treatments, operative treatments provided a more successful outcome in terms of failure of treatment to maintain reduction for patients with cervical facet fractures. Operative treatment appears to provide superior results to the nonoperative treatments assessed.

  14. Development of an improved mirror facet for space applications

    NASA Technical Reports Server (NTRS)

    Schertz, Paul; Saifee, Shabbar; Lammert, Luke

    1991-01-01

    A fabrication technique was successfully developed for a metallic aluminum honeycomb, high-accuracy, lightweight, and long-life solar concentrator (mirror) for Advanced Solar Dynamic Space Power Systems. The program scope was limited to the development, fabrication, evaluation, and delivery of a solar concentrator facet (petal) that was sized for a 2-meter deployable solar concentrator. A surface accuracy of 1.0 mrad was achieved. The development incorporated tooling design, material selection, facet forming, adhesive selection, testing, and analysis. Techniques for applying levelizing, reflective, and protective optical coatings were also developed.

  15. Kinetic faceting and anomalous coarsening in elastically inhomogeneous multiphase systems.

    PubMed

    Perez, Danny; Lewis, Laurent J

    2007-02-16

    With a view of finding a route toward microstructural stability in alloys, we numerically study the impact of elastic inhomogeneities on the growth of inclusions in multiphase systems. We show that growth can proceed either continuously at rough interfaces, or in a layer-by-layer fashion following an elastically induced kinetic faceting process. In the former case, the chemical potential of the inclusions is a smooth function of size, while in the latter case, elasticity increases the barrier for nucleation of new terraces on the facets, leading to an oscillatory behavior of the chemical potential and hence a strong resistance against coarsening, opening up the possibility to stabilize the structure.

  16. Ceramic joints

    DOEpatents

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  17. From facets to facets: how does work function vary over a gold nanocluster?

    NASA Astrophysics Data System (ADS)

    Gao, Lingyuan; Souto, Jaime; Chelikowsky, James; Demkov, Alex

    Owing to their potential applications in catalysis, gold nanoclusters are a focus of intense research. The work function Φ, which can be measured using photoemission spectroscopy is a key parameter used to characterize the catalytic performance of the cluster. Φ is determined by the difference between the electrostatic potential just outside the metal surface and the Fermi energy of the cluster. We use a relativistic version of the real space first-principles code PARSEC to compute the work function of gold nanoclusters with dimensions on the order of a nanometer, which is similar in size to those used in experiment. We illustrate how the work function depends on the surface orientation of the nanocluster facets and compare our results with available experimental data We acknowledge supports from SciDAC program, Department of Energy, Office of Science, Advanced Scientific Computing Research and Basic Energy Sciences grant DE-SC0008877 for work on algorithms. Two of us (JRC and JS-C) acknowledge support for the work on nanostructures from grant from the U.S. Department of Energy: DE-FG02-06ER46286.

  18. The Cool and Belkin Faceted Classification of Information Interactions Revisited

    ERIC Educational Resources Information Center

    Huvila, Isto

    2010-01-01

    Introduction: The complexity of human information activity is a challenge for both practice and research in information sciences and information management. Literature presents a wealth of approaches to analytically structure and make sense of human information activity including a faceted classification model of information interactions published…

  19. Beyond Conflict: Functional Facets of the Work-Family Interplay

    ERIC Educational Resources Information Center

    Wiese, Bettina S.; Seiger, Christine P.; Schmid, Christian M.; Freund, Alexandra M.

    2010-01-01

    The present paper deals with three positive facets of the work-family interplay, i.e., transfer of competencies, transfer of positive mood, and cross-domain compensation. The latter refers to the experience that engagement in one domain helps dealing with failures in the other domain. In two correlational studies (N[subscript 1] = 107 working…

  20. Hinge specification for a square-faceted tetrahedral truss

    NASA Technical Reports Server (NTRS)

    Adams, L. R.

    1984-01-01

    A square-faceted tetrahedral truss is geometrically analyzed. Expressions are developed for single degree of freedom hinges which allow packaging of the structure into a configuration in which all members are parallel and closely packed in a square pattern. Deployment is sequential, thus providing control over the structure during deployment.

  1. Lumbar facet stress fracture in a ballet dancer.

    PubMed

    Fehlandt, A F; Micheli, L J

    1993-12-01

    A frequent cause of back pain in athletes and dancers is stress injury to the posterior vertebral elements. Stress fractures affect the pars interarticularis and, rarely, other vertebral regions. The authors present their experience with the diagnosis and treatment of a fourth lumbar inferior articular facet stress fracture in a ballerina in this brief report and discuss the literature concerning posterior element stress fractures.

  2. Personality Facets and RIASEC Interests: An Integrated Model

    ERIC Educational Resources Information Center

    Armstrong, Patrick Ian; Anthoney, Sarah Fetter

    2009-01-01

    Research examining links between personality and interest have typically focused on links between measures of the five factor model and Holland's RIASEC types. However, the five factor model of personality can be divided in to a larger set of narrow domain personality scales measuring facets of the "big five" traits. Research in a number of fields…

  3. Calculation of farfield distortion for a tilted-facet SOA

    SciTech Connect

    Ratowsky, R.P.; Dijaili, S.; Walker, J.; Patterson, F.; Kallman, J.; Deri, R.

    1996-04-01

    Semiconductor optical amplifiers (SOAs) are very important elements for telecommunications, computer communications, and signal processing applications. For stable, low noise operation, the modal reflection into the guided SOA mode must be minimized; modal reflectivity typically has to be kept below about {minus}40 dB. This can be accomplished by antireflection (AR) coatings, or by tilting of the SOA end facet. The latter approach has been vigorously pursued recently, because effective AR coatings require very high tolerances and have polarization-dependent reflectivities. Consequently, there has been a great deal of theoretical effort aimed at calculating the modal reflectivity from tilted interfaces, using a variety of approaches. However, there has been little attention directed toward calculating the transmitted field of a tilted-facet SOA. This is a problem of considerable importance, because the coupling of the SOA light to an element such as an optical fiber depends critically on the field distribution at the entrance plane to the fiber. Moreover, experimental measurements of the farfield of tilted-facet SOAs have revealed a curious crescent-shaped intensity distribution. To improve coupling efficiency it is important to understand to what extent this phenomenon is due to the SOA modal field distribution and to what extent it is due to the tilted interface. The authors explain the crescent-shaped farfield intensity distribution of tilted-facet SOAs using vector wave optics, and discuss implications for coupling to other optical elements.

  4. Empirical Identification of the Major Facets of Conscientiousness

    ERIC Educational Resources Information Center

    MacCann, Carolyn; Duckworth, Angela Lee; Roberts, Richard D.

    2009-01-01

    Conscientiousness is often found to predict academic outcomes, but is defined differently by different models of personality. High school students (N = 291) completed a large number of Conscientiousness items from different models and the Big Five Inventory (BFI). Exploratory and confirmatory factor analysis of the items uncovered eight facets:…

  5. Facet-Dependent Photoreduction on Single ZnO Crystals.

    PubMed

    Debroye, Elke; Van Loon, Jordi; Yuan, Haifeng; Janssen, Kris P F; Lou, Zaizhu; Kim, Sooyeon; Majima, Tetsuro; Roeffaers, Maarten B J

    2017-01-19

    Photocatalytic reactions occur at the crystal-solution interface, and hence specific crystal facet expression and surface defects can play an important role. Here we investigate the structure-related photoreduction at zinc oxide (ZnO) microparticles via integrated light and electron microscopy in combination with silver metal photodeposition. This enables a direct visualization of the photoreduction activity at specific crystallographic features. It is found that silver nanoparticle photodeposition on dumbbell-shaped crystals mainly takes place at the edges of O-terminated (0001̅) polar facets. In contrast, on ZnO microrods photodeposition is more homogeneously distributed with an increased activity at {101̅1̅} facets. Additional time-resolved measurements reveal a direct spatial link between the enhanced photoactivity and increased charge carrier lifetimes. These findings contradict previous observations based on indirect, bulk-scale experiments, assigning the highest photocatalytic activity to polar facets. The presented research demonstrates the need for advanced microscopy techniques to directly probe the location of photocatalytic activity.

  6. Facet-Dependent Photoreduction on Single ZnO Crystals

    PubMed Central

    2016-01-01

    Photocatalytic reactions occur at the crystal–solution interface, and hence specific crystal facet expression and surface defects can play an important role. Here we investigate the structure-related photoreduction at zinc oxide (ZnO) microparticles via integrated light and electron microscopy in combination with silver metal photodeposition. This enables a direct visualization of the photoreduction activity at specific crystallographic features. It is found that silver nanoparticle photodeposition on dumbbell-shaped crystals mainly takes place at the edges of O-terminated (0001̅) polar facets. In contrast, on ZnO microrods photodeposition is more homogeneously distributed with an increased activity at {101̅1̅} facets. Additional time-resolved measurements reveal a direct spatial link between the enhanced photoactivity and increased charge carrier lifetimes. These findings contradict previous observations based on indirect, bulk-scale experiments, assigning the highest photocatalytic activity to polar facets. The presented research demonstrates the need for advanced microscopy techniques to directly probe the location of photocatalytic activity. PMID:28001412

  7. Mechanisms of surface alloy segregation on faceted core-shell nanowire growth

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Voorhees, Peter W.; Davis, Stephen H.

    2017-03-01

    A general two-dimensional faceted model that accounts for capillarity and deposition of an AxB 1-x alloy is developed for the growth of the shell on a hexagonal core. With this model, the surface alloy segregation and morphological evolution in the processes of the faceted core-shell nanowire growth are studied both analytically and numerically. Mechanisms of formation of Al-rich stripes along { 112 } facets and Al-poor quantum dots/wires at the apices of { 112 } facets are identified. More specifically, it is found that diffusion tends to move the atoms from { 112 } facets to { 110 } facets. The formation of Al-rich stripes along the { 112 } facets is due to the large ratios of mobilities of Al atoms and Ga atoms on { 112 } facets, even though Al atoms diffuse slower than Ga on the { 110 } facets. In addition, the difference of interaction parameters in the enthalpy on different facets can also lead to lines of enhanced concentration of Al behind { 112 } facets. If the attachment rates of Al on the { 112 } facets are smaller than that on { 110 } facets, Al-poor dots will grow at the end of the Al-rich stripes because the growth process switches from diffusion dominant to deposition dominant when the size of the nanowire gets large. Moreover, influences of different parameters on the distribution of concentrations of the atoms in the shell are investigated in details.

  8. Etiology and Progression of Acute Muscle Tension Related Low Back Pain Occurring During Sustained Activity Including Combat Training Exercises

    DTIC Science & Technology

    1992-01-31

    myelogram consistent with HNP. b. DEGENERATIVE ARTHROSIS , SPONDYLOLYSIS, SPONDYLOLISTHESIS: (1) Radiographic findings consistent with spondylolysis...spondylolisthesis, or degenerative arthritis. This would include facet arthrosis , oseteophyte formation, disc space narrowing, anterior/posterior

  9. Terahertz Light Source and User Area at FACET

    SciTech Connect

    Wu, Z.; Li, S.Z.; Litos, M.; Fisher, A.D.; Hogan, M.J.; /SLAC

    2011-11-08

    FACET at SLAC provides high charge, high peak current, low emittance electron beam that is bunched at THz wavelength scale during its normal operation. A THz light source based coherent transition radiation (CTR) from this beam would potentially be the brightest short-pulse THz source ever constructed. Efforts have been put into building this photon source together with a user area, to provide a platform to utilize this unique THz radiation for novel nonlinear and ultrafast phenomena researches and experiments. Being a long-time underutilized portion of the electromagnetic spectrum, terahertz (100 GHz {approx} 10 THz) spectral range is experiencing a renaissance in recent years, with broad interests from chemical and biological imaging, material science, telecommunication, semiconductor and superconductor research, etc. Nevertheless, the paucity of THz sources especially strong THz radiation hinders both its commercial applications and nonlinear processes research. FACET - Facilities for Accelerator science and Experimental Test beams at SLAC - provides 23 GeV electron beam with peak currents of {approx} 20 kA that can be focused down to 100 {mu}m{sup 2} transversely. Such an intense electron beam, when compressed to sub-picosecond longitudinal bunch length, coherently radiates high intensity EM fields well within THz frequency range that are orders of magnitude stronger than those available from laboratory tabletop THz sources, which will enable a wide variety of THz related research opportunities. Together with a description of the FACET beamline and electron beam parameters, this paper will report FACET THz radiation generation via coherent transition radiation and calculated photon yield and power spectrum. A user table is being set up along the THz radiation extraction sites, and equipped with various signal diagnostics including THz power detector, Michelson interferometer, sample stages, and sets of motorized optical components. This setup will also be

  10. [Kapandji-Sauvé procedure for chronic disorders of the distal radioulnar joint with special regard to the long-term results].

    PubMed

    Daecke, W; Martini, A K; Streich, N A

    2003-05-01

    We present the preliminary results of a retrospective study on 56 patients who underwent the Kapandji-Sauvé procedure for chronic disorders of the distal radioulnar joint (DRUJ). Outcome was assessed with special regard to the long-term results. The average follow-up was 5.9 years (1 to 12 years). 15 of the 56 operations were performed before 1996. Most procedures were performed because of secondary arthrosis or chronic dislocation of the DRUJ after distal radius fracture. Patients were assessed for pain, range of motion of wrist and forearm and radiological features. The DASH score and Mayo wrist score were used. Pain was improved in 94 % of the patients, but only 53 % were free of symptoms during heavy manual labour concerning the operated site. In four cases symptoms of ulnar impingement were found. Improvement in range of motion of wrist and forearm was significant. The post-operative DASH score was 22.6 +/- 20.0 and the Mayo wrist score was 79.5 +/- 14.6. One non-union of the DRUJ with consecutive fracture of the fixation screw and an algodystrophy in another case were found as postoperative complications. The only long-term complication consisted of a beginning humeroradial arthrosis ten years after the operation. The results demonstrate high patient satisfaction and reliable improvement in range of motion. Our results confirm the Kapandji-Sauvé procedure to be a reliable salvage procedure for arthrosis or chronic dislocation of the DRUJ even after long-term follow up.

  11. Compliant joint

    NASA Technical Reports Server (NTRS)

    Eklund, Wayne D. (Inventor); Kerley, James J. (Inventor)

    1990-01-01

    A compliant joint is provided for prosthetic and robotic devices which permits rotation in three different planes. The joint provides for the controlled use of cable under motion. Perpendicular outer mounting frames are joined by swaged cables that interlock at a center block. Ball bearings allow for the free rotation of the second mounting frame relative to the first mounting frame within a predetermined angular rotation that is controlled by two stop devices. The cables allow for compliance at the stops and the cables allow for compliance in six degrees of freedom enabling the duplication or simulation of the rotational movement and flexibility of a natural hip or knee joint, as well as the simulation of a joint designed for a specific robotic component for predetermined design parameters.

  12. Joint Commission

    MedlinePlus

    Skip to main content The Joint Commission Log In | Request Guest Access Forgot password? | Log In Help Contact Us | Careers | JCR Web Store | Press Room Search Home Accreditation Accreditation Ambulatory Health ...

  13. How Many Facets are Needed to Represent the Surface Energy Balance of an Urban Area?

    NASA Astrophysics Data System (ADS)

    Porson, Aurore; Harman, Ian N.; Bohnenstengel, Sylvia I.; Belcher, Stephen E.

    2009-07-01

    We investigate the question of how many facets are needed to represent the energy balance of an urban area by developing simplified 3-, 2- and 1-facet versions of a 4-facet energy balance model of two-dimensional streets and buildings. The 3-facet model simplifies the 4-facet model by averaging over the canyon orientation, which results in similar net shortwave and longwave balances for both wall facets, but maintains the asymmetry in the heat fluxes within the street canyon. For the 2-facet model, on the assumption that the wall and road temperatures are equal, the road and wall facets can be combined mathematically into a single street-canyon facet with effective values of the heat transfer coefficient, albedo, emissivity and thermodynamic properties, without further approximation. The 1-facet model requires the additional assumption that the roof temperature is also equal to the road and wall temperatures. Idealised simulations show that the geometry and material properties of the walls and road lead to a large heat capacity of the combined street canyon, whereas the roof behaves like a flat surface with low heat capacity. This means that the magnitude of the diurnal temperature variation of the street-canyon facets are broadly similar and much smaller than the diurnal temperature variation of the roof facets. Consequently, the approximation that the street-canyon facets have similar temperatures is sound, and the road and walls can be combined into a single facet. The roof behaves very differently and a separate roof facet is required. Consequently, the 2-facet model performs similarly to the 4-facet model, while the 1-facet model does not. The models are compared with previously published observations collected in Mexico City. Although the 3- and 2-facet models perform better than the 1-facet model, the present models are unable to represent the phase of the sensible heat flux. This result is consistent with previous model comparisons, and we argue that this

  14. The role of surface passivation in controlling Ge nanowire faceting

    DOE PAGES

    Gamalski, A. D.; Tersoff, J.; Kodambaka, S.; ...

    2015-11-05

    In situ transmission electron microscopy observations of nanowire morphologies indicate that during Au-catalyzed Ge nanowire growth, Ge facets can rapidly form along the nanowire sidewalls when the source gas (here, digermane) flux is decreased or the temperature is increased. This sidewall faceting is accompanied by continuous catalyst loss as Au diffuses from the droplet to the wire surface. We suggest that high digermane flux and low temperatures promote effective surface passivation of Ge nanowires with H or other digermane fragments inhibiting diffusion and attachment of Au and Ge on the sidewalls. Furthermore, these results illustrate the essential roles of themore » precursor gas and substrate temperature in maintaining nanowire sidewall passivation, necessary to ensure the growth of straight, untapered, <111>-oriented nanowires.« less

  15. Faceting and commensurability in crystal structures of colloidal thin films.

    PubMed

    Ramiro-Manzano, F; Meseguer, F; Bonet, E; Rodriguez, I

    2006-07-14

    This Letter investigates the influence of finite size effects on the particle arrangement of thin film colloidal crystals. A rich variety of crystallographic faceting with large single domain microcrystallites is shown. Optical reflectance experiments together with scanning electron microscopy permit the identification of the crystal symmetry and the facet orientation, as well as the exact number of monolayers. When the cell thickness is not commensurable with a high symmetry layering, particles arrange themselves in a periodic distribution of (111)- and (100)-orientated face centered cubic (fcc) microcrystallites separated by planar defects. These structures can be described as a fcc ordering orientated along a vicinal surface, modified by a periodic distribution of fcc (111) stacking faults.

  16. The role of surface passivation in controlling Ge nanowire faceting

    SciTech Connect

    Gamalski, A. D.; Tersoff, J.; Kodambaka, S.; Zakharov, D. N.; Ross, F. M.; Stach, E. A.

    2015-11-05

    In situ transmission electron microscopy observations of nanowire morphologies indicate that during Au-catalyzed Ge nanowire growth, Ge facets can rapidly form along the nanowire sidewalls when the source gas (here, digermane) flux is decreased or the temperature is increased. This sidewall faceting is accompanied by continuous catalyst loss as Au diffuses from the droplet to the wire surface. We suggest that high digermane flux and low temperatures promote effective surface passivation of Ge nanowires with H or other digermane fragments inhibiting diffusion and attachment of Au and Ge on the sidewalls. Furthermore, these results illustrate the essential roles of the precursor gas and substrate temperature in maintaining nanowire sidewall passivation, necessary to ensure the growth of straight, untapered, <111>-oriented nanowires.

  17. Recurrent gallstone ileus: beware of the faceted stone.

    PubMed

    Gandamihardja, Tasha A K; Kibria, Shah M G

    2014-11-12

    A 73-year-old man with gallstone disease was admitted with right upper quadrant abdominal pain. He was treated for cholecystitis with intravenous antibiotics. Two days later, he reported of new onset left iliac fossa pain, with tenderness and guarding. An abdominal X-ray demonstrated small bowel obstruction, a CT scan demonstrated an impacted gallstone within the proximal ileum. He was treated for a gallstone ileum and underwent an uncomplicated laparotomy, small bowel enterotomy and removal of a faceted gallstone. Three months later, the patient re-presented with generalised abdominal pain, guarding and rebound tenderness. Small bowel obstruction was again demonstrated with an impacted gallstone within the distal ileum seen on CT scan. A second laparotomy revealed two further faceted gallstones, which were removed through an enterotomy. The densely adherent gallbladder to the duodenum precluded a surgical repair of the cholecystoduodenal fistula. He made an uneventful recovery and was subsequently discharged home.

  18. Extraversion and psychopathology: A facet-level analysis.

    PubMed

    Watson, David; Stasik, Sara M; Ellickson-Larew, Stephanie; Stanton, Kasey

    2015-05-01

    The goal of this study was to explicate how the lower order facets of extraversion are related to psychopathology. We used a "bottom-up" approach in which specific extraversion scales from 3 comprehensive personality inventories were used to model these facets as latent factors. We collected both self-report and interview measures of a broad range of psychopathology from a large community sample. Replicating previous findings using a similar approach (Naragon-Gainey & Watson, 2014; Naragon-Gainey, Watson, & Markon, 2009), structural analyses yielded four factors: Positive Emotionality, Sociability, Assertiveness, and Experience Seeking. Scores on these latent dimensions were related to psychopathology in correlational analyses and in two sets of regressions (the first series used the four facets as predictors; the second included composite scores on the other Big Five domains as additional predictors). These results revealed a striking level of specificity. As predicted, Positive Emotionality displayed especially strong negative links to depressive symptoms and diagnoses. Sociability also was negatively related to psychopathology, showing particularly strong associations with indicators of social dysfunction and the negative symptoms of schizotypy (i.e., social anxiety, social aloofness, and restricted affectivity). Assertiveness generally had weak associations at the bivariate level but was negatively related to social anxiety and was positively correlated with some forms of externalizing. Finally, Experience Seeking had substantial positive associations with a broad range of indicators related to externalizing and bipolar disorder; it also displayed negative links to agoraphobia. These differential correlates demonstrate the importance of examining personality-psychopathology relations at the specific facet level.

  19. Nonjudging Facet of Mindfulness Predicts Enhanced Smoking Cessation in Hispanics

    PubMed Central

    Spears, Claire Adams; Houchins, Sean C.; Stewart, Diana W.; Chen, Minxing; Correa-Fernández, Virmarie; Cano, Miguel Ángel; Heppner, Whitney L.; Vidrine, Jennifer I.; Wetter, David W.

    2015-01-01

    Although most smokers express interest in quitting, actual quit rates are low. Identifying strategies to enhance smoking cessation is critical, particularly among underserved populations including Hispanics, for whom many of the leading causes of death are related to smoking. Mindfulness (purposeful, non-judgmental attention to the present moment) has been linked to increased likelihood of cessation. Given that mindfulness is multifaceted, determining which aspects of mindfulness predict cessation could help to inform interventions. This study examined whether facets of mindfulness predict cessation in 199 Spanish-speaking smokers of Mexican heritage (63.3% male, mean age=39, 77.9% ≤ high school education) receiving smoking cessation treatment. Primary outcomes were 7-day abstinence at weeks 3 and 26 post-quit (biochemically-confirmed and determined using an intent-to-treat approach). Logistic random coefficients regression models were utilized to examine the relationship between mindfulness facets and abstinence over time. Independent variables were subscales of the Five Facet Mindfulness Questionnaire (Observing, Describing, Acting with Awareness, Nonjudging, Nonreactivity). The Nonjudging subscale (i.e., accepting thoughts and feelings without evaluating them) uniquely predicted better odds of abstinence up to 26 weeks post-quit. This is the first known study to examine whether specific facets of mindfulness predict smoking cessation. The ability to experience thoughts, emotions, and withdrawal symptoms without judging them may be critical in the process of quitting smoking. Results indicate potential benefits of mindfulness among smokers of Mexican heritage and suggest that smoking cessation interventions might be enhanced by central focus on the Nonjudging aspect of mindfulness. PMID:25961148

  20. Nonjudging facet of mindfulness predicts enhanced smoking cessation in Hispanics.

    PubMed

    Spears, Claire Adams; Houchins, Sean C; Stewart, Diana W; Chen, Minxing; Correa-Fernández, Virmarie; Cano, Miguel Ángel; Heppner, Whitney L; Vidrine, Jennifer I; Wetter, David W

    2015-12-01

    Although most smokers express interest in quitting, actual quit rates are low. Identifying strategies to enhance smoking cessation is critical, particularly among underserved populations, including Hispanics, for whom many of the leading causes of death are related to smoking. Mindfulness (purposeful, nonjudgmental attention to the present moment) has been linked to increased likelihood of cessation. Given that mindfulness is multifaceted, determining which aspects of mindfulness predict cessation could help to inform interventions. This study examined whether facets of mindfulness predict cessation in 199 Spanish-speaking smokers of Mexican heritage (63.3% male, mean age of 39 years, 77.9% with a high school education or less) receiving smoking cessation treatment. Primary outcomes were 7-day abstinence at weeks 3 and 26 postquit (biochemically confirmed and determined using an intent-to-treat approach). Logistic random coefficient regression models were utilized to examine the relationship between mindfulness facets and abstinence over time. Independent variables were subscales of the Five Facet Mindfulness Questionnaire (Observing, Describing, Acting With Awareness, Nonjudging, and Nonreactivity). The Nonjudging subscale (i.e., accepting thoughts and feelings without evaluating them) uniquely predicted better odds of abstinence up to 26 weeks postquit. This is the first known study to examine whether specific facets of mindfulness predict smoking cessation. The ability to experience thoughts, emotions, and withdrawal symptoms without judging them may be critical in the process of quitting smoking. Results indicate potential benefits of mindfulness among smokers of Mexican heritage and suggest that smoking cessation interventions might be enhanced by central focus on the Nonjudging aspect of mindfulness.

  1. Multibeam Altimeter Navigation Update Using Faceted Shape Model

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Brugarolas, Paul; Broschart, Steve

    2008-01-01

    A method of incorporating information, acquired by a multibeam laser or radar altimeter system, pertaining to the distance and direction between the system and a nearby target body, into an estimate of the state of a vehicle upon which the system is mounted, involves the use of a faceted model to represent the shape of the target body. Fundamentally, what one seeks to measure is the distance from the vehicle to the target body.

  2. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    SciTech Connect

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  3. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect

    Krasheninnikov, Sergei; Pigarov, Alexander

    2011-10-15

    The FACETS (Framework Application for Core-Edge Transport Simulations) project of Scientific Discovery through Advanced Computing (SciDAC) Program was aimed at providing a high-fidelity whole-tokamak modeling for the U.S. magnetic fusion energy program and ITER through coupling separate components for each of the core region, edge region, and wall, with realistic plasma particles and power sources and turbulent transport simulation. The project also aimed at developing advanced numerical algorithms, efficient implicit coupling methods, and software tools utilizing the leadership class computing facilities under Advanced Scientific Computing Research (ASCR). The FACETS project was conducted by a multi-discipline, multi-institutional teams, the Lead PI was J.R. Cary (Tech-X Corp.). In the FACETS project, the Applied Plasma Theory Group at the MAE Department of UCSD developed the Wall and Plasma-Surface Interaction (WALLPSI) module, performed its validation against experimental data, and integrated it into the developed framework. WALLPSI is a one-dimensional, coarse grained, reaction/advection/diffusion code applied to each material boundary cell in the common modeling domain for a tokamak. It incorporates an advanced model for plasma particle transport and retention in the solid matter of plasma facing components, simulation of plasma heat power load handling, calculation of erosion/deposition, and simulation of synergistic effects in strong plasma-wall coupling.

  4. Female students' disordered eating and the big five personality facets.

    PubMed

    MacLaren, Vance V; Best, Lisa A

    2009-08-01

    Female undergraduate students at two Canadian universities (N = 378) completed the NEO PI-R (Costa, P.T. & McCrae, R.R. (1992). NEO PI-R Professional Manual. Lutz, FL: Psychological Assessment Resources) and the Eating Attitudes Test (EAT-26; Garner, D. M., Olmstead, M. P., Bohr, Y. & Garfinkel, P. E. (1982). The Eating Attitudes Test: Psychometric features and clinical correlates. Psychological Medicine, 12, 871-878.). Eating disorder symptomatic (N = 43) and nonsymptomatic (N = 335) women differed on facets of Neuroticism, Extraversion, and Agreeableness. Among symptomatic women, the Oral Control subscale of the EAT-26 was correlated significantly with facets of Neuroticism, Agreeableness and Conscientiousness. Specifically, the Impulsivity facet of Neuroticism was positively correlated with the Bulimia and Food Preoccupation subscale of EAT-26, but negatively correlated with the Oral Control and Dieting subscales. Overall, results suggest that high scores on Neuroticism may be a risk factor for development of disordered eating behavior and that the degree of Impulsiveness may predict the eating disorder subtype to which one is most susceptible.

  5. The Chernyshenko Conscientiousness Scales: A New Facet Measure of Conscientiousness.

    PubMed

    Green, Jessica A; O'Connor, Daryl B; Gartland, Nicola; Roberts, Brent W

    2016-06-01

    The current research sought to validate the Chernyshenko Conscientiousness Scales (CCS), a novel measure designed to assess six facets of conscientiousness. Data from 7,569 U.S. participants and 649 U.K. participants were analyzed to assess the internal reliability and factorial structure of the scales. Test-retest reliability, convergent and divergent validity, and criterion-related validity were also evaluated using a separate U.K. sample (n = 118; n = 80 for test-retest). The results showed that those items designed to measure industriousness, order, self-control, traditionalism, and virtue were best represented by a five-factor structure, broadly consistent with the five scales. However, the content and structure of the responsibility scale requires further investigation. Overall, the CCS has the potential to be a useful alternative to the faceted measures of conscientiousness that are currently available. However, future research is required to refine a number of problematic items and to clarify which facets can be better described as interstitial dimensions between conscientiousness and other Big Five domains.

  6. LEEM Investigation of the Faceting of the Pt Covered W (111) Surface

    SciTech Connect

    Hannon, J.B.; Kellogg, G.L.; Madey, T.E.; Pelhos, K.

    1999-01-20

    A low energy electron microscope (LEEM) has been used to investigate the faceting of W(111) as induced by Pt. The atomically rough W(111) surface, when fully covered with a monolayer film of Pt and annealed to temperatures higher than {approximately} 750 K, experiences a significant morphological restructuring: the initially planar surface undergoes a faceting transition and forms three-sided pyramids with {211} faces. The experiments demonstrate the capability of LEEM for imaging both the fully and partially faceted surface. In addition, we have observed the formation of the facets in real time, when Pt is dosed onto the heated surface. We find that the transition from planar surface, to partially faceted surface, and to fully faceted surface proceeds through the nucleation and growth of spatially separated faceted regions.

  7. Modeling Integration and Reuse of Heterogeneous Terminologies in Faceted Browsing Systems

    PubMed Central

    Harris, Daniel R.

    2017-01-01

    We integrate heterogeneous terminologies into our category-theoretic model of faceted browsing and show that existing terminologies and vocabularies can be reused as facets in a cohesive, interactive system. Commonly found in online search engines and digital libraries, faceted browsing systems depend upon one or more taxonomies which outline the structure and content of the facets available for user interaction. Controlled vocabularies or terminologies are often externally curated and are available as a reusable resource across systems. We demonstrated previously that category theory can abstractly model faceted browsing in a way that supports the development of interfaces capable of reusing and integrating multiple models of faceted browsing. We extend this model by illustrating that terminologies can be reused and integrated as facets across systems with examples from the biomedical domain.

  8. Hypermobile joints

    MedlinePlus

    ... A.M. Editorial team. Related MedlinePlus Health Topics Joint Disorders Browse the Encyclopedia A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an ...

  9. Elbow arthroscopy for posttraumatic arthrosis.

    PubMed

    Geib, Timothy M; Savoie, Felix H

    2009-01-01

    Posttraumatic stiffness is a common complication after injury to the elbow. The loss of motion may significantly limit an individual's ability to perform normal activities of daily living. If conservative measures including medication, physical therapy, static splinting, and selective injection fail to restore functional range of motion, surgical intervention may be warranted. Open procedures have been described with reasonable success in restoring motion. However, arthroscopic techniques may provide several advantages in these patients who have often undergone previous extensive open surgery.

  10. [External femorotibial transfixation in femoral fracture with joint involvement in a child].

    PubMed

    Nounla, J; Bennek, J; Bühligen, U; Rolle, U

    2001-07-01

    Long bone fractures combined with joint injuries run a high risk of destabilising the articulations. Remaining joints incongruence can lead to early arthosis especially in cases of severe injuries or not achieved anatomical reduction. A number of osteosynthesis methods are available for anatomical repair of the articular facet. This report presents a seven years old boy with an open comminuted fracture of the distal femur and consecutive joint instability, treated with a Transfixation (Orthofix) of the knee joint. The functional results suggest this method as an alternative treatment.

  11. Facet-selective charge carrier transport, deactivation mechanism and stabilization of a Cu2O photo-electro-catalyst.

    PubMed

    Li, Yang; Yun, Xiaogang; Chen, Hong; Zhang, Wenqin; Li, Yongdan

    2016-03-14

    A facet-dependent photo-deactivation mechanism of Cu2O was verified and reported, which is caused by the facet-dependent charge carrier transport. During irradiation, the {100} and {110} crystal facets are selectively corroded by the photo-generated holes, while the {111} facets are comparatively stable.

  12. Effects of unilateral facet fixation and facetectomy on muscle spindle responsiveness during simulated spinal manipulation in an animal model

    PubMed Central

    Reed, William R.; Long, Cynthia R.; Pickar, Joel G.

    2013-01-01

    Objectives Manual therapy practitioners commonly assess lumbar intervertebral mobility before deciding treatment regimens. Changes in mechanoreceptor activity during the manipulative thrust are theorized to be an underlying mechanism of spinal manipulation (SM) efficacy. The objective of this study was to determine if facet fixation or facetectomy at a single lumbar level alters muscle spindle activity during 5 SM thrust durations in an animal model. Methods Spinal stiffness was determined using the slope of a force-displacement curve. Changes in the mean instantaneous frequency of spindle discharge were measured during simulated SM of the L6 vertebra in the same 20 afferents for laminectomy-only, 19 laminectomy & facet screw conditions; only 5 also had data for the laminectomy & facetectomy condition. Neural responses were compared across conditions and five thrust durations (≤ 250ms) using linear mixed models. Results Significant decreases in afferent activity between the laminectomy-only and laminectomy & facet screw conditions were seen during 75ms (P<.001), 100ms (P=.04) and 150ms (P=.02) SM thrust durations. Significant increases in spindle activity between the laminectomy-only and laminectomy & facetectomy conditions were seen during the 75ms (P<.001) and 100ms (P<.001) thrust durations. Conclusion Intervertebral mobility at a single segmental level alters paraspinal sensory response during clinically relevant high velocity low amplitude SM thrust durations (≤150ms). The relationship between intervertebral joint mobility and alterations of primary afferent activity during and following various manual therapy interventions may be used to help to identify patient subpopulations who respond to different types of manual therapy and better inform practitioners (eg, chiropractic, osteopathic) delivering the therapeutic intervention. PMID:24161386

  13. Sub-Facet Heterogeneity of the Urban Surface Energy Budget

    NASA Astrophysics Data System (ADS)

    Ramamurthy, P.; Bou-Zeid, E.; Smith, J. A.; Baeck, M. L.; Welty, C.

    2013-12-01

    The Princeton Urban Canopy Model (PUCM) and observational data are combined to understand the influence of urban sub-facet heterogeneity, and the associated influence of material properties, on the urban surface energy budget. This heterogeneity is related to the different surfaces and materials (asphalt, concrete, grass, black roofs, green roofs, etc.) that are typically found within one urban facet (roof, wall, and ground). Of particular interest is the role of water storage and evaporation from urban surfaces in modulating the energy budget. The PUCM is evaluated at sites of various urban densities. Subsequently, one densely-built site is selected for in-depth analysis and the model is applied, with sub-facet resolution, to simulate the water and energy budgets. Our analyses show that while all built surfaces convert most of the incoming energy into sensible rather than latent heat, sensible heat fluxes from asphalt and non-reflective rooftops are twice as high as those from concrete surfaces and light colored roofs. Another important and commonly observed characteristic of urban areas- the shift in peak time of sensible heat compared to rural areas, is shown to be mainly linked to concrete's high heat storage capacity. Our results also indicate that while evaporation from built surfaces is discontinuous and intermittent, overall, these surfaces accounted for nearly 16% of latent heat fluxes (LE) at the study site during the study period. More importantly, this contribution is mainly concentrated during the 48 hours following a rain event and thus its accurate representation is critical to our understanding of the urban surface energy budget during wet periods.

  14. Status of Plasma Electron Hose Instability Studies in FACET

    SciTech Connect

    Adli, Erik; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; An, Weiming; Mori, Warren; /UCLA

    2011-12-13

    In the FACET plasma-wakefield acceleration experiment a dense 23 GeV electron beam will interact with lithium and cesium plasmas, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons may lead to a fast growing electron hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the plasma, we investigate the transverse behavior of the beam in the plasma as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future plasma wakefield accelerators due to the electron hose instability. The FACET plasma-wakefield experiment at SLAC will study beam driven plasma wakefield acceleration. A dense 23 GeV electron beam will interact with lithium or cesium plasma, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons drives the electron hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and plasma parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the plasma, and observing the transverse behavior of the beam in the plasma as function. The long-term objective of these studies is to quantify potential limitations on future plasma wakefield accelerators due to the electron hose instability.

  15. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  16. Joint Warrior

    DTIC Science & Technology

    2011-05-04

    hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...reflect my own personal views and are not necessarily endorsed by the NWC or the Department of the Navy. 14. ABSTRACT The way we fight wars has been...evolving over thousands of years. Today, the U.S. Navy, finds itself in the post- modern area of war fighting . Joint warfare is the latest

  17. Optimization of spherical facets for parabolic solar concentrators

    NASA Technical Reports Server (NTRS)

    White, J. E.; Erikson, R. J.; Sturgis, J. D.; Elfe, T. B.

    1986-01-01

    Solar concentrator designs which employ deployable hexagonal panels are being developed for space power systems. An offset optical configuration has been developed which offers significant system level advantages over previously proposed collector designs for space applications. Optical analyses have been performed which show offset reflector intercept factors to be only slightly lower than those for symmetric reflectors with the same slope error. Fluxes on the receiver walls are asymmetric but manageable by varying the tilt angle of the receiver. Greater producibility is achieved by subdividing the hexagonal panels into triangular mirror facets of spherical contour. Optical analysis has been performed upon these to yield near-optimum sizes and radii.

  18. An Enhanced Facet Determination Scheme in 3D

    NASA Astrophysics Data System (ADS)

    Reivinen, M.; Salonen, E.-M.; Todoshchenko, I.; Vaskelainen, V. P.

    2017-01-01

    An enhanced scheme for the determination of equilibrium crystal shapes is introduced. The emphasis of the present study is put on the proper detection of the facets appearing on the crystal surface. The original formulation presented in [1] employs the principle of the virtual work, and the enhanced scheme additionally makes use of a penalty formulation approach. The derivation of the penalty terms is discussed in detail. Finally, the corresponding discrete method is applied to a certain problematic example case presented in [1] resulting now in the correct crystal shape.

  19. Singular orientations and faceted motion of dislocations in body-centered cubic crystals.

    PubMed

    Kang, Keonwook; Bulatov, Vasily V; Cai, Wei

    2012-09-18

    Dislocation mobility is a fundamental material property that controls strength and ductility of crystals. An important measure of dislocation mobility is its Peierls stress, i.e., the minimal stress required to move a dislocation at zero temperature. Here we report that, in the body-centered cubic metal tantalum, the Peierls stress as a function of dislocation orientation exhibits fine structure with several singular orientations of high Peierls stress-stress spikes-surrounded by vicinal plateau regions. While the classical Peierls-Nabarro model captures the high Peierls stress of singular orientations, an extension that allows dislocations to bend is necessary to account for the plateau regions. Our results clarify the notion of dislocation kinks as meaningful only for orientations within the plateau regions vicinal to the Peierls stress spikes. These observations lead us to propose a Read-Shockley type classification of dislocation orientations into three distinct classes-special, vicinal, and general-with respect to their Peierls stress and motion mechanisms. We predict that dislocation loops expanding under stress at sufficiently low temperatures, should develop well defined facets corresponding to two special orientations of highest Peierls stress, the screw and the M111 orientations, both moving by kink mechanism. We propose that both the screw and the M111 dislocations are jointly responsible for the yield behavior of BCC metals at low temperatures.

  20. Singular orientations and faceted motion of dislocations in body-centered cubic crystals

    PubMed Central

    Kang, Keonwook; Bulatov, Vasily V.; Cai, Wei

    2012-01-01

    Dislocation mobility is a fundamental material property that controls strength and ductility of crystals. An important measure of dislocation mobility is its Peierls stress, i.e., the minimal stress required to move a dislocation at zero temperature. Here we report that, in the body-centered cubic metal tantalum, the Peierls stress as a function of dislocation orientation exhibits fine structure with several singular orientations of high Peierls stress—stress spikes—surrounded by vicinal plateau regions. While the classical Peierls-Nabarro model captures the high Peierls stress of singular orientations, an extension that allows dislocations to bend is necessary to account for the plateau regions. Our results clarify the notion of dislocation kinks as meaningful only for orientations within the plateau regions vicinal to the Peierls stress spikes. These observations lead us to propose a Read-Shockley type classification of dislocation orientations into three distinct classes—special, vicinal, and general—with respect to their Peierls stress and motion mechanisms. We predict that dislocation loops expanding under stress at sufficiently low temperatures, should develop well defined facets corresponding to two special orientations of highest Peierls stress, the screw and the M111 orientations, both moving by kink mechanism. We propose that both the screw and the M111 dislocations are jointly responsible for the yield behavior of BCC metals at low temperatures. PMID:22949701

  1. Temperature-dependent side-facets of GaAs nanopillars

    NASA Astrophysics Data System (ADS)

    Soo, Mun Teng; Zheng, Kun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati; Zou, Jin

    2016-09-01

    In this study, the effect of growth temperature on the structural properties of Au-catalysed epitaxial GaAs semiconductor nanopillars grown by metal-organic chemical vapour deposition is investigated by electron microscopy. It has been found that the growth temperature plays a significant role on the evolution of side-facets of zinc-blende structured GaAs nanopillars. At a growth temperature of 550 °C, six \\{112\\} side-facets are formed; whereas at a higher growth temperature of 600 °C, six \\{110\\} side-facets are observed. It is believed that the formation of \\{112\\} side-facets is a kinetically dominated process while the formation of \\{110\\} side-facets is a thermodynamical process. Besides, the diffusion-induced nanopillar foundations present the same \\{112\\} edge side-facets regardless of the growth temperature.

  2. Tailoring molecular specificity toward a crystal facet: a lesson from biorecognition toward Pt{111}.

    PubMed

    Ruan, Lingyan; Ramezani-Dakhel, Hadi; Chiu, Chin-Yi; Zhu, Enbo; Li, Yujing; Heinz, Hendrik; Huang, Yu

    2013-02-13

    Surfactants with preferential adsorption to certain crystal facets have been widely employed to manipulate morphologies of colloidal nanocrystals, while mechanisms regarding the origin of facet selectivity remain an enigma. Similar questions exist in biomimetic syntheses concerning biomolecular recognition to materials and crystal surfaces. Here we present mechanistic studies on the molecular origin of the recognition toward platinum {111} facet. By manipulating the conformations and chemical compositions of a platinum {111} facet specific peptide, phenylalanine is identified as the dominant motif to differentiate {111} from other facets. The discovered recognition motif is extended to convert nonspecific peptides into {111} specific peptides. Further extension of this mechanism allows the rational design of small organic molecules that demonstrate preferential adsorption to the {111} facets of both platinum and rhodium nanocrystals. This work represents an advance in understanding the organic-inorganic interfacial interactions in colloidal systems and paves the way to rational and predictable nanostructure modulations for many applications.

  3. Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC and its Radiological Considerations

    SciTech Connect

    Mao, X.S.; Leitner, M.Santana; Vollaire, J.

    2011-08-22

    Facility for Advanced Accelerator Experimental Tests (FACET) in SLAC will be used to study plasma wakefield acceleration. FLUKA Monte Carlo code was used to design a maze wall to separate FACET project and LCLS project to allow persons working in FACET side during LCLS operation. Also FLUKA Monte Carlo code was used to design the shielding for FACET dump to get optimum design for shielding both prompt and residual doses, as well as reducing environmental impact. FACET will be an experimental facility that provides short, intense pulses of electrons and positrons to excite plasma wakefields and study a variety of critical issues associated with plasma wakefield acceleration [1]. This paper describes the FACET beam parameters, the lay-out and its radiological issues.

  4. Modification of flux profiles using a faceted concentrator

    SciTech Connect

    Lewandowski, A.; Scholl, K.; Bingham, C.

    1993-01-01

    The use of a faceted solar concentrator allows for some flexibility in aiming strategy and in the intensity of the resulting flux profile at the target. This can be an advantage when considering applications that do not necessarily require maximum concentration, particularly emerging, new applications in solar processed advanced materials. This paper will describe both an analysis of predicted flux profiles for several different aiming strategies using the SOLFUR computer code and experiments to characterize the actual flux profiles realized with a selected aiming strategy. The SOLFUR code models each of the furnace components explicitly. Aim points for each facet can be specified. Thus many strategies for adjusting aim points can be easily explored. One strategy calls for creating as uniform a flux over as large an area as possible. We explored this strategy analytically and experimentally. The experimental data consist of flux maps generated by a video imaging system calibrated against absolute flux measurements taken with circular foil calorimeters. Results from the analytical study and a comparison with the experimental data indicate that uniform profiles can be produced over fairly large areas.

  5. Intensity Effects of the FACET Beam in the SLAC Linac

    SciTech Connect

    Decker, F.-J.; Lipkowitz, N.; Sheppard, J.; White, G.R.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-07-03

    The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ('chirp') along the linac, so it can be compressed in two chicanes, one at the midpoint in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 3 {micro}m-rad in Sector 2 blew up to 150 {micro}m-rad in Sector 11 but could be reduced to about 6-12 {micro}m-rad, for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations.

  6. Comparing Linkage Designs Based on Land Facets to Linkage Designs Based on Focal Species

    PubMed Central

    Brost, Brian M.; Beier, Paul

    2012-01-01

    Least-cost modeling for focal species is the most widely used method for designing conservation corridors and linkages. However, these designs depend on today's land covers, which will be altered by climate change. We recently proposed an alternative approach based on land facets (recurring landscape units of relatively uniform topography and soils). The rationale is that corridors with high continuity of individual land facets will facilitate movement of species associated with each facet today and in the future. Conservation practitioners might like to know whether a linkage design based on land facets is likely to provide continuity of modeled breeding habitat for species needing connectivity today, and whether a linkage for focal species provides continuity and interspersion of land facets. To address these questions, we compared linkages designed for focal species and land facets in three landscapes in Arizona, USA. We used two variables to measure linkage utility, namely distances between patches of modeled breeding habitat for 5–16 focal species in each linkage, and resistance profiles for focal species and land facets between patches connected by the linkage. Compared to focal species designs, linkage designs based on land facets provided as much or more modeled habitat connectivity for 25 of 28 species-landscape combinations, failing only for the three species with the most narrowly distributed habitat. Compared to land facets designs, focal species linkages provided lower connectivity for about half the land facets in two landscapes. In areas where a focal species approach to linkage design is not possible, our results suggest that conservation practitioners may be able to implement a land facets approach with some confidence that the linkage design would serve most potential focal species. In areas where focal species designs are possible, we recommend using the land facet approach to complement, rather than replace, focal species approaches. PMID

  7. A model for the geomorphic development of normal-fault facets

    NASA Astrophysics Data System (ADS)

    Tucker, G. E.; Hobley, D. E. J.; McCoy, S. W.

    2014-12-01

    Triangular facets are among the most striking landforms associated with normal faulting. The genesis of facets is of great interest both for the information facets contain about tectonic motion, and because the progressive emergence of facets makes them potential recorders of both geomorphic and tectonic history. In this report, we present observations of triangular facets in the western United States and in the Italian Central Apennines. Facets in these regions typically form quasi-planar surfaces that are aligned in series along and above the trace of an active fault. Some facet surfaces consist mainly of exposed bedrock, with a thin and highly discontinuous cover of loose regolith. Other facets are mantled by a several-decimeter-thick regolith cover. Over the course of its morphologic development, a facet slope segment may evolve from a steep (~60 degree) bedrock fault scarp, well above the angle of repose for soil, to a gentler (~20-40 degree) slope that can potentially sustain a coherent regolith cover. This evolutionary trajectory across the angle of repose renders nonlinear diffusion theory inapplicable. To formulate an alternative process-based theory for facet evolution, we use a particle-based approach that acknowledges the possibility for both short- and long-range sediment-grain motions, depending on the topography. The processes of rock weathering, grain entrainment, and grain motion are represented as stochastic state-pair transitions with specified transition rates. The model predicts that facet behavior can range smoothly along the spectrum from a weathering-limited mode to a transport-limited mode, depending on the ratio of fault-slip rate to bare-bedrock regolith production rate. The model also implies that facets formed along a fault with pinned tips should show systematic variation in slope angle that correlates with along-fault position and slip rate. Preliminary observations from central Italy and the eastern Basin and Range are consistent

  8. The Asymmetric Assignment Problem and Some New Facets of the Traveling Salesman Polytope.

    DTIC Science & Technology

    1987-05-01

    vAD-A±6L2 365 THE ASYMMETRIC ASSIGNMENT PROBLEM AND SOME NEW FACETS 1.11 OF THE TRAVELING SR..(U) CARNEGIE-MELLON UNIV PITTSBURGH PA MANAGEMENT...FACETS OF THE TRAVELING SALESMAN POLYTOPE by Egon Balas Graduate School of Industrial Administration William Larimer Mellon, Founder Pittsburgh, PA...SOME NEW FACETS OF THE TRAVELING SALESMAN POLYTOPE by Eson Balas May 1987 The research underlying this report was supported by Grant ECS 8601660 of the

  9. Sustentaculum Lunatum: Appreciation of the Palmar Lunate Facet in Management of Complex Intra-Articular Fractures of the Distal Radius.

    PubMed

    Paryavi, Ebrahim; Christian, Matthew W; Eglseder, W Andrew; Pensy, Raymond A

    2015-09-01

    Fracture of the distal radius is the most common wrist injury. Treatment of complex intra-articular fractures of the distal radius requires an accurate diagnosis of the fracture pattern and a thoughtful approach to fixation. We propose a new term, sustentaculum lunatum, for the palmar lunate facet. The sustentaculum lunatum deserves specific attention because of its importance in load transmission across the radiocarpal joint. It is also key to restoring the anatomy of the palmar distal radial metaphysis during internal fixation. We provide a review of the structure and function of the sustentaculum lunatum and describe fixation techniques. This article is intended to promote awareness of this fragment in the treatment of fractures of the distal radius.

  10. Facets formation mechanism of GaN hexagonal pyramids on dot-patterns via selective MOVPE

    SciTech Connect

    Hiramatsu, Kazumasa; Kitamura, Shota; Sawaki, Nobuhiko

    1996-11-01

    Three-dimensional GaN pyramids have been successfully obtained on dot-patterned GaN(0001)/sapphire substrates by using the selective MOVPE technique. The dot-pattern is a hexagon arranged with a 5{micro}m width and a 10{micro}m spacing. The GaN structure comprises a hexagonal pyramid covered with six {l_brace}1{bar 1}01{r_brace} pyramidal facets on the side or a frustum of a hexagonal pyramid having a (0001) facet on the top. The facet formation mechanism has been investigated by observing the facet structure with the growth time. The {l_brace}1{bar 1}01{r_brace} facets are very stable during the growth. The (0001) facet growth is dominant at the initial growth but almost stops at a certain growth time and then the facet structure is maintained. The appearance of the self-limited (0001) facet is attributed to the balance of flux between incoming Ga atoms from the vapor phase to the (0001) surface and outgoing Ga atoms from the (0001) surface to the {l_brace}1{bar 1}01{r_brace} surface via migration. The longer the diffusion length of the Ga atoms on the (0001) surface is, the more the surface migration is enhanced, resulting in the appearance of the wider (0001) facet on the top.

  11. FACET: an object-oriented software framework for modeling complex social behavior patterns

    SciTech Connect

    Dolph, J. E.; Christiansen, J. H.; Sydelko, P. J.

    2000-06-30

    The Framework for Addressing Cooperative Extended Transactions (FACET) is a flexible, object-oriented architecture for implementing models of dynamic behavior of multiple individuals, or agents, in a simulation. These agents can be human (individuals or organizations) or animal and may exhibit any type of organized social behavior that can be logically articulated. FACET was developed by Argonne National Laboratory's (ANL) Decision and Information Sciences Division (DIS) out of the need to integrate societal processes into natural system simulations. The FACET architecture includes generic software components that provide the agents with various mechanisms for interaction, such as step sequencing and logic, resource management, conflict resolution, and preemptive event handling. FACET components provide a rich environment within which patterns of behavior can be captured in a highly expressive manner. Interactions among agents in FACET are represented by Course of Action (COA) object-based models. Each COA contains a directed graph of individual actions, which represents any known pattern of social behavior. The agents' behavior in a FACET COA, in turn, influences the natural landscape objects in a simulation (i.e., vegetation, soil, and habitat) by updating their states. The modular design of the FACET architecture provides the flexibility to create multiple and varied simulation scenarios by changing social behavior patterns, without disrupting the natural process models. This paper describes the FACET architecture and presents several examples of FACET models that have been developed to assess the effects of anthropogenic influences on the dynamics of the natural environment.

  12. Incremental validity of the Psychopathy Checklist facet scores: predicting release outcome in six samples.

    PubMed

    Walters, Glenn D; Knight, Raymond A; Grann, Martin; Dahle, Klaus-Peter

    2008-05-01

    The incremental validity of the 4 facet scores (Interpersonal, Affective, Lifestyle, Antisocial) of the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003) and the Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) was evaluated in 6 forensic/correctional samples with average follow-ups ranging from 20 weeks to 10 years. Results indicated that whereas Facet 4 (Antisocial) achieved incremental validity relative to the first 3 facets (Interpersonal, Affective, and Lifestyle) in predicting recidivism in all 6 samples, a block of the first 3 facets achieved incremental validity relative to the 4th facet in only 1 sample. Thus, although there was consistent support for the incremental validity of Facet 4 above and beyond the first 3 facets, there was minimal support for the incremental validity of Facets 1, 2, and 3 above and beyond Facet 4. The implications of these findings for the psychopathy construct in general and the PCL-R/SV in particular are discussed.

  13. Giant photoluminescence emission in crystalline faceted Si grains

    PubMed Central

    Faraci, Giuseppe; Pennisi, Agata R.; Alberti, Alessandra; Ruggeri, Rosa; Mannino, Giovanni

    2013-01-01

    Empowering an indirect band-gap material like Si with optical functionalities, firstly light emission, represents a huge advancement constantly pursued in the realization of any integrated photonic device. We report the demonstration of giant photoluminescence (PL) emission by a newly synthesized material consisting of crystalline faceted Si grains (fg-Si), a hundred nanometer in size, assembled in a porous and columnar configuration, without any post processing. A laser beam with wavelength 632.8 nm locally produce such a high temperature, determined on layers of a given thickness by Raman spectra, to induce giant PL radiation emission. The optical gain reaches the highest value ever, 0.14 cm/W, representing an increase of 3 orders of magnitude with respect to comparable data recently obtained in nanocrystals. Giant emission has been obtained from fg-Si deposited either on glass or on flexible, low cost, polymeric substrate opening the possibility to fabricate new devices. PMID:24056300

  14. Lumbar facet fracture in an adolescent ice hockey player.

    PubMed

    Shaffer, W O; Taylor, M R; Sundaram, M

    1999-11-01

    A 14-year-old boy was checked hard as he was winding up to shoot in an ice hockey game. He experienced low-back pain during the game but when examined later for complaints of pain and fever, he denied trauma. Plain x-rays were normal, but a bone scan showed increased uptake at L-3. MRI evaluation revealed a lumbar mass; a CT scan showed the mass to be a hematoma and edema secondary to a facet fracture. Acute severe back pain in a hockey player should prompt a careful history and a search for musculoskeletal injury. When trauma in the lumbar spine is suspected and plain radiographs are nondiagnostic, CT scans are more precise than MRI for diagnosing injury.

  15. Reverse Epitaxy of Ge: Ordered and Faceted Surface Patterns

    NASA Astrophysics Data System (ADS)

    Ou, Xin; Keller, Adrian; Helm, Manfred; Fassbender, Jürgen; Facsko, Stefan

    2013-07-01

    Normal incidence ion irradiation at elevated temperatures, when amorphization is prevented, induces novel nanoscale patterns of crystalline structures on elemental semiconductors by a reverse epitaxial growth mechanism: on Ge surfaces irradiation at temperatures above the recrystallization temperature of 250°C leads to self-organized patterns of inverse pyramids. Checkerboard patterns with fourfold symmetry evolve on the Ge (100) surface, whereas on the Ge (111) surface, isotropic patterns with a sixfold symmetry emerge. After high-fluence irradiations, these patterns exhibit well-developed facets. A deterministic nonlinear continuum equation accounting for the effective surface currents due to an Ehrlich-Schwoebel barrier for diffusing vacancies reproduces remarkably well our experimental observations.

  16. Do different facets of impulsivity predict different types of aggression?

    PubMed

    Derefinko, Karen; DeWall, C Nathan; Metze, Amanda V; Walsh, Erin C; Lynam, Donald R

    2011-01-01

    This study examined the relations between impulsivity-related traits (as assessed by the UPPS-P Impulsive Behavior Scale) and aggressive behaviors. Results indicated that UPPS-P Lack of Premeditation and Sensation Seeking were important in predicting general violence. In contrast, UPPS-P Urgency was most useful in predicting intimate partner violence. To further explore relations between intimate partner violence and Urgency, a measure of autonomic response to pleasant and aversive stimuli and facets of Neuroticism from the NEO PI-R were used as control variables. Autonomic responsivity was correlated with intimate partner violence at the zero-order level, and predicted significant variance in intimate partner violence in regression equations. However, UPPS-P Urgency was able to account for unique variance in intimate partner violence, above and beyond measures of Neuroticism and arousal. Implications regarding the use of a multifaceted conceptualization of impulsivity in the prediction of different types of violent behavior are discussed.

  17. Do Different Facets of Impulsivity Predict Different Types of Aggression?

    PubMed Central

    Derefinko, Karen; DeWall, C. Nathan; Metze, Amanda V.; Walsh, Erin C.; Lynam, Donald R.

    2011-01-01

    The current study examined the relations between impulsivity-related traits (as assessed by the UPPS-P Impulsive Behavior Scale) and aggressive behaviors. Results indicated that UPPS-P Lack of Premeditation and Sensation Seeking were important in predicting general violence. In contrast, UPPS-P Urgency was most useful in predicting intimate partner violence. To further explore relations between intimate partner violence and Urgency, a measure of autonomic response to pleasant and aversive stimuli and facets of Neuroticism from the NEO PI-R were used as control variables. Autonomic responsivity was correlated with intimate partner violence at the zero-order level, and predicted significant variance in intimate partner violence in regression equations. However, UPPS-P Urgency was able to account for unique variance in intimate partner violence above and beyond measures of Neuroticism and arousal. Implications regarding the use of a multifaceted conceptualization of impulsivity in the prediction of different types of violent behavior are discussed. PMID:21259270

  18. Examining student rating of teaching effectiveness using FACETS.

    PubMed

    Mat Daud, Nuraihan; Abu Kassim, Noor Lide

    2011-01-01

    Students' evaluations of teaching staff can be considered high-stakes, as they are often used to determine promotion, reappointment, and merit pay to academics. Using Facets, the reliability and validity of one student rating questionnaire is analyzed. A total of 13,940 respondents of the Human Science Division of International Islamic University Malaysia were involved in the study. The analysis shows that the student rating questionnaire used was valid and reliable, and it allows identification of staff for the institution's prestigious teaching excellence awards, and those needing in-service training. It was found that there was no significant difference in terms of rank, age and gender of the staff. The study also shows that the majority of staff have problems keeping the class interested and getting students to participate in class activities. Faculty also hardly discussed common errors in assignments and tests.

  19. “Decoding” Angiogenesis: New Facets Controlling Endothelial Cell Behavior

    PubMed Central

    Sewduth, Raj; Santoro, Massimo M.

    2016-01-01

    Angiogenesis, the formation of new blood vessels, is a unique and crucial biological process occurring during both development and adulthood. A better understanding of the mechanisms that regulates such process is mandatory to intervene in pathophysiological conditions. Here we highlight some recent argument on new players that are critical in endothelial cells, by summarizing novel discoveries that regulate notorious vascular pathways such as Vascular Endothelial Growth Factor (VEGF), Notch and Planar Cell Polarity (PCP), and by discussing more recent findings that put metabolism, redox signaling and hemodynamic forces as novel unforeseen facets in angiogenesis. These new aspects, that critically regulate angiogenesis and vascular homeostasis in health and diseased, represent unforeseen new ground to develop anti-angiogenic therapies. PMID:27493632

  20. Nitrogen-induced reconstruction and faceting of Re(112{sup ¯}1)

    SciTech Connect

    Wang, Hao; Chen, Wenhua; Bartynski, Robert A.; Kaghazchi, Payam; Jacob, Timo

    2014-01-14

    The surface morphology of Re(112{sup ¯}1), tailored on the nanometer scale by kinetic control of nitrogen, has been investigated using low energy electron diffraction, scanning tunneling microscopy, Auger electron spectroscopy, and density functional theory (DFT) in combination with the ab initio atomistic thermodynamics approach. Experiments show that when exposing to NH{sub 3} (>0.5 L) at 300 K followed by annealing in ultra-high vacuum at 700 K or 900 K, the initially planar Re(112{sup ¯}1) surface becomes (2 × 1) reconstructed or partially faceted, respectively. Upon annealing in 100 L NH{sub 3} at 900 K, Re(112{sup ¯}1) becomes fully faceted and covered by N. The fully faceted surface consists of two-sided ridges formed by (134{sup ¯}2) and (314{sup ¯}2) facets. The (2 × 1) reconstruction may serve as a precursor state for faceting of Re(112{sup ¯}1). The DFT calculations provide an atomistic understanding of facet formation in terms of binding sites and energies of N on Re surfaces of the substrate and facets as well as the corresponding surface phase diagram. The N-covered faceted Re(112{sup ¯}1) surfaces are promising nanoscale model catalysts and nanotemplates. Our findings should be of importance for the design and development of Re-based heterogeneous catalysts operating under nitrogen-rich conditions.

  1. A Facet Theory Model for Integrating Contextual and Personal Experiences of International Students

    ERIC Educational Resources Information Center

    Hackett, Paul M. W.

    2014-01-01

    The purpose of this article is to use a facet theory research approach to provide a clear, coherent, and integrated model of international students' experiences based upon the findings of psychological research into students when studying abroad. In research that employs a facet theory approach events are classified in terms of their constituent…

  2. The Effects of Multidimensional Polytomous Response Data on Unidimensional Many-FACET Rasch Model Parameter Estimates.

    ERIC Educational Resources Information Center

    Wang, Shudong; Wang, Ning

    When categorical responses were simulated from a Multidimensional Many-FACETS Rasch Compensatory Model (MMFRCM), the effects of ability, task difficulty, and step difficulty estimates with the unidimensional Many-FACETS Rasch Model (MFRM; Linacre, 1999) were examined in terms of three error indexes, average absolute difference (AAD), bias, and…

  3. Exploring relations among mindfulness facets and various meditation practices: Do they work in different ways?

    PubMed

    Cebolla, Ausiàs; Campos, Daniel; Galiana, Laura; Oliver, Amparo; Tomás, Jose Manuel; Feliu-Soler, Albert; Soler, Joaquim; García-Campayo, Javier; Demarzo, Marcelo; Baños, Rosa María

    2017-03-01

    Several meditation practices are associated with mindfulness-based interventions but little is known about their specific effects on the development of different mindfulness facets. This study aimed to assess the relations among different practice variables, types of meditation, and mindfulness facets. The final sample was composed of 185 participants who completed an on-line survey, including information on the frequency and duration of each meditation practice, lifetime practice, and the Five Facet Mindfulness Questionnaire. A Multiple Indicators Multiple Causes structural model was specified, estimated, and tested. Results showed that the Model's overall fit was adequate: χ(2) (1045)=1542.800 (p<0.001), CFI=0.902, RMSEA=0.042. Results revealed that mindfulness facets were uniquely related to the different variables and types of meditation. Our findings showed the importance of specific practices in promoting mindfulness, compared to compassion and informal practices, and they pointed out which one fits each mindfulness facet better.

  4. Measured and predicted root-mean-square errors in square and triangular antenna mesh facets

    NASA Technical Reports Server (NTRS)

    Fichter, W. B.

    1989-01-01

    Deflection shapes of square and equilateral triangular facets of two tricot-knit, gold plated molybdenum wire mesh antenna materials were measured and compared, on the basis of root mean square (rms) differences, with deflection shapes predicted by linear membrane theory, for several cases of biaxial mesh tension. The two mesh materials contained approximately 10 and 16 holes per linear inch, measured diagonally with respect to the course and wale directions. The deflection measurement system employed a non-contact eddy current proximity probe and an electromagnetic distance sensing probe in conjunction with a precision optical level. Despite experimental uncertainties, rms differences between measured and predicted deflection shapes suggest the following conclusions: that replacing flat antenna facets with facets conforming to parabolically curved structural members yields smaller rms surface error; that potential accuracy gains are greater for equilateral triangular facets than for square facets; and that linear membrane theory can be a useful tool in the design of tricot knit wire mesh antennas.

  5. Effect of ZnO facet on ethanol steam reforming over Co/ZnO

    SciTech Connect

    Yu, Ning; Zhang, He; Davidson, Stephen D.; Sun, Junming; Wang, Yong

    2016-01-01

    The effects of ZnO facets on ethanol steam reforming (ESR) were investigated over Co/ZnO catalysts synthesized using ZnO with different fractions of (10-10) non-polar facet. Co supported on ZnO with a higher fraction of (10-10) non-polar facet shows higher C-C cleavage activity and higher selectivity to CO2 (lower selectivity to CO) compared with Co supported on ZnO with less (10-10) non-polar facet exposed. The improved ethanol steam reforming performances are attributed to the high fraction of metallic Co stabilized by the ZnO (10-10) non-polar facet, which enhanced C-C cleavage and water-gas-shift (WGS) activities.

  6. Evolution of (001) and (111) facets for selective epitaxial growth inside submicron trenches

    SciTech Connect

    Jiang, S. Heyns, M.; Merckling, C.; Guo, W.; Waldron, N.; Caymax, M.; Vandervorst, W.; Seefeldt, M.

    2014-01-14

    The evolution of (001) and (111) facets for the epitaxial growth inside submicron trenches is systematically studied in this report. The analysis with the method of “Lagrange multiplier” indicates the equilibrium crystal shape. In the case of non-equilibrium without external fluxes, we employed the “weighted mean curvature” method to mathematically model the inter-facet migration rate for two extreme kinetic cases: “surface diffusion limited” and “surface attachment/detachment limited.” Coupled with external supply of atoms, the self-limited behavior of facet size is theoretically predicted. Moreover, we find that the self-limited stable facet size in trenches of different widths has a specific relationship determined by the surface energy ratio, kinetic rate ratio, and isolated growth rate difference. The two limited cases could be discriminated according to the mathematical fitting of one exponent in this relationship based on the stable facet size in trenches of different widths.

  7. Psychopathy, attention, and oddball target detection: New insights from PCL-R facet scores.

    PubMed

    Anderson, Nathaniel E; Steele, Vaughn R; Maurer, J Michael; Bernat, Edward M; Kiehl, Kent A

    2015-09-01

    Psychopathy is a disorder accompanied by cognitive deficits including abnormalities in attention. Prior studies examining cognitive features of psychopaths using ERPs have produced some inconsistent results. We examined psychopathy-related differences in ERPs during an auditory oddball task in a sample of incarcerated adult males. We extend previous work by deriving ERPs with principal component analysis (PCA) and relate these to the four facets of Hare's Psychopathy Checklist Revised (PCL-R). Features of psychopathy were associated with increased target N1 amplitude (facets 1, 4), decreased target P3 amplitude (facet 1), and reduced slow wave amplitude for frequent standard stimuli (facets 1, 3, 4). We conclude that employing PCA and examining PCL-R facets improve sensitivity and help clarify previously reported associations. Furthermore, attenuated slow wave during standards may be a novel marker for psychopaths' abnormalities in attention.

  8. Autologous adipose stem cells and polylactide discs in the replacement of the rabbit temporomandibular joint disc

    PubMed Central

    Ahtiainen, Katja; Mauno, Jari; Ellä, Ville; Hagström, Jaana; Lindqvist, Christian; Miettinen, Susanna; Ylikomi, Timo; Kellomäki, Minna; Seppänen, Riitta

    2013-01-01

    The temporomandibular joint (TMJ) disc lacks functional replacement after discectomy. We investigated tissue-engineered bilayer polylactide (PLA) discs and autologous adipose stem cells (ASCs) as a potential replacement for the TMJ disc. These ASC discs were pre-cultured either in control or in differentiation medium, including transforming growth factor (TGF)-β1 for one week. Prior to implantation, expression of fibrocartilaginous genes was measured by qRT-PCR. The control and differentiated ASC discs were implanted, respectively, in the right and left TMJs of rabbits for six (n = 5) and 12 months (n = 5). Thereafter, the excised TMJ areas were examined with cone beam computed tomography (CBCT) and histology. No signs of infection, inflammation or foreign body reactions were detected at histology, whereas chronic arthrosis and considerable condylar hypertrophy were observed in all operated joints at CBCT. The left condyle treated with the differentiated ASC discs appeared consistently smoother and more sclerotic than the right condyle. The ASC disc replacement resulted in dislocation and morphological changes in the rabbit TMJ. The ASC discs pre-treated with TGF-β1 enhanced the condylar integrity. While adverse tissue reactions were not shown, the authors suggest that with improved attachment and design, the PLA disc and biomaterial itself would hold potential for TMJ disc replacement. PMID:23720535

  9. [Endoprosthesis for the fractured elbow: uni- and bicompartmental alloarthroplasty of the humero-ulnar joint].

    PubMed

    Weber, O; Burger, C; Stein, G; Gravius, S; Wirtz, D C; Pennekamp, P H; Kraft, C N; Müller, M

    2010-12-01

    Posttraumatic arthrosis or rheumatoid arthritis located at the elbow, in particular at the humero-ulnar joint will probably not occur in increasing numbers in the future due to new antirheumatic medications and modern implants. However, the demographic development with an increase of the geriatric population and the typical physical changes is evident. Due to osteoporosis with a resulting poor bone quality severe fracture patterns may occur at the site of the distal humerus after a simple collapse. The usual surgical aim consisting of an exact anatomic reduction may be impossible to achieve by applying the standard operative treatment. Several studies have proven that a prosthetic replacement of such a severely damaged elbow is a viable solution for elderly people. A mobile, pain-free and stable elbow joint promotes a fast recovery of the patient with a quick return to former activities. Nevertheless, elbow prostheses cannot withstand great strains and the surgeon has to identify those fractures which require a prosthetic replacement. The surgical implantation procedure requires an adequate knowledge of both elbow anatomy and prosthetic options.

  10. Joint x-ray

    MedlinePlus

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  11. Improving personality facet scores with multidimensional computer adaptive testing: an illustration with the NEO PI-R.

    PubMed

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A W

    2013-02-01

    Narrowly defined personality facet scores are commonly reported and used for making decisions in clinical and organizational settings. Although these facets are typically related, scoring is usually carried out for a single facet at a time. This method can be ineffective and time consuming when personality tests contain many highly correlated facets. This article investigates the possibility of increasing the precision of the NEO PI-R facet scores by scoring items with multidimensional item response theory and by efficiently administering and scoring items with multidimensional computer adaptive testing (MCAT). The increase in the precision of personality facet scores is obtained from exploiting the correlations between the facets. Results indicate that the NEO PI-R could be substantially shorter without attenuating precision when the MCAT methodology is used. Furthermore, the study shows that the MCAT methodology is particularly appropriate for constructs that have many highly correlated facets.

  12. Spacesuit mobility knee joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1979-01-01

    Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  13. Spacesuit mobility joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1978-01-01

    Joints for use in interconnecting adjacent segments of an hermetically sealed spacesuit which have low torques, low leakage and a high degree of reliability are described. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics. Linkages which restrain the joint from longitudinal distension and a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli are featured. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  14. Improving Personality Facet Scores with Multidimensional Computer Adaptive Testing: An Illustration with the Neo Pi-R

    ERIC Educational Resources Information Center

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A. W.

    2013-01-01

    Narrowly defined personality facet scores are commonly reported and used for making decisions in clinical and organizational settings. Although these facets are typically related, scoring is usually carried out for a single facet at a time. This method can be ineffective and time consuming when personality tests contain many highly correlated…

  15. Obtaining Content Weights for Test Specifications from Job Analysis Task Surveys: An Application of the Many-Facets Rasch Model

    ERIC Educational Resources Information Center

    Wang, Ning; Stahl, John

    2012-01-01

    This article discusses the use of the Many-Facets Rasch Model, via the FACETS computer program (Linacre, 2006a), to scale job/practice analysis survey data as well as to combine multiple rating scales into single composite weights representing the tasks' relative importance. Results from the Many-Facets Rasch Model are compared with those…

  16. Stabilization of the sacroiliac joint.

    PubMed

    Shaffrey, Christopher I; Smith, Justin S

    2013-07-01

    Lower back pain and pain involving the area of the posterior iliac spine are extremely common. Degeneration of the sacroiliac joint (SIJ) is one potential cause for lower back pain and pain radiating into the groin or buttocks. Degenerative changes to the lumbar spine and sacroiliac joints are common. A recent study evaluating SIJ abnormalities in a primary low back pain population demonstrated 31.7% of patients demonstrated SI joint abnormalities. (4) As is the case for the evaluation and management of isolated lower back pain, the evaluation, management, and role for surgical intervention in SIJ pain is very controversial. Many patients have degenerative changes of the disc, facet joints, and SIJs. A recent systematic review performed to determine the diagnostic accuracy of tests available to clinicians to identify the disc, facet joint, or SIJ as the source of low back pain concluded that tests do exist that change the probability of the disc or SIJ (but not the facet joint) as the source of low back pain. (3) It was also concluded that the usefulness of these tests in clinical practice, particularly for guiding treatment selection, remains unclear. (3) Although there is general agreement that SIJ pathological changes are a potential cause of pain, there is far less agreement about the optimal management of these conditions. A variety of conditions can cause SIJ dysfunction including degenerative and inflammatory arthritis, trauma, prior lumbosacral fusion, hip arthritis, limb length inequality, infections, and neoplasia. (8) There is increasing evidence that image intensifier-guided single periarticular injection can correctly localize pain to the SIJ but the optimal management strategy remains controversial. Recent publications have compared surgical versus injection treatments and fusion versus denervation procedures. (1 , 8) A systematic review found improvement regardless of the treatment, with most studies reporting over 40% improvement in pain as measured

  17. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    SciTech Connect

    Amann, J.; Bane, K.; /SLAC

    2009-10-30

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  18. Patterns of astragalar fibular facet orientation in extant and fossil primates and their evolutionary implications.

    PubMed

    Boyer, Doug M; Seiffert, Erik R

    2013-07-01

    A laterally sloping fibular facet of the astragalus (=talus) has been proposed as one of few osteological synapomorphies of strepsirrhine primates, but the feature has never been comprehensively quantified. We describe a method for calculating fibular facet orientation on digital models of astragali as the angle between the planes of the fibular facet and the lateral tibial facet. We calculated this value in a sample that includes all major extant primate clades, a diversity of Paleogene primates, and nonprimate euarchontans (n = 304). Results show that previous characterization of a divide between extant haplorhines and strepsirrhines is accurate, with little overlap even when individual data points are considered. Fibular facet orientation is conserved in extant strepsirrhines despite major differences in locomotion and body size, while extant anthropoids are more variable (e.g., low values for catarrhines relative to non-callitrichine platyrrhines). Euprimate outgroups exhibit a mosaic of character states with Cynocephalus having a more obtuse strepsirrhine-like facet and sampled treeshrews and plesiadapiforms having more acute haplorhine-like facets. Surprisingly, the earliest species of the adapiform Cantius have steep haplorhine-like facets as well. We used a Bayesian approach to reconstruct the evolution of fibular facet orientation as a continuous character across a supertree of living and extinct primates. Mean estimates for crown Primatomorpha (97.9°), Primates (99.5°), Haplorhini (98.7°), and Strepsirrhini (108.2°) support the hypothesis that the strepsirrhine condition is derived, while lower values for crown Anthropoidea (92.8°) and Catarrhini (88.9°) are derived in the opposite direction.

  19. Facet morphology response to nonuniformities in nutrient and impurity supply. II. Numerical simulations

    NASA Astrophysics Data System (ADS)

    Lin, Hong; Vekilov, Peter G.; Rosenberger, Franz

    1996-02-01

    A model for the evolution of facet morphologies in growth from solutions is presented. The numerical model links, for the first time, bulk transport of solute and impurities in a solution growth cell with microscopic interfacial kinetics processes. The macroscopic transport is dealt with as in the 2D model [H. Lin, F. Rosenberger, J.I.D. Alexander and A. Nadarajah, J. Crystal Growth 151 (1995) 153] of a crystallization cell used for lysozyme in our laboratory. The microscopic kinetics is incorporated through a meso-scale continuum model of growth step motion in response to the interfacial concentration distributions. Local growth step velocities are linearly interpolated from the values obtained at the grid points of the bulk transport simulation. Experimentally determined kinetics and transport coefficients are employed. We find that the facets remain macroscopically flat, in spite of the lower nutrient and impurity concentrations in the facet center regions. This stabilization is achieved through the formation of a microscopic depression in the facet, with nonuniform vicinal slope (step density). If the step density in the facet center exceeds a certain value, no further stabilization results on further steepening, and the facet loses its macroscopic morphological stability. This loss of morphological stability depends sensitively on the value of the steps' kinetic coefficient. For pure lysozyme-precipitant solutions, we obtain microscopic depressions with a higher slope at the facet center than at the edge. However, with an impurity that impedes step kinetics and is preferentially incorporated into the crystal, the simulations produce microscopic facet depressions with higher slope at the edge. Impurity depletion at the interface, due to low initial concentration and/or slow diffusion leads to mixed shapes, and eventually to shapes typical of growth from pure solution. Quantitative agreement with facet morphologies observed on lysozyme crystals [P.G. Vekilov and

  20. Design of a solar concentrator with hexagonal facets

    NASA Astrophysics Data System (ADS)

    Herrera Vázquez, Joel; Vázquez y Montiel, Sergio

    2007-09-01

    In this work we present the optical design of a solar concentrator for an High-Flux solar furnace of a solar laboratory, these concentrator is compound for an aspheric mirror surface sectioned in 121 hexagonal facets to simplify the construction process, its total diameter is 6.6 m and a focal length is 3.68 m, also was developed the corresponding algorithm to determine the correct position and orientation of each hexagonal section that compound the arrangement. We present the results of the focused energy of this configuration and we propose a modification on the original position of the mirrors for optimizing the focusing of energy by the sun furnace. These modifications produces an increment on the energy focused on a small area in a remarkable way similar to used a parabolic mirror. The algorithm before mentioned was programmed in MathCAD and it calculates the modification of the original position of each hexagonal mirror giving us a file that ZEMAX can read. This file contains the information of each 121 mirrors from the arrangement and also the correct form, position and direction, simplifying the traditional input process one by one.

  1. V-groove faceted reflector for enhanced module output

    NASA Astrophysics Data System (ADS)

    Amick, J. A.; Kurth, W. T.

    In the manufacture of present-day photovoltaic modules, single crystal wafers of silicon serve as the starting point. Because of the high cost of the silicon, it is not economical to convert the circular wafers into square or rectangular cells, even though these cells would more nearly fill the available area in a module. Accordingly, a substantial portion, typically 20 to 25%, of the module area is not filled with silicon. Incident light falling on these 'interstitial' regions between cells is largely lost, leading to module inefficiencies. One technique for recovering a portion of the 'lost' light is to use a white, scattering background behind the cells. The cell output can generally be improved by 5 to 10%. The present study is concerned with an improved method of recovering the light falling on the interstitial regions by which nearly 50% increase in cell output has been realized in favorable cases. The method makes use of an optically transparent medium above the cells, and a series of V-groove facets provided in the interstitial regions between cells.

  2. Friction in Total Hip Joint Prosthesis Measured In Vivo during Walking

    PubMed Central

    Damm, Philipp; Dymke, Joern; Ackermann, Robert; Bender, Alwina; Graichen, Friedmar; Halder, Andreas; Beier, Alexander; Bergmann, Georg

    2013-01-01

    Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al2O3 ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was calculated in 3D throughout the whole gait cycle, and average values of the friction-induced power dissipation in the joint were determined. On average, peak contact forces of 248% of the bodyweight and peak friction moments of 0.26% bodyweight times meter were determined. However, contact forces and friction moments varied greatly between individuals. The friction moment increased during the extension phase of the joint. The average coefficient of friction also increased during this period, from 0.04 (0.03 to 0.06) at contralateral toe off to 0.06 (0.04 to 0.08) at contralateral heel strike. During the flexion phase, the coefficient of friction increased further to 0.14 (0.09 to 0.23) at toe off. The average friction-induced power throughout the whole gait cycle was 2.3 W (1.4 W to 3.8 W). Although more parameters than only the synovia determine the friction, the wide ranges of friction coefficients and power dissipation indicate that the lubricating properties of synovia are individually very different. However, such differences may also exist in natural joints and may influence the progression of arthrosis. Furthermore, subjects with very high power dissipation may be at risk of thermally induced implant loosening. The large increase of the friction coefficient during each step could be caused by the synovia being squeezed out under load. PMID:24260114

  3. The effect and safety of highly standardized Ginger (Zingiber officinale) and Echinacea (Echinacea angustifolia) extract supplementation on inflammation and chronic pain in NSAIDs poor responders. A pilot study in subjects with knee arthrosis.

    PubMed

    Rondanelli, Mariangela; Riva, Antonella; Morazzoni, Paolo; Allegrini, Pietro; Faliva, Milena Anna; Naso, Maurizio; Miccono, Alessandra; Peroni, Gabriella; Degli Agosti, Irene; Perna, Simone

    2017-06-01

    The study aimed to evaluate the effect of Zingiber officinale and Echinacea angustifolia extract supplementation (25 mg of ginger and 5 mg of Echinacea) for 30 days on inflammation and chronic pain in knee osteoarthritis (OA). Consecutive nonsteroidal anti-inflammatory-drugs (NSAIDs) poor responders with chronic inflammation and pain due to knee arthrosis were assessed (15 subjects, age: 67.2 ± 7.9, body mass index: 30.6 ± 7.1, men/women:2/13). The primary endpoint was to determine pain improvement from baseline to Day 30 by Tegner Lysholm Knee Scoring. The secondary endpoints were the assessment of Visual Analog Scale for Pain, health-related quality of life, by the ShortForm36 (SF-36), anthropometric parameters, hydration. After supplementation, a significant improvement of 12.27 points was observed for Lysholm scale score (p < 0.05), SF-36 (p < 0.05), and a decrease in -0.52 cm in knee circumference (left) (p < 0.01). This pilot study provides feasibility and safety data for the use of highly standardised ginger and Echinacea extract supplementation in people with knee OA.

  4. Facet-controlled facilitation of PbS nanoarchitectures by understanding nanocrystal growth

    NASA Astrophysics Data System (ADS)

    Loc, Welley Siu; Quan, Zewei; Lin, Cuikun; Pan, Jinfong; Wang, Yuxuan; Yang, Kaikun; Jian, Wen-Bin; Zhao, Bo; Wang, Howard; Fang, Jiye

    2015-11-01

    Nanostructured lead sulphide is a significant component in a number of energy-related sustainable applications such as photovoltaic cells and thermoelectric components. In many micro-packaging processes, dimensionality-controlled nano-architectures as building blocks with unique properties are required. This study investigates different facet-merging growth behaviors through a wet-chemical synthetic strategy to produce high-quality controlled nanostructures of lead sulphide in various dimensionalities. It was found that 1D nanowires or 2D nanosheets can be obtained by the merging of reactive {111}- or {110}-facets, respectively, while promoting {100} facets in the early stages after nucleation leads to the growth of 0D nanocubes. The influence of temperature, capping ligands and co-solvent in facilitating the crystal facet growth of each intermediate seed is also demonstrated. The novelty of this work is characterized by the delicate manipulation of various PbS nanoarchitectures based on the comprehension of the facet-merging evolution. The synthesis of facet-controlled PbS nanostructures could provide novel building blocks with desired properties for use in many applications.Nanostructured lead sulphide is a significant component in a number of energy-related sustainable applications such as photovoltaic cells and thermoelectric components. In many micro-packaging processes, dimensionality-controlled nano-architectures as building blocks with unique properties are required. This study investigates different facet-merging growth behaviors through a wet-chemical synthetic strategy to produce high-quality controlled nanostructures of lead sulphide in various dimensionalities. It was found that 1D nanowires or 2D nanosheets can be obtained by the merging of reactive {111}- or {110}-facets, respectively, while promoting {100} facets in the early stages after nucleation leads to the growth of 0D nanocubes. The influence of temperature, capping ligands and co-solvent in

  5. Progress report for FACETS (Framework Application for Core-Edge Transport Simulations): C.S. SAP

    SciTech Connect

    Epperly, T W

    2008-10-01

    The mission of the Computer Science Scientific Application Partnership (C.S. SAP) at LLNL is to develop and apply leading-edge scientific component technology to FACETS software. Contributions from LLNL's fusion energy program staff towards the underlying physics modules are described in a separate report. FACETS uses component technology to combine selectively multiple physics and solver software modules written in different languages by different institutions together in an tightly-integrated, parallel computing framework for Tokamak reactor modeling. In the past fiscal year, the C.S. SAP has focused on two primary tasks: applying Babel to connect UEDGE into the FACETS framework through UEDGE's existing Python interface and developing a next generation componentization strategy for UEDGE which avoids the use of Python. The FACETS project uses Babel to solve its language interoperability challenges. Specific accomplishments for the year include: (1) Refined SIDL interfaces for UEDGE to meet satisfy the standard interfaces required by FACETS for all physics modules. This required consensus building between framework and UEDGE developers. (2) Wrote prototype C++ driver for UEDGE to demonstrate how UEDGE can be called from C++ using Babel. (3) Supported the FACETS project by adding new features to Babel such as release number tagging, porting to new machines, and adding new configuration options. Babel modifications were delivered to FACETS by testing and publishing development snapshots in the projects software repository. (4) Assisted Tech-X Corporation in testing and debugging of a high level build system for the complete FACETS tool chain--the complete list of third-party software libraries that FACETS depends on directly or indirectly (e.g., MPI, HDF5, PACT, etc.). (5) Designed and implemented a new approach to wrapping UEDGE as a FACETS component without requiring Python. To get simulation results as soon as possible, our initial connection from the FACETS

  6. Four-facet PCL-R structure and cognitive functioning among high violent criminal offenders.

    PubMed

    Sreenivasan, Shoba; Walker, Sarah Cusworth; Weinberger, Linda E; Kirkish, Patricia; Garrick, Thomas

    2008-03-01

    High violent inmates (N = 126) were administered the Psychopathy Checklist-Revised (PCL-R; Hare, Clark, Grann, & Thornton, 2000; Hare et al., 1990) and neuropsychological measures. No significant correlations were present between the overall PCL-R score and 14 cognitive measures. A violence score, computed as the total number of violent acts across all situations and types, was significantly correlated with the PCL-R total score and Facet 2 but not with the other three facets. Our data suggest that Facet 2 elevations may prove relevant to violence risk assessment; this link, however, needs further exploration with larger samples.

  7. The peroneocuboid joint: morphogenesis and anatomical study.

    PubMed

    Guimerá, V; Lafuente, A; Zambrana, L; Rodriguez-Niedenführ, M; Sañudo, J R; Vazquez, T

    2015-01-01

    The peroneocuboid joint, between the peroneus longus tendon and the cuboid bone, has not been anatomically well-defined and no embryological study has been published. Furthermore, the ossification of the os peroneum (a sesamoid inside the peroneus longus tendon) and its associated pathology has been considered to be generated by orthostatic and/or mechanical loads. A light microscopy analysis of serially sectioned human embryonic and fetal feet, the analysis of human adult feet by means of standard macroscopic dissection, X-ray and histological techniques have been carried out. The peroneus longus tendon was fully visible until its insertion in the 1st metatarsal bone already at embryonic stage 23 (56-57 days). The peroneocuboid joint cavity appeared at the transition of the embryonic to the fetal period (8-9th week of gestation) and was independent of the proximal synovial sheath. The joint cavity extended from the level of the calcaneocuboid joint all the way to the insertion of the peroneus longus tendon in the 1st metatarsal bone. The frenular ligaments, fixing the peroneus longus tendon to the 5th metatarsal bone or the long calcaneocuboid ligament, developed in the embryonic period. The peroneus longus tendon presented a thickening in the area surrounding the cuboid bone as early as the fetal period. This thickening may be considered the precursor of the os peroneum and was similar in shape and in size relation to the tendon, to the os peroneum observed in adults. To the best of our knowledge, this is the first study to show that the os peroneum, articular facets of the peroneus longus tendon and cuboid bone, the peroneocuboid joint and the frenular ligaments appear during the embryonic/fetal development period and therefore they can not be generated exclusively by orthostatic and mechanical forces or pathological processes.

  8. The peroneocuboid joint: morphogenesis and anatomical study

    PubMed Central

    Guimerá, V; Lafuente, A; Zambrana, L; Rodriguez-Niedenführ, M; Sañudo, J R; Vazquez, T

    2015-01-01

    The peroneocuboid joint, between the peroneus longus tendon and the cuboid bone, has not been anatomically well-defined and no embryological study has been published. Furthermore, the ossification of the os peroneum (a sesamoid inside the peroneus longus tendon) and its associated pathology has been considered to be generated by orthostatic and/or mechanical loads. A light microscopy analysis of serially sectioned human embryonic and fetal feet, the analysis of human adult feet by means of standard macroscopic dissection, X-ray and histological techniques have been carried out. The peroneus longus tendon was fully visible until its insertion in the 1st metatarsal bone already at embryonic stage 23 (56–57 days). The peroneocuboid joint cavity appeared at the transition of the embryonic to the fetal period (8–9th week of gestation) and was independent of the proximal synovial sheath. The joint cavity extended from the level of the calcaneocuboid joint all the way to the insertion of the peroneus longus tendon in the 1st metatarsal bone. The frenular ligaments, fixing the peroneus longus tendon to the 5th metatarsal bone or the long calcaneocuboid ligament, developed in the embryonic period. The peroneus longus tendon presented a thickening in the area surrounding the cuboid bone as early as the fetal period. This thickening may be considered the precursor of the os peroneum and was similar in shape and in size relation to the tendon, to the os peroneum observed in adults. To the best of our knowledge, this is the first study to show that the os peroneum, articular facets of the peroneus longus tendon and cuboid bone, the peroneocuboid joint and the frenular ligaments appear during the embryonic/fetal development period and therefore they can not be generated exclusively by orthostatic and mechanical forces or pathological processes. PMID:25384452

  9. Optimized Bolted Joint

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.; Bunin, B. L.; Watts, D. J.

    1986-01-01

    Computer technique aids joint optimization. Load-sharing between fasteners in multirow bolted composite joints computed by nonlinear-analysis computer program. Input to analysis was load-deflection data from 180 specimens tested as part of program to develop technology of structural joints for advanced transport aircraft. Bolt design optimization technique applicable to major joints in composite materials for primary and secondary structures and generally applicable for metal joints as well.

  10. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    SciTech Connect

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  11. A facet approach to extending the normative component of the theory of reasoned action.

    PubMed

    Donald, I; Cooper, S R

    2001-12-01

    Using facet theory, this study addresses the weak explanatory power of normative influence in theories of reasoned action or planned behaviour. A broad normative construct is hypothesized as being characterized by two facets--social unit and behavioural modality--each of which is examined in relation to recreational drug use. A questionnaire was developed from the facets and administered to undergraduate students. Data (N = 181) were analysed using Smallest Space Analysis (SSA). The results suggest that the facets provide an adequate description of the normative construct and that personal and social normative beliefs, behavioural norms and behavioural intentions can be distinguished empirically. The results also lend partial support to Ajzen's (1988; Ajzen & Fishbein, 1977) principle of compatibility. Implications for how social influence is operationalized and conceptualized are also discussed.

  12. Atomic force microscopy and scanning electron microscopy study of MgO(110) surface faceting

    NASA Astrophysics Data System (ADS)

    Giese, D. R.; Lamelas, F. J.; Owen, H. A.; Plass, R.; Gajdardziska-Josifovska, M.

    2000-06-01

    Phosphoric- and nitric-acid etching of the MgO(110) surface generates vicinal faceting in both the <001> and <110> directions. Vacuum annealing (to 1000°C) does not introduce thermal faceting, and does not alter the chemical-etch morphology. Three types of acid-induced faceting (early-stage pits, later-stage grooves, and inverted trapezoidal pyramids) are seen as a function of etching time. Facet-angle analysis by atomic force microscopy (AFM) and scanning electron microscopy (SEM) shows the etch morphology to be vicinal, with angles in the range of 9° to 23°, not the low-energy {100} planes expected from minimization of surface energy.

  13. Facets of emotional awareness and associations with emotion regulation and depression.

    PubMed

    Boden, Matthew Tyler; Thompson, Renee J

    2015-06-01

    Emotion theories posit that effective emotion regulation depends upon the nuanced information provided by emotional awareness; attending to and understanding one's own emotions. Additionally, the strong associations between facets of emotional awareness and various forms of psychopathology may be partially attributable to associations with emotion regulation. These logically compelling hypotheses are largely uninvestigated, including which facets compose emotional awareness and how they relate to emotion regulation strategies and psychopathology. We used exploratory structural equation modeling of individual difference measures among a large adult sample (n = 919) recruited online. Results distinguished 4 facets of emotional awareness (type clarity, source clarity, involuntary attention to emotion, and voluntary attention to emotion) that were differentially associated with expressive suppression, acceptance of emotions, and cognitive reappraisal. Facets were associated with depression both directly and indirectly via associations with emotion regulation strategies. We discuss implications for theory and research on emotional awareness, emotion regulation, and psychopathology.

  14. Is lumbar facet fusion biomechanically equivalent to lumbar posterolateral onlay fusion?

    PubMed

    Toth, Jeffrey M; Foley, Kevin T; Wang, Mei; Seim, Howard B; Simon Turner, A

    2017-02-03

    OBJECTIVE This study was designed with the following research objectives: 1) to determine the efficacy of facet fusion with recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS) in an ovine lumbar facet fusion model; 2) to radiographically and histologically compare the efficacy of lumbar facet fusion with rhBMP-2/ACS to facet fusion with an iliac crest bone graft (ICBG); and 3) to biomechanically compare lumbar facet fusion with rhBMP-2/ACS to lumbar posterolateral fusion (PLF) with ICBG. METHODS The efficacies of the 3 treatments to induce fusion were evaluated in an instrumented ovine lumbar fusion model. Eight sheep had 10 cm(3)/side ICBG placed as an onlay graft for PLF at L2-3. At the adjacent L3-4 level, 0.5 cm(3)/side ICBG was placed for facet fusion. Finally, 0.5 cm(3)/side rhBMP-2/ACS (0.43 mg/ml) was placed for facet fusion at L4-5. CT scans were obtained at 2, 4, and 6 months postoperatively with 2 reviewers conducting an evaluation of the 6-month results for all treated spinal levels. All 8 sheep were killed at 6 months, and all posterolateral instrumentation was removed at this time. The spines were then sectioned through L3-4 to allow for nondestructive unconstrained biomechanical testing of the L2-3 and L4-5 segments. All treated spinal levels were analyzed using undecalcified histology with corresponding microradiography. Statistical comparisons were made between the treatment groups. RESULTS The PLF with ICBG (ICBG PLF group) and the rhBMP-2 facet fusion (rhBMP-2 Facet group) treatment groups demonstrated similar levels of stiffness, with the rhBMP-2 Facet group having on average slightly higher stiffness in all 6 loading directions. All 8 levels in the autograft facet fusion treatment group demonstrated CT radiographic and histological fusion. All 8 levels in the rhBMP-2 Facet group showed bilateral CT radiographic and histological fusion. Six of 16 rhBMP-2/ACS-treated facet defects demonstrated small

  15. Electrostatics-driven assembly of uni-lamellar catanionic facetted vesicles

    NASA Astrophysics Data System (ADS)

    Leung, Cheuk-Yui; Palmer, Liam; Kewalramani, Sumit; Sknepnek, Rastko; Vernizzi, Graziano; Greenfield, Megan; Stupp, Samuel; Bedzyk, Michael; Olvera de La Cruz, Monica

    2012-02-01

    Nature utilizes shape to generate function. Organelle and halophilic bacteria wall envelopes, for example, adopt various polyhedral shapes to compartmentalize matter. The origin of these shapes is unknown. A large variety of shell geometries, either fully faceted polyhedra or mixed Janus-like vesicles with faceted and curved domains that resemble cellular shells can be generated by coassembling water-insoluble anionic (--1) amphiphiles with high valence cationic (+2 and +3) amphiphiles. Electron microscopy, X-ray scattering, theory and simulations demonstrate that the resulting faceted ionic shells are crystalline, and stable at high salt concentrations. The crystallization of the co-assembled single tail amphiphiles is induced by ionic correlations, and modified by the solution pH. This work promotes the design of faceted shapes for various applications and improves our understanding of the origin of polyhedral shells in nature.

  16. Facet-Specific Assembly of Proteins on SrTiO3 Polyhedral Nanocrystals

    NASA Astrophysics Data System (ADS)

    Dong, Lingqing; Luo, Qi; Cheng, Kui; Shi, Hui; Wang, Qi; Weng, Wenjian; Han, Wei-Qiang

    2014-05-01

    Precisely controlling the protein-nanomaterial interactions at selective sites is crucial in engineering biomolecule composite architectures with tailored nanostructures and functions for a variety of biomedical applications. This strategy, however, is only beginning to be explored. Here, we demonstrate the facet-specific assembly of proteins, such as albumin, immunoglobulin and protamine, on {100} facets of SrTiO3 polyhedral nanocrystals, while none on {110} facets. Molecular dynamics simulations indicate the immobile surface hydration layer might play a barrier role to effectively prevent proteins adsorption on specific {110} facets. This work thus provides new insights into the fundamentally understanding of protein-nanomaterial interactions, and open a novel, general and facile route to control the selective adsorption of various proteins on various nanocrystals.

  17. Polyhedral Au nanocrystals exclusively bound by {110} facets: the rhombic dodecahedron.

    PubMed

    Jeong, Gyoung Hwa; Kim, Minjung; Lee, Young Wook; Choi, Wonjun; Oh, Won Taek; Park, Q-Han; Han, Sang Woo

    2009-02-11

    The rhombic dodecahedral Au nanocrystals enclosed by 12 {110} facets could be readily prepared without the use of any seeds, surfactants, or foreign metal ions but only with N,N-dimethylformamide as both reductant and solvent.

  18. GaAs-based self-aligned stripe superluminescent diodes processed normal to the cleaved facet

    NASA Astrophysics Data System (ADS)

    Ghazal, O. M. S.; Lei, D.; Childs, D. T.; Stevens, B. J.; Babazadeh, N.; Hogg, R. A.; Groom, K. M.

    2016-03-01

    We demonstrate GaAs-based superluminescent diodes (SLDs) incorporating a window-like back facet in a self-aligned stripe. SLDs are realised with low spectral modulation depth (SMD) at high power spectral density, without application of anti-reflection coatings. Such application of a window-like facet reduces effective facet reflectivity in a broadband manner. We demonstrate 30mW output power in a narrow bandwidth with only 5% SMD, outline the design criteria for high power and low SMD, and describe the deviation from a linear dependence of SMD on output power as a result of Joule heating in SLDs under continuous wave current injection. Furthermore, SLDs processed normal to the facet demonstrate output powers as high as 20mW, offering improvements in beam quality, ease of packaging and use of real estate.

  19. Pathological eating behaviors, BMI, and facet-level traits: the roles of conscientiousness, neuroticism, and impulsivity.

    PubMed

    Ellickson-Larew, Stephanie; Naragon-Gainey, Kristin; Watson, David

    2013-12-01

    The current study examined the bivariate and multivariate associations of personality with Body Mass Index (BMI) and several eating behavior inventories, focusing on facets of Neuroticism, Conscientiousness, and Impulsivity. Simultaneous multiple regressions showed that the facets Traditionalism, Urgency, and low Vulnerability were significant predictors of BMI. A factor analysis of the eating behavior scales revealed two dimensions: (a) Food and Body Preoccupation and (b) Cued Eating; Neuroticism, low Conscientiousness, and Perfectionism were significant predictors of both eating behavior factors. In addition, the Depression facet predicted Food and Body Preoccupation, and low Temperance predicted Cued Eating. Implications are discussed for the structure of eating pathology and the specificity of facet traits to eating behaviors and obesity.

  20. Openness to Experience and Mortality in Men: Analysis of Trait and Facets

    PubMed Central

    Turiano, Nicholas A.; Spiro, Avron; Mroczek, Daniel K.

    2013-01-01

    Objectives We examined whether specific facets are more robust predictors of mortality risk than overall trait openness in a sample of older men. Methods The current investigation used data from 1,349 men from the Veterans Affairs Normative Aging Study. From 1990–1991 to 2008, 547 (41%) had died. We used exploratory factor analysis to extract facets of openness, followed by proportional hazards modeling to examine 18-year mortality risk. Results Two facets emerged from the openness adjectives: intellect and creativity. In the fully adjusted model, only creativity predicted mortality risk. A 1-SD increase in creativity was associated with a 12% decrease in mortality risk. Discussion The study demonstrated that consideration of facets allows for a more precise understanding of the personality–health association. Higher levels of creativity predict longer survival in a sample of older men which provides preliminary support of the protective role creativity has on health even at advanced ages. PMID:22219209

  1. Facet-dependent electrochemical properties of Co3O4 nanocrystals toward heavy metal ions

    PubMed Central

    Yu, Xin-Yao; Meng, Qiang-Qiang; Luo, Tao; Jia, Yong; Sun, Bai; Li, Qun-Xiang; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-01-01

    We revealed an interesting facet-dependent electrochemical behavior toward heavy metal ions (HMIs) based on their adsorption behaviors. The (111) facet of Co3O4 nanoplates has better electrochemical sensing performance than that of the (001) facet of Co3O4 nanocubes. Adsorption measurements and density-functional theory (DFT) calculations reveals that adsorption of HMIs is responsible for the difference of electrochemical properties. Our combined experimental and theoretical studies provide a solid hint to explain the mechanism of electrochemical detection of HMIs using nanoscale metal oxides. Furthermore, this study not only suggests a promising new strategy for designing high performance electrochemical sensing interface through the selective synthesis of nanoscale materials exposed with different well-defined facets, but also provides a deep understanding for a more sensitive and selective electroanalysis at nanomaterials modified electrodes. PMID:24097175

  2. Erosion Triangular Facets as Markers of Order in an Open Dissipative System

    NASA Astrophysics Data System (ADS)

    Paliaga, Guido

    2015-07-01

    The complexity and non-linearity of the morphogenetic system which is responsible for shaping the Earth's surface have been widely recognised by many authors who have documented the fractal nature of erosion. In this paper, two peculiar kinds of landforms are compared to point out ordered structures, i.e. triangular facets that arise in different geomorphic systems, due to the principle of morphologic convergence. Occurrence of triangular facets has been documented in mountainous areas in relation to base level changes and hydrographical network evolution; similarly shaped landforms are present even in recent tectonic uplift areas along faults. The spatial distribution of the two kinds of facets has been investigated in two river basins located in Liguria (northern Italy) and in a mountainous area in Oman. The results of this analysis document the different spatial features of the two kinds of facets.

  3. Distinct water activation on polar/non-polar facets of ZnO nanoparticles

    SciTech Connect

    Zhang, He; Sun, Junming; Liu, Changjun; Wang, Yong

    2015-11-01

    ZnO nanoparticles with differing dominant facets were prepared and characterized by a complimentary of techniques such as X-ray diffraction, electron microscopy, temperature programmed desorption of H2O, and Fourier transform infrared spectroscopy analysis of adsorbed D2O. For the first time, water interaction/activation is compared on ZnO polar and non-polar facets. We report that non-polar facets exhibit high activity in water activation, which favors reactions such as ketonization and steam reforming in which dissociated water is involved. The distinct water dissociation on ZnO non-polar facets could be related to its facile formation of oxygen vacancies under realistic reaction conditions.

  4. Fabrication of lithographically defined optical coupling facets for silicon-on-insulator waveguides by inductively coupled plasma etching

    SciTech Connect

    Yap, K.P.; Lamontagne, B.; Delage, A.; Janz, S.; Bogdanov, A.; Picard, M.; Post, E.; Chow-Chong, P.; Malloy, M.; Roth, D.; Marshall, P.; Liu, K.Y.; Syrett, B.

    2006-05-15

    We present a technique to lithographically define and fabricate all required optical facets on a silicon-on-insulator photonic integrated circuit by an inductively coupled plasma etch process. This technique offers 1 {mu}m positioning accuracy of the facets at any location within the chip and eliminates the need of polishing. Facet fabrication consists of two separate steps to ensure sidewall verticality and minimize attack on the end surfaces of the waveguides. Protection of the waveguides by a thermally evaporated aluminum layer before the 40-70 {mu}m deep optical facet etching has been proven essential in assuring the facet smoothness and integrity. Both scanning electron microscopy analysis and optical measurement results show that the quality of the facets prepared by this technique is comparable to the conventional facets prepared by polishing.

  5. Local and social facets of planetary boundaries: right to nutrients

    NASA Astrophysics Data System (ADS)

    Kahiluoto, Helena; Kuisma, Miia; Kuokkanen, Anna; Mikkilä, Mirja; Linnanen, Lassi

    2015-10-01

    Anthropogenic nutrient flows exceed the planetary boundaries. The boundaries and the current excesses vary spatially. Such variations have both an ecological and a social facet. We explored the spatial variation using a bottom-up approach. The local critical boundaries were determined through the current or accumulated flow of the preceding five years before the planetary boundary criteria were met. Finland and Ethiopia served as cases with contrasting ecology and wealth. The variation in excess depends on historical global inequities in the access to nutrients. Globally, the accumulated use per capita is 2300 kg reactive nitrogen (Nr) and 200 kg phosphorus (P). For Finland, the accumulated use per capita is 3400 kg Nr and 690 kg P, whereas for Ethiopia, it is 26 kg Nr and 12 kg P. The critical N boundary in Finland is currently exceeded by 40 kg cap-1 a-1 and the accumulated excess is 65 kg cap-1 a-1, while the global current excess is 24 kg cap-1 a-1 and there is space in Ethiopia to increase even the accumulated flow. The critical P boundary is exceeded in Finland and (although less so) in Ethiopia, but for contrary reasons: (1) the excessive past inflow to the agrifood system in Finland and (2) the excessive outflow from the agrifood system triggered by deficits in inflow and waste management in Ethiopia. The critical boundaries set by Finnish marine systems are lower and those set by freshwaters are higher than the planetary boundaries downscaled per capita. The shift to dominance of internal loading in watercourses represents a tipping point. We conclude that food security within the safe boundaries requires global redistribution of nutrients in residues, soils and sediments and of rights to use nutrients. Bottom-up assessments reveal local dynamics that shed new light on the relevant boundary criteria and on estimates and remedies.

  6. Facet Model and Mathematical Morphology for Surface Characterization

    SciTech Connect

    Abidi, B.R.; Goddard, J.S.; Hunt, M.A.; Sari-Sarraf, H.

    1999-11-13

    This paper describes an algorithm for the automatic segmentation and representation of surface structures and non-uniformities in an industrial setting. The automatic image processing and analysis algorithm is developed as part of a complete on-line web characterization system of a papermaking process at the wet end. The goal is to: (1) link certain types of structures on the surface of the web to known machine parameter values, and (2) find the connection between detected structures at the beginning of the line and defects seen on the final product. Images of the pulp mixture (slurry), carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. This characterization algorithm succeeded where conventional contrast and edge detection techniques failed due to a poorly controlled environment. The images obtained have poor contrast and contain noise caused by a variety of sources. After a number of enhancement steps, conventional segmentation methods still f ailed to detect any structures and are consequently discarded. Techniques tried include the Canny edge detector, the Sobel, Roberts, and Prewitt's filters, as well as zero crossings. The facet model algorithm, is then applied to the images with various parameter settings and is found to be successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image computed. Carefully tailored morphological operators are then applied to detect and segment regions of interest. Those regions are then selected according to their size, elongation, and orientation. Their bounding rectangles are computed and represented. Also addressed in this paper are aspects of the real time implementation of this algorithm for on-line use. The algorithm is tested on over 500 images of slurry and is found to segment and characterize nonuniformities on all 500 images.

  7. Physical facets of ultrasonic cavitational synthesis of zinc ferrite particles.

    PubMed

    Reddy, Bhaskar Rao; Sivasankar, Thirugnanasambandam; Sivakumar, Manickam; Moholkar, Vijayanand S

    2010-02-01

    This paper addresses the physical features of the ultrasonic cavitational synthesis of zinc ferrite particles and tries to establish the relationship between cavitation physics and sonochemistry of the zinc ferrite synthesis. A dual approach of coupling experimental results with simulations of radial motion of cavitation bubbles has been adopted. The precursors for the zinc ferrite, viz. ZnO and Fe(3)O(4) are produced in situ by the hydrolysis of Zn and Fe(II) acetates stimulated by (*)OH radicals produced from the transient collapse of the cavitation bubbles. Experiments performed under different conditions create significant variation in the production of (*)OH radicals, and hence, the rate of acetate hydrolysis. Correlation of the results of experiments and simulations sheds light on the important facets of the physical mechanism of ultrasonic cavitational zinc ferrite synthesis. It is revealed that too much or too little rate of acetate hydrolysis results in smaller particle size of zinc ferrite. The first effect of a higher rate of hydrolysis leads to excessively large growth of particles, due to which they become susceptible to the disruptive action of cavitation bubbles. Whereas, the second effect of too small rate of hydrolysis of Zn and Fe(II) acetates restricts the growth of particles. It has been observed that the initial reactant concentration does not influence the mean particle size or the size distribution of zinc ferrite particles. The present investigation clearly confirms that the rate-controlling step of zinc ferrite synthesis through ultrasonic cavitational route is the rate of formation of (*)OH radicals from cavitation bubbles.

  8. Observations of Facet Formation in Near-a Titanium and Comments on the Role of Hydrogen

    DTIC Science & Technology

    2010-10-01

    transverse to the bar axis by wire electrical discharge machining . All the tests were performed on material in the as-received condition. The blanks were... machined into round specimens with diameters of either 5.08 mm (cyclic and dwell loading) or 4.06 mm (static loading) with gauge lengths of 19.05 mm and...small, semielliptical faceted region near the surface of the specimen. The region of faceted growth transitioned to more conventional striation

  9. Stress Corrosion Cracking Facet Crystallography of Ti-8Al-1Mo-1V (Preprint)

    DTIC Science & Technology

    2011-05-01

    both specimens, the regions not characterized by faceted fracture generally consisted of features like flutes [33;34] and dimples consistent with...received specimen studied here switches from ductile dimple / fluted growth [34] to faceted growth with increasing crack length. Since crack formation...Crystallography of fluted fracture in near-α titanium alloys, Metall. Mater. Trans. A. 41 (2010) 22-25. [35] J.C. Chesnutt, J.C. Williams, Comments on the

  10. Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC

    ScienceCinema

    Andrei Seryi

    2016-07-12

    Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

  11. Deformation due to migration of faceted ? twin boundaries in magnesium and cobalt

    NASA Astrophysics Data System (ADS)

    Ostapovets, Andriy; Buršík, Jiří; Gröger, Roman

    2015-12-01

    Recent experimental observations show that ? twin boundaries in hexagonal close-packed (hcp) metals are frequently faceted. The objective of this paper is to investigate the influence of this faceting on the strain produced by twinning. We show that basal-prismatic (BP) facets are terminated by opposite disclinations and the migration of these facets along a straight ? twin boundary produces ordinary twinning shear. On the other hand, joining conjugate twins gives rise to BP facets terminated on the parent twin boundaries by identical disclinations. In this case, the strain produced by the migration of BP facets is an average between the strains produced by the individual conjugate twins. These theoretical studies are complemented by two EBSD measurements on cobalt that is closely related to magnesium. The misorientation profiles measured across two conjugate twin boundaries yield a misfit of approx. 7° consistent with the theoretical prediction that the corner of a twin embryo is terminated by two identical disclinations, each accommodating a misfit of 3.7°.

  12. Modeling of Human Joint Structures.

    DTIC Science & Technology

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  13. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... arthritis, or JRA), systemic lupus erythematosus (SLE), and Lyme disease. Joint aspiration is diagnostic but it also can ... Parents MORE ON THIS TOPIC Evaluate Your Child's Lyme Disease Risk Living With Lupus Bones, Muscles, and Joints ...

  14. Culture - joint fluid

    MedlinePlus

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  15. Temporomandibular Joint Dysfunction

    MedlinePlus

    The temporomandibular joint (TMJ) connects your jaw to the side of your head. When it works well, it enables you to ... For people with TMJ dysfunction, problems with the joint and muscles around it may cause Pain that ...

  16. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  17. Large displacement spherical joint

    DOEpatents

    Bieg, Lothar F.; Benavides, Gilbert L.

    2002-01-01

    A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

  18. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  19. Fracture-dislocations of the elbow joint--strategy for treatment and results.

    PubMed

    Lill, H; Korner, J; Rose, T; Hepp, P; Verheyden, P; Josten, C

    2001-01-01

    Between January 1993 and December 1996, 41 patients with fracture dislocation of the elbow joint were treated in our department. In 28 patients (median age 46 years, range 15-77 years; 16 male, 12 female), a clinical and radiological follow-up was obtained after median 34 months (range 12-59 months). In addition to the humero-ulnar dislocation, isolated fractures were present in 13 patients and combined fractures in 15 (all with involvement of the radial head). Primary neurological deficits were found in 7 and open fractures in 3 patients. In 7 patients, primary definitive surgical therapy was carried out by open reduction and internal fixation. A two-step surgical management (initial closed reduction and immobilization, 5 patients with external fixator, 7 with plaster; secondary open surgical procedure) was performed in 12 and conservative treatment in 9 patients. According to the Leipzig Elbow Score, taking subjective, clinical and radiological criteria into consideration, 4 patients achieved 'excellent' and 5 patients a 'good' result. Ten patients were scored 'moderate' and 9 'poor'. The rate of secondary complications necessitating revision was 36%. Poor results were primarily caused by extensive initial soft-tissue damage, delayed definitive surgical therapy, and ectopic heterotopic ossification. In contrast, fracture localization and degree of arthrosis were not of significant importance for the final outcome. In fracture dislocations, the goal is a primary definitive surgical treatment aiming for early postoperative physiotherapy.

  20. Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, ...

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

    Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie & Diagonal Brace Joint Detail; Chord, Panel Post, Tie & Crossbracing Joint Detail - Dunlapsville Covered Bridge, Spanning East Fork Whitewater River, Dunlapsville, Union County, IN

  1. Facets : a Cloudcompare Plugin to Extract Geological Planes from Unstructured 3d Point Clouds

    NASA Astrophysics Data System (ADS)

    Dewez, T. J. B.; Girardeau-Montaut, D.; Allanic, C.; Rohmer, J.

    2016-06-01

    Geological planar facets (stratification, fault, joint…) are key features to unravel the tectonic history of rock outcrop or appreciate the stability of a hazardous rock cliff. Measuring their spatial attitude (dip and strike) is generally performed by hand with a compass/clinometer, which is time consuming, requires some degree of censoring (i.e. refusing to measure some features judged unimportant at the time), is not always possible for fractures higher up on the outcrop and is somewhat hazardous. 3D virtual geological outcrop hold the potential to alleviate these issues. Efficiently segmenting massive 3D point clouds into individual planar facets, inside a convenient software environment was lacking. FACETS is a dedicated plugin within CloudCompare v2.6.2 (http://cloudcompare.org/ ) implemented to perform planar facet extraction, calculate their dip and dip direction (i.e. azimuth of steepest decent) and report the extracted data in interactive stereograms. Two algorithms perform the segmentation: Kd-Tree and Fast Marching. Both divide the point cloud into sub-cells, then compute elementary planar objects and aggregate them progressively according to a planeity threshold into polygons. The boundaries of the polygons are adjusted around segmented points with a tension parameter, and the facet polygons can be exported as 3D polygon shapefiles towards third party GIS software or simply as ASCII comma separated files. One of the great features of FACETS is the capability to explore planar objects but also 3D points with normals with the stereogram tool. Poles can be readily displayed, queried and manually segmented interactively. The plugin blends seamlessly into CloudCompare to leverage all its other 3D point cloud manipulation features. A demonstration of the tool is presented to illustrate these different features. While designed for geological applications, FACETS could be more widely applied to any planar

  2. Joint Enrollment Report, 2014

    ERIC Educational Resources Information Center

    Iowa Department of Education, 2014

    2014-01-01

    The Iowa Department of Education collects information on joint enrollment in Iowa's 15 community colleges. Jointly enrolled students are high school students enrolled in community college credit coursework. Most jointly enrolled students enroll through Senior Year Plus (SYP) programs such as Postsecondary Enrollment Options (PSEO) and concurrent…

  3. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Joint Aspiration (Arthrocentesis) KidsHealth > For Parents > Joint Aspiration (Arthrocentesis) Print A A A What's in ... español Aspiración articular (artrocentesis) What It Is A joint aspiration (arthrocentesis) is a test that involves withdrawing ( ...

  4. Mindfulness facets, trait emotional intelligence, emotional distress, and multiple health behaviors: A serial two-mediator model.

    PubMed

    Jacobs, Ingo; Wollny, Anna; Sim, Chu-Won; Horsch, Antje

    2016-06-01

    In the present study, we tested a serial mindfulness facets-trait emotional intelligence (TEI)-emotional distress-multiple health behaviors mediation model in a sample of N = 427 German-speaking occupational therapists. The mindfulness facets-TEI-emotional distress section of the mediation model revealed partial mediation for the mindfulness facets Act with awareness (Act/Aware) and Accept without judgment (Accept); inconsistent mediation was found for the Describe facet. The serial two-mediator model included three mediational pathways that may link each of the four mindfulness facets with multiple health behaviors. Eight out of 12 indirect effects reached significance and fully mediated the links between Act/Aware and Describe to multiple health behaviors; partial mediation was found for Accept. The mindfulness facet Observe was most relevant for multiple health behaviors, but its relation was not amenable to mediation. Implications of the findings will be discussed.

  5. Selectivity on Etching: Creation of High-Energy Facets on Copper Nanocrystals for CO2 Electrochemical Reduction.

    PubMed

    Wang, Zhenni; Yang, Guang; Zhang, Zhaorui; Jin, Mingshang; Yin, Yadong

    2016-04-26

    Creating high-energy facets on the surface of catalyst nanocrystals represents a promising method for enhancing their catalytic activity. Herein we show that crystal etching as the reverse process of crystal growth can directly endow nanocrystal surfaces with high-energy facets. The key is to avoid significant modification of the surface energies of the nanocrystal facets by capping effects from solvents, ions, and ligands. Using Cu nanocubes as the starting material, we have successfully demonstrated the creation of high-energy facets in metal nanocrystals by controlled chemical etching. The etched Cu nanocrystals with enriched high-energy {110} facets showed significantly enhanced activity toward CO2 reduction. We believe the etching-based strategy could be extended to the synthesis of nanocrystals of many other catalysts with more active high-energy facets.

  6. Can Big Five Facets Distinguish between Hedonic and Eudaimonic Well-Being? A Dominance Analysis.

    PubMed

    Marrero, Rosario J; Rey, Mar; Hernández-Cabrera, Juan Andrés

    2016-11-22

    In this study, the aim was to analyze the relative importance of Five-Factor Model (FFM) personality facets for eudaimonic or psychological well-being (PWB) and hedonic or subjective well-being (SWB) through dominance analyses. The participants were 1,403 adult residents of Spain (mean age 37.2 years, SD = 13.9). As expected, facets captured a substantial proportion of the variance in PWB and SWB, with PWB being better predicted than SWB (explaining around 36-55% of the variance of PWB vs. 25% of the variance of SWB). Some facets were common to both types of well-being such as depression (explaining between 5-33% of the variance), vulnerability (explaining between 4-21% of the variance), positive emotions (explaining between 2-9% of the variance) and achievement striving (explaining between 2-10% of the variance), whereas others made a unique contribution according to type of well-being. Certain facets had a greater relative importance for women's well-being -e.g., positive emotions explained 9% of the variance of self-acceptance for women vs. 3% for men- and others for men's well-being -e.g., achievement striving explained 9% of the variance of personal growth for men vs. 2% for women-. The present results contribute to the literature by identifying which Big Five facets showed greater relative importance in explaining and distinguishing between PWB and SWB for women and men.

  7. Parallel syndromes: two dimensions of narcissism and the facets of psychopathic personality in criminally involved individuals.

    PubMed

    Schoenleber, Michelle; Sadeh, Naomi; Verona, Edelyn

    2011-04-01

    Little research has examined different dimensions of narcissism that may parallel psychopathy facets in criminally involved individuals. In this study, we examined the pattern of relationships between grandiose and vulnerable narcissism, assessed using the Narcissistic Personality Inventory-16 and the Hypersensitive Narcissism Scale, respectively, and the four facets of psychopathy (interpersonal, affective, lifestyle, and antisocial) assessed via the Psychopathy Checklist: Screening Version. As predicted, grandiose and vulnerable narcissism showed differential relationships to psychopathy facets, with grandiose narcissism relating positively to the interpersonal facet of psychopathy and vulnerable narcissism relating positively to the lifestyle facet of psychopathy. Paralleling existing psychopathy research, vulnerable narcissism showed stronger associations than grandiose narcissism to (a) other forms of psychopathology, including internalizing and substance use disorders, and (b) self- and other-directed aggression, measured with the Life History of Aggression and the Forms of Aggression Questionnaire. Grandiose narcissism was nonetheless associated with social dysfunction marked by a manipulative and deceitful interpersonal style and unprovoked aggression. Potentially important implications for uncovering etiological pathways and developing treatment interventions for these disorders in externalizing adults are discussed.

  8. Differential relations of depression and social anxiety symptoms to the facets of extraversion/positive emotionality.

    PubMed

    Naragon-Gainey, Kristin; Watson, David; Markon, Kristian E

    2009-05-01

    Previous research has shown that both depression and social anxiety--2 facets of internalizing psychopathology--are characterized by low levels of extraversion/positive emotionality (E/PE). However, little is known about the relations of the facets of E/PE with the symptoms of depression and social anxiety. This study utilized multiple measures of each facet of E/PE, as well as depression and social anxiety symptoms. Self-report data were collected from large samples of college students and psychiatric outpatients. Separate factor analyses in each sample revealed a 4-factor structure of E/PE consisting of Sociability, Positive Emotionality, Ascendance, and Fun-Seeking. Structural equation modeling revealed that, after controlling for the higher order internalizing factor and the overlap among the E/PE facets, social anxiety was broadly related to all 4 facets of E/PE, whereas depression was strongly related to only low positive emotionality. Implications for hierarchical models of personality and psychopathology, assessment and treatment, and etiological models are discussed.

  9. Defeaturing CAD models using a geometry-based size field and facet-based reduction operators.

    SciTech Connect

    Quadros, William Roshan; Owen, Steven James

    2010-04-01

    We propose a method to automatically defeature a CAD model by detecting irrelevant features using a geometry-based size field and a method to remove the irrelevant features via facet-based operations on a discrete representation. A discrete B-Rep model is first created by obtaining a faceted representation of the CAD entities. The candidate facet entities are then marked for reduction by using a geometry-based size field. This is accomplished by estimating local mesh sizes based on geometric criteria. If the field value at a facet entity goes below a user specified threshold value then it is identified as an irrelevant feature and is marked for reduction. The reduction of marked facet entities is primarily performed using an edge collapse operator. Care is taken to retain a valid geometry and topology of the discrete model throughout the procedure. The original model is not altered as the defeaturing is performed on a separate discrete model. Associativity between the entities of the discrete model and that of original CAD model is maintained in order to decode the attributes and boundary conditions applied on the original CAD entities onto the mesh via the entities of the discrete model. Example models are presented to illustrate the effectiveness of the proposed approach.

  10. Drinking Motives Mediate the Relationship between Facets of Mindfulness and Problematic Alcohol Use.

    PubMed

    Vinci, Christine; Spears, Claire A; Peltier, MacKenzie R; Copeland, Amy L

    2016-06-01

    Mindfulness is a multi-faceted construct, and research suggests that certain components (e.g., Acting with Awareness, Nonjudging) are associated with less problematic alcohol use. Recent research has examined whether specific drinking motives mediate the relationship between facets of mindfulness and alcohol use. The current study sought to extend this research by examining whether certain drinking motives would mediate the relationship between facets of mindfulness and problematic alcohol use in a sample of 207 college students classified as engaging in problematic drinking. Participants completed the Five Facet Mindfulness Questionnaire (FFMQ), Drinking Motives Questionnaire-Revised (DMQ-R), and Alcohol Use Disorders Identification Test (AUDIT). Results indicated that lower levels of Coping motives significantly mediated the relationship between greater Acting with Awareness and lower AUDIT score and between greater Nonjudging and lower AUDIT score. Lower levels of Conformity motives significantly mediated the relationship between greater Acting with Awareness and lower AUDIT score. These findings offer insight into specific mechanisms through which mindfulness is linked to less problematic drinking, and also highlight associations among mindfulness, drinking motives, and alcohol use among a sample of problematic college student drinkers. Future research should determine whether interventions that emphasize Acting with Awareness and Nonjudging facets of mindfulness and/or target coping and conformity motives could be effective for reducing problematic drinking in college students.

  11. Facet-dependent electrical conductivity properties of Cu2O crystals.

    PubMed

    Tan, Chih-Shan; Hsu, Shih-Chen; Ke, Wei-Hong; Chen, Lih-Juann; Huang, Michael H

    2015-03-11

    It is interesting to examine facet-dependent electrical properties of single Cu2O crystals, because such study greatly advances our understanding of various facet effects exhibited by semiconductors. We show a Cu2O octahedron is highly conductive, a cube is moderately conductive, and a rhombic dodecahedron is nonconductive. The conductivity differences are ascribed to the presence of a thin surface layer having different degrees of band bending. When electrical connection was made on two different facets of a rhombicuboctahedron, a diode-like response was obtained, demonstrating the potential of using single polyhedral nanocrystals as functional electronic components. Density of state (DOS) plots for three layers of Cu2O (111), (100), and (110) planes show respective metallic, semimetal, and semiconducting band structures. By examining DOS plots for varying number of planes, the surface layer thicknesses responsible for the facet-dependent electrical properties of Cu2O crystals have been determined to be below 1.5 nm for these facets.

  12. Progress report for FACETS (Framework Application for Core-Edge Transport Simulations)

    SciTech Connect

    Epperly, T W

    2009-04-20

    This role of this computer science SAP is to facilitate FACETS design and development by contributing CCA component technology and new application-specific technology. From a software perspective, the FACETS project is a very complex project. It is a combination of legacy software written in Fortran, Python, and C++ by various coding groups along with new software modules being written from scratch. The FACETS team is spread among 11 organizations and is geographically distributed from coast to coast. The fusion physics modules to be incorporated vary in terms of the model dimensions, typical time scale, and type of interactions with other components. Because FACETS is a complex project, it requires a component-based framework to facilitate the definition and composition of scientific applications from a suite of available fusion physics components. Component architectures have proven themselves in the business world and more recently in the scientific computing world. The CS SAP contributes fundamental tools like Babel to the FACETS framework and helps develop application-specific interfaces appropriate for the fusion physics modules.

  13. Mechanisms of morphological evolution on faceted core-shell nanowire surfaces

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Aqua, Jean-Noël; Voorhees, Peter W.; Davis, Stephen H.

    2016-06-01

    Core-shell nanowires with radial heterostructures hold great promise in photonic and electronic applications and controlling the formation of these heterostructures in the core-shell configuration remains a challenge. Recently, GaAs nanowires have been used as substrates to create AlGaAs shells. The deposition of the AlGaAs layer leads to the spontaneous formation of Al-rich stripes along certain crystallographic directions and quantum dots/wires near the apexes of the shell. A general two-dimensional model has been developed for the motion of the faceted solid-vapor interfaces for pure materials that accounts for capillarity and deposition. With this model, the growth processes and morphological evolution of shells of nanowires around hexagonal cores (six small facets {112} in the corners of six equivalent facets {110}) are investigated in detail both analytically and numerically. It is found that deposition can yield facets that are not present on the Wulff shape. These small facets can have slowly time-varying sizes that can lead to stripe structures and quantum dots/wires depending on the balances between diffusion and deposition. The effects of deposition rates and polarity (or asymmetry) on planes {112} on the development of the configurations of nanowires are discussed. The numerical results are compared with experimental results giving almost quantitative agreement, despite the fact that only pure materials are treated herein whereas the experiments deal with alloys.

  14. Enhanced photocatalytic activity of N-doped TiO2 nanocrystals with exposed {001} facets

    NASA Astrophysics Data System (ADS)

    Li, Di; Chen, Fen; Jiang, Deli; Shi, Weidong; Zheng, Wenjun

    2016-12-01

    N-doped TiO2 nanocrystals with exposed {001} facets have been synthesized by a two-step method. Firstly, we synthesized anatase TiO2 nanocrystals with exposed {001} facets by an original hydrothermal method using HBF4 and n-BA to coordinated the regulation of size and morphology. Then, ethylenediamine has been used as N dopant source to dope with the as-prepared TiO2 nanocrystals. The effects of both HBF4 and n-BA in synthesis of anatase TiO2 nanocrystals with exposed {001} facets have been investigated. The enlarged localized profiles of the XRD pattern and XPS spectra demonstrate the existence of N element. The photocatalytic property studies showed that the N-doped TiO2 nanocrystals with exposed {001} facets exhibited much higher photocatalytic activity than that of the N-doped P25, which might be ascribed to the high percentage of exposed {001} facets. In addition, the stability study suggests that the as-synthesized photocatalyst is a promising material for the application of wastewater purification.

  15. Surface Area of Patellar Facets: Inferential Statistics in the Iraqi Population

    PubMed Central

    Al-Zamili, Zaid; Omar, Rawan

    2017-01-01

    Background. The patella is the largest sesamoid bone in the body; its three-dimensional complexity necessitates biomechanical perfection. Numerous pathologies occur at the patellofemoral unit which may end in degenerative changes. This study aims to test the presence of statistical correlation between the surface areas of patellar facets and other patellar morphometric parameters. Materials and Methods. Forty dry human patellae were studied. The morphometry of each patella was measured using a digital Vernier Caliper, electronic balance, and image analyses software known as ImageJ. The patellar facetal surface area was correlated with patellar weight, height, width, and thickness. Results. Inferential statistics proved the existence of linear correlation of total facetal surface area and patellar weight, height, width, and thickness. The correlation was strongest for surface area versus patellar weight. The lateral facetal area was found persistently larger than the medial facetal area, the p value was found to be <0.001 (one-tailed t-test) for right patellae, and another significant p value of < 0.001 (one-tailed t-test) was found for left patellae. Conclusion. These data are vital for the restoration of the normal biomechanics of the patellofemoral unit; these are to be consulted during knee surgeries and implant designs and can be of an indispensable anthropometric, interethnic, and biometric value. PMID:28348891

  16. Do as You're Told! Facets of Agreeableness and Early Adult Outcomes for Inner-City Boys.

    PubMed

    Kern, Margaret L; Duckworth, Angela L; Urzúa, Sergio; Loeber, Rolf; Stouthamer-Loeber, Magda; Lynam, Donald R

    2013-12-01

    With data from the middle cohort of the Pittsburgh Youth Study, a prospective longitudinal study of inner-city boys, we examined whether Big Five agreeableness facets could be reliably recovered in this sample, and whether facets predicted educational, occupational, social, and antisocial life outcomes assessed a decade later. Caregivers described their adolescent boys' personalities using the Common California Q-Set; twelve years later, participants were interviewed and court records were obtained. Factor analyses recovered two facets: compliance and compassion. Compliance predicted more schooling and lower risk of unemployment, teenage fatherhood, and crime; compassion related to longer committed relationships. Findings highlight the value of studying personality at the facet level.

  17. Management of Neglected Traumatic Bilateral Cervical Facet Dislocations Without Neurological Deficit

    PubMed Central

    Farooque, Kamran; Khatri, Kavin; Gupta, Babita; Sharma, Vijay

    2015-01-01

    Introduction: Sub axial cervical spine dislocations are common and managing these cases by closed reduction is successful in the majority of cases. However, treatment of old and neglected cases is difficult and the results may vary in terms of neurological and functional outcomes. Case Presentation: We present two cases of traumatic bilateral cervical facet dislocation with no neurological deficit (ND) who referred four months after the injury. They were managed via single stage anterior discectomy, posterior facet reduction, instrumentation, and then anterior reconstruction with bone graft and cervical plate. The patients had no ND in the postoperative period and returned to work. Discussion: Patients presenting with neck pain after a history of trauma should be evaluated thoroughly with radiographs and computed tomography. The management of old neglected facet dislocations is difficult, lengthy, and fraught with potential neurological complications; operative intervention can substantially improve the quality of life in these patients. PMID:26543838

  18. GPU accelerated Discrete Element Method (DEM) molecular dynamics for conservative, faceted particle simulations

    NASA Astrophysics Data System (ADS)

    Spellings, Matthew; Marson, Ryan L.; Anderson, Joshua A.; Glotzer, Sharon C.

    2017-04-01

    Faceted shapes, such as polyhedra, are commonly found in systems of nanoscale, colloidal, and granular particles. Many interesting physical phenomena, like crystal nucleation and growth, vacancy motion, and glassy dynamics are challenging to model in these systems because they require detailed dynamical information at the individual particle level. Within the granular materials community the Discrete Element Method has been used extensively to model systems of anisotropic particles under gravity, with friction. We provide an implementation of this method intended for simulation of hard, faceted nanoparticles, with a conservative Weeks-Chandler-Andersen (WCA) interparticle potential, coupled to a thermodynamic ensemble. This method is a natural extension of classical molecular dynamics and enables rigorous thermodynamic calculations for faceted particles.

  19. Plasmonic crystal cavity on single-mode optical fiber end facet for label-free biosensing

    NASA Astrophysics Data System (ADS)

    He, Xiaolong; Yi, Hui; Long, Jing; Zhou, Xin; Yang, Jie; Yang, Tian

    2016-06-01

    Surface plasmon resonance (SPR) devices on single-mode optical fiber (SMF) end facets are desired for label-free biosensing, due to flexible light delivery, in vivo inspection capability, and seamless integration with fiber-optic communication techniques. We report a plasmonic crystal cavity structure that has a steep resonance near the plasmonic bandedge, a fabrication process to efficiently transfer and align the structure onto a bare SMF end facet, and characterization of its sensing performance. With a sensitivity of 571 nm RIU-1, a figure of merit of 68 RIU-1 and a real-time refractive index detection limit of 3.5 × 10-6 RIU, our sensors can be readily applied in common SPR biosensing experiments. They are over an order of magnitude more sensitive than reported modified-end multimode fiber SPR devices, while there are no reports on previous SMF end facet devices' detection limits which have very low figures of merit.

  20. The 3 facets of regulation of herpes simplex virus gene expression: a critical inquiry

    PubMed Central

    Roizman, Bernard; Zhou, Guoying

    2015-01-01

    On entry into the body herpes simplex viruses (HSV) replicate in a series of steps that involves derepression of viral DNA activated by VP16, a virion protein, and sequential transcription of viral genes in a cascade fashion. HSV also enters into neurons in which viral DNA maintained as heterochromatin and with few exceptions viral gene expression is silenced. A third face of the interaction of HSV with its host cells takes place at the moment when the silenced viral genome in neurons is abruptly derepressed. The available data do no reveal evidence that HSV encodes different regulatory programs for each facet of its interaction with its host cells. Rather the data point to significant gaps in our knowledge of the mechanisms by which each facet is initiated and the roles of the infected cells at each facet of the interaction of viral gene products with the host cell. PMID:25771487

  1. Which facets of mindfulness are related to problematic eating among patients seeking bariatric surgery?

    PubMed

    Levin, Michael E; Dalrymple, Kristy; Himes, Susan; Zimmerman, Mark

    2014-04-01

    There has been growing research indicating the potential positive benefits of mindfulness-based interventions for obesity, but few studies have examined the relationship of mindfulness processes to obesity-related behaviors, particularly among clinical populations such as bariatric surgery candidates. The current study examined the relationship of specific mindfulness facets to a variety of problematic eating behaviors assessed through diagnostic interviews in a clinical sample of 820 patients seeking bariatric surgery. Results indicated that greater mindfulness on specific facets, particularly acting with awareness, was related to less binge and emotional eating. Greater mindfulness was also related, though less consistently, to less habitual overeating and grazing. The observing facet was generally unrelated to problematic eating, but in a few cases being more observant related to having greater eating problems. The results of the study and future directions are discussed in relation to research on problematic eating in obesity and mindfulness-based interventions.

  2. Rotary encoding device using polygonal mirror with diffraction gratings on each facet

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B. (Inventor)

    1993-01-01

    A device for position encoding of a rotating shaft in which a polygonal mirror having a number of facets is mounted to the shaft and a monochromatic light beam is directed towards the facets. The facets of the polygonal mirror each have a low line density diffraction grating to diffract the monochromatic light beam into a number of diffracted light beams such that a number of light spots are created on a linear array detector. An analog-to-digital converter is connected to the linear array detector for reading the position of the spots on the linear array detector means. A microprocessor with memory is connected to the analog-to-digital converter to hold and manipulate the data provided by the analog-to-digital converter on the position of the spots and to compute the position of the shaft based upon the data from the analog-to-digital converter.

  3. Facets on the convex hull of d -dimensional Brownian and Lévy motion

    NASA Astrophysics Data System (ADS)

    Randon-Furling, Julien; Wespi, Florian

    2017-03-01

    For stationary, homogeneous Markov processes (viz., Lévy processes, including Brownian motion) in dimension d ≥3 , we establish an exact formula for the average number of (d -1 ) -dimensional facets that can be defined by d points on the process's path. This formula defines a universality class in that it is independent of the increments' distribution, and it admits a closed form when d =3 , a case which is of particular interest for applications in biophysics, chemistry, and polymer science. We also show that the asymptotical average number of facets behaves as ˜2 (T /Δ t)lnd -1, where T is the total duration of the motion and Δ t is the minimum time lapse separating points that define a facet.

  4. A glimpse behind the mask: facets of narcissism and feelings of self-worth.

    PubMed

    Zeigler-Hill, Virgil; Besser, Avi

    2013-01-01

    This study examined the connections that the facets of narcissism captured by the Narcissistic Personality Inventory (NPI; Raskin & Hall, 1979) and the Pathological Narcissism Inventory (PNI; Pincus et al., 2009) have with self-esteem. This was accomplished by asking 372 participants to complete measures of narcissism and self-esteem level as well as daily diary measures concerning their state self-esteem and daily experiences. Our analyses found that the facets of narcissism differed in their associations with average level of self-esteem, fluctuations in state self-esteem over time, and self-esteem reactions following daily events. These results suggest that it is important to consider specific facets of narcissism when examining feelings of self-worth rather than relying on broader composite measures of narcissistic personality features. Implications of these results for our understanding of the dynamics of the narcissistic personality are discussed.

  5. Visualization of Bacterial Microcompartment Facet Assembly Using High-Speed Atomic Force Microscopy

    PubMed Central

    2015-01-01

    Bacterial microcompartments (BMCs) are proteinaceous organelles widespread among bacterial phyla. They compartmentalize enzymes within a selectively permeable shell and play important roles in CO2 fixation, pathogenesis, and microbial ecology. Here, we combine X-ray crystallography and high-speed atomic force microscopy to characterize, at molecular resolution, the structure and dynamics of BMC shell facet assembly. Our results show that preformed hexamers assemble into uniformly oriented shell layers, a single hexamer thick. We also observe the dynamic process of shell facet assembly. Shell hexamers can dissociate from and incorporate into assembled sheets, indicating a flexible intermolecular interaction. Furthermore, we demonstrate that the self-assembly and dynamics of shell proteins are governed by specific contacts at the interfaces of shell proteins. Our study provides novel insights into the formation, interactions, and dynamics of BMC shell facets, which are essential for the design and engineering of self-assembled biological nanoreactors and scaffolds based on BMC architectures. PMID:26617073

  6. Visualization of Bacterial Microcompartment Facet Assembly Using High-Speed Atomic Force Microscopy.

    PubMed

    Sutter, Markus; Faulkner, Matthew; Aussignargues, Clément; Paasch, Bradley C; Barrett, Steve; Kerfeld, Cheryl A; Liu, Lu-Ning

    2016-03-09

    Bacterial microcompartments (BMCs) are proteinaceous organelles widespread among bacterial phyla. They compartmentalize enzymes within a selectively permeable shell and play important roles in CO2 fixation, pathogenesis, and microbial ecology. Here, we combine X-ray crystallography and high-speed atomic force microscopy to characterize, at molecular resolution, the structure and dynamics of BMC shell facet assembly. Our results show that preformed hexamers assemble into uniformly oriented shell layers, a single hexamer thick. We also observe the dynamic process of shell facet assembly. Shell hexamers can dissociate from and incorporate into assembled sheets, indicating a flexible intermolecular interaction. Furthermore, we demonstrate that the self-assembly and dynamics of shell proteins are governed by specific contacts at the interfaces of shell proteins. Our study provides novel insights into the formation, interactions, and dynamics of BMC shell facets, which are essential for the design and engineering of self-assembled biological nanoreactors and scaffolds based on BMC architectures.

  7. Highly ordered self-assembled nanoscale periodic faceting in GaAs(631) homoepitaxial growth

    NASA Astrophysics Data System (ADS)

    Cruz-Hernández, E.; Shimomura, S.; Méndez-García, V. H.

    2012-08-01

    We report on the self-assembly of large-order-correlated nanoscale faceting on GaAs(631)A substrates grown by molecular beam epitaxy. The surface morphology of the grown samples as a function of the growth temperature and the As-beam equivalent pressure was studied using atomic force microscopy. A two-dimensional autocorrelation function analysis was performed in order to quantitatively determine the uniformity of the surface corrugation. By optimizing the growth conditions, correlated faceted areas as large as 1.7 × 1.7 μm2 are obtained. The highly ordered surface corrugation discussed here provides useful insights to prepare highly ordered facet planes for the self organized growth of quantum wires.

  8. Cross-cultural evidence for the two-facet structure of pride

    PubMed Central

    Shi, Yan; Chung, Joanne M.; Cheng, Joey T.; Tracy, Jessica L.; Robins, Richard W.; Chen, Xiao; Zheng, Yong

    2016-01-01

    Across six studies conducted in Mainland China and South Korea, the present research extended prior findings showing that pride is comprised of two distinct conceptual and experiential facets in the U.S.: a pro-social, achievement-oriented “authentic pride”, and an arrogant, self-aggrandizing “hubristic pride”. This same two-facet structure emerged in Chinese participants’ semantic conceptualizations of pride (Study 1), Chinese and Koreans’ dispositional tendencies to experience pride (Studies 2, 3a, and 3b), Chinese and Koreans’ momentary pride experiences (Studies 3a, 3b, and 5), and Americans’ pride experiences using descriptors derived indigenously in Korea (Study 4). Together, these studies provide the first evidence that the two-facet structure of pride generalizes to cultures with highly divergent views of pride and self-enhancement processes from North America. PMID:27158171

  9. On the Faceting and Linking of PROV for Earth Science Data Systems

    NASA Astrophysics Data System (ADS)

    Hua, H.; Manipon, G.; Wilson, B. D.; Tan, D.; Starch, M.

    2015-12-01

    Faceted search has yielded powerful capabilities for discovery of information by applying multiple filters to explore information. This is often more effective when the information is decomposed into faceted components that can be sliced and diced during faceted navigation. We apply this approach to the representation of PROV for Earth Science (PROV-ES) to facilitate more atomic units of provenance for discovery. Traditional bundles of PROV are then decomposed to enable finer-grain discovery of provenance. Linkages across provenance components can then be explored across seemingly disparate bundles. We will show how mappings into this provenance approach can be used to explore more data life-cycle relationships from observation to data to findings. We will also show examples of how this approach can be used to improve the discovery, access, and transparency of NASA datasets and the science data systems that were used to capture, manage, and produce the provenance information.

  10. Contemporary cybernetics and its facets of cognitive informatics and computational intelligence.

    PubMed

    Wang, Yingxu; Kinsner, Witold; Zhang, Du

    2009-08-01

    This paper explores the architecture, theoretical foundations, and paradigms of contemporary cybernetics from perspectives of cognitive informatics (CI) and computational intelligence. The modern domain and the hierarchical behavioral model of cybernetics are elaborated at the imperative, autonomic, and cognitive layers. The CI facet of cybernetics is presented, which explains how the brain may be mimicked in cybernetics via CI and neural informatics. The computational intelligence facet is described with a generic intelligence model of cybernetics. The compatibility between natural and cybernetic intelligence is analyzed. A coherent framework of contemporary cybernetics is presented toward the development of transdisciplinary theories and applications in cybernetics, CI, and computational intelligence.

  11. The FACETS project: integrated core-edge-wall modeling with concurrent execution

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Balay, S.; Candy, J.; Carlsson, J. A.; Cohen, R. H.; Epperly, T.; Estep, D. J.; Fahey, M. R.; Groebner, R. J.; Hakim, A. H.; Hammett, G. W.; Indireshkumar, K.; Kruger, S. E.; Maloney, A. D.; McCune, D. C.; McInnes, L.; Morris, A.; Pankin, A.; Pletzer, A.; Pigarov, A.; Rognlien, T. D.; Shasharina, S.; Shende, S.; Vadlamani, S.; Zhang, H.

    2009-11-01

    The multi-institutional FACETS project has the physics goals of using computation to understand of how a consistent, coupled core-edge-wall plasma evolves, including energy flow, particle recycling, and the variation of power density on divertor plates with plasma under different conditions. FACETS is being developed to take advantage of Leadership Class Facilities (LCFs), while still being able to run on laptops with reduced fidelity models. This presentation will provide a high-level overview of the project, discussing the issues of componentization, solvers, performance monitoring, testing, visualization and first physics results for core-edge coupling.

  12. Corner wetting during the vapor-liquid-solid growth of faceted nanowires

    NASA Astrophysics Data System (ADS)

    Spencer, Brian; Davis, Stephen

    2016-11-01

    We consider the corner wetting of liquid drops in the context of vapor-liquid-solid growth of nanowires. Specifically, we construct numerical solutions for the equilibrium shape of a liquid drop on top of a faceted nanowire by solving the Laplace-Young equation with a free boundary determined by mixed boundary conditions. A key result for nanowire growth is that for a range of contact angles there is no equilibrium drop shape that completely wets the corner of the faceted nanowire. Based on our numerical solutions we determine the scaling behavior for the singular surface behavior near corners of the nanowire in terms of the Young contact angle and drop volume.

  13. Percutaneous radiofrequency rhizotomy of lumbar spinal facets: the results of 46 cases.

    PubMed

    Göçer, A I; Cetinalp, E; Tuna, M; Ildan, F; Bağdatoğlu, H; Haciyakupoğlu, S

    1997-01-01

    The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients, with operations other than fusion. No patient had previously undergone fusion. Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.

  14. Preliminary Conceptual Design Report for the FACET-II Project at SLAC National Accelerator Laboratory

    SciTech Connect

    Hogan, Mark

    2016-04-22

    Plasma wakefield acceleration has the potential to dramatically shrink the size and cost of particle accelerators. Research at the SLAC National Accelerator Laboratory has demonstrated that plasmas can provide 1,000 times the acceleration in a given distance compared with current technologies. Developing revolutionary and more efficient acceleration techniques that allow for an affordable high-energy collider is the focus of FACET, a National User Facility at SLAC. The existing FACET National User Facility uses part of SLAC’s two-mile-long linear accelerator to generate high-density beams of electrons and positrons. FACET-II is a new test facility to develop advanced acceleration and coherent radiation techniques with high-energy electron and positron beams. It is the only facility in the world with high energy positron beams. FACET-II provides a major upgrade over current FACET capabilities and the breadth of the potential research program makes it truly unique. It will synergistically pursue accelerator science that is vital to the future of both advanced acceleration techniques for High Energy Physics, ultra-high brightness beams for Basic Energy Science, and novel radiation sources for a wide variety of applications. The design parameters for FACET-II are set by the requirements of the plasma wakefield experimental program. To drive the plasma wakefield requires a high peak current, in excess of 10kA. To reach this peak current, the electron and positron design bunch size is 10μ by 10μ transversely with a bunch length of 10μ. This is more than 200 times better than what has been achieved at the existing FACET. The beam energy is 10 GeV, set by the Linac length available and the repetition rate is up to 30 Hz. The FACET-II project is scheduled to be constructed in three major stages. Components of the project discussed in detail include the following: electron injector, bunch compressors and linac, the positron system, the Sector 20 sailboat and W chicanes

  15. Facet effects of palladium nanocrystals for oxygen reduction in ionic liquids and for sensing applications

    NASA Astrophysics Data System (ADS)

    Tang, Yongan; Chi, Xiaowei; Zou, Shouzhong; Zeng, Xiangqun

    2016-03-01

    Palladium nanocrystals enclosed by {100} and {110} crystal facets, were successfully synthesized through an aqueous one-pot synthesis method. A new thermal annealing approach was developed for fabricating these palladium nanocrystals as a working electrode on a gas permeable membrane to study the facet effects of the oxygen reduction process in an ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Bmpy][NTf2]). Results were compared with the same processes at a conventional platinum electrode. Our study shows that the structural difference between the two facets of Pd nanocrystals has little effect on the oxygen reduction process but significantly affects the oxidation process of the superoxide. It is found that the Pd{110}/IL interface can better stabilize superoxide radicals revealed by a more positive oxidation potential compared to that of Pd{100}. In addition, the analytical characteristic of utilizing both palladium nanocrystals as electrodes for oxygen sensing is comparable with a polycrystal platinum oxygen sensor, in which Pd{110} presents the best sensitivity and lowest detection limit. Our results demonstrate the facet-dependence of oxygen reduction in an ionic liquid medium and provide the fundamental information needed to guide the applications of palladium nanocrystals in electrochemical gas sensor and fuel cell research.Palladium nanocrystals enclosed by {100} and {110} crystal facets, were successfully synthesized through an aqueous one-pot synthesis method. A new thermal annealing approach was developed for fabricating these palladium nanocrystals as a working electrode on a gas permeable membrane to study the facet effects of the oxygen reduction process in an ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Bmpy][NTf2]). Results were compared with the same processes at a conventional platinum electrode. Our study shows that the structural difference between the two facets of Pd

  16. Intradiscal and intra-articular facet infiltrations with plasma rich in growth factors reduce pain in patients with chronic low back pain

    PubMed Central

    Kirchner, Fernando; Anitua, Eduardo

    2016-01-01

    Context: Low back pain (LBP) is a complex and disabling condition, and its treatment becomes a challenge. Aims: The aim of our study was to assess the clinical outcome of plasma rich in growth factors (PRGF-Endoret) infiltrations (one intradiscal, one intra-articular facet, and one transforaminal epidural injection) under fluoroscopic guidance-control in patients with chronic LBP. PRGF-Endoret which has been shown to be an efficient treatment to reduce joint pain. Settings and Design: The study was designed as an observational retrospective pilot study. Eighty-six patients with a history of chronic LBP and degenerative disease of the lumbar spine who met inclusion and exclusion criteria were recruited between December 2010 and January 2012. Subjects and Methods: One intradiscal, one intra-articular facet, and one transforaminal epidural injection of PRGF-Endoret under fluoroscopic guidance-control were carried out in 86 patients with chronic LBP in the operating theater setting. Statistical Analysis Used: Descriptive statistics were performed using absolute and relative frequency distributions for qualitative variables and mean values and standard deviations for quantitative variables. The nonparametric Friedman statistical test was used to determine the possible differences between baseline and different follow-up time points on pain reduction after treatment. Results: Pain assessment was determined using a visual analog scale (VAS) at the first visit before (baseline) and after the procedure at 1, 3, and 6 months. The pain reduction after the PRGF-Endoret injections showed a statistically significant drop from 8.4 ± 1.1 before the treatment to 4 ± 2.6, 1.7 ± 2.3, and 0.8 ± 1.7 at 1, 3, and 6 months after the treatment, respectively, with respect to all the time evaluations (P < 0.0001) except for the pain reduction between the 3rd and 6th month whose signification was lower (P < 0.05). The analysis of the VAS over time showed that at the end point of the

  17. Sacroiliac joint pain.

    PubMed

    Dreyfuss, Paul; Dreyer, Susan J; Cole, Andrew; Mayo, Keith

    2004-01-01

    The sacroiliac joint is a source of pain in the lower back and buttocks in approximately 15% of the population. Diagnosing sacroiliac joint-mediated pain is difficult because the presenting complaints are similar to those of other causes of back pain. Patients with sacroiliac joint-mediated pain rarely report pain above L5; most localize their pain to the area around the posterior superior iliac spine. Radiographic and laboratory tests primarily help exclude other sources of low back pain. Magnetic resonance imaging, computed tomography, and bone scans of the sacroiliac joint cannot reliably determine whether the joint is the source of the pain. Controlled analgesic injections of the sacroiliac joint are the most important tool in the diagnosis. Treatment modalities include medications, physical therapy, bracing, manual therapy, injections, radiofrequency denervation, and arthrodesis; however, no published prospective data compare the efficacy of these modalities.

  18. Acromioclavicular Joint Separations

    DTIC Science & Technology

    2013-01-01

    non-surgical measures, high-grade inju- ries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as...sports [1–3]. While most injuries can be managed non-operatively, high-grade separations may result in per- sistent pain or functional decline and...joint pathology (cross arm adduction and loading of the AC joint) can be helpful to localize shoulder pain to the AC joint. These tests are especial- ly

  19. Joint Program Management Handbook

    DTIC Science & Technology

    1994-12-01

    the Engieermg and Manufacuring Devopment Phase. Nfilestoae HI- Develommen Annros Devopment approval marks a significant step for any program, but it is...to review concept formulaton. Systems Engilneertn As with service programs, systems engineering in joint program management is an essential tool . I...MANAGEMENT HANDBOOK On=e wd Umawtaiutt As discussed in Chapter 7, systems analysis of relationships is a usef tool for joint program managers. The joint

  20. [Injuries to the superior ankle joint from the viewpoint of accident surgery].

    PubMed

    Zwipp, H

    1991-12-01

    The treatment of bony, osteochondral, and ligamentous injuries of the tibio-talar joint requires precise preoperative planning by radiological investigation. This is essential to a correct understanding of the underlying pathology and will allow a proper classification of the injury, which is the basis of treatment. Conventional radiography using anteroposterior and lateral X-rays with comparative views of the noninjured side and, if necessary, rotated spot views and tomography are of high value especially in osteochondral fractures of the talus. Intraoperative control images in both planes after osteosynthesis are mandatory. For evaluation of the postoperative course and severity of arthrosis formation, the classification system of Bargon has proved its worth. In addition, tomography of the tibio-talar joint in two planes is useful especially in tibial pilon fractures, some malleolar fractures, and peripheral talar fractures. In talar fracture dislocations with concomitant compartment syndrome an emergency CT scan can be helpful to determine the optimal surgical approach. In these cases a 3-D reconstruction also might be of assistance. If there is evidence of partial or total talar necrosis, magnetic resonance imaging can be extremely helpful. However, in most cases implants considerably limit the validity of the image obtained. Ultrasonography offers a noninvasive, reproducible, and very inexpensive alternative and should be performed in cases of chondral-osteochondral talar rim avulsions and juvenile osteochondral ligament ruptures. It can also be used as a dynamic method for stress examination in fibular ligament ruptures and soft tissue injuries such as dislocation of the peroneal tendons. The use of Arthrography, stress tenography, and Arthro-CT scan nowadays has become extremely limited.

  1. Skeletal development of hallucal tarsometatarsal joint curvature and angulation in extant apes and modern humans.

    PubMed

    Gill, Corey M; Bredella, Miriam A; DeSilva, Jeremy M

    2015-11-01

    The medial cuneiform, namely the curvature and angulation of its distal facet with metatarsal 1, is crucial as a stabilizer in bipedal locomotion and an axis upon which the great toe medially deviates during arboreal locomotion in extant apes. Previous work has shown that facet curvature and angulation in adult dry-bone specimens can distinguish African apes from Homo, and can even distinguish among species of Gorilla. This study provides the first ontogenetic assessment of medial cuneiform curvature and angulation in juvenile (n = 68) and adult specimens (n = 102) using computed tomography in humans and extant ape specimens, including Pongo. Our data find that modern human juveniles initially have a convex and slightly medially oriented osseous surface of the developing medial cuneiform distal facet that flattens and becomes more distally oriented with age. The same pattern (though of a different magnitude) occurs developmentally in the chimpanzee medial cuneiform, but not in Gorilla or Pongo, whose medial cuneiform facet angulation remains unchanged ontogenetically. These data suggest that the medial cuneiform ossifies in a distinguishable pattern between Pongo, Gorilla, Pan, and Homo, which may in part be due to subtle differences in the loading environment at the hallucal tarsometatarsal joint-a finding that has important implications for interpreting fossil medial cuneiforms.

  2. Soils and geomorphic evolution of bedrock facets on a tectonically active mountain front, western Sangre de Cristo Mountains, New Mexico

    NASA Astrophysics Data System (ADS)

    Menges, Christopher M.

    1990-09-01

    Soil profiles, colluvial stratigraphy, and detailed hillslope morphology are key elements used for geomorphic interpretations of the form and long-term evolution of triangular facets on a 1200 m high, tectonically active mountain front. The facets are developed on Precambrian gneisses and Tertiary volcanic and plutonic rocks along a complexly segmented, active normal-fault zone in the Rio Grande rift of northern New Mexico. The detailed morphologies of 20- to 350 m high facets are defined by statistical and time-series analyses of 40 field transects that were keyed to observations of colluvium, bedrock, microtopography, and vegetation. The undissected parts of most facets are transport-limited hillslopes mantled with varying thicknesses (0.1 to > 1 m thick) of sand and gravel colluvium between generally sparse (≤10-30%) bedrock outcrops. Facet soils range from (a) thin (≤ 0.2 m) weakly developed soils with cumulic silty A or transitional A/B epipedons above Cox horizons in bedrock or colluvium, to (b) deep (≥0.5-1 m) moderately to strongly developed profiles containing thick cambic (Bw) and/or argillic (Bt) horizons that commonly extend into highly weathered saprolitic bedrock. The presence of strongly weathered profiles and thick colluvium suggests that rates of colluvial transport and hillslope erosion are less than or equal to rates of soil development over at least a large part of the Holocene. The catenary variation of soils and colluvium on selected facet transects indicate that the degree of soil development generally increases and the thickness of colluvium decreases upslope on most facets. This overall pattern is commonly disrupted on large facet hillslopes by irregular secondary soil variations linked to intermediate-scale (20-60 + m long) concave slope elements. These features are interpreted to reflect discontinuous transport and erosion of colluvium down-slope below bedrock outcrops. The degree of weathering in subsurface bedrock commonly

  3. Facets of psychopathy among mentally disordered offenders: clinical comorbidity patterns and prediction of violent and criminal behavior.

    PubMed

    Wallinius, Märta; Nilsson, Thomas; Hofvander, Björn; Anckarsäter, Henrik; Stålenheim, Gunilla

    2012-07-30

    The complexity and consequences of psychopathy are still debated, and its relation to other mental disorders, pathological personality traits, and criminality needs to be further investigated by clinical, longitudinal studies using structured diagnostic instruments. The present study used two groups of mentally disordered offenders (N=153) investigated with in-depth clinical assessments and prospective long-term follow-up to identify the convergence between 1) the four facets of psychopathy defined by the Psychopathy Checklist-Revised (PCL-R; Interpersonal, Affective, Lifestyle, and Antisocial), 2) mental disorders according to SCID I and II interviews, 3) personality traits as measured by the Karolinska Scales of Personality, and 4) criminal recidivism. The Interpersonal facet differed substantially from the other three facets by not being significantly associated with substance use disorders, antisocial personality disorder (the other facets at P≤0.001 level), or personality traits involving impulsive and aggressive antisocial behaviors (the other facets at P<0.01 level). Furthermore, the interpersonal facet could not predict violent recidivism better than random. The Antisocial facet outperformed not only the other facets but also the total PCL-R score in the prediction of violent recidivism, P<0.001.The findings confirm psychopathy as a heterogeneous phenomenon and have clinical implications for assessments of psychopathy and violence risk assessments in clinical and forensic contexts.

  4. Violence Risk Assessment and Facet 4 of the Psychopathy Checklist: Predicting Institutional and Community Aggression in Two Forensic Samples

    ERIC Educational Resources Information Center

    Walters, Glenn D.; Heilbrun, Kirk

    2010-01-01

    The Psychopathy Checklist and Psychopathy Checklist-Revised (PCL/PCL-R) were used to predict institutional aggression and community violence in two groups of forensic patients. Results showed that Facet 4 (Antisocial) of the PCL/PCL-R or one of its parcels consistently achieved incremental validity relative to the first three facets, whereas the…

  5. Mechanics of Sheeting Joints

    NASA Astrophysics Data System (ADS)

    Martel, S. J.

    2015-12-01

    Physical breakdown of rock across a broad scale spectrum involves fracturing. In many areas large fractures develop near the topographic surface, with sheeting joints being among the most impressive. Sheeting joints share many geometric, textural, and kinematic features with other joints (opening-mode fractures) but differ in that they are (a) discernibly curved, (b) open near the topographic surface, and (c) form subparallel to the topographic surface. Where sheeting joints are geologically young, the surface-parallel compressive stresses are typically several MPa or greater. Sheeting joints are best developed beneath domes, ridges, and saddles; they also are reported, albeit rarely, beneath valleys or bowls. A mechanism that accounts for all these associations has been sought for more than a century: neither erosion of overburden nor high lateral compressive stresses alone suffices. Sheeting joints are not accounted for by Mohr-Coulomb shear failure criteria. Principles of linear elastic fracture mechanics, together with the mechanical effect of a curved topographic surface, do provide a basis for understanding sheeting joint growth and the pattern sheeting joints form. Compressive stresses parallel to a singly or doubly convex topographic surface induce a tensile stress perpendicular to the surface at shallow depths; in some cases this alone could overcome the weight of overburden to open sheeting joints. If regional horizontal compressive stresses, augmented by thermal stresses, are an order of magnitude or so greater than a characteristic vertical stress that scales with topographic amplitude, then topographic stress perturbations can cause sheeting joints to open near the top of a ridge. This topographic effect can be augmented by pressure within sheeting joints arising from water, ice, or salt. Water pressure could be particularly important in helping drive sheeting joints downslope beneath valleys. Once sheeting joints have formed, the rock sheets between

  6. FAST (Faceted Application of Subject Terminology) Users: Summary and Case Studies

    ERIC Educational Resources Information Center

    Mixter, Jeffrey; Childress, Eric R.

    2013-01-01

    Over the past ten years, various organizations, both public and private, have expressed interest in implementing the Faceted Application of Subject Terminology (FAST) in their cataloging workflows. As interest in FAST has grown, so too has interest in knowing how FAST is being used and by whom. Since 2002 eighteen institutions in six countries…

  7. Controlled synthesis and facets-dependent photocatalysis of TiO2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Roy, Nitish; Park, Yohan; Sohn, Youngku; Pradhan, Debabrata

    2015-04-01

    Titanium dioxide (TiO2) is a wide band gap semiconductor that has been extensively used in several environmental applications including degradation of organic hazardous chemicals, water splitting to generate hydrogen, dye sensitized solar cells, self cleaning agents, and pigments. Herein we demonstrate the synthesis of TiO2 nanocrystals (NCs) with the shapes of ellipsoids, rods, cuboids, and sheets with different exposed facets using a noncorrosive and nontoxic chemical (i.e. diethanolamine) as the shape controlling agent, unlike hydrofluoric acid commonly used. The TiO2 NCs of diverse shapes with different exposed facets were tested for photocatalytic hydroxyl radical (OH•) formation, which determines their photocatalytic behavior and the results were compared with the standard P-25 Degussa. The formation rate of OH• per specific surface area was found to be >6 fold higher for rod-shaped TiO2 NCs than that of commercial Degussa P25 catalyst. The highest photocatalytic activity of rod-shaped TiO2 NCs is ascribed to the unique chemical environment of {010} exposed facets which facilitates the electron/hole separation in presence of {101} facets.

  8. Photocatalytic selective oxidation of phenol in suspensions of titanium dioxide with exposed {0 0 1} facets

    NASA Astrophysics Data System (ADS)

    Ye, Hengpeng; Lu, Shaoming

    2013-07-01

    Anatase TiO2 nanocrystals with exposed {0 0 1} facets were tailored by hydrothermal treatment of Ti(OC4H9)4-HF-H2O mixed solution. The photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms and X-ray photoelectron spectroscopy (XPS). The effect of structure of the photocatalyst on the photocatalytic selective oxidation of phenol under UV irradiation was studied. The experiment results showed that (1) the percentage of the exposed {0 0 1} facets of the nanocrystal increases with increasing the nominal atomic ratio of fluorine to titanium (RF), (2) catechol and hydroquinone are main intermediates detected during photocatalytic oxidation of phenol, and (3) both photocatalytic oxidation of phenol and selectivity (yield) of catechol are positively correlated with the percentage of exposed {0 0 1} facets of the high-energy TiO2 nanocrystals. The enhanced conversion of phenol and selectivity (yield) of catechol were ascribed to the synergistic effects of the exposed high-energy {0 0 1} facets and surface fluorination. This study may provide new insight into the selective oxidation of organics.

  9. A Multi-Faceted Formative Assessment Approach: Better Recognising the Learning Needs of Students

    ERIC Educational Resources Information Center

    Jenkins, James O.

    2010-01-01

    Students are increasingly subject to a series of learning pressures that prevent effective engagement in assessment. Thus, the aim of this study was to create a multi-faceted formative assessment approach that better enabled students to engage in the assessment process. A formative assessment approach, consisting of six key initiatives, is…

  10. Longitudinal Stability Study for the FACET-II e+ Damping Ring

    SciTech Connect

    Bane, Karl

    2016-11-29

    This is an initial study of the longitudinal, single-bunch stability in the proposed FACET-II e+ damping ring. It is preliminary because, at present, only a few specific features of the vacuum chamber are known.

  11. Synthesis of ZnWO4 Electrode with tailored facets: Deactivating the Microorganisms through Photoelectrocatalytic methods

    NASA Astrophysics Data System (ADS)

    Zhan, Su; Zhou, Feng; Huang, Naibao; Liu, Yujun; He, Qiuchen; Tian, Yu; Yang, Yifan; Ye, Fei

    2017-01-01

    The exotic invasive species from the ballast water in the ship will bring about serious damages to ecosystem. Photocatalyst films have been widely studied for sterilization. In this study, ZnWO4 with different exposed facets was synthesized by hydrothermal method, and ZnWO4 film electrodes have been applied in ballast water treatment through the electro-assisted photocatalytic system. Then the samples were investigated by X-ray diffraction (XRD), X-ray photo-electron spectroscopy (XPS), Field emission on scanning electron microcopy (FE-SEM), Transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), BET specific surface area analysis, Fourier transform infrared (FT-IR) and Electrochemical impedance spectra (EIS). ZnWO4 with an appropriate exposure of (0 1 1) facets ratio exhibited the best photocatalytic and photoelectrocatalytic activities. The microorganisms deactivated completely in 10 min by ZnWO4 films with 3 V bias. The mechanisms of (0 1 1) facets enhanced the photocatalytic and photoelectrocatalytic activities which were deduced based on the calculated result from the first principles. Simultaneously, appropriate exposed facets and applied bias could reduce the recombination of the photogenerated electron-hole pairs, and improve the photocatalytic activities of ZnWO4.

  12. Teachers' Perceptions Structured through Facet Theory: Smallest Space Analysis versus Factor Analysis.

    ERIC Educational Resources Information Center

    Maslovaty, Nava; Marshall, Anne E.; Alkin, Marvin C.

    2001-01-01

    Examined the facet theory (FT) of L. Gutman and compared it to factor analysis (FA) in the context of two research studies, one of desirable student traits perceived by 203 Israeli teachers and the other of the perceptions of 92 Israeli teachers regarding teacher professionalism. By using FT and FA, the multidimensional theory and structural…

  13. Exploring the Relationship between Workaholism Facets and Personality Traits: A Replication in American Workers

    ERIC Educational Resources Information Center

    Aziz, Shahnaz; Tronzo, Casie L.

    2011-01-01

    In this study, we further explored whether any of the dimensions in the five-factor model of personality (i.e., openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism) were related to facets of workaholism (i.e., work involvement, work drive, and work enjoyment) in a sample of American workers in various…

  14. Correlations between the Myers-Briggs Type Indicator and the Neo Personality Inventory facets.

    PubMed

    MacDonald, D A; Anderson, P E; Tsagarakis, C I; Holland, C J

    1995-04-01

    Using data obtained from 48 male and 161 female undergraduate students in psychology, correlations between scores on the scales of the Myers-Briggs Type Indicator and the facets of the Neuroticism, Extraversion, and Openness domains of the NEO Personality Inventory were low to moderate.

  15. CO-CO coupling on Cu facets: Coverage, strain and field effects

    NASA Astrophysics Data System (ADS)

    Sandberg, Robert B.; Montoya, Joseph H.; Chan, Karen; Nørskov, Jens K.

    2016-12-01

    We present a DFT study on the effect of coverage, strain, and electric field on CO-CO coupling energetics on Cu (100), (111), and (211). Our calculations indicate that CO-CO coupling is facile on all three facets in the presence of a cation-induced electric field in the Helmholtz plane, with the lowest barrier on Cu(100). The CO dimerization pathway is therefore expected to play a role in C2 formation at potentials negative of the Cu potential of zero charge, corresponding to CO2/CO reduction conditions at high pH. Both increased *CO coverage and tensile strain further improve C-C coupling energetics on Cu (111) and (211). Since CO dimerization is facile on all 3 Cu facets, subsequent surface hydrogenation steps may also play an important role in determining the overall activity towards C2 products. Adsorption of *CO, *H, and *OH on the 3 facets were investigated with a Pourbaix analysis. The (211) facet has the largest propensity to co-adsorb *CO and *H, which would favor surface hydrogenation following CO dimerization.

  16. Synthesis of bismuth vanadate nanoplates with exposed {001} facets and enhanced visible-light photocatalytic properties.

    PubMed

    Xi, Guangcheng; Ye, Jinhua

    2010-03-21

    Well-defined m-BiVO(4) nanoplates with exposed {001} facets have been synthesized by a facile hydrothermal route, without the use of any template or organic surfactant. The as-prepared m-BiVO(4) nanoplates exhibit greatly enhanced activity in the visible-light photocatalytic degradation of organic contaminants and photocatalytic oxidation of water for O(2) generation.

  17. Redox enzyme-mimicking activities of CeO2 nanostructures: Intrinsic influence of exposed facets.

    PubMed

    Yang, Yushi; Mao, Zhou; Huang, Wenjie; Liu, Lihua; Li, Junli; Li, Jialiang; Wu, Qingzhi

    2016-10-17

    CeO2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce(3+)/Ce(4+) ratio and oxygen vacancies on the surface have been considered as the major originations responsible for the redox enzyme-mimicking activities of CeO2 NPs. Herein, CeO2 nanostructures (nanocubes and nanorods) exposed different facets were synthesized via a facile hydrothermal method. The characterizations by X-ray photoelectron spectroscopy, Raman spectroscopy, and UV-Vis spectroscopy show that the Ce(3+)/Ce(4+) ratio and oxygen vacancy content on the surfaces of as-synthesized CeO2 nanostructures are nearly at the same levels. Meanwhile, the enzymatic activity measurements indicate that the redox enzyme-mimicking activities of as-synthesized CeO2 nanostructures are greatly dependent on their exposed facets. CeO2 nanocubes with exposed {100} facets exhibit a higher peroxidase but lower superoxide dismutase activity than those of the CeO2 nanorods with exposed {110} facets. Our results provide new insights into the redox enzyme-mimicking activities of CeO2 nanostructures, as well as the design and synthesis of inorganic nanomaterials-based artificial enzymes.

  18. Redox enzyme-mimicking activities of CeO2 nanostructures: Intrinsic influence of exposed facets

    NASA Astrophysics Data System (ADS)

    Yang, Yushi; Mao, Zhou; Huang, Wenjie; Liu, Lihua; Li, Junli; Li, Jialiang; Wu, Qingzhi

    2016-10-01

    CeO2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce3+/Ce4+ ratio and oxygen vacancies on the surface have been considered as the major originations responsible for the redox enzyme-mimicking activities of CeO2 NPs. Herein, CeO2 nanostructures (nanocubes and nanorods) exposed different facets were synthesized via a facile hydrothermal method. The characterizations by X-ray photoelectron spectroscopy, Raman spectroscopy, and UV-Vis spectroscopy show that the Ce3+/Ce4+ ratio and oxygen vacancy content on the surfaces of as-synthesized CeO2 nanostructures are nearly at the same levels. Meanwhile, the enzymatic activity measurements indicate that the redox enzyme-mimicking activities of as-synthesized CeO2 nanostructures are greatly dependent on their exposed facets. CeO2 nanocubes with exposed {100} facets exhibit a higher peroxidase but lower superoxide dismutase activity than those of the CeO2 nanorods with exposed {110} facets. Our results provide new insights into the redox enzyme-mimicking activities of CeO2 nanostructures, as well as the design and synthesis of inorganic nanomaterials-based artificial enzymes.

  19. A Faceted Taxonomy for Rating Student Bibliographies in an Online Information Literacy Game

    ERIC Educational Resources Information Center

    Leeder, Chris; Markey, Karen; Yakel, Elizabeth

    2012-01-01

    This study measured the quality of student bibliographies through creation of a faceted taxonomy flexible and fine-grained enough to encompass the variety of online sources cited by today's students. The taxonomy was developed via interviews with faculty, iterative refinement of categories and scoring, and testing on example student…

  20. Redox enzyme-mimicking activities of CeO2 nanostructures: Intrinsic influence of exposed facets

    PubMed Central

    Yang, Yushi; Mao, Zhou; Huang, Wenjie; Liu, Lihua; Li, Junli; Li, Jialiang; Wu, Qingzhi

    2016-01-01

    CeO2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce3+/Ce4+ ratio and oxygen vacancies on the surface have been considered as the major originations responsible for the redox enzyme-mimicking activities of CeO2 NPs. Herein, CeO2 nanostructures (nanocubes and nanorods) exposed different facets were synthesized via a facile hydrothermal method. The characterizations by X-ray photoelectron spectroscopy, Raman spectroscopy, and UV-Vis spectroscopy show that the Ce3+/Ce4+ ratio and oxygen vacancy content on the surfaces of as-synthesized CeO2 nanostructures are nearly at the same levels. Meanwhile, the enzymatic activity measurements indicate that the redox enzyme-mimicking activities of as-synthesized CeO2 nanostructures are greatly dependent on their exposed facets. CeO2 nanocubes with exposed {100} facets exhibit a higher peroxidase but lower superoxide dismutase activity than those of the CeO2 nanorods with exposed {110} facets. Our results provide new insights into the redox enzyme-mimicking activities of CeO2 nanostructures, as well as the design and synthesis of inorganic nanomaterials-based artificial enzymes. PMID:27748403

  1. Age and Gender Differences in the Relation between Self-Concept Facets and Self-Esteem

    ERIC Educational Resources Information Center

    Arens, A. Katrin; Hasselhorn, Marcus

    2014-01-01

    This study tested whether the gender intensification hypothesis applies to relations between multiple domain-specific self-concept facets and self-esteem. This hypothesis predicts gender-stereotypic differences in these relations and assumes they intensify with age. Furthermore, knowledge about gender-related or age-related differences in…

  2. Considering the Differential Impact of Three Facets of Organizational Health Climate on Employees' Well-Being.

    PubMed

    Zweber, Zandra M; Henning, Robert A; Magley, Vicki J; Faghri, Pouran

    2015-01-01

    One potential way that healthy organizations can impact employee health is by promoting a climate for health within the organization. Using a definition of health climate that includes support for health from multiple levels within the organization, this study examines whether all three facets of health climate--the workgroup, supervisor, and organization--work together to contribute to employee well-being. Two samples are used in this study to examine health climate at the individual level and group level in order to provide a clearer picture of the impact of the three health climate facets. k-means cluster analysis was used on each sample to determine groups of individuals based on their levels of the three health climate facets. A discriminant function analysis was then run on each sample to determine if clusters differed on a function of employee well-being variables. Results provide evidence that having strength in all three of the facets is the most beneficial in terms of employee well-being at work. Findings from this study suggest that organizations must consider how health is treated within workgroups, how supervisors support employee health, and what the organization does to support employee health when promoting employee health.

  3. A practical scale for Multi-Faceted Organizational Health Climate Assessment.

    PubMed

    Zweber, Zandra M; Henning, Robert A; Magley, Vicki J

    2016-04-01

    The current study sought to develop a practical scale to measure 3 facets of workplace health climate from the employee perspective as an important component of a healthy organization. The goal was to create a short, usable yet comprehensive scale that organizations and occupational health professionals could use to determine if workplace health interventions were needed. The proposed Multi-faceted Organizational Health Climate Assessment (MOHCA) scale assesses facets that correspond to 3 organizational levels: (a) workgroup, (b) supervisor, and (c) organization. Ten items were developed and tested on 2 distinct samples, 1 cross-organization and 1 within-organization. Exploratory and confirmatory factor analyses yielded a 9-item, hierarchical 3-factor structure. Tests confirmed MOHCA has convergent validity with related constructs, such as perceived organizational support and supervisor support, as well as discriminant validity with safety climate. Lastly, criterion-related validity was found between MOHCA and health-related outcomes. The multi-faceted nature of MOHCA provides a scale that has face validity and can be easily translated into practice, offering a means for diagnosing the shortcomings of an organization or workgroup's health climate to better plan health and well-being interventions.

  4. Guttman-Jordan Facet Design and the Study of Law-Related Attitudes.

    ERIC Educational Resources Information Center

    Jacobson, Michael; Palonsky, Stuart

    The development of an Attitude-Behavior Scale through an application of Guttman-Jordan facet design is detailed. The attitude scale was constructed to meet the need in law-related education for a valid attitudinal instrument to be used in research settings and in attitude change situations. A legal education program was used as a treatment in a…

  5. Facet Energy versus Enzyme-like Activities: The Unexpected Protection of Palladium Nanocrystals against Oxidative Damage.

    PubMed

    Ge, Cuicui; Fang, Ge; Shen, Xiaomei; Chong, Yu; Wamer, Wayne G; Gao, Xingfa; Chai, Zhifang; Chen, Chunying; Yin, Jun-Jie

    2016-11-22

    To develop nanomaterials as artificial enzymes, it is necessary to better understand how their physicochemical properties affect their enzyme-like activities. Although prior research has demonstrated that nanomaterials exhibit tunable enzyme-like activities depending on their size, structure, and composition, few studies have examined the effect of surface facets, which determine surface energy or surface reactivity. Here, we use electron spin-resonance spectroscopy to report that lower surface energy {111}-faceted Pd octahedrons have greater intrinsic antioxidant enzyme-like activity than higher surface energy {100}-faceted Pd nanocubes. Our in vitro experiments found that those same Pd octahedrons are more effective than Pd nanocubes at scavenging reactive oxygen species (ROS). Those reductions in ROS preserve the homogeneity of mitochondrial membrane potential and attenuate damage to important biomolecules, thereby allowing a substantially higher number of cells to survive oxidative challenges. Our computations of molecular mechanisms for the antioxidant activities of {111}- and {100}-faceted Pd nanocrystals, as well as their activity order, agree well with experimental observations. These findings can guide the design of antioxidant-mimicking nanomaterials, which could have therapeutic or preventative potential against oxidative stress related diseases.

  6. A Complete Description of Cones and Polytopes Including Hypervolumes of All Facets of a Polytope

    ERIC Educational Resources Information Center

    Jubete, F.; Castillo, E.

    2007-01-01

    In this paper methods and algorithms for identifying the main elements (edges and facets of any dimension) of a cone and a polytope, and calculating the corresponding hypervolumes are presented. The cones and polytopes are supposed to be given as the non-negative linear combination and the convex hull generated by a, not necessarily minimal, set…

  7. Analysis of Rater Severity on Written Expression Exam Using Many Faceted Rasch Measurement

    ERIC Educational Resources Information Center

    Prieto, Gerardo; Nieto, Eloísa

    2014-01-01

    This paper describes how a Many Faceted Rasch Measurement (MFRM) approach can be applied to performance assessment focusing on rater analysis. The article provides an introduction to MFRM, a description of MFRM analysis procedures, and an example to illustrate how to examine the effects of various sources of variability on test takers' performance…

  8. Applying Perkins's Facets of a Learning Environment for Information Literacy Instruction

    ERIC Educational Resources Information Center

    Blummer, Barbara

    2008-01-01

    Perkins, a professor of Education at Harvard University, promoted the use of constructivism in conjunction with information processing technologies to facilitate students' understanding and active use of knowledge and skills. He identified five facets of a learning environment including: information banks, symbol pads, construction kits,…

  9. The Relation between Different Facets of Creativity and the Dark Side of Personality

    ERIC Educational Resources Information Center

    Dahmen-Wassenberg, Phoebe; Kämmerle, Monika; Unterrainer, Human-Friedrich; Fink, Andreas

    2016-01-01

    This study examined the relation between different facets of creativity and personality, focusing on the dark side of personality. In a sample of 247 students, psychometric measures for the assessment of the dark triad of personality (subclinical narcissism, Machiavellianism, subclinical psychopathy), personality organization (structural deficit:…

  10. Facets of clinicians' anxiety and the delivery of cognitive behavioral therapy.

    PubMed

    Levita, Liat; Salas Duhne, Paulina Gonzalez; Girling, Carla; Waller, Glenn

    2016-02-01

    Psychological therapists commonly fail to adhere to treatment protocols in everyday clinical practice. In part, this pattern of drift is attributable to anxious therapists being less likely to undertake some elements of evidence-based therapies - particularly the exposure-based elements. This study considers what facets of anxiety (cognitive, behavioral, physiological) are related to junior clinicians' reported use of cognitive-behavioral therapy techniques. Thirty-two clinicians (mean age = 28.9 years; mean length of CBT experience = 1.5 years; 23 female, nine male) who offered CBT were assessed for their cognitive, behavioral and physiological characteristics (Intolerance of Uncertainty scale; risk taking; skin conductance response and heart rate variability). While the three different facets of anxiety were relatively poorly associated with each other, as is usual in this literature, each facet was linked differently to the reported delivery of CBT techniques (P < .05). Overall, higher anxiety levels were associated with a poorer use of exposure methods or with a greater use of other behavioral or cognitive methods. Of the three facets of anxiety, only physiological reactivity showed an association with the clinicians' temporal characteristics, with more experienced therapists being more likely to have greater skin conductance responses to positive and negative outcomes. These findings suggest that clinicians who are more anxious are less likely to deliver the full evidence-based form of CBT and to focus instead on less challenging elements of the therapy. Potential ways of overcoming this limitation are discussed.

  11. Mind Your Words: Positive and Negative Items Create Method Effects on the Five Facet Mindfulness Questionnaire

    ERIC Educational Resources Information Center

    Van Dam, Nicholas T.; Hobkirk, Andrea L.; Danoff-Burg, Sharon; Earleywine, Mitch

    2012-01-01

    Mindfulness, a construct that entails moment-to-moment effort to be aware of present experiences and positive attitudinal features, has become integrated into the sciences. The Five Facet Mindfulness Questionnaire (FFMQ), one popular measure of mindfulness, exhibits different responses to positively and negatively worded items in nonmeditating…

  12. Construct Validity of the Five Facet Mindfulness Questionnaire in Meditating and Nonmeditating Samples

    ERIC Educational Resources Information Center

    Baer, Ruth A.; Smith, Gregory T.; Lykins, Emily; Button, Daniel; Krietemeyer, Jennifer; Sauer, Shannon; Walsh, Erin; Duggan, Danielle; Williams, J. Mark G.

    2008-01-01

    Previous research on assessment of mindfulness by self-report suggests that it may include five component skills: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. These elements of mindfulness can be measured with the Five Facet Mindfulness Questionnaire (FFMQ). The authors…

  13. Oral Performace Scoring Using Generalizability Theory and Many-Facet Rasch Measurement: A Comparison Study

    ERIC Educational Resources Information Center

    Alkahtani, Saif F.

    2012-01-01

    The principal aim of the present study was to better guide the Quranic recitation appraisal practice by presenting an application of Generalizability theory and Many-facet Rasch Measurement Model for assessing the dependability and fit of two suggested rubrics. Recitations of 93 students were rated holistically and analytically by 3 independent…

  14. An Examination of Blue- versus White-Collar Workers' Conceptualizations of Job Satisfaction Facets

    ERIC Educational Resources Information Center

    Hu, Xiaoxiao; Kaplan, Seth; Dalal, Reeshad S.

    2010-01-01

    This study examined the degree to which blue- versus white-collar workers differentially conceptualize various job facets, namely the work itself, co-workers, supervisors, and pay. To examine these potential differences, we conducted a series of analyses on job satisfaction ratings from two samples of university workers. Consistent with the study…

  15. Analyzing Process Quality of Early Childhood Education with Many Facet Rash Measurement Model

    ERIC Educational Resources Information Center

    Basturk, Ramazan; Isikoglu, Nesrin

    2008-01-01

    Quality of early childhood education institutions specifically, dimensions of process quality should be evaluated. Purpose of this study is to analyze process quality of early childhood education by using many-facet Rasch measurement model (MFRM). In this study, data were collected from twelve early childhood education institutions by four…

  16. FACET: A simulation software framework for modeling complex societal processes and interactions

    SciTech Connect

    Christiansen, J. H.

    2000-06-02

    FACET, the Framework for Addressing Cooperative Extended Transactions, was developed at Argonne National Laboratory to address the need for a simulation software architecture in the style of an agent-based approach, but with sufficient robustness, expressiveness, and flexibility to be able to deal with the levels of complexity seen in real-world social situations. FACET is an object-oriented software framework for building models of complex, cooperative behaviors of agents. It can be used to implement simulation models of societal processes such as the complex interplay of participating individuals and organizations engaged in multiple concurrent transactions in pursuit of their various goals. These transactions can be patterned on, for example, clinical guidelines and procedures, business practices, government and corporate policies, etc. FACET can also address other complex behaviors such as biological life cycles or manufacturing processes. To date, for example, FACET has been applied to such areas as land management, health care delivery, avian social behavior, and interactions between natural and social processes in ancient Mesopotamia.

  17. A hybrid approach to software repository retrieval: Blending faceted classification and type signatures

    NASA Technical Reports Server (NTRS)

    Eichmann, David A.

    1992-01-01

    We present a user interface for software reuse repository that relies both on the informal semantics of faceted classification and the formal semantics of type signatures for abstract data types. The result is an interface providing both structural and qualitative feedback to a software reuser.

  18. Four Facets of Privacy and Intellectual Freedom in Licensing Contracts for Electronic Journals

    ERIC Educational Resources Information Center

    Rubel, Alan; Zhang, Mei

    2015-01-01

    This is a study of the treatment of library patron privacy in licenses for electronic journals in academic libraries. We begin by distinguishing four facets of privacy and intellectual freedom based on the LIS and philosophical literature. Next, we perform a content analysis of 42 license agreements for electronic journals, focusing on terms for…

  19. Automatic methods for the adjustment of faceted solar-energy concentrators and heliostats

    NASA Astrophysics Data System (ADS)

    Zakhidov, R. A.; Khakimov, R. A.; Abdurakhmanov, A. A.; Sizov, Iu. M.; Baranov, V. K.

    An automatic adjustment technique is described which makes possible a considerable simplification of the operation of solar-energy installations. Diagrams of devices for the automatic adjustment of the facets of a composite concentrator and of a plane heliostat are presented. An error analysis shows that the accuracy of the adjustment method is 4-5 arcmin.

  20. Facets of Mindfulness Mediate the Relationship between Depressive Symptoms and Smoking Behavior.

    PubMed

    Vinci, Christine; Spears, Claire A; Peltier, MacKenzie R; Copeland, Amy L

    2016-12-01

    The relationship between cigarette smoking and depressive symptoms is well-established. Dispositional mindfulness has been associated with lower depressive symptoms, lower smoking dependence, and higher odds of smoking cessation. Given that mindfulness is multi-faceted, the current study examined which facets of mindfulness might mediate the relationship between depressive symptoms and smoking behavior. Participants (n = 72) completed the Smoking Consequences Questionnaire (SCQ), Center for Epidemiologic Studies Depression Scale (CESD), and Kentucky Inventory of Mindfulness Skills (KIMS; subscales-Observe, Describe, Acting with Awareness, Accepting without Judgment), and indicated number of cigarettes smoked per day (CPD). Simple mediation models (followed by multiple mediation when more than one facet was significant) tested whether mindfulness facets mediated the relationship between CESD and smoking behavior (CPD and SCQ subscales). Results indicated that 1) lower depressive symptoms were associated with higher Accepting without Judgment, which was related to lower Negative Reinforcement expectancies, 2) lower depressive symptoms were associated with increased Describe, which was associated with greater perceived Negative Consequences, 3) lower depressive symptoms were associated with higher Accepting without Judgment, which was associated with lower Negative Consequences expectancies, and 4) higher depressive symptoms were associated with higher scores on Observe, which related to both greater Positive Reinforcement and Negative Consequences expectancies. Greater Accepting without Judgment and Describe aspects of mindfulness may serve as protective factors in the relationship of depressive symptoms and smoking.

  1. Facet-Dependent Catalytic Activity of Platinum Nanocrystals for Triiodide Reduction in Dye-Sensitized Solar Cells

    PubMed Central

    Zhang, Bo; Wang, Dong; Hou, Yu; Yang, Shuang; Yang, Xiao Hua; Zhong, Ju Hua; Liu, Jian; Wang, Hai Feng; Hu, P.; Zhao, Hui Jun; Yang, Hua Gui

    2013-01-01

    Platinum (Pt) nanocrystals have demonstrated to be an effective catalyst in many heterogeneous catalytic processes. However, pioneer facets with highest activity have been reported differently for various reaction systems. Although Pt has been the most important counter electrode material for dye-sensitized solar cells (DSCs), suitable atomic arrangement on the exposed crystal facet of Pt for triiodide reduction is still inexplicable. Using density functional theory, we have investigated the catalytic reaction processes of triiodide reduction over {100}, {111} and {411} facets, indicating that the activity follows the order of Pt(111) > Pt(411) > Pt(100). Further, Pt nanocrystals mainly bounded by {100}, {111} and {411} facets were synthesized and used as counter electrode materials for DSCs. The highest photovoltaic conversion efficiency of Pt(111) in DSCs confirms the predictions of the theoretical study. These findings have deepened the understanding of the mechanism of triiodide reduction at Pt surfaces and further screened the best facet for DSCs successfully. PMID:23670438

  2. Precursor salt assisted syntheses of high-index faceted concave hexagon and nanorod-like polyoxometalates

    NASA Astrophysics Data System (ADS)

    Pal, Jaya; Ganguly, Mainak; Mondal, Chanchal; Negishi, Yuichi; Pal, Tarasankar

    2014-12-01

    This paper describes an effective method for a precursor salt assisted fabrication and reshaping of two different polyoxometalates [(NH4)2Cu(MoO4)2 (ACM) and Cu3(MoO4)2(OH)2 (CMOH)] into five distinctive shapes through straightforward and indirect routes. Explicit regulation of the structural arrangements of ACM and CMOH has been studied in detail with altered precursor salt concentration employing our laboratory developed modified hydrothermal (MHT) method. Morphologically different ACM 3D architectures are evolved with higher molybdate concentration, whereas 1D growth of CMOH is observed with increased copper concentration. Interesting morphological transformation of the products has been accomplished employing one precursor salt at a time without using any other foreign reagent. It has been proven that large ACMs become labile in the presence of incoming Cu(ii) and NH4+ ions of the precursor salts. A new strategy for the conversion of faceted ACMs (hexagonal plate, circular plate and hollow flower) to exclusive CMOH nanorods through a Cu(ii) assisted reaction has been adopted. According to thermodynamic consideration, the synthesis of rare concave nanostructures with high index facet is still challenging due to their higher reactivity. In this study, concave hexagonal ACM with high index facet {hkl} has been successfully prepared for the first time from hexagonal ACM through simple etching with ammonium heptamolybdate (AHM), which is another precursor salt. Hexagonal ACM corrugates to a concave hexagon because of the higher reactivity of the {001} crystal plane than that of the {010} plane. It has been shown that high index facet exposed concave hexagonal ACM serves as a better catalyst for the photodegradation of dye than the other microstructures enclosed by low index facets.This paper describes an effective method for a precursor salt assisted fabrication and reshaping of two different polyoxometalates [(NH4)2Cu(MoO4)2 (ACM) and Cu3(MoO4)2(OH)2 (CMOH)] into

  3. Joint Newspaper Operating Agreements.

    ERIC Educational Resources Information Center

    Parsons, Marie

    The number of competing daily newspapers in American cities has dwindled until only about 50 cities boast two papers. Of the newspapers in those cities, 23 now maintain separate editorial operations but have joint printing, advertising, and circulation departments. The concept of joint operation is 50 years old, dating from the Depression years…

  4. Jointness, A Selected Bibliography.

    DTIC Science & Technology

    1997-02-01

    Joint warfare is team warfare. Joint Pub 1 purple- suiter -An officer assigned to duty on a staff where no particu- lar service predominates. This may...Force Quarterly, no. 5 (Summer 1994): 64-70. Winton, Harold R. "Partnership and Tension: The Army and Air Force Between Vietnam and Desert Shield

  5. TiO2 crystal facet-dependent antimony adsorption and photocatalytic oxidation.

    PubMed

    Song, Jiaying; Yan, Li; Duan, Jinming; Jing, Chuanyong

    2017-02-24

    Anatase TiO2 crystal facets are garnering increasing attention due to their unique surface property. However, no specific linear relationship had been derived between the facet exposed on TiO2 and the surface adsorption capacity as well as photocatalytic performance. This study systematically explored the facet effects on antimony (Sb) adsorption and photocatalytic oxidation using high-index {201} and low-index {101}, {001}, and {100} TiO2. The results suggest that high-index {201} TiO2 exhibits the best Sb(III) adsorption and photocatalytic activity compared to the low-index TiO2. Both the Sb(III) adsorption density and the amount of OH and O2(-) generated in solution were correlated to the magnitude of surface energy on TiO2 facets. Photocatalytically generated OH and O2(-) were responsible for Sb(III) photooxidation as evidenced by radical-trapping experiments. The great contribution of OH was observed only on {201}, not on low-index TiO2. This phenomenon was found to be attributable to the high surface energy on {201}, which enables the generation of a large amount of photogeneration OH to compensate for the fast rate of OH dissipation. Therefore, the predominant participation of OH in Sb(III) photooxidation was only possible on high-index {201} TiO2, which resulted in an enhanced photocatalytic rate. On the other hand, O2(-) dominated the Sb(III) photocatalytic oxidation on low-index TiO2. The intrinsic facet-dependent adsorption and photocatalytic mechanism obtained from this study would be useful for developing TiO2-based environmental technologies.

  6. Precursor salt assisted syntheses of high-index faceted concave hexagon and nanorod-like polyoxometalates.

    PubMed

    Pal, Jaya; Ganguly, Mainak; Mondal, Chanchal; Negishi, Yuichi; Pal, Tarasankar

    2015-01-14

    This paper describes an effective method for a precursor salt assisted fabrication and reshaping of two different polyoxometalates [(NH4)2Cu(MoO4)2 (ACM) and Cu3(MoO4)2(OH)2 (CMOH)] into five distinctive shapes through straightforward and indirect routes. Explicit regulation of the structural arrangements of ACM and CMOH has been studied in detail with altered precursor salt concentration employing our laboratory developed modified hydrothermal (MHT) method. Morphologically different ACM 3D architectures are evolved with higher molybdate concentration, whereas 1D growth of CMOH is observed with increased copper concentration. Interesting morphological transformation of the products has been accomplished employing one precursor salt at a time without using any other foreign reagent. It has been proven that large ACMs become labile in the presence of incoming Cu(II) and NH4(+) ions of the precursor salts. A new strategy for the conversion of faceted ACMs (hexagonal plate, circular plate and hollow flower) to exclusive CMOH nanorods through a Cu(II) assisted reaction has been adopted. According to thermodynamic consideration, the synthesis of rare concave nanostructures with high index facet is still challenging due to their higher reactivity. In this study, concave hexagonal ACM with high index facet {hkl} has been successfully prepared for the first time from hexagonal ACM through simple etching with ammonium heptamolybdate (AHM), which is another precursor salt. Hexagonal ACM corrugates to a concave hexagon because of the higher reactivity of the {001} crystal plane than that of the {010} plane. It has been shown that high index facet exposed concave hexagonal ACM serves as a better catalyst for the photodegradation of dye than the other microstructures enclosed by low index facets.

  7. Nanocrystalline Anatase Titania Supported Vanadia Catalysts: Facet-dependent Structure of Vanadia

    SciTech Connect

    Li, Wei-Zhen; Gao, Feng; Li, Yan; Walter, Eric D.; Liu, Jun; Peden, Charles HF; Wang, Yong

    2015-07-09

    Titania supported vanadia, a classic heterogeneous catalyst for redox reactions, typically has nonhomogeneous vanadia species on various titania facets, making it challenging not only to determine and quantify each species but also to decouple their catalytic contributions. We prepared truncated tetragonal bipyramidal (TiO2-TTB) and rod-like (TiO2-Rod) anatase titania with only {101} and {001} facets at ratios of about 80:20 and 93:7, respectively, and used them as supports of sub-monolayer vanadia. The structure and redox properties of supported vanadia were determined by XRD, TEM, XPS, EPR, Raman, FTIR and TPR, etc. It was found that vanadia preferentially occupy TiO2 {001} facets and form isolated O=V4+(O-Ti)2 species, and with further increase in vanadia surface coverage, isolated O=V5+(O-Ti)3 and oligomerized O=V5+(O-M)3 (M = Ti or V) species form on TiO2 {101} facets. The discovery on support facet-dependent structure of vanadia on anatase titania is expected to enable the elucidation of structure-function correlations on high surface area TiO2 supported vanadia catalysts. This work was supported by U. S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences. The research was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research, and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for DOE by Battelle.

  8. Measurement of intraarticular wrist joint biomechanics with a force controlled system.

    PubMed

    Erhart, Stefanie; Lutz, Martin; Arora, Rohit; Schmoelz, Werner

    2012-09-01

    Pathologies of the wrist, such as fractures or instabilities, can lead to alterations in joint biomechanics. Accurate treatment of these pathologies is a frequent challenge for the surgeon. For biomechanical investigations, a test-setup that applies physiological loading of the wrist joint is necessary. A force controlled test-bench with agonistic and antagonistic muscle forces was built to move six fresh frozen human upper extremities through flexion and extension of the wrist joint. Tendon forces, range of motion, intraarticular contact area and contact pressure of the lunate and scaphoid facet as well as tendon excursion were investigated and compared with the current literature. During wrist motion the extensors exerted double the force of the flexors. Capsulotomy and sensor insertion decreased the range of motion from 63.4° (SD 14.1) to 45.9° (SD 23.7). The ratio of force transmitted through the radius and ulna was 77:23 and pressure distribution between the scaphoid and lunate facet showed a 70:30 relationship. The obtained data indicate a good agreement with the available literature. Therefore, the force controlled test-bench in combination with intraarticular radiocarpal measurements can be used to investigate the influence of wrist pathologies on joint biomechanics.

  9. Jointness for the Rest of Us: Reforming Joint Professional Development

    DTIC Science & Technology

    2016-06-10

    Vision 2020 (JV 2020 ) is the conceptual template established to guide the transformation of America’s Armed Forces. According to this template, the...of Staff. Joint Vision 2020 , (Washington DC. Office of the Chairman of the Joint Chiefs of Staff Joint Electronic Library, February 2001):1. 2 Ibid...Staffs of Staff, 2011. __________. Joint Vision 2020 .Washington DC. Office of the Chairman of the Joint Chiefs of Staff Joint Electronic Library

  10. [Partial replacement of the knee joint with patient-specific instruments and implants (ConforMIS iUni, iDuo)].

    PubMed

    Beckmann, J; Steinert, A; Zilkens, C; Zeh, A; Schnurr, C; Schmitt-Sody, M; Gebauer, M

    2016-04-01

    Knee arthroplasty is a successful standard procedure in orthopedic surgery; however, approximately 20 % of patients are dissatisfied with the clinical results as they suffer pain and can no longer achieve the presurgery level of activity. According to the literature the reasons are inexact fitting of the prosthesis or too few anatomically formed implants resulting in less physiological kinematics of the knee joint. Reducing the number of dissatisfied patients and the corresponding number of revisions is an important goal considering the increasing need for artificial joints. In this context, patient-specific knee implants are an obvious alternative to conventional implants. For the first time implants are now matched to the individual bone and not vice versa to achieve the best possible individual situation and geometry and more structures (e.g. ligaments and bone) are preserved or only those structures are replaced which were actually destroyed by arthrosis. According to the authors view, this represents an optimal and pioneering addition to conventional implants. Patient-specific implants and the instruments needed for correct alignment and fitting can be manufactured by virtual 3D reconstruction and 3D printing based on computed tomography (CT) scans. The portfolio covers medial as well as lateral unicondylar implants, medial as well as lateral bicompartmental implants (femorotibial and patellofemoral compartments) and cruciate ligament-preserving as well as cruciate ligament-substituting total knee replacements; however, it must be explicitly emphasized that the literature is sparse and no long-term data are available.

  11. {331}-Faceted trisoctahedral gold nanocrystals: synthesis, superior electrocatalytic performance and highly efficient SERS activity

    NASA Astrophysics Data System (ADS)

    Song, Yahui; Miao, Tingting; Zhang, Peina; Bi, Cuixia; Xia, Haibing; Wang, Dayang; Tao, Xutang

    2015-04-01

    We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by using 3.0 nm CTAC-Au seeds or as-prepared 70 nm TOH Au NCs as seeds. We find that the electrocatalytic performance on methanol oxidation and surface enhancement Raman spectroscopy (SERS) activity of {331}-faceted TOH Au NCs is size-dependent. In comparison with well-known nanoporous gold (0.088 mA cm-2), {331}-faceted TOH Au NCs with sizes of 110 nm exhibit fairly high catalytic activity (0.178 mA cm-2) on methanol oxidation (1.0 M) in alkaline media due to the presence of increasing density of atomic steps, ledges, and kinks on the NC surfaces. Their current density is reduced by less than 7% after 500 cycling tests. {331}-Faceted TOH Au NCs with sizes of 175 nm exhibit the highest SERS activity for 4-aminothiophenol (4-ATP) molecules. The enhancement factors of a1 modes of 4-ATP molecules can reach the order of 109 when the 4-ATP concentration is 3 × 10-6 M. Moreover, Raman signals (ag modes) of 4,4'-dimercaptoazobenzene (DMAB) molecules on TOH Au NCs are stronger than those on spherical Au NCs of comparable size due to the enhanced laser-induced transformation of 4-ATP molecules by high-index {331}-facets during SERS measurement. Furthermore, the SERS intensities of 4-methylbenzenethiol (4-MTP) molecules on TOH Au NCs are also higher than those on spherical Au NCs of comparable size due to sharp extremities.We investigate the effect of gold (Au) seeds prepared in cetyltrimethylammonium chloride solution (CTAC-Au seeds) on the index facets of trisoctahedral gold nanocrystals (TOH Au NCs). We demonstrate that monodisperse {331}-faceted TOH Au NCs with controllable sizes (from 60 to 255 nm) can be successfully prepared in high yield by

  12. Pressure vessel flex joint

    NASA Technical Reports Server (NTRS)

    Kahn, Jon B. (Inventor)

    1992-01-01

    An airtight, flexible joint is disclosed for the interfacing of two pressure vessels such as between the Space Station docking tunnel and the Space Shuttle Orbiter bulkhead adapter. The joint provides for flexibility while still retaining a structural link between the two vessels required due to the loading created by the internal/external pressure differential. The joint design provides for limiting the axial load carried across the joint to a specific value, a function returned in the Orbiter/Station tunnel interface. The flex joint comprises a floating structural segment which is permanently attached to one of the pressure vessels through the use of an inflatable seal. The geometric configuration of the joint causes the tension between the vessels created by the internal gas pressure to compress the inflatable seal. The inflation pressure of the seal is kept at a value above the internal/external pressure differential of the vessels in order to maintain a controlled distance between the floating segment and pressure vessel. The inflatable seal consists of either a hollow torus-shaped flexible bladder or two rolling convoluted diaphragm seals which may be reinforced by a system of straps or fabric anchored to the hard structures. The joint acts as a flexible link to allow both angular motion and lateral displacement while it still contains the internal pressure and holds the axial tension between the vessels.

  13. Compliant Joints For Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James J., Jr.

    1990-01-01

    Compliant joints devised to accommodate misalignments of tools and/or workpieces with respect to robotic manipulators. Has characteristics and appearance of both universal-joint and cable-spring-type flexible shaft coupling. Compliance derived from elastic properties of short pieces of cable. Compliance of joint determined by lengths, distances between, relative orientations, thickness of strands, number of strands, material, amount of pretwist, and number of short pieces of cable. Worm-drive mechanism used to adjust lengths to vary compliance as needed during operation.

  14. Joint Robotics Program

    DTIC Science & Technology

    2008-04-23

    Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= JOINT ROBOTICS PROGRAM Published: 23 April 2008 by Joel Brown and Paul Varian 5th Annual Acquisition Research...3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Joint Robotics Program 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...ëóåÉêÖó=Ñçê=áåÑçêãÉÇ=ÅÜ~åÖÉ=======- 464 - = = Joint Robotics Program Presenter: Joel Brown, Defense Acquisition University Author: Paul Varian

  15. Total ankle joint replacement.

    PubMed

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  16. Highly reactive {001} facets of TiO2-based composites: synthesis, formation mechanism and characterization.

    PubMed

    Ong, Wee-Jun; Tan, Lling-Lling; Chai, Siang-Piao; Yong, Siek-Ting; Mohamed, Abdul Rahman

    2014-02-21

    Titanium dioxide (TiO2) is one of the most widely investigated metal oxides due to its extraordinary surface, electronic and catalytic properties. However, the large band gap of TiO2 and massive recombination of photogenerated electron-hole pairs limit its photocatalytic and photovoltaic efficiency. Therefore, increasing research attention is now being directed towards engineering the surface structure of TiO2 at the most fundamental and atomic level namely morphological control of {001} facets in the range of microscale and nanoscale to fine-tune its physicochemical properties, which could ultimately lead to the optimization of its selectivity and reactivity. The synthesis of {001}-faceted TiO2 is currently one of the most active interdisciplinary research areas and demonstrations of catalytic enhancement are abundant. Modifications such as metal and non-metal doping have also been extensively studied to extend its band gap to the visible light region. This steady progress has demonstrated that TiO2-based composites with {001} facets are playing and will continue to play an indispensable role in the environmental remediation and in the search for clean and renewable energy technologies. This review encompasses the state-of-the-art research activities and latest advancements in the design of highly reactive {001} facet-dominated TiO2via various strategies, including hydrothermal/solvothermal, high temperature gas phase reactions and non-hydrolytic alcoholysis methods. The stabilization of {001} facets using fluorine-containing species and fluorine-free capping agents is also critically discussed in this review. To overcome the large band gap of TiO2 and rapid recombination of photogenerated charge carriers, modifications are carried out to manipulate its electronic band structure, including transition metal doping, noble metal doping, non-metal doping and incorporating graphene as a two-dimensional (2D) catalyst support. The advancements made in these aspects are

  17. Defect character at grain boundary facet junctions: Analysis of an asymmetric Σ = 5 grain boundary in Fe

    DOE PAGES

    Medlin, D. L.; Hattar, K.; Zimmerman, J. A.; ...

    2016-11-16

    Grain boundaries often develop faceted morphologies in systems for which the interfacial free energy depends on the boundary inclination. Although the mesoscale thermodynamic basis for such morphological evolution has been extensively studied, the influence of line defects, such as secondary grain boundary dislocations, on the facet configurations has not been thoroughly explored. In this paper, through a combination of atomistic simulations and electron microscopic observations, we examine in detail the structure of an asymmetric Σ = 5 [001] grain boundary in well-annealed, body-centered cubic (BCC) Fe. The observed boundary forms with a hill-and-valley morphology composed of nanoscale {310} and {210}more » facets. Our analysis clarifies the atomic structure of the {310}/{210} facet junctions and identifies the presence of an array of secondary grain boundary dislocations that are localized to these junctions. Analysis of the Burgers vectors of the grain boundary dislocations, which are of type (1/5)<310> and (1/5)<120>, shows that the defect density is consistent with that required to accommodate a small observed angular deviation from the exact Σ = 5 orientation relationship. As a result, these observations and analysis suggest a crucial role for secondary grain boundary dislocations in dictating the length-scale of grain boundary facets, a consideration which has not been included in prior analyses of facet evolution and equilibrium facet length.« less

  18. Defect character at grain boundary facet junctions: Analysis of an asymmetric Σ = 5 grain boundary in Fe

    SciTech Connect

    Medlin, D. L.; Hattar, K.; Zimmerman, J. A.; Abdeljawad, F.; Foiles, S. M.

    2016-11-16

    Grain boundaries often develop faceted morphologies in systems for which the interfacial free energy depends on the boundary inclination. Although the mesoscale thermodynamic basis for such morphological evolution has been extensively studied, the influence of line defects, such as secondary grain boundary dislocations, on the facet configurations has not been thoroughly explored. In this paper, through a combination of atomistic simulations and electron microscopic observations, we examine in detail the structure of an asymmetric Σ = 5 [001] grain boundary in well-annealed, body-centered cubic (BCC) Fe. The observed boundary forms with a hill-and-valley morphology composed of nanoscale {310} and {210} facets. Our analysis clarifies the atomic structure of the {310}/{210} facet junctions and identifies the presence of an array of secondary grain boundary dislocations that are localized to these junctions. Analysis of the Burgers vectors of the grain boundary dislocations, which are of type (1/5)<310> and (1/5)<120>, shows that the defect density is consistent with that required to accommodate a small observed angular deviation from the exact Σ = 5 orientation relationship. As a result, these observations and analysis suggest a crucial role for secondary grain boundary dislocations in dictating the length-scale of grain boundary facets, a consideration which has not been included in prior analyses of facet evolution and equilibrium facet length.

  19. An investigation into the effect of joint frequency and spatial positioning on pre-splitting

    SciTech Connect

    Tariq, S.M.; Worsey, P.N.

    1995-12-31

    Pre-splitting is now widely used to minimize overbreak and to protect final surface rock excavation profiles in large scale civil construction projects, open pit mining and quarrying. Jointing has been shown to affect the success of pre-splitting and the smoothness and integrity of the resulting rock face. Many facets of jointing have been investigated in detail, including the inclination of joints with respect to the desired pre-split plane, the effects of various filling materials, etc. However, the effects of joint frequency and spatial positioning has been paid little attention. The paper addresses this issue. The results of experimental model testing carried out in concrete blocks are presented. The program consisted of modeling closed joints with varying frequency between two 3/8 inch boreholes, drilled in 12 x 9 x 6 inch concrete blocks charged with 15 grains per foot PETN cord. It was found that by increasing the joint frequency from zero to two between boreholes decreases the maximum successful split-hole spacing. However, with increasing joint frequency the trend is reversed. These results are attributed to the overall rock mass being weakened by the slabs between the discontinuities becoming thinner with increasing discontinuity frequency. It was also revealed that the spatial positioning of discontinuities plays an important role in pre-split formation and integrity.

  20. A bright side, facet analysis of histrionic personality disorder: the relationship between the HDS Colourful factor and the NEO-PI-R facets in a large adult sample.

    PubMed

    Furnham, Adrian

    2014-01-01

    This study looks at "bright-side," Big Five Personality trait correlates of a "dark-side" Personality Disorder, namely Histrionic Personality Disorder (HPD). More than 5000 British adults completed the Neuroticism Extraversion Openness Personality Inventory-Revised (Costa & McCrae, 1985), which measures the Big Five Personality factors at the Domain (Super Factor) and the Facet (Factor) level, as well as the Hogan Development Survey (HDS; Hogan & Hogan, 2009), which has a measure of HPD, exclusively called "Colourful" in the HDS terminology. Correlation and regression results confirmed many of the associations between these "bright" and "dark" side individual difference variables. The Colourful (HPD) score from the HDS was the criterion variable in all analyses. Colourful individuals are high on Extraversion and Openness, but also Stable and disagreeable. The Facet analysis identified Assertiveness and Immodesty as particularly characteristic of that type. The study confirmed work on HPD using different population groups and different measures, showing that personality traits are predictable and correlated with various personality disorders.

  1. An investigation into the effect of varying joint aperture and nature of surface on pre-splitting

    SciTech Connect

    Tariq, S.M.; Worsey, P.N.

    1996-12-01

    Presplitting is now a universally accepted perimeter control technique in rock excavation. The success of presplitting and the smoothness and integrity of the resulting perimeter is largely dependent on the nature of joints in any given formation. Many facets of jointing have been previously investigated. The results of the effects of joints frequency and spatial positioning were presented by the authors at the ISEE annual meeting last year. This paper includes the results of further research into the mechanism of presplit blasting being carried out at the Rock Mechanics and Explosives Research Center of the University of Missouri-Rolla. The results of experimental model testing carried out in concrete blocks are presented. The research comprised of modeling both closed and open joints between 3/8 inch blastholes loaded with 15-grain per foot PETN detonating cord. The closed joints were (a) simple (rough) machine-cut and (b) surface ground (smooth-matching). The precision ground joints were modeled to simulate tight fractures as found in real rock mass. Precision spacers of varying thicknesses were used to create opening between the joint surfaces. It was found that precision ground joints have no significant effect on the maximum blasthole spacing up to two joints, and act like a continuous medium. This is because ground surfaces provide a relatively perfect match thereby transmitting most of the energy through the joint. However beyond two ground joints, the effects of attenuation is evident and the maximum blasthole spacing has to be reduced to obtain a presplit plane. A simple machine cut joint, on the other hand, has some undulations that results in loss of energy, making it necessary to bring the blastholes closer to achieve a presplit plane (for up to two joints). It was observed that a ground joint with spacer thickness of 0.012 inch behaves like a free surface.

  2. Shoulder Joint Replacement

    MedlinePlus

    ... examination. This will assess shoulder motion, stability, and strength. joint. (Right) Osteoarthritis of the shoulder. Note the ... you can start moving sooner and get your strength back more quickly. Talk with your surgeon if ...

  3. Panel Post & Diagonal Brace Joint Detail; Crossbracing Center Joint ...

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

    Panel Post & Diagonal Brace Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie Bar, & Diagonal Brace Joint Detail; Chord, Tie Bar, & Crossbracing Joint Detail - Medora Bridge, Spanning East Fork of White River at State Route 235, Medora, Jackson County, IN

  4. Jointness: A Selected Bibliography

    DTIC Science & Technology

    2010-12-01

    JOINTNESS A Selected Bibliography U.S. ARMY WAR COLLEGE LIBRARY December 2010 Report Documentation Page Form...Lenore Garder 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army War College...of the U.S. Army War College. A revised and updated version of our earlier bibliographies on jointness, it focuses on aspects of United States

  5. Successfully Developing Joint Leaders

    DTIC Science & Technology

    2010-07-26

    least for the ROTC aspect of the Navy commissioning source, this is about to change at the University of South Florida (USF). In fact the “Joint...get their training over a six- month period at Fort Sill, Oklahoma. A Marine aviator will go through Pensacola Naval Air Station, Florida alongside...MCAS Beaufort, he served in Afghanistan as “Commanding Officer of Taskforce Panther , a joint coalition taskforce in support of OEF” (http

  6. Exploring facets of personality in a patient sample of hypersexual women compared with hypersexual men.

    PubMed

    Reid, Rory C; Dhuffar, Manpreet K; Parhami, Iman; Fong, Timothy W

    2012-07-01

    This study explored group differences among a treatment-seeking sample of hypersexual women (n = 31) and hypersexual men (n = 47) across facets of personality using the NEO-Personality Inventory-Revised and the Hyper sexual Behavior Inventory. A number of striking parallels emerged between the two groups, including similar levels of impulsivity, emotional dysregulation, and difficulties coping with stress. Hypersexual women, compared to men, exhibited higher levels of distrust toward others, lower levels of self-confidence and ambition, and a greater preference for excitement and stimulation. These findings suggest that several common facets of personality precipitate or perpetuate hypersexual behavior in men and women, with some variations across genders. The implications of these findings for treatment interventions are discussed.

  7. Drinking Motives Mediate the Negative Associations between Mindfulness Facets and Alcohol Outcomes among College Students

    PubMed Central

    Roos, Corey R.; Pearson, Matthew R.; Brown, David B.

    2014-01-01

    Mindfulness and drinking motives have both been linked to affect regulation, yet the relationship between mindfulness and drinking motives is poorly understood. The present study examined whether drinking motives, particularly mood regulatory motives, mediated the associations between facets of mindfulness and alcohol-related outcomes among college students (N = 297). We found three specific facets of mindfulness (describing, nonjudging of inner experience, and acting with awareness) to have negative associations with alcohol outcomes. Importantly, specific drinking motives mediated these associations such that lower levels of mindfulness were associated with drinking for distinct reasons (enhancement, coping, conformity), which in turn predicted alcohol use and/or alcohol problems. Our findings suggest that drinking motives, especially mood regulatory and negative reinforcement motives, are important to examine when studying the role of mindfulness in college student drinking behavior. PMID:25546142

  8. [How I explore the various statistical facets of 2 x 2 tables in medicine].

    PubMed

    Albert, A

    2013-09-01

    In the medical scientific literature, 2 x 2 contingency tables are widely used to display the distribution of binary data. They are associated with the definition of basic concepts in medicine and epidemiology that are universally utilized. They are usually taught in any basic course in biostatistics early in the medical curriculum; their interpretation however is not always straightforward. We have discerned at least eight different facets of such fourfold tables: homogeneity test, independence test, McNemar test, Cohen kappa coefficient, incidence relative risk, prevalence relative risk, odds ratio, diagnostic value of a clinical test. Each facet is illustrated by a clinical problem used as an example. This article should help the reader to understand which table he/she is actually dealing with.

  9. Platinum-Based Nanocages with Subnanometer-Thick Walls and Well-Defined Facets

    SciTech Connect

    Zhang, Lei; Wang, Xue; Chi, Miaofang; Mavrikakis, Manos; Roling, Luke; Xia, Younan

    2015-07-24

    A cost-effective catalyst should have a high dispersion of the active atoms, together with a controllable surface structure for the optimization of activity, selectivity, or both. We fabricated nanocages by depositing a few atomic layers of platinum (Pt) as conformal shells on palladium (Pd) nanocrystals with well-defined facets and then etching away the Pd templates. Density functional theory calculations suggest that the etching is initiated via a mechanism that involves the formation of vacancies through the removal of Pd atoms incorporated into the outermost layer during the deposition of Pt. With the use of Pd nanoscale cubes and octahedra as templates, we obtained Pt cubic and octahedral nanocages enclosed by {100} and {111} facets, respectively, which exhibited distinctive catalytic activities toward oxygen reduction.

  10. Platinum-Based Nanocages with Subnanometer-Thick Walls and Well-Defined Facets

    DOE PAGES

    Zhang, Lei; Wang, Xue; Chi, Miaofang; ...

    2015-07-24

    A cost-effective catalyst should have a high dispersion of the active atoms, together with a controllable surface structure for the optimization of activity, selectivity, or both. We fabricated nanocages by depositing a few atomic layers of platinum (Pt) as conformal shells on palladium (Pd) nanocrystals with well-defined facets and then etching away the Pd templates. Density functional theory calculations suggest that the etching is initiated via a mechanism that involves the formation of vacancies through the removal of Pd atoms incorporated into the outermost layer during the deposition of Pt. With the use of Pd nanoscale cubes and octahedra asmore » templates, we obtained Pt cubic and octahedral nanocages enclosed by {100} and {111} facets, respectively, which exhibited distinctive catalytic activities toward oxygen reduction.« less

  11. Quantum dots (QDs) immobilization on metal nanowire end-facets for single photon source application

    NASA Astrophysics Data System (ADS)

    Kim, J.; Lee, B. C.; Kang, C.; Lee, S. Y.; Park, J. H.; Shin, H. J.

    2010-02-01

    We introduce a fabrication process to immobilize cadmium selenide (CdSe) Quantum Dots (QDs) on end-facets of metal nanowires, which can be possibly used as a cavity-free unidirectional single photon source with high coupling efficiency due to high Purcell factor. Nanowires were fabricated using E-beam lithography, E-beam evaporation, and lift-off process and finally covered with chemically deposited silicon dioxide (SiO2) layer. End-facets of metal nanowires were defined using wet etching process. QD immobilization was accomplished through surface modifications on both metal and QD surfaces. We immobilized thiol (-SH) functionalized 15 base pair (bp) ssDNA on Au nanowire surface to hybridize with its complimentary amine (- NH3) functionalized 15bp ssDNA and conjugated the amine functionalized 15bp ssDNA with QD. Presenting QD immobilization method showed high selectivity between metal nanowire and SiO2 surfaces.

  12. Difficulty in Fixation of the Volar Lunate Facet Fragment in Distal Radius Fracture

    PubMed Central

    Obata, Hiroyuki; Futamura, Kentaro; Obayashi, Osamu; Mogami, Atsuhiko; Tsuji, Hideki; Kurata, Yoshiaki; Kaneko, Kazuo

    2017-01-01

    Recent reports suggest the presence of a rare fracture type for which reduction and fixation cannot be achieved with volar locking plate (VLP). In particular, it is difficult to achieve reduction and fixation with volar lunate facet (VLF) fragments present on the volar ulnar aspect of the lunate facet, because of the anatomical structure and biomechanics in this region. Herein, we report two challenging cases of difficulty in fixation of the VLF fragment in distal radius fracture. For this fracture type, it is most important to identify the volar ulnar bone fragment before surgery; it may also be necessary to optimize distal placement of the VLP via a dual-window approach and to apply additional fixations, such as a small plate, anchor, and/or external fixation. PMID:28255487

  13. Antibody molecules discriminate between crystalline facets of a gallium arsenide semiconductor.

    PubMed

    Artzy Schnirman, Arbel; Zahavi, Efrat; Yeger, Hadas; Rosenfeld, Ronit; Benhar, Itai; Reiter, Yoram; Sivan, Uri

    2006-09-01

    Seamless integration of biomolecules with manmade materials will most likely rely on molecular recognition and specific binding. In the following we show that combinatorial antibody libraries, based on the vast repertoire of the human immune system, can be harnessed to generate such binders. As a demonstration, we isolate antibody fragments that discriminate and bind selectively GaAs (111A) facets as opposed to GaAs (100). The isolated antibodies are utilized for exclusive localization of a fluorescent dye on (111A) surfaces in a structure comprising a mixture of (100) and (111A) surfaces. The potential importance of structure rigidity to facet recognition is suggested vis-a-vis published experiments with short and longer peptides.

  14. Mass spectrometric monitoring of interfacial photoelectron transfer and imaging of active crystalline facets of semiconductors

    NASA Astrophysics Data System (ADS)

    Zhong, Hongying; Zhang, Juan; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Li, Rui; Chen, Disong; Wang, Peng; Yuan, Zhiwei

    2017-02-01

    Monitoring of interfacial electron transfer (ET) in situ is important to understand the ET mechanism and designing efficient photocatalysts. We describe herein a mass spectrometric approach to investigate the ultrafast transfer of photoelectrons that are generated by ultraviolet irradiation on surfaces of semiconductor nanoparticles or crystalline facets. The mass spectrometric approach can not only untargetedly detect various intermediates but also monitor their reactivity through associative or dissociative photoelectron capture dissociation, as well as electron detachment dissociation of adsorbed molecules. Proton-coupled electron transfer and proton-uncoupled electron transfer with radical initiated polymerization or hydroxyl radical abstraction have been unambiguously demonstrated with the mass spectrometric approach. Active crystalline facets of titanium dioxide for photocatalytic degradation of juglone and organochlorine dichlorodiphenyltrichloroethane are visualized with mass spectrometry imaging based on ion scanning and spectral reconstruction. This work provides a new technique for studying photo-electric properties of various materials.

  15. Studying nanostructured nipple arrays of moth eye facets helps to design better thin film solar cells.

    PubMed

    Dewan, Rahul; Fischer, Stefan; Meyer-Rochow, V Benno; Özdemir, Yasemin; Hamraz, Saeed; Knipp, Dietmar

    2012-03-01

    Nipples on the surface of moth eye facets exhibit almost perfect broadband anti-reflection properties. We have studied the facet surface micro-protuberances, known as corneal nipples, of the chestnut leafminer moth Cameraria ohridella by atomic force microscopy, and simulated the optics of the nipple arrays by three-dimensional electromagnetic simulation. The influence of the dimensions and shapes of the nipples on the optics was studied. In particular, the shape of the nipples has a major influence on the anti-reflection properties. Furthermore, we transferred the structure of the almost perfect broadband anti-reflection coatings to amorphous silicon thin film solar cells. The coating that imitates the moth-eye array allows for an increase of the short circuit current and conversion efficiency of more than 40%.

  16. Optical characterization of synthetic faceted gem materials grown from hydrothermal solutions

    NASA Astrophysics Data System (ADS)

    Lu, Taijin; Shigley, James E.

    1998-10-01

    Various non-destructive optical characterization techniques have been used to characterize and identify synthetic gem materials grown from hydrothermal solutions, to include ruby, sapphire, emerald, amethyst and ametrine (amethyst-citrine), from their natural counterparts. The ability to observe internal features, such as inclusions, dislocations, twins, color bands, and growth zoning in gem materials is strongly dependent on the observation techniques and conditions, since faceted gemstones have many polished surfaces which can reflect and scatter light in various directions which can make observation difficult. However, diagnostic gemological properties of these faceted synthetic gem materials can be obtained by choosing effective optical characterization methods, and by modifying optical instruments. Examples of some of the distinctive features of synthetic amethyst, ametrine, pink quartz, ruby and emerald are presented to illustrate means of optical characterization of gemstones. The ability to observe defects by light scattering techniques is discussed.

  17. It's in the mix: psychological distress differs between combinations of alexithymic facets

    PubMed Central

    Alkan Härtwig, Elif; Crayen, Claudia; Heuser, Isabella; Eid, Michael

    2014-01-01

    Alexithymia is a personality trait characterized by difficulties in identifying, describing, and communicating one's emotions. The aim of the present study is to examine the usefulness of a typological approach considering the interaction between distinct alexithymic features within a population of high-alexithymic German adults (N = 217). Latent profile analysis (LPA) was employed to test for possible underlying profiles. A 3-profile solution showed the best fit: The profiles can be described as (1) “low”: lower load on all facets of alexithymia, (2) “mixed”: specific problems on identifying emotions, and (3) “high”: higher load on all facets of alexithymia. Moreover, this study tested how these profiles differed in psychological distress. “Mixed” profile, with specific problems on identifying emotions showed the highest levels of psychological distress. The present study suggests the importance of a specific combination of alexithymic features, rather than total alexithymia scores, as a risk factor for psychological distress. PMID:25429275

  18. Axis-oriented, continuous anatase titania films with exposed reactive {100} facets.

    PubMed

    Van, Thanh-Khue; Nguyen, Cuong Ky; Kang, Young Soo

    2013-07-08

    Homogeneous TiO2 single crystals with high exposure of {100} reactive facets were constructed as a seed monolayer on transparent conductive substrates with the desired orientation of reactive facets. A secondary growth process was subsequently carried out on the monolayer seed film to form an axis-oriented continuous reactive film. Performing secondary growth with different precursors led to optimized conditions for high-performance photoelectrochemical activity of anatase TiO2 films. Experimental techniques such as UV/Vis absorption spectroscopy, X-ray diffraction, high-resolution SEM, and photoelectrochemistry were used to characterize the structural, optical, and photoelectrochemical properties of the as-synthesized films. As a photoanode in a photoelectrochemical cell, the axis-oriented reactive film shows a maximum photocurrent density of 0.3 mA cm(-2), as opposed to 0.075 mA cm(-2) for non-axis-oriented (randomly oriented) TiO2 film.

  19. Facets of impulsivity in the relationship between antisocial personality and abstinence.

    PubMed

    Sargeant, Marsha N; Bornovalova, Marina A; Trotman, Adria J-M; Fishman, Shira; Lejuez, Carl W

    2012-03-01

    Most individuals who enter drug treatment programs are unable to maintain long-term abstinence. This problem is especially relevant for those presenting with Antisocial Personality Disorder (ASPD). In examining potential mechanisms underlying the relationship between ASPD and abstinence, one factor that may be especially useful is the personality variable of impulsivity. Thus, the current study examined ASPD status in relation to longest abstinence attempt among 117 substance use treatment-seeking individuals, considering the mediating role of five facets of impulsivity: urgency, perseverance, premeditation, control, and delay discounting. Results indicated that individuals with ASPD evidenced shorter previous abstinence attempts and lower levels of perseverance and control than those without ASPD. Further, lower levels of control were associated with shorter abstinence attempts. Finally, control mediated the relationship between ASPD and longest quit attempt. These results suggest the potential value of multiple facets of impulsivity in efforts to understand relapse and subsequent treatment development efforts.

  20. Drinking motives mediate the negative associations between mindfulness facets and alcohol outcomes among college students.

    PubMed

    Roos, Corey R; Pearson, Matthew R; Brown, David B

    2015-03-01

    Mindfulness and drinking motives have both been linked to affect regulation, yet the relationship between mindfulness and drinking motives is poorly understood. The present study examined whether drinking motives, particularly mood regulatory motives, mediated the associations between facets of mindfulness and alcohol-related outcomes among college students (N = 297). We found 3 specific facets of mindfulness (describing, nonjudging of inner experience, and acting with awareness) to have negative associations with alcohol outcomes. Importantly, specific drinking motives mediated these associations such that lower levels of mindfulness were associated with drinking for distinct reasons (enhancement, coping, conformity), which in turn predicted alcohol use and/or alcohol problems. Our findings suggest that drinking motives, especially mood regulatory and negative reinforcement motives, are important to examine when studying the role of mindfulness in college student drinking behavior. (PsycINFO Database Record

  1. Mass spectrometric monitoring of interfacial photoelectron transfer and imaging of active crystalline facets of semiconductors

    PubMed Central

    Zhong, Hongying; Zhang, Juan; Tang, Xuemei; Zhang, Wenyang; Jiang, Ruowei; Li, Rui; Chen, Disong; Wang, Peng; Yuan, Zhiwei

    2017-01-01

    Monitoring of interfacial electron transfer (ET) in situ is important to understand the ET mechanism and designing efficient photocatalysts. We describe herein a mass spectrometric approach to investigate the ultrafast transfer of photoelectrons that are generated by ultraviolet irradiation on surfaces of semiconductor nanoparticles or crystalline facets. The mass spectrometric approach can not only untargetedly detect various intermediates but also monitor their reactivity through associative or dissociative photoelectron capture dissociation, as well as electron detachment dissociation of adsorbed molecules. Proton-coupled electron transfer and proton-uncoupled electron transfer with radical initiated polymerization or hydroxyl radical abstraction have been unambiguously demonstrated with the mass spectrometric approach. Active crystalline facets of titanium dioxide for photocatalytic degradation of juglone and organochlorine dichlorodiphenyltrichloroethane are visualized with mass spectrometry imaging based on ion scanning and spectral reconstruction. This work provides a new technique for studying photo-electric properties of various materials. PMID:28224986

  2. High pressure ceramic joint

    DOEpatents

    Ward, Michael E.; Harkins, Bruce D.

    1993-01-01

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  3. High pressure ceramic joint

    DOEpatents

    Ward, M.E.; Harkins, B.D.

    1993-11-30

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

  4. First results from core-edge parallel composition in the FACETS project

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Candy, J.; Cohen, R. H.; Krasheninnikov, S.; McCune, D. C.; Estep, D. J.; Larson, J.; Malony, A. D.; Pankin, A.; Worley, P. H.; Carlsson, J. A.; Hakim, A. H.; Hamill, P.; Kruger, S.; Miah, M.; Muzsala, S.; Pletzer, A.; Shasharina, S.; Wade-Stein, D.; Wang, N.; Balay, S.; McInnes, L.; Zhang, H.; Casper, T.; Diachin, L.; Epperly, T.; Rognlien, T. D.; Fahey, M. R.; Cobb, J.; Morris, A.; Shende, S.; Hammett, G. W.; Indireshkumar, K.; Stotler, D.; Pigarov, A. Y.

    2008-07-01

    FACETS (Framework Application for Core-Edge Transport Simulations), now in its second year, has achieved its first coupled core-edge transport simulations. In the process, a number of accompanying accomplishments were achieved. These include a new parallel core component, a new wall component, improvements in edge and source components, and the framework for coupling all of this together. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists, and applied mathematicians on the team.

  5. Size Dependence of S-bonding on (111) Facets of Cu Nanoclusters

    SciTech Connect

    Boschen, Jeffery S.; Lee, Jiyoung; Windus, Theresa L.; Evans, James W.; Liu, Da-Jiang

    2016-04-21

    We demonstrate a strong damped oscillatory size dependence of the adsorption energy for sulfur on the (111) facets of tetrahedral Cu nanoclusters up to sizes of ~300 atoms. This behavior reflects quantum size effects. Consistent results are obtained from density functional theory analyses utilizing either atomic orbital or plane-wave bases and using the same Perdew–Burke–Ernzerhof functional. Behavior is interpreted via molecular orbitals (MO), density of states (DOS), and crystal orbital Hamilton population (COHP) analyses.

  6. Composition Tunability and (111)-Dominant Facets of Ultrathin Platinum-Gold Alloy Nanowires toward Enhanced Electrocatalysis.

    PubMed

    Chang, Fangfang; Shan, Shiyao; Petkov, Valeri; Skeete, Zakiya; Lu, Aolin; Ravid, Jonathan; Wu, Jinfang; Luo, Jin; Yu, Gang; Ren, Yang; Zhong, Chuan-Jian

    2016-09-21

    The ability for tuning not only the composition but also the type of surface facets of alloyed nanomaterials is important for the design of catalysts with enhanced activity and stability through optimizing both ensemble and ligand effects. Herein we report the first example of ultrathin platinum-gold alloy nanowires (PtAu NWs) featuring composition-tunable and (111) facet-dominant surface characteristics, and the electrocatalytic enhancement for the oxygen reduction reaction (ORR). PtAu NWs of different bimetallic compositions synthesized by a single-phase and surfactant-free method are shown to display an alloyed, parallel-bundled structure in which the individual nanowires exhibit Boerdijk-Coxeter helix type morphology predominant in (111) facets. Results have revealed intriguing catalytic correlation with the binary composition, exhibiting an activity maximum at a Pt:Au ratio of ∼3:1. As revealed by high-energy synchrotron X-ray diffraction and atomic pair distribution function analysis, NWs of this ratio exhibit a clear shrinkage in interatomic bonding distances. In comparison with PtAu nanoparticles of a similar composition and degree of shrinking of atomic-pair distances, the PtAu NWs display a remarkably higher electrocatalytic activity and stability. The outperformance of NWs over nanoparticles is attributed to the predominant (111)-type facets on the surface balancing the contribution of ensemble and ligand effects, in addition to the composition synergy due to optimal adsorption energies for molecular and atomic oxygen species on the surface as supported by DFT computation of models of the catalysts. The findings open up a new pathway to the design and engineering of alloy nanocatalysts with enhanced activity and durability.

  7. Facet-dependent disorder in pristine high-voltage lithium-manganese-rich cathode material.

    PubMed

    Dixit, Hemant; Zhou, Wu; Idrobo, Juan-Carlos; Nanda, Jagjit; Cooper, Valentino R

    2014-12-23

    Defects and surface reconstructions are thought to be crucial for the long-term stability of high-voltage lithium-manganese-rich cathodes. Unfortunately, many of these defects arise only after electrochemical cycling which occurs under harsh conditions, making it difficult to fully comprehend the role they play in degrading material performance. Recently, it has been observed that defects are present even in the pristine material. This study, therefore, focuses on examining the nature of the disorder observed in pristine Li1.2Ni0.175Mn0.525Co0.1O2 (LNMCO) particles. Using atomic-resolution Z-contrast imaging and electron energy loss spectroscopy measurements, we show that there is indeed a significant amount of antisite defects present in this material, with transition metals substituting on Li metal sites. Furthermore, we find a strong segregation tendency of these types of defects toward open facets (surfaces perpendicular to the layered arrangement of atoms) rather than closed facets (surfaces parallel to the layered arrangement of atoms). First-principles calculations identify antisite defect pairs of Ni swapping with Li ions as the predominant defect in the material. Furthermore, energetically favorable swapping of Ni on the Mn sites was observed to lead to Mn depletion at open facets. Relatively, low Ni migration barriers also support the notion that Ni is the predominant cause of disorder. These insights suggest that certain facets of the LNMCO particles may be more useful for inhibiting surface reconstruction and improving the stability of these materials through careful consideration of the exposed surface.

  8. Evaluation of Temporal Diagnostic Techniques for Two-Bunch Facet Beam

    SciTech Connect

    Litos, M.D.; Bionta, M.R.; Dolgashev, V.A.; England, R.J.; Fritz, D.; Gilevich, S.; Hering, Ph.; Hogan, M.J.; /SLAC

    2011-08-19

    Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, singleshot, high resolution measurement of the beam's temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria. Based on our laboratory testing, numerical calculations, and simulations of the three single-shot temporal diagnostic devices, the X-band TCAV system is the best candidate for resolving FACET's two-bunch beam, with an estimated resolution of 7 {micro}m. Both the S-band TCAV system and the EO system could resolve the peak-to-peak separation of the two bunches in the FACET beam with estimated resolutions of 25 {micro}m and 30 {micro}m, respectively, but would be unable to resolve the temporal profiles of the individual bunches themselves. Because the TCAV signal is more easily interpreted and because the reliability of the EO system is less well known, however, the S-band TCAV system would be the next preferred option after the X-band TCAV system. The Fesca-200 streak camera, though simple, compact, and reliable, is unable to achieve a resolution that would be of use to FACET.

  9. Facet Dependent Disorder in the Pristine High Voltage Lithium-Manganese-Rich Cathode Material

    DOE PAGES

    Dixit, Hemant M.; Zhou, Wu; Idrobo Tapia, Juan Carlos; ...

    2014-11-21

    Defects and surface reconstructions are thought to be crucial for the long term stability of high-voltage lithium-manganese-rich cathodes. Unfortunately, many of these defects arise only after electrochemical cycling which occur under harsh conditions making it difficult to fully comprehend the role they play in degrading material performance. Recently, it has been observed that defects are present even in the pristine material. This study, therefore, focuses on examining the nature of the disorder observed in pristine Limore » $$_{1.2}$$Ni$$_{0.175}$$Mn$$_{0.525}$$Co$$_{0.1}$$O$$_2$$ (LNMCO) particles. Using atomic resolution Z-contrast imaging and electron energy-loss spectroscopy measurements we show that there are indeed a significant amount of anti-site defects present in this material; with transition metals substituting on Li metal sites. Furthermore, we find a strong tendency of segregation of these types of defects towards open facets (surfaces perpendicular to the layered arrangement of atoms), rather than closed facets (surfaces parallel to the layered arrangement of atoms). First principles calculations identify anti-site defect pairs of Ni swapping with Li ions as the predominant defect in the material. Furthermore, energetically favorable swapping of Ni on the Mn sites were observed to lead to Mn depletion at open facets. Relatively, low Ni migration barriers also support the notion that Ni are the predominant cause of disorder. These insights suggests that certain facets of the LNMCO particles may be more useful for inhibiting surface reconstruction and improving the stability of these materials through careful consideration of the exposed surface.« less

  10. Mass transport, faceting and behavior of dislocations in GaN

    SciTech Connect

    Nitta, S.; Kashima, T.; Kariya, M.; Yukawa, Y.; Yamaguchi, S.; Amano, H.; Akasaki, I.

    2000-07-01

    The behavior of threading dislocations during mass transport of GaN was investigated in detail by transmission electron microscopy. Mass transport occurred at the surface. Therefore, growing species are supplied from the in-plane direction. The behavior of threading dislocations was found to be strongly affected by the mass transport process as well as the high crystallographic anisotropy of the surface energy of the facets particular to GaN.

  11. Adatom Ascending at Step Edges and Faceting on fcc Metal (110) Surfaces

    SciTech Connect

    Zhu, W.; de Mongeot, F. B.; Valbusa, U.; Wang, E. G.; Zhang, Zhenyu

    2004-01-01

    Using first-principles total-energy calculations, we show that an adatom can easily climb up at monatomic-layer-high steps on several representative fcc metal (110) surfaces via a place exchange mechanism. Inclusion of such novel adatom ascending processes in kinetic Monte Carlo simulations of Al(110) homoepitaxy as a prototypical model system can lead to the existence of an intriguing faceting instability, whose dynamical evolution and kinetic nature are explored in comparison with experimental observations.

  12. Facet Dependent Disorder in the Pristine High Voltage Lithium-Manganese-Rich Cathode Material

    SciTech Connect

    Dixit, Hemant M.; Zhou, Wu; Idrobo Tapia, Juan Carlos; Nanda, Jagjit; Cooper, Valentino R.

    2014-11-21

    Defects and surface reconstructions are thought to be crucial for the long term stability of high-voltage lithium-manganese-rich cathodes. Unfortunately, many of these defects arise only after electrochemical cycling which occur under harsh conditions making it difficult to fully comprehend the role they play in degrading material performance. Recently, it has been observed that defects are present even in the pristine material. This study, therefore, focuses on examining the nature of the disorder observed in pristine Li$_{1.2}$Ni$_{0.175}$Mn$_{0.525}$Co$_{0.1}$O$_2$ (LNMCO) particles. Using atomic resolution Z-contrast imaging and electron energy-loss spectroscopy measurements we show that there are indeed a significant amount of anti-site defects present in this material; with transition metals substituting on Li metal sites. Furthermore, we find a strong tendency of segregation of these types of defects towards open facets (surfaces perpendicular to the layered arrangement of atoms), rather than closed facets (surfaces parallel to the layered arrangement of atoms). First principles calculations identify anti-site defect pairs of Ni swapping with Li ions as the predominant defect in the material. Furthermore, energetically favorable swapping of Ni on the Mn sites were observed to lead to Mn depletion at open facets. Relatively, low Ni migration barriers also support the notion that Ni are the predominant cause of disorder. These insights suggests that certain facets of the LNMCO particles may be more useful for inhibiting surface reconstruction and improving the stability of these materials through careful consideration of the exposed surface.

  13. Photonic crystal cavity on optical fiber facet for refractive index sensing.

    PubMed

    Wang, Bowen; Siahaan, Timothy; Dündar, Mehmet A; Nötzel, Richard; van der Hoek, Marinus J; He, Sailing; van der Heijden, Rob W

    2012-03-01

    Using a micromanipulation technique, a planar photonic crystal nanocavity made from a thin semiconductor membrane is released from the host semiconductor and attached to the end facet of a standard single-mode optical fiber. The cavity spectrum can be read out through the fiber by detecting the photoluminescence of embedded quantum dots. The modified fiber end serves as a fiber-optic refractive index sensor.

  14. Long-Term Function, Pain and Medication Use Outcomes of Radiofrequency Ablation for Lumbar Facet Syndrome

    PubMed Central

    McCormick, Zachary L.; Marshall, Benjamin; Walker, Jeremy; McCarthy, Robert; Walega, David R.

    2015-01-01

    Objective Radiofrequency ablation (RFA) of the medial branch nerves for facet-mediated low back pain demonstrates clinical benefit for 6–12 months and possibly up to 2 years. This study investigated function, pain, and medication use outcomes of RFA for lumbar facet syndrome in a cohort with long-term follow-up. Methods Individuals evaluated in a tertiary academic pain practice between January, 2007–December, 2013, 18–60 years of age, with a clinical and radiologic diagnosis of lumbar facet syndrome, who underwent ≥1set of diagnostic medial branch blocks with resultant >75% pain relief and subsequent RFA were included. Outcomes measured were the proportion of individuals who reported ≥50% improvement in function, ≥50% improvement in pain; change in median NRS pain score, daily morphine equivalent consumption (DME), Medication Quantification Scale III (MSQ III) score and procedure complications. Results Sixty-two consecutive individuals with a median age and 25%–75% interquartile range (IQR) of 34 years (35, 52) met inclusion criteria. Seven individuals were lost to follow-up. Duration of pain was <2 years in 42%, 2–5 years in 40%, >5 years in 18% of individuals. Median duration of follow-up was 39 months (16, 60). Function and pain improved by ≥50% in 58% (CI 45%, 71%) and 53% (CI 40%, 66%) of individuals, respectively. The median reduction in MQS III score was 3.4 points (0, 8.8). No complications occurred in this cohort. Conclusions This study demonstrates a durable treatment effect of RFA for lumbar facet syndrome at long-term follow-up, as measured by improvement in function, pain, and analgesic use. PMID:26005713

  15. First results from core-edge parallel composition in the FACETS project

    SciTech Connect

    Cary, John R.; Candy, Jeff; Cohen, Ronald H.; Krasheninnikov, Sergei; McCune, Douglas; Estep, Donald J; Larson, Jay; Malony, Allen; Pankin, A.; Worley, Patrick H; Carlsson, Johann; Hakim, A H; Hamill, P; Kruger, Scott; Miah, Mahmood; Muzsala, S; Pletzer, Alexander; Shasharina, Svetlana; Wade-Stein, D; Wang, N; Balay, Satish; McInnes, Lois; Zhang, Hong; Casper, T. A.; Diachin, Lori; Epperly, Thomas; Rognlien, T. D.; Fahey, Mark R; Cobb, John W; Morris, A; Shende, Sameer; Hammett, Greg; Indireshkumar, K; Stotler, D.; Pigarov, A

    2008-01-01

    FACETS (Framework Application for Core-Edge Transport Simulations), now in its second year, has achieved its first coupled core-edge transport simulations. In the process, a number of accompanying accomplishments were achieved. These include a new parallel core component, a new wall component, improvements in edge and source components, and the framework for coupling all of this together. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists, and applied mathematicians on the team.

  16. First results from core-edge parallel composition in the FACETS project.

    SciTech Connect

    Cary, J. R.; Candy, J.; Cohen, R. H.; Krasheninnikov, S.; McCune, D. C.; Estep, D. J.; Larson, J.; Malony, A. D.; Pankin, A.; Worley, P. H.; Carlsson, J. A.; Hakim, A. H.; Hamill, P.; Kruger, S.; Miah, M.; Muzsala, S.; Pletzer, A.; Shasharina, S.; Wade-Stein, D.; Wang, N.; Balay, S.; McInnes, L.; Zhang, H.; Casper, T.; Diachin, L.

    2008-01-01

    FACETS (Framework Application for Core-Edge Transport Simulations), now in its second year, has achieved its first coupled core-edge transport simulations. In the process, a number of accompanying accomplishments were achieved. These include a new parallel core component, a new wall component, improvements in edge and source components, and the framework for coupling all of this together. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists, and applied mathematicians on the team.

  17. Intentions to Cheat: Ajzen's Planned Behavior and Goal-Related Personality Facets.

    PubMed

    Lonsdale, Damian

    2017-02-17

    This study sought to test antecedents to college students' intentions to cheat by utilizing Ajzen's ( 1991 ) theory of planned behavior (TPB), and four goal-related personality facets. Those facets were behavioral approach, behavioral inhibition, need for achievement-hope of success, and need for achievement-fear of failure. As hypothesized, perceived friends' and parents' attitudes toward academic dishonesty (two subjective norms) and perceived ease of cheating (perceived behavioral control) all positively predicted overall intentions to cheat. Perceived friends' attitudes seemed to play a more influential role than perceived parents' attitudes. Interestingly, male students reported greater parental acceptance of academic misconduct than female students reported. Among the personality facets, behavioral approach and need for achievement-hope of success were positive and negative predictors of cheating intentions, respectively. A more fine-grained examination of take-home assignments revealed that students considered them easier to cheat on and reported greater intentions to cheat on them in comparison to other forms of academic work (e.g., exams and papers). Also, need for achievement-fear of failure positively predicted intentions to cheat on take-home assignments, but not other cheating intentions. Implications and suggestions for future research are discussed.

  18. Estimating surface flow paths on a digital elevation model using a triangular facet network

    NASA Astrophysics Data System (ADS)

    Zhou, Qiming; Pilesjö, Petter; Chen, Yumin

    2011-07-01

    This study attempts to develop a method for the simulation of surface flow paths on a digital elevation model (DEM). The objective is to use a facet-based algorithm to estimate the surface flow paths on a raster DEM. A grid DEM was used to create a triangular facet network (TFN) over which the surface flow paths were determined. Since each facet in the network has a constant slope and aspect, the estimations of, for example, flow direction and divergence/convergence are less complicated compared to traditional raster-based solutions. Experiments were undertaken by estimating the specific catchment area (SCA) over a number of mathematical surfaces, as well as on a real-world DEM. Comparisons were made between the derived SCA by the TFN algorithm with some algorithms reported in the literature. The results show that the TFN algorithm produced the closest outcomes to the theoretical values of the SCA compared with other algorithms, deriving more consistent outcomes and being less influenced by surface shapes. The real-world DEM test also shows that the TFN was capable of modeling flow distribution without noticeable "artifacts," and its ability of tracking flow paths makes it an appropriate platform for dynamic surface flow simulation.

  19. Studies of the Facetting of the Polished (100) Face of CaF2

    NASA Astrophysics Data System (ADS)

    Dabringhaus, H.; Schick, M.; Wandelt, K.; Deuster, V.; Kayser, Th.; Klapper, H.

    2003-12-01

    The present paper deals with studies of the facetting of the polished (100) surface of CaF2 during annealing and growth in UHV using low energy electron diffraction (LEED), atomic force microscopy (AFM), and transmission electron microscopy (TEM). First morphological modifications of the polished surfaces become visible at temperatures of T = 874 K. Surfaces annealed at T = 974 K exhibit a micro-roughening with pyramidal protrusions and corresponding depressions. LEED studies indicate the evolution of {111} facets. Reflexes from the (100) surface are not seen. After growth of about 660 monolayers of CaF2 at T = 1093 K and a saturation ratio S = 33 from the vapor phase, larger pyramid-like or hip roof-like crystallites are developed. The results of AFM height profiles as well as of the LEED investigations indicate again the formation of {111} facets as proved by their angles of 54.7° with the base (100) surface. This shows that the crystallites are homoepitaxially grown on the underlying CaF2 substrate.

  20. Studies of the facetting of the polished (100) face of CaF 2

    NASA Astrophysics Data System (ADS)

    Deuster, V.; Schick, M.; Kayser, Th.; Dabringhaus, H.; Klapper, H.; Wandelt, K.

    2003-04-01

    The present paper deals with studies of the facetting of the polished (1 0 0) surface of CaF 2 during annealing and growth in UHV using low energy electron diffraction (LEED), atomic force microscopy (AFM), and transmission electron microscopy (TEM). First morphological modifications of the polished surfaces become visible at temperatures of T=874 K. Surfaces annealed at T=974 K exhibit a micro-roughening with pyramidal protrusions and corresponding depressions. LEED studies indicate the evolution of {1 1 1} facets. Reflexes from the (1 0 0) surface are not seen. After growth of about 660 monolayers of CaF 2 at T=1093 K and a saturation ratio S=33 from the vapor phase, larger pyramid-like or hip roof-like crystallites are developed. The results of AFM height profiles as well as of the LEED investigations indicate again the formation of {1 1 1} facets as proved by their angles of 54.7 o with the base (1 0 0) surface. This shows that the crystallites are homoepitaxially grown on the underlying CaF 2 substrate.

  1. Dynamics of Faceted Nanoparticles Formation in a Crystalline Matrix During Ion Implantation Processing.

    PubMed

    Li, Kun-Dar

    2016-02-01

    The faceted nanoparticle synthesized by ion implantation, such as Zn, Cu or Ag nanoparticles, is one of the promising materials for the next generation of optical devices. To understand and better control the manufacturing processes of ion implantation, a theoretical model is applied to investigate the formation and evolution of faceted nanoparticles under various experimental conditions of implantation processing. In this study, the mechanisms of the anisotropic interfacial energy and kinetics with different ion distributions are taken into consideration to demonstrate the role of the crystallographic symmetry, ion energy and temperature on the faceted nanoparticles formation in a crystalline matrix. As presented in the numerical results, the morphological shape of the nanoparticles is mainly affected by the crystallographic symmetry, while the distribution of the precipitates is principally determined by the ion energy. For the condition of high-temperature implantation, a high mobility of ions causes the characteristic length of nanostructures to increase and creates a coarsening morphology of nanoparticles. It is attributed to a longer diffusion distance during the nucleation and growth processes. This model can be widely used for the predictions of the nanostructures formation with various ion implantation processes.

  2. Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite

    NASA Astrophysics Data System (ADS)

    Leblebici, Sibel Y.; Leppert, Linn; Li, Yanbo; Reyes-Lillo, Sebastian E.; Wickenburg, Sebastian; Wong, Ed; Lee, Jiye; Melli, Mauro; Ziegler, Dominik; Angell, Daniel K.; Ogletree, D. Frank; Ashby, Paul D.; Toma, Francesca M.; Neaton, Jeffrey B.; Sharp, Ian D.; Weber-Bargioni, Alexander

    2016-08-01

    Photovoltaic devices based on hybrid perovskite materials have exceeded 22% efficiency due to high charge-carrier mobilities and lifetimes. Properties such as photocurrent generation and open-circuit voltage are influenced by the microscopic structure and orientation of the perovskite crystals, but are difficult to quantify on the intra-grain length scale and are often treated as homogeneous within the active layer. Here, we map the local short-circuit photocurrent, open-circuit photovoltage, and dark drift current in state-of-the-art methylammonium lead iodide solar cells using photoconductive atomic force microscopy. We find, within individual grains, spatially correlated heterogeneity in short-circuit current and open-circuit voltage up to 0.6 V. These variations are related to different crystal facets and have a direct impact on the macroscopic power conversion efficiency. We attribute this heterogeneity to a facet-dependent density of trap states. These results imply that controlling crystal grain and facet orientation will enable a systematic optimization of polycrystalline and single-crystal devices for photovoltaic and lighting applications.

  3. Ga-polar GaN nanocolumn arrays with semipolar faceted tips

    NASA Astrophysics Data System (ADS)

    Urban, A.; Malindretos, J.; Klein-Wiele, J.-H.; Simon, P.; Rizzi, A.

    2013-05-01

    Selective area growth of GaN nanocolumns (NCs) by molecular beam epitaxy on laser ablated pre-patterned GaN(0001) templates is shown to provide regular arrays of Ga-polar NCs. The Ga diffusion-assisted growth mechanism is analyzed and the experiments suggest that the effective growth conditions vary with the height of the NCs due to Ga diffusion on the mask and the NC sidewalls, ranging from N-rich up to stoichiometry. The obtained morphology with semipolar facets at the tip is discussed within the framework of equilibrium thermodynamics, which provides a consistent picture also for the growth of N-polar NCs with flat tips. The structural investigation reveals almost defect-free semipolar \\{1\\overline {1}02\\} GaN facets at the top of the NCs, which is known to be a promising way of producing templates for nanoscale semipolar GaN-based heterostructures. Almost no polarization discontinuity is expected for InxGa1-xN/GaN interfaces on such facets.

  4. Facets of career satisfaction for women physicians in the United States: a systematic review.

    PubMed

    Rizvi, Rabab; Raymer, Lindsay; Kunik, Mark; Fisher, Joslyn

    2012-01-01

    Women make up a growing proportion of the physician workforce, and their career satisfaction may affect their health. The authors hypothesized that many facets adversely affecting career satisfaction in women physicians were extrinsic, therefore, preventable or modifiable. The authors conducted a systematic review of the literature in English published through February 2010 to examine facets of career satisfaction of U.S. women physicians. The authors used the women physician AND job satisfaction OR career satisfaction Medical Subject Headings (MeSH) terms, and reviewed bibliographies of key articles to ensure inclusion of relevant studies. The authors used the "Strengthening the Reporting of Observation Studies in Epidemiology" quality tool. Of an initial 1,000 studies, only 30 met the inclusion criteria. Facets reported most frequently to influence career satisfaction for women physicians were income/prestige, practice characteristics, and personal/family characteristics. Overall, career satisfaction for women and men physicians was 73.4% (range = 56.4% to 90%) and 73.2% (range = 59% to 90%), respectively. When compared with men, women physicians were more concerned with perceived lack of time for relationships with patients, colleagues, and family; less satisfied with mentoring relationships and support from all sources; and less satisfied with career-advancement opportunities, recognition, and salary. Career satisfaction can affect health, as well as health and safety of patients. Many factors adversely affecting career satisfaction for women physicians are extrinsic and, therefore, modifiable.

  5. Efficient gaseous toluene photoconversion on graphene-titanium dioxide nanocomposites with dominate exposed {001} facets.

    PubMed

    Shang, Qianqian; Tan, Xin; Yu, Tao; Zhang, Zhiyang; Zou, Yunling; Wang, Siyu

    2015-10-01

    A series of GnTiO2 {001} nanocomposites (GTN) with dominate exposed {001} facets has been synthesized by various dosage of graphite oxide (GO) and hydrofluoric acid (HF) during a facile solvothermal process successfully. The photocatalytic degradation efficiency (PDE) of the optimal sample reached up to 98.7% for liquids methyl orange and up to 78.6% for gaseous toluene under the UV-light irradiation for 30 min, which is much higher than P25. The effects mechanism of HF and GO on the percentage of {001} facets exposed and the crystal morphology are investigated by XRD, SEM, TEM, UV-Vis, XPS and BET measurement, particularly. Cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS) were used to explore the electron transfer mechanisms of GnTiO2 {001} nanocomposites. These results reveal the enhanced photocatalytic properties attribute to the excellent electron transport of Gn and highly reactive {001} facets can facilitate the separation of photo-generated charge carriers. Moreover, Gn can extend the absorption range of light and improve the adsorptivity of pollutant molecules.

  6. The big five personality factors as predictors of changes across time in burnout and its facets.

    PubMed

    Armon, Galit; Shirom, Arie; Melamed, Samuel

    2012-04-01

    We tested the effects of Neuroticism and Conscientiousness on burnout across time, controlling for age, gender, work hours, and depressive symptoms. Our theoretical model included both global burnout and its physical, emotional, and cognitive facets, consistent with the bifactor approach to modeling second-order constructs in structural equation modeling. Data were gathered from 1,105 respondents (63% men) who completed questionnaires at Time 1 (T1) and approximately 24 months later at Time 2 (T2). Neuroticism positively predicted T1 global burnout and negatively predicted T1 and T2 emotional exhaustion. Conscientiousness negatively predicted T1 global burnout and T1 and T2 cognitive weariness, and positively predicted T1 and T2 emotional exhaustion. Our gender-specific exploratory analysis revealed that for each gender, Neuroticism and Conscientiousness predicted different facets of burnout at T1 and T2. We recommend that future research test the possibility that the associations of Neuroticism and Conscientiousness with global burnout and its facets may be gender specific.

  7. Influence of the feeding rate on the packing properties of faceted particles

    NASA Astrophysics Data System (ADS)

    Hidalgo, R. C.; Acevedo, M.; Zuriguel, I.; Pagonabarra, I.; Maza, D.

    2013-06-01

    The effect of the filling mechanism on the packing of faceted particles with different aspect ratios has been examined. We have experimentally measured the particle angular distribution and the packing fraction of ensembles of faceted particles deposited in a bidimensional box. The granular system has been numerically simulated using a two-dimensional model of faceted particles. We found that increasing the feeding rate results in an enhancement of the disorder in the final deposit and, consequently, in a reduction of the number of particles oriented in their most stable configuration. In this regime, the final packing fraction monotonically decreases as the feeding rate increases. The correlations between the final packing morphology and the stress transmission were examined by describing the micromechanical properties of the deposits. For the case of elongated particles, increasing the feeding rate leads to an enhancement of the stress transmission towards the sides of the box. On the contrary, for the case of square particles, increasing the feeding rate promotes vertical transmission of the stress.

  8. (100) facets of γ-Al2O3: the active surfaces for alcohol dehydration reactions

    SciTech Connect

    Kwak, Ja Hun; Mei, Donghai; Peden, Charles HF; Rousseau, Roger J.; Szanyi, Janos

    2011-05-01

    Temperature programmed desorption (TPD) of ethanol, and methanol dehydration reaction were studied on γ-Al2O3 in order to identify the catalytic active sites for alcohol dehydration reactions. Two high temperature (> 473 K) desorption features were observed following ethanol adsorption. Samples calcined at T≤473 K displayed a desorption feature in the 523-533 K temperature range, while those calcined at T ≥ 673 K showed a single desorption feature at 498 K. The switch from the high to low temperature ethanol desorption correlated well with the dehydroxylation of the (100) facets of γ-Al2O3 that was predicted at 550 K DFT calculations. Theoretical DFT simulations of the mechanism of dehydration. on clean and hydroxylated γ-Al2O3(100) surfaces, find that a concerted elimination of ethylene from an ethanol molecule chemisorbed at an Al3+ pentacoordinated site is the rate limiting step for catalytic cycle on both surfaces. Furthermore, titration of the pentacoordinate Al3+ sites on the (100) facets of γ-Al2O3 by BaO completely turned off the methanol dehydration reaction activity. These results unambiguously demonstrate that only the (100) facets on γ-Al2O3 are the catalytic active surfaces for alcohol dehydration.

  9. Optical antenna arrays on a fiber facet for in situ surface-enhanced Raman scattering detection.

    PubMed

    Smythe, Elizabeth J; Dickey, Michael D; Bao, Jiming; Whitesides, George M; Capasso, Federico

    2009-03-01

    This paper reports a bidirectional fiber optic probe for the detection of surface-enhanced Raman scattering (SERS). One facet of the probe features an array of gold optical antennas designed to enhance Raman signals, while the other facet of the fiber is used for the input and collection of light. Simultaneous detection of benzenethiol and 2-[(E)-2-pyridin-4-ylethenyl]pyridine is demonstrated through a 35 cm long fiber. The array of nanoscale optical antennas was first defined by electron-beam lithography on a silicon wafer. The array was subsequently stripped from the wafer and then transferred to the facet of a fiber. Lithographic definition of the antennas provides a method for producing two-dimensional arrays with well-defined geometry, which allows (i) the optical response of the probe to be tuned and (ii) the density of "hot spots" generating the enhanced Raman signal to be controlled. It is difficult to determine the Raman signal enhancement factor (EF) of most fiber optic Raman sensors featuring hot spots because the geometry of the Raman enhancing nanostructures is poorly defined. The ability to control the size and spacing of the antennas enables the EF of the transferred array to be estimated. EF values estimated after focusing a laser directly onto the transferred array ranged from 2.6 x 10(5) to 5.1 x 10(5).

  10. Laser-induced asymmetric faceting and growth of a nano-protrusion on a tungsten tip

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Hirofumi; Zadin, Vahur; Kunze, Karsten; Hafner, Christian; Aabloo, Alvo; Kim, Dong Eon; Kling, Matthias F.; Djurabekova, Flyura; Osterwalder, Jürg; Wuensch, Walter

    2016-12-01

    Irradiation of a sharp tungsten tip by a femtosecond laser and exposed to a strong DC electric field led to reproducible surface modifications. By a combination of field emission microscopy and scanning electron microscopy, we observed asymmetric surface faceting with sub-ten nanometer high steps. The presence of faceted features mainly on the laser-exposed side implies that the surface modification was driven by a laser-induced transient temperature rise on a scale of a couple of picoseconds in the tungsten tip apex. Moreover, we identified the formation of a nano-tip a few nanometers high located at one of the corners of a faceted plateau. The results of simulations emulating the experimental conditions are consistent with the experimental observations. The presented technique would be a new method to fabricate a nano-tip especially for generating coherent electron pulses. The features may also help to explain the origin of enhanced field emission, which leads to vacuum arcs, in high electric field devices such as radio-frequency particle accelerators.

  11. Facet-selective nucleation and conformal epitaxy of Ge shells on Si nanowires

    DOE PAGES

    Nguyen, Binh -Minh; Swartzentruber, Brian; Ro, Yun Goo; ...

    2015-10-08

    Knowledge of nanoscale heteroepitaxy is continually evolving as advances in material synthesis reveal new mechanisms that have not been theoretically predicted and are different than what is known about planar structures. In addition to a wide range of potential applications, core/shell nanowire structures offer a useful template to investigate heteroepitaxy at the atomistic scale. We show that the growth of a Ge shell on a Si core can be tuned from the theoretically predicted island growth mode to a conformal, crystalline, and smooth shell by careful adjustment of growth parameters in a narrow growth window that has not been exploredmore » before. In the latter growth mode, Ge adatoms preferentially nucleate islands on the {113} facets of the Si core, which outgrow over the {220} facets. Islands on the low-energy {111} facets appear to have a nucleation delay compared to the {113} islands; however, they eventually coalesce to form a crystalline conformal shell. As a result, synthesis of epitaxial and conformal Si/Ge/Si core/multishell structures enables us to fabricate unique cylindrical ring nanowire field-effect transistors, which we demonstrate to have steeper on/off characteristics than conventional core/shell nanowire transistors.« less

  12. Facet-selective nucleation and conformal epitaxy of Ge shells on Si nanowires

    SciTech Connect

    Nguyen, Binh -Minh; Swartzentruber, Brian; Ro, Yun Goo; Dayeh, Shadi A.

    2015-10-08

    Knowledge of nanoscale heteroepitaxy is continually evolving as advances in material synthesis reveal new mechanisms that have not been theoretically predicted and are different than what is known about planar structures. In addition to a wide range of potential applications, core/shell nanowire structures offer a useful template to investigate heteroepitaxy at the atomistic scale. We show that the growth of a Ge shell on a Si core can be tuned from the theoretically predicted island growth mode to a conformal, crystalline, and smooth shell by careful adjustment of growth parameters in a narrow growth window that has not been explored before. In the latter growth mode, Ge adatoms preferentially nucleate islands on the {113} facets of the Si core, which outgrow over the {220} facets. Islands on the low-energy {111} facets appear to have a nucleation delay compared to the {113} islands; however, they eventually coalesce to form a crystalline conformal shell. As a result, synthesis of epitaxial and conformal Si/Ge/Si core/multishell structures enables us to fabricate unique cylindrical ring nanowire field-effect transistors, which we demonstrate to have steeper on/off characteristics than conventional core/shell nanowire transistors.

  13. Joint Doctrine for Civil Affairs

    DTIC Science & Technology

    2007-11-02

    Authorities ( MACA ), DODD 5525.5, DOD Cooperation with Civilian Law Enforcement Officials, and JP 3-07.7, Joint Doctrine for Civil Support. II-15 Civil Affairs...Joint Operation Planning and Execution System JP joint publication JTF joint task force LOAC law of armed conflict MACA military assistance to civil

  14. Joint Electromagnetic Spectrum Management Operations

    DTIC Science & Technology

    2012-03-20

    synchronizing, and deconflicting JEMSMO actions (p. IV-7) Doctrine Update for JP 6-01, Joint Electromagnetic Spectrum Management Operations...communications system directorate of a joint staff (J-6), to support joint planning, coordination, and control of the spectrum for assigned forces. Executive...in the respective Service or joint publications. Interference Resolution To ensure critical frequencies and spectrum-dependent systems are

  15. Spatial separation of photogenerated electrons and holes among {010} and {110} crystal facets of BiVO4

    NASA Astrophysics Data System (ADS)

    Li, Rengui; Zhang, Fuxiang; Wang, Donge; Yang, Jingxiu; Li, Mingrun; Zhu, Jian; Zhou, Xin; Han, Hongxian; Li, Can

    2013-02-01

    Charge separation is crucial for increasing the activity of semiconductor-based photocatalysts, especially in water splitting reactions. Here we show, using monoclinic bismuth vanadate crystal as a model photocatalyst, that efficient charge separation can be achieved on different crystal facets, as evidenced by the reduction reaction with photogenerated electrons and oxidation reaction with photogenerated holes, which take place separately on the {010} and {110} facets under photo-irradiation. Based on this finding, the reduction and oxidation cocatalysts are selectively deposited on the {010} and {110} facets respectively, resulting in much higher activity in both photocatalytic and photoelectrocatalytic water oxidation reactions, compared with the photocatalyst with randomly distributed cocatalysts. These results show that the photogenrated electrons and holes can be separated between the different facets of semiconductor crystals. This finding may be useful in semiconductor physics and chemistry to construct highly efficient solar energy conversion systems.

  16. Spatial separation of photogenerated electrons and holes among {010} and {110} crystal facets of BiVO4.

    PubMed

    Li, Rengui; Zhang, Fuxiang; Wang, Donge; Yang, Jingxiu; Li, Mingrun; Zhu, Jian; Zhou, Xin; Han, Hongxian; Li, Can

    2013-01-01

    Charge separation is crucial for increasing the activity of semiconductor-based photocatalysts, especially in water splitting reactions. Here we show, using monoclinic bismuth vanadate crystal as a model photocatalyst, that efficient charge separation can be achieved on different crystal facets, as evidenced by the reduction reaction with photogenerated electrons and oxidation reaction with photogenerated holes, which take place separately on the {010} and {110} facets under photo-irradiation. Based on this finding, the reduction and oxidation cocatalysts are selectively deposited on the {010} and {110} facets respectively, resulting in much higher activity in both photocatalytic and photoelectrocatalytic water oxidation reactions, compared with the photocatalyst with randomly distributed cocatalysts. These results show that the photogenrated electrons and holes can be separated between the different facets of semiconductor crystals. This finding may be useful in semiconductor physics and chemistry to construct highly efficient solar energy conversion systems.

  17. Development of a novel radiographic measure of lumbar instability and validation using the facet fluid sign

    PubMed Central

    Guyer, Richard D.; Zigler, Jack E.; Ohnmeiss, Donna D.; Wharton, Nicholas D.

    2015-01-01

    Background Lumbar spinal instability is frequently referenced in clinical practice and the scientific literature despite the lack of a standard definition or validated radiographic test. The Quantitative Stability Index (QSI) is being developed as a novel objective test for sagittal plane lumbar instability. The QSI is calculated using lumbar flexion-extension radiographs. The goal of the current study was to use the facet fluid sign on MRI as the "gold standard" and determine if the QSI is significantly different in the presence of the fluid sign. Methods Sixty-two paired preoperative MRI and flexion-extension exams were obtained from a large FDA IDE study. The MRI exams were assessed for the presence of a facet fluid sign, and the QSI was calculated from sagittal plane intervertebral rotation and translation measurements. The QSI is based on the translation per degree of rotation (TPDR) and is calculated as a Z-score. A QSI > 2 indicates that the TPDR is > 2 std dev above the mean for an asymptomatic and radiographically normal population. The reproducibility of the QSI was also tested. Results The mean difference between trained observers in the measured QSI was between -0.28 and 0.36. The average QSI was significantly (P = 0.047, one-way analysis of variance) higher at levels with a definite fluid sign (2.3±3.2 versus 0.60±2.4). Conclusions Although imperfect, the facet fluid sign observed may be the best currently available test for lumbar spine instability. Using the facet fluid sign as the "gold standard" the current study documents that the QSI can be expected to be significantly higher in the presence of the facet fluid sign. This supports that QSI might be used to test for sagittal plane lumbar instability. Clinical Relevance A validated, objective and practical test for spinal instability would facilitate research to understand the importance of instability in diagnosis and treatment of low-back related disorders. PMID:26273555

  18. Catastrophic optical degradation of the output facet of high-power single-transverse-mode diode lasers. 1. Physical model

    SciTech Connect

    Miftakhutdinov, D R; Bogatov, Alexandr P; Drakin, A E

    2010-09-10

    The physical model of catastrophic optical degradation (COD) of the output facet of high-power single- transverse-mode diode lasers is developed. The model excels other models both in completeness of the physical analysis of the processes leading to COD and in allowance for design feature of lasers used to increase the COD threshold - protective coating of the output facet and current limitations near it. (lasers)

  19. Co3 O4 Hexagonal Platelets with Controllable Facets Enabling Highly Efficient Visible-Light Photocatalytic Reduction of CO2.

    PubMed

    Gao, Chao; Meng, Qiangqiang; Zhao, Kun; Yin, Huajie; Wang, Dawei; Guo, Jun; Zhao, Shenlong; Chang, Lin; He, Meng; Li, Qunxiang; Zhao, Huijun; Huang, Xingjiu; Gao, Yan; Tang, Zhiyong

    2016-08-01

    A heterogeneous catalyst made of well-defined Co3 O4 hexagonal platelets with varied exposed facets is coupled with [Ru(bpy)3 ]Cl2 photosensitizers to effectively and efficiently reduce CO2 under visible-light irradiation. Systematic investigation based on both experiment and theory discloses that the exposed {112} facets are crucial for activating CO2 molecules, giving rise to significant enhancement of photocatalytic CO2 reduction efficiency.

  20. Final Report for Project "Framework Application for Core-Edge Transport Simulations (FACETS)"

    SciTech Connect

    Estep, Donald

    2014-01-17

    This is the final report for the Colorado State University Component of the FACETS Project. FACETS was focused on the development of a multiphysics, parallel framework application that could provide the capability to enable whole-device fusion reactor modeling and, in the process, the development of the modeling infrastructure and computational understanding needed for ITER. It was intended that FACETS be highly flexible, through the use of modern computational methods, including component technology and object oriented design, to facilitate switching from one model to another for a given aspect of the physics, and making it possible to use simplified models for rapid turnaround or high-fidelity models that will take advantage of the largest supercomputer hardware. FACETS was designed in a heterogeneous parallel context, where different parts of the application can take advantage through parallelism based on task farming, domain decomposition, and/or pipelining as needed and applicable. As with all fusion simulations, an integral part of the FACETS project was treatment of the coupling of different physical processes at different scales interacting closely. A primary example for the FACETS project is the coupling of existing core and edge simulations, with the transport and wall interactions described by reduced models. However, core and edge simulations themselves involve significant coupling of different processes with large scale differences. Numerical treatment of coupling is impacted by a number of factors including, scale differences, form of information transferred between processes, implementation of solvers for different codes, and high performance computing concerns. Operator decomposition involving the computation of the individual processes individually using appropriate simulation codes and then linking/synchronizing the component simulations at regular points in space and time, is the defacto approach to high performance simulation of multiphysics

  1. Periprosthetic Joint Infections

    PubMed Central

    Lima, Ana Lucia L.; Oliveira, Priscila R.; Carvalho, Vladimir C.; Saconi, Eduardo S.; Cabrita, Henrique B.; Rodrigues, Marcelo B.

    2013-01-01

    Implantation of joint prostheses is becoming increasingly common, especially for the hip and knee. Infection is considered to be the most devastating of prosthesis-related complications, leading to prolonged hospitalization, repeated surgical intervention, and even definitive loss of the implant. The main risk factors to periprosthetic joint infections (PJIs) are advanced age, malnutrition, obesity, diabetes mellitus, HIV infection at an advanced stage, presence of distant infectious foci, and antecedents of arthroscopy or infection in previous arthroplasty. Joint prostheses can become infected through three different routes: direct implantation, hematogenic infection, and reactivation of latent infection. Gram-positive bacteria predominate in cases of PJI, mainly Staphylococcus aureus and Staphylococcus epidermidis. PJIs present characteristic signs that can be divided into acute and chronic manifestations. The main imaging method used in diagnosing joint prosthesis infections is X-ray. Computed tomography (CT) scan may assist in distinguishing between septic and aseptic loosening. Three-phase bone scintigraphy using technetium has high sensitivity, but low specificity. Positron emission tomography using fluorodeoxyglucose (FDG-PET) presents very divergent results in the literature. Definitive diagnosis of infection should be made by isolating the microorganism through cultures on material obtained from joint fluid puncturing, surgical wound secretions, surgical debridement procedures, or sonication fluid. Success in treating PJI depends on extensive surgical debridement and adequate and effective antibiotic therapy. Treatment in two stages using a spacer is recommended for most chronic infections in arthroplasty cases. Treatment in a single procedure is appropriate in carefully selected cases. PMID:24023542

  2. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  3. 13. Sacroiliac joint pain.

    PubMed

    Vanelderen, Pascal; Szadek, Karolina; Cohen, Steven P; De Witte, Jan; Lataster, Arno; Patijn, Jacob; Mekhail, Nagy; van Kleef, Maarten; Van Zundert, Jan

    2010-01-01

    The sacroiliac joint accounts for approximately 16% to 30% of cases of chronic mechanical low back pain. Pain originating in the sacroiliac joint is predominantly perceived in the gluteal region, although pain is often referred into the lower and upper lumbar region, groin, abdomen, and/ or lower limb(s). Because sacroiliac joint pain is difficult to distinguish from other forms of low back pain based on history, different provocative maneuvers have been advocated. Individually, they have weak predictive value, but combined batteries of tests can help ascertain a diagnosis. Radiological imaging is important to exclude "red flags" but contributes little in the diagnosis. Diagnostic blocks are the diagnostic gold standard but must be interpreted with caution, because false-positive as well as false-negative results occur frequently. Treatment of sacroiliac joint pain is best performed in the context of a multidisciplinary approach. Conservative treatments address the underlying causes (posture and gait disturbances) and consist of exercise therapy and manipulation. Intra-articular sacroiliac joint infiltrations with local anesthetic and corticosteroids hold the highest evidence rating (1 B+). If the latter fail or produce only short-term effects, cooled radiofrequency treatment of the lateral branches of S1 to S3 (S4) is recommended (2 B+) if available. When this procedure cannot be used, (pulsed) radiofrequency procedures targeted at L5 dorsal ramus and lateral branches of S1 to S3 may be considered (2 C+).

  4. Temporomandibular joint disorders.

    PubMed

    Buescher, Jennifer J

    2007-11-15

    Temporomandibular joint disorders are common in adults; as many as one third of adults report having one or more symptoms, which include jaw or neck pain, headache, and clicking or grating within the joint. Most symptoms improve without treatment, but various noninvasive therapies may reduce pain for patients who have not experienced relief from self-care therapies. Physical therapy modalities (e.g., iontophoresis, phonophoresis), psychological therapies (e.g., cognitive behavior therapy), relaxation techniques, and complementary therapies (e.g., acupuncture, hypnosis) are all used for the treatment of temporomandibular joint disorders; however, no therapies have been shown to be uniformly superior for the treatment of pain or oral dysfunction. Noninvasive therapies should be attempted before pursuing invasive, permanent, or semi-permanent treatments that have the potential to cause irreparable harm. Dental occlusion therapy (e.g., oral splinting) is a common treatment for temporomandibular joint disorders, but a recent systematic review found insufficient evidence for or against its use. Some patients with intractable temporomandibular joint disorders develop chronic pain syndrome and may benefit from treatment, including antidepressants or cognitive behavior therapy.

  5. Dissimilar metals joint evaluation

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.; Apodaca, L. E.

    1974-01-01

    Dissimilar metals tubular joints between 2219-T851 aluminum alloy and 304L stainless steel were fabricated and tested to evaluate bonding processes. Joints were fabricated by four processes: (1) inertia (friction) weldings, where the metals are spun and forced together to create the weld; (2) explosive welding, where the metals are impacted together at high velocity; (3) co-extrusion, where the metals are extruded in contact at high temperature to promote diffusion; and (4) swaging, where residual stresses in the metals after a stretching operation maintain forced contact in mutual shear areas. Fifteen joints of each type were prepared and evaluated in a 6.35 cm (2.50 in.) O.D. size, with 0.32 cm (0.13 in.) wall thickness, and 7.6 cm (3.0 in) total length. The joints were tested to evaluate their ability to withstand pressure cycle, thermal cycle, galvanic corrosion and burst tests. Leakage tests and other non-destructive test techniques were used to evaluate the behavior of the joints, and the microstructure of the bond areas was analyzed.

  6. Chemically assisted ion beam etching of laser diode facets on nonpolar and semipolar orientations of GaN

    NASA Astrophysics Data System (ADS)

    Kuritzky, L. Y.; Becerra, D. L.; Saud Abbas, A.; Nedy, J.; Nakamura, S.; DenBaars, S. P.; Cohen, D. A.

    2016-07-01

    We demonstrate a vertical (<1° departure) and smooth (2.0 nm root mean square line-edge roughness (LER)) etch by chemically assisted Ar ion beam etching (CAIBE) in Cl2 chemistry that is suitable for forming laser diode (LD) facets on nonpolar and semipolar oriented III-nitride devices. The etch profiles were achieved with photoresist masks and optimized CAIBE chamber conditions including the platen tilt angle and Cl2 flow rate. Co-loaded studies showed similar etch rates of ˜60 nm min-1 for (20\\bar{2}\\bar{1}),(20\\bar{2}1), and m-plane orientations. The etched surfaces of LD facets on these orientations are chemically dissimilar (Ga-rich versus N-rich), but were visually indistinguishable, thus confirming the negligible orientation dependence of the etch. Continuous-wave blue LDs were fabricated on the semipolar (20\\bar{2}\\bar{1}) plane to compare CAIBE and reactive ion etch (RIE) facet processes. The CAIBE process resulted in LDs with lower threshold current densities due to reduced parasitic mirror loss compared with the RIE process. The LER, degree of verticality, and model of the 1D vertical laser mode were used to calculate a maximum uncoated facet reflection of 17% (94% of the nominal) for the CAIBE facet. The results demonstrate the suitability of CAIBE for forming high quality facets for high performance nonpolar and semipolar III-N LDs.

  7. Spontaneous resolution of symptoms associated with a facet synovial cyst in an adult female – a case report

    PubMed Central

    Ngo, Trung; Decina, Philip; Hsu, William

    2013-01-01

    Background: Facet cysts are implicated in neural compression in the lumbar spine. Surgery is the definitive treatment for symptomatic facet cysts since the failure rate for conservative treatment is quite high; however, the role of physical/manual medicine practitioners in the management of symptomatic facet cysts has not been well explored. This case report will add to the body of evidence of spontaneous resolution of symptoms associated with facet cysts in the chiropractic literature. Case: A 58 year old female presented with acute low back and right leg pain which she attributed to a series of exercise classes that involved frequent foot stomping. Physical examination did not elicit any objective evidence of radiculopathy but MRI and CT scans revealed a facet cyst impinging on the right L5 nerve root. Injections and surgery were recommended; however, the patient’s radicular symptoms completely resolved after three months without surgical intervention. Summary: There is currently a paucity of data in the literature regarding the chiropractor’s role in the management of symptomatic facet cysts. The case presented here has added to this literature and possible areas for future research have been explored. PMID:23483069

  8. Morphotectonic evolution of triangular facets and wine-glass valleys in the Noakoh anticline, Zagros, Iran: Implications for active tectonics

    NASA Astrophysics Data System (ADS)

    Bahrami, Shahram

    2012-07-01

    The Noakoh anticline is located in Kermanshah province and is part of the Simply Folded Belt of Zagros. Boundaries of 97 triangular facets and 67 wine-glass (W-G) valleys, which formed on anticline limbs, were delineated using Quickbird satellite imagery. The strata dip (D), area (A), base length (BL), topographic slope (S) of facets, the maximum width (M), outlet width (O) and ratio of maximum width to outlet width (W index) of W-G valleys were analysed in detail. Noakoh anticline was subdivided into 9 tectonic zones on the basis of dip, topographic slopes and width of limbs. Results show that there are strong positive correlations between means of D-BL and S-BL pairs. Poor positive correlations exist between means of D-A and S-A pairs. Among W-G valley metrics, the W index has strong relations with D and S parameters. Based on the results, steep facets with long bases and well developed W-G valleys with narrow outlets and wide upper parts are associated with more rotated limbs having steep slopes. Facets on the northeastern slope have more forest cover, micro-organism activity, karstic features and soil cover, whereas facets on relatively drier southwestern slope are characterized by physical weathering processes and minor karstic landforms. This study demonstrates that, apart from tectonic activity as a major control on the morphometry of facets and valleys, climate and slope aspect have also acted as secondary factors on the development of the studied landforms.

  9. Failure of articular process (zygaphophyseal) joint development as a cause of vertebral fusion (blocked vertebrae).

    PubMed Central

    Chandraraj, S

    1987-01-01

    Examination of congenitally fused (blocked) vertebrae in this study suggests that non-development of the joint between articular facets results in fusion of the vertebral arches which in turn leads to secondary fusion of the bodies and hypoplasia of the intervertebral discs. The presence of independent pedicles and transverse processes do not favour the concept that such an abnormality is the result of non-segmentation of the sclerotome. The condition is probably linked to a defect of an inductor substance which influences normal morphogenesis of the vertebral arch in the embryonic period. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:3429327

  10. [The temporomandibular joint].

    PubMed

    Louryan, S

    1992-10-01

    With its discordant articular surfaces and complete division in two cavities separated by a disk, the temporomandibular joint appears as a complex anatomical and functional entity. Combined movements involving anteroposterior gliding between the disk and temporal bone in the upper cavity, anteroposterior condyle translation, hinge and rotation movements between the disk and mandibular condyle contribute to the different movements of the jaw. With dental occlusion, the masticatory apparatus therefore includes five functionally coordinated articular compartments. Various impairments of the normal static and dynamic features of the temporomandibular joint may lead to relatively frequent pathological conditions which can be easily diagnosed by modern imaging and arthroscopic methods.

  11. Joint for deployable structures

    NASA Technical Reports Server (NTRS)

    Craighead, N. D., II; Preliasco, R. J.; Hult, T. D. (Inventor)

    1985-01-01

    A joint is described for connecting a pair of beams to pivot them between positions in alignment or beside one another, which is of light weight and which operates in a controlled manner. The joint includes a pair of fittings and at least one center link having opposite ends pivotally connected to opposite fittings and having axes that pass through centerplates of the fittings. A control link having opposite ends pivotally connected to the different fittings controls their relative orientations, and a toggle assemly holds the fittings in the deployed configuration wherein they are aligned. The fittings have stops that lie on one side of the centerplane opposite the toggle assembly.

  12. Prosthetic Joint Infection

    PubMed Central

    Tande, Aaron J.

    2014-01-01

    SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

  13. The morphological characteristics of the antebrachiocarpal joint of the cheetah (Acinonyx jubatus).

    PubMed

    Ohale, L O C; Groenewald, H B

    2003-03-01

    A morphological study of the structures of the antebrachiocarpal (AC) joint of the cheetah was carded out by dissection of eight forelimbs obtained from four adult cheetahs culled from the Kruger National Park, Republic of South Africa. The aim was to evaluate the deviations of this joint from the normal feline pattern and to consider their possible relationship to the cheetah's adaptation to speed. Although published data on the AC joint of the other felids show general resemblance to that of the cheetah, there are nevertheless slight, but significant variations and modifications which tend to suggest adaptation to speed. The shafts of the radius and ulna of the cheetah are relatively straight and slender, with poorly developed distal ends. The ulnar notch is reduced to a very shallow concavity while the corresponding ulnar facet is a barely noticeable convexity, separated from the distal ulnar articular facet by an ill-defined groove. The movement of the distal radio-ulnar joint is highly restricted by the presence of a fibro-cartilaginous structure and a strong interrosseous membrane, limiting pronation and supination normally achieved by the rotation of the radius around the ulna. The extensor grooves at the distal extremity of the radius are deep and narrow and are guarded by prominent ridges. A thick extensor retinaculum anchors the strong extensor tendons in these grooves. The distal articular surface of the radius is concave in all directions except at the point where it moves into its stylold process. At this point it is convex in the dorsopalmar direction, with a surface that is rather deep and narrow. The proximal row of carpal bones presents a strongly convex surface, which is more pronounced in the dorsopalmar direction with the greatest convexity on the lateral aspect. Medially, there is a ridge-like concavity across the base of the tubercle, which rocks on the flexor surface of the radius, limiting excessive flexion as well as restricting lateral

  14. New Joint Sealants. Criteria, Design and Materials.

    ERIC Educational Resources Information Center

    Building Research Inst., Inc., Washington, DC.

    Contents include--(1) sealing concrete joints, (2) sealing glass and metal joints, (3) metal and glass joint sealants from a fabricator's viewpoint, (4) a theory of adhesion for joint sealants, (5) geometry of simple joint seals under strain, (6) joint sealant specifications from a manufacturer's viewpoint, (7) joint sealant requirements from an…

  15. Investigation of fatigue crack initiation facets in Ti-6Al-4V using focused ion beam milling and electron backscatter diffraction.

    PubMed

    Everaerts, J; Verlinden, B; Wevers, M

    2017-03-15

    In the very high cycle fatigue regime, internal crack initiation can occur in Ti-6Al-4V because of the formation of facets, which are α grains that have fractured in a transcrystalline and planar manner. Because this crack initiation phase occupies most of the fatigue life, it is essential to understand which mechanisms lead to facet formation. Fatigue tests have been performed on drawn and heat-treated Ti-6Al-4V wires, and the facets at internal crack initiation sites have been analysed in detail in terms of their appearance, their spatial orientation and their crystallographic orientation. The facets were not smooth, but showed surface markings at the nanoscale. In nearly all cases, these markings followed a linear pattern. One anomalous facet, in a sample with the largest grain size, contained a fan-shaped pattern. The facets were at relatively steep angles, mostly between 50° and 70°. Cross-sections of the fracture surfaces have been made by focused ion beam milling and were used to measure the crystallographic orientation of facets by electron backscatter diffraction. Most facet planes coincided with a prismatic lattice plane, and the linear markings were parallel to the prismatic slip direction, which is a strong indication that prismatic slip and slip band formation led to crack initiation. However, the anomalous facet had a near-basal orientation, which points to a possible cleavage mechanism. The cross-sections also exposed secondary cracks, which had formed on prismatic lattice planes, and in some cases early stage facet formation and short crack growth phenomena. The latter observations show that facets can extend through more than one grain, and that there is crack coalescence between facets. The fact that drawn wires have a specific crystallographic texture has led to a different facet formation behaviour compared to what has been suggested in the literature.

  16. Examining the knee joint.

    PubMed

    Monk, Daniel

    2013-04-01

    Appropriate history taking and examination can ensure accurate diagnosis of common knee problems, and rapid and effective interventions or referral to orthopaedic specialists. This article describes the anatomy of the knee joint and discusses relevant history taking, the examination process, special tests and radiology, as well as common knee injuries and their management.

  17. Jointness: A Selected Bibliography

    DTIC Science & Technology

    2007-08-01

    Straus, Giroux, 2000. (UA23 .O94 2000) Perry, Mark. Four Stars. Boston: Houghton Mifflin, 1989. 412pp. (UA23.7 .P47 1989) 4 Quinn , Dennis J., ed...U.S. Naval Institute 131 (June 2005): 77-79. ProQuest 23 Strabbing, Timothy R., and Elliot L. Ackerman. "Preparing Lieutenants for the Joint

  18. Clad metal joint closure

    SciTech Connect

    Siebert, O.W.

    1985-04-09

    A plasma arc spray overlay of cladding metals is used over joints between clad metal pieces to provide a continuous cladding metal surface. The technique permits applying an overlay of a high melting point cladding metal to a cladding metal surface without excessive heating of the backing metal.

  19. Joint Operation Planning

    DTIC Science & Technology

    2006-12-26

    feasibility — only then does he issue an order.” General Mathew B. Ridgway The Korean War, 1967 SECTION A. JOINT STRATEGIC PLANNING — TYPES AND SCOPE 1...necessary. Meanwhile from the west would come the U.S. (sic) Army’s power punch. Looking at [Commander, XVIII Airborne Corps, Lieutenant General] Gary

  20. The role of zygapophysial joint orientation and uncinate processes in controlling motion in the cervical spine.

    PubMed Central

    Milne, N

    1991-01-01

    Five linear and 2 angular measurements on each of C3 to T1 in a sample of 67 human skeletons were used to examine 3 hypotheses about the function of uncinate processes and zygapophysial joints in the cervical vertebral column. The material was sexed and each vertebra was rated for pathological changes. The effects of gender and pathology on the measures was assessed. The upper 4 vertebrae studied had the largest disc-facet angles, supporting the view that the articular facet orientation is responsible for the greater intervertebral disc translation occurring during sagittal motion in the neck. These upper 4 vertebrae also have the largest uncinate processes, and this observation supports the hypothesis that uncinate processes function to guide and control the anteroposterior translation which occurs during sagittal motion. The 3rd hypothesis that uncinate processes function to facilitate axial rotation is not supported by the recorded interfacet angles which appear to promote axial rotation only in the lower 4 vertebrae. Two further hypothesis are suggested. First, that the interfacet angle is responsible for controlling how strictly lateral flexion and axial rotation are coupled in cervical motion segments. Second, the suggestion is made that the high frequency of pathological change seen at the disc margins of the middle cervical vertebrae may be a result of the unusual combination of disc-facet and interfacet angles permitting more degrees of freedom than the cervical intervertebral discs can withstand. Images Fig. 3 Fig. 6 PMID:1810926